Zheng Yuange, Zheng Hao, Gao Ruitao, Jiang Xin, Zhu Hongbin, Zhao Ji, Nie Jiaxiang, Wang Xiaoxia
Power China Huadong Engineering Corporation Limited, Hangzhou, 311122, China.
Huadong Eco-Environmental Engineering Research Institute of Zhejiang Province, Hangzhou, 311122, China.
Bioprocess Biosyst Eng. 2025 Jul 22. doi: 10.1007/s00449-025-03208-3.
Combining partial nitrification and anammox with denitrifying phosphorus removal (DPR) is considered a promising strategy for nitrogen and phosphorus removal. However, the low nitrate nitrogen availability (produced from anammox) in the side-stream DPR system could affect nutrient removal and the competition between denitrifying phosphate-accumulating organisms (DPAOs) and denitrifying glycogen-accumulating organisms (DGAOs). In this study, the nitrogen and phosphorus removal performance, microbial structure shifts, and key functional groups in a DPR reactor were investigated under long-term nitrate-limited conditions. Over 205 days of DPR operation, with the nitrate concentration at the beginning of the anoxic stage gradually decreasing from 15 to 7.5 mg/L, stable and efficient nitrogen removal was maintained, while phosphorus removal efficiency reached 96.7 ± 1.6%, despite a reduction in phosphorus release amount. Microbial community analysis revealed that Candidatus_Competibacter became dominated, increasing from 2.3% to 42.2%, which contributed to efficient nitrogen removal. Meanwhile, DPAOs declined to a certain abundance but still maintained phosphorus removal performance. The result indicated that carbon and nitrate availability are the key factors driving microbial succession in the DPR system. Additionally, short-term batch tests demonstrated that the DPR system remained its capability to handle higher nitrate concentrations after long-term nitrate-limited conditions.
将部分硝化、厌氧氨氧化与反硝化除磷（DPR）相结合被认为是一种很有前景的氮磷去除策略。然而，侧流DPR系统中（由厌氧氨氧化产生的）硝酸盐氮可用性较低，可能会影响养分去除以及反硝化聚磷菌（DPAOs）和反硝化糖原积累菌（DGAOs）之间的竞争。在本研究中，在长期硝酸盐限制条件下，研究了DPR反应器中的氮磷去除性能、微生物结构变化和关键功能群。在205天的DPR运行过程中，随着缺氧阶段开始时硝酸盐浓度从15mg/L逐渐降至7.5mg/L，氮去除保持稳定高效，尽管磷释放量减少，但磷去除效率仍达到96.7±1.6%。微生物群落分析表明，“竞争杆菌属（Candidatus_Competibacter）”占主导地位，从2.3%增加到42.2%，这有助于高效氮去除。同时，DPAOs丰度下降到一定程度，但仍保持磷去除性能。结果表明，碳和硝酸盐可用性是驱动DPR系统中微生物演替的关键因素。此外，短期批次试验表明，在长期硝酸盐限制条件后，DPR系统仍保持处理更高硝酸盐浓度的能力。
