Management and Minimization of Hazardous Waste Under RCRA

Management andMinimization of HazardousWaste Under RCRA

Prepared by Jerome Kohl and L. A. Weaver, III

Copyright 1992

North Carolina State University

Industrial Extension Service

College of Engineering

North Carolina State University

Raleigh, North Carolina

September, 1992

Support for preparation of this manual was provided by the Hazardous Waste Section of the

Division of Solid Waste Management, the Department of Environment, Health, and Natural

Resources, State of North Carolina.

SECTION 9THE USED OIL

PICTURE

A. What is a Used Oil?

Used oils fall into several categories including:hydraulic oils, used transformer oil,

usedand spent lubricating oils. used metalworking fluids,

For an overview of the options forused OIL management, see Fig. 9.1.

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FIGURE 9.1: MANAGEMENT OF USED OILS

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We are concerned with the following types of oil:

1. Hydraulic Oil

Hydraulic oils are composed of various synthetic andpetroleum compositions. These fluids are used in all types ofmachinery from large presses to landing gears of airplanes. Thefunction of hydraulic fluid is to maintain an incompressiblestable state for as long as possible. Some reservoirs holdingthe hydraulic fluids can hold up to several thousand gallons.Most of the fluids have a useful life of 1 to 3 years, dependingon their use.

2. Transformer Oil

Transformer oils consist of petroleum products, siliconefluids, and high molecular weight hydrocarbons. These fluids areused in transformers for cooling and to provide a dielectricconstant which is greater than that of air. Cooling is requiredto remove the resistance heating produced in the transformercoils. High dielectric constants allow for minimum size andmaximum efficiency of the transformer. Transformer oils becomecontaminated in one of the following ways: 1) electricalbreakdown can lead to carbon build-up, 2) air leaks can letmoisture into the fluid, 3) oxidation of the fluid is possible,and 4) dirt and other solids can enter the fluid by internalbreakdown or outside contamination (through leaks). Volumes offluids used in transformers can range from a few gallons tothousands of gallons. The life of transformer oil can be tenyears or greater.

3. Metalworking Fluids

Metalworking fluids are used for both lubrication andcooling in various machinery processes (cutting, grinding,stamping, and milling). Metalworking fluids exist in 3 types.Soluble oil is composed of 30 to 90 percent oil in theconcentrated form. When the oil is diluted with water for -various industrial uses, the oil-water mixture forms a stableemulsion. Tramp oils (unwanted oils which enter a system) floaton the fluid surface or sometimes mix with the fluid, going intothe emulsion, thus contaminating the fluid.

The second type of metalworking fluid is termed semi-synthetic fluid. This fluid contains 1-30 percent soluble oil inconcentrated form. This emulsion is much tighter, thus making itharder for tramp oils to enter the system.

The final type of metalworking fluid is commonly termed thesynthetic. This synthetic contains O-l percent soluble oils.The tramp oils are rarely able to penetrate this emulsion.

"Tramp Oil""Tramp" oil is the common name given to all unwanted oil

which enters a metalworking fluid stream or reservoir. The trampoil most often comes from lubricating oil. Basically tramp oils

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occur in three forms: 1) free oils, 2) mechanically emulsifiedoils, 3) chemically emulsified oils. Free oils consist of largedroplets which are easily separated by gravity in an area oflittle turbulence. Mechanically emulsified oil is created whenfree oil is dispersed in a metalworking fluid, often due to thepumping action of the machine tool. Chemically emulsified trampoil is unwanted oil which is held in suspension by chemicalemulsifiers. This tramp oil is the most difficult to remove.

Tramp oil causes several problems. First, it can becomecontaminated with bacteria which breaks down the oil and formshydrogen sulfide which has a bad odor. The tramp oils can alsocarry dirt or hazardous contaminants into the "clean" fluid.Finally, tramp oil can enter some emulsions and cause asubsequent breakdown of fluid qualities. The most common andcost effective way to remove tramp oil is to collect thecontaminated fluid in a reservoir and skim the lighter tramp oiloff the top. The skimming procedure is discussed in thefollowing section.

4. Lubricating Oil

Lubricating oils are most often pure petroleum productscomprising a variety of grades. The largest user of lubricatingoil is the country's road vehicles, which account for well over abillion gallons of used oil each year. Lubricating oils areoften Contaminated with lead from leaded engine fuels, wearmetals, or with halogens from degreasing solvents which are mixedwith spent oil.

B. The Used Oil Picture in the United States

Approximately 55% of all used oil generated in the UnitedStates enters a used oil management system (U.O.M.S.). Theremaining 45% is disposed as waste, through landfilling,incineration or dumping. Over 400 million gallons were disposedof in the mid-1980's, with half coming from do-it-yourselfers(DIYers -- people who change their own crankcase oil), and largeequipment operators (farmers, mining and construction companies,and the military).

EPA studies have shown over 40 million gallons of DIYer usedoil is disposed of improperly, by dumping with municipal solidwastes, in backyards, sewers, storm drains, or on roadsides.

Used Oil Management System (U.O.M.S.)

Five basic groups are represented in the functions of theU.O.M.S. These include:

- generators- independent collectors- processors/re-refiners- marketers- end-users

Companies involved with used oil interact with each other to

perform one or more of the functions from generator to end-user.

Generators

Generators of used oil fall into two broad categories:- Automotive Generators- Industrial Generators

Major automotive generators include service stations, repair andmaintenance shops, vehicle dealers, fleet shops and recyclingcenters. A used oil generator accumulates used oil in an on-sitestorage container, usually a drum or steel tank. The used oil.may be reused on site, but it is generally picked up by acollector for off-site processing and/or reuse. On-site reuseincludes:

- burning directly in space heaters, industrialboilers, and industrial furnaces

- burning as diesel fuel/used oil mixtures (such astruck fleets and military

- road oiling (such as construction, mining, andforestry)

- mixing with fuel in on-site boilers (such as militarybases)

Industrial generators produce three major types of used oil:1) straight mineral oils, 2) emulsified oils, and 3) syntheticoils. The three types are generated from applications whichinclude:

- hydraulic - compressor- turbine - metalworking- gear (lubrication) - refrigeration- process - marine- railroad diesel - natural gas engine- transformer

Industrial generators of used oil treat the oil on-site forreuse. Much of the used oil generated is transferred to anindependent collector. In some cases, a generator will improvethe quality of the oil and then transfer it to an independentcollector.

Independent Collectors

Independent collectors pick up both automotive andindustrial used oils in bulk by tankers or in drums by van.Independent collectors store and sell 65 percent of collectedused oil to processors and re-refiners. The remaining 35 percentis sold directly to end-users, who might include burners, fueloil dealers, and road oilers.

Processors and Re-refiners

Processors of used oil collect, process and sell improvedProduct oil. Primary processors collect used oil from generatorsand separate water and some solids by using basic settlingtechniques for water removal, shaking and filtration for solids

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removal, and perhaps some heat addition to aid in both.Processed oil is then sold to markets such as virgin fuel oildealers, some burners (asphalt companies), road oilers, secondaryused oil fuel processors and non-fuel industrial users, such asfor flotation oils.

Secondary processors collect used oil from generators andbuy used oil from independent collectors, as well as fromprocessors. The used oil is processed to remove water and solidcontaminants through the use of screen filtration, heatedsettling, centrifugation, light fraction distilling and blending.A clean product is sold as fuel oil, to virgin fuel oil dealers,road oilers, etc.of in some manner.

The residual water and solids must be disposedThe most common water and solids disposal

techniques are discharged to the publicly owned treatment works(P.O.T.W.) or road "oiling."

