Adsorption of palladium and platinum from aqueous solutions by chitosan and activated carbon coated with chitosan

Abstract

ABSTRACT In this work, the potential of chitosan and activated carbon coated with chitosan for palladium and platinum adsorption from aqueous solutions was investigated. The observed results showed that the optimum operating conditions for palladium and platinum adsorption on chitosan were initial pH 2, particle size of adsorbent = 0.21 mm and adsorbent dose = 10 g/L. Equilibrium studies showed that palladium and platinum adsorption on chitosan was of spontaneous and exothermic nature. Equilibrium results fitted with Langmuir, Freundlich, Temkin and Dubinin‐Radushkevich models for two adsorbents. The maximum adsorption capacities for palladium and platinum adsorption were 62.50 and 66.66 mg/g of chitosan and 43.48 and 52.63 mg/g of activated carbon coated with chitosan, respectively. Kinetic data were found to confirm pseudo‐second‐order kinetic model. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.