What are the components of a chlorine residual?

The components of chlorine residual include both combined chlorine and free chlorine. Free chlorine refers to the chlorine molecules that are available and active for disinfection, primarily in the form of hypochlorous acid and hypochlorite ions. Combined chlorine, on the other hand, consists of chloramines, which are formed when chlorine reacts with ammonia or organic nitrogen compounds during the disinfection process.

Understanding that the chlorine residual is a measure of how much chlorine remains in the water after disinfection is crucial for water treatment processes. This residual is important as it protects against recontamination and helps ensure water safety throughout the distribution system. Thus, combined chlorine forms, along with free chlorine, are essential to accurately assess and manage chlorine levels in water treatment.