Nanobubble Validation and Research Library

Crop growth

Positive studies 8

• Greenhouse cucumber yield up 22–28% with oxygenated irrigation

  Reported that greenhouse cucumbers grown with oxygenated irrigation water at 9 mg/L dissolved oxygen yielded 22–28% more than the control.

  Paper details · Study conditions · Detailed results

  Original title

  Micro-nano oxygenated irrigation improves the yield and quality of greenhouse cucumbers under-film drip irrigation

  Summary

  Cucumbers were grown for two seasons with plastic-mulched drip irrigation in a greenhouse in Ningxia, China, comparing irrigation water dissolved oxygen of 4 (control), 6, 7.5 and 9 mg/L.

  Key findings

  Compared with the control, the 9 mg/L treatment showed yield +22.47% (spring-summer) and +28.04% (autumn-winter), irrigation water use efficiency +22–28% and soil oxygen +33–35%, with vitamin C up and nitrate down (yield effect P<0.05). Bubble size and count were not reported.

  Gas used

  Not stated (micro-nano oxygenation device)

  Bibliographic information

  Ouyang et al. (5 authors) · 2023 · Scientific Reports 13: 19453 · DOI 10.1038/s41598-023-45121-3

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• Drip irrigation with nanobubble-oxygenated treated wastewater improves soil aeration

  Reported that lettuce yield increased in both soil types when drip-irrigated with treated wastewater oxygenated by nanobubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Drip irrigation with nanobubble oxygenated treated wastewater improves soil aeration

  Summary

  Lettuce was grown with surface and subsurface drip irrigation on a sandy soil and a clayey soil, comparing treated wastewater with and without oxygen nanobubbles.

  Key findings

  Yield increased and leaf membrane leakage fell significantly in both soils and both irrigation methods. An oxygen mass balance showed that the oxygen supplied by irrigation water was about 1% of daily soil oxygen flux, and the mechanism behind the observed growth changes is presented as a subject for further research.

  Gas used

  Oxygen

  Bibliographic information

  Baram et al. (8 authors) · 2022 · Scientia Horticulturae 291: 110550 · DOI 10.1016/j.scienta.2021.110550

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• Nitrous oxide emissions down 14–37% with oxygen nanobubble irrigation

  Reported that irrigation with treated wastewater containing oxygen nanobubbles raised soil oxygen and cut nitrous oxide emissions by 14–37%.

  Paper details · Study conditions · Detailed results

  Original title

  Irrigation with treated wastewater containing nanobubbles to aerate soils and reduce nitrous oxide emissions

  Summary

  In soil-filled lysimeters, treated wastewater was applied by surface and subsurface drip irrigation, comparing soil oxygen and greenhouse gas emissions with and without nanobubbles.

  Key findings

  Soil oxygen rose from 15.6 to 19.7% with surface drip (p=0.0001) and from 18.2 to 19.2% with subsurface drip (p=0.0266), and cumulative nitrous oxide emissions fell by 37% (surface) and 14% (subsurface). Crop yield was not reported.

  Gas used

  Oxygen

  Bibliographic information

  Baram et al. (4 authors) · 2021 · Journal of Cleaner Production 280: 124509 · DOI 10.1016/j.jclepro.2020.124509

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• Optimal dissolved oxygen and timing of micro-nanobubble water oxygation in greenhouse crops

  Reported that micro-nanobubble oxygenated irrigation raised yield and irrigation water use efficiency in greenhouse tomato and cucumber, with 15 mg/L dissolved oxygen more effective than 25 mg/L.

  Paper details · Study conditions · Detailed results

  Original title

  Appropriate dissolved oxygen concentration and application stage of micro-nano bubble water oxygation in greenhouse crop plantation

  Summary

  Over two greenhouse seasons, irrigation water dissolved oxygen (15, 25 mg/L), treatment timing (seedling/flowering or fruiting) and water source (reclaimed water or groundwater) were compared in combination.

  Key findings

  When applied at the fruiting stage, there were significant differences in vitamin C (both crops) and lycopene (tomato) (p<0.05). The authors recommended combining 15 mg/L dissolved oxygen with treatment at the fruiting stage.

