Tennessee Wastewater Operator Practice Exam

To support a stable digestion process, how should feed sludge be administered?

1. Fed quickly to maintain pressure

2. Fed slowly to avoid overloading methanogens

3. Fed in large quantities for efficiency

4. Fed intermittently to maintain balance

The correct answer is: Fed slowly to avoid overloading methanogens

Feeding sludge slowly is essential for supporting a stable digestion process because it allows for the effective management of the microorganisms involved, particularly methanogens. These microbes are responsible for breaking down organic material to produce methane—a critical aspect of anaerobic digestion. If feed sludge is administered too quickly, it can lead to an overload of organic material in the digestion system. This overload can inhibit the activity of methanogens, as they may not be able to process the influx of substrate efficiently. When overloaded, it can cause an imbalance in the microbial community, leading to decreased methane production and potential instability in the digestion process. By feeding sludge slowly, the digestion system can maintain a consistent and appropriate concentration of substrates, ensuring that the methanogens can effectively perform their function without becoming overwhelmed. This gradual approach promotes a stable environment where microbial populations can thrive, contributing to efficient waste treatment and optimal biogas production.