Removal of Chromium from Waste Water Using Yam Peel Activated Carbon

Abstract

The paper examined the use of yam peel to develop an adsorbent material with good surface characteristics for the removal of chromium (vi) from waste water. Activated carbons were produced from yam peel under varying conditions; temperature, time and preparation sequence in order to determine the optimum conditions. It's efficiency on the adsorption of chromium from waste water was investigated through batch adsorption studies using direct reading spectrophotometer. Samples of yam peels, 100g each were carbonized under varying temperatures of 100, 200, 300, 400, and 500ºC ,with varying carbonization time of 20, 30, 40, 50 and 60 minutes. The result revealed that 80% of chromium was removed at 200ºC and 40 minutes as the optimum carbonization temperature and time respectively. Effect of preparation sequence was equally evaluated, i.e. raw (powdered form), carbonization without activation, activation with (ZnCL2) before carbonization and activation after carbonization with (ZnCL2) and their adsorbing capacities under an initial concentration of 0.05mg/l were obtained to be 20, 100,100 and 60% respectively. Further increase in concentration results in 100% chromium removal for activation before carbonization and 80% for carbonization without activation. Hence, yam peel activated carbon is recommended for the removal of chromium from wastewater using activation before carbonization procedure at the above optimum conditions.