  Gas used

  Not stated (micro-nanobubble oxygenation)

  Bibliographic information

  Zhou et al. · 2019 · Agricultural Water Management 223: 105713 · DOI 10.1016/j.agwat.2019.105713

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• Micro/nanobubble oxygenated irrigation raises soil phosphorus availability and yield by shifting soil bacterial communities and keystone microbes

  Reported that spring maize irrigated with oxygenated water at 30 mg/L dissolved oxygen yielded 18.7% more than the control.

  Paper details · Study conditions · Detailed results

  Original title

  Micro-/nanobubble oxygenation irrigation enhances soil phosphorus availability and yield by altering soil bacterial community abundance and core microbial populations

  Summary

  Spring maize was grown in field soil columns, comparing micro-nanobubble oxygenated irrigation water at 30 mg/L dissolved oxygen with ordinary irrigation water (8–9 mg/L).

  Key findings

  Yield was 17,942.72 vs. 15,118.5 kg/ha (+18.7%, p<0.01), and available soil phosphorus rose 21.3%. Fungal diversity did not differ. This was a one-season soil column trial, and bubble size was not measured.

  Gas used

  Oxygen (90%)

  Bibliographic information

  Bian et al. · 2025 · Frontiers in Plant Science 15: 1497952 · DOI 10.3389/fpls.2024.1497952

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• Cotton yield up about 20% with oxygenated irrigation in saline soil

  Reported that in saline soil, oxygenated irrigation at 30 mg/L dissolved oxygen alone raised cotton yield by 20%, and by 45% when combined with a microbial agent.

  Paper details · Study conditions · Detailed results

  Original title

  Effects of combined technology of micro-/nanobubble oxygenation irrigation and microbial agents on saline soil remediation and cotton yield

  Summary

  Cotton was grown in a saline field in Xinjiang, China (10 m × 5 m plots, 4 treatments × 3 replicates), applying oxygenated irrigation and a microbial agent alone or together.

  Key findings

  Seed cotton yield was 4,344.26 (control), 5,216.49 with oxygenated irrigation alone (+20.08%) and 6,278.65 kg/ha with the microbial agent (+44.53%), all P<0.05. Oxygenated irrigation alone reduced soil salinity by 16.36%. Results are from one season.

  Gas used

  Oxygen (90%)

  Bibliographic information

  Bian et al. · 2025 · Frontiers in Plant Science 16: 1605834 · DOI 10.3389/fpls.2025.1605834

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• Turf quality maintained with 50% less irrigation using oxygen nanobubble water

  Reported that turf quality was maintained even with 50% less irrigation when oxygen nanobubble irrigation water was used.

  Paper details · Study conditions · Detailed results

  Original title

  Irrigation Water Treated with Oxygen Nanobubbles Decreases Irrigation Volume While Maintaining Turfgrass Quality in Central Chile

  Summary

  In central Chile, turf was irrigated over a summer with oxygen nanobubble water or ordinary water, and quality was compared at reduced irrigation volumes.

  Key findings

  The treatment with 50% less irrigation and no nanobubbles showed lower quality.

  Gas used

  Oxygen

  Bibliographic information

  Calvo et al. · 2025 · Grasses 4(1): 6 · DOI 10.3390/grasses4010006

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• Potential effects of aqueous oxygen and nitrogen nanobubbles on the plant rhizosphere microbiome

  Reported that oxygen and nitrogen nanobubble irrigation water significantly changed the composition of microbial communities around tomato roots.

  Paper details · Study conditions · Detailed results

  Original title

  Unveiling the potential impacts of oxygen and nitrogen nanobubbles in water on plant rhizosphere microbiome

  Summary

  Tomatoes were irrigated for 34 days with oxygen nanobubble water (dissolved oxygen 9.30 and 26.73 mg/L) or nitrogen nanobubble water (2.69 and 8.84 mg/L), and rhizosphere microbes were analyzed.

  Key findings

  Both gases significantly changed rhizosphere microbial communities, and the proportion of specific microbes increased at high concentrations. These are results on rhizosphere microbial community change, separate from quantitative improvements in crop growth.

