Zhao Yiyi, Zheng Min, Ni Bing-Jie, Ni Shou-Qing
School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, China.
School of Public Health, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China.
Water Res X. 2024 Dec 11;27:100295. doi: 10.1016/j.wroa.2024.100295. eCollection 2025 May 1.
Anaerobic ammonia oxidation (anammox) which converts nitrite and ammonium to dinitrogen gas is an energy-efficient nitrogen removal process. One of the bottlenecks for anammox application in wastewater treatment is the stable supply of nitrite for anammox bacteria. Dissimilatory nitrate reduction to ammonium (DNRA) is a process that converts nitrate to nitrite and then to ammonium. Significantly, it has been reported that some anammox bacteria can perform DNRA by reducing nitrate to nitrite and ammonium nitrogen with little low-molecular-weight organic acids such as volatile fatty acids. Here, we propose an innovative nitrogen removal process, i.e., nitrification and anammox coupled with partial DNRA (i.e., NPDA), and make a theoretical comparison with previously accepted partial nitrification and anammox (PNA) and partial denitrification and anammox (PdNA) for nitrogen removal. Under similar conditions of oxygen consumption, removal efficiency, external carbon source addition, and greenhouse gas emission, the novel NPDA process can better facilitate resource-effective and environment-friendly wastewater treatment. Thermodynamic analysis indicates that partial DNRA-anammox appears to be preferred, oxidizing per mole of NH produces higher energy gain than that of conventional anammox alone. The carbon source limitation rather than nitrate limitation is the key to the realization of NPDA process. This perspective highlights the positive role of DNRA for sustainable wastewater management.
厌氧氨氧化（anammox）是一种将亚硝酸盐和铵转化为氮气的节能脱氮过程。厌氧氨氧化应用于废水处理的瓶颈之一是为厌氧氨氧化细菌稳定供应亚硝酸盐。异化硝酸盐还原为铵（DNRA）是一个将硝酸盐转化为亚硝酸盐然后再转化为铵的过程。值得注意的是，据报道一些厌氧氨氧化细菌可以通过利用挥发性脂肪酸等低分子量有机酸将硝酸盐还原为亚硝酸盐和铵氮来进行DNRA。在此，我们提出一种创新的脱氮工艺，即硝化与厌氧氨氧化耦合部分DNRA（即NPDA），并与先前公认的部分硝化与厌氧氨氧化（PNA）和部分反硝化与厌氧氨氧化（PdNA）进行脱氮的理论比较。在相似的耗氧量、去除效率、外部碳源添加和温室气体排放条件下，新型NPDA工艺能够更好地促进资源高效和环境友好型废水处理。热力学分析表明，部分DNRA-厌氧氨氧化似乎更具优势，每氧化一摩尔NH产生的能量增益高于单独的传统厌氧氨氧化。碳源限制而非硝酸盐限制是实现NPDA工艺的关键。这一观点突出了DNRA在可持续废水管理中的积极作用。
