Adsorption of Pb2+ and Zn2+ from aqueous solutions by sulfured orange peel

In this study, sulfured orange peel (MOP) was used as adsorbent to investigate its adsorption behaviors of Pb2+ and Zn2+ from aqueous solutions. The effects of solution pH, adsorption time and metal ion concentration on adsorption were studied in batch experiments. Both adsorption kinetics of Pb2+ and Zn2+ proceeded rapidly and could be well described by pesudo-second-order equation. The maximum Langmuir adsorption capacities for Pb2+ and Zn2+ removal by MOP were evaluated as 164 and 80 mg/g, respectively. A binary mixture of Pb2+ and Zn2+ was studied by using a packed column, suggesting that effective mutual separation and pre-concentration of Pb2+ away from Zn2+ using MOP could be satisfactory achieved. The results indicate that MOP could be employed as an effective low-cost adsorbent for adsorption and separation of Pb2+ and Zn2+ from wastewater. (C) 2011 Elsevier B.V. All rights reserved.