After more than a year of dedicated effort, Dr. Wen Zhang’s research team successfully delivered the first industrial-grade ozone nanobubble generator, developed in collaboration with Purenano Tech. The recipient, Geogreen—a pioneering urban indoor farm in New Jersey—received the system on August 1, 2025. Dr. Zhang and his Ph.D. student, Yihan Zhang, worked alongside Geogreen’s founder, Desmond Hayes, to install the unit at the farm’s laboratory, where it will be tested for reclaimed water disinfection and surface cleaning. This initiative is supported by funding from the EPA Pollution Prevention (P2) Program (NP-96259122-0) and the CSTI program.
Conversion of ozone gas into nanobubbles in water may address current ozonation challenges.1 For example, the low buoyancy and high surface-to-volume ratio of ozone nanobubbles permit greater transfer efficiency and retention time of ozone into water and thus enable long-lasting disinfection power.2 Previous studies reported that ozone nanobubbles increased the dissolved O3 concentration and mass transfer coefficient by 1.7 and 4.7 times respectively, compared to ozone microbubbles (the bubble diameter less than 1 µm).1, 3 Moreover, ozone nanobubble has a half-life that is 23 times longer than O3 microbubbles and can generate higher concentrations of hydroxide radicals (•OH) than regular ozonation.3-5 Particularly, some previous studies reported that ozone nanobubbles water is more effective in reducing algal toxins and inactivating pathogens in synthetic and real waters.6, 7 Thus, ozone nanobubbles have the potential to enhance water disinfection through the improved ozone solubility, elevated oxidation capacity, and enhanced interactions with chemical and biological contaminants.
References
1. Atkinson, A. J.; Apul, O. G.; Schneider, O.; Garcia-Segura, S.; Westerhoff, P., Nanobubble Technologies Offer Opportunities To Improve Water Treatment. Acc Chem Res 2019, 52 (5), 1196-1205.
2. Fan, W.; An, W.; Huo, M.; Xiao, D.; Lyu, T.; Cui, J., An integrated approach using ozone nanobubble and cyclodextrin inclusion complexation to enhance the removal of micropollutants. Water Research 2021, 196, 117039.
3. Yang, X.; Chen, L.; Oshita, S.; Fan, W.; Liu, S., Mechanism for Enhancing the Ozonation Process of Micro- And Nanobubbles: Bubble Behavior and Interface Reaction. ACS ES&T Water 2023.
4. Arrojo, S.; Nerin, C.; Benito, Y., Application of salicylic acid dosimetry to evaluate hydrodynamic cavitation as an advanced oxidation process. Ultrasonics Sonochem 2007, 14 (3), 343-349.
5. Soyluoglu, M.; Kim, D.; Karanfil, T., Characteristics and Stability of Ozone Nanobubbles in Freshwater Conditions. Environmental Science & Technology 2023, 57 (51), 21898-21907.
6. Jhunkeaw, C.; Khongcharoen, N.; Rungrueng, N.; Sangpo, P.; Panphut, W.; Thapinta, A.; Senapin, S.; St-Hilaire, S.; Dong, H. T., Ozone nanobubble treatment in freshwater effectively reduced pathogenic fish bacteria and is safe for Nile tilapia (Oreochromis niloticus). Aquaculture 2021, 534, 736286.
7. He, H.; Zheng, L.; Li, Y.; Song, W., Research on the feasibility of spraying micro/nano bubble ozonated water for airborne disease prevention. Ozone: Sci & Eng 2015, 37 (1), 78-84.