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1D - Soil and Sediment Contamination (TU9/9) Effect of catastrophic flood on copper distribution and partitioning in soils of flooded area. Twardowska, Irena1, Janta-Koszuta, Krystyna1, Stefaniak, Sebastian1, Kyziol, Joanna1, 1 Polish Academy of Sciences, Institute of Environmental Engineering, Zabrze, Silesia, Poland ABSTRACT- Catastrophic floods have recently become a frequent disaster in Europe that may exert a long-term impact on the soil quality of flooded areas. In 2000, three years after the flood of 1997, which affected Poland, Germany and Czech Republic, a survey for evaluating its consequences to soils in the Upper Odra River valley in Poland (Silesia Land) was conducted. Within this study, the effect of flood on the spatial and vertical distribution of Cu, as well as on its partitioning with respect to chemical forms of binding and susceptibility to mobilization were assessed in view of potential risk to receptors. In the selected area, which was strongly affected by flood, background concentrations of Cu were at the well-documented low natural level (<1-19.5, mean 4.6 mg Cu/kg); agricultural land use and heavy alluvial soils with pH>6.5 predominated, though light- and strongly acidic soils also occurred. The post-flood alteration of spatial distribution of Cu, assessed with use of GIS model, appeared to be a resultant of two diverse processes: washout by floodwater from light acidic sandy and brown soils and in the tributary estuarine area, where Cu reduction range was 0-7 mg Cu/kg, and precipitation of high-metal river sediments on the heavy alluvial soils in the water stagnation areas that resulted in Cu enrichment in soils, mostly in the range of 10-20 mg Cu/kg, locally up to 40-44 mg Cu/kg. Average increase in the whole area accounted for 13.63 mg Cu/kg compared to the background level. The highest Cu concentration occurred in the top 0-40 cm of the soil profile, with maximum in the 5-40 cm layer. In all surveyed soils Cu was predominantly enriched in the moderately reducible fraction (average 46-84%) and showed high affinity to amorphous Fe-oxides in the whole soil profile and also to of humic substances in the top 0-40 cm layer, which determined relative stability of this metal in the solid phase. Scarce labile forms of Cu binding were represented almost entirely by carbonates (average 3-13%), while stable forms, bound mostly in residuum, accounted for 22-42% of the total. Precipitation of river sediments resulted in the significant elevation of total Cu concentration in flooded soils in the Upper Odra River valley; both total concentrations and mobile forms did not though exceed guide values protecting ecological multifunctionality of soil Key words: sediments, soil contamination, copper, partitioning |
