LIYan,LIUYing-shi,YUXiang,et al.Nitrous Oxide Emission Characteristics and Formation Mechanism in AAOA-MBR Process[J].China Water & Wastewater,2025,41(21):96-103.
Nitrous Oxide Emission Characteristics and Formation Mechanism in AAOA-MBR Process
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第21期
Page:
96-103
Column:
Date of publication:
2025-11-01
- Keywords:
- nitrous oxide (N2O); emission factor; AAOA-MBR process; microbial community structure; nitrogen metabolic pathway
- Abstract:
- A comprehensive investigation was conducted on nitrous oxide (N2O) emission throughout the entire process and the emission factor was calculated for a full-scale anaerobic-anoxic-aerobic-anoxic and membrane bioreactor (AAOA-MBR) wastewater treatment plant (WWTP). The emission characteristics of N2O along the AAOA-MBR process were analyzed. Furthermore, the microbial community structure and key nitrogen metabolic pathways involved in the process were elucidated by integrating metagenomic whole-genome sequencing technology. The total N2O emission from the entire wastewater treatment process amounted to 12.303 kg/d. The pretreatment stage exhibited the highest N2O emission, reaching 2.709 kg/d. Within the biochemical treatment stage, the MBR demonstrated the greatest N2O emission of 1.940 kg/d. The N2O emission factor for the entire process at this WWTP was 0.001 534 kgN2O-N/kgNinf, which was lower than both the IPCC recommended value (0.016 kgN2O-N/kgNinf) and the average value reported for AAO process cases in Guidelines for Carbon Accounting and Emission Reduction in the Urban Water Sector (0.004 66 kgN2O-N/kgNinf), while being consistent with the results from certain AAO process cases in China derived using the measurement-based method. In the AAOA-MBR process, Comamonas was the predominant genus associated with nitrogen metabolism, exhibiting a relative abundance of 1.90%-2.96%. During nitrogen metabolism, all metabolic pathways were detected except for the Anammox pathway.
Last Update:
2025-11-01