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Nutrient Control Design Manual
Office of Research and DevelopmentNational Risk Management Research Laboratory - Water Supply and Water Resources Division
EPA/600/R-10/100 | August 2010 | www.epa.gov/n
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EPA/600/R10/100August2010
NutrientControlDesignManual
by
TheCadmusGroup,Inc
57WaterStreet
Watertown,MA02472
Scientific,Technical,Research,Engineering,andModelingSupport(STREAMS)
TaskOrder68
ContractNo. EPC05058
GeorgeT.Moore,TaskOrderManager
UnitedStatesEnvironmentalProtectionAgency
OfficeofResearchandDevelopment/NationalRiskManagementResearchLaboratory
26WestMartinLutherKingDrive,MailCode445
Cincinnati,Ohio,45268
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NutrientControlDesignManual iii August2010
Foreword
TheU.S.EnvironmentalProtectionAgency(EPA)ischargedbyCongresswithprotectingtheNations
land,air,andwaterresources. Underamandateofnationalenvironmentallaws,theAgencystrivesto
formulateandimplementactionsleadingtoacompatiblebalancebetweenhumanactivitiesandthe
abilityofnaturalsystemstosupportandnurturelife.Tomeetthismandate,EPAsresearchprogramisprovidingdataandtechnicalsupportforsolvingenvironmentalproblemstodayandbuildingascience
knowledgebasenecessarytomanageourecologicalresourceswisely,understandhowpollutantsaffect
ourhealth,andpreventorreduceenvironmentalrisksinthefuture.
TheNationalRiskManagementResearchLaboratory(NRMRL)istheAgencyscenterforinvestigationof
technologicalandmanagementapproachesforpreventingandreducingrisksfrompollutionthat
threatenhumanhealthandtheenvironment. Thefocusofthelaboratorysresearchprogramison
methodsandtheircosteffectivenessforpreventionandcontrolofpollutiontoair,landwaterand
subsurfaceresources;protectionofwaterqualityinpublicwatersystems;remediationofcontaminated
sites,sedimentsandgroundwater;preventionandcontrolofindoorairpollution;andrestorationof
ecosystems. NRMRLcollaborateswithbothpublicandprivatesectorpartnerstofostertechnologies
thatreducethecostofcomplianceandtoanticipateemergingproblems. NRMRLsresearchsolutionsto
environmentalproblemsby:developingandpromotingtechnologiesthatprotectandimprovethe
environment;advancingscientificandengineeringinformationtosupportregulatoryandpolicy
decisions;andprovidingthetechnologicalsupportandinformationtransfertoinsureimplementationof
environmentalregulationsandstrategiesatthenational,state,andcommunitylevels.
ThispublicationhasbeenproducedaspartoftheLaboratorysstrategiclongtermresearchplan. Itis
publishedandmadeavailablebyEPAsOfficeofResearchandDevelopmenttoassisttheuser
communityandtolinkresearcherswiththeirclients.
SallyGutierrez,Director
NationalRiskManagementResearchLaboratory
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Notice
ThisdocumentwaspreparedbyTheCadmusGroup,Inc.(Cadmus)underEPAContractNo.EPC05058,
TaskOrder68.TheCadmusTeamwasleadbyPatriciaHertzlerandLauraDufresnewithSeniorAdvisors
CliffordRandall,EmeritusProfessorofCivilandEnvironmentalEngineeringatVirginiaTechandDirector
oftheOccoquanWatershedMonitoringProgram;JamesBarnard,GlobalPracticeandTechnology
LeaderatBlack&Veatch;DavidStensel,ProfessorofCivilandEnvironmentalEngineeringatthe
UniversityofWashington;andJeanetteBrown,ExecutiveDirectoroftheStamfordWaterPollution
ControlAuthorityandAdjunctProfessorofEnvironmentalEngineeringatManhattanCollege.
Disclaimer
Theviewsexpressedinthisdocumentarethoseoftheindividualauthorsanddonotnecessarily,reflect
theviewsandpoliciesoftheU.S.EnvironmentalProtectionAgency(EPA). Mentionoftradenamesor
commercialproductsdoesnotconstituteendorsementorrecommendationforuse.Thisdocumenthas
beenreviewedinaccordancewithEPAspeerandadministrativereviewpoliciesandapprovedfor
publication.
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Abstract
ThepurposeofthisEPAdesignmanualistoprovideupdated,stateofthetechnologydesign
guidanceonnitrogenandphosphoruscontrolatmunicipalWastewaterTreatmentPlants(WWTPs).
SimilartopreviousEPAmanuals,thismanualcontainsextensiveinformationontheprinciplesof
biologicalnutrientremovalandchemicalphosphorusremovaltoserveasthebasisfordesign.Adetaileddescriptionoftechnologies,bothconventionalandemerging,servesasaresourceforpreliminary
technologyselection. BecausemostWWTPsintheUnitedStatesareequippedwithsecondary
treatment,thefocusofthisdesignmanualisonretrofitstoaddnutrientremovaltoexistingWWTPs
ratherthanonnewtreatmentplantdesign,althoughguidanceforgreenfielddesignispresented. Also
newfrompreviousversions,designguidancehereinisbasedontheuseofmathematicalmodelsand
simulators.Simulatorsallowdesignerstostudykinetic aswellastimebasedsolutionswhile
determiningthetotalmassbalancesofmanyconstituents.Theyhavebecomeincreasinglypowerful,
easytouse,andwidelyacceptedforthedesignofbiologicalnutrientremovalfacilities. Themanualalso
includesnewinformationonemergingissuesintheindustrysuchassustainabilityinwastewater
treatmentdesignandoperation,nutrientrecoveryandreuse,effluentdissolvedorganicnitrogen,and
measurementoflowphosphorusconcentrations.
ThisreportwassubmittedinfulfillmentofEPAContractNo.EPC05058,TaskOrder68,byThe
CadmusGroup,Inc.underthesponsorshipoftheUnitedStatesEnvironmentalProtectionAgency.This
reportcoversaperiodfromNovember2007throughApril2010andrepresentsworkcompletedasof
April2010.
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Contents
AcronymsandAbbreviations ....................................................................................................... xviii
Acknowledgements ....................................................................................................... xxii
1. Introduction ....................................................................................................... 111.1 HistoryofNutrientRemoval.................................................................................... 11
1.2 PurposeandScopeofthisManual.......................................................................... 13
1.3 ManualOrganization............................................................................................... 15
1.4 References ....................................................................................................... 16
2. NeedforandBenefitsofNitrogenandPhosphorusRemoval............................................. 21
2.1 Introduction ....................................................................................................... 21
2.2 SourcesofNitrogenandPhosphorusinWastewater.............................................. 22
2.2.1 Nitrogen...................................................................................................... 22
2.2.2 Phosphorus................................................................................................. 23
2.3 StatusofWastewaterTreatmentintheUnitedStates........................................... 23
2.4 NutrientImpairmentofU.S.Waterways................................................................. 25
2.4.1 NorthernGulfofMexico............................................................................. 25
2.4.2 ChesapeakeBay......................................................................................... 26
2.4.3 GreatLakes................................................................................................. 26
2.4.4 LongIslandSound....................................................................................... 26
2.5 ClimateChangeImpacts.......................................................................................... 27
2.6 FederalandStateRegulationsandInitiativestoReduceNutrientPollution..........28
2.6.1 WaterQualityStandards............................................................................ 28
2.6.2 TotalMaximumDailyLoads(TMDLs)......................................................... 210
2.6.3 NPDESPermitting....................................................................................... 210
2.6.4 WaterQualityTrading................................................................................ 211
2.6.5 TechnologyEvaluationandGuidance......................................................... 212
2.7 IndustryInitiativesTheWERFNutrientRemovalChallenge................................. 213
2.8 BenefitsofNutrientRemoval.................................................................................. 214
2.8.1 ImprovedPlantPerformance...................................................................... 214
2.8.2 CoRemovalofEmergingContaminants..................................................... 214
2.8.3 NutrientRecoveryandReuse..................................................................... 215
2.9 ChallengesofNutrientRemoval.............................................................................. 215
2.9.1 EnergyRequirements.................................................................................. 215
2.9.2 ReleaseofNitrousOxide............................................................................ 217
2.10 References ....................................................................................................... 218
3.
Principles
of
Phosphorus
Removal
by
Chemical
Addition
....................................................
