含盐生活污水处理中的硝化菌种群优化英文叶柳

46320105ActaScientiarumNaturaliumUniversitatisPekinensisVol.46No.3May2010“”2006BAC19B03PHR200905022009-10-202009-12-14NitrifyingPopulationOptimizationinMunicipalSalineWastewaterTreatmentYELiuWANGShuyingZHAOKaifengPENGYongzhenCollegeofEnvironmentalandEnergyEngineeringBeijingUniversityofTechnologyBeijing100124[e-mail]@bjut.edu.cnAbstractAsludgepopulationoptimizationstrategyaimstoselecttheammoniaoxidationbacteriaAOBbyusingsodiumchlorideNaClasaselectiveinhibitortonitriteoxidationbacteriaNOBisappliedinbiologicalnitrogenremovalprocessduringmunicipalwastewatertreatmentusingasequencingbatchreactorSBR.Differentsalinitytestscontributedtothebestinhibitionsalinitychosenwereapplied.Inordertooptimizenitrifyingmicrobialcommunitiestogetsteadynitritepathway7.6g/Lsalinityand4monthsaltinhibitionperiodwereapplied.FISHanalysisindicatedthatAOBNitrosospirabecamethedominantnitrifyingbacteriaandNOBNitrobacterhadbeenwashedoutoftheactivatedsludge.AnunderstandingofsaltinhibitionmechanismonNOBisalsodiscussed.Keywordsnitrifyingpopulationoptimizationsaltinhibitionnitrogenremovalvianitritemunicipalsalinewastewaterinhibitionmechanism100124[e-mail]@bjut.edu.cnNaClNOBAOB。AOBNOB7.6g/L。495%。FISHAOBNitrosospiraNOBNitrobacterNOB。NOB。X703BiologicalnitrogenremovalBNRbasedonutilizingthefunctionofcertainactivesludgetoremovethetargetpollutanthasbeenusedworldwide.Sludgepopulationoptimizationstrategyaimstoselectthemostdesirableorganismoraconsortiumoforganismtoperformarequiredfunctionwhichisparticularlyimportantfornitrificationoneofthemostimportantanddelicatestepsinmodernwastewatertreatmentplants1.FacedtotheenergycrisisthenitrogenremovalthroughthenitritepathwayNH+4-NO－2-N2ispreferredinmanyoftheplantsforthesignificantlyenergysaving2.Theshot-cutnitrogenremovalhasbeensuccessfullyachievedforvarioustypesofwastewatersinthelastfewyears3-7.TheprincipleistoeliminatenitriteoxidizingbacteriaNOBandmakeammoniaoxidizingbacteriaAOBbethedominantpopulationofnitrifiersinnitrification.Howeverit224DOI10.13209/j.0479-8023.2010.0623shouldtakeasubstantialtimeintheorderofyearstocompletelyremovetheNOBusingon-lineaerobicdurationcontrolorothercontrolasthesoleselectionfactorunlessanNOBinhibitorisused8.SaltaneconomicalselectiveinhibitortoNOBratherthanAOBissuggestedbyCuietal.9andYeetal.10toachievenitritepathwayquicklyinBNRprocess.SalinewastewaterrichinbothsaltmainlyNaClandorganicmatterareoftengeneratedduringthemanufactureofchemicalsandoilandgasrecoveryoperationsprofessionallyknownasproducedwatersandcaneasilyreachintowastewaterbymanymeans11.Inadditiontohypersaline-producedwaterproblemsusingseawaterinthesituationswhichhighqualitywaterisnotessentialsuchastoiletflushingalsopromotetogeneratelotsofsalinewastewaters.Anumberofresearches12-13haveprovedthatcertainconcentrationsalinityininfluentcouldstronglyinhibitthemetabolismoffunctionalbacteriaandcauseafailuretolocalwastewatertreatmentplantWWTP.Neverthelesstherearesignificantgapsinthecurrentknowledgeespeciallyontheunderstandingofthesaltinhibitionmechanismonnitrifiersandhowtooptimizenitrifyingpopulationinsalinewastewatertreatmentprocess.WithoutconsideringtheadverseeffectofsodiumchlorideNaClthisworkpaysmoreattentiononhowtoutilizethenaturalsaltinseawater.ThisstudyaimedtoutilizeNaClthemainlysaltinseawaterselectivelyinhibitedNOBbutnotAOBtooptimizethenitrifyingpopulationbyalongperiodoftimeandnitritepathwaycouldberapidlyachievedduringbiologicalnitrification/denitrificationprocess.Bothbatchandlong-termexperimentsarecarriedoutinthisstudy.Differentsalinitytestscontributedtothebestinhibitionsalinitychosenandtheunderstandingofmechanismofsaltinhibitiontonitrifyingcommunitieswereappliedinthisstudy.ThefluorescenceinsituhybridizationFISHmethodwasperformedtomonitorthequantitativechangesofnitrifyingmicrobialcommunitiesintheactivatedsludgeduringandaftersaltinhibitionperiods.InthemeanwhilethemechanismofsaltinhibitiononNOBwasalsodiscussed.1MaterialsandMethods1.1ReactoroperationandmunicipalsalinewastewaterAbench-scalesequencingbatchreactorSBRwasinoculatedwithsludgefromafull-scaledomestictreatmentplantinBeijing.Thereactorhadaworkingvolumeof10L.Thecycletimewas12hwhichconsistedofapproximately7haerobic3hanoxicand2hsettle/decantperiods.Constantaerationwasappliedduringtheaerobicperiod.SupplementaryexternalcarbonsourceacetateNaAcwasaddedatthebeginningofanoxicphasestoachievedenitrification.ThehydraulicretentiontimeHRTwas24h.ThemixedliquorsuspendedsolidsMLSSwaskeptatalevelofapproximately2.5g/L.ThesludgeretentiontimeSRTwascontrolledatabout15days.ThewastewaterwascollectedfromawetwelllocatedintheBeijingUniversityofTechnologyonadailybasis.TheinfluentcharacteristicsarelistedinTable1.CommercialcrudeNaClsaltisaddedintostoragetanktoformsalinesewageasSBRfeedduringachievingnitritebuild-up.Thesalinityisadjustedaccordingtoexperimentdesign.TheactivatedsludgeASforSBRAisdeliveredinitiallyfromthelocalWWTPreturnactivatedsludgeline.1.2ExperimentdesignFeededbythefreshsewagesludgeisacclimatedtogetcompletenitrificatio