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The objective of this paper is to identify the level of changes in the ecological status of surface reservoirs of Dnipropetrovsk region under the impact of anthropogenic factors and to find a rationale for the limit loads on aquatic ecosystems, based on a quantitative assessment of their assimilative capacity values using GIS-technologies.To characterize and evaluate economic activity in the river basins of Dnipropetrovsk re- gion, the data of state statistical reporting by the form of 2-TP "Water resources management" of the State Agency for Water Re- sources of Ukraine were used. Parameters characterizing the assimilative capacity of water bodies were determined by taking into consideration the perennial average values of river runoff resources of the priority watercourses of Dnipropetrovsk region in the years with varying degrees of supply: with an average (50%), a low (75%) and a very low (95%) river water content. The main indicators characterizing the assimilative capacity of the water bodies of Dnipropetrovsk region are actual and necessary multiplicity of waste- water dilution, the limit to assimilative capacity of surface reservoirs, index of assimilative capacity utilization of river runoff re- sources of varying degrees of supply. A classification that characterizes the level of assimilative capacity utilization for water bodies is proposed. The level of assimilative capacity utilization of the Dnipro River in the reservoir areas, regardless of the degree of river runoff supply, is estimated as “allowable” . At 95% degree of river runoff supply, the level of assimilative capacity utilization of the Oril and Vovcha Rivers is characterized as “moderate”, the Samara River (after the confluence with the Vovcha River) as “high” and the Ingulets River with tributary the Saksagan River, and the Samara River (before confluence with the Vovcha River) as “veryhigh”. It should be noted that irrespective of the level of river runoff supply, the index of assimilative capacity utilization of the Samara River (before its confluence with the Vovcha River) exceeds the limit value by 19-115 times. For the spatial analysis of hydrological parameters and visualizion of the data in the form of thematic maps, the geoinformation system “Rivers of Dnipropetrovsk region” was developed on the basis of the ESRI ArcGIS Desktop10 software package. Using the geoprocessing tools, on the basis of hydrological indices of 7 priority watercourses for each of the 22 administrative-territorial districts of Dnipropetrovsk region, the main indicators characterizing the assimilative capacity of water resources were calculated and ranked. The use of indicatorscharacterizing the assimilative capacity of river runoff resources allows us to identify the threshold levels of anthropogenic transfor- mation of aquatic ecosystems, develop and implement environmental measures to improve the ecological status and ensure environ- mental safety of surface reservoirs.

Rock mass transloading from bunkers to conveyors or from conveyors to conveyors in quarries is accompanied by intense releases of dust into the atmosphere, which is a significant danger to the environment. The regularities of the interaction process between dust particles and droplets of a liquid (water) in polluted air flow are determined. It is established that when the pressure of compressed air is changed from 0.1 to 0.4 MPa (approximately in the range of 1 to 4 atm.), the average size of droplets decreases from 26 to 9 microns. Justification of the localization method of dust emissions into the atmosphere, arriving from the units of dust formation in crushing and sorting complexes of quarries, is done with the use of air-and-water ejectors − irrigators with highly efficient water use, sprayed with separate nozzles. Variants of air-and-water ejectors placement on dust formation sources are grounded. The choice of the optimal mode of air-and-water ejectors operation depends on the characteristic sizes of the formed dust particles, which are determined by the parameters of the crushing and sorting equipment in the quarry. Reducing dust emissions within the sanitary protection zone of the quarries prevents its dispersion in the adjacent zone.

In the case of mechanical treatment of mine water in settling tanks according to the existing technology the concentration of suspended solids during the discharge of clarified effluents into water bodies does not correspond to the maximum permissible content of mechanical impurities set for surface water bodies. The technology of mine water cleaning has been improved due to the introduction of a horizontal settling tank of modernized construction and installation of purification of fast open granular filters with downward liquid flow at the final stage. The expected technological parameters of the proposed horizontal settling tank for the conditions of water disposal of the operating coal mining enterprise are determined. The dependences between the depth of sedimentation of particles of the suspension of a certain hydraulic size in the proposed horizontal settling tank, its length and clarifying efficiency of mine water pre-treated with a solution of aluminium sulphate are obtained. It is established that the overall efficiency of clarifying of mine waters pumped to the surface by a coal mining enterprise, after treatment by the proposed technology will be 94-95% of the initial concentration of suspended solids, which does not exceed the relevant quality of surface water.

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