Tennessee Wastewater Operator Practice Exam

What does MLVSS measure that makes it more effective for process control compared to MLSS?

1. Inorganic suspended solids

2. Organic suspended solids

3. Wastewater temperature

4. Soluble pollutants

The correct answer is: Inorganic suspended solids

MLVSS, or Mixed Liquor Volatile Suspended Solids, is a measurement that specifically quantifies the organic fraction of suspended solids in a wastewater treatment system. This measurement is more effective for process control compared to MLSS, which stands for Mixed Liquor Suspended Solids, because MLVSS focuses on the volatile components that are primarily comprised of microorganisms that are actively involved in the biological treatment processes. In biological wastewater treatment, the organic content is crucial since it directly relates to the biomass that consumes pollutants. Evaluating MLVSS allows operators to get a clearer picture of the concentration of active bacteria and other microorganisms capable of degrading organic matter. Higher levels of MLVSS indicate a healthier microbial population, which is essential for effective treatment. Other options do not directly relate to the effectiveness of MLVSS for process control. Inorganic suspended solids, for example, do not contribute to the biological activity within the treatment system and can even lead to inaccuracies in assessing the health and effectiveness of the microbial community. Thus, focusing on MLVSS provides operators with critical insight into the biological processes ongoing within the treatment facility and aids in making informed decisions about operational adjustments.