Environmental Science & Technology 1974 Vol.8 No.9

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Ifyou'reaboutto buyan airqualitymonitoring system,maybeyou oughttoconsideronethe EPAis buying.

That's the air quality monitoring systemfrom the Science Center of RockwellInternational. It's the only totally automatedsystem selected for the federal government'smost extensive and important air qualityprograms: RAPS, the EPA's 25-stationRegional Air Pollution Study of the greaterSt. Louis area, and CHAMP, the nationwideCommunity Health Air Monitoring Programheadquartered at the EPA's ResearchTriangle Park, North Carolina facility.

Science Center's credentials also includedesigning and building the air quality monitoring system for the State of California'sAerosol Characterization Study.

Rockwell is involved in an entire spectrumof air quality monitoring activities. From

basic laboratory investigations in atmospheric and related sciences, to the design andconstruction of specialized equipment, tothe integration and operation of entiremonitoring networks.

And our continuing research into aerosols,analytical chemistry, spectroscopy, chemicalkinetics and computer automation willkeep our customers right on top of thelatest, most effective developments in airquality monitoring.

If you're interested in how Rockwell'sexperience in air quality monitoring can payoff for you, call William L. Dowdy at(805) 498-4545, or write: Science Center,Rockwell International, P. O. Box 1085,Thousand Oaks, California 91360.

~I~ Science Centerp.~ Rockwell International

...where science gets down to business

CIRCLE 15 ON READER SERVICE CARD

Circle 24

3rd InternationalPollution Engineering

Exposition &. CongressSept. 9-12, 1974 Chicago, Illinois

EXHIBITORS

The Practical Answer to AutomatedOn-Line AnalysisMonitors for ammonia. cyanide. chloride. copper. chlorine. nuoride and sulfide are among a series of continuous analyzersoffered by Orion Research.

These rugged instruments run completely unallended for 30 dayperiods by utilizing long life filters. automatic system recalibration. and low reagent consumption.

By employing proven ion electrode analytical methods. thesemonitors offer laboratory accuracy over a wide concentrationrange.

Booth 246 See Advertisement on Page 853 Circle 21

New DSL Probe From CEA InstrumentsExtends Use of U2-DS Into The StackThe high level DSL probe is an accessory for the CEA Instruments Model U2-DS Ultra Portable SOl Analyzer. It extends thenormal maximum range of the U2-DS. which is 0-20 PPM in sixsteps (0-0.5. 0--1. 0--2. 0--5. 0--10. and 0--20) by a factor of 200.This results in a maximum range of 0-4000 PPM down to 0-100PPM full scale in six steps. allowing fast. direct measurements ofvery high SOl levels as found in stationary sources. processsystems. etc.

Booth 800 Circle 22

Obtain direct readout of ambient and in-plantparticulate concentrationsGCA/Technology Division will be exhibiting its full line of directreadout particulate monitoring instrumentation. GCA's newAPM Ambient Particulate Monitor will be highlighted as well asits line of respirable dust monitors now being utilized by numerous industrial and regulatory agencies. including OSHA. NIOSHand the Bureau of Mines.

All instruments give you immediate readout following thesampling period. utilize beta-radiation absorption as the measurement principle and represent state-of-the-art technology.

Booth 308 Circle 25

Du Pont Source Monitoring Systems forS02. N02• NO •• H2S. CI2Proved in :xtensive field use. the Du Pont systems provide reliablemeasurement of stack gas emissions. Complete. with samplesystems. ready for installation.

Available for both continuous or sequential sampling: plusHlS/SOl ratio analyzer for Claus sulfur recovery process control.

Analyzer system also available for monitoring low levels ofphenols in wastewater.

Du Pont Co.. Instrument Products DivisionWilmington. DE 19~9~

800th 342 See Advertisement on Page 792

RAC Exhibiting Wide Range of Equipment forSampling/Monitoring Ambient Air &ProcessEmissionsResearch Appliance Company (RAC) will display a variety of newand improved instruments. systems and related accessories forsampling and monitoring gaseous and particulate air pollutants.

New designs include (I) an all-new. precision. electro-opticalRAC Transmissometer that accurately measures from 0 to 100';0opacity in stack efnuents to EPA requirements: (2) a fully-automated stack monitor with an integral minicomputer that accurately measures the particulate mass in stack efnuents by the betaradiation absorption technique. and then provides a summaryprintout: and (3) a small. lightweight. two-module sample casefor RAC Staksamplr systems.


Automated Instruments for Monitoring WaterQuality to be Featured at Technicon BoothTechnicon Automated Analysis Systems. approved and evaluatedby the EPA. for measuring more than 30 water quality parameterswill be exhibited:

The Technicon™ AutoAnalyzer™ II Continuous-Flow Analytical Instrument System for rapid. precise and specific laboratory measurement of ammonia. nitrite. nitrate. phosphate. totalnitrogen. total phosphate. sulfur dioxide. oxides of nitrogen. andsulfides: with distillation techniques for cyanides. phenol andnuoride.

The Technicon ™ Monitor IV for continuous monitoring ofwaters including process streams. plant efnuents. and waterways.featuring a unique total cyanide method.

The Technicon™ BD-40 Block Digestor with semiautomateddigestion methods for Kjeldahl nitroge; and phosphorus.


PRO-TECH Discrete/CompositeLiquid SamplerThe new Pro-MULTI-Tech Model DEL-400S liquid sampler hastwo dozen 500-ml bollies in a refrigerated compartment to receive discrete (one shot) or sequential composite (up to 99 shotseach) liquid samples. or even simple composite samples in sizesas large as 10 to 20 liters when the 24-bollle feature is not in use.The volume of liquid diverted to a sample bottle at each shot canbe set at 10 to 350 mi. and the interval between successive shotscan be varied from a few minutes to hours or days.

Pro-Tech Inc.Malvern. Pa. 19355(215) 644-4420

Booth 134 Circle 28

TRACE METALS IN AIRAnew technique

Traditionally, the onlymethod available for measuring thetrace metal concentration in air hasbeen to draw air through a filter fora long time (say, 8 or 24 hours) andthen to identify the particlestrapped on the filter by analysis.This procedure gives an averagemetal concentration but cannotgive a measure of variations duringthe sampling period. To measurethe variations, we need to analyzesmall samples of air, drawn througha filter for a very short time.

A new technique has nowbeen developed by Varian Techtronfor the specific purpose ofcollecting and measuring thesesmall samples.

The Varian Techtron AirMicrosampler is a new, highlysensitive air particulate samplingmethod which supplements theexisting large-volume methods. Forthe first time, simple and effectivetracking of the variations in tracemetallic elements in air is possible.

In practice, a disk of filtermaterial is placed in a smallgraphite cup with a perforatedbase, and air is drawn through thefilter with a simple pump.Collection time is about twominutes. The cup with its sample isthen transferred to the VarianTechtron Carbon Rod Atomizer foranalysis.

@varian

In the Carbon Rod Atomizer,the cup is heated electricallythrough three programmed stages:drying, ashing and thenatomization. In the atomizationstage the pollutant concentrationis measured by atomic absorption.

The Air Microsamplermakes the most of the excellentanalytical sensitivity of the CarbonRod Atomizer by allowing very lowconcentrations of metals in air tobe quantified. The sensitivity forlead analysis in a 200 ml air sampleis 0.1,.,g/m3 , and for cadmiumthe sensitivity is 0.008,., g/m3•*

In principle, the Air Microsampler could be applied to anymetal of interest, and in anyatmosphere. In each situation thenew method will give a measurement of the airborne metalconcentration at a point in time,and by consecutive sampling thevariations can be followed over anextended period.

Further details are availablefrom Varian offices.

*Matousek J. P., Brodie K. G.,Direct Determination of Lead Airborne Particulates byNon-Flame Atomic Absorption, Anal. Chem., 45, (9),1606, 1973.

Brodie K. G., Matousek J. P.,Determination of Cadmium in Air by Non-FlameAtomic Absorption Spectrometry, Anal. Chim. Acta.,69, (1), 200, 1974.

Varian TechtronPalo Alto, Cal., U.S.A.Georgetown, ant., CanadaZug, SwitzerlandSpringvale, Vic., Australia


772 Environmental Science & Technology

Volume 8, Number 9, September 1974

EnvironmentalScience & Technology

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800

784

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CONTENTS

Special report

793 Catalysts are 1975 automakers' choice totame exhaust emissions

PAT reports

788 Ceilcote venturi scrubbers controlgaseous, liquid, solid emissions

790 Balston's glass impregnated filter meetsautomaKers' monitoring needs

Features

800 EPA's Horowitz tells of controversial plansfor 66 U.S. air quality regions

807 Consultant Hayes asks how the U.S. canpay for new car em ission controls

Outlook

784 Selected fungi convert wastes into glucoseand single-cell protein

786 ASTM hopes to establish standard watersampling methods and terminology

Departments

777 Editorial

778 Letters

781 Currents

853 Industry trends

855 New products

857 New literature

859 Books

861 Meeting guide

862 Classified section

863 Consulting services

Current research

774 Contents

811 Papers

@Copyright 1974 by the American Chemical SocietyPublished monthly. with additional Pollution Control Directory in November. by the American Chemical Sociely.

from 20th and Northampton SIS.. Easton, Pa. 18042. Executive offices: Editorial Headquarters. 1155 16th 51.. N.W..Washington. D.C. 20036. Advertising office: 50 West Stale St.. Westport. Conn 06880, Second-class postage paid alWashington, D.C .. and al additional mailing ollices.

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SUBSCRIPTION SERVICE: Send all new and renewal subscriptions with paymel1( to: Office of the Controller,1155 16th St., N.W" Washington. D.C. 20036. Subscriptions should be renewed promptly to avoid a break in theseries. All correspondence and telephone calls regarding changes or address. claims for missing issues. subscription service. the status 01 records and accounts should be directed to: Manager. Membership and SubscriptionServices. American Chemical Society. P.O. BOlt 3337. Columbus. Ohio 43210. Telephone (614) 421-7230. Onchanges of address. include both otd and new addresses with ZIP code numbers, accompanied by mailing labelfrom a recent issue, Allow four weeks for change to become ef/ective

SUBSCRIPTION RATES 1974: Members. domestic and foreign. 1 year $6.00; nonmembers, domestic and foreign$9,00; 3 years, members $15. nonmembers $22. Postage: Canada and Pan American Union, $4.00 per year; allother countries. $5.00 per year. Air freight rates. Europe $7.00 per year: Far Easf $14 per year. Single copies:current issues. $1.50: Pollution Control Direcfory, $3.00; rates lor back issues or volumes are available from Special Issues Sales Department. 1155 16th St., N.W.. Washington. D.C. 20036. Claims for missing numbers will notbe allowed (1) if loss was due 10 failure of notice of change in address to be received before the date specifiedabOve. (2) if received more than sixty days from date of issue plus time normally required tor postal delivery ofjournal and claim. or (3) il the reason lor the claim is "issue missing from liles."

Those interested in joining the American Chemical Society should wrile to Admissions Department of WashingtonOffice.

The American Chemical Society assumes no responsibility lor the statements and opinions advanced by contributors to its publications.

Volume 8. Number 9. September 1974 773- --_. ... ~

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CURRENT RESEARCH

Economic air pollution control model lor Los AngelesCounty in 1975 811

John Trijonis

A two·part paper. Part I formulates a mathematical model fordetermining the least cost of attaining various air quality levels.Its two basic inputs consist of a submodel for the control costemission level, and the emission level-air quality relationship.Part II applies this model to find the least cost required to reachvarious levels of 0 3 and NOz in Central Los Angeles in 1975.

Problems with IIame ionization detectors in automotiveexhaust hydrocarbon measurements 826

Keith Scholield

Three major problems in measuring hydrocarbon emissions fromengines using flame ionization detectors were examined. They arethe correlation discrepancies for analyses run on differentinstruments under different test conditions, the magnitude of theoxygen interlerence effect. and an extensive study of factorsaffecting response times.

Selectivity 01 strongly basic anion exchange resins lororganic anions 834

Michael Semmens* and John Gregory

Exchange equilibria for six different polystyrene resins werestudied using carboxylate ions of various chain length. As chainlength increased. so did resin selectivity. Free energy change forion transfer was always about the same. This supports theconclusion that hydrophobic interactions are responsible forincreasing selectivity_

Determination 01 lead in atmospheric particulates bylurnace atomic absorption 840

J. F. Lech,* Duane Siemer, and Ray Woodriff

Flameless atomic absorption determination of particulate leadwas simplified by using porous graphite cups as particulatesfilters. The samples could be directly atomized from the cupswithout further treatment. The method compares favorably withmillipore filtration .

• To whom correspondence should be addressed.

This issue contains no papers lor which there is supplementary material in microform.


Ellects 01 intermittently chlorinated cooling towerblowdown on lish and invertebrates 845

K. L. Dickson, * A. C. Hendricks, J. S. Crossman, andJohn Cairns, Jr.

Effects of Intermittent chlorine in cooling tower blowdown werestudied in the Clinch River using bluegill sunfish and snails. Nofish deaths occurred, but in one small region, the blowdown wastoxic to 50% of the snails after 72 hours.

NOTES

Determination 01 submicrogram quantities 01 monomethylmercury in aquatic samples 850

J. J. Bisogni, Jr., * and A. W. Lawrence

Monomethyl mercury is separated from inorganic mercury bybenzene extraction and then analyzed by flameless atomicabsorption. I'ntertering agents and methods to attenuate theseinterferences are discussed. Mean recovery efficiency of over90% was obtained with a spiked microbial biomass.

Credits: 784, New Brunswick Scientific Co.. Inc.; 786, EPA; 800. 802. 804. 807, 808,Gerald M. Quinn.

Cover: Gerald M. Quinn

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Precise Mass Marking. AllFinnigan models can be equippedwith our Multiple Mass Marker tounambiguously mark every massunit with higher amplitude marks forevery 10th amu and direct readingmarks for every 100th amu.Finnigan's Multiple Mass Marker isdirect reading at any point in thespectrum, saving you the time anderror potential of manually assigningmass numbers and attempting toidentify peaks by interpolationbetween widely spaced marks.Other Finnigan Advances. In thecourse of pioneering GC/MStechnology, Finnigan has developedseveral unique features whichhelped make GC/MS the powerfulanalytic tool you know today. Thesefeatures are incorporated in (oraccessories to) all Finnigansystems, and include: ChemicalIonization Source with CI and EImodes of operation; Interactive DataSystem with real-time display of GCand MS data during acquisition;1000 amu/second Repetitive ScanSpeed, indispensable forhigh-quality analysis with a

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With the introduction of our Model3200 and Model 3300, Finnigan hasadvanced the standards of GC/MSperformance again. In addition totheir extended single mass ranges(800 amu/Model 3200, 1000amu/Model 3300) these newsystems incorporate many novelfeatures which simultaneouslyincrease the power of GC/MSanalysis and improve yourcommand control of the analyticalprocess.High Mass Sensitivity. Both newFinnigan systems incorporate aunique new ionizer concept (patentapplied for) which enhancesinjection of high mass ions into themass analyzer. The amplitude ratioof high mass to low mass ions iscomparable to conventional sectorinstruments, with excellent masspeak shape and low electrical noise.QuantitativeMass Fragmentography. MostFinnigan systems incorporateelectronics which achieve newstandards of stability, ... vital toquantitation in mass fragmentography.Finnigan's are the only GC/MSsystems equipped for high-sensitivityquantitative mass fragmentography,... with simultaneous monitoring ofup to eight individual ions anywherein the mass range, switching speedsto 1 kHz, low SWitching noise,variable sensitivity and dwell time.

Volume 8, Number 9, September 1974 775

procedure which is routine and unattended, assuring a highlevel of accuracy from all system components.

Functional Versatility-Each Monitor N detects andmeasures one parameter. However, if a change of parameters is wanted, it is a simple matter to replace one methodwith another. Over 30 chemical parameters may be measured using Monitor IV methods.

The cost of operating the Monitor IV is reasonable andhighly competitive. You may purchase the Monitor IV orselect from a variety of lease or rental plans. Trouble-freeoperation is further assured through a network of Technicon-owned service centers strategically located throughoutthe country.

For additional information on the Monitor N and otherTechnicon analytical systems, write Department 208.

Continuous Performance-On-line monitoring is theonly method that affords total protection against acddentaldischarge of pollutants. While regulatory agency reportingrequirements may specify periodic analysis reports, a plant isresponsible for its effluent content at all times. Grab or composite sample monitoring is like having part-time insurance.

The Technicon Monitor N operates 24 hours a day,requiring no attention for up to 7 days at a time. It providesa continuous, rellable, protective record of wastewater quality for presentation to regulatory agendes. It monitors planteffluent at the source-before, not after, the effluents leavethe plant. You are protected both ways.

EPA Evaluation and Approval- The TechniconMonitor N has been EPA evaluated* and uses EPA approved analytical techniquestwhere applicable. We know ofno other on-line chemical analyzer that can make this claim.

Continuous Quality Control-The entire mechanical, chemical and electronic performance of the Monitor Nis quality controlled through an automated recalibration*Analytical Quality Control N€lAlSletter, EPA. Cincinnati: Issue No.2!, April. 1974; page 13t Federal Register. October 16,1973 II

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Editor: James J. Morgan

WASHINGTON EDITORIAL STAFFManaging Editor: Stanton S. MillerAssistant Editor: Lena C. GibneyAssistant Editor: Julian Josephson

MANUSCRIPT REVIEWINGManager: Katherine I. BiggsEditorial Assistant: David Hanson

MANUSCRIPT EDITINGAssociate Production Manager:

Charlotte C. Sayre

GRAPHICS AND PRODUCTIONHead: Bacil GuileyManager: Leroy L. CorcoranArt Director: Norman FavinArtist: Gerald M. Quinn

Advisory Board: P. L. Brezonik, David Jenkins,Charles R. O'Melia, John H. Seinfeld,John W. Winchester

Published by theAMERICAN CHEMICAL SOCIETY1155 16th Street. N.W.Washington. D.C. 20036

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Director: Richard L. Kenyon

ADVERTISING MANAGEMENTCentcom. Ltd.

For offices and advertisers, see page 866

Please send research manuscripts to Manu·script Reviewing, feature manuscripts toManaging Editor.

For author's guide and editorial policy. seeJune 1974 issue, page 549. or write Katherine I.Biggs, Manuscript Reviewing Office. ES& T

EDITORIAL

This public form of addictionIt's your play. Cards? No. But, it's a card-like game, thisbusiness of transportation. Getting from here to there.From home to work and vice versa, vacation, weekendtrips, and the lot. Take your car most of the time, don'tyou? It's American automobile addiction at its best. Fewcared until pollution was upon us, as it is now.

This issue of ES& T is all about cleanup oftransportation, mainly cars. In a special report, ES& T'sGibney points out that a majority of domestic automakershave opted for the catalytic converter, that technologicalanswer for changing noxious emissions into innocuousones, for their 1975 cars. On the other hand, if you arestuck with that old car for another year or so, then retrofitinformation from MECA, the Manufacturers of EmissionsControl Association, is helpful.

One Feature author points out that in 66 air qualitycontrol regions in the U.S.-from Albuquerque, N.M., toWashington, D.C.-at least one of the air standards, thosemeasures to protect the public health, is exceeded. Theseregions also contain 60% of the nation's population. So,transportation control strategies-reduced driving, masstransportation, carpooling, and the like-are needed here.

Another Feature author questions whether the publicreally knows what cleanup from cars will cost. He findsthat the cost could be as high as $20 billion a year, andthe fuel penalty translates to the loss of several hundredthousand jobs in a gasoline-starved economy.

In some states, inspection and maintenance programsare in order, programs that will keep all car emissionsbelow a prescribed level. New Jersey leads the nationhere; two other states are contemplating similarprograms, and more than 20 others are thinking aboutthem.

Testing of prototype vehicles before the '75 carsbecome available this month is another aspect of thegame. Here a PAT report dwells on the key to reliableemissions data-a glass-impregnated filter. Without thisdevelopment, reliable emissions testing data for the newcars simply could not have been attained.

It all boils down to a number of options-new car, oldcar, mass transit, busing, carpooling. It's your choice; it'syour play; it's your air as well as ours.

Volume 8. Number 9. September 1974 777

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778 Environmental Science &Technology

LETTERS

Drinking biorefractories

Dear Sir: Our laboratory staff ofRotterdam Water Supply read the article on drinking biorefractories(E5& T, Jan. 1973, p 14) with greatinterest. We are producing waterfrom the highly polluted river Rhineand did some analytical work on volatile industrial solvents by a self-developed headspace technique. Thesubstances we could detect thus farmatch with some of the 34 chemicals given in the blue table on page14. Our findings are published in theWater Treatment and Examination.Vol. 21, 1972, pp 259-74. Our latestresults were published in Vol. 23,June 1974,

We fully agree with your comments that other industrial wastetreatment must be found. We wishyou in the U.S. all the success. InEurope it took 20 years of negotiations by the International River RhineCommittee before some success wasachieved.

J. J. Rook, Chief ChemistRotterdam WaterworksThe Netherlands

Sludge incineration

Dear Sir: In a sense, it's unfortunate that the PAT report (E5& T, May1974, p 412) concentrated so stronglyon Envirotech, BSP equipment. Itleads a reader to think that this maybe the only source available. At leasttwo other firms are also well established in the MHF (multiple hearthfurnace) fieid, and these are: NicholsEngineering and Research Corp.(New York, N.Y.) and MSI Industries, Inc, (Denver, Colo.).

Nichols, particularly, has been acompetitor of BSP's in this field formany years, while MSI, with long experience in MHF's for industriai use,has entered the municipal water pollution control field more recently. Allthree firms should be contacted byanyone specifying this type of equ ipment who is interested in obtainingcompetitive bids.

There are indications in the articlethat these systems produce inertash. The meaning is that the ash isbiologically inert, of which there is little question. By no means, however,should anyone overlook the fact thatthe ash may not be chemically inert,and the article does mention a highphosphate content sludge ash beingmarketed in Japan as a fertilizer.Phosphorus would be considered aprime water pOllutant, as would anymetals contained in the sludge whichmight be leached out of an ash landfill. Particular care is required in the

engineering of the sanitary landfillsite for th is reason.

Although sludge cake at 30-35%solids is autogenous and no auxiliaryfuel is required during normal operation once the MHF is up to temperature, start-up fuel requirements maybe very large in plants designed toserve growing populations in whichthe original installation has beensized to meet a future capacity requirement. 'Such plants will operatethe MHF's only a few days a weekduring the early years, often on a single-shift basis, which can be very expensive fuelwise. Often it would bepreferable to: a) install the units on astaged basis, in parallel with load requirements as the plant load increases, or b) combine the sludgeincineration function with refuse(solid waste) incineration, using therefuse as a "free fuel" for start-uppurposes, or c) when the plant isvery small (1 or 2 mgd), it may bemore economical to select fluidizedbed incineration equipment, whose"thermal flywheel" characteristicsare very effective in reducing start-upfuel requirements.

JamesA. FifeChas. T. Main, Inc.Boston, Mass. 02199

Peterson interview

Dear Sir: The format of your interview with Dr. Russell W. Peterson,Chairman of the President's Councilon Environmental Quality (E5& T,April 1974, p 303), is one of the bestto date because it highlights a widerange of salient issues in a limitedspace.

As conveyed by the three photographs, including the cover, Dr. Peterson is a very dynamic man to inverview, and certainly dedicated tothe cause of the environment. Insome future issues, may I urge thatyou also interview the other Councilmembers, Mr. John Busterud and Dr.Beatrice Willard,

Such interviews might be equallyinteresting and informative, since theCouncil is in a pivotal position in thisnational administration to influencethe course of events on both policyand implementation.

Scott D, Hamilton, Jr,Conservation Council for HawaiiHonolulu, Hawaii 96815

Debunking scrap rates discrimination

Dear Sir: I have belatedly iearnedof and read an article entitled,"Transportation: bugaboo of scrapiron recycling," by Herschel Cutlerand Gerald S. Goldman (E5& T, May1973, p 408). I am employed by arailroad and, not surprisingly. take exception to much of the article. However, if unjust rate discriminationwere found to exist by an impartialbody (the ICC presumably falls in

this category and has failed to findsuch fault), one would be intellectually as well as legally, obliged to accept such findings,

Cutler and Goldman attempted tolend the requisite aura of legitimacyand impartiality to their positionthrough reference to findings of theBattelle Memoriai Institute study,"The Impact of Railroad FreightRates on the Recycl ing of FerrousScrap,," by T. M. Barnes. It is of interest in evaluating the weight to begiven Battelle's study that Dr. Cutler,even though employed as executivedirector of the Institute of Scrap Ironand Steel, was author of a significantportion of the study and was responsible for the transportation values referred to in the article in your magazine.

I am attaching for your perusal acopy of the Battelle study, a copy ofan article from the July / August 1970issue of Waste Age magazine by Dr.Cutler, and a copy of my commentson the Battelle study (which werewritten before I learned that Cutler,not Barnes, had developed the transportation values).

Several facts should be noted: 1)Much of Section B of the Battellestudy is taken verbatim from theWaste Age article, without reference.2) The technique and transportationvalues for Section C were supplied toBattelle by the Institute and usedwithout attribution. I verified this factin a telephone conversation with Mr.Barnes. 3) My comments demonstrate the erroneous nature of mostof the transportation values used,and contain alternative values whichreverse the results given in the Battelle study. I submitted my comments to both Mr. Barnes and Dr.Cutler. Mr. Barnes acknowledged myeffort in the phone call mentionedearlier. Dr. Cutler has not replied.

Richard L. LewisSt. Louis-San Francisco Railway Co.St. Louis. Mo. 63101

More on DDT

Dear Sir: Robert M. Devlin, in hisarticle, "DDT: A Renaissance?"(ES&T. April 1974, p 322), neglectsto discuss one very important problem associated with the use ofDDT-the problem of DDT resistancein insects. While the lives of millionsof human beings may have beensaved by the use of DDT in the past,"the lives of millions of humanbeings" cannot continue to "dependon DDT." as Dr. Devlin suggeststhey will, if the incidences of insectresistance continue to increase. In acursory search of the literature. Ifound that the American ChemicalSociety held a "Symposium on theBiochemistry of Insect Resistance"at the 165th ACS National Meeting,Dallas, Tex" April 1973, and that

Robert L. Metcalf discussed DDT resistance in his review article on"DDT Substitutes" (Metcalf, R. L.,"DDT Substitutes," CRC-CriticalReviews of Environmental Control,August 1972, p 25). In this article,Dr. Metcalf cited many examples ofDDT resistance in insect species,some of which have hampered malarial control efforts. Resistantspecies include the housefly, Muscadomestica; the human body louse,Pediculus corporis, the bedbug,Cimex lectularius; the German cockroach, Blatta germanica; the codlingmoth, Carpocapsa pomonella; thecorn earworm, Heliothis zea; thecabbage looper, Trichoplusia ni. atleast 19 species of culicine mosquitoes and at least 15 species of anopheline mosquitoes. DDT resistancein A. stephensi has resulted in malarial outbreaks in Iran, Iraq, and India.

In addition, Dr. Devlin discussesthe problems of analyzing for DDTresidues, particularly the possibilityof PCB-contaminated DDT extracts.However, Dr. Devlin fails to mentionthe possibility that DDT can photodegrade to PCB through the intermediate dichlorobenzophenone (DCB)(Moilanen, K. W., and Crosby, D.G.,"Vapor-Phase Photodecomposition ofp,p' -DDT and Its Relatives," No. 21,Pesticide Chemistry Division, 165thACS National Meeting, Dallas, Tex"April 9-13, 1973).

Finally, Dr. Devlin states (paragraph 4) that "The only effectivecontrol of the tussock moth is DDT."In the same ES&T issue in which Dr.Devlin's article appears, is publisheda letter from Bert Van Tassell of Nutrilite Products. Inc. Mr. Van Tassellclaims that Nutrilite's tussock mothpolyhedrosis virus and Biotrol XK(Bacillus thuringiensis) achieved99% and 95% control, respectively,of the tussock moth when appliedaerially to forested land.

The information that I turned up inone-half hour on the topics that Dr.Devlin addresses in his article leadsme to conclude that Dr. Devlin didnot thoroughly research the topics hereported on. In any future unbiasedarticle on DDT, the studies andclaims that I mentioned should bepresented and evaluated.

Linda J. GardinerCenter for the Environment & Man, Inc.Hartford, Conn. 06120

Wet scru bber and sludge

Dear Sir: I wish to clarify twoitems that appeared in the article,"The largest U.S. wet scrubber system," (ES&T. June 1974. p 516). Radian Corp. does not have a scrubbersludge treatment process per se. Weare under contract to the ElectricPower Research Institute to examinethe environmental acceptability ofthe surface disposal of scrubber

sludge. Further, in our work on theprocess design of limestone wetscrubber systems in conjunction withJoy Manufacturing Co" we haveachieved better scrubber sludge-handling characteristics by virtue of process modifications. This is not atreatment process, however. Finally,Radian Corp. is not located in Dallas,but Austin, Tex.

Donald M. Carlton, PresidentRadian Corp.Austin, Tex. 78766

Four Corners

Dear Sir: Your one-sided coverstory (ES&T. June 1974, p 516)about the Four Corners pollution controls was akin to ascribing perpetualmotion to the electric car-you neglected to mention the batteries. It isa delusion to imply the fine antipollution efforts being made by ArizonaPublic Service Co. have been selfstarting. Countless hours of effort byone, then a hundred, then thousandsof citizens beginning in 1966 andlater by state officials led to lawsuits, U.S. Senate investigations, andliterally weeks of hard-fought regulatory hearings prior to where yourstory begins.

The "moving target" APS complains of largely resulted from theirown efforts at these regulatory hearings to establish weak and ineffectual emission restrictions. At 1969New Mexico hearings, power companies spent one full day arguingthat 97% control of fly ash was thebest attainable at Four Corners. Dustemitted from the plant at 97% cleanup would be over 100 tons per day,nearly the same tonnage of particulates as is emitted by all sources inLos Angeles. It is not surprising thatas soon as regulators discovered97% was far from the best, the targetwas appropriately moved.

APS's discussion of scrubber reliability also tells but half the story. Tobe sure, there have been problemswith the scrubbers which, at leastduring shakedown, reduced the capacity factor of the units. However the capacity factor never got asIowan units with scrubbers as it didduring shakedown on the larger,newer units without scrubbers. According to APS data for the 12months ending September 1973, thecapacity factor for three units withscrubbers averaged 65.4%; the capacity factor for two units withoutscrubbers averaged 65.0% at FourCorners,

Nobody likes malfunctions, butpollution control problems should betold in context with the other problems industry normally accepts without battle or fanfare.

John R, Bartlil, State ChairmanNew Mexico Citizens for Clean Air & WaterLos Alamos, N.M. 87544

Volume 8. Number 9, September 1974 779

Toxic organics in yourwastewater?Time to call in Calgon Adsorption Service:

We don't have to tell you abouttoxic organic chemicals. But we do .want to tell you how we can help youachieve an acceptable discharge.

Adsorption with granular activated carbon is the most effective andeconomical process for removing alleight toxics listed above. It will probably remove related dissolved organicsof the same type including benzidine.

The Calgon Adsorption Serviceprovides these additional benefits:

• No major capital investmentnecessary

• No air pollution or sludgedisposal problems

• Minimum 18-month contractassures short-term commitment,long-term solution

• Calgon assumes risk of pollutioncontrol obsolescence

·Calgon Adsorption Service is a service mark ofCalgon Corporation.

We erect, operate and maintain acompact modular treatment system onyour plant site. We remove and replace the exhausted carbon. We monitor the treated effluent to be sure itmatches our agreed-on standards. Ifyour requirements change, we caneasily add modular units to increaseremoval levels or volume treated.

The best part is that, after feasibility tests are done and contractterms settled, we can have a CalgonAdsorption Service system operatingat your plant within months . .. notyears.

Call D. G. Hager today at (412)923-2345. Or write for a brochure toCalgon Adsorption Service,Calgon Corporation, P.O. Box 1346,Pittsburgh, Pa. 15230.

Calgon Adsorption ServiceExpansion-A new sales engineeringoffice is open in Houston, Texas. Callthem at (713) 681-5426.


The Water Managers

6~~~SUBSIDIARY OF MERCK & CO" INC.

WASHINGTON

The EPA released clarifications for"indirect source" facilities which willbe constructed after next Janu-ary. These facilities. such as highways. parking lots. garages. and airports. are potential sou rces of significant amounts of auto-related air pollution. The clarifying amendments tothe regulation. requiring review of theair quality impact prior to construction include air pollution predictionmethods. construction permit applications. data requirements. and various definitions of regulatory language. The regulation took effectJuly 1 of this year. and does notcover indi rect sources under the"management of parking supply"provisions of the agency's transportation control plans.

EPA administrator Russell Train recently presented an overview of enforcement accomplishments in a 15month period. "Enforcement ensuresthat the environmental laws result incleaner air and water and safer useof pesticides." he said. From Januaryto March 1974.2846 enforcementactions were taken against violatorsof water. air. and pesticide laws. Atthe same conference. Alan Kirk. EPAassistant administrator for enforcement and general counsel. announced that EPA is developing anew enforcement strategy for ensuring that new production automobilesconform to emission standards at theassembly line. He also said that theaftermarket parts certification program now under development will bethe first step toward establishing performance warranties on vehicleemission control systems.

EPA administrator Train called on 21chlorine producers to give priority attention to supplying chlorine forwater supply and wastewater disinfection. though federal chlorine allocation authority is pending in Congress. Train also asked for a cooperative effort between governors andEPA regional officers for voluntarysharing of chlorine.

The House passed its strip-mininglegislation by a 291-81 vote. in lateJuly. The bill requires the restorationof surface-mined lands to their original contours. and restricts mining on

CURRENTS

Strip mine

slopes steeper than 20°. With theSenate approving its version lastyear. the way seems clear for thepassage of the first federal strip-minelegislation this year. Differences remain to be resolved between theHouse and the Senate. however. Themajor conflicts include a Senate provision that bars any strip mining ofcoal on federal lands. a House provision granting surface-right ownersthe option to refuse permission forthe mining of underlying coal. andHouse restrictions on undergroundmining.

The TVA is going to invest $180 million in pollution control this new fiscal year. up from $135 million spentlast year. A major part of the moneywill go toward the installation of newelectrostatic precipitators of veryhigh efficiency to meet present federal and state standards for the control of fly-ash from coal-burningpower plants. Seven of the TVA'spower plants will get these precipitators. At three nuclear power plantsunder construction, cooling towersystems are being installed for thecontrol of thermal pollution. TVA saidthat progress is impaired by factorssuch as material shortages. andcomplexities of scheduling installations.

The EPA will voluntarily prepare environmental impact statements onsome of its major regulatory actionstaken after October 15 of this year.The decision to do this came afterthe House urged the EPA. in appropriation hearings this spring, to prepare impact statements as part of itsregulatory process. The 1974 Appropriations Act for Agriculture, Environmental. and Consumer ProtectionPrograms has provided $5 million for

that purpose. To date. the EPA hasissued such statements only withconstruction grants for pubiiclyowned waste treatment plants, in accordance with P.L. 92-500. Underthe new policy. statements will beprepared on matters relating to theClean Air Act; Noise Control Act;Atomic Energy Act; Marine Protection. Research. and Sanctuaries Act;and the Federal Insecticide. Rodenticide. and Fungicide Act.

STATES

A key steel can recycling facility inCalifornia has returned to operation.The plant, situated in Roseville. anddestroyed by an explosion nearby.will open before other plants in Oakland and Martinez. These plants willconvert scrap steel cans to "precipitation iron" which is used in a chemical leaching process to recover copper from low-grade ore (£5& T. February 1973. p 100). The Rosevilleplant will process about 400 millionscrap steel cans reclaimed fromhousehold garbage in the comingyear. Portable magneti c separatorswill also be used to reclaim cansfrom landfill. Industrial officials estimate that about 500.000 tons of steelscrap are currently used in copperextraction.

Nashville (Tenn.) will be the site forcentralized sludge incineration. Two10-hearth incinerators from NicholsEngineeri ng & Research Corp.(£5& T. May 1974. p 399) will beadded to the 55-mgd Central wastewater treatment plant·, by the year'send. to handle additional sludge froma neighboring plant. Each incineratorwill have a 24-hr capacity of 240tons of filter cake resulting from bothplants. Both incinerators will be fittedwith wet scrubbers on their flue gasoutlets. An oxygen analyzer will monitor the amount of air entering the incinerators. City officials expect tosave about $50.000 in operatingcosts per year and $4 million in construction costs.

Workers in a Columbus. Ohio. plantare sUffering from nervous disorders,Scientists and doctors studying theoutbreak say that the cause is mostprobably the industrial solvent.methyl-n-butyl ketone. Research iscontinuing.


A sewer's candid camera

The sewer lines in Harrisburg, Pa.,are being televised this summer. Infiltration/inflow through leaks in sewers. surface runoff, and basementdrainage are detected by loweringclosed-circuit television equipmentinto a manhole. The leaks are thenisolated by a pneumatic packer andplugged in seconds with a polymersealant. This inspection, conductedby the Gannett Fleming Corddry andCarpenter group, will reduce wastewater loads at treatment facilitiesand benefit the homeowner in theend.

Central Pennsylvania residents maybe drinking acid mine drainage watersoon. The solution to their watershortage is a new water treatmentplant which will convert acid waterfrom the abandoned mines intoclean, potable water by means of ionexchange resins. The Rohm andHaas process uses ionized plasticbeads to exchange unwanted material in water for desired compounds orcompounds easily removed by another treatment process. As much as800,000 gpd of water are now processed. with anticipated capacity of1 million gpd by next year.

Air quality may be a problem forareas in New York, New Jersey, andPuerto Rico. The Environmental Protection Agency has proposed to designate 25 areas as regions likely toencounter problems in maintainingclean air standards between 197585. These proposed areas would undergo further analyses by the statesto determine whether control plansare necessary. Recommended control strategies include modificationsto existing methods for minimizingemission of pollutants from new andexisting sources. and to state implementation plans. Plans for controllinganticipated problems-particulatematter. sulfur dioxide. carbon monoxide, photochemical oxidants. and nitrogen dioxide-are slated for submission to the EPA by next June.

Water quality in New Orleans, La"was examined by federal and state


agencies. This joint effort, involvingthe Environmental Protection Agencyand the state's stream control commission and health and social rehabilitation services, sampled water atthree water purification plants whichservice over 800,000 residents. Analyses are expected to continuethrough next month. This supplementary intensified program, which is inaddition to the regular monitoring activities being conducted by local andstate agencies, was undertaken because of recent allegations thatdrinking water in New Orleans andJefferson Parish pose eminent healthhazards.

MONITORING

Reports on air polfution instrumentation and water pollution instrumenta:tion are available from Frost & Sullivan (New York, N.Y.). The air instrumentation reports forecast, through1985, dollars, numbers, and pricesfor 32 products for air analysis, stationary source monitoring, and 'exhaust analysis applications. It isdated February 1974, and identifiedas Report 233. The water instrumentation report is dated April 1974, andidentified as Report 262. It, too, forecasts needs through 1985 for bothmunicipal and private water supply,as well as municipal and industrialwastewater monitoring needs. Theaddress is 106 Fulton Street, NewYork, N.Y. 10038.

"An automated method for analysisof sample and complex cyanides inwater is available." say A, Conetta,J. Jansen, and J. Salpeter of Technicon Industrial Systems. An analysisrate of 30 samples/hr is possiblewith a detection limit of 10 p.g/1.Modifications can lower the detectionlimit to 2 p.g/1. The breakdown ofcomplex metal cyanides is accomplished by uv digestion and high-temperature distillation; a uv digester iscommercially available. The molecular HCN formed is separated fromthe matrix automatically and continuously by a distillation assembly andmeasured by means of the standardpyridine-barbituric acid or pyridinepyrazolone procedures.

TECHNOLOGY

Removal of vinyl chloride monomer(VCM) in air to nondetectable levelswith granular activated carbon (GAC)was accomplished in tests run byCalgon Corp. GAC of 12 X 30 meshadsorbed up to 30% of its ownweight of VCM when breakthroughoccurred. According to Calgon, virtually complete removal is possiblewith two carbon adsorbers in parallel.Air flow is alternated to each bedwhen adsorbers become saturated.One GAC bed can be regeneratedwhile the other adsorbs VCM. TheVCM can then be steam-stripped forrecycling back to the manufacturingprocess.

Obtaining chemical energy from organic farm wastes is feasible, according to an assessment by the University of Wisconsin (UW). A UW research team believes that it can develop an efficient means of converting large amounts of animal wastesto methane. The UW system wouldscrub the methane to remove sulfur.and prod uce protein and soil conditioner by microbiological techniques.If the UW research team is successful, it is estimated that a 1DO-animaldairy farm could produce 12,500ft3/day of methane. which would exceed heating and drying needs.Later, the system might be able to beused on domestic sewage.

Combating excess phosphate, nitrate. and nitrile in raw or partiallytreated sewage with algae and brineshrimp shows promise, according totest results obtained by the NationalOceanic and Atmospheric Administration (NOAA). Best results wereobtained when certain algae werecultured in aerated sewage effluent.and brine shrimp were then introduced; best pH range was 6.4-8.3.In a treatment system. algae wouldbe grown in sewage effluent in 1-2days; the liquid and algae then go toa brine shrimp tank. The ultimate result is expected to be equal to tertiary-treated sewage. The brine shrimpcould later be used as a food basefor mariculture.

Breaking down sewage material inthe pipe on the way to the plant canbe done with selected cultured bacteria. Stabilization. without extrasewage plant loads, is possible. Offensive odor-producing chemicals arealso reduced by this method. according to Lathrop Laboratories. Fresno.Calif. The bacteria are metered intosewage lines on a continuous basis.along with any additives appropriateto prevailing conditions in a givensewer system. Extended retentiontime gained with this technique increases separation and aeration capacity by 20%. according to Lathrop.Resulting low-odor sludge can beprocessed for soil conditioner andfertilizer.

flU Fa. -.11 IIf.•

Reducing NOx at stationary sourceswith ammonia as a reducing agentcalls for a dry-type catalytic denitrification process. This process. developed by Japan Gasoline Co .. Ltd ..Tokyo, uses a catalyst unaffected bycoexisting sax or water content inthe flue gas. and is able to maintainstable performance of over 95% denitrification for a long time. Applications for the system are found in NO xremoval from stationary sources.such as flue gas from furnaces andfuel-oil burning boilers. Because of alow ammonia-to-NOx ratio. and thecatalyst that is unaffected by sax.ammonium sulfate or ammonium sulfite fouling of the system is obviated.

CURRENTS

INDUSTRY

Browning-Ferris Industries. Inc. (BFtHouston. Tex.). largest solid wastesysfems company in the U.S.. hasunveiled a business office suitemade from recycled solid wastes. atHouston's Astrohall. The 15 x 40-ftoffice suite contains a desk and deskchair, three pull-up chairs. twolounge chairs. a sofa. a coffee table,two end tables with lamps. ash trays,

Browning-Ferris'Vanderveld

planters, and miscellaneous decorative pieces. The "walls" comprise 164 X 8-ft panels of paper. glass, andcloth. BF I's senior vice-president.John Vanderveld. Jr., says that. "Thetechnology is available today to recover all reusable resources from ourwastes." and expects economics ofrecycling to achieve parity with "virgin" materials.

The American Paper Institute (API.New York, N.Y.) is hoping for legislative changes which will replace the"simplistic" goal of zero discharge ofpollutants (ZOP) with a program that"integrates all environmental. energy,and economic objectives in a balanced program." The API lists actions by which it charges that EPAhas "deviated from the course charted by Congress and has chosen toblaze its own trail." These actions, inthe API's view. include failure to consider all technological factors. settingstandards by mills of atypically highperformance. setting effluent limitsbeyond current available technologies, reducing the role of states to aclerical one. and modifying statestandards more rigidly in a way thatpredates the 1972 Act.

A new dyestulls industrial groupThe Ecological and Toxicological Association of the Dyestuff's Manufacturing Industry (ETAO)-was recently founded at Zurich. Switzerland,and will have its permanent secretariat at Basel. Switzerland. ETAO'sgoals are to coordinate and unify efforts of synthetic organic dyestuffmakers to lower ecological impact inuse and applications of the industry'sproducts; and to provide best possible and practicable protection toproduct users. ETAO seeks to solveecological and toxicological problems arising from use of dyestuffs inconsumer industries. ACNA, BASF.Bayer, Ciba-Geigy, Hoechst. ICI, Mitsubishi, Sandoz. and YorkshireChemicals are charter member firmsof ETAO.

Bethlehem Steel Corp. "is spendingmillions 01 dollars for a large piece ofequipment which will sit around andcollect dust." This equipment. atBethlehem's plant at Steelton. Pa.. isa baghouse "about two-thirds thesize of a football field and 100 feettall." according to Robert Summers.the Steelton plant's general manager.The baghouse, working much like avacuum cleaner, will extract dust anddirt. and store them for disposal-or.in the case of making steel. recycling. The facility is expected to bringthe Steelton plant's electric furnacemelt shop into compliance withPennsylvania's very strict regulationsfor emission control.

The Purity Corp.. Elk Grove Village,III.. a manufacturer of pollutionabatement equipment, recently determined. through a nationwide survey, that 250 of the nation's largestindustrial companies predict a resurgence in the industrial use of coal by1984. Purity also learned that onethird of these companies are now engaged in feasibility studies for converting operations to coal use. According to Purity, while the executives queried see coal as the answerto their energy problems. they alsofeel that more human and financialresources in coming years will bechanneled to extracting greateramounts of oillrom the ground thanto the redevelopment of coal as apower source.


OUTLOOK

Making sugar and protein from trashSpecially cultured fungus strains work busily at producing enzymes

which break cellulose down to glucose. or produce single cellproteins on low-grade syrup. They don't ask for too much in return

No doubt during World War II,there were many G I's on variousSouth Pacific islands who used deleted expletives after witnessing theeffects of the fungus Trichoderma viride, This fungus had a voracious appetite for garments, as well as justabout anything else that containedavailable cellulose,

What the men were seeing wasthe biochemical effect of the fungus'cellulase enzymes which break cellulose down to reducing sugars, suchas glucose, But that very effectwhich made the fungus the soldier'sbane may be the solid waste processor's boon, For this reason, two mutant strains of Trichoderma viride(OM9123 and QM9414), capable ofproducing two to four times the cellulases the parent strain (OM6a) produces, have been developed over thepast 20 years, This work was theoutgrowth of the Army's efforts originally aimed at overcoming the fungus' destructive properties,

Sweetening the pot

Cellulose is a renewable raw ma-

terial produced by photosyntheticprocesses to the tune of 100 billiontons per year. worldwide, Much or allof it ends up in municipal trash (4060% cellulose) and as animal feedlotand agricultural wastes, The Army'sNatick Laboratories (Natick. Mass.)are converting this waste cellulose toglucose syrup in concentrations of2-10% by weight. The system approach for this conversion was developed by Fermentation Design, Inc,(FDI, Bethlehem, Pa.), a Division ofNew Brunswick Scientific Co .. Inc"in collaboration with the Natick Labs,

Different cellulose sources, su chas peanut waste, municipal waste,straw, cotton. bagasse (sugar canewaste), and rice hulls were tried:however, waste newspaper was chosen for the FDI/Natick Labs' pilotplant because it is more easily saccharified (broken down to glucose).If pilot results, aiming at 1000 Ib/moof cellulose to be treated, are favorable, a 200,000-lb/mo demonstrationplant would be the next step.

To be sure. cellulose from trashmay be directly converted to chemi-

cats or acid-hydrolyzed to glucose.However, noncellulosic impurities,such as lignin and plastic, can takepart in these reactions. Moreover.the nature and amounts of these impurities vary with different trashsources. By contrast, enzymatic hydrolysis with cellulases is highly selective. Resulting crude glucose syrups are reasonably free of extraneous matter and reversion compounds, and thus, rather constant incomposition. although it may be derived from various waste sources.

The recovered glucose makes afine substrate for culturing single-cellprotein (SCP). From the glucose,ethanol. for fuel and other (sometimes more pleasantl) uses, may bederived; the glucose may also be abase for chemical feedstocks. Thecellulose from which the glucose ismade is itself a cheap, abundant, renewable substrate for these particular mutated fungi.

The pot is not altogether sweet,however. Cellulose is crystalline andinsoluble; and, if its origin is trash, itwill contain lignin and other foreign

Cellulose to glucose. The aim of this pilot plant is to break 1000 Ib/mo of old newspaper down to glucose

Glasa reentry

SiIIII-eeU prlttilsEtIIlHI

QllliullelllstKks


Carob pods. From waste to food

matter. This combination at properties and impurities makes waste cellulose a very difficult substrate withslow "glucosification." These difficulties are mitigated, however, bybreaking the substrate down beforeprocessing, and the best knownmeans of doing so is ball milling. Ballmilling reduces crystallinity while itincreases bulk density and exposesmore surface to cellulase enzymeaction.

Pilot studies

The pi lot plant co nsists of a 30liter seed culture vessel, with a 400liter fermentor and a 250-liter enzyme reactor. Additional vessels areprovided so that concentrations ofsuch additives as enzyme inducers.substrates. and chemical defoamersmay be changed. The inoculumgrown in the seed vessel is fed intothe fermentor where cellulases aremade. Pure cellulase enzymes andcellulose substrates than go to theenzyme reactor where the cellulosebreaks down to glucose. Conditionsof atmospheric pressure, pH 4.8, and50°C give the best results.

FDI designed the fermentationsystem for interfacing with a computer for fast data acquisition and analysis. and process optimization. Dataacquired would include temperature,pressure. gas flow. agitation speed,pH, dissolved oxygen concentration,and analysis of liquid weight and exitgas. Determination of the status ofthe process and formulation of refinements would be greatly eased.Hopefully, the computer will be online at the end of this year.

The pilot studies must determinethe final (and optimum) glucoseyields and reaction rates which mightbe expected, especially on a demonstration scale. Fermentation methodsmust be refined, and the best combination of enzymes for break ing finelydivided cellulose down to glucose,and for counteracting bonds betweencellulose chains must be ascertained. Also needed is a way to combat unfavorable mass transfer effectsof impurities, especially in concentrated reaction mixtures. so that acontinuous process becomes trulyworkable.

Further "down the pike," the Natick Labs' scientists want to find otherorganisms which can be cellulase

sources. They would also Ii ke to fi ndor develop organisms or enzymesthat could degrade leftover lignins(now burnable as fuel or usable as anonfermentation source of chemicals), as well as a means to recoveror reuse cellulase enzymes. Also onthe "to do" list is a comprehensiveeconomic analysis of the final process. and of potentials of recovery asagainst direct use of product syrups.

Meanwhile, in England ...

Tate & Lyle ltd. (Reading, England) is a household name in England, where the company has beenthe major sugar purveyor for a fewhundred years. The American branchof the company, Tate & Lyle USA, islocated in Washington, D.C.

Acutely conscious of spiraling worldprotein requirements, Tate & Lylehas been looking into the upgradi ngof agricultural crop wastes into highgrade animal feed by means of selected microorganisms. Under scrutiny were bagasse, beet pulp, carobhusks, tomato pulp, and potato peelings and starch water. These wastesare used directly as low-grade animalfeed, but in most cases, they mustbe supplemented with expensive feedadditives. Might the microorganisms,grown on agricultural waste substrates, not themselves be the protein source that upgrades the animalfeed?

