Tennessee Wastewater Operator Practice Exam

What is a potential consequence of having a high concentration of filamentous bacteria in the activated sludge process?

1. Improved clarification

2. Enhanced floc formation

3. Increased effluent quality

4. Settling problems in the clarifier

The correct answer is: Settling problems in the clarifier

The presence of a high concentration of filamentous bacteria in the activated sludge process can lead to settling problems in the clarifier. Filamentous bacteria can create a mass of interconnected filaments which can disrupt the normal settling characteristics of the sludge. This can result in a condition known as "bulking," where the sludge does not settle properly during the clarification process. As a consequence, this can lead to higher levels of suspended solids in the effluent, thereby affecting the quality of the treated wastewater. Good settling is crucial for effective separation of solids from the liquid in the clarifier, and when filamentous growth dominates, it hampers this process, leading to operational challenges. Operators must monitor and control filamentous bacteria levels to maintain optimal performance in the wastewater treatment system.