Low cost materials for metal uptake from aqueous solutions

Abstract

In this work the ability of some vegetable wastes from industrial processes such as cork and yohimbe bark, grape stalks and olive pits, to remove metal ions from aqueous solutions has been investigated. The influence of pH, sodium chloride and metal concentration on Ni(II) and Cu(II) uptake was studied. Metal uptake showed in all the cases a pH-dependent profile. Maximum sorption was found at an initial pH around 5.0-6.0. In some cases an increase of sodium chloride concentration induced a decrease in metal removal. Adsorption isotherms at the optimum pH were expressed by the noncompetitive Langmuir adsorption model. When comparing the four materials, yohimbe bark waste was found to be the most efficient adsorbent for both metals studied. © 2005 Springer-Verlag Berlin Heidelberg.