Understanding Chlorination Breakpoint

Chlorination involves adding chlorine to water for disinfection. The 'breakpoint' is a critical point in this process. It's the level of chlorine addition where most chlorine-demand substances (like ammonia and organic matter) are oxidized. Beyond this point, any added chlorine remains as a 'free chlorine residual', which is a powerful disinfectant.

Chlorination Processes Relative to Breakpoint

• Plain Chlorination: Chlorine is added *before* the breakpoint. This results mostly in combined chlorine residuals (chloramines), which are weaker disinfectants and can cause taste/odor issues.
• Break Point Chlorination: Chlorine is added *up to* the breakpoint. This process minimizes combined chlorine and establishes a minimal free chlorine residual.
• Super Chlorination: Chlorine is added *significantly above* the breakpoint. This ensures the complete destruction of ammonia, organic matter, and other substances, creating a substantial free chlorine residual. It is often followed by dechlorination to reduce the residual to acceptable levels.
• Dechlorination: This is a separate process to remove excess chlorine, usually performed after super chlorination.

Identifying Process Above Breakpoint

The question asks for the process that involves chlorination above the breakpoint. Based on the definitions:

• Plain chlorination occurs below the breakpoint.
• Super chlorination occurs above the breakpoint, ensuring oxidation of impurities and establishing a strong free chlorine residual.

Therefore, super chlorination is the process that includes chlorination above the breakpoint.