Rotating biological contactors are adversely affected by temperatures below what degree Fahrenheit?

Rotating biological contactors (RBCs) are crucial components in wastewater treatment processes, primarily used for biological treatment of wastewater. They consist of a series of discs rotating in a tank partially filled with wastewater. The microorganisms grow on the surfaces of the rotating discs and treat the wastewater as the discs turn in and out of the liquid.

The correct answer highlights that RBCs are adversely affected by temperatures below 55 degrees Fahrenheit. This is significant because lower temperatures can inhibit the metabolic activity of the microorganisms responsible for breaking down organic matter in the wastewater. When temperatures drop below this threshold, the efficiency of the RBCs can decrease significantly, leading to suboptimal treatment performance. Microbial activity is temperature-dependent, and processes involving these organisms typically slow down as the temperature drops, resulting in reduced degradation of waste.

Other temperatures offered as choices may also affect microbial activity, but 55 degrees Fahrenheit is a critical point often cited in operational guidelines for RBC systems. At temperatures lower than this, the risk of inadequate treatment increases, making it an essential operational parameter for wastewater operators to monitor.