Removal of copper from aqueous solutions by adsorption onto chestnut shell and grapeseed activated carbons

Activated carbons prepared from chestnut shell and grapeseed were used as adsorbent for the removal of Cu (II) ions from aqueous solutions. Adsorption experiments were performed by varying initial metal ion concentration, temperature and pH. Freundlich and Langmuir isotherms were used to analyze the equilibrium data obtained at different adsorption conditions. It was observed that Freundlich isotherm provided better fit to the equilibrium data than Langmuir isotherm. Effects of temperature. pH and adsorbent surface area on the adsorption capacity constant of Freundlich and Langmuir isotherms were statistically investigated by using a two-level factorial design technique and empirical regression equations were developed. It was determined that the adsorption capacities of adsorbents increased with increasing temperature, pH and surface area. The SEM images of adsorbents before and after adsorption were compared. (C) 2009 Elsevier B.V. All rights reserved.