Nutrient removal performance in an intermittent aerated sequencing batch membrane bioreactor

In this study, a sequencing batch membrane bioreactor (SBMBR) was operated with intermittent aeration to perform partial nitrification nutrient removal. Several batch experiments were also carried out to investigate the nutrient removal characteristics. The removal efficiencies of suspended solid (SS), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) for the SBMBR process were 96.7, 95.5, 73.6 and 98.1%, respectively. It was also found that all the organic‐ and ammonia‐nitrogen was nitrified into nitrite rather than nitrate form, showing partial nitrification. The results of the batch experiments showed that heterotrophic nitrification occurred and nitrite was still the predominant oxidized nitrogen species. It was also observed that autotrophic denitrification occurred during the denitrification batch experiments, although the autotrophic denitrification rate was only 34% of the heterotrophic denitrification rate. In addition, there was no significant difference in the phosphate uptake rate observed between nitrite and nitrate as electron acceptors. Finally, five nutrient removal related bacteria were identified in the SBMBR reactor using the pure culture method.