Tennessee Wastewater Operator Practice Exam

What is one of the key functions of an aerobic digester in wastewater treatment?

1. Reducing pathogens

2. Increasing solids volume

3. Filtering heavy metals

4. Stabilizing chemical pollutants

The correct answer is: Reducing pathogens

The key function of an aerobic digester in wastewater treatment is primarily to reduce pathogens. This process takes place in an oxygen-rich environment, where microorganisms break down organic matter, including pathogens, effectively reducing their numbers. Aerobic digestion utilizes the metabolic activity of these microorganisms, which requires oxygen, to decompose the waste material, resulting in a stabilized product typically referred to as biosolids. This reduction of pathogens is crucial for public health and environmental safety, as it helps ensure that treated wastewater can be safely discharged or reused without posing a risk of disease transmission. Aerobic digesters provide an efficient means of pathogen reduction while simultaneously stabilizing organic solids, which enhances the overall treatment process. The other options focus on different aspects of wastewater treatment that do not accurately describe the primary role of aerobic digesters. For example, while stabilizing chemical pollutants and filtering heavy metals are important in other treatment processes, they are not the main function of aerobic digestion. Additionally, aerobic digestion typically aims to decrease, rather than increase, solids volume, as it converts organic solids into simpler compounds, thereby minimizing the volume of sludge requiring further handling and disposal.