What is considered the most practical method for disinfection in water treatment?

Chlorine is regarded as the most practical method for disinfection in water treatment primarily due to its established effectiveness, cost-efficiency, and ease of application. It effectively inactivates a wide range of pathogens including bacteria, viruses, and some protozoa, making it a widely used disinfectant in municipal water systems. Chlorine has a residual effect, meaning it remains in the water and continues to provide disinfection as it travels through the distribution system, helping to prevent recontamination.

Additionally, chlorine's widespread use has led to extensive knowledge regarding its application, potential chemical reactions, and the byproducts it may form, allowing operators to manage water quality effectively. The familiarity with chlorine in various systems makes it practical for most water treatment facilities, particularly in regions where quick access to disinfection methods is crucial.

While other methods like ozone or ultraviolet light have their advantages—such as not forming harmful disinfection byproducts or providing immediate disinfection without residual—chlorine’s combination of practicality, cost-effectiveness, and operational ease solidifies its position as the go-to method in many water treatment processes.