Ozone
The ozone molecule is the most powerful oxidizing agent used in water and air treatment. Ozone (O3) is produced through an electrical discharge that joins the oxygen molecule (O2) with an extra oxygen atom (O). Ozone is a colorless or slightly bluish gas.
In nature, ozone can be produced by thunderstorms, the high voltage discharges, which occur during storms, produce ozone from oxygen in the atmosphere. The damp earth smell that is felt after a storm results from the production of ozone by nature. The word ozone itself comes from the Greek word “ozein”, which means odor.
The ozone molecule is a powerful oxidizing agent
When the ozone molecule comes into contact with something possible to oxidize, the exta oxygen atom frees itself from the ozone and will bond with the other material/microorganism, oxidizing it. This is because ozone is extremely unstable and tends to decay into the oxygen molecule. The use of ozone allows the oxidation of all organic matter as well as the elimination of all pathogens present in the water.
Ozone is mainly used in municipal water treatment, drinking water treatment plants (as a disinfectant) and is increasingly being used in industrial water applications. For example, it is used in the food industry as a disinfectant, in the paper and textile industry. The main advantage comes from its clean character, since it only oxidizes and hardly forms secondary products. At the same time it is safe to work with ozone, as any leakage is easily detectable through its characteristic smell.
Ozone is an oxidizer 100 times more powerful than chlorine and 3,000 times faster
Comparison of treatment between chlorine and ozone:
Chlorine (Cl) |
Ozone (O3) |
|
Oxidizing potential (Volts) |
1,36 |
2,07 |
Odor |
spicy |
none |
Taste |
unpleasant |
none |
Color |
slightly yellow |
none |
Antiviral activity |
none |
very effective |
Antibacterial activity |
uncertain |
very effective |
Action on chemical compounds |
little |
high |
Algae and protozoan elimination |
little |
high |
Elimination of Fungi |
little |
high |
Elimination of spores and cysts |
little |
high |
Elimination of micro-contaminants (hydrocarbons, phenols, detergents, dyes, pesticides) |
little |
high |
Action on organic molecules of color and flavor |
none |
high |
Type of reaction |
indirect oxidation and production of chlorophenols, etc. |
direct oxidation with oxygenation of water |
Residues from the reaction |
chloramines |
none |
It is a very competitive solution, as it does not need to transport and store reagents. The reagent that consumes is oxygen and is available in large amounts in air.
Ozone can be used for:
– Disinfection of swimming pools and spas;
– Chlorine replacement in the water disinfection;
– Disinfection of factories in the food sector, hospitals;
– Elimination of color in dyeing water;
– Elimination of bacteria in food;
– Elimination of insects from cereals;
– Parasite elimination.