Mixed matrix membranes for efficient adsorption of copper ions from aqueous solutions

This work presents adsorption of copper (Cu2+) ions from aqueous solutions using mixed matrix membrane (MMM) and its elution afterwards. The developed flat sheet MMM, comprises of chitosan beads incorporated in Ethylene vinyl alcohol (EVAL) polymer porous matrix and exhibits static Cu2+ ion adsorption capacity of 410.5 mg Cu2+ ions per g chitosan bead, which is higher than earlier studies reported on chitosan as adsorbent (beads, membranes and hydrogel). Dynamic adsorption of Cu2+ ions from aqueous solution with MMM is similar to static adsorption but it is achieved much faster (15 min versus 60 min). Attempts to desorb Cu2+ ions from chitosan beads in packed bed column resulted in bead aggregation, restriction of Cu2+ ion desorption and reusability of the column. Under similar experimental conditions, Cu2+ ions desorbed successfully from the MMM without loss of beads from the membrane structure and the MMM was reusable. Overall, the MMM developed in this study shows superiority over packed bed columns in terms of low pressure drop, high adsorption capacity, successful desorption of Cu2+ ions and reusability for few cycles. (C) 2012 Elsevier B.V. All rights reserved.