为探讨滴水湖水系各形态氮的污染特征、不同水体间的各形态氮对比特征、滴水湖水体各形态氮与环境因子的关系,2013年春季,在上海市最大人工湖水系采集表层水样品28个、沉积物样品22个,测定各形态氮及总氮含量,并通过模拟实验着重探讨滴水湖水体盐度对沉积物向上覆水体释放 NH3-N、NO3--N 的影响。结果显示,滴水湖水体各氮污染水平较高,表层水体氮的空间差异性相对沉积物中氮的差异性较小。滴水湖水体无机氮以 NO3--N 为主,沉积物中氮以有机氮为主。周围水系含氮量较高,其中引入水源氮是滴水湖水体中氮的主要来源之一。盐度模拟实验显示,随着上覆水体盐度的增大,底泥中NO3--N的释放量会增加并趋于平衡,NH3-N的释放量则有降低并趋于稳定的趋势。%To investigate the characteristics of nitrogen, compare different nitrogen forms in different systems and analyze the relations of nitrogen and environmental factors, twenty-eight surface water samples and twenty-two sediment samples were collected from the largest man-made lake system in Shanghai in spring of 2013 to examine the contents of nitrogen. By simulating experiments on the effect of salinity in the overlying water, the exchange of ammonia and nitrate in the sediment-water was analyzed. The results indicated that average level of nitrogen in Dishui Lake system was high. The spatial differences of nitrogen in the surface water were smaller than that in the sediment. Nitrate was the main form of inorganic nitrogen in the water and organic nitrogen was the main nitrogen form in the sediment. The contents of nitrogen in rivers around the Dishui Lake were higher, suggesting that this river water was one of the main nitrogen sources of the Dishui Lake. The simulated experiments showed when the salinity in the overlying water was increased, the content of nitrate released from the sediments to the water would increase and tend to balance out with each other. but the content of ammonia released from the sediments to the water would decrease then reach a stable staye.
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