Achieving single‐stage partial nitritation and anammox (PN/A) using a submerged dynamic membrane sequencing batch reactor (DM‐SBR)

Single-stage partial nitration and anammox (PN/A) is achieved using a submerged dynamic membrane (DM-SBR) in this study. The DM-SBR was stably operated for 200 days, and the nitrogen removal efficiency (NRE) was sustained at 70.3 ± 7.2% at a nitrogen loading rate (NLR) ranging from 0.1 to 0.3kgN/m3/d with a hydraulic retention time (HRT) of 24 h. When the NLR was 0.2 kgN/m3/d, the NRE achieved was high as 80% with a low concentration of dissolved oxygen (DO) of 0.13 mg/L. In addition, the specific activity of anammox bacteria (AnAOB) and ammonia-oxidizing bacteria (AOB) reached was 2.72 and 16.80 gN/gVSS/d, respectively. The dynamic membrane (DM) intercepted the biomass due to the lamellar, intact, dense biofilm self-generated on the surface of the supporting material, which had an effluent turbidity of 10 NTU. The enriched anammox functional bacteria were Candidatus Jettenia, and the relative abundance was 11.06%. The AOB-like functional bacteria consisted primarily of Nitrosomonas, with a relative abundance of 2.76%, which ensured the nitrogen removal process reaction. This study provides a novel reactor configuration of the single-stage PN/A process in the view of practical applications.