FEATURES OF INTERACTION IN THE WATER–ROCK SYSTEM: A CASE STUDY OF THE IMANDRA LAKE CATCHMENT (THE KOLA PENINSULA)

Abstract

The relevance of the research is caused by the fact that when assessing the ecological and geochemical state of the natural environment, it is necessary to take into account the ratio of natural and technogenic processes occurring in all its components (soil, water, air, etc.). So, the main natural process that determines the enrichment of water with chemical elements is their interaction with rocks. However, the processes in the water–rock system can be significantly affected by the anthropogenic factor. In this regard, a deep understanding of the characteristics of hydrogeochemical processes within territories subject to significant technogenic impact is an important task of modern ecogeochemistry. The main aim is to study the water–rock interaction features under technogenic environment conditions in a case of Lake Imandra catchment (the Kola Peninsula). Objects of the research are natural waters of the Imandra lake catchment (the Kola Peninsula). Methods. Classical methods of analysis were used to determine the major ion concentration. To determine the trace elements in water, a NexION 300D inductively coupled plasma mass spectrometer was used. Saturation index (SI) was calculated by PHREEQC. Results. It has been established that within the catchment area of ​​Lake Imandra, low-mineralized natural waters of predominantly hydrocarbonate calcium composition with a neutral and slightly alkaline environment are widespread. The specificity of the chemical composition of the waters of the western and eastern parts of the territory under consideration is determined by the combined influence of natural and anthropogenic factors. Thus, the technogenic impact of the Severonickel plant is confirmed by the increased concentrations of nickel and copper in the surface waters of the western part of the territory. The considered natural waters are not in equilibrium with the primary aluminosilicate minerals and are saturated with hydroxides, iron and aluminum oxides and, to a lesser extent, copper, kaolinite, and, at some points, illite, Ca- and Mg-montmorillonite. From the standpoint of evolutionary development, the high intensity of water exchange in the territory under consideration is a factor that determines the presence of the water-rock system at the initial stages. The presence of copper oxides and hydroxides in the equilibrium mineral phase indicates the influence of technogenic factors on the processes of interaction in the water-rock system.

Keywords

• hydrogeochemical conditions
• chemical composition
• natural waters
• spring
• imandra lake
• kola peninsula
• water equilibrium
• water saturation
• saturation index