Sorption Potential of Chestnut (Castanae sativa) Shell as a Biomaterial for the Removal of Heavy Metals from Acid Mine Drainage

摘要

This research was undertaken to explore the sorption potential of chestnut shell as suitable adsorbent for scavenging divalent cations of lead (Pb) and cadmium (Cd) from Acid mine Drainage (AMD). In this regard, powdered carbon was produced from chestnut shell as adsorbent to remove lead and cadmium from wastewater. Batch experiments were conducted to obtain the optimum conditions for lead and cadmium. Effect of parameter like pH, adsorbent dose, contact time, temperature and initial metal ion concentration were also determined. The optimum conditions obtained were; 180 minutes contact time, 50°C temperature and pH 8 for cadmium, and 120 minutes contact time, 60°C temperature and pH 6 for lead. The removal of Pb~(2+) ion from Acid Mine Drainage at the optimum conditions is found to be 97.94%, while that of Cd~(2+) ion is 95.96%. Adsorption studies were carried out using the Langmuir Isotherm. The kinetics of adsorption was described using pseudo first order, pseudo second order, intra particle diffusion and Elovich kinetic model. The result of the kinetic model correlate well to pseudo second order, with R~2 of 0.999 for both ions. The results from the adsorption study shows that Chestnut shell can effectively be utilized for the removal of lead (II) and cadmium (II) ions.