Preliminary assessment of total dissolved trace metal concentrations in Sava River water

Abstract
This study provides the preliminary data set for total dissolved trace metal concentrations in the surface water of the Sava River in Croatia and the assessment of Sava River water quality status. The highest levels of total dissolved metals were observed for Fe, Mn, and Zn (12.6 ± 7.8 μg L − 1, 3.44 ± 3.95 μg L − 1, and 2.27 ± 1.53 μg L − 1, respectively), the intermediate concentrations for Ni, Cu, and Cr (0.59 ± 0.14 μg L − 1, 0.54 ± 0.14 μg L − 1, and 0.32 ± 0.06 μg L − 1, respectively), and the lowest levels for Co, Pb, and Cd (0.064 ± 0.022 μg L − 1, 0.055 ± 0.051 μg L − 1, and 0.011 ± 0.004 μg L − 1, respectively). The results refer to the grab water samples taken at five sites in the period from March to June, 2006. For four trace metals (Mn, Pb, Zn, and Fe), the high temporal variability within one season was observed. It can present a problem for reliable evaluation of total dissolved concentrations of these metals in the river water, if the assessment is based on the occasional grab water sampling. The comparison of results obtained in this study with previously reported data for several unpolluted rivers indicated that Sava River water reflects a certain anthropogenic impact. However, according to the levels proposed by European regulations, it still can be classified as water containing total dissolved trace metals in concentrations not significantly above the natural level.