Microbubble and Nanobubble Technology: How Do They Work with Ozone? | OCS Ozo
Introduction
One of the most critical factors determining the effectiveness of ozone applications is how efficiently ozone can be transferred into water. Conventional diffuser systems generate large air bubbles — these rise quickly and leave the system, leaving ozone little time to dissolve into the water.
Microbubble and nanobubble technology solves this problem at its root. Much smaller bubbles remain in water far longer, offer far greater surface area, and achieve far higher ozone transfer rates. The result: significantly higher treatment efficiency from the same ozone dose.
This technology has been expanding rapidly across water treatment, aquaculture, food processing, and agricultural irrigation in recent years.
What Is a Microbubble?
A microbubble is a gas bubble with a diameter between 1 and 100 micrometres (µm). Considering that a human hair is approximately 70–100 µm in diameter, microbubbles are the same size as or smaller than a strand of hair.
The practical consequences of this small size are significant:
Slow rise velocity: Large bubbles rise to the surface rapidly. Microbubbles rise much more slowly — their residence time in water is tens of times longer. This means far more time for ozone to dissolve into the water.
High surface-area-to-volume ratio: The total surface area per unit volume of small bubbles is very large. Ozone transfer occurs across this surface — more surface means more transfer.
Pressure effect: The internal pressure inside small bubbles is high (Young-Laplace effect). This pressure accelerates the dissolution of gas molecules into water.
What Is a Nanobubble?
A nanobubble is a gas bubble with a diameter below 1 micrometre (1,000 nanometres), typically in the range of 100–200 nanometres. This scale is so small that they cannot be seen with the naked eye — but can be detected with laser scattering measurement instruments (DLS, NTA).
Nanobubbles have a more powerful characteristic than microbubbles: they can remain stable in water for days or even weeks. While a gas bubble would normally be expected to rise and burst, nanobubbles carry negative surface charges that prevent them from merging with each other or rising to the surface.
This extraordinary stability makes nanobubbles particularly valuable for:
- Disinfection applications requiring long contact times
- Agricultural irrigation water — oxygen or ozone can reach plant roots
- Drinking water treatment — ozonated water remains active for extended periods
Microbubble/Nanobubble + Ozone: Why Is the Synergy So Powerful?
Ozone has relatively low solubility in water (approximately 13 mg/L at 20°C). In conventional diffusion systems, achieving this solubility limit requires high ozone doses, and transfer efficiency is low due to large bubbles.
Microbubble and nanobubble technology changes this equation:
| Parameter | Conventional Diffuser | Microbubble | Nanobubble |
|---|---|---|---|
| Bubble diameter | 1–5 mm | 1–100 µm | < 1 µm |
| Residence time in water | Seconds | Minutes | Days |
| Transfer efficiency | 10–30% | 60–80% | 90%+ |
| Ozone consumption | High | Medium | Low |
| Surface area | Low | High | Very high |
Practical outcome: Far less ozone is required to reach the same treatment target. This both reduces operating costs and lowers residual ozone risk.
Application Areas
Aquaculture and Water Quality
Delivering ozone and oxygen to fish tanks via microbubble provides substantially higher dissolved oxygen levels than conventional aeration. Pathogen control is achieved simultaneously. Small bubbles do not damage fish gills.
Wastewater Treatment
Delivering oxygen to biological treatment tanks via microbubble increases activated sludge efficiency. In ozone applications, microbubble transfer efficiency raises COD and colour removal achieved from the same dose.
Food Processing and Washing
In fruit and vegetable washing systems, producing ozonated water via microbubble enables better ozone penetration into product surfaces, increasing pesticide and bacteria removal efficiency.
Agricultural Irrigation
Irrigation water containing ozone or oxygen via nanobubble carries active gas all the way to plant roots. Soil disinfection, prevention of root diseases, and improved plant growth are achieved.
Drinking Water Treatment
Using microbubble ozonation, the same disinfection efficacy is achieved at lower ozone doses. The need for chlorinated by-products such as trihalomethanes (THMs) is eliminated.
Microbubble Generation Methods
Pressurised Dissolution (DAF principle): Water is saturated with gas under pressure; microbubbles form as pressure is released.
Mechanical Shear (Rotor-Stator): Rotating mechanical elements convert a gas-liquid mixture into microbubbles through shear force.
Ultrasonic: High-frequency sound waves generate nanobubbles through cavitation in the liquid.
Electrolytic: Nanobubbles are produced directly in water through water electrolysis. Combination with BDD electrolytic systems is highly effective.
Membrane Diffusion: Small bubbles are produced by passing gas through nanoporous membranes.
Microbubble Integration in OCS Ozon Systems
At OCS Ozon, we integrate microbubble diffusion technology into our ozone systems for aquaculture, wastewater, and food applications. This integration:
- Raises ozone transfer efficiency to 60–80%
- Reduces the ozone dose required for the same treatment target
- Lowers residual ozone risk
- Optimises operating cost
Contact us for a site-specific microbubble integration design for your facility.
Conclusion
Microbubble and nanobubble technology is a technology platform that dramatically increases ozone transfer efficiency into water, enabling ozone applications to reach a much greater potential. It outperforms conventional diffusion systems across cost, performance, and safety dimensions.
At OCS Ozon, we integrate this technology into our projects to deliver advanced ozone solutions to our clients.