6评估厌氧消化最佳稀释比

Assessmentofoptimumdilutionratioforbiohydrogenproductionbyanaerobicco-digestionofpressmudwithsewageandwaterB.Radjarama,⇑,R.Saravananeb,1aDepartmentofCivilEngineering,PondicherryEngineeringCollege,Puducherry605014,IndiabEnvironmentalEngineeringLaboratory,DepartmentofCivilEngineering,PondicherryEngineeringCollege,Puducherry605014,IndiaarticleinfoArticlehistory:Received21March2010Receivedinrevisedform16November2010Accepted17November2010Availableonline26November2010Keywords:PressmudSewageUASBBiohydrogenCo-digestionabstractAnaerobicco-digestionofpressmudwithwaterorsewageatratiosof1:7.5,1:10and1:12.5wereper-formedincontinuouslyfedUASBreactorsforhydrogenproduction.Ataconstanthydraulicretentiontimeof30h,thespecifichydrogenproductionratewas187mL/gvolatilesolids(VS)reducedduringmax-imumbiohydrogenproductionof7960mL/dayata1:10ratioofpressmudtosewage.Chemicaloxygendemand(COD)andVSreductionsof61%and59%werenotedonpeakbiohydrogenyield.ApHrangeof5–6wassuitableatambienttemperatureforentireprocess;alowerpHwasinhibitory.Co-digestionofacidicpressmudwithsewagecontrolledpHforfermentation.Hencepressmudcanbeexploitedforbio-hydrogenproduction.�2010ElsevierLtd.Allrightsreserved.1.IntroductionHydrogenisapromisingalternativetocarbon-basedfuelsbe-causeitisclean,renewableandhasahighenergyyieldof122kJ/g(ChangandLin,2004).Atpresent,hydrogenisproducedmainlyfromfossilfuels,biomassandwaterusingchemicalorbio-logicalprocesses.Onesuchbiologicalprocessisanaerobichydro-genfermentationwhichcanutilizehighlyconcentratedorganicwastewaterandbiomass,suchasmunicipalsolidwastesandsew-agesludgeasrawmaterial(DasandVeziroglu,2001).Pressmudisanotherpotentialwastesourceforhydrogenproduction.About4%ofcrushedsugarcaneisconvertedtopressmud,andannuallyabout4.2milliontonsofpressmudisavailablefromthesugarindustryinIndia(SaravananeandRadjaram,1998).Itisanacidic,thusmildlycorrosive,compressedfibrouswastethatcontains5–15%sugar(ParthaandSivasubramanium,2006)and84%isbio-degradable.Earlierstudiesonpressmudexaminedthefeasibilityof