What is Chlorine Dioxide?
Chlorine dioxide (ClO2) is a yellowish gas formed by two oxygen atoms and one chlorine atom. This chemical compound forms an effective disinfectant when dissolves in water used for a variety of antimicrobial uses including water and wastewater disinfection. Chlorine Dioxide destroys bacteria, viruses, fungi, spores, algae, and many different pathogens that make cause sicknesses, such as Cryptosporidium parvum and Giardia lamblia.
Like Chlorine, Chlorine Dioxide is an oxidizing agent (electron receiver). However, Chlorine Dioxide can absorb five electrons whereas chlorine has the capacity to only take in two, which means that ClO2 is 2.6 times more effective than chlorine.
Chlorine Dioxide behavior as an oxidizing agent is quite dissimilar. Like ozone, the predominant oxidation reaction mechanism for chlorine dioxide proceeds through a process known as free radical electrophilic (i.e. electron-attracting) abstraction rather than by oxidative substitution or addition (as in chlorinating agents such as chlorine or hypochlorite). This means that chlorinated organic compounds such as THMs and HAAs are not produced as a result of disinfection using chlorine dioxide.