CHEMICAL AND MINERALOGICAL FORMS AND MOBILIZATION OF COPPER AND LEAD IN SOILS FROM A CU-SMELTING AREA IN POLAND

Sequential chemical extraction, scanning electron microscopy/energy di spersive microanalysis (SEM/EDX) and x-ray diffraction (XRD) were used to determine the chemical and mineralogical forms of copper and lead in a soil sample containing 7400 and 1960 mg/kg of these metals respec tively, taken from the vicinity of a copper smelter at Legnica in sout hern Poland. Sequential extraction suggests that a high proportion of copper and lead (about 70 and 60% respectively) could be mobilized fro m the exchangeable and carbonatic fractions of the soil. SEM/EDX analy sis of soil particle size fractions indicates however, that the Cu and Pb are mainly associated with sulphides and/or sulphates but to a min or extent with carbonates and on exchange sites. The SEM micrographs s uggest that the heavy metals occur in three major forms, namely single grains, aggregates, and thin patches on or in silicate and carbonate minerals.