淀山湖沉积物的反硝化脱氮能力及其环境意义

In May and July 2016, sediment samples collected from 13 sampling sites in Dianshan Lake were analyzed for their denitrification rates by the acetylene inhibition method. The result shows that the denitrification rates of the 6 cm undisturbed soil vary from 5.72~65.82 μmol•m ^-2 •h ^-1 with a significant spatiotemporal deviation. The denitrification rate in spring is (28.52±26.21) μmol•m ^-2 •h ^-1 and the denitrification rate in summer is (29.31±17.11) μmol•m ^-2 •h ^-1 . On the spatial scale, the denitrification rate in the 0~3 cm layer ((17.91±11.80) μmol•m ^-2 •h ^-1 ) was higher than that in the 3~6 cm layer ((11.02±10.40) μmol •m ^-2 •h ^-1 ); NH ₄ ⁺ -N content is significant positively correlated with the denitrification rate and coupled Nitrification-denitrification is the main mechanism. Based on the research data, it is estimated that the first half year of the lake area can remove about 278.70 t N by denitrification, which is of great significance to control the nitrogen concentration level and reduce the nitrogen load of water body.