Speciation of heavy metals in bottom sediments of lakes in the area of Wielkopolski Na tional

This paper reports results of speciation analysis of selected heavy metals (Fe, Mn, Zn, Ni, Cu, Pb, Cd) in bottom sediment samples collected from 11 lakes in the area of Wielkopolski National Park, which is a protected area subjected to limited anthropogenic factors. The main aim of the study was determination of the distribution of the metals among five speciaiton forms defined by Tessier: exchangeable, bound to carbonates, bound to hydrated oxides of iron and manganese, bound to organic matter and others. The particular forms were isolated by sequential extraction