Research And Insight

Chlorine Dioxide

Water disinfection with chlorine dioxide is a very efficient and gentle way of fighting legionella bacteria and all kinds of micro-organisms in water such as viruses, parasites and fungus spores.

Chlorine dioxide kills micro-organisms in the water by an irreversible oxidative destruction of the transport proteins in the living cells. Chlorine dioxide has a much more powerful disinfecting action against all kinds of germs and contaminants such as viruses, bacteria, fungi and algae than most other biocides. The oxidation potential is higher than with chlorine and fewer chemicals are required. Furthermore, germs that are resistant to biocides can be killed completely with chlorine dioxide.

Chlorine dioxide is generated from sodium chlorite and hydrochloric acid. When the two components are mixed, the oxidising disinfectant chlorine dioxide is formed in a chemical reaction along with the harmless by-products salt and water.


  • Removes biofilm effectively
  • Effective against bacteria in biofilm and free bacteria floating in the water
  • Effective to bacteria and biofilm in dead-legs without water flow
  • Very long residual effect in the system. The ClO2 stay in the water for days
  • Does not affect smell and taste of the water
  • Not sensitive to pH-value of the water
  • Low life cycle cost


  • If hydrochloric acid (HCl) and sodium chlorite (NaClO2) are mixed, while handling, there is a risk that chlorine dioxide gas will be formed which is harmful

Grundfos supplies the Oxiperm chlorine dioxide (ClO2) preparation and dosing system for water disinfection.

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