Abstract:
In order to explore the distribution and ecological risk of heavy metal elements in the surface water of coastal wetland in Southern Laizhou Bay, the authors collected 105 surface soil samples to analyze the contents of 8 heavy metal elements, including Cu, Cr, Zn, Ni, As, Pb, Cd and Hg. The soil pollution was evaluated through Nemerow comprehensive pollution index method and Hakanson potential ecological risk index method. The results show that the contents of the heavy metal elements in this area exceeded the standard, and Nemerow comprehensive pollution index show the overall pollution is moderate. The correlation analysis show that there is a significant positive correlation between the contents of heavy metal elements in the study area. The source of Cu, Zn, Cd, Pb and As is related to industrial and agricultural production and transportation activities, and the source of Cr and Ni is mainly influenced by geological background and geochemistry. Besides, the source of Hg is mainly influenced by atmospheric deposition. The single factor potential ecological risk degree of heavy metal elements in the surface soil of the study area was Hg>Cd>As>Cu>Pb>Ni>Cr>Zn. Hg was at the level of comparatively heavy risk, and Cd was at the level of moderate risk. While other heavy metal elements were at the level of low risk, and most of the studied areas are moderate and low potential ecological risks. It is suggested that the early warning of heavy metal pollution should be strengthened in the later stage and remediation restoration measures should be developed. The research results could provide some data support for soil remediation and ecological environment protection.