The use of pyrolusite to remove Pb and Cd in aqueous solutions : isotherm and thermodynamic

The utilization of natural material as an adsorbent to eliminate contaminants in the water is of great interest. Natural material can be directly used without further treatment that may lead to higher environmental impact. In this study, pyrolusite which is immensely available in Indonesia, especially in East Nusa Tenggara, were used to adsorb Cadmium (Cd) and Lead (Pb) in single and simultaneous condition. Several operational parameters such as initial concentration, pH and temperature were applied in order to elaborate the sorption mechanism and to determine the adsorption capacity. The amount of absorbed Cd and Pb were increased at a higher pH and reached the optimum condition at pH 7 for both. The adsorption isotherm for both adsorbate were best modeled following The Langmuir equation, giving an adsorption capacity as high as 108.70 mg/g and 123.45 mg/g for Cd and Pb respectively. Additionally, thermodynamics data showed that the adsorption process in this study was endothermic process