MBRRO组合工艺中定期冲洗缓解RO膜污染的研究

MBR/RORO邢锴1,张宏伟1,龙树勇2,陶若虹3(1.天津大学环境科学与工程学院,天津300072;2.天津机电进出口有限公司,天津300040;3.北京交通大学土木建筑工程学院,北京100044):针对MBR/RO组合工艺,以RO的膜污染机理为理论基础,分别以清水和Na+K+盐溶液为冲洗用水,研究了采用定期冲洗缓解RO膜污染的效果结果表明,采用清水定期冲洗可以消减结构松散的污染层,缓解膜污染的发生RO进水溶液中,Ca2+以架桥作用络合有机物分子,加速了有机物污染层的形成,然而高浓度的Na+或K+盐溶液不但可置换出架桥于有机物之间的Ca2+,而且其产生的渗透压可迫使污染层发生膨胀,减弱了有机物分子间的结合因此,用高浓度的盐溶液冲洗不但具有清水冲洗的作用,而且可对密实的有机物污染层产生一定程度的破坏,更有效地延长了RO的运行周期就4种盐溶液(NaClKClNaNO3Na2SO4)而言,采用NaCl溶液冲洗对缓解膜污染的效果最好:MBR/RO组合工艺;膜污染;定期冲洗;盐溶液:X703:C:1000-4602(2010)11-0056-04:(06FZZDSH00900)EffectofPeriodicalCleaningonReductionofROMembraneFoulinginCombinedMBR/ROProcessXINGKai1,ZHANGHong-wei1,LONGShu-yong2,TAORuo-hong3(1.SchoolofEnvironmentalScienceandTechnology,TianjinUniversity,Tianjin300072,China;2.TianjinMachineryandElectricEquipmentImportandExportCo.Ltd.,Tianjin300040,China;3.SchoolofCivilEngineeringandArchitecture,BeijingJiaotongUniversity,Beijing100044,China)Abstract:IncombinedMBR/ROprocess,theeffectofperiodicalcleaningwithcleanwaterandsaltsolutiononreductionofROmembranefoulingwasstudied.Theresultsshowthatthecleaningwithcleanwatercanrelievemembranefoulingbyreducingunconsolidatedfoulinglayer.InROfeedwater,Ca2+canbridgeorganicsubstances,whichresultsindenserfoulinglayer.ButthesaltsolutionwithhighconcentrationofNa+orK+canreplacetheCa2+betweenorganicsubstances,andthehighosmoticpres-surecausedbyhighsaltconcentrationcanexpandthefoulinglayerandweakenthecombinationbetweenorganicsubstances.Therefore,thecleaningwithhighconcentrationsaltsolutionhastheadvantageofwa-tercleaningandbreaksthedensefoulinglayertoacertainexten,twhichcaneffectivelyprolongtheoper-ationcycleofRO.Incomparisonamong4typesofsaltsolutions(NaC,lKC,lNaNO3andNa2SO4),NaClisfoundtobethemosteffectiveone.Keywords:combinedMBR/ROprocess;membranefouling;periodicalcleaning;saltsolu-56第26卷第11期2010年6月中国给水排水CHINAWATER&WASTEWATERVo.l26No.11Jun.2010tion,(RO)(MBR)[1],RO,MBRRO[2]deRoever,[3]LiMoMBR,Ca2+,RO,[45]Contreras,,,[6]MBR/RO,MBR/RO,RORO,Na+K+,RO,1材料与方法11MBR/RO11MBR/ROFig.1SchematicdiagramofMBR/ROsystemMBR,2.0m2,,0.22m,8min2min,15L/(m2h)RO,,0.3m2,0.5MPa25300mg/LNaCl,97%12,MBRCODBOD5TNTP,TOC,DDS-307RO,RO,0.6106Pa30h,(J/J0)[5],J,J0RO[7]RO18L/h,5.1L/h,,,RO5.1L/hRORO,20%[8],,20%RORO2结果与讨论21,MBRRO,,1()1Tab.1QualityofeffluentMBRROCOD/(mgL-1)26624BOD5/(mgL-1)1032.3TOC/(mgL-1)120.5TN/(mgL-1)52311.2TP/(mgL-1)5.94.30.09/NTU24.10.3/(Scm-1)1721165236.31,ROMBR,22MBR/RO,RO,[9]RO,57邢锴,等:MBR/RO组合工艺中定期冲洗缓解RO膜污染的研究第26卷第11期,RO,,35h0.71,35h0.74,RO,,,50mmol/LNaClRO,,NaCl120min,,0.710.87,Gozlvez-Zafrilla[10];NaCl,0.740.93,60min,0.710.79,NaCl60min,0.740.86,,23RO,27%,RO,RO,24h1h,,RO,Nghiem[9],RO342h373h,9.06%,:,,,,,,,,,RO,,,RO,,[11],,,NaClRO,10305080mmol/LNaCl,24h1h,RO,,NaClRO,NaClNaCl50mmol/L,401h,17.25%NaCl,50mmol/LKClNaNO3Na2SO4,24h1h,RO,50mmol/LNaCl,50mmol/L,4,NaCl,,13%24MBR/RO,RO,,Ca2+,,[12],Ca2+,:,;,Ca2+,,,[5],,Ca2+,Ca2+,LeeNaClRO,Ca2+,Na+Ca2+[13],,58第26卷第11期中国给水排水结论RO,NaClRORO,,RO342h373h,NaClRO,NaCl50mmol/L,NaClKClNaNO3Na2SO4Ca2+,,,,,RO,RO:[1]NgHY,TayKG,ChuaSC,etal.Novel16-inchspira-lwoundROsystemsforwaterreclamationaquantumleapinwaterreclamationtechnology[J].Desalination,2008,225(1-3):274-287.[2]KimJ,DigianoFA,ReardonRD.Autopsyofhigh-pres-suremembranestocompareeffectivenessofMFandUFpretreatmentinwaterreclamation[J].WaterRes,2008,42(3):697-706.[3]deRoeverEWF,HuismanIH.Microscopyasatoolforanalysisofmembranefailureandfouling[J].Desalina-tion,2007,207(1-3):35-44.[4]LiQilin,XuZhihua,PinnauIngo.Foulingofreverseos-mosismembranebybiopolymersinwastewatersecondaryeffluent:Roleofmembranesurfacepropertiesandinitialpermeateflux[J].JMembrSc,i2007,290(1-2):173-181.[5]MoH,TayKG,NgHY.Foulingofreverseosmosismembranebyprotein(BSA):EffectsofpH,calcium,magnesium,ionicstrengthandtemperature[J].JMem-brSc,i2008,315(1-2):28-35.[6]ContrerasAE,KimA,LiQL.Combinedfoulingofnanofiltrationmembranes:Mechanismsandeffectofor-ganicmatter[J].JMembrSc,i2009,327(1-2):87-95.[7]ChongTH,WongFS,FaneAG.Implicationsofcriticalfluxandcakeenhancedosmoticpressure(CEOP)oncolloidalfoulinginreverseosmosis:Experimentalobser-vations[J].JMembrSc,i2008,314(1-2):101-111.[8]Glucinak,AlvarezA,LaineJM.Assessmentofaninte-gratedmembranesystemforsurfacewatertreatment[J].Desalination,2000,132(1-2):73-82.[9]NghiemLD,HawkesS.Effectsofmembranefoulingonthenanofiltrationoftraceorganiccontaminants[J].De-salination,2009,236(1-3):273-281.[10]Gozlvez-ZafrillaJM,Sanz-EscribanoD,Lora-GarcaJ,etal.Nanofiltrationofsecondaryeffluentforwastewaterreuseinthetextileindustry[J].Desalination,2008,222(1-3):272-279.[11]TanselB,SagerJ,GarlandJ,etal.Depositionofextra-cellularpolymericsubstances(EPS)andmicrotopo-graphicalchangesonmembranesurfacesduringintermi-ttentfiltrationconditions[J].JMembrSc,i2006,285(1-2):225-231.[12]LeeS,AngWS,ElimelechM.Foulingofreverseosmo-sismembranesbyhydrophilicorganicmatter:implica-tionsforwaterreuse[J].Desalination,2006,187(1-3):313-321.[13]LeeS,ElimelechM.Saltcleaningoforganic-fouledre-verseosmosismembrane[J].WaterRes,2007,41(5):1134-1142.:(022)2740829813821381967E-mail:haoti