Spatial Distribution and Evaluation of Nitrogen, Phosphorus and Organic Matter in Surface Sediments from Western Lakeside Belt of Lake Taihu
太湖西岸湖滨带沉积物氮磷有机质分布及评价

The surface sediments in western lakeside belt of Taihu Lake were collected. The spatial distribution of nutrients and pollution evaluation were studied. The results showed that concentration of the nitrogen, phosphorus and organic matter in the surface sediments had an increasing tendency from inshore to the far shore. The concentration of organic matter in the sediments ranged from 2261.78 mg·kg-1 to 11963.10 mg·kg-1, with the average of 7124.00 mg·kg-1. Total nitrogen concentration in the sediments ranged from 343.20 mg·kg-1 to 1390.12 mg·kg-1, with the average of 819.20 mg·kg-1. The total phosphorus concentration in the sediments ranged from 197.46 mg·kg-1 to 570.85 mg·kg-1, with the average of 379.39 mg·kg-1. The C/N ratio in the lake sediment was 9.5. Organic matter and nutrient were from alga and aquatic plant in lake. Based on the organic index and organic nitrogen, we can concluded that the surface sediments in western lakeside belt of Taihu Lake still belong to less clean category. The average values of organic index and organic nitrogen were 0.037% and 0.044%, respectively. The organic index and organic nitrogen in offshore were high, which indicated the risk of organic pollution.