Bromine Chemistry for Disinfection

Chemically, bromine is closely related to chlorine as they are both halogens and next to one another in the periodic table. As a result, bromine can be used as an alternative disinfectant to chlorine, however there are some key differences. Versus chlorine, bromine is more stable at high temperatures and a more effective sanitizer at higher pH levels. For example, at a pH of 8 just over 20% of chlorine is available as hypochlorous acid whereas more than 80% of bromine is available as hypobromous acid. Furthermore, in environments having ammonia, bromine will continue to provide disinfection even after it reacts with ammonia to form bromamines since bromamines are unstable and will revert to hypobromous acid. For these reasons bromine is effective for applications such as microbiological control in cooling towers with pH in the 7.5 to 9.0 region.