Biological Treatment of Wastewater
N2O Occurs in both Denitrification and Nitrification
During wastewater treatment, the biological conversion of ammonium (NH4+) to free nitrogen (N2) forms N2O.
Originally, scientists described N2O as an intermediate product of the denitrification, the conversion of nitrate (NO3-)/nitrite (NO2-) to free nitrogen. However, today the scientific community has documented that N2O is a significant byproduct from the nitrification as well. The conversion of NH4+ to NO2- and to NO3- results in the formation of N2O.
You can read about the main processes and factors for nitrous oxide formation below. In addition, you can find a schematic overview from the Global Water Research Coalitions state of science report “N2O and CH4 Emission from Wastewater Collection and Treatment Systems”.