Distribution And Transport of Heavy Metals In Surface Sediments of Chengbei Sea Area In The Bohai Sea Under The Action of Multiple Factors

This study analyzed the distribution characteristics of Cu, Zn, Cd, Cr, and Pb in surface sediments of Chengbei Sea area and estimated the pollution status using grain size and heavy metal data of surface sediments from June 2015. Furthermore, the main controlling factors of the distribution and transport of heavy metals are discussed from the two aspects of natural processes and human activities. The results showed that the surface sediments were not polluted by the heavy metals, except for Cd, which exhibited a small degree of pollution. Cu, Zn, and Cd were mainly attributable to natural sources, and their distribution characteristics were basically the same. Areas with high concentrations of Cu, Zn, and Cd were mainly distributed in the northeast of the study area, reflecting a clear correspondence to the zonation of the sedimentary dynamic environment. Their distribution characteristics were mainly controlled by the grain size of surface sediments. Areas with high concentrations of Cr and Pb were mainly distributed in the northwest and east-central parts of the study area, and the corresponding relationship with the zonation was not obvious. Their distribution characteristics were mainly affected by sediment transport and tidal residual current.