Achieving nitritation and phosphorus removal in a continuous-flow anaerobic/oxic reactor through bio-augmentation

► Nitritation/anammox is thought to make sewage treatment energy-neutral. ► Nitritation is the key for successful anammox in sewage treatment. ► Nitritation could be quickly start-up, and reconstructed by using bio-augmentation and controlling DO at below 0.96 mg/L. ► Phosphorus could be removed biologically by 96.43% when nitrite accumulation rate was above 78.60%. ► Sludge settleablity was good even under high nitrite accumulation rate.