Threecontrollab省略ofEGSBreactor李慧莉

JournalofHarbinInstituteofTechnology(NewSeries),Vol.15,No.3,2008ThreecontrollablefactorsofsteadyoperationofEGSBreactorLIHui-li1,LUBing-nan1,LIFang2李慧莉,　　吕炳南,　李　芳　(1.SchoolofMunicipalandEnvironmentalEngineering,HarbinInstituteofTechnology,Harbin150090,China,E-mail:[e-mail];2.SchoolofArchitectureEngineering,DaqingPetroleumInstitute,Daqing163318,China)Abstract:Thebench-scaleEGSB(expandedgranularsludgebed)reactorwasoperatedtostudytheeffectofsludgeloadingrate,pHvalueandnutrientelementontheoperationoftheEGSBreactorandthecontrolruleofthesefactors.Continuousflowwasusedtotreatsyntheticwastewatercontainingdextroseandbeer,andthetem-peratureofreactorwascontrolledatmesophilestemperature(33℃).Theexperimentalresultsdemonstratedthatthepropersludgeloadingratewas0.9-1.42kgCOD/(kgVSS·d);thepHvalueinthereactorwascon-trolledbyaddingsodiumbicarbonate,theproperadditivequantitywas1000-1200mg/L;theadditivequantityofnutrientelementwasasfollows:41.3mg/(SS·d)ofFeCl2·4H2O,4.3mg/(SS·d)ofCoCl2·6H2O,8.2mg/(SS·d)ofNiCl2·6H2O,7.5-13mg/(SS·d)ofCaCO3,and56.7-22.7mg/(SS·d)of7Na2S·9H2O,respectively.Whentheseparameterswereproperlydetermined,theEGSBreactorcouldtreatwastewaterwith400-5000mg/LCODconcentration.TheCODremovalefficiencywasover85%.Theopera-tionoftheEGSBreactorwassteadyandtheEGSBreactorhadstronganti-shockloadability.Keywords:EGSBreactor;organicloadingrate;pHvalue;nutrientelementCLCnumber:X703.1　　　Documentcode:A　　　　ArticleID:1005-9113(2008)03-0411-04　　ExpandedGranularSludgeBedwasdevelopedbyWageingenAgricultureUniversityinHollandatthebe-ginningof1990.Thetechniquewasconcreteapplicationofsolid-flowedtechniqueontreatingwithorganicwastewater.TheEGSBhadtheadvantageoftheUASBreactorandtheAFBreactorasretaininghighsludgeconcentration,highsludge-liquidcontact,mixefficiencyandhighorganicloadingrate.TheEGSBreactorwasusedtotreatnotonlyorganicwastewaterwithhighcon-centrationbutalsoorganicwastewaterwithmoderateandlowconcentration.Thehighefficientanaerobicbioreac-torisprospectiveinwastewatertreatmentfield[1-3].ThestudyandapplicationoftheEGSBreactorwasmainlyinEurope,thepracticalapplicationwasrareinChina[10].Thebench-scaleExpandedGranularSludgeBedreactorwasoperatedtostudytheinfluencingfac-torsoftheoperationalEGSBreactorandthecontrollingrule,whichprovidedtheoreticalbasisforthefutureen-gineeringapplication.1　MaterialsandMethods1.1　ExperimentalSet-upFig.1showsaschematicdiagramoftheexperi-mentalapparatusconsistingofaPlexiglasreactor.TheEGSBreactorhasaninternaldiameterof90mmwithaheightof1.6mandatotalvolumeof12.5L(including10Lreactionregion).ThemethanegaswascollectedbyMariottebottle.Thereactortemperaturewaskeptat33±1℃byheatinginfluentandrecycleeffluent,andmaterialofheatpreservationwasusedoutofreactor.1.Recycleeffluenttank;2.Waterbathe;3.Influentwatertank;4.Peri-stalticpump;5.Adjustvalve;6.Threephaseseparator;7.Mariottebottle;8.Measuringcylinder;9.Smallgranulesludge;10.Biggranulesludge;11-13.Samplingtube1-3;14.Materialofheatpreservation;15.EGSBreactorFig.1　SchematicdiagramoftheEGSBreactor1.2　InoculaThereactorwasinoculatedwithgranularsludgefromabench-scalereactortreatingsyntheticwastewater.Theinitialgranuleconcentrationwas25.5gVSS/L.Thedensity,maximumspecificmetha-nogenicactivityandVSS/SSoftheseedsludgewereReceived2006-06-06.SponsoredbytheNationalHighTechnologyResearchandDevelopmentProgramofChina(GrantNo.2003AA601090).·411·JournalofHarbinInstituteofTechnology(NewSeries),Vol.15,No.3,20081045kg/m3,1.48gCODCH4/(gVSS·d),0.66,re-spectively.1.3　FeedCompositionAsyntheticwastewaterwasusedtosimulatethecompositionofbeerwastewater.Thecompositionofthesyntheticwastewaterwasasfollowing:thecarbon,theni-trogenandthephosphorussourceofinfluentweredex-troseandbeer,NH4ClandKH2PO4,theratioofCOD∶N∶Pwas100∶3∶1;macronutrientsandmicronutri-entswereNa2S·9H2O,FeCl2·4H2O,CoCl2·6H2O,NiCl2·6H2O,theratioofS∶P,S∶Fe2+,Fe2+∶Co2+∶Ni2+was1∶2,3∶1,and10∶1∶2,respectively.Atthesametime,NaHCO3wasaddedconsistentlytomaintainproperpHat6.0-8.0andbufferingcapacities.YeastgreaseandCaCO3orCaCl2[5]wasaddedforpromotingMethanogenicactivityandgranulatingofsludge.1.4　AnalysisThesolublechemicaloxygendemand(COD),to-talsuspendedsolids(TSS)andvolatilesuspendedsol-ids(VSS)weredeterminedaccordingtostandardmethods[3].Alkalinityandvolatilefattyacids(VFA)weremeasuredbyalkalinitytwo-steptitrationmethodswithapHS-3CpH/mvmeter[4].2　ResultsandDiscussion2.1　SludgeLoadingRate2.1.1　ExperimentalprocedureTheexperimentincludedfourperiods.Thevola-tilesuspendedsolids(VSS),sludgeloadingrate(SLR),volumeloadingrate(VLR)andtheinfluentofCODweredifferentineachperiod.TheoperationalparameterswereshowninTab.1.Tab.1　ParameterofdifferentperiodsperioddInitialVSSgVSS·L-1SLRkgCOD·(kgVSS·d)-1VLRkgCOD·(m3·d)-1CODmg·L-1EndingVSSgVSS·L-1Ⅰ-2325.50.5-0.96.2-13.1393-136717.5Ⅱ-1917.50.9-1.426.4-34.2393-569626.4Ⅲ-1817.71.42-2.012.1-20.91689-334922.9Ⅳ-1528.92.0-2.519.4-34.03989-534320.72.1.2　DiscussionandresultTheexperimentalresultwasindicatedthattheEGSBreactorcouldbare0.5-2.5kgCOD/(kgVSS·d)sludgeloadingrate.WhenSLRwaslessthan0.5kgCOD/(kgVSS·d),microbewa