Re-refiners collect or buy used or processed oil and,through acid-clay or vacuum distillation, re-refine the oil toobtain and sell lube base stock. Light hydrocarbon fuel isproduced in the process, which is burned on-site. Residuals aresold as asphalt extenders.

End-User

End-users of collected, processed, and re-refined used oilshave been mentioned previously. Nearly 50 percent of collectedused oil is burned in boilers, kilns, diesel engines, and usedoil heaters. Because of recent regulatory changes, much of theused oil burned must be blended with virgin fuel oil products.Other major reuse markets include road oil and re-refined lubeproducts. Minor markets include flotation oils, asphaltextenders, and form oils.

Note : Blending is not-required for high quality processed'fuels for burning characteristics--only to meetregulatory specifications.

C. The Used Oil Picture in North Carolina

Used Oil Management System

The U.O.M.S. in North Carolina consists of generators,collectors, processors, marketers, and end-users. There arecurrently no re-refiners in the state.

Generators

Major automotive generators include service stations, K--Mart, Sears, Kwick Lube, auto dealers of nearly all makes, truckmanufacturers, and repair shops. Currently some stores andservice stations are offering free accumulation service to DIYers(Do It Yourself Oil Changers) for crankcase oils.

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The EPA describes a used oil generator as one who"accumulates used oil in an on-site storage container, Usually adrum or steel tank..." which suggests that any auto owner whodoes not accumulate his oil is not the generator of that oil, butrather the shop that changes the oil is the used oil generator.In the same light, the N.C. Petroleum Council reports that it islegal for a service station to change auto oil and give the usedoil back to the customer.

Many larger industrial oil generators employ a collectionservice and appear to be doing little to improve the quality ofthe used oil prior to collection.during accumulation and storage.

Some gravity settling occursCase studies presented in the

chapter describe some companies which are actively involved involume reduction and re-using used oils.

Collectors/Processors

The companies involved with collecting and processing usedoil in N.C. differ greatly in size, processing technology,analytical abilities, markets,received.

and type and quantity of oilMany processors are the end-users for collectors since

these processors burn the oil as fuel.collectors directly to end-users,

Used oil had been sold by

industrial boilers.such as asphalt plants and

Many of these same end-users have sincestopped buying used oil directly from collectors and now relyheavily on virgin oils with some processed used oil added. Somecollectors are engaged in road oiling activities for dustsuppression.

Waste oil processors in North Carolina typically employgravity settling techniques to separate water from used oil.Water represents up to 95 percent of the volume of some oilywaste. Shakers and screens are used to separate solids. Thesolids are usually disposed in a secured landfill, such as GSXServices in Pinewood, SC. Most municipal landfills will notaccept oily solids from this process. Steam as well as chemicalbreaking is used to drive water out of used oils. Membraneseparators have become popular as water/oil separationtechniques. One process employs a complete waste water treatmentprocess using a filter press.

Sources which used oil processors and collectors rely onfor a steady supply of used oil include machine coolants andhydraulic fluids, tank bottoms, mop and rinse waters, crankcaseoils, transmission fluids and ultrafiltration concentrate.

Processors characterize current and future used oil streamswith varying degrees of specificity1. A pre-shipment visit to

1 These range from wet chemical laboratory tests for totalchlorine content to use of gas chromatography/mass spectrometryto identify specific constituents in the oil.

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large generators or collectors by the processor is commonpractice and allows for a more thorough understanding of the usedoil generated. A few processors require a manifest withshipments of used oils destined for processing.

Major end-users of processed used oil include burners suchas asphalt plants and a few industrial boilers, who blend theused oil with virgin oil. Most processors are not usingprocessed oil on-site. Road oiling was at one time a fairlylarge market for used oils, however road oiling in North Carolinais now discouraged by the DOT, NRDC and the Solid and HazardousWaste Management Branch.

REGULATION OF USED OILS

This chapter deals with a variety of regulations whichconcern used oils. These regulations come under: 1) The ResourceConservation and Recovery Act (RCRA), 2) The ComprehensiveEnvironmental Response, Compensation and Liability Act, or(CERCLA) Superfund, 3) The North Carolina General Statute on OilPollution and Hazardous Substance Control, 4) The Clean Air Act,5) The Clean Water Act, and 6) North Carolina Solid WasteManagement Rules.

A. Background Information

"Used Oil", as defined by EPA, "is petroleum-derived orsynthetic oil including, but not limited to oil which is used asa lubricant, hydraulic fluid, metalworking fluid, insulatingfluid or coolant and which is contaminated through use orsubsequent management." Used oil varies greatly in itscomposition, depending on the type of oil, the extent to which itwas used, and the intentional or unintentional addition of otherwastes to the oil.

Contaminants of Used OilUnused motor oils contain additives and detergents which may

contain elements such as lead, zinc, phosphorus, barium andvanadium. Used motor oils contain even higher concentrations ofheavy metals such as lead, from the tetraethy lead of gasolineand chromium from wear of metal parts in the engine. Used motoroil often contains fuel, water and anti-freeze. Used oils fromvehicle repair facilities are subject to contamination withdegreasing solvents, i.e. chlorinated hydrocarbons, which arefound in used oil as a result of intentional and unintentionalmixing practices.

Metalworking fluids frequently contain higher levels ofheavy metals and chlorinated compounds than do other industrial

-oils (including hydraulic, compressor, turbine, and electrical).Many times the metalworking and hydraulic oils contain extremepressure additives which are chlorinated hydrocarbons.

As much as 30 percent of used oil exhibits a flash point of

less than 140oF, which is the criterion for "ignitable" underhazardous waste regulations. However, a 100°F flash point is the"on" or "off" specification level for used oil.

Prior to the recent RCRA regulations, used oil was avaluable yet often wasted resource. Re-refining and burning weresomewhat controlled, but dumping, land farming, and dust controlwere used extensively as methods for disposal of used oil.

A favorite method for disposal of used oil and oilywastewater separated from oils had been as a dust suppressant.Unfortunately, oil is a good solvent for hazardous chemicals suchas PCB, pesticides, and degreasing solvents. One reportestimates that some 120 million gallons of used oil was sprayedannually onto rural roads for dust control purposes. Used oilreclaimers have, in the past, mixed dioxin sludges with used oiland sprayed the mixture for dust control. Both PCBs and dioxinshave been blended into used oil which has been buried inresidential boil&s which are not capable of destroying the toxiccomponents in the mixture.

In the 1970's, more than half of the used oil generated inthe United States was managed un-wisely, as judged by our presentstandards.

B. Past RegulationsPast history of improper used oil disposal practices created

a need for Federal intervention and regulation. The U.S. EPA(Environmental Protection Agency) recognized used oil as avaluable source of energy having a BTU (British Thermal Units)rating equivalent to crude oil. In 1974, the EPA produced thefirst comprehensive report on used oil, estimating that over 28million barrels of used oil were generated nationwide yearly,with the energy potential to heat and cool some 675,000 homes oroperate over 1.3 million cars for a year. The EPA found that 43percent of this oil was burned without regard to problems of airpollution, 18 percent was used on roads, 8 percent was re-refined, and the fate of the remaining 31 percent was unknown.Used oils were clearly posing a significant threat to humanhealth and the environment.

Congress took an interest in conserving used oil as early as1976 and directed the Department of Commerce to developprocurement guidelines for used oil to insure that at least thegovernment would be a market for used oil. By the end of 1980,there existed no such guidelines. Disposal of used oil was thento be regulated by the RCRA (Resource Conservation and RecoveryAct), but EPA decided not to classify used petroleum oil as ahazardous waste.

