Monitoring of chemical and biological composition of bottom silt (literature review)

Abstract

The work is devoted to the study of the formation of bottom sediments and silt, their impact on the state of aquatic ecosystems, effective research methods and their practical application. Due to the continuous anthropogenic load, heavy metals, polycyclic aromatic hydrocarbons and other pollutants constantly accumulate in the silt and bottom formations. They undergo various chemical processes that can produce compounds that are even more toxic. The accumulation of this complex of pollutants subsequently becomes a source of secondary pollution, affecting the quality of water in reservoirs, reducing the species diversity of aquatic organisms and, through migration and movement along food chains, negatively affecting the condition of plants, animals and people, ultimately violating the processes of self-purification. Silt and bottom sediments thus become indicators of water pollution. On secondary deposits, biological processes are inhibited, anaerobic conditions arise, acidity increases, which contributes to the constant release and entry of harmful gases into the atmosphere. One of the main consequences of this process is the greenhouse effect and the violation of the heat balance. One of the ways to monitor bottom sediments is bio testing. In this method, crustaceans are chosen as test organisms because of their sensitivity to pollution, wide distribution. Bio testing can be used as an independent method for assessing the state of aquatic ecosystems, and in their integral assessment. Now in Russia there is no system for assessing the quality of bottom sediments, which greatly complicates the assessment of the state of surface water bodies and the prediction of negative processes. Thus, data on the composition of pollutants in silt and bottom sediments are not applicable for ecological characterization. Therefore, it seems necessary to create a unified methodology and establish interdepartmental communication of specialists in order to fully assess the pollution of water bodies and respond in time to threatening levels.