3
1
3.1 Introduction ....................................................................................................... 31
3.2 AvailableFormsofMetalSaltsandLime................................................................. 31
3.3 EquationsandStoichiometry................................................................................... 32
3.3.1 RemovablePhosphorus.............................................................................. 32
3.3.2 ReactionsofMetalSaltsandPhosphorus.................................................. 32
3.3.3 ReactionsofLimewithPhosphorus............................................................ 35
3.4 SolidsSeparationProcesses..................................................................................... 35
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3.5 EffectsonSludgeProductionandHandling............................................................. 36
3.6 TwoFactorsthatMayLimittheAbilityofPlantstoAchieve
VeryLowEffluentLevels.......................................................................................... 37
3.7 References ....................................................................................................... 38
4. PrinciplesofBiologicalNitrogenRemoval........................................................................... 41
4.1 Introduction ....................................................................................................... 41
4.2 NitrogenRemovalbyBiomassSynthesis................................................................. 42
4.3 MicrobiologyofNitrification.................................................................................... 43
4.4 ReactionsandStoichiometryofNitrification........................................................... 45
4.5 NitrificationKinetics................................................................................................. 46
4.5.1 AOBkinetics................................................................................................ 410
4.5.2 NOBkinetics................................................................................................ 413
4.5.3 EffectsofTemperatureandDissolvedOxygenonNitrificationKinetics....414
4.5.4 AOBandNOBKineticsatHighTemperature(SHARONprocess).............416
4.6 InhibitoryEffectsofEnvironmentalConditionsonNitrification............................. 417
4.7 DenitrificationFundamentals.................................................................................. 420
4.8 MicrobiologyofDenitrification................................................................................ 420
4.9 MetabolismandStoichiometryofHeterotrophicDenitrification........................... 421
4.10 BiologicalDenitrificationKineticswithInfluentWastewater.................................. 422
4.11 DenitrificationCarbonSourcesandRelativeConsumptionRatios.......................... 424
4.12 DenitrificationKineticsofExogenousCarbonSources............................................ 428
4.12.1 DenitrificationKineticswithMethanol....................................................... 428
4.12.2 AlternativeExogenousSubstratesandDenitrificationKinetics.................430
4.12.3 AcclimationTimeandDegradativeAbilityofDenitrifyingBacteriawith
ExogenousSubstrates................................................................................. 431
4.13 SpecificDenitrificationRates(SDNR)....................................................................... 432
4.14 SimultaneousNitrificationDenitrification............................................................... 434
4.15
Metabolism
and
Stoichiometry
and
Kinetics
of
ANAMMOX
.................................
4
35
4.16 ImpactsonSludgeProductionandHandling........................................................... 436
4.17 EffluentDissolvedOrganicNitrogen........................................................................ 436
4.18 References ....................................................................................................... 439
5. PrinciplesofBiologicalPhosphorusRemoval....................................................................... 51
5.1 OverviewoftheBiologicalPhosphorusRemovalProcess....................................... 51
5.2 SubstrateRequirements.......................................................................................... 53
5.3 SourcesofVolatileFattyAcids................................................................................. 55
5.3.1 FermentationintheCollectionSystem...................................................... 56
5.3.2 AnaerobicFermentationofPrimaryorReturnActivatedSludge...............57
5.3.3 CommercialSources................................................................................... 510
5.4 EnvironmentalConditions....................................................................................... 511
5.4.1 DissolvedOxygenandNitratesintheAnaerobicZone.............................. 511
5.4.2 OxygenintheAerobicZone........................................................................ 511
5.4.3 pH ....................................................................................................... 512
5.4.4 Temperature............................................................................................... 512
5.4.5 Cations ....................................................................................................... 513
5.5 Kinetics ....................................................................................................... 513
5.5.1 SolidsRetentionTime(SRT)........................................................................ 513
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5.5.2 HydraulicRetentionTime(HRT) ................................................................ 514
5.6 ImportantDesignandOperationalConsiderations................................................. 514
5.6.1 AvoidingSecondaryReleaseofPhosphorus............................................... 514
5.6.2 AvoidingBackmixing................................................................................... 516
5.6.3 FlowandLoadBalancing............................................................................ 517
5.7 ImpactsonSludgeProcessingandHandling........................................................... 517
5.8 References ....................................................................................................... 518
6. OverviewofNitrogenandPhosphorusRemovalTechnologies........................................... 61
6.1 Introduction ....................................................................................................... 61
6.2 NitrogenRemovalTechnologies.............................................................................. 62
6.2.1 NitrogenRemovalinSingleProcessUnit.................................................... 63
6.2.1.1ModifiedLudzackEttinger(MLE)Process..................................... 63
6.2.1.2 4StageBardenpho........................................................................ 65
6.2.1.3MLEor4StageBardephowithMembraneBioractor(MBR)........65
6.2.1.4 SequencingBatchReactor(SBR).................................................... 66
6.2.1.5 OxidationDitchwithAnoxicZone................................................. 67
6.2.1.6 StepFeedBiologicalNitrogenRemoval(BNR).............................. 68
6.2.1.7 SimultaneousNitrificationDenitrification(SNdN)........................ 69
6.2.1.8 IntegratedFixedFilmActivatedSludge(IFAS)............................... 610
6.2.1.9MovingBedBiofilmReactor(MBBR).............................................. 611
6.2.2 SeparateStageProcessesNitrification.................................................... 612
6.2.2.1 SuspendedGrowthNitrification.................................................... 612
6.2.2.2 AttachedGrowthNitrification....................................................... 612
6.2.3 SeparateStageProcessesDenitrification................................................ 613
6.2.3.1 DenitrificationFilters..................................................................... 614
6.3 PhosphorusRemovalTechnologies......................................................................... 616
6.3.1 PhosphorusRemovalbyChemicalAddition............................................... 616
6.3.2
Biological
Phosphorus
Removal
..................................................................
6
19
6.3.2.1 Phoredox(A/O)............................................................................. 620
6.3.2.2 OxidationDitchwithAnaerobicZone............................................ 621
6.4 CombinedNitrogenandPhosphorusRemovalTechnologies................................. 622
6.4.1 Biological..................................................................................................... 622
6.4.1.1 3StagePhoredox(A2/0)............................................................... 622
6.4.1.2 5StageBardenpho........................................................................ 623
6.4.1.3 UniversityofCapetown(UCT),ModifiedUCT,andVirginiaInitiative
Project(VIP)................................................................................... 624
6.4.1.4Westbank....................................................................................... 626
6.4.1.5 OxidationDitchwithAnoxicandAnaerobicZones....................... 626
6.4.1.6 SequencingBatchReactor(SBR).................................................... 627
6.4.2 HybridChemical/Biological....................................................................... 627
6.4.2.1 BluePlainsProcess........................................................................ 628
6.4.2.2 BiologicalChemicalPhosphorusandNitrogenRemoval(BCFS)
Process.......................................................................................... 628
6.5 EffluentFiltration..................................................................................................... 629
6.5.1 ConventionalDownflowFilters................................................................. 629
6.5.2 ContinuousBackwashingUpflowSandFilters(Dynasand)........................ 629
6.5.3 PulsedBedFilters........................................................................................ 630
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6.5.4 TravelingBridgeFilters............................................................................... 630
6.5.5 Discfilters.................................................................................................... 630
6.5.6 MembraneFilters....................................................................................... 631
6.6 SidestreamManagement........................................................................................ 632
6.7 TechnologyPerformance......................................................................................... 634
6.7.1 RemovalEfficienciesofBNRTechnologiesGeneralDiscussion...............636
6.7.2 TechnologyPerformanceStatisticsbasedonFullScaleOperatingData...637
6.8 FactorsinSimultaneouslyAchievingLowNitrogenandPhosphorusEffluent
Concentrations ....................................................................................................... 642
6.9 References ....................................................................................................... 643
7. EstablishingDesignObjectives.............................................................................................. 71
7.1 Introduction ....................................................................................................... 71
7.2 CharacterizingExistingTreatment........................................................................... 72
7.3 DesignFlowRates.................................................................................................... 73
7.3.1 CharacterizingExistingFlow....................................................................... 73
7.3.2 ProjectingFutureConditions...................................................................... 75
7.3.3 SettingDesignFlowRates........................................................................... 76
7.4 Wastewatercharacteristics..................................................................................... 77
7.4.1 DataCollection............................................................................................ 77
7.4.2 DataVerification......................................................................................... 710
7.5 TargetEffluentConcentrationsforTotalNitrogenandTotalPhosphorus..............715
7.6 GoalsforReliability,Sustainability,andProcessFlexibility..................................... 716
7.7 SludgeTreatmentOptions....................................................................................... 718
7.8 SiteConstraints ....................................................................................................... 718
7.9 SelectinganOverallProcessDesignFactor............................................................ 719
7.10 References ....................................................................................................... 720
8.
Selecting
Candidate
Treatment
Processes
for
Plant
Upgrades
...........................................
