Tennessee Wastewater Operator Practice Exam

Activated sludge systems primarily use what kind of treatment process?

1. Biological treatment

2. Physical-chemical treatment

3. Chemical treatment

4. Mechanical treatment

The correct answer is: Physical-chemical treatment

Activated sludge systems primarily utilize biological treatment processes. This method relies on microorganisms, particularly bacteria, to break down organic matter in wastewater. During the process, aerated environments are created in which these microorganisms can thrive, consuming the organic pollutants as their food source. The primary goal of biological treatment in activated sludge systems is to reduce the biochemical oxygen demand (BOD) of the water, meaning the amount of oxygen required by bacteria to decompose organic materials is decreased. This process is efficient and effective for treating a wide range of wastewater types. While other treatment methods exist, such as physical-chemical, chemical, and mechanical treatments, they play different roles in wastewater management. These methods may be used in combination with biological treatment but are not the primary function of activated sludge systems. In summary, the key focus of activated sludge systems is their biological approach, utilizing naturally occurring processes to achieve treatment objectives.