The Performance Of Activated Carbon Based Cola Nuts Shells For The Removal Of Co(II) And Ni(II) Ions From Aqueous Solution

Abstract

The removal of Ni(II) and Co(II) ions from aqueous solution by activated carbon from kola nuts shells was investigated. The influences of the contact time, adsorbent dose, pH and the initial concentration were experimentally done at 25°C by batch adsorption technique. The experimental results showed that the optimum pH of adsorption were 4.3 and 6 corresponding to 275 mg/g and 260 mg/g of the quantities of Co(II) and Ni(II) ions adsorbed respectively. The Langmuir, D-K-R and Tempkin adsorption isotherms described well the adsorption data for both adsorbates. The maximum adsorption capacities Qmax determined using the D-K-R isotherm model was found to be 286.862 mg/g and 302,778 mg/g respectively for Co(II) and Ni(II) ions. The pseudo-second order kinetic model fitted the adsorption of both the adsorbates owing to their correlation coefficients closer to unity. According to the DKR isotherm model, the adsorption mechanism seems to be chemisorption. Finally, results indicated that the activated carbons from kola nuts shells are performant for the removal of Ni(II) and Co(II) ions from aqueous solution.