Binding cadmium and copper ions with chemically modified cellulosic materials.

Equilibrium sorption of cadmium and copper ions by modified and unmodified maize stalk was studied using a range of metal-ion concentrations and temperatures at various metal ion-substrate contact periods. The amount of metal ion removed from solution depended on the metal ion concentration, the metal ion-substrate contact period and the metal ion type. The level of metal ion uptake reached 15 mg/g of the substrate for cadmium ions at 0 degree C and was of the order Cd(II) greater than Cu(II). Modification improved the metal ion binding capacity of the substrate and increased the rate of metal ion uptake. The influence of temperature on the level and rate of metal ion uptake by the substrate was investigated.