The carob is a member of the peafamily. Also known as the locustbean or St. John's bread, it is foundin Mediterranean regions and in partsof Africa, South America, and theU.S. It grows relatively well on barren land. Its seeds are used mainlyin gum production. The husks orpods, containing up to 70% carbohydrates, can be a source of poor quality sugar syrup (carob syrup) andlow-grade animal feed. Curiouslyenough, principally during June andJuly, the pods' sugar content jumpsfrom about 20% to over 50%.

In fact, a high-quality sugar syrupfor various industrial uses can be obtained from kibbled (broken up)carob pods. This process would beeconomical if a use could be foundfor residual low-quality syrup. Thisresidual poor syrup and waste couldserve as a substrate for microbialprotein production, and, of 300 microorganisms considered for the pur-

pose, Tate & Lyle selected a strain ofthe fungus ·Aspergillus niger (M1),isolated from naturally rotting carobmaterial in Greece. The M1 fungus iscapable of doubling its weight in afew hours if a few inorganic nutrientsupplements are added to the substrate.

The process is being pilot tested atthe University of Aston (Birmingham,England) with a main fermentor of1000-liter capacity. The product obtained is a bland-flavored, slightly fibrous coarse powder easily blendedwith other ingredients when feed isbeing prepared. The product is apparently nutritious and nontoxic,judging from feeding trials; based onanalysis, amino acid content compares favorably with UN Food andAgricultural Organization referenceprotein, according to Tate & Lyle.

The M 1 fungus seems to performanother service. Unprocessed carobwaste is very high in tannins (up to1.5% by weight) which intertere withdigestive enzymes of pigs and ru minants. The M1 fungus produces atannase enzyme which breaks thesetannins down, thereby increasing thepotential usefulness and value of theproduct.

"Village technology"

According to Tate & Lyle, the relative simplicity and reasonable capitaland operating costs would give thisfermentation system for protein production utility in various warm-climate areas in Africa, Asia, the Middie East, South America, and thesouthern U.S. First of all, the need toupgrade feed by buying (and often,importing) expensive high-proteinsupplements would be sharply curtailed. Second, the problem of disposing of large amounts of certainagricultural wastes is mitigated. Finally, the system is sufficientlyrugged so that system temperaturescan go as high as 36°C before theprocess is markedly impaired.

Tate & Lyle plans to expand its English pilot facility to produce one toniweek of dried protein from the M1 fungus. The company also plans, on apilot basis, to test out the "villagetechnology" concept in Belize, Central America.

In any case, as the various processes prove out and are "debugged," it is quite possible that boththe Tate & Lyle approach and theArmyIFDI approach-perhaps onecomplementing the other-may helpto turn mountains of waste economically into rich chemical and biological resources, and perhaps prOVidenew light industries to many parts ofthe world where they are sorelyneeded. JJ


Developingwater

samplingstandards

Up to now, there have not reallybeen any standard methods andterminology for water sampling.

ASTM hopes to see them established Sampling, This sample was taken at Washington. D.C.

Finding out exactly how polluted agiven wastewater stream is involvesa cut-and-dried procedure. Onetakes samples. analyzes them, andrecords data so obtained. Unfortunately, things are not quite so simple, the 0-19 Symposium on AquaticSampling and Measurement forWater Pollution Assessment, sponsored by the American Society forTesting and Materials (ASTM), andheld at Washington, D.C., in June,was told.

For openers, there was generalagreement that no standard samplingequipment or technique really exists.Moreover, there is no piece of sampling equipment that can performevery desired function, nor is there acriterion by which the "optimum"sampler may be defined. Indeed,there does not appear to be even astandard nomenclature or terminology for sampling devices and methods. The 0-19 Symposium's principalobject was to take meaningful stepstoward correcting this situation.

In the field

William Keffer of the EPA (KansasCity, Mo.) and the people who workwith him are well acquainted with effluent sampling problems, since theyactually conduct "permit" or compliance sampling in the field. He hasevaluated about 16 different makesof samplers, and has 50 of these various devices on order. On the basis ofhis experience, he cautioned thatone cannot just buy a sampler "offthe shelf," insert the intake into the


wastestream, and expect the machine to perform immediately according to its designed functions. Healso said no one sampler will have allthe capabilities that the field manseeks.

Usually, Keffer and the field people with him will take 20-25 composite samples/day to obtain the mostrepresentative possible samples. Heestimates costs involved at about$100/sample. Keffer recommendedtime composite sampling overflowcomposite sampling, since the lattertechnique offers doubtful technicalaccuracy improvement, and requiresmore investment, as well as 20-30additional man-hours. He also recommended that the sampler have asingle intake hose whose nozzle ispointed into the direction of flow.

In the course of his field work,Keffer has taken grab and compositesamples with various types of samplers. He told the symposium thatthese samplers can cost $3001500/unit, and that the user shouldknow all of the sampler's characteristics and capabilities. Keffer alsospoke of permanently installed samplers, which can cost $3000-4000each, to be used for permit compliance; however, he recommendedthat a permit holder take more samples, with "portable" samplers, thanhis permit requires.

Storm sewers

One of the toughest samplingtasks is to obtain representativesamples from storm or combined

sewers. Philip Shelley, director of engineering of Hydrospace-Challenger,Inc. (Rockville, Md.), pointed outthat such sewers combine widelyvarying flow rates, pollutant concentrations, and materials carried by thewastewater (from oil particles to engine blocks!) with complex channelhydraulics. Industrial and domesticsewage, often present because of illegal hookups, or lax or poorly enforced ordinances concerning sewerconnections, adds to the headaches.

To define methods of sampling thissewer effluent, Shelley lists:

• discrete samples, collected atselected intervals, with each sampleretained separately for analysis

• simple composite samples,made up of aliquots of constant volume, collected at regular time intervals, and combined in a single container

• flow-proportional compositesamples, collected in relation to flowvolume during the period of compositing, and indicating the "average"waste condition during this period

• sequential composite samples,consisting of a series of short-periodcomposites, each of which is held inan individual container.

For best sampling results, Shelleyrecommended sampling sites whichfeature maximum accessibility andsafety, discourage vandalism, andprovide information desired. Henoted that the site should be farenough downstream from tributaryinflow so that tributary and mainsewage are well mixed. The site

should also be in a straight length ofsewer, at least six sewer widthsbelow bends, and preferably at apoint of maximum turbulence (bestjust downstream from a drop or hydraulic jump). He pointed out thatsiting and installation must take intoaccount cost/effectiveness.

Equipment

Karl Fox, marketing director ofPro-Tech, Inc., defined "grab samples" as samples taken at one timeor point. He reminded the symposium that equipment and samplingstandards are still largely in a formation stage, and that there are 60-80different samplers on the market. Heproposed that equipment standardsshould emphasize intake, transport,tubing and piping, sample size, flowcontrol, power sources, and temperature control.

It is most important, Fox reported,that the sampler be built of tough,corrosion-resistant materials, such asTeflon, polyvinyl chloride, or the like.Where gas samples are to be taken,a vacuum pump should be replacedby a submerged pump. Holes in intake screens should be Y.-% in. indiameter. The sample size should notincrease in proportion to lift. Refrigeration should be provided for BODsamples.

EPA's Keffer, however, said that ifice can provide sufficient coolinguntil the sample arrives at the laboratory, money can be saved, since refrigeration is rather expensive. Hewas also very emphatic about notletting a sample come into contactwith most metals. Keffer told thesymposium what features he, as afield man, would like to see samplershave (see box).

Hydrospace-Challenger's Shelleyalso mentioned a few attributeswhich could apply very well to stormand combined sewer samplers. Shelley, for example, would like to seemore than one intake port, so thatvalid samples can be obtained eventhough one port is clogged (and it isamazing what can clog an intake!).He would also like to have a 6-meterlift, as well as 1-liter (at least) discrete samples and 4-8 liter composite samples. However, Shelley saidthat the samples should be smallenough to be easily transported. Hecalled for flow meter signals, as wellas a signaled start-that is, a sampling start triggered by rainfall runoffor water level in the sewer, with thesampler unattended. Also, Shelleystressed the need for a reliabiepower source for the sampler, and agood method to deliver the sample tothe laboratory without precontamination, and expressed a preference forrefrigeration over chemical preservation where possible.

ApplicationsJ. William Sugar of Union Carbide

Corp, (South Charleston, W.Va.) reported that sampler technology in hisindustry must be equal to monitoringwastewater of highly variable chemical composition, especially in thelight of "best practicable" (1977) and"best available" (1983) technology.These samplers would monitor cooling and process water, as well asterminal waste treatment.

Union Carbide therefore designeda 24-hr composite sampler whichcan also take grab samples on demand. This sampler, which monitorsmainly carbon and organics, workson a chromatography principle, andhas a foam detector based on fluidamplification (fluidics). Measurementis in ppm; total cost (1973), including all engineering, supervision,

Suggested sampler features

• Operation on ac/dc, 120 hr, 24 hr /day,with 3 days' reliable sampling. samples 1 hrapart; batteries must not need rechargingevery other day

• Operation in standard manhole with uniform atmosphere and protection from vandalism or tampering

• Battery weight less than 40 Ib

• Collection intervals adjustable from 10min to 4 hr (10 min needed for compliancestudies)

• Capability for flow-proportional and timecomposite sampling

• Capacity for 2 1h-gal sample

Source: EPA/Kansas City, Mo .. symposiumpaper

labor, material, and associated expenses, was $53,350 (though thesampler alone cost $750). Fluidicswere used to replace optical foamdetection which often fouled andgave false alarms.

Sugar reported that the benefits hehopes to see from reliable samplerswould be real-time data, reduced accidental losses, savings in products,equitable wastewater treatmentcharges to production, and earlywarning to protect the wastewaterplant. He also expressed hopes foridentification of process techniqueswith high pollution potential, optimization of wastewater treatment, andvalid historical data.

Further sampler applications,some with bothersome problems, involve wastewater monitoring aboardNavy ships, since wastes can nolonger simply go overside. Samplingdifficulties involve erratic flow ratesand solid content, as well as thenumber of outfalls which, on a supercarrier, for example, can number asmany as 150. The U.S. Naval ShipResearch and Development Center(NSRDC. Annapolis, Md.) is devel-

oping samplers engineered for useaboard ship. Andres Talts of NSRDCsaid that while ASTM and EPA givegood guides for industrial and municipal effluent sampling, those guidesfall short with shipboard constraints.

Other specialized sampler applications will be in the detection of organophosphate pesticides, such asparathion (extremely toxic), ethion,trithion, and others, in parts per billion. C. Wu of Drexel University (Philadelphia, Pa.) discussed the development of such a sampler, based onliqUid-liquid extraction. Another application will be a device to measuresuspended solids (SS) through depolarization of backscaltered polarizedradiation, as described by John liskowitz of the Newark (N.J.) Collegeof Engineering. Badger InstrumentCorp. (Milwaukee, Wis,) has been Ii-

• Able to multiplex

• Inner diameter of intake at least %in.

• Variable intake of 2-10 ft/sec by dialsetting

• Lift of 20 ft

• Explosion-proof

• Watertight exterior case

• Security lock

• Separation 01 sample from all metal

• Operable from -10 to +40°C

• Capability of purge in case intake becomes clogged

• Amenable to routine field repair

censed to develop and market aneasy-to-handle unit of this type thatcan detect SS from 1-2 ppm to asmuch as 100,000 ppm.

David Thomas of NASA (Hampton,Va.) described a remote sampler formarshland waters. This device is installed and removed at a remotearea with the aid of a helicopter, andcan telemeter its data via a satellite.Because of its general inaccessibility, vandalism and theft, which canfrequently plague samplers, becomematters of low probability.

Getting it all together

Complaints heard at the Symposium were that different samplers willg1ve widely varying readings for thesame or similar wastewater batches,and that no truly standard monitoringtechniques and terminology havebeen evolved. Information developedat the Symposium, and at relatedASTM workshops should, however,go a long way to help resolve thesedifficulties and to develop samplerswhich would prove reliable for theparticular tasks to which they wouldbe assigned. JJ


tf

rlnr 1 '111111 '1't!1

PAT REPORTPRACTICAL. AVAILABLE TECHNOLOGY

Removing three air pollutants at once

The Modine Manufacturing Co.,Racine, Wis., produces aluminum finand tube-type condensers for automotive air conditioning units. Theirmanufacturing operation begins withthe assembly of preshaped fins andtubes temporarily clamped togetherand drenched with a slurry mix. Thenthe assemblies are passed throughgas-fired ovens where they aresubjected to a high temperature,often in excess of 1000°F, to weldthe fins and tubes into a single unit.Subsequent operations includequenching, drying, assembly of additional components, hydrostatic testing, and painting.

Both gaseous pollutants and particulate matter result from this operation. For example, the aluminumbonding ovens release a corrosivecombination of hydrogen chloridegas and aluminum hydroxide and aluminum chloride particles. Of Modine's 14 operating plants, the one atClinton, Tenn., has been equippedwith an air and water pollution control system costing approximately$285,000.

But not all the 13 other Modi neplants will be equipped with scrubbers because they are not required.Operations vary from plant to plant.For example, a plant at McHenry,III., also has a Ceilcote scrubber fora completely different set of reasons.A small prototype unit also was installed recently at Racine, Wis.

The Ceil cote Co., Berea, Ohio, designed and manufactured the venturiscrubbers which are unique in thatthe venturi diverging section is located within the main scrubber chamberand passes vertically through thepacked entrainment separator. Theprincipal advantage of this design, inaddition to saving considerablespace, is the fact that water and gasare discharged directly into a separator sump at the bottom of the scrubber, where most of the larger entrained liquid particles from the venturi throat are removed.


While the discharge from theovens is reasonably mild, the Tennessee Department of Air Pollutionrequired the installation of an air pollution system.

Before the Ceilcote scrubber wasinstalled at Clinton, hydrogen chloride was being emitted at the rate of50 Ib/hr. After the installation, theamount was virtually undetectable.Also, before the scrubber installation,particulate matter was emitted at therate of 50 Ib/hr. After installation,particulate matter was being emittedat the rate of 3 Ib/hr.

Stephen Schwartz, Modine's manager of environmental protection,says, "The combined' water and airpollution control system at the CI inton, Tenn., plant incorporates almosttotal water reuse. The system goes along way in allowing the company tocomply with state effluent limits

He continues, "Another importantfeature of the system is that the entire oven emission is vented throughfiberglass-reinforced resins (with theexceptions of the fans), which shouldrequire almost no replacement or repair due to corrosion."

Schwartz says, "The plant's twooperating ovens release approximately 65 Ib/hr of aluminum hydroxide and aluminum chloride. Particulate matter averages about 0.3 !J. indiameter. "The selection of high energy venturi units corrected the emissions problem."

Schwartz says that air and waterpollution control is being solved on acontinuous basis and most Modineplants do not present any majorproblems. While the Clinton, Tenn ..plant processes aluminum, mostother plants are working with copperand brass. He said that by the end of1974, the company will haveachieved 85-90% control at allplants.

How the scrubber works

In operation, gas effluent from thealuminum bonding oven enters the

top of the scrubber at the rate of approximately 35,000 acfm while wateris injected at 200 gpm. Both waterand gas speed through the highlyconstricted venturi throat and arethoroughly mixed as the water passes over a small turbulent producing"knee" projection around the periphery of the venturi throat.

Each 16-ft high scrubber is fabricated of %-in. thick fiberglass-reinforced plastic using a bisphenol-typepolyester with Dynel veiling A 12-in.thick entrainment separator is setapproximately 6 ft above the base ofthe scrubber and is packed with a1-in. diameter Tellerette plastic packing. The entrainment separatorserves as a second stage scrubbingoperation.

Modine's SchwartzComplying with ell/uent /imilalions

A circular spray header locatedbelow the separator plays a constantoverlapping pattern of fresh water upinto the packing to keep the packingclean of lime scale and to give further absorption of HCI gas. Passagethrough the packing provides additional contact time between thewater and the gas stream, and theunique shape of the filamentous Tellerettes provides the final absorptionof the last traces of hydrogen chloride and removal of entrained liquidparticles down to those submicronand larger in size.

Another spray header located

Ceilcote venturi scrubbers clean emissionsfrom an automotive air conditioning unitmanufacturing plant in Tennessee; theycontrol gaseous, liquid, and solid emissions

65 Ib/hr

50 Ib/hr50 Ib/hr

above the packing section can beused to spray acid, when the scrubber is not in operation, to dissolveaccumulated scale,

The inlet section of the venturi utilizes an underflow weir for liquid distribution, an arrangement which eliminates the possibility of dry spotsleading to solids buildup, which overflow weir or sprays may induce.

When water and gas drop to thebottom of the scrubber, the waterfalls into a sump area while the air,containing some entrained liquiddroplets, makes a 180° turn and isdrawn back up through the entrainment separator.

This complete turnaround of the airstream causes most of the entrainedliquid particles to drop out in thesump. Cleansed air is pulled ·throughtwo 32-in. diameter exhaust pipes (at16,000 acfm each) at the top of thescrubber, then to the base of a 40-fthigh exhaust stack.

Exhausted air is approximately99% free of pollutants and produces

Breakdown of pollutants andcontrol costsAluminum hYdrOXide}Aluminum chlorideHydrogen chlorideParticulate matter

Costs

Scrubbers' $ 30,000Other major equipment' 50,000Installation of all equipment 205,000

TOTAL $2lffiJi60" Including fans. motors, starters. lime

system. clarifier drive. pumps, pH in·strumentation. and stack.

b Including concrete pads. piping, electrical and structural supports.

a barely visible steam plume thatdissipates itself within about 20 ft ofthe stack, depending primarily on thedifference between ambient temperature and the heat of the stack discharge.

Passage of the gas through thescrubber system is handled by fansdownstream of the scrubbers whichare powered by 250-hp motors. Eachfan develops 25,000 scfm at 34 in.w.g. of pressure. Fan blades are 4 ftin diameter and are of mild steelconstruction with a baked phenoliccoating.

In-plant water reuse

At this Modine plant, water doesdouble duty. The same water used inthe manufacturing process is alsoused in the pollution control system.At Clinton, approximately 4.5 milliongal of water are maintained at pH 7.5in a 2.5-acre, man-made pond located about 100 yd from the plant.

From the pond, the water ispumped to the plant where it is utilized first as a quench for cleaningthe fin and tube assemblies after thebonding process. The water is thenpumped to the oven hoods where itserves as a coolant and lowers discharge gas temperature from 800°Fto 140°F.

How water is recycled

t

From the oven hoods, the water(which by now has picked up considerable acid) is gravity fed to a rapidmix tank where a lime slurry is automatically added to bring the pH ofthe water up to 9. From there, thewater is pumped to the top of thescrubbers where it begins its work asa gas cleaning agent.

Heavily laden with gas and solidpollutants, the water drops to thebottom of the scrubbers.

A 6-in. diameter drain set 16 in.from the bottom of the scrubbercreates a 16-in. deep water sump.The velocity of the air stream in thesystem keeps the sump water in acontinuous state of agitation, whichprecludes particulate matter fromsettling in the bottom of the scrubber. Agglomerated particles andwater overflow from the sump,through the drain, and 1I0w by gravityto a 16-ft diameter concrete clarifier,where a sludge raking blade rotatesat Va rpm and helps move sludge,settled along the sloped floor, to thecenter of the clarifier overflow. Theythen drain back into the pond at aslightly alkaline pH of 8.0 Virtuallyfree of any pollutants, except somesolids that settle in the pond, andlong before reaching the water intakefor recycle.

Rapid mix tank Oven BOO'F Quench forproduci cooling

PAT REPORTPRACTICAL, AVAILABLE TECHNOLOGY

Key to reliable exhaust emissions dataBalston, Inc.'s glass-impregnated filter protects delicate,

production on-line analyzers and satisfies the monitoring needsof both instrument and automobile manufacturers

With the advent of Federal standards, the need for accurate vehicleemissions data has become as mucha part of automotive development asthe need for data generated at thetest track, But despite their complexity and, in many cases, their size,analytical instruments used in emissions testing remain extremely delicate pieces of equipment whosefunctional parts must be adequatelyprotected if they are to operate reliably and produce the data required,

Instrument manufacturers, as wellas end users, have found that goodprotection of· their analytical instruments need not be expensive andactually can pay handsome rewards-increased sales for manufacturers,decreased downtime for end usersin addition to more reliable data.

Instrument makers

Dennis A. Mach, vice-president ofthe Instrument Division of Heath International, Inc.-one of the majoremissions test systems suppliers tothe auto industry-says, "We havegood evidence- that our constant volume samplers and analytical benches operate significantly longer without downtime caused by contamination since we started using a relatively inexpensive but remarkably efficient filter to protect critical parts."The filter Mach referred to is a tu beconstructed of borosil icate glass microfibers bonded with epoxy resinmanufactured by Balston, Inco ofLexington, Mass.

Heath International's Mach"Iilter protects critical parts"


Photomicrograph. Random network01 glass fibers leads to highly

efficient Iiltration

A look around the industry indicates that Heath is not the only company with evidence that these uniquefilters in emissions test equipmentmake a big difference in instrumentperformance. In fact, if there is anytrend toward uniformity in the emissions test instrument field, despitethe diversity of equipment used, thenumber of manufacturers building itand the number of companies usingit, it would appear to be in the selection of Balston filters.

One by one over the last two yearsor so, more and more original equipment manufacturers and end usershave been installing these filters ontheir emissions test equipment-usually after first trying some other filterand finding it not efficient enough,too costly, or both.

Heath, for example, builds all custom-engineered systems, from singletest units-such as constant volumesamplers-to completely integratedanalytical test benches capable ofperforming several vehicle exhaustemissions tests. Heath buys components from a host of manufacturersafter first carefully testing and evaluating them, and constructs whatDennis Mach describes as "the bestpossible package" to meet a specificcustomer need.

Like many other instrument builders, Heath originally used 7-cmpaper wafer filters on its test equ ipment to protect critical pumps and

valves. However, these paper filtersprovided protection against particulate matter only down to about 5 !J.in size. Since contaminants thatcould foul the instruments oftenare smaller than 1 !J. in size, therewas a potential reliability problem. Itwas a serious threat since one ofHeath's strongest selling points tocustomers is the reliability of its instrument systems.

After some searching and quite abit of testing, Heath discovered theBalston filter. Tests confirmed thatthese tilter units were capable of aretention efficiency not obtainablewith other filters, even those costingconsiderably more. In addition, thefact that Balston filter tubes could bereplaced quickly and easily in thefield appealed to Heath, since thecompany stressed easy serviceabilityof its systems. Heath now recommends Balston filters on all its newunits and h'as suggested that customers with older units switch fromthe paper filters to Balston tubes.

"We have found," Mach reports,"that with Balston filters in place,there is considerably iess downtimeand far less cleaning required on allour equipment."

Other instrument suppliers

For the world's largest builder ofchemiluminescent gas anaiyzers,Thermo Electron of Waltham, Mass.,the problem of finding the proper filter was, perhaps, more difficult than

Chrysler Corp's Lane"Iilter eliminates downtime

problems"

Heath's. Thermo Electron was producing a new analyzer that would beused in the auto industry for exhausttests, as well as by utilities and government agencies monitoring stackemissions.

The filter used on the sample linenot only had to be efficient, but ithad to have a long service life, havegood resistance to gases and corrosion, provide a minimum pressuredrop, and be compact enough to fitinto their design. Moreover, it had tomeet very strict cost parameters.

After looking at several likely filters available, Thermo Electron production and engineering people selected a Balston filter. David Brown,manufacturing manager, noted that,"When it comes to cost, compactness and filtering efficiency, the Balston filter had the others beat." Thermo Electron now uses these filterson its full line of chemiluminescentgas analyzers, varying the Balstonmodel according to sample conditions.

Several other prominent instrumentsuppliers to the auto industry, including Sun Electric of Chicago; Air Monitoring, Inc., a division of Ethyl Corp.;Beckman Instruments; Barnes Engineering; and Hamilton Standard Division of United Aircraft have specifiedBalston filters on their auto em issions test equipment for some timenow.

And in the field of continuous sampling gas chromatographs, one of thebest known and most widely respected manufacturers, Mine Safety Appliances, has concluded the filterthat works best on its equipment isBalston. The conclusion is much toMSA's credit and possibly is the kindof reason the company keeps the respect it enjoys, since MSA previouslyused in its instruments, filters thecompany itself designed.

End users, the real test

From the standpoint of end usersof vehicle exhaust test equipmentthe auto companies themselves-thetrend to Balston also is evident.

The Vehicle Emissions Departmentat Chrysler Corp. uses analyticalcarts built by a Chrysler InstrumentDivision as well as some built by outside suppliers to test raw exhaust forN02 , propane gas, and carbon monoxide. In the process, the exhaust,which comes from the engine hot, iscooled in a coil before going into theanalyzer. In cooling, however, moisture condenses and flows with thesample stream to sample cells wherethe readings are made. This moistureprevents accurate readings and canseverely damage the instrumentation.

Jack Lane, supervisor of the Methods and Procedures Group in theEmissions Department, said, "Blow-

ing out any accumulated water is atime-consuming process that wascausing us a serious downtime problem. But, once we put in the Balstonfilters, we eliminated the problem."

At another Detroit area plant, technicians conduct a wide range ofemissions tests to produce data required by development engineers andfederal and state agencies. One goalat this facility is minimum downtimeof test equipment.

The technicians here use chemiluminescent analyzers (CLAs) suppliedby several manufacturers and, at onetime, they all had two things in common; each came equipped with 7-cmpaper filters, and each required toomuch service attention. It didn't takethe experienced instrument maintenance people long to pinpoint thetrouble.

The paper filters, designed to protect the CLAs, actually were foulingthem. Particulate matter in the sample stream was punching holes in thefilters and lillie bits of paper becameentrained, clogging the instrumentation. Fortunately, the maintenancepeople had learned of Balston filtersand tried them on the CLAs. The result was a remarkable decrease indowntime for these vital instruments.

In another area, engineers performa series of raw exhaust tests on engines and use diaphragm pumps tocirculate samples to an array of testinstruments. According to one engineer, pump failure caused by a pumpvalve clogging with particulate matterwas a big maintenance problem.Once again, the engineers installedBalston filters and once again theysolved this problem. "In general,"the engineer said, "we have hadconsiderable success using Balstonfilters in our emissions test instruments."

At yet another emissions laboratory, engineers were experiencingproblems on their constant volume

samplers (CVS). The CVS systemsare back-pressure regulated systems; a critical element of each is apressure regulator. Test engineersfound that these regulators were failing too frequently as a result of particles in the sample lines. This wascausing inaccurate test data to begenerated and a great deal of costlylost test time. But when these engineers tested a Balston filter in thesystem, they found their regulatorproblem was solved.

Similarly, when these same engineers encountered an instrument failure problem on their exhaust emissions bench analyzers, which sampleraw exhaust for CO, CO2 , NOx andhydrocarbons, they turned to Balstonfilters to solve it. The filter effectivelyeliminated moisture and particulatematter from the sample stream,thereby providing the protection required for the instruments to producereliable data.

The value of these filters in em issions testing was, perhaps, bestsummarized by Ford Motor Co.which reported that at its EmissionsTesting Laboratory (Dearborn,Mich.), "The application of Balstonfilters in the emissions analyzer trainresulted in a significant red uction inequipment downtime. The filters haveproved their worth by reducing thedeteriorating effects of particulateand liquid contamination that interfere with the proper operation of analyzers, pumps, solenoids, andvalves."

Why it works

The reason for the apparent trendtoward Balston filters by instrumentmakers and users is, if you askthem, obvious; they simply work better. But the reason they work bettermay not be that obvious, although itis relatively simple.

The heart of this filter is the filtertube which has 'la-in. thick walls


DuPont source• •monltonng systems

letyou provecompltance reliablYmonth after montfiafter month after...Whether you need to monitor 502 or NOx in your

stack gas, Du Pont Instruments provides a sourcemonitoring system that's comp-Iete from sample probeto readout and field proven in power plants, smelteroperations, refineries, pulp mills and other manufacturing plants.

All systems are designed with your needs andEPA guidelines and regulations in mind. All providedata acceptable to regulatory agencies. And all arebuilt to give you years of dependable operation withminimal maintenance.

Most systems have capability for multiple-pointsampling with a single analyzer, resulting in significantcost savings for many installations. All employ theDu Pont UV-Visible Photometric Analyzer-proven inthe field in over a thousand installations-as thebasic detector.

Systems are available for continuous monitoringof one pollutant, for sequential monitoring of pollutants, and for laboratory or survey use.

If compliance with emission standards is yourresponsibility, Du Pont Instruments can help you. Forfull information on Du Pont Pollution SourceMonitoring Systems, write Du Pont Instruments,Room 24004A, Wilmington, DE 19898.

<[(J PORD Instruments"fr;us_.... a*·



composed of glass fibers of a uniform diameter. Under a microscope,they would be seen as a random network of fibers. During the filtrationprocess, fluid or gas passing throughthe fiber bed moves along a tortuouspatl1, and suspended particles are retained when they contact the fiber.The retention mechanism is based onintermolecular (van der Waals) forces.Since particle retention is not asieving action, the particles retainedare much smaller than the spacesbetween the fibers.

In gas filtration, such as in vehicleexhaust applications, particles smaller than 0.3 11 exhibit a random(Brownian) motion superimposed onthe directional motion of the gasflow. The Brownian motion greatly Increases the chance of contact withand capture by the filter fibers. Forparticles larger than 0.3 11, collisionof particles with the fibers as a resultof inertial forces is effective for efficient capture. The two mechanismsof particle capture result in a minimum retention efficiency in gases at0.3-0.6 11, with higher retention efficiencies for both larger and smallerparticles.

Balston produces several gradesof filter tubes with the grade determined by the diameter of the fibers.Balston Grade D filter tubes, for example, which are most frequentlyused in automobile emission analyzersample lines, have a filtration efficiency of 90% for 0.6-11 particles,when measured by standard testmethods for high efficiency filters(DOP Test and Sodium Flame Test).Finer Balston filters, such as theGrade B (99.95% efficiency) orGrade A (99.99+% efficiency), aresometimes used in particularly demanding sampling applications.

Aside from superior filtration efficiency, original equipment manufacturers and users of analytical instruments have found other advantagesin specifying Balston filters.

For one thing, Balston offers awide range of filter hardware in termsof sizes and materials of construction. The filter tubes themselves aredisposable, so that when a filter mustbe changed, the hardware stays inplace. And tubes are easy to installand seal since tubes are self-gasketing and don't require the use ofrubber gaskets. With all this, Balstonfilters cost no more, and in mostcases far less, than other currentlyavailable high efficiency filters.

What all this evidence seems to indicate is that the analytical instrument field, particularly in the area ofautomobile exhaust emissions testing, has found a filter that provides asignificant improvement in reliabilityand accuracy of test data.

SPECIAL REPORT

Catalyticconverters:an answerfromtechnology

ES& Ts Lena Gibney findsthat these units are a choiceof '75 automakers, tameharmful exhaust emissions.and vie for future use

10

Stoichiomeltic

Effect of air·fueI ratioon exhaust compoeItion

crease fuel economy and decreaseNOz production. To resolve this incongruity, devices such as the catalytic converters came into being.

Catalytic HC and CO control

For almost all new '75 Californiacars and a majority of other newcars nationwide, Detroit and manyforeign car manufacturers have chosen the catalytic route, using an oxidation catalyst to convert HC and COto carbon dioxide and water. EPAhas stipulated that the catalyticallyequipped cars must meet interimstandards at 50,000 miles. allowingfor one catalyst change. Tests by allthe car and catalyst makers haveshown compliance. For 1975 cars,there will be two types of catalystsa blend of noble metals in pellet ormonolithic form.

The noble metals were chosenafter testing many of the chemicalelements (outside of the rare gases)

how the industry is coping with theemission standards, some fundamentals must be defined.

Emissions within the engine areformed when the hydrocarbon fuel isburned incompletely to HC and CO inthe engine's combustion chamber.Ideally, the fuel and oxygen in the airentering the chamber yield harmlessexhaust products-carbon dioxide,water vapor, and inert nitrogen. Butthe generation of the pollutants CO.HC. and NOz (mainly NO) is a function of the proportional amounts ofair and fuel. At lean air-fuel (A/F)ratio, CO and HC emissions are decreased because of the greaterquantity of oxygen available for combustion. When the A/F becomes toolean, however, HC emissions will increase again.

NOz , on the other hand, is an exponential function of flame temperature. At low temperature, nitrogenand oxygen from the air will not uniteto form significant concentrations ofNO. Low temperature is achieved atA/F mixtures richer and leaner thanthe optimum, because of the diluenteffect exerted by unburned fuel in theformer case and the excess air in thelatter.

What then is optimum burningwithin the engine? It is close to thestoichiometric point, where theamount of fuel is matched exactlywith the amount of oxygen to burn itcompletely. For most gasolines, thestoichiometric value falls between14.5-15 Ib of air per Ib of fuel, withmaximum fuel economy at 16-16.5.It is interesting to note that NOz formation peaks at about the same A/Fratio as fuel efficiency.

Emissions outside of the engineare another matter. High exhaust gastemperatures are needed for the control of HC and CO. And yet lower exhaust gas temperatures would in-

To earthlings. cars have been anearly indispensable mode of transportation. thing of beauty. and sometimes symbol of status. Yet thesesame wonderful machines are onesource of polluted air, exhaustingsuch pollutants as carbon monoxide(CO), hydrocarbons (HC). and nitrogen oxides (NO.,,). In 1970. the federal government took action, with theClean Air Act. against the cars andset forth a set of exhaust emissionstandards in the hopes of righting thewrongs.

The standards underwent changesand what became the interim 1975standards have elicited a spectrumof responses and tactics from the automobile manufacturers. The new '75passenger cars will come equippedwith diverse emission control devices. Particularly so are the carsmaking the scene in California. theforerunner of the clean air cause, thestate with even more stringent standards than the rest of the nation.These new California cars will makeup approximately 10% of new carsales this fall.

With Congress approving the extension of the interim 1975 standardsthrough 1977, prospects look goodfor the car industry to improve furthertheir control devices and design evenbetter ones. 1975 will, however. givethe public the first inkling of the results of massive research and effortson the part of the industry to protectour air.

Basic concepts

To comprehend the varied subjectof automotive emissions control and

Exhaust emission.reductionHYDROCARBONS CARBON MONOXIDE

NOzLevel, Red,%tton, Leve_, Red'l,tlon, Level,I/ml I/ml I/ml

Pre-1968 vehicles(uncontrolled) 8.6 87.5 3.5

1975 national interim1.5standards 83 15 83 3.1

1975 California interimstandards 0.9 90 9.0 90 3.1

1975 Clean Ai r Standards 0.41 95 3.4 96 3.1

in the periodic table. singly or' incombination. They placed firstamong three possible categoriesbase metals. noble metals. andmetal alloys.

Specifically. platinum (Pt). palladium (Pd). or a Pt/Pd blend will beused. The unison of Pt and Pd is particularly desirable because they arefound together in the earth and arethus mined at the same time. Eventhough these noble metals are moreexpensive than nonnoble types. theyare not as subject to poisoning bysulfur compounds in the gasoline.Besides. lesser amounts are neededto achieve the same control as othertypes. Only about 0.05-0.1 troy oz(1.5-3 grams) of active metal percar will be needed.

The catalyst(s) in their beds aremounted before the muffler. as closeas possible to the engine manifold onthe exhaust pipe. The selection ofone of two geometric configurations-pellet (beaded) or monolith-depends on the operating conditionsunder' which the catalyst functions: inother words, on the design of the individual car itself.

The pellets (Ya- 3/s in. in diameter)are largely alumina and generally exhibit a larger surface area per unitmass. They do, however, have lowercrush resistance than the monolith ..This could result in a loss of catalystand substrate during car operation,according to National Academy ofSciences' (NAS) committee onmotor vehicle emissions.

The monolith, on the other hand,offers low attrition loss, low pressuredrop, and quick warm-up due to itslow total mass. In the form of a cylinder (3-6 in. in diameter) or an elliptic cylinder of equivalent volume.containing an internal honeycombstructure extending in a longitudinaldirection along the entire length ofthe cylinder. and surrounded by anintegral outer skin (alumina or cordierite), it has good mechanicalstrength with high resistance to


shock and vibration. The monolithdoes have breakage problems, suffers from lack of movement, and ismore expensive than the pellets as ittakes more noble metal loading.

Availability

The aspect of metal loading bringsforth the costs and the question ofwhether the supply of Pt and Pd willmeet the demand. At press time, Ptis selling at $190/troy oz, and Pd at$84/troy oz. World production of Ptplus Pd has been 3677 troy oz/yrduring the period 1969-72, accordingto the "Mineral Yearbook." Projectedworld consumption of these samemetals could be as high as 6219 troy

oz in the year 1980, with the U.S. demanding at least 17% of that for automotive and 23% of that for otherneeds. To thwart the possible unavailability of the metals and unsurmountable prices, there will have to be amore conscious effort to recyclethese metals.

During the past few years, about25% of the to'tal domestic consumption of Pt and Pd has been recycledmaterial. But this has essentially involved the chemical and petroleumindustries. To retrieve some 1 milliontroy oz of metals from the automobiles will be a more complex problemand a more urgent need.

Poisoning

Much is said about the poisoningof catalysts by the additives in the

gasoline and lube oils.Lead in gasoline is harmful to

noble and also to some base metalcatalysts. Sulfur in gasoline andphosphorus and other impurities inlube oils are likewise poisonous, sulfur to a lesser extent than phosphorus. What really happens is that thelead coats and insulates the metal,making it inaccessible to the exhaustgases. But all catalyst makers agreethat an accidental fillup or two withleaded fuel will not kill the noblemetal catalyst, only render it inactivefor a period of time. Upon return tounleaded fuel. the catalyst will recover.

This phenomenon leads back to

the catalyst configuration, in thatlead tends to migrate to the center ofthe pellet system and thereforeleaves the surface area open forconversion. When unleaded fuel isre-introduced, the poisoned pelletsmove into a high heat zone, and asthey do so, the lead is volatilized andthe catalyst cleansed.

The same holds true for sulfur.Much discussion has evolved aroundthe conversion by the catalyst of sulfur to undesirable sulfates. Accordingto GM, at a Senate subcommitteehearing in late 1973, sulfur also migrates to the center of the pellet andstores itself there until the car reaches a high speed. At that point, itburns off. Sulfur content in unleadedfuel is not a problem. It averagesabout 0.024% (by weight). If it ever

19751n1er1m

becomes too much of a problem,desulfurization of gasoline has beensuggested as a solution, which willopen up heated debates between theoil industry and the EPA,

The phosphorus limit has been setat 0,005 g/gal by the EPA, as opposed to the 0,05 g/gal for lead, Lastyear, Matthey Bishop's president, V,W, Makin, testified that phosphorus,in the form of a heavy metal or aszinc dialkyldithiophosphate in lubeoil. exerts a negligible effect on thenoble metal catalyst. However, present as organic thiophosphate (antiwear additive), it deactivates thiscatalyst.

This business of unleaded fuel

Since lead fluid (tetraalkylead pluschloride and bromide scavengers)has been found to have health effects and also has proved to be themost harmful to the noble metal.EPA is asking that lead be graduallyphased out of all Qasoline until thepermissible lead concentration is 0,05g/gal by 1979, Meanwhile, EPA hasruled that some 111,000 gasolinestations across the nation sell atleast one grade of unleaded gasolineby July 1, of this year. It also proposed that an additional estimated10,000 stations, mostly in ruralareas, be required to sell unleadedfuel after January 1 of next year,

This could mean that by next year,more than one out of every two stations will be required to pump unleaded gasoline, These stations areexpected to serve from 60-85% (estimated 6 million) of new '75 modelswhich are equipped with catalyticconverters,

Unleaded gasoline, or as otherscoin it-lead free or clear, with ectane number 91, will be sold atpumps with a hose nozzle somewhatsmaller than other pumps, Only thesenozzles will fit the catalyticallyequipped cars and thus are the suremeans of preventing an inadvertentfillup with leaded gasoline,

Making unleaded gasoline available has drawn forth certain controversy, Exxon researchers confirmtheir earlier findings that trace leadin amounts up to 0,10 g/gal will havelittle effect on activity maintenanceof noble metals during long-termaging studies, In the case of the inadvertent contamination of unleadedgasoline by lead, Exxon does have aprocess which will reduce the leadcontent from as high as 0,20 g/galdown to the federally specified 0,05g/gal limit. Their technique uses activated carbon,

In fact, the culprit may not be leadafter all. It could be ethylene dibromide, another gasoline additive included in lead fluid, Chrysler Corp, reported, Based on its laboratoryfindings, Chrysler is going ahead withroad test data before draWing a fullconclusion,

As far as energy requirements go,Texaco's vice-president of environmental protection, W, J, Coppoc, testified before a Senate subcommitteethis Spring that the production oflead-free gasoline and the gradualphase reduction of lead in existingleaded gasolines will cut U,S, gasoline supply by a minimum of almost800 million barrels between now and1980, This figure, he said, representsan annual loss of 5% in consumptionat zero growth in domestic demand;furthermore, the figure does not include the fuel economy loss with thelower compression engines whichmust accompany unleaded fuel. Hefelt that lead traps or filters are feasible alternatives,

The American Petroleum Institutesupported Texaco's views in that itfelt there would be substantial andexpensive modifications of refineryoperations to manufacture the higheroctane blending stocks needed to replace lead, The cost could run ashigh as $15 billion, and constructionmodification could take four years ormore,

Arguing that such high costs could

1977.,...

be offset by savings in maintenanceare engineers from American Oil.They reported their findings at theAutomotive Engineering Congressheld in Detroit last year, The use oflead-free gasoline will reduce theneed for frequent replacements ofspark plugs, mufflers, and otherhardware, they said, so much so thata clear-cut cost advantage canamount to $0,05/gal over the lifetimeof the average car,

Besides, calculations show thatthe energy requirement for the production of lead antiknock compoundsis equivalent to a major portion ofthe internal refinery energy requirement during the production of thehigher octane lead-free gasoline,Universal Oil Products' V, Haensel,vice-president of science and technology, told ES& T,

Perhaps lead could be replaced byrare-earth metals and their compounds, Researchers have found cerium compounds encouraging as antiknock additivies at Wright-PattersonAir Force Base, but translation ofthese compounds into everyday useis far off.

Meanwhile, there is the naggingthought that maybe there will not beenough of the unleaded gasoline togo around this fall, American Automobile Association seems to thinkso,

Health hazards

Apprehensions have been expressed by many, particularly byJohn Moran of EPA's EnvironmentalResearch Center (North Carolina),that Pt and Pd and sulfur (convertedby catalyst to sulfur trioxide whichreacts with water in the air to formsulfuric acid mists) emissions maybe dangerous to man, He confirmedthat sulfuric acid is emitted from thecatalytic-equipped cars at a rate of0,05 g/mi, between 9-50 times higher than emissions from noncatalyticcars, This rate could affect peoplewith lung or heart trouble,


Moran was also concerned that Ptand Pd, once they escaped to the atmosphere, might undergo methylation in drinking water and pose athreat. There could be i:Jegradation ofthe biosphere when cars are eventually junked, he asserted further.

GM's Engelhard and others havetestified that Pt and Pd are not toxicin the metallic form. The president ofthe National Academy of Scienceshas also testified that Pt is ratherinert.

A comprehensive survey of openliterature would reveal that Pt is onlytoxic in its water-soluble salt forms.As such, they can cause respiratoryor skin irrations. The Pt from theconverter, according to some scientists, is changed to the oxide vaporwhich subsequently undergoes decomposition and condensation to afinely dispersed Pt metal aerosol asthe exhaust gas cools.

Not much has been publishedabout the toxicity of Pd or its salts.Studies made at catalytic crackingoperations of refineries show thatthere has been no evidence that exposure to metallic platinum and palladium has caused employees to suffer from pulmonary or cancerous diseases.

Much has been done on toxicity of

sulfur oxides, but not much on sulfuric acid. Hazleton Laboratories(Vienna, Va.) have found that monkeys, exposed continuously to a mixture of S02, fly ash, and 100 Ilg/m3of sulfuric acid, did not demonstrateany significant changes after 18months.

The divergence of reports from thevarious authorities has led to the callfor information on the part of thePanel on Environmental Science andTechnology of the Senate Committeeon Public Works. Hearings startedthis May 'on the present state ofknowledge about the health effectsof lead particulates emitted from thecars and the technology available fortheir control.

Requests for data on sulfur emissions (sulfur trioxide, sulfuric acid,and sulfates) were made by the EPA.They placed emphasis on the magnitude of sulfate emissions, their impact on ambient air quality andhealth, and the feasibility of controlmethods.

Benefits

Rubbing out HC and CO with acatalyst, in face of the clamor aboutthe ill consequences, can lead to increased fuel economy and improveddriveability. The catalyst itself does

not command that. It simply replacesformer controls, such as retardedspark timing, which consume morefuel. According to Eric Stork, EPA'sdirector of mobile source pollutioncontrol, gasoline mileage improvement should be better than the 7%pred.icted by EPA last year and the11-\3% predicted by GM this year.He bases his optimism on EPA's testdata on cars submitted by manufacturers for the 4000-mile certificationrun. As much as 26% better mileagewas obtained with one car in the5500-lb class.

Another plus for the catalyst, saidEPA administrator Russell Train, isthe 95-98% control of "unregulatedemissions," such as benzene, toluene, xylene, and the carcinogenicpolynuclear aromatics in engine exhaust.

NOx control

For 1975 cars and at least for thenew cars in the next couple of years,nitrogen oxides (mostly nitric oxide)emissions will be handled by theEGR (exhaust gas recirculation) system. The concept here is to use aninert gas to reduce peak temperaturewhich in turn reduces NOx formation.The exhaust gases are just thesource for a continuous supply of

Many '75 automakers are relying on catalysts '"u.s. Manufacturer Type Supplier Catalyst plant

Monolith Pt/Pd Matthey Bishop Royston, EnglandMonolith Pt/Pd Matthey Bishop Royston, Engla nd

Monolith Pt/Pd Engelhard Minerals & Chemicals Huntsville, Ala.Monolith Pt/Pd Engelhard Minerals & Chemicals Huntsville, Ala.

Monolith PI/Pd Engelhard Minerals & Chemicals Huntsville, Ala.Monolith PI/Pd 50% Matthey Bishop Royston, England

50% Degussa Frankfurt, Germany

Monolith Pt/Pd Engelhard Minerals & Chemicals Huntsville, Ala.

Pellet Pt/Pd Universal Oil Products Shreveport, La.

General Motors

Ford

ChryslerAmerican MotorsForeign Imports'

English Manufacturers

Rolls RoyceBritish Leyland

French Manufacturers

PeugeotRenault

German Manufacturers

MercedesVolkswagen

Swedish Manufacturer

Volvo

Italian Manufacturer

Fiat

Pellet" PI: Pd 70: 30

Monolith PI/PdMonolith PI/PdMonolith Pt/PdPellet PI/Pd

25% from Engelhard Minerals & Chemicals Corp.25% from Air Products & Chemicals Inc.25% from W,R. Grace25% from The Catalyst Company

(joint venture American Cyanamid with JapanCatalytic Chemicals Inc.)

60% from Engelhard Minerals & Chemicals Corp.40% from Matthey BishopUniversal Oil ProductsBuy from General Motors

Newark, N.J.Calvert City, Ken.Curtis Bay, Md.Azusa, Calif.

Newark, N.J.Devon, Pa.Tulsa Port of Catoosa, Okla.

Japanese Manufacturer

Daihatsu KogyoNissan

(Datsun)Toyota

Pellet Pt/Pd Universal Oil Products Shreveport, La.Monolith Pt/Pd Engelhard Minerals & Chemicals Huntsville, Ala.Pellet Pt/Pd Universal Oil Products Shreveport, La.Monolith Pt/Pd Engelhard Minerals & Chemicals Huntsville, Ala.Pellet Pt/Pd Universal Oil Products Shreveport, La.

(l Pt-platinum, Pd-palladium; substrate suppliers-American Lava, division of 3M (Chatanooga. Tenn.); Corning Glass (Erwin, N.Y.).b Catalysts for most foreign customers are canned overseas; Arvin (Columbus, Ind.) is canning for most U.S. customers. General Motors is

canning all its catalysts at its AC Sparks Oiv. plant in Oakcreek (Wis.), and Flint(Mich.).


inert gases. These gases serve to dilute the combustion chamber charge,slow the combustion process, andlower the peak combustion temperature. The trick is to use the correctamounts of these gases.

The EGR valve does that job ofproper metering. Mounted on the intake manifold and operated by atimed vacuum signal from a port onthe carburetor throttle body, it ensures calibrated recirculation.

EGR systems are not new. In thepast they have been associated withdriveability and fuel economy problems. The cause has not been theexhaust gases themselves. but howthey were recirculated. 1975 cars willhave a much more sophisticated system so that mileage and driveabilitywill no longer be penalized.

Catalysts for NOx control are notan impossibility to some manufacturers. Reduction could be via a dualbed or a three-way system. The former consists of an oxidation catalystplaced downstream of the reductioncatalyst, with the engine operating atrich. NOx passing through the reduction catalyst will be reduced to inertnitrogen and water. Air will have tobe added before the HC and CO,traveling on through to the oxidationcatalyst. can be converted to harm-

less carbon dioxide and water. Thisextra air causes problems becauseany ammonia which may form fromthe reduction will be reoxidized toNOx by the oxidation catalyst.

Engelhard, in a statement beforethe Senate subcommittee, reportedprogress with their ruthenium catalyst which converts very little NOx toammonia. Previous difficulties withthe loss of ruthenium during engineoperation on the oxidizing side forextensive lengths at high temperatures have been minimized.

Matthey Bishop also reported improved ruthenium stability which theyobtained by the reaction of alkalineor rare earths with ruthenium in thecatalyst bed. This reaction gives ruthenates which have less tendencyto volatilize. Synthesizing the ruthenates in position on the monoliths orpellets has resulted in a decreasedweight loss of the noble metal.

Gould has been successful withtheir reduction catalyst, nickel/copper on a metallic monolith, so muchso that they were reported to be ableto meet the statutory 1976 NOx standards, during an evaluation test atEPA labs.

Unlike the dual-bed system, thethree-way catalyst system performsthe oxidation and reduction functions

in one catalyst bed. Controlling allthree components at the same timewould involve the operation of theengine near stoichiometric, by theuse of an oxygen sensor. This sensorwould detect how much oxygen is inthe exhaust and then feed back asignal to a reliable fuel-metering system. The correct content of oxygenwill have to be maintained to be justsufficient to oxidize the HC and COand yet not enough to impede theNOx reduction. Another consideration is catalyst durability at suchclosely controlled A/F ratio. However, the catalyst manufacturers,mum as they are about the composition of the three-way catalyst, areconfident that the system is a veryviable one.

