What does MLSS stand for in the context of wastewater treatment?

In the context of wastewater treatment, MLSS stands for Mixed Liquor Suspended Solids. This term refers to the concentration of suspended solids present in the mixed liquor, which is the combination of raw wastewater and activated sludge in the aeration basin of a treatment facility.

Tracking the MLSS concentration is crucial as it serves as an indicator of the performance and effectiveness of the biological treatment process. The concentration of suspended solids influences the biological activity and helps operators maintain the right balance between the amount of microorganisms and the organic material available for treatment.

Monitoring MLSS also aids in determining the proper aeration time, ensuring adequate contact between the microorganisms and contaminants, and optimizing the sedimentation process that follows in clarifiers. This understanding is essential for achieving effective treatment and maintaining compliance with discharge regulations.