Estimation of N2O emission during wastewater nitrification with activated sludge: Effect of ammonium and nitrite concentration by regression analysis

Empirical N2O emission correlations were developed from wastewater nitrification in a controlled laboratory scale batch reactor. The results showed that higher concentrations of ammonium and nitrite emitted more N2O. The N2O-N yields were 0.092–0.124 (synthetic wastewater) and 0.124–0.152 kg N2O-N/kg consumed NH4+-N (municipal wastewater). Regression analysis showed that N2O emission had positive linear correlation with logarithm of NH4+-N concentration and exponential of NO2−-N concentration. The results indicate that nitrite is the most influential component on N2O emission in wastewater nitrification. The models can be used to estimate and to mitigate N2O emission from wastewater treatment plant.