What Can Be Used in a Sewer to Help Prevent Odor?

• A. Chlorine
• B. Ammonia
• C. Oxygen
• D. Sulfuric Acid

Answer: (A)

Odors in sewers mainly come from hydrogen sulfide produced when bacteria operate in low-oxygen conditions. The way to curb those odors is to oxidize the sulfide compounds before they escape. Chlorine does exactly that: it oxidizes hydrogen sulfide and other reduced sulfur compounds, turning them into less odorous forms like sulfate. It also provides disinfection, which helps reduce odor-causing bacteria. That combination makes chlorine a practical and effective choice for odor control in sewer systems. Ammonia isn’t used to suppress sewer odors and can contribute to odor in other forms; introducing extra oxygen into existing sewers is usually impractical and not as direct or reliable; sulfuric acid is dangerous, corrosive, and not a standard odor-control method.