The Research On Nitrogen And Phosphorus Nutrients Characteristic Of Poyang Lake

For understanding of nitrogen and phosphorus cycle of Poyang Lake District This paper takes Poyang Lake as the research object,learning about the characteristics of distribution of nitrogen and phosphorus of Poyang Lake Basin、effects of nitrogen and phosphorus on Poyang Lake in atmospheric wet deposition、effects of nitrogen and phosphorus nutrients on phytoplankton、the nitrogen inputs from five river andthe amount nitrogen and phosphorus outputs of Poyang lake、status of nitrogen and phosphorus pollution in rural areas of Poyang Lake underground drinking water and the purification effect of Wetland sediment for nitrogen and phosphorus, providing a basis for nitrogen and phosphorus cycling study。Through research, the main conclusions are as follows:(1) using trophic state index for the wet period Poyang be eutrophic evaluation: in 17 sampling points, 7 points in nutrition for 41%; two sampling points in moderate eutrophication for 12%;8 points in a mild eutrophication for 47%--eutrophication indicates 10 in eutrophic state : Poyang Lakeinwet period most of the waterin eutrophic;(2) According to drinking water health standards,the method of water quality indexes was applied to the evaluation of water quantity security in rural area around Poyang Lake.The results showed that in the dry season, seven points of 20 sampling points were the first-class water quality, nine points were the second order of standards,the rest points were the third order of standards. In the wet season, one point was the first-class water quality, eleven points were the second order of standards,eight points were the third order of standards;(3) The content of nitrogen and phosphorus has obvious seasonal in 2012:The settlement of TN up to 2095.29 kg/km2, followed by the spring of 1494.30 kg/km2,1077.62 kg/km2 in the winter, autumn 673.37 kg/km2. The settlement of TP is small.It is 72.28 kg/km2 in autumn, 51.07 kg/km2 in winter, 50.13 kg/km2 in summer, 29.64 kg/km2 in spring。(4) Refer to VGPM: The average of primary production of phytoplankton is 193.33 mgC·m-3·d-1 in January 2011, primary production of phytoplankton has Negative correlations with TN and TP. In July 2011, The average of primary production of phytoplankton is 412.12 mgC·m-3·d-1,it has Negative correlations with TP and has no correlations with TN;(5) The experiment was that nutrients nitrogen and phosphorus absorbed by different sediment nutrients. Results showed that in July 2012,the purification efficiency of NH4+-N、NO3-N、TP and TN absorbed by different sediment nutrients was the same, which is Marsh> Light Beach> mud beach. In January 2012, the purification efficiency of NH4+-N、NO3-N、TP and TN absorbed by different sediment nutrients was different, except for TP as follows: marsh> mud beach> mudflat outside,NH4+-N、NO3--N and TN purification rates were as follows: marsh> Light beach> mud beach.