Cadmium and lead sorption behaviour of selected English and Indian soils

The environmental impact of metal additions to a soil depends on the metal sorption ability of the soil, This study compared the Cd and Pb sorption abilities of some selected English and Indian soils. The results showed that the English soils generally sorbed Cd and Pb more strongly and in greater amounts compared to the Indian soils. Soil pH, CEC, contents of organic matter, clay and CaCO3 were all positively correlated with Freundlich metal retention parameters (log K-f and 1/n) whereas the sand content had a negative correlation. The contents of free Fe oxide (FFeO) and easily reducible hydrous Mn oxide (HMnO) had no major influence on Cd and Pb sorption by these soils, except HMnO on 1/n for Cd sorption. Correlation and regression analyses indicated that clayey textured soils with neutral to alkaline pH or soils with appreciable (greater than or equal to 10%) amounts of CaCO3 and organic matter would be the most suitable for the disposal of Cd and Pb containing wastes, The results also showed that the application of a sewage sludge significantly increased the sorption of both Cd and Pb by all English soils, but a considerable decline in Pb sorption by most Indian soils was observed. (C) 1998 Elsevier Science B.V. All rights reserved.