Heavy metals mobility associated with the molybdenum mining-concentration complex in the Buryatia Republic, Germany

Mining of Dzhida ore deposits in Russia has caused the formation of a large tailings dam with technogenic sands and contamination of nearby district soils. Geochemical fractions of technogenic sands were divided by a sequential extraction procedure. The sampling points with maximum concentration of Pb, Cu, and Zn were selected for investigation of heavy metal mobility. Two previously described methods of heavy metal fractionation using selective extraction were applied: a procedure developed by the Community Bureau of Reference of the Commission of the European Communities (BCR procedure) and Tessier's fractionation scheme. Despite some differences in Pb extractions, the two procedures describe equally well the distribution of heavy metals on geochemical fractions. BCR procedure was chosen as a fast method of heavy metal mobile form estimation. For considered mining object, it is revealed that there are different characters of heavy metal mobility sequence in the soils Zn > Cu > Pb and technogenic sands Pb > Zn > Cu.