Congress enacted the Used Oil Recycling Act in 1980 whichprovided the states with $5 million for both 1982 and 1983development of used oil recycling programs. It also authorizedthe EPA to promulgate regulations and take aggressive action

toward governing used oil to protect human health and theenvironment.

Next came the HSWA, The Hazardous and Solid Waste Amendmentsof 1984 to RCRA which had a direct impact on oil recycling. Anyreclaimed oil fuel containing hazardous waste or exhibitingcharacteristics of hazardous waste was to be labeled with thestatement "This Fuel Contains Hazardous Wastes." EPA was alsorequired to make a decision by November 8, 1986 whether or not tolist crankcase oil as a hazardous waste as well as how to regardall other used oils. HSWA also placed a ban on the use of wasteor used oil or other material that is contaminated or mixed withdioxin or any other hazardous waste, (other than a waste which ishazardous only through the ignitability characteristics) for dustsuppression or road treatment.

Some additional regulations on used oil burning andmarketing were issued on November 29, 1985. These regulationsestablish a/specification-based regulatory system for used oilfuel as discussed in the next section.

C. RCRA Regulation of Used Oil

1. Disposal of Used OilAs a result of widespread mismanagement and resulting health

hazards associated with used oils, the EPA has adopted severalRCRA regulations concerning the burning of these oils. The threeclassifications of used oil fuels covered under these regulationsare: on-specification, off-specification, and hazardous wasteused oils. Although these regulations impact only used oilsdestined for burning, the state of North Carolina discouragesdisposal of any used oils on roads and prohibits disposal inlandfills; therefore, all used oil disposed of in North Carolinamust be treated as one of the three classes. The analyses whichdetermine a used oil's classification are as follows:1) on-specification metal content (maximum) arsenic - 5ppm

cadmium - 2ppmchromium - 10ppmlead - 100ppm

flash point (minimum) > 100°FTotal Halogens' 1000 ppm(chlorine) (rebuttable)

4000 ppm max(non-rebuttable)

2) Off specification exceeds one of the above prescribed limitsbut has not been mixed with hazardous waste.3) Hazardous used oil fuels - used oils exceeding 1000 ppm totalchlorine, or used oils which have been mixed with a hazardouswaste.

2 If the total halogens are in the range 1000 to 4000 ppmand one can prove that this oil has not been mixed with hazardouswaste, then this oil will meet the on-specification criteria.

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See Figure 9.2 for a decision making flow chart of theclassifications of used oil. The tables following this figureexplain the RCRA regulations as they apply to the generators,transporters, marketers/recyclers, and burners of used oils.

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FIGURE 9.2: USED OIL FUEL CLASSlFICATlON UNDER RCRA

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D. Superfund (CERCLA) Regulations

1. Under section 114(c) of CERCLA, any service station collectingused oil from light duty motor vehicles and household appliances,or their owners shall not be held liable for any response costsor damages which occur as a result of a release or threatenedrelease of this oil. See rule 114(c).

RULE 114(c)SUPERFUND (CERCLA) REGULATIONS

SEC 114 RELATIONSHIP TO OTHER LAW.(a) Used Oil - Section 114(c) of CERCLA amended to read as

follows:"(c) Recycled Oil -

"(1) Service Station Sealers, Etc. - No person(including the United States or any State) may recover,under the authority of subsection (a)(3) or (a)(4) ofsection 107,, from a service station dealer for any response

costs or damages resulting from a release or threatenedrelease of recycled oil, or use the authority of section 106against a service station dealer other than a persondescribed in subsection (a)(l) or (a)(2) of section 107, ifsuch recycled oil -

"(A) is not mixed with any other hazardous substanceand,"(B) is stored, treated, transported, or otherwisemanaged in compliance with regulations or standardspromulgated pursuant to section 3014 of the SolidWaste Disposal Act and other applicable authorities.

Nothing in this paragraph shall affect or modify in any waythe obligations or liability of any person under any otherprovision of State or Federal law, including common law, fordamages, injury, or loss resulting from a release orthreatened release of any hazardous substance or for removalor remedial action or the costs of removal or remedialaction.

"(2) Presumption. - Solely for the purposes of thissubsection, a service station dealer may presume that-asmall quantity of used oil is not mixed with other hazardoussubstances if it -

"(A) has been removed from the engine of a light dutymotor vehicle or household appliances by the owner ofsuch vehicle or appliances, and"(B) is presented, by such owner, to the dealer forcollection, accumulation, and delivery to an oilrecycling facility.

"(3) Definition - For purposes of this subsequent, theterms 'used oil' and 'recycled oil' have the samemeanings as set forth in sections 1004(36) and 1004(37)of the Solid Waste Disposal Act and regulationspromulgated pursuant to that Act."(4) Effective Date - The effective date of paragraphs(1) and (2) of this subsection shall be the effectivedate of regulations or standards promulgated under

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section 3014 of the Solid Waste Disposal Act thatinclude, among other provisions, a requirement toconduct corrective action to respond to any releases ofrecycled oil under subtitle C or subtitle I of suchAct".

2. Reportinq of SpillsReportable Quantities - Chemical Spill Notification

All who handle hazardous substances or hazardous waste mustcomply with the Superfund Act or (CERCLA) ComprehensiveEnvironmental Response Compensation and Liability Act of 1980.This applies to the conditionally exempt quantity generatorWSQG), the small quantity generator (SQG), the large quantitygenerator (LQG) and the treatment storage and disposal facility(TSDF).

To date about 700 chemicals have been designated ashazardous substances under CERCLA. A spill or release of any ofthese chemicals in some cases in quantities as little as onepound requires immediate notification to the National ResponseCenter (NRC) (800) 424-8802.

The prime purpose of the notification requirements is toalert EPA officials to the release of hazardous substances thatmay require rapid response to protect public human health and theenvironment: EPA may respond, if there is an imminent andsubstantial danger to the public. The reporting is a triggeringmethod but EPA will not necessarily respond to all reportedreleases. The reportable quantities in and of themselves do notrepresent any determination that the release of a particular sizeis actually harmful to human health or the environment.

A release onto the environment (land, water, air) is definedas any spilling leaking, pumping, pouring, emitting, emptying,discharging, injecting, dumping or disposing. There are fourexclusions, the most important of which is releases which resultin "exposures solely within the workplace" for which claimsagainst the employer or other persons are available. This makesit doubly important to dike in-plant storage to contain spills.A release of a hazardous substance does not enter the environmentand need not be reported if the spill is wholly contained on theconcrete floor of the facility. If the spilled materialevaporates into the air in an amount equal to the reportablequantity, then it must be reported. The other exclusions areengine exhausts, radioactive releases and fertilizerapplications.

In North Carolina for oil/chemical release/spills, the 24hour number is (800) 662-7956 or during work hours call (919)733-5291. Be prepared to answer a long checklist of questionsabout the release when you call.

Although it will take coordination with other agencies andin some cases changes in other acts, CERCLA is trying to

designate the National Response Center as the one notificationpoint that will satisfy all notification requirements for all thevarious acts. Presently there are notification requirements forspills and releases in the following acts:

1) RCRA, for operator of treatment, storage, and disposalfacility.

2) DOT 49 CFR 172.101 Hazardous Materials Table.3) Clean Water Act 40 CFR Section 3114) Federal Water Pollution Control Act.5) CERCLA 40 CFR Part 302.

The reportable quantities are different in different acts tothe extent that compliance with one standard may constitute non-compliance with another standard or regulation. For instance,certain releases would be subject to CERCLA and not CWA Section311; still others subject to CWA Section 311 and not to CERCLA.

However for small generators reporting spills of one (1)pound or more will usually be a conservative action that willlead to guidance to the proper action.

