What does the term "dose-demand" refer to in water treatment?

The term "dose-demand" in water treatment refers to the amount of residual needed to effectively treat the water. In this context, "dose" pertains to the quantity of a chemical additive (like chlorine or other disinfectants) that is applied to the water, whereas "demand" relates to the amount of that chemical that is consumed or reacted with contaminants present in the water, such as pathogens or organic matter.

Understanding the concept of dose-demand is crucial for ensuring that the proper amount of treatment chemicals are applied. If the dose is set too low, there may not be enough residual to effectively disinfect or achieve the desired water quality. Conversely, applying too much might lead to excessive chemical use or undesirable tastes or odors in the treated water.

This definition helps water treatment operators balance the necessary chemical amounts to maintain effective water quality while avoiding unnecessary waste or potential negative impacts on public health.