《东昌湖补水过程中氮的变化及沉积物对氨氮的吸附-解吸特征研究》由会员分享，可在线阅读，更多相关《东昌湖补水过程中氮的变化及沉积物对氨氮的吸附-解吸特征研究（80页珍藏版）》请在金锄头文库上搜索。
1、 I 东昌湖 补水过程中氮的 变 化 及 沉积物对 氨氮的吸附 -解吸特征研究 摘 要 氮的外源污染、 沉积物的内源 氮 污染和 氮的 形态转化与释放规律是当前湖泊研究的热点，也是治理湖泊富营养化面临的主要问 题。 城市浅水湖泊具有与深水湖泊不同的独特特点，其 水体和沉积物 中氮的迁移转化规律更为复杂，东昌湖是我国北方城市 人工 浅水湖泊的典型代表 ，研究 东昌湖中氮的迁移转化规律和沉积物对氨氮的吸附 -解吸特征可以为浅水湖泊富营养化的 治理 提供一定的 参考 依据 。 本文以 东昌湖为研究对象， 监测分析了引黄河补水期间水体 溶解态氮、颗粒态氮等 的迁移转化规律， 运用连续分级浸取法 分析了
2、 表层 沉积物中氮的不同形态含量及其赋存特征，探讨了氮的不同形态在沉积物 -水界面氮循环中的作用， 并通过室内模拟实验 研究了 沉积物的特性如粒度、有机质、扰动、粘土矿物成 分 4个因素 对氨氮吸附 -解吸的影响 。 本文的主要研究结果和结论如下： （ 1） 高污染负荷高含沙量的黄河补水对东昌湖水体和沉积物中氮的赋存特征都造成了 很 大影响。 湖 泊 水体中主要污染物是 TN 和 CODcr，两者含量基本都高于 类水质标准 ，水体有呈现富营养化趋势。 临近补水口的湖区受黄河补水影响最显著， 水体 各形态氮的迁移转化 主要受外源补水、颗粒物的吸附作用和硝化细菌、氨化细菌的作用影响，其中氨氮的变化
3、受黄河悬浮泥沙颗粒物的影响最大。悬浮泥沙颗粒物对水体中氮的迁移转化和降低氮的污染负荷起到了积极作用。 （ 2） 沉积物的 可转化态 氮含量较高， 内源氮释放 导致的水体富营养化 可能性较大。 总可转化态氮含量在 214.01440.47 mg/kg 之间，其占总氮的百分比在18.86%59.20%之间 。 和 湖区 表层沉积物中总可转化态氮含量较其他湖区高，这与该两湖区临近两个补水口，常年受黄河补水影响有关。 （ 3） 沉积物 中各形态氮 的赋存特征和参与氮循环的能力 差异较大 。 各形态氮对总可转化态氮的贡献率大小依次是 强氧化剂可提取态氮（ SOEF-N） 弱碱可提取态氮（ WAEF-N）
4、 强碱可提取态氮（ SAEF-N） 离子可交换态氮（ IEF-N） ， II 其中 IEF-N 最易释放到水体 中 ，对湖泊的富营养化贡献最大的氮形态，其 来源可能是与铁锰氧化物有关， SAEF-N 与 SOEF-N 可能具有相似的来源。 沉积物的粒度和有机质含量对各形态氮的含量和分布有重要影响 ， 非转化态氮主要存在于0.0040.032mm 的细粉砂沉积物中。 （ 4） 有机质含量的增加、粒度的减小和一定范围内扰动强度的增加都可以使沉积物对氨氮的吸附固定能力增加。粘土矿物成分和含量对沉积物中氨氮的吸附 -解吸影响显著， 其对氨氮的吸附和固定能力随着粘土矿物含量的升高而增大，整体来看对氨氮的
5、吸附固定能力大小依次是掺杂沸 石的沉积物 掺杂膨润土的沉积物 掺杂高岭土的沉积物，这主要是 由于各粘土矿物的结构特点和性质决定的。 （ 5） 通过 3 种吸附 -解吸模型对氨氮的吸附 -解吸 过程 拟合发现， Freundlich模型是描述沉积物对氨氮的吸附 -解吸 过程 的最优模型，其中参数值 KF能较好地反映沉积物对氨氮的吸附能力。 关键词：东昌湖 ； 氮；迁移转化； 沉积物；氨氮；吸附 -解吸。 III Research on Nitrogen Variation during Water Supply and Characteristics of Ammonia Nitrogen Ad
6、sorption and Desorption of Sediments in Dongchang Lake Abstract The research of nitrogen pollution and migration and transformation of nitrogen forms is a hotspot in lakes, and it is also the main problem in control the eutrophication of lakes. Urban shallow lakes have the unique characteristics in
7、comparison with the deep-water lakes, and nitrogen migration and transformation is more complicated in its water and sediments. Dongchang Lake is a typical artificial urban shallow lake in the north of China, the research of nitrogen migration and transformation rules and ammonia nitrogen adsorption
8、- desorption characteristics of sediments can provide some reference for controlling the eutrophication of artificial shallow lakes. The Dongchang Lake was selected as the research object in this paper, the migration and transformation rules of dissolved nitrogen and particulate nitrogen during the
9、Yellow River water supply was monitored, the content and characteristics of different forms of nitrogen in the surface sediments were analyzed by the chemical sequential extraction methods. And the role of different nitrogen forms in the nitrogen cycle of the interface of sediments and water was dis
10、cussed. The influence of different factors such as granularity, organic matter, hydrodynamic disturbance and different clay minerals on the behaviour of ammonia nitrogen adsorption-desorption in sediments was also studied by simulation experiments. The main research results and conclusions are as fo
11、llows: (1) The Yellow River water supply, which had high content of pollutants and suspended sediments, had a great influence on the nitrogen existing forms in water and sediments. The total nitrogen (TN) and chemical oxygen demand (COD) is the main pollutants in Dongchang Lake. The content of both
12、is basically higher than the quality standards of V water, the whole water presents a tendency of eutrophication. IV The water supply had a great influence on lake zones near the water inlet, the migration and transformation of different nitrogen forms was mainly affected by the exogenous water supp
13、ly, adsorption of particulate matters and the function of nitrifying bacteria, ammonifying bacteria. The influence of ammonia nitrogen by suspended sediments of the Yellow River was biggest. The suspended sediments played an importantly positive role in the migration and transformation of nitrogen a
14、nd reducing the nitrogen pollution load. (2) The content of transferable nitrogen is high, then the probability of lake eutrophication caused by internal nitrogen release in sediments is bigger. The content of total transferable nitrogen (TTN) is between 214.01440.47 mg/kg, the percentage of TTN/TN
15、is between 18.86%59.20%. The content of TTN in and lake zones is higher than other lake zones, because the two lake zones are more closer to the water inlet, then sediments are influenced perennially by the Yellow River water. (3) There are big differences on the characteristics of different nitroge
16、n exisiting forms and their abilities of participating in the nitrogen cycle. The rate of contribution of different nitrogen forms to TTN is in turn strong oxidant extractable form (SOEF-N) weak acid extractable form (WAEF-N) strong alkali extractable form (SAEF-N) ion exchangeable form (IEF-N), IEF-N will be most easily release into the water, it is the largest contributor to the eutrophication of lakes, and its sources are more related
