Tennessee Wastewater Operator Practice Exam

What is one advantage of a complete mix type activated sludge system?

1. Increased recovery of nutrients

2. Reduction of energy consumption

3. Dilution of shock loads

4. Minimization of operational complexity

The correct answer is: Dilution of shock loads

A complete mix type activated sludge system offers the advantage of effectively managing and diluting shock loads, which can occur due to sudden inflows of wastewater that have higher concentrations of pollutants. In such systems, the mixed liquor is constantly stirred and mixed, creating a uniform environment throughout the tank. This mixing helps to mitigate the impact of these sudden loads on the microbial community, preventing potential toxicity or damage that high concentrations can cause. Additionally, this type of system ensures that the microorganisms can readily interact with the incoming wastewater, allowing for more stable biological treatment even when the characteristics of the influent fluctuate. This means that even in situations of increased organic loading, the complete mix system can maintain efficient operation, which is crucial for protecting both the treatment process and the environment. Although the other options may present benefits in some contexts or other types of systems, the primary strength of a complete mix activated sludge system lies in its ability to accommodate fluctuations in wastewater strength through effective dilution and mixing, making it particularly resilient to shock loads.