State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
KENTECH Institute of Environmental & Climate Technology, Korea Institute of Energy Technology (KENTECH), Naju 58330, South Korea.
Bioresour Technol. 2023 Nov;387:129616. doi: 10.1016/j.biortech.2023.129616. Epub 2023 Aug 6.
Integrated fixed-film activated sludge (IFAS) is a superior system for achieving simultaneous nitrification and denitrification (SND), however, the impact of dissolved oxygen (DO) has not been fully elucidated. Therefore, this study investigated the effect of DO concentration on performance and mechanism of SND in IFAS system. Results showed that IFAS outperformed control systems and achieved optimal SND performance at a DO concentration of 0.5 mg/L, with an SND efficiency of 88.51% and total nitrogen removal efficiency of 82.78%. Typical cycles analysis demonstrated limited-DO promoted SND performance. Further analysis implied biofilms exhibited high biomass and denitrification activity with decreasing DO. Microbial community analysis revealed low DO concentrations were responsible for abundant functional groups and genes associated with SND and promoted unconventional nitrogen removal pathways. Moreover, co-occurrence network analysis elucidated microbial interactions, responses to DO, and keystone genera. This study helps understanding the roles of DO for enhanced SND in IFAS.
一体式固定膜活性污泥（IFAS）是一种实现同步硝化反硝化（SND）的优越系统，但溶解氧（DO）的影响尚未得到充分阐明。因此，本研究考察了 DO 浓度对 IFAS 系统中 SND 性能和机制的影响。结果表明，IFAS 优于对照系统，在 DO 浓度为 0.5mg/L 时达到最佳 SND 性能，SND 效率为 88.51%，总氮去除效率为 82.78%。典型的周期分析表明，限氧促进了 SND 性能。进一步的分析表明，生物膜表现出高生物量和反硝化活性，随着 DO 的降低而降低。微生物群落分析表明，低 DO 浓度是与 SND 相关的丰富功能群和基因的原因，并促进了非常规氮去除途径。此外，共生网络分析阐明了微生物的相互作用、对 DO 的响应和关键属。本研究有助于了解 DO 在增强 IFAS 中的 SND 中的作用。
