Chlorine is one of the most commonly used disinfectants in water treatment facilities. Its primary role is to eliminate harmful microorganisms that may be present in sourced water, including bacteria, viruses, and protozoa. Chlorination is a process where chlorine gas or chlorine compounds, such as sodium hypochlorite, are added to water. When chlorine reacts with the water, it forms hypochlorous acid, which is highly effective at killing pathogens.