高浓度活性污泥曝气池脱氮除磷研究

硕士学位论文高浓度活性污泥曝气池脱氮除磷研究RESEARCHONNITROGENANDPHOSPHORUSREMOVALINANAERATIONTANKWITHHIGHACTIVATEDSLUDGE王阳哈尔滨工业大学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：628.356密级：公开工学硕士学位论文高浓度活性污泥曝气池脱氮除磷研究硕士研究生：王阳导师：张景成副教授申请学位：工学硕士学科：市政工程所在单位：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:628.356DissertationfortheMaster’sDegreeinEngineeringRESEARCHONNITROGENANDPHOSPHORUSREMOVALINANAERATIONTANKWITHHIGHACTIVATEDSLUDGECandidate：WangYangSupervisor：Assoc.Prof.ZhangJingchengAcademicDegreeAppliedfor：MasterofEngineeringSpeciality：MunicipalEngineeringAffiliation：SchoolofMuni.&Envir.Eng.DateofDefence：July,2012Degree-Conferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学工学硕士学位论文-I-摘要随着经济的发展和人们生活水平的提高，表面水体受到很严重的污染。氮磷是促使藻类以及其他进行光合作用的微生物生长的关键性营养物质，为了避免水体的富营养化必须将其从污水中去除。在全世界范围内，越来越多的人意识到控制氮磷排放的必要性，这也体现在日趋严格的排放标准上，因此人们在污水处理中增加了脱氮除磷功能。很多污水处理工艺正面临着如何提高脱氮除磷效果的难题。高浓度生物相曝气池不仅具有很好的脱氮除磷效果，还具有耗能少、产泥量低等优点，对其他污水处理厂的新建或改造具有很大的参考价值。高浓度生物相曝气池在低溶解氧，高污泥浓度下运行，在同一反应池中实现了脱氮除磷效果。大比例的混合液回流，使该曝气池兼具推流式和完全混合式的一些优点，整个流程中污染物质浓度梯度很小。高浓度生物相曝气池在低污泥负荷条件下运行，活性污泥中微生物处于内源呼吸期，污泥颗粒较小，在低溶解氧高污泥浓度下不会产生污泥膨胀现象，且产泥量低。溶解氧和污泥浓度对该系统影响很大，分析结果表明，溶解氧的增加对硝化作用和反硝化作用都起到促进作用，但是却抑制了除磷效果。高污泥浓度促进了脱氮除磷效果。当溶解氧控制在0.3~0.5mg/L，污泥浓度控制在6000~7000mg/L时，系统处理效果最佳。对CODCr、TN、TP的去除率分别达到92%、81%、97%，CODCr、TN、TP的平均出水浓度为26.54mg/L、8.63mg/L、0.12mg/L。该系统具有很好的抗冲击负荷能力，在水质水量波动较大时依然能保证出水水质达标排放。在冬季水温较低时，脱氮除磷效果依然很显著。关键词：低溶解氧；高浓度活性污泥；大比例混合液回流哈尔滨工业大学工学硕士学位论文-II-AbstractWiththedevelopmentofeconomyandimprovementofpeople’sliving,surfacewaterhasbeenseriouslypollutedinChina.Nitrogen(N)andphosphorys(P)arethekeynutrientsthatstimulatethegrowthofalgaeandotherphotosyntheticmicroorganisms,andmustberemovedfromwastewatertoavoideutrophicationinaquaticwatersystems.Aroundtheworld,agrowingawarenessoftheneedtocontrolNandPemissions,whichisreflectedinincreasinglystringentregulations,hasmadeNandPremovalwidelyemployedinwastewatertreatment.AgreatmanywastewatertreatmentplantshavetofacewiththeadvancedremovalofNandP.TheaerationtankwithhighbiomassconcentrationspromotestheremovalofNandPfromwastewaterwithlessenergyconsumptionandlowsludgeproduction,whichhasgreatreferencevaluefortheotherwastewatertreatmentplants.Theaerationtankrunningunderlowdissolvedoxygen(0.3~0.5mg/L)andhighmixedliquorsuspendedsolids(MLSS,5000~8000mg/L),hasachievedtheremovalofNandPinthesametime.Ithassomeadvantagesoftheplugflowandthecompletemixing,becauseofthehighinternalmixedliquorrecirculation.Thegradientofpollutantsisverylowalongtheflow.MicroorganismswillbeinhibitedintheconditionsoflowdissolvedoxygenandhighMLSS,growinglowlyinthetimeofendogenousrespiration.Asaresult，itwon’tappearthesludgebulkingphenomenon.DissolvedoxygenandMLSSdohaveagreatinfluenceonthesystem.Theresultsshowthattheincreaseinoxygensupplymightgiveapositiveeffectonnitrificationanddenitrification,butinhibitedtheremovalofP.ThehighMLSSenhancedtheremovalofNandP.TheaerationtankcangetthebestNandPremovalintheconditionswithdissolvedoxygen(0.3~0.5mg/L)andMLSS(6000~7000mg/L).TheaverageremovalratesofCODCr,TNandTPare92%,81%,97%.TheaverageeffluentconcentrationsofCODCr,TNandTPare26.54mg/L,8.63mg/L,0.12mg/L.Thesystemhasgoodresistancetofluctuationsofthewateryield,waterqualityandtemperature.Keywords:lowdissolvedoxygen,highactivatedsludge,highinternalmixedliquorrecirculation哈尔滨工业大学工学硕士学位论文-III-目录摘要..........................................................................................................................IAbstract.......................................................................................................................II第1章绪论...........................................................................................................11.1课题的背景及研究的目的和意义..............................................................11.2水体中氮磷的危害....................................................................................11.3生物脱氮理论...........................................................................................21.3.1传统生物脱氮理论....................................................................................21.3.2生物脱氮新理论........................................................................................61.4生物除磷理论...........................................................................................71.4.1传统生物除磷理论....................................................................................71.4.2生物除磷新理论........................................................................................81.5同步生物脱氮除磷工艺研究现状..............................................................91.5.1SBR工艺....................................................................................................91.5.2氧化沟工艺................................................................................................91.5.3A2/O工艺.................................................................................................101.5.4UCT工艺..................................................................................................101.5.5BCFS工艺.......................................................................................