Tennessee Wastewater Operator Practice Exam

Fine bubble diffusers create bubbles that are typically how many millimeters in diameter?

1. 0.1-0.5

2. 1.0-3.0

3. 3.0-5.0

4. 5.0-10.0

The correct answer is: 1.0-3.0

Fine bubble diffusers are designed to introduce air into wastewater treatment processes through the generation of small bubbles. The diameter of the bubbles produced by these diffusers typically ranges from 1.0 to 3.0 millimeters. This size range is crucial for maximizing the contact area between the air and the wastewater, enhancing the efficiency of oxygen transfer. Smaller bubbles have a larger surface area relative to their volume compared to larger bubbles, which allows for a greater amount of oxygen to be absorbed into the water. This is particularly important in biological treatment processes where oxygen is necessary for the metabolism of microorganisms. By producing bubbles in the 1.0 to 3.0 mm range, fine bubble diffusers can provide effective aeration, supporting the biological processes involved in breaking down organic matter in wastewater. In contrast, larger bubbles would rise too quickly to allow sufficient oxygen transfer, making the smaller bubbles produced by fine bubble diffusers the preferred choice for many wastewater treatment applications.