Spatial distribution and risk assessment of heavy metals in bottom sediments of two small dam reservoirs (south-east Poland)

Abstract

Sediments of two dam reservoirs in SE Poland, Zalew Zemborzycki (ZZ) and Brody Iłżeckie (BI) were studied. The sediments from both reservoirs were sampled in the transects perpendicular to the shoreline, at the river inflow and the frontal dam. The total concentration of Mn, Zn, Pb, Cd, Cu, Cr and Ni was determined by ICP-EAS method after the sample digestion in the mixture of concentrated HNO3 and HClO4 acids. The statistical analyses: value intervals, mean values, variation coefficient, the median and the skewed distribution were performed. To estimate differences between the means for transects, Tukey’s test was applied with least significant difference (LSD) determination. The maps of the metal spatial distribution were drawn and sediment quality according to the geochemical and ecotoxicological criteria evaluated. Differences between the reservoirs in terms of heavy metals concentration in bottom sediments, and regularities in their spatial distribution were found. In the ZZ sediments the concentration was at the level of geochemical background (Zn, Cr), slightly (Cd, Cu, Ni) or moderately (Pb) contaminated sediments. The metal concentration in the sediments of the BI was up to eight times higher as compared to the ZZ. Moreover, sediments from the BI reservoir showed a greater variability of metal concentration than those from ZZ, which resulted from the dredging operation performed in the part of the reservoir. Metal concentration in sediments of the dredged part was ca. 2–5 times lower than in the undredged one, which indicates that after the dredging operation, accumulation of these metals was slight. The concentrations of Zn, Pb and Cd from the undredged part of BI were at the level of contaminated sediments and exceeded the probable effects level (PEL). In the ZZ, the greatest accumulation of metals occurred in the upper part of the reservoir and at the frontal dam, and the lowest in the middle part of the reservoir. In BI, the lower outflow of water in this reservoir caused a lower metal concentration in the sediments at the frontal dam, as compared with the other sediments in the undredged part of the reservoir. The results indicate that in small and shallow reservoirs, areas of accumulation of heavy metals depend on such factors as a parent river current, reservoir depth, water waving, reservoir shape (narrowing, coves/bays), and type of water outflow.

Bioecological and statistical risk assessment of toxic metals in sediments of a worldwide important wetland: Gala Lake National Park (Turkey)

“…Many indices have been developed to evaluate the environmental risks of toxic elements in surface sediments and they are widely used to evaluate the sediment quality (Smal et al 2015, Borowiak et al 2016. Potential Ecological Risk Index (RI) and Biological Risk Index based sediment quality guidelines (mERM-Q) are two of the most widely used sediment indices used to evaluate the environmental risks (Çiçek et al 2013).…”

Impact of copper sulfate application at an urban Brazilian reservoir: A geostatistical and ecotoxicological approach

“…In order to understand the spatial distribution of copper throughout the Guarapiranga ELU, a kriging interpolation method was implemented using Geovisual v. 5.0 software, following the procedure of Yamamoto and Landim (2015). This technique has been used in other similar studies (Smal, 2015;Batista, 2011;Alcantara, 2008;Burgos-León et al, 2012), and it has been shown to be an excellent tool for spatial analysis (Cressie, 1993;Camargo et al, 1999Camargo et al, , 2001Machado et al, 2004).…”

Ecological risk assessment of metals and metalloid in bottom sediments of water reservoir located in the key anthropogenic “hot spot” area (Poland)

“…The chemical composition of bottom sediments, which are an integral part of aquatic environment, is conditioned by many natural and anthropogenic factors. It results from the geological structure of the catchment, land geomorphology, climate conditions, the way of management and use of catchment area, as well as the amount of contaminants reaching surface waters (Smal et al 2015). The natural sources of metals and metalloids in water bodies are atmospheric inputs, as well as geological weathering of rocks and soil (Ghaleno et al 2015;Wardhani et al 2017), but the majority of these toxic elements are of anthropogenic origin (mining, disposal of wastewaters, metal chelates from different industries, use of fertilizers, atmospheric deposition, etc.)…”

“…Within Kłodnica catchment, hard coal mines, industrial plants and wastewater treatment plants, etc., are located (Barbusińki and Nocoń 2011). It is important to note that properties of toxic elements, i.e., their concentrations, non-biodegradability and toxicity are the major reason for their monitoring in an aquatic environment (Smal et al 2015). Strong attention should be, therefore, put to ecological state of contaminated water bodies located in Silesian Region, which makes this issue one of the most current research topic in Poland.…”