In a chlorination process, which chemical is crucial for maintaining water quality?

Free chlorine plays a crucial role in the chlorination process for maintaining water quality because it acts as a strong disinfectant that effectively eliminates harmful pathogens and microorganisms present in the water. Free chlorine is the form of chlorine that is available to react and provide disinfection.

When present in water, free chlorine can oxidize contaminants and kill bacteria, viruses, and protozoa, making it essential for ensuring that drinking water and recreational water are safe for human use. The ability of free chlorine to provide a residual disinfectant effect is also important, as it continues to protect the water as it travels through the distribution system.

Other chemicals mentioned have different roles; for example, hydrogen peroxide serves primarily as an oxidizing agent rather than a bactericide, ammonium sulfate is used primarily as a fertilizer, and calcium hypochlorite, while also a chlorine compound used in water treatment, provides a source of chlorine rather than being the active disinfectant itself. Therefore, free chlorine remains essential for effective disinfection and water quality maintenance.