Chlorine is most commonly used in water treatment for:

Chlorine is primarily used in water treatment for disinfection purposes. The introduction of chlorine into the water supply effectively eliminates harmful microorganisms such as bacteria, viruses, and protozoa, which can pose serious health risks to the public. This process is vital in ensuring that the water is safe for drinking and other uses, thereby reducing the incidence of waterborne diseases.

Chlorination is particularly valued for its ability to provide a residual effect, meaning that even after the initial treatment, chlorine remains in the water to continue exerting disinfectant properties as the water travels through the distribution system. This residual chlorine helps in controlling further microbial growth, ensuring that the water remains safe over a longer period.

While chlorine can have other applications in water treatment processes, such as reacting with organic compounds to form chlorinated byproducts or providing some level of corrosion control, its primary and most recognized function in water treatment is specifically for disinfection, making it a critical component of public health protection in drinking water systems.