Reduction of N2O emission from biological nitrogen removal processes by Alcaligenes faecalis augmentation

Abstract

Immobilized Alcaligenes jaecalis gels were augmented into an intermittent aeration reactor treating wastewater to control the emissions of N2O gas. An increase in the hydraulic retention time (HRT) in response to an applied loading caused a significant increase in N2O production. Through A. jaecalis augmentation, the N20 conversion per influent total nitrogen (T-N) was reduced to 50 % of that in a control reactor. Although dissolved oxygen (DO) affected the N2O emission in both the activated sludge and the A. jaecalis-augmented culture, the emission in the A. faecalis-augmented reactor at a low DO level was much lower than that in the control activated sludge reactor.