Unveiling performance stability and its recovery mechanisms of one-stage partial nitritation-anammox process with airlift enhanced micro-granules

The performance stability and its recovery mechanisms of a partial nitritation-anammox process were investigated. A one-stage airlift enhanced micro-granules (AEM) system was operated for 650 days continuously to treat 50 mg-NH4/L wastewater. During the stable stage, high nitrogen removal efficiency 72.7 ± 8.4% lasting 230 successfully achieved under 0.28 L/min aeration rate 0.10–0.20 mg/L dissolved oxygen (DO) concentration. microbial consortium with good granularity appeared in red. specific activity anammox ammonia oxidation increased 1.02 0.93 g-N/g-VSS/d, respectively. Meanwhile, analysis showed AEM shifted dominant microflora from Proteobacteria Planctomycetes which Candidatus Brocadia abundance reached 35.0%. results reveal that long-term airlift-aeration promoted granulation further activities, abundances bacteria, suppressed nitrite-oxidizing bacteria. Optimizing DO control is also critical increment recovery.