Kinetic and Batch Equilibrium Adsorption of Nickel (II) and Copper (II) Ions from Aqueous Solution On to Activated Carbon Prepared from Balanites aegyptiaca Shells

Abstract

The adsorption capacity of Nickel (Ni2+) and Copper (Cu2+) ions from an aqueous solution by activated carbon prepared from Balanites aegyptiaca shells. ¶Prepared activated carbon was characterized by Fourier transform infra red spectroscopy FTIR, and by determination of the iodine number and the carbonization yield. ¶To implement the adsorption capacity of activated carbon, of the contact time, adsorbent mass, pH, initial concentration of the adsorbate and the addition of the sodium chloride electrolyte (NaCl). ¶To analyze the adsorption mechanism, Langmuir isotherms, Freundlich models were studied.  Dubinin-Kaganer-Radushkevich (D-K-R) as well as the kinetic models of pseudo-first order, pseudo-second order, Elovich and intra particulate diffusion. ¶The iodine index gave a value of 550.11 mg/g. ¶The adsorption equilibrium is quickly reached at the end of 10 min and 12 min for Ni2+ and Cu2+ ions respectively. ¶The maximum adsorbed quantities are of 540 mg/g and 491 mg/g for Ni2+ and Cu2+ ions respectively. ¶These values are slightly higher than the quantities calculated by the Langmuir model, which implies better adsorbates adsorption on the activated carbon. Adsorption took place in an acidic medium with optimal pH values of 4 and 5 for the Ni2+ and Cu2+ ions respectively. The pseudo-first order and pseudo-second order models describe the kinetics adsorption of Ni2+ and Cu2+ ions respectively. ¶ ¶The addition of NaCl electrolyte showed a very significant increase in the adsorbed quantities, because of increase in the ionic force of the solution. This study revealed that activated carbon obtained from Balanites aegyptiaca shells is a good adsorbent for the elimination of Ni2+ and Cu2+ ions from aqueous solution.