Abstract :
The major objective of this study was to investigate the chemical forms in which selected metals occur in soils polluted with metallurgical dusts as well as to estimate potential mobility and bioavailability of these metals. Six soil profiles situated at different distances from Cu smelters were chosen and soil samples were taken from top- and sub-surface layers. The soils differed in their textures but all of them showed high contents of sand fraction and were neutral or slightly alkaline in reaction, due to liming. Ale research involved the analysis of the total contents of 8 metals (Al, Fe, Mu, Zn, Cr, Ni, Cu and Pb) and their speciation according to the Zeien and Bruemmer method. Total concentrations of metals varied in the following ranges (mg/kg): Al, 1420–11,400; Fe, 1710–19,700; Mn, 55–470; Zn, 6.4–153; Cr, 2.15–16.9; Ni, 1.18–13.8; Cu, 7.4–1710; Pb, 11–460. The metal fractions determined were: mobile, exchangeable, occluded in MnOx, organically bound, occluded in amorphous and crystalline FeOx and residual. The metalsʹ behaviour in soils depended both on the soil properties and the metalsʹ origin. Typically lithogenic metals (Al, Fe, Cr, Ni) occured in the soils predominantly in stable fractions (bound to FeOx and silicates), whereas metals of anthropogenic origin (Cu, Pb) showed considerably higher percentages of mobile and exchangeable fractions, which together made up 17.0–59.7% of Cu and 2.5–38.8% of Pb. The highest contributions of those fractions occured in the top layers of sandy soils. Therefore, it is concluded that anthropogenic metals are likely to be leached from the polluted soils, especially the sandy ones.
