污水处理的英文文献中英文翻译.docx

污水处理的英文文献中英文翻译.docx

《污水处理的英文文献中英文翻译.docx》由会员分享，可在线阅读，更多相关《污水处理的英文文献中英文翻译.docx（25页珍藏版）》请在冰豆网上搜索。

NutrientremovalinanA2O-MBRreactorwithsludgereduction

ABSTRACT

Inthepresentstudy,anadvancedsewagetreatmentprocesshasbeendevelopedbyincorporatingexcesssludgereductionandphosphorousrecoveryinanA2O-MBRprocess.TheA2O-MBRreactorwasoperatedatafluxof77LMHoveraperiodof270days.Thedesignedfluxwasincreasedstepwiseoveraperiodoftwoweeks.ThereactorwasoperatedattwodifferentMLSSrange.ThermochemicaldigestionofsludgewascarriedoutatafixedpH（11）andtemperature（75℃）for25%CODsolubilisation.Thereleasedpbospborouswasrecoveredbyprecipitationprocessandtheorganicswassentbacktoanoxictank.ThesludgedigestiondidnothaveanyimpactonCODandTPremovalefficiencyofthereactor.Duringthe270daysofreactoroperation,theMBRmaintainedrelativelyconstanttransmembranepressure.Theresultsbasedonthestudyindicatedthattheproposedprocessconfigurationhaspotentialtoreducetheexcesssludgeproductionaswellasitdidn'tdetonatedthetreatedwaterquality.

Keywords:

A2Oreactor; MBR; Nutrientremoval; TMP

1.Introduction

Excesssludgereductionandnutrientsremovalarethetwoimportantproblemsassociatedwithwastewatertreatmentplant.MBRprocesshasbeenknownasaprocesswithrelativelyhighdecayrateandlesssludgeproductionduetomuchlongersludgeageinthereactor（Wen

etal.,2004）.SludgeproductioninMBRisreducedby28-68%,dependingonthesludgeageused（Xiaetal.,

2008）.However,minimizingthesludgeproductionbyincreasingsludgeageislimitedduetothepotentialadverseeffectofhighMLSSconcentrationsonmembrane（Yoonetal.,2004）.ThisproblemcanbesolvedbyintroducingsludgedisintegrationtechniqueinMBR（Youngetal.,2007）.Sludgedisintegrationtechniqueshavebeenreportedtoenhancethebiodegradabilityofexcesssludge（VlyssidesandKarlis,2004）.Inoverall,thebasisforsludgereductionprocessesiseffectivecombinationofthemethodsforsludgedisintegrationandbiodegradationoftreatedsludge.Advancesinsludgedisintegrationtechniquesofferafewpromisingoptionsincludingultrasound（Guoetal.,2008）,pulsepower（Choietal.,2006）,ozone（Weemaesetal.,2000）,thermal（Kimetal.,2003）,alkaline（Lietal.,2008）acid（Kimetal.,2003）andthermochemical

（VlyssidesandKarlis,2004）.Amongthevariousdisintegrationtechniques,thermochemicalwasreportedtobesimpleandcosteffective（WeemaesandVerstraete,1998）.Inthermal-chemicalhydrolysis,alkalisodiumhydroxidewasfoundtobethemosteffectiveagentininducingcelllysis（Rockeretal.,1999）.

Conventionally,thenutrientremovalwascarriedoutinanA2Oprocess.Ithasadvantageofachieving,nutrientremovalalongwithorganiccompoundoxidationinasinglesludgeconfigurationusinglinkedreactorsinseries（Tchobanoglousetal.,2003）.Thephosphoroesremovalhappensbysubjectingphosphorousaccumulatingorganisms（PAO）bacteriaunderaerobicandanaerobicconditions（AkinandUgurlu,2004）.TheseoperatingproceduresenhancepredominancePAO,whichareabletouptakephosphorousinexcess.Duringthesludgepretreatmentprocessestheboundphosphorouswassolubilisedanditincreasesthephosphorous

concentrationintheeffluentstream（Nishimura,2001）.So,itisnecessarytoremovethesolubilisedphosphorusbeforeitentersintomainstream.Besides,thereisagrowingdemandforthesustainablephosphorousresourcesintheindustrializedworld.Inmanydevelopedcountries,researchesarecurrentlyunderwaytorecoverthephosphoroesboundinthesludge'sofenhancedbiologicalphosphorusremovalsystem（EBPR）.Thereleasedphosphorouscanberecoveredinusableproductsusingcalciumsaltsprecipitationmethod.Keepingthisfactinmind,inthepresentstudy,anewadvancedwastewatertreatmentprocessisdevelopedbyintegratingthreeprocesses,whichare:

（a）thermochemicalpretreatmentinMBRforexcesssludgereduction（b）A2Oprocessforbiologicalnutrientremoval（c）Precoverythroughcalciumsaltprecipitation.Theexperimentaldataobtainedwerethenusedtoevaluatetheperformanceofthisintegratedsystem.

2.Methods

2.1.Wastewater

Thesyntheticdomesticwastewaterwasusedastheexperimentalinfluent.Itwasbasicallycomposedofamixedcarbonsource,macronutrients（NandP）,analkalinitycontrol（NaHCO3）andamicroelementsolution.Thecompositioncontained（/L）210mgglucose,200mgNH4C1,220mgNaHCO3,22一34mgKH2PO4,microelementsolution（0.19mgMnCl24H20,0.0018mgZnCl22H2O,

0.022mgCuCl22H2O,5.6mgMgSO47H2O,0.88mgFeCl36H2O,

1.3mgCaCl2·2H2O）.Thesyntheticwastewaterwaspreparedthreetimesaweekwithconcentrationsof210±1.5mg/Lchemicaloxygendemand（COD）,40±1mg/Ltotalnitrogen（TN）and5.5mg/Ltotal

phosphorus（TP）.

2.2.A2O-MBR

TheworkingvolumeoftheA2O-MBRwas83