低pH对高负荷厌氧氨氧化反应器性能的影响

厌氧氨氧化(ANAMMOX)工艺是一种新型生物脱氮工艺,具有良好的应用前景。但ANAMMOX以亚硝酸盐为电子受体,需与短程硝化(SHARON)联合应用。SHARON是一个产酸反应,而ANAMMOX是一个嗜碱反应,后者会受前者的干扰。试验结果表明,低进水pH冲击对高负荷(总氮负荷9.3～27.7kg·(m3·d)-1)ANAMMOX反应器效能具有显著影响。在一定范围内,提高总氮负荷可削弱低进水pH冲击的影响,设置回流也可缓解低进水pH冲击所致的负面效应。低进水pH冲击对厌氧氨氧化反应器效能的影响主要来自低pH与游离亚硝酸毒性的双重抑制,其中低pH的直接作用对反应器效能的影响更大。低进水pH冲击所致的反应器效能恶化可采用停车自然恢复、清水冲洗恢复和外加碱液恢复。

Effect of Low pH on the Performance of High-loaded ANAMMOX Reactor

Anaerobic ammonia oxidation (ANAMMOX) process is a new biotechnology for nitrogen removal and is promising in the wastewater treatment engineering. However, it should be combined with SHARON (single reactor high activity ammonia removal over nitrite) process because it needs nitrite released from the latter process. The performance of ANAMMOX process could be interfered by the low pH of effluent from SHARON process. The results show that the low pH shock has serious influence on the performance of ANAMMOX reactor with total nitrogen loading rate (NLR) between 9.3～27.7 kg·(m~3·d)~(-1). But the influence of low pH shock could be alleviated by using recirculation or higher nitrogen loading rate. The effect of low pH on ANAMMOX reactor is mainly caused by the inhibitions of acidity and free nitrous acid, between them, the inhibition of acidity is even more serious. It was proved that, according to the injured degree, the performance of the ANAMMOX reactor deteriorated by low pH shock can be restored by taking strategies of stopping the feeding of the reactor, flushing the reactor with fresh water, and adding alkali solution into the reactor, respectively.