Domestic Wastewater Treatment

ENGINEERMANUALEM1110-3-172 May1984 ENGINEERINGANDDESIGN DomesticWastewater Treatment MobilizationConstruction DEPARTMENTOFTHEARMY CORPSOFENGINEERS OFFlCEOFTHECHIEFOF.ENGINEERS DAEN-ECE-G EngineerManual No.1110-3-172 DEPARTMENTOFTHEARMY u.s.ArmyCorpsofEngineers Washington,D.C.20314 EngineeringandDesign DOMESTICWASTEWATERTREATMENT MobilizationConstruction EM1110-3-172 11May1984 1.Purpose.Thismanualprovidesguidancefortheplanninganddesignof domesticwastewatertreatmentplantsatu.s.Armymobilizationfacilities. 2.Applicability.Thismanualisapplicabletoallfieldoperating activitieshavingmobilizationconstructionresponsibilities. 3.Discussion.Criteriaandstandardspresentedhereinapplytoconstruction consideredcrucialtoamobilizationeffort.Theserequirementsmaybe alteredwhennecessarytosatisfyspecialconditionsonthebasisofgood engineeringpracticeconsistentwiththenatureoftheconstruction.Design andconstructionofmobilizationfacilitiesmustbecompletedwithin180days fromthedatenoticetoproceedisgivenwiththeprojectedlifeexpectancyof fiveyears.Hence,rapidconstructionofafacilityshouldbereflecteuin itsdesign.Time-consumingmethodsandprocedures,normallypreferredover quickermethodsforbetterquality,shouldbede-emphasized.Lessergrade materialsshouldbesubstitutedforhighergradematerialswhenthelesser gradematerialswouldprovidesatisfactoryserviceandwhenuseofhigher gradematerials wouldextendconstructiontime.Workitemsnotimmediately necessaryfortheadequatefunctioningofthefacilityshouldbe e f ~ r r e untilsuchtimeastheycanbecompletedwithoutdelayingthemobilization effort. FORTHECOMMANDER: Colo Oref ./ / ofEngineers EngineerManual No.1110-3-172 DEPARTMENTOFTHEARMY USArmyCorpsofEngineers Washington,D.C.20314 EngineeringandDesign DOMESTICWASTEWATERTREATMENT MobilizationConstruction EM1110-3-172 11May1984 ParagraphPage CHAPTER1. CHAPTER2. CHAPTER3. CHAPTER4. CHAPTER5. GENERAL Purposeandscope ... Overalldesignconsiderations . Definitions .................... . CONSIDERATIONSFORSITESELECTION Location ....................... . Spacerequirements ..... Access . TREATMENTREQUIREMENTS Generalconsiderations ... Evaluationofwastewater treatmentprocesses ..... BASICDESIGNCONSIDERATIONS General ........................ . Periodofdesign ...... Estimatingservicedemand Volumeofwastewater .. Wastewatercharacteristics . Plantsitepreparation . Plantlayout . Planthydraulics .. Plantauxiliaryfacilities Meteringandinstrumentation Sampling . ...................... . Standarddrawings SELECTIONOFTREATMENTPROCESSES General ........................ . Recommendedtreatmentscheme .. Alternativetreatmentdesigns Regulatoryrequirements ... Impactonreceivingwaters . 1 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12 5-1 5-2 5-3 5-4 5-5 1-1 1-1 1-1 2-1 2-1 2-1 3-1 3-1 4-1 4-1 4-1 4-2 4-3 4-4 4-4 4-5 4-5 4-6 4-6 4-6 5-1 5-1 5-4 5-4 5-4 EM1110-3-172 11May84 CHAPTER6. CHAPTER7. CHAPTER9. CHAPTERlo; FLOW-MEASURINGDEVICES Generalconsiderations ....... Typesof!low-measuring Cf:eViCeS..... SCREENING General. considerations ..... Bclrscreens .................... . SEDIMENTATION Generalconsiderations ..... Functionsaridtypesof sedimentationunits ....... Designparameters ........... Tanktypesanddesign .................... . Imhofftanks ................. Sludgecharacteristics ...... WASTESTABILIZATIONPONDS Waste.stabilizationpond classification: ......... Designpar;ainetersforwaste .stcibilizal:ion...... Pondfacilityrequirements ... F!LTERPLANTS Gerieraicorisiderations : .....