8
1
8.1 Introduction ....................................................................................................... 81
8.2 TechnologySelectionFactors.................................................................................. 81
8.2.1 SeasonalPermitLimits................................................................................ 81
8.2.2 Footprint..................................................................................................... 82
8.2.3 HydraulicConsiderations............................................................................ 83
8.2.4 Chemicalneeds........................................................................................... 83
8.2.5 AvailableSludgeTreatmentandOptions................................................... 83
8.2.6 EnergyConsiderations................................................................................ 84
8.2.7 StaffingandTrainingRequirements........................................................... 85
8.2.8 TechnologySelectionConsiderationsforSmallFlowSystems...................85
8.3 AdvantagesandDisadvantagesofTechnologyTypes............................................. 86
8.4 OverviewofRecommendedApproach.................................................................... 88
8.5 RecommendedUseofAdvancedTools................................................................... 811
8.6 Patentissues ....................................................................................................... 812
8.7 References ....................................................................................................... 813
9. DesignApproachforPhosphorusRemovalbyChemicalAddition ...................................... 91
9.1 Introduction ....................................................................................................... 91
9.2 SelectingaChemicalPrecipitant.............................................................................. 91
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9.2.1 AdvantagesandDisadvantagesofMetalSalts........................................... 91
9.2.2 AdvantagesandDisadvantagesofLime..................................................... 93
9.2.3 Costs ....................................................................................................... 93
9.3 SelectingPoint(s)ofApplication.............................................................................. 94
9.4 DeterminingtheChemicalDose.............................................................................. 97
9.5 DesigningaChemicalFeedSystem.......................................................................... 910
9.5.1 Liquidfeedsystems.................................................................................... 911
9.5.1.1 Storagetanks................................................................................. 911
9.5.1.2 FeedMethods................................................................................ 911
9.5.2 DryFeedSystems........................................................................................ 912
9.5.2.1 Storage........................................................................................... 912
9.5.2.2 FeedMethods................................................................................ 913
9.5.2.3 LimeSlaking................................................................................... 914
9.6 DesigningforRapidMixandFlocculation............................................................... 915
9.6.1 TypesofMixers........................................................................................... 915
9.6.2 DesignFactors............................................................................................. 917
9.6.2.1 VelocityGradient........................................................................... 917
9.6.2.2 PowerRequirements..................................................................... 918
9.6.2.3 HydraulicRetentionTime.............................................................. 919
9.6.2.4 VesselGeometry............................................................................ 920
9.6.3 SummaryofTypicalDesignParameters..................................................... 920
9.7 SolidsSeparationProcesses..................................................................................... 921
9.7.1 PrimaryandSecondaryClarification........................................................... 922
9.7.2 TertiaryProcesses....................................................................................... 922
9.8 OperationalFactors................................................................................................ 922
9.8.1 DoseControl............................................................................................... 922
9.8.2 MakeupWater........................................................................................... 923
9.8.3 SludgeProductionandHandling................................................................ 923
9.8.4
pH
Adjustment
............................................................................................
9
25
9.8.5 EffectonBiosolidsApplications.................................................................. 925
9.9 References ....................................................................................................... 925
10. DesignApproachforBiologicalNutrientRemoval............................................................... 101
10.1 Introduction ....................................................................................................... 101
10.2 PreliminaryDesignApproach.................................................................................. 103
10.3 OverviewofRecommendedApproachforPlantModeling..................................... 105
10.4 EstablishingModelingObjectivesandRequirements............................................. 107
10.4.1 IntendedModelUse................................................................................... 107
10.4.2 GoalsforModelAccuracy........................................................................... 107
10.4.3 Dynamicvs.SteadyStateSimulation.......................................................... 108
10.5 SelectingaProcessSimulationModel..................................................................... 109
10.6 DataCollection ....................................................................................................... 1012
10.6.1 ProcessConfiguration................................................................................. 1013
10.6.2 OperatingConditions.................................................................................. 1016
10.7 CharacterizationofOrganicMaterial...................................................................... 1016
10.7.1 RelationshipofOrganicMaterialandSuspendedSolidsinWastewater...1020
10.7.2 MethodsforDeterminingCODFractions................................................... 1022
10.7.3 DataChecks................................................................................................. 1025
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10.8 CharacterizationofNutrientFractions.................................................................... 1026
10.8.1 Nitrogen...................................................................................................... 1026
10.8.2 Phosphorus................................................................................................. 1029
10.9 KineticandStoichiometricParameters................................................................... 1032
10.10 Calibration ....................................................................................................... 1033
10.11 Validation ....................................................................................................... 1037
10.12 SimulationofDesignAlternativesforNutrientRemoval........................................ 1038
10.13 AdditionalProceduresforDesign............................................................................ 1039
10.13.1SequencingBatchReactors(SBRs)............................................................. 1039
10.13.2DenitrificationFilters.................................................................................. 1040
10.13.3PrimarySludgeFermenters........................................................................ 1041
10.14 DesignChecksforBiologicalNitrogenandPhosphorusRemoval........................... 1042
10.15 References ....................................................................................................... 1047
11. DesignApproachforEffluentFiltration............................................................................... 111
11.1 Introduction ....................................................................................................... 111
11.2 SelectionofFiltrationTechnology........................................................................... 112
11.3 GranularMediaFilters............................................................................................. 113
11.3.1 InfluentWaterQuality................................................................................ 114
11.3.2 MediaSpecifications................................................................................... 114
11.3.3 FilterLoadingRate...................................................................................... 116
11.3.4 Headloss...................................................................................................... 116
11.3.5 BackwashRequirements............................................................................. 117
11.3.6 FlowControl............................................................................................... 119
11.4 ClothMediaFilters................................................................................................... 1110
11.5 LowPressureMembranes....................................................................................... 1111
11.5.1 MembraneMaterial.................................................................................... 1112
11.5.2 MembraneConfiguration........................................................................... 1113
11.5.3
Process
Considerations
...............................................................................
11
14
11.5.4 PressureDrop............................................................................................. 1115
11.5.5 FluxDetermination..................................................................................... 1115
11.5.6 PerformanceData....................................................................................... 1116
11.6 EmergingFiltrationTechnologiesforPhosphorusRemoval.................................... 1116
11.6.1 TwoStageFiltration.................................................................................... 1116
11.6.2 IronOxideCoatedMedia............................................................................ 1117
11.7 References ....................................................................................................... 1118
12. OperationandOptimizationtoEnhanceNutrientRemoval............................................... 121
12.1 Introduction ....................................................................................................... 121
12.2 AnalysisofExistingOperations................................................................................ 121
12.2.1 DataAnalysis............................................................................................... 122
12.2.2 UseofProcessSimulationModels.............................................................. 125
12.3 IncorporatingSCADAandotherInstrumentation................................................... 126
12.4 CommonOperationalChanges................................................................................ 126
12.4.1 AdjustSRT................................................................................................... 126
12.4.2 AdjustAerationRates................................................................................. 127
12.4.3 AddBafflestoCreateHighFoodtoMicroorganism(F/M)Conditions.......127
12.4.4 ChangeAerationSettingsinPlugFlowBasins............................................ 127
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12.4.5 MinimizeImpactofRecycleStreams.......................................................... 128
12.4.6 ReconfigureFlowthroughExistingUnits.................................................... 128
12.4.7 IncreaseVFAsforBiologicalPhosphorusRemoval..................................... 129
12.5 References ....................................................................................................... 1210
13. InstrumentationandControls..................................................................................................... 131
13.1 Introduction ....................................................................................................... 131
13.2 FactorsinSelectingInstrumentation....................................................................... 132
13.3 BasicOnlineInstrumentation.................................................................................. 133
13.3.1 Flow ....................................................................................................... 133
13.3.2 TotalSuspendedSolids(TSS)...................................................................... 134
13.3.3 SludgeBlanketDepth.................................................................................. 135
13.3.4 DissolvedOxygen(DO)............................................................................... 135
13.3.5 pH ....................................................................................................... 135
13.3.6 ORP ....................................................................................................... 136
13.4 OnlineInstrumentationforNutrientControl.......................................................... 136
13.4.1 NitrogenCompounds.................................................................................. 136
13.4.2 PhosphateandTotalPhosphorus............................................................... 137
13.4.3 NADH(activebiomass)............................................................................... 138
13.4.3 Respirometry.............................................................................................. 138
13.5 TypesofControl....................................................................................................... 139
13.5.1 Feedforward.............................................................................................. 139
13.5.2 Feedback..................................................................................................... 1310
13.5.3 Feedforwardandfeedback........................................................................ 1310
13.5.4 Cascade....................................................................................................... 1310
13.5.5 AdvancedControl....................................................................................... 1310
13.6 ControlEquipmentSCADA.................................................................................... 1311
13.7 References ....................................................................................................... 1313
14. SustainableNutrientRecoveryandReuse............................................................................ 141
14.1 Introduction ....................................................................................................... 141
14.2 SeparatingandTreatingWasteOnSite................................................................... 141
14.3 UsingWastewaterTreatmentByproducts.............................................................. 142
14.3.1 Durham,OR,AdvancedWastewaterTreatmentFacility............................ 143
14.3.2 EastBayMunicipalUtilityDistrict,CA........................................................ 144
14.4 References ....................................................................................................... 145
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Appendices
AppendixA. RecommendationsforMethanolSafety
AppendixB. OrganicCompoundsandInhibitoryConcentrationstoNitrification
AppendixC. MathematicalModelsforWastewaterTreatment
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Tables
Table31. ChemicalPrecipitants.............................................................................................. 32
Table41. PhylogenyofAmmoniaOxidizingBacteria.............................................................. 44
Table42. PhylogenyofNitriteOxidizingBacteria................................................................... 45
Table43. SummaryofTestResultsonMeasuringSpecificEndogenousDecayCoefficient
Rates(AllRatesat20C)........................................................................................... 411
Table44. SummaryofAOBNitrificationKineticCoefficientValues........................................ 412
Table45. ComparisonofNitrificationHalfVelocityCoefficients(mg/L)inMBRand
ConventionalActivatedSludge(CAS)Systems........................................................ 412
Table46. SummaryofNOBNitrificationKineticCoefficientValues....................................... 414
Table47. NH4NandNO2NConcentrationsthatMayInhibitNitrificationasaFunction
ofpHat20C. ....................................................................................................... 419
Table48. HeterotrophicBacteriaKineticCoefficientsinAnoxic/AerobicActivated
Sludge ....................................................................................................... 424
Table49. BiomassYieldsReportedforExogenousCarbonSources....................................... 428
Table
4
10.
