How Do Ozone Generators Work: Understanding Ozone

Most modern ozone generators use a controlled electrical discharge to provide the energy required to convert oxygen into ozone. Oxygen-containing gas passes through an electrical discharge field created between electrodes separated by a dielectric material.

The electrical energy causes a portion of the O₂ molecules to dissociate into oxygen atoms. These atoms then react with additional oxygen molecules to form ozone:

O₂ + energy → 2O

O + O₂ → O₃

The resulting ozone is a powerful oxidizing agent. When transferred into water or introduced into a gas stream, it reacts with microorganisms and a wide range of oxidizable compounds.

Industrial ozone generators are designed to provide precise and consistent ozone production for demanding treatment processes. Most use dielectric barrier discharge (DBD), also known as corona discharge or silent electrical discharge.

In these systems, oxygen or an oxygen-enriched feed gas passes through the generator while a high-voltage electrical field is applied across a dielectric barrier. The generator converts a controlled portion of the oxygen into ozone while maintaining the desired production rate and concentration.

Generator performance depends on factors such as feed-gas quality, oxygen concentration, gas flow rate, electrical power, cooling, operating pressure, and generator design. Proper control of these parameters is essential for stable ozone production.

Ozone can be generated using several technologies, with electrical discharge and ultraviolet (UV) radiation being the two most common methods.

Electrical Discharge

Electrical discharge is the primary technology used in modern industrial ozone generators. It uses high-voltage electrical energy to dissociate oxygen molecules and produce ozone.

This method can produce significantly higher ozone concentrations and production rates than UV-based systems, making it well suited for applications requiring substantial ozone production.

Ultraviolet (UV) Radiation

UV ozone generators use specific wavelengths of ultraviolet radiation to dissociate oxygen molecules and initiate ozone formation. UV systems generally produce lower ozone concentrations and production rates than electrical-discharge systems.

UV-based ozone generation can be useful for certain low-output applications, while electrical-discharge technology is generally preferred when higher ozone production or concentration is required.

Two important specifications when evaluating an ozone generator are ozone production and ozone concentration. These values describe different aspects of generator performance and should not be considered interchangeable.

Ozone production is the amount of ozone generated over a specific period, commonly expressed in grams per hour (g/h), kilograms per day (kg/day), or pounds per day (ppd).

Ozone concentration describes the amount of ozone present in the product gas. It may be expressed as a percentage by weight, grams per cubic metre (g/Nm³), or other concentration units depending on the application and measurement method.

For water treatment, ozone concentration is particularly important because higher gas-phase ozone concentration can improve ozone mass transfer and help achieve the dissolved ozone concentration required by the treatment process.

For this reason, selecting an ozone generator based solely on its ozone production rating can result in an improperly selected system. Both ozone production and ozone concentration should be evaluated together with the requirements of the treatment process.

Industrial ozone generators and smaller ozone-generating devices marketed for air treatment are designed for different applications and operating requirements.

Industrial ozone generators are designed for controlled ozone production and integration with treatment equipment. They can provide the production rates, ozone concentrations, monitoring, and process controls required for applications such as water treatment, wastewater treatment, aquaculture, industrial oxidation, and odour control.

Smaller ozone-generating devices may be intended for limited-volume applications and generally do not provide the capacity or process control required for industrial treatment systems.

Ozone is a powerful oxidant and can be harmful when inhaled at elevated concentrations. Ozone-generating equipment should therefore be properly installed, operated, monitored, and ventilated according to the application requirements and applicable safety standards.

Because ozone combines strong oxidation with rapid microbial inactivation, ozone generators can be used in many applications.

• Water Treatment: Ozone is used for microbial inactivation, oxidation, colour reduction, taste and odour control, and treating selected organic and inorganic contaminants.
• Wastewater Treatment: Ozone can be used as an oxidation and disinfection step to help reduce microorganisms, colour, odour, and selected contaminants, depending on the wastewater characteristics and treatment objectives.
• Air and Odour Treatment: Ozone can oxidize odour-causing compounds and selected contaminants in controlled treatment systems. Applications require appropriate ozone containment, monitoring, and safety controls.
• Food and Beverage Processing: Ozone can be used in appropriately designed systems for treating process water, wash water, equipment surfaces, and certain food-contact applications where permitted and properly controlled.
• Aquaculture: Ozone is used to improve water quality and provide microbial control in recirculating and other aquaculture systems. Proper ozone residual management is essential to protect aquatic organisms.
• Industrial Oxidation: Ozone can be incorporated into industrial processes that require a strong oxidizing agent, including selected applications in chemical processing, advanced water treatment, and other specialized industries.