Retrofit

Pre-'75 cars in California and inother states where transportationcontrol plans are in effect. will, unlike their new catalytically controlledfamily, need retrofit devices to meetthe ambient air quality standards proposed by the Clean Air Act. California has been involved in retrofit programs since the mid 1960·s. At thepresent time, there are two retrofitprograms in California. One program,for HC control, affects 2.8 million

t some prefer other exhaust emission controlsForeign Imports

Honda

Saab

MercedesNissan (Datsun)OpelPeugeotToyo Kogyo

(Mazda)

Control technique

CVCC (compound vortex controlledcombustion) or 3·valve or stratifiedcharge engine system. There aretwo combustion chambers-mainand auxiliary-instead of one percylinder. One carburetor meters arich mixture into the auxiliary cham- _ber which is connected to the mainchamber by a little passageway.Another carburetor meters a lea nmixture to the main chamber. Thespark plug ignites the rich mixture,and the resulting flame shootsthrough the passageway and ignites the lean mixture. The overalleffect is a leaner air fuel ratio. Thisreduces HC and CO. The low avail·ability of oxygen in the auxiliarychamber, on the other hand, keepsthe nitrogen oxides at low levels.Allows use of conventional leadedgasoline

Improved fuel-metering syst~m, amore advanced fuel injection system and installation of a thermalreactor, alteration of ignition timing

Diesel-powered

Rotary engine; air·cooled thermal reactor with "mod ulated" air injection. No controls needed for NOr'

Allows use of low lead or leadedgasoline.

Choice. It's noble metals. not types. that count


1955-65 cars. The second programcovers 4.5 million 1966-70 cars andis intended to control NOx (42% minimum) by exhaust gas recirculationor vacuum spark advance disconnect.

Dana Corp's Retronox unit is anexample of EGR mechanism. It ismounted on the engine with a stainless steel tube that runs down to theexhaust pipe. The spark advance isdelayed for a short time at lowspeeds until a vacuum delay valveallows the EGR valve to open, permitting a small portion of the exhaustgas to recycle back to the engine.The device is bolted-on, requires nochange in tuning specifications anddoes not disconnect the vacuumspark advance. Hence fuel economyand performance are unaffected.

For areas that need HC and COcontrol (Arizona and Colorado, forexample), Retronox also comes withan oversized PCV (positivecrankcase ventilation) valve whichacts as an air bleed. This air bleedleans the combustion mixture to giveabout a 35% reduction in HC and40-55% in CO, depending on altitudeconditions. This unit costs $40.

Catalytic retrofit is also available.UOP's Purzaust system fits in the engine compartment just after the exhaust manifold and reduces HC by68%, CO by 69% and NOx by 13%. Itis the noble metal type and utilizesan air pump for the adequate supplyof oxygen in the exhaust. The totalcost can be as low as $105 and ashigh as $260, depending on the requirement for an air pump.

All pollution control retrofit deviceshave to be accredited by the state ofCalifornia and the particular state involved. The rule of thumb in theseaccreditation procedures is that thedevice, designed to control one ortwo pollutants. will not inadvertentlyincrease the emissions of the third.Such was the earlier experience inCalifornia. Engine modificationsmade to reduce HC and CO in the1966-70 vehicles increased NOx by30%. The NOx in turn combined withthe HC to form what is prevalent asthe Los Angeles smog.

California, the first state to commence accreditation, has sanctionedeight devices at press time, includingAir Ouality's Pure Power, GM's device, Carter's Kit, Contignitron'sEqualizer, Dana's Retronox, Echlin'sdevice, STP's device, and UOP's Purzaust system.

Looking to MECA

Whenever there is a wide range ofchoices, there emerge some foresighted people who will band together to offer guidance and uniformity inthe selection process. And the Manu-


facturers of Emission Control Association was formed last September. Itwas formed primarily out of a need tohave a more unified voice in dealingwith the automobile emission controlprograms in California.

MECA then expanded to a multipurpose organization concerned with:

• achieving a coordinated voicefor the automotive emission controlindustry in promoting their systemsas an effective means of reducing airpollution from new and used motorvehicles at a reasonable cost

• providing coordinated lobbyingactivities at the federal and statelevel to speak for or against legislation, rules, or regulations which affect the interests of MEC", members,the industry, and the public

• monitoring EPA programs related to the setting, promulgation, andenforcement of standards and to theresearch and development for emission controls

• providing expert testimony atadministrative and legislative hearings

• providing general or technicalinformation to consumer. environmental and public interest organizations seeking expertise in automotiveemission control

• providing publications and upto-date information to members.

Basically, the association aidsstates (17 at present) affected by theclean air program. It sets up evaluation programs with the state to determine the nature of the problem andthe suitable type of control technology. Then the floor is opened to suitable device manufacturers who willgo about getting their devices accredited in that particular state.

MECA's involvement is timely. ThisMarch. EPA proposed to developersand marketers of auto emission control retrofit systems a voluntary evaluation program to be operated byEPA. This program would eliminateunnecessary duplication of datagathering and testing by individualstates in that each manufacturer releases the test data of his device tothe EPA which in turn evaluates thedata and provides the information toall interested states.

In fact, one of the prerequisites forjoining MECA is that the manufacturer sells a device that "does what itsays it does." Weeding out the"phonies," said Mac McCullough(Dana Corp.), vice-president ofMECA, is the objective. There is sufficient expertise in the associationand available test data for just that,he pointed out.

Currently, Robert L. Joseph ofUOP heads the MECA group of five,all manufacturers of retrofit devicesaccredited by California. While

MECA is primarily made up of retrofitdevice manufacturers, Joseph ishopeful that other companies in theautomotive emissions control industry will join the association. Thereare monthly meetings and a newsletter. MECA's first concern is modification of EPA's proposed voluntaryevaluation test procedures.

Futuristic investigations

A substantial amount of work hasbeen performed on the thermal reactor, a chamber for HC and CO combustion external to the engine. It isusually bolted to the cylinder headinstead of the normal exhaust manifold.

There are two basic types of thethermal reactor-fuel rich and fuellean. The former suffers from poorfuel economy but gives better NOxcontrol than the latter.

Thermal reactors plus catalyst systems are also being developed. GM'scombination system has a bypassmode which is sealed with a valve atlow speed. When the speed goesabove 55 mph, the catalyst (dual inthis case) system is bypassedthrough a thermal reactor. Ouestor'sapproach, at an approximate cost of$125, consists of a partial oxidationof HC and CO in a thermal reactorbolted onto the cylinder head, followed by NOx reduction over a catalyst, and final oxidation in anotherthermal reactor. Both met 1975-76statutory standards.

Improvements are being made tothe not-so-new stratified charge andWankel engines. practiced by Hondaand Toyo Kogyo (Mazda), respectively. Ford is targeting its versionof the stratified charge engine for1978. Called Ford Proco, meaningprogramed combustion. the car willnot include a prechamber. Stratification will be created by a fuel injectorwhich shoots a cloud directly into thecylinder, a cloud rich in the centerand lean on the outside.

Steam-propeled cars are still in therunning. EPA confirmed that a carequipped with steam engine from JayCarter Enterprises (Bur kburnett,Tex.) and a test bed steam enginefrom Scientific Energy Systems Inc.(Waltham, Mass.) achieved 1975statutory standards. Electric cars arealready on the road (see ES& T. May1974, p410).

A vast amount of work remains tosolve the problems associated witheach of the futuristic approaches:driveability, improved mileage, adaptability to larger cars-to mention afew.

The same holds true for the use ofhydrogen as a fuel. The low energydensity of hydrogen gas requires atank, much larger than a gasoline

We design and builddrying systems

for waste water control.

Koch-Lurgi can plan, design and build a dehydration systemthat will solve your waste water problems and conserve energyat the same time.

Our system utilizes the heat energy present in the exhaustgas (which is usually discarded), thus evaporating waste waterwith minimal energy consumption. The evaporation yields a lowvolume solid which is easily disposed of and which, in somecases, may have useful applications. The system also insuresthat effluent gases meet air pollution emission standards.

With our extensive experience in the design, testing,evaluatlon and construction of processing facilities, we can offerthe most efficient solution to your waste water problems,and to sludge dehydration problems as well.

For further information, write for Bulletin KSD-8, or call;Koch Engineering Company, Inc., 161 E 42 Street, New York 10017.(212) 682-5755.

tank, to keep the gas at 1000 belowzero. In addition, this very cold material does not store weil, leaking off tomaintain a constant low temperature.Storage systems are being studiedsuch as the metal hydrides.

Tests have been made, generatinghydrogen on board a vehicle by reforming gasoline. This method seemsto defeat the purpose of substitutinghydrogen for gasoline.

Another fuel, patented and movingfrom the tube to the tank stage, isGoodyear's alcohol-water combination. "As much as 65% reduction inspecific pollutants have beenachieved compared with today'sfuels," said researchers K. J. Frechand J. J. Tazuma. They believe thatthe blend of 25% I-butyl alcohol, 3%water, and 72% gasoline is particularly encouraging. This blend, theyfell, could be preblended at refineriesand could boost the octane numberof basic gasoline to a rating at whichvirtually any high compression engine could run knock-free, withoutlead, that is.

In perspective

At a cost of $50-100 and weighingabout 10-30 Ib, the cataiytic converters must gain general acceptance.Industry has made its choice; thepublic awaits answers to their concerns:

• increased cost-per-gallon of unleaded gasoline arising from themodifications in refining technology,and distribution systems at the stations

• supply of unleaded gasoline• possible health hazard contrib

uted by sulfuric acid• odor from traces of hydrogen

sulfide which may be formed• cost of replacing the catalyst

after the end of the warranty whichcovers one replacement within thefirst 50,000 mi.

One remembers that catalysts arenot new in refining needs, accordingto UOP's Herman Bloch, recipient ofthe 1974 Murphree Award from theAmerican Chemical Society. But theyare new in the adaptation to the requirements of automotive use. Thereis further research and probing intothis requirement: The National Academy of Sciences plans to release itsfinal recommendations to Congressthis fall; car and catalyst makers areaiming to improve catalyst perfor- ,mance and durability; and all are'watching the health effects.

Meanwhile-at least in 1975-thecatalysts will be coming down on"the side of angels in improving ecology," as Engelhard president M.Rosenthal aptly put it.

14~2!;A!:!SPRAY DRYING DIVISION

161 E 42 Street, New York 10017(212) 682-5755. Ucensee 01

6!1EICIRCLE lOON READER SERVICE CARD


Federal spokesman of the Environmental Protection Agency spells out those controversial details and plans needed in 66 of this nation's air quality control regions where 60%of the population resides in order to explain . ..

Transportationcontrots are reallyneeded in the aircleanup fightJoel L. HorowitzU.S. Environmental Protection Agency,Washington, D.C. 20460

FJ!iIi

The Clean Air Act Amendments of 1970 directed theEnvironmental Protection Agency (EPA) to establish national ambient air quality standards whose attainmentwould protect the public health and welfare from the adverse effects of major air pollutants. The poll utants forwhich health-based air quality standards now exist include carbon monoxide and photochemical oxidants,presence of which in urban air is primarily attributable toautomobile emissions of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

The air quality standard for CO is exceeded in 42 airquality control regions (AOCR's) in the U.S., and the oxidant standard is exceeded in 56 (Table 1). The 66AOCR's where at least one of these standards is exceeded contain approximately 60% of the nation's population.The automobile is the source of roughly 70-90% of COemissions, 50-80% of HC emissions, and 40-50% ofNOx emissions, depending on the AOCR.

Because of the importance of the automobile relativeto other sources of CO, HC, and NOx, the reduction ofautomobile emissions is a major objective of programs toimprove air quality. The principal means of ach ieving thisobjective is the control of emissions from new cars.Since 1968 nationally and 1966 in California, new carshave been subject to increasingly stringent emissionsstandards.

As a result, new model year 1974 cars emit only about25% as much CO and HC and 65% as much NOx as pre1968 cars. Present law requires model year 1976 cars toemit less than 5% of the CO and HC emitted by pre-1968cars, In addition, model year 1977 cars must have theirNOx levels reduced to about 10% of pre-1968 levels.

The new car controls are expected to produce substantial reductions in automobile emissions as old, highemitting cars are replaced by newer and cleaner vehicles(Figure 1), By 1985, when most cars in use will beequipped with 1976-77 emissions controls, the automobile population as a whole will emit approximately 20% ofthe HC, CO, and NOx that it now emits.

Despite these emissions reductions, the new car controls, even when accompanied by maximum feasible control of nonautomotive emissions, do not reduce automobile emissions enough to achieve and maintain the airquality standards for CO and oxidant in all AOCR's. Thethree principal reasons for this are:

• The new car controls reduce emissions gradually asnew cars replace old ones. This replacement does notnecessarily happen fast enough to satisfy the Clean AirAct's requirements that the air quality standards beachieved by 1977.

• Some regions are so severely polluted that controlonly of new cars and nonautomotive emissions sourceswill not result in the achievement of the air quality standards any time in the foreseeable future.

• After 1985, automobile emissions are likely to increase gradually due to growth in automobile use.

There are now 30 AOCR's in which the new car controls must be supplemented by add itional measures to reduce automobile emissions (Table 1). The additionalmeasures. called transportation controls, can be dividedinto two general classes: measures that reduce in-useautomobiles' emissions rates (i.e., emissions per mile

traveled), and measures that reduce automobile travel.The former class includes inspection/maintenance andretrofit. The latter includes transit improvements, carpooling programs, and restrictions on the use of automobiles,

Inspection/maintenance (1M)

1M consists of an exhaust emissions test (inspection)followed by appropriate maintenance if emissions arefound to be excessive, The inspection phase requires theavailability of a suitable short emissions test procedure,The accepted standard technique for estimating roademissions, the Federal Certification Test Procedure, istoo costly and time consuming to be feasible for inspecting large numbers of vehicles. Two types of short emissions tests are now available.

In the idle emissions test the exhaust gas is analyzedfor CO and HC using a tail pipe concentration measurement during idle operating conditions. Vehicles with excessive emissions are required to undergo maintenance.Ordinarily, excessive HC emissions are related to thesecondary ignition system, idle adjustments, and valvemalfunctions. High CO emissions are indicative of carburetor maladjustment or malfunctioning of other components within the induction system.

In the loaded emissions test, the exhaust gas is analyzed for CO and HC using a tail pipe concentration measurement during idle operating conditions and with theengine under load. Vehicles are operated on a chassisdynamometer during this test. Vehicles with excessiveemissions are required to undergo maintenance, This testnormally produces more information useful in identifyinghigh emitters than the idle test. For example, the frequency of misfire, resulting in excessive HC emissions, ismuch greater at high load.

Presently available data indicate that a program of annual IM can achieve reductions in automobile exhaustemissions of 10% CO and 11 % HC if an idle test is used,and 12% CO and 15% HC if a loaded test is used. In addition, IM reduces fuel consumption by approximately2%. IM does not significantly affect NOx emissions.

How much does it cost?

The investment cost of an annual IM program is about$2 per car if an idle test is used, and $3 per car with aloaded test. The cost of inspection is about $1.50 per carper year for either test. Maintenance costs for vehiclesthat fail the emissions test are typically about $25. However, not more than 50% of the cars inspected are normally expected to fail an emission test. Moreover, mostcars receive some voluntary maintenance during a year.As a result. the increase in the average car's annualmaintenance cost due to IM is expected to be about$3. IM programs using idle tests are now in operationin New Jersey and Chicago.

Retrofit

Devices that may be added or modifications that maybe made to in-use automobiles for the purpose of reducing their emissions are called retrofits. Three retrofit approaches are currently under consideration for widespread implementation.

In Vacuum Spark Advance Disconnect (VSAD), the

idle air-fuel mixture is made leaner than normal, idlespeed is increased, and the vacuum timing advance ismade inoperative during normal engine operation. Thisapproach is applicable to pre-1968 vehicles (pre-1966 inCali!.). In Air Bleed to Intake Manifold, an air valve enables the air-fuel ratio to be increased by metering additional air to the intake system. This approach is applicable to pre-1972 vehicles.

In Oxidizing Catalytic Converter retrofit, an oxidizingcatalyst is installed in the exhaust system. This device requires the use of lead-free fuel and, therefore, is applicable only to vehicles that can operate without excessiveengine wear on commercially available lead-free gasoline. Considerable work remains to be done on identifyingthe specific makes and models of automobiles that fulfillthis requirement.

At present, EPA estimates that about 75% of 1971-74vehicles and 20% of 1968-70 vehicles could operate oncommercial lead-free fuel and be considered for retrofitcatalysts. Starting in model year 1975, new cars will befactory-equipped with catalysts or other equally effectiveemissions controls. Hence, retrofit for 1975 and later automobiles is not under consideration.

The average emissions reductions per vehicle and thecosts of the three retrofit approaches are shown (Table2). All of the retrofits require periodic maintenance, andall function most effectively on vehicles in good operatingcondition. Therefore, emissions control programs usingretrofit should include 1M.

Of the three retrofit approaches, only VSAD, which isused in the California retrofit program, has been implemented on a large scale. The other approaches are atvarying stages of development, and additional work isneeded to firmly establish their effectiveness, durability,applicability, and costs.

The air bleed and catalyst effectiveness and cost data(Table 2) are based on tests involving fewer than 100cars and are, therefore, subject to considerable uncertainty. EPA is currently developing procedures to facilitate the further development and testing of retrofits. I f noserious developmental difficulties arise, air bleed retrofitsshould be ready for implementation by 1976 and catalysts by 1977.

Lowering total emissions

The reductions in total automobile emissions achieveable through IM and retrofit can be illustrated by considering two hypothetical 1M and retrofit programs. Program1 consists of loaded-test IM for all cars and air bleed retrofits for pre-1972 vehicles. Program 2 has loaded-testIM for all cars, air bleed retrofit for pre-1972 vehicles,and catalyst retrofit for 75% of 1972-74 vehicles. Theemissions reductions achieved by the two programs inthe period 1977-85 are displayed (Table 3). Both programs achieve fuel savings of roughly 2% in all yearsowing, principally, to the effects of 1M.

As shown, the effectiveness of both the 1M and retrofitprograms decreases with time. This is caused by the replacement of retrofitted vehicles with post-1974 vehicles.In 1985, all of the program 1 emissions reductions and60% of the program 2 reductions are attributable to 1M.Retrofit is a Short-range approach to emissions control.


FIGURE 1.

Automobile Emissions Trends

20001990

Relative emissions-1974 = 100

1980

co

1970NO,

50

50

150

150

100

100

Most transit systems in the U.S. do not provide thehigh-quality service needed to attract a high ridership.For example, nearly 50% of urban area residencies arelocated three or more blocks from the nearest tra~sitstop. Transi,t routes are heavily downtown oriented, butonly about 10% of trips go downtown. Transit trips takenearly twice as long as automobile trips. Moreover,subsidized free or reduced rate parking confers a costadvantage on the automobile. Transit service of this quality is illustrated by point 0 of Figure 2. Ridership is 4%.

Methods of improving transit service include prioritytreatment of buses on streets and freeways, increaseduse of limited-stop and express service. better collectionand distribution systems to reduce walk distances andtravel times, increased schedule frequencies, and increased crosstown and suburban service. In addition, automobile user charges can be increased or parking limitations can be imposed to compensate for the provisionof free parking. Such restrictions of automobile use willalso compensate for the improvement in automobile service quality that will occur as the diversion of automobiledrivers to transit reduces or eliminates traffic congestion.

Reducing automobile use

Automobile use and emissions can be reduced by diverting automobile trips to other modes of transportation.Compared to retrofit. this approach to emissions reduction has the important advantage that it serves such social goals as energy conservation. reduced noise andcongestion. and reduced need for further highway construction, in addition to improving air quality. The diversion of automobile driver trips to the two most readilyavailable alternative modes, bus transit and carpools, isconsidered here.

Transit ridership is determined by the relative quality ofservice provided by transit and the automobile. The mostimportant service variables involve travel times andcosts. An example of the quantitative relationship between the service variables and transit ridership for worktrips is shown (Figure 2). This example is based upon theresults of a study of travel behavior in Pittsburgh, Pa. Theservice variables included in the figure are the time towalk to and from the transit stop, the difference betweenautomobile and transit travel times, and the differencebetween automobile and transit costs. The importance ofthese variables in determining transit ridership can be illustrated by considering the case where transit service isequal in quality to that of the automobile (point A of Figure 2). The figure indicates that 66% of work trips wouldtake place by transit. In contrast. average work trip transit ridership in the U.S. is currently about 14%.

In practice, it is unlikely that bus transit can offerwidespread service which is as good as that of the car. Amore realistic example of high-quality transit is illustratedby point B. Here, the walk time is 5 minutes (about 3blocks): transit travel time exceeds automobile traveltime by 10 min, and the transit fare and automobile costare equal. Transit ridership is 21%. If the walk and traveltimes remain unchanged and the automobile is penalized$2 per work trip relative to transit through parking charges, free transit. or other means, transit ridership increases to about 90% (point C). This corresponds to an88% reduction in work trip automobile vehicle miles traveled (VMT), and approximately a 35% reduction in totalautomobile VMT.

The reductions in the combined emissions of automobiles and transit vehicles thus achieved depend on thekinds of transit vehicles used and the details of the design and operation of the transit system. If, for example,diesel buses meeting the California 1975 heavy-duty diesel emissions standards are used and these buses carryan average load of 20 passengers, the reductions incombined 'emissions are roughly 30% for CO and HC and15% for NOx in 1977. In 1985, when automobile emissions will be less than in 1977, the CO and HC reductionsare 20% and 25%, respectively. However, NOx emissionsincrease by about 20%. This NOx increase would beeliminated if an average bus occupancy of 30 passengerswere achieved.

These quantitative results are approximate owing totheir reliance on a single behavioral study and rathercrude measures of trip characteristics. However, theconclusion that high-quality transit can attract high levelsof ridership is consistent with the experience of existinghigh-quality transit operations. For example, the ShirleyHighway Express in the Washington, D.C" area, whosebuses operate in specially reserved, congestion-freelanes, has achieved a peak period ridership of 40% compared with 19% for the Washington area as a whole. InLos Angeles, charter buses are being used to carry workers from outlying residential areas to industrial employment centers. Service is provided on a subscription basisat a cost below that of the car. The bus operator estimates that the bus service carries over 90% of potentialusers.

1970 1980 1990 2000802 Environmental Science &Technology

TABLE 1

AQCR's exceeding CO and oxidant air quality standards.AQCR co Oxidant AQCR CO Oxidant AQCR

Albuquerque • • Honolulu • Pittsbu rgh"Atlanta • Houston" • Portland, Ore."Atlantic City • Indianapolis" • • ProvidenceAustin • Indio • Richmond, Va.Baltimore" • • Jacksonville • • Rochester, N.Y."Beaumont" • Kansas City • • Sacramento"Birmingham • • Las Vegas" • • St. Louis"Boston" • • Los Angeles" • • Salt Lake CitY"Buffalo • • Louisville • • San AntoniO"Charleston, W.Va. • Memphis • San Diego"Charlotte • Miami • San Francisco"Chicago" • • Milwaukee • Seattle"Cincinnati" • Minneapolis" • Spokane"Cleveland • • Mobile • Springfield, Mass."Columbus • Monterey • SyracuseCorpus-Christi • Nashville • • TampaDallas" • New York" • • ToledoDayton • Norfo)k • TulsaDenver" • • Oklahoma City • • WichitaDes Moines • Omaha • Washington, D.C."EIPaso • • Paducah • TotalFairbanks" • Philadelphia" • •Fresnou • • Phoenix" • •

G Transportation controls required, total 30.

CO Oxidant

• •• ••

••

• •• •

••••

• •42 56

The attraction of large numbers of work trips from theautomobile to transit will also require substantial expansions of bus fleets. For example, to accommodate thetravelers displaced by a 10-20% reduction in auto usethat is achieved primarily through diversion of work trips,fleet expansions varying from 50% to over 300%. depending on the city involved. may be required.

The cost of bus transit depends on the detailed characteristics of the bus system, notably on vehicle occupancies. Buses cost roughly $1.00 per mile to operatecompared to $0.07 per mile for cars. A transit systemthat carries 40 riders per vehicle round trip costs aboutthe same as the commuter automobile. With lower occupancies. costs can increase by as much as $900 perrider per year. Higher occupancy systems, however,could save $100 per rider per year relative to the cost ofcontinued automobile operation. Thus, transit offers thepossibility of achieVing reductions in automobile emissions at a net cost saving if transit systems can be designed and operated so as to achieve both high vehicleoccupancies and high-quality service over large portionsof urban areas.

Carpooling

Even under the best of conditions, the diversion oflarge numbers of automobile drivers to transit is likely torequire at least three years owing to the delays involved

in acquiring new vehicles and modifying operating policies. However, moderate reductions in automobile usecan be achieved very quickly through the use of carpools. Average automobile occupancy in the U.S. isabout two persons per car. Average occupancy for worktrips is about 1.4 persons per car. Since most cars arecapable of carrying at least four persons. there is considerable room for reducing automobile use and emissionsthrough carpooling.

The principal obstacle to carpooling is that carpoolsare highly restrictive in terms of the service offered. Carpoolers must have trip origins and destinations that areclose to one another, must desire to travel at the sametimes of day, and, to minimize the problems of locatingcarpool partners, must make trips that are repetitive fromday to day. As a result. the greatest potential for increased carpool use is in connection with peak periodwork trips. These trips are responsible for about 25% ofurban area automobile emissions.

Experience to date with carpool programs indicatesthat policies to encourage carpooling, such as locatorsystems combined with parking priorities, can double automobile occupancies for downtown peak period worktrips. These trips cause roughly 10% of automobile emissions in cities. Much more limited expe ience with carpooling for nondowntown peak period work 11 ips suggeststhat carpool programs can increase automobile occupan-

TABLE 2

Comparison of rett_ofit approachesVSAD- Air bleed Catalyst

Applicability

co reduction

HC reduction

NO. reductionInstalled costAnnual maintenance costFuel benefit (+)

or penalty (-)• Vacuum spark advance disconnect

Pre·1968

25%

23%$20$5

-5%

Pre-1972

58% (pre-1968 cars)40% (1968-71 cars)21% (pre·1968 cars)25% (1968-71 cars)

o$20-60

$7+0-4%

20% of 1968-70 cars75% of 1971-74 cars

50%

50%

o$125-200

$25 bienniallyNegligible


TABLE 3

Total automobile emissions reductionsdue to retrofit with inspection/maintenance

1977 1980 1985

CO, HC, NO" CO, HC, NO" CO, HC, NO..%%%%%%%%%

Prog ram 1 37 19 0 28 16 0 12 9 0Program 2 46 29 0 40 25 0 20 15 0

cies for these trips by 10-50%. If these preliminary indications are confirmed by future experience, then programs to encourage carpooling should be capable of reducing total urban area automobile emissions by 5-10%.

Carpool programs appear capable of achieving netcost savings. A carpool program for the Washington,D.C., area based on a locator system and parking restrictions is estimated to require an initial investment of $1.3million and to have operating costs of $0.6 million peryear. If this system achieves a 3% increase in automobile occupancies for peak period downtown work trips,the savings it achieves in automobile operating costs willequal the annualized cost of the system.

Transportation control plans

Such plans are now in effect in 27 of the 30 AOCR·sthat require transportation controls, and plans are beingdeveloped for the other three. The automobile emissionsreduction measures included in these plans are shown(Table 4). 1M is included in 25 plans, retrofit in 20, carpools or transit improvements in 22, and automobile restrictions in 20. The initial phases of plan implementationare now under way.

It is still too early to forecast the speed or successwith which the transportation control plans will be imple-

mented. Present law requires that the plans be fully implemented and that the air quality standards be achievedin all of the affected AOCR·s by 1977. However, as indicated in the previous discussion, there is still considerable uncertainty as to both the effectiveness and cost ofmost of the measures included in the plans. Many ofthese uncertainties can be resolved only through widespread experimentation with the various measures. Moreover, in some heavily polluted AOCR·s, the achievementof the automobile-related air quality standards by 1977requires traffic curtailments that would severely disrupteconomic and social activity.

Because of these difficulties, the EPA is seeking anamendment to the Clean Air Act that would provide formore flexibility in the deadlines for achieving the automobile-related air quality standards without sacrificing theneed to attain the standards as rapidly as possible. In addition to eliminating the need for disruptive traffic curtailments, it is hoped that this additional flexibility will facilitate extensive experimentation with transportation controlmeasures.

More importantly, it is hoped that scheduling flexibilitycombined with the requirement for improving air qualityas rapidly as possible will encourage the development ofan integrated transportation planning and decision-making framework in which decisions about air quality anddecisions about interacting social objectives, such asmobility and energy conservation, can be made together.This framework would enable coincidences and conflictsamong objectives to be identified, trade-offs to be madewhere necessary, and full advantage to be taken of coincidences between air quality objectives and other socialobjectives.

Thus, the present transportation control plans do notsignify the end of the automobile emissions problem.

Walk time = 0

201510

Walk time = 5 min

~-"'""!i..._- t ~_ Walk time = 10 min

5-5

.............................................................. C

, ..................... . ................ . ............ . .............. . .••••••••• _"1, Walk time = 5 min.............................................................

--, Walk time = 10 min

20

40

60

80

-10

FIGURE 2

Dependence of transit ridership on service quality100

Transit Time-Auto Time (min.)


TABLE 4

Summary of transportation control plansTransit

improvementsand/or Auto re-

AQCR 11M Retrofit carpools strictions

Baltimore • • • •Beaumont Plan being developedBoston • • • •Chicago • • •Cincinnati •Dallas •Denver • • • •Fairbanks • • •Fresno • • • •Houston • • • •Indianapolis •Las Vegas Plan being developedLos Angeles • • • •Minneapolis •New York City • • • •Phoenix • • • •Pittsburgh • • • •Philadelphia • • • •Portland, Ore. • • • •Rochester, N.Y. •Sacramento • • • •St. Louis Plan being developedSalt Lake City • • • •San Antonio • •San Diego • • • •San Francisco • • • •Seattle • • • •Spokane • • • •Springfield, Mass. • •Washington, D.C. • • • •

Total 25 20 22 20

Rather. they represent the beginning of a process oflearning to design and manage urban transportation systems in a manner that is consistent with air quality needsas well as other social objectives.

Additional reading

"Control Strategies for In-Use Vehicles." EnvironmentalProtection Agency, Office of Mobile Source Air Pollution Control,November 1972."A Disaggregated Behavioral Model of Urban Travel Demand,"prepared by Charles River Associates. Inc., for the Federal Highway Administration under Contract No. FH-11-7566, March 1972.Horowitz, J. L. "Cost-Effectiveness Analysis of Alternative Strategies for Reducing Emissions from Motor Vehicles," Proceedingsof the Third International Clean Air Congress, pp. F35-F36, VFIVerlag GmbH, Dusseldorf, Federal Republic of Germany, 1973.Holmes, J. G., Horowitz, J. L., Reid, R. 0 .• Stolpman, P. M.•"The Clean Air Act and Transportation Controls: An EPA WhitePaper." U.S. Environmental Protection Agency. Office of Airand Water Programs, August 1973.

Kain. J. F.. "How to Improve Urban Transportation at PracticallyNo Cost," Public Policy, Vol. XX, No.3 pp 335-58, Summer 1972.

Joel L. Horowitz is a senior researchanalyst in the Office of Policy Analysis at EPA. His primary interests arein the area of transportation controls.His work has included cost-effective:ness analyses of mechanical approaches to reducing in-use vehicleemissions and studies of the air quality improvements that could resultfrom ne w approaches to the designand management of urban transportation systems.

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Volume 8, Number 9. September 1974 805

Introducing theRAe on-stack transmissometer

OPTICAL HEAD ASSEMBLY

STACK WALL

optical head and retroreflector units, after fine aiignment, arelocked in position by external, threaded connections, assuringa vibration proof installation.

The RAC system can be set to operate on either 115 or 230VAC. In addition, its normal 5-second electrical response canbe modified in the field to any response value between 1 and10 seconds.

A variety of optional accessories-including blower units toprotect the optics (when required), computer interfacing, aremote strip-chart recorder, and a system response test kitare available to enhance the RAC transmissometer's capabilities for optimum performance with minimum attention.

TYPICAL INSTALLATION

A precision electro-optical device with advanced design features(patents pending), the RAC transmissometer accurately measures the opacity ot stack gas streams by means of a modulatedlight beam. This new system has simpler optic and electronicsystems than competitive units. Its improved design assuresoptimum optical performance, minimizes operating problems,and reduces normal servicing/maintenance requirements.

The RAC transmissometer features a unique chopper designand a solid-state automatic control circuit. These componentsmake the system insensitive to ambient light, provide continuous recalibration (every 0.1 second), and automatically compensate for light and temperature changes as well as aging/driftin the electronics. This system also features greater sensitivityin the 0 to 50% opacity range (50% on scale=30% opacity).

The system's normal, span point, and zero opacity calibration operating modes can be actuated manually with controlsin the optical head, or remotely by an optional remote controlpanel. The automatic control circuit overrides the manual modeat hourly intervals (approx) and provides a sequential span andzero opacity recalibration signal to the instrument's meter andto the output connection for a remote recorder.

The RAC transmissometer aiso has an adjustable set-pointthat will automatically activate relay contacts for an externalalarm, or an accessory package, if stack stream opacity reachesa preset limit. The accessory package permits remote settingand sensing of the variable set-point.

Once properly installed, this compact, lightweight system(47 Ibs) normally requires no further on-stack adjustments. The

RETROREFLECTORASSEMBLY

This newly-developed system measures... and provides direct readouts ... foroto 100% opacity in stack effluents,with accuracy to ±3% .

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Send for BULLETIN 2700 for details.


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Environmenta/lnstruments / Laboratory Products


FEATUREFormer chief scientist in one federal agency, and now a Washington. D.C.-based consultanon materials and energy, seriously questions how much we as a nation can afford to be ...

Paying for newar

Earl T. Hayes

Consultant, Silver Spring, Md. 20901

For want of a nail the shoe was lost is a well-knownstory leading up to how a battle was lost. It could well bethat we have a similar situation coming to resolution thisyear which might do irreparable damage to the whole environmental movement and gains of the past seven oreight years. The particular nail is the automobile emissionstandards which bid fair to be the most expensive experiment of all history. The cost could be as high as $20 billion a year and the fuel penalty translates to the loss ofseveral hundred thousand jobs in a gasoline starvedeconomy. There is no clear cut evidence as to whyAmerica should be called upon to pay such a price.

In the few years that have passed since the passage ofthis act there has been a radical change in the U.S. energy demand and supply picture. The price of petroleumhas more than tripled and the whole economic structureof the country is facing drastic change in view of soaringpetroleum prices.

The fuel penalty incurred in reaching the present standards is now known to be at least 500,000 barrels ofcrude oil per day and attaining the 1976 standards will

raise the total penalty to something between 750,000 and1,500,000 barrels per day. The Achilles heel of all theseregulations is the one for NOx for which there is no demonstrated need or supporting evidence to say that itshould be removed to the levels now on the books. TheAmerican public has so far failed to grasp the principalproblem of a permanent change in their way of life andcertainly have been unable to adjust to the petroleumsupply levels of 1973-74.

Times have changed since the passage of the first environmental laws when no one dared vote against anylaw with the word environment in it and when it was assumed that our affluent life would be able to achieve thegoals of zero risk to the health of the American public atany cost. The thundering vote which passed the AlaskaPipeline Bill 380 to 4 shows that public sentiment canchange drastically in a very short time especially when itaffects the gasoline tanks of 100 million American drivers.

Assessing the petroleum situation

The U.S. is in a bind now and forever as regards petroleum. With a 16th of the world's population we consumeover a third of its total energy. However, we possess only5% of the world's petroleum reserves, and the Arabs andMiddle Eastern nations have at least 53%. We are heavilydependent on a liquid and gaseous hydrocarbon economysince 44% of our total energy use is in the form of petroleum and 34% in natural gas. We are particularly vulnerable in petroleum because 25% of the national total energyis used for transportation, and there are simply no nearterm ·alternatives for replacing the internal combustionengine which is used in more than 100 million automobiles in America today.

We have not been a prudent or forward planning nationin almost any sense when it came to determining whatthe automobile population ought to be in terms of a national resource economy. The insatiable petroleum appetite of the last 10 years, and the probable course for thenext 6-10 years is shown (Table 1). Since 1920 the useof petroleum has compounded at a rate of 4% a year gradually growing to 6% in the last two years. What this meansis that our demands for petroleum were growing eachyear at a rate of a million barrels per day. Also, since wepassed the peak of production that we could ever hope toattain from this country's oil fields and those of Alaskaand the Continental Shelf some years ago, all this increase had to come by way of imports.

We have the situation then that whereas our importswere about 20% of our petroleum requirements 6-10years ago, they have risen to 6.7 million barrels per dayor 38% of our total use. In terms of dollars the effect ofthe tightening of the noose by the Arabs on October 20,1973, pulled the rug out from under all known economics. In the years just passed the average price of oilranged from $3.00-$3.50 a barrel. Even last year, afterprices started to rise, we had an oil import bill of onlyabout $9 billion. However, in the year 1974 alone, just tobuy us last year's imported oil will cost $18-25 billion.

The alternatives are quite clear. If we conti nue to import oil at the increasing rate of the last three years ouroil import deficit will rise to more than $30 billion in 1976and $40 billion in 1980. It is obvious, therefore, that therewill be no growth in oil imports and that we are facedwith a steady state economy, otherwise known as a zerogain of the gross national product.


The legal requirements

In the 1960's it became apparent that with the carpopulation growing each year something had to be doneabout the tail pipe products of the internal combustionenQine. Three gases-HC (hydrocarbons), CO (carbonmonoxide), and NO", (nitrogen oxides)-were identified asrequiring control for reasons of health and air quality. Adigest of these is shown in Table 2.

The original standards were set by arbitrary decision at90-97% of pre-1968 values and have no positive chemicalor physiological basis for the lower limits. They are somuch tougher than the heretofore stringent Californiastandards that the term "overkill" has been used. In afloor speech June 18, 1973, Sen. William Brock (RTenn.) said " ...but as former EPA Administrator WilliamRuckelshaus has stated, it has become apparent that thedata on which some of these decisions were made areeither out of date, or were inaccurate in the first place."

He continued, "It is now obvious that it is not necessary to reduce automobile emissions of nitrogen oxide to

hour air quality standard of 9 ppm CO more than once ayear. ... Present federal emission requirements of 0.41gpm HC and 0.4 gpm NO", seem more restrictive thanneed be by a factor of about three ... These conclusionssuggest that the 90% reduction of CO and NO", specifiedin Sec. 202 of the Clean Air Act may be more than is required to meet the present national air quality standardsfor CO, NOx , and oxidant."

There was fairly rapid progress from 1968 to 1973 inlowering the pollutants by making various changes in theengine carburetion, compression ratio, and other modifications but other approaches are needed to meet the future lower standards. This takes the form of a platinumcatalyst in the exhaust system to convert the pollutants toless noxious forms. Here we come to the crux of thewhole automobile emission problem (aside from the indefensible low standards). Lead fouls up the catalyst rapidlyand must be removed from gasoline. This is a real contradiction because lead in the form of a chemical additivehas been the greatest conservation measure ever de-

a level of 0.4 gram per mile in order to have a safe andhealthful atmosphere. The figure is probably too low by afactor of three or four. Yet, by setting that figure in 1970,Congress has had an almost unimaginable effect onAmerican industry. The result of that single figure hasbeen that oil companies have found it necessary to diverta substantial portion of their production to no-lead gasoline, which requires an apprOXimately 7% greater consumption of energy on their part. At the same time, thisfigure has severely restricted the options of the automobile makers in the kinds of antipollution devices theymight use on their cars. It excluded, for example, thepromising stratified charge engines, as well as thermalreactor systems. And now millions of dollars later, we aretold the figure wasn't even right in the first place."

Along the same line Rowe in The Wall Street Journat ofSeptember 28, 1973, reported, "It's now almost a totalcertainty that Congress erred in selling the stringent autoemission standards of the 1970 Clean Air Act. And unlessit amends the law this session, consumers will have topay for the mistake for more than a decade."

There's no need for this, as testimony before theHouse subcommittee on public health and environmenthas revealed. Perhaps the only completely independentand objective source that has studied the issue told thepanel that the federal emission standards are tougherthan necessary.

Representing the National Academy of Sciences' Committee on Motor Vehicle Emissions, Prof. Arthur Stern ofthe University of North Carolina's School of Public Healthtestified, "An emission limit for CO approximately threetimes as high as that promulgated by EPA for 1975 vehicles would give assurance of not exceeding the eight-


vised for giving increased engine performance to theAmerican automobile over the last 50 years.

There is another reason for taking the lead out and thatis the unsubstantiated fear that the fine particles discharged by the cars will eventually produce a health hazard. Over the long term this removal remains a desirablegoal. Rapid technology development by reputable firmshas developed filters in the last three years that can beinstalled on all cars both new and old. Even now an 80%recovery of the lead appears feasible and this can certainly be improved. There is the bonus that the leaded filters would be available for saving lead by recycling. Trueenough, they would cost $20-40 for a life installation butwould not incur an energy penalty. The lead filter development appears to be far ahead of the catalytic converterdevelopment. In short, modern American technology hassolved the lead problem in a much more satisfactorymanner than EPA proposals or present regulations, bothfrom the standpoint of technology and conservation.

The costs

It must be remembered that the 450,000-600,000 barrels of oil per day fuel penalty has only brought us to January 1974. Going on to meet the statutory standards of1976 will result in an additional fuel penalty of the samemagnitude. In the late 1970's then we have low estimatesof the loss of 700,000-850,000 barrels of oil per day byEPA and high estimates of over 1,000,000 barrels per dayby the Bureau of Mines and 1,750,000 by industry.

In a letter to Science February 15, 1974, Naumanngives the following estimate of these costs, "If we assume that 10 million cars are sold each year, the totalcost for these devices (in 1975) will be $3.14 billion per

year. Replacement of catalytic converters every 50,000miles requires an amortized cost of $40 per year for eachcar. The total annual cost will thus be $4 billion. The fuelconsumption of cars manufactured in 1973 is already30% higher than that of 1970 models and we are nowhere near meeting the 1976 emission standards. Even ifwe assume that these standards can be met with no further sacrifice in economy, the cost of the 30% increasein fuel consumption is more thari $12 billion at currentprices. Thus, we can estimate that the implementation ofthe 1976 automotive emission standards will cost approximately $20 billiOri per year."

The real pric~ of this fuel penalty is its effect on theGross National Product and unemployment. The NationalPetroleum Council in a report of November 15, 1973, estimated that a loss of 2 million barrels a day of petroleumimports would cut the GNP $48 billion and raise unemployment by roullhly a million people. The low estimatesof fuel penalty for emission controls could mean the lossof 100,000-250,000 jobs, the hillh estimates are several

.' TABLE 1

Petrole'llm statistics'(Mtllions of gallons per Clay)

Dom.stic supplY'. .crude + n.tura.

V.a. gas liquids Im..,orts

1'964 8.8 2.3 11.21966 9.6 2.6 12.41968 10.6 2.8 '13.81970 11.3 3.4 15.11972 11.2 4,8 16.41973 10.7 6.7' 17.3~76 10.2 6.7 ' 16191980 11.8' 6.7 18.5

• No growth in h;npo~s. 1Iinciudes Alaska oil.

hundred thousand. This latter would be in the range ofa $20-35 billion, drop in the GNP.

The benefits

There is no clear cut case that the 1973 auto emisSionlevels need to be decreased. In a March 29, 1973, floorspeech Sen. Philip Hart (D-Mich.) originally a strong supporter of the Clear Air Act, called for its re-examinationand stated that little time was given to cost-benefit questions when the laws were passed. He said, "There is nosound scientific evidence that the '75-'76 standards willdo anything to improve health. If it can credibly be saidfour years from now that we have caused the expenditureof billions to no purpose or to questionable purpose, theclean air cause will be dealt a blow from which it will bedifficult to recover."

likewise, no direct evidence has ever been presentedfor taking lead but of gasoline. This was well stated byDr. William A. Vogley, Deputy Assistant Secretary of theInterior, in a December 7, 1973, letter to Mr. Alvin L. Aim,Assistant Administrator for Planning and Management,EPA, "In the final analysis, these draft regulations continue to threaten a substantial impact on our Nation's limited oil resoUrces. Considering that the conclusions relative to the health issue are largely jUdgmental and somewhat subjective and the health effect of airborne lead is acontroversial question that is unlikely to be resolved satiSfactorily one way or the other by available scientific evidence, we cannot agree that any,·impact on our inadequate fuel supply is justified. Analysis of these impactsand reasonable alternatives to the limiting of lead remainthe same as stated in our previous review."

The confrontation

No one has ever really told the American public whatthese costs are all about. Phillip Gramm writing in TheWall Street Journal November 30, 1973, said, "Another

step in solving the energy problem is to inform society ofthe cost of environmental and ecological programs andallow the people to choose. If people want the end products of such programs they will have to pay the cost inhigher energy prices. Without adequate information, society will not be able to decide which programs are worththe cost and which are not... Such a system seems preferable to allowing a bureaucrat to decide for them."

At this time there appears to be no change in the EPAobjective to enforce the statutory standards in 1977. Thisposition is holding in spite of the fact that numerous people have questioned the validity of the data on which thestandards were based, that the assumptions made on thefuture car population are now known to be in seriouSerror, that we are approaching a no-growth economy,that the cost of imported oil has risen from $7 billion to$18-25 billion between 1973 and 1974, and that the totalcost of attaining the statutory standards is of the order of$20 billion a year with the accompanying unemploymentof perhaps hundreds of thousands of people. We were

'iTABLE .2'

AutOnfol)ile emission stand~rdsHC·,CO "NO.

... (g.am.. per mil.)

Pre196ao 8.6 87.5 3.51973 3 28. 3:11975 (orlgl,;,.al) 0.41 3.4 3:11975 (Interim) 1.5 15 3.11976 (original) 0.41 3.4 0.41976 {Interim) 0.41 3.4 2.01917 0.41 3.4 0.4

."'0 standards.

never that rich as a nation arid in the developing prioriiybattle in social, productivity, and environmental gains, amore realistic assessment of the trUe benefits will haveto be made.

Up to now, the general public has been in good agree~

ment with all the environmental causes. Clean water andsulfur dioxide removal efforts have no specific emotionaleffect, but when 100 million motorists are further curtailed in their driving they will rebel. An hysterical outburst could demand complete repeal of the Clean Air Actor at least the auto emission controls section.

Remember two ihings: The American public only hasan attention span of a few years and witness the overwhelming vote on the Alaska Pipeline Bill. In this newball game we are not a rich enough nation to pay $20 bil 7

lion a year and have several hundred thousand out ofwork for future health standards Which have no solidbasis in fact.

Unless there is a rapid meeting of the minds on whatthis all costs and the American pUblic is given a voice inthe selection of auto emission standards: we will witnessa tearing down of present laws. Total repeal would be disastrous, for no matter what the new way of life that wemust adjust to in the coming years, the quality of that lifewill be just as important as today.

Earl T. Hayes is a consultant on materials and energy. Until recently hewas chief scientist of the Bureau ofMines in the U.S. Department of theInterior where he spent most of hisprofessional career. Dr. Hayes is'aregistered professional engineer andhas been concerned with planning,evaluating, and directing researchprograms in the area of energy, mining, metallurgy, and mineral supply.


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CURRENT RESEARCH

Economic Air Pollution Control Model for Los Angeles County in 1975General Least Cost-Air Quality Model

John C. Trijonis 1

Caltech-EOL, Pasadena. Calif. 91109

• An economic air pollution control model is formulatedfor determining the least cost of reaching various air quality levels. The model takes the form of a general, nonlinear, mathematical programming problem. The two basicinputs to this model are the least cost of attaining variousemission levels and the relationship between emission levels and air quality. A linear programming submodel ispresented for deriving the first input, the control costemission level relationship. Empirical-statistical air quality submodels are outlined for obtaining the second input,the emission level-air quality relationship. The combination of these two inputs to solve the nonlinear programming problem is illustrated graphically. Part II of thispaper (page 816) applies the model to photochemicalsmog in Los Angeles in 1975.

Environmental economics indicates that air pollutioncontrol policy should be based on a systematic comparisonof all control costs associated with pollution abatementand all damage costs associated with atmospheric pollution levels. The most simplistic economic optimization iscost-benefit analysis. According to cost-benefit analysis,control strategies and resulting air quality levels should bechosen so as to minimize total social cost, the sum of pollution control and damage costs. To perform this optimization, two key inputs are required: the least control costassociated with reaching various air quality levels and thedamage costs associated with various air quality levels.These two inputs would also be of fundamental importance in economic analyses that are more general than thecost-benefit approach.

This paper develops a methodology for deriving the firstof the fundamental economic inputs described above. PartI formulates a general, mathematical model for determining the least control cost needed to attain various airquality levels. Part II applies this model to a specific situation, photochemical smog in Los Angeles County in1975.

Model Development

Figure 1 presents the basic air pollution system thatwill be under consideration. Air pollution, a result of theinteraction of emissions from human activities and meteorology, is to be abated through emission control.

Certain qualifications are in order with regard to Figure1; this basic conceptual model is not inclusive of all airpollution systems. For one, air pollution arises from natural processes as well as from man-made sources. Examplesare volcanic eruptions, forest fires, dust storms, and heavy

1 Present address: TRW, Environmental Services, R4/1120, Redondo Beach, Calif. 90278

fogs. At the present time, however, these sporadic naturalair pollution episodes are not nearly so important as thepersistent air quality problems resulting from human activities, particularly in metropolitan areas. Here, only anthropogenic air pollution will be considered.

Second, man affects air quality by altering meteorological and topographical conditions, as well as by emittingcontaminants into the air. An example of this type of interference is the destruction of vegetation in certain areasleading to high dust levels and low organic gas concentrations. However, this type of effect is usually not of majorimportance; contaminant emissions are the dominantproblem.

Third, two general control methods, other than emission control, are available for air pollution problems. Meteorological control can be used to improve the assimilative capacity of the atmosphere. An example is the recently proposed scheme to suck freeway and street air intosewer systems. Receptor control, established on plants,animals, materials, or humans damaged by pollution, isalso possible. Examples of this form of control are developing air-pollution-resistant vegetation, staying in air-filtered buildings, or changing place of residence. However,most meteorological control schemes are impractical, anda general policy of receptor control appears ruled out byaesthetic considerations. Only emission control will beconsidered in this paper.

The control problem to be investigated is the determination of the minimum (control) cost of reaching given air

EMISSlON CONTROL

METEOROLOGY

AIR POllUTION

Figure 1. Basic conceptual model for air pollution control


quality levels. This problem will be formulated mathematically. in terms of equations, in such a way that the solution of these equations provides the answer to the controlproblem. Already. by examining Figure 1. one can see thebasic form that this mathematical model will take. In theleast cost-air quality control problem. there are threebasic sets of parameters. emission control cost, emissionlevels. and air quality. Among these parameters there aretwo basic relationships. the control cost-emission level relationship and the emission level-air quality relationship.Once these two relationships have been put in mathematical form, the model is completed by their synthesis.

Before taking up the mathematical formulation. itshould be noted that some type of time specification mustbe made for the problem. One alternative is to examine afixed time period. Sucli a static model could be either ashort-term or a long-term model-e.g.• it could find thecost of achieving given air quality levels during either atwo-day smog episode or some entire year in the future. Asecond alternative is to formulate a more complex, dynamic model that examines the cost of various "air quality paths" for "n" successive time periods. Seinfeld andKyan (1) have examined the dynamic problem and haveindicated how it might be solved with dynamic programming techniques. However. the complexity of the dynamicproblem has precluded actual solutions for large-scalereal-life air polluttion systems. Here, a simpler, longterm, and static model is constructed to calculate the costof reaching various air quality levels for some given yearin the future. .

