MABR
Under the "dual carbon" initiative, urban wastewater management is transitioning towards carbon resource utilization. The traditional nitrification/denitrification process cannot meet the nitrogen removal requirements of the new era. The partial nitritation/anammox (PN/A) process, which does not require an external carbon source, represents an economically viable and highly efficient solution for wastewater nitrogen removal. However, given the significant greenhouse gas (N2O) emissions associated with conventional bubble aeration, the membrane aerated biofilm reactor (MABR) offerred a promising alternative. By leveraging oxygen functional partitioning, membrane aeration can effectively suppress nitrite-oxidizing bacteria (NOB), thereby achieving the PN/A process while simultaneously reducing N2O emissions caused by agitation. Based on existing PN/A reactor designs, a membrane-aerated PN/A reactor (MA-PN/A) and its operational methodology were developed. This study investigates the nitrogen removal efficiency, N2O emission characteristics, sludge properties, microbial community structure, and elucidates the underlying mechanisms of N2O emission reduction.