生物活性炭滤池细菌致病风险分析与控制措施研究

硕士学位论文生物活性炭滤池细菌致病风险分析与控制措施研究RESEARCHOFPATHOGENRISKANALYSISANDCONTROLMEASURESINBACFILTER李拓哈尔滨工业大学2011年12月国内图书分类号：X172学校代码：10213国际图书分类号：606密级：公开工学硕士学位论文生物活性炭滤池细菌致病风险分析与控制措施研究硕士研究生：李拓导师：张金松教授申请学位：工学硕士学科：市政工程所在单位：深圳研究生院答辩日期：2011年12月授予学位单位：哈尔滨工业大学ClassifiedIndex:X172U.D.C:606ThesisfortheMasterDegreeinEngineeringRESEARCHOFPATHOGENRISKANALYSISANDCONTROLMEASURESINBACFILTERCandidate：TuoLiSupervisor：Prof.JinsongZhangAcademicDegreeAppliedfor：MasterofEngineeringSpeciality：MunicipalEngineeringAffiliation：ShenzhenGraduateSchoolDateofDefence：December,2011Degree-Conferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学工学硕士学位论文-I-摘要本文在对生物活性炭滤池进行细菌泄露风险分析的基础上，研究了代表性病原菌在生物活性炭滤池中的迁移特征，进行了病原菌灭活控制研究，并通过中试与生产性试验，提出了控制生物活性炭滤池细菌泄露风险的工艺改进与运行优化措施。通过连续监测研究了生物活性炭滤池细菌泄露的短期与长期风险。结果表明，生物活性炭滤池出水细菌总数与进水细菌总数及水温显著相关。水温升高时泄露风险增大，出水大于104CFU/mL的泄露峰值中有91%出现在水温高于25℃的时段。在滤池出水中检出两种条件致病菌，其中铜绿假单胞菌检出频繁，在出水中的比例最高为1.44%，生物活性炭滤池有潜在的病原风险。选取铜绿假单胞杆菌、伤寒沙门氏菌与肠出血性大肠杆菌O157:H7三种代表性病原菌为试验菌种。通过冲击性病原污染中试试验，得出三种病原菌在滤池内的衰减速率分别为0.14log/day、0.33log/day与0.31log/day。伤寒沙门氏菌、肠出血性大肠杆菌O157:H7在污染24h内的泄露风险高；铜绿假单胞杆菌在滤池中出现沿炭床深度迁移的现象，具有持续泄露风险。病原菌可被无脊椎摄食携带而穿透滤池，携带量与无脊椎动物个体大小成正比。剑水蚤在污染72h内其体内携带三种病原菌的数量分别达到10.37CFU/ind、66.67CFU/ind、26.67CFU/ind。在240h出水轮虫体内仍能检测出病原菌，具有持续风险。控制生物活性炭滤池出水无脊椎动物的数量，是控制滤池出水病原菌风险的有效措施。对病原菌进行灭活控制小试研究，加氯灭活滤池出水中的铜绿假单胞杆菌、伤寒沙门氏菌与肠出血性大肠杆菌O157:H7，泄露初期灭活率达4log时的CT值分别为15mg·min/L、10mg·min/L与10mg·min/L。对附着在炭滤料表面的代表性病原菌加氯灭活，泄露初期灭活率达4log时的CT值分别为75mg·min/L、45mg·min/L与45mg·min/L。为保障出水安全，应采取生物活性炭滤池加氯反冲与出水消毒强化的联合手段控制病原菌风险。通过生产性试验研究，预氧化单元对生物活性炭滤池进水微生物风险控制起重要作用。在单纯预氯化工况条件下，主臭氧的停止投加会增大病原菌进入生物活性炭滤池的风险。添加粒径为0.4~0.8mm高度为500mm的石英砂垫，可在高水温阶段能削减出水细菌总数峰值67.68%，从而有效地控制细菌大量泄露风险。关键词：病原菌；微生物风险；生物活性炭滤池；迁移特征；风险控制哈尔滨工业大学工学硕士学位论文-II-AbstractOnthebasisofmicrobialriskanalysisinozonationbiologicallyactivatedcarbon(BAC)filters,thecharacteristicsstudyofrepresentativebacteriapathogenicmigrationinBACfilterisdoneinthispaper.Andthecontrolmeasuresofpathogenicbacterialeakisstudiedtoo.Throughthepilotandproductiveexperiment,theprocessimprovementandoperationoptimizationmeasureswereputforwardtocontrolthebacterialeakrisk.Throughthecontinuousmonitoring，thebacterialeakriskinshort-termandlong-termwerebothstudied.TheresultsshowedthatthetotalbacterialcountinBACfilter’soutletweresignificantcorrelatedwithwatertemperatureandinlet’stotalbacterialcount.Theleakriskincreasedwhenwatertemperatureincreased,91%oftheleakpeaksmorethan104cfu/mLappearedintheperiodthatwatertemperatureabove25°C.TwoopportunisticpathogenswerecheckedoutinBACfilter’seffluentPseudomonasAeruginosaappearedfrequentlyineffluentandit’sratiowasupto1.44%.TherearepotentialpathogenrisksoftheBACfilter.Threekindsofpathogen,PseudomonasAeruginosa,SalmonellaTyphoidBacillus,andEnterohemorrhageEcoliO157:H7wereselectedasrepresentativepathogen.Throughthepathogensimpactoutbreakpilottest，theattenuationrateofthesepathogensinBACfilterwere0.14log/day,0.33log/dayand0.31log/day.TheleakriskofSalmonellaTyphoidbacillusandEnterohemorrhageEcoliO157:H7in24hwasatthighlevel.PseudomonasAeruginosainBACfilterappearedobviouslymigrationalongthecarbonlayerdepth.Thepathogencouldbefoodofinvertebratesandcarrythroughtheirbody.Biggerthevolumeofinvertebrates,themoreofthepathogencarried.PathogencarriedbyMesocyclopsthermocyclopoidesin72hrespectively,were10.37CFU/ind,66.67CFU/ind,and26.67CFU/ind.Rotiferacancarrysmallnumberofpathogenicbacteriain240h,alsohavecontinuedrisk.Therefore,controlthenumberofinvertebratesoutlet,iseffectivemeasuretocontroltheriskofpathogen.ChlorinewasaddedtodisinfectPseudomonasAeruginosa,SalmonellaTyphoidbacillus,EnterohemorrhageEcoliO157:H7inthewater.TheCTvalueforpathogensininitialleakstagetobeinactivatedto4logrespectively,were15mg·min/L,10mg·min/Land10mg·min/L.Chlorinewasaddedtoinactivated哈尔滨工业大学工学硕士学位论文-III-representativepathogensadheretotheBACcarbonfiltermaterialsurface.TheCTvalueforpathogensininitialleakstagetobeinactivatedto4log,respectively,were75mg·min/L,45mg·min/Land45mg·min/L.Therefore,tocontrolthepathogenriskseffectively,backwashwithchlorineshouldbeusedwhenchlorinewasaddedtostrengthenwaterdisinfection.Theproductiveexperimentresultsindicatethatthepre-oxidationunitplaysanveryimportantroleforcontroltheinfluentmicrobialrisk.Butinthepurepre-chlorinatedworkingcondition,theozoneunitstopandcanleadtoBACfilterinletbacteriaincreased,whichincreasestheriskofpathogenicbacteriaintoBACfilter.67.68%oftotalbacterialcount’speakcanbecutwhen500mmquartzsandpadwhichparticlesizeof0.4~0.8mmwasadded,andtherisksofbacterialeakcanbeeffectivelycontrolled.Keywords:pathogen,microbialrisk,BACfilter,migrationcharacteristics,riskcontrol哈尔滨工业大学工学硕士学位论文-IV-目录摘要...........................................................................................................................IAbstract.........................................................................................................................II第1章绪论.................................................................................................................11.1课题背景.........................................................................