College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, PR China.
College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, PR China.
J Environ Manage. 2022 Jun 15;312:114920. doi: 10.1016/j.jenvman.2022.114920. Epub 2022 Mar 28.
Endogenous partial denitrification (EPD) and denitrifying phosphorous removal (DPR) were combined in a novel A/O - MBBR (Anaerobic Anoxic Oxic - Moving Bed Biofilm Reactor) system for low carbon/nitrogen (C/N) ratio wastewater treatment. The DPR performance was compared and the nutrient metabolism was elucidated based on the optimization of hydraulic retention time (HRT, 4-12 h) and nitrate recycling (R, 200%-600%). In the continuous-flow, the nitrate (NO) denitrification accompanied by nitrite (NO, via EPD) accumulation with the nitrate-to-nitrite transformation ratio (NTR) of 35.87%-43.31% in the anoxic zones. At HRT of 12 h with R of 500%, batch test initially revealed the DPR mechanism using both NO and NO as electron acceptor, where denitrifying phosphorus accumulation organisms (DPAOs) and denitrifying glycogen accumulation organisms (DGAOs) were the main contributors for EPD with incomplete denitrification (NO → NO). Furthermore, stoichiometry-based functional bacteria analysis displayed that higher bioactivity of DPAOs (NO→N, 57.30%; NO→N, 35.85%) over DGAOs (NO→N, 6.85%) facilitated the anoxic NO reduction. Microbial community analysis suggested that Cluster I of Defluviicoccus-GAO group (∼4%) was responsible for stable NO accumulation performance via EPD, while increased Accumulibacter-PAO group (by ∼15%) contributed to the advanced nutrient removal. Based on the achievement of NO accumulation, the application feasibility of integrated EPD - DPR - Anammox for deep-level nutrient removal was discussed.
内源部分反硝化（EPD）和反硝化除磷（DPR）在新型 A/O-MBBR（厌氧-缺氧-好氧-移动床生物膜反应器）系统中结合，用于处理低碳氮比（C/N）废水。通过优化水力停留时间（HRT，4-12 h）和硝酸盐回收（R，200%-600%），比较了 DPR 的性能并阐明了营养物质代谢。在连续流中，硝酸盐（NO）反硝化伴随着亚硝酸盐（NO 通过 EPD）积累，缺氧区的硝酸盐-亚硝酸盐转化比（NTR）为 35.87%-43.31%。在 HRT 为 12 h、R 为 500%的批试验中，最初揭示了使用 NO 和 NO 作为电子受体的 DPR 机制，其中反硝化磷积累菌（DPAOs）和反硝化糖原积累菌（DGAOs）是不完全反硝化（NO→NO）的 EPD 的主要贡献者。此外，基于计量学的功能细菌分析显示，DPAOs（NO→N，57.30%；NO→N，35.85%）的生物活性高于 DGAOs（NO→N，6.85%），有利于缺氧条件下的 NO 还原。微生物群落分析表明，Defluviicoccus-GAO 组的 I 类（约 4%）负责通过 EPD 实现稳定的 NO 积累性能，而 Accumulibacter-PAO 组（增加约 15%）有助于深度脱氮。基于 NO 积累的实现，讨论了集成 EPD-DPR-Anammox 进行深度脱氮的应用可行性。