Reported
Maximum
Specific
Growth
Rates
at
20C
and
Temperature
CoefficientsforMethanolUtilizationunderAnoxicandAerobicconditions..........429
Table411. ReportedKsvaluesforNO3Nreductionwithmethanolat20C............................. 429
Table412. ComparisonofMaximumSpecificGrowthratesforMethanol,Acetate,andCorn
SyrupatHighandLowTemperatures..................................................................... 430
Table413. ForBNRActivatedSludge,RatioofDenitrificationRatewithSubstrateAddition
toDenitrificationRatewithNoAddition................................................................. 431
Table414. RatioofDenitrificationRatesforOtherSubstratesatDay50withEthanolor
MethanolAdditionVersusnoAddition................................................................... 432
Table415. RangeofreportedSDNRvaluesinBNRactivatedsludgetreatment...................... 433
Table4.16. ANAMMOXBacteriaBiokineticParametersat300C............................................. 435
Table51. VolatileFattyAcidsTypicallyFoundinFermentedWastewater............................. 54
Table52. MinimumRatiosforAchievingTotalPhosphorusEffluentConcentrationof
lessthan1.0mg/L.................................................................................................... 54
Table53. EffectofCorrosionandOdorControlTechniquesonVFAProductionin
WastewaterCollectionSystems.............................................................................. 57
Table61. MatrixofBiologicalNitrogenRemovalTechnologies.............................................. 63
Table62. IFASMediaTypes,Applications,andDesignConsiderations.................................. 610
Table63. MatrixofPhosphorusRemovalTechnologies........................................................ 616
Table64. MatrixofCombinedBiologicalPhosphorusandNitrogenRemovalTechnologies.622
Table65. MatrixofTertiaryFiltrationTechnologies............................................................... 629
Table71. InfluentFlowComponents...................................................................................... 74
Table72. FlowCharacterization.............................................................................................. 74
Table73. ComparisonofFlowRatesandFlushVolumesBeforeandAfterU.S.Energy
PolicyAct ....................................................................................................... 75
Table74. ExamplePermitLimitsforNutrients........................................................................ 716
Table81. AdvantagesandDisadvantagesofTechnologyTypes............................................ 87
Table82. ExternalCarbonSources......................................................................................... 812
Table83. IFASMediaTypes,Applications,andDesignConsiderations.................................. 815
Table91. AdvantagesandDisadvantagesofCommonAluminumandIronSalts...................92
Table92. AdvantagesandDisadvantagesofMetalSaltApplicationPoints........................... 96
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Table93. TypesofChemicalFeeders...................................................................................... 910
Table94. CommonlyUsedEquipmentforRapidMixing......................................................... 916
Table95. ValuesofNPandNQforVariousTypesofImpellers................................................ 918
Table96. TypicalDesignParametersforTurbineandPropellerMixer................................... 921
Table101. CommonlyUsedProcessSimulators....................................................................... 1010
Table102. CODandParticulateFractionsinMunicipalWastewater....................................... 1019
Table103. TKNFractionsinMunicipalWastewater.................................................................. 1028
Table104. TotalPhosphorusFractionsinMunicipalWastewater............................................ 1031
Table105. DesignChecksforBiologicalNitrogenRemoval...................................................... 1043
Table106. DesignChecksforBiologicalPhosphorusRemoval................................................. 1045
Table111. CommonFilterMediaandCharacteristics.............................................................. 115
Table112. FilterMediaDepthsandParticleSizes.................................................................... 115
Table113. MembraneCharacteristics....................................................................................... 1114
Table114. AdvantagesandDisadvantagesofMembraneMaterials........................................ 1115
Table115. PhosphorusRemovalReportedFromMembranePilotStudies.............................. 1119
Table116. PilotTestResultsfortheBlueWaterBluePROSystem........................................ 1121
Table121. RecommendedParametersforDataEvaluation..................................................... 123
Table131. SummaryofBasicOnLineInstrumentation............................................................ 132
Table132. ComparisonofOnlineNitrateAnalyzers ................................................................ 137
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Figures
Figure21. PopulationservedbyPOTWsnationwideforselectyearsbetween1940and2004
andprojectedto2024(ifallneedsaremet),organizedbywastewater
treatment type........................................................................................................ 25
Figure22. WaterqualitybasedapproachoftheCleanWaterAct.......................................... 210
Figure41. PercentnitrogenremovalduetobiomasssynthesisasafunctionofSRTand
influentBOD/Nratio................................................................................................ 43
Figure42. EffectofSRTandtemperatureoneffluentNH4+NandNO2
Nconcentrations
usingkineticdatainTable46and44forCMAS.................................................... 415
Figure43. EffectofDOconcentrationoneffluentNH4+NandNO2
Nconcentrations
usingkineticdatainTable44and46andat15CforCMAS............................... 415
Figure44. EffectoftemperatureonminimalwashoutSRTAOB,HandNOB,Hfrom
Hellingaetal.(1998)andAOB,MandNOB,MfromTables42and44................417
Figure45. RatioofCODrequiredtoNO3NcompletelyreduceNO3N(CRNO3)asa
functionofthebiomassyield.................................................................................. 426
Figure51. TheoryofBPRinactivatedsludge........................................................................... 51
Figure52. BPRataWWTP ....................................................................................................... 53
Figure53 BiologicalPathwaysofMethaneFormation............................................................ 5.8
Figure54. Exampleofsecondaryreleaseinsecondanoxiczone............................................. 514
Figure61. ModifiedLudzackEttinger(MLE)process............................................................... 64
Figure62. 4stageBardenphoprocess..................................................................................... 65
Figure63. Commonconfigurationforamembranebioreactor4stagebardenphotreatment
system ....................................................................................................... 66
Figure64. Operatingperiodsofasequencingbatchreactor................................................... 67
Figure65. Exampleoxidationditchconfiguration.................................................................... 68
Figure66. Stepfeedbiologicalnitrogenremoval..................................................................... 67
Figure67. Downflowdenitrificationfilter................................................................................ 614
Figure68. Continuousbackwashupflowsand(CBUS)filters................................................... 615
Figure69. Closeupofcontinuousbackwashupflowsand(CBUS)filter.................................. 615
Figure610. Densadeghighrateclarificationprocessflowdiagram......................................... 618
Figure611. CoMagTMprocessflowdiagram............................................................................ 619
Figure612. Phoredoxprocess(A/O)......................................................................................... 621
Figure613. Oxidationditchwithanaerobiczone....................................................................... 622
Figure614. 3StagePhoredoxprocess(A2/O)........................................................................... 623
Figure615. 5stageBardenphoprocess.................................................................................... 624
Figure616. UCTandModifiedUCTprocess............................................................................... 625
Figure617. Westbankprocess.................................................................................................... 626
