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

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.