Is it necessary to satisfy chlorine demand when chlorine is used before disinfection for odor control?

When chlorine is used before disinfection primarily for odor control, it is not necessary to satisfy chlorine demand before the disinfection process. The primary purpose of adding chlorine at this stage is to alleviate odors, which can often be the result of organic compounds or sulfides that generate unpleasant smells.

In these instances, the focus is mainly on the effectiveness of the chlorine in neutralizing these odors rather than ensuring that there is a residual amount of chlorine left for disinfection purposes. The disinfection process typically comes later, where the chlorine demand would need to be satisfied to ensure that sufficient free chlorine is available to effectively kill pathogens.

While there are circumstances where maintaining a chlorine residual is important, in the context of odor control preceding disinfection, the main objective is to address the immediate needs related to odors without being overly concerned about the chlorine demand being fully satisfied. This can help ensure that the water treatment process operates effectively and that the primary issue of odor is resolved promptly.