Removal of cadmium and copper ions from aqueous solution with cellulose graft copolymers

Cellulosic materials containing various amounts of grafted polyacrylonitrile and poly(acrylic acid) molecules were used to remove Cd(II) and Cu(II) ions from aqueous solution. It was found, that grafting enhanced the metal ion binding capacity of the cellulosic material; the extent of enhancement depended on the metal ion type, the level and nature of the incorporated graft polymer. The equilibrium sorption data fitted the Langmuir isotherm equation and values of maximum metal ion binding capacity, As and binding constant k, determined for the grafted cellulosic materials were markedly higher than for the unmodified cellulosic material. Reuse of the grafted cellulosic materials after one sorption cycle resulted in less than 10% reduction in the sorption capacity of the material, suggesting that the grafted cellulosic materials is a multiple-use adsorbent. Recovery of the adsorbed metal ions from the grafted cellulosic materials using 2% (v/v) HNO3 was quantitative. (C) 2004 Elsevier B.V. All rights reserved.