在缺氧池中，反硝化菌利用污水中的有机物作碳源，将回流混合液中带入的大量

在缺氧池中，反硝化菌利用污水中的有机物组成的碳源，将回流混合液中带入的大量NO3-N和NO2-N还原为N2释放到空气中，因此BOD5浓度下降，NO3-N浓度大幅度下降，而磷的变化很小。<br>在好氧池中，有机物被微生物生化降解，而继续下降;有机氮被氨化继而被硝化，使NH3-N浓度显着下降，但随着硝化过程使因此，，A2 ／ O工艺可能会同时完成有机物的排放，硝化脱氮，磷的替代而被替代。等功能，脱氮的组成就是NH3-N完全硝化，好氧池能完成这一功能，缺氧池则完成脱氮功能。厌氧池和好氧池联合完成除磷功能。

这不会发生。NO3-NNO2-N"N2"，"N2"，"3-305"（NO3-N），<br>"这不会是最后一个。" "NH3-N" - 'NO3'，N'N'。"O.K."，"A2/O.I."O.K."NH3-N'N'，"N'N'N'，"N'N'"，"O.K"。不会是最后一个

In anoxic tank, denitrifying bacteria use organic matter in sewage as carbon source to reduce a large number of NO3-N and NO2-N brought in the backflow mixture to N2 and release them to the air. Therefore, the concentration of BOD5 is decreased, the concentration of NO3-N is greatly reduced, and the change of phosphorus is very small.<br>In the aerobic tank, the organic matter is degraded by microorganism, but continues to decline; the organic nitrogen is ammoniated and then nitrated, which makes the NH3-N concentration significantly decrease, but with the nitrification process, the NO3-N concentration increases, and with the excessive uptake of phosphorus accumulating bacteria, P also decreases at a faster speed. Therefore, the A2 / O process can remove organic matter, nitrification and denitrification, and excessive uptake of phosphorus at the same time. The premise of denitrification is that NH3-N should be completely nitrated, and aerobic tank can complete this function, while anoxic tank can complete the denitrification function. The anaerobic tank and aerobic tank jointly complete the phosphorus removal function.<br>