What does an increase in MLVSS indicate in an aeration tank?

An increase in MLVSS, or Mixed Liquor Volatile Suspended Solids, indicates increased microbial activity within the aeration tank. MLVSS measurements reflect the amount of living microorganisms, primarily bacteria, present in the mixed liquor, which is the combination of wastewater and activated sludge in the aeration tank.

When there is a rise in MLVSS, it suggests that microbial populations are thriving, which usually happens when conditions within the aeration tank, such as sufficient food supply (organic material) and optimal environmental parameters (e.g., temperature and pH), are favorable for growth. Increased microbial activity leads to more effective biodegradation of organics, subsequently enhancing overall treatment performance.

Hence, an increase in MLVSS directly correlates with stronger biological activity and a more robust treatment process, ultimately aiming for better removal of pollutants from the wastewater.