What is a common practice in an activated sludge process?

In an activated sludge process, recirculating activated sludge is a common practice utilized to maintain a healthy population of microorganisms capable of effectively treating wastewater. By returning a portion of the settled sludge back to the aeration tank, operators ensure that a sufficient number of active microorganisms are available to break down organic matter and facilitate the biological treatment process. This recirculation helps maintain the desired concentration of biomass, optimizing the treatment efficiency.

The process is integral in creating a balanced environment where microorganisms can thrive, leading to effective degradation of pollutants. This practice not only enhances treatment performance but also stabilizes the biological system against fluctuations in load. Maintaining a stable population of microorganisms through recirculation is crucial in sustaining the effectiveness of the activated sludge system, as it directly influences the system's ability to handle varying wastewater characteristics.