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.This study requires the establishment and stabilization of PN under high DO concentration conditions.The high-throughput sequencing results showed that Nitrosomonas was the dominant genus with an abundance of 68.62%, which has not been observed in similar studies. It shows that Nitrosomonas can proliferate rapidly as an r-strategy bacteria with a faster growth rate under high DO concentration.