Removal of Ni (II) ions from aqueous solution using chitosan and activated carbon: isotherms and kinetics

Abstract

The present study deals with adsorption of Ni (II) ions from aqueous solution using chitosan (CHI) and activated carbon (ACC) as adsorbents. Several parameters such as pH, contact time, adsorbent dosage, concentration of adsorbate and radiation dose were varied to achieve an optimized adsorption of the metal ions. It was concluded that maximum removal of Ni (II) ions (92.2%) using CHI was observed at pH 3, dosage 1 g and contact time 240 min. Maximum removal of Ni (II) ions (82.3%) was achieved using ACC at pH 2, dosage 2.5 g for 120 min. The percentage removal of Ni (II) ions increases slightly after irradiation with Co-60. The adsorbents were characterized before and after irradiation and adsorption using FTIR and SEM techniques which clearly indicated the occurrence of adsorption of metal ions. Harkin-Jura and Jovanovic isotherms study indicated multilayer adsorption. The adsorption process follows pseudo-second-order kinetics.