Journal of Chemical Technology and Biotechnology, Vol.75, No.9, 812-816, 2000
Heavy metal uptake from aqueous solution by cork and yohimbe bark wastes
In this work the ability of cork and yohimbe bark wastes to remove Cu(II) and Ni(II) from aqueous solutions has been studied. The influence of pH, sodium chloride and metal concentration on metal uptake was investigated. Metal uptake showed a pH-dependent profile. Maximum sorption for both metals was found to occur at around pH 6-7. In the case of cork an increase of sodium chloride concentration provoked a decrease in metal removal. Adsorption isotherms at the optimum pH were expressed by the non-competitive Langmuir adsorption model, and model parameters were determined. It was seen that the adsorption equilibrium data fitted very well to the model in the concentration range studied. When comparing both biomaterials, yohimbe bark waste was found to be the most efficient adsorbent for both metals studied.