Which oxidant is used for purification of drinking water?

The most common oxidant used for the purification of drinking water is chlorine. Chlorine is added to water in the form of chlorine gas, sodium hypochlorite (liquid bleach), or calcium hypochlorite (solid) to disinfect and kill harmful microorganisms such as bacteria, viruses, and protozoa. It helps in making the water safe for consumption by destroying or inactivating these disease-causing pathogens.

Chlorine is widely used in water treatment plants because of its effectiveness, cost-efficiency, and residual disinfection properties that help maintain water quality as it travels through the distribution system. However, it's worth noting that other oxidants like ozone and chloramines are also used in some water treatment processes depending on the specific needs and requirements of the water supply system.