Which chemical is primarily used for odor control in wastewater treatment?

The correct choice for the chemical primarily used for odor control in wastewater treatment is not Ferric Chloride, but in fact, Sodium Bisulfite.

Sodium Bisulfite acts effectively as a reducing agent and is utilized specifically to eliminate odors associated with hydrogen sulfide and other sulfur compounds in wastewater systems. This compound helps in the treatment of wastewater by chemically altering the nature of the odor-causing substances, thereby mitigating the foul smells often encountered in treatment facilities.

Ferric Chloride, while effective in coagulation processes to remove suspended solids and phosphorus, does not have the properties necessary for controlling odors. Chlorine Gas is primarily used for disinfection purposes and can also contribute to odor issues rather than control them. Alum, typically used as a coagulant in sedimentation processes, also does not play a significant role in odor management.

In the context of wastewater treatment, controlling odors is essential for maintaining a safe and pleasant environment for both workers and surrounding communities, and Sodium Bisulfite is a key player in achieving that goal.