Cadmium-copper competitive sorption in soils

Abstract

Wasterwastes of municipal and industrial origin used to irrigate farmlands contain heavy metals which are sorbed on the surfaces of soil particles. Among those metals are cadmium (Cd) and copper(Cu). The degree to which each other for similar sorption sites can influence the retention of each other in the surface of the soil profile or leaching to groundwater. The extent of sorption of Cd and Cu in soils has been reported in a number of studies including those of CAVALLARO and McBRIDE (1978), ELLIOTT et al. (1986), KING (1988a; 1988b), KUO and BAKER (1983), KURDI and DONER (1983), and LEHMAN and HARTER (1984). Not many papers, however, have reported the competitive sorption of heavy metals in soils of various characteristics. Heavy metal sorption is probably a function of numerous factors such as clay content and type, organic matter, oxides and soluble salts. However, the soil properties more significantly affecting sorption at trace levels are, according to CAVALLARO and McBRIDE (1978), not well defined. More recent work by ELLIOTT et al. (1986) has shown that the type of organic matter can play an important role in heavy metal sorption. The objective of this study was to determine the sorption of Cd and Cu with and without the presence of the other to establish the competitive sorption by soils of different properties.