Potential ecological risk index of bottom sediments from small water reservoirs

Abstract

The aim of this study was to determine the degree of contamination of bottom sediments from two water reservoirs, Rejów and Wojciechów, with heavy metals based on geochemical criteria. These reservoirs differ in terms of their lifetime, capacity, and the size and land use of the catchment area. The sediment samples were analyzed for group of heavy metals (HM) including cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), zinc (Zn), nickel (Ni), manganese (Mn) and iron (Fe). Additionally, the pH, particle size distribution of the sediments was examined and the content of organic matter expressed as losses on ignition (LOI), total content of nitrogen and phosphorus, TN and TP, respectively were determined. The degree of contamination of the sediments with selected HM was assessed using the enrichment factor, geoaccumulation index (Igeo) and potential ecological risk index. Analysis showed that the sediments from two reservoirs were characterized by high variability in both the content of HM and their contamination index, which may be related to the source of the elements, as well as with the development of the catchment areas.