Peculiarities of formation of water quality of surface sources of water supply as a factor of a choice of a method of water treatment

The current state and formation of water quality in reservoirs that serve as sources of drinking water supply were considered. It was revealed that phytoplankton becomes one of the main factors influencing the formation of water quality in reservoirs in the warm period from June to November, especially during the period of reservoirs “blooming”. Mostly these processes are triggered by the explosive development of blue-green algae (cyanobacteria). The factors accompanying this phenomenon are shown. The characteristic of the influence of global climate change and new composition of wastewater on water quality in surface water supply sources is given. If earlier the sewage contained significant volumes of heavy metals, oil products, phenols, etc., now they are observed to decrease at several times and vice versa - an increase in the volume of biogenic compounds, especially phosphates is observed. The emergence of phosphates is caused both by the ingress of phosphate fertilizers into water bodies, and by household reasons - the massive distribution of phosphate-based detergents and the inability of existing sewage treatment plants to efficiently process them. Screening monitoring of the Dnieper river basin showed extremely high levels of the predicted safe concentration of herbicides, insecticides, fungicides, as well as pharmaceutical substances such as carbomazepine, lopinavir, diclofenac, efavirenz, etc. in water. That is, among organic pollutants, the focus changes from classic petrochemical products to the products related to agricultural and pharmaceutical production, which, in certain concentrations, can stimulate the development of phytoplankton. The effective methods for treating surface water in modern conditions are as follows: - physical retention of coarse fractions of phytoplankton using new designs of water intake structures; - the use of new filter materials that effectively trap finely dispersed phytoplankton fractions at the main treatment facilities and are capable of regenerating the filter media; - the use of new oxidizing agents-disinfectants that do not form toxic organochlorine compounds, with preliminary extraction of phytoplankton masses;