The aeration tank volume for a residential system is to be how many times greater than average daily wastewater flow?

In designing a residential sewage treatment system, the aeration tank volume is critical for effectively treating wastewater. The requirement for the aeration tank to be at least two times greater than the average daily wastewater flow ensures that there is sufficient time for the biological processes to occur efficiently.

When wastewater is introduced into the aeration tank, microorganisms break down organic material, and having a larger tank volume helps maintain an adequate retention time for this biological activity to take place. This design allows for better mixing and oxygenation, which are essential for the health of the microorganisms responsible for treating the sewage.

If the aeration tank volume were set at only one time the average daily flow, there would be insufficient capacity to accommodate the biological treatment processes effectively. A volume of three or four times might provide even more capacity, but the standard and more efficient requirement is to have it at least double the average daily flow to balance treatment effectiveness with system size and cost considerations. Thus, establishing the aeration tank volume at two times the average daily wastewater flow is a well-accepted best practice in the design of residential wastewater treatment systems.