Chlorine Dioxide in Potable Water Treatment

Chlorine dioxide (ClO2) is a versatile, broad-spectrum biocide with a 75-year track record of safe and effective drinking water treatment, industrial water treatment, and wastewater treatment. It selectively oxidizes biological pathogens without co-generating trihalomethanes (THMs), bromates, and other toxic disinfection by-products (DBPs). This selectivity enables lower applied dosages, which saves costs and provides lasting residuals that maintain disinfection beyond the application point (unlike ozone and UV methods).

Chlorine dioxide is one of four EPA-approved disinfectants for drinking water with CT values second only to ozone in biocidal efficacy, but without the ozonation by-products, high capital expense, or residual limitations. It also offers water treatment entities a quick and simple solution to DBP regulatory compliance without costly plant upgrades. Be sure to view the EPA’s treatability database for more information about water treatment options.

Municipal water professionals will also appreciate these additional qualities of chlorine dioxide water treatment:

The broad-spectrum disinfection efficacy of ClO2 and low CT values enhance a plant’s ability to achieve compliance. Chlorine dioxide offers water treatment utilities a simple solution to meet primary disinfection requirements.

Chlorine Dioxide can be administered in various locations of a treatment plant to enhance overall water quality, as shown in this EPA illustration:

chlorine dioxide water treatment system

Potable water plants may experience unpleasant tastes and odors in finished waters. Chlorine dioxide is effective in oxidizing low-threshold odor compounds at typical treatment dosages and has the advantage of not chlorinating organics.

Iron and manganese concerns affect more water systems than almost any other quality issue and are the root cause of most customer complaints received by water facilities. ClO2 offers a realistic solution to intermittent or year-round iron and manganese problems.

Nitrification is a microbial process by which reduced nitrogen compounds (primarily ammonia) are sequentially oxidized to nitrite and nitrate. To maintain compliance with DBP rules, chlorine dioxide, in extremely low dosages, is very effective in controlling episodes of nitrification.

Even in low-bromide waters, using Chlorine Dioxide pre-oxidation provided the best control for overall genotoxicity. This is evidence that ClO2 can increase the quality of any surface water treatment facility where precursors for DBPs are present. In higher bromide source waters, the formation of bromate (a known mutagen) would be an even larger concern with ozone implementation.

The chart below offers a side-by-side comparison of chloride dioxide vs. other water disinfectants. The advantages (and disadvantages) of ClO2 truly depend on your water treatment needs.

chlorine dioxide water treatment advantages and disadvantages

The appropriate chlorine dioxide dosing system is dependent upon the desired reaction chemistry. There are five main chemical reactions used to safely generate chlorine dioxide for municipal water treatment. Each chemical reaction produces different efficiencies and byproducts.

Learn more about dosing systems and related chlorine dioxide generation systems.

The widespread invasion of zebra mussels has led to infestations that can completely clog water intake facilities and cause plant shutdowns. Chlorine dioxide is a proven oxidant for controlling population growth and contamination.

Case Studies

Pennsylvania Water Utility
Converts Multiple Plants to Chlorine Dioxide

Pennsylvania Water Treatment Facility Equipment

Virginia Water Treatment Plant Remains in Compliance and Improves Safety

virginia-water-treatment plant

Municipal Plant Uses Sodium Chlorate/Hydrogen Peroxide Precursor for Chlorine Dioxide Production

municipal sodium chlorate plant

Potable Water Treatment Expertise

International Dioxcide is the leading producer of chlorine dioxide precursor chemistries and ClO2 generation systems in North America. We provide safe, reliable, and cost-effective water treatment solutions for commercial applications. Our skilled team of engineers, field technicians, and customer service personnel design, build, and implement custom ClO2 solutions for each treatment site.