Researches of the chemical composition of surface water in Ukraine, 1920-2020 (review)
Authors: Khilchevskiy Valentyn K. , Sherstyuk Natalia P. , Zabokrytska Myroslava R. 
Published: July 2020

The development of researches of the chemical composition of surface waters (rivers, lakes, reservoirs and ponds) is due to problems that are solved at one stage or another in the development of the country’s economy and are related to water quality issues. Depending on the tasks set during hydrochemical researches, attention is paid to a particular group of chemical components in water: 1) the main ions and their total amount (water mineralization); 2) dissolved gases; 3) biogenic elements; 4) organic matter; 5) microelements (including heavy metals); 6) radioactive elements; 7) specific pollutants. The article presents an analytical review of studies of the chemical composition of surface waters of Ukraine from the beginning of systematic research in the first half of the 20th century to the present day (1920-2020). The authors identified four typical chronological periods in the history of hydrochemical studies of surface waters in Ukraine. I period (1920s-1950s) – the beginning of systematic hydrochemical studies of surface waters; the appearance of regular observations of the chemical composition of water at the posts of hydrometeorological service on the Dnipro and Southern Bug rivers (1930s) and publication of these data in “Hydrological Yearbooks”; hydrochemical studies for selected large projects (Dnipro hydroelectric power station). II period (1950s-1970s) - expansion of hydrochemical research to meet the needs of water and hydropower construction, forecasting their possible impact on the country’s water resources; increasing the number of observation points for the chemical composition of water on large and medium-sized rivers; development of hydrochemistry of reservoirs. III period (1970s – at the beginning of the 2000s) – development of complex hydrochemical researches in the conditions of increasing anthropogenic load on water objects; creation of a system of hydrochemical monitoring of water bodies within the framework of the national system of observation and control of the environment (1973); application of sanitary and hygienic criteria for assessment of water quality – universal maximum acceptable concentrations (MAC); publication of quarterly “Hydrochemical Bulletins” (since 1967); development of radioecological studies of natural waters after the Chernobyl accident (1986); first publication in Ukraine of textbooks on hydrochemistry. IV period (after the beginning of the 2000s) – reformatting of hydrochemical research (monitoring system) to the requirements of the Water Framework Directive of the European Union, especially after the signing of the EU-Ukraine Association Agreement in 2014; reforming the water monitoring system based on environmental rationing with the identification of reference indicators; components of state monitoring of surface waters are the monitoring of biological, hydromorphological, chemical and physico-chemical parameters. The article also describes scientific hydrochemical schools: Institute of Hydrobiology of NAS of Ukraine; Taras Shevchenko National University of Kyiv; Ukrainian Hydrometeorological Institute of the State Emergency Service of Ukraine and NAS of Ukraine.