An ozone generator works by converting oxygen (O₂) into ozone (O₃). In most industrial and commercial systems, this is done using corona discharge, where high-voltage electricity splits oxygen molecules and allows oxygen atoms to recombine as ozone.
The ozone gas is then applied to water, air or a process stream for oxidation, disinfection, odour control or other treatment duties. System performance depends on more than the generator alone. Feed gas quality, ozone concentration, transfer conditions, contact time and control strategy all affect the final result.
What Does an Ozone Generator Do?
An ozone generator creates ozone gas and supplies it to a treatment process. In most practical applications, the ozone is then injected into water, introduced into an air stream, or used within an enclosed process system.
Because ozone is unstable, it is normally generated on site rather than stored for later use. This is one of the main reasons ozone systems are designed around the application rather than treated as simple chemical storage or dosing systems. If you need a general introduction first, see our guide on what ozone is.
The 3-Step Ozone Generation Process
Although ozone systems can vary significantly in size and configuration, the basic process can be understood in three steps.
- Oxygen supply: The ozone generator receives oxygen from dry air, an oxygen concentrator, bottled oxygen or a PSA oxygen system.
- Ozone production: Electrical energy or UV light splits oxygen molecules, allowing oxygen atoms to recombine as ozone (O₃).
- Application: The ozone gas is injected into water, mixed with air or supplied to a process where it acts as an oxidant.
How Ozone Is Generated
Ozone is generated by converting part of an oxygen-containing gas stream into ozone. In most systems, this is done by applying energy to the gas in a controlled way so that some oxygen molecules are transformed into ozone molecules.
The efficiency of this process depends on the generation method, the feed gas, the operating conditions and the system design. In practical terms, this is why ozone output and ozone concentration can vary significantly from one machine to another.
This distinction matters. Two ozone generators may have a similar rated output, but they may not perform the same way if the feed gas quality, oxygen concentration, cooling, pressure and control method are different.
Main Ozone Generation Methods
Several methods can be used to generate ozone, but the most common commercial and industrial approach is corona discharge. Other methods, such as ultraviolet generation and electrolytic generation, may be used in more specialised or lower-output applications.
Corona Discharge Ozone Generation
Corona discharge ozone generators use a high-voltage electrical field to convert part of an oxygen-containing gas stream into ozone. The gas passes through a discharge gap where electrical energy breaks some oxygen molecules apart. The oxygen atoms then recombine with oxygen molecules to form ozone.
Corona discharge is the most widely used method in industrial and commercial ozone systems because it can produce higher ozone concentrations and higher ozone outputs than most alternatives. It is commonly used in industrial ozone generators, ozone water treatment systems, process water treatment, wastewater treatment, odour control and food hygiene applications.
Ultraviolet Ozone Generation
UV ozone generation uses ultraviolet light at a specific wavelength to produce ozone from oxygen. This method is generally associated with lower-output applications and is not normally the first choice where higher ozone production, higher ozone concentration or industrial process performance is required.
UV systems can be useful in selected applications, but they are usually more limited than corona discharge systems when higher ozone output is needed.
Electrolytic Ozone Generation
Some systems generate ozone electrolytically. This method is used in certain specialised applications, particularly where ozone is generated directly in water or where a compact low-output arrangement is suitable.
Electrolytic ozone generation can be useful in specific situations, but it is less common than corona discharge in mainstream industrial ozone installations.
Corona Discharge vs UV Ozone Generation
For most industrial and commercial ozone applications, corona discharge is preferred because it can deliver higher ozone outputs and higher ozone concentrations. UV ozone generation is generally more suitable for smaller or lower-intensity duties.
| Method | Typical use | Main point |
|---|---|---|
| Corona discharge | Industrial and commercial ozone systems | Higher output and higher ozone concentration |
| UV ozone generation | Lower-output or specialised applications | Usually less suitable for larger process duties |
| Electrolytic generation | Selected specialist applications | Useful where the process specifically suits electrolytic ozone |
What Affects Ozone Output?
Ozone output is influenced by more than the generator model alone. In real systems, performance depends on the operating conditions and the quality of the feed gas.
The main factors include:
- generation method
- feed gas quality
- oxygen concentration
- humidity and dew point
- cooling and operating temperature
- system pressure
- electrical design and control
- maintenance condition
In general, ozone generators perform more effectively when the feed gas is clean, dry and suitable for the selected generation method. Moisture in the feed gas can reduce ozone production efficiency and may also create unwanted by-products or reliability issues in poorly prepared systems.
For a more detailed explanation of feed gas choices, see our guide to ozone feed gas options.
Ozone Output vs Ozone Concentration
Ozone output and ozone concentration are related, but they are not the same thing.
