What chemicals combine to form chloramines?

Chloramines are formed through a chemical reaction between chlorine and ammonia. When chlorine, which is commonly used as a disinfectant in water treatment, is added to ammonia in the presence of water, a series of reactions occur that ultimately produce chloramines. These compounds, which include monochloramine, dichloramine, and trichloramine, are used in some water treatment processes because they can provide prolonged disinfection and are less likely to produce harmful byproducts than free chlorine.

The association between chlorine and ammonia is particularly important in water treatment because the presence of ammonia helps to stabilize the disinfecting effect of chlorine over time, making chloramines a suitable choice for maintaining water quality in distribution systems.

Chloramines are significant in water treatment, especially where long-term disinfection is required and the potential for the formation of harmful byproducts, such as trihalomethanes, from the use of chlorine alone is a concern. Thus, understanding the formation of chloramines through the combination of chlorine and ammonia is crucial for water operators and their practices in ensuring safe and effective drinking water.