The paper discusses the integral indicators of the quality or level of contamination of natural waters, allowing for an assessment of their ecological status. It has been established that the criterion for the quality of treated wastewater discharged into a water body is a regulatory allowable discharge, but it is not always possible to calculate it, especially for small rivers characterized by low flow rates of the river runoff compared to the flow of wastewater. An integral indicator is proposed for assessing the level of pollution of wastewater discharged, a formula for calculating it, as well as criteria for assessing the quality of wastewater discharged according to the proposed integral indicator. The method of calculating the integral indicator is based on the assessment of the quality of wastewater discharged in terms of BOD5, dissolved oxygen, and nutrient elements. Using the wastewater discharged from the Novocherkassk wastewater treatment plant as an example, an integral indicator of the level of contamination was calculated, which made it possible to characterize the wastewater discharged as “dirty” and make a conclusion about the need for additional treatment.

Keywords: wastewater, water pollution level, integral indicator of water quality, sewage treatment facilities

The paper considers the main factors determining the quality of underground water deposits within the RO, done hydrochemical and geoecological assessment of groundwater RO. The entropy of the groundwater ecosystem is calculated. It was found that most of the deposits have an entropy of less than 30%. that is, the water is clean enough, not experienced external influences. However, the water quality has deviations in individual indicators from the requirements of SanPiN 2.1.4.1074-01, which can be eliminated by conventional methods of water treatment.

Keywords: groundwater, hydrogeochemical heterogeneity, classification of groundwater, drinking water

The article describes the chemical composition of groundwater in the Rostov area. On the basis of sanitary and environmental assessment of the chemical composition of groundwater from wells, one of the areas of the South-Eastern part of the Rostov area, which are sources of water of the Egorlykskaya station, it was found that the concentration of hydrogen sulfide exceeds the MPC by about 1000 times. Analysis of methods of water purification from hydrogen sulfide, the main of which include: oxidation with molecular chlorine, sodium hypochlorite, hydrogen peroxide, showed the advantage of using the hydrogen peroxide. A new reactor design is proposed, which allows to increase the contact time of the treated water with the oxidant by hydrogen peroxide without increasing the size of the structure. This allows the maximum transfer of dissolved hydrogen sulfide in the solid phase.

Keywords: groundwater; hydrogen sulfide, purification, hydrogen peroxide, chemical reactor, economic efficiency

the paper presents characteristics of the solid waste landfill in the town of Novocherkassk, and the dynamics of pollutants’emissions from the landfill site for the period between 2015-2017 as well. The characteristic of the atmospheric air on the border with the nearby residential development and Novocherkassk landfill on the basis of the calculated air pollution index (API) and the complex index of atmospheric airpollution.

Keywords: landfill site, the contaminants, the maximum surface concentration, maximum permissible concentration, air quality

The aim of this work is to study the degree of protection of underground waters of the Kuibyshev district of Rostov region. The study area represented by the geological deposits of Quaternary (recent sediments) Qh, Neogene and Paleogene systems (Oligocene) P3, Cretaceous (upper division) K2 and the Carboniferous system (upper, middle and lower portions) S1,2,3 based. On the analysis of geological structure of water-bearing rocks in the Kuibyshev district of the Rostov region, which showed an insufficient degree of protection of underground waters against pollution and, as a consequence, insufficient supply of public drinking water, built map of underground waters protection of the Kuibyshev district of the Rostov region

Keywords: groundwater, Geology, classification of water, pollution, drinking water, rural settlement