基于营养盐通量估算的再生水补给湖泊底泥管理对策研究OA

There are plenty of nutrients in the reclaimed water.When recharged into lake,the reclaimed water will lead to high risk of internal pollution in the sediment and the corresponding eutrophication as well as other problems in the water body.Through the orthogonal simulation experiments indoor,one lake recharged by reclaimed water for the Yangtze River Conservation was taken as a case study,to discuss the nutrient release from sediments into overly-ing water under varied conditions of temperature,overlying water types,and disturbance of water body.The manage-ment strategies for the lake sediments were proposed accordingly.The results show that the internal pollution is the moderate level in the sediment of the lake.The descending rank of the three influencing factors on nitrogen flux is as follows:overlying water types,ambient temperature,and presence or absence of water body disturbance,whereas,for phosphorus flux,the descending rank is overlying water types,presence or absence of water body disturbance,and ambient temperature.It is estimated that TN release from the sediments is about 3×10-2 tons,and TP deposition into sediments is 4×10-4 tons annually,indicating that sediments act as a"source"of nitrogen and a"sink"of phos-phorus in the lake.It is recommended to manage the sediments by enhancing the dissolved oxygen levels in the overly-ing water,reducing the disturbance of water body,and dredging the sediments in time.