Ozone is a very unstable gas that is made up of three oxygen atoms (O3). Considered one of the strongest oxidants, this gas is easily degraded back to oxygen (O2). The transition from O3 to O2 occurs when a free oxygen atom, or free radical (O-) is formed.
The free oxygen atom is extremely reactive and has a short duration; under normal conditions, the free radical survives only a few milliseconds.
Some details about ozone
Ozone is a colorless gas that has an odor similar to the sharp electrical smell of the air after a heavy thunderstorm. The formation of oxygen into ozone occurs with the use of energy. This process is achieved by an electric discharge field as in CD ozone generators (simulating the corona discharge of lightning), or by ultraviolet radiation as in UV ozone generators (simulating the ultraviolet radiation of the sun). In addition to these commercial methods, ozone can also be produced by electrolytic and chemical reactions. In general, an ozonation system involves passing dry, clean air through a high-voltage electrical discharge, i.e., a corona discharge, which creates an ozone concentration of about 1% or 10,000 mg/L.
To treat small amounts of waste, UV ozonation is most common, while large-scale systems use corona discharge or other mass ozone production methods. Ozone test strips are a must.
We often see ozone injected into the process upstream of a tank to maximize the contact time between the gas and the impurities in the water. It is important to include an ozone destructor at the atmospheric outlet of such a tank to avoid a significant accumulation of ozone that could have a negative impact on the downstream system components (especially corrosion).
Main advantages of ozone
Ozone is effective over a wide pH range and reacts rapidly with bacteria, viruses and protozoa; its germicidal properties are stronger than those of chlorine. It has a very high oxidizing power with a short reaction time.
The treatment process does not add chemicals to the water.
Ozone can remove a wide variety of inorganic, organic and microbiological problems as well as taste and odor problems. Microbiological agents include bacteria, viruses and protozoa such as Giardia, Cryptosporidium and other waterborne pathogens.