Ecology, Environment and Conservation Paper

ADSORPTIVE REMOVAL OF NI AND CD BY BENTONITE FROM AQUEOUS SYSTEM

P. Kumararaja and K. M. Manjaiah

Abstract

Bentonite clay mineral rich in montmorillonite was characterized and evaluated for removal of Ni and Cd from aqueous solution by batch adsorption study. The variables which affect metal sorption capacity such as adsorbent dose, pH and initial concentration of metals on the extent of adsorption were investigated. The experimental data were fitted with Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich adsorption isotherms. The Langmuir and Freundlich adsorption isotherms were fitted the sorption data better than other isotherms. The Langmuir maximum monolayer adsorption capacity of bentonite was found to be 13.95 mg g-1and 9.41 mg g-1 for Ni (II) and Cd (II), respectively. The study revealed that bentonite could be potentially used for removal of Ni (II) and Cd (II) ions from effluents laden with heavy metals.