Tennessee Wastewater Operator Practice Exam

One advantage of rotating screens over stationary screens is that rotating screens generally:

1. Require less maintenance

2. Do not dam the flow

3. Are more cost-effective

4. Are easier to operate

The correct answer is: Do not dam the flow

Rotating screens offer the distinct advantage of not damming the flow in a wastewater treatment system. This characteristic is particularly important in maintaining consistent flow rates and preventing upstream flooding or backup situations that can occur with stationary screens. The design of rotating screens allows for continuous movement, which helps to facilitate the removal of solids without significantly hindering the flow of water through the system. This continuous operation also minimizes the opportunity for clogging, as debris is constantly being moved away from the screening area, thereby ensuring that the flow remains unimpeded. The other options, while they may describe benefits of certain types of equipment, do not capture the primary operational benefit unique to rotating screens. For instance, while rotating screens can indeed require less maintenance due to their self-cleaning nature, this is not universally true across all designs and installations. Similarly, cost-effectiveness can vary based on the specific circumstances and requirements of a wastewater treatment facility. Finally, operational ease can depend on many factors, including the specific model and design of the equipment in use, making it a less definitive advantage compared to the flow characteristics.