Ozone disinfection is a chemical process utilizing ozone as an oxidizing agent to destroy a variety of waterborne organisms. Ozone purification and disinfection methods are more effective than chlorination for removing potentially harmful bacteria and viruses. Ozone purification is also effective at killing yeast and mold spores as well as protozoa. Ozone disinfection is sometimes used in concert with other water treatment methods and systems such as chlorination, filtration and UV sterilization.
Ozone is a reactive unstable gas with a very short half-life. Ozone readily gives up one of its three oxygen atoms, and this atom then bonds with unwanted substances and waterborne contaminants causing them to oxidize. Oxidization breaks down many types of organic chemicals that commonly cause taste or odor problems. Ozone oxidizes waterborne contaminants and materials 3,200 times faster than chlorine and up to 5,600 times faster than bromine. Water treatment systems that utilize ozone disinfection manufacture ozone on-site just prior to use.
Ozone purification methods may produce harmful byproducts such as formaldehyde and bromate. Ozone disinfection is also unable to remove heavy sediments such as dissolved minerals and salts. Use of ozone oxidization to purify water to treat municipal water supplies and wastewater dates back to 1906.