Anammox反应器运行稳定性及其机理研究

采用模拟废水研究了厌氧氨氧化UBF(upflow biofilm filter)的运行性能。结果表明，在高负荷工况下，厌氧氨氧化反应器的稳定性较差。当容积负荷超过反应器的最大转化潜能时，反应器性能恶化。厌氧氨氧化反应是致碱反应，引起反应器内pH值长期维持在8.50~9.05，超出了厌氧氨氧化菌生长的最适pH范围(6.70~8.30)，直接抑制厌氧氨氧化菌的生长和代谢，导致厌氧氨氧化反应器失稳。pH值过高引起反应器内游离亚硝酸浓度（free nitrous acid, FNA）降低至(1.9±4.3)×10-5 mg•L-1~(2.2±2.5)×10-5 mg•L-1，低于Anammox菌FNA半速率常数(KS,FNA)，会造成亚硝酸“饥饿”。pH升高还可引起游离氨浓度（free ammonia, FA）升高至178.1 mg•L-1，超过了Anammox菌FA半抑制常数KI,FA，严重抑制Anammox菌的生长和代谢，并加剧反应器性能恶化以致失稳并且不能自行恢复。反应器性能失稳后，应及时用清水从反应器内洗出残余基质，反应器功能可快速恢复。

Stability and Mechanism of Anammox Bioreactors 

The performance of two Anammox upflow biofilm filters (UBF) was investigated using synthetic wastewater. Results showed that the Anammox UBFs became unstable under high nitrogen loading rate. Performance deterioration was observed when the nitrogen loading rate exceeded the maximum removal capacity of the reactors. Effluent pH was increased to 8.50~9.05 because of Anammox reaction, which were higher than the optimum pH range of Anammox bacteria, i.e. 6.70~8.30, resulting in direct inhibition of Anammox bacteria and subsequent destabilization of the two Anammox UBFs. Unfortunately, deficiency of free nitrous acid only (1.9±4.3)×10-5-(2.2±2.5)×10-5 mg•L-1] and excess of free ammonia (as high as 178.1 mg•L-1), both of which were the substrates of Aanammox bacteria, were induced by high pH, resulting in starvation effect of free nitrous acid and toxicity of free ammonia to Anammox bacteria, strengthening instability of the Anammox UBFs. Moreover, the performance of the bioreactors can not recover automatically. Tap water was used necessarily to rinse the bioreactors to wash out the residues. After that, performance recovery can be reached quickly by applying low nitrogen loading rate.