How Ozone Works

Ozonation is one of the many methods used for the purification of water. It is a technology substantially more effective than others.

Ozone has been used to treat ground and surface water in many European cities for years, with Paris, France opening its first ozone treatment plant in 1906. Now, there are more than 2,000 municipal water treatment plants worldwide using ozone. Ozone is also the industry standard for treating bottled water.

Ozone, also referred to as triatomic oxygen, is an unstable gas having life in water of minutes. Oxygen, which is normally biatomic, becomes ozone through the addition of a third unstable atom. Ozone, because of its instability, cannot be generated and stored for future use. It must be generated and used for treatment immediately. It is created by one of two generation methods: Ultraviolet radiation or corona discharge. Of the two, corona discharge produces the substantially higher ozone concentration needed for the removal of complex impurities. Generated ozone is pumped into the water through a diffuser of fine porosity, creating very small bubbles which rise slowly through the water. The slower the bubbles rise through the water, the greater the amount of ozone transferred to the water. Most critically for water quality, ozonation does not add chemicals to the water as does chlorine, chlorine dioxide, permanganate, etc. As the ozone passes through the water, the third unstable atom detaches, attacks, and destroys impurities in the water. The residue in the water is pure oxygen, which quickly dissipates in a few minutes. Any excess dissolved ozone which is not needed for treatment, reverts to simple oxygen in about 20-30 minutes.

Ozone has also received GRAS (Generally Recognized As Safe) status from the FDA.

Effects of Ozone Purification

The primary effects of ozonation of drinking water are:

1. Bacterial disinfection and viral inactivation.
2. Oxidation of inorganics such as iron, manganese, organically bound heavy metals, cyanides, sulfides, and nitrates.
3. Oxidation of organics such as detergents, pesticides, herbicides, phenols, taste and odor caused by impurities.

The action of the ozone in each of these cases follows:

... Disinfection and Viral inactivation

The extent of bacteria destruction and viral inactivation is related to the concentration of ozone in the water and its contact tome with the microorganisms. Bacteria are the most rapidly destroyed. E-Coli bacteria are destroyed by ozone concentrations just over .01mg/liter and contact time if 25 degrees C (77 degrees F) and 30 degrees C (86 degrees F).* Streptococcus Fecalis are much more easily destroyed. At ozone concentrations of about 0.025 mg/L, 99.99% inactivation is obtained in 20 seconds or less at both temperatures. Viruses are more resistant than bacteria. Pioneering studies by French public health scientists in the 1960's have shown that poliovirus types I, II, III are inactivated by exposure to concentrations of dissolved ozone of 0.4 mg/L over a four minute contact period.

... Oxidation of Inorganics

In the case of iron, manganese and the several arsenite or arsenate compounds, oxidation takes place very rapidly leaving insoluble compounds, which are easily removed by an activated carbon filter. Sulfide ions are oxidized sequentially to sulfate ions, an innocuous substance. The first stage of this oxidation is very rapid, quickly and efficiently removing any sulfurous odors. Nitrite ions are oxidized to nitrate ions, which are stable and innocuous.

... Oxidation of Organics

Ozone is a very powerful agent in treating organic materials. Organics are either natural (humic and fulvic acids) or synthetic (detergents, pesticides) in nature. Some organics react with ozone very rapidly to destruction, within minutes or even seconds (phenol, formic acid), whereas others react more slowly with ozone (humic, fulvic acids, several pesticide, trichloroethane, etc.). In some cases, organic materials are only partially oxidized with ozone. A major advantage of partial oxidation of organic materials is that in becoming partially oxidized, the organic materials become much more polar than originally, producing complex insoluble materials which are removed by activated carbon filters.

Ozone vs. Activated Carbon Filters

Activated carbon filters have a definite place in water purification systems as they are the principal effective way to remove insoluble matter from water. However, used by themselves they have serious disadvantages. Activated carbon will not trap certain types of virus, bacteria or cysts, such as those that cause dysentery.

In fact, unless their output water is tested frequently, a process usually unavailable in the household, they can be a breeding ground for harmful bacteria. They must be changed on a regular basis, at considerable expense, or they will become saturated with bacteria and other contaminants, which then allow hazardous compounds to run out of the tap at levels higher than found in unfiltered tap water.

However, if the water has been purified by ozonation prior to passage through an activated carbon filter the only remaining task of the filter is to remove insoluble, non-toxic matter from the water. This latter material will not breed bacteria, and such filters need to be changed far less frequently.

Ozone vs. Chlorine

Ozone has been used for years to produce high quality potable water worldwide. It has only been gaining acceptance in the U.S. in the last 10-15 years, chlorine having been the most widely accepted purification agent for most municipal systems.

