Sources and assessment of heavy metals in sediments in Shuangtaizi estuary

Being based on the monitoring results of six heavy metals (Cu, Pb, Zn, CD, Hg and as) in sediments from 12 sample stations in Shuangtaizi Estuary of Panjin from 2017 to 2019, the potential ecological risk index method of Hakanson was used to assess the ecological risk.With the analyze of the data in organic carbon and particle size, the characteristics and sources of heavy metals were also researched by means of mathematical statistics and Pearson correlation analysis. The research showed that the contents of Pb and Zn met the first class of marine sediment quality standards, while Cu, Cd, Hg, As exceeded the standard in some extent, which the proportion of stations was 27.8%, 2.8%, 27.8% and 5.5%, respectively. However, all of them met the second class of marine sediment quality standards. The content of heavy metals in the East Bank was higher than that in the West Bank, which content decreased with the increase of offshore distance revealed that some heavy metal elements were enriched in this area. The ecological risk status in the study area was at medium risk on the whole, with an order of heavy metal risk Hg>Cd>As>Cu>Pb>Zn. Hg and Cd in the study area had the similar sources, which may be the introduction of petrochemical industry projects and offshore oil and gas development activities. Pb, Zn and Cu mostly came from the use of fossil fuels and chemical production process, while As mainly came from agricultural pollution. © 2021, Editorial Board of China Environmental Science. All right reserved.