Distribution and potential ecological risk evaluation of heavy metals in surface sediments of Fangcheng bay of Guangxi

Surface sediment samples were selected from 11 sampling sites in Fangcheng bay.The concentrations of Cu,Pb,Zn,Cd,Cr were determined by atomic absorption spectrophotometry,while Hg and As were analyzed by atomic fluorescence spectrophotometry.The average content of each element was 20.7×10^-6,34.9×10^-6,61.14×10^-6,0.18×10^-6,28.2×10^-6,0.078×10^-6 and 8.49×10^-6,respectively.And the results meet the requirement of the marine functional zoning.The contents of all the heavy metals gradually decreased from the inner bay to the bay mouth.The good positive correlations occurred between Cu,Pb and Zn,as between Cr,Hg and As.It was revealed that the potential ecological risk of the single factor of each heavy metal determined was slight through Hakanson potential ecological risk assessing.The order of potential ecological risks of these heavy metals is Hg> Cd> Pb> As> Cu> Cr> Zn.