Changing the Hydrogeochemical Condition in the Eastern Donbass for 25 years

Abstract

For decades, the coal industry has had an intense negative impact on all environmental components in Eastern Donbass. Mine water is one of the most powerful factors in the transformation of hydrogeochemical conditions. Particularly intense changes in the concentrations of macro components in mine waters have occurred in the last 25 years the field of mass liquidation of coal mines in the region. For all the limited macrocomponents, the MAC exceeded the water supply of household-drinking, cultural, and domestic water use in average concentrations, and for some components even on minimum values. For an average concentration of 20 micronutrients, excess of MAC was found in 53 % of components, at a maximum concentration of 73 %. The average concentrations of a number of elements are ten times higher than the corresponding MAC, and at maximum concentrations the excess is hundreds of times. In groundwater and surface waters there was an increase in average, median and maximum concentrations of macro components by 1.2-2.0 times. On average concentrations, the excess of MAC was observed for 67 %, and for the maximum – for 83-100% of the limited components. For average concentrations of trace elements in groundwater, excess was observed in 40 %, and for maximum values in 67 % of cases. Average concentrations of trace elements exceed MAC several times, maximum concentrations – tenfold. After the liquidation of coal mines, there was a sharp increase in the oxidation processes of sulphides and sulfur contained in coals and consumable rocks, and the dissolution of sulfates. Comparison of hydrogeochemical conditions in Eastern Donbass before and after the mass liquidation of coalmines (for 25 years) revealed a significant deterioration in the quality of mine water and increased groundwater pollution processes in the region. All of this demonstrates the need for rehabilitation measures and improvements in treatment technologies.