The first step in formulating the least cost-air qualitycontrol problem mathematically is to put the basic parameters of the system into symbolic notation. Total control cost can be represented by a scalar, C, measured indollars. To allow systematic comparison of initial and recurring expenditures, the costs can be put in an "annualized" form. Emission levels for N primary contaminantsca~ be represe'nted by N source functions, 0;(E,r), i = 1.... , N, giving the rate of the ith contaminant emitted perunit volume at all points, ~ and times, r. in the air basinand year under consideration. The final pollution resulting from these emissions is also a vector-valued functionof space and time. It can be specified by functions,<P j(x,t), j = 1, ...• K, giving the levels of K final pollutants at positions. x. and times, t.

Actually. the rigorous specification of air quality (finalpollutant levels). is even more complicated than indicatedabove. Since we are dealing with some future year, andsince meteorology is uncertain, final pollution is more appropriately specified by probability distributions of thefunctions. <P j(x.t). For this investigation. in order to simplify the statement of air quality, it is assumed that anintegration over these probability distributions and overspace and time have been made so that air quality isspecified by a set of air quality indices. Pj • j = 1•...• M.Such indices are the type of air quality measures actuallyused by control agencies. Example would be:

Pl =the expected yearly average concentration of a certain pollutant at a given monitoring station

P2 = the expected number of days per year that a certainpolfutant exceeds some standard for 1 hr at agiven monitoring station

P3 = the probability that the maximum 1-hr concentration of a certain pollutant exceeds some standard atany point in the basin and at any time during theyear

Figure 2 shows the least cost-air quality control problem with the mathematical notation introduced so far.This figure emphasizes the two functional relationshipsthat must be found before the model can be completed.First. there is the control cost-emission level relationship.This is a techno-economic relationship which gives theminimum cost of achieving any given level and pattern ofemissions. It is found by taking each emission level.oi(trl. i = 1•...• N, technically determining the subsetof contr.ols that exactly achieves that emission level, andchoosing the specific control plan with minimum cost. C.This relationship, the minimum cost of reaching variousemission levels, will be denoted by G.

C = G[8 j (;.T)\ = C[8 t(;.T) ..... 8 N(;.T)] (1)

Second. there is the emission level-air quality relationship. This is a physical relationship which gives expectedair quality levels. Pi. as functions of emission levels,c; i(~,rl. Finding these functions is a problem in atmospheric physics and chemistry. Here. these relationshipswill be denoted by Fj.'

CONTROL COST - EMISSION LEVEL

RELATIONSHIP

Col ~8j(i..T)

EMISSION LEVEL - AIRQUALITY RELATIONSHIP

.. ~ P j

CONTROL COSTEMISSION

AIR QUALITY- EMISSIONS

/CONTROL

METEOROLOGY

Figure 2. Formulation of least cost-air quality model in mathematical notation


(a) (5)

The mathematical statement of the cost minimizationproblem, once the constants S" L.... c i, E"o, E,,', A'i, Dmj,and B,.} are given is: Find x I that minimizes

achieving given emission levels for several pollutants in anair basin. This model, in a modified form, can be used todetermine the function, C = G(E

".. , EN). the minimal

cost of attaining G(E"

...• EN). The modification relates tothe fact that Kohn's model expresses emission level constraints as inequalities. That is, Kohn's model finds theset of controls which minimizes the cost of at least achieving specific emission levels, G(E

"...• EN). In this study,

the function, G. should represent the cost of exactlyachieving G(E

"... , EN). Thus, some of the constraints in

Kohn's model become equalities.The linear programming model to be used here employs

the following definitions:

The ith component of a vector specifying the magnitude of all emissionsources (e.g., the number of largepower plant boilers, or the number ofrefmery heaters).The ith component of a vector specifying the supply limits of fixed supply inputs into control activities(e.g., the total available natural gas.Natural gas is a clean-burning fuelthat can be used to reduce emissionsfrom automobiles as well as powerplant boilers).The jth component of a vector specifying the levels of control activities,X} (e.g., the number of a certain control device added to 1970 vehicles).The jth component of a vector specifying the costs of one unit of eachcontrol activity (e.g.• the cost of adding a certain control device to one1970 vehicle).The kth component of a vector specifying the yearly emission levels of theN contaminants under considerationwith "no control" (x) = 0) (e.g., withno controls installed, the averageNO x emission level, say in tons/day).The kth component of a vector specifying the yearly emission levels oftheN contaminants to be obtained bythe control activities X}.The number of units of source i controlled by one unit of activity j (e.g.,one 1970 vehicle is controlled by adding one unit of a certain control device to 1970 vehicles).The amount of the mth limited supply input used by one unit of the jthcontrol activity (e.g., the amount ofnatural gas used by a unit of a givencontrol activity).The emission reduction of the kthcontaminant resulting from one unitof the jth control activity (e.g., thereduction in NO x emissions resultingfrom addition of one control deviceto a 1970 vehicle).

E•• k = 1•.. .• N

Dmj, m = 1, .. .• lj = I, ..., r

B.j, k = 1•... , NJ= 1, .. .,r

E.o. k = 1•.. .• N

Aij, i = 1, .. .,sj = 1•..., r

Xj,j = 1•... , r

Cbj = 1, .. o,r

Lm • m = 1•.. .,l

Si, i = 1, .. 0' S

Stated in words, one chooses that emission level whichhas the minimum control cost subject to the constraintthat the emission level will at least reach the air qualitygoals.

Need for Simplifications

Equation 3 is the complete mathematical controlmodel. To find the minimum cost of reaching given airquality levels. one determines the control cost-emissionlevel relationship, G. finds the air quality-emission levelfunctions. F

"and solves Equation 3. This problem though

very simply stated. is extremely complex to actually solve.The main factor that leads to complexity is that in finding G. finding the F/s. and solving Equation 3, one mustconsider all possible space and time patterns of emissionsas well as total emission levels. In applying the model to areal-life air pollution problem. some simplifications wouldhave to be made in describing the space and time distributions of emissions. For instance, freeways might be considered line sources. power plants as point sources, andnonfreeway traffic as a uniform surface source. In the example that will be taken up here, the ultimate simplification is made; the space and time pattern of emissions isnot considered at all. It is assumed (although this is certainly not exactly true), that emission control programsdo not alter the pattern, so that emission level changesoccur in the same proportion at all points in space andtime. With the emission pattern fixed, emissions can simply be measured by total emission levels in the air basinfor each primary contaminant and represented by a vector. E. independent of space and time.

With this simplification. the model becomes the following:

Choose E i .i=1•... ,N

that minimizes C = G(E i ) = G(E\, ...• EN)

subject to F/ ~ Fj(E\, ... ,E N )

j = 1, ... ,M (4)

where G(E, E,,) is the minimum control cost ofachieving (E, Es ). and F,(E

".... Es).j = I, ... , M,

give expected air quality levels as functions of emissionlevels.

The solution to the complete model proceeds in threesteps: (1) find G. (2) find F i , and .(3) solve Equation 4.The next three sections will discuss the general methodology that will be used in Part II to accomplish each ofthese steps.

Control Cost-Emission Level Relationship: G(E j )

Kohn (2) has formulated a mathematical linear programming model for determining the minimal cost of

Choose that 8 i(~' T), i = 1, ... , N

which minimizes C = Gr8i(~' T)]

subject to FjO~ Fjr8i(~' T)]j = 1, ... ,M (3)

FA8\(~. T), .... 8 N(~' T)I

j = 1, ... ,M (2)

When we a~sume the techno-economic relationship, G.and the physicochemical relationship. F i • have been detennined. the problem of finding the minimum cost of atleast reaching air quality goals, P,o, reduces to the following mathematical problem:


subject to the constraints:

LB,jXj = E.o - E. I? = 1, ... ,N, (b)jo 1

(emissions are reduced to E.)

Then, by Equations 1 and 2 and the linearity of theequation of advective diffusion describing the dispersionof an inert pollutant, pollution levels on any day arestrictly proportional to the yearly emission level, E =crEO. Thus, at any emission level, E, the correspondingdistribution function, N(P), is

r

LAjjX j :5 Sj i = 1, ... ,s (c)jo 1

(no more of source i than Sj can be controlled)r

L Dmjxj :5 Lm In = 1, ... , I (d)jot

N(P)dP = NO(P/cr)d(P/cr)=the expected number of days per year that the

maximum n-hour pollutant concentration is inthe range P ~ P + dP at emission level E =('/Eo

But, when we know N(P), the air quality at any emission level is simply calculated by

NO(x,y)dxdy =the expected number of days per year thatthe morning concentrations of the primarycontaminants are in the ranges x ~ x + dx

The calculations proceeds as follows: At some baseyearly emission level of the primary contaminants, (E10,

E2°) , one determines from atmospheric monitoring datathe following two distribution functions:

p.. the standarda. the emission level

function of NO. the distribution functionmeasured at one emissionlevel

J~ N(P)dPp

sthe expected numberof days per year thatthe n -hour standard.Ps• is exceeded at anyemission level. E =aE

D

In Part II this model is applied to the I-hr Californiastandard for nitrogen dioxide. Of course, O2 is certainlynot an inert pollutant. Equivalently, the assumption ismade that maximal N02 levels are strictly proportional toNOx emissions.

The second statistical model is applicable to mid-dayair quality levels of a secondary, photochemical pollutant,Z, produced by reactions stemming from two primarycontaminants, X and Y. The basic idea for this model wasput forth in a paper by Schuck et al. (4). The expectednumber of days per year that a given standard for the pol.lutant, Z, is exceeded as a function of emission levels ofthe two primary contaminants is determined from airmonitoring data taken at given yearly emission levels,(E1°(x, t), E20(x, t)). Four physical assumptions underliethe model:

(1) Emission reductions of X and Y occur homogene·ously.

(2) In the air mass that will lead to the pollution of anyday, emissions of X and Yaccumulate without reacting toproduce final (morning) concentrations x and y, respectively.

(3) Accumulation stops and then certain weather vari·abIes act on the primary contaminant concentrations, xand y, to produce a (mid-day) level z of the secondary contaminant, Z.

(4) The weather factors that determine the level of Z produced from given x and yare statistically independent ofthe distribution of x and y.

Letting C denote the minimum of CT , the solution tothis problem (for fixed S" L m , Cj, A,j, Dm ;, and B.· i ) forvarious values of E. gives the emission control cost function, C = G(E.).

There are several assumptions inherent in the linearprogramming emission cost model of Equation 5. The interested reader is referred to Kohn (2) or Trijonis (3) for adiscussion of these assumptions and the applicability ofthe model.

Emission Level-Air Quality Relationship: F(E,)

Determination of the relationship between air qualityand emissions, Pj = Fj(Ej ), is a problem in atmosphericphysics and chemistry. There are two basic approaches tofinding such a relationship. One, which can be called thephysicochemical simulation approach, is to model the atmosphere mathematically and solve the appropriatechemical and physical equations on a computer. Diffusionmodeling is a prime example of this approach. The secondis a statistical-empirical approach; past atmospheric monitoring data and simple physical assumptions are used toderive the relationship.

In the Los Angeles photochemical smog application(Part II), this study will use "management-type" air quality indices; air quality will be measured by the expectednumber of days per year violating state standards. Physi·cochemical models are not suited for providing this typeof air quality function because solutions are needed forthe whole distribution of meteorology. Thus, the statistical approach is used. Two statistical models have beendeveloped for this application, one for primary contaminants and one for secondary contaminants. The mathematical forms of these models are summarized below.

The first statistical model uses monitoring data takenat a given yearly emission level, EO, to determine the expected number of days per year that an n-hour standardfor a primary pollutant, P, is exceeded as a function ofemission level. Two physical assumptions underlie themodel: (1) that the pollutant is an inert, primary contaminant and (2) that emission level changes are homogeneous (that they occur proportionately in space and timeto the emission pattern existing at EO-i.e., E (x, t) =crEO (x, t).

The calculations proceed as follows: At some base yearly emission level, EO, one determines from atmosphericmonitoring data the distribution function, N°' P), where

NO(P)dP =the expected number of days per year that themaximum n-hour pollutant concentration isin the range P~ P + dP at emission level EO

(supply limits of fixed inputs, L m , are not exceeded)

x j "" 0 j = 1, ... , Y (e)

(nonnegativity of control activities)


and y - y + dy, respectively, at emissionlevel (E1°, E2°)

= the probability that z exceeds some standard z." on a day with morning concentrations x and y of the primary contaminantsat emission level (E1°, E2°)

Then, [as discussed in Trijonis (3)], Equations 1-4imply that at any emission level, (E1, E2 ) = (<>E1°,/3E20) ,

the corresponding distribution functions are

N(x,y)dxdv = NO(x/a,y/(3}d(x/a)d(y/{3)

Pl·\·,y) = PsO(x,y)

But, knowing N(x,y) and PsO(x,y), the air quality forany emission level is simply calculated by

the expected number Of\days per year that G ~ ~

exceeds the standard, = f f N(x, y) xG S' at emission level, ° °(E l , E 2) = (aE 10, (3E 20) Ps(x, v)dxdy

J~f~ NO(x/a,I'/{3) x PsO(x,y)d(x/a)d(y/{3)

° °(7)

!a and {3, emission levelsNO and psG, distribution functions

= function of measured at a baseemission level for agiven standard. Gs

In Part II this model is applied to the problem of midday ozone in central Los Angeles (Downtown, Pasadena,Burbank area). The relevance of this application in regardto assumptions of Equations 1-4 is discussed at length inTrijonis (3).

Solution ofComplete Model

Once the control cost-emission level relationship, G,and the air quality-emission level relationship, F, havebeen determined, the least cost of achieving various airquality levels is found by solving the system of Equations4. It consists of a nonlinear mathematical programmingproblem. The development of techniques for solving nonlinear programming problems has been a rapidly advancing field of applied mathematics during the past 10 years[Abadie (5)]. Many different numerical solution methodshave been developed. For a specific problem, the choice ofsolution method depends on N, M, and the form of thefunctions G and Fi • If G is determined by the linear programming model of Equation 5, it is necessarily a convex

Figure 3. Two-dimensional illustration of solulion to leasl costair quality model

function; this should aid in the solution of Equation 4[Baumol (6)]. However, it is not the purpose here to become involved in an extended discussion of nonlinear programming; suffice if to note that techniques for the solution of Equation 4 have been developed.

For a two-dimensional emission vector, (N = 2), the solution of the model can be illustrated graphically. Figure3 presents a schematic diagram for the case of two airquality constraints, (M = 2). The axes of the graph measure total emission levels, E1 and E2• The uncontrolled orbase emission level for the basin is the point, (E10, E20).

The curves labeled C1, C2, etc., are iso-cost curves-i.e.,G(E1, E2 ) = C1, G(E1, E2 ) = C2, etc. Along any curve labeled C., the minimum cost of reaching any point on thatcurve is C•. As emission levels fall (downward and to theleft in the graph), control costs rise. Thus, C1 < C2 < ...< C~. The air quality constraints are represented by thetwo curves F1(E1, E2 ) = P10 and F2(E1, E2 ) = P2o, Theconstraint of at least reaching air quality level P1°for thefirst pollutant requires that emissions be reduced belowthe P1° curve. The constraint that air quality be at leastas good as P20 for the second pollutant requires that emissions be reduced to the left of the P20 curve. The emissionlevels which satisfy both air quality constraints lie in thecross-hatched region. This is the admissible air quality region. The minimum cost of meeting both air quality constraints is C~, and the solution is to reduce emissions topointA.

(Part II follows on nex t page)


Application of Model to Photochemical Smog in Los Angeles County in 1975

• The general least cost-air quality model of Part I ischaracterized for the problem of photochemical smog inLos Angeles County in 1975. Emission levels are specifiedby average tons/day emissions of reactive hydrocarbons(RHC) and nitrogen oxides (NOxl. Air quality, also twodimensional, is specified by the expected number of daysper year that oxidant and nitrogen dioxide in Central LosAngeles exceed the California 1-hr state standards. Thebaseline for additional control policy is the 1975 emissionlevel with the present federal new car control program andwith other sources having the degree of control existing in1971. The least cost of reaching various emission levels isfound by applying linear programming to 23 major sourcetypes and 31 potential "add-on" controls. Expected 0 3

and NO2 levels are found as functions of emission levelsusing empirical-statistical air quality models. These results are combined to yield the least cost of attaining various 0 3 and N02levels in Central Los Angeles in 1975.

The specific air pollution problem to be investigatedwith the least cost control model is photochemical smogin Los Angeles County in 1975. Los Angeles County is selected as the region of study because a fairly completesource inventory is available for the County, mostly fromthe Los Angeles County Air Pollution Control District(APCD) (7). Photochemical smog, the main symptoms ofwhich are eye irritation, plant damage, visibility reduction, and high concentrations of oxidizing gases such as 0 3

and N02. is selected because it is generally considered tobe the most damaging part of Los Angeles air pollution.Photochemical smog serves as a particularly good examplebecause the model is general enough to incorporate nonlinearities in the relationship between air quality andemissions. 1975 is selected as a control date because it isthe first target date of the Federal Clean Air Act.

Problem Definition

Before the control model can be solved for this example,bounds for the problem which define the parameters inthe model must be established. In particular, explicitemission and air quality vectors must be chosen.

First, let us consider the question of an appropriateemission vector. Starting with the work of Haagen-Smitin the early 1950's, 20 years of research on photochemicalsmog have established that it results basically from hydrocarbon (HC) and nitrogen oxide (NO,) emissions[Haagen-Smit (8), Leighton (9), Altshuller and Bufalini(10)].

Hydrocarbons, or organic gases, are emitted during theuse of organic fuels, such as gasoline, and organic solvents, such as those found in paints. NO, emissions resultalmost exclusively from combustion processes whereinsome of the nitrogen and oxygen in the air combine. Otheremitted contaminants-e.g., S02 and CO, may take somepart in the photochemical reactions, but HC and NO x aredefinitely the basic precursors of photochemical smog.

Thus, for emissions, HC and NO, are chosen. Actually,the emission category, hydrocarbons, is very complex. Itconsists of a wide variety of organic gases with differentdegrees of photochemical reactivity, ranging from nearlyinert methane and propane to highly reactive olefins andaromatics. Photochemical reactivity is a measure of the


potential of a HC to produce various photochemical smogsymptoms when mixed with NO., and irradiated with sunlight. Reactivity can be measured according to severalscales; HC consumption rate, NO., formation rate, ozoneproduction, and eye irritation production are the principalones, [Altshuller and Bufalini (10)). The rankings according to these different scales are often inconsistent withone another [Altshuller (11)], which adds to the complexity.

Some allowance should be made for HC reactivity; itmakes a significant difference to air quality whether agiven reduction in HC emissions is obtained by controllingolefins or methane. Here, HC emissions will be actuallyspecified by reactive hydrocarbons (RHC), using the LosAngeles APCD's reactivity scale [Brunelle et al. (12)1966].

The emission vector is chosen. It is two-dimensional reactive hydrocarbons and nitrogen oxides. The next step isto select an air quality vector. For air quality indices,there are four major candidates: visibility reduction, eyeirritation, ozone, and nitrogen dioxide. The Los AngelesAPCD continuously monitors these four photochemicalsmog symptoms and reports air quality in terms of thenumber of days per year that state standards for each areexceeded. The visibility problem is very complex. It is oneof the least understood aspects of photochemical smog.Visibility depends significantly on S02 and particulateemissions as well as RHC and NO,. Since this work dealswith only RHC and NO x emissions, and since it is so difficult to formulate air quality models for visibility, visibility reduction is not included in the air quality index eventhough it is a very important smog symptom.

Using a statistical-empirical approach, this study hasdeveloped air quality models for eye irritation, ozone, andnitrogen dioxide which determine how the levels of thesepollutants depend on RHC and NOx emission levels.These models are empirical models which estimate the relationship between pollution and emissions by using pastatmospheric monitoring data. The results are stated interms of the expected number of days per year that statestandards are exceeded as a function of emission levels.Because of limitations in the availability of monitoringdata, eye irritation and ozone results can only be obtainedfor mid-day in the Central Los Angeles area. To correspond to these results, N02 air quality is also taken asthat in Central Los Angeles. Since eye irritation is such asubjective measure of pollution and since the results foreye irritation turn out to be very similar to those forozone, only N02 and 0 3 will be included in this discussion. Summarizing these remarks, the final choices for airquality indices are the number of days per year that statestandards for 0 3 and N02 are exceeded in Central LosAngeles.

The least cost-air quality model can now be stated forthe Los Angeles photochemical smog problem as follows:To find the minimum cost of reaching air quality levelsplo andP2°

Choose (E t • E 2)

that minimizes C = G(E t • E 2)

p tO Fj(E j • E 2)

(8)subject to 2: Pj

and pO 2: P2 F 2(E 10 E 2 )2

where E, = the average (tons/day) emission level ofRHC in Los Angeles County in 1975

E2 =the average (tons/day) emission level ofNO.. in Los Angeles County in 1975

P, = the expected number of days per yearthat mid-day 0 3 exceeds the State standard(0.10 ppm for 1 hr) in Central LosAngeles

P2 = the expected number of days per yearthat N02 exceeds the State standard(0.25 ppm for 1 hr) in Central LosAngeles

G(E" E2 ) = the minimum cost of reaching emissionlevels (E" E2 ), and F,(E" E2 ), andF2(E" E2 ) = air quality as a function ofemission levels

The solution to this problem now proceeds in threesteps. First, the minimum cost of reaching various RHCand NO.. emission levels in Los Angeles County by 1975 isdetermined. Second, the expected number of days peryear that 0 3 and N02 exceed State standards in CentralLos Angeles is found as a function of RHC and NO.. emission levels. Finally, these relationships are combined inEquation 8 to determine the least cost of reaching various0 3 and N02 air quality levels.

Control Cost-Emission Level Relationship

The first step in finding the cost of reaching variousRHC and NOx emission levels in Los Angeles County in1975 is to prepare an inventory of emission sources andcontrol methods. Such an inventory, presented below, wasorganized from the published literature and by examiningreports and interviewing representatives of the Los Angeles County APCD, the California ARB, the Departmentof Health, Education and Welfare, energy suppliers, andnumerous industrial firms. As evidenced by conflictingviews from various reports and officials, considerable uncertainty exists in much of the information on sources,and particularly, on control methods. The data presentedbelow are thus onIv approximate, and the list is not intended to be a defi~itive statement of sources and controlmethods. The approximations are discussed in detail byTrijonis (3).

For the purpose of this study, RHC and Ox emissionsources in Los Angeles County were divided into 35 categories, 15 types of stationary NO.. sources, 8 types of stationary RHC sources, and 12 types of mobile RHC andNO x sources. For each source, information was gatheredon the number of source units, source usage, source expected lifetime, and RHC and NO x emissions per sourceunit (all referenced to 1975). The baseline emission levelfor each source (the "zero" control level for this study)was defined to be the emission level with the present California and federal new car control program and with nonvehicular sources having the degree of control existing in1971. The left side of Table I lists the sources, the numberof source units. and total emissions from each source category in 1975.

Over 70 potential control methods were considered forthe various RHC and NO x sources. For each control, information was gathered on capital cost, operating andmaintenance cost (or savings), reductilln in RHC and NO..emissions per source unit. and feasibility of implementation by 1975. The capital. operating, and maintenancecosts (or savings) were combined into a total, annualizedcost for each control using a 10% discount rate. From thisgroup of potential controls, those which appeared technically infeasible for 1975 (e.g., catalytic or thermal reactorsfor used cars). which lacked sufficient documentation for

estimating cost and effectiveness (e.g., reduced driving),or which were strictly inferior to an alternative controlmethod for the same source (in the sense that the othercontrol method produced a greater emission reduction atless cost) were eliminated from the study. This process ofelimination left 31 control methods for 23 major sources.These control methods, along with estimates of percentage emission reduction and cost per ton of contaminantprevention (annualized cost divided by annual tons controlled), are presented on the right side of Table I. An extensive discussion of all the sources and control methodscan be found in Trijonis (3),

The information on sources and controls was enteredinto the linear programming model described in Part I todetermine the minimum cost of reaching various emissionlevels. This model is basically just a computer programthat considers all the controls, their effects, and theircosts and selects the control strategy that llchieves a givenemission level at least cost. In order to correspond withphysical reality, the program was constrained so that notmore than the existing sources be controlled and that notmore than the available supply of natural gas to Los Angeles County (about 110,000,000 equiv. bbl/year in 1975)[Ralph and Walker (13)] be consumed by the controlmethods. The results of these programming calculations,the least cost of reaching various RHC and NOx emissionlevels in Los Angeles County by 1975, are presented inFigure 4.

The axes in Figure 4, (E" E2 ), measure total RHC andNO, emission levels in Los Angeles County. For reference,the ·1969 emission level is marked at (1300 tons/day RHC,1000 tons/day NOx ). The California new car control program, the stationary source control level of 1971, alongwith growth and attrition of various sources results in abaseline ("zero" control for this study) emission level of(666 tons/day RHC, 786 tons/day NO,·) in 1975. The minimum annualized cost (in addition to the costs of the newcar control program and 1971 stationary source controls)of achieving further emission reductions is illustrated byiso-cost curves, G(E,. E2 ) = $2 million, ... , G(E" E2 ) =$200 million. To obtain an approximate estimate of totaloverall expenditure, the annualized costs should be multiplied by about seven. The specific control programs associated with various emission levels are presented by Trijonis(3).

There are two important features in Figure 4. First,with all the controls considered here established, at an

1969 EMISSION LEVU-

([~~\• ~~~m~E~~~"P£~~}H~0L

SOURCE CONTROL,10

2050

200 150 leo

ADDITIONAL ANNUAL COST (MILLION S)

. ,)o 200 ~c.o to:..O C;"Xl lOill 1200

L.A. COUNTY REAcrtVE HYDROCARBON EMISSION LEVEL, 1975(TONS!llAY)

Figure 4. Minimal cost of attaining various NOx and RHC emission levels in L.A. County by 1975. G(E lo E,)Costs are in addition 10 new car control program cost and 10 cosl associated with 1-1-71 degree 01 stationary source control


Table I. Emission Sources and Control Methods

RHC NOr RHC reo NO.7 reoCost per Cost perton RHC ton NO.J:

emissions. emissions. duction. duction, reduction, reduction.Source No. of units tons/day tons/day Control % % $ $

Stationary Sources of NOz

Large, non power plant, boilers 140 boilers 28 Low excess air firing 40 34Low excess air and 70 195

flue gas recircu-lation

Medium-size boiler 6,000 boilers 41 Low excess air firing 40 1270Low excess air and 70 1590

flue gas recircu-lation

Large refinery heaters 60 heaters 14 Low excess air firing 40 27Small refinery heaters 160 heaters 10 Low excess air firing 40 226Large power plant boilers with 8 boilers 30 Substitution of 33 0

advanced NOz combustion natural gas for fuelcontrol oil

Large power plant boilers with 8 boilers 76 Substitution of 33 0primary NOr combustion natural gas for fuelcontrol oil

Advanced NOz 40 158combustion control

Substitution of na- 60 105tural gas and ad-vanced NOr com-bustion control

Small power plant boilers 37 boilers 23 Low excess air firing 30 200Low excess air and 50 450

flue gas recircula-tion

Large stationary int. combus- 140 engines 25 Water injection or ex- 75 13tion engines ha ust gas recircu-

lationSmall compressor engines 360 engines Water injection or ex- 75 37

haust gas recircu-lation

Residential fuel combustion 28Metallurgical and mineral 8

furancesCatalytic regenerators in 10

refineriesSmall commercial and indus- 9

trial boilersOil well pump engines 2Miscellaneous 3

Stationary Sources of RHC

Underground service station 34,000 tanks 20 Vapor recycle filling 99 205tanks systems

Service stations, automobile 11,300 stations 40 Va por recycle systems 76 333fueling on fuel nozzles

Surface coating 51 tons/day 51 Substitution of non- 75 330reactive solventsand processchanges

Degreasers using trichloro- 26 tons/day 23 Substitution of 1,1,1- 100 -10etha ne (TCE) trichloroethane

Dry cleaners using petroleum- 25 tons/day Activated carbon ab- 95 48based solvent cleaners sorption systems

Petroleum refining industry 7Miscellaneous manufacturing 15

processesOther organic solvent users 14

Mobile Sources of NOr and RHC

Pre-1966 autos, exhaust 1,100,000 vehicles 94 50 Capacitor discharge- 60 35 500 1550emissions ignition optimiza-

tion systemExhaust gas recircu- 15 55 9600 4900

lation and con-trolled spark retar-dation

Pre-1966 autos, evaporative 1,100,000 vehicles 77 Evaporative control 85 3500emissions retrofit device


RHC NOremissions emissions.tons/day tons/day

Table I. (Continued)

Source

1966-£9 autos, exhaustemissions

No. of units

1,380,000 vehicles 65 143

Control

Ca pacitor dischargeignition optimization

Vacuum spark advance disconnectand tuning adjustments

Cost per Cost perRHC re- NO.1' re- ton RHC ton NO.rduction, duction, reduction, reduction

% % $ $

10 55 590 48

30 40 1170 390

Mobile Sources of NOr and RHC (Contin ued)

1966-£9 autos 1,380,000 vehicles 97 Eva porative control 85 2300retrofit device

1970 autos 390,000 vehicles 20 58 Capacitor discharge- 55 0ignition optimization

1971-74 fleet vehicles suitable 345,000 vehicles 34 65 Conversion to natural 94 79 880 550for gaseous fuel use gas

Conversion to propa ne 82 70 4500 2700JT8D jet aircraft engines 2,500 engines 14 Combustion chamber 95 -20 2100

redesignNon·JT8D jet aircraft engines 2,900 engines 4 Combustion chamber 95 -20 8000

redesignL.A. County piston aircraft 7,000 engines 12 4 Afterburner control 75 130

engines device1971-74 nonfleet motor vehicles 1,390,000 vehicles 69 124Diesel-powered motor vehicles 18Non-L.A. County registered 2

piston aircraftTotal baseline RHC NOrEmission levels in 1975 666 786

It is interesting that new car NO" control shows the samecost nonlinearity as the controls considered here. NO.,emissions from combustion sources can initially be reduced rather easily, but once they are cut in about half,further control becomes very costly.

Figure 6 presents the cost of NO" control alone. Starting at the 1975 baseline level of 786 tons/day, controlcosts rise according to the curve up to $85M at 460 tons/day. Reaching point A (640 tons/day NO, at $lM peryear) involves primary control of large industrial boilersand large refinery heaters, exhaust control on 1966-70used cars, control of stationary engines, and burningavailable natural gas in power plants. The average costeffectiveness of these controls is only $19/ton NO,·. Toreach point B (540 tons/day NO., at $l1M per year), oneadds primary control to small power plant boilers andsmall refinery heaters, converts fleet cars to natural gas,and adds advanced control to large power plant boilers,The average cost effectiveness of these extra controls is$280/ton NO,.. Finally, to attain point C (460 tons/dayNO, at $85M per year), one adds advanced control tolarge industrial and small power plant boilers, controlsmedium-sized boilers, and puts exhaust control on pre1966 cars. The average cost-effectiveness of these controlsis $2500/ton NO".

For comparison, the cost-effectiveness of new car NO,·control has been calculated to be as follows:

annual cost of over $200 million, RHC emissions can onlybe reduced to about 260 tons/day and NO.. emissions toabout 460 tons/day. Thus, even a rather extensive controlprogram will by no means rid the Los Angeles atmosphereof pollutants by 1975. Second, it can be seen from Figure4 that for a given level of RHC control, NO.. control is almost free for considerable reductions, but then it becomesvery expensive for further slight reductions. For instance,at an RHC emission level of 500 tons/day, emission reductions of 10, 80, 160, 240, and 320 tons/day NO., cost($20M, $20M, $20M, $25M, and $85M), respectively. Thisphenomenon results from two properties of the controlmethods. First, exhaust controls for RHC in used cars alsoreduce NO,,_ In buying RHC control for these vehicles,one gets some NO., control free. Second, NO,. intensivecontrol methods tend to divide into two categories, manyvery inexpensive controls and a few very expensive controls. This explains the highly nonlinear behavior of totalNO.,· control costs.

Figure 5 presents the cost of RHC control alone, irrespective of NO" control. From the baseline emission levelof 666 tons/day, control costs rise according to the curveto about $210M per year at an emission level of 260 tons/day. Reaching point A (550 tons/day at $10M per year)involves control of stationary RHC sources, gas stations,and various users of organic solvents. The average costeffectiveness of this control is $240 per ton RHC. To attain point B (420 tons/day at $50M per year), one addsexhaust control to pre- 1969 used cars, converts fleet vehicles to natural gas, and controls aircraft emissions. Theaverage cost-effectiveness of these added controls is $840/ton RHC. Reaching point C (260 tons/day at $21OM peryear) basically requires evaporative control to pre-1969cars. The cost-effectiveness of evaporative control retrofitis $2810/ton RHC.

For comparison, the cost-effectiveness of some parts ofthe new car control program have been calculated to be asfollows:

Control

Exhaust control, 1966-69 carsEva porative control, 1970+ carsExhaust control, 1975+ cars

Control

Exhaust control, 1972 carsExhaust control, 1975 cars

Cost-Effectiveness

$ 100/ton RHC600/ton RHC

1750/ton RHC

Cost-Effectiveness

$ 60/ton NOr1700/ton NOr


200 400 600 600 1000 1200

L,A. COUNTY NOX EMISSION lEVEL, 1975 (TONS!t>AY)

Figure 6. Minimal cost of NO,. control alone

was found by the first statistical air quality model presented in Part I. Five years of data (1966-70), on maximaldaily 1-hr NOz concentrations was obtained from the LosAngeles County APCD. These data were used to determine the distribution of daily maximal 1-hr concentrations for a fixed average (yearly) NOx emission level (Figure 7). The proportionality assumption allowed calculation of this distribution for any emission level. Knowingthis distribution for any emission level, one can simplycount off the annual number of days exceeding the 25pphm standard at any emission level. A similar procedurehas been used for 1956-57 CO in Los Angeles by Larsen(16), but with the more specific assumption that the frequency of exceeding specified concentrations was given bya log normal distribution.

The results of this analysis are presented in Figure 8.The expected number of days per year that exceed the1-hr NOz standard is plotted against Los Angeles CountyNO.,· emission levels. For comparison, results were obtained for Downtown, Burbank, and Lennox, the threehighest NOz stations in the Los Angeles basin (APCDProfile, 1971). However, only the Downtown results will beused here in the least cost-air quality model [as the function Pz = Fz(Ez)].

Figure 8 indicates that as NO, emissions are reducedNOz air quality improves, with standard violations fallin~to about two days per year at 400 tons/day NOx . A veryimportant feature of Figure 8 is the change in slope of theair quality curve at an NO.,· emission level of about 600tons/day. Above that emission level, a given emission reduction buys quite a few less standard violations per yearthan below that level. This is especially significant because it costs more for a given emission reduction at thelower emission levels. Thus, when marginal emission control costs are rising, marginal improvement in air qualityis falling.

For ozone, the situation is more complex. Atmosphericozone levels depend significantly on both RHC and NO,emissions. To determine how the annual number of ozoneviolations in Central Los Angeles depend on RHC andNO, emission levels, a probabilistic model was used. Thismodel rests on three assumptions: (1) that morning RHCand NOx concentrations (7:30-9:30 PDT averages) areproportional to their respective emission levels, (2) thatthese morning concentrations are the basic precursors ofmid-day (11:00 a.m.-1:00 p.m.) ozone, and (3) that theweather factors which govern the production of ozone fromgiven morning concentrations are statistically independent of the distribution of morning concentrations. Thediscussion of the applicability of these assumptions is verylong and will not be taken up here. The interested readeris referred to Trijonis (3) for this discussion.

Based on these assumptions, the ozone air quality analysis was performed according to the second statisticalmodel described in Part I. For given (yearly) RHC andNOx emission levels, the joint distribution of morningRHC and NO., concentrations (7:30-9:30 averages) forDowntown Los Angeles was determined from five years ofAPCD monitoring data (1966-70). Then, using APCDozone data, for the same years, the probability that the1-hr ozone standard (10 pphm), would be violated on anyday was found as a function of the morning concentrations. For the ozone measurement, an average was takenof maximum 1-hr values between 11:00 a.m. and 1:00 p.m.at Downtown, Burbank, and Pasadena, weighted according to wind speed and direction, so that the maximumozone would correspond as closely as possible to that inthe air mass that had been Downtown in the morning(and in which the morning concentrations had been measured). To better meet assumption 3, above, the calcula-

1975 EMISSION LEvEL WITH PRESENTNEW CAR CONTROL PROGRAM t..NDWITH 1-1-71 DEGREE OF STATIONARYSOURCE CONTROL

\

1975 EMISSION LEVEL WITH P~ESENT

NEW CAR CONTROL PROGRAM ANDWITH 1-1-71 DEGR~E OF STATIONARY

:or'"o'

c

200

'"zQ

i ISO

0v:< 100::>Zz.,:<z SO0

"g.,0

0

120

110

100

'" 90

Z0 80OJi 70

060v

:<::> 50ZZ.,:< ."

zQ 30

is0., 20

10

200 400 600 SOO 1000 1200

L,A, COUNTY REACTIVE HYDROCAR80N EMISSION lEVEL 1975(TONS/l)AV') ,

Figure 5. Minimal cost of RHC control alone

Air Quality-Emission Level Relationship

After minimum control costs are determined as a function of emission levels, the next step toward completingthe least cost-air quality model is to relate air quality toemission levels. Specifically, the expected number of annual 0 3 and NOz standard violations in Central Los Angeles is found as a function of Los Angeles CountyRHCand NO., emission levels.

For NOz, it was assumed that atmospheric NOz levelsare directly proportional to NO", emission levels. This assumption is supported by photochemical smog chamberexperiments [Korth et al. (14) and Altshuller et al. (15)].It would hold exactly, by the linearity of the equation ofadvective diffusion, if two conditions were met: (1) if NOzwere an inert pollutant (which it certainly is not) and (2)if all sources of NO x were reduced in proportion (homogeneously) in emission level changes. The applicability ofthe proportionality assumption and its relation to theabove two conditions are discussed in detail by Trijonis(3) .. With the proportionality assumption, the expectednumber of days per year that NOz exceeds the ~-hr Statestandard (25 pphm) as a function of NO x eI)1ission levels


NO(P) dP • Number of days per yearwi th maximum one hourconcentration in the rangeP~P+dP

30

EXPECTED DAYS PERYEAR EXCEED I NGSTANDARD

20

10

10 20 30 40 50 60 70

N02

CONCENTRATION (pphm)

Figure 7. Distribution of daily 1-hr maximal NO, concentrations for downtown Los Angeles at emission level of 1000 tonsper day of NO.

10

TOTAL He 1'41NUS ONE pp~ FOR BACKGROUND METHANE

100

MOlt (pphm)

.,,; ,-

i,lIJi,'.·'--------+ +-__ HC, 'ppmc

50 ....

ISO

'OIl '00 1000--1-200........----1-'600-- E,

l,A.. COUNTY NITROGEN OXIDES EMISSIONS (TONS!DAY)

soillu1;\

Figure 8. NO, air quality vs. NO. emission levels at three stations

Figure 9. Distribution of summer morning concentrations(7:30-9:30 average)

tions were split into winter and summer, separate analyses being carried out for each season. Figure 9 and 10 illustrate the joint morning concentration distribution andthe probability function for the summer data.

According to proportionality assumption 1, the distribution of morning concentrations could 'be calculated for anyRHC and NO.T emission levels from the distribution forfixed emission levels. By assumptions 2 and 3, the probability of an ozone standard violation remained the samefunction of morning concentrations at all emission levels.Knowledge of the morning concentration distributionfunction and the standard violation probability function

for all emission levels allowed calculation of the expectedannual number of standard violations for all emission levels according to Equation 7, Part I.

The results of this analysis are presented in Figure 11.The ozone air quality function is represented by the solid,iso-air quality curves. Along each curve (150, 100, 50, and10), the expected number of mid-day ozone standard violations in Central Los Angeles is constant. It is evidentthat an ozone air quality "hill" exists as a function ofRHC and NO x emission levels. Moving to the left in Figure 11, reducing RHC decreases ozone. Moving downward,reducing NO. first increases, then decreases, ozone.


A close examination of Figure 11 reveals that for givenpercentage reductions from the reference 1969 emissionlevels, ozone in Central Los Angeles is better controlledby RHC emission reductions than by NO.. emission reductions. However, the reader should note that the importance of RHC emissions relative to NO.. emissions inozone production may not hold for stations in the eastern,downwind portions of the Los Angeles Basin-e.g. Azusa,

Pomona, or Riverside. Decreasing the RHC/NOx reactantratio tends to delay or retard the photochemical reactions[Glasson and Tuesday (17)J. This delay effect makes RHCcontrol particularly effective for mid-day ozone in CentralLos Angeles. However, retarding the reaction may not beas effective in controlling photochemical smog later in theday at downwind stations. In any case, a decision onwhich type of emission control is most efficient in an eco-

SYMBOL

o6.D

•...•

MORNING HC (ADJUSTED FOR NAT.BACKGROUND METHANE)

0.5 ppmc

1.5 ppmc

2.7 ppmc

4.0 ppmc

6.5 ppmc

10.0 ppmc

5 10 20 35 50 60MorninQ NOx ConcenTration (pphm)

70 80 90 100

Figure 10. Probability that mid-day maximum l-hr average ozone in central Los Angeles is greater than 10 pphm (summer)

200

L----;::200~==:;40bo==~600~;~800~;::;10~OO;:::=~12~OO~==14~OO~==1=600~~E1.L.A. COUNTY RHC EMISSIONS (TONSIDAYj

>-<t

~z2'"zQ'"'"~x

0Z

-<> ~'" z

:;)

0U

<t-'

12~C'

lCC~

8eo

Figure 11. Mid-Day 0 3 and NO, air quality in central Los Angeles vs. RHC and NOx emission levels


nomic sense must wait for a comparison of the cost of reducing each primary contaminant. The cost factor will beadded in the next section.

The horizontal dashed lines in Figure 11 are iso-airquality curves for N02 , taken from Figure 8. Of course,because of the assumptions made here, N02 air quality isimproved by reducing NO, emissions. Figure 11 thus givesboth of the air quality functions in the least cost model,the expected number of days per year that 0 3 (Pl) andN02 (P2 ) exceed State standards in Central Los Angelesas functions of RHC and NO.,- emission levels.

Least Cost of Reaching Various Air Quality Levels

The minimum cost of reaching various RHC and ;'o.IOxemission levels in Los Angeles County by 1975, C = 0(E1,

E2 ), was presented in Figure 4. Ozone and nitrogen dioxide air quality levels as functions of RHC and NO x emissions, P1 = F1(E1, E2 ) and P2 = F2 (E2 ) were presented inFigure 11. This section combines these relationships tosolve the complete least cost-air quality problem as givenby Equation 8.

Since the problem is two dimensional (in emission levels), simple graphical analysis can provide the solution.For this purpose, Figures 4 and 11 have been combined inFil(ure 12. Figure 12 illustrates the solution of the modelfor the case PI° equal to 50 ozone violations per year andp20 equal to 10 nitrogen dioxide violations per year. Thepoints in emission space which satisfy both the 0 3 andN02 air quality constraints lie in the shaded rel(ion. Theminimum cost of at least attaining p10 and p20 is foundby taking that point in the shaded region that has theleast emission control cost. For this example, the optimalpoint occurs at A, (E1 = 430, E2 = 620), and the cost is$50 million per year.

By using the curves in Figure 12, the minimum cost ofreaching any air quality levels (P10, P20) can be found bysimilar graphical analysis. The results for several selectedair quality levels are presented in Table II. For the specific emission control strategies associated with each airquality level, the reader is referred to Trijonis (3).

