What is chloramine commonly referred to as?

Chloramine is commonly referred to as combined chlorine. This term is used to describe the compounds formed when chlorine reacts with ammonia in water. Combined chlorine does not provide the same disinfection effectiveness as free chlorine, which is the form of chlorine that is available for disinfection in water treatments. While chloramine (specifically monochloramine) does have some disinfectant properties, it is often applied in situations where a more persistent residual is needed in the distribution system compared to free chlorine. Understanding the distinction between combined and free chlorine is important, as it affects water treatment processes and the overall quality of drinking water.

The term combined chlorine encompasses all chloramines formed in the water, which includes monochloramine along with dichloramine and trichloramine. This highlights the broader category that chloramine falls under, reinforcing the correct answer in the context of water treatment and public health.