By how much can chlorine demand decrease from summer to winter?

Chlorine demand in water treatment can vary significantly between summer and winter due to factors such as temperature, organic matter concentration, and biological activity. In warmer months, the higher temperatures promote greater biological activity, leading to an increased demand for chlorine to maintain water quality and ensure disinfection. Conversely, in winter months, the lower temperatures generally reduce biological activity and the presence of organic matter, resulting in a reduced chlorine demand.

It is well documented that chlorine demand can decrease by up to 20% from summer to winter. This reduction is influenced by the lower rates of bacterial growth and other reactions that occur in colder water, which means less chlorine is required to achieve effective disinfection. Recognizing this seasonal variability is important for water treatment operators to adjust chlorine dosing appropriately throughout the year, ensuring both safety and efficiency in the treatment process.