Since it was assumed that maximal N02 concentrationswere proportional to NOx emissions and were independentof RHC emissions N02 air quality depends only on NO.•emissions; improving N02 air quality, P2, requires reductions in NOx , E2 . Ozone air quality depends on both RHCand NOx emissions and can be improved by reducing either E1 or E2. However, Figure 12 reveals that RHC control is much more cost-effective in reducinl( ozone in Central Los Angeles than is NO x control. From the 1975 starting point, RHC reductions take Central Los Angeles directly down the "ozone hill," while moderate NO,- reduc-

Table II. Minimum Cost of Reaching Various AirQuality levels

Air qualityAssociated

PzO, expected Minimum emission levelsnumber of NO~ cost.

p.lI, expected number violations per millions E" E"of OJ violations per year year of dollars RHC NO,

1975 level - 80 25 670 79080 15 1 670 69080 10 2 650 62080 5 12 630 55080 3 (lowest 80 590 460

feasible)50 25 45 430 70050 15 50 420 69050 8 60 400 60050 3 (lowest 150 380 460

feasible)25 25 120 370 76025 15 125 350 69025 8 140 320 60025 3 (lowest 220 290 460

feasible)10 (lowest 25 180 300 750

feasible)10 15 185 280 69010 8 (lowest 220 260 600

feasible)

200

1200

~-.:~ 1000Z2Z 8CO0~

~0. 600

Z

'"~

N Z=> 4000u

~-'

