The process of feeding enough chlorine to meet demand and form a free chlorine residual is called what?

The process of feeding enough chlorine to meet demand and form a free chlorine residual is known as breakpoint chlorination. Breakpoint chlorination refers to a pivotal point in the chlorination process where the amount of chlorine applied surpasses the combined chlorine demand (which includes reactions with organic matter and ammonia compounds in the water). Once this threshold is exceeded, additional chlorine will begin to create free chlorine residual. This is crucial in water treatment as it ensures adequate disinfection and protection against pathogens by maintaining a residual level of free chlorine in the water.

In contrast, continuous chlorination involves the consistent addition of chlorine to maintain a specific residual in water but does not explicitly address the concept of achieving or exceeding the breakpoint. Batch chlorination refers to a method where a specific volume of water receives chlorination at a given time, which does not necessarily imply reaching breakpoint conditions. The term disinfection process is more general and encompasses all methods of killing or inactivating pathogens, which includes but is not limited to chlorination practices. Thus, breakpoint chlorination is the most accurate term for the condition described in the question.