Aircraft Water Disinfection

Airlines face the critical task of ensuring safe, potable water for passengers and crew, whether for drinking, food preparation, or handwashing. Traditional chemical disinfection methods, like chlorine, are slow, wasteful, and environmentally taxing. Enter ozone—a game-changing solution that a major U.S. airline adopted to transform its aircraft water system maintenance. Partnering with Oxidation Technologies, the airline deployed a custom, trailer-based ozone disinfection system, slashing disinfection time, cutting costs, and boosting sustainability. Here’s how it worked and why it’s a model for the aviation industry.

Ozone can be used to disinfect aircraft water holding tanks and water systems to ensure safe, potable water during flight.  The use of ozone water for disinfection can save time vs chemical disinfection methods and lower water consumption as no rinsing of chemicals from the system is required.

Commercial aircraft implement water storage tanks to store water for use during flight.  This water may be used for:

- Drinking and beverage preparation

- Food preparation – rehydrating or cooling certain meals and cleaning utensils

- Handwashing

- Toilet flushing

It is important that the water holding tanks remain disinfected to ensure water is potable and safe.  It also important to ensure biofilms do not build-up in the tanks or water lines.  Ozone dissolved in water can provide sufficient disinfection for these applications.

Benefits of Ozone vs. Chemical Treatment Options:

Chemical treatments, such as chlorine-based disinfectants (e.g., Purogene, sodium hypochlorite), are traditionally used for airplane water systems but have significant drawbacks compared to ozone. Below are the key benefits of ozone disinfection over chemical methods, tailored to airplane water systems:

Faster and More Effective Disinfection:

- Ozone disinfection saves time.  As ozone reactions with bacteria area faster than chemicals and ozone requires no rinsing steps the process using ozone can save time.  The ozone disinfection process can be completed in as much as 30 minutes, compared to an 8-hour process used previously.

Biofilm Removal and Inhibition:

- As a gas, ozone penetrates and destroys biofilms in water lines and tank surfaces without requiring wetted contact, preventing bacterial regrowth. This is critical for airplane systems, where hoses and appliances (e.g., coffee makers) are prone to contamination if not properly cleaned.

Environmental and Safety Benefits:

- Produces no hazardous wastewater, as it reverts to oxygen, allowing safe disposal without environmental impact. It eliminates the need for chemical storage, transport, and handling, reducing risks to ground crew

Reduced Maintenance and Cost Savings:

- The automated ozone system reduces disinfection time (20–30 minutes vs. hours for chemical soaking and rinsing), lowering labor costs and aircraft downtime. It improves component reliability (e.g., faucets, water heaters) by minimizing chemical corrosion, reducing maintenance costs. Field tests show significant cost savings over traditional methods.

Ozone Process:

There are a variety of airplanes and water systems used on various aircraft.  The ozone system must work well with each aircraft design.  The two main aircraft differences are:

Fill/Drain – The aircraft water system may be drained and filled with ozone water from the ozone system.  Fresh water containing ozone residuals will flow into the tank and through the water facets and water piping to drain.  When full, the ozone process can be ceased.  Ozone in water will decay naturally to oxygen with no additional flushing of the system required.

Water Circulation – Water can be circulated through the aircraft water system eliminating the need to drain water from the system.  Water flows from the aircraft to the ozone water system, ozone is dissolved into water, and water flows back to the aircraft.  Water is circulated for a period of time, ranging from 15-20 minutes until a target dissolved ozone level in the water system is reached.  When complete, the ozone in water will decay naturally to oxygen with no additional water circulation of flushing required.

Practical Applications:

Oxidation Technologies has provided ozone water systems to airlines for water system disinfection.  Ozone systems have been provided as a stand-alone cart, and as a skid to be implemented with a more comprehensive system.  Should you have questions on the right ozone system for your application, please contact our ozone application engineers for assistance.  We would be glad to help.

The Challenge: Safe Water, High Stakes:

Commercial aircraft rely on potable water tanks to supply water for everything from coffee to toilet flushing. These systems must remain free of bacteria, viruses, and biofilms to comply with the U.S. EPA’s Aircraft Drinking Water Rule (ADWR) and ensure passenger safety. However, traditional chlorine-based disinfectants (e.g., Purogene, sodium hypochlorite) pose significant challenges:

- Time-Intensive: Chemical disinfection requires an 8-hour soak-and-rinse cycle, grounding planes and driving up labor costs.

