Texas Wastewater Class B Practice Exam

If an activated sludge system displays no aeration, what operational issue should be suspected?

1. Excessive sludge wasting

2. Loss of aeration equipment

3. Insufficient oxygen supply

4. Clogged aerators

The correct answer is: Insufficient oxygen supply

The ideal functioning of an activated sludge system relies heavily on the presence of adequate aeration, as this process is essential for maintaining the necessary dissolved oxygen levels that support the metabolic activity of microorganisms. If there is no aeration, it can lead to insufficient oxygen supply, which directly impacts the health and functionality of the biological community in the system. Without sufficient oxygen, microorganisms cannot effectively break down organic matter, ultimately leading to a decline in water quality and treatment efficiency. While there may be other factors to consider, such as clogged aerators or issues with the aeration equipment, the primary and most immediate concern when aeration is absent is the failure to provide enough oxygen to sustain biological processes.