Distribution and transport of heavy metals in surface sediments of the Zhejiang nearshore area, East China Sea: Sedimentary environmental effects

Abstract

Surface sediment and vibrocore samples were collected in the Zhejiang nearshore area to study the distribution and transportation of heavy metals on the basis of grain size, elements, and ²¹⁰Pb dating analyses. The results indicated that the spatial patterns of heavy metal (Zn, Cr, Pb, Ni, Cu, and Co) were closely related to the sediment types. Heavy metal concentrations in the clayey silt were the highest, the second for silt and the least for fine sand. Moreover, Heavy metal concentrations were positively correlated with the mean diameter of sediment, silt, and clay contents. And there were conspicuous positive correlations between Al₂O₃ and heavy metal, suggesting that terrigenous sediment from the Yangtze River was a dominating factor controlling the spatial variations of heavy metals. Sedimentary environment, including hydrodynamics, sediment transport, and sedimentary rates, would dominate the distribution and transport of heavy metal pollutants through controlling the transport pathway of surface sediment.

Keywords: Distribution patterns; Heavy metals; Surface sediment; Transport pathway; Zhejiang nearshore area.