Penalties for not reporting a spill under CERCLA are up to$5,000 per violation. The three possible violations includehaving the spill', failing to clean the spill, and failing toreport the spill.

Table 9.1 summarizes the above information.

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TABLE 9.1

SPILL REPORT

PHONE NUMBERS

NATIONAL RESPONSE CENTERl-800-424-8802

STATE WARNING POINTl-800-662-7956

NRC REQUIRED REPORTING

OIL DISCHARGES INTO U.S. WATERSHAZARDOUS SUBSTANCES DISCHARGES IN EXCESS OF REPORTABLEQUANTITYTRANSPORTATION ACCIDENTS INVOLVING HAZARDOUS MATERIALS,SUBSTANCES, AND WASTESHAZARDOUS WASTE TSD FACILITY RELEASE, FIRE, OREXPLOSION WITH THREAT TO HUMAN OR ENVIRONMENTHAZARDOUS WASTE DISCHARGES FROM ABANDONED DUMP SITES BYANYONE OBSERVINGTHREATS OF DISCHARGES OR RELEASES

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Oil spills are also regulated on the state level by NRCD. Thefollowing section explains the state law.

E. North Carolina General Statue on Oil Pollution and HazardousSubstances Control

1. Oil Spills

All oil spills or discharges must be reported to the NRCD"Department, or any of its agents." The time, location, andmeasures of action taken to clean-up the spill are required.

2. Road Oiling

Dust suppressing is controlled as indicated in Section 143-215.83 of The General Statutes of North Carolina, which states itis "unlawful to discharge or cause to be discharged" any oilwithout permit onto water or land. Federal regulations prohibitroad oiling with hazardous waste although it has been commonpractice in the past, North Carolina state agencies presentlydiscourage use of used oil for road oiling.

F. Clean Air ActAir Quality RegulationsBurning Used Oils

In 1970 the Clean Air Act addressed the hazardous airpollutants problem by listing hazardous air pollutants andsetting national emission standards. In 1985 the Air ToxicStrategy Program was developed to involve state and localagencies in regulating area sources of air pollution. Airquality permits are issued by the Air Quality Section of theDivision of Environmental Management (DEM). DEM treats theburning of used oil like any other substance

Before issuing a permit the DEM must know what pollutantsare in the oil and approve the burning of that oil on the maximumcontent of selected contaminants. The type of fuel to be burnedmust be specified by number, for example #2 fuel oil. The BTUcontent per pound and per gallon of used oil fuel and the weightper gallon or specific gravity is also required.

There are some used oils that are burned as fuels which areexempt from the permit requirement as “on specification"virgin oil does not have to be permitted, but must have a

oil,

chemical analysis that proves its classification as an "onspecification" oil. A space heater burning off-specification oilmay also be exempt if the following requirements are met:

1. The heater burns only used oil that the owner oroperator generate or used oil from do-it-yourself oilchangers who generate used oil as household wastes:

2. The heater is designed to have a maximum capacity of

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not more than 500,000 BTU's per hour; and

3. The combustion gases from the heater are vented to theambient air (outside).

The 1990 Clean Air Act has currently not specified changesto the burning of used oils. However, as the regulations areforthcoming, it is important to determine what effects the 1990Air Act will have on existing air quality permits.

G. Clean Water ActRestriction of the Use of the Sanitary Sewer as a Means ofHazardous Waste Disposal

Water Pollution

Water pollution has two major origins: point sources andnonpoint sources. Point sources are specific points ofdischarge, such as outfall pipes from industrial facilities orsewage treatment plants. Nonpoint sources, on the other hand,cannot be located so precisely. Runoff from city streets, fromconstruction sites, and from farms and mines are examples ofnonpoint sources. Both sources contribute heavily to thepollution of our nation's waters.

There are federal, state and city regulations, and ordinances restricting what can be put in the sanitary sewersystem. The objectives of these regulations are to controlpollutants which pass through or interfere with treatmentprocesses in publicly owned treatment works or which maycontaminate sewage sludge, and to improve opportunities torecycle and reclaim municipal and industrial waste waters andsludges.

National Pollutant Discharge Elimination System

The National Pollutant Discharge Elimination System (NPDES)permit program is perhaps the most significant enforcementmechanism contained in the entire Clean Water Act. This programregulates discharges into the Nations water from point sources,including municipal, industrial, commercial, and certainagricultural sources. All such sources must obtain an NPDESpermit from EPA or an approved State agency.issued, however,

No permit may beunless it complies with all applicable sections

of the Act.

Federal Water Pollution Control Act

The act controlling wastewater is the Federal WaterPollution Control Act as amended by the Clean Water Act of 1977(40CFR403). Pollutants from non-domestic sources are subject tothe National Pretreatment Standards which prohibit pollutantsthat:

l- create a fire or explosion hazard2- cause corrosive structural damage (pH under 5)3- cause obstruction to flow4- have biological oxygen demand5- inhibit biological activity because of high heat (over

104o F)

Many cities pass on similar restrictions to their customers.As an example, the Raleigh City code under Article C, "Use ofSanitary Sewer System" list 25 wastes that are prohibited andrequire pretreatment. The list includes among other substances:

l- any designated individual waste2- limited concentration of 12 heavy metals3- oils and greases4- 12 other chemicals5- toxic or poisonous substances including cyanide6- solid and viscous substances

H. North Carolina Solid Waste Management RulesSanitary Landfill Acceptance PracticesLandfillinq Used Oil and Solids Containing Used Oil

North Carolina sanitary landfills do not accept liquidwastes of any kind. However, a sanitary landfill will acceptused oily absorbent material, or oily solids if they are "non-bleeding" and certain criteria are met and by properly completinga "Waste Determination Form" which is available from the Solidand Hazardous Waste Management Branch. Large quantity generatorsmust dispose of these materials through a contrator.

The chemical analysis must be reported to the Solid andHazardous Waste Management Branch for approval, along with acompleted "Waste Determination Form."

Oily sludges, which are substances that do not have any freestanding liquid, may be accepted by a landfill when accompaniedby a chemical analysis and an approval by the Solid and HazardousWaste Management Branch.

Used Oil FiltersThe Toxicity Characteristic (TC) regulations have left many

people wondering if used oil filters are now a hazardous waste.The possibility exists that these oil filters could exhibit thischaracteristic and thus be a hazardous waste.

All petroleum wastes contain benzene. If 0.5 ppm or more ofbenzene leaches out in a TCLP, then the filter is a hazardouswaste,

According to limited lab results, used oil filters whichhave been drained for 24 hours pass the TCLP. Some of thesefilters have to be punctured so they will drain. For thisreason, The N.C. Hazardous Waste Section is not currently

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requiring all generators to perform the TCLP on oil filters whichhave been drained for 24 hours. Businesses which generate alarge number of oil filters are asked to crush their filters toremove as much oil as possible before sending them to a sanitarylandfill.

The preferred method would be recycling. At the presenttime, the Hazardous Waste Section does not know of any scrapmetal recyclers accepting crushed/drained oil filters. If youknow of any recyclers accepting used filters please call theHazardous Waste Section and the Pollution Prevention Program at(919) 571-4100.

RECOMMENDATIONS FOR MANAGEMENT OF USED OIL

The first part of this section describes simple managementpractices and good housekeeping techniques which help to minimizethe volume of used oils, and also the quantity of potentiallyhazardous waste produced. The second part of this section goesinto detail on alternatives for managing used metalworking andlubricating oil.

A. Good Housekeeping Practices with Used Oil

Minimize the Quantity of Used Oil Generated

The amount of used oil generated in a particular process canbe decreased or sometimes eliminated by modifying or completelychanging a given process. Water-based coolants and fluids oftenperform equally or better than similar oil-based fluids. Usedoil concentrated at the source of generation helps to segregatetypes of oils and oily water and helps to reduce the risk ofcontamination with other hazardous materials.

