A Study on the Adsorption of Cadmium(II) from Aqueous Solution onto Activated Carbon Originated from Bombax ceiba Fruit Shell

Abstract

Under the present study, the adsorption capability of the activated carbon originated from Bombax ceiba fruit shell was examined using batch experimental mode. Bombax ceiba fruit shell was carbonized and chemically activated using zinc chloride (ZnCl₂) as activating agent. The surface structure of the prepared activated carbon was examined by using scanning electron microscope (SEM). Some important experimental parameters namely pH of the solution, contact time and initial metal ion concentration in the solution, which affect the adsorption process were optimized. Maximum cadmium(II) removal from the aqueous solution was found at pH 9 with 0.3g/30mL adsorbent dose. The equilibrium in adsorption was attained after about 90 min of contact. Different adsorption isotherm models namely Langmuir, Freundlich and Temkin adsorption isotherm models were fitted to explain the equilibrium data obtained for the adsorption system. Temkin isotherm was found to show stronger correlation for cadmium(II) adsorption from the experimental solution onto the prepared adsorbent surface.