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Energy recovery of various types is an urgent task in the development of control systems for electromechanical devices. rational and careful use of energy resources. The purpose of this work is to analyze four-quadrant asynchronous electric drives with vector frequency-current control systems and autonomous voltage inverters with sinusoidal pulsewidth modulation based on IGBT modules. The design algorithm is considered and the results of modeling of such energy recovery systems are given. The proposed control system of the recovery device can be used as an integral part of a specialized controlled electric drive for escalator stations of the subway, electric transport and other electromechanical systems in order to save energy consumed.

The work presents the results of studying the content of potentially toxic elements (Mn, Cu, Zn, Cr, Pb, Ni and Cd) in bottom sediments sampled at monitoring stations in the natural-anthropogenic systems of the Lower Don adjacent to the impact zone of the Novocherkassk Power Plant. The relationship between the content of metals in bottom sediments and their sorption properties is largely determined by the conditions of formation and the type of bottom sediments. Evaluation of the potentially toxic element content in sediments indicated that in particle size fractions (≤ 0.001 mm) could accumulate more than 15 times the levels of Cr and Zn and more than 6 times the levels of Cu, Cd and Ni in comparison to the particle size fractions that are 1.0 mm. Local zones of polyelemental pollution of bottom sediments with respect to Cu, Zn, Pb Cd and Cr were determined. These zones are confined to the geochemical sorption barriers of small watercourses of the power plant.

The regularities of the accumulation and distribution of metals (Zn and Cd) in various parts of wild herbaceous plants and the agricultural crop of the impact zone in Rostov region (Russia) was considered. A large accumulation of elements in wild herbaceous plants of the Asteraceae family was noted compared with Triticum aestivum. The pollution of Triticum aestivum by Cd was observed. Wild herbaceous plants of the Asteraceae family were contaminated mostly with Zn. It was found that Artemisia austriaca and Ambrosia artemisiifolia accumulated Zn and Cd in the aboveground part. Achillea nobilis accumulated Cd mainly in the root system. Closer location monitoring plots to the source of anthropogenic load and the location of the northwest winds prevailing in the region were main influencing factors leading to higher pollution.

Based on the cumulative pollution index, spatial distribution maps were obtained to establish categories of soil pollution taking into account the total content of heavy metals and the mobile forms of metals in the Don River estuarine region. The objects of the study included samples of zonal soils (Chernozem) and intrazonal soils (Fluvisols) from monitoring plots. The total concentrations of Mn, Cr, Ni, Cu, Zn, Pb, and Cd in the soils were determined by X-ray fluorescent scanning spectrometer. Mobile heavy metals compounds were transferred to a solution by extraction of 1 N NH4Ac, pH 4.8. When calculating the total metal content, it was shown the studied soils had generally an acceptable pollution category but taking into account mobile forms the categories of soils contamination variate up acceptable to extremely dangerous. The most polluted sites are associated with the estuary of small rivers and the branches flowing into the Taganrog Bay, the territory of the Taganrog port and its terminals, and road bridges. In line with hight categories of pollution, the use of the soils for cropping should be limited, and the cultivation of concentrator plants is excluded.

An analysis of the results of the reproduction of land in an open development of a horizontal mineral deposit has been carried out. The interconnection of the method and the system of open development of the deposit with the qualitative and quantitative levels of land reclamation, as well as their monetary estimation according to the direction of use, is substantiated. The principle of this approach to the planning of land abandonment measures at a mining enterprise from the point of view of the subordination of the technological processes of mining of minerals to the results of the reproduction of land in previous periods is proposed, which allows to take into account the quality of reproduction of land for determining the extent of their violation. The technological scheme of organization of mining works and land reclamation works is shown, which involves synchronization of these processes in terms of disturbance and reproduction of lands, as well as formation of a more qualitative soil layer due to its selective displacement. The components and peculiarities of the formation of the economic effect are determined from the introduction of dynamic schemes for the development of a quarry field on their relation to the cost of land leakage in the development of horizontal mineral deposits in the stages of the life cycle of a quarry.