Simple treatment, such as gravity settling, promotes theseparation of oil/water wastes to substantially reduce the volumeof used oil. Avoid using more of the virgin oil product oilproduct than is necessary. Simple employment of an oil inventoryprogram produces immediate results in more effectively managingthe quantities of used oil generated. Adopt practices for usingand re-using materials as much as possible.

Maximize the Quality of Used Oil Generated

Avoid contamination with other liquids, both hazardous andnon-hazardous. A clean used oil has more value in themarketplace. Look for creative uses; a used oil generated in oneprocess can sometimes be used in another.

Performing some on-site treatment, i.e. gravity settling,centrifugation, ultrafiltration, etc.,of used oil for reuse on-site,

will improve the qualityas well as decrease the amount for

collection off-site.

9-20

Remain Informed

Stay current with government regulations involving used oil.Examine plant operations periodically to determine types andquantities of oily waste being generated. New products enter themarket constantly which can offer savings, as well asperformance.

Proper Selection of Collector or Processor

Investigate and thoroughly understand your collector- orprocessor's practices and policies. The used oil industry isfederally regulated and highly technical,services is not a simple task.

so choosing reclamationAnother person's improper

handling of your used oil can result in your liability. A sitevisit is a must.

B. Storage and In-Plant Collection of Used Oils

When storing oil for future collection, several practicesshould be followed. First, the storage area should be protectedfrom the weather. This can be accomplished by storing the oil inplant or building a small covering over the storage area. Also,the area should be protected from unauthorized access. Thiscould mean a fence with a lock. Preventing unauthorized accesscould also prevent the unwanted mixing of other wastes (possiblyhazardous waste) with the used oil. If the oil is to be storedin any open area the storage container should have a labelindicating that the container is for used oil and that no othersubstances are to be placed in this container.such a label is given in Fig. 9.3.

An example ofNext, the areas should be

diked for the capacity of the storage tank or drum to eliminatepotential overflow from spills. A non-draining sump would bedesirable to eliminate overflow from rain or the possiblecontamination of other "clean" streams. Finally, the storagearea floor should be made concrete to ensure no absorbing of thehazardous material could take place.

Clean-up of Oil Spills on Land and WaterSeveral technologies are available for cleaning up oil

spills on land. The most common method of cleaning up small oilspills is with clay adsorbents such as "Kitty-litter" and "Oil-Dry." Other material commonly used for both large and smallspills include sand and hay. The problems which come from theabove adsorbents are that the absorption is not always effective,the oily waste is often hard to handle, and the material must belandfilled.

A new technology for "cleaning-up" used oil spills on landinvolves using a sock-like roll of absorbent to absorb thespilled oil. The sock may be called a hog, sausage, or snake byvarious manufacturers. The absorbent filler has a very goodabsorption rate and capacity.

9-21

FIGURE 9.3: USED OIL CAUTION LABEL

9-22

For controlling oil spills on water, several floatingsynthetic materials are used. These synthetics absorb the oiland are then removed. Some of these materials must be disposedof directly in landfills. Others can be "squeezed out" andreused, thus eliminating landfill liability and savingreplacement costs.

Dust-Suppressing (Road Oiling)For years road oiling has been a common practice for

controlling dust on roads in North Carolina. However, at thepresent time, all involved state agencies are frowning on thepractice. It is illegal to use oil on roads without receiving apermit from NRCD. Many people are turning to other, safermaterials for dust control. A list of some of these materialsand the companies supplying them is included below.

Dust suppressant materials consists of a mixture of organicsubstances such as semi-liquid nonvolatile petroleum resins and awetting solution. An example trade bane and supplier is:

Soil SementMidwest Industrial Supply, Inc.P. O. Box 8431Canton, OH 44711l-800-321-0699

C. Management of Metalworking FluidsRecycling and purification processes most commonly rely on

the physical properties of waste fluids when removingcontaminants. Various life extension and volume reductionprocesses include: 1) time settling, 2) filtration,3) ultrafiltration and reverse osmosis, 4) magnetic separation,5) centiifugation, 6) hydrocyclone separation, 7) distillation,8) aeration, 9) pasteurization, 10) chemical treatment, 11)biological treatment, 12) carbon adsorption, and 13) coalescing.Each method is commonly used when the situation parametersdictate it to be the most efficient and economical method.Although each method can be used independently, it is more commonto see several operating in series. The following explains-thedesired characteristics and preferred situation for the use ofeach unit operation. For a summary of the advantages anddisadvantages of each operation, see Table 9.2. Figure 9.4presents the schematic representation of several of theseoperations.

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Aeration (R,D)

Skimming (R,D)

- Handles high solids contents- Reliable, easy operation- Can be used on variety of load

sizes

- Low cost- Many options (belt, wheels, etc.)- Most cost effective way for

removing tramp oils or freefloating oils

- Requires chemicals and thereforesludge disposal

- Not effective on emulsions orsoluble oils

FIGURE 9.4: PURIFICATION/DISPOSAL OF METALWORKING FLUIDS

9-27

1. Life Extension OperationsTime/Gravity Settling

Time settling or retention is the simplest and perhaps themost common of separation techniques. Time settling involvesusing a holding device to contain the "dirty" fluid. Thespecific gravity of various solid contaminants allows them todrop to the bottom and "settle" out. The lighter components,usually tramp oils, float to the top of the holding tank wherethey can be skimmed off. When the heavy particulates havesettled, manual or automatic operations can be used to remove thesettled wastes. Manual cleanout is time consuming, laborintensive and a certain amount of downtime is required while thecleaning operations are taking place. Automatic cleanout usuallyinvolves a conveyor belt with blades which "pull" the solids upan incline (45o - 60o) and releases them into a disposalcontainer. The dirty fluid inlet is positioned near the middleof the tanks liquid level to let the heavy particulates fall outand the flotsam (tramp oil) rise to the top. The clean fluidoutlet is usually positioned at an opposite end from the dirtyfluid inlet. Weirs and baffles are used to extend the separatortime and control turbulence.

While retention chambers are simple and quite popular, thereare several cases in which they are inappropriate. First, whenthe contaminated fluid is extremely viscous, settling time isvery long, thus making the operation impractical. When theparticulate matter is extremely fine, the "falling out" time isonce again greatly increased. Certain wastes "clog" the bottom,sides, baffles, and weirs, thus changing the desired flowcharacteristics within the chamber and reducing effectiveness.

While retention chambers are sometimes used alone, they canbe used in conjunction with other separating devices to reduceretention time, and effect a better separation. In these casesthe retention tank is used primarily to remove large particulate:before the fluid enters a second separating device.

Filtration

Filtration is one of the most widely applicable and commonlyused purification techniques. Conventional filters can becategorized into two divisions, unaided and aided filters. Anunaided filter is able to use the cake (build up of oldcontaminants) as a filtering media while an aided filter must usa filter aid to induce filtration. The three most common filteraids include diatomaceous earth, fullers earth and a woodcellulose material. Aided filters are normally used insituations where contaminant levels are low and a pure product isdesired. Typically, aided filters can filter down to levels aslow as two microns. Often industries use disposable paper mediawhich can be disposed of along with the contaminated cake whenthe cake becomes too thick.

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Conventional filters can be further subdivided into surfacefilters and depth filters. Surface filters hold the contaminantson top of the media. Depth filters hold the undesirable speciesin the intermediate spaces in the cake.

The driving force which causes the filtration process totake place includes gravity, vacuum, suction, and pressure. Itis obvious that filtration as a unit operation must take manyprocess variables into account, depending on the situation athand.

