Home – Home – Jornals – Contemporary Problems of Ecology 2021 number 6

The results of three-year measurements (2018-2020) of hydrophysical and hydrochemical indicators of the Vychegda River in places where treated wastewater is discharged from the Mondi Syktyvkar JSC pulp and paper mill are presented. At conventionally background stations and exposed to wastewater in concentrations significantly lower than the MPC: mineralization, the content of ions of Ca²⁺, Mg²⁺, Cl^-, SO4^2-, NO3^-, heavy metals, oil products, anionic surfactants, benz[a]pyrene were noted, an excess of MPC was noted for Suspended substances, COD, РО4^3-, Fe, Mn. Studies have shown that in connection with the modernization of the treatment facilities of Mondi Syktyvkar JSC, there is a noticeable improvement in the quality of wastewater and a decrease in the environmental load on the ecosystem of the Vychegda River in places of their discharge. With a high water level in the Vychegda River (2018-2019) for all investigated hydrochemical indicators in the places of wastewater discharge, no significant excess over conditionally background values - was revealed. It was possible to register the impact of pollutants only in the low-water period (2020), with a decrease in the degree of dilution by river waters of effluent from treatment facilities. During this period, at the observation points in the places of wastewater discharge, a significant increase was noted relative to the conditionally background indicators of the concentration of ions Cl^-, SO4^2-, РО4^3-, NH₄⁺, S_tot, K, Na, Fhenol, as well as COD, Permanganate Value, turbidity, electrical conductivity. In terms of environmental, sanitary and toxicological indicators, the waters of all surveyed observation points were assigned to the 3rd class of water quality (satisfactory purity).