The DO after degassing process

Hi everyone, The wastewater is treated by Anoxic, Oxic, and by degassing process. The sludge after the DAF process will return to the Anoxic process. Does the DO after degassing process meet the need of the microorganism in Anoxic tank? and to maintain the denitrification reaction rate (about 50%) in the A/O process ? while the DO of Oxic process could be 5~8 ppm. your feedback much appreciated