Total chlorine is defined as the sum of which two components?

Total chlorine is defined as the sum of free chlorine and combined chlorine. Free chlorine refers to the chlorine that is present in water as hypochlorous acid (HOCl) and hypochlorite ion (OCl-), which are effective in disinfection processes. On the other hand, combined chlorine is formed when free chlorine reacts with organic compounds in the water, resulting in chloramines and other chlorinated compounds that may also contribute to disinfection but are less effective than free chlorine.

Understanding this definition is essential for managing water treatment processes, as it helps ensure that an adequate level of chlorine is maintained for effective disinfection while also preventing the formation of chloramines, which can lead to undesirable tastes, odors, or irritation. By measuring both components, water treatment professionals can adjust chlorine levels appropriately to meet safety and regulatory standards. This knowledge is crucial for maintaining high water quality and effective disinfection practices in various water systems.