CADMIUM AND LEAD SORPTION BEHAVIOR OF SELECTED ENGLISH AND INDIAN SOILS

The environmental impact of metal additions to a soil depends on the m etal sorption ability of the soil, This study compared the Cd and Pb s orption abilities of some selected English and Indian soils. The resul ts showed that the English soils generally sorbed Cd and Pb more stron gly and in greater amounts compared to the Indian soils. Soil pH, CEC, contents of organic matter, clay and CaCO3 were all positively correl ated with Freundlich metal retention parameters (log K-f and 1/n) wher eas the sand content had a negative correlation. The contents of free Fe oxide (FFeO) and easily reducible hydrous Mn oxide (HMnO) had no ma jor influence on Cd and Pb sorption by these soils, except HMnO on 1/n for Cd sorption. Correlation and regression analyses indicated that c layey textured soils with neutral to alkaline pH or soils with appreci able (greater than or equal to 10%) amounts of CaCO3 and organic matte r would be the most suitable for the disposal of Cd and Pb containing wastes, The results also showed that the application of a sewage sludg e significantly increased the sorption of both Cd and Pb by all Englis h soils, but a considerable decline in Pb sorption by most Indian soil s was observed. (C) 1998 Elsevier Science B.V. All rights reserved.