Tennessee Wastewater Operator Practice Exam

What is typically true about anaerobic treatment processes compared to aerobic ones?

1. They require more oxygen

2. They produce less sludge

3. They operate at higher temperatures

4. They require less energy input

The correct answer is: They require less energy input

Anaerobic treatment processes typically require less energy input compared to aerobic treatment processes. This is primarily because anaerobic systems do not rely on the introduction of oxygen into the treatment process. Instead, these systems utilize naturally occurring anaerobic microorganisms that can break down organic matter without oxygen, which reduces the need for aeration. In an aerobic process, significant energy is often required for aeration to maintain dissolved oxygen levels conducive to the aerobic bacteria that decompose waste. Conversely, anaerobic treatment systems can often function effectively at ambient temperatures and do not need energy-intensive aeration equipment, leading to lower operational costs and reduced energy usage. This inherent efficiency in energy use is a key characteristic that distinguishes anaerobic processes from their aerobic counterparts. Furthermore, anaerobic processes often generate biogas as a by-product, providing an additional potential energy source, which can further decrease overall energy dependence.