Which chemical is frequently used for disinfection in water treatment?

Chlorine is often used for disinfection in water treatment due to its effectiveness in killing bacteria, viruses, and other pathogenic microorganisms present in water. It acts as a strong oxidizing agent that disrupts cellular processes in microorganisms, leading to their destruction. Chlorine can be added in various forms, such as chlorine gas, sodium hypochlorite, or calcium hypochlorite, and it provides not only immediate disinfection but also residual protection against recontamination, making it a vital component in water treatment processes.

In contrast, fluoride is primarily used for the purpose of dental health in community water fluoridation rather than disinfection. Calcium carbonate and sodium bicarbonate are mainly involved in water hardness control and pH balancing, but they do not possess disinfection properties. Therefore, chlorination remains the standard practice in water treatment for ensuring microbial safety in drinking water.