What technique is used to ensure adequate mixing in aeration tanks?

The technique that ensures adequate mixing in aeration tanks is mechanical aeration with mixers. This method involves using machinery, such as paddle mixers or diffusers, to introduce air into the water and create turbulence. The introduction of air not only provides the necessary oxygen for aerobic bacteria to thrive but also helps circulate the wastewater, ensuring that the mixed liquor is uniformly aerated. This uniformity is vital for promoting efficient biochemical reactions, enhancing the breakdown of organic matter, and preventing the settling of solids.

In aeration tanks, it is essential to maintain proper mixing to keep the microorganisms evenly distributed and in contact with the organic matter they need to degrade. Mechanical aeration systems are designed specifically for this purpose, making them the most effective choice for ensuring adequate mixing in the process. Other methods like gravity settling, centrifugation, or filtration do not provide the necessary mixing action required in aeration tanks and serve different functions in wastewater treatment.