engleski

Environmental risk associated with water in the abandoned mines

There is a strong need for mine water risk assessment. In Europe, the majority of mine water problems are associated with abandoned mines, thousands of which can be found in nearly all European countries. The abandoned mines are the mine sites that are no longer operational, not actively managed, not rehabilitated. These sites include open pits and waste disposal areas, such as tailing dumps and ponds. The most serious problems are linked to the interruption of dewatering, leading to flooding in mines and discharge of mine water to surface water and to river valleys. The major problem affecting water resources is acid mine drainage (AMD). That is the consequence of the interaction of sulphides such as pyrite minerals, with oxygenated water. Due the increased mobility of metals at low pH, acid mine waters with elevated concentrations of toxic metals and metalloids, such as As, can affect water quality and thereby also aquatic biota. The mine water can pose serious health hazards for the communities around the area, and can affect the livelihood of communities that depend on fishing. In the Balkans region, we have investigated the quality of the water and sediment in the lakes that have formed naturally in the place of former open pits (OP) of the Smreka iron mine, Drage coal mine, Vinjani bauxite mine, as well as in the Veovača tailing lake, located in the location of the of abandoned Zn-Ba-Pb mine. Metal concentrations were determined using ICP-MS techniques. It was found that lakes are not acidic ; the pH values are circum-neutral due to the presence of carbonates. At the location of the coal mine, the water is characterized by elevated Mn (55.8 - 84.3 μg/L), Ni (30.7 - 33.1 μg/L) and uranium (up to 33.7 μg/L) concentrations. Number of metals (Cd, Pb, V, Mn, Fe, Cu, Zn, Sb, Ba, As) showed high enrichment in sediments of the lakes Smreka and Veovača. In both lakes, concentrations of As, Cd, Cu, Pb and Zn in sediment are above the Probable Effect Levels (PELs) values, according to the Canadian Sediment Quality Guidelines. However, the concentrations of metals in the water of these lakes are low suggesting that metals deposited in sediment are not very mobile. Mine water studies and designing monitoring program allow timely recognition of risks and the development of methods to minimize their adverse impact.

Environmental risk ; water ; abandoned mines

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