Adding chlorine to water treatment can cause the formation of what?

• A. Chlorinated hydrocarbons
• B. Trihalomethanes
• C. Chloramines
• D. Oxidized materials

Answer: (B)

The formation of trihalomethanes (THMs) is a significant concern in water treatment processes where chlorine is used as a disinfectant. When chlorine reacts with organic matter present in water, such as dissolved natural organic materials from plant or animal sources, it can produce these compounds. Trihalomethanes are a group of chemical compounds that include chloroform, bromoform, bromodichloromethane, and dibromochloromethane. These byproducts can pose health risks, including potential carcinogenic effects, which is why monitoring and mitigating their levels in treated drinking water is critical.

While chlorinated hydrocarbons and chloramines are associated with chlorine use in water treatment, they do not specifically represent the concern of trihalomethane formation. Chloramines are formed when chlorine reacts with ammonia in water, whereas oxidized materials can refer to a broad range of compounds resulting from the oxidation processes. Trihalomethanes are the specific compounds of interest regarding the disinfection byproducts resulting from chlorine treatment, making this the most relevant answer in the context of concerns associated with water disinfection.