Time and spatial variability in concentrations of selected metals and their species in water and bottom sediments of Dzierżno Duże (Poland).

Poland is an industrialized country in which industries (especially the heavy ones) have had a tremendous influence on the environment. It is particularly visible in the Upper Silesia region, where the observed air, soil and water pollution levels are the most highest. The aim of this study was to determine the time and spatial variability in: concentrations of selected metals (Co, Ni, Zn, Cr, Mn, Pb, Cd), and, to a limited extent, of Cu, V, Al and Sr; concentrations of inorganic ions (Cl-, SO42-, Na+, K+, Ca2+ and Mg2+) and values of pH, conductivity and redox potential. The enlisted parameters were determined for the water and bottom sediments of Dzierżno Duże, a water reservoir located in Poland (Upper Silesia region). Additionally, fractions of a few characteristic metals were determined in the bottom sediments of the discussed reservoir with the BCR method. The investigation was carried out in 2017. It showed that the reservoir surface water was not polluted with the determined metal contents. However, it was highly polluted with the inorganic ions. The metal contents determined in the bottom sediments were high. If the conditions for releasing them from the bottom sediments had been favorable, this situation could have posed a potentially considerable environmental threat.