高氨氮垃圾渗滤液厌氧好氧工艺除有机物及深度脱氮英文孙洪伟

Advancedremovaloforganicandnitrogenfromammonium-richlandfillleachateusingananaerobic-aerobicsystem☆HongweiSun1,⁎,HuananZhao1,BaoxiaBai3,YuyingChen1,QingYang2,YongzhenPeng21SchoolofEnvironmentalandMunicipalEngineering,LanzhouJiaotongUniversity,Lanzhou730070,China2KeyLaboratoryofBeijingWaterQualityScienceandWaterEnvironmentRecoveryEngineering,BeijingUniversityofTechnology,Beijing100124,China3DiseasePreventionandControlOfficeofUrumqiRailwayBureau,Urumqi830010,ChinaabstractarticleinfoArticlehistory:Received8June2013Receivedinrevisedform26December2013Accepted18March2014Availableonline6March2015Keywords:LandfillleachateNitrogenremovalDenitritationMonodmodelFluorescenceinsituhybridizationAnovelsystemcouplinganup-flowanaerobicsludgeblanket(UASB)andsequencingbatchreactor(SBR)wasintroducedtoachieveadvancedremovaloforganicandnitrogenfromammonium-richlandfillleachate.UASBcouldremove88.1%oftheinfluentCODatavolumetricloadingrateof6.8kgCOD·m−3·d−1.Nitritation–denitritationwasresponsibleforremoving99.8%ofNH4+-Nand25%oftotalnitrogenintheSBRunderalternatingaerobic/anoxicmodes.SimultaneousdenitritationandmethanogenesisintheUASBenhancedCODandTNremoval,andreplenishedalkalinityconsumedinnitritation.FortheactivatedsludgeofSBR,ammoniaoxidizingbacteriawerepreponderantinnitrifyingpopulation,indicatedbyfluorescenceinsituhybridization(FISH)anal-ysis.TheMonodequationisappropriatetodescribethekineticbehaviorofheterotrophicdenitrifyingbacteria,withitskineticparametersdeterminedfrombatchexperiments.©2015TheChemicalIndustryandEngineeringSocietyofChina,andChemicalIndustryPress.Allrightsreserved.1.IntroductionWastewaterusuallycontainshighconcentrationsoforganicsandammonia,sonitrogenlandfillleachatewithouttreatmentwillpollutetheenvironmentseriously[1].Cost-effectiveandhighlyefficienttreat-mentsforleachateareofgreatinterest.Intermsofcost-effectivenessandreusability,biologicalmethodspredominatecomparedtoothertreatmentmethods,suchasammoni-umtripping,ozoneoxidizationandreverseosmosis[2–7].Inbiologicalprocesses,organicandnitrogenintheleachatecanbetransformedintocarbondioxideandnitrogengas,respectively,whichmeansrealremov-aloforganicandnitrogenwithoutsecondarypollution.Thebiologicalprocesswithananaerobic–aerobicsystemisafeasibleandsustainabletechnologyforremovingorganicandnitrogenfromlandfillleachate[8–11].Inthemajorityofrecentlypublishedpapers,organicandammo-niumremovalhigherthan90%couldbeachieved,butthetotalnitrogen(TN)removalefficiencyisnothighduetotheshortageofcarbonsourceavailablefordenitrification[12,13].Inordertoimprovethenitrogenremovalefficiency,nitritation–denitritationtheoryhasbeenproposedinrecentyears,involvingoxida-tionofammoniumtonitriteandthenreductiontonitrogengas.Comparedwithconventionalbiologicalprocesses,thenitritation–denitritationprocesscanreducetheamountofaerationby25%andcarbonneededby40%[14–16].Toenhancethedenitritationefficiency,simultaneousdenitritationandmethanogenesis(SDM)wasusedinanaerobicreactor[17,18].SDMhasbecomeanattractivetechnologyforimprovingTNremovalbecauseitleadstobettereconomicbenefit.Inthisstudy,anovelsystemcouplinganup-flowanaerobicsludgebed(UASB)andsequencingbatchreactor(SBR)isdevelopedfororganicandnitrogenremovalfromleachate.ThemainfunctionoftheUASBistoimproveCODandTNremovalthroughSDM.TheSBRisoperatedunderaerobic/anoxicmodetoachieveidealperfor-mancefornitrogenremovalvianitritation–denitritation.Further-more,batchexperimentsareconductedtodeterminethekineticmodelforheterotrophicdenitritation.2.MaterialsandMethods2.1.ReactorandoperationFig.1showstheexperimentalsystemwithanUASBandaSBR.TherawleachatesortedinthefeedtankwasusedastheinfluentofUASB.Anequalizationtankwasdesignedtomeettherequirementofcontinu-ouseffluentofUASBandintermittentinfluentofSBR,withleachateintheequalizationtankutilizedastheinfluentofSBR.Theworkingvol-umeofUASBandSBRwas3Land12L,respectively,whichismadeofpolymethylmethacrylate.FortheSBR,dissolvedoxygen(DO)andpHChineseJournalofChemicalEngineering23(2015)1047–1051☆SupportedbytheNationalNaturalScienceFoundationofChina(51168028,51168027)andScienceandTechniqueFoundationProjectforYouthofGansuProvince(1107RJYA279).⁎Correspondingauthor.E-mailaddress:[e-mail](H.Sun).©2015TheChemicalIndustryandEngineeringSocietyofChina,andChemicalIndustryPress.Allrightsreserved.ContentslistsavailableatScienceDirectChineseJournalofChemicalEngineeringjournalhomepage:(30±2)°CfortheUASB,whiletheSBRreactorwasoperatedatambienttemperatureof(20.5–31.4)°C.NitrifiedsupernatantintheSBRwasreturnedtotheUASBfordenitrificationwith300%ofrecirculationflowratio.Inaddition,hydraulicretentiontimeoftheUASBwas24h.TheSBRhadacycletimeof12h,with8haerobic,0.5hsettling,0.5hSNSrecycling,2hanoxic,0.5hsettling,and0.5hdecantingperiods.Theexchangevolumetricratewas50%.2.2.LandfillleachateRawle