Changing parameters of waters chemical composition in the Lake Arakhley water column (Eastern Transbaikalia)

The need to preserve the quality of water resources under conditions of anthropogenic impact is one of the most urgent problems of our time. The purpose of this work was to study the features of the distribution of the parameters of the chemical composition of the waters of Lake Arakhley in a vertical section. The investigated waters are characterised by a constancy of mineralisation and chemical composition, both within the water area and in the vertical section. The waters are ultra-fresh (salinity less than 200 mg / L), neutral and slightly alkaline (average pH 7.9), HCO3 Mg-Ca chemical composition. The carbon dioxide content in the water column has a significant impact on the concentration of hydrogen ions, as evidenced by the inverse relationship between pH and CO 2 content. The observed increase in the nitrogen form and CO 2 contents in the bottom part of the lake is most likely related to the life processes of organisms and vegetation. The recorded excess concentrations of Mn, Cu, Ni, and Al over maximum permissible concentrations indicate the need for additional studies to identify their sources.