Adsorption Kinetic Study for Removal of Heavy Metal from Aqueous Solution by Natural Adsorbent

Abstract

This paper deals with studying the removal of toxic heavy metals ions, such as Chromium (VI) and Manganese (II) from wastewater using activated carbon obtained from palm kernel at different conditions as contact time, amount of adsorbent, temperature, initial concentration and pH. In order to find out thermodynamic and kinetic parameters, equilibrium adsorption models were applied. The experimental data was confirmed with both Langmuir and Freundlich isotherm models. Adsorption rate constant was determined from Lagergren equation and pseudo-second order equations. The sorption ions of Chromium (VI) and Manganese (II) onto palm kernel was strongly adsorbed dependent on contact time, initial Chromium (VI) and Manganese (II) concentration, adsorbent dosage, temperature and pH value. thermodynamic parameters can be stated as, negative value of ΔG ° and positive value of ΔS ° show that the adsorption of Cr (VI) and Mn (II) ions onto palm kernel is a spontaneous process and positive value of ΔH ° indicates that the adsorption is endothermic in nature. Finally, it can be seen that the pseudo-second order equation provided the best correlation coefficient (R 2 ) for the adsorption data.