Wen Ruolan, Ye Min, Liu Yanxu, Lin Chihao, Li Yu-You, Liu Jianyong
School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China.
Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan.
J Environ Manage. 2025 Aug;389:126145. doi: 10.1016/j.jenvman.2025.126145. Epub 2025 Jun 9.
High-rate partial nitritation (HRPN) of municipal wastewater is receiving increasing attention, but how to achieve the rapid start-up and stable operation of municipal wastewater HRPN in continuous flow reactor remains a technical challenge. In this study, a feasible and economical strategy based on optimization sludge retention time (SRT) operation was proposed to address this issue, leveraging the kinetic differences between ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). A HRPN reactor was operated for 225 days with dissolved oxygen (DO) of 2.2-5.6 mg/L and high nitrogen loading rate (NLR) of 1.2-1.6 kg N/m/d. Under the SRT of 3 days, the HRPN reactor was successfully started up in 11 days (nitrite accumulation rate, NAR ≥90 %) and the ratio of nitrite to ammonia nitrogen in the effluent is 1. Optimization of SRT during the later operation stage successfully restored the NAR from 71.35 % to 90.93 %, achieving stable operation 80 days of HRPN in continuous flow reactor. The findings of this study demonstrate that both kinetics and microbiology indicate that SRT optimization helps to selectively enrich fast-growing AOB, which is critical for the stability of HRPN in municipal wastewater. The two-stage HRPN-Anammox process proposed in this study has demonstrated superior stability and efficiency in mass balance analysis. Furthermore, it has been shown to be more cost-effective and sustainable in reducing chemical dosage and biomass compared to the traditional PN.
城市污水的高速率部分亚硝化（HRPN）受到越来越多的关注，但如何在连续流反应器中实现城市污水HRPN的快速启动和稳定运行仍然是一项技术挑战。在本研究中，提出了一种基于优化污泥停留时间（SRT）运行的可行且经济的策略来解决这一问题，利用氨氧化细菌（AOB）和亚硝酸盐氧化细菌（NOB）之间的动力学差异。一个HRPN反应器在溶解氧（DO）为2.2 - 5.6mg/L和高氮负荷率（NLR）为1.2 - 1.6kg N/m³/d的条件下运行了225天。在3天的SRT下，HRPN反应器在11天内成功启动（亚硝酸盐积累率，NAR≥90%），且出水亚硝酸盐与氨氮的比例为1。在后期运行阶段对SRT的优化成功地将NAR从71.35%恢复到90.93%，在连续流反应器中实现了80天的HRPN稳定运行。本研究结果表明，动力学和微生物学均表明SRT优化有助于选择性富集生长快速的AOB，这对于城市污水中HRPN的稳定性至关重要。本研究提出的两级HRPN - 厌氧氨氧化工艺在质量平衡分析中表现出卓越的稳定性和效率。此外，与传统的部分亚硝化相比，该工艺在减少化学药剂用量和生物质方面已被证明更具成本效益和可持续性。
