What does chlorine demand refer to?

Chlorine demand refers to the specific amount of chlorine that is required to react with impurities in water, such as organic matter, bacteria, and other materials present before any chlorine residual is established. This demand is crucial for water treatment processes, as it essentially gauges how much chlorine is needed to disinfect and purify the water effectively.

By understanding the chlorine demand, operators can accurately dose chlorine during treatment to ensure that a sufficient amount is available not only for disinfection but also to meet the needs imposed by the water's contaminants. This understanding helps avoid under-dosing, which may lead to ineffective treatment, or over-dosing, which may result in unnecessary costs and potential adverse effects on water quality.