lntrlckilni :i _, .... ; .. .......... . icts .... ...... . Otherfiitercomponents ..... AttvAfkostUridk n.. 11 ParagraphPage 6-1 6-2 7-1 7-2 8-1 8-2 8-3 8-4 8-5 8-6 9-1 9-2 9-3 10-1 10-2 ib-3 10-4 10-5 u..:1 il-2 ii-j ii-4 ii-6 ii-7 6-1 6-1 7-1 7-1 8-1 8-1 8-1 8-5 8-6 8-6 9-1 9-3 9-4 10-1 io-1 lQ-7 10-7 10-8 11-i il-l 11-s il-6, tt-to 11-H l1-'i2 CHAPTER12. CHAPTER13. CHAPTER14. CHAPTER15. APPENDIXA. APPENDIXB. APPENDIXC. Figure5-l. 5 2 ~EM1110-3-172 11May84 ParagraphPage SLUDGEHANDLING,TREATMENT,ANDDISPOSAL Generalconsiderations .. Sludgepumping .. ............... . Sludgedigestion .. Sludgestorage ..... Sludgedrying . ................. . Sludgedisposal ... ,, . DIS INFECTION Generalconsiderations . Typesofchemicaldisinfectants. Designbasisandcriteria .. Chlorinefeedingequipment Chlorinecontactchambers ... Residuallimitations .... SMALLSEWAGETREATMENTFACILITIES Generalconsiderations .. Septictankdesignfactors Subsurfaceirrigationdesign factors ....................... . Packagetreatmentplants .. SAFETYFEATURES Generalconsiderations . Applicablestandards . , Safetyfeaturesinplant design .. ...................... . Safetyequipment QuickShower ................... . SAMPLEPROBLEMS OXYGENSOLUBILITYTABLE REFERENCES LISTOFFIGURES 12-1 12-2 12-3 12-4 12-5 12-6 13-1 13-2 13-3 13-4 13-5 13-6 14-1 14-2 14-3 14-4 15-1 15-2 15-3 15-4 15-5 12-1 12-1 12-1 12-6 12-7 12-7 13-1 13-1 13-1 13-2 13-5 13-5 14-1 14-1 14-1 14-2 15-1 15-1 15-1 15-2 15-3 A-1 B-1 C-1 Treatmentschemeforflowslessthanorequalto0.2 mgd. Treatmentschemeforflowsgreaterthan0.2mgd. iH EM1110-3-172 11May84 Figure6-1. 7-1. 7-2. 8-1. Table 8-2. 10-1. 10-2. 11-1. 3-1. 3-2. 3-3. 4-1. 4-2. 6-1. 6-2. 7-1. 8-1. 8-2. 8-3. 9-1. 9-2. 9-3. 10-1. 10-2. 10-3. 11-1. 11-2. 11-3. 12-1. 12-2. 12-3. 12-4. 13-1. Parshallmeasuringflume. Schematicofheavydutymechanicallycleanedbarscreen. Estimateofscreeningscollectedonbarscreens. Effectivesurfaceareaadjustmentsfor inlet-outletlossesinrectangularclarifiers,L:W=4 Effectivesurfaceareaadjustmentsfor inlet-outletlossesincircularclarifiers. Commonflowdiagramsforsingleandtwo-stagehigh-rate tricklingfilters. Tricklingfiltercomponents. ActivatedsludgeflowLISTOFTABLES Evaluationofwastewatertreatmentprocesses. Approximateperformancedataforvariouswastewater processes. Operationalcharacteristicsofvarioustreatment processes. Sewagecharacteristics. Capacityfactors. Typesofmeasuringdevicesapplicabletowastewater treatment. Parshallflumeflowvalues. Efficienciesofbarspacing. Surfaceloadingratesforprimarysettlingtanks. Surfaceloadingratesforsecondarysedimentationtanks. Typicalcharacteristicsofdomesticsewagesludge. Classificationanddesignparametersforwastewater treatmentponds. Mechanicalmixingenergyrequiredforoxygendispersion. BODremovalefficienciesforaeratedwastewater treatmentponds. Designdataandinformationfortricklingfilter processes. Designrecirculationratesforhigh-ratefilters. Miscellaneoustricklingfiltercomponentdesign criteria. Designcriteriaforactivatedsludgemodifications. Oxygenandairrequirementsforactivatedsludge modifications. Powerrequirementsfordifferenttypesofaerators. Aerobicdigestiondesignparameters. Standard-rateanaerobicdigestercapacitydesign criteria. High-rateanaerobicdigestercapacitydesigncriteria. Arearequiredforsludgedryingbeds. Typicalchlorinedosagesrequiredforsewage disinfection. CHAPTER1 GENERAL EM1110-3-172 11May84 1-1.