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1、上海交通大学硕士学位论文长泥龄膜生物反应器中活性污泥各组分的膜污染研究姓名:刘淑舒申请学位级别:硕士专业:环境工程指导教师:许振明;DarrenDelaiSun20090101上海交通大学工程硕士学位论文摘要胶体和溶解性物质在膜污染中的重要作用也无法忽略。此外,为了对膜污染的机理有更深入的了解,对各种膜阻力的大小也进行了进一步研究。由结果可知,在微滤膜错流过滤污泥时,浓差极化层阻力(Rcp,31~73%)和滤饼层阻力(Rc,23~63%)是总的膜阻力(Rt)的主要组成,而膜内部污染阻力(Rif,0.7~2.4%)和膜
2、固有阻力(Rm,1.2~6.4%)几乎可以忽略不计。操作条件对膜污染的影响结果表明,悬浮颗粒始终是膜污染的主要贡献者,而占主导地位的各种阻力随污泥浓度、过膜压力和错流速度的变化而变化。污泥浓度和过膜压力增大,错流速率减小,均会增大总的膜阻力,加剧膜污染。本次实验中所得最佳操作条件为:MLSS=320mg/L,TMP=0.5bar,CFV=0.438m/s。提高流速,减小压力可以有效抑制膜污染,降低清洗频率,延长膜组件的使用寿命,从而节约操作成本,推广长泥龄膜生物反应器的应用。关键词:膜生物反应器,长泥龄,污泥组分,膜
3、污染,膜阻力上海交通大学工程硕士学位论文ABSTRACTStudyonmembranefoulingcausedbydifferentsludgefractionsfromamembranebioreactorwithlongsolidretentiontimeABSTRACTComparedwiththeconventionalactivatedsludgeprocess,themembranebioreactor(MBR)canminimizesludgedisposalandreducethebioreacto
4、rsizewithhigherbiomassloading.However,MembranefoulinglimitstheindustrialapplicationofMBRswithlongSRT.Moreover,themixedliquorcompositionvarieswithoperatingconditions,andthecontributionofeachsludgefractiontomembranefoulingischangedalongwithdifferentoperatingcondi
5、tions.Therefore,itisnecessarytoinvestigatetheinfluencesofMLSSconcentration,trans-membranepressureandcross-flowvelocityonmembranefoulingtohaveabetterunderstandingofthefoulingbehavioursinMBRswithlongSRTconditions.A300-daySRTMBRand10-daySRTSBRweresetupforthestudy.
6、Activatedsludgetakenfromthesesystemswasfractionedintosuspendedsolids,colloidsandsolutes;andtheirrelativecontributionstomembranefoulingduringcrossflowfiltrationwerecalculated.Furthermore,sub-dividedfiltrationresistanceswereanalysedusingresistance-in-seriesmodel.
7、上海交通大学工程硕士学位论文ABSTRACTResultsfromthisstudyindicatedthatthesuspendedsolidwasthemainfoulingfraction,withtherelativecontributiontothetotalresistanceof70%and85%inMBRandSBR.Ontheotherhand,theimportanceofcolloidsandsolutescouldnotbeneglected.Moreover,sub-dividedresis
8、tanceswereanalysedtohaveadeepunderstandingaboutthefoulingmechanism.Itwasdemonstratedthattheresistancesofconcentrationpolarization(Rcp,31~73%)andcakelayer(Rc,23~63%)mainlycon