Sorption kinetic analysis for the removal of cadmium ions from effluents using bone char

The adsorption of cadmium ions onto bone char has been studied using a batc h adsorber. The experimental data was analyzed using four sorption kinetic models-the pseudo-first order, the Ritchie second order, the modified secon d order and the Elovich equations-to determine the best fit equation for th e sorption of metal ions onto bone char. The best-fit equation was identifi ed using the sum of the errors squared (SSE). Finally, equilibrium studies were used to evaluate the sorption capacity of bone char for cadmium ions a nd experimental results showed this to be 0.57 mmol g(-1) at an equilibrium solution concentration of 3.0 mmol dm(-3) Since the sorption capacity is r elatively high, bone char can be considered as a suitable sorbent for the a dsorption of cadmium in wastewater treatment systems. (C) 2001 Elsevier Sci ence Ltd. All rights reserved.