Chlorine is commonly used for what purpose in water treatment?

Chlorine is predominantly used in water treatment for disinfection purposes. The primary role of chlorine in this context is to eliminate harmful pathogens, including bacteria, viruses, and parasites, that can contaminate drinking water and pose health risks to consumers. When chlorinated, water undergoes a chemical reaction, allowing chlorine to effectively kill or inactivate these microorganisms, ensuring that the water is safe for human consumption.

The disinfection process is critical in public health, as it significantly reduces the incidence of waterborne diseases. By maintaining a residual level of chlorine in the distribution system, water treatment facilities ensure ongoing protection against contamination that may occur after treatment.

In contrast, deodorization involves the removal of odors from water, filtration refers to the physical separation of particles from water, and fluoridation involves adding fluoride for dental health benefits. While all these processes are important in water treatment, they do not serve the primary purpose of disinfecting water. This is what distinguishes chlorine's role in water treatment, solidifying disinfection as the correct answer.