Zawartość rtęci w osadach dennych rzek Rudawa i Prądnik

Abstract

Mercury content in the bottom sediments from the Rudawa and Prądnik rivers.A b s t r a c t. Aquatic ecosystems, including river sediments, are particularly vulnerable to contamination with mercury compounds. One of the most visible effects of increased mercury pollution are changes in the concentration of this element in the bottom sediments of rivers that collect surface water from industrial areas, where numerous sources of mercury emissions are found. The aim of the study conducted in 2014, was to assess mercury contamination of the bottom sediments in the Rudawa and Prądnik rivers in areas with different land use: urban-industrial and agricultural, and thus to recognize the possibility of a potential threat to the environment including the groundwater. For the purpose of comparison, results of research conducted by the authors for the Chechło river bottom sediments in 2007 were used. Mercury contamination of bottom sediments of the Rudawa, Prądnik rivers and the previously studied Chechło river is characterizedby considerable diversity and variability from the spring to their mouth. The highest mercury contamination was found in the sediments of the Chechło river, especially in the mining area. Average mercury content in the sediments of the Chechło river is 0.380 mg/kg. The studies have shown the lowest mercury content in the Rudawa river sediments, where the mean values are between 0.066 mg/kg and 0.071 mg/kg, depending on the depth of sampling. The mean levels of mercury in the sediments of the Prądnik river are higherat between 0.203 and 0.246 mg/kg. Mercury contamination in the river Prądnik’s sediments increases in the lower course, particularly in the vicinity of Krakow metropolitan area. No observed a clear correlation between total mercury content in the test samples and the share of silt and clay fractions in the bottom sediments.