ENVIRONMENTAL ASSESSMENT OF CONTAMINATION OF THE TEREK RIVER IN THE TERRITORY OF THE CHECHEN REPUBLIC

Abstract. Aim. The aim of this work was to study the content of poisonous substances in the aquatic environment of the river Terek during the year of 2016 in the territory of the Chechen Republic. Materials and methods. Water samples of the river Terek were analyzed in the Laboratory of Environmental Control of the Ministry of Natural Resources and Environmental Protection. Dry residue was determined by weight analysis; stiffness by acid-base titration; acid-base properties by potentiometric method; the ion content was determined spectrophotometrically; concentration of heavy metals was identified with voltammetric analyzer; concentration of calcium and magnesium ions was measured titrometrically with Trilon B in the presence of an appropriate indicator. Results. The intensity of contamination of the water body was assessed according to the following parameters: total hardness, dry residue, permanganate value, pH, chlorides, dissolved oxygen, sulfates, nitrates and heavy metals content. In the course of the study, sensory characteristics such as smell, taste, turbidity and color were also determined; indicator value - permanganate value, which characterizes the contamination of water bodies with industrial and household wastewater as well as atmospheric precipitation. Conclusion. Studies of the ecological state of Terek, the main river of the Chechen Republic, have shown that the quality of the water body corresponds to hygienic standards: the content of pollutants is much lower than the maximum permissible concentration. In terms of water quality, the Terek River belongs to the 2nd class of surface water bodies, the water quality characteristic is relatively clean and the river pollution index corresponds to II