Which treatment is ineffective for sewer odor control?

• A. Hydrogen peroxide
• B. Sulfuric acid
• C. Aeration
• D. Chlorine

Answer: (B)

Odor control in sewer systems focuses on reducing hydrogen sulfide by either oxidizing it or preventing its formation and release. Hydrogen peroxide and chlorine are oxidants that convert sulfide to sulfate, directly lowering odor potential, while aeration helps strip volatile compounds and promotes aerobic conditions that limit sulfide production. Using sulfuric acid, on the other hand, is not effective because lowering the pH shifts sulfide chemistry toward more undissociated hydrogen sulfide, which is more prone to volatilize as a rotten-egg odor. It also corrodes concrete and metal in the sewer system, causing damage. For these reasons, sulfuric acid isn’t used for odor control, whereas the other options actively reduce sulfide odors.