-Purposeandscope.Thismanualprescribesgeneralinformation anddesigncriteriaforguidanceint ~ planninganddesignofdomestic wastewatertreatmentplantsatArmymobilizationfacilities. 1-2.Overalldesignconsiderations.Wastewatertreatmentplantdesign willbeassimpleasiscommensuratewiththerequireddegreeof treatment.Plantswillbecapableoftreatingnormallaundrywastes togetherwithsanitarywastewater.Sometypesofindustrialwastemay beadmittedtowastewatertreatmentplants.Theseincludecooling towerdischarge,boilerblowdown,vehiclewashrackwastewater,swimming poolfilterdischarges,andaircraftwashwast_esusingbiodegradable detergents.Pretreatmentwillbeprovidedwhenconditionsrequireit. Indesignforexpansionofexistingplantsconstitutingnew construction,criteriacontainedhereinregardingflowsandwastewater characteristicsmaybemodifiedtoconformtoexistingplant performancedataiftheplanthasbeeninoperationlongenoughtohave establishedaccuratedata.Packagetreatmentplantsoffermany advantagesandwillbeconsideredforallfeasibleapplications. 1-3.Definitions.Thefollowingdefinitionsapplytothismanual. a.Auto-oxidation.Utilizationoftheendogenousphaseof biologicalmetabolismforthecompletestabilizationoforganicwastes. b.Biochemicaloxygendemand(BOD).Thequantityofoxygenusedin thebiochemicaloxidationoforganicmatterinaspecifiedtime,ata specifiedtemperature,andunderspecifiedconditions.Itisnot relatedtotheoxygenrequirementsinchemicalcombustion,being determinedentirelybytheavailabilityofthematerialasbiological foodandbytheamountofoxygenutilizedbythemicroorganismsduring oxidation.Unlessotherwisestated,BODreferstothebiochemical oxygendemandin5daysat20degreesC. c.Biologicaloxidation.Theprocesswherebylivingorganismsin thepresenceofoxygenconverttheorganicma'ttercontainedin wastewaterin toamorestableform-. - . d.Biologicaltreatment.Biologicaltreatmentsystemsare"living" systemswhichrelyonmixedbiologicalculturestobreakdownwaste organicsandremoveorganicmatterfromsolution. e.Chemicaloxygendemand(COD).Theoxygenequivalentofthat portionoifo'rganicmattersusceptibletooxidationbyastrongchemical oxidan't. 1-1 EM1110-3-172 11May84 f.Chlorinedemand.Thedifferencebetweentheamountofchlorine addedtothewastewaterandtheamountofresidualchlorineremaining attheendofaspecificcontacttime.Thechlorinedemandforgiven watervarieswiththeamountofchlorineapplied,timeofcontact, temperature,pH,andthenatureandamountofimpuritiesinthewater. g.Combinedsewersystem.Atransportsystemwhichcarriesboth sanitarywastewaterandstormorsurfacewaterrunoff. h.Effluent.Anywastewaterorliquidflow(raw,partiallyor completelytreated)leavingatreatmentprocessunitoroperation. 1.Endogenousrespiration.Anauto-oxidationofcellularmaterial, whichtakesplaceintheabsenceofassimilableorganicmaterial,to furnishenergyrequiredforthereplacementofprotoplasm. j.Filterablesolids.Thequantityofmaterialwhichpasses throughthefilterpaperwhenaquantityofwater,sewage,orother liquidisfilteredthroughanasbestosfilterinaGoochcrucible. k.Foodtomicroorganismratio.Anaerationtankloadingdesign parameter.Foodmaybeexpressedinpoundsofsuspendedsolids,COD, orBODaddedperdaytotheaerationtank,andmicroorganismsmaybe expressedasmixedliquorsuspendedsolids(MLSS)ormixedliquor volatilesuspendedsolids(MLVSS)intheaerationtank. 