"Ozone is produced for use in water purification by exposing oxygen to high voltage electrical discharges. Its chief advantage over chlorine is that it not only kills bacteria, but it also destroys viruses and water-borne parasites. Further, ozone removes smells and color from the water, and leaves no residue. By the time the water comes out of the tap, the ozone is gone without a trace. The problem is especially serious for areas that obtain their water from rivers or reservoirs rather than wells. Such surface water contains high amounts of organic material from plants and animals, which reacts with chlorine to produce such chemicals as chloroform, a known carcinogen." ‚Business Week, May 7 1984

About Ozone When Ozone Was First Used: The "ozone advantage" is simple, yet profound: chemical free/low or no maintenance! Ozone has been used to treat water for more than a century. It began in Oudshoorn, Netherlands, in 1893. The first ozone water treatment plant treated their drinking water. Nice, France, was the first large city to use ozone for their drinking water. Now, thousands of communities throughout the world use ozone. Los Angeles, California, is the world¼s largest (600 million gallons a day) water treatment plant to use ozone for water decontamination. A three-year-old LACDWP study completed in 1983 proved that the use of ozone as a pretreatment for adequate water was the most economical way to meet or exceed new state and federal water quality standards. Ozone treatment is now easier more efficient and less costly than conventional methods. The "revolution" in ozone treatment is that it works- and works well - at an affordable price. Ozone is no longer an obscure method of treating water! Ozone has been accepted by municipalities, bottling and beverage companies, the EPA (10 state standards), Wisconsin DILHR, Water Quality Association and many foreign authorities. How Ozone is Made: Ozone (O3) is commonly found in nature. Ozone is formed whenever lightning occurs, or when an electrical discharge creates a spark. The ozone layer in the upper atmosphere provides a screen against dangerous solar radiation. The generation of ozone is a relatively simple process. Air, dry air or oxygen is drawn into our patented ozone generators, at which point the air is charged with a high voltage. The air is made up of diatomic oxygen (O2) and nitrogen (N2). Diatomic oxygen is a molecule composed of two oxygen atoms (O) held together by four equally shared electrons. As the air is drawn through the ozone generator, the high voltage splits some oxygen molecules into oxygen atoms. Some of these atoms then quickly react with oxygen molecules to form ozone: (O1) + (O2) =(O3). Ozone is second only to fluorine as the most powerful oxidant. Ozone inactivates and oxidizes organic metals and most organisms faster than chlorine. Ozone also functions as a micro flocculating agent to "polish" the water and improve clarity (clarifying iron, sulphur, and manganese). Cooling Towers Advantages of Using Ozone: Ozone use in the cooling tower industry has become a very popular and less expensive method of water problem elimination. An Ozonator is a device that creates ozone gas/ Ozone gas is a very strong oxidizer and disinfectant, which is commonly found in nature. Ozone is produced by ultraviolet light, lightning and almost any electrical discharge. Even copy machines create small amounts of ozone. Ozone has been used to take the place of chlorine. Ozone has been used in the following applications: Residential, Commercial/Industrial water treatment for the removal of iron, sulphur, manganese. (Homes, livestock, irrigation, agriculture, aquaculture) Bottled water for maintaining bacteria free water to sell, increase shelf life, and improve taste. Cooling towers for eliminating scale, bacteria, algae, organics, and reducing chemical dependence. Swimming pools/spas to eliminate/reduce the need for chlorine, and to produce spring like water. The Primary Uses Are: Bacterial/viral reduction. Improved clarity in sump. Scale reduction. Cooler running temperatures. Algae reduction. Reduction or elimination of blow down. Reduction or elimination of chemicals needed for algae control. All this with no regularly scheduled maintenance on the ozone unit! The Ozone Treatment System is Simple ... Just 3 Easy Steps ... I. Ozone Injection We create the ozone in our automatic, self-contained, maintenance free ozone unit then inject into the side stream flow via our durable, exclusive OZONE PUMP. Oxidation starts to take place in microbes, organics, bacteria, and virus immediately. II. Contact Mixing Chamber Our unique contact tanks help further the ozone¼s ability to oxidize particles allowing them time to react prior to returning to the system. III. Filtration, Scale Control, Particle Removal Possibly the most important aspect of any water treatment is the removal of the particles that have been oxidized. Without this step all you have done with the ozone is change the structure of the particles by making them insoluble, or heavier. This step is necessary for systems that require scale control, and particulate removal. What Is Simple Oxidation "SO"? "SO" pertains to certain items such as IRON, SULFUR, and MANGANESE that oxidize very quickly and easily when the ozone comes in contact with them. These items will require very little ozone and no detectable ozone residual. What Is Complex Oxidation "CO"? "CO" pertains to the oxidation of items such as VOC¼s and bacteria. "CO" also pertains to the need to have an ozone residual. When sizing an ozone unit for "CO", the gpm and the water analysis must be ascertained. A rule of thumb is 0.3ppm=03 residual for a 3 minute contact is sufficient to kill certain amounts and types of bacteria.

What Systems Require An Ozone Residual And What Does Not?

Needs an Ozone Residual Bottle Water   Cooling Towers   Water Reclamation   Swimming Pools   VOC Reduction   Bacteria Contamination

Does NOT Need An Ozone Residual Iron/Iron Bacteria Sulphur/Sulphur Bacteria Manganese Iron/Iron Bacteria: Soluble ferrous iron, which is not filterable, is oxidized to insoluble ferric acid thus making it easily filtered. Bacterial iron can be killed through oxidation and by denying its food source (ferris iron). Sulphur/Sulphur Bacteria: Odorous hydrogen sulfide, which is not filterable, is quickly converted to elemental sulphur, which can be easily filtered. A portion of the sulphur is de-volatized and off gassed in step #2. Again the bacterial form is killed and filtered. Manganese: Manganese is oxidized and filtered in the same manner as iron. Bacteria: Ozone oxidizes the organic material in bacterial membranes, which weakens the cell wall and leads to cellular rupture. This exposes the organism to the external environment, which causes almost immediate death of a cell. Its similar to a knife deeply cutting skin. (Bacteria systems are sized differently than iron, sulphur and manganese systems.)

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