engleski

Trace element concentration of alluvial soils in Eastern Croatia

Recent studies indicated elevated levels of some toxic trace elements (Cd and Pb) in alluvial soils of Drava River in North-West Croatia and Slovenia. It is assumed that the source of trace elements is industry upstream of Drava River. Current research investigates alluvial soils of Drava River further downstream in the main agricultural region of Croatia. Research on trace elements of this region (Eastern Croatia) so far involved wider area where agricultural and forest soils were studied. Comparing agricultural and forest soils the results showed no elevated levels of toxic trace elements due to the agricultural practice. However, more in-depth research on alluvial soils is necessary to examine possible transport of trace elements by river flow from upstream sources. Current study is a preliminary study of toxic trace element concentrations (Cd, Cr and Pb) in alluvial soils of Drava River in Eastern Croatia. Samples were taken from surface soil of 20 locations upstream of the mouth of Drava River into the Danube River. In addition two soil profiles were opened as well. Soil properties of the investigated area were in average: pH(H2O) – 8.3 ; CEC – 17.2 cmol/kg ; SOM - 2.4% ; Clay content – 8%. Total concentrations of Cd, Cr and Pb were determined by Aqua Regia digestion (HNO3 : HCl – 1:3). The results showed that 19 out of 20 samples had concentrations of toxic trace elements below maximum permissible concentrations (MPC) prescribed by the Croatian legislation. Sample closest to the mouth of two rivers have shown elevated levels for Cd and Pb indicating possible contamination from the Danube River. However, soil properties, such as high pH are immobilizing trace elements and preventing their uptake by plants and into our food chain. Two soil profiles have shown decreasing trace metal concentration from top to the bottom of the profile suggesting that source of trace elements in top soil is not from geogenic origins. The findings indicate no reason for alarm, however since this is Croatian main agricultural region it is necessary to regularly monitor soil status. Therefore, further research collecting more samples from alluvial soils of Drava River, but Danube River as well, is necessary to have a more clear insight in the soil concentrations and source of trace elements in the alluvial soils of Eastern Croatia.

Trace elements ; alluvial soils ; Eastern Croatia

nije evidentirano