The Removal of Heavy Metals from Aqueous Solutions by Commercial Activated Carbon

Abstract

The sorption of three divalent metal ions; copper, cadmium and zinc from aqueous solution onto commercial activated carbon in single component systems has been investigated. Hexavalent chromium was also studied with respect to various experimental conditions for instant; solution pH, initial adsorbate concentrations, particle sizes and contact time. The monolayer sorption capacity of individual Cd(II), Cu(II), Zn(II) and Cr(VI) on activated carbon granules determined by Langmuir model was found to be 43.33, 44.56, 53.98 and 62.857 mg/L, respectively. Adsorption showed pseudo-second order rate kinetics at different initial concentration of heavy metals. Ion exchange may be the main mechanism for the adsorption of Cd(II), Cu(II) and Zn(II). On the other hand, it was evident that the adsorption mechanism of Cr(VI) may involves the adsorption of both hexavalent chromium (anionic) and trivalent chromium (cationic) on the activated carbon surface.