Good mixing is critical to performance of the activated sludge system, regardless of how your aeration tank/reactor is configured. Good mixing will ensure that the microorganisms are in contact with the food, the oxygen, and each other, and that the entire volume of the aeration basin/reactor is being used to treat the wastewater. You can confirm good mixing by visual inspection of surface mixing or distribution of bubbles in your aeration tank.  You can also measure dissolved oxygen (DO) and or mixed liquor suspended solids (MLSS) at several locations within the tank; the results should be similar at each location.

How do you confirm good mixing is occurring in your aeration basin / reactor?