Tennessee Wastewater Operator Practice Exam

Which chemical is NOT commonly used as a disinfectant in wastewater treatment?

1. Chlorine

2. Bromine

3. Fluorine

4. Ozone

The correct answer is: Fluorine

Fluorine is not commonly used as a disinfectant in wastewater treatment. While chlorine, bromine, and ozone are widely recognized for their disinfectant properties and are actively employed in various stages of wastewater treatment, fluorine does not have the same applications in this context. Chlorine is a traditional disinfectant, effective in killing bacteria and viruses, making it a staple in many treatment facilities. Bromine, although less common than chlorine, can also serve as a disinfectant in certain situations, especially in hot water systems. Ozone is used for its strong oxidative properties, allowing it to disinfect water effectively without leaving a residual chemical. Fluorine, on the other hand, is typically not utilized for disinfection owing to its reactivity and tendency to form compounds with organic matter rather than effectively eliminating pathogens in treated wastewater. This makes it impractical and less safe for use in treatment processes compared to the other disinfectants listed.