Which of the following is a method used to disinfect water?

Chlorination is a widely utilized method for disinfecting water, primarily because it is effective in killing a broad spectrum of pathogens, including bacteria, viruses, and some parasites. This process involves the addition of chlorine or chlorine compounds to water, which react with the microorganisms and destroy them, rendering the water safe for drinking and other uses.

In addition to its effectiveness, chlorination also has residual properties, meaning that it leaves behind a small amount of chlorine that continues to disinfect the water as it travels through distribution systems. This is crucial, as it helps prevent recontamination that may occur during transport.

While other methods like ultraviolet light and reverse osmosis do serve specific roles in water treatment, they do not provide the same residual disinfection effect as chlorination. Ultraviolet light is indeed effective in disinfecting water by killing microorganisms through exposure to UV radiation; however, it does not leave a residual disinfectant in the water. Reverse osmosis primarily focuses on removing dissolved solids and impurities rather than disinfecting the water. Filtration can remove particulates but generally does not effectively kill microorganisms or disinfect the water without an additional treatment step.

Thus, chlorination remains a foundational technique in water treatment due to its effectiveness, cost-efficiency, and ability to