Mainstream anammox still faces the challenges of non-ideal NO₂^-/NH₄⁺ ratios and excess nitrate resulted from the instability of partial nitrification (PN) in municipal wastewater. To address these problems, in this study, we developed a novel two-sludge process that combined PN with synchronous anammox and endogenous partial denitrification (SAEPD); the process was tested with pre-treated domestic sewage at ambient temperatures for 205 d. High nitrogen removal efficiency of 91.2% was achieved with an influent C/N ratio of 1.7 at 15.4 °C; the success was attributed to the fact that EPD replenished the deficient nitrite by reducing nitrate and the excess nitrite was further reduced to nitrogen gas. With a non-ideal NO₂^-/NH₄⁺ ratio of 0.89, the contribution of the SAEPD-sequencing batch reactor (SBR) during the anoxic stage reached 98.2% and the proportional contributions of the anammox and denitrification pathways were 77.2% and 22.8%, respectively. Although the low nitrite accumulation (66.1%) caused 10.8 mg N/L of nitrate to be transported into the SAEPD-SBR and the anammox reaction also converted 20% of nitrite to nitrate, only 1.1 mg N/L of nitrate remained in the effluent. High-throughput sequencing analysis revealed that although NH₂OH was added, some genera of nitrite-oxidizing bacteria (0.73%) remained in the PN-SBR and potentially resulted in the oxidation of nitrite to nitrate. In the SAEPD-SBR, anammox and endogenous denitrifying bacteria co-existed and synergistically achieved the removal of ammonium, nitrite, and nitrate. Overall, the PN-SAEPD process has great potential for achieving cost-effective and energy-efficient municipal wastewater treatment.

厌氧氨氧化主流仍面临非理想NO的挑战₂ ^- / NH ₄ ⁺的比率和过量的硝酸导致从市政污水局部硝化（PN）的不稳定性。为了解决这些问题，在这项研究中，我们开发了一种新型的二污泥工艺，该工艺将PN与同步厌氧氨水和内源性部分反硝化（SAEPD）相结合。该过程在环境温度下用预处理的生活污水测试了205天。在15.4°C下进水C / N比为1.7时，实现了91.2％的高脱氮效率；该成功归因于以下事实：EPD通过还原硝酸盐来补充不足的亚硝酸盐，并将过量的亚硝酸盐进一步还原为氮气。与非理想的NO ₂ ^- / NH₄ ⁺比率为0.89，在缺氧阶段SAEPD测序间歇反应器（SBR）的贡献达到98.2％，厌氧氨氧化和反硝化途径的比例贡献分别为77.2％和22.8％。尽管亚硝酸盐的低累积量（66.1％）导致将10.8 mg N / L的硝酸盐运输到SAEPD-SBR中，并且厌氧氨氧化反应也将20％的亚硝酸盐转化为硝酸盐，但废水中仅残留1.1 mg N / L的硝酸盐。高通量测序分析表明，尽管NH ₂加入OH后，PN-SBR中残留了一些亚硝酸盐氧化细菌（0.73％），并可能导致亚硝酸盐氧化为硝酸盐。在SAEPD-SBR中，厌氧氨氧化菌和内源性反硝化细菌共存并协同去除了铵，亚硝酸盐和硝酸盐。总体而言，PN-SAEPD工艺具有实现具有成本效益和能源效率的市政废水处理的巨大潜力。