正渗透过程中水与溶质的传递现象

正渗透过程中正渗透过程中水与溶质溶质的传递传递现象现象边丽霞，方彦彦，王晓琳（清华大学化学工程系膜材料与工程北京市重点实验室，北京100084）摘要摘要：正渗透是一种利用渗透原理的新兴膜技术，近年来在国内外受到了广泛的关注。解析该过程中溶剂水的传递和驱动溶质的反向传递对其发展和应用至为关键。首先开展了两种膜的取向下，正渗透过程中的水通量和溶质反向摩尔通量的实验研究。当驱动溶液在膜分离层侧时，水通量更高，而溶质反向摩尔通量更低，表明水的传递对溶质的反向传递有限制作用。而后分别考察了不同的单一溶质和二元混合溶质作为驱动溶质时，水和溶质的传递现象。当单一中性溶质或电解质作为驱动溶质时，水通量和溶质反向摩尔通量均随驱动溶液浓度的升高而增大；在相同操作条件下，驱动溶质的扩散系数越小，溶质反向摩尔通量越小；中性溶质与电解质混合溶液为驱动溶液时，溶质分子之间存在耦合传递效应。关键词关键词：正渗透；水通量；溶质反向摩尔通量；传递现象DOI：中图分类号中图分类号：TQ028.8文献标志码文献标志码：A文章编号文章编号：WaterandsolutetransportphenomenainforwardosmosisprocessBIANLixia，FANGYanyan，WANGXiaolin(BeijingKeyLaboratoryofMembraneMaterialsandEngineering,DepartmentofChemicalEngineering,TsinghuaUniversity,Beijing100084,China)Abstract：Asanoveltechnologyusingtheprincipleofosmosis,forwardosmosishasdrawnworldwideattentionsinrecentyears.Understandingthesimultaneouswatertransportandsolutereversetransportintheforwardosmosisprocessesisessentialtothedevelopmentandapplicationofthisemergingtechnology.Inthisstudy,theeffectsoftwomembraneorientationsonsolutereversemolarfluxandwaterfluxwereinvestigated.Thewaterfluxinthemodeofactivelayerfacingdrawsolutionwashigherthanthatinthemodeofactivelayerfacingfeedsolution,whereassolutereversemolarfluxpresentedacontraryresult,whichindicatedthattransportofwaterwouldrestrictthereversetransportofsolute.Theeffectsofdifferenttypesofsolute,includingonesinglesoluteandtwo-componentmixedsolutes,onsolutefluxandwaterfluxwerealsoinvestigated.Waterfluxandsolutereversemolarfluxincreasedwithincreasingdrawsolutionconcentrationwhenusingsingleneutralsoluteorelectrolyteassolute.Underthesameoperationcondition,thesmallerthediffusioncoefficientwas,thelowerthesolutereversemolarfluxwas.Furthermore,thecoupledtransportofthesoluteswasobservedinthemixeddrawsolution.正渗透drawsolution可用，drawsolute似不如单单solute,请作者確认Keywords：forwardosmosis；waterflux；solutereversemolarflux；transportphenomena2014-00-00收到初稿，2014-00-00收到修改稿。联系人：联系人：王晓琳。第一作者：第一作者：边丽霞（1986—），女，硕士研究生。基金项目：基金项目：国家高技术研究发展计划项目（2009AA062901，2012AA03A604）；国家重点基础研究发展计划项目（2009CB623401）；北