Distribution and chemical forms of heavy metals in the flood 1997 sediments of the Upper and Middle Odra river and its tributaries, Poland

At the beginning of August 1997, 72 samples of flood sediments were taken a long the Upper and Middle Odra river and its tributaries. The concentration s of Zn, Pb, Cu, Cd, Co, Ni, Cr, Mn, and Fe in the bulk samples and in the <20 mu m fraction were determined by AAS method. The contents of metals var y in wide ranges and are significantly higher in the <20 mu m fraction of s ediments. The range concentrations vary as following: Zn 274...3 656 mg/kg, Pb 79...1 773 mg/kg, Cd 1.7...11.8 mg/kg, Cu 38...2 244 mg/kg, Cr 14...384 mg/kg, Co 4...73 mg/kg, Hg 0.2...3.9 mg/kg, Mn 214...6 972 mg/kg, and Fe 1 .5...16.3%. The highest amount of; the metals was found in the Wroclaw and Glogow regions. The mobile (exchangeable and carbonatic fractions) portions of metals reached up to 50% of Zn, 40% of Pb and Cu and 60% of Mn.