Geochemical characteristics and ecological risk assessment of heavy metals in surface sediments of Baiyangdian Lake, Xiong'an New Area

This peper is the result of environmental geological survry engineering.

Objective Baiyangdian Lake(BYD Lake)is the main ecological function area of Xiong'an New Area. In order to provide support for ecological restoration and protection of BYD Lake, we conducted a comprehensive survey on the environmental quality of the surface sediments in BYD Lake.

Methods We collected 484 sets of surface sediment samples from Baiyangdian wetland, identified the geochemical characteristics of heavy metals in surface sediments of Baiyangdian lake, and used multiple methods such as geo- accumulation index method and potential ecological risk index method to evaluate the ecological risk of heavy metals.

Results The results indicate that the average content of most heavy metal elements in the surface sediments of BYD Lake is significantly higher than the soil background value in Hebei Province. The entrance of Fuhe river and Baigou river are the main rich areas of heavy metal elements, rivers are the main sources of heavy metals in the surface sediments of BYD Lake. The distribution area of clean and pollution-free grade is 144.54 km², accounting for 96.68% of the total surface sediment distribution area. The pollution degree of each heavy metal can be ranked as Cd > Cu > Hg > Pb > Zn > Ni > Cr > As. The pollution degree of Cd is mainly moderate, the pollution degree of Cu is mainly light and clean, and the pollution degrees of other elements are mainly clean and pollution-free. The potential ecological risk of heavy metals in the surface sediments of BYD Lake is mainly mild and moderate, and the potential ecological risk level of heavy metals near the river entrance is higher than that of other areas. The potential ecological risk levels can be ranked as Nanliuzhuang > Shaochedian > Xiaobaiyangdian > Wangjiazhai > Zaozhadian > Laowangdian > Chiyudian > Fanyudian.

Conclusions The environmental quality of the surface sediments in BYD Lake is generally good, with heavy metals exceeding the standard in some areas. The environmental quality of surface sediments in Baiyangdian is generally good. There are potential ecological risks of heavy metal pollution in Nanliuzhuang and other areas, and Cd is the main pollution element.