- Chemical Residues: Chlorine leaves behind taste, odor, and potential health risks (e.g., trihalomethanes), requiring extensive rinsing.

- Environmental Impact: Chemical wastewater demands special disposal, and storage poses safety risks for ground crews.

- Biofilm Issues: Chlorine struggles to penetrate biofilms in pipes and appliances, leading to persistent contamination risks.

The airline needed a faster, safer, and greener solution to maintain water quality across its fleet.

The Solution: Ozone-Powered Disinfection:

Oxidation Technologies delivered a cutting-edge ozone water disinfection system, integrated into a custom trailer designed to the airline’s specifications. This mobile, self-contained unit included:

- Ozone Generator: Used corona discharge to produce ozone gas on-site, eliminating chemical storage needs.

- Gas Generator: Powered the system, enabling operation on the tarmac without external electricity.

- Water Holding Tank: Supported flexible disinfection for various aircraft tank designs.

- Portability: The towable trailer allowed deployment to any aircraft, anywhere, anytime.

The system offered two disinfection methods to suit different aircraft:

- Fill/Drain Method: Ozonated water filled the aircraft tank, flowed through pipes and faucets, and drained. Ozone naturally decayed to oxygen in 20–30 minutes, requiring no rinsing.

- Circulation Method: Water circulated between the aircraft and trailer, with ozone injected until a target level (0.2–0.4 ppm) was reached in 15–20 minutes, followed by natural ozone decay.

Automated sensors ensured precise ozone levels for 99.0% microbe reduction (per EPA standards), while an activated carbon adsorber safely neutralized excess ozone gas.

Implementation: On the Tarmac, Across the Fleet:

The airline rolled out the ozone system across over 250 aircraft, testing it on major commercial models. Ground crews towed the trailer to planes on the tarmac, connected it via hoses, and completed disinfection in just 20–30 minutes per tank—a stark contrast to the 8-hour chemical process. The system’s automation and self-sufficiency streamlined operations, allowing maintenance at any airport, regardless of local resources.

Benefits of Ozone Over Chemical Disinfection:

Ozone proved transformative, offering clear advantages over chlorine-based methods:

- Lightning-Fast Disinfection: Ozone’s oxidative power—3,000 times faster than chlorine—cut disinfection time to 20–30 minutes, slashing aircraft downtime and labor costs.

- Biofilm Buster: Ozone penetrated and destroyed biofilms in tanks, pipes, and appliances like coffee makers, preventing bacterial regrowth without manual cleaning.

- No Chemical Residues: Ozone decomposed into oxygen, delivering taste- and odor-free water with no rinsing, unlike chlorine’s lingering taste and health risks.

- Eco-Friendly: Zero hazardous wastewater and no chemical transport reduced environmental impact and simplified disposal.

- Cost Savings: Faster processes, lower water use, and reduced corrosion of components (e.g., faucets, heaters) drove significant savings, validated by field tests.

- Passenger Comfort: Clean, chemical-free water enhanced the in-flight experience, free of chlorine’s taste or irritation.

Results: A Win for Efficiency and Sustainability:

The ozone system delivered impressive outcomes:

- Time Savings: Disinfection time dropped from 8 hours to 20–30 minutes, boosting fleet availability.

- Cost Reduction: Lower labor, water, and maintenance costs yielded substantial savings.

- Water Quality: Achieved EPA’s 99.0% microbe reduction and FDA-compliant ozone levels, ensuring safe, palatable water.

- Sustainability: Eliminated chemical waste, supporting the airline’s green initiatives.

- Versatility: The trailer’s design worked seamlessly with diverse aircraft, from fill/drain to circulation systems.

Why Ozone is the Future of Aircraft Water Disinfection:

This case study showcases ozone’s potential to revolutionize aviation water treatment. Its speed, effectiveness, and eco-friendliness make it a superior alternative to chemical methods, aligning with the industry’s push for efficiency and sustainability. The trailer-based system’s mobility and automation further enhance its practicality, offering a scalable solution for airlines worldwide.

Ready to explore ozone for your aircraft water systems? Contact Oxidation Technologies’ ozone application engineers at https://www.oxidationtech.com/contact/ to find the perfect system for your needs. Let’s make safe, clean water take flight!

Disclaimer: This blog post is based on a real-world case study and reflects the performance of Oxidation Technologies’ ozone systems as implemented by a major U.S. airline. Results may vary depending on specific aircraft systems and operational conditions.