Figure618. VT2processschematic............................................................................................. 627
Figure619. TheBluePlainsprocess............................................................................................ 628
Figure620. Probabilityplotofsecondaryeffluentphosphorusdata......................................... 639
Figure621. Technologyperformancestatisticsfornitrogenremovalplants............................. 640
Figure622. Technologyperformancestatisticsforphosphorusremovalplants....................... 640
Figure71 Netsludgeproductionversussolidsretentiontimeandtemperature ..................714
Figure91. Possibleapplicationpointsforchemicaladdition(C)............................................. 94
Figure92. Schematicofcommonjartestingapparatus........................................................... 99
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Figure93. Typicaldrychemicalfeedsystem............................................................................ 913
Figure101. Unifiedprotocolforactivatedsludgemonitoring.................................................. 106
Figure102. Essentialrequirementsforwastewatertreatmentprocesssimulation..................1013
Figure103. Examplesimulatorconfigurationforabiologicalnutrientremovalplant..............1014
Figure104. CODcomponentsformunicipalwastewater........................................................... 1018
Figure105. RelationshipbetweenBOD,COD,TSS,andVSS...................................................... 1021
Figure106. TKNcomponentsformunicipalwastewater........................................................... 1027
Figure107. Phosphoruscomponentsinmunicipalwastewater................................................ 1030
Figure111. Upflowcontinuousbackflowfilter.......................................................................... 1111
Figure112. OperationalmodelsoftheFuzzyFilter.................................................................. 1112
Figure113. CutawayviewofAquaDiskclothmediafilter........................................................ 1113
Figure114. Hollowfibermembraneconfigurationwithinsidetooutsideflow........................ 1116
Figure115. ParksonDynasandD2advancedfiltersystem......................................................... 1120
Figure116. BluePROprocess................................................................................................... 1121
Figure121. Spatialandtemporalprofilesofammonia.............................................................. 125
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AcronymsandAbbreviations
A/O Anaerobic/Oxic,Phoredox
A2/O Anaerobic/Anoxic/Oxic,3StagePhoredox
AMO AmmoniaMonooxygenase
ANAMMOX AnaerobicAmmoniaOxidation
AOB AmmoniaOxidizingBacteria
AS ActivatedSludge
ASCE AmericanSocietyofCivilEngineers
ASM ActivatedSludgeModel
AT3 AerationTank3
BABE BioAugmentationBatchEnhanced
BAF BiologicalAeratedFilter
BAR BioAugmentationRegeneration/Reaeration
BCFS BiologicalChemicalPhosphorusandNitrogenRemoval
bDON BiodegradableFractionofDissolvedOrganicNitrogen
BHRC
Ballasted
High
Rate
Clarification
Processes
BNR BiologicalNutrientRemoval
BOD BiochemicalOxygenDemand
BOD5 BiochemicalOxygenDemand(5day)
BPR BiologicalPhosphorusRemoval
CCF ContinuousContactFiltration
CFD ComputationalFluidDynamic
CIP CleaninPlace
CMAS CompletelyMixedActivatedSludge
C/N CarbontoNitrogenRatio
COD ChemicalOxygenDemand
COV CoefficientofVariation
CR ConsumptiveRatio
CSO CombinedSewerOverflow
CSTR ContinuousStirredTankReactors
CWA CleanWaterAct
CWSRF CleanWaterStateRevolvingFund
DAF DissolvedAirFlotation
DO DissolvedOxygen
DON DissolvedOrganicNitrogen
DSS DesignatedSuspendedSolids
EBPR EnhancedBiologicalPhosphorusRemoval
EDC EndocrineDisruptingChemicals
EDTA EthyleneDiamineTetraaceticAcid
ENR EnhancedNutrientRemoval
EPA U.S.EnvironmentalProtectionAgency
FFS FixedfilmSystems
F/M FoodtoMicroorganismratio
FWPCA FederalWaterPollutionControlAct
FWS FreeWaterSurface
GAO GlycogenAccumulatingOrganism
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GMP GoodModelingPractices
HRSD HamptonRoadsSanitationDistrict
HRT HydraulicRetentionTime
iDON InertDissolvedOrganicNitrogen
IFAS IntegratedFixedFilmActivatedSludge
ISF IntermittentSandFilter
ISS InertSuspendedSolids
IWA InternationalWaterAssociation
JHB JohannesburgProcess
LOT LimitofTechnology
MAUREEN MainstreamAutotrophicRecycleEnhancedNremoval
MBBR MovingBedBiofilmReactor
MBR MembraneBioreactor
MCL MaximumContaminantLevel
MF Microfiltration
MGD MillionGallonsperDay
mg/L Milligramsperliter
MLE ModifiedLudzackEttinger
MLSS MixedLiquorSuspendedSolids
MLVSS MixedLiquorVolatileSuspendedSolids
MMDF MaximumMonthDesignFlow
MUCT ModifiedUniversityofCapetown
MWRDGC MetropolitanWaterReclamationDistrictofGreaterChicago
N Nitrogen
NF Nanofiltration
NTU NephelometricTurbidityUnits
NOAA NationalOceanicandAtmosphericAdministration
NOB NitriteOxidizingBacteria
NPDES
National
Pollutant
Discharge
Elimination
System
NTT NitrogenTradingTool
ORD EPAOfficeofResearchandDevelopment
ORP OxidationReductionPotential
OSHA OccupationalSafetyandHealthAdministration
OUR OxygenUptakeRate
OWASA OrangeWaterandSewerAuthority
OWM EPAOfficeofWastewaterManagement
P Phosphorus
PACl PolyaluminumChloride
PAH PolycyclicAromaticHydrocarbons
PAO PhosphateAccumulatingOrganism
PHA Polyhydroxyalkanoate
PHB Polyhydroxybutyrate
PHV Polyhydroxyvalerate
PID PhasedIsolationDitch
PLC ProgrammableLogicController
POTW PubliclyOwnedTreatmentWorks
PPCPs PharmaceuticalsandPersonalCareProducts
RAS ReturnActivatedSludge
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RBC RotatingBiologicalContactor
rbCOD ReadilyBiodegradableChemicalOxygenDemand
rDON RecalcitrantDissolvedOrganicNitrogen
RO ReverseOsmosis
RSF RecirculatingSandFilters
SAV SubmergedAquaticVegetation
SBCOD SlowlyBiodegradableChemicalOxygenDemand
SBR SequencingBatchReactors
SCADA SupervisoryControlandDataAcquisition
SCM SurfaceComplexationModeling
SDNR SpecificDenitrificationRate
SHARON SingleReactorHighActivityAmmoniaRemovalOver Nitrite
SNdN SimultaneousNitrificationDenitrification
SRT SolidsRetentionTime
SSO SanitarySewerOverflow
STAC ChesapeakeBayProgramScientificandTechnicalAdvisory
Committee
SWIS SubsurfaceWastewaterInfiltrationSystem
TAL TechnologyAchievableLimit
TAN TotalAmmoniaNitrogen
TDS TotalDissolvedSolids
TKN TotalKjeldahlNitrogen
TMDL TotalMaximumDailyLoads
TN TotalNitrogen
TP TotalPhosphorus
TSS TotalSuspendedSolids
TUDP BioPModeloftheDelftUniversityofTechnology
UCT UniversityofCapetownProcess
UF
Ultrafiltration
UOSA UpperOccoquanSewageAuthority
USDA U.S.DepartmentofAgriculture
USEPA U.S.EnvironmentalProtectionAgency
USGS U.S.GeologicalSurvey
VFA VolatileFattyAcid
VIP VirginiaInitiativePlant
VSS VolatileSuspendedSolids
WAS WasteActivatedSludge
WEF WaterEnvironmentFederation
WEFTEC WaterEnvironmentFederationTechnicalExhibitionand
Conference
WERF WaterEnvironmentResearchFoundation
WQS WaterQualityStandards
WWTP WastewaterTreatmentPlant
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Acknowledgements
Theprincipleauthorsofthisdocument,titledNutrientControlDesignManual,were:
Dr.CliffordRandall,ProfessorEmeritusofCivilandEnvironmentalEngineeringatVirginiaTechand
DirectoroftheOccoquanWatershedMonitoringProgram
Dr.JamesBarnard,GlobalPracticeandTechnologyLeaderatBlack&Veatch
Dr.H.DavidStensel,ProfessorofCivilandEnvironmentalEngineeringattheUniversityofWashington
LauraDufresne,SeniorEngineer,theCadmusGroup,Inc.
EPAtechnicaldirectionandoversightwereprovidedbyDanMurray,EPAOfficeofResearchand
Development,NationalRiskManagementLaboratory.
EPAtechnicalreviewsofthedocumentwereperformedby:
EPAOfficeofResearchandDevelopmentDonaldBrown
DouglasGrosse
RichardBrenner
JamesSmith
MarcMills
JeffryYang
EdwinBarth
EPAHeadquartersDonaldAnderson
PhilZahreddine
JamesWheeler
EPARegionsDavidPincumbe,Region1
RogerJanson,Region1
RussMartin,Region5
DaveRagsdale,Region10
Externaltechnicalreviewsofthedocumentwereperformedby
JeanetteBrown,StamfordWaterPollutionControlAuthority
TanyaSpano,MetropolitanWashingtonCouncilofGovernments(MWCOG)
S.JohKang,TetraTech
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ThefollowingmembersoftheOhioWaterEnvironmentAssociation:
DaleE.Kocarek,StantecConsulting,Inc.
WilliamBarhorst,ARCADIS
DennisP.Meek,DMEngineering
KimRiddell,CityofDelphos
PaulFletcher,Jones&HenryEngineers
JasonTincu,CityofXenia
GaryHickman,CityofColumbus
RogerF.Gyger,m2tTechnologies
TedMarten,CityofTwinsburg
DavidWilson,ButlerCountyWaterandSewer
KarenHarrison,Jordan,Jones,Goulding
MaryLong,Black&Veatch
RobertHollis,SummitCounty
RickNoss,StantecConsulting
ThepingChen,AECOM
ShaunBeauchesne,HachCompany
DavidFrank,ARCADIS
ThefollowingmembersoftheWaterEnvironmentResearchFoundation(WERF)NutrientsChallenge
Team:
JBNeethling,HDREngineering,Inc.
MarioBenisch,HDREngineering,Inc.
