Yuan Chun-Yan, Huo Jia-Hao, Nie Cai-Long, Zhang Ke-Xin, Su Xiao-Li, Song Zi, Yi Gen-Ping, Sun Fei-Yun
State Key Laboratory of Urban Water Resource and Environment, School of Ecological Environment, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Bioresour Technol. 2025 Nov;436:133021. doi: 10.1016/j.biortech.2025.133021. Epub 2025 Jul 21.
Global demands for energy-neutral wastewater treatment drive innovation in sustainable nitrogen removal. A single-biofilm membrane biofilm reactor (MBfR) was constructed for efficient aerobic methane oxidation coupled with simultaneous ammonia oxidation and denitrification (AME-AOD). Through meticulous refinement in aspects such as membrane materials and gas-to-feed ratios, the best-performing biofilm achieved a high total nitrogen (TN) removal efficiency of 97 % ± 2 %. The system ultimately reduced TN from 51.6 ± 0.7 mg l to approximately 5 mg l within 16 h with a methane conversion efficiency of 30.0 ± 0.9 mg-CH/mg-N. From startup, the biofilm supported stable coexistence of aerobic and anoxic processes, with gene abundances related to nitrification and denitrification increasing by 1.6-fold and 1.2-fold, respectively. After long-term operation, ecological niche differentiation enabled coexistence and synergistic interaction of methanotrophs, anaerobic ammonium oxidation (anammox), denitrifiers, and nitrifiers within each layer of the biofilm. Overall, this study offers a new strategy to advance sustainable mainstream nitrogen removal in wastewater.
