MOBILE FRACTION OF ELEMENTS IN TECHNOSOLS OF TAILINGS STORAGE FACILITY OF THE NERCHINSK POLYMETALLIC COMPLEX

Contamination of soils adjacent to the tailings storage facility of the Nerchinsk Polymetallic Complex (East Transbaikalia) is caused by the behaviour of Aeolian processes in a dry sharply continental climate. The studied territory is characterized by a high gross content (mg/kg) of zinc up to 5000, arsenic up to 1400, lead up to 600, cadmium up to 36, antimony up to 30. The method of sequential extraction in static mode was used to determine the ion-exchange water- and acid-soluble, reducible, oxidizable, residual forms of elements. The elements of physical-chemical mobility and bioavailability are arranged in the following series according to their decreasing sequence Zn>Mn>Pb>Ni>Cu>As>Fe. The rhizosphere (root zone) of plants is characterized by the content of oxidized forms of copper, zinc, lead and hard-to-reach forms of arsenic, iron, nickel exceeding that in technosols.