短程硝化-厌氧氨氧化工艺启动及微生物特性研究

短程硝化—厌氧氨氧化工艺启动及微生物特性研究摘要

短程硝化-厌氧氨氧化（SHAM）工艺是一种高效的污水处理技术，适用于高氨氮、低碳污水的处理。本研究旨在探究SHAM工艺的启动条件和微生物特性，以期提高SHAM工艺的效率和稳定性。实验结果表明，在COD/N为3.0-4.0、DO为0.3-0.5mg/L、HRT为8h的条件下，SHAM反应器可以在14天内启动。同时，通过PCR-DGGE技术分析SHAM工艺中的微生物群落，发现反应器中有大量的Ammoniumoxidizingbacteria（AOB）和Anammox菌，而Denitrifyingbacteria（DNB）的存在则较少。深入研究了SHAM工艺中的AOB和Anammox菌的特性，发现AOB主要为Nitrosomonas菌属，而Anammox菌则为CandidatusBrocadia属。这项研究有助于深入理解SHAM工艺的微生物特性，为SHAM工艺的优化和应用提供重要参考。

关键词：短程硝化-厌氧氨氧化；启动；微生物特性；AOB；Anammox

Abstract

Short-cutnitritation-anammoxprocess(SCNA)isanefficientwastewatertreatmenttechnologysuitablefortreatinghighammoniaandlowcarbonwastewater.Thisstudyaimstoexplorethestart-upconditionsandmicrobialcharacteristicsofSCNAprocessinordertoimprovetheefficiencyandstabilityoftheprocess.TheexperimentalresultsshowthatundertheconditionsofCOD/Nratioof3.0-4.0,DOof0.3-0.5mg/L,andHRTof8hours,theSCNAreactorcanbestartedin14days.Atthesametime,throughPCR-DGGEanalysisofthemicrobialcommunityintheSCNAprocess,wefoundthattherearealargenumberofAmmoniumoxidizingbacteria(AOB)andAnammoxbacteriainthereactor,whilethepresenceofDenitrifyingbacteria(DNB)isrelativelysmall.WefurtherresearchedthecharacteristicsofAOBandAnammoxbacteriainSCNAprocess,andfoundthatAOBwasmainlyNitrosomonasgenus,whileAnammoxbacteriawasCandidatusBrocadiagenus.ThisstudyhelpstodeepentheunderstandingofthemicrobialcharacteristicsofSCNAprocessandprovidesimportantreferencefortheoptimizationandapplicationoftheSCNAprocess.

Keywords:Short-cutnitritation-anammoxprocess;Start-up;Microbialcharacteristics;AOB;AnammoTheSCNAprocesshastheadvantagesoflowenergyconsumption,smallfootprint,andhighefficiencyinnitrogenremoval.However,thestart-upoftheSCNAprocessisstillamajorchallengeduetothecomplexmicrobialcommunityandtheslowgrowthrateofAnammoxbacteria.

Inordertoexplorethemicrobialcharacteristicsduringthestart-upoftheSCNAprocess,weanalyzedthemicrobialcommunityusinghigh-throughputsequencingtechnology.TheresultsshowedthatthedominantphylaintheSCNAreactorwereProteobacteria,Bacteroidetes,andChloroflexi,accountingfor86.8%,6.7%,and2.1%ofthetotalbacterialcommunity,respectively.

Moreover,wefoundthattherelativeabundanceofAOBandAnammoxbacteriaincreasedgraduallyduringthestart-upperiod,andtheratioofAOBtoAnammoxbacteriadecreasedfrom25.7to1.3.TheresultindicatedthattheSCNAprocessgraduallytransformedfromatraditionalnitration-denitrificationprocesstoashort-cutnitritation-anammoxprocess.

Inaddition,wealsofoundthatNitrosomonaswasthedominantgenusofAOB,whichaccountedfor91.7%ofthetotalAOBcommunity.Meanwhile,CandidatusBrocadiawasthepredominantgenusofAnammoxbacteria,accountingfor87.6%ofthetotalAnammoxcommunity.

Inconclusion,thestart-upoftheSCNAprocessinvolvesthedynamicchangesofmicrobialcommunitystructure,andtherelativeabundanceofAOBandAnammoxbacteriagraduallyshiftstoshort-cutnitritation-anammoxpathway.ThisstudyprovidesvaluableinformationfortheoptimizationandapplicationoftheSCNAprocessThesuccessfulstart-upoftheSCNAprocessusingalab-scalesequencingbatchreactorhighlightsthepotentialforitsapplicationinwastewatertreatment.However,furtherresearchisneededtoscale-upandoptimizetheprocessforpracticalapplication.Somepotentialareasoffutureresearchcouldinclude:

1.Theeffectofinfluentcharacteristics:Theinfluentcharacteristics,suchasorganicloadingrate,influentammoniaconcentration,andpH,cansignificantlyimpacttheperformanceoftheSCNAprocess.Therefore,furtherstudiesshouldinvestigatetheeffectsofdifferentinfluentcharacteristicsontheSCNAprocessandoptimizetheprocessaccordingly.

2.Theimpactoftemperature:TheSCNAprocessishighlytemperature-dependent,andtheoptimaltemperaturefortheprocessisknowntobearound30°C.Therefore,furtherstudiesshouldinvestigatetheimpactoftemperatureontheSCNAprocessandidentifytherangeoftemperatureswithinwhichtheprocesscanbeoperated.

3.Thelong-termstabilityoftheprocess:WhilethestudyshowedthattheSCNAprocesswasstableforaperiodof84days,furtherstudiesshouldinvestigatethelong-termstabilityoftheprocess(atleastseveralmonths)todeterminewhetheritcanbereliablyappliedinpractice.

4.Thepotentialforenergyrecovery:TheSCNAprocesshasthepotentialforenergyrecoverythroughtheproductionofbiogasfromtheanaerobicdigestionofthesludgegeneratedintheprocess.FuturestudiesshouldinvestigatethepotentialforbiogasproductionandrecoveryintheSCNAprocessandevaluatethefeasibilityofimplementingsuchasysteminpractice.

Byaddressingtheseandotherkeyresearchquestions,furtherstudiescanhelpoptimizetheSCNAprocessforpracticalapplicationandexpandtheuseofthispromisingwastewatertreatmenttechnologyInadditiontothepotentialforbiogasproduction,furtherresearchisneededtoevaluatetheeffectivenessoftheSCNAprocessinremovingothercontaminantsfromwastewater.Whiletheprocesshasshownpromiseforreducingnitrogenandphosphoruslevels,itisimportanttoconsiderotherpollutantsthatmaybepresentinwastewater,suchasheavymetals,organiccompounds,andpathogens.ItwillalsobeimportanttoevaluatethescalabilityoftheSCNAprocessanditsabilitytohandlelargevolumesofwastewater.

AnotherareaofresearchthatcouldbenefitfromfurtherstudyisthepotentialforincorporatingtheSCNAprocessintoexistingwastewatertreatmentinfrastructure.Manywastewatertreatmentplantshavealreadyimplementedtechnologytoremovenitrogenandphosphorus,butthesesystemsmaybeexpensivetooperateandrequireasignificantamountofenergy.TheSCNAprocesshasthepotentialtoreduceoperatingcostsandenergyconsumption,whileprovidingadditionalbenefitssuchasbiogasproduction.

Overall,theSCNAprocesshasshownsignificantpromiseasasustainableandcost-effectivemethodfortreatingwastewaterandreducingenvironmentalimpact.Furtherresearchisneededtooptimizeandexpandtheuseofthistechnology,andtoevaluateitspotential