Electrokinetics methods to Control membrane Fouling

ElectrokineticsMethodsToControlMembraneFoulingS.NadhJagannadhandH.S.Muralidhara*Cargill,Inc.,P.O.Box5699,Minneapolis,Minnesota55440-5699Theefficiencyofaseparationprocessusingmembranesisoftenhinderedbymembranefoulingandconcentrationpolarization.Asaconsequence,membranecleaningcostsincrease,membranelifeisshortened,and/ormorecapitalisspentonpurchasingmoremembranearea.Thecurrentpracticestominimizetheeffectofthesefactorsonmembraneperformanceareclassifiedintofourgeneralgroupsbasedontheirmechanismsandarebrieflyreviewedinthispaper.Oneoftheapproaches,theexternalfieldsapproach,utilizesdcelectricfieldanditselectrokineticsasoneofthemeanstocontrolmembranefouling.Theelectricfieldapproachisthemajorfocusofthispaper.Duringtheelectricfieldapplication,thephenomenaofelectrophoresisandelectroosmosisoccurasaresultofelectrokinetics.Besidesthesephenomena,electrolysis,Joule’sheating,ionmigration,etc.,alsooccur.Oneormoreofthesemechanismssimultaneouslyactontheappliedmembranesystemandimproveitsperformance.Theelec