不同类型湖泊沉积物中氮释放规律研究

通过对武汉市东湖子湖郭郑湖、庙湖以及南湖这3个不同类型的湖泊进行释氮模拟实验,结果表明:(1)在厌氧条件下,不同污染程度的湖泊中沉积物释氮作用均比较明显。为了抑制沉积物向上覆水释氮,控制湖泊富营养化,保持湖泊较高的溶解氧水平是必要的。(2)在厌氧条件下,高温对不同类型湖泊总氮和氨氮的释放均能起到促进作用。(3)沉积物与上覆水间污染物的浓度梯度越大,总氮和氨氮的释放速率与释氮量也越大,此时温度的影响不明显。(4)通过比较3类湖泊沉积物上覆水中总氮和氨氮两者的释放浓度可知,氨氮的释放贡献十分显著,因此控制氨氮的释放量对于控制湖泊氮释放量具有显著效果。

Nitrogen Release from Sediments in Different Types of Urban Lakes

Nitrogen release from different types of urban lakes including South Lake and two sub-lakes of East Lake, Guozheng Lake and Miao Lake was simulated.Results showed that there was an obvious nitrogen release from sediments of different polluted lakes under anaerobic conditions.It is necessary to maintain dissolved oxygen at a high level to suppress the nitrogen release.Under anaerobic conditions,higher temperatures can significantly improve the release of total nitrogen and ammonia in different types of lakes,but the promoting effect is different.The higher concentration gradient between sediments and overlying water,the greater release will happen.Ammonia has large contribution to the total nitrogen in all types of lakes.Reducing ammonia nitrogen is effective to control nitrogen release in the lake.