Feasibility of applying intermittent aeration and baffles for achieving granular nitritation in a continuous...

It was difficult to obtain a stable and efficient short-cut denitrification and phosphorus removal process for domestic sewage treatment, therefore, the possibility of using granulation technology of nitritation sludge and intermittent aeration was evaluated to resolve the difficulty. Results showed that the nitrogen and phosphorus removal efficiencies of the system were 72% and 93%, respectively, under the condition of mode 3 (a period of 10 min with aeration 8 min and stop 2 min) with aeration energy consumption decreasing 20%. Microbial community revealed that Rhodocyclales was the dominant short-cut denitrifying phosphorus removing bacteria in the process, closely related to the performance of short-cut denitrifying phosphorus removal. Furthermore, Thauera and Denitratisoma belonging to the Rhodocyclales play a significant role of short-cut denitrifying phosphorus removal in the process. In addition, Aeromonas improved the performance of short-cut denitrifying phosphorus removal. Finally, nutrient removal efficiency was improved 8% in intermittent aeration mode 3 based on short-cut denitrifying phosphorus removal.