Chemozem formation under conditions of prolong exposure to aero-industrial emissions from a mining and smelting plant

Introduction. The mining and processing industry, as one of the complex, high energy-consuming production processes is the most problematic from an environmental point of view. As a result of processing raw materials from ore, a huge amount of waste of practically all types, solid, liquid and gaseous, is generated. In some areas, tones of slag dumps and tailings are stored, which in one way or another are exposed to external impact and are transported by Aeolian streams to the adjacent environment. Hydrogenic surface runoff is also formed from the surface of dumps and the territory of enterprises with atmospheric precipitation, and gas-dust emissions flying into the atmosphere are deposited on the nearby landscapes. In aggregate, all the above mentioned technogenic flows carry pollutants, including heavy metals, which accumulate in the depositing environments, changing them in one way or another. Thus, for more than 100 years, in the Soymanovskaya Valley of the Chelyabinsk Region, as a result of the Karabashmed Copper Smelting Plant, soils and other landscape components have been undergoing changes under the influence of anthropogenic flows. Research methods and materials. As a result of this work, in order to study the impact of air-industrial emissions of the plant on the soil cover, soil samples were taken both from the adjacent landscapes in the vicinity of the plant and at a distance of more than 20 km from the source of gas-dust emissions. In the selected soil samples, the determination of the main physical and chemical parameters of soils was carried out: pH, Sorg content, exchangeable calcium and magnesium cations. To identify the degree of contamination of the territory, the gross content of Zn, Cd, Pb, Cu, Ni, Mn was determined by atomic adsorption spectroscopy. According to the obtained data of heavy metals content in the surface layer of soils, the total pollution coefficient was calculated. Research results. In the course of works, it was determined that in the lower illuvial horizons of soils of natural and anthropogenic landscapes the concentrations of heavy metals are practically at the same level. In the upper layers of soils, a significant difference with excess of heavy metal concentrations in soils of anthropogenic landscapes in comparison with soils of background areas was recorded, which may indicate the entry of pollution from the surface. Soils with a small thickness of profile (up to 45 cm), located near the mill, have a fully contaminated profile, from the surface to the lower horizons, as a result of which these soils are transformed into chemozems. With the distance from the mill a sharp decrease of concentrations to values close to background was revealed, even within the city limits. The obtained calculations of the total pollution coefficient Zc, indicate that all chemozems have skillfully dangerous and extremely dangerous category of pollution. Background soils have acceptable category of pollution. When comparing background soils and chemozems located in the zone of intensive anthropogenic load, it is established that there is no influence of bedrock on soil profile modification and transformation. In the lower horizons of such soils, both in chemozems and background soils, physico-chemical parameters practically do not change. Comparative analysis of the upper soil stratum showed significant exceedances of concentrations in comparison with clark and background content. Exceedances relative to these values are 50 times for Cd, 40 times for Cu, 45 times for Pb and 30 times for Zn. Conclusions. As a result of the conducted researches it was proved that the influence of air-industrial emissions of the combine on the transformation of native soils and formation of chemozems from them. This circumstance occurs for more than 100 years, as a result of the Karabash area, anomalous zones with high concentrations of heavy metals are formed, which directly changes the regional background. The results of the research can be useful in adjusting the regional geochemical background of heavy metals, making geochemical maps of the degree of soil contamination, as well as can serve as a basis for the development of measures to eliminate the degree of soil contamination.