Nitrous Oxide Generation, Influencing Factors and Emission Reduction in Anaerobic-Anoxic-Oxic Process Wastewater Treatment Plant

Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China

^a h.sq@msn.com
^b* Corresponding author’s email: lxhfei@163.com

Abstract

To achieve the reduction of emissions and control of non-CO₂ greenhouse gases in municipal wastewater treatment plants, this study conducted a one-year monitoring of N₂O in the A²O process of a large municipal wastewater treatment plant in Beijing. N₂O released from the water surface of the A²O process was collected by using a gas flux chamber, and the key influencing factors affecting N₂O were analysed using statistics. The results showed that N₂O was not easy to be released under non-aerated conditions, and the aerobic zone was its main emission area. Temperature leads to high N₂O emissions in winter and low in summer. Correlation analyses showed that NO₂-N is one of the most critical factors affecting N₂O production, and its accumulation level directly affects the amount of N₂O produced in the system. DO also has a great influence on the production of N₂O, and the amount of N₂O produced decreases with the increase of the DO concentration, and the effect on the enzyme activity also makes the pH have a significant effect on the production of N₂O.