Abstract:

To evaluate the environmental risk of eutrophication and heavy metal accumulation in sediments and substrate of Shuifeng Lake basin, in May (normal water period), August (high water period) and November (freezing period) of 2014, sediment and substrate samples were collected from 9 sampling points in the Shuifeng Lake basin. The contents of total nitrogen (TN), total phosphorus (TP), organic matter, Zn, Cd, Cr, Pb, Hg, Cu, Ni and As in sediments and substrate were analyzed, and the eutrophication and heavy metal pollution were evaluated by using the organic pollution evaluation standard of water substrate and the Hakanson potential ecological risk evaluation method. The results showed that the content of TN in sediments and substrate was 0.172% and 0.167%, respectively, which was generally in a rich state (17/27 and 16/27). The content of TP was 0.192% and 0.174%, respectively, which was at a high level (25/27 and 20/27). The average content of organic matter in sediments and substrate was 29.85 g/kg and 27.87 g/kg, respectively, showing a low level. In terms of heavy metals, the pollution of Hg and Cu were relatively serious, and most of the sampling points were moderately polluted (7/9), and there was a high degree of potential risk. In general, the eutrophication of sediment and substrate in Shuifeng Lake basin is high, and the contents of some heavy metals exceed the standard. Although serious pollution has not occurred, it is necessary to strengthen the control of the accumulation of nutrients and heavy metals.

Key words: Shuifeng Lake, sediment, substrate, nutrients, heavy metals