Removal of Dissolved Cadmium by Adsorption onto Walnut and Almond Shell Charcoal: Comparison with Granular Activated Carbon (GAC)

Abstract

In the present study, adsorption of dissolved Cadmium (Cd) onto walnut and almond shell charcoal and the standard granular activated carbon (GAC) has been investigated and compared. The effect of pH value, initial concentration of dissolved Cadmium and amount of adsorbent on the adsorption of Cd by the mentioned adsorbents were investigated. Results showed that the adsorption process was highly dependent on pH. Maximum Cd removal was achieved when the final pH of the mixture fell within 6.5-7. Adsorption test results revealed that Cd adsorption on the studied adsorbents could be better described by Longmuir isotherm. Maximum Cd removal efficiencies were obtained by walnut shell charcoal (91%), almond shell charcoal (85%), and GAC (81%).

Keywords

• Adsorption
• Walnut Shell
• Almond shell
• Charcoal
• cadmium