Adsorption of chromium (III) from aqueous solution using vesicular basalt rock

Abstract

Chromium (III) is one of the chemicals widely used in various industrial processes. The wastewater containing Chromium (III) can be interconverted to Cr (VI) in the environment, which is one of the most toxic chemicals to biological systems. This paper investigates the removal of chromium (III) from aqueous solutions by adsorption process using abundant vesicular basalt available around Abbay River in Ethiopia. The batch adsorption method has been employed to evaluate the effect of various experimental parameters (pH, ionic strength, initial concentration and contact time) on Cr (III) adsorption. The adsorption process was highly dependent on pH. The maximum adsorption capacity was 0.976 mg g−1 at pH 6, initial concentration of 100 mg L−1 and adsorbent dosage of 50 g L−1. Kinetic experiments indicated that the pseudo-second-order model displayed the best correlation with adsorption kinetic data. The adsorption mechanism of Cr (III) onto the surface of the vesicular basalt involved film diffusion and/or intraparticle diffusion during the reaction. Equilibrium studies indicated that the Langmuir Isotherm model was found to be in better correlation with experimental data. This study indicated that vesicular basalt rock owned good potential for the treatment of Cr (III) containing polluted water.