Tennessee Wastewater Operator Practice Exam

At what pH do aerobic digesters perform best?

1. 6.5

2. 7.0

3. 7.5

4. 8.0

The correct answer is: 7.0

Aerobic digesters operate most effectively at a pH level near neutral, which is around 7.0. This neutral pH facilitates optimal microbial activity, allowing bacteria and other microorganisms to thrive and efficiently break down organic matter. At this pH, the digestive processes can proceed without significant inhibition caused by acidity or alkalinity, which can otherwise negatively impact the metabolic activities of the microorganisms involved. A pH that is too low (acidic) can lead to a decrease in microbial activity and an increase in detrimental conditions, while a pH that is too high (alkaline) can also be harmful, potentially affecting enzyme functions and leading to imbalances in the microbial population. Hence, maintaining a pH around 7.0 is crucial for promoting a healthy environment for the microorganisms and allowing the aerobic digestion process to work effectively.