AmitPramanik,WERF
Diagramsforillustrationofspecificconceptswereprovidedby:
Dr.CliffordRandall,VirginiaTech
Dr.JamesBarnard,BlackandVeatchDr.H.DavidStensel,UniversityofWashington
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1.IntroductionChapter1covers:
1.1 HistoryofNutrientRemoval
1.2 PurposeandScopeofthisManual1.3 ManualOrganization
1.4 References
1.1 HistoryofNutrientRemoval1Biologicalnutrientremoval(BNR)atwastewatertreatmentplants(WWTP)beganintheearly
1960s.PioneerssuchasLudzackandEttinger(1961)andWuhrman(1964)madeeffortstodevelop
biologicalnitrogenremoval(nitrificationdenitrification)wastewatertreatmentsystems.Levinand
Shapiro(1965)researchedbiologicalphosphorusremoval,anddevelopedapatentedprocessforit,
knownasPhoStrip.However,thesystemsdevisedbyLudzack,Ettinger,andWuhrman,didnotutilizean
internalrecycletoobtainsignificantutilizationoftheinfluentbiochemicaloxygendemand(BOD),and
theproposedbiologicalmechanismsofthePhoStripprocessremainedcontroversialbecauseitstwo
finalstepswerethereleaseofphosphorusfromactivatedsludgeunderanaerobicconditionsandthen
chemicalprecipitationofthereleasedphosphorusinaseparatereactor.
Themajorprocessdevelopmentbreakthroughsforbiologicalremovalofbothnitrogenand
phosphorusutilizingtheinfluentBODresultedfromtheworkofJamesBarnardinSouthAfricainthe
early1970s.Hefirstdevelopedasinglesludgeprocessconfigurationwithinternalrecyclethatutilized
theinfluentBODfordenitrification(1973).Itsubsequentlybecamethestandardnitrogenremoval
processforthewastewaterindustry.ItisnowknownasthemodifiedLudzackEttinger(MLE)process.
Healsodemonstratedthatanaerobicaerobicsequencingofactivatedsludge,withinfluentBODfirst
flowingintotheanaerobiczone,wasnecessarytoobtainrobustbiologicalphosphorusremoval(BPR).
Thisdiscoverywasfirstpublishedin1975.Theoreticalsupportthatthemechanismwasbiologicaland
notchemicalwassuppliedbyFuhsandChen(1975)inthesameyear.Barnarddevelopedseveral
processconfigurationsforbothseparateandcombinedbiologicalremovalofnitrogenandphosphorus.
Afourstageanoxicaerobicanoxicaerobicprocessdesignedprimarilyfornitrogenremovalwas
patentedastheBardenphoProcess(1978).Thefivestageversion,createdbyaddingananaerobiczone
asthefirststagebecameknownastheModifiedBardenphoProcess.
Alsoduringthemid1970s,ananaerobicaerobicwastewatertreatmentconfigurationwasbeing
developedintheUnitedStatesforcontroloffilamentousgrowthsinactivatedsludge.Thisprocesswas
patented
by
Marshall
Spector
and
acquired
by
Air
Products
and
Chemical,
Inc.
They
learned
from
BarnardthatanaerobicaerobicsequencingofactivatedsludgealsocouldbeusedtoaccomplishBPR
andpatentedtheconfigurationastheAnaerobicOxic(AO)process,whichwasidenticaltothePhoredox
configurationdevelopedbyBarnardinSouthAfrica.Theythencombineditwithananoxiczoneand
patentedtheresultingconfigurationastheAnaerobicAnoxicOxic(A2/O)process,againidenticaltoa
configurationdevelopedbyBarnard.Atthistime,thedetrimentalimpactsofnitraterecycleinreturn
1ByDr.CliffordRandall,ProfessorEmeritus,VirginiaTech
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activatedsludge(RAS)totheanaerobiczoneonBPRperformancewasnotfullyunderstood,andmany
ofthePhoStrip,Phoredox/A2/O,andModifiedBardenphoplantswereremovingphosphoruserratically.
TheSouthAfricanGovernmentrequestedthatProfessorGerritMaraisandhiscoworkersatthe
UniversityofCapeTowninvestigateandresolvetheissue.Theydevelopedamodificationofthe
Phoredox/A2/Oconfiguration,dubbedtheUniversityofCapeTown(UCT)process,thatfirstsentthe
RAStotheanoxiczonethenaddedasecondinternalrecycletorecycledenitrifiedmixedliquorfromthe
effluentoftheanoxiczonebacktotheinfluentoftheanaerobiczone.Basedonthesuppositionthat
denitrificationwouldoccuronlyintheanoxiczone,amodifiedversionoftheUCTprocesswas
developedforwastewaterswithahighTotalKjeldahlNitrogen(TKN)toBODratio.
BNRwasintroducedtoNorthAmericaintheearly1980sthroughimplementationofBNR
facilitiesatKelowna,BC,Canada,andatOrangeCounty,FL.BNRwasintroducedtotheChesapeakeBay
regionin1984byaseminarandaworkshoporganizedbyDr.CliffordRandall(VirginiaTech)andheldat
Richmond,VA.Then,workingwiththeHamptonRoadsSanitationDistrict(HRSD)andtheVirginiaWater
PollutionControlBoard,apilotplantstudyofahighrateUCTprocesswasconductedattheHRSD
LambertsPointprimarytreatmentplantin198586,andfollowedbyfullscaleresearchdemonstrations
oftheA/O,A2/OandUCTprocessesattheHRSDYorkRiverPlantfrom198690.OverlappingtheYork
Riverdemonstrations,whichresultedinpatentingoftheVirginiaInitiativePlant(VIP)BNRprocess,were
fullscaledemonstrationsofBNR(bothNandPremoval)attheAnneArundelCounty,MD,Maryland
CityWWTP,andtheBowie,MD,WWTP.Alsooverlappingtheseeventswerethedesignand
constructionoftheMauldinRoadWWTP,Greeneville,SC,andmodificationoftwoplantsinCharlotte,
NC.NorthAmericanBNRdevelopmentsmovedrapidlyinthelate1980sandearly1990s,resultingin
BPRandBNRimplementation,designandconstructionatsitesasdiverseastheBonnybrookWWTP,
Alberta,Canada,HillsboroughCounty,FL,Frederick,MD,Atlanta,GA,andmodificationoftheHoward
County,MD,WWTPfromthePhoStriptothePhoredox/A2/Oconfiguration.
BNRbegantobeimplementedinEuropeonawidespreadbasisin1987,firstinGermanyand
TheNetherlands,followedbyDenmark,Austria,CzechRepublic,ItalyandFrance.SchreiberKlarenlagen
with
their
unique
Simultech
Process
wherein
BPR,
nitrification,
and
denitrification
all
occurred
simultaneouslyinonecontinuousflowreactorwasapacesetterinGermanywhileKruger,Inc.,ledthe
wayinDenmarkundertheguidanceofProfessorPoulHarremoesandhiscoworkersattheDanish
InstituteofTechnology.
TheengineeringartofBNRhasprogressedtowardsmaturityduringthepasttwodecadeswith
theadditionofadvancedpracticessuchasprefermentationofprimarysludgetoenhanceBPR,
integrationoffixedfilmmediaintoactivatedsludge(IFAS)toenhancenitrogenremoval,utilizationof
biologicalfiltersfornitrogenremoval,andwidespreaduseoftertiaryfiltersfordentrificationand
chemicalphosphorusremovaltolowerlevels.Recenteffortstodevelopeconomicalmethodsforthe
nutrientremovalinsiteswithlimitedspaceforexpansionhaveresultedintheemergenceoftwo
innovativetechnologicalapproaches:
1) Technologiessuchasmembranebioreactorsorballastedflocculationtoremovesuspended
solidstoverylowconcentrationsandsimultaneouslyeliminateorgreatlyreducethesizeof
secondarysettlingbasins.
2) SidestreamprocessessuchasSHARON,ANAMMOX,INNITRIandotherstoeitherremove
nitrogenfromammoniarichflowsfromsludgeprocessingorenhanceremovalinthemain
streamprocess.
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NitrogenremovalhasbeenwidelyimplementedalongtheConnecticutcoastofLongIsland
Sound.Morestringenteffluentstandards,typically3.0milligramsperliter(mg/L)totalnitrogen(TN)and
0.1orlowermg/Ltotalphosphorus(TP),inregionssuchastheChesapeakeBaywatershed,coastal
areasofNorthCarolina,OkanaganLakeareaofBritishColumbia,Canada,midColoradoandKalispell,
WY,haveadvancedtheartfromBNRtoenhancednutrientremoval(ENR).AcombinationofBNR,
chemicaladditionsandeffluentfiltrationaretypicallyusedtoaccomplishENR.
Acleartrendofthewastewatertreatmentindustryisagreateremphasisonincorporating
elementsofrecycle,recovery,andreuseintoplantdesignandoperation.Sustainablenutrientrecovery
andreuseisgainingnationalandinternationalattentionaswastewaterutilitieslookforwaysto
decreaseenergycostsandgreenhousegasemissions,utilizeexcesscapacity,generatenewrevenue,
andaddressevermorestringentregulatoryrequirements.Thisevolutioninthinkingismoving
wastewatertreatmenttoenhancedenergyefficiencyandchangingtheroleofwastewatertreatment
facilitiesfromwastegeneratorstoresourceproviders.
