Modern State of the Dnieper (Zaporozhye) Reservoir in terms of Some Hydrochemical Indices

Abstract

Results of the study of the modern state of the Dnieper Reservoir in terms of some hydrochemical indices, including the content of dissolved oxygen, pH, and the content of inorganic forms of nitrogen and readily oxidized organic matter, are discussed in the paper. The concentration of oxygen dissolved in the water was characterized by low values both in summer and in autumn 2007. The same phenomenon was observed in winter. The studied section of the reservoir was characterized by a high content of ammonium, which was conditioned by its contamination by sewage, and also by possible migration of this compound from bottom sediments as a result of oxygen deficiency in the near bottom layer of water. A degree of contamination of the reservoir by readily oxidized organic matter was determined based on the values of permanganate oxidizability. At the same time, data on BOD5 inadequately reflect the degree of reservoir contamination by readily oxidized organic matter. It is likely that they are somewhat underestimated as a result of the toxic influence of pollutants on the vital activity of microorganisms.