MBR-RO组合工艺中定期冲洗缓解RO膜污染的研究

MBR/RO组合工艺中定期冲洗缓解RO膜污染的研究邢�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)��摘�要:�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(NaCl、KCl、NaNO3、Na2SO4)而言,采用NaCl溶液冲洗对缓解膜污染的效果最好。��关键词:�MBR/RO组合工艺;�膜污染;�定期冲洗;�盐溶液中图分类号:X703��文献标识码:C��文章编号:1000-4602(2010)11-0056-04��基金项目:天津市科技创新专项基金资助项目(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&WASTEWATER�������������Vo.l26No.11Jun.2010tion��在污水资源化利用中,用反渗透(RO)深度处理膜生物反应器(MBR)出水被认为是一种可行且有效的