Abstract:

Moshui Lake is a representative of urban lakes heavily polluted by heavy metals in China.Study on distribution characteristics of heavy metals in the overlying water and pore water of the sediments of Moshui Lake was carried out.The change and transport patterns of major heavy metals were comprehensively discussed.According to the diffusion fluxes of heavy metals in the pore water of the sediments，the influence on the overlying water was qualitatively estimated.The results showed that the concentration of the following six heavy metals in Moshui Lake decreased in the order of Mn>Fe>Zn>Cu>Cr>Pb.The concentration profiles of heavy metals in the overlying water and pore water of the sediments were in typical peak shapes indicating the widespread occurrence of remobilization of heavy metals after deposition.The concentrations of Fe and Mn in the pore water of the bottom sediments were much higher than those in the overlying water，and redox processes mainly controlled their distribution patterns.The concentrations of Cr，Cu，Pb and Zn in the pore water of the surface sediments fluctuated under the impact of redox processes and mineral equilibrium.The quality of the overlying water is influenced by the diffusion fluxes of heary metals in the pore water of the sediments.

Key words: Moshui Lake, heavy metals, overlying water, pore water of sediments, distribution