Magnetic Separation

The next process for clarifying metalworking fluids utilizesmagnetic separation. This method of separation involvesseparating solid ferrous contaminants from used metalworkingfluids by inducing a magnetic field around a collective device.This collection device releases the "waste" particles by either abreak in the magnetic field or some type of scraping device.

Centrifugation

A common unit operation used for the separation of bothsolids and tramp oils from a metalworking fluid iscentrifugation. A centrifuge consists of a series of conicaldisks stacked on top of each other which spin at relatively highvelocities. Each disk contains holes in the periphery area inorder to let fluid rise through the discs. As the centrifugespins the solids and oil sludges are "whipped" toward the outsidewalls by centrifugal force. The clean fluid rises through theholes and is collected midway on the centrifuge by a collectiontube. Tramp oil, the lightest component, rises through themiddle and is collected on the top of the centrifuge. The wasteswhich collect on the periphery of the centrifuge may be cleanedeither manually or automatically. Manual cleaning of acentrifuge is labor intensive since up to 30 disks must becleaned and the "cake" which builds up can often be difficult toremove. This manual-cleaning must be done after every few uses,depending on the amount of contaminants present in the spentfluids. Automatic cleaning is preferred, if large volumes mustbe handled so as to maximize the efficiency of a steady stateoperation. This "automatic" cleaning process usually involvespurging the solid waste with either high pressure or mechanicalprobes for short periods of time at regular intervals.

Hydrocyclones

Hydrocyclones operate with centrifugal force, much as thecentrifuge does. The contaminated fluid enters the top of aconical tank where a whirlpool effect takes place. The solidsare pushed out to the sides and down in the conical tank untilthey reach a small opening in the tank's bottom. The centrifugalforce produced in the cyclone can separate solids down to the 5micron range. These solids pass through this opening for some

9-29

type of future disposal while the lighter liquid layer goes up toan overflow. While not able to produce the same amount ofcentrifugal force as does the centrifuge, the hydrocyclone'spopularity arises from its relative effectiveness in separatinglarge solids in an economical and simple unit operation.

Vacuum Distillation

Vacuum distillation is a unit operation most commonly usedon straight oil fluids. The process involves using adistillation column to remove water from the desired oil layer bycreating a low temperature (140" or less) vacuum within thecolumn. The low temperature keeps the oil from oxidationbreakdown. A prefilter is usually necessary to remove solids.Manufacturers of vacuum distillation equipment indicate the unitscan handle streams containing 5 - 40% water. Obviously, removing40% water with this technique would require excess time andenergy and therefore be uneconomical.

Coalescing

Coalescing is a popular method of gravity separation foremulsified oils. This operation involves pumping the waste fluidthrough a series of coalescing plates. Oil droplets deposit onthese plates and then rise to the surface where they can be"skimmed" off. Occasionally heavy particles will not coalesce,and therefore have to be removed using an alternate method.

Skimming

The next means of separation includes skimming. Roll, drumand belt skimming can be used to remove almost all "free oils"from waste streams. The oily waste which is skimmed off can then'be consolidated for further disposal. Skimming is most oftenused in series with other unit operations such as gravityseparation (coalescing), filtration, and biological or chemicaltreatment.

2. Disposal of Metalworking Fluids

Recycling used metalworking fluids in order to extend theirlife is often an economical and practical management option.However, due to large quantities of suspended solids, rancidodor, or product degeneration, there comes a time when thesefluids must ultimately be disposed of. When amounts of oilywastewater exceed 200 gallon/day it usually becomes economicalfor a plant to maintain its own treatment/disposal facility.Several methods of disposal which are widely used include:membrane separation, chemical treatment, biological treatment,coalescing, and carbon adsorption.

Membrane Separation

Membrane separation processes include reverse osmosis and

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ultrafiltration. Reverse osmosis uses a semipermeable membraneto separate contaminants from the waste stream. The stream to beclarified must have a pressure against the membrane of 200-600psi. Most of the permeate passing through reverse osmosisprocesses is suitable for discharge into the ordinary sewer.usually, the sensitivity of the membrane makes reverse osmosisimpractical for use with even moderately contaminated fluids. Aprior treatment method is normally desired.

One such prior treatment method is ultrafiltration.Ultrafiltration is another membrane separation process.ultrafiltration is used primarily to remove emulsified oils fromwastewater. This process involves passing a contaminated streamparallel to a series of semipermeable polymeric membranes. Thepolymeric membrane is used under moderate pressures (up to 50psi) and high flow rates to preferentially separate (down to .OOlmicrons) materials with high molecular weights (oils) by size,shape, and chemical structure. Under normal conditions, themembranes must be cleaned weekly. Although ultrafiltrationremoves free oils effectively, these are more economicallyremoved by skimming or using some other drag out system. Severalfactors which could influence one to use ultrafiltration include:

l- it is functional at broad range of temperature and pHvalues;

2- no chemicals are necessary since the is a physicalseparation:

3- volume reduction of waste is usually 95-97%.

Obviously the volume handled by ultrafiltration systems are muchless than those of conventional filters.

Chemical Treatment

The most widely used method for treating waste metalworkingfluids is chemical treatment. The most common method forbreaking emulsions with chemicals involves using acids, bases,and precipitating agents (aluminum sulfate, ferric chloride,ferric sulfate). The acid is added to the-mixture to drop pH to4 or less. Next the precipitation agent is mixed in and the pHis raised by adding a basic solution. Metal-hydroxideprecipitates out as "floc" which attaches itself to otherparticles (such as oils) and absorbs and attracts oils. Thisclarification process is complete when the oily "floc" is removedeither by settling or floating. Often the clarification issufficient for treatment by the municipal facility.

Most metalworking fluids contain negatively chargedparticles which help hold the oils in the emulsion. The abovementioned chemicals used for creating floc are unchargedinorganics with relatively low molecular weights. However, highmolecular weight, positively charged, organic molecules known aspolymers can be added to the anionic emulsion to neutralize thesolution and therefore break some oils and solids out. These

9-31

"oils and solids" act as the floc. The advantages of usingpolyelectrolytes are that a pH change is not necessary and lesssludge is produced. Cost is the main drawback.

Carbon Adsorption

Carbon adsorption is a treatment method used to remove oilsand other organics that have not been removed by pretreatmentsteps such as emulsion, breaking, and ultrafiltration. Activatedcarbon is able to handle pretreated streams with up to 50 ppmsuspended solids and 10 ppm oils. Usually several carbon bedsare used in series since the carbon beds must regenerateperiodically.

Biological Treatment

Biological treatment of metalworking fluids is anotheroption for the treating of spent metalworking fluids. Bothaerobic bacteria and anaerobic bacterial can be used to consumethe oily section of a wastewater.

It is common to have these bacteria in both small reactorsand large stabilization ponds. The bacteria form a biologicalfloc for decomposition reactions.removal of suspended solids.

Typical results have up to 90%Obviously, ponds and lagoons where

the decomposition takes place can be quite large.

3. Economics

Cost effectiveness is the key principal in deciding whichtype and method of purification to use when working withmetalworking fluids. The various options which are available forreclaiming and disposing of fluids have already been discussed.Now, feasibility and economics of two operations will bediscussed.

