Adsorption of Cadmium and Copper Ions in Aqueous Solution by Using Activated Carbon Resulting from Hulls of Neem

The present work aimed at the adsorption of cadmium (Cd2+) and Copper (Cu2+) ions from an aqueous solution by activated carbon prepared from hulls of Neem by a simple process of pyrolysis preceded by a chemical impregnation in zinc chloride. The process was optimized on the basis of the analysis of the index of iodine of carbon prepared according to the parameters of the preparation. Prepared activated carbon was characterized by Fourier transform infra-red spectroscopy (FTIR), and by determination of the iodine number and the carbonization yield. To implement the adsorption capacity of activated carbon, of the contact time, adsorbent mass, and initial concentration of the adsorbate. The adsorption equilibrium is quickly reached at the end of 10 min and 15 min for Cd2+ and Cu2+ ions respectively. The maximum adsorbed quantities are of 8.382 mg/g and 52.356 mg/g for Cd2+ and Cu2+ ions respectively. The pseudo-second order models describe the kinetics adsorption of Cd2+ and Cu2+ ions. The use of zinc chloride, as chemical agent, favors the adsorption of molecule of very small sizes. The isotherms of adsorption of Cu2+ and Cd2+ on the prepared activated carbon are of type L and are compatible with the model of Langmuir. This study revealed that activated carbon obtained from Neem shells is a good adsorbent for the elimination of Cd2+ and Cu2+ ions from aqueous solution. This study aims to contribute to clean up the waters.