Achieving partial nitrification : a strategy for washing NOB out under high DO condition

Under high dissolved oxygen at about 1.5-2.5 mg/L and environmental temperatures conditions, the NOB was utterly washed out, and partial nitrification was successfully achieved after 180 days of operation. The inoculated sludge was first enriched and incubated for 37 days, and the nitrification capacity increased rapidly, and then, the kinetic parameters of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria were determined.Contrary to the findings of conventional studies, the affinity of NOB for DO was stronger than that of AOB in this study.This study requires the establishment and stabilization of PN under high DO concentration conditions.