Zhao Lianrong, Chen Ziwei, Zhang Xiaoling, Chen Aixia
School of Water and Environment, Chang'an University, Xi'an, People's Republic of China.
Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of the Ministry of Education, Chang'an University, Xian, People's Republic of China.
Environ Technol. 2025 Apr;46(10):1693-1703. doi: 10.1080/09593330.2024.2398811. Epub 2024 Sep 5.
Although anaerobic ammonia oxidation (anammox) is considered a promising process due to its high efficiency and low energy in nitrogen removal, nitrite inadequacy was one of the bottlenecks for the application of anammox. However, endogenous partial denitrification (EPD) has been emerging as a stable pathway to provide nitrite for anammox. Furthermore, denitrifying glycogen-accumulating organisms (DGAOs) are believed to be associated with EPD. In this study, firstly, GAOs were gradually enriched in a sequencing batch reactor (SBR) with the dual strategy of influent phosphorus limitation and withdrawal after the anaerobic stage. DGAOs were successfully induced by adding sodium nitrate solution at the end of the anaerobic stage, resulting in NO-N concentration increasing from 15 to 30 mg/L. During a typical SBR cycle, DGAOs contributed up to 96% of the conversion of intracellular carbon sources and up to around 95% of nitrate reduction during the anoxic stage. The maximum nitrate-to-nitrite transformation ratio (NTR) of the system reached 80%. Microbial community analysis demonstrated that the Compatibactors were the dominant functional bacteria for EPD, with a relative abundance of 31.12%. However, the relative abundance of phosphorous-accumulating organisms (PAOs) was only 1.02%. This study reveals the important role of DGAOs in the EPD process, which can provide a stable nitrite for anammox.
尽管厌氧氨氧化（anammox）因其在氮去除方面的高效率和低能耗而被认为是一个有前景的工艺，但亚硝酸盐不足是厌氧氨氧化应用的瓶颈之一。然而，内源性部分反硝化（EPD）已成为为厌氧氨氧化提供亚硝酸盐的稳定途径。此外，反硝化聚磷菌（DGAOs）被认为与EPD有关。在本研究中，首先，通过进水磷限制和厌氧阶段后排水的双重策略，在序批式反应器（SBR）中逐渐富集聚磷菌。在厌氧阶段结束时添加硝酸钠溶液成功诱导出反硝化聚磷菌，导致NO-N浓度从15 mg/L增加到30 mg/L。在典型的SBR周期中，反硝化聚磷菌在缺氧阶段贡献了高达96%的细胞内碳源转化和高达约95%的硝酸盐还原。系统的最大硝酸盐-亚硝酸盐转化比（NTR）达到80%。微生物群落分析表明，兼容杆菌是EPD的主要功能细菌，相对丰度为31.12%。然而，聚磷菌（PAOs）的相对丰度仅为1.02%。本研究揭示了反硝化聚磷菌在EPD过程中的重要作用，可为厌氧氨氧化提供稳定的亚硝酸盐。
