厌氧氨氧化UASB系统对氨氮的超量去除机制研究

采用UASB反应器在改变NO₂^--N/NH₄⁺-N比条件下，考察厌氧氨氧化系统对NH₄⁺-N的超量去除特征、相关酶的催化活性以及污泥菌群结构.结果表明，随着进水NO₂^--N浓度降低，反应器对NH₄⁺-N的去除量相比理论较大，在停供NO₂^--N情况下，反应器内NH₄⁺-N去除可达55 mg/L.反应器内NH₄⁺-N的去除并不是是来自进水中SO₄^2-和Fe³⁺/EDTA络合物，而是存在NH₄⁺-N的好氧硝化.过氧化氢酶测定联合分子生物学技术分析显示，好氧硝化的所需氧量分别来自进水和过氧化氢酶产氧.反应器底部污泥层的氨氧化菌（AOB）、厌氧氨氧化菌（AnAOB）活性优于上部污泥层，相反，上部污泥层的异养反硝化菌（HDB）活性优于底部污泥层，二者协同将NH₄⁺-N转化为N₂.

Mechanism of excessive removal of ammonia nitrogen by anammox UASB system

The UASB reactor was used to investigate the excess removal characteristics of NH₄⁺-N by the anaerobic ammonia oxidation system, the catalytic activity of related enzymes, and the bacterial community structure of the sludge with changing ratio of NO₂^--N/NH₄⁺-N. The results showed that as the concentration of influent NO₂^--N decreaseed, the removal of NH₄⁺-N by the reactor increaseed compared to the theory. When the supply of nitrite was stopped, the removal of NH₄⁺-N in the reactor reached up to 55mg/L. The removal of NH₄⁺-N was not due to the anaerobic ammonia oxidization by the SO₄^2- and Fe³⁺/EDTA complex from the feed water, but the aerobic nitration of NH₄⁺-N. The analysis of catalase determination combined with molecular biology technology showed that the oxygen required for aerobic nitrification came from influent water and catalase oxygen production. The activity of ammonia oxidizing bacteria (AOB) and anaerobic ammonia oxidizing bacteria (AnAOB) in the bottom sludge bed was better than that in the upper sludge bed. On the contrary, the activity of heterotrophic denitrifying bacteria (HDB) in the upper sludge bed was better than that in the bottom sludge bed, and the two parts of sludge bed synergistically converted NH₄⁺-N into N₂.