When disposal is the desired option, the fluid is generallytreated as an oily wastewater. It has been shown that when thevolume of wastewater exceeds 200 GPD, it becomes economical tooperate a treatment facility rather than having the waste hauledoff. The most common disposal technique with the lowest capitalcost is chemical treatment with acid-alum or high molecularweight polymer. The only process equipment which is absolutelynecessary is a holding tank (a 55 gallon drum could be used).However,justified

to have an integrated system which will be economicallyover contract hauling,

are generally met.the following minimum criteria

The equipment must consist of a tank which 1)can contain 500 gallons (minimum),ratio of l:l, 3) has a mixer,

2) has a diameter to depthand 4) has a drain.

as this require moderate initial costs.Systems such

For example, a systemcapable of treating 1000 gallons/day would cost about $20,000.

An alternative generally regarded to be more economical thanchemical treatment involves ultrafiltration. The drawback to

ultrafiltration involves the high initial cost. A system capableof handling 1000 gallons/day of wastewater would cost at least$50,000. However, once the system is in operation, the systemhas no associated chemical costs. Generally, it is noted thatultrafiltration involves an associated cost of 6 to 9 cents pergallon to get the desired 90+ percent volume reduction.

Various studies have indicated that a volume of less than2000 gallons/day is most economically treated by ultrafiltration.In the example on the following page (Table 9.3), this is shownto be true. The cost for ultrafiltration (12.8 cents/gallonprocessed) came out to be almost 20 percent less than chemicaltreatment (16.6 cents/gallon processed). The systems studiedinclude process equipment as it is shown in Figures 9.5 and 9.6.

This simple example illustrates that high initial cost isnot always the most important consideration when purchasingrecycling/disposal equipment. As with all unit operations,simple modeling can be used to experiment with different stagesand the economics of their operation. Techniques such as thisshould always be employed before deciding to purchase a "system."

D. Management of Used Lubricating Oils

The proper management of used lubricating oils is importantfor the following reasons:

l- Used lube oils may contain hazardous substances such aslead, chromium, barium, cadmium, and acids.

2- The breakdown of additives causes the presence ofhalogenated compounds in the used oil.

9-33

Table 9.3 Chemical Treatment vs. Ultrafiltration

Depreciat ion = Instal led(10 years) cost

10 yrs$19,500 + 19,500 = $3,900

1 0

Capital Payment ( Instal led)@ 20% interest over 10 yrs. = $5,000

Total = $25,800 Total $30,100

$50,000 + $25,000 = $7,50010

= $10,000

Total Process Cost $25,880 + $15,700 $30,100 + $2,000

= $41,580/yr x yr/250,000 gallons processed $32,100/yr x yr/250,000 gallons processed

= 16.6 cents/gallon processed = 12.8 cents/gallon processed

3- Carcinogenic chemicals may be found in used industrialoils and used engine oils.

Acceptable management practices include reclamation,reprocessing, and re-refining of used lubricating and hydraulicoils. Reclaiming is a process by which water and solids areremoved from the used oil by heat, gravity, settling, and eitherscreening, centrifugation, or filtration. The products of thisaction are fuels, fuel supplements, or concrete form oil.Reprocessing is a technique for removing water, solids, and someoil-soluble contaminants from the used oil. This technology usesheat, surfactants, chemicals, clay treatments, filtration, andcentrifugation. Reprocessing results in oils which can be usedas clean fuels, metalworking base stocks, non-criticallubricants, and concrete form oil. Some oils can be reprocessedto original quality for reuse as lubricating oils.

A company generating used lube oils should examine thepossibility of an on-site reprocessing program. One company inIllinois had produced a large volume of oil/water emulsion fromthe cooling and lubrication of five large milling machines. Theypreviously controlled the tramp oil by skimming, collecting theskimmings for disposal,fluid.

and using the remaining oil as hydraulicThe high cost of disposal of the scrap, and the poor

performance of the used oil as a hydraulic fluid prompted thecompany to purchase an industrial centrifuge. Weeklycentrifugation of the mill emulsions removed brass and copperparticles, as well as 99% of tramp oils, resulting in an oil pureenough to re-use in the milling operation.

Re-refining is practiced to remove water, solids, and oil-soluble contaminants to produce a lube oil comparable to virginoil. This is achieved by pretreatment of the oil with acids,caustics, or solvents to remove the major. portion of unwantedcompounds, high temperature distillation, and clay contact orhydrotreating to remove residual contaminants. The re-refinedoil works as a base stock for engine, hydraulic, metalworking,and gear oils,lubricants.

as well as transmission fluids, and bearing

Mohawk Oil Corporation, A Canadian company, offers a usedoil re-refining service for the British Columbia area. They havedeveloped a distillation/hydrotreatment technique which can re-refine oil to "equivalent to virgin-oil" standards. Theirprocess consists of three steps: 1) dehydration, to remove waterand light hydrocarbons, 2) fuel removal in a vacuum column toremove gasoline and diesel fuel, and 3) a two-stage vacuumdistillation unit consisting of two series-connected wiped filmevaporators. The residues (bottoms) which result from thedistillation process are sold to an asphalt company.

The distilled base oil is pumped to a hydrofinishing unit,which uses hydrogen over a metallic catalyst to improve the oil'scolor and reduce the level of sulphur and nitrogen compounds.

9-38

The re-refined oil resulting from the level of sulphur andnitrogen compounds. The re-refined oil resulting from thisprocess is of quality comparable to crude lubricating oil and isblended into many types of hydraulic oils, industrial oils, andspecification engine oils.

The state of North Carolina operated a used oil re-refiningplant in Garner, but found the operation to be a money loser.The plant was shut down and the equipment sold for salvage.

The optimal alternative for used oil management is toconverse oil at use point, thus minimizing the waste which musteventually be treated. Conservation can best be achieved bymonitoring the oil for a clue as to the need for an oil change.

An arbitrary schedule of lubricant change in industrialequipment is bound to result in the wasting of oil which stillhas useful life,lubricant fluid.

or damaged machinery resulting from overuse of aA program of used-oil analysis can provide

insight on the condition of the oil and of the engine from whichit came. The analysis can help with a preventive maintenanceprogram and can tell oil condition, i.e., should the oil continueto be used or changed?

Sampling and analysis of oils used in each machine must bedone at regular intervals to develop a lubricant change intervalnecessary for the piece of equipment. It is helpful to study thecost of repairing the machine, the potential impact of amachine's failure and subsequent down-time, and past productionschedules to determine if the machine is loaded more heavily inany particular month.

Chemical and physical properties of the used-oil sample suchas total 'base number (TBN)3 pH, viscosity, fuel and anti-freeze.dilution, and wear particle content will reflect not only theintegrity of the lubricant, but also the condition of themachine. Wear particles are generated at the wearing, oil-wettedsurfaces. Depending on-the size, shape, and composition-of wearparticles, the source and mode of wear in a machine can bedetermined, and the likelihood of catastrophic failure measured.

Tests such as metal spectroscopy, particle counting, andferrography provide useful data from a used oil sample.Spectroscopy helps determine drain intervals by revealing theconcentration and types of metals in a sample. In spectroscopy,a small oil sample is burned with voltage sufficient to causeeach metal in the sample to give off light at a particularwavelength. The amount of each metallic element will beproportional to the intensity of the wavelength.

3 Total base number refers to alkalinity reserve which isavailable to neutralize acids of combustion.

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Particle counting is performed to show a buildup of harmfulsolid particles in the lubricant. A change in the particle countof samples from a machine over a period of time may suggest theintroduction of a contaminant, or the imminent failure of themachine.

Ferrography is a study of the type and quantity of ferrousand non-ferrous particles in a sample. The DR ferrograph showsthe amount of wear or contamination in the oil. An analyticalferrograph requires the additional step of examining the wearparticles under microscope, and is usually done only when the DRferrogram indicates a problem in the machine's operation.

