CASS工艺在城市污水厂处理效能的研究

硕士学位论文CASS工艺在城市污水厂处理效能的研究STUDYONTREATMENTEFFICIENCYOFCASSPROCESSINURBANWASTEWATERTREATMENTPLANT张锋哈尔滨工业大学2012年7月国内图书分类号：TU992.3学校代码：10213国际图书分类号：628.3密级：公开工程硕士学位论文CASS工艺在城市污水厂处理效能的研究硕士研究生：张锋导师：李玉华教授副导师：史炎高级工程师申请学位：工程硕士学科：建筑与土木工程所在单位：市政环境工程学院答辩日期：2012年7月授予学位单位：哈尔滨工业大学ClassifiedIndex:TU992.3U.D.C:628.3StudyonTreatmentEfficiencyofCASSProcessinUrbanWastewaterTreatmentPlantSTUDYONTREATMENTEFFICIENCYOFCASSPROCESSINURBANWASTEWATERTREATMENTPLANTCandidate：ZhangFengSupervisor：Prof.LiYuhuaViceSupervisor：ShiYanAcademicDegreeAppliedfor：MasterofEngineeringSpeciality：ArchitectureandCivilEngineeringAffiliation：SchoolofMuni.&Env.EngDateofDefence:July,2012Degree-Conferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学工程硕士学位论文-I-摘要东北地区H市污水厂在2010年通过调试后，进入了正常运行状态。在接下来的运行过程中，由于上游某制药企业所排放的污水并未经过有效处理，原水的可生化性大大降低，出水水质严重恶化。为使得水厂出水水质达标，需要针对现有水质条件重新调试，并在此基础上，对CASS工艺处理效能的影响因素进行了一系列试验研究。通过实地调研工作发现，该污水厂的进出水主要存在如下问题：进水中污染物浓度波动较大，对CASS工艺造成了一定的冲击；进水中B/C平均值低于0.30，污水的可生化性较差；出水中除BOD5和氨氮基本达到出水设计标准以外，其余水质指标的出水浓度仍不达标。污泥的培养和驯化工作结束后，引入了化粪池污水来增加CASS池中的碳源，同时加大污泥回流比，调整运行周期为0.5h进水、3h曝气、0.5h搅拌、1h静沉和1h滗水。经过调整，出水水质全部达标。通过改变曝气时间、污泥回流比、碳氮比和充水比等运行参数，研究了以上各因素对CASS工艺处理效果的影响。试验结果表明：曝气时间的增加，有助于COD和氨氮的去除，而总氮和总磷的出水浓度随着曝气时间的延长，出现了不同幅度的上升；污泥回流比对总氮和总磷的去除影响较大，随着回流比的增加，硝化液回流量增大，脱氮作用得到加强的同时抑制了释磷过程，影响了总磷的去除；碳氮比对工艺的影响主要体现在脱氮作用上，当碳氮比增加至15.5时，硝化细菌的生长繁殖受到抑制，氨氮去除率明显下降，但足量的碳源促进了反硝化，提高了总氮的去除率；充水比的变化对各项污染物的去除并没有产生显著的影响。同时通过夏季与冬季出水水质的对比，发现温度较高时，微生物活性也相对较高，出水水质有一定程度的上升。最后针对该污水处理厂的实际情况和CASS工艺本身存在的缺陷，对CASS工艺的改造提出了两条建议：一种是仿照两段SBR法，将两套CASS工艺进行串联，强化有机物的去除和短程硝化反硝化作用；另一种即充分利用反硝化除磷技术，解除缺氧环境对聚磷菌过量摄磷的限制，实现缺氧环境下反硝化脱氮与反硝化除磷的有机结合。关键词：CASS；污水处理；影响因素；脱氮除磷哈尔滨工业大学工程硕士学位论文-II-AbstractThroughdebugging,certainurbanwastewatertreatmentplantgotintonormaloperationconditionintheyearof2010.Becauseofineffectivelytreatmentofwastewaterfrompharmaceuticalcompany,biodegradabilityofwastewaterreducesgreatly,whichresultsinseriousdeteriorationofeffluent.Toensurethisplantcangetcheckedandacceptedsmoothly,anewdebuggingwasimplemented.Andthenonthisbasis,studiesoninfluencefactorsofCASSprocesswerecarriedout.Byinvestigation,mainproblemsaffectedthequalityofeffluentwasfounded,suchaslargefluctuationofinfluentconcentrationofpollutants,theaverageofB/Clowerthan0.30,poorbiodegradabilityofwastewater,belowstandardqualityofmosteffluentindexes,etc.Byanalyzingcharacteristicsofinfluentquality,somecertainmeasuresweretakentosolveaboveproblemsaftercultivationandacclimationofactivatedsludge.Toincreasecarbonsource,septicsewagewasintroduced.Sludgereturnratiowasalsoincreased,atthesametime,runningperiodwaschangedto:influenttime0.5h,aerationtime3h,stirringtime0.5h,precipitationtime1handdecantationtime1h.Aftertheseadjustments,alltheindexesofeffluentqualityreachedthestandard,andthisplantfinallygotcheckedandaccepted.Changingdifferentoperationparameters,studiesoninfluencefactorsofCASSprocesswerecarriedout.Theresultsshowedthat,theincreaseofaerationtimeishelptotheremovalofCODandammonia,butnottototalnitrogenandphosphorus.Sludgereturnratiohasagreatimpactontheremovaloftotalnitrogenandphosphorus,andwithincreaseoftheratio,theamountofnitrificationliquidraised,theremovalofnitrogenwasstrengthened,butthingsweredifferenttotheremovalofphosphorus.C/Nmainlyaffectedtheremovaloftotalnitrogen,whenC/Nincreasedto15.5,growthandreproductionofnitrifyingbacteriawasrestricted,removalefficiencyofammoniadecreasedsignificantly,butbytheaddingofcarbonsource,denitrificationwasstrengthened,andtheremovalefficiencyoftotalnitrogengotincreased.Changesofthewaterfillingratiodidnotresultedinasignificantimpactontheprocessingperformance.Throughcomparisonofoperationdatabetweensummerandwinter,itindicatedthat,increaseoftemperatureimprovedthemicrobialactivityandtreatmenteffecttoacertainextent.DuetoactualsituationofthiswastewatertreatmentplantanddisadvantagesofCASSprocess,twotentativeplanswerecomeupwith.OneisimitationoftwostageSBR,maketwosetsofCASSprocesscombinedtogether,whichmayenhancetheremovaloforganicsandshortrangeofnitrificationanddenitrification.Theotheroneis哈尔滨工业大学工程硕士学位论文-III-totakefulladvantagesofdenitrifyingphosphorusremoval,andmakephosphorusuptakeunderhypoxicenvironmentpossible,whichcanachievethecombinationbetweendenitrificationandphosphorusremoval.Keywords:CASSprocess;wastewatertreatment;influencefactors;removalofnitrogenandphosphorus哈尔滨工业大学工程硕士学位论文-IV-目录摘要..........................................................................................................................IABSTRACT................................................................................................................II第1章绪论..............................................................................................................11.1课题背景及研究的目的和意义.....................................................................11.1.1课题背景.............................................................................................11.1.2课题来源.............................................................................................21.1.3课题研究的目的及意义......................................................................21