Aeration control in a full-scale activated sludge wastewater treatment plant: impact on performances, energy consumption and N2O emission

International audience; This work investigated the impact of aeration control strategy on energy consumption and nitrous oxide (N2O) emission in a full-scale wastewater treatment plant. Two identical activated sludge processes treating the same effluent but operated with different aeration control strategies were compared. Aeration tank 1 was operated with a new control strategy favouring the simultaneous nitrification denitrification (SND) whereas aeration tank 2 was operated with a conventional control strategy with distinct nitrification and denitrification phases. Results indicated that whereas the N2O emission factor was comparable in both systems (in the order of magnitude of 0.004% of the influent TKN load), N2O emission pattern was dependent on the adopted aeration control strategy. It has been observed that high aeration