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. T he effects of particle size and of carbon doses were evaluated by batch exp eriments. The kinetics of sorption were followed, based on the amounts of m etal sorbed at various time intervals. The modeling of kinetic and isotherm curves has also been investigated. The rate constant and the reaction orde r 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 capacit y of metal ions sorbed was derived. (C) 2001 Elsevier Science BN. All right s reserved.