  Gas used

  Oxygen, nitrogen

  Bibliographic information

  Le et al. · 2025 · Rhizosphere 35: 101163 · DOI 10.1016/j.rhisph.2025.101163

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Neutral studies 2

• No increase in lettuce yield, but lower leaf nitrate

  Reported that in deep-water culture lettuce, nanobubble aeration did not change yield but affected quality, lowering leaf nitrate by 8.5%.

  Paper details · Study conditions · Detailed results

  Original title

  Nanobubble- and Microbubble Aeration Affect Leaf Quality Without Changing Yield of Lettuce Grown in Floating Systems

  Summary

  In greenhouse deep-water hydroponic lettuce (3 treatments × 5 replicates), no aeration, venturi aeration, and venturi plus nanobubble aeration were compared over one winter season.

  Key findings

  End-of-season dissolved oxygen was 2.98, 7.76 and 7.91 mg/L, but shoot fresh and dry weight did not differ among treatments. Nanobubble aeration lowered leaf nitrate by 8.5% and raised phosphorus, manganese, zinc, copper and magnesium, while calcium fell.

  Gas used

  Air

  Bibliographic information

  Fiore et al. · 2025 · Horticulturae 11(9): 1141 · DOI 10.3390/horticulturae11091141

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• No significant improvement in soil oxygen or turf quality on a golf course

  Reported no significant differences in soil oxygen or turf quality on golf greens irrigated with oxygen nanobubble water.

  Paper details · Study conditions · Detailed results

  Original title

  Field Evaluation of the Impact of Oxygenated Nanobubble Water on Turfgrass Growth and Soil Health

  Summary

  On a bermudagrass putting green over two years (2021–2022), oxygen nanobubble water and ordinary water were applied, comparing soil oxygen, roots, turf quality and soil microbes (2 treatments × 4 replicates).

  Key findings

  Dissolved oxygen was about 32 mg/L immediately after generation and 22 mg/L at the sprinkler nozzle. Soil oxygen (P=0.083), turf quality and soil microbes and enzymes did not differ, and root mass rose 26% in 2022 only. The authors cited oxygen loss from overhead application as a limitation.

  Gas used

  Oxygen

  Bibliographic information

  Molini et al. · 2025 · HortScience 60(11): 1942-1947 · DOI 10.21273/HORTSCI18855-25

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Aquaculture

Positive studies 6

• Ozone nanobubble treatment improves survival of Nile tilapia infected with multidrug-resistant bacteria

  Reported that Nile tilapia challenged with a pathogen survived significantly better in rearing water treated with ozone nanobubbles than in untreated water.

  Paper details · Study conditions · Detailed results

  Original title

  Ozone nanobubble treatments improve survivability of Nile tilapia (Oreochromis niloticus) challenged with a pathogenic multi-drug-resistant Aeromonas hydrophila

  Summary

  In a recirculating rearing system, Nile tilapia were infected with multidrug-resistant bacteria (Aeromonas hydrophila) and the effect of ozone nanobubble treatment was examined. In a 14-day safety test, no abnormal behavior or mortality occurred.

  Key findings

  Relative survival in the treated groups was 64.7–66.7%. Bacterial counts in rearing water fell 15.9–35.6% over the first two days in the treated groups and rose 13.1–27.9% in the untreated groups.

  Gas used

  Ozone

  Bibliographic information

  Dien et al. · 2021 · Journal of Fish Diseases 44(9), 1435-1447 · DOI 10.1111/jfd.13451

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• Better shrimp survival with combined biofloc and ozone nanobubbles

  Reported that in the nursery phase of whiteleg shrimp, survival with combined biofloc and ozone nanobubbles was 82%, higher than in clear water (40%).

  Paper details · Study conditions · Detailed results

  Original title

  Integration of Biofloc and Ozone Nanobubbles for Enhanced Pathogen Control in Prenursery of Pacific White Shrimp (Penaeus vannamei)

  Summary

  Four rearing methods were compared in the nursery phase of whiteleg shrimp: clear water, clear water with ozone, biofloc, and biofloc with ozone.

