水力负荷对厌氧氨氧化反应器运行影响的研究

Study on influence of hydraulic loading for running of ANAMMOX reactor

采用一套有效容积为4．46L的UASB-ANAMMOX反应器，通过对水力负荷进行3个阶段的调节，研究水力停留时间对ANAMMOX反应器处理效果的影响。3个阶段的水力负荷分别为0．20～0．25、0．38～0．43、0．16～0．20L／（L·d）。在试验过程中，水力负荷的冲击对NH4^＋-N、NOF2^--N的去除率影响明显。其中水力负荷为0．20～0．25L／（L·d）时，NH4^＋-N、NO2^--N去除率都能达到99％以上；当水力负荷为0．38～0．43L／（L·d）时，NH4^＋-N、NO2^--N去除率分别降至64％和62％；当水力负荷为0．16～0．20L／（L·d）时，NH4^＋-N、NO2^--N去除率立刻分别回升至94％和97％。ANAMMOX反应过程中，NO2^--N和NH4^＋-N的去除量比值基本在1．3：1．0左右变化，ANAMMOX反应的优势菌种代谢在运行过程中会将一部分NO2^--N转化为NO3^--N，水力负荷的改变对NO3^--N的出水浓度影响不大；但NO3^--N日生成量与水力负荷的大小成正比。试验表明，UASB-ANAMMOX反应器对水力负荷冲击有较强的抵抗力，但是仍会造成一定量的ANAMMOX反应的优势菌流失，使该反应器在短时间内不能恢复最佳的去除效果。

The influence of hydraulic loading on the anaerobic ammonium oxidation （ANAMMOX） process is studied in three sequential periods with a 4.46 L Up-flow Anaerobic Sludge Blanket reactor （UASB）. The hydraulic loading in each period is 0. 20-0. 25 ,0. 38-0. 43,0.16-0. 20 L/（L · d）. During the experimental process, the step shift of hydraulic loading has obvious effect in ammonia and nitrite removal. The removal rate of ammonia and nitrite can reach 99% when the hydraulic loading is at 0.20-0.25 L/（L · d）, and decline to 64% and 62% respectively at 0.38- 0. 43 L/（L · d）, but is back up to 94% and 97% respectively when the loading is adjusted to 0. 16-0. 20 L/（L · d）. The removal ratio of ammonia-N and nitrite-N remains in a range of 1.0 to 1.3 throughout the test periods. Part of the nitrite is converted to nitrate by microorganisms in ANAMMOX process; and the change of hydraulic loading has little influence on the effluent nitrate concentration. But the amount of nitrate produced during each period is directly related to the HRT. The result shows that UASB-ANAMMOX bioreactor is resilient when undergoing step changes of hydraulic loading. However, high hydraulic loading can still cause the loss of microbial mass, and the reactor cannot reach its best removal efficieney of nitrite and ammonium in the short term.