Adsorption of copper(II) ions onto hazelnut shell and apricot stone activated carbons

Activated carbons prepared from hazelnut shells and apricot stones were used as adsorbents for the removal of copper(II) ions from aqueous solution. Adsorption studies were carried out by varying the initial metal ion concentration, the temperature and the pH. The amount of Cu(II) ions adsorbed increased with increasing temperature, pH and initial Cu(II) ion concentration. The equilibrium data were analyzed using the Freundlich and Langmuir isotherms. The parameters of the isotherm models were determined for two activated carbons; it was found that the Freundlich model showed a better fit of the adsorption data than the Langmuir model. The physical and chemical properties of hazelnut shell and apricot stone activated carbons were determined for comparative purposes.