  Key findings

  Compared with clear water, the combined biofloc and ozone nanobubble group showed a final body weight of 11.65 vs. 10.32 mg, 61% lower total ammonia nitrogen and 78% lower nitrite nitrogen, and Vibrio fell from 228,885 to 107 CFU/mL. Because these results come from use with biofloc, they cannot be attributed to ozone nanobubbles alone.

  Gas used

  Ozone (0.3 mg/L or higher, 15 minutes a day)

  Bibliographic information

  Liang et al. · 2025 · Fishes 10(5), 218 · DOI 10.3390/fishes10050218

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• Higher survival in live fish transport using nanobubble technology

  Reported that in 12-hour live transport using ozone or oxygen nanobubbles, survival of trout fry exceeded 99%, higher than with conventional oxygen supply (64.5–76.7%).

  Paper details · Study conditions · Detailed results

  Original title

  Enhancing the Survival Rate in Live Fish Transport by Utilizing Nanobubble Technology

  Summary

  Trout fry were transported for 12 hours in sealed bags (500–750 per bag) and open tanks, comparing nanobubble treatment with conventional oxygen supply.

  Key findings

  Survival was 99.3–99.6% with ozone nanobubbles vs. 64.5% with conventional oxygen packing in sealed transport, and 99.0% with oxygen nanobubbles vs. 76.7% with conventional aeration in open transport (P<0.05). Nanobubble groups maintained dissolved oxygen of 8–9 mg/L and ammonia of 0.01–0.03 mg/L. The study was published in a regional journal.

  Gas used

  Oxygen, ozone, air

  Bibliographic information

  Devkota et al. · 2023 · Nepalese Journal of Aquaculture and Fisheries 10(1): 33-42 · DOI 10.3126/njaf.v10i1.78789

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• Control of Vibrio parahaemolyticus (AHPND strain) and water quality improvement with nanobubble technology

  Reported that a shrimp pathogen (the Vibrio strain causing AHPND) fell to undetectable levels after 6 minutes of ozone nanobubble treatment.

  Paper details · Study conditions · Detailed results

  Original title

  Control of Vibrio parahaemolyticus (AHPND strain) and improvement of water quality using nanobubble technology

  Summary

  In 100 L tanks at 15‰ salinity (3 replicates), air, oxygen and ozone nanobubbles were applied for one week, comparing Vibrio counts and water quality.

  Key findings

  Final counts relative to the control were 69% with air nanobubbles, 46% with oxygen nanobubbles (60 minutes a day), and 23%, 2.2% and 0% with ozone nanobubbles for 2, 4 and 6 minutes. Oxygen and ozone nanobubbles raised oxidation-reduction potential and oxygen concentration.

  Gas used

  Air, oxygen, ozone

  Bibliographic information

  Nghia et al. · 2021 · Aquaculture Research 52(6): 2727-2739 · DOI 10.1111/are.15124

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• Improved growth of whiteleg shrimp with nanobubbles in an indoor raceway

  Reported that when whiteleg shrimp were raised for 81 days in an indoor raceway, the nanobubble group had higher dissolved oxygen and faster growth.

  Paper details · Study conditions · Detailed results

  Original title

  Enhancement of Penaeus vannamei shrimp growth using nanobubble in indoor raceway pond

  Summary

  Whiteleg shrimp were reared at high density (680/m³) for 81 days in a 50 ㎡ indoor raceway, comparing nanobubble supply with diffuser aeration.

  Key findings

  The nanobubble group showed survival of up to 95%, mean weight of 15.1 g, harvest of 436 kg and productivity of 8.7 kg/m³, with harvest and productivity reported as about double. Dissolved oxygen was significantly higher and feed conversion ratio lower. Mean bubble size was about 82 nm.

  Bibliographic information

  Rahmawati et al. · 2021 · Aquaculture and Fisheries 6(3), 277-282 · DOI 10.1016/j.aaf.2020.03.005

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• Oxygen and air nanobubble water promote the growth of plants, fish and mice

  Reported that total body weight of sweetfish and rainbow trout raised in air nanobubble water increased much more than in ordinary water.

