长寿湖表层沉积物中氮的赋存形态及污染评价

为揭示长寿湖表层沉积物中营养盐的赋存特征，于2009年4月采集了该湖15个样点的表层沉积物，利用化学提取法测定并分析了表层沉积物中氮的赋存形态和污染程度。结果表明:（1）长寿湖表层沉积物中总氮（TN）的含量为1240.0～5110.0 mg/kg，其组成部分为有机氮（ON）、无机氮（IN）中以氨态氮（NH₄⁺—N）为主。（2）各形态氮的变异系数均为0.1～1.0，属于中等强度变异。（3）水流作用对长寿湖表层沉积物中氮的分布和迁移起到重要作用，养殖活动对其影响并不显著；水位高低对氮的分布也有一定影响。（4）相关性分析表明，总氮（TN）的含量和空间分布几乎完全受到有机氮（ON）控制，无机氮（IN）的变化主要受到氨态氮（NH₄⁺—N）的影响。（5）长寿湖表层沉积物的污染较为严重，应加强治理。

Forms and Pollution Assessment of Nitrogen in Surface Sediments of Changshou Lake

In order to illuminate nutrient occurrence characteristics in surface sediments of Changshou Lake,sediments samples at 15 sampling sites were collected in April of 2009.Forms and pollution degree of nitrogen in the surface sediments of Changshou Lake were analyzed by chemical extraction in this paper.Results were as followed.(1) Content of total nitrogen(TN) ranged from 1 240.00 mg/kg to 5 110.00 mg/kg.The main form of total nitrogen(TN) was organic nitrogen(ON).Ammonium nitrogen(NH+4—N) was the dominant part of inorganic nitrogen(IN).(2) Coefficient of variation of every nitrogen forms ranged between 0.1 and 1.0,which belonged to moderate intensity of variation.(3) Current of water played an important role in the distribution and migration of nitrogen,the impact of aquaculture was not obvious.But the water degree had some influences on distribution of nitrogen.(4) The correlation analysis among different nitrogen forms suggested that the concentrations and distribution of total nitrogen(TN) were mainly controlled by organic nitrogen(ON),and inorganic nitrogen(IN) was affected by ammonium nitrogen(NH+4—N) almost.(5) The surface sediments showed moderate degree pollution,so local government should strengthen the monitoring and management of Changshou Lake urgently.