Sorption and Desorption of Cr(III) in Soils of Tamil Nadu

Adsorption of Cr in eight surface soils was carried out in batch test to know the kinetics of its sorption and time required for its equilibration in soil. The adsorption experiments in original and organ:c matter oxidized soils and desorption experiments in original soils werc conducted. The aclsorption of Cr, though rapid, required 24 h to reach equilibrium Chromium adsorption on soils conformed to both Langmuir and Freundlich adsorption isotherms. The sorption maxima (b values) ranged from 6.3 to 11.3 mg μl in original soils and 1.2 to 3.11 mg μl in organic matter oxidized soils, showing a considerable reduction to thc tunc of about 70 pcr cent as compared to the original soils. The amount of Cr desorbed by watcr increased with increased levcl of its adsorption which rangcd from 1.12 to 2.80 per cent.