Influence of HCO3- on nitrogen removal in an ANANMMOX reactor
HCO3-浓度对厌氧氨氧化反应器脱氮效能的影响

The influence of the content of HCO3- on nitrogen removal was investigated by measuring the nitrogen removal rate in an ANANMMOX reactor. The results showed that the effluent pH values increased sharply when the ratio of HCO3- to NH4+-N concentration was 0.21 in the influent. Correspondingly, the removal of nitrogen decreased substantially, which was attributed to the inhibition on the activity of the ANANMMOX bacteria. On the other hand, when the ratio of HCO3- to NH4+-N concentration was 1.13 in the influent, the effluent pH values decreased to the level favorable for the ANAMMOX bacteria. As a result, the removal of nitrogen was raised gradually. The excessive HCO3- had little impact on the ANAMMOX reaction. This suggested that the content of HCO3- played an important role in maintaining pH values and nitrogen removal in the reactor. The optimized ratio of the concentration of HCO3- and NH4+-N was 1.13 in the influent.