What are the different situations of ozone is generated ?

Where does ozone come from?

Discussed in this article refers to ground-level ozone gas or ozone gas in indoor spaces generated by human activities.

Indirect ozone emissions

On the one hand, ozone is generated by photochemical reactions of nitrogen oxides emitted from various industrial production activities such as fossil fuel combustion and metal smelting and processing under sunlight. On the other hand, exhaust gases emitted by motor vehicles and other means of transportation also contain “precursors” for ozone formation.
On the other hand, volatile organic compounds emitted during industrial production activities such as painting and baking processes in the automotive, furniture, and home appliance industries, the production of organic chemical raw materials, and the manufacture of pharmaceuticals and pesticides can also generate ozone through photochemical reactions under sunlight.
The emission of these source gases directly contributes to the production of ozone gas in the near-surface atmosphere.

Ozone byproducts during equipment operation

Due to strong light, high temperature, or high voltage discharge during equipment operation, oxygen in the air is excited and converted into ozone.
1. The electric arcs generated during welding/cutting processes in welding/cutting workshops (especially those generated by argon arc welding and plasma cutting) are usually accompanied by strong ultraviolet radiation. When strong ultraviolet radiation irradiates the air, it generates ozone.
2. When UV curing equipment is used in printing/coating workshops to cure inks or coatings, strong ultraviolet rays will generate ozone when they irradiate the air.
3. When ultraviolet analyzers, ultraviolet germicidal lamps, and other equipment are used in the laboratory, ozone will be directly generated in the air if the wavelength includes 185nm.
4. In high-voltage equipment workshops, if the insulation of high-voltage transformers, electrostatic precipitators, and high-voltage switchgear is inadequate or the air is humid, corona discharge may occur, generating ozone.
5. In our daily lives, air purifiers may be a significant contributor to ozone production. The problem mainly lies in the purification technology, including electrostatic precipitators, ion generators, and ultraviolet photolysis. While these technologies purify the air, they inevitably trigger the dissociation and recombination of oxygen molecules, thus generating ozone as a byproduct.

Man-made ozone

Another scenario involving ozone production is the artificial generation of ozone in certain environments where its strong oxidizing properties are needed for pollution degradation, cleaning, and disinfection. These locations are typically equipped with ozone generators that use high-voltage discharge or ultraviolet irradiation to convert oxygen into ozone.
1. In the water treatment workshop, ozone generated by high-voltage corona discharge is used to sterilize and disinfect drinking water and swimming pool water and remove odors.
2. In food/pharmaceutical workshops, ozone generated by ultraviolet irradiation (185nm band) is used to sterilize and disinfect production equipment, packaging materials, and workshop air.
3. In chemical/dyeing workshops, ozone generated by corona discharge is used to bleach, decolorize, and degrade organic pollutants in industrial wastewater.
4. In semiconductor/electronic workshops, ozone generated by ultraviolet irradiation is used to clean the surfaces of wafers and precision components to remove organic residues.
Why ozone need to be decomposed?

When near-surface ozone concentrations exceed standards, it becomes a harmful pollutant, being a major component of photochemical smog. On the one hand, it exacerbates air pollution and intensifies the atmospheric greenhouse effect; on the other hand, it poses a direct threat to living organisms. Ozone gas produced in workshops or indoor spaces poses a direct threat to human health.
Near-ground ozone pollutants need to be “intercepted” and treated from the emission of “precursor” pollutants.
Ozone byproducts in workshops and indoor spaces, or residual ozone gas after artificial production, need to be recovered and decomposed by air ventilation systems or water treatment systems.
We will provide our solution suggestions based on specific scenarios in the next chapter.