200

~~~~~~~~~~~~~~~El400 600 800 1000 1200 1400 1600

L.A. COUNTY RHC EMISSIONS (TONS/DAY)

Figure 12, Cost of various air quality levels


tions just slide along the contours of the "ozone hill."Fifty million dollars spent on RHC control reduces ozoneviolations from 80 to 50 days per year. Fifty million dollars spent on NO, control slightly increases violations to85 days per year. The two-dimensional photochemical airquality problem thus contains two one-dimensional subproblems: (1) the cost of 0 3 control by RHC emission reductions and (2) the cost of N02 control by NO, emissionreductions. Before taking up these two subproblems, theinterrelationshi ps and trade-offs in the two-dimensionalproblem Nill be discussed.

From Figure 12 and Table II, it is apparent that neitherN02 nor 0 3 violations can be completely eliminated withthe control methods considered in this study-N02 violations can only be reduced to about three days per year ata cost of $80M; 0 3 violations can only be reduced to abouteight days per year at a cost of $210M. A trade-off effectexists between maximal 0 3 and N02 reductions. Best possible N02 air quality, three violations per year, limitsozone to above 25 violations per year at a cost of $220M.Best possible 0 3 air quality, eight days per year, limitsN02 violations to above 10 days per year, also at a cost of$220M. Basically, this trade-off results because used carscan either be intensively NO, controlled (improving N02

air quality) or intensively RHC controlled (improving 0 3

air quality). Choosing high NO,(N02 ) control for usedcars limits possible RHC (0 3 ) control and vice versa.

Earlier, it was noted that for given RHC control, NO,control is inexpensive for initial, rather large reductions,but then becomes very expensive for further, slight reductions. This property of the cost function is illustrated bythe vertical character of the cost curves over rather largeregions in Figures 4 and 12. This effect carries over to airquality costs, so that for given 0 3 control, N02 control isfairly inexpensive for initial reductions and then becomesvery expensive. For instance, at 80 days per year 0 3 violations, N02 violations of 25, 15, 8, and 3 days per year, respectively, cost 0, 1, 3, and 80 million dollars. For given

N02 air quality, ozone control costs rise more consistently. For instance, at 15 days per year N02 violations, 80,50, 25, and 10 days per year 0 3 violations, respectively,cost 1, 50, 125, and 185 million dollars.

Figure 13 gives the cost of ozone air quality improvements by RHC emission control alone, irrespective of N02

air quality. Starting at "zero" control cost for 80 violations per year (the bas~ control level for this study), control costs rise to $21OM for eight days per year. Althoughthe curve is nonlinear (increasing slope or marginal control cost), it does not have very great curvature.

Figure 14 presents the cost of N02 air quality improvements by NO, emission control, irrespective of 0 3 airquality. Additional control costs rise from $0 to $85 million per year as violations fall from 25 to three days peryear. This control cost-air quality curve is strikingly nonlinear. Above 10 violations per year, the marginal cost ofair quality improvements is $100,000 per day of violationreduction (dollars/year + days violation/year). Below sixviolations per year, marginal costs rise to about$35,000,000 per day reduction. This effect results for tworeasons: (1) because NO, emission control costs are highlynonlinear (as shown in Figure 6) and (2) because (asshown in Figure 8) marginal air quality improvements forgiven NO., emission reductions fall when the standard isexceeded only a few days per year.

Out of all the possible air quality levels and associatedcontrol costs in Figure 12 and Table II, the air pollutionpolicymaker must choose one. This choice depends onhow ozone and nitrogen dioxide standard violations areevaluated in comparison to control dollars. Even if reducing violations has utmost priority, so that control dollarsdo not count, some value must be attached to the relativeimportance of 0 3 and N02 violations. It is not the purposeof this work to make such evaluations. The objective hereis only to delineate the basic technical relationships between costs and air quality so that some of the trade-offsin the total air pollution control problem become more

Figure 13. Cost of attaining various ozone air quality

80

70

'"Z 60

°~~

0 50

v<i:lZ

40Z

";;z

°;:: 30cc

"20

10

200

150

'"zQ

~

ov

" 100:lZZ

"<i6;:<5c

" 501975 AI~ QUALITY LEVELWITH PRESENT NEW CARCONTROL PROGRAM AND WITH1-1-71 DEGREE OF STATIONARYSOURCE CONTROL

1969 lEVel

25 50 75 100 125 150\

DAYSIY[AR MID-DAY OZONE [XCEWS STANDARD

(.10 ppm FOR 1 HOUill IN CENTRAL L.A.

1975 AIR QUALITY lEVEL

WITH PRESENT NEW CARCONTROL PROGRAM AND WITH

1-1·71 DEGREE OF STATIONARY

L-_--::.::._----::

5

':-O_U.'/_E_C..,.O:-N_T_'O_l---i:--_---i.-./LEVEl

10 20 30 40 50

DAYS/YEAR N02 STANDARD (.25 ppm FOR I HOUR) IS

EXCEEDED IN DOWNTOWN lOS ANGELES

Figure 14. Cost of attaining various nitrogen dioxide air qualitylevels in L.A. County by 1975


It is notable that even though stationary sources ofRHC have been controlled by several Los Angeles CountyAPCD regulations in the 50's and 60's, further control forthese sources is the least expensive form of RHC control.Evaporative control retrofits for used cars is by far themost expensive of the RHC controls considered here.Many NO.,· SOurces are very inexpensive to control, but,once these sources are controlled, further NO, reductionsbecome very costly. Both mobile and stationary sources ofNO, are found in both the inexpensive and expensive control categories. Comparisons to the cost-effectiveness ofthe new car strategy are given in the text.

Literature Cited

(1) Seinfeld, J. H., Kyan. C. P., Socio-EcrJn. Pion. Sci .. 5, 17390 (l97t).

(2) Kohn, Rohert E., PhD Thesis, Washington University. St.Louis, Mo., 1970.

(3) Trijonis, J. C., PhD Thesis. California Institute of Technology, Pasadena. Calif. 1972.

(4) Schuck, E. A., Pitts, .J. N., Wan, J. K. S.. Air Wofer Pollut.Int. J .. 10,689-711 (1966).

(5) Abadie, J. t "Integer and Nonlinear Programming," AmericanElsevier, New York, N.Y., 1970.

(6) Baumol, W. J., "Economic Theory and Operations Analvsis,"Prentice-Hall, Englewood Cliffs, N..J.. 1965.

(7) APCD (Air Pollution Control District of Los Angeles County)."Profile in Air Pollution Control," 1971.

(8) Haagen-Smit, Arie J.,lnd. Eng. Chern .. 44, 2086 (1953).(9) Leighton, Philip A., "Photochemistry of Air Pollution," Aca

demic Press, New York, N.Y., 1961.(10) Altshuller. A. P., Bufalini. J. J.. Environ. Sci. Techno!.. 5,

39-64 (1971). .(11) Altshuller, A. P., J. Air Polluf. Contr. A"s.. 16, 257-60

(1966).

Azusa, Pomona, and Riverside which experience the highest ozone values in the Los Angeles basin. Not only willthe ozone "hill" (as a function of RHC and NO,· emissions) be "higher" for these stations, but it also may havea somewhat different shape. A principal effect of the RHCto NO, input ratio is to delay or retard the photochemicalreactions. This effect makes RHC control particularly effecti~e for Central Los Angeles (with a usual ozone peakat mid-day); it may not be as effective for inland stations(with ozone peaks later in the afternoon). An ozone airquality function for inland stations will be considerablymore difficult to derive; it will require a more detailed examination of transport processes and/or an analysis of theeffect of RHC and NO, emissions on the time distributionof ozone concentrations.

4. Control Cost-Effectiveness. Table I presents detailed data on cost-effectiveness of control for varioussources. Here, to summarize, sources of RHC and NO.,. aregrouped i~to three categories of control cost-effectiveness:

apparent. The air pollution policymaker can use these results for a more systematic evaluation of the problem andarrive at decisions by making the appropriate evaluations.

Implications of Results

The application of the least cost-air quality model tothe Los Angeles photochemical smog example has yieldedseveral implications which are directly relevant to policyissues. Partial answers have been obtained to four basicpolicy questions:

1. What air quality levels can be achieved in CentralLos Angeles County by 1975?

2. About how much would these levels cost?3. Should control efforts be concentrated on RHC or

NO.,. emissions?4. Which sources should be controlled first according to

a cost-effectiveness criterion?In summary, the following four answers have been indi

cated:I. Possible Air Quality Levels. In 1969, expected air

quality in Central Los Angeles was 150 standard violationsper year by mid-day ozone and 55 standard violations peryear by N02 . The present new car control programs andthe degree of stationary source control existing in 1971(the base or zero control level for this study), should reduce pollution levels to 80 expected 0 3 violations and 25expected N02 violations per year in 1975. Even with allthe add-on control methods considered in this study ineffect,. neither 0 3 nor N02 violations can be eliminated.Best possible pollution levels in 1975 are three N02 violations and 25 0 3 violations per year for maximal N0 2 reduction strategy and 10 N02 violations and eight 0 3 violations per year for maximal 0 3 reduction strategy. Further reductions in 0 3 and N02 would require further controls than those considered here, such as reduced driving(by a mass transit system or by decreased driving incentives), control of NO.,· from residential sources, stricternew car control, etc.

2. Cost of Various Air Quality Levels. In 1969, with150 0 3 and 55 N02 violations per year in Central Los Angeles, total air pollution costs in Los Angeles County wereabout $25 million [Ulbrich (I8); HEW (19)J. In 1975, present control policy will yield 80 0 3 and 25 N02 violationsper year at a total annual cost in Los Angeles County of$175 million [Ulbrich (18); National Academy of Sciences(20)]. For $220 million more per year, violations could bereduced to 25 0 3 and three N02 or eight 0 3 and 10 N02

days per year (Table II). Most of this $220M, about$150M, would be for evaporative control retrofits to pre1970 used cars. Without evaporative control retrofits(which are of uncertain implementability), violationscould be reduced to about 60 0 3 and three N02 or 40 0 3

and 10 N02 days per year at an annual cost of $70M.3. RHC Control vs. NO, Control. Controlling N02 pol

lution requires reductions in NO., emissions. Ozone, onthe other hand, can be controlled by reducing either RHCor NO.,· emissions. However, the results of this study indicate that, for Central Los Angeles, RHC control is muchmore effective than NO.,. control in reducing ozone. Infact, the most efficient strategy for reducing only ozone inCentral Los Angeles might be to reduce RHC emissionswhile not reducing NO, (or even better, letting NO, increase). The optimal strategy to attain air quality goalsfor both N02 and 0 3 would be to reduce NO.,. only enoughto meet the N02 objective and then reduce RHC to meetthe 0 3 objective.

An important qualification is in order here. The aboveresults pertain to Central Los Angeles only. The ozone airquality function may be distinctly different for other locations in the basin, in particular for inland sections such as

RHC sourcesStationary sources (gas stations and

organic solvent users)Pre·1969 used car exhaust, 1971-74 fleet

cars, and aircraftPre·1969 used car evaporative emissions

NOr sourcesLarge industrial boilers and heaters

(primary control), 1966-70 used carexhaust, stationary engines

Small refinery heaters, small power plantboilers (primary control), 1971-74 fleetcars, and large power plant boilers(adva need control)

Large ind ustrial and small power plantboilers (advanced control), mediumsize industrial boilers, pre-1966 usedcars

Average costper ton

controlled

$ 240

840

2810

20

280

2500


(12) Brunelle, M. F .. Dickinson, J. E., Hamming, W..J .. "Effectivene" of Organic Solvents in Photochemical Smog Formation," APCD of the County of Los Angeles, Los Angeles, Calif..1966.

(13) Ralph, H. D., Walker. G. D., "Evaluation of Gaseous FuelsSupply for Motor Vehicle Usage in the Los Angeles Basin.PACE Co., Houston, Tex .. 1971.

(14) Korth, M. W., Rose, A. H., Stahman. R. C.. J. Air Pollut.Contr Ass., 14,168 (1964).

(15) Altshuller, A. P., Kopczynski. S. L., Lonneman, W. A.. Sulterfield, F. D.. Wilson, D. L.. Environ. Sci. Technul.. 4, 503(1970),

(16) Larsen, Ralph I.. J. Air Pollut. Contr. Ass.. 11 (2). 71-6(1961) .

(17) Glasson, W. A.. Tuesday, C. S.. Environ. Sci. Technol.. 4,37-44 (1970).

(18) Ulbrich, E. A., Socio-Econ. Pion. Sci., 1,423-40 (1970).(19) HEW (Department of Health, Education. and Welfare),

"Control Techniques for Carbon Monoxide, Nitrogen Oxide andHydrocarbon Emissions from Mobile Source," Washington,D.C., 1970.

(20) National Academy of Sciences. "Semiannual Report by theCommittee on Motor Vehicle Emissions," Washington, D.C.,1972. .

Received forreL'iew October 17,1972. Accepted Apri/24. 1974.

Problems with Flame Ionization Detectors in Automotive ExhaustHydrocarbon Measurements

Keith Schofield 1

Delco Electronics-Santa Barbara Operations, Calif. 93017

• Three of the major problems encountered in measuringconcentration and mass emissions of hydrocarbons fromengines using name ionization detectors (FID's) have beenstudied in detail. The magnitude of possible correlationdiscrepancies for analyses run on various commercial instruments as a function of operating conditions and exhaust type has been estimated from measured relativemolar response values. Large variations are found undercertain circumstances. Results also imply that the largeranalyses values occasionally observed with heated analyzers may result from increased relative molar responses tothe various individual hydrocarbons rather than decreasedline absorption effects. The magnitude of the oxygen interference effect (synergism), important for real-time automotive testing, has been measured on various FlO's atdifferent conditions. A simple modification to minimizethe effect is recom mended for the majority of analyzersthat exhibit this feature. Finally, an extensive study of instrument response times has been completed for a varietyof sampling lines. The relative importance of such factorsas the analyzer operating temperature, sample line temperature, instrument sample pressure, bypass now rate,sample line length, diameter, and material has been established. Optimum response was realized with a heatedFID using heated 'I.-in. o.d. stainless steel or Tenon linesand a high bypass sample now rate.

The name ionization detector (FID) now is generallyaccepted as being the best analyzer for integrating thetotal carbon content of a mixture of hydrocarbons. The instrument's ability to respond in an approximately uniformmanner to saturated, unsaturated or aromatic carbonatoms in a variety of organic structures has provided ameans for realistically monitoring the total concentrationor mass emission of unburned hydrocarbons from combustion engines. Little changed since its introduction about15 years ago. name ionization detectors currently areavailable in a variety of about 15 commercial total hydrocarbon analyzers. Of these, five are high-temperature

1 Present address. Chern Data Research, 2800 Williams Way.Santa Barbara. Calif. 93105


models for use where high molecular weight, high boilingpoint hydrocarbons may be encountered. Their analyzertrain, the sample line, pump, filter, valving and burnerassembly are all heated to temperatures up to about400'F. Although all these units are basically very similarand involve measuring the extent of the chemi-ionizationproduced when a hydrocarbon sample is injected into asmall hydrogen diffusion l1ame, certain concerns havebeen expressed that different models may not correlateexactly when measuring the complex mixture of hydrocarbons emitted from gasoline or diesel engines. This concernis quite understandable since differences in l1ame composition. burner and electrode design, and a lack of specificrecommended operating parameters provide many variations which could conceivably affect the relative responsesto the different hydrocarbons and so alter the resulting integral measure. In a period when the magnitude of exhaust analyses are of prime importance to various concerned groups, a lack of instrument correlation is of particular interest. Consequently some effort has been directed toward establishing the extent of such variation andconveying how closely the integral measure approximatesthe true exhaust hydrocarbon content.

As the need for accurate real time and integral concentration and mass measurements of vehicular emissions hasdeveloped, several operational problems have become evident. One concerns the different FlO response observedfor the same hydrocarbon sample in either air or an inertbackground gas. Since raw exhaust is neither one nor theother, the analyst is confronted with the dilemma of howto calibrate the instrument. Another centers upon the response time of the sampling system and analyzer. Sincethe monitoring instrumentation must be somewhat removed from the vicinity of the automobile dynamometertest area, it is important that source concentrationchanges be not degraded by the sampling system. Suchproblems form the basis lor this paper and will be considered individually in detail.

It is surprising for an instrument that performs so well,combining the desired features of linear response, highsensitivity, good stability, and an insensitivity to minorchanges in operating parameters, that our basic understanding of the l1ame processes is still quite poor (1).

Suitability of FID for Vehicular Exhaust Analyses

It may be appropriate initially to illustrate why the FIDbecame so widely accepted as the total hydrocarbon analyzer for automotive applications. With this detector thehydrocarbon concentration of a vehicular exhaust generally is expressed in terms of the equivalent concentration ofpropane. It is quoted in t,erms of parts per million carbonequivalent (i.e., propane equivalent x3). The implicit assumption is that all exhaust hydrocarbons have equal FIDresponses per unit carbon, equal in fact to that of the carbon atom in propane. This not being strictly the case, themeasured concentration will only approximate the truehydrocarbon cencentration.

To illustrate the extent of possible dive~gencies and theability of the instrument to sum such complex mixturesrealistically, consider the case of the two different typehydrocarbon emissions illustrated in Table I. These represent gas chromatographic analyses of hydrocarbon emissions from reciprocating and rotary type engines. The former contains hydrocarbons resulting mainly from incomplete combustion, whereas the latter is more representative of the gasoline fuel. The hydrocarbons present only intrace amounts have been summed together at the bottomof the table and listed as "Other Paraffins," and so forth.The number of contributing species to each such sum isshown in parentheses. Sternberg et al. (2) were instrumental from the start in establishing tables of the effective instrument relative sensitivities to various hydrocarbon types. Their values have changed little and relativeto methane taken as 1.0, the unit carbon responses forhydrocarbons are generally considered as aliphatic

Table I. Representative Volume Compositions ofHydrocarbon Component of VehicularEmissions (4)

Recipr~cating Rotaryengine. engine,

% %Methane 24.27 4.88Acetylene 17.51 3.30Ethylene 14.12 8.09Propylene 7.34 5.34Toluene 5.97 16.34I·Butene,l,3-butadiene 4.07 2.99Benzene 2.15 1.31Ethane 1. 97 1. 323 Ethyl pentane, 2,2,4.trimethyl

pentane 1.81 2.89Isopentane 1. 73 8.64"·Butane, 2,2-dimethyl propane 1. 59 4.512,3· and 3,3·Dimethyl hexane, 2,3,3-

and 2,3A-trimethyl pentane 1. 54 2.73p,rn-Xylene 1.30 5.57Propadiene 1.00 0.95a-Xylene, phenyl ethylene 0.76 2_67cis-l-Phenyl·l-propene, ,-butyl

benzene, 1,2A-trimethyl benzene 0.76 2.452,3-Dimethyl pentane, 2-methyl

hexane 0.64 2.862-Methyl pentane 0.55 1.36I-Methyl 3- or 4-ethyl benzene 0.52 2.31Ethyl benzene 0.51 1.67cis·2· Butene 0.51 0.25I-Methyl-2-ethyl benzene, 2-

phenyl-I-propene 0.45 1.072A-Dimethyl pentane, 2,2,3-

t"methyl butane 0.38 1. 32Other paraffins 4_07 (26) 6.26(29)Other aromatics 1.11 (20) 3.78(20)Other olelins 3.37 (62) 5.11(76)

0.94, olefinic 0.90, aromatic 0.89, and acetylenic 1.30.These approximate values will be used initially in thispreliminary illustration. Their variations with operatingconditions will be described in detail later. When we integrate over the spectrum of exhaust hydrocarbons listed inTable I, it can be concluded that for these mixtures anFID calibrated with propane will record a parts per :nillion carbon equivalent that is about 1.7% higher than thetrue value for the reciprocating engine and about 2_8%lower for the rotary engine case.

By means of a dynamometer and a constant volumesampler, concentration measurements can be convertedinto hydrocarbon mass emissions per vehicular mile. However, in so doing, an additional assumption invoked isthat a mean density (16.33 gJft3 per carbon atom at 68'Fand 1 atm pressure) may be taken for the hydrocarbonmixture. The mean density of the two exhausts consideredabove can readily be calculated from the data in Table Iand are 16.33 and 16.15, respectively. Consequently, massmeasurements in these cases would be 1.7% too high and1.7% too low, respectively_ This illustrates how remarkably well suited the FID is for realistically integrating theconcentration and mass of the complex hydrocarbon mixture emitted from internal combustion engines. True variations may be slightly more or less than these figures, dependent upon the actual relative molar responses for theparticular instrument used. However, analyses are not expected to be seriously in error at present. This resultsfrom the larger relative response to acetylene being counterbalanced by the lower responses of olefinic and aromatic hydrocarbons. Nevertheless, with the advent of catalytic converters and emission controls, which profoundlysimplify the nature of the hydrocarbons present in the exhaust, this may not continue to be strictly the case.

Measured Relative Molar Responses

To better illustrate the extent of possible intermodelvariations with various type exhausts, the relative carbonsensitivities have been measured for several hydrocarbonson three FlO models operating at a variety of conditions.The individual hydrocarbons investigated were methane(CH.), ethylene (C2 H.), acetylene (C2 H2 ), tuluene(C7 Hg ), and propane (C3 Hg ). With the exception of propane, used solely as a reference species, these constitutethe single most important group of organic compoundsemitted from vehicles and together can represent typicallyfrom 30-90% by volume of the total, depending on the engine type and emission control features. The analyzersavailable to this program were manufactured by BeckmanInstruments, Inc., and consist of a Model 402 (analyzertrain heated in the range 200-400'Fl, a Model 400 (thermostatically controlled at 120'Fl, and a Model 108A (ambient temperature operation). Although from the samemanufacturer, these are quite differently designed instruments, varying in burner and electrode design, and operating temperatures. They should typify generally availablecommercial instruments. More recent work appears toconfirm this conclusion (3). The Model 400 was operatedin both its normal and a modified mode. The latter, to bedescribed in more detail. consisted of a modification tominimize the response difference generally noted betweenequivalent samples of the hydrocarbon in either air or aninert background gas. Individual gas cylinders of 2000ppm by volume of methane (CH.), 980 ppm ethylene(C2 H.), 900 ppm acetylene (C2 H2 ), 310 ppm toluene(C7 Hg ), and 500 ppm propane (C3 Hg ), all in air were obtained as primary gas standards. Their relative responseswere measured on the three analyzers. The heated modelwas operated at either 200' or 400'F and all models


Table II. Flame Ionization Detector Molar Responses for SeveralModel 402" Model 400

196°F 391°F Normal

HjN, HjHe HjN, H,/He HjN,C H~/Hed

---- ----- -----Hyd roca rbon 5' 3 5 3 5 3 5 3 5 3 5 3

Methane, CH. 1.096 1.057 1.051 0.996 1.055 1.004 0.994 0.949 1.169 1.072 1.063 0.999Ethylene, C,H. 1.781 1. 903 1.963 2.031 1. 987 2.037 2.056 2.058 1.718 1.837 1.915 1.994Acetylene, C,H, 2.852 2.788 2.801 2.677 3.156 3.022 2.938 2.974 2.954 2.623 2.690 2.532Toluene, C,H, 6.339 6.382 6.940 6.899 6.865 6.935 7.395 7.403 6.398 6.386 6.909 6.921Propane, C;IHs 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000

n Fuel 30 psi, Air 20 psi. I, Fuel 30 psi, Air 30 psi. (' Fuel 30 psi, Air 13 psi (Normal), 10 psi (Modified). d Fuel 30 psi, Air 16 psi (Normal), 14 psi (Modified).

burned 40% hydrogen/60%nitrogen or 40% hydrogen/60%helium standard FID mixed fuels. Fuel/air flows were typically of the order of about 100 and 250-400 cm3 min-I,respectively. Sample addition rates were either at theirmaximum setting, 5 psi gauge pressure, which corresponds to a flow of about 18 cm3 min-lor at 3 psi (10 cm3

min-I). The instruments fuel/air settings were those forwhich a maximum signal could be produced. This criteri'on for locating the optimum flow rates produces an instrument with maximum response and has been shown to beleast sensitive to slight instabilities in the fuel or air flowsat such settings. The measured responses to the five hydrocarbons, suitably corrected so that each refers to thesame molar concentration of hydrocarbon are listed inTable II for the various cases considered. The values represent, relative to propane taken as three, the effectivenumber of carbon atoms in the hydrocarbons structure asmonitored by the FID. The values of these effective carbon number/molecule fall in the generally accepted range;that is, methane (1.1), ethylene (1.9), acetylene (2.8), toluene (6.6), relative to propane (3.0) but are seen to varyextensively between instruments and for different conditions. None of the data was degraded by instrumentalnonlinearity problems.

The accuracy with which the cylinder concentrations

are known only affects the results insofar as their absolutemolar response scale. Any such error would affect all thedata for a particular hydrocarbon by the same factor.Since it has already been noted that the effective molarresponses do fall within the usual prescribed ranges, thecylinder concentrations appear to be sufficiently accuratefor this program. The range of variations for a specific hydrocarbon, which is of prime interest here, will be unaffected by such considerations. The spread of the data inTable II is extensive and shows a maximum scatter invalues of 25% for methane, 21% for ethylene, 24% for acetylene, and 17% for toluene between the highest and lowestrecorded sensitivities for each. General trends can be observed which may be important in explaining quantitativecorrelation differences that have been observed in exhaustanalyses. For example, whereas the heated Model 402 operating at 400°F has the largest responses of all to ethylene, acetylene, and toluene, it is the least sensitive tomethane. At 200°F it responds not too differently from theModel 400. On hydrogen-nitrogen mixed fuel, the relativeresponses of methane and acetylene are higher than onhydrogen-helium fuel. However, the opposite is the casefor ethylene and toluene. Reduction of the sample flowrate decreases the relative responses to methane and acetylene but increases that of the ethylene. Such interestingfeatures can be invoked in explaining exhaust analysescorrelation differences.

Methane 10.7 4.9 64.2 47.1Ethylene 22.3 8.1 24.4 22.6Acetylene 14.5 3.3 0.9 8.1Toluene 7.0 16.3 1.9 2.0% Representation of total

hydrocarbon emission 54.5 32.6 91.4 79.8

Extent of Exhaust Analysis Variations

Gas chromatographic analyses of the hydrocarbon components in a multitude of automobile exhausts for a variety of test cycles have been performed by Jackson (4).

These illustrate the particular predominance of methane,ethylene. acetylene, and toluene. Their relative importancein four representative exhausts, chosen because of the diverse nature of their compositions is illustrated in TableIII. Together, the four components constitute from 32-91%by volume of the total hydrocarbons emitted. Consideringsolely this part of the total hydrocarbon exhaust, it is possible, utilizing the measured relative molar responses of

EPAcycles

1-18EPA

cycles3-10

Prototype engineWankelengine

EPA1st cycleHyd roca rbon

Table III. Selected Hydrocarbon Exhaust Compositions-Percentage by Volume of the TotalHydrocarbon Emission

350 CID V8engine

EPAcycles13-18

Table IV. Calculated Variability of Analyses for Various MixturesModel 402 Model 400

---------------196°F 391°F Normal

H,/N, HjHe HjN, H,/He HjN, HjHe---- ---- - ----

Exhaust type mixtures 5/, 3 5 3 5 3 5 3 5 3 5 3350 CID V8 engine 97.1 98.3 102.1 101.3 105.8 105.1 106.8 106.9 98.0 95.7 100.1 99.3Wankel engine 95.1 96.0 102.9 102.3 103.0 103.6 108.9 108.9 95.9 95.3 102.0 102.0Prototype, cycles 3-10 98.9 99.3 101.0 99.4 101.8 100.2 10D.? 98.5 101.5 98.7 100.5 98.7Prototype, cycles 1-18 99.0 99.3 101.1 99.4 103.8 102.1 102.2 100.8 101.2 97.7 99.9 98.0

If Scaled to a mean value of 100 ppm propane equivalent for each mixture. II Sample operating pressure, psi.


Modified Model l08Ah

Hydrocarbons Measured Relative to PropaneModel 400 (contd.)

5 3

1.216 1.1341.660 1. 7693.161 2.7586.437 6.3683.000 3.000

5 3

1.111 1. 0511. 839 1. 9242.893 2.6316.922 6.8663.000 3.000

5 3

1.143 1. 0541. 724 1. 8512.810 2.5786.231 6.2833.000 3.000

HdHe

5 3

1.039 0.9951. 930 1. 9892.518 2.4886.777 6.8293.000 3.000

11

I 19

.."

/if

i 17

II

"Sample operating pressure, psi. 15

5psi· 3p~i 5p~i 3psi

fuel lHtN21 Fuel lHIHel

Operating Mode

of Methane, Ethylene, Acetylene, and Toluene"Model 400 (contd.)

Table II to calculate the expected variability of analysesof mixtures of CH4 , CZH 4 , CzHz, and C7Hg formulated inthe proportions typifying such exhaust types. The resultsfor such hypothetical analyses are listed in Table IV. Forconvenience they have been scaled in each case to a meanvalue of 100 ppm propane equivalent to better illustratethe range of variation. It is seen, for example, that for oneof the mixtures representing a prototype engine exhaust,91.4% of the total hydrocarbons are in the form of CH4 ,

CZH4 , CzHz, and C7 Hg . Analysis of such a mixture in thesame proportions would produce values on this set of instruments differing at the most by 5%, dependent on theFID and mode of operation. Since the four hydrocarbonsrepresent just about the entire hydrocarbon emission inthis particular example, this total variation would be expected for the actual exhaust analyses. For the othermixtures, calculated variation are larger, 12.1% for the350 CID (in.3 displacement) V8 engine, 15.4% for theWankel, and 7.0% for the second set of prototype enginedata. The particular extent of the scatter is controlled bythe relative contributions of each hydrocarbon and the indivdual variations of the response sensitivity. For example, the 15.4% figure noted for the Wankel engine renectsalmost entirely the variation of the response to toluene.The 12.1% scatter for the 350 CID V8 mixture arises fromalmost equal contributions from CZH 4 , CzHz, and C7Hg ,

with a negligible contribution from CH4 , whereas for theprototype mixtures CH4 and CZH 4 , contributions are predominant. For these cases where the four hydrocarbonsconstitute only a fraction of the hydrocarbon emission, itis not possible to assess without additional data whetherthe variation for the total hydrocarbon exhaust analyseswill change to quite the same extent. The variation of therelative sensitivities of the additional species may modifythis to a greater or lesser extent. Actual exhaust analyses,however, confirm that such possible modification appearsslight. For example. diluted exhaust samples from a 350CID V8 engine were collected in a Tedlar bag and analyzedon several occasions with all the instruments under theirvarious possible operating modes. The data showed iden-

Modified Model108A

Figure 1. Analysis of a diluted exhaust sample taken from a 350CID V8 engine on a variety of analyzers under different operatingmodes

tical trends and one such set of values has been plotted inFigure 1. A line representing the magnitude of a 2%change on the same scale illustrates the extensive spread.The difference between minimum and maximum values isof a 14% magnitude. However, when scaled to the data ofTable IV, the distribution can be superimposed almostexactly on that representing a 350 CID V8 type mixture ofonly the four basic hydrocarbons, agreement being to better than about 2%.

The analyses (Figure 1) confirm that substantially higher values are obtained in this instance with the heatedFill. Also, values are seen to be larger in general when theinstruments operate on the hydrogen-helium fuel. Va, iations for a particular instrument as a function of operatingmode are much smaller and are typically ± ~3%.

It appears safe to conclude that although the FID does acreditable job in integrating the carbon content of an exhaust mixture and is undoubtedly accurate to within 10%,large variations between commercial instruments are possible under certain circumstances. These will tend to beless with exhaust emissions rich in the light hydrocarboncomponents and more pronounced for example with rotaryengines not fitted with control features to reduce the contribution from toluene. The results also illustrate that it isquite possible that the higher analysis values generallynoted with heated FID's may not result altogether fromreduced absorption/condensation of high-molecularweight-boiling point hydrocarbons but be a consequenceof larger relative molar sensitivities.

ResponseDifferences Betlceen Samples of SameConcentration in Nitrogen and in Air-Oxygen Interference

Flame ionization detectors invariably burn a diffusionname of hydrogen fuel on a small diameter jet in a surrounding now of air. The sample generally is added to thefuel now just prior to combustion. It has long been realized (2) that the background gas of otherwise similar sampies can affect the resulting name response. The termsoxygen effect, synergism, or interference have been usedinterchangeably to describe this. The extent of the interference depends on various factors including the particular analyzer model and its operating parameters, theburner and electrocie design, the fuel type, the organicspecies, and the oxygen content of the sample. Given thesame concentration of propane in nitrogen or in air, thelatter will produce a lower name ionization. However, dependent upon their nature, some hydrocarbons can showan enhanced response. This effect is particularly important in cases where it is not possible to use calibration

HdHe

5 3

97.8 98.3100.1 100.899.3 98.398.1 97.4

5 3

95.6 94.893.5 94.0

100.0 97.999.2 96.8

5 3

101.4 99.4102.4 101.4101. 6 100.0101.7 99.2

5 3

99.8 96.496.7 95.3

102.9 100.6103.3 99.6


\00 ,-------,----~--___r---.__--~--_____,

Hydrogen! Hydrogen!nitrogen fuel, helium fuel,

sample sample .Burner pressu re, psi pressu re, pSI

chamberAnalyzer temp, OF 5 2 5 2

Model 402 398 13.3 9.3 2.0 2.8203 14.5 10.4 5.3 3.7165 13.5 10.0 5.8 4.4

ModeJ 400 120 17.2 14.4 8.5 6.2Model108A Ambient 14.5 10.4 6.2 5.8Modified

Model 400 120 9.2 8.1 0.3 2.3.a Differences expressed as percentages: % effect = I(signalrr/x~-

slgnah'r/.\;r)!mean signal) X 100.

Figure 3. Schematic of burner flow configuration (a) in typicalflame ionization detector (b) modified as recommended for min·imizing the sample oxygen interference

Table V. Response Differences Between Samples ofSame Propane Concentration in Nitrogen andin Air"

stalled on the Beckman Model 400. However, the conceptshould apply equally to all FID's and provide a means ofminimizing the sample oxygen interference effect. If atrace of air can be continually added to the fuel and sample mixture just prior to combustion, little differenceshould be observed between a similar sample of hydrocarbon in air or in nitroge'l. Moreover, such a small additionas suggested should not otherwise change to any markedextent the nature of the burner flame or modify the general performance of the instrument. The plumbing of mostFID's is readily adaptable for such a modification whichinvolves tapping the high pressure part of the air line andbleeding the required trace of air through a flow restrictorinto the fuel line. This is illustrated in Figures 3a and 3b.In this way the burner air, fuel, and sample flow rates remain unchanged.

No safety hazards are introduced with this new arrangement since the porous metal plug flow restrictors in eachline prevent mixing of fuel and air upstream in the highpressure sections. Initially, calibrated amounts of air werebled into the fuel-sample line and the magnitude of theoxygen effect was measured as a function of this for propane samples. Small additions produced marked reductions and a minimum interference was obtained with aflow rate of about 7 cm3 min-'. Larger flows rates increased the magnitude of the effect again. Similar behavior was noted at any sample flow rate (2-5 psi setting).Fitted with a restrictor through which the flow was 6.9cm3 min-' for an air pressure of 15 psi, the oxygen effectwas reduced to those values quoted at the bottom ofTable V. The hydrogen-helium data, which are of prime in-

.'"371

.\I ... llfk~l

~,

300125Propane (ppm)

1'"

-11<·,'~,.",nM,.k·IIOO

- - - - Iko'k,,,.,,, ~l•• k·l IO~

l1,.dr"l:''11_lIdlum f ..dS,mvl" I""o""n' ~ I.~I

10

III

Figure 2. Response differences between samples of propane innitrogen and propane in air

gases having an identical gas medium to that of the sample. Such is the case for real-time analyses of undilutedautomotive exhausts in which a variable oxygen contentexists. For these it is necessary to minimize this interference to an acceptable level.

The extent of the oxygen synergism has been measuredfor propane on the Beckman Model 402, and Models 400and 108A with both hydrogen-nitrogen and hydrogen-helium mixed fuels at various sample pressures and analyzertemperatures. Instrument operational settings, as mentioned before, always were those which would give an optimum response to an organic sample. Four cylinders ofpropane in nitrogen (50.5, 100, 214, and 410 ppm) and fourpropane in air (49.6, 96.3, 194, and 357 ppm) formed thebasis for the data. The extent of the effect is illustratedfor various cases in Figure 2, and its magnitude, expressedas a percentage effect, is listed in Table V for a variety ofconditions. Since the instrument response is linear inthese concentration ranges and refers to a common zero,the effect expressed in this way is independent of hydrocarbon concentration. The interference is significant inmost cases and is particularly pronounced when the instruments are operated on hydrogen-nitrogen fuel. Withthe exception of the heated FID operating with its analyzer train maintained at its maximum temperature of400°F, the effect is still quite large even on hydrogen-helium fuel which is generally recommended for minimizingthe interference. Sample pressure effects are rather unpredictable. It might have been reasonable to expect thatsince a 5-2 psi change in sample pressure decreases thesample flow rate and, consequently, sample air by about afactor of three, that a much lower oxygen synergism wouldresult. Although reduced effects are noted in most cases,the decrease is by less than a half; in fact, occasionally,an increase is observed.

Typically, in these instruments, about 125 cm3 min-'of 40% hydrogen-60% helium fuel burns in a flow of about400 cm3 min-' of air. Sample flow at 5 psi is about 20cm3 min-I This means that 4 cm 3 min-' of oxygen arebeing premixed (1.4 cm3 min-' at 2 psi) with about 50cm3 min -, of hydrogen; 25 cm3 min -, would be requiredfor a complete stoichiometric premixture. A trace additionof as low as 1.4 cm3 min" of oxygen, that is about 1% ofthe gas flow through the burner tip, can under certainconditions produce these large differences observed. Consequently, the results of Table V illustrate that as long assome minimum trace of oxygen is present in the sample,almost the full extent of the interference is realized. Thisobservation formed the basis for the development andcharacterization of a modification which was initially in-


terest, show significant improvement being reduced almost to zero.

The absolute accuracy of the data presented in Table Vdepends on the accuracy of the eight calibration cylindersused in the investigation. From previous studies, the concentrations of the four propane-air and the four propanenitrogen cylinders are known to be internally consistent tobetter than 1% in each set. However, the accuracy of thetwo sets relative to each other is more difficult to assess.They were originally manufactured to an accuracy of±2%, but experience has shown the necessity for confirmation. The fact that a minimum value of 0.3% wasachieved with the modification in this program, thesmallest effect yet recorded on any instrument, tends tosuggest that this magnitude may be the maximum extentof the error in the values of Table V due to cylinder concentration uncertainties.

These data of course only concern the oxygen synergismfor propane. Automobile exhaust contains a multitude ofhydrocarbons and, in fact, very little propane, so that theappropriateness of the measurements to a problem associated with raw exhaust analyses requires justification.Johnston (5) has measured the oxygen synergism on theModel 400 for various hydrocarbons as a function of thepercentage oxygen in the sample. His data for hydrogenhelium fuel show that generally the effect decreases withpercentage oxygen. Hydrocarbons such as ethane, hexane,and 1.3 butadiene behave similarly to propane, but ethylene, propylene, and benzene produce a slightly higher effect. Methane, butane, and butene-l curiously show anegative effect, and, for these samples in air, produce alarger response than in nitrogen. It is probably safe toconclude that in minimizing the effect for propane, we arealso minimizing the problem for a complex hydrocarbonmixture. The effect will introduce at the most, an error ofa few percent on the Model 402 operating on hydrogenhelium at 400°F, and this error will decrease with oxygencontent of the sample. This should be quite acceptable forany type of exhaust analyses work. Unheated FlO's require modification before they can be used in situationswhere the sample oxygen content is variable.

A reexamination of the FID performance with and without this modification fully confirmed its acceptability. Nochange occurred in the instrument response linearity. Relative molar sensitivities discussed previously and illustrated in Table II for both the normal and modified Model400 show values for toluene unchanged within experimental error. The modification increases the relative responseto methane and acetylene, effective carbon atom numbersbeing increased by the order of 5% and 6%, respectively,

Table VI. Sampling Lines

whereas the sensitivity to ethylene is decreased on the average by 4%. However, such differences between the twosets of data are not particularly significant when it is realized that larger variations have been noted on the samemodel by solely changing the sample pressure from 5 to 3psi. The predicted variability of analyses for gas mixturesof CH., C2H., C2H2, and C7Hs in air, formulated to typify various exhaust types, also have been illustrated inTable IV. Dependent upon the type of mixture analyzed,the results show that the modified instrument will produce either the same analysis value or one slightly higher,by up to 2%. When viewed relative to the much largervariations that occur with fuel type or sample pressuresetting, it is reasonable to conclude that no important differences are to be expected between normal and modifiedinstruments. This was finally confirmed by actual exhaustanalyses, illustrated in Figure 1. Consequently, this lowcost simple modification appears to affect negligibly theFill performance in all respects with the one exception oflargely eliminating the sample air interference.

Before concluding this discussion it would be appropriate to summarize the current explanations of the observedeffects. However, the mechanism of the oxygen interferencestill is not understood (I). It appears to arise from a partial oxidizing and/or thermal cracking of the hydrocarbons in the sample as they pass through the preheatedflame zone immediately prior to combustion. Any modification of the sample's organic structure in this way willaffect its flame response. It is well known that a heliumbased fuel drastically reduces the magnitude of the oxygen interference but whether this is due to the higher diffusivity of helium producing a more diffuse reaction zoneor otherwise modifying the flame shape, a higher thermalconductivity more rapidly equilibrating the liberated energy and producing a higher flame temperature whichpossibly enhances these precombustion features is no better characterized now than when initially studied and discussed by Sternberg et al. (2).

Sampling Automotive Exhausts

For accurate analyses and particularly for measurements aimed at following the real-time fluctations of avariable concentration source, it is important that neitherthe sampling lines nor the instrument perturb the totalhydrocarbon concentration. It is necessary for all of theconstitutents of the sample to be transmitted in phasethrough the system. A retention of higher-molecularweight hydrocarbons over lighter species will distort tovarious degrees the real-time fluctuations. Inert samplinglines are required, with flow rates enabling reasonablyshort transit time. Previous studies with diesel and aircraft engine emissions (6, 7), although far from exhaustive,have established that stainless steel and Teflon are thepreferred line materials. Teflon lines, usually purchasedwith a flexible braided stainless steel protective cover,have a great advantage of flexibility and also can be heated to 450°F. Stainless steel necessitates a more rigid sampling arrangement. A systematic program to assess theperformance of a variety of lines, listed in Table VI, hasbeen completed. Teflon and stainless steel lines and connecting fitments had heating tapes attached and werethen wrapped with asbestos cloth. They were tested whenheated to about 350-4oo°F and when cold. Polyethylenelines can only be used at ambient temperatures.

A delay or "hangup" of the instrument response to asample may originate internally or externally to the analyzer. It may depend on the FlO internal chamber temperature, on the sample line temperature, on the samplepressure, or on the sample bypass flow rate. It may be a

3.358.380.942.36

1.18

1.442.893.613.041.18

Linetransittime,'~

secLine type

Stainless steel, Type 304

a.d.,in.

0.30

0.3750.25

0.25

I.d.,in.

0.19

0.300.19

0.21

10

Stainless steel, Type 304Teflon heated line, Beck·

manTeflon, braided cover,

Aeroquip 280710 0.32 0.43 Teflon, braided cover,25 Aeroquip 280710 0.17 0.25 Polyethylene, Imperial25 Eastman, Polyflo 44-P·1/4

a Quoted for a flow rate of 6 standard ft3jhr.

length,It

1020251010


function of the sample line length, line diameter, or linematerial and certainly depends on the composition of theexhaust. The higher-molecular-weight, higher boilingpoint hydrocarbons are responsible for the observed effects, and exhausts rich in these hydrocarbons are moredemanding of the sampling technique. To provide a reasonably constant composition test mixture, diluted automobile exhaust bags with a concentration of about 25-35ppm propane equivalent were collected from the same vehicle throughout. Sample bags of toluene, C7Hs, in air,with concentrations of about 100 ppm propane equivalentalso have been used for comparison. These were obtainedby diluting with zero air a gas cylinder of higher concentration.

No standard procedures for measuring sample line hangup are available. I have chosen to use the criterion ofpassing the sample down a line previously purged to a lowhydrocarbon level with zero air for 5 min. The time forthe instrument response to attain 95% and 98% of thefinal steady reading from the time of the initial rise isthen taken as a measure of the retentive nature or inertquality of the line surface material to hydrocarbonmixtures. Compatibility of the connecting fixtures and theline diameters was maintained in all cases. Each line wastested either heated or cold with two sample bypass flowrates. The Model 402 was operated with internal chambertemperatures of either 200° or 400°F. Sample pressureswere set at either 3 or 5 psi which varies the flow rate tothe flame through the sample capillary by about a factorof two.

The test procedure involved purging the whole samplingtrain for five minutes with zero air, then connecting it tothe exhaust-filled sample bag. A trace of the instrumentresponse then was monitored for either 1 or 2 min ata recorder speed of 5 or 10 sec to an inch of paper, respectively, dependent upon the response character. At theend of this period a selection valve was quickly turned topermit zero air to flush out the instrument section from

1),.•", ....1\.·'Ur1O'<IlO "~D ~ •

the valve to the flame. Several of these traces are illustrated in Figure 4. If the final equilibrated signal levelhad not been attained in this test cycle, it was then established by flowing the sample for a longer period. Timesfrom the initial rise point to 95% and 98% of the finalreading have been read off such traces and are listed inTable VII. These times are a measure of the hangup inthe total sample trai~ from the bag to the FID burnerflame. Data for the times to attain the 98% final signallevel are a more sensitive measure of the line performancethan the 95% data in some cases. The signal decay at theend of each trace represents the time necessary to flushsolely the interior of the instrument, and times for a 98%signal decrease also have been reported. These representthe internal component of the hangup. Actual line transittimes are quoted in Table VI for a bypass flow rate of 6scfh (standard cubic feet/hour). Data for the dilute exhaust and for the toluene in air samples were in excellentagreement under similar conditions. Therefore, it appearsreasonable to expect that generalizations and recommendations resulting from the analysis of this data do havebroad implications for any mode of vehicular analysis operation.

It is necessary to establish from the data the relativeimportance of seven factors: FlO internal chamber temperature, sample line temperature, instrument samplepressure, bypass flow rate, sample line length, diameter,and material. An answer to the question of whether hangup occurs within the instrument, particularly in thesample capillary, or in the connecting sampling lines is ofconsiderable interest. An analysis of the information inTable VII leads to certain generalities. Occasionally, inconsistencies in the data may be noted, but on the whole,the following five facts appear to be valid:

The heated FlO showed a minimal internal hanguptime. For all conditions tested, on turning the oven chamber valve from an exhaust sample to a zero air sample, thesignal fell by 98% in I-Ph sec. This implies negligible

---='l - 'Il"'ln,lllt4ldIn'l- - ~.

r

~1'1.'"'.11 .1«lf14O?OwnCh."ilJIortOOOI!0'11llfllld110(t,i~I....~ Sll'rl. ~• ..,pl, 1"f\\UH ~ pI;

flo<. ~ SOli'pilon: ~.mplt P'fH'Hf I ~I

flol\ I ~flH

O,I"'l'l'If.~....\l !>1"OI, I~PD" ""OCWnf £qui.... lml

__ TIME

Figure 4. Time-resolved instrument response to diluted exhaust sample passed through zero air purged sampling lines for typicalheated commercial flame ionization detector


sample capillary or other internal hangup effects, andconsequently the response time will be independent of theinstrument sample pressure setting. For the lower temperature Model 400, sample hangup occurs both within theinstrument and the sampling lines. Internal hangup, assessed from the time for a 98% signal decay, has a minimum value of about 8 sec for a high sample pressure andbypass flow rate.

Instrument response times are at their lowest for highbypass flow rates. On the Model 400 this appears to bemore important than the slight improvement realized internally from a high sample pressure (increased capillaryflow rate).

Stainless steel appears to perform equally well whethercold or heated with these samples. Teflon performance isimproved at high temperatures and becomes comparableto that of stainless steel. Severe hangup occurs in polyethylene lines. This material should not be used in emissionstest facilities. The data show a slight preference for usingstainless steel. Aviation testing by Wagner (7) reported favoring Teflon ..

Based on the data for the 10- and 25-ft, ~3fs-in. o.d.Teflon and the 10- and 20-ft. 'I.-in. o.d. stainless steellines, with the exception of cold Teflon lines, only a slightdependence on line length is noted. The cold Teflon linesshow a marked line length dependence. Previous aviationemissions measurements similarly concluded that instrument response is insensitive to the length of a stainlesssteel line (7).

The smaller l/.-in. o.d. lines appear better. Although the25-ft, 'I.-in. o.d. and the lO-ft, 3k-in. o.d. stainless steellines have similar sample transit times, the 'I.-in. o.d.

lines show better performance. One-quarter-inch o.d. Teflon and stainless steel lines perform similarly if heated.Stainless steel is the better material if the lines are cold.For the %-in. lines, Teflon appears slightly better thanstainless steel.

In summary the best response performance (l to 2 sec)is realized with a heated FID using heated l/.-in. o.d.stainless steel or Teflon lines. Bypass flow rate should beas high as is practicable.

Low-temperature models appear unsuitable for analyzing rapidly varying hydrocarbon concentrations, optimumresponse times being of the order of 5 sec (95% rise time)for the Model 400. To estimate to what extent the samplecapillary hangLip effects contribute to this long responsetime, this instrument was modified by installing a largerdiameter sample capillary tube. When the instrument wasoperated at 1.6 psi sample pressure, the flow rate of 17.6cm3 min -1 through this to the flame was identical to thatthrough the original capillary operating at 5 psi. A comparison of performance at these two settings should therefore illustrate the effect of capillary size since the flamecomposition and instrument behavior otherwise will beidentical in all respects in the two cases. For this study, external lines were preconditioned with the exhaust samplewhile the interior of the analyzer was purged with zero airfor 5 min prior to admitting the sample. The recordedtimes for the response signal to attain 95% or 98% of itsfinal level from the point of initial signal rise were reduced to 2.1 and 6.5 sec, respectively, with the larger capillary from the corresponding original values of 3.6 and 9.0sec. Although these measures of the internal instrumenthangup illustrate some improvement in the response per-

Table VII. Response Times for Variety of Sampling Lines and Operating Conditions on Beckman Models 400 and 402Model 400 Model 402

formance and confirm that the sample capillary is responsible to a certain extent for the effect, the noted improvement is insufficient to justify this approach as a techniquefor overcoming the inferior performance chanacteristics ofunheated FID's. In conclusion it would appear that heatedtype FlO's are required for accurate real-time concentrations and modal mass automotive measurements.

Acknowledgments

The author gratefully acknowledges the interest and cooperation shown by J. Blanke and R. E. Belcher of Beckman Instruments, Inc., during the course of this pro~ram.

Literature Cited

(I) Blades, A. T.,J. Chromatog. Sci.. 11,251-5 (1973).

(2) Sternberg, J. C., Gallaway, W. S., .lones, D. T. L., "GasChromatography," N. Brenner, J. E. Callen, M. D. WeISS,Eds., pp 231-67. Academic Press. ew York, N.Y., 1962.

(3) Mohan, P., General Motors Proving Ground, private commu·nication, 1973.

(4) Jackson, M. W.. General Motors Research Laboratories, ibid..1971. ..

(5) Johnston, M .. Beckman Process Instruments Division, IbId ..1971. _

(6) Siegel, R. D., J Air pollut. Contr. Ass.. 22,845-53 (1972).(7) Wagner. T. 0 .. SAE Paper No. 700338. Society of Automotive

Engineers, National Air Transportation Meeting, New York,N.Y .. 1970.

Received for reviel/' December 5. 1973. Accepted April 24. 1974.Mention of commercial products is for identification only anddoes not constitute endorsement or recommendation for Wj€.

Work supported under contract from the Vehicle Emi.'"ions Laboratory of General Motors Proving Ground.

Selectivity of Strongly Basic Anion Exchange Resins for Organic Anions

Michael Semmens*' 1 and John Gregory

Department of Civil and Municipal Engineering. University College Landor,. London WC1. England

• Exchange equilibria between chloride and a series ofcarboxylate ions are presented for a variety of strong-baseanion exchange resins. Six polystyrene resins differingwidely in structure, type, and cross-link density were examined. The carboxylate ions ranged from butyrate to decanoate; within this range, no significant electrolyte sorption or uptake of free acid occurred so that sorption wasaccounted for entirely by ion exchan~e. All of the resinsshowed a regular increase in selectivity for carboxylate asthe chain length of the latter increased and values for thestandard free energy change for the transfer of a methylene group from aqueous solution to the resin phase havebeen estimated for each resin. Despite the differences instructure and cross-link density all resins yielded a valueof approximately -2200 J mol- 1; a similar value obtainedfrom independent selectivity data available for the exchange between hydrogen and a series of alkyl ammoniumions. These results confirm earlier reported results andsupport the conclusion that hydrophobic interaction between the resin matrix and the hydrocarbon chains of thecarboxylates is responsible for the increasing selectivity.

One of the most important characteristics of stronglybasic anion exchangers is their high selectivity for certainlarge or~anic ions, which may be desirable or undesirabledepending upon their application. For instance, advantageis taken of the resins' selectivity for organics in the studyand characterization of organic color in natural waters (I),for the removal of color from products in the food processing industry (2), and in large varieties of organic and biochemical separation processes (3). However, the samecharacteristic is responsible for the problems of organicfouling (4) whenever these resins are used in the demineralization of surface waters-a problem of major concern inwater treatment practice.

I Present address, Department of Civil Engineering, Universityof lliinoig, Urbana, Ill. 61801.


The research into organic fouling like the vast literatureon organic separations is mainly of an empirical nature,and comparatively little effort has been made to investigate systems which will develop an understanding of theinteractions that give rise to the observed behavior.

In this study, the exchange of a series of carboxylateions for chloride on a variety of strongly basic anion resinshas been investigated, and an attempt has been made toindicate which factors are operative in determining resinselectivity.

Experimental

Resins. Six commercially available stron~-base anionexchangers were studied. The properties of the variousresins are summarized in Table I. The resins were firstcleaned by alternate treatments with hot water and coldmethanol and conditioned with alternate treatments of1M NaOH and 1M HC!. Capacities were measured byelution of chloride with aN03 and subsequent argentometric titration with potassium chromate indicator. Resinsamples were stored in deionized water and were not allowed to dry.

Reagents

The purest available forms of no-butyric, n-hexanoic, n·octanoic, n·nonanoic, and n-decanoic acids (at least 98%pure) were obtained from B.D.H. Ltd., England. Thesecompounds were used without further purification. Analarpotassium chloride, sodium nitrate, potassium hydroxideam puIs, and hydrochloric acid ampls were also obtainedfrom B.D.H. Ltd.

Stock solutions (0.1N) of the potassium salts of the carboxylic acids were made by neutralizing the appropriateweiaht of acid with the contents of a volumetric ampul ofpot;ssium hydroxide. Dilution water was distilled anddeionized.

Equilibration Procedure

The apparatus used was similar to that of Kressmanand Kitchener (5), with a plastic mesh resin container

Table I. Resin Characteristics

• Butyrote ... Hexonoote 0 Oetonooleo Nononoote tl Deconoote

Figure 1. Ion exchange equilibria at 25°C between chloride andcarboxylate ions for a variety of strong-base polystyrene resins

(1)

Per-centagecross·

linkage Type- Matrix Manufacturer

2-3 Polystyrene Permutit




Polystyrene Permutit

DeaciditeFF-IP isoporous



beaciditeN·I P isoporous

DeaciditeK-MP macroporous

IRA·910 2 Polystyrene Rohm &Haas

Ty<Jp~Yf~e~i~eSs~noSnf~i~t~ii~~~~y~~~~~an~:~:;'if~:~~ig~~~.grOUPsl whereas

Resin

f(C\A = MA·''!..Cl (2)·\fA ·.IIc I

where M .., and M n are molal concentrations of carboxylate and chloride in solution, and bars indicate corresponding quantities in the resin. By use of Equation 2, resin

XA'XC1

XA'XC1

and will generally depend upon total solution concentration and X". For the present case of uni-univalent exchange, the separation factor is numerically equal to themolal selectivity coefficient, given by:

selectivity increased with increasing chain length of theorganic ion.

The equilibrium curves may be used to calculate separation factors, for given conditions. The separation factoris defined (6) as:

Results

The equilibrium results are presented in the form of X,against X, plots, where X, is the equivalent fraction ofcarboxylate in the resin and X, the equivalent fraction insolution. If A is preferred, the equilibrium curve is negatively curved and lies above the diagonal, and if the chloride is preferred, the curve is positively curved and liesbelow the diagonal. In this way, the distribution of carboxylate between resin and solution can easily be seen.

Figure 1 shows the curves obtained for the various resins with carboxylates containing 4, 6. 8, 9, and 10 carbonatoms. The figure shows that similar selectivity curveswere obtained for all the resins and that in all cases resin

that could be rotated in the solution. Rotation of the container was at 900 rpm to give a rapid flow of solutionthrough the resin and ensured thorough mixing of the solution. The solution vessel was equipped with platinumelectrodes so that the conductance of the solution couldbe followed during equilibration. The electrodes were connected to a Wayne-Kerr Bridge B 221, with Auto-BalanceAdaptor AA 221, the signal from the latter being fed to aServoscribe RE 511.20 chart recorder.

Solutions used contained potassium carboxylate andpotassium chloride, the total concentration being fixed at10 meq/l. The equivalent fraction of carboxylate variedfrom 0.2-1.0 (i.e., 2 to 10 meq/l.), and the solution volume was always 250 ml. A known amount of chloride-formresin (3-8 meq, depending on expected uptake of carboxylate) was placed in the mesh container and lowered intothe solution of least carboxylate concentration in a series.The resin was rotated at 900 rpm and the uptake of carboxylate was followed conductometrically. During exchange of carboxylate for chloride, conductance of the solution increased since the equivalent conductance of thechloride ion is considerably greater than that of any of thecarboxylates used. For each carboxylate, a calibrationcurve was obtained so that the composition of the solutioncould be determined from conductance readings. Thismethod is, of course, only valid when the carboxylate isremoved from solution entirely by ion exchange.

Several times the chloride level in solution was checkedindependently by titration with standard silver nitrate solution, and the results were always in close agreementwith the values obtained from conductance readings.Since solution pH was always greater than six it is unlikely that significant uptake of free acid occurred. From therecorded conductance trace it could easily be seen whenequilibrium had been attained and the final reading gavethe composition of the equilibrium solution and, hence,the amount of carboxylate removed from solution.

Information on exchange kinetics was also obtained bythis method, but apart from noting that equilibration forall the ions could be achieved in 7 hr or less, only equilibrium results will be considered here. After each equilibration, the resin sample was stirred in the next solution,containing a higher fraction of carboxylate, and the newequilibrium condition was established. The resin was notregenerated to the chloride form between equilibrationsand, thus, the amount of carboxylate exchanged each timehad to be added to give a cumulative resin concentration.The final solution contained initially 10 meq/l. carboxylate and, after stirring in this solution, the resin was regenerated with NaCI solution. In some cases, the equilibration was carried out in the reverse order-i.e., exchangingchloride for carboxylate to check the reversibility of theexchange.

Most of the experiments were carried out at a temperature of 25 ± 0.05°C, although a few were conducted athigher and lower temperatures.


gen bonding among the neighboring water molecules,thereby giving rise to an increase in water structure (IO,11). The decrease in entropy associated with the increasein water structure is unfavorable and tends to excludenonpolar solutes from solution. There is good reason tobelieve that the water surrounding an alkyl chain is morestructured than free water and that the degree of structuring increases as chain length increases (I 2).

The water inside the resin, however, is likely to be verydifferent in structure from that in the dilute external solution (I3). The water content of the resin is restricted bythe extent to which the matrix is able to swell which is, inturn, dependent upon the cross-linking. A medium crosslinked resin will, in the swollen form, contain only about50% water and this water is confined within the narrowpores and channels of the hydrophobic organic matrix.The diameters of the pores and channels vary with the degree of cross-linking. Pore sizes have been crudely estimated for resins with 1, 2, and 4% cross-linking as 3, 1.5,and 1 nm on the basis of interchain distances in the rodlike polyelectrolyte model of Fuoss et al. (I 4).

The hydrophobic nature of the organic matrix shouldtend to promote water-water interactions and increasewater structure within the resin, but this effect is morethan offset by the large number of fixed ionic groups andtheir counterions. The limited amount of water must satisfy the competing hydration demands of these ions, andas there is considerably less water per ion available thanin the dilute external solution, much of the water withinthe resin may be expected to be involved in ion-water interactions.

Water-water interactions within the resin are thereforephysically limited in the extent to which they may occurand are hindered by the disruptive effect of such a largenumber of ions. The effect a hydrocarbon chain has on thesurrounding water within the resin phase is thus signifi-'cantly reduced and transfer of the hydrocarbon chain tothe resin phase results in an overall increase in entropy.As the hydrocarbon chain increases in length, this interaction becomes increasingly more favorable.

(b) Hydrophobic interactions (I5) between the hydrocarbon chains and the resin matrix may occur (I 2). Thesewould depend stronlily upon the nature of the matrix, perhaps also upon charge density but very little upon crosslink density.

(c) When the previous interactions do not occur, it ispossible that carboxylate ions in the resin might interacthydrophobically with each other, to give structures analogous to micelles in bulk solution (16. 17).

Another tendency with increasing chain length would betoward a greater effect of swelling pressure, due to the increasing size of the resin for the carboxylate, and would bemore significant with higher crosslinking (I8).

(2) Interactions Involving the Polar Group. (a) Theintense electric field around an ion or polar group attractsand polarizes a shell of water molecules. The water molecules in this tightly bound shell are referred to as electrostricted molecules. The more intense the electric field surrounding the ion, the larlier the size of the electrostrictedshell becomes and the more strongly the ion is hydrated.Thus a small ion, such as lithium, has a large electrostricted shell whereas larger ions which create less intenseelectric fields have smaller electrostricted hydration shellsand in some cases have none. As mentioned above theamount of water within the resin phase is limited and ionsin the resin will not be hydrated to the same extent asions in the dilute external solution. Following the theoryof Diamond et al (13), all ions will favor the dilute solution where they may satisfy their hydration requirement;however, this preference will be greater for the more

1.0

ID

Resin =FF-IP(7-9"lo)Temperature =25° C

1.0,.------.------....

XA

Figure 2. Temperature variation studies

Discussion

Many factors may affect resin selectivity for carboxylateions (7-9), and some of the possible interactions of significance are outlined below. For simplicity the interactionsmay be divided into two sections: (1) those involving thenonpolar hydrocarbon chain and (2) those involving thepolar carboxylic group.

0) Interactions Involving the Hydrocarbon Chain(Nonpolar). (a) Water-water interactions. Water molecules are largely covalent in nature and tend to hydrogenbond to one another in pure water. Varying degrees of interaction are possible and a water molecule may hydrolienbond to a maximum of four neighboring molecules. As thedegree of association between molecules increases, thewater becomes more "structured." In dilute solution, theintroduction of a nonpolar solute tends to promote hydro-

0- 4x10-3M Solution

• -- IcJ2 M Solution

0 •• -- Butyrate6 •• - Octonoate

Resin" N-IP

XA

Figure 3. The eftect of solution concentration octanoate-chloride equilibria

I.o,.------.------~

selectivities have been calculated from the equilibriumcurves in Figure 1 for X A = 0.5. The results are tabulatedin Table II to enable easy comparison of the resins.

The results of temperature variation studies on exchange equilibria for butyrate and octanoate systems areshown in Figure 2 for the N-IP resin. The results indicatethat the selectivity for the organic ions is increased slightly by increasing the temperature.

The influence of solution concentration was demonstrated for the octanoate system with the FF-IP (7-9%)resin and solutions of 1O-2M and 4 x 1O-3M total ionicstrength. The equilibrium curves obtained are presentedin Figure 3, and show that selectivity increased when solution concentration increased over this range.


Table II. Measured Selectivity Coefficients K~IA

atXA =0.5FF-IP. FF-IP, FF-IP.

Organic ion K·MP IRA·910 N-IP 2-3% 3-5% 7-9%

Butyrate 0.12 0.13 0.15 0.13Hexanoate 0.32 0.27 0.38 0.63 0.25 0.26Octanoate 1.41 1.13 1.82 2.60 1.00 0.70Nonanoate 4.55 5.26 2.22 1.94Decanoate 6.7 9.0 11.5 14.4 7.30 5.20

strongly hydrated ions and the weakly hydrated ions willbe "forced" into the resin.

(b) The reduction in the degree of ionic hydration within the resin brings about a corresponding increase in thestrength of electrostatic interactions since ionic chargesare not screened as effectively as they are in the dilute external solution. Rice and Nagasawa (19) have estimatedthat the dielectric constant within a resin is approximately 30 but may be lower for resins with higher charge density.

Effect of Functional Type

From Table II it is seen that the type 2, N-IP resinshowed markedly higher selectivities for all the carboxylate ions than the type 1, FF-IP resin of similar cross-linkdensity. The larger ethanolic groups in the type 2 resinmust be responsible for this difference. It has also beenshown that type 2 resins are more selective toward phosphate (20) and nitrate (21) ions in exchange with chlorideions than their type 1 counterparts. These results may beexplained using the theory of Eisenman (22). As the functional group increases in size the electrostatic interactionsbecome less important in determining selectivity. Thenonhydrated radii of the nitrate, phosphate, and the carboxylate group are all greater than that of the competingchloride ion. Therefore, the electrostatic interaction between the chloride and the functional group is likely to bemore significantly reduced, which gives rise to the observed increase in selectivity for the above ions.

