Removal of Cr(VI) from aqueous solutions by adsorption on fly ash-wollastonite

Abstract

The ability of a homogeneous mixture of fly ash and wollastonite (1:1) to remove Cr(VI) from aqueous solutions by adsorption has been investigated. The extent of removal is dependent on concentration, pH and temperature of the solution. The applicability of the Langmuir isotherm for the present system has been tested and the surface mass transfer coefficient at 30 degree C and pH 2. 0 determined. Maximum removal was observed at pH 2. 0 and 30 degree C. The adsorption is first governed by diffusion followed by surface compound formation. The thermodynamic parameters, desorption results and infrared studies indicated that the surface compounds, formed by interaction of adsorbate ions and different constituents of mixed absorbent, were stable in nature.