  Paper details · Study conditions · Detailed results

  Original title

  Oxygen and Air Nanobubble Water Solution Promote the Growth of Plants, Fishes, and Mice

  Summary

  Sweetfish (3 weeks) and rainbow trout (6 weeks) were raised in air nanobubble water (bubbles below 200 nm) or ordinary water, comparing total fish weight. The same paper also covered plants and mice.

  Key findings

  Total fish weight went from 3.0 to 10.2 kg for sweetfish (ordinary water 3.0 to 6.4 kg) and from 50.0 to 148.0 kg for rainbow trout (ordinary water 50.0 to 129.5 kg).

  Gas used

  Air

  Bibliographic information

  Ebina et al. · 2013 · PLoS ONE 8(6): e65339 · DOI 10.1371/journal.pone.0065339

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Neutral studies 2

• Air nanobubbles increase viable bacteria and nitrifying bacteria and lower nitrite in a seawater recirculating aquaculture system

  Reported that air nanobubbles in a seawater recirculating aquaculture system made no difference to growth, survival or dissolved oxygen, while nitrite was lower.

  Paper details · Study conditions · Detailed results

  Original title

  Air Nanobubbles Enhance Viable Bacteria Counts, Abundance of Nitrifying Bacteria, and Reduce Nitrite Levels in Marine Recirculation Aquaculture Systems

  Summary

  Three fish species were reared for 6 weeks in two seawater recirculating aquaculture systems (RAS), comparing a system with air nanobubbles against one without.

  Key findings

  Growth rate, survival (95–100%), feed conversion ratio and dissolved oxygen showed no significant differences. Nitrite was lower with nanobubbles (0.99 vs. 1.40 mg/L), and nitrifying bacteria increased. The authors cited low stocking density and high water exchange as limitations.

  Gas used

  Air

  Bibliographic information

  Sean et al. · 2025 · Fishes 10(11), 550 · DOI 10.3390/fishes10110550

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• Effects of hyperoxia during oxygen nanobubble treatment on innate immunity, growth, gill histology and gut microbiota of Nile tilapia

  Reported no harmful effects on growth or immunity in tilapia raised for 26 days in water whose dissolved oxygen was raised to 24 mg/L by oxygen nanobubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Effects of hyperoxia during oxygen nanobubble treatment on innate immunity, growth performance, gill histology, and gut microbiome in Nile tilapia, Oreochromis niloticus

  Summary

  Nile tilapia were raised for 26 days in water supersaturated with oxygen nanobubbles (24.2 mg/L after 10 minutes of treatment) and in ordinary water, comparing growth, immunity, gill histology and gut microbiota.

  Key findings

  Growth, survival and immune gene expression did not differ from the control, and there were no signs of gas bubble disease. Mild histological changes were occasionally observed in the gills. There was no growth-promoting effect; the study confirmed the safety of high dissolved oxygen.

  Gas used

  Oxygen

  Bibliographic information

  Linh et al. · 2023 · Fish and Shellfish Immunology 143: 109191 · DOI 10.1016/j.fsi.2023.109191

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Microbial Culture & Fermentation

Positive studies 3

• Investigation of the effect of ultrafine bubbles on bacterial growth

  Reported that E. coli and Staphylococcus aureus grew better in media containing hydrogen and air ultrafine bubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Investigating the effects of ultrafine bubbles on bacterial growth

  Summary

  Ultrafine bubbles were generated in culture media by ultrasound, and two bacteria were grown in static culture at 37 ℃, comparing growth and cell size with ordinary media.

  Key findings

  Growth and dry cell weight ranked hydrogen > air > control (shown only in figures), and cell area was smaller in bubble media (p<0.05). Bubble size and concentration were not measured, and the authors noted that bubbles could interfere with turbidity measurements.

  Gas used

  Air, hydrogen

  Bibliographic information

  Vu et al. · 2024 · RSC Advances · DOI 10.1039/d3ra07454d

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• Microalgae biomass up about 10% with CO₂ nanobubbles

  Reported that when carbon dioxide was supplied as nanobubbles in microalgae culture, biomass after 14 days was about 10% higher than with ordinary bubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Comparative study of CO2 nanobubbles and macrobubbles: Effects on water chemistry, microalgal growth, and carbon utilization

  Summary

  Microalgae (Scenedesmus obliquus) were cultured for 14 days, comparing carbon dioxide supplied as nanobubbles with carbon dioxide supplied as ordinary-sized bubbles.

