Adsorption of cadmium and strontium on cellulose/alginic acid ion-exchange membrane

Abstract Cellulose/alginic acid (RC–AC) ion-exchange membrane was prepared by coagulating a blend of cellulose cuoxam and alginate solution. The RC–AC membrane was used satisfactory for the adsorption of Cd 2+ and Sr 2+ ions. The effects of ion concentrations, ionic strength, pH, adsorption time, desorption time and species of complexing agents on adsorbed amount ( c A ) of the RC–AC membrane were studied by a batch method, and the metal ions concentrations were measured with atomic absorption spectrophotometer (AAS). The c A values of Cd 2+ and Sr 2+ on the membrane were 0.79 meq g −1 at pH 5.8, and 0.75 meq g −1 at pH 6.0, respectively. After adding EDTA or oxalic acid, the c A values of Cd 2+ and Sr 2+ in the solution including Cu 2+ and Fe 3+ were much larger than those of Cu 2+ and Fe 3+ , and the EDTA was more efficient in the enhancement of the c A values of Cd 2+ and Sr 2+ than oxalic acid. In this case (EDTA), the selectivity of the metal ions adsorbed into the membrane was in the order of Sr 2+ >Cd 2+ >Fe 3+ >Cu 2+ . The preparation of RC–AC membrane is simple and less expensive.