Adsorption of Heavy Metals on Alumina from Electrolytic Aqueous Solutions

摘要

Adsorption of heavy metal ions (Cu(2+), No(2+), Co(2+), PR(3+), Nd(3+), Er(3+) onalumina in aqueous media was studied as a function of temperature. Spectrophotometry was used as the technique to measure the extent of adsorption. The adsorption isotherms followed Langmuir and Freundlich equations from which thermodynamic parameters such as enthalpy, free energy and entropy of adsorption were calculated. The values of free energy of adsorption for Ni(2+), Pr(3+), and ER(3+) are found to increase with the increase of temperature. While for Cu(2+), Co(2+) and Nd(3+), these values increase with the rise of temperature. Sorption mean free energy of adsorption was also calculated from Dubinin-Radushkevich equation and interpreted.