Institute of Environmental Health and Ecological Safety, Jiangsu University, Zhenjiang 212013, China.
Institute of Environmental Health and Ecological Safety, Jiangsu University, Zhenjiang 212013, China.
Sci Total Environ. 2022 Jan 20;805:150212. doi: 10.1016/j.scitotenv.2021.150212. Epub 2021 Sep 10.
The traditional biological nitrogen removal (BNR) follows the conventional scheme of sequential nitrification and denitrification. In recent years, novel processes such as anaerobic ammonia oxidation (anammox), complete oxidation of ammonia to nitrate in one organism (comammox), heterotrophic nitrification and aerobic denitrification (HN-AD), and dissimilatory nitrate reduction to ammonium (DNRA) are gaining tremendous attention after the discovery of metabolically versatile bacteria. Among them, HN-AD offers several advantages because individual bacteria could achieve one-stage nitrogen removal under aerobic conditions in the presence of organic carbon. In this review, besides classical BNR processes, we summarized the existing literature on HN-AD bacteria which have been isolated from diverse habitats. A particular focus was given on the diversity and physiology of HN-AD bacteria, influences of physiological and biochemical factors on their growth, nitrogen removal performances, as well as limitations and strategies in unraveling HN-AD metabolic pathways. We also presented case studies of HN-AD application in wastewater treatment facilities, pointed out forthcoming challenges of HN-AD in these systems, and presented modulation strategies for HN-AD application in engineering. This review may help improve the existing design of wastewater treatment plants by harnessing HN-AD bacteria for effective nitrogen removal.
传统的生物脱氮 (BNR) 遵循序批式硝化反硝化的传统方案。近年来，随着代谢多功能细菌的发现，厌氧氨氧化 (anammox)、氨的完全氧化为硝酸盐在一个生物体中 (comammox)、异养硝化和好氧反硝化 (HN-AD) 和硝酸盐异化还原为铵 (DNRA) 等新型工艺引起了极大的关注。其中，HN-AD 具有许多优势，因为在有氧条件下存在有机碳时，单个细菌可以实现一阶段的氮去除。在本综述中，除了经典的 BNR 工艺外，我们还总结了从不同生境中分离出的 HN-AD 细菌的现有文献。特别关注了 HN-AD 细菌的多样性和生理学、生理生化因素对其生长、氮去除性能的影响，以及揭示 HN-AD 代谢途径的限制和策略。我们还介绍了 HN-AD 在废水处理设施中的应用案例研究，指出了 HN-AD 在这些系统中即将面临的挑战，并提出了 HN-AD 在工程中的应用的调节策略。本综述可以通过利用 HN-AD 细菌进行有效的氮去除来帮助改进现有的废水处理厂设计。
