Heavy metal distribution features and pollution assessment in different grain-size surface sediments at the Yellow River Estuary

摘要

Heavy metals are important pollutants in sediments, which cause a great potential hazard. In this paper, surface sediment samples collected from the Yellow River Estuary were categorized by their grain sizes, and then concentrations of Cu, Pb, Zn and Cd in unsized sediments and in sediments with grain size < 63 μm were measured. The results showed that concentrations of the four heavy metals in sediments with grain size < 63 μm were higher than those in unsized sediments. This indicated that concentrations of heavy metals were higher in sediments with a smaller grain size and higher organic content. On the whole, heavy metal concentrations were relatively low at the Yellow River Estuary, and high concentrations of heavy metals appeared around Lijin pontoon. Single-factor pollution statuses of heavy metals belonged to the 'low' or 'moderate' level, which was relatively low overall and led to the 'low' potential ecological risk of the study area.