一段式PN/A中NOB细菌的常见抑制策略研究进展

Research Advancement in Common NOB Suppression Strategies in One-stage PN/A System

厌氧氨氧化是最具前景的低能耗、高效污水生物脱氮技术,一段式部分亚硝化/厌氧氨氧化(one-stage partial nitritation/Anammox,一段式PN/A)系统是厌氧氨氧化常用的工艺。在一段式PN/A系统中,部分亚硝化是为厌氧氨氧化提供亚硝酸盐底物的关键步骤,亚硝酸盐氧化菌(nitrite oxidizing bacteria,NOB)的存在可能消耗大量亚硝酸盐,导致PN/A系统运行不稳定。目前,众多研究者对NOB的抑制手段进行了探索。介绍了污水处理厂中两种常见的NOB,重点讨论了几种常见NOB抑制策略。总结了游离氨(free ammonia,FA)和游离亚硝酸(free nitrous acid,FNA)对NOB及其他功能菌的抑制阈值,并讨论了FA和FNA的交替处理及其在侧流处理中的应用;其中,曝气策略包括调节溶解氧、间歇曝气与实时控制,具体参数的设置对NOB抑制具有较大影响;针对一段式PN/A系统中常用的生物膜法和颗粒污泥法,通过污泥龄控制可以有效洗脱絮状污泥中富集的NOB;最后对未来NOB抑制策略提出了建议。

Anammox is the most potential,low-energy consuming and efficient biological denitrification technology for wastewater.One-stage partial nitritation/Anammox(one-stage PN/A)system is commonly used in Anammox and partial nitrification is the key step to provide substrate nitrite for Anammox.The presence of nitrite oxidizing bacteria(NOB)may consume a large amount of nitrite,leading to the unstable operation of PN/A system.Therefore,the methods for NOB suppression have become a hot research topic.Two common NOB in wastewater treatment plants were introduced,and several common NOB suppression strategies were discussed in detail.The inhibition thresholds of free ammonia(FA)and free nitrous acid(FNA)on NOB and other functional bacteria were summarized,and the alternative treatment of FA and FNA and their application in sidestream treatment were discussed.The aeration strategies include adjusting dissolved oxygen,intermittent aeration as well as real-time control,and the setting of specific parameters has a great impact on NOB suppression.Sludge retention time(SRT)control of biofilm and granular sludge that are commonly used in one-stage PN/A system can effectively wash out NOB enriched in floc sludge.Finally,some suggestions for future NOB suppression strategies were proposed.