Grain size partitioning of mercury in sediments of the middle Odra river (Germany/Poland)

摘要

The aim of this study is to determine the distribution of mercury in different grain size fractions of surface sediments from the middle course of the Odra river. Mercury concentrations were determined in bulk sediments of different grain size fractions using the cold vapor atomic fluorescence spectrometry method. The total mercury concentration in bulk sediments varied from 0.051 to 1.31 mg/kg dry weight. The concentration of total mercury was determined in the grain size fractions < 0.2, 0.2 -0.5,0.5-1.0, 1.0 - 2.0 and > 2.0 mm to be (in mg/kg d. w.): 0.118- 2.99, 0.033 - 0.99, 0.034 -1.17, 0.035 - 1.97 and 0.017 - 3.65, respectively. Gradual decrease in the mercury concentration with increasing grain size from fine to coarse fraction has been observed only for sediments taken from the riverbed. Although, no similar gradual decrease in the mercury concentrations has been observed for sediments from the river-banks, finer sediments (< 0.2 mm) still tend to show higher concentrations of mercury.