Adsorption of Pb(II) from aqueous solutions using activated carbon developed from Apricot stone

Low-cost activated carbon was prepared from Apricot stone material by chemical activation with sulphuric acid for the adsorption of Pb(II) from dilute aqueous solution. The activated carbon developed shows substantial capacity to adsorb Pb(II) from dilute aqueous solutions. The parameters studied include physical and chemical properties of adsorbent, pH, adsorbent dose, contact time and initial concentrations. The percent removal increased with pH from 1.5 to 5. The optimum pH required for maximum adsorption was found to be 6.0. Adsorption kinetics data were modeled using the pseudo-first and pseudo-second-order models. The results indicate that the second-order model best describes adsorption kinetic data. The isotherm equilibrium data were well fitted by the Langmuir and Freundlich models. The estimated maximum capacities of lead ions adsorbed by Apricot stone activated with sulphuric acid were 21.38 mg g(-1). The adsorbent derived from this material is expected to be an economical product for metal ion remediation from water and wastewater. (C) 2011 Elsevier B.V. All rights reserved.