Some diesel engine owners mix used oil with the diesel fuelin their engines. Cummins Diesel Engine Company suggests thattheir customers purchase a "Cummins Fuel/Oil Blender." Theblender mixed the used oil into diesel fuel in a 5% solution, theoil/fuel mixture can then be used as fuel in the diesel engine.

Considering that a typical truck travels over 100,000 milesper year, and an oil change (average 9 gallons in a dieselengine) is due every 10,000 to 15,000 miles, the fuel/oil blendercan greater reduce the amount of used oil which must be disposedof.

ANALYTICAL TECHNIQUES FOR USED OILS

The analysis of contaminants in used oil is an importantconsideration when handling, marketing,oil. The concerns,

or treating the affectedas mentioned before, tend to be centered

primarily on the amount of chlorinated organics which becomemixed with the oils and also with metals such as lead, cadmium,and chromium. To a lesser degree, flash point and PCBconcentration are important considerations. A brief synopsis ofanalytical techniques for these parameters is presented in thischapter.

A. Halogen Testing

The primary reason used oils were originally proposed to beregulated as hazardous waste results from mismanagement practiceswhich included mixing chlorinated solvents, normally used fordegreasing and cleaning purposes,uncontaminated used oils.

with a quantity of relativelyCommon examples of these solvents

include l-l-l trichloroethane and trichlorethylene. The presentlimits for burning used oil without restrictions are > 1000 ppmtotal chlorine or < 4000 ppm if it can be proven that the oil hasnot been mixed with a hazardous waste. Some common and promisingtechniques used for measuring the chlorine content in used oilare: 1) microcoulometry,

-combustion,2) x-ray fluorescence, 3) oxygen bomb

4) wet chemical analysis, and 5) test kits. Thediscussion in this section is based on a report on chlorine in

9-40

used oils complied by RTI under EPA contract.4 The finalversion of this report will serve as the background document fora proposed rule making certain methods mandatory for thistesting. An overall evaluationRTI, is presented in Table 9.4.

4 Evaluation of methods foroils. Alvia Gaskill, RTI. Draft

determining chlorine in usedAugust 1986.

of these methods, prepared by

9-41

B. Metal Testing

The next set of important analysis procedures involvedetermining various elemental contents in used oil. The elementsregulated by the EPA and their maximum limits, for an on-specification fuel, are as follows:

lead 100 ppmchromium 10 ppmcadmium 2 ppmarsenic 5 ppm

Popular techniques for analyzing oil samples for these metalsinclude flame AAS (atomic absorption spectroscopy), graphitefurnace AAS, and ICP (inductively coupled plasma spectrometry).Each of these techniques can be used effectively by a skilledoperator. However, unlike chlorine analysis, no test kits arecurrently available.

C. Flash Point

In analyzing used oil, flash point is another importantconsideration. EPA burning regulations also require that usedoil burned as fuel have a flash point of at least 100°F minimum.The most common method to measure flash point is the closed-cuptest.' This involves putting a small amount of sample (5-50 ml)in a container, which is then heated at a specified rate (usuallyincrements of 3-5°F). After each of these increments, a flame isinserted in the vapor space above the fluid. When the vapor"flashes" the flash point has been reached. The temperature inthe cup is then reduced to a level below the flash point andreheated in smaller increments to more precisely determine theactual flash point temperature. Two standard instruments used inanalytical laboratories include the Pensky-Martens and Endcoinstruments.

9-43

D. PCB Analysis

For determining PCB's often found in transformer oils, butseldom found in used oils, the sample is subjected to a series ofclean-up steps to remove interferences and then analyzed by gaschromatography/mass spectroscopy.

The EPA manual "Test Methods for Evaluating Solid Waste -SW-846" serves as the official source for methods of testing usedoil under the burning regulations.

9-44

Generator

TABLE 9.5RCRA Regulations

ON-SPEC OFF-SPEC H. W. FUEL

The first person claiming the oil to

be on-spec must analyze oil des-

tined for burning to determine specifi-

cation. Often, marketer, transporter,

or burners will agree to do this analy-

sis. If the generator turns his own

fuel he must analyze it to prove that

if is on-spec.

1) The generator may burn off-

spec oil on site:

a Without notifying EPA if

burned in an oil fire

space heater if:

l of less than 500,000l vented to ambient air

b. In industrial furnaces and

boilers if NC is notified

with EPA form 8700-12

(Rev 11-85)§.

2) If generator sells directly to

the burner, he must comply

with the following:

must notify EPA with Form

8700-12

must invoice shipments

must obtain one time

certification from burners

which states he has noti-

fied EPA and will burn

only in industrial devices

or furnacesmust keep this certifica-tion for 3 years

§Even if you have filed an old

form 8700-12 and have an EPA

I. D. number you need to fill in

this new form to report used oil

activities.

If used oil has 2 1000 PPM total†

halogens, the generator must com-

ply with RCRA standards for hazar-

dous waste generators (40 CFR

262) which consists of:

1) Obtaining an EPA ID number

2) Completing a N. C. hazardous

waste manifest

3) Meeting pre-transport require-

ments:

l packaging per DOT regula-

tions

l labeling and marking per

DOT and EPA

l placarding

meeting maximum accum-

ulation¥ and time require-

ments

4) Recordkeeping and reporting

shipments

†If the total halogens are in the

range 1000-4000 ppm and one can

prove that this oil has not been

mixed with hazardous waste, then

this oil will meet specification

criteria.¥90 days for generators; 180 days

for small generators or 279 days if

have to ship over 250 miles.

9-45

Transporter

TABLE 9.5RCRA Regulations (cont.)

ON-SPEC OFF-SPEC H. W. FUEL

none Must take part in invoice

record-keeping system.

†lf the total halogens are in the

range 1000-4000 ppm and one can

prove that this oil has not been

mixed with hazardous waste, then

this oil will meet specification.

MarketerMust analyze or have proof of Must notify EPA with form 8700- Must notify EPA with form 8700-12

analysis to determine classification 12 (Rev 11-85) (Rev 11-85)

Must receive certification form

customer that states:

l they will burn only in

industrial boilers and

furnaces

l they have notified EPA

Marketer/recycler must keep

this certification for 3 years

Must take part in invoice

record-keeping system

If the used oil has > 1000 ppm†

total halogens, the transporter must

comply with standards for hazardous

waste transporters (40 CFR 263)

which consists of:

1) Meeting all DOT standards

2) Obtaining an EPA I. D. number

3) Must comply with an EPA regula-

ted manifest system

4) If a discharge occurs during

transporting, the transporter must

notify EPA and take appropriate

action to protect human health

and the environment

Must file for a part A permit to store

Can sell only to persons who have

notified EPA and who burn oil in

industrial furnaces or boilers

Must receive certification from

customer stating:

l they will burn only in industrial

l they have notified EPA

Must keep this certification for 3

years

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TABLE 9.5

B u r n e r

RCRA Regulations (cont.)

ON-SPEC

Must have analysis performed or

proof of oils composition to

determine specification

OFF-SPEC H. W. FUEL

Must notify EPA with form Must notify EPA with form 87000-12

8700-12 (Rev 11-85) (Rev 11-85)

Must be permitted with DEM to burn Illegal to burn in non-industrial Must file RCRA Part A on all storage

(Air Quality Standards) boilers and furnaces tanks

Must inform supplier that he, Burner must certify to marketer that:

the burner, has notified EPA and l he has notified EPA

will burn off-spec oil in an l he will burn oil only in industrial

industrial boiler or furnace only boilers or furnaces

Must keep invoices of all ship-

ments received

Must be permitted with DEM to burn

(Air Quality Standards)

Waste fuel must have 5000-

8000 BTU/lb. to be legitimately

burned as fuel

Must be permitted with DEM to

burn (Air Quality Standards)