Tennessee Wastewater Operator Practice Exam

What is the likely cause of turbulence in one area of an activated sludge basin?

1. Excessive chemical dosing

2. Damaged or missing diffuser

3. Inadequate aeration

4. High organic loading

The correct answer is: Damaged or missing diffuser

The situation described involves turbulence occurring in one area of an activated sludge basin, which is typically related to the aeration system. When there is a damaged or missing diffuser, the air that would normally be evenly distributed throughout the basin may become localized, leading to an increase in turbulence in that specific area. Diffusers are designed to introduce air into the wastewater in small bubbles, ensuring adequate mixing and aeration across the basin. Damage or absence can result in uneven air distribution, creating pockets of turbulence rather than the desired calm, evenly mixed environment. In contrast, excessive chemical dosing may alter the water chemistry and affect the sludge settling, but it wouldn't specifically create localized turbulence. Inadequate aeration could lead to insufficient mixing overall but does not focus on one area causing turbulence. High organic loading might affect the treatment process but would not typically result in localized turbulence in the aeration basin. Thus, the presence of a damaged or missing diffuser directly correlates to the described issue of turbulence in a specific location within the activated sludge basin.