Ozone output is usually expressed as grams per hour (g/h) or kilograms per hour (kg/h). This describes how much ozone the generator can produce over time. Ozone concentration describes how much ozone is present in the gas stream, often expressed as g/Nm³, % by weight or ppm depending on the context.
This matters because an ozone generator with a high output is not automatically suitable for every process. The required concentration, gas flow, injection method, contact time and transfer efficiency all affect the final design.
How Ozone Generators Fit into Real Systems
An ozone generator is only one part of the overall ozone system. In practice, performance also depends on how the ozone is transferred, controlled and applied within the process.
A complete ozone system may also include:
- an oxygen supply or air preparation stage
- ozone generation equipment
- ozone injection equipment
- a static mixer, contact tank or treatment zone
- dissolved ozone or ORP monitoring
- ambient ozone monitoring
- off-gas handling or ozone destruction
- control logic, alarms and interlocks
This is why selecting ozone generators is not just about output. The generator must also match the application, the feed gas arrangement, the transfer method and the wider system design.
What Happens After Ozone Is Produced?
Once ozone is produced, it needs to be applied correctly. For water treatment, ozone is usually injected into the water using equipment such as a venturi injector, static mixer, contact tank or dedicated ozone water treatment skid. For air and odour applications, ozone may be introduced into a controlled air stream or enclosed treatment zone.
The contact stage is critical. Ozone needs enough contact time and the right transfer conditions to react effectively. A generator may produce enough ozone on paper, but poor mixing, short contact time or unsuitable process conditions can reduce treatment performance.
For more on this, see our guide to ozone CT and contact time.
Ozone Generator vs Ozone System
An ozone generator produces ozone gas. An ozone system applies that gas to a real process.
This difference is important. A generator alone does not guarantee treatment performance. The wider system must consider ozone transfer, contact time, water or air quality, materials compatibility, monitoring, off-gas control and safe operation.
For example, an ozone water treatment system may need dissolved ozone monitoring, contact time, off-gas destruction and control logic. An odour control system may need airflow assessment, safe dosing, extraction control and ambient ozone monitoring.
Basic Safety Considerations
Ozone is a useful treatment gas, but it must be handled with proper engineering controls. Safe operation depends on controlling ozone where it is generated, transferred and applied.
Important safety measures may include:
- leak detection
- adequate ventilation
- correct materials of construction
- controlled ozone dosing
- off-gas destruction where required
- ambient ozone monitoring
- alarm and shutdown logic
For practical handling precautions, monitoring and exposure considerations, see our ozone safety guidelines.
Choosing the Right Ozone Generator
The right ozone generator depends on the application. A small air treatment duty, a water disinfection process, a wastewater oxidation duty and a food hygiene application may all require different equipment configurations.
Before selecting a generator, it is important to understand:
- the treatment objective
- the flow rate or process volume
- the required ozone dose or residual
- the water or air quality
- the required contact time
- the feed gas arrangement
- the monitoring and control requirements
- the safety and installation constraints
For industrial and commercial projects, the best starting point is usually not the generator size, but the process requirement. Ozcon supports ozone system selection for water treatment, process water, wastewater, food processing, odour control and other specialist applications.
You can explore our ozone generators, review industrial ozone generators, or contact us to discuss the application.
Frequently Asked Questions
How does an ozone generator make ozone?
An ozone generator makes ozone by applying energy to oxygen. In corona discharge systems, high-voltage electricity splits oxygen molecules and allows oxygen atoms to recombine as ozone (O₃).
What gas goes into an ozone generator?
Ozone generators normally use dry air, concentrated oxygen, bottled oxygen or oxygen from a PSA system. Oxygen-fed systems usually produce higher ozone concentrations than air-fed systems.
Is corona discharge better than UV ozone generation?
For most industrial and commercial applications, corona discharge is preferred because it can produce higher ozone outputs and concentrations. UV ozone generation is generally used for lower-output or more specialised duties.
Can ozone be injected into water?
Yes. Ozone gas can be injected into water using a venturi injector, static mixer, contact tank or integrated ozone water treatment system. The design must consider transfer efficiency, contact time and off-gas management.
How long does ozone last?
Ozone is unstable and naturally decomposes back to oxygen. Its half-life depends on temperature, pH, water quality, humidity and the substances present in the process.
What size ozone generator do I need?
The required size depends on the application, flow rate, treatment objective, ozone dose, transfer efficiency, contact time and operating conditions. Generator size should be selected as part of the overall system design.
Need Help With an Ozone Application?
Ozcon supports ozone system selection, process design, monitoring and integration across a wide range of applications. If you are reviewing ozone for water treatment, food processing, wastewater, odour control, aquaculture, cold rooms or another process, we can help assess the practical requirements.
Contact Ozcon or explore our ozone generator systems.
© Ozcon Environmental. This article is provided for general guidance. Contact us for site-specific advice.