3.14萬字                 68頁

摘  要

     藍藻暴發(fā)帶來的水污染是當前頗值得關注的一個問題，而其腐解導致的水質變化也不容忽視。本實驗就藍藻腐解后氮元素的遷移轉化進行研究。采用來自太湖xx湖的藍藻和底泥沉積物，設置三組圓柱體容器對照實驗，其中分別為同時含有藍藻和沉積物、僅含有藍藻以及僅含有沉積物。分別測量不同時間段內各體系的理化指標，并得出結論如下：

1、 藍藻腐解過程中釋放了大量氮素，導致體系上覆水中氮元素整體呈上升趨勢；

2、 總氮在含藍藻組中先增后降，表明有部分氮素轉化為氮氣逸出水體。而在僅含沉積物組中沒有太大變化。

3、 氨氮變化趨勢與總氮相同，在含藍藻組中表現(xiàn)為先升后降，僅含沉積物組中沒有太大變化；而硝態(tài)氮則在三組中都沒有太大變化，相對而言，僅含沉積物組中硝態(tài)氮變化最大。

4、 高錳酸鹽指數(shù)在含藻組中先升后降，在僅含沉積物組中變化不大；電導率在三組容器中都呈上升趨勢；pH值在三組實驗中呈現(xiàn)先降后升的趨勢，而DO則在三組實驗中呈現(xiàn)了下降的總體趨勢。

本實驗的結果有助于了解湖泊中氮元素的循環(huán)機制，并提出更符合生態(tài)環(huán)保的湖泊治理方案。

關鍵詞：藍藻；腐解；氮元素；遷移轉化

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