Nitrogen Removal Technologies for Meeting Nitrogen

NitrogenRemovalTechnologiesforMeetingNitrogenLoadReductionsintheChesapeakeBayWatershedNancyG.LoveProfessorDepartmentofCivil&EnvironmentalEngineeringDepartmentofBiolo[e-mail],Iwill:•Reviewtheproblem•Reviewnitrogenmetabolism•Discussbasicdesignprinciplesofnitrogenremoval•Reviewnitrogenremovaltechnologies•SomeresearcheffortsatVirginiaTechthatrelatetothistopicPointsourcesaccountedfor20%ofthenitrogenloadtotheBayin2002SourcesofNitrogentotheChesapeakeBay(DatafromStateoftheBay,2002)UrbanandSeptic16%AtmospherictoWater7%MixedOpen6%Forest13%Agriculture38%PointSource20%Whydoweneedtoremovenutrients?Algaecomposition=C106H263O110N16P1gNyields16galgae1gPyields114galgae,N2OOxicAnoxicNitrificationNitrificationDenitrificationDenitrificationN2FixationAssimilationAssimilation/AmmonificationAdaptedfromMadiganetal.,1997ConventionalNremovalinvolvescouplingaerobicnitrifierswithanoxicdenitrifiersNH4+NH2OHNO2-NO3-NON2ON2O2AerobicNitrificationAnoxicHeterotrophicDenitrificationOrganicmatterNeedtooptimizeorganiccarbonloadingtoachievehighqualityeffluentGrady,DaiggerandLim,1999NeedtooptimizeorganiccarbonloadingtoachievehighqualityeffluentGrady,DaiggerandLim,1999ConventionalNremovalinvolvescouplingaerobicnitrifierswithanoxicdenitrifiersNH4+NH2OHNO2-NO3-NON2ON2O2AerobicNitrificationAnoxicHeterotrophicDenitrificationOrganicmatterNitrification•Processimplicationsfromkinetics–Nitrifiersareslowgrowers(definesSRT)–Nitrificationtendstobean“all-or-none”phenomenon(onoroff)SludgeagemustbeselectedtoensurenitrificationGrady,DaiggerandLim,1999Nitrification•Processimplicationsfromkinetics–Nitrifiersareslowgrowers(definesSRT)–Nitrificationtendstobean“all-or-none”phenomenon(onoroff)–Kineticsofgrowthareverysensitiveto:•temperature•dissolvedoxygenconcentration•pH(optimal7.5-8.6)•C:Nratio•inhibitingcompoundsDissolvedoxygenmustbesufficienttoensurecompletenitrificationGrady,DaiggerandLim,1999ConventionalNremovalinvolvescouplingaerobicnitrifierswithanoxicdenitrifiersNH4+NH2OHNO2-NO3-NON2ON2O2AerobicNitrificationAnoxicHeterotrophicDenitrificationOrganicmatterConventionalnitrogenremovalcanbeachievedthrougharangeoftreatmentconfigurations•Singlesludgesystems•Postbioreactorfiltrationsystems•Integratedfixedfilm/activatedsludgesystems•FixedfilmsystemsMLEProcessGrady,DaiggerandLim,1999-TotalN:4to8mg/L-Anoxicvolume:Aerobicvolume~30:70Four-StageBardenpho-ImprovedNremovalwithsecondstage-ReliableTotalNto3mg/LunlikelyGrady,DaiggerandLim,1999VirginiaInitiativePlant(VIP)Grady,DaiggerandLim,1999SeparatestagesinglesludgeNremovalprocessMethanolorFermentationproducts-3to5daySRT-Costofsupplementalorganicsourcemustbeconsidered-CommonretrofitstrategyGrady,DaiggerandLim,1999FixedfilmdenitrificationornitrificationcanbeusedaswellODIBioforSystemscBODremovalNitrificationFactorsthatAffectBNR•SRT•WastewaterBOD5/Nutrientratios•Organicmattercomposition•EffluentTSS•EnvironmentalFactors•-Temperature•-pH•-DissolvedO2concentration•SludgeHandlingPracticesConsidertheimpactofeffluentTSSConsideraflocofbacteria:C5H7O2N10mg/LeffluentTSS=1.5mg/LeffluentTotalNSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCUpflowcontinuousbackwashfiltersprovideenhancedperformanceforTNremovalSlidesbyChrisdeBarbadillo,BlackandVeatch,Charlotte,NCFactorsthatAffectBNR•SRT•WastewaterBOD5/Nutrientratios•Organicmattercomposition•EffluentTSS•EnvironmentalFactors•-Temperature•-pH•-DissolvedO2concentration•SludgeHandlingPracticesConsidertheimpactofrejectwateronoverallNremovalcapacityofaplantBiologicalTreatmentSystemAnaerobicSludgeStabilizationResidualsRejectWaterEffluentSludgeConsidertheimpactofrejectwateronoverallNremovalcapacityofaplantBiologicalTreatmentSystemAnaerobicSludgeStabilizationResidualsRejectWaterEffluentSludgeNitrogenRemovalConventionalNitrification/Denitrification1.90BiomassFormation(gbiomassasCOD/gNremoved)3.70Alkalinityconsumption(gCaCO3/gNremoved)4.60O2Required(gO2/gNremoved)4.33CODInputRequired(gCOD/gNremoved)ConventionalNRemovalNH4+NH2OHNO2-NO3-NON2ON2AerobicNitrificationAnoxicHeterotrophicDenitrificationSinglereactorsystemforHighAmmoniaRemovalOverNitrite(SHARON)0.761.90BiomassFormation(gbiomassasCOD/gNremoved)1.853.70Alkalinityconsumption(gCaCO3/gNremoved)3.404.60O2Required(gO2/gNremoved)2.604.33CODInputRequired(gCOD/gNremoved)SHARONConventionalNRemovalNH4+NH2OHNO2-NO3-NON2ON2AerobicNitrificationAnoxicHeterotrophicDenitrificationXAnaerobicAmmoniumOxidation(ANAMMOX)AdaptedfromYeetal