浅水湖泊沉积物-水界面可交换态氮赋存特征

Characteristics of Exchangeable Nitrogen Occurrence in Sediment-water Interface of Shallow Lakes

以可交换态氮(EN)为主的负荷是湖泊水质的决定参数之一。以里下河地区受到不同人类活动方式影响的九龙口、大纵湖、蜈蚣湖和得胜湖4个浅水湖泊为研究对象,通过现场调查采样与实验测试方法,分析其沉积物-水界面中总氮(TN)和EN的分布特征。结果表明,EN的分布受人类活动方式影响明显;沉积物中的生物和微生物活动频繁,上覆水、间隙水和沉积物中的EN含量较低。另外,沉积物-水界面处的氧化还原条件对表层沉积物中EN的分布也有影响。

The Nitrogen load, which is mainly composed of exchangeable nitrogen, is one of the determinants of lake water quality. Four shallow lakes of Jiulong Kou, Dazong Lake, Wugong Lake and Desheng Lake, which are affected by different human activities in Lixiahe area, are selected as study objects, the distribution characteristics of total nitrogen and exchangeable nitrogen in sediment-water interface are analyzed by field investigation and experiment. The results show that, （a） the distribution of exchangeable nitrogen is significantly affected by human activities; and （b） as the biological and microbial activities in sediments are frequent, the content of exchangeable nitrogen in overlying water, interstitial water and sediments are low. In addition, the redox conditions at sediment-water interface also influence the distribution of exchangeable nitrogen in surface sediments