FEATURES OF NATURAL WATERS COMPOSITION IN ONE OF THE LARGEST INDUSTRIAL ZONES IN EUROPE.

The authors of the article consider the features of the composition of surface and groundwater in the industrial zone named Nizhnekamskfaya and its surroundings in 1979–2018. Industrial zone Nizhnekamskaya is one of the largest in Europe. It is located within the Tatarstan Republic and includes many large petrochemical and oil refineries. According to the analysis of hydrochemical data, the authors can claim that the composition of natural waters in the vicinity of the industrial zone has not changed significantly over the past 40 years. Waters with a salinity of less than 0.5-0.6 g/l and a total hardness of less than 7-8 mmol/l with the composition HCO3/Ca and HCO3/Mg-Ca are most common here. Groundwater salinity can reach 1.25 g/l, hardness can reach 17.7 mmol/l, and permanganate index can reach 17.3 mgO/l within industrial zones. The composition of underground water has the strongest changes within and near industrial landfill sites. Salinity can reach 12 g/l here, the hardness is 135 mmol/l, and the concentration of the most characteristic pollutants (mg/l): petroleum products - no more than 500–982; phenols - no more than 13.9; total iron - no more than 153. However, the concentrations of many pollutant components can decrease by 1-2 orders of magnitude already at a short distance from the landfill (at a distance of 150-200 m), and at a distance of 1.0-1.5 km from it, signs of pollution of natural waters disappear. The composition of natural waters in the vicinity of the industrial zone named Nizhnekamskfaya does not change over time due to the high buffer (protective) properties of its geological environment. [ABSTRACT FROM AUTHOR]