Abstract:
The membrane aerated biofilm reactor (MABR), as a novel wastewater treatment technology, has garnered extensive attention for its high nitrogen removal performance and reduced nitrous oxide (N
2O) emissions.In the context of conventional biological nitrogen removal process, N
2O is produced through four main pathways, including hydroxylamine oxidation, AOB denitrification, heterotrophic denitrification, and chemical reactions.Remarkably, the MABR exhibits a lower potential for N
2O emission compared to traditional aeration methods.This decrease is primarily due to its unique substrate counter-diffusion mechanism and bubbleless aeration, which mitigate N
2O production potential and emission level.This paper summarizes the pathways of N
2O generation and reduction in MABR systems, discusses the influencing factors and control strategies of N
2O generation and emission, and looks forward to the future research directions for N
2O emission management in MABRs, thereby highlighting the advantages of MABR in further engineering application in carbon emission reduction.