1.2 PurposeandScopeofthisManualResearchandtechnologydevelopmentthroughthemid70swerethebasisforEPAsfirstdesign
manualfornitrogencontroltechnologies.Thisdocument,ProcessDesignManualforNitrogen
Control,(EPA,1975)waspublishedin1975.Thismanualcoveredabroadrangeofprocessesthatwere
beingevaluatedandappliedatthetime.Theintentofthemanualwastopresentdesigninformationfor
technologiesthatappearedtohaveaviable,practicalapplicationtonitrogencontrol.Twobroad
categoriesoftreatmentprocesseswereaddressed.Thefirstgroupofprocessesprovidesforthe
conversionoforganicandammoniumnitrogenbyoxidationtonitratenitrogen.Theseprocessesare
biologicalandaregenerallyreferredtoasnitrification.Thesecondgroupofprocessesremovesnitrogen
fromthewastewater.Theseprocessesarealsobiological,usingananoxicdenitrificationstepwith
nitrification.Physical/chemicalprocesseswerealsopresentedfornitrogenremoval,includingion
exchange,ammoniastripping,andbreakpointchlorination.Betweenthepublicationofthefirstnitrogencontrolmanualandtheupdateofthemanualin1993,thetrendinnitrogencontroltechnologywas
almostexclusivelytowardsbiologicalprocesses.Biologicalprocessesbecameprovenandwell
demonstratedandweremostefficientlyexpandedorupgradedforbiologicalnitrificationortotal
nitrogenremoval.Thefocusofthe1993updateddocument,ManualNitrogenControl,(EPA,1993)
wasonbiological/mechanicalprocessesthatwerefindingwidespreadapplicationfornitrificationand
nitrogenremoval.
In1971,EPApublisheditsfirstphosphoruscontroldesignmanual.Thismanual,ProcessDesign
ManualforPhosphorusRemoval,(EPA,1971)focusedonphosphorusremovalmethodsthatinvolve
chemicalprecipitation.Primarily,themanualfocusedonthechemicalprecipitationofphosphorususing
saltsofaluminumandiron,andlime.Thechemicalapplicationpointsaddressedinthemanualwere
beforeprimarysettling,intheaerationtanks,beforefinalsettling,orinatertiaryprocess.In1976,
ProcessDesignManualforPhosphorusRemoval(EPA,1976)wasupdated.Specifically,design
guidanceforphosphorusremovalusingmineraladditionandlimeadditionbeforeprimarysettlingwas
revised.Also,guidanceforchemicalstorage,chemicalfeedsystemsandresidualshandlinganddisposal
wasupdated.In1987,EPApublishedtwotechnicaldocumentsthataddressedphosphoruscontrol.The
firstwasanupdatetothe1976ProcessDesignManualforPhosphorusRemoval(EPA,1987a).The
secondwasahandbooktitled,HandbookRetrofittingPOTWsforPhosphorusRemovalinthe
ChesapeakeBayDrainageBasin.(EPA,1987b)Theupdateofthedesignmanualincludedamajor
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additionofguidanceforbiologicalphosphorusremoval.Also,theuseoflimeadditionwasnotcovered
inthisupdateduetoitslossofpopularityinthe80s.Thetechnicalguidanceprovidedinthe1987
handbookwasfocusedontheuniquephosphorusremovalrequirementsbeingappliedtomunicipal
wastewatertreatmentplantsintheChesapeakeBaywatershed.Becauseofthevaryinglevelsof
phosphoruscontrolwithinthewatershed,thehandbookincludedanassessmentoftechnologiesfor
meetingtotalphosphoruseffluentlimitsof0.2mg/L,0.5mg/L,1mg/L,and2mg/L.Becausesome
treatmentplantsintheChesapeakeBaywatershedneedtocontrolbothnitrogenandphosphorus,the
handbookincludedachaptertitled,CompatibilityofChemicalandBiologicalPhosphorusRemovalwith
NitrogenControl.
In2007,EPAinitiatedtheprocesstodevelopupdateddesignguidanceforbothnitrogenand
phosphorusremovalatmunicipalWWTPs.Thefirststepwasanextensive,stateofthetechnology
reviewofnitrogenandphosphoruscontroltechnologiesandtechniquescurrentlyappliedandemerging
atmunicipalwastewatertreatmentplants.Thistechnologyreviewculminatedwiththepublicationof
theNutrientControlDesignManual:StateoftheTechnologyReviewReport(USEPA2009)asan
interimdocumentinthedevelopmentoftheupdateddesignmanuals.
ThepurposeofthisEPAdesignmanualistoprovideupdated,stateofthetechnologydesign
guidanceonnitrogenandphosphoruscontrolatmunicipalWWTPstowastewaterutilityownersand
operators,stateandEPApermitwriters,andenvironmentalengineeringprofessionals.Similarto
previousEPAmanuals,thismanualincludesextensiveinformationontheprinciplesofbiological
nutrientremovalandchemicalphosphorusremovaltoserveasthebasisfordesign.Adetailed
descriptionoftechnologies,bothconventionalandemerging,servesasaresourceforpreliminary
technologyselection.Themanualpresentsnewinformationonemergingissuesintheindustrysuchas
sustainabilityinwastewatertreatmentdesignandoperation,nutrientrecoveryandreuse,effluent
dissolvedorganicnitrogen,andmeasurementoflowphosphorusconcentrations.Althoughthismanual
providessomeexamplesofproprietaryandemergingtechnologies,EPArecognizesthattheindustryis
continuallyevolvingandthatnewtechnologiesnotidentifiedinthismanualmayemergeinthefuture.
BecausethemajorityofWWTPsintheUnitedStatesareequippedwithsecondarybiological
treatment,thefocusofthisdesignmanualisonprocessandtechnologymodifications/additionsfor
nutrientremovalatexistingWWTPsratherthanonnewtreatmentplantdesign,althoughguidanceforgreenfielddesignispresented. Alsonewfrompreviousversions,designguidancehereinisbasedonthe
useofmathematicalmodelsandsimulators.Simulatorsallowdesignerstostudykinetic aswellastime
basedsolutionswhiledeterminingthetotalmassbalancesofmanyconstituents.Theyhavebecome
increasinglypowerful,easytouse,widelyaccepted,andrecommendedbyWEFandASCE(2010)forthe
designofbiologicalnutrientremovalfacilities. EarlierversionsofEPAnutrientcontrolmanuals(USEPA
1993;USEPA1987a;USEPA1987b)stillcontainveryusefulguidance(includingexamples)onprocess
designusinghandcalculationsthatcanbeusedforverypreliminarysizingorchecksonsimulation
results.
Thismanualcomplimentsdetailedcostdataandindepthfacilitycasestudiespublishedinthe
MunicipalNutrientRemovalTechnologiesReferenceDocument(USEPA2008a)andanalysisofemerging
technologiesfornutrientremovalpresentedintheEmergingTechnologiesReportonWastewater
Treatment(USEPA2008b). BothdocumentsareavailablefordownloadfromEPAswebsiteat
http://www.epa.gov/OWM/mtb/publications.htm
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1.3 ManualOrganizationThisdesignmanualhas14chaptersand3appendices.Itisgenerallyorganizedwiththetheory
ofnutrientremovalpresentedfirstfollowedbyadescriptionofnutrientremovaltechnologies;guidance
onestablishingdesignobjectivesandselectingcandidatetreatmentprocesses;anddesignapproaches
forchemicalphosphorusremoval,biologicalnutrientremoval,andeffluentfiltration. Laterchapters
describeoperationalimprovementsforenhancingtechnologyperformanceandguidanceon
instrumentationandcontrols. Thelastchapter,Chapter14,discussessustainablerecoveryandreuse. A
moredetaileddescriptionofeachchapterisprovidedbelow.
Chapter2.NeedforandBenefitsofNitrogenandPhosphorusRemovalprovidesbackgroundinformationonsourcesofnitrogenandphosphorusinwastewater.Itreviewsthestatusof
wastewatertreatmentintheU.S.,theimpairmentofwaterwaysbyexcessivenutrients,
governmentandindustryinitiativestoreducenutrientpollution,andtheadditionalbenefitsand
challengesofnutrientremoval.
Chapter3.PrinciplesofPhosphorusRemovalbyChemicalAdditiondescribestheavailableformsofmetalsaltsandlimeandtheirreactionswithphosphorus.Itprovidesageneral
descriptionofsolidsseparationprocessandtheeffectsofvarioustreatmentoptionsonsludge
productionandhandling.
Chapter4.PrinciplesofBiologicalNitrogenRemovalexaminesthefundamentalmicrobiologybehindnitrificationanddenitrificationincludingstoichiometricsandkinetics.Itdiscusses
denitrificationkineticswithinternalandexternalcarbonsources.Simultaneousnitrification
denitrificationandpotentialimpactsonsludgehandlingarealsodiscussed.
Chapter5.PrinciplesofBiologicalPhosphorusRemovalprovidesadetaileddiscussionofthebiologicalphosphorusremovalprocessincludingkinetics,substraterequirements,
environmentalconditions,designandoperationalconsiderations,andimpactsonsludge
processingandhandling.
Chapter6.OverviewofNitrogenandPhosphorusRemovalTechnologiesdescribesthetechnologiesavailableforremovingnitrogen,phosphorus,orbothfromwastewater.Diagrams
areprovidedformosttechnologies.Itpresentsinformationontechnologyperformance
includingdesignandoperationalfactorsaffectingaplantsabilitytoachieveloweffluent
concentrations.
