National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China.
SDIC Xinkai Water Environment Investment Co., Ltd, China Water Environment Group Ltd, Beijing, China.
J Environ Manage. 2023 Nov 1;345:118761. doi: 10.1016/j.jenvman.2023.118761. Epub 2023 Sep 6.
Despite the advantages of the combined anammox and fermentation-driven denitrification process in nitrogen removal and energy consumption, stable performance at decreased temperatures remains a challenge. In this study, a robust and high-efficient nitrogen removal efficiency (95.0-93.1 ∼ 86.8-93.4%) with desirable effluent quality (3.0-4.1 ∼ 7.9-4.9 mg/L) under long-term decreased temperatures (30 °C→25 °C→20 °C) was achieved in a zero-external carbon Partial Nitritation/Anammox combined with in-situ sludge Fermentation-Denitrification process treating sewage. Excellent sludge reduction averaged at 14.9% assuming no microbial growth. Increased hzsB mRNA (2.2-fold) and reduced E (80.9 kJ/mol) proved resilient anammox to lower temperature. RT-qPCR tests revealed increased NarG/NirK (5.1) and NarG/NirS (4.9) mRNA at 20 °C, suggesting higher NO→NO over NO→N pathway. Metagenomics unraveled dominant anammox bacteria (Candidatus_Brocadia, 2.27%), increased denitritation bacteria containing more NarG (Hyphomicrobium, 0.8%), fatty acid biosynthesis and CAZymes genes. Enhanced denitritation with recovered organics from sludge reserved nitrite for anammox and facilitated higher anammox contribution to N removal at 20 °C (42.4%) than 30 °C (39.5%). This study proposed an innovative low-temperature strategy for in-situ sludge fermentation, and demonstrated stability of advanced municipal wastewater treatment and sludge disposal through energy savings and carbon recovery under decreased temperatures.
尽管同时进行厌氧氨氧化和发酵驱动反硝化在脱氮和能耗方面具有优势，但在低温下保持稳定的性能仍然是一个挑战。在这项研究中，采用零外部碳部分亚硝化/厌氧氨氧化与原位污泥发酵-反硝化相结合的工艺，在长期低温（30°C→25°C→20°C）下实现了高效的氮去除效率（95.0-93.1∼86.8-93.4%）和良好的出水质量（3.0-4.1∼7.9-4.9mg/L）。假设没有微生物生长，污泥平均减少了 14.9%。hzsB mRNA 增加了 2.2 倍，E 值降低到 80.9kJ/mol，证明厌氧氨氧化对低温有较强的适应能力。RT-qPCR 测试显示，在 20°C 时，NarG/NirK（5.1）和 NarG/NirS（4.9）mRNA 增加，表明 NO→NO 途径比 NO→N 途径更占优势。宏基因组学揭示了优势厌氧氨氧化菌（Candidatus_Brocadia，2.27%）的存在，增加了含有更多 NarG 的反硝化菌（Hyphomicrobium，0.8%），以及脂肪酸生物合成和 CAZymes 基因。通过从污泥中回收有机物，增强了反硝化作用，为厌氧氨氧化保留了亚硝酸盐，并促进了在 20°C（42.4%）时比在 30°C（39.5%）时更高的厌氧氨氧化对氮去除的贡献。本研究提出了一种创新的低温原位污泥发酵策略，通过在低温下节能和碳回收，实现了先进城市污水处理和污泥处置的稳定性。
