N2O Emission from Partial Nitrification and Full Nitrification in Domestic Wastewater Treatment Process

Abstract

Using actual domestic wastewater as the research object, nitrogen compounds and their combinations were added to different nitrification (partial nitrification, full nitrification) processes to investigate nitrous oxide (N2O) emission and its nitrification mechanisms. The presence of influent NH4+ was the driving force of N2O emission during nitrification. Compared with full nitrification, NO2− in partial nitrification more readily generated N2O by denitrification. Under the proportional gradient of NH4+-N:NO2−-N/NO3−-N, 30:0, 20:10, 10:20, and 0:30, total N2O emissions during partial nitrification were 2.81, 11.30, 65.20, and 11.67 times greater than the total N2O emissions during full nitrification. Full nitrification was more beneficial to N2O emission reduction. This provides a control strategy for N2O emission reduction in wastewater treatment processes under the background of reducing the production of greenhouse gases.