Heavy metals removal by adsorption onto peanut husks carbon: characterization, kinetic study and modeling

Carbon prepared from peanut husks (PHC) has been used for the adsorption of Pb2+, Zn2+, Ni2+ and Cd2+, over a range of initial metal ion concentration (0.15 mM). Chemical and physical characteristics of PHC were determined. The effects of particle size and of carbon doses were evaluated by batch experiments. The kinetics of sorption were followed, based on the amounts of metal sorbed at various time intervals. The modeling of kinetic and isotherm curves has also been investigated. The rate constant and the reaction order have been calculated. The results show that Pb2+ has best affinity to PHC than Cd2+, Ni2+, Zn2+. From these results an order of the sorption capacity of metal ions sorbed was derived. (C) 2001 Elsevier Science BN. All rights reserved.