In wastewater treatment, what form is chlorine usually applied?

The application of chlorine in wastewater treatment processes is commonly done using chloramine, which is a compound formed when chlorine is combined with ammonia. This method is often favored because chloramine is a more stable form of chlorine with longer-lasting disinfecting properties in water. It significantly reduces the formation of disinfection by-products that can occur with other forms of chlorine, particularly when organic matter is present in the water. This stability and reduced reactivity allow chloramine to effectively disinfect water over a longer period, making it suitable for many water treatment facilities.

While pure chlorine gas, calcium hypochlorite, and sodium hypochlorite are all valid forms of chlorine used in various disinfection processes, each has its own specific use cases and limitations. For instance, pure chlorine gas can be hazardous and requires careful handling, while calcium hypochlorite and sodium hypochlorite may not provide the same residual disinfection ability as chloramine in certain settings. Thus, chloramine’s unique properties make it an attractive and commonly used choice in wastewater treatment applications.