Evaluation of adsorptive capacity of Various Agricultural Wastes for the Removal of Cadmium from Electroplating Wastewater

An attempt has been made in the present study to evaluate the agricultural wastes such as coconut shell, walnut shell and almond shell for the removal of cadmium from electroplating industrial effluent. Adsorption experiments were performed to evaluate the performance. The maximum removal efficiency for Cd (II) is 83.7% at pH 6.5 for coconut shell. The percentage removal of cadmium increases with decrease in metal concentration. The extent of removal depends on the metal concentration, adsorbent dose, contact time, and particle size. Coconut shell is found to be most effective with respect to removal efficiency. Cadmium adsorption follows second order rate equation for coconut shell. The isotherm data obtained more closely follows the Freundilch adsorption isotherm for coconut shell, while walnut shell and almond shell follows the Langmuir adsorption isotherm better. The powder of coconut shell has the potential to remove cadmium ion from electroplating wastewater. The present experimental study evaluates and compares the potentials of agricultural waste materials has been used as absorbents for investigating the removal of cadmium from the electroplating wastewater.