Tennessee Wastewater Operator Practice Exam

What percentage of volatile solids reduction (VSR) do most anaerobic digesters typically achieve?

1. 35-45

2. 45-55

3. 55-65

4. 65-75

The correct answer is: 45-55

Most anaerobic digesters typically achieve a volatile solids reduction (VSR) in the range of 45-55%. This efficiency is significant in the context of wastewater treatment because it reflects the ability of anaerobic digestion to break down organic matter and reduce the volume of waste material, contributing to a more efficient overall treatment process. Achieving this level of VSR is essential for holding down the costs associated with handling and processing sludge, as well as reducing the environmental impact of waste disposal. Additionally, the anaerobic digestion process not only reduces the organic content in the waste but also generates biogas, which can be harnessed as a renewable energy source. The selected percentage also represents a typical operational range that facilities aim for when properly maintained under optimal conditions. It is important for wastewater operators to understand these expectations to effectively monitor and manage the performance of anaerobic digestion systems.