Adsorption and Desorption of Copper by Calcareous Arid Soils

Abstract

The study on adsorption of copper by calcareous arid soils of Rajasthan, India, showed that with increasing additions of copper from 2 to 500 mg Cu L^-1 there was slight increase in the equilibrium concentration values in Khajwan, Panchroli, Pali (0.114 to 0.285 mg L^-1) and in Asop I and Asop II (0.859 to 3.33 mg L^-1) soils.The amount of copper adsorbed at 2mg L^-1 (0.01 to 0.019 mg g^-1) increased to 4.99 mg g'l at 500 mg Cu L^-1 addition, Adsorption of copprr followed the Freundlich's equation. The same concentration of desorbed copper (1.79x10^-6 to 1.35x10^-5 moles L^-1 low concentration of desorbed copper· (2.69x10^-6 to 2.19x1O^-5 moles L^-1) at 500 mg Cu L^-1 and the copper hydroxide potential values in the range of 185 to 19.9 indicated precipitation of added copper rather than multi layer adsorption.