Adsorption of Cd by peanut husks and peanut husk biochar from aqueous solutions

This study was conducted to investigate the best absorbent for cadmium (Cd) present in aqueous solutions. Among the selected absorbents (n = 22), peanut husk biochar (PHB) was the best absorbent for Cd and its adsorption reached to equilibrium within 12 h. In this study, the optimum conditions observed for Cd adsorption were pH 5.0, an initial Cd concentration of 200 mg L−1, a PHB dosage of 40 g L−1, and room temperature. The Cd removal efficiency of the tested biochar reached to 99.9% at these optimum conditions. EDX analysis confirmed that Cd was adsorbed onto PHB more than onto PHs. It is concluded that PHB can be used as a good remediating material for removal of Cd from contaminated environmental matrixes.