Occurrence of heavy metals in bottom sediments of a heated reservoir (the Rybnik Reservoir, southern Poland)

Analysis of changes in the content of metals in the different layers of bottom sediments (0-5 cm, 5-10 cm, 10-15 cm, and 15-20 cm) showed that the content of chromium, copper, iron, and manganese decreased with depth of the sediment, confirming a constant increase in the inflow of these metals to the reservoir. The smallest content of cadmium was found in the surface layer of the sediment. Analysis of chemical similarity of the bottom sediments at various stations permitted the statement that in the surface layer the content of metals was similar at stations lying in the shallow zone of the reservoir. A great similarity of the chemical composition also occurred in the sediments sampled in the deep zone. -Authors