Chapter7.EstablishingDesignObjectivessummarizesthiscriticalstepinupgradingorretrofittinganexistingWWTP.Itprovidesguidanceonestablishingdesignflowrates,
characterizingflowandcontaminantsininfluentwastewaterincludingdetailedsampling
methodologiesanddataverificationsteps,andsettinggoalsforprocessreliability,sustainability,
andflexibility.Thechapteralsodescribessolidshandlingoptionsandsiteconstraints. Chapter8.SelectingCandidateTreatmentProcessesforPlantUpgradesdescribestechnology
selectionfactorsincludingtreatmentgoals,availablefootprint,hydraulicconsiderations,
chemicalneeds,solidsprocessingcapabilities,andenergyconsiderations.Itsummarizes
advantagesanddisadvantagesofdifferenttechnologytypes.Italsoprovidesanoverviewofa
recommendedapproachtotechnologyselectionanddiscussesuseofadvancedtools.
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Chapter9.DesignApproachforPhosphorusRemovalbyChemicalAdditionprovidesguidelinesonselectingachemicalprecipitant,choosingapplicationpoints,anddeterminingchemicaldose.Itprovidesdetailedguidanceondesigningachemicalfeedsystemandconsiderationsforrapid
mix,flocculation,andsolidsseparationprocessestomaximizephosphorusremoval.
Chapter10.DesignApproachforBiologicalNutrientRemovalpresentsastepbystepapproachfordesigningwastewatertreatmentupgradesfornutrientremovalusingmathematicalmodels.
Itprovidespracticalrecommendationsfordatacollectionandevaluationandmodelcalibration.
Itincludesdesignchecksfornitrogenandphosphorusremoval. Thischapteralsoprovidesan
alternativedesignapproachusinghandorspreadsheetcalculationsthatdesignerscanuseto
prepareroughestimatesand/ortocheckmodeloutputs.
Chapter11.DesignApproachforEffluentFiltrationdiscussestheoptionsinfiltrationtechnologyforeffluentpolishingandnutrientremoval. Itprovidesdesignguidanceongranular
mediafiltersandalternativetechnologiessuchasclothfilters,diskfilters,andmembranes.
Informationonemergingfiltrationtechnologiesforremovalofphosphorustoloweffluent
concentrationsisalsoprovided.
Chapter12.OperationandOptimizationtoEnhanceNutrientRemovalincludesinformationonhowtooptimizetheperformanceofexistingoperationsbyincorporatingSCADAandother
instrumentation.Thechapteralsodiscussescommonoperationalchangestoimprovesystem
performanceandenhancethecosteffectivenessoftreatmentprocesses. Chapter13.InstrumentationandControlsdiscussesonlineinstrumentationfornutrientcontrol
includingautomatedcontrolandoptimization,advancedautomatedcontrol,andSCADA
equipment,allofwhichcanleadtobetterprocessoptimizationandmorestabletechnology
performance.
Chapter14.SustainableNutrientRecoveryandReuseexaminesthelatestadvancesinnutrientrecoveryincludingseparatingandtreatingwasteonsiteandhowtousewastewatertreatment
byproductstodecreaseenergycostsandgreenhousegasemissions,takeadvantageofexcess
capacity,andgeneratenewrevenue.
The manual is supported by three technical appendices containing recommendations on
methanolsafety(AppendixA),alistoforganiccompoundsandinhibitoryconcentrationstonitrification
(Appendix B), and background information onmathematicalmodels for biological nutrient removal
(AppendixC).
1.4 ReferencesBarnard,J.L.1973.BiologicalDenitrification.JournalofWaterPollutionControl72(6):705720.
Barnard,J.L.1975.NutrientRemovalinBiologicalSystems.JournalofWaterPollutionControl,143154.
Barnard,J.L.1978.TheBardenphoProcess.In:AdvancesinWaterandWastewaterTreatmentBiological
NutrientRemoval.M.P.WanielistaandW.W.Eckenfelder,Jr.(eds.),AnnArborScience,AnnArbor,MI.
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Fuhs,G.W.andM.Chen. 1975.MicrobiologicalBasisofPhosphateRemovalintheActivatedSludge
ProcessfortheTreatmentofWastewater.MicrobialEcology.2(2):11938
Levin,G.V.andJ.Shapiro.1965.MetabolicUptakeofPhosphorusbyWastewaterOrganisms.Journalof
theWaterPollutionControlFederation(JWPCF),37(6):800821.
Ludzack,F.J.,andM.B.Ettinger.1961.ControllingOperationtoMinimizeActivatedSludgeEffluent
Nitrogen.JournaloftheWaterPollutionControlFederation(JWPCF),34(9):920931,1961
Wuhrman,K.1964.NitrogenRemovalinSewageTreatmentProcesses.Verhandlungenden
InternationalenVereinLimnologie,15:580596,1964.
USEPA.1971.ProcessDesignManualforPhosphorusRemoval.October1971.
USEPA.1975.ProcessDesignManualforNitrogenControl.October1975.
USEPA.1976.ProcessDesignManualforPhosphorusRemoval.EPA/625/176001a,April1976.
USEPA.1987a.DesignManualPhosphorusRemoval.EPA/625/187/001,September1987.
USEPA.1987b.HandbookRetrofittingPOTWsforPhosphorusRemovalintheChesapeakeBayDrainage
Basin.EPA/625/687/017,September1987.
USEPA.1993.ManualNitrogenControl.EPA/625/R93/010,September1993.
USEPAb.2008a.MunicipalNutrientRemovalTechnologiesReferenceDocument. OfficeofWastewater
Management,MunicipalSupportDivision. EPA832R08006. Availableonline:
http://www.epa.gov/OWM/mtb/publications.htm
USEPA.2008b.EmergingTechnologiesforWastewaterTreatmentandInPlantWetWeather
Management. EPA832R06006. Availableonline:http://www.epa.gov/OW
OWM.html/mtb/emerging_technologies.pdf
USEPA.2009.NutrientControlDesignManual:StateofTechnologyReviewReport.OfficeofResearch
andDevelopment.EPA/600/R09/012.January2009.Availableonlineat
http://www.epa.gov/nrmrl/pubs/600r09012/600r09012.pdf#22
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2.NeedforandBenefitsofNitrogenandPhosphorusRemoval
Chapter2covers:
2.1 Introduction
2.2 SourcesofNitrogenandPhosphorusinWastewater
2.3 StatusofWastewaterTreatmentintheUnitedStates
2.4 NutrientImpairmentofU.S.Waterways
2.5 ClimateChangeImpacts
2.6 FederalandStateRegulationsandInitiativestoReduceNutrient
Pollution
2.7 IndustryInitiativestheWERFRemovalChallenge
2.8 BenefitsofNutrientRemoval
2.9 ChallengesofNutrientRemoval
2.10 References
2.1 Introduction
Theharmfuleffectsofeutrophicationduetoexcessivenitrogenandphosphorusconcentrations
intheaquaticenvironmenthavebeenwelldocumented. Algaeandphytoplanktongrowthcanbe
acceleratedbyhigherconcentrationsofnutrients,leadingtoharmfulalgalblooms,hypoxia,andlossof
submergedaquaticvegetation(SAV).Dependingonthespecificwaterbodycharacteristics,either
nitrogenorphosphoruscanbelimiting(i.e.,presentinthesmallestamountcomparedtogrowth
requirements).Inadditiontostimulatingeutrophication,nitrogenintheformofammoniacanexerta
direct
demand
on
dissolved
oxygen
(DO)
and
can
be
toxic
to
aquatic
life.
Even
if
a
wastewater
treatmentplant(WWTP)convertsammoniatonitratebyabiologicalnitrificationprocess,theresultant
nitratecanstimulatealgaeandphytoplanktongrowth.
Fromapublichealthperspective,eutrophicationmayalsocauseriskstohumanhealth,resulting
fromconsumptionofshellfishcontaminatedwithalgaltoxinsordirectexposuretowaterbornetoxins.
Eutrophication,inparticular,cancreateproblemsifthewaterisusedasasourceofdrinkingwater.
Chemicalsusedtodisinfectdrinkingwaterwillreactwithorganiccompoundsinthesourcewaterto
formdisinfectionbyproducts,whicharepotentialcarcinogensandareregulatedbytheUSEPA. Excess
levelsofnitratesabovethemaximumcontaminantlevel(MCL)indrinkingwater(10ppm)cancause
numerousnegativehealtheffectsduetothebodysconversionofnitratetonitrite,includingserious
illnessandsometimesdeath.Infantsinparticulararesusceptibletotheseeffects,whichcaninterfere
withtheoxygencarryingcapacityoftheblood.Thisinterferencecanleadtoanacuteconditioninwhich
healthdeterioratesrapidlyoveraperiodofdays.Symptomsincludeshortnessofbreathandbluenessof
theskin(methemoglobinemia;alsoknownasBluebabySyndrome).
Forthesereasons,itisimportanttolimitnitrogenandphosphoruscontaminationofsurfaceand
groundwater. Onewaytominimizethiscontaminationistoreducelevelsofnitrogenandp