Influence of Cross-linking

Comparing the' selectivities of the FF-IP resins for thecarboxylates, shown in Table II, it is apparent that selectivity increases with decreasing cross-link density. As thecross-link density of a resin decreases, the followingchanges occur: (1) the swelling pressure decreases, (2) theaverage pore size increases, and (3) the resin absorbs morewater. Clearly the reduced swelling pressure may be responsible for the increase in selectivity since the carboxylate ions are considerably larger than the competing chloride ions and would therefore swell the resins to a greaterextent. As will be shown below, however, swelling pressureconsiderations are not responsible for the observed behavior. Limited access of the larger carboxylate ions to all theexchange sites in the more highly cross-linked resins mayalso account for the observations; however, this is considered unlikely since it was demonstrated that all resinscould be completely converted to the decanoate form. Itis, therefore, suggested that the variation in selectivitywith cross-linking results from the changes brought aboutby the increased amount of water within the resin.

As the water content of the resin increases the resinphase becomes more like the dilute external solution. Thedifferences in water structure between the resin and thedilute external solution are reduced, and it is likely thatthe hydrocarbon chain-water interactions will become lessimportant in determining selectivity. The additionalwater also reduces electrostatic interactions and the ion-

water interactions which contribute to resin selectivity. Ofthese two changes, the changes in water structure cannotaccount for the observed increase in selectivity with decreased cross-linking since it would support the oppositefinding. The explanation for the observed behavior mostprobably lies, therefore, with the influence of cross-linkingon the interactions involving the polar group.

For the lower members of the carboxylate series nonpolar interactions are of little significance, and selectivity isprincipally influenced by interactions involving the polarcarboxylate group. Thus the observed low selectivities forbutyrate and hexanoate indicate that the resins prefer thechloride ion to the carboxylate group. From section 2(a)this might be interpreted as the preference of the morestrongly hydrated carboxylate for the dilute external solution. Alternatively from 2(b) it may result from more favorable interactions between the partially "dehydrated"chloride ion and the functional groups of the resin.Whichever explanation is chosen the preferred ion, chloride, will be favored by an increase in resin cross-linkingwhich thus accounts for the observed behavior.

Influence of Solution Concentration

From Figure 3 the lower selectivity for the octanoate ionin the 0.004 molar solution may result from the increasedpreference of the strongly hydrated carboxylate group forthe more dilute external solution. The influence of solution concentration upon resin selectivity may be viewed asanalogous to the influence of resin cross-linking, in respectof the ion-water interactions. Dilution is equivalent to anincrease in resin cross-linking, since both increase the differences in water structure and ionic hydration betweenthe phases. Conversely, an increase in solution concentration is tantamount to a decrease in resin cross-linking.Since the observed increase in resin selectivity for the octanoate ions with decreasing cross-linking arises principally from ion-water interaction, it follows that selectivitywill increase with solution concentration.

Influence of Chain Length

As the hydrocarbon chain length of the anion increasesbeyond butyrate, the character of the carboxylic group(e.g., pH value) will not change significantly and so theincreased affinity must, therefore, arise from interactionsinvolving the hydrocarbon chain.

If we use the values from Table II, when loglo KnA isplotted against n, the number of carbon atoms in the carboxylate ion, for the resins, values for n ~ 8 lie on reason·ably straight lines. Example curves are drawn in Figure 4.Although K,·,A is not a thermodynamic equilibrium constant, it is possible to relate the slope of these lines to thestandard free energy of transfer of a methylene group fromaqueous solution to resin.

If we consider the resin as a separate phase (12), differentstandard states of the ions in the resin and bulk solutionare assumed. At equilibrium, the free energy of exchangebetween chloride and carboxylate is given by:

where 1'.\0 and I'no are the standard chemical potentials ofcarboxylate and chloride ions in bulk solution, a,\ and a,',the corresponding activities at equilibrium. As before,bars indicate quantities in the resin phase. V\ and VI" arethe partial molal volumes in the resin and II the swellingpressure of the resin. Introducing the molal selectivitycoefficient from Equation 2 and activity coefficients, 'Y",')'n, etc.:


Table IV. Variation of oVA/on with Cross-linking

Table III. Values Obtained for RT o(ln KCIA)/onResin Value obtained, J mol-I

-RT In KC,A = (/lAO - /-LAO) + (/-LCIO - -;:;CIO) +

RT In (YAYC/YAYC') + nO'A - JlCI } (4)

If attention is restricted to the change in K,·,A withchain length of the carboxylate ion, then all the chlorideterms can be ignored. Also, it is reasonable to assume thatthe activity coefficient ratio, 'Y .• /'I A, will not change appreciably with chain length, provided the hydrocarbon interactions are included in the term (!lAO - I'AO), which isthe standard free energy change for the transfer of carboxylate from aqueous solution to resin phase, ::'G..,0 . Hence,

-RT 0 (In Kc/}/{JII = O(f:.GAO)/OIl + noVA/Oil (5)

Values of RT o(ln Kc,A)/on may be estimated from theslopes of the lines in Figure 4. Values so obtained are presented below in Table Ill.

All of the polystyrene resins give a value for RT o(lnKetA)/on of approximately 2200 J mol-I, apart fromK-MP which yields a slightly lower result.

The last term in Equation 5 cannot be calculated accurately as there is very little information available onswelling pressures in conventional resins and none for macroporous resins. However, when we take the swellingpressures in Table IV as approximate values for conventional resins and assume the partial molar volume permethylene group to be 16 ml mol-I, although this is thevalue in water (24), the swelling pressure for the isoporousresins may be estimated.

Although the estimated swelling pressure contributionsin Table IV, may be contained within the margins of ex:perimental error it is unlikely when five resins, includingIRA 910, all yield the same result for RT o(ln KnA)/on.This result suggests that swelling pressure effects are neghgJble for all the resins with the possible exception ofK-MP.

The only comparable data for exchange on polystyreneresin are the results of Starobinets and Chizhevskaya (23).These researchers measured the selectivity of Dowex 50containing 2% and 8% cross-linking for a series of alkylammonium ions. When we take their results for aqueoussolution only (they measured the selectivity in a range ofaqueous methanol mixtures), a similar plot to Figure 4may be drawn for the alkylammonium ions as shown inFigure 5. The slopes of these plots are identical and yielda value for RT o(ln KHA)/on of 2100 J mol-I. These reosuits therefore support the results obtained with the carboxylates and also confirm that the swelling pressure termin Equation 5 is indeed negligible.

It is interesting to compare these values with others reported for the transfer of hydrocarbon chains out of aque·ous solution. An incremental value of ::'G"o of about-2500 J mol- I has been obtained for the adsorption ofsurfactants at an air-water interface, while the slightlylarger values of -3400 and -3100 J mol- I have been obtained at the oi'l-water interface (26, 27). It is apparentthat the values obtained for six quite different resins andvalues obtained by Starobinets et al. are similar and closeto the corresponding value obtained for adsorption at theair-water interface. Calorimetric data would be valuablefor a detailed interpretation of these results but the tern·perature variation studies suggest that ::'H would besmall. Some interpretation in terms of the mechanismsl(a) and l(b) is warranted, however.

It is felt that hydrophobic interactions between the carboxylate chain and the resin matrix are primarily responsible for the increase in resin selectivity with chain length.This conclusion stems from the fact that hydrophobic interactions are not affected significantly by the degree ofcross-linking, as noted above, and they therefore morereadily account for the constant results obtained with resins of varying cross-link density. This is not to suggestthat water-water interactions do not contribute to selectivity however. Substantial evidence suggests they do, butthe magnitude of water-water interactions arising fromthe hydrocarbon chain in the resin phase would have to be

o+ 75+250

2150 ± 1502200 ± 1502200 ± 1502200 ± 1502200 ± 1501950 ± 150

o50

150

Approximate swellingpressure (25), bars

N·JPFF-IP (2-3%)FF-IP (3-5%)FF·IP (7-9%)IRA 910

K·MP

2-33-57-9

Resin percentcross·linking

3.0r---r--r---r--r--r-,...-...,

2.0,-..,.---,r-..,.---,-..,.---,r-..,.--., • Dowex 50 II 2o Dowex 50 x8

II n - Number of Corbon Atoms inthe Alkylommonium Ions

Figure 5. Variation of log,o KHA (XA = 0.5) with the chainlength of alkylammonium ions for two Dowex resins. From thedata of Starobinets and Chizhevskaya (23)

• -FF-'P C2-3'¥.)o ---FF-IP 13-5,¥.1

,",-' CC_>,".'):101- /.../ ,;,

~////

~..... I I I I I I-1.03 4 5 6 7 B 9 10

n - Number of Corbon Atoms in Ire Carboxylate

Figure 4. Variation of 10glO KCIA with carboxylate chain lengthfor the FF·IP resins

2.0

RT 100 K~

1.0


constant in order to explain the above results. One couldargue that the water structure within the resin phase is sostrongly influenced by the resin matrix and functionalgroups that the introduction of a long-chain carboxylatehas little influence upon the degrees of water-water interactions even in resins with low cross-link densities. However, in the absence of more detailed thermodynamic datathis seems unlikely and it is more likely that water-waterinteractions would occur to a greater extent in more dilutehighly swollen resins. Thus it appears that the extent ofwater-water interaction contribution to selectivity is limited to the removal of the hydrocarbon chain from the dilute external solution. Hydrophobic interactions betweenthe resin matrix and the hydrocarbon chain would minimize interaction between the hydrocarbon chain and theresin water, and would therefore be affected very little bythe increased water content of highly swollen resins.

No association between carboxylate ions was observedin the polystyrene resins and so l(c) did not contribute inany way to resin selectivity. However, earlier reported results (17) show that carboxylate association is of majorimportance in determining selectivity for certain acrylicresins.

Literature Cited(1) Grigoropoulos, S. G., Smith, J. W.. in "Organic Compounds

in Aquatic Environments," S. ,J. Faust and J. V. Hunter, Eds.,Marcel Dekker, New York, N.Y., 1971.

(2) Parker, K. J., "Ion Exchange in the Sugar Industry," Chern.Ind., 20,782 (1972).

(3) Colman, C., Kressman, T. R. E., Eds., "Ion Exchange in Or·ganic and Biochemistry," Interscience, New York, N.Y., 1957.

(4) Ward, R. F., "Organic Fouling of Strongly Basic Anion Ex·change Resins," PhD Thesis, Washington University, St. Louis,Mo., June 1964.

(5) Kressman, T. R. E., Kitchener, J. A., "Cation Exchange witha Synthetic Phenolsulphonate Resin. Part III. Equilibria withLarge Organic Cations," J. Chern. Soc., 1949, p 1208.

(6) Helfferich, F., "Ion Exchange," p 153, McGraw-Hill, NewYork, N.Y., 1962.

(7) Chu, B., Whitney, D. C., Diamond, R. M., "On Anion-Exchange Selectivities," J. Inorg. Nucl. Chern .. 24,1405 (1962).

(8) Marinsky, J. A., Ed., "Ion Exchange," Vol. I, Marcel Dekker,New York, N.Y., 1966.

(9) Ibid., Vol. II, 1969.(10) Frank, H. S., Wen, W. Y., "III. Ion Solvent Interaction.

Structural Aspects of Ion-Solvent Interaction in Aqueous Solutions: A Suggested Picture of Water Structure," Discuss. Faraday. Soc., 24, 133 (1957).

(11) Nemethy, G., Scheraga, H. A., "Structure of Water and Hydrophobic Bonding in Proteins. II. Model for the Thermodynamic Properties of Aqueous Solutions of Hydrocarbons," J.Chern. Phys., 36,3401 (1962).

(12) J. Feitelson, Ref. 9, p 135.(13) Diamond, R. M., Whitney, D. C., in Ref. 8, p 277.(14) Fuoss, R. M., Katchalsky, A., Lifson, S., "The Potential of

an Infinite Rod-Like Molecule and the Distribution of CounterIons," Proc. Nat. Acad. Sci., 37,579 (1951).

(15) Nemethy, G., Angew. Chern. Int. Ed., 6,195 (1967).(16) Richter, G., Z. Phys. Chern., 12,247 (1957).(17) Gregory, J., Semmens, M. J., "Sorption of Carboxylate Ions

by Strongly Basic Anion Exchangers," J. Chern. Soc., FaradayTrans. I, 68, 1045 (1972).

(18) Gregor, H. P., "A General Thermodynamic Theory of IonExchange Process," J. Arner. Chern. Soc., 70, 1293 (1948).

(19) Rice, S. A., Nagasawa, M., "Polyelectrolyte Solutions," p461, Academic Press, New York, N.Y., 1961.

(20) Gregory, J., Dhond, R. V., "Anion Exchange Equilibria Involving Phosphate, Sulphate and Chloride," Water Res., 6, 695(1972).

(21) Roberts, G. 0., Miller, J. R., "Effects of Chemical and Physical Structure on Anion Exchange Equilibria in QuaternaryAmmonium Ion Exchangers," "Ion Exchange in the Process Industries," S.C.!. Symposium, London, 1970.

(22) Reichenberg, D., in Ref. 8, p 227.(23) Starobinets, G. L., Chizhevskaya, A. B., "Exchange of n

Alkylammonium Ions for Hydrogen and Lithium Ions in Aqueous Methanol Solutions," Russ. J. Phys. Chern., 44 (8), 1135(1970).

(24) Corkill, J. M., Goodman, ,J. F., Walker, T., Trans. Faraday.Soc., 63,768 (1967).

(25) Ref. 6, p 112.(26) Davies, J. T., Rideal, E. K., "Interfacial Phenomena," p

158, Academic Press, New York, N.Y., 1973.(27) Watanabe, A., Tarnai, H., Kolloid Z., 246,587 (1971).

Received for review Decernber 10, 1973. Accepted May 6, 1974.Work supported by the Science Research Council.


Determination of Lead in Atmospheric Particulates byFurnace Atomic Absorption

Jerome F. Lech, if<.1 Duane Siemer, and Ray Wood rill

Department of Chemistry. Montana State University. Bozeman. Mont. 59715

• By use of flameless atomic absorption techniques, it ispossible to determine traces of lead in atmospheric particulates in very small samples. The implementation offlameless techniques is greatly simplified by using porousgraphite as a filter medium. Using the Woodriff furnace asthe atomization device and cups made of porous graphite,one can take an air sample and insert the cup into thefurnace for determination with no other chemical or physical treatment. The sensitivity of the determination basedon a minimum detectable recorder deflection of 1% is 2.5X 10- 12 gram/sample. This is equivalent to 0.005 /lg/m 3

for a 100-cc air sample. When a standard particulate generator was used, the porous graphite compared favorablywith Millipore filters. Organic lead, however, was notfound to be retained by either type of filter. The techniques described should be readily applicable to othertypes of flameless devices.

Lead is the most widely used of the nonferrous metals.Atmospheric lead comes from manufacturing, use of pesticides, incineration of refuse, and combustion of coal andleaded gasoline. Of these, gasoline combustion is themajor source (T). Since 1923 lead alkyls have been addedto most gasolines as antiknock compounds. The organicscavengers ethylene dichloride and ethylene dibromide arealso added to prevent lead oxide from depositing in thecombustion chamber. This results in a discharge to theatmosphere of the mixed chloride and bromide salts oflead (2). Currently ambient concentrations of atmosphericlead are rising at approximately 5%/year.

The toxicological effects of inhaled lead have been documented (3, 4) and will not be discussed. On the otherhand, a discussion of the relationship of particle size torespiratory retention is pertinent to this study. In developing a filtration method, it is helpful to know the mechanisms and efficiencies of deposition of particles in the respiratory system and of the retention in and clearancefrom the system. Ideally if atmospheric particulate concentrations are to be related to health hazards, the filtration system should have collection characteristics similarto or the same as the human lung. The U.S. Departmentof Health, Education and Welfare publication (4) carriesan excellent discussion of this thesis. The size of a particlehas a bearing on whether it is dep()sited and where. Largerparticles tend to deposit in the mucous linings of the nasopharyngeal passages. The maximum efficiency of deposition in the alveolar region is at a particle size between 1and 211m. There is minimum efficiency for a size of about0.4 11m, but the efficiency increases again as particle sizedecreases.

According to the results of the National Air Surveillance cascade impactor network (5), 75-85% of the leadparticulates for six cities were less than 2 11m mass median diameter for the year 1970 and 60-70% were less than 111m. The annual mass median diameter ranged from0.42-0.69 11m for lead. Lead associated aerosols, however,

1 Present address. Varian Instrument Division. 611 HansimWay. Palo Alto. Calif.


have a fairly large particle size distribution. The geometric standard deviation from this mass median diameterranges from 3.61-5.56. By comparison, this value is muchgreater for lead-associated aerosols than for those of otherelements. This is in agreement with the findings of earlierworkers who investigated the size distribution of particulate automobile exhausts (2).

Although there has been a great deal of considerationgiven to the possibility of converting to the use of leadfree automotive fuels, industrywide change to unleadedgasoline of the current octane rating would require extensive replacements and additions of refinery equipment (6).Therefore, change would not be immediate and suddenbut, at best, a slow phasing out of leaded fuels is the mostthat can be expected. In the meantime, monitoring theconcentrations of lead in the atmosphere is still a necessary task. For this reason, development of accurate andsensitive methods of determining lead in the atmospherewhich are also expedient yet inexpensive are desirablegoals. Atomic absorption, particularly coupled with modem flameless devices, is ideally suited for this purpose.Various authors have sought to make use of the advantages of atomic absorption for the determination of metalsin air (7-9). More recently, flameless atomization deviceshave been applied due to the increased sensitivity that results from their use (10-/2).

A short time ago a new method of filtration using porous graphite was briefly introduced (13), which, whencoupled with the atomic absorption furnace of Woodriff etal. (14, /5), gives both simplicity of use and great sensitivity. Here we intend to consider further some of the aspectsof the method not investigated in the brief introductoryarticle, such as the accuracy and sensitivity of the filtration medium compared with membrane filters, as well asother advantages of porous graphite filtration.

Experimental

Apparatus and Materials. The spectroscopic apparatus and the atomic absorption furnace used have been described previously (15, 16), and for the sake of brevity willnot be repeated here.

Two types of cups are used for different purposes. Thecups used for direct filtration are of the same dimensionsas those commonly used in emission spectroscopy for carrier distillation (ASTM No. S3). These cups, however, aremade of a type of graphite with a closely controlled porosity. This graphite has been described more fully in an earlier work (13). The cups used for solutions are similar butare 4 mm shorter and are made of a higher density graphite. It is necessary for this graphite to be impervious torelatively concentrated (,5M) nitric acid solutions. Whenthe cup was wetted by these solutions, the reagent blankwas quite high, probably due to the fact that the wetoutsides of the cup in contact with the titanium cup holder picked up trace contaminants on the surface. This condition was overcome by making cups of Poco grade FX 91,found to be impervious to nitric acid.

The cupholder used for air filtration (Figure I) is machined from Teflon bar stock. This material was ideal forthis purpose because it could be soaked in a large varietyof solvents for cleaning, and it exhibited no memory ef-

fects from one operation to the next.. This design is animprovement from the one used earlier (I3) because it hasno threaded sidearm, a source of leaks, and the linear design is easier to insert into a line.

Millipore filters used for comparison were type HAWPplain white cellulose ester filters, 13 mm in diameter,with a pore diameter of 0.45 11m. Swinnex 13 adapterswere used to hold the Millipore filters during the filtration. Glassware used was soaked overnight in hot 2-3Mnitric acid prepared from reagent grade nitric acid andthen in hot 2-3M nitric acid prepared from redistilled nitric acid. The latter step was repeated until the values obtained from blank determinations no longer deviated significantly from those determined previously.

The apparatus depicted in Figure 2 was constructed togenerate standard particulate atmospheres. It consists of asurplus multiple unit tube furnace with a Pyrex or Vycortube through the center. Air from the house line is bled inat 50 ml/min through a miniature valve of the type usedin small aquaria, and the flow rate is monitored on a Gilmont flow meter. Lead chloride is placed in a ceramicboat run into the hottest zone of the Vycor tube. At theexhaust end is a two-way valve. One is usually connectedto the filter apparatus and the other is led through a tubeup into the exhaust duct to prevent contamination of thework area.

Organic lead standards were generated in an apparatusconsisting simply of a sidearm test tube with a one-holerubber stopper at the top and a capillary tube down thecenter. Ten microliters of an appropriate concentration oftetramethyllead (TML) in toluene is pipetted into thebottom of the tube. The sampling apparatus is attachedat the sidearm. A capillary is used to increase the linearvelocity of the sweep gas (air) as it impinges the TML solution at the bottom. To ensure that all of the sample hasbeen swept from the tube, a volume of sweep gas is allowed to pass through the tube equal to several times theinternal volume after the TML solution can no longer bedetected visibly.

Reagents. Concentrated nitric acid used was distilledonce in Pyrex. Organic lead used for standardization was80% TML in toluene obtained from Alfa Inorganics.Water used was low-conductivity water distilled twice inPyrex. TML solutions were diluted with reagent grade toluene from J. T. Baker Co.

Procedure. To determine the optimum furnace temperature for determining lead, approximately 1 ng of lead isadded to the impervious cups as lead nitrate solution. Thecups are then placed under an infrared heat lamp and thesolutions are evaporated to dryness. The cups are thenplaced in a desiccator to prevent possible contamination.Each cup is then threaded onto a 'Is-in. graphite rod andinserted into the furnace. Absorbance values are measured in triplicate at various furnace temperatures. Priorto use the cups must be cleaned of possible contaminants,best done by merely inserting the unused cups into thefurnace and removing them when the absorbance readszero (about 112 min).

Standard curves are then run in the same manner except that the furnace temperature is held constant andthe amount of lead added to the cups is varied. Standardcurves were run for each type of graphite cup at the217.0-nm lead line. Standards were also run at the lesssensitive 368.3-nm lead line. This line is not commonlyused for absorbance measurements; however, a Boltzmanncalculation shows that the lower energy level of this line oflead is sufficiently populated at 1850°C to enable absorbance to occur from this metastable state. Background absorbance of all types of samples was checked at the nomesonance 220.35-nm lead line and none was present.

Figure 1. Teflon cupholder

Figure 2. Particulate generator


Figure 3. Temperature curve for lead

Figure 5. Results of samples taken on the Montana State University campus

8 9 105 6X 10'0

Figure 4. Lead standard curves at 217.0 nml:i. Porous graphite. 0 Impervious graphite

co'

~c GAINES HAll

A IA

bs 1.2orbl.Oan .8ce

IBt

.4L,...--,c6----c:'7,-------:'''"S------,'9::-----;c20

Temperature ]I; 10-2

.6

c.

The filtering procedure for porous graphite cups is relatively simple. After a set of cups has been cleaned by insertion into the furnace and has cooled down, one of themis placed in the Teflon holder. A syringe is attached to oneend of the holder with a piece of surgical tubing in such away that, on drawing out the plunger, air is forced to flowthrough the cup from the inside to the outside. The resultis the deposition of the particulates on the inner surface ofthe cup. The volume of air sampled can be adjusted sothat a sufficient amount of deposited lead gives significantabsorbance. Commonly 100 cm3 are sufficient. The lead inthe filtrate can then be determined without further pretreatment by inserting the cup into the furnace and reading the resulting absorbance.

For membrane filters, on the other hand, after the airsample is drawn through the filter, the filters must undergo digestion to decompose the filter material, thus eliminating background absorbance. Wet digestion is preferredover dry ashing since the filters vaporize rather vigorouslyduring the dry ashing procedure with a possible loss ofsample. After the filtration step, the membrane filter isremoved from the holder and placed in the bottom of agraduated centrifuge cone. Concentrated distilled nitricacid (300 Ill) is then added. The centrifuge cone is placedin a boiling water bath, and the filter is digested until thesolution ceases to fume and appears nearly colorless. Thesolution is then diluted to 1 ml, and 100 III aliquots areplaced in the impervious cups, and the absorbance is determined as described earlier.

Results and Discussion

Figure 3 shows the variation of absorbance with temperature for 10- 9 gram of Pb at the 217.0-nm line. Approximately the same curve is obtained with different furnacesand different optical arrangements. From this curve it canbe seen that the best operating temperature for lead is1845°C. If standard curves are run as close to this temperature as possible, then the temperature for running samples can vary as much as ±25°C without losing accuracy.

The standard curves for lead shown in Figure 4 are atthe usual 217.0-nm analytical lines. Since the shapes ofthe two types of cups differ, as well as the densities andheat capacities of the two different graphites used, it isnecessary to run standard curves for each. The sensitivities for the two are similar (2.5 x 10- 12 gram). Bothcurves were run under the same conditions-i.e., photomultiplier 850 V, hollow cathode 6 ma, entrance slit 150Ilm, exit slit 120 Ilm, reciprocal linear dispersion 11A/mm.

By use of the porous graphite cups, several 100 cm3 airsamples were taken throughout the day on the MontanaState University campus approximately one week beforeand one week after the beginning of the school term. Because it takes only a few minutes to collect a sample, it ispossible to determine short-term variations in atmospheric concentrations. In Figure 5 are comparative plots of thetime variations in concentration on these two days.Weather conditions were similar on both days. The effectof student population on the local concentrations of leadin the air can be seen. Not only is the average concentration greater on September 27, but the fluctuations arealso greater with sharp increases occurring during the between-class periods.

Figure 6 shows the results of samples taken along Interstate 90 north of Bozeman, Mont., one day before and oneweek after the official opening of that section of highway.Care was taken to select a location as far removed fromlocal traffic centers as possible. Even though vacationtraffic was already at an end, there is a noticeable difference in the atmospheric concentrations on the two days.


On the average, the lead concentrations on the latter datewere twice as high; however, it should be pointed out thatthe anomaly at 4:40 is due to the traffic from the construction workers.

To determine the validity of these results, it was feltthat the porous graphite cups used should be characterized with respect to precision and accuracy. For this, thepreviously described apparatus shown in Figure 2 wasused. It was later found that compressed air from thehouse line could be used in place of the nitrogen tank withno additional blank absorbance. A rheostat was also connected in series with the tube furnace to enable finer adjustment of the furnace temperature. A cardboard andglass shield was constructed around the furnace and thetube to serve as a convection shield since drafts wouldrather suddenly change the system temperature by a fewdegrees. A regulated power supply was also necessary because locally there are substantial voltage fluctuations.With these modifications, the temperature at the centerof the tube within the furnace could be held constant towithin ±1/.0C for several hours. With lead bromide in theceramic boat, a temperature of 381°C, and a samplingtime of 1 min at a flow rate of 50 ml/min, 18 sampleswere taken. The average amount of lead collected was 9.7X 10- 10 gram and the relative standard deviation was10.0%.

When nitrogen instead of air was used, several samplesof the particulate containing carrier gas, after being filtered through the porous graphite, were injected directlyinto the furnace. This could be done by fitting a shortened

Figure 6. Results of highway samples

Conclusion

The results obtained seem to indicate that using porousgraphite as a filter medium for air particulates comparesfavorably with Millipore filters of the type generally usedfor this purpose. Other authors (18) have shown that thereis some variation between different portions of a filterwhen large filters are cut into portions and each portion isanalyzed separately. We have found that there is somevariation between filters when the whole filter is used. Atleast some of this variation can be attributed to the in-

side arm with a rubber septum and injecting both unfiltered and filtered gas into the furnace through the septum. Filtration of the particulates by the porous graphiteproved to be quantitative.

Photomicrographs of the particles generated are shownin Figure 8, a and b. These particles were collected byplacing microscope slides in the bottom of the Pyrex tubeof Figure 2 and lowering the flow rate to 5-10 ml/min toallow the condensation particles to settle. Figure 8a istaken 8 cm from the ceramic boat and Figure 8b, 23 cmfrom the boat. The particles range in size from 0.1-1.5I'm. This is very similar to the situation typically found inair samples (5).

Since activated carbon has been successfully used byothers to adsorb organic lead quantitatively (17), the adsorptive properties of our porous graphite cups for organicleads were investigated. When 10- 7 gram of lead as TMLin toluene was pipetted into the organic lead evaporatormonitoring the less sensitive 368.3-nm line, there was noabsorbance above blank values detected for several determinations, for either the graphite cups or the Milliporefilters. To determine if there is some saturation pointbelow which organic leads are quantitatively adsorbed,the same procedure was repeated using 10- 9 gram of leadas TML and monitoring the more sensitive 217.0-nm line.Again, no organic lead was retained by the porous graphite cups.

To determine the accuracy for filtration of particulatesby porous graphite, a comparison with membrane filterswas attempted since an absolute air particulate standardwould be a difficult task. Several filters from four different lots of 13-mm Millipore filters had an average of about9 ng/filter, with relative standard deviations for the different lots ranging from 18-67%. The results are shown inTable I. This is unsuitable for comparison at the 217.0-nmline, so a pair of standard curves was made at the 368.3nm line (Figure 7) having a lower sensitivity-i.e., 1 X

10- 9 gram. This enabled a comparison between the twofiltration methods, because the Millipore filter blank wasinsignificant at this line.

By use of the particulate generator of Figure 2, sampleswere taken of the effluent particulate containing gases alternating between porous graphite filters and Milliporefilters so that any drifts in the rate of evolution of leadwould be seen in both filters. It turned out, however, thatno such drifts or trends were observed. The results of thiscomparison are listed in Table II. Since the Millipore filters are digested and only an aliquot used for analysis,particulates from the generator are collected for a longerperiod of time. To facilitate comparison, then, the number of grams collected per minute is calculated. Thevalues obtained were similar at 95% confidence, using thestudent's t analysis. The value obtained for twas 2.00 asopposed to a rejection criteria of 2.08 for that confidencelevel. An F value of 4.1 shows that the precision of porousgraphite filtration is greater than that for filtration usirgMillipore filters. In both cases, one value was rejected at95% confidence as a result of a rejection quotient calculation.

Ii 10Il

Sept. 2. 71

Sep!. la, '71

INTERSTATE 90

4 5 6Grams X 108

Figure 7. Standard curves at 368.3 nm6 Porous graphite. 0 Impervious graphite

coN

C.

UG

~2


'. " ~. -: J.

"

"

:<.,

Figure 8. Photomicrographs at 400X of particles resulting from the particulate generatorLeft, 8 em from boat; right. 23 em from boat

Ta"le II, Comparison of Methods for ParticulateFiltration

Ta"le I. Lead Content of Millipore FiltersNo. of Av amt in Rei std

Lot no. samples ngjfilter 5td deY deY

5840813 12 7.8 4.1 537602012 8 9.0 2.8 318823 10 9.3 1.6 1895434 13 9 9.4 6.2 67

creased handling necessary when using these membranefilters, especially when we consider the low levels withwhich we are working.

On the other hand, if we are working with less sensitivedevices or methods which require higher concentrationand therefore larger volume air sampling, these considerations are of less importance. Furthermore, the blank levelsin the filters can be reduced with pretreatment.

It is not difficult to envision other interesting applications of porous graphite filtration, especially in view of thefavorable properties that graphite has for different typesof analytical devices,

Method

No. of samplesG/min X 1lJSStd deyRei std deyPopulation mea n at 95%

confidence

Porousgraphite

143.160.258%

I' = 3.16± 0.15

Milliporefilter

92.840.51

18%I' = 2.84

± 0.39

Acknowledgment

The authors wish to thank Varian Techtron for assistance given for this study. The authors are also indebtedto Don Fritts of the Veterinary Research Lab, MontanaState University, for the microscopic work.

Literature Cited

(1) Hall. S. K., Environ. Sci. Techno/.. 6.31-5 (1972).(2) Hirschler, D. A.. Gilbert, L. F., Lamb. F. W.. Niebylski, L.

M., Ind. Eng. Chern .. 49,1131-42 (1957).(3) Kehoe, R. A.. J. Air Pollut. Contr. Ass., 19,690-700 (1969).(4) U.S. Department of Health, Education, and Welfare, "Air

Quality Criteria for Particulate Matter," National Air Pollution Control Administration Publication No. AP-49, 1969.

(5) Lee, R. E. Jr.. Goranson, S. S., Enrione. R. E., Morgan. G.B., Environ. Sci. Technol., 6, 1025-30 (1972).

(6) American Chemical Society, Washington, D.C., "CleaningOur Environment, the Chemical Basis for Action," 1969.

(7) Thilliez, G., Anal. Chern., 39,427-32 (1967).(8) Daines, R. H., Motto, H., Chilko, D. M.. Environ. Sci. Tech

nol., 4,318-22 (1970).(9) Hwang, J. Y., Feldman, F. J., Appl. Spectrosc., 24, 371-4

(1970).(10) Loftin, H. P., Christiao, C. M., Robinson, .J. W., Spectrosc.

Lett., 3, 161-74 (1970).(11) Matousek, J., Brodie. K., Varian Techtron Atomic Absorp-

tion Application :-.Iotes, Rull. No. 10-CRA-II. 1-6 (1972).(12) Omang, S. H., Anal. Chim. Acta. 55,439-41 (1971).(13) Woodriff, R., Lech. J. F., Anal. Chern .. 44, 1323-5 (1972).(14) Woodriff, R.. Stone, R. W.. Held, A. M.. Appl. Spectros.. 22,

408-11 (1968).(15) Woodriff, R., Shrader. D., Anal. Chern., 43, 1918-20 (1971).(16) Woodriff, R.. Culver, B., Shrader, D.. Super, A. B.. ibid.. 45,

230-4 (1973).(17) Snyder, L. J., ibid., 39, 591-5 (1967).(18) Pierce, J. 0., Meyer. J. H., Atmos. Environ., 5, 811-13

(1971).

Received lor review July 9, 1973. Accepted May 24. 1974. Worksupported in part by NSF Grant No. GP2805.5.


Effects of Intermittently Chlorinated Cooling TowerSlowdown on Fish and Invertebrates

Kenneth l. Dickson,* Albert C. Hendricks, John S. Crossman, 1 and John Cairns, Jr.

Biology Department and Center for Environmental Studies. Viriginia Polytechnic Instituteand State University. Blacksburg. Va. 24061

• An in situ bioassay was conducted to evaluate the effects of intermittently chlorinated cooling tower blowdownfrom Appalachian Power Co.'s Carbo, Va., plant on bluegillsunfish (Lepomis macrochirus RaL) and a snail (Anculosasp.). Cooling towers at the plant were treated for slimecontrol with 0.75 mg/1. of chlorine for 30 min four times aday. The cooling tower blowdown was discharged to theClinch River. Caged fish and invertebrates were placed atvarious distances downstream from the blowdown discharge and observed for 96 hr. Amperometric determinators for both free and total chlorine were made at lO-minintervals at selected stations throughout the study period.No fish deaths occurred which could be attributed to theblowdown discharges. However the blowdown was acutelytoxic in 72 hr to 50% of the snails exposed to less than0.04 ppm total residual chlorine for less than 2 hr/dayand to 80 /1g/1. copper plus other blowdown constituents.Nevertheless the impact of the cooling tower blowdown onthe total ecology of the Clinch River was probably of noimportance since the observed mortalities were restrictedto an area extended not over 20 ft from the left bank and800 ft downstream.

Despite the widespread distribution of power plants andmany years of operation there is very little evidence onthe effects of intermittently chlorinated cooling towerblowdown from power plants on aquatic organisms. Brook(1) described the effect of such chlorination practices onthe photosynthesis and respiration of algae and reported adefinite reduction in both photosynthesis and respirationimmediately after chlorination. Brungs (2) suggests that0.1 mg/1. not to exceed 30 min/day or 0.05 mg/1. not toexceed 2 hr/day should not result in significant kills ofaquatic organisms or adversely affect the aquatic ecology.However, as Brungs (2) states, the recommendations fordiscontinuous total residual chlorine in fresh water are notfounded on solid ground. Field studies by Basch (3) conducted with caged fish below a sewage outfall where chlorinated and nonchlorinated effluents were dischargedfound toxic conditions existing for rainbow trout (Salmogairdneri) 0.8 mile below the outfall. Tsai (4, 5) found areduction in number and species of fish below plants discharging chlorinated sewage. Both Basch and Tsai attributed the toxic conditions to the chlorinated effluents.Sprague and Drury (6) demonstrated an avoidance byrainbow trout of 0.001 mg/1. free chlorine. Brungs (2) in apersonal communication with Truchan and Basch reported that "Fifty percent of brown trout placed in cagesin a power plant discharge died within four days whenchlorination occurred for only 30 minutes per day. Themean total residual chlorine concentration during thechlorination periods was 0.06 mg/I."

Brungs (7) in a review article evaluating the effects ofresidual chlorine on aquatic life suggested that an interimcriteria for intermittent chlorination should be that the

1 Present address, Teledyne Brown Engineering. Research Park.Mail Stop 5. Huntsville. Ala.

total residual chlorine not exceed 0.04 mg/1. for a periodof 2 hr/day to protect most species of fish. However, if ahigh percentage of residual chlorine exists as free chlorinethen the total residual chlorine should not exceed 0.01mg/1. for a period of 30 min/day to protect sensitivespecies such as trout and salmon. Brungs indicates thatno similar criteria for warm water fish could be made because of lack of data.

The purpose of this paper is to report the results of astudy initiated at the Appalachian Power Co.'s ClinchRiver plant, Carbo, Va., on September 11, 1972, to determine the effect of chlorinated cooling tower blowdown onorganisms placed in the river. The in situ tests were performed utilizing bluegill sunfish (Lepomis macrochirusRaf.) and an operculate snail (Anculosa sp.).

Location and Description of Stations. Six stations,each divided into three substations, were established inthe vicinity of the Clinch River Power Plant (Figure 1).The substations were designated left (L), middle (M), andright (R) and were positioned more by the flow characteristics of the system than proximity to a bank. SubstationsL were nearest the left bank when the observer was facingdownstream. Substations M were located somewhat farther from the left bank than substations L, except at station 1 where substation M was at midchannel. Substations R were at midchannel except at station 1 where thesubstation was close to the right bank. At all stationsbelow the outfall, substations Land M were in the outfall's plume area. The plume area was determined byplacing rhodamine dye in the cooling water blowdown discharge and observing its diffusion pattern. Thus one couldapproximate the outer limits of the plume. All stationswere similar in substrate composition, water depth, andother habitat characteristics. River flow was rather constant during the study ranging from 400-600 cfs. Flow velocities ranged from 0.47 ft/sec to 2.0 ft/sec at the variousstations.

Chlorination Regimen in Cooling Towers. Appalachian Power Co.'s Carbo plant has three cooling unitswith towers 1 and 2 in unit :1, towers 3 and 4 in unit :2,and tower 5 in unit :3. All three units are cooled byclosed-cycle, evaporative systems equipped with mechanical draft-cooling towers. Makeup water is untreated waterfrom the Clinch River. The cooling water is treated onlyby feeding sulfuric acid for control of pH, and by intermittent chlorination for control of slime on the condensertube surfaces and of algae and other aquatic growths inthe cooling towers. Units 1 and 2 were chlorinated at 10:00a.m., 4:00 p.m., 10:00 p.m., and 4:00 a.m. with an averageof 0.75 mg/1. of chlorine for 30 min. Unit 3 was chlorinated at 7:00 a.m., 1:00 p.m., 7:00 p.m., and 1:00 a.m. withan average of 0.75 mg/1. of chlorine for 30 min. The waterfrom units 1 and 2 were combined with water from unit 3and then discharged into the river. Flow-through times inthe towers were approximately 14 min.

Materials and Methods

Chemical Analyses. Water was collected for routinechemical analyses (Table I has a list of characteristics determined) at all stations. The samples were sent to the


Figure 2. Total residual chlorine levels of blowdown water before going into Clinch River. September 14.1972

Figure 1. Diagrammatic sketch of river showing distances between the outfall and the sampling stations and distances ofsubsamples from lett bank

American Electric Power Service Corp. General Laboratbry at Huntington, W.Va. Chlorine determinations (bothfree and total) were made with a Wallace & Tiernan amperometric titrator in the field. Chemicals and proceduresoutlined in the Wallace & Tiernan amperometric titratormanual were utilized. Chlorine tests were run before the

cooling water entered the river and at stations 2, 3, 4, and5. The chlorine determinations were initiated at 1:45 p.m.on September 11 and continued 24 hr a day until 4: 15p.m. September 14. The samples were taken at 5-10-minintervals and at varying distances from the left bank. Thispermitted determination of the times when the peak loadsof chlorine appeared in the river and the duration of thechlorine contact time at the various stations. The chlorinetests were performed at a particular station through oneor more chlorination cycles. In this way the minimumchlorine concentrations in the river before and after chlorine dosing and the maximum value during dosing weredetermined. A number of the stations were tested morethan once during the study period.

Test Organisms. Bluegill sunfish (Lepomis macrochirus RaL) and a snail (Anculosa sp.) were utilized as thetest organisms because they represent indigenous species.The fish were caged in the river in nylon live bags (20 x30 in.), and the snails were caged in plastic screen conesequipped with draw strings to prevent the animals fromescaping. Ten fish and 10 snails were exposed at each substation in cages attached to iron rods driven into the riverbed. The fish were transported from the Aquatic EcologyLaboratory at Virginia Polytechnic Institute and StateUniversity to the Clinch River for acclimation to riverconditions six days before the tests began. During the acclimation period they were caged in the river approximately 500 yd above the plant's outfall. The snails werecollected from a riffle approximately 100 yd upstreamfrom the power plant outfall the day that testing began.

The test organisms were placed into the river at 4:00p.m. September 11, 1972. Animals were inspected anddead organisms removed at 8:00 a.m., 2:00 p.m., and 8:00p.m. each day. On the 12th of September 1972 the animals were also checked at 2:00 a.m .. These hours werechosen since they occur approximately 1 hr after chlorination of unit =3. Mortality of the fish was determined byobserving the animals. The snails were considered deadwhen no movement could be detected after repeatedlytouching the soft parts of the organisms with a probe.

Results and Discussion

Figure 2 is a graph of the total residual chlorine concentrations before the water entered the Clinch River. Thewater was collected in a water box before discharge to theriver. There was a marked chlorine peak approximately30-40 min after the chlorination of unit t!3 (unit =3 waschlorinated at 1:00 and 7:00-i.e., four times a day). During the five dosing periods of the study the maximumtotal residual chlorine levels ranged from 1.31-0.64 mg/1.in unit =3. The free chlorine concentration ranged from0.0-88.0% of the total residual chlorine with a mean percentage of 17.3%. The concentration of free chlorine in thedischarge ranged from 0.0-0.35 mg/I. with a mean concentration of 0.08 mg/I. Figures 3, 4, and 5 were generatedfrom chlorine data collected at stations 2, 3, and 4, respectively. As might be expected, the highest total residual chlorine values in the river were found at station 2some 23 ft below the point of discharge (0.55 mg/I.). However, the difference between the maximum values recorded at stations 3 and 4 was not anticipated. There was adrop of approximately 0.40-0.35 mg/I. of total residualchlorine between stations 2 and 3, a distance of 80 ft,while no appreciable drop occurred between stations 3 and4, a distance of 170 ft. This suggests that much of thechlorine entering the river was reduced within the first100 ft.

The ammonia concentration in the Clinch River at thetime of the study had a range of 0.15-0.25 mg/1. with amean concentration of 0.20 mg/I. The presence of this

L2"

M10'·

STaTION • (zaN')

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STATK* • (447')It M L

a' 13' .'

STATION 4 (271')It M L

a1' 13' s·

STATION 3 U10')

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CU""lNT

It ~T'~

STATION 2122"It M L

411' 13' .'

STATION 1 (1OS')

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Table I. Chemical Analyses of Clinch River Water Collected on 9-15-73Station

Analyses

Calcium, mgjl. 35.0Magnesium 10.8Sodium 18.5Bicarbonate 152.2Sulfate 14.4Chloride 5.5Dissolved solids 177.2Hardness (CaC03) 131.9Net ignition loss 13.2Orga nic matter· 1. 51pH 7.5Specific conductivity 283.0Chromium' 4.23Copper' 1.6Lead' 5.81Mercury' 0.93Nickel' 3.43Zinc' 5.55

a KMn04 consumed as 01. b Expressed in ppb.

125.035.085.0

142.9282.328.5

722.5456.283.24.766.9

821.012.42

240.011.360.038.72

80.00

107.530.585.0

144.6229.622.0

633.3394.075.25.006.9

732.010.82

160.09.250.035.55

60.0

97.527.085.0

144.2183.518.6

337.6354.666.83.917.2

653.09.25

140.05.280.035.02

50.00

71.322.343.8

146.7116.114.2

396.5269.952.03.367.1

506.06.61

80.06.870.033.43

22.19

57.516.043.8

147.954.38.5

285.0209.527.62.477.3

377.04.23

32.87.930.032.38

10.04

0.10

W0.14

liJ 0.12Zcr9"U..J

~

~~60MIOOtWI~160100~2W~~~~~340~

MINUTES

Figure 4. Maximum total residual chlorine in discharge plume atpoint in river 100 It downstream from Unit 3. Time 0 is 1900 hron September 13. 1972

0.18

0.16

0,20,-,---,-----,-,----.-,---,-----.----.--.----;,-,---,----,-,-----r-r-,

0.50

-:F 0.40

WZcr9 0:30

"u..J«~ 0,20

20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 3.20 340 360

MINUTES

Figure 3. Maximum total residual chlorine in discharge plume atpoint in river 23 ft downstream from Unit 3. Time 0 is 1300 hron September 12. 1972

\

004

0.01

0.02

O'''io 14 ~

::: to II I

: :::fi 007U

...J 0,06

§r-- 0,05

~ ~ W 00 100 I~ 140 IW IOOW02W

MINUTES

Figure S. Maximum total residual chlorine in discharge plume atpoint in river 270 It downstream from Unit 3 discharge. Time 0is 0100 hr for broken line and time 0 is 1300 hr for solid line onSeptember 14, 1972

ammonia plus possibly other reduced compounds probably accounts for the levels of free chlorine being lower atall sampling stations (range equaled 0.0-0.07 mg/I., meanequaled 0.02 mg/I.) than in the discharge to the river(range equaled 0.0-0.35 mg/I., mean equaled 0.08 mg/!.).Table II summarizes the maximum total residual chlorine found at the various stations plus the farthest distance from the left bank that any residual was found andthe longest length of time that any residual remained.

Table I is a compilation of the other chemical analysesperformed on the river. water collected along the left bankat the various stations. Such attributes as hardness, conductivity, and dissolved solids increased below the discharge of blowdown water. Also, there was an increase ofall the heavy metals analyzed in the plume, except mercury.

In these in situ studies, it is impossible to separate theeffects of chlorine from the effects of other constituents inthe blowdown. However the concentration of heavy metalswith the possible exception of copper do not appear to behigh enough to produce acute lethality.

Fish mortality results indicate that none of the deathsobserved were due to chlorine or other materials in theblowdown plume (Table III). At station 1 three fish died,one at each substation. These fish were not exposed to the


blowdown discharge and certainly died from other causes.However, station 1 provided adequate controls since 90%of the fish survived. No deaths occurred at station 2, eventhough 20 fish were maintained in the plume area 23 ftbelow the outfall. Only one death occurred at station 3(substation 3M). This fish appeared to have physicalabrasions (loss of scales, frayed fins) and probably died asa consequence of being trapped in a portion of the nylonnet. At stations 4 and 6 all of the deaths appeared to bedue to similar physical factors. At substations 4M, 4R,and 6R the fish that died also showed physical abrasionsfrom fouled nets. Since no chlorine reached the organismsat substation 6M, (Table III), the deaths there were dueto factors other than the chlorine. Only one death occurred at station 5, and this death was outside the areaaffected by the blowdown discharge.

Snail mortality data are shown in Table III. 0 snaildeaths occurred at stations 1 and 6, and no deaths occurred at the R substations at stations 2, 3, 4, and 5. Thisindicates that the controls were quite adequate throughout the study. Snail deaths were recorded at substations2L, 2M, 3L, 3M, 4L, and 5L. All of these deaths appearedto be associated with the blowdown water since all of thesubstations were in the plume as verified by the chemicaldata.

If one plots the snail mortality data against time (Figure 6) a rather interesting picture emerges. The length oftime required to kill 50% of the snails at the various substations are: 2L = 27.5 hr, 2M = 32.0 hr, 3L = 36.0 hr, 4L= 31.0 hr, and 5L = 72.0 hr. It appears that the data fromsubstation 4L is somewhat out of line. However, if one inspects the chlorine data (Table Ill, one finds that thechlorine concentrations were almost as high at substation4L (0.14 ppm) as they were at substation 3L (0.19 ppm).Also of interest is the observation that the snail survivalrate increased as the distance from the left bank increased. This also agrees with the chlorine data sincehigher concentrations were always found. near the left

Table II. Chlorine Residuals in Clinch River

bank and then decreased toward the outer limits of theplume.

The literature does not reveal any work that has beendone on bluegill sunfish and chlorine under in situ conditions. However, it would seem to be worthwhile to compare our findings with the interim criteria for freshwateraquatic life suggested by Brungs (7). He suggested thatfor intermittent chlorination that more resistant species offish (i.e., not trout and salmon) would not be protected ifthe total residual chlorine exceeded 0.2 mg/1. for a periodof 2 hr/day. From Figure 3 it can be determined that thetotal residual chlorine stayed about 0.2 mg/1. for approximately 50 min for that one fourth of the daily chlorinationcycle. For four chlorination periods a day it would appearthat the fish caged at station 2 were exposed to at least0.2 mg/1. for more than 3 hr/day. Also, they were exposedto 0.4 mg/1. for approximately 1 hr/day. These preliminary data tend to indicate that the Brungs (7) criterion of0.2 mg/1. for a period of 2 hr/day will probably be adequate to protect more resistant warm water fish such asthe bluegill.

The snail mortality suggests that the chlorine was eliciting a response from the organisms particularly the snaildeaths that occurred at station 5. It should be pointed outthat the snails possibly were responding to the heavy metals in the effluent; however, all of these ions were rather lowexcept for copper (Table I). The copper was low (80 jJ.g/I.) at station 5 where we did get snail mortality. It is chfficult to determine from the literature what the response ofthis particular snail might be to the range of copper concentration encountered in the plume area. A study byWurtz and Bridges (1961) gave an LCoo value of 0.27mg/1. of CuSO. for 96 hr for Physa heterostropha. Thiswas in laboratory-prepared water and highly controlledconditions, and on a snail of a different family (familyPhysidae) than the snails we utilized (Anculosa sp.) familyPleuroceidae). In the Wurtz and Bridges publication theLCoo values were for CuSO. and not Cu2 +; however, the

Distance from left

Distance fromHighest total Highest free bank that any Longest length of time

residual chlorine, chlorine residual, chlorine residual was that any chlorineStation no. Outfall,ft mg/I. mg/I. found, It residual remained, min

2 23 0.55 0.07 13-17 3003 100 0.19 0.04 N.D. >36lJa4 270 0.14 N.D. 12-14 2105 447 0.04 N.D. 4 767 < 1156 2203 0.00 N.D.

a Residual did not fall before following chlorination period. N.D. = not determined.

Table III. Fish and Snail Mortality Results from Clinch River-Chlorine Studies"Station il Station #2 Station ~3 Station tt Station ~5 Station ~6

Duration, ----Date Time hr M R L M R Lh M R M R M R M R

9-11-72 8 p.m. 3.5 _d

9·12-72 2 a.m. 9.58 a.m. 15.5 1/0 0/1 0/1 9/0 1/0 1/02 p.m. 21.5 1/0 0/1 1/0 2/08 p.m. 27.5 1/0 0/5 0/2 0/4 1/0 x' 5/0

9-13-72 8 a.m. 39.5 0/3 0/5 0/3 1/0 1/0 1/02 p.m. 45.5 0/2 0/1 0/3 0/4 0/18 p.m. 51.5 0/1 0/2 0/1

9-14-72 8 a.m. 63.5 0/1 0/12 p.m. 69.5 0/1 0/18 p.m. 75.5 1/0

9-15-72 8a.m. 87.5 0/44:30p.m. 96.0 1/0 0/1 1/0

a Number to left of slash equals number of observed fish mortalities. Number to right of slash equ.als the number of snail mortalities. I, Began bioassays at 4: 30 p.m., 9-11-72. {' Three snails were lost from bag. II No fish or snail mortality.·' X one snail was lost from bag.


Acknowledgments

We would like to thank G. E. Campbell, G. Crawford,D. Jonas, and G. Munsey of American Electric Power Service Corp. for their aid and assistance.

Literature Cited(1) Brook, A. J., Baker, A. L., Science, 176 (4042), 1414-15

(\972).(2) Brungs, W. A., "Water quality criteria recommendations for

total residual chlorine in fresh surface waters," Memorandumto F. T. Mayo, Regional Administrator EPA, Region V, 1971.

(3) Basch, R. E., "In situ investigation of the toxicity of chlorinated municipal wastewater treatment plant effluents to rainbow trout (Salmo gairdneri) and fathead minnows (Pimephalespromelas)," 50 pp, Bureau of Water Management, MichiganDepartment of Natural Resources, Lansing, Mich., 1971.

(4) Tsai, C., Chesapeake Sci., 9 (2), 83-93 (1968).(5) Ibid., 11 (1),34-41 (1970).(6) Sprague, J. 8., Drury, D. E., 1969. "Avoidance reactions of

salmonid fish to representative pollutants," in S. H. Jenkins(Ed.), "Advances in water pollution research," pp 169-79, Proc.4th Int. Cant., Prague, Pergamon Press, New York, N.Y., andOxford, England.

(7) Brungs, W. A., JWPCFA, 45 (10), 2180-93 (1973).(8) Wurtz, C. 8., Bridges, C. H., Proc. Po. Acad. Sci., 35, 51-6

(1961).(9) Cairns, John, Jr., Crossman, John S., Dickson, Kenneth L.,

Purdue Univ. Engrg. Bull. 137 (\), 182-92 (\972).

Summary

Even though a few fish deaths occurred during thestudy, none of these could be directly linked to the chlorine residuals in the river. Of the deaths, 87% occurredoutside the area influenced by chlorine.

The snail deaths appeared to be directly related to theblowdown discharge, and the snail survival rate increasedas the distance away from the outfall increased. Also,snail survival rates increased as the distance from the leftbank increased.

The snails demonstrated a higher sensitivity to theblowdown discharge than the fish.

Since the chlorine dissipates rather rapidly (none detected at 800 ft and no snail mortalities at 2203 ft) andsince the plume stayed close to the left bank, we feel thatthe portion of the river affected by the cooling water blowdown discharge will have little if any impact on the totalecology of the Clinch River.

Our preliminary data indicate that Brung's 1973 recommended criteria for total residual chlorine (0.2 mg/1. notto exceed 2 hr per day) will probably be adequate to protect more resistant warm water fish such as the bluegill.

However, Our study also indicates that more work isneeded to understand the toxicity of intermittently chlorinated cooling tower blowdown since we observed significant snail mortality at lower concentrations of chlorinewith less exposure time than Brung's 1973 recommendedcriteria of 0.04 mg/1. not to exceed 2 hr/day. It appearsfrom our data that the toxicity observed may not be afunction of chlorine toxicity alone but may involve coppertoxicity either independently or synergistically with chlorine.

Received for review October 9, 1973. Accepted June 17, 1974. Worksupported by American Electric Power Service Corp.

avoid the chlorine. Also the chlorine dissipated ratherquickly (none found at BOO ft and no mortality at 2203 ftbelow the outfall); therefore, a very minor area of the leftside of the river was under stress froin the blowdown discharge. Fish were observed in the vicinity of the dischargeplume during the study. However, previous studies at theplant have identified a "shadow" effect on the macrobenthos extending 2.5 mi below the plant particularly alongthe left bank of the river (9).

10000'0

".0 <\e7.~ 'f,7~' '\69.5 '\63.5

'\

51. '\

45.5 \', , \, Q

~I,

'\"- ,,,"-

,'"

,,0: , ,:J " ,0 , \r

,,27.5 ><:~

,,,,21,5 \ 0,

sueSTATIQN \0----0 ,. \O----<J. " \

15.5 e>----Q "o---~. "

40 60

% SURVIVAL

Figure 6. Time until death for 50% of snails at various substations

value we obtained at station 5 for Cu2 + was less than theamount of Cu2 + Wurtz and Bridges had in solution-i.e.,80 /lg/l. Table I vs. 108/Jg/1.

The information in Brungs (7) is of little or no valuewhen trying to interpret the snail mortality data. For intennittent chlorination, Brungs only considers species offish. He does mention in his summary, however, thatwarm water fish, snails and crayfish are less sensitive tochlorine than trout, salmon, and some fish-food organisms. As can be seen in Figures 4 and 5, the chlorine levels never exceeded 0.2 mg/1. at stations 3 and 4 but stillthe snail mortality rate was high for these stations. Againit might be suggested that copper was acting independently or synergistically to cause this lethality.

Nevertheless, it is significant that at station 5 (447 ftbelow outfall) the maximum recorded total residual chlorine concentration was 0.04 mg/1. and that a 50% mortality of snails was observed in 72 hr. While it is not possibleto determine from the data how long the test organismswere exposed to 0.04 mg/1. total residual chlorine, thesedata show that there were some significant responsesi.e., mortality of snails. Extrapolation of the data in Figure 5 (270 ft below the outfall) shows that the total chlorine residual probably exceeded 0.04 ppm for approximately 160 min in 24 hr. Due to the rate of dissipation ofchlorine as it proceeds downstream (shown in Figures 2-4)it is highly unlikely that the test organisms at station 5(447 ft below the outfall) were exposed to 0.04 ppm totalresidual chlorine for 2 hr/day. While the data on snailmortality indicate that toxic conditions exist due to theblowdown it is not possible to explicitly identify the causeof the toxicity. However the analytical data indicate thatthe probable cause of the toxicity was chlorine and/orcopper either independently or acting synergistically. Additional work is needed to allocate the toxic effects of thevarious constituents of the blowdown.

It appears, however, that the total impact of the chlorine and other blowdown constituents of the dischargeplume at the Clinch River plant was quite negligible onthe total ecology of the stream. The chlorine plume extends into the river approximately 20 ft; therefore, anyorganisms moving up- or downstream would be able to


NOTES

Determination of Submicrogram Quantities of Monomethyl Mercuryin Aquatic Samples

James J. Bisogni, Jr., * and Alonzo Wm. Lawrence

Department of Environmental Engineering, Cornell University, Ithaca, N.Y. 14850

• A method of measuring submicrogram quantities ofmonomethyl mercury is described. The procedure combines aspects of several published methods of mercuryanalysis. Methyl mercury is separated from inorganicmercury by benzene extraction. The extracted methylmercury is then analyzed by a flameless atomic absorption procedure. Thin-layer chromatography is employed asa verification step. The procedure is applicable to a widevariety of aquatic samples containing monomethyl mercury. Interfering agents include elevated concentrations ofchlorides, organic solvents, inorganic mercury, dimethylmercury, and other forms of organic mercury. Methods toattenuate these interferences are discussed. Mean recovery efficiencies of greater than 90% were obtained withcoefficients of variation less than 4.1% for monomethylmercury spiked into microbial biomass. The appropriateanalytical apparatus can be set up at a relatively low cost.

The recent discovery of high concentrations of mercury,particularly methyl mercury, in some aquatic life [Irukayama et al. (1) J has initiated much investigation intomethods of analyzing for organomercurials. Several different techniques have been utilized by various investigators[Gage (2), Westoo (3), Talton and Wagstaffe (4)]. Thesetechniques are all concerned with: separating total mercury from its organic or inorganic matrix, separating the organomercurial from the inorganic mercury, and quantitatively measuring the segregated mercury forms.

The method described here incorporates modificationsof several schemes to analyze for monomethyl mercury inaqueous solution, biomass, or inorganic and organic sediment. The analsis is a modified combination of We~too's

(3) benzene-cysteine extraction procedure and Hatch andOtt's (5) cold vapor atomic absorption technique. Theprocedure involves essentially three steps: separation ofthe organic mercury from inorganic mercury, identification of the separated organomercury with thin-layer chromatography, and measuring the amount of separated organomercury.

Step 1 includes a separation of the monomethyl mercury from its binding matrix (if present), as well as separation from inorganic forms of mercury. The chemistry ofthis extraction step is presented by Westoo (3). The Westoo extraction procedure is accomplished by converting allmonomethyl mercury forms to methyl mercuric chloride.The conversion is carried out by acidifying a homogenizedsample with HCl. The methyl mercuric chloride is thenextracted into benzene. This extraction separates the organomercurials from most of the inorganic mercury andfrom the original methyl mercury matrix. Following theextraction into benzene, methyl mercuric chloride is partitioned back into an aqueous phase. This is accomplishedby converting the methyl-mercuric chloride to methylmercuric cysteine [CH3HgSCH2CH(NH2)COOH]. Themethyl mercuric cysteine is partitioned favorably into the


aqueous phase because of its carboxyl group's affinity forwater.

Step 2 involves taking a portion of the benzene extractand identifying the organomercurials that are present. Organic mercury compounds, such as phenyl, methoxyethyl,and ethyl mercury, tend to be extracted in Step 1. It isthe intent of this analysis to measure only monomethylmercury, so it is necessary to verify that monomethylmercury is the predominant extracted mercury form. Thisverification can be accomplished by employing the thinlayer chromatography technique developed by Westoo (3).

Step 3 of the analysis is concerned with measuring theamount of methyl mercury yielded from the extractionprocess of Step 1. This procedure is essentially the flameless atomic absorption (FAA) technique proposed byHatch and Ott (5) and used by Kopp et al. (6). The analysis consists of a wet oxidation of all forms of mercury tothe mercuric form, followed by a reduction of mercuric ionto metallic mercury. The metallic mercury is vaporizedand pumped through an absorption cell of a photometer.Mercury vapor absorbs light at a characteristic wavelength of 2537 nm. Absorbance is proportional to mercuryvapor concentration according to Beer's Law.

Procedure

The seven-step procedure for monomethyl mercuryanalysis is given here:

Homogenize 50 ml of sample. This sample should contain less than 4 I'g of methyl mercury as mercury. Solidsamples should be suspended in 50 ml of deionized water.

Place the homogenate in a 500-ml separatory funnel andacidify with 15 ml of concentrated hydrochloric acid. Mixthe acidified sample thoroughly.

Add 70 ml of A. R. graqe thiophene-free benzene andshake vigorously for 5 min. Let the phases separate anddrain off a portion of the organic solvent; centrifuge thisextract to obtain a clear benzene layer.

To a 60-mt separatory funnel, transfer an appropriatevolume of the clear benzene solution. The volume usedwill depend on the initial concentration of methyl mercury in the sample and calibration range of the FAA instrument.

Add 5.0 ml of 1.0% cysteine acetate solution to the benzene extract. The cysteine acetate solution is prepared bydissolving 1.0 gram of cysteine hydrochloride monohydrate, 0.744 gram of sodium acetate trihydrate and 12.5grams of anhydrous sodium sulfate in 100 ml of deionizedwater.

Shake the benzene-cysteine acetate mixture vigorouslyfor 2-3 min. Allow the phases to separate. If a clear aqueous layer (bottom layer) is not obtained, this layer mustbe centrifuged. Care must be taken not to allow any benzene to be transferred with the aqueous phase, since benzene is an interfering agent in the FAA analysis.

Submit an appropriate aliquot of clarified (clear) aqueous solution to the FAA total mercury analysis as described below.

The flameless atomic absorption method for total mercury analysis is given in five steps as follows:

To a aoo-mt BOD bottle transfer the sample containingan amount of mercury which falls into the calibrationrange of the atomic absorption spectrophotometer. Addenough distilled water to bring the total volume to 100 ml.Mix thoroughly and add 5 ml of concentrated sulfuric acidand 5 ml of concentrated nitric acid.

Add 1 ml of 5% (w!v) KMnO. solution to the bottle,shake, and add additional portions of potassium permanganate solution until the purple color persists for 15 min.Add 2 ml of 5% (w!v) K2S2 0 S and heat the bottle andcontents for 2 hr at 95°C.

Remove bottle from heat source and bubhle mercuryfree nitrogen or oxygen through the sample for 10-15 min.This is done to strip the sample of any benzene contamination.

After the bottle and sample have cooled to room temperature, add 2 ml of 12% (w!v) hydroxylamine hydrochloride solution to reduce excess permanganate.

Add 5 ml of 10% (w!v) stannous chloride solution andimmediately attach the bottle to the aeration apparatus ofthe atomic absorption spectrophotometer. Record thepeak absorbance. Remove the bubbler from the BOD bottle and vent the system into an exhaust hood.

The quantity of mercury in the sample is determinedfrom a calibration curve and adjustment of this value byappropriate dilution factors.

A. R. grade chemical reagents are employed for allanalyses. A careful check on blank values is necessary toensure low background mercury levels. Glassware shouldbe cleaned with hot soapy water, followed by a nitric acidwash, and a final rinse with deionized water.

Results

A series of mercury analyses was performed on severaltypes of aquatic samples to determine the accuracy, precision, and recovery efficiency of the proposed method ofanalysis.

Table I presents the results of a series of experimentsused to evaluate the accuracy and precision of direct FAAtotal mercury analysis used in this research.

Table II shows the recovery efficiency, precision, andaccuracy of direct FAA total mercury analysis when themercury was spiked into anaerobic or aerobic microbialbiomass. The anaerobic and aerobic microbial biomasswas obtained from laboratory microbial reactors used inaerobic and anaerobic mercury methylation studies (7).

Table III shows the overall accuracy, precision, and recovery efficiency for the benzene-cysteine extraction followed by the FAA total mercury analysis.

Discussion

The combined extraction-atomic absorption techniquefor monomethyl mercury analysis is straightforward. Theusual precautions must be observed when handling allforms of mercury. In addition, care must be taken toavoid prolonged contact and inhalation of benzene.

Organic solvents, particularly benzene, absorb radiationat a wavelength of 25:17 nm and thus interfere with theFAA analysis. Chloride ions can be oxidized to chlorine inthe oxidation step of the total mercury analysis. Chlorinealso absorbs 2537 nm light. Both benzene and chloride interference can be eliminated by aerating the sample afterthe oxidation step in the FAA procedure.

Inorganic mercury can interfere with the organic mercu-

Table III. Recovery Efficiencies of Benzene-CysteineAcetate Procedure for Organic MercuryAnalysis

Meanmeasured

True concn, COllcn,"p/i. "gil.

Coeff ofvariation

Mean % (n = 4).recovery %

99.1 1.20

97.7 2.96

91.3 4.05

Table I. Accuracy, Precision, and Recovery Efficiencyof Direct FAA Total Mercury Analysis

Meanmea- Coeff

True sured of Meanconen, value, Std dev, varia- %re·

Sample "gil. "gil. 0=4 tion, % covery

Inorganic mercury(J 0.68 0.67 ±0.04 5.60 99.3(HgCI,)

Organic mercury" 4.20 4.16 ±0.10 2.62 99.2(phenylmercuricacetate)

Methylmercuric 2.00 1.99 ±0.06 3.37 99.9chloride

<I EPA reference sample.

Table II. Accuracy, Precision, and Recovery Efficiencyof Direct FAA Total Mercury Analysis forInorganic and Organic Mercury Spiked inMicrobial Biomass

Sample

Phenylmercuric 0.132acetate in de·ionized H,O

CH,HgCI in de· 0.118ionized H,O

CH,HgCI in 800 mgt 4.00I. anaerobic mi·crobial solids sus·pension

CH,HgCI in 800 mgt 4.00l. aerobic micro-bial solids sus·pension

0.131

0.115

3.65

3.71 92.8 3.51

Mean Coeff ofTrue mcaSllred variation

conen, conen. Mean % (n = 4),Sample J,lgjl. J.lgJI. recovery %

Mercuric chloride 1.00 0.92 92.0 3.1spiked in anaerobicmicrobial biomass

Mercuric chloride 1.00 0.94 94.0 2.8spiked in aerobicmicrobial biomass

Methylmercuric 3.00 2.77 92.3 6.8chloride spiked inanaerobic microbialbiomass

Methylmercuric 3.00 2.83 94.3 5.6chloride spiked inaerobic microbialbiomass

Table IV. Inorganic Mercury Interference in BenzeneCysteine Acetate Analysis for Organic Mercury

