What are the most common chemicals used in the disinfection of drinking water?

The most widely used chemicals for the disinfection of drinking water are chlorine, chlorine-ammonia, chlorine dioxide, and ozone. These disinfectants are effective in killing bacteria, viruses, and other pathogens in the water, making it safe for human consumption.

Chlorine is the most commonly used disinfectant due to its effectiveness, availability, and low cost. It acts quickly to eliminate harmful microorganisms and provides residual disinfectant protection in the distribution system. Chloramine, formed by the reaction of chlorine with ammonia, is used in some systems to maintain longer-lasting disinfection without the strong taste and odor associated with chlorine.

Chlorine dioxide is another effective disinfectant that can help control certain pathogens that chlorine alone may not be effective against, such as Giardia and Cryptosporidium. Ozone is a powerful oxidant that can also serve as an effective water disinfectant, although its use is less common due to the need for special equipment and the lack of a residual effect in the water supply.

The other options do not represent the common practices for drinking water disinfection. While iodine is sometimes used in emergency situations or for small-scale water treatment, it is not a standard for municipal drinking water systems. Bleach, primarily sodium hypochlorite,