Which compound is a byproduct formed during chlorination and belongs to disinfection byproducts?

• A. Chloroform
• B. Bromodichloromethane
• C. Trihalomethanes
• D. Chloramine

Answer: (C)

Chlorination can react with natural organic matter in water to form disinfection byproducts. The most common group of these byproducts is trihalomethanes, a class that includes compounds like chloroform and bromodichloromethane. The question asks for a compound that is produced as a byproduct of chlorination and belongs to disinfection byproducts, so naming the group Trihalomethanes identifies the whole category of byproducts formed in this process. Chloramine, by contrast, is a disinfectant residual, not a disinfection byproduct; chloroform and bromodichloromethane are specific members of the THMs group.