Which disinfection method is effective but can form disinfection byproducts?

Which disinfection method is effective but can form disinfection byproducts?

• A. Chlorination
• B. Chloramination
• C. UV
• D. Ozone

Answer: (A)

Disinfection methods that are very effective can still produce unwanted byproducts when they react with substances in the water. Chlorination is a widely used, strong disinfectant that reliably inactivates a broad range of pathogens, but it reacts with natural organic matter and other compounds in source water to form disinfection byproducts such as trihalomethanes and haloacetic acids. That combination—strong disinfection plus potential DBP formation—is why chlorine is the best choice for this item. In contrast, UV disinfection inactivates microbes physically without adding chemicals, so it doesn’t create chemical DBPs (though it offers no residual disinfectant). Ozone can inactivate pathogens as well but can generate different byproducts (like bromate) under certain conditions, and chloramines tend to form fewer DBPs but can still produce some.

Disinfection methods that are very effective can still produce unwanted byproducts when they react with substances in the water. Chlorination is a widely used, strong disinfectant that reliably inactivates a broad range of pathogens, but it reacts with natural organic matter and other compounds in source water to form disinfection byproducts such as trihalomethanes and haloacetic acids. That combination—strong disinfection plus potential DBP formation—is why chlorine is the best choice for this item. In contrast, UV disinfection inactivates microbes physically without adding chemicals, so it doesn’t create chemical DBPs (though it offers no residual disinfectant). Ozone can inactivate pathogens as well but can generate different byproducts (like bromate) under certain conditions, and chloramines tend to form fewer DBPs but can still produce some.