xx湖泊蓝藻腐解过程中上覆水氮元素的迁移转化研究.doc

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摘  要

     蓝藻暴发带来的水污染是当前颇值得关注的一个问题，而其腐解导致的水质变化也不容忽视。本实验就蓝藻腐解后氮元素的迁移转化进行研究。采用来自太湖xx湖的蓝藻和底泥沉积物，设置三组圆柱体容器对照实验，其中分别为同时含有蓝藻和沉积物、仅含有蓝藻以及仅含有沉积物。分别测量不同时间段内各体系的理化指标，并得出结论如下：

1、 蓝藻腐解过程中释放了大量氮素，导致体系上覆水中氮元素整体呈上升趋势；

2、 总氮在含蓝藻组中先增后降，表明有部分氮素转化为氮气逸出水体。而在仅含沉积物组中没有太大变化。

3、 氨氮变化趋势与总氮相同，在含蓝藻组中表现为先升后降，仅含沉积物组中没有太大变化；而硝态氮则在三组中都没有太大变化，相对而言，仅含沉积物组中硝态氮变化最大。

4、 高锰酸盐指数在含藻组中先升后降，在仅含沉积物组中变化不大；电导率在三组容器中都呈上升趋势；pH值在三组实验中呈现先降后升的趋势，而DO则在三组实验中呈现了下降的总体趋势。

本实验的结果有助于了解湖泊中氮元素的循环机制，并提出更符合生态环保的湖泊治理方案。

关键词：蓝藻；腐解；氮元素；迁移转化

ABSTRACT

The water pollution caused by cyanobacteria outbreak is currently an issue of concern, and its decomposition leading to changes of water quality is also not allowed to ignore. This paper studies about migration and transformation of nitrogen during cyanobacteria decomposition. The experiament uses cyanobacteria and sediments from Taihu Lake and sets up three cylinder containers for comparison, which respectively contains cyanobacteria and sediment at the same time, contains cyanobacteria only, and contains sediments only. Measure physical and chemical index of three systems in different periods. The main outcomes can be summarized as follows:

1、During the process of decomposition, cyanobacteria release a number of nitrogen, which leads to a whole nitrogen increase of overlying water.  

2、The total nitrogen in the group which contains both cyanobacteria and sediments rise first and fall later, suggesting that some into nitrogen escape from water. The group containing sediments only have no big change.

 3、Ammonia nitrogen and total nitrogen have the same trend. It rises first and fall later in the group which contains both cyanobacteria and sediments, but have no big change in the group containing sediments only; But nitrate have no big changes in the all three groups. By contrast, nitrate have the biggest change in the group containing sediments only.

4、Permanganate index rise first and fall later in the group which contains both cyanobacteria and sediments, but have no big change in the group containing sediments only. Conductivity in all three groups are on the rise. pH of the three groups fall first and rise later and DO show the tendency of decline in the three groups.

The results of this study are useful to understand the nitrogen cycle mechanism of lakes, and put forward more useful ideas which are consistent with Environmental protection concept.

Key words: cyanobacteria；decomposition；nitrogen；migration and transformation