Preparation and Application of Chitosan Membranes to Filter Silver from X-ray Film Processing Wastes

摘要

Chitosanisanaturalpolysaccharidebiopolymerwhichhasbeenwidelyusedindifferentprocessesandapplications.Chitosanbasedmembraneshavebeenusedinreverseosmosis,gasseparation,dialysisandpervaporation.Theobjectofthisresearchwasinvestigatingthepossibilityofchitosanmembraneusedasafilterforremovingsilver(Ag)fromX-rayfilmprocessingwastes.SeveralofchitosanmembranessuchasM1,M2,M3andM4havebeenpreparedforthepurposeandfiltrationwasdoneusingdead-endfiltrationmethod.ThefiltrationexperimentswereperformedonaflatsheetmembraneusingpurewaterandX-rayfilmprocessingwastesasfeeds.Theanalysisofsilverconcentrationhasbeendonebyatomicabsorptionspectrometers(AAS).TheresultsshowthatchitosanmembraneM2gavethehighestfiltrationcoefficient(Rcoeff)i.e.99.9%,withthepurewaterflux(PWF)andproductflux(PF)are2972.56L/m2hand1761.18L/m2hrespectively.Therejectioncoefficientofthemembranesdecreaseswithincreasingtheamountofchitosan,whilethepurewaterfluxandproductfluxareincreased.ThefiltrationcoefficientsshowthatthechitosanmembranesareabletofiltersilverwastefromX-rayfilmprocessingwasteswithperformancedependentontheircharacteristicsuchasporessize.Thissuggeststhat,chitosanmembranecanbeusedasonemethodthatissafeandfriendlyenvironmentforrecoveringsilverfromX-rayfilmprocessingwastetoimprovethequalityoftreatedtoanacceptablequalitylevel...