Both Ozone and UV are well recognized methods for municipal drinking water treatment and disinfection. Each can be used for the inactivation of viruses, giardia, cryptospordium, bacteria and other microbial contaminants. While UV is limited to disinfection, ozone is also an effective treatment for taste, odor and color removal, iron and manganese reduction, as well as being a flocculating agent. Ozone and/or UV require a relatively short residence times for disinfection unlike chemicals such as chlorine and chlorine derivatives.
- 1886 - First Experimental Ozone use for Disinfection of Water de Meritence, France.
- 1892 - Several Experimental Plants Operating throughout Europe.
- 1906 - First Full Scale Ozone Plant by Marius Paul Otto in Bon Voyage, France.
- 1909 - Second full scale plant in Nice, France.
- 1911 - Ozone Generators started in St. Petersburg, Kiev, Gorski and Moscow.
- 1940 - First Ozone Water Treatment Plant in Whiting, IN USA.
- 1949 - Ozone Drinking Water Treatment in Philadelphia, PA, USA.
- 1950 - 136 Ozone Plants in France, England and Germany serving 8 MM people.
The formation of oxygen into ozone occurs with the use of energy. This process is carried out by an electric discharge field as in the CD-type ozone generators (corona discharge simulation of the lightning), or by ultraviolet radiation as in UV-type ozone generators (simulation of the ultra-violet rays from the sun). In addition to these commercial methods, ozone may also be made through electrolytic and chemical reactions.
Ozone is a naturally occurring component of fresh air. It can be produced by the ultraviolet rays of the sun reacting with the Earth's upper atmosphere (which creates a protective ozone layer), by lightning, or it can be created artificially with an ozone generator.
The ozone molecule contains three oxygen atoms whereas the normal oxygen molecule contains only two. Ozone is a very reactive and unstable gas with a short half-life before it reverts back to oxygen. Ozone is the most powerful and rapid acting oxidizer man can produce, and will oxidize all bacteria, mold and yeast spores, organic material and viruses given sufficient exposure.
The advantages of using Ozone include
Ozone is primarily a disinfectant that effectively kills biological contaminants. Ozone also oxidizes and precipitates iron, sulfur, and manganese so they can be filtered out of solution. Ozone will oxidize and break down many organic chemicals including many that cause odor and taste problems. Ozonation produces no taste or odor in the water.
Since ozone is made of oxygen and reverts to pure oxygen, it vanishes without trace once it has been used. In the home, this does not matter much, but when water companies use ozone to disinfect the water there is no residual disinfectant, so chlorine or another disinfectant must be added to minimize microbial growth during storage and distribution.
