短程硝化过程中NO2对NH省略H2OH氧化产生N2O的影响刘越

20153CIESCJournal1133March2015663Vol.66No.3NO2NH+4NH2OHN2O1112111001242230088N2ON2ONH+4NH2OHNO2NO2NH+4NH2OHN2ONH+4NH2OH30min180minN2ON2O25%NH4+NH2OH30minN2O0.2mgL1NH2OHN2ONH+4NH2OHAOBNO2N2OCODNO2NOSN2O17%11.07mgL1N2ONO2NH2OHDOI10.11949/j.issn.0438-1157.20141165X703A04381157201503113309EffectofNO2onN2OproductionbyNH+4andNH2OHoxidationduringnitritationprocessLIUYue1,PENGYi1,LIPengzhang1,HOUHongxun2,PENGYongzhen11KeyLaboratoryofBeijingforWaterQualityScienceandWaterEnvironmentRecoveryEngineering,EngineeringResearchCenterofBeijing,BeijingUniversityofTechnology,Beijing100124,China;2AnhuiGuozhenEnvironmentalProtectionEnergy-savingTechnologyLimitedLiabilityCompany,Hefei230088,Anhui,ChinaAbstract:Nitrousoxide(N2O)isoneofthemostimportantgreenhousegases,about265timesstrongerthancarbondioxide(CO2),anditmayalsodestroytheozonelayer.Inthebiologicalwastewatertreatmentprocess,autotrophicnitrificationhasbeenthoughttobethemajorsourceofN2Oproduction.SoitbecomesincreasinglyimportanttopreventN2Oemissionfromsewagetreatment.Inthisstudy,byaddingNH+4,NH2OHandNO2totheeffluent,theeffectofNO2onN2OproductionbyNH+4andNH2OHoxidationduringthenitritationprocesswasinvestigatedinalaboratorybatch-scalesystemwithactivatedsludgefortreatingdomesticwastewater.Withinthefirst30minofNH+4andNH2OHoxidationprocess(totaltesttime:180min)N2Oaccountedformorethan25%ofthetotalproduction.AsNH+4orNH2OHwasconsumedcompletely,theamountofN2Onetproductionreducedtolessthan0.2mgL1inthelast30min.Furthermore,theconcentrationofNO2-NcouldaffectN2Oproduction.2014-08-012014-11-06199020142014-K7-02220111103130002Receiveddate:2014-08-01.Correspondingauthor:Prof.PENGYongzhen,[e-mail]661134TheincreaseofNO2-NwouldpromotegenerationofN2O.ThemaximumtotalN2Onetproductionwas6.86mgL1whentheconcentrationofNO2was60mgL1.NH2OHoxidationplayedakeyroleinN2Oproductionattheverybeginningoftheexperimentwhilenitrifierdenitrificationbecameamainpathwaylater.WhenthedomesticsewagewastreatedunderDOlimitedconditions,duetothepresenceofCOD,theremightoccurheterotrophicdenitrificationduringtheaerationphase.However,oxygenandNO2hadstronginhibitionontheactivityofnitrousoxidereductase(NOS),consequentlyN2OcouldnotbereducedtoN2completely.Itledtomorethan17%N2Owasproducedandthemaximumtotalnetproductionreached11.07mgL-1.Hence,thecontributiontoN2Oproducedbydenitrificationcouldnotbeignoredduringthedomesticwastewatertreatment.Besidesco-existenceofNH+4andNH2OHcouldsignificantlyincreaseN2OproductionandthisprocessalsoemittedmoreN2OwhentheconcentrationofNO2wasincreased.Keywords:nitritationprocess;nitrite;NH2OHoxidation;heterotrophicdenitrificationN2O3(CO2CH4N2O)CO2265[1][2]N2O2/3[3]N2O[4]N2ON2ONH+4AOB(NH2OH)NO2NO2NOBNO3HETNO3N2NO2NON2O3N2O[5]1NH2OHNH2OHNO2HNON2O2H2N2O[6]AOB[7]N2ONH2OHNH2OHNO2[8](AOB)AOBNO2NONH2OHN2OAOBNO2NON2ONIRkNOR[9]N2O[10][11][12]N2ON2O1N2OFig.1SchemeofrelevantN2Oproductionpathwaysinbiologicalwastewatertreatment3NO2NH+4NH2OHN2O1135[11,13][14][15]pH[16][12]AOBN2O[17]N2ONO2NH2OHN2ON2ONO2NH+4NH2OHN2O11.1SBR10L30113min240min120min30min10min20min3/50Lh11Table1QualityofactualdomesticwastewaterItemCOD/mgL1NH+4-N/mgL1NO2-N/mgL1NO3-N/mgL1pHmaximum210.6780.252.552.677.67minimum160.9648.490.0506.98average185.8264.371.31.347.54100ml30003200mgL115d1.0ml23dN2O30minN2ON2ONH+4-NNO2-NNO3-NCODMLSSMLVSS1.31.223L2L520.6Lmin1180min30minN2O0.5molL1NaHCO30.5molL1HClpH7.50.12411.31.3.1NH+4-NNO2-NNO3-NMLSSMLVSS及pHDO的测定2Fig.2SchematicdiagramofSBRforbatchtests2Table2ExperimentalconditionsappliedinbatchtestTestSubstrateAims1activatedsludge+NH+4-N+NO2-N+effluenteffectofNO2onN2OproductionbyNH+4oxidation2activatedsludge+NH2OH+effluentN2OproductsbyNH+4oxidation3activatedsludge+NH2OH+NO2-N+effluenteffectofNO2onN2OproductionbyNH2OHoxidation4activatedsludge+ATU+NH2OH+NO2-N+wastewaterN2Oproducedbyheterotrophicdenitrification5distilledwater+NH2OH+NO2-NN2OproducedbychemicalreactionConcentrationofNH+4-Nis30mgL1NH2OHis10mgL1ATUis20mgL1.ConcentrationofNO2-Nhasgradientwhichis15,30,45,60mgL1.EffluentiseffluentfromSBRwhichisaerated30mintoremoveavailableCOD.661136NH+4-NNO2-NNO3-NLACHATQuikChem8500Series230min0.45mMLSSMLVSSpHDOWTWMulti340ipHDO1.3.2N2O测定方法40L30minN2ON2O30min1N2OAgilent6890NHP-Plot/××30m×0.53mm×25mN2O110180ECD3002N2ON2O20ml5ml0.5ml1000mgL1HgCl25mlN23030minN2ON2O1.3.3计算方法tN2O1N2O=MN2O,t(n+1)MN2O,,t(n)+N2O(1)N2O=∑CN2O,gasQairtCN2O,gasN2OmgN2O-NL1Qairt22.1N2O30dNO2-N90%NO3-N1mgL1NH+4-NNO2-NNO3-N1mgL1N2O5%7%3aNO3-NNOBAOB3bN2O30minNH+4-NNO2-NNH+4-NN2O0NH+4-N3N2OFig.3VariationsofwaterqualityandN2Oproductionsituationduringnitritationanddenitrification3NO2NH+4NH2OHN2O1137NH+4-NNO2-NN2ONO2-NN2O2h30min1.44mgL1NH+4-NN2ON2ONO2-NN2ON2ON22.2NO2-NNH+4-NN2O4NO2-NNH+4-NN2O4aNO2-NNH+4-NNO2-NNH+4-NNO2-N15mgL1NO2-N304560mgL12hNH+4-NNO2-N32.5hAnthonisen[18]FAAOBNOB10150mgL10.11.0mgL1FNAAOBNOB0.02mgL10.4mgL1NO2-NFA0.630.65mgL1NH+4-NFNA0.001mgL10.064mgL1NOBNO3-N4b30minN2O3hN2O4cNH+4-NN2O3hN2ONH+4-NN2ONO2-NN2ONO2-N15mgL13.76mgL1NO2-N60mgL16.86mgL