Nitrous oxide production during nitrogen removal from domestic wastewater in lab-scale sequencing batch reactor

The production of N20 during nitrogen removal from real domestic wastewater was investigated in a lab-scale aerobic-anoxic sequencing batch reactor with a working volume of 14 L. The results showed that the total N20-N production reached higher than 1.87 mg/L, and up to 4% of removed nitrogen was converted into N20. In addition, N20 led to a much higher greenhouse effect than C02 during aerobic reaction phase, this proved that N20 production could not be neglected. The N2ON production during nitrification was 1.85 mg/L, whereas, during denitrification, no N20 was produced, nitrification was the main source of N20 production during nitrogen removal. Furthermore, during denitrification, the dissolved N20 at the end of aeration was found to be further reduced to N2. Denitrification thus had the potential of controlling N20 production.