  Key findings

  Biomass was 10.11% higher than with ordinary bubbles, and nanobubble carbon utilization efficiency was 27.86%. The reported mass transfer coefficients were 12.41–18.91 h⁻¹ for nanobubbles and 10.18 h⁻¹ for ordinary bubbles, but variability was large and the ranges overlap.

  Gas used

  Carbon dioxide

  Bibliographic information

  Li et al. · 2026 · Water Research 288, 124714 · DOI 10.1016/j.watres.2025.124714

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• Comparison of gas utilization and bioconversion productivity between fine-bubble and macrobubble aeration

  Reported that at the same oxygen transfer conditions, fine-bubble aeration raised enzymatic reaction productivity by 32% and greatly increased gas utilization compared with ordinary bubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Comparative investigation of fine bubble and macrobubble aeration on gas utility and biotransformation productivity

  Summary

  In an enzymatic reaction converting glucose to gluconic acid, fine-bubble and ordinary-bubble aeration were compared at the same oxygen transfer coefficient (kLa).

  Key findings

  At the same kLa, gas utilization was 25–44 times higher, gluconic acid productivity rose 32% and oxygen utilization was 41.6 times higher. Enzyme damage from foam and gas consumption were reduced. This is an enzymatic reaction, not a microbial culture, and a microbubble study.

  Gas used

  Air

  Bibliographic information

  Thomas et al. · 2021 · Biotechnology and Bioengineering 118(1): 130-141 · DOI 10.1002/bit.27556

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Neutral studies 1

• Effect of nanobubble water on the growth and lactic acid production of Lactobacillus acidophilus 1028

  Reported that in lactic acid bacteria culture, nitrogen and hydrogen nanobubble water raised early growth but made no difference to final biomass, and carbon dioxide nanobubble water had no effect.

  Paper details · Study conditions · Detailed results

  Original title

  Effects of nanobubble water on the growth of Lactobacillus acidophilus 1028 and its lactic acid production

  Summary

  Lactic acid bacteria were cultured in media made with nanobubble water of four gases, comparing growth and lactic acid production.

  Key findings

  At 90% nanobubble water, growth at 6 hours of culture rose by 51.1% with nitrogen and 34.2% with hydrogen. From about 15–21 hours onward, in the stationary phase, there was no significant difference from the control. Because medium dissolved oxygen and pH varied with the gas, the effect of the bubbles alone is difficult to isolate.

  Gas used

  Air, nitrogen, hydrogen, carbon dioxide

  Bibliographic information

  Guo et al. · 2019 · RSC Advances 9(53), 30760-30767 · DOI 10.1039/c9ra05868k

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Surface cleaning

Positive studies 4

• Removal of oil contamination from glass and microchannels with nanobubbles

  Reported that nanobubble water removed more cooking oil from glass and microchannel surfaces than ultrapure water.

  Paper details · Study conditions · Detailed results

  Original title

  Surface Cleaning of Oil Contaminants Using Bulk Nanobubbles

  Summary

  Sunflower oil on glass, microchannels and ceramic dishes was washed with nanobubble water made by water electrolysis (about 100 nm, 7.78×10⁸/mL) and compared with ultrapure water.

  Key findings

  In hydrophilic microchannels, about 85% of the oil was removed in 90 seconds, versus about 7% with ultrapure water. When glass was immersed and stirred, oil area fell about 80% in 10 minutes, versus about 20% with ultrapure water. Replicates and statistical tests were not reported.

  Gas used

  Gas produced by water electrolysis

  Bibliographic information

  Hansen et al. · 2024 · ChemSusChem 17(21), e202400802 · DOI 10.1002/cssc.202400802

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• A study on cleaning and purification with fine bubbles

  Reported that fine bubbles removed oil from plastic surfaces and salt from aluminum foil surfaces, with removal efficiency related to the total surface area of the bubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Research