ClO₂ is an effective biocide at concentrations as low as 0.1 PPM and over a wide pH range. ClO₂ penetrates the bacteria cell wall and reacts with vital amino acids in the cytoplasm of the cell to kill the organism. Because ClO₂ is more soluble and has greater oxidative capacity than chlorine (5 electrons
to 2), ClO₂ can be 10 to 50 times more effective than chlorine.

Chlorine dioxide is environmentally friendly. In fact, chlorine dioxide technology protects the environment and human health from bacteria and by-products formed by other disinfection methods. For example, in the pulp and paper industry, the use of ClO₂ has virtually eliminated dioxin in mill wastewater and has led to significant improvements in surrounding ecosystems. As a result, the Federal government is phasing out the use of chlorine in pulp mills over the next few years.

Although chlorine dioxide (ClO₂) contains a chlorine atom, its chemistry and properties make it more similar to oxygen that chlorine—making it an effective and environmentally safe biocide ideal for disinfecting vital water supplies to exacting standards.

Like chlorine and ozone, chlorine dioxide is an oxidizing biocide that kills microorganisms by disrupting nutrients across the cell rather than disrupting the metabolic process. While non-oxidizing biocides also kill microorganisms, they can only kill them when the microorganisms are active. Since microorganisms spend most of their time in a dormant state, non-oxidizing biocides must be used at much higher concentrations and more frequently to effectively kill microbial pollutants. In addition, microorganisms become resistant to non-oxidizing biocides over time. Chlorine dioxide is an especially effective disinfectant because bacteria can not develop a resistance to it.

Ozone and chlorine are very reactive and will react with most organic compounds. As a result, they must be used in much larger doses to maintain a residual effect sufficient to kill microorganisms. But their greatest drawback is that they produce dangerous disinfection by-products (DBPs) which are unacceptable according to new standards established by the Environmental Protection Agency. In contrast, ClO₂ is far less reactive. Regardless of its concentration or contact time, chlorine dioxide reacts immediately with the cell walls of microorganisms.

Like ozone, chlorine dioxide is soluble as a true gas. The ClO₂ molecule remains a true gas in solution—making it more energetic and able to reach all points in a system. Because it is a true gas and soluble in virtually anything, it can penetrate bacterial slime layers—biofilm.

Finally, chlorine dioxide and its primary by-products—chlorite and chlorate—all break down to sodium chloride. This, along with failure to form toxic and carcinogenic chlorination by-products and produce a build-up of toxic organic or inorganic by-products like bromates, makes chlorine dioxide the most eco-friendly biocide that can be used.

A growing number of industries are relying on the superior disinfection and environmentally-friendly properties of chlorine dioxide. Chlorine dioxide is quickly becoming the preferred bleaching agent in the pulp and paper industry because it minimizes the environmental impact of the bleaching process. ClO₂ is also used to not only disinfect municipal and drinking water supplies, but also control the water’s taste, odor and color. In the food industry, chlorine dioxide disinfects water used to sanitize equipment and preparation surfaces, wash fruits and vegetables, and prevent salmonella and e-coli from contaminating meat and poultry. In commercial and institutional applications, ClO₂ is used to prevent the spread of legionella in hotels, hospitals and universities. Industrially, chlorine dioxide is an effective membrane treatment, as well as a biocide for cooling and wastewater. It is used in the production of ethanol, microelectronics, nitrogen and ammonia. Discover why a growing number of businesses and communities trust PureLine to disinfect their water supplies safely, effectively and affordably.

ClO₂ can be generated by combining gaseous chlorine and sodium chlorite or sodium hypochlorite and acids and other variations. Although effective in producing ClO₂, these processes require the transportation, storage and mixing of these hazardous chemicals. These safety issues have been one of the significant barriers for more widespread use of ClO₂.

PureLine has a patented process to generate ClO₂ on site using common salts, water, and electricity. The PureLine process virtually eliminates all transportation, storage and handling of hazardous chemicals (whether one uses traditionally generated ClO₂ or other traditional biocides like chlorine) while delivering the significant advantages of ClO₂.

Want to know more about the disinfecting power of chlorine dioxide? Click on www.mixeddisinfectants.com to read “Chlorine Dixoide Water Treatment Disinfectant and Byproducts Research by Doug Ritman, Ph.D., P.E., Water/Wastewater Consultant