Evaluation of Efficiency of Treatment Facilities Cities of Ternopil by the Complex of Hydrochemical Parameters of the River Seret

Introduction. The quality of wastewater treatment in settlements is an important task of our time. To assess the efficiency of treatment plants in a particular city often use the hydrochemical parameters of the reservoir into which the treated wastewater is discharged. The paper describes the modern sewerage system of the city of Ternopil and the technological process of operation of citywide sewage treatment plants (STP). The purpose of the work is to find out how effectively the Ternopil STP work and whether their activity poses a danger to the Seret River and the inhabitants of coastal settlements. Methods. Hydrochemical parameters of these water samples were studied in the laboratory according to appropriate regulatory methods. Potentiometric, gravimetric, photometric and other methods of chemical analysis were used for research. Results of the research. 2 samples of water from the river Seret were taken for laboratory research. One sample was taken upstream near the outlet of the drain pipes of these structures, the second sample - downstream. Based on the obtained numerical results of the analyzes, the efficiency of the city's treatment facilities was assessed. It is shown that the overall water quality in the Seret River downstream after the discharge of the city's wastewater treatment  plants is satisfactory. The levels of nitrates and phosphates in the studied samples are almost on the border of the MPC, but this is not necessarily due to the poor performance of the city's treatment facilities. There are many agricultural lands on the banks of the river, which often use nitrogen and phosphorus fertilizers. Significant exceeding of the limit value for chemical oxygen consumption can be explained by the warm season (September). At this time, a lot of biological organic matter has accumulated in natural reservoirs. Conclusions. As a result of researches it is established that treatment facil-ities of the city of Ternopil work in a regular mode and provide sufficient sewage treatment. According to open sources, the annual dynamics of the mentioned treatment facilities is shown. As a result, it has been found that since 2017, the efficiency of the city's wastewater treatment at sewage treatment plants remains stable. Such indicators testify to the sufficient efficiency of the treatment facilities of the Ternopilvodokanal utility company