Ecological Systems and Devices Annotation << Back ABOUT FEATURES OF PHYSICAL AND CHEMICAL PROCESSES IN NATURAL WATERS AND FORMS OF CHEMICAL ELEMENTS N.N. Roeva, O.A. Zaytseva, S.S. Voronich, A.G. Chernobrovina, I.A. Zaytseva, N.S. Voronich, A.V. Klyueva He main reason for the modern degradation of natural waters is anthropogenic impact. It is huge and takes place for a long time, presenting a great danger due to several reasons: 1) slow self-cleaning processes: the frequency of a complete exchange of a mass of water, which is close to the period of natural cleaning, is up to 2 500 years; 2) more diverse sources of pollution, which include wastewater from industrial enterprises, municipal services of cities and other settlements, drains of irrigation systems, surface drains from fields and other agricultural objects, atmospheric precipitation, etc.; 3) in water, as a solvent, the depth of chemical reactions increases, leading to the formation of new (secondary) compounds, even more toxic than primary ones. In this regard, in the presented article, the authors consider the features of the occurrence of physical and chemical processes and the most probable existence of various chemical elements in them. Keywords: Natural waters; toxicants; heavy metals; organic substances; phosphorus compounds. DOI: 10.25791/esip.03.2020.1142 Pp. 21-26.