Abstract:Inoculated with conventional activated sludge, the enrichment of anaerobic ammonium oxidizing bacteria (AnAOB) and nitrogen removal performance were investigated in continuous aeration SBR mode to treat ammonium rich influent. For the DO concentration of 0.8 to 1.0 mg·L-1, 9% of nitrogen compound was removed after the treatment for one year at the temperature of 30 to 31 ℃. For decreased DO concentration of 0.3 to 0.5 mg·L-1,when aeration time was prolonged from 330 to 450 min per cycle, autotrophic nitrogen removal was achieved. The maximum TN removal efficiency and removal rate were 79.8% and 0.15 kg·kg-1·d-1, respectively. The sludge structure was changed from floc to granules. By microscope detection and FISH analysis, it was found that something like ball was distributed in floc and AnAOB was enriched in sludge. The results show that the enrichment of AnAOB and single autotrophic nitrogen removal can be achieved in suspended system by continuous aeration mode.