Scientific substantiation of the possible use of Dniprovsky reservoir as the potable water source in contemporary conditions

Abstract

The research of the water quality from potable water source - Dniprovsky reservoir near the coastal pump stations of the first lift (CPS-1 and CPS-2) JSC Zaporizhstal (the location of water intake - Dnipro river above the SI DniproHES dam), potable water after the water treatment facilities, and water from water intake cranes of JSC Zaporizhstal was conducted. It was found that water quality within the first sanitation zone of water intake during the research period in all locations of water intake met the 2-3 quality class according to the DSTU4808:2007 “Sources of centralized potable water supply. Hygienic and ecological requirements to water quality and intake rules”. According to SanPiN 4630-88 “Sanitary regulations for the protection of surface water from the pollution” the source water had a steadily high consistent of organic substances: chemical oxygen demand (its content was from 19,2 to79,2 mg/l), biochemical oxygen demand during the 20 days (its content was from 2,16 TO 34,3 mg/l), iron (maximum content-0,44 mg/l), and phenols (from 0,001 to 0,07 mg/l). The determined quality of water from Dnipro in the location of potable water intake characterizes all reservoirs of Dnipro cascade and attributed to natural and anthropogenic factors. It was found that traditional technology of potable water purification on the water treatment facilities of JSC Zaporizhstal does not provide the potable water with required hygienic standards, the determined problematic indicators are: toxic (second class of hazard- chloroform (93,2 – 138 µg/l), sum HMUA (117 – 182,5 µg/l), bromdichlormethan (22,7 –  40,9 µg/l), and “indicator” according to the European legislation (third class of hazard–permanganate demand (5,9 – 10,4mg/l), iron (0,13 – 0,94mg/l), manganese (0 - 0,19 mg/l)), and fourth class of hazard – phenols (maximum content-0,005 mg/l). Toxic substances are formed during the primary chlorination of surface water, other pollutants are transferred with the surface water through the water pipes to the potable water. The water quality in Dniprovsky reservoir (the location of water intake - Dnipro river above the SI DniproHES dam), coastal pump stations of the first lift (CPS-1 and CPS-2), water intake structures in contemporary conditions can be used for the potable water production provided the technologies of potable water preparation which is currently used on the JSC Zaporizhstal will be improved based on current state and water quality in the water source. It can be done using different ways: by adding to the current technology the additional stage of water purification, firstly from the organic substances before the natural water inflow to the main treatment facilities, by using of more effective coagulants and flocculants, sorption bedding for filters, disinfection agents etc.