What is the primary function of the aeration tank in a sewage treatment facility?

The primary function of the aeration tank in a sewage treatment facility is to facilitate the breakdown of organic matter by microorganisms. During this process, wastewater is introduced into the tank where it is mixed with air, creating an environment that supports the growth and activity of these microorganisms. As they digest the organic material present in the sewage, the microorganisms convert it into more stable compounds, thereby reducing the levels of pollutants in the water.

The effectiveness of the aeration process greatly depends on maintaining adequate oxygen levels for the microorganisms, which are essential for their metabolic activities. This not only helps in decomposing organic solids but also contributes to the overall reduction of biochemical oxygen demand (BOD) in the wastewater, making it more suitable for subsequent treatment steps.

Other processes in a sewage treatment facility serve different purposes, such as removing heavy metals, clarifying the wastewater, or disinfecting the effluent, but the key role of the aeration tank specifically focuses on the biological treatment of organic waste.