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| Speciation distribution and potential ecological risk assessment of heavy metals in sediments of Taihu Lake |
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Abstract BCR three stage sequential extraction procedure was applied to examine the speciation and concentration of four heavy metals(Ni,Cu,Zn and Pb) in sediments of Lake Taihu,and the potential ecological risk of these heavy metals was assessed based on the rations secondary phase and primary phase (RSP). Concentrations of heavy metals in surface sediments were significantly higher than the background value of Taihu Lake sediment, which was 80.3%, 13.5%, 25.9%, 69.6% beyond the background value of Ni, Cu, Zn, Pb. The major speciation of four heavy metals were Fe-Mn oxide fractions and residue fraction, the percentage of fractions extracted form in total content was greater than 50%, the four heavy metals had a high potential for secondary release.Base on the RSP, the potential ecological risk of heavy metals was in the descending order of Ni, Zn, Cu and Pb. Total content of fractions extracted of heavy metals in the spatial distribution of apparent north bay>west lake>other regions.
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Received: 21 January 2011
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