~n_o_,g_'._n_ic_m_e_,_c_u,_y_concentra_l_io_n _

Sample 1 mgtl. as Hg 5 mgt/. as Hg 100 mg/1. as Hg

Deionized water 0.002 "g Hg/ O.OOl"g Hg/ 0.035 "g Hg/ml CoHo mIC,H, mIC,H,

Aerobic microbial Not Not 0.006 "g Hg/solids suspen· detectable detectable ml C,H,sion, 1000 mg/I.

Anaerobic micro· Not Not 0.001 "g Hg/bial solids sus- detectable detectable ml C,H,pension, 1000mg/I., total S =10 mg/I.

Volume 8, Number 9. September 1974 851

ry analysis because it can be carried over during the benzene extraction. The degree of interference from inorganicmercury depends on the nature of the sample and theconcentration of inorganic mercury in the sample. TableIV shows the effect of sample type and inorganic mercuryconcentration on inorganic mercury carryover into benzene. The magnitude of the error caused by inorganicmercury will depend on the amount of organic mercurythat is being extracted. Error calculations should be performed for each analysis. If very small quantities of organic mercury are to be extracted in the presence of highbackground levels of inorganic mercury, addition of 10grams of NaCl to the homogenized sample, before extraction, will minimize inorganic mercury interference. Theformation of complexes, such as aHgCI3 or Na2HgCI4,probably prevents the inorganic mercury from being partitioned into the benzene phase (8). A solution containing10 mg/1. mercuric mercury was treated with NaCI andsubmitted to the benzene extraction procedure. Inorganicmercury carryover was not detected in the extract.

It is apparent from Tables I and III that extraneous organomercurials (in this case phenylmercury) can be extracted and detected by the above analysis. This type ofinterference is difficult to overcome. Samples with highconcentrations of extraneous organomercurials (not methyl mercury) should not be analyzed with the describedprocedure.

In such situations the only practical recourse is to usethe more expensive gas-liquid chromatography system.Fortunately, in many natural aquatic systems, not directly contaminated by specific organomercurials, monomethyl mercury appears to be the dominant organomercurial.For such situations the procedure described is attractive.

Finally, dimethyl mercury can interfere with monomethyl mercury analyses if excess mercuric ions are present in the sample. Under acidic conditions and excessmercuric mercury, dimethyl mercury is converted to monomethyl mercury according to Equation 1.

"C1CH,H~CH:I ' HgCl 2 2CH:,HgCI (I)

Dimethyl mercury interference should not present significant problems in most samples because of the relatively low water solubility and high volatility of (CH3l2Hg. It


should be noted that dimethyl mercury analyses can beperformed by adding excess mercuric ions to the sample,converting to monomethyl mercury (Equation I), then analyzing the monomethyl mercury according to the procedure described above.

The recovery efficiencies reported here are higher thanthose reported by Westoo (3). WestiiO explains that therelatively low recovery «90%) of methyl mercury iscaused mainly by unfavorable partition coefficients ofmethyl mercuric chloride between aqueous and benzenephases. The procedure described above has one less extraction step than the Westoo procedure and hence is lesssusceptible to partition coefficient related recovery problems.

The necessary apparatus to perform this monomethylmercury analysis is relatively inexpensive (about $1500).The FAA instrument used for the above analysis was aColeman MAS-50 (Maywood, 111.).

Summary

The proposed monomethyl mercury analysis appears tobe relatively accurate and precise with recovery efficiencies 'greater than 90% and standard deviation less than4.1% for monomethyl mercury samples spiked in inorganicand organic matrices. Dimethyl mercury can interferewith the analysis in the presence of excess mercuric ions.Interfering agents, such as inorganic mercury, organic solvents, and chloride, can be readily eliminated. Extraneousorganomercurials can make the analysis unacceptable.

Literature Cited

(1) lrukayama. K., Kujiki. M.. Kai, F.. Kondo, T.. KumamotoMed .•J.. 14, 157-63 (1961) (.Japan.).

(2) Gage. J. C.. Analy"t. 56, 457-9 (1961).(3) Westoo, G.. Acta. Chern. Scand.. 21, 1790-1800 (1967).(4) Tatton, J. O·G.. Wagstaffe. P. J .. J. Chromato/i.. 44, 284-9

(1969).(5) Hatch. W. R.. Ott. W. L.. Anal. Chern .. 40,2085-7 (1968).(6) Kopp. J. F.. Longbottom, M. C.. Lobring, L. B.. J. Amer.

Water Work" Ass., 64,20-5 (1972).(7) Bisogni. J. J .. Lawrence, A. Wm.. Technical Report 63. Cor·

nell University Water Resources and Marine Sciences Center,Ithaca. .Y. (1973).

(8) Linhardt. G. A.,.J. Amer. Chern. Soc .. 37.258-74 (1915),

Received for review AU/iu"t 22. 1973. Accepted Ma." 23. 1974.

INDUSTRY TRENDS

The Badger Co., Inc., has been selected by the Koppers Co. to expandits phthalic anhydride facility at Chicago, III. The facility will have a175-million-lb/yr capacity.

Goodyear and The Oil Shale Corp.(TOSCO) are operating a pilot plantto test a TOSCO process for making

General Dynamics Corp. will build aprototype environmental data buoyfor the National Oceanic and Atmospheric Administration (NOAA). The$873,000 award includes an optionfor five additional buoys.

Westinghouse Electric Corp. receiveda $500.000 contract from the National Science Foundation to design. install. and analyze a solar heating andair conditioning system, the first for alarge building. at the George A.Towns Elementary School (Atlanta.Ga.).

A major breakthrough inchemical analyses. An electro

system for the continuous measuof ammonia in process and

streams. Strip chart recordalarm/controlou

On~line

NHsAnalysis

Roy F. Weston, Inc. announced thesale of the assets and business of itsWeston & Stack subsidiary to Rexnord, Inc., for cash and an undisclosed amount of stock.

LFE Environmental Analysis Laboratories Division (Richmond, Calif.), adivision of LFE Corp.. was accreditedby the American Board of IndustrialHygiene, whose accreditation program is funded by N10SH.

Versar Inc. (Springfield. Va.) got acontract from EPA to conduct microeconomic analyses of the usagesof various toxic substances in theU.S. economy. Contract value was$136.835.

first pressurized water nuclear powerplant in Sweden. and is 820.000 kW.The plant achieved criticality in lessthan 4 Y2 years from the beginning ofconstruction.

American Smelting and Refining Co.(ASARCO) announced that the initialphase of its test program of an elemental sulfur pilot plant. for treati ngstack S02. interrupted by a reactorbreakdown in 1972. has now beencompleted. The plant is at EI Paso.Tex.

The Midrex Corp. has recently beenformed by the Korf Group at Charlotte. N.C. Midrex provides turn-keyservices for a patented process toconvert iron oxides as pellets or lumpore to highly reduced iron materialfor electric arc steelmaking.

Systems, Science & Software has received a contract from the U.S. Inte- "rior Department's Geological Survey •to study fluid rock interaction as ameans of predicting earthquakes.

International Paper Co. has withdrawn its offer to General Crude OilCo. to merge General Crude into asubsidiary of International. and hasterminated negotiations with respectto the transaction.

Ecodyne Limited (Canada) has beenawarded three contracts in excess of$5 million for water and wastewatertreatment equipment. Work will bedone at the Tar Sands (Alberta) andin Ontario and Quebec.

A Westinghouse-supplied reactor inSweden is a part of Ringhals 2. the

Met-Pro Corp. announced that RobertSmith has been named president of arecently formed subsidiary. Met-ProSystems, Inc.

WAPORA. Inc. (Washington. D.C.)has announced the opening of twobranch offices at La Crosse. Wis..and Davenport, Iowa.

Eastman Kodak Co. awarded RichardMills. 17. of Okeechobee. Fla. $100first award in the 25th International ,---------------------------------

Science and Engineering Fair for awell-documented study which concluded that the Food and Drug Administration's allowable mercury levelin drinking water could still be toohigh for human safety.

Enviro Development Co.. Inc.. hasrecently been formed at Palo Alto.Calif. The company specializes inworldwide discovery and placementof environmental control technology.



Whatman'" Glass Microfiber papers give more efficient monitoring offine particles-with much lower resistance to flow of air, stack effluents,or other gases-than cellulose papers.

oil and other materials from scraprubber tires.

Milton Roy Co. (St. Petersburg, Fla.)will purchase the assets of theCheminert valve and fitting line ofSpectra Physics, Inco (MountainView, Calif.). Terms were not disclosed.

WAPORA, Inc. has hired one of thenation's top experts in paint-relatedpollution, Francis Scofield, as SeniorAdviser.

Commonwealth Associates Inc.(Jackson, Mich.) has com pleted anenvironmental impact study for theIsland of Bob-lo Co., in connectionwith docking facilities for additionalaccess to Bois Blanc (Bob-lo)Island in the Detroit River.

Zimmite Corp. (Cleveland, Ohio) announces availability of limmite lC305, a synergistic blend of nonpolluting corrosion and deposit inhibitorsformulated for use in large industrialrecirculating cooling water systems.

Biospherics, Inc, (Rockville, Md.)and Union Carbide Corp. have signeda letter of 1ntent for a license agreement by which Union Carbide willprovide worldwide marketing of Biospherics' patented PhoStrip process

• High retention efficiencyfor particles down to 0.01 lJ ingaseous systems

• Excellent optical propertiesimmersion in benzene, for example, makes GF papers transparent, allowing examinationof filtered particles by conventional microscopy

• Chemical/biologicalresistance-for oil mists and polycyclic hydrocarbons as well as microorganisms

Liquid Filtration, TooThese binder-free 100%-boro

silicate glass papers have controlled fiber size to filter liquid

for removing phosphorus from wastewater.

The Heil Co. (Milwaukee, Wis.) solda complete waste shredding systemto Chaffee County, Colo. The systemwill pulverize wastes at a rate of upto 15 tons/hr.

Maxon Industries. Inc. (HuntingtonPark, Calif.), manufacture:rs of oneman-operated refuse collection/compaction vehicles, has acquired controlling interest in Bemars, Inc., largest Western maker of front-loadingrefuse collection/compaction vehicles.

Research-Cottrell, Inc. acq uired allof the operating assets and liabilitiesof Jeffco Steel Fabricators, Inc.Jeffco supplies Research-Cottrellwith 250 tons/mo of fabricated steelfor Research-Cottrell's pollution control equipment.

H. V. Weeks, Inc. (Somerville, N.J.)is engaged in electrical engineeringand other consulting work for theFluorspar Co. of Kenya, Ltd., whichexpects to complete a new fluorsparbeneficiation plant on the KimwarerRiver, Kenya, in early 1975.

Howard Needles Tammen & Bergendoff (HNTB, Kansas City, Mo.) has

systems more effectively thanfinest cellulose papers and muchfaster with much higher capacities than membranes. New ultrafine grade retains submicronparticles.

For details, write

H. Reeve Angel & Co., Inc.9 Bridewell Place .Clifton, N.J. 07014

JIB, reeve angel

created Frankfurter Inc., following itsacquisition of Frankfurter & Associates, Inc., a company with broadexperience in facility design for thewood, pulp, and paper industry.

A Health-Chem Corp. (New YorkCity) subsidiary has received a temporary EPA permit to conduct fieldevaluations of a new insecticidaltape in areas where roaches poseproblems.

Pfizer Inc. is treating coconut palmsin Florida, threatened by lethal yellowing, with "terramycin" after EPAapproved a registration petition toallow its use. lethal yellowing hasreached epidemic proportions inFlorida.

Combustion Equipment Associates.Inc. will negotiate a contract for thedesign, construction, and operationof a regional waste utility with theHousatonic Valley Council of ElectedOfficials (Danbury, Conn.). Capitalcost could be $35 million.

General Environmental Equipment,Inc. (Jacksonville, Fla.) will providetemporary sewage treatment facilities for the Sangaree developmentbeing built near Charleston, S.C., thelargest project of its type in SouthCarolina history.

Ecodyne Corp. foresees that its second and third quarter earnings will beadversely affected by continuing materials shortages, effects of inflation,and high costs of money.

Wheelabrator-Frye Inco has beenawarded an order by Republic SteelCorp. for a "Dustube Collector" airpollution control system to be installed at Republic's Melt Shop atCanton, Ohio. Cost will exceed $5million.

Crane Co. reports that five of nine 10X 15 ft microstrainers, to be installedfor tertiary sewage treatment, arrivedin Chicago late in July. Shipped fromScotland, they will be installed at theDowners Grove, III. Sanitary District.

Con Edison, New York, N.Y., is transplanting over 30,000 hatchery-rearedstriped bass to the Hudson River totry to prove that artificially reared fishcan survive in the river. The fish studies are related to Con Ed's proposedpumped-storage power plant.

Universal Oil Products Co. is introducing a new, nonpolluting liquid polymeric compound which loosens anddisperses dirt, silt, and organic deposits in cooling' water systems.

Simpson Timber Co., Seattle, Wash.,recently set a reforestation milestoneby planting redwood seedlings on a50,000-acre tract of the company'snorthern California timberlands.



Lead test kitLead-in-gasoline field test kit provides quantitative measurement ofthe lead in unleaded gasoline in therange 0.00-0.10 g/gal. The unit canbe used for gasoline-containing traces of any lead alkyl type. includingTML. TEL. reaction mixes 25..50.and 75. and any physical mix of TMLand TEL. Features of the kit includelight weight. and automatic timer.Beckman Instruments. Inc. 101

Chemical feed pumpSelf-priming. diaphragm positive displacement pump is designed for controlling feeding to cooling towers.sumps. and water mains. Constructed of Penton. the pump headand suction and discharge fittingsare made to resist corrosive chemicals. The housing and base are fiberglass-rei nforced polyester. Pressureratings range from 20 in. of vacuumto 100 psi. Neptune Chemical Co.

102

Particle analyzerParticle analyzer with patented ell iptical mirror sensor exceeds federalspecifications for monitoring controlled environments. Model displaysparticle counts on a 5-decade digitaldisplay. with size selection of 0.5. 1.3. 5. 10 Ii. and greater under controlof a switch selectable count cycle of1 or 4 min. Also features flow meter.Climetlnstruments Co. 103

Weather monitorSystem is patterned after standardESSA/Weather Bureau and Air Forcesystems for monitoring atmospherictemperature and dew point atmeterological stations. The dew pointmeasurement is accomplished with aspecial lithium chloride sensor thatfeatures platinum electrodes on awoven glass bobbin. Temperaturesare measured with platinum RTDs.General Eastern Corp. 104

NEW PRODUCTS

Salts scrubberSystem abates zinc chloride and ammonium chloride particles fromfumes at plants that galvanize steelstrip. It collects the fumes at the galvanizing tank through two hoodswhere the sheet steel enters the molten zinc. The hot gases are cooledand passed through pressurized liquid sprays. Cyclone separator removes the remaining solids. Heil Process Equipment Co. 105

Coliform testerConstant-temperature water bath isdesigned for determination of fecalcoliform content of water and sewage samples at 44.5 ± 0.2°C. asspecified by the EPA. The unit features solid state circuitry and automatic push-button temperature setting for the specified 44.5°C. withprecise temperature control whenfully loaded. GCA/Precision Scientific 106

Mud removersTreatment is designed to conditionand effectively prevent and removedeposits of mud. sediment. ironoxide. and other foul ants commonlyfound in once-through or recirculating cooling systems. Expected to findwide application in the steel industryfor blast furnace. BOF. and othercooling applications. The treatmentalso is ideally suited for use in thepetroleum and chemical industries.Zimmite Corp. 107

Permeation tubesPermeation tubes for the accurateand reproducible calibration of gasesare offered in a variety of substancesover a wide range of concentrationlevels. Design provides concentrations that vary less than 3% per °c.This allows for both greater accuracy

and greater economy since temperature control precision is minimized.Guaranteed for one year. Tracor Instruments. 108

Chlorine analyzerMultirange chlorine analyzer usesunique solid state probe. Devicemeasures true sanitizing power as itresponds to the various chlorineforms in direct proportion to their efficiency as disinfectants. It providesfast and accurate tests in water supply, sewage. and pollution control. industrial process and waste treatment. as well as cooling tower water.Delta Scientific 110

Particle monitorCompact high-concentration andhighly sensitive automatic particlecounter is designed for ambient airanalysis. Particle concentration is100.000.000 particles/ft3 Sensitivityis 0.5 Ii standard and greater with incremental selection over the full dynamic range. All solid state unit features a built-in 5-channel data memory system. Royco Instruments. Inc.

111

Water analyzerProbe colorimeter for water analyzereliminates sample handling andneeds no special glassware or cuvettes. I t utilizes fiber optics andphase-shifted light. The device canencompass 19 water and waste analyses from nitrogen and selenium at420 nm through fluids and ammoniaat 650 nm including cyanide andchloride at 620 nm. Brinkmann Instruments Inc. 109

Dust controllerSystem works with virtually any dustybulk material and is particularly applicable in situations where dust isgenerated at a wide variety of points

(Continued on poge 856)

Need more information about anyitems? If so. iust circle the appropriate numbers on one of the readerservice cards bound into the back ofthis issue and mail in the card. Nostamp is necessary.


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where other systems are prohibitivelyexpensive. It controls dust by meansof specially prepared dust suppressant diluted at the ratio of 1-1000 galof water. The Johnson-March Corp.

112

VCM monitorSystem monitors vinyl chloride monomer in air and provides a log ofthe analyses. A flame ionization detector provides a maximum sensitivity of 0-1 ppm. with a detection capability of approximately 25 ppb. Amaximum of 15 sample points located up to 1500 ft away can be monitored and logged. Audible and visualalarms indicate when preset concentration levels have been exceeded.TC Systems. Inc. 113

Screening systemEconomical and attractive screeningsystem is designed for cooling towers and other mechanical equipment.Fabricated from 0.020 in. thick aluminum in a 3 in. wide X 1'/4 in. deepmodule. the product is appropriatewherever unsightly equipmentcreates an eye sore. The system isinexpensively installed. and maintenance free. Construction Specialties.Inc 114

Vapor disposaf unitDisposal unit eliminates hydrocarbonvapors from gasoline loading operations. It is 99.9% efficient and iscompletely automatic, quiet. andeconomical to operate. Two or foursmall oil or gas burners fire in pairs.as required. to assist oxidation of thev<1pors. Safety features include threestage flashback protection. and a series of interlocks. National AiroilBurner Co .. Inc. 115

Vibratory separatorNew 72-inch diameter separator features high-capacity vibratory screening for wastewater cleanup in meatand poultry plants. as well as vegetable. fruit. and other canneries.Screen blinding is kept to a minimumby self-cleaning kit composed ofsharp-edged cylinders that scrape offfibrous material and particles fromthe screen cloth. Sweco. Inc. 116

Waste concentratorEvaporation process is more efficientthan conventional evaporation processes because it does not use vac-

uum or condenser water. The process is multistage, Low-temperaturestack gases emit pollution-free exhaust. It can be used in any plant operation requiring this steam evaporation system. It operates according toa forced circulation flash evaporationmethod. Ozark-Mahoning Co. 117

Electrostatic precipitatorDry electrostatic precipitator handlesa gas flow of 780.000 cfm at 285°F.Efficiency is 99%. A major designadvance has increased significantlyboth the mechanical life and theoverall efficiency of the unit. A rigidelectrode bar configuration is used inplace of a weighted wire electrodegrid. Maintenance problems are reduced. United States Filter Corp.

125

Air monitoring systemComprehensive monitoring systemprovides data to assess accuratelyair quality and meterological conditions. All software and hardware required by electric utilities. industrialcompanies. and governmental agencies undertaking such monitoringchores are included. Sensors and analyzers inside the station continuously monitor S02. NOx • particulates.photochemical oxidants. hydrocarbons. and CO2. Westinghouse Electric Corp. 126

Glass crusherCrusher grinds up 1-gal and smallersize bottles and jugs to reduce wastehandling and removal costs. The unitfits atop any standard 30- or 55-galdrum. and crushes glass containersto one fifth their previous volume. Itcan handle up to 600 bottles perhour. Unit is powered by a 'h-hpelectric motor, A window at chute'sbase shows when the drum is full.Uhrden, Inc. 127

NEW LITERATUREBaghouses and evaporative coolers.A technical catalog of latest air pollution control equipment also contains an engineering evaluation by anend user on various types of collectors on coal-fired boilers. as well astechnical articles. Standard HavensInc. 151

Refrigeration probes. Bulletin FC-2describes immersion probes capableof achieving ultimate low temperatures of -90°C (-130°Fj with refrigeration capacities to 1900 Btu/hr at-40°C (-40°F). Eliminates need forDry Ice. FTS Systems Inc. 152

Sludge density controller. Two-pagebulletin PDS-4100 describes thecompany's Sensall 494T sludge density controller. Instrument ultrasonically senses sludge density and controls pumps in waste treatmentplants. National Sonics 153

Specialty gas. Picture booklet describes company's efforts to ensureproduct purity for largest inventory ofspecialty gases in the world. Matheson Gas Products 154

Opacity monitor. Six-page brochureon RM7A opacity monitor describestransmissometer system designed toprovide accurate. continuous measurement of opacity of smoke anddust emissions at various facilities.Lear Siegler 155

Lubricant analysis. Booklet details ananalysis service available from thecompany, and explains why fluids inhydraulic equipment and machinetools should be tested periodically.Contamination effects are described.Rexnord Inc. 156

NO-NOx analyzer. Data sheet concerning the company's Model 12Aultrasensitive NO-NOx chemiluminescent analyzer, designed for labo,ratory use where a wide range ofscales is required, is available. Thermo Electron Corp. 157

Need more information about anyitems? If so. just circle the appropriate numbers on one of the readerservice cards bound into the back ofthis issue and maif in the card. Nostamp is necessary.

NO-NOx analyzer. Company's Model44 analyzer, designed specifically forautomotive testing, is described infour-page catalog. Thermo ElectronCorp. 158

Multicartridge fillers. New productdata bulletin describing the company's multiple cartridge filter housingsfor high-efficiency liquid and gas filtration is now available. Balston, Inc.

159

Systems leasing. Capital conservation through environmental systemsleasing is featured in a new 12-page,full-color brochure entitled "Environmental financing; financial alternatives for capital conservation."Wheelabrator Financial Corp. 160

Atomic absorption. Brochure covering the company's improved HGA2100 furnace describes sensitivity increase by the furnace of an atomicabsorption instrument simplifyingtrace determinations, such as toxicmetal pollutants in blood serum andwater. Perkin-Elmer Corp. 161

,IIIIIIII

Your time is valuable.So, before you come to the International Pollution Engi

neering Exposition, write to find out what we will highlight atthe show and what our capabilities are. If we have theequipment and services that can solve your problem, visitour information center there.

And if we don't, your time can be spent more productivelyelsewhere.

If you'd like specific information about our equipmentbefore you attend the show, write for our brochure, "TheEnvironment and Combustion Engineering." If you don'tplan on attending, send for our brochure anyway.

See us in Booth 642 at the Third International PollutionEngineering Exposition & Congress, Chicago, Illinois,Sept. 9-12.

If you have pollution control problems,don't waste your time in ourbooth at the I.P.E.E.Show;r--

IIIII Combustion Engineering, Inc.

Depl. 692-19E, Prospect Hill Road

I Windsor, Conn. 06095o Please send me the C-E brochure, "TheEnvironment and Combustion Engineering."

I =Name;;-------

.....--1"2 COMBUSTION I =:::=i~:=:y _~t....=J ENGINEERING I Address I

The EnergySystems Company L Cily Slale Zip ES-9_______i:.I



Products forWastewaterAnalysis::::::::

Hach Chemical Company offers you all kinds of wastewater analysis information.It's geared to assist municipaland industrial wastewatertreatment plants in conducting the many EPA tests whichare now required.

Simplified methods, necessary chemicals, apparatus,and glassware are listed.

Write today for your freeHach Wastewater Analysisinformation.

CHEMICAL COMPANYP.O. Box 907· Ames, Iowa 50010 U.S.A.

Phone: 515-232-2533TWX: 910-520-1158

And: Hach Europe Namur, BelgiumCIRClE 8 ON READER SERVICE CARD


Cyanide analysis. Brochure describesautomatic instrument for analysis oftotal cyanide in waste streams. Technicon Industrial Systems 162

Aquatic research systems. Six-pagebulletin describes and illustrates acomplete line of systems, equipment,and materials for aquatic researchand life-science education. AquariumSystems Inc. 163

Temperature recorders. Four-pagebrochure describes a complete lineof adhesive-backed temperature recorders for 100-500°F. TelatempCorp. 164

Titration electrodes. Bulletin 120013-639 describes electrodes for precise pH measurement. Forty differentelectrodes are Iisted along with specifications. Fisher Scientific Co. 165

Sump pumps. Catalog 12.0 describesa complete line of "Sump-Gard"heavy-duty engineered all-plasticsump pumps with capacities of5-500 gpm and depths to 12 It. Vanton Pump & Equipment Corp. 166

Sample storage. Brochure describessample storage system for collecting,cataloging, and storing liquid, powdered, and solid specimens in labeled glass vials. Over 25 samplestorage set models are covered. R.P. Cargille Laboratories, Inc. 167

NOx meter. Two-page bulletin No.5742100 describes and gives specifications for the company's new NO,N02. and NOx measuring device,MEC-2100. McMillan ElectronicsCorp. 168

Corrosion control. Four-page bulletin717 describes chromate-based andnonchromate inhibitors that providean environmentally sate corrosioncontrol program. Betz 169

Filter company. Booklets and brochures describe 70-year-old firmwhich fabricates a variety of fillersfor water quality and pollution control. Products are also described.Star Tank & Filter Corp. 170

Air pOllution apparatus. A four-pagebrochure of products for air testinglaboratories, including bubblers, impingers, COllection tubes, and relatedproducts, is now available. Manyitems feature joints which seal without grease. Wheaton Scientific 171

Isotopes. Catalog describing and listing stable isotopes and labeled compounds and nmr reference standardsis now available. Matheson GasProducts 172

Flow diverters. Revised, eight-pagebUlletin H302-091 gives features, applications, and specifications for thecompany's lines of flow diverters.General Resource Corp. 173

Servorecorders. Bulletins F-610. F611. and F-612 describe the company's new miniature servorecorder linewhose units utilize a 10-cm widthchannel. Esterline Angus 174

Laboratory equipment. General bulletin covers the company's entire product line, which comprises researchand development equipment for lifescience. general laboratory work,and developmental engineering.Bench Scale Equipment Co. 175

Soil testing. New 144-page catalogon engineering testing equipment forsoils has been published. Testingmach ines and instru ments used instudies of soils and aggregates arecovered. Soillest, Inc. 176

Replacement windows. New. easilyinstalled, heat or cooling loss-inhibiting replacement windows, Model105, are described in new product literature. Season-all Industries. 177

Refuse transfer. Booklet SWH72598-574 describes the company'srefuse transfer systems which serveto consolidate high solid waste tonnages before hauling in trailer loadsto remote disposal sites. The HeilCo. 178

Low-energy wet scrubber. Four-pagebrochure describes operating principles and specifications for the company's FR-100 low-energy wet scrubber for economical particulate andS02 control. Celesco Industries. Inc.

179

Chromatograph. Catalog. 32 pages.describes line of thin-layer chromatograph and laboratory equipment,along with line of prescored platesdesigned to provide convenience andup to 30% savings. Anallech, Inc.

180

Chart readers. Literature concernsdevices that read and analyze chartsand are convenient for drafting anddigitizing tables. Some contain remote control boxes. CoO Manufacturing Co., Inc. 181

Recycling from garbage. A 12-pagereport sets forth latest plans andtrends in recovering energy and steelfrom garbage. Title is "Progress report on recycling." Steel ProductsNews Bureau. 633 Third Ave., NewYork, N. Y. 10017 (write direct)

Solid waste testing. EPA circular670/2-74-007 describes comprehensively four additional proceduresfor physical, chemical, and microbiological solid waste testing. Office ofResearch and Development. NationalEnvironmental Research Center, U.S.Environmental Protection Agency,Cincinnati. Ohio 45268 (write direct)

Rural Resource Development. M. C.Whitby et al. 244 pages. Barnes &Noble Books, 10 East 53rd St .. NewYork, N.Y. 10022. 1974. $9.00, hardcover.

Considers whether we as a nationhave established the public policiesand institutions to identify and bringabout the best possible use of land,labor, and capital. Beginning with astudy of the decision-making process, book provides a description ofthe British planning system. It discusses land use, recreation and conservation, farm policy, and otherrural problems.

Sanitary Landfill. National Center forResource Recovery, Inc. xiii + 119pages. Lexington Books, D. C. Heath& Co., 125 Spring St .. Lexington,Mass. 02173. 1974. $12.50, hardcover.

Begins with the assumption thatburial in the ground, in properly designed and controlled operation, willremain ultimate method for disposing

BOOKS

of solid waste. Points out that incineration, recycling of some products,and other methods will still result in aresidue that must be disposed. Considers planning, site selection, operation, economics, and public healthissues.

Pollution Detection and MonitoringHandbook. Marshall Sittig. ix + 401pages. Noyes Data Corp., ParkRidge, N.J. 07656. 1974. $36, hardcover.

Deals with monitoring as a basictool in pollution control, since it is required in obtaining discharge permitsand needed as a device to measurethe effectiveness of abatement programs. Attention is given not only toanalytical methods but to the rationalanalysis behind the methods. Individual industrial effluents are consideredin detail.

Water and Its Impurities, 2d ed.Thomas R. Camp, Robert L. Meserve. xii + 384 pages. Dowden,

Hutchinson & Ross, Inc .. P.O. Box699, Stroudsburg, Pa. 18360. 1974.$22, hard cover.

Revised and updated edition ofCamp's book on the fundamentalphysical, chemical, and biochemicalproperties of water. It features 13chapters, ranging in subject matterfrom the physical properties of pureand impure water to the uses andquality standards of public waters. Ofspecial interest are sections on corrosions, oxygen balance, and fluoridation.

Man, Nature and Ecology. Keith Reidet al. 447 pages. Doubleday & Co.,Inc., 245 Park Ave., New York, N.Y.10017. 1974. $14.95, hard cover.

Maintains that only the scale ofman's interference with nature isnew-man has always upset naturalecosystems in an attempt to turnthem to his advantage. Book reviewsthose areas in wh ich man haslearned his lesson and has changedhis role from exploiter to conserver.

ENGINEERSR&D

MikroPul currently has a need for Engineers (BS/MS,Chem E, ME) in our R&D Department. We are a majormanufacturer of industrial air pollution control equipmentexperiencing a period of expansion as a result of the demand for our product. We are located in the New Jerseysuburbs convenient to both New York City and the JerseyShore.

OUR NEEDS ARE AS FOLLOWS:

PROJECT ENGINEERWill design and evaluate performance of Baghouse andWet Electrostatic Precipitators. Requires approximately 4years related experience.

ENGINEER

(Air/Water Pollution Control)Will perform applications research and product development pertaining to dust control equipment. Requires approximately 1-2 years related experience.We offer a full package of fringe benefits. Salary will becommensurate with experience. Please send resume instrict confidence including salary history and requirements Alln: Asst. Personnel Director.

EiWMjkroPulUNITED STATES FILTER CDRPDRATIDN

10 Chatham Road Summit, N. J. 07901

Equal Opportunity Employer

CIRCLE 18 ON READER SERVICE CARD CIRCLE 9 ON READER SERVICE CARD


Also discusses those more dangerous areas where man has not foundsatisfactory answers.

Ozone in Water and Waste WaterTreatment. iv + 131 pages. U.S. Department of the Interior. Water Resources Scientific Information CenterOffice of Water Resources Research,Washington D.C. 20240. 1974. $3.00,paper.

This bibliography is one of a seriesdesigned to exploit the Center's rapidly expanding information base.Contains a Descriptor Index. the Bibliography itself, a ComprehensiveIndex, and an Author Index. Abstracts on various aspects of ozoneusage are listed in ascending accession number order. The Center saysit is unable to provide copies of documents cited.

Environment U.S.A.: A Guide toAgencies, People, and Resources.The Onyx Group, Inco xii + 451pages. R. R. Bowker Co .. 1180 Avenue of the Americas, New York, N.Y.10036. 1974. $15.95, hard cover.

Compiles, organizes, and summarizes all environmental activities nowgoing on in the United States. Divided into 14 chapters, more than 5800entries are included. Some 900 federal and state agencies working inthe environmental field are included

"TEFLON Is a Reg. T.M.of DUPONT CD.

in the first section. Private environmental organizations, corporationand labor executives, and consultants, in other sections.

Should Trees Have Standing? TowardLegal Rights lor Natural Objects.Christopher D. Stone. xvii + 102pages. William Kaufmann, Inc., OneFirst St.. Los Altos, Calif. 94022.1974. $6.95, hard cover.

Proposes that natural objects suchas trees. mountains, rivers, andlakes should-like corporationshave legal rights. The U.S. SupremeCourt's opinions in the controversialMineral King-Disney-Sierra Club suitare included in full. Shows that therehas been a long development towardconferring rights on groups of peopleand on "entities."

New Concepts in Air Pollution Research. Jan-Olaf Williams, Ed. 184pages. Halsted Press, a Division ofJohn Wiley & Sons. Inc., 605 Th irdAve., New York, N.Y. 10016. 1974$11.95, paper.

Contains sections written by 20young scientists, all under 35, fromall over the world, with educationalbackgrounds in a broad number ofdisciplines. The approach is thatthese scientists, with their fresh educational expertise, may systhesizeideas for new concepts needed to

solve the environmental crisis. Socialand biological consequences of pollution are considered.

Advances in Environmental Scienceand Technology. Vol. 3. James N.Pitts, Jr.. Robert L. Metcalf. Alan C.Lloyd, Eds. ix + 385. John Wiley &Sons, Inc., 605 Third Ave., NewYork. N.Y. 10016. 1974. $19.95,hard cover.

This th ird in a series is concernedwith lead in the environment, and iswritten by Ben B. Ewing and John E.Pearson. Book seeks an understanding of lead's potential for hazardous consequences, and howthese consequences might be controlled. I t contains sections on theproduction and utilization of lead,lead in the environment. its health effects, and abatement methods.

Congress in Action: The Environmental Education Act. Dennis W. Brezina, Allen Overmyer. xx + 210pages. Free Press, 866 Third Ave.,New York, N.Y. 10022. 1974. $7.95.hard cover.

Presents in vivid detail the 1970Environmental Education Act's initiation, eventual passage. and problematic implementation. Written bytwo former legislative assistants, theevents are seen pri marily from acongressional point of view. Showshow oversight hearings and perseverance finally forced the creation of theOffice of Environmental Education.

Modeling the Eutro phication Processes. E. Joe Middlebrooks, DonnaH. Falkenborg, Thomas E. Maloney,Eds. 228 pages. Ann Arbor SciencePublishers, Inc., P.O. Box 1425, AnnArbor, Mich. 48106. 1974. $14.50,hard cover.

Consists of original monographscollected from a group of scientistsand engineers actively engaged inthe modeling and evaluation of theeutrophication process. The groupwas convened at Utah State University. Logan, Utah, with the support ofthe U.S. Environmental ProtectionAgency for the purpose of exchang·ing ideas and information.

• non-reactive• non-contaminating

Won't contaminate or destroy inert or chemically active gases,requires no lubrication. Ideal for air pollution studies, ozonemeasurement, lab gas analysis, trace gas measurement. ACand DC models from 150 ml/min to 1 liter/min. Tiny in size.

Write forFREE

DescriptiveBulletin,

IICi~2f!!.~~P~~p~~a~~~Phone' (609) 963·7700


Manganese. Committee on BiologicEffects of Atmospheric Pollutants,Division of Medical Sciences, National Research Council. vii + 191pages. Printing & Publishing Office,National Academy of Sciences, 2101Constitution Ave.. Washington, D.C.20418.1974. $6.25, paper.

Document is one of series that theU.S. Environmental Protection Agen·cy has asked the National Academyof Sciences to prepare. The mainthrust of the book is to examine theeffects of airborne manganese, butbiologic intakes from other routesalso are considered. It presents acritical evaluation of the literature,through July 1, 1972.


September 22-24 Tulsa, Okla.American Water Works Association-Southwest & Texas Sections Conference. Water and WastewaterEquipment Manufacturers Association

Write: WWEMA, 744 Broad St.. Rm.3401, Newark. N.J. 07102

September 23-25 Washington, D.C.Annual Conference, Marine Technology Society

Theme is "National Needs and OceanSolutions." Write: MTS, 1730 M St.. N.W..Washington, D.C. 20036

September 25-27 San Antonio, Tex.North American Conference onMotor Vehicle Emission Control.Texas Air Control Board

Write: H. E. Sievers, TACB, 8520Shoalcreek Blvd .. Austin, Tex. 78758

September 26-27 Chapel Hill, N.C.National Symposium on the State ofAmerica's Drinking Water. TriangleUniversities and others

Write: Water Resources Research Institute, U. of North Carolina, 124 RiddickBldg., Raleigh, N.C. 27607

September 30-0ctober 2 PensacolaBeach, Fla.Electrostatic Precipitators for theControl of Fine Particles. EPA andSouthern Research Institute

Write: S. Oglesby. Jr .. SRI, 2000 9thAve .. S., Birmingham, Ala. 35205

September 30-0ctober 3 Boston,Mass.Secondary Fiber Pulping Conference.TAPPI

Contact: S. J. Hayes. TAPPI, 1 Dunwoody Park, Atlanta, Ga. 30341

September 30-0ctober 4 New Orleans, La.Navy Health and Safety Workshop.Dept. of the Navy

Emphasis on federal occupational safety and health and environmental quality.Write: W. A. Redman. Jr.. Navy Environmental Health Center. 3333 Vine St.. Cincinnati, Ohio 45220

October 6-11 Denver. Colo.1974 WPCF Conference. Water Pollution Control Federation

Contact: Robert Canham. WPCF. 3900Wisconsin Ave .. Washington. D.C. 20016

October 7-10 Chicago, III.Pack Expo 1974, Fibre Box Association

Write: FBA, 224 S. Michigan Ave.. Chicago, III. 60604

MEETING GUIDE

October 7-11 Gaithersburg, Md.Seventh Materials Research Symposium. National Bureau of Standards

Symposium will concentrate on accuracy in trace analysis, sampling, methodology, and interpretation of results. Contact: M. Jacobs, NBS, Washington. D.C.20234

October 14-18 Champaign, III.Precipitation Scavenging. Atomic Energy Commission

Write: R. W. Beadle. Physical andChemical Transport Program. Div. of Biomedical and Environmental Research,AEC, Washington, D.C. 20545

October 14-19 Denver, Colo.Annual Meeting. Association of Engineering Geologists

Write: William Rogers, Tech. ProgramChairman, Box 15124. Denver. Colo.80215

October 15-17 Research TrianglePark. N.C.Seventeenth Biological Safety Conference. Becton, Dickinson, and Co.

Subjects to be covered include NCIguideline for carcinogens, environmentalpOllution, and OSHA and EPA regulationsfor biological labs. Write: L. A. Taylor,B-D Co.. P.O. Box 12016. ResearchTriangle Park, N.C. 27709

October 15-17 Toronto, CanadaThe Corrosive World Around Us. National Association of Corrosion Engineers-Canadian Region

Emphasis on how soil. air, and waterenter into corrosion situation, applicableto process industries and utility operations. Write: J. R. Alexander, c/o AcresConsulting Services Ltd.. 20 Victoria St..Toronto. Ont. M5C1Yl

October 16-18 Honolulu, HawaiiAmerican Water Works Association-California Section Conference.Water and Wastewater EquipmentManufacturers Association

Write: WWEMA, 744 Broad St .. Rm.3401, Newark, N.J. 07102

October 21-23 Madison, Wis.Lake Protecti~n and Management.EPA and others

Write: Lake Protection & ManagementConference. U. of Wisconsin-Extension,1815 University Ave.. Madison, Wis.53706

October 21-25 Kansas City, Mo.Environmental Engineering Meeting.Arrerican Society of Civil Engineers

Write: ASCE. 345 E. 47 St .. New York,N.Y. 10017

October 22-24 Louisville, Ky.Coal and the Environment Exposition.The National Coal Association andothers

Contact: M. B. Wolf. P.O. Box 17413.Dulles International Airport, Washington.D.C. 20041

October 23-24 Washington. D.C.Annual Meeting. American Society ofGas Engineers

Write: ASGE, 47A North Ave.. Mendon.Mass. 01756

October 24 Dallas. Tex.Sixth Food Engineering Forum. Dairyand Food Industries Supply Association

Award address is "Process Modification to Avoid Pollution." Will be held during Food and Dairy Expo (Oct. 20-24).Write: DFISA, 5530 Wisconsin Ave..Washington, D.C. 20015

October 27-November 1 Washing-ton, D.C.National Meeting. American NuclearSociety

Write: ANS. 244 E. Ogden Ave..Hinsdale, III. 60521

October 29-31 Seattle, Wash.Annual Meeting. Association of SeaGrant Program Institutions

Write: ASGPI, U. of Washington. Div.of Marine Resources, 3716 BrooklynAve.. N.E.. Seattle. Wash. 98195

November 4-9 Atlanta, Ga.Annual Meeting. Federation of Societies for Paint Technology

Write: FSPT, 121 S. Broad St.. Philadelphia. Pa. 19107

November 6-8 Fresno, Calif.Twelth Annual Show. GovernmentalRefuse Collection and Disposal Association

Program covers agricultural wastes.resource recovery. administrative andtechnical aspects of refuse collection.landfill. and other disposal methods.Write: Tom King. City of Hanford. 400 N.Douty. Hanford. Calif. 93230

November 12-14 Santa Barbara,Calif.Los Angeles Reactive Pollutant Program. Coordinating Research Council

Results of the measurement of chemical reactions in well-defined air parcelsare reported. Write: T. Redington, CRC.30 Rockefeller Plaza. New York. N.Y.10020

rContintJed on page 863)


CLASSIFIED SECTION • POSITIONS OPEN

GROWTH POSITIONSENVIRONMENTAL SYSTEMS

$12,000-$25,000ENGINEERING·-RESEARCH·-MANAGEMENT

MARKETING -MANUFACTURING APPLICATIONFees comp;IIlY p.lid. InduJe present s;l1:l.r~·, minimum s;ll·;lry re"luirell1ent ;lnJ Ic)(;I!ion lltxibilrn' with resume.~n,·irorllllenl.ll S)'s!ems Di,·,. L(}n.~~rry Erllpluyment S~r\"l(e, Inc, 650 :-.Ilks B;lnk BId,.:., Nlles. Ohi", HH6.

Opportunities in

WATER MANAGEMENT

ENVIRONMENTAL ENGINEERS

Head, Department of Energy EngineeringUniversity 01 Illinois at Chicago Circle

'!he DepcHlment oHers dredS 01 concentrdtion!edoing towdrn B.S., M.S., dnd Ph.D. degrees inChemicdl Engineering, Environmentdl Engineer.ing, Fluids Engineenng, dnd fhcrmomechdnksdnd Energy Conversion. t.dndlddles shouldhdve d strong resedrch record In ("ne or more efthese dredS dnd demonitrdled t:dPdbdltles dndWIde Interest in t'-le ge'lerdl fields of enzrgydnd the environment. An Equdl Opportunlty/Affirmdlive Actron Employer

Send resume to:

Dr. Richard M. Micha~ls

Chairm'!n of S~arch Committ~~Director. Urban Syst~ms LaboratoryUniversity of Illinois at Chicago Grcl~

80x 4348. Chicago, Illinois 60680

The Water Management Branch of theCarborundum Company has immediate openings for creative persons to

fi~~~ it~~t~I~;~~i,o;~pfi~~~t~e~iill1,~~~c~Technical Degree and technical serviceexperience in the field of water andwaste water treatment, with emphasison either activated carbon, polyelectrolytes, suspended solids or sludgeremoval.

for immediate consideration, sendresume of education, experience andsalary history in complete confidenceto Mr. Thomas T. Pradelski, Personnel

~.aO.a~~~,3~9~N~:~~~~uFna~I~~N~~~1~3~l'

An Equal Opportunity Employer(M/F)

CARBORUNOUM ~

NUCLEAR/ENVI RONMENTALENGINEERS

Top salaries & outstanding growthpotential with leaders in the powerfield for engineers with solid nuclearor environmental backgrounds. Ourclients pay all fees ..

Please send resu me to:Nancy Root

SPARKS ASSOCIATES, INC.1335 Rockville Pike,Rockville, MD 20852

(301) 424·5516(A personnel referral service

specializing in the power field.)

NoUce 01 Employment Opportunity-The Utah Water ResearChLaboratOfy. Utah State University. has IwO openings. one in each01 the genet'al areas 01 waler quali1y biology and 01 enywonmentalengineering Minimum quafilications include a PhD degree al'M:lsome speciliC research experience III the water quaNty area. Salary and appocntmenl commensurate with Quafilications. Subrrit anexperience resume. transetipt of university work, a briel outline ofcurrent researCh, and ttw'ee Ienefs 01 recommendation. Personsinlerested in researCh on alleets 01 oil deyelopment. mineral eJ:tfaction. and diffuse sources on tne biological and chemical integrity of slreams and lakes and methods 01 treating municipal and industrial wastes in rural areas are invited 10 apply to Dr. Jay M. Bagl.y, DIrector, Utah Waler Research laboratory, Utah State Un!yer5Jty. logan. Utah 84322.

IMPORTANT NOTICE

WATER RESOURCES SPECIALIST

Send resumes in confidence to Ann McArdle,Personnel· Department

Environmental Research &Technology, Inc.429 Marrett Road, Lexington, MA. 02173 E.O.E. mit

SEMINAR

MS Civil Engineering and d minimum of 2 years experience in environmentaldssessment of water resources projects. Experience with applicdtion of hydrologic and water quality computer models is required. Position will involveproject management of water resources impact studies.

MANAGER(WATER QUALITY RESOURCES DEPT.)

Ph.D. with 5 yedrS experience of MS with 10 yedrS experience in water resourceproject activities. Individual will be mdndger of multi·disciplindrY depdrtmentinterfdcing with the other disciplines, economics, sociology! etc. for environ-mentdl impdct dssessment studies. Individudl will be responsible for development dnd leddership of technicdl personnel dnd coordindtion of market effortsdnd contrdcts supervision.

AUSTRALIAPublic Service of Victoria

MINISTRY FOR CONSERVATIONDIRECTOR OF ENVIRONMENTAL STUDIES

REF. NO. (Z!02)

YEARLY SALARY: AS 19,302 USS 28,663DUTIES: To direct the activities of the Environmental Stud

ies Group of the Ministry. To represent the Ministryat policy level in the formulation of integrated environmental studies and in the planning and conductof those studies.To plan and implement the actions necessary tocoordinate the activities of Government departments Universities and other groups participatingin such studiesTo prepare appropriate reports and advice.To participate in the application of research findings to multi-resource planning for environmentalmanagement.

QUALIFICATIONS: A higher degree in the physical or biological sciences or in engineering, or equivalent qualifications, and evidence of experience in more than onediscipline; proven abiliy to initiate and supervisean integrated set of inter-disciplinary investigations required to understand the resources of a region and the constraints to be exercised in theiruse and management.The applicant must have had experience or a closerelationship with Govern ment, University and

. Industry.LOCATION: The Director will be based in Melbourne, Australia.

Provision will be made for paymet of at least partof removal and transportation expenses to Melbourne.

Applicants should indicate the earliest date they will be available tocommence duty, and, at least three letters of reference and the namesof three persons who can substantiate their credentials.Applications quoting reference number (Z/02), should be addressed tothe Secretary, Public Service Board of Victoria, State Public Offices, No.1 Treasury Place, Melbourne, 3002, Australia, by not later than 9.30 am.on Wednesday 25th. September, 1974, together with statements of experience and qualifications and date and piace of birth.

General Guidelines forEcological I",Imct Assessments

Chicago-Oct. 2Allanta-Oct. 24New York Nov. 14

Contact:New England Research, Inc.15 Sagamore RoadWorcester, Ma. 01605

V:HIOlJS ~tilte l:hYS ag;llllst d,scrlnllrl;ltlon <Hld tileFederal C'vil R'ghts ACt of 1964 prOll'!)lt (jlsC/lrn,rl;l·1,o11 In employmerlt bec;lll::.c 01 r;lce color religionnational Ollgln. age. ;In<! "ex (unless based on a bona"de occuPiltlOrl<11 qualification) Help w;lIlted iln(1",Illat,ons wanted ndvert'sements on Th('<;e pages;He 'or le,ld~rs corwen,ence and are flat 10 be can·SlllJed as IIlSlfurnenlS leading to llrll;IWful (tl::.CllmU).,·lion

We luH n1.lrl~· "",iii",] np~llin<:, ill l·.S. fo:· profl"ssi'lIJ.dsc·xp~nrll,~·.1 III fhl" d~~igll, .lppli,.\trO:1 .l·d or S.ll<; of .lir.w.lta "I' W.lqr p~lllll!IOn "mtml ('lJUIPIll~1l1, ,h~miC.lls

.lId ,~·<t~·rn~. Crir:ll[ lnrnp.1l1i~·~ r I~' fl"c,. Stn,j rr.lllm:& ,.d.lr~· 'u,r,'r~' HI l":lti.l:.":l.-~ (,I R(l~~·r :-'1. Il,ffnl.lll.

ESSEX PLACEMENT ASSOCIATES2 ~"nh \1.UI1

MEETING GUIDE (continued) professional consulting services directory

ENVIRONMENTAL IMPACT REPORTS

APPLIED RESEARCH ENGINEERING CONSULTING

DIFFUSION METEOROLOGY STACK TESTING

MARINE TECHNOLOGY ANALYTICAL LABORATORIES

We perform over 750 differentchemical and biological tests.

Write for complete list and prices.

November 12-14 Philadelphia, Pa.Seventh Mid-Atlantic IndustrialWaste Conference, Drexel University

Write: Dr. Lagrega, Institute of Environmental Studies, Drexel U.. Philadelphia, Pa. 19104

CoursesSeptember 23-November Los An-geles, Calif.Environmental Management Institute.EPA and University of Southern California

Fee: $97 per unit of credit. Write: Gloria C. Barbaro, Director. EMI, U. ofSouthern Calif., Civic Center Campus,311 South Spring St .. Room 420, Los Angeles, Calif. 90013

September 23-24 New York, N.Y.Real Estate and the Environment.Practising Law Institute

Among topics to be discussed areproblems of the realtor and developer incomplying with EPA laws, and state andlocal environmental legislation. Write:PLI, 810 7th Ave., New York. N.Y. 10019

••WARF INSITrUTE, INC.A Full Service Independent Laboratory

Box 2599 Dept. JMadison, Wisconsin 53701Phone: 608/257-4851

RADIATION MANAGEMENT CORPORATIONUNIVERSITY CITY SCIENCE CENTER

3508 MARKET STREET, PHilADElPHIA, PA. 19104Phone (21~) 386-1 805

The Research Corporation of New England125 Silas Deane Highway Wethersfield, Connecticut 06109

(203) 563-1431

~CQNSULTATION AND LABORATORY SERVICES

• Radionuclide Analysis • Bioassay• Environmental Studies • Health Physics Services• Low Level Tritium Counting • Whole Body Counting

• Licensing Assistance (Mobile)• Emergency Medical Planning

October 14-18 Cleveland, OhioIndustrial Noise Control Seminars.B&K Instruments, Inc.

Fee: $200. Write: Bill Rhodes. Directorof Communications. B&K Instruments.5111 W. 164th St., Cleveland. Ohio 44142 Ir-----------------------------,

October 7-8 Madison, Wis.Solid Waste Management and Technology. University of Wisconsin

Fee: $100. Write: U. of Wisconsin Extension, Dept. of Engineering, 432 N.Lake St.. Madison. Wis. 53706

October 2 Chicago, 111.General Guidelines for Ecological Impact Assessments. New England Research. Inc.

Same course held October 24 in Atlanta (Ga.) and November 14 in New York(N.Y.) Fee: $65 for early registrants.Write: NERI, 15 Sagamore Rd.. Worcester. Mass. 01605

International

October 7-9 Klamath Falls, Ore.Geothermal Resources. Oregon Insti-tute of Technology I

Features energy utilization areas-industrial. agricultural. and commercialresidential. Write: P.O. Box 1901, Klamath Falls, Ore. 97601

October 8-9 Ontario. CanadaCanadian Government Affairs Seminar. Canadian Air Pollution ControlAssociation

Write: Dr. deKoning, EPS, EnvironmentCanada. Rm. 242, Environmental HealthCentre, Tunney's Pasture. Ottawa, Ont ..Canada K1AOH3

ENVIRONMENTAL SERVICES DEPARTMENT

II! ·Industrial air, water, solids, and noise pollution control• • Laboratory and Pilot Plant Studies• • Environmental Impact Reports

BECHTEL CORPORATION50 California Street, San Francisco, Calif. 94111

Phone: (415) 764-5893Other offices: Houston, Texas - Gaithersburg (Md)

'_".'II~' COMPLETE ENVIRONMENTAL SERVICES:•....... -.... !~', Environmental impact statements ... Pollutant emis-

Stea~~~!o~~o . j sian,. air qU~lity & water qualit~ monitoring ... Dis-perSion estimates ... Ecological consulting ...

Meteorological field studies & consulting services. Contact

(Continued on page 866)

ENVIRONMENTAL SCIENCES DIVISION(303) 758-1122

P. O. Box 5888Denver, Colorado 80217


professional consulting services di rectory

One Penn Plaza, New York, NY 10001

ENVIROENGINEERING, INC.27 WARREN STREET, SOMERVILLE, N.J. 08876

TE L. (201) 526-2700

air. water. solid waste. noise. osha

surveys. certification. testingsystems engineering & designturn key. impact statements

PARSONSBRINCKERHOFF

QUADEDOUGLAS

EngineersDesigners & Planners

..\ir QualIty • W:uC"r QU:.Ility• \Vater Ro:source" • MunIcipal&. In<lustri~1 WAter &. Wa~IO:

W..Ito:r • Ri"o:r B..lsio SluJio:s

• Dr..lin..l~e & FlooJ Conlrol• $oIlJ \\;;1,,[0: • RO:.l:;lon:a1 P/.to

[lln.~ • Imp..i(1 I\ssc"smo:n[sM..In..lJ,:o:nxnl.

1 ;-;("01{ I'(ll~ ,\-1 I IJ

TEXAS INSTRUMENTS

,..DIVISION OF H_V.WEEKS, INC. - INDUSTRIAL CONSULTANTS

SOMERVILLE, N.J. - GOLDEN, COLO.

lexas Instruments Provides Ecological& Environmental ServicesFor Industry, Engineering, Utilities, Government

• Field Investigations - Terrestrial, Air, • Research & Development - HydrologicalAquatic, Water Quality. and Ecosystems, Sensor Systems,

• Aerial Surveys - Infrared, Photogeology. Monitoring Systems.• Laboratory Services _ Chemical, Biological Waste-Treatment

Biological, PhysicaL • Systems.• Data Processing _ Acquisition, Storage. • Professional Consulting - Environmental

Retrieval, Analysis, Reduction, Impact Statements.Interpretation. • NPDES Permits, 316(a) Applications.

For information contact Texas Instruments Incorporated, Ecological Services,13500 N. Central Expressway - P.O. Box5621 ( MS-949 I, Dallas, Texas 75222.Telephone: 214 I 238-3444.

."'lfflflff,. Hmdoll. /)"fU'N, 1I00wb,t".SlIff Frlllln·.,,/·o. Tn"t/oll. ""II."hil/~/fflft. /).(:.

Laboratory and Process Development

Industrial Waste Water Control

liqUid and Solid Incineration

Air Pollution Control

In·plant Control and Process Modifications

Desalination

CATALYTICINC.

Consultants. Engineers. ConstructorsEnvironmental Systems Division

... 1528 Walnut Street. Philadelphia. Pa. 19102 .J

..... 215-KI5·75OO ....

f'LSON COMPLETE LABORATORY SERVICESCOMPANYE. HOI N EERS AIR, WATER AND NOISE POLLUTIONARC HITECTS t SAMPLING AND ANALYSIS

POLLUTION CONTROL PROCESS STUDIES AND SYSTEMS DESIGNBOX 28 BOX 1526 BOX 3305

SALINA, KS 67401 ARLINGTON, TX 67010 ALBUQUERQUE. NM 87110

~BLACK & VEATCH / CONSULTING ENGINEERSCOMPLETE ENGINEERING SERVICES FOR POLLUTION CONTROL

AIR • WATER • WASTEWATER • INOUSTRIAL WASTESSOLIO WASTES • ENVIRONMENTAL PLANNING

1500 MEADOW LAKE PARKWAY, KANSAS CITY. MISSOURI 64114DALLAS' DENVER. ORLANDO' NEW YORK. SAN FRANCISCO' WASHINGTON D,C.

NORMANDEAU ASSOCIATES, INC.686 Mast Road • Manchester. N. H 03102

PHONE (603) 669-7911

• Ambient Air Studies• Air & Water Pollution Control• Complete Analytical Laboratory• Source Testing & Stack Sampling• Industrial Hygiene & Safety• Combustion Studies

ONE RESEARCH DRIVESTAMFORD, CONNECTICUT 06906

(203) 325-1371

WESTERN DIV.-DENVER, CO(303) 758.4100

YORK RESEARCH CORP.

• TERRESTRIAL AND AQUATICBASE LINE STUDIES

• WATER OUALITY ANALYSIS• OCEAN ENGINEERING• HYDROTHERMAL SURYEYS• MARINE FOULING STUDIES• ECOLOGICAL MONITORING• ENVIRONMENTAL IMPACT REPORTS

Ji¥.,rb~(j;;;,HILABORATORIES INC.

545 Commerce St Fr"nkl.n L"kes N J 07417201-337-4774 2018918787

• Atomic Absorption • Optical EmiSSion• Chemical • X.ray Specbomcby

Complete Andlytlc,,1 Services forEnvlronment,,1 StudIes & PollutIon Control

COMPLETE ENVIRONMENTAL

.I~IIRESEARCH AND SERViCES

METAIRIE, LA. 70002

.I!J;.~ accu-Iabs research, inc.11'8~W" 48TH AVENUE. WHEAT RIDGE, COLOfIAOO 1lOO33. (3lI.lj 423_2166

• Environmental Impact Studies• Air, Water and

Waste Analysis• Trace Elements in Coals and

Fly Ashes• Ultra Trace Mercury in Coals

and Tissues• Trace Elements in

Biological Samples• Identification of

Contaminants11485 W. 48TH AVE.. WHEAT RIDGE, CD 80033

(303) 423·2766

2932 LIME STREET

WATER AND AIR POLLUTION CONSULTANTSEnvironmental Services - Water and Air Quality

Testing - Emission & Ambient Air Testing Microbiological and Chemical Analyses

ANALYSIS LABORATORIES, INC.(504) 889-0710


• WATER TREATMENT/OISTRIBUTION/LEAK ANO fLOW STUOIES

• SEWERAGE/COLLECTION AND TREATMENT• SOLIO WASTE PLANNING ANO MANAGEMENT• AIR POLLUTIONIINVESTIGATION/

EVALUATION/CONTROL• COMMUNITY PLANNING• INDUSTRIAL WASTEiSTUOYITREATMENT• SUPERVISION Of CONSTRUCTION

AND OPERATION

f"libert Associates Inc

CalspanEnvironmental

Services

Specialists in Industrial PollutionProblems

. Air, Water and Solid WasteEngineering

Pollution Control EconomicsMobile LaboratoriesField Engineering Teams

Versar Inc.6621 ElectroniC DnveSpringfield, Va. 22151

17031 354·3350

ComplCle Water Aif SolId PollutIonConltol Services• Research l nqlllpl'flng anl! Consulting

Product EQUtj)nlt'nt ;}nd PfOCP$SE v<lluallonsFI('ld ane! L~lboralory Invesllqatlons'HHI $,mulallonEnVlronrnenla, t monel J\ssessrnenls

Y:RjAR INC.

Calspan CorporationPO 80x 235 8ufl;Jlo NY 14221

(716) 632-7500 Ext 538

ENGINEERS/PLANNING CONSULTANTSRuom9. Pa • Sp"ngheld MilSS • "'rliladelph,a. POl

CROBAUGH LABORATORIESSINCE 1894

AIR AND WATER POLLUTIONSampling - Measurements

Analysis - Consulting

COMPLETE LABORATORY SERVICEChemislry-Melallurgy-Speclroscopy

Particle Size Analysis-Alomic AbsorplionInfrared-Chromalography-X ·Ray Diffraclion

21&·881·73203800 Perkins Ave.

Cleveland, Ohio 44114Member Amellca" CounCil of Independent Labolillofles

Complele Waler and Wasle Waler ServicesAtomic Adsorption Wet ChemicalOptical Emission X-Ray Spectroscopy

Bacteriological

JOHN H. BANKS LABORATORIES, INC.49 Cannonball Road, Pompton Lakes, NJ201-839-3450 Tele.: 130494 212-564-3934

S""n"h~~:l:::1 :;;; :'.:~l:r::::i',:;/,;.~ ~:f"'.V<I< WI,!

WAVES· CURRENTS· WINUS

ENVIRONMENTAL SERVICES DIVISION:••

GRUMMAN r' 'iI'

-----.,,--

'Ii ,~."'.J ,I

1111 S1EWl\lH I\VI.NUI

PC T'lF'V\Gr:.N£\Nyt'JRK11714IELrPltONr ~.16575·2<'17.J

Environmental EngineeringIndustrial-Municipal- Water-Sewage

Solid Wastes ManagementAir Pollution Control-Power Engineering

ENGINEERS DESIGNERS CONSTRUCTORS393 Seventh Avenue New York NY 10001

A Sut)sltllary 01 Dravo COfDOral,on

Gibbs e Hill. Inc.

ENVIRONMENTAL SYSTEMS & SERVICESMarine and Terrestrial Studies

• Dala AC(ltiISllIOfl _l"v"OlHllcnl," AnalysIS

• HvdrO<jf,lOhy Survey::. .5,1111(1 Stulllc::,

• MalhemilllC:l1 Modehny. Thermal Mapl>lny

Turner, Collie & Braden, Inc.

p, O. BOX 13089 _ HOUSTON, TEll.AS 11019 -1713) 528·6361

COMPLETE ENVIRONMENTAL ENGINEERINGAND LABORATORY SERVICES

DUNN LABORATORIES, INC.Chemists and Chemical Engineers

Chemical Analysis and Consultation717 Edgehill Ave. N. W.

Atlanta, Ga, 30318Tel. 404·873·6159

Industrial - Domestic WastewatersWater Resources - Treatment

Analyses. Research, Impacts, Permits, GrantsDefinition - Treatabilities - Design - Operations

Field work and studies in:Environmental, Safety, & Systems Engineering

IRIDENT~ENGINEERINGASSOCIATES. INC.

Arm,I!,.,I,::, M;lfylaJlIJ 301 1167·81 2R

professional consulting services directory

CHARLES R VELZYASSOCIATES, INC.

CONSULTING ENGINEERSWATER POLLUTION CONTROL. SOLID

WASTE DISPOSAL. AIR POLLUTIONCONTROL. INDUSTRIAL WASTES.

DRAINAGE. WATER SUPPLY350 Executive Boulevard

Elmsford. New York 10523Mineola, New York Babylon. New York

STUDIES, OESIGNS AND

CONSTRUCTION SERViCES FOR WATER,

WASTEWATER AND SOLlD WASTES

ENGINEERS

~ MINERALOGICAL i BIOLOGICAL MICROSCOPY .,.... POPULATION i EiOJYJTEM HUDIEf .,~ iOAlfAL lONE ITUDIU .,.

....... ROCK mUnURE ANALY!15 -..... CEOMAPP INC ~---CHIASMA CONSULTANTS, INC.

::A~~~TJ"t~T:E~1 1HOI 803722-4l'b

OLSON LABORATORIESANALYSIS-WATER-WASTE WATERBOD - COD - ATOMIC ABSORPTION

HEAVY METALS - FLAMELESS AAMERCURY - INDUSTRIAL

AGRICULTURAL - 68 E. MONTEREY ST.,FREEPORT, ILL. 61032 - TEL. 815·232·9110

GREEL.EY ANC HANSEN

GEOLOGICAL SERVICETesling & Moniloring Laboralories

Chemical • Atomic Absorption • InfraredEmission Specl • Chromatographic • MicroscollY

All Water Testing • Pollution • QualityCorrosion Control • Geothermal • Waste Disposal

1539 W. 16th Street (213) 436 4254Long Beach, CA 90813

.:111' ,'~r,"''i1[f~'.

LABORATORYChemical Analyses

For Envlfonmental SludlesAnd Pollullon Contfol

525A$hlood SI., NOflh Adorns, MA 012471el. 413/663-6769

,/aatdYC'~a.1eA. &kf/)CONSUL1'ING CHEMIST

• Po!ltJl,on AnalVSlS and MOllltOflf'!1• Tle,Hab,IHV and Impact S,udles p.O. BOK 203

• Product Llab,lltv ltK,nglnn.Miss.02113

• SafelV and HV9'ene (611) 646·0220• Complete lab()fa10fV Selvlces

WATER ANALYSISMetals - Pesticides - T.O.C. - Etc.

Government approved procedures.!'hQtlf, ur lI'riff' for furlhrr if/forma/iotl.

GALBRAITH LABORATORIES, Inc., 80,4187Knoxville. Tenn. 37921. (615) 546-1335

222.5. RiverSide Plaza. Chicago. Il60606 . [3121-648-1155New York 1OCXJ7 Ph!ladelphla 19103Richmond 23230 Tampa 33607

MEETING GUIDE (continued) INDEX TO ADVERTISERS IN THIS ISSUE

Commerce Clearing House,Inc. 805

Combustion Engineering 857Coordinated Communications Inc.

NUS Corp. 778Ketchum, Macleod & Grove Inc.

Hydrolab Corporation 859Reed-Poland, Inc.

Philadelphia 19034 Anthony J. Giamanco,CENTCOM, LTD., 535 Pennsylvania Avenue,Fori Washington, Pa., (Area Code 215) 6432586

Advertising management for theAmerican Chemical Society Publications

CENTCOM, LTD.

Thomas N. J. Koerwer. President; Clay S.Holden. Vice President; Benjamin W. Jones,Vice President: Robert L. Voepel, VicePresident; C. Douglas Wallach, Vice President: 50 West State Street. Westport. Connecticut 06880 (Area Code 203) 226-7131

San Francisco ... Clay S. Holden, CENTCOM, LTD.,(Area Code 213) 776-0552

Westport, Ct. 06880 ... Donald B. Davis, Anthony J.Giamanco. CENTCOM, LTD., 50 West StateStreet. (Area Code 203) 226-7131

ADVERTISING SALES MANAGER

SALES REPRESENTATIVES

At~~~~e WX 2:::ert E. Moran. CENTCOM, LTD.,

Chicago 60093 ... Eugene Eldridge, CENTCOM.LTD., 540 Frontage Rd., Northfield, III. (AreaCode312) 441-6383

Cleveland Michael Hayes, CENTCOM. LTD.,20340 Center Ridge Rd., Rocky River, Ohio44116. (Area Code 216) 331-2324

Denver ... Clay S. Holden, CENTCOM, LTD., (AreaCode 213) 776-0552

Houston Michael Hayes, CENTCOM, LTD.,(Area Code 216) 331-2324

Los Angeles 90045 ... Clay S. Holden. CENTCOMLTD., Airport Arcade Bldg .• 8820 S. SepulvedaBlvd., Suite 215, (Area Code 213) 776-0552

New York 10017 ... Anthony J. Giamanco, CENTCOM. LTD.• 60 E. 42nd Street, (Area Code 212)972-9660

Thomas N. J. Koerwer

PROFESSIONAL CONSULTINGSERVICES DIRECTORY 863-865

CLASSIFfED SECTION 862

771

771

... 771.853

Pro-Tech, Inc.

Orion ResearchORC Advertisers

Hach Chemical 858Wesley Day & Co., Inc.

H. Reeve Angel & Co., Inc. 854Arthur Falconer Associates Corp.

Finnigan Corp. 775Bachrach Advertising

GCA/Technology Division 771Culver Advertising

MikroPul 859lewis Adv. Agency

CEA InstrumentslHO Incorporated

Bureau of Nationaf Affairs IBCVansant Dugdale Advertising

Koch Engineering 799Raniere, Saslaw, Mohr &Assoc. Inc.

Mine Safety App. Co. 810Ketchum, Macleod & Grove Inc.

Calgon 780Ketchum, Macleod & Grove Inc.

E.!. DuPont de Nemours &Co. . 771, 792

N.W. Ayer & Son, Inc.

Environmental Science Division-The Bendix Corporation 810

D'Arcy-MacManus & Masius

November 3-7 Chicago, III.First World Energy Engineering Exposition and Congress. Clapp & Poliak

Write: C&P, Inc., 245 Park Ave., NewYork, N.Y. 10017

September 30 deadlineManagement and Disposal of Residues from Treatment of IndustrialWastewaters. EPA and InformationTransfer, Inc.

Conference will be held in February1975, in Washington, D.C. Submit to:Harold Bernard, c/o EQSI, 6110 Executive Blvd., Suite 750, Rockville, Md.20852

October 23-26 Graz. AustriaProjekt 2000. U.S. Dept. of Commerce and others

International trade fair on pollutioncontrol, with emphasis on solid waste disposal, noise abatement, air and waterpollution control, and sewage treatment.Write: David Katz, DOC, Office of International Marketing, Rm. 1015C, Washington, D.C. 20230

October 24. 1974-September 6,1975 Delft, The NetherlandsInternational Course in Environmental Science and Technology. UNESCO and WHO

A postgraduate course for chemistsand biologists involved in environmentalresearch-water resources. land uses,and others. Write: Registrar, NUFFIC, 27Molenstraat, The Hague. The Netherlands

Call for papers

October 10-11 Beaumont, Tex.First International Symposium onTechniques of liquid-liquid Separations. Lamar University

Contact: R. A. McAllister, Dept. ofChemical Engineering, lamar U.• P.O.Box 10053. Beaumont. Tex. 77710

October 16-18 Toronto, CanadaSeventh Canadian Chemical and Process Equipment Exhibition. SouthexLtd.

Write: Southex, 1450 Don Mills Rd.,Don Mills. Ont., Canada

October 1 deadlineAnnual Meeting. Cooling Tower Institute

Conference will be held February 1975.For details, contact: Ernest Petrey, c/oTretolite Div., Petrolite Corp., 369 Marshall Ave., St. louis, Mo. 63119

November 30 deadlineFourth National Symposium on Radioecology. Atomic Energy Commission and others

Conferences will be held May 12-14,1975, at Corvallis, Ore. Emphasis on increasing role of nuclear energy in thetotal energy picture, and upon the radioecological implications of energy resource development. Submit to: C. E.Cushing, Jr., Ecosystems Dept., Battelle,Pacific Northwest labs, Richland, Wash.99352

Research Appliance Company771,806

W. F. Minwick & Associates, Inc.

Rockwell International IFCCampbell-Ewald Co. Adv.

Science Pump Corp. 860Ferguson Adv.

Technicon Corp. . .771. 776Mediad Incorporated

Thermo Electron Corp. OBClangler-Stevens, Inc.

Union Carbide Corp. 856J. M. Ferrazza Assoc. Adv.

Varian Techtron 772Ahern Advertising Agency

Great Britain and Western Europe. Malcolm

Thiele, Technomedia Ltd., Wood Cottage. Beenhams Heath. Shurlock Row. Reading RG10 OOE.Berkshire, England

Japan ... Haruo Moribayashi, International MediaRepresentatives, LId., 1, Shibe-Kotohiracho,'Minato-Ku, Tokyo, Telephone 502-0656.

PRODUCTION DIRECTOR

Joseph P. Stenza

PRODUCTION ASSISTANT

Alice M. Hansen



No. Product

QuickSearch!An added ES&T service enablingyou to get fast. free data on wholegroups of product types. Simplyscan this list. Then, circle the appropriate numbers in the QuickSearch section of the adjacentreply card.

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15 16 17 18 19 20 21 22 23 24 25 26 27 28

29 30 31 32 33 34 35 36 37 38 39 40 41 42

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SEPTEMBER 1974

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Air Purification EquipmentAuto Emission Instruments

Books. Journals. Publications

Construction Services

Consulting Services

Chemicals & Gases

Noise Measuring Instruments

Residue Analysis Instruments

Solid Waste Equipment

Telemetering & Data Acquisition

Waste Disposal Services

Water Pollution Instruments

Water Purification Equipment

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NEW PRODUCTS. NEW LITERATURE:

101 102 103 104 105 106 107 108 109 110 111 112 113 114

115116 117 118 119 120 121 122 123 124 125 126 127 128

129 130 131 132 133 134 135 136 137 138 139 140 141 142

143 144 145 146 147 148 149 150 151 152 153 154 155 156

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201 202 203 204 205 206 207 208 209 210 211 212 213 214

NAME _

TITLE _

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STREET _

CITY

STATE - ZIP --.,--~..,..,-- _

PLEASE CHECK: 0 ACS MEMBER 0 NONMEMBER

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NAME _

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No. Product

201 Air Pollution Instruments

202 Air Purification Equipment203 Auto Emission Instruments204 Books, Journals, Publications205 Construction Services206 Consulting Services207 Chemicals & Gases208 Noise Measuring Instruments209 Residue Analysis Instruments210 Solid Waste Equipment211 Telemetering & Data Acquisitiol212 Waste Disposal Services213 Water Pollution Instruments214 Water Purification Equipment

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STREET _

SEPTEMBER 1974

ADVERTISED PRODUCTS:

1 2 3 4 5 6 7 8 9 10 II 12 13 1415 16 17 18 19 20 21 22 23 24 25 26 27 2829 30 31 32 33 34 35 36 37 38 39 40 41 4243 44 45 46 47 48 49 50 51 52 53 54 55 5657 58 59 60 61 62 63 64 65 66 67 68 69 7071 72 73 74 75 76 77 78 79 80 81 82 83 84

NEW PRODUCTS, NEW LITERATURE:

101 102 103 104 105 106 107 108 109 110 III 112 113 114

115 116 117 118 119 120 121 122 123 124 125 126 127 128

129 130 131 132 133 134 135 136 137 138 139 140 141 142

143 144 145 146 147 148 149 150 151 152 153 154 155 156

157 158 159 160 161 162 163 164 165 166 167 168 169 170

171 172 173 174 175 176 177 178 179 180 181 182 183 184

185 186 187 188 189 190 191 192 193 194 195 196 197 198

QI.I;cliSearch:201 202 203 204 205 206 207 208 209 210 211 212 213 214

TITLE _

~THE BUREAU OF NATIONAL AFFAIRS. INC.

C Dept. ER·531

BNA. 0~3s~i~~~n~t~~~t. 2Nri6'37

Please send me Environment Reporter on a 45-day approval basis. At the end of the approval

r~~i~~~rr~\ ~~~e:p~~~~~l ~~~io~:I~~~:t~r~naV~~;:rl:,"~~i~~~\~~~~:~~~~r annual rate ($420), effective from

(Signed) _

Zip

Title

State

II

IlinciUding news of techno, as well as legal and legis-

Isections are: Federal Laws,bons, State Air Laws (2; Water Laws (2 volumes),i Waste-Land Use in fullp as they happen.~phs are a series of scholarlya wide range of specific toprms records the outcome ofrnmental cases in state and,\how your system stacks up~re, the courts, and EPA,1st Environment Reporter.


Address

City

Name

Organization

When youstandards yoBNA's Enviryou'll find thpliance withall in one placfind the facts

The eightporter keep ynificant develenvironmenta .

Current Deweekly coverafield-with aing off everyeach item rna

Both disks rotate at speeds well abo~

the transient time of atmospheric NOyand NO gas. Thus the chemilumf'nescent signals, generated by the 1'oW

continuous reactions - NO and NOy'- time share the same photomullipl""tube and pre-amplifier electronics. Thegeneration of the real time NO, bdone by subtracting the value of 11_"NO channel signal from that of NOt·The result is a sensitive, accurate, i~

terference-free analyzer with unex·celled capability to measure low NO.·NOx concentrations. Ranges vary from.0-50 ppb, to 0-10 ppm, and are iineu.throughout.

Write us for full details.

~ Thermo l

ric Electronc;n:2o~~a2s~;:: ~1~iO~ .1

85 First AvenueWaltham, Mass. 02154

(617) 890-8700

New Dual Chamber, Single T'Jbe~Chemiluminescent NO-NOx Anal:;m'

I=.; Two chambers,P.L~,~ one tube, that's

the best wayto measure ambient air concentrations ofNO-NO x wi.!hThermo E lec

tron's new Model 14D,

Here's how it works. The samplegas enters the instrument, separatinginto two equal flows: one segment ofthe sample flows into a NO, to NOconverter and the ottier' segment bypasses the converter, Both segmentsflow continuously and in phase intoseparate reactors where the chemiluminescent reaction with ozone takesplace.

An optical chopper alternately exposes a single, thermo electricallycooled photomultiplier tube to the NOand NOx <;:hemiJuminescent reactions.The photomultiplier tube, therefore,sees two separate and simultaneouschemiJuminescent reactions for everychopper disk revolution.

A second chopper disk provides locator or sync signals to the electroniccircuits for the identification and separation of the NOx and NO channels.

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Environmental Science & Technology 1974 Vol.8 No.9

Documents