1.Hydraulicsurfaceloading. appliedtoaunitofsurfacearea, filtrationprocesses. Theflow(volumeperunittime) applicabletotricklingfilterand m.Influent.Wastewaterorotherliquid--raworpartially treated--flowingintoareservoir,basin,treatmentprocess,or treatmentplant. n.Mixedliquor.Amixtureofactivatedsludgeandwastewater undergoingbiologicaltreatment1ntheaerationtank. o.Mixed-liquorvolatilesuspendedsolids. volatilesuspendedsolidsinanaerationbasin. toequalthebiologicalsolidsconcentrationin Theconcentrationof Itiscommonlyassumed thebasin. p.Organicloading.PoundsofBODappliedperdaytoabiological reactor.Canalsoberelatedtoreactorsurfaceareaorvolume. q.Oxygenuptakerate.Theamountofoxygenbeingutilizedbyan activatedsludgesystemduringaspecifictimeperiod. 1-2 EM1110-3-172 11May84 r.Screening.Aphysicalprocessprecedingprimarytreatment.Its functionistoprotectsubsequenttreatmentunitsandtominimize operationalproblems. s.~ r i m r y treatment.Anyphysicalorchemicaltreatmentforthe removalofsettleableandfloatablematerials. t.Rawsludge.Settledsludgedirectly tanksbeforedecompositionhasprogressed. undigestedsludge. removedfromsedimentation Frequentlyreferredtoas u.Recirculationrate.Therateofreturn(giveninpercent)of partoftheeffluentfromatreatmentprocesstotheheadendofthat process. v.Secondarytreatment.Anytreatmentprocesscapableofproducing aneffluentcontainingaBODandsuspendedsolids(SS)concentrationno greaterthan30mg/1each. w.Sanitarysewer.Asewerintendedtocarrydomesticwastewater fromhomes,businesses,andindustries. x.Stormsewer.Stormwaterrunoffcollectedandtransportedina separatesystemofpipes. y.Sludgeage.Intheactivatedsludgeprocess,ameasureofthe lengthoftimeaparticleofsuspendedsolidshasbeenundergoing aeration,expressedindays.Itisusuallycomputedbydividingthe weightofthesuspendedsolidsintheaerationtankbythedaily additionofnewsuspendedsolidshavingtheiroriginintherawwaste. z.Sludgedensityindex.Atermusedintheexpressionofsettling characteristicsofactivatedsludge;100/sludgevolumeindex. aa.Sludgevolumeindex(SVI).Anumericalexpressionofthe settlingcharacteristicsofactivatedsludge.Theratioofthevolume 1nmillilitersofsludgesettledfroma1,000-mlsamplein30minutes totheconcentrationofmixedliquorinmilligramsperlitermultiplied by1,000. ab.Surfacesettlingrate.Oneofthecriteriaforthedesignof settlingtanksandgravitysludgethickeners,expressedingallonsper daypersquarefeetofsurfaceareainthetank. ac.Suspendedsolids.Solidsthateitherfloatonthesurfaceof (orinsuspensionin)water,wastewater,orotherliquids,andwhich areremovablebylaboratoryfiltering. ad.Totaloxygendemand(TOD).Aninstrumentalmethodthatisused tomeasuretheorganiccontentofwater,wastewater,orotherliquids. 1-3 EM1110-3-172 11May84 Inthetest,organicsubstancesand,toaminorextent,inorganic substancesareconvertedtostableendproductsinaplatinum-catalyzed combustionchamber.'Thetotaloxygendemandisdeterminedby monitoringtheoxygencontentpresentinthenitrogencarriergas. ae.Volatilesolids.Theamountof~ o l i materialpresentinthe solidfractionofwastewaterorsludgethatiscombustibleat550 degreesC, af.Wastedsludge.Theportionofsettledsolidsfromthefinal clarifierremovedfromthewastewatertreatmentprocessestothesolids handlingfacilitiesforultimatedisposal. CHAPTER2 CONSIDERATIONSFORSITESELECTION EM1110-3-172 11May84 2-1.Location.Majorfactorsinsiteselectionoftreatment facilitiesare:topography;availabilityofasuitabledischarge point;maintenanceofreasonabledistancefromlivingquarters,working areas,andpublicuseareas;andproposedfacilitiesasreflectedby themasterplans.Plants,andwastewatertreatmentpondsof size,willnotbelessthanonequartermilefromsuchfacilities.The locationofwastewaterfacilitiesmustaddresstheproblemsof unacceptablenoiseandodorlevels.Wastewatertreatmentfacilities shouldbelocated,totheextentpossible,accordingtothefollowing: -Downwindofliving workingareas,andpublicuse areas. - Locatedinareasnotsubjecttoprolongedand/orfrequentair stagnation,fog,ormistcover. - Situatedatalowerelevationthanlivingquarters,working areas,andpublicuseareas. - Situatedsuchthatgroundwateratthewastewaterfacilityflows awayfromoccupiedareas. Exceptionstotheone-quartermilerestrictioncanbemadeforcold climatemodulecomplexeswherethetreatmentsystemispartofthe modulecomplex.Sewagetreatmentworkswillnotbelocatedwithinthe samemoduleaslivingquarters.Standardseptictanksystemswith sub-surfacedrainfieldsdonotfallundertheone-quartermile restriction. 2-2.Spacerequirements.Sufficient.spacemustbeallocatedfor suitablearrangementofalltreatmentunitsandassociatedplant piping. 2-3.Access.Thesitewillbeselectedsothatanall-weatherroadis availableorcanbeprovidedforaccesstotheplant. 2-1 CHAPTER3 TREATMENTREQUIREMENTS EM1110-3-172 11May84 3-1 Generalconsiderations.Beforetreatmentplantdesignisbegun, treatmentwillbedeterminedonthebasisofmeetingstreamand effluentrequirementssetbytheFederalandstategovernments. a.Standards.Theregulatoryagencieswillissueeffluent standardscoveringthedischargeoftoxicpollutants.Strict limitationsondischargesand,insomecases,completeprohibitionmay beimposed. b.Pretreatment.PublicLaw92-500,withsubsequentamendments, requirespretreatmentofpollutantswhichmayinterferewithoperation ofasewagetreatmentplantorpassthroughsuchaplantuntreated. c.Stateregulations.Thedesignermustreviewtheapplicable stateguidelinesbeforesettingthetreatmentlevelorselectingthe treatmentprocesses. d.Localregulations.Ingeneral,localgovernmentsdonotspecify requirementsforwastewatertreatmentfacilitiesperse.Construction ofwastewatertreatmentfacilitiesmustconformtoapplicablezoning, OccupationalSafetyandHealthAdministration(OSHA)requirements,and toAR200-1. 3-2.Evaluationofwastewatertreatmentprocesses.Table3-1provides asummaryevaluationofwastewatertreatmentprocessestobeconsidered formobilizationconstruction.Tables3-2and3-3illustratethe applicableprocessesandtheirpossibleperformance.Alloftheabove willbeusedforguidanceinselectingaprocesschainoftreatment units. 3-1 w I N TreatmentProcess 1.PRELIMINARY Screening 2.PRIMARYTREATMENT Sedimentatioo Table3-1.EvaluationofWastewaterTreatmentProcesses Application Wastestreamscontaining largesolids(wood,rags, etc.) Wastestreamscontaining settleablesuspended solids Advantagesand Capabilities 1.Preventspumpandp1pe clogging Disadvantagesand Limitations 1.Maintenancerequired topreventscreen plugging,ineffective forstickysolids 1.Reducesinorganicand1.Possiblesepticityand organicsolidsloadingsodors tosubsequentbiological units 2.Byfartheleastex-pensiveandmostcommon methodofsolid-liquid separation 3.Suitablefortreatment ofawidevarietyof wastes 4.Requiressimplerequip-mentandoperationthan otherprocesses 5.Demonstratereliability asatreatmentprocess 2.Adverselyaffectedby variationsinthe natureofthewaste 3.Moderatelylargearea requirement 1-'trl 1-':S:: :S::t-' !lJ1-' 'W, 1tlherefore: row2"":Volume II) 'W= .Volume ,' __ _ [;()!eD 'l'het:efore,thebasic .chlorinecontacttank.dimensionsare: 153feetby15.3feetby8feet{6feetSWD) Bafflingisusedtoconstructamoreregulartankshapeandtoprevent flowshort-ci:rcuiting.(:RefertotPAProcessDesignManualfor UpgradingExistingWastewi!lterTrei!ltmen:tPlantsforlayoutoftan:k baffles).Usingalowchannelwidthof15.3feetand4side-'by-side ,plugflowcotnpatttnent:s,theo.veralltankwidthis: it93