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

At present an important role in solving energy conservation problem is assigned to thermal pumping plants (TPP). Using processes of evaporation and condensation of easily boiling liquid circulating in the system they extract low potential heat from environmental objects and provide heat supply for buildings, constructions, greenhousee and so on. Artificial sources of low potential heat for TPP of different capacity can be, for instance, ventilation air and exhaust gases, circulating and waste water,ground. Energy efficient reasonability of TPP use in the system of water disposal for the town of Novocherkassk in Rostov region is considered. Calculations indicate that there is a technical potential to replace a boiler house operating on expensive gas fuel and emissing into the atmospere more than 850 t of carbon dioxide - greenhouse gas - with ecologically clean TPP, one of which uses heat of waste water and the other - heat of ground.

Keywords: thermal pumping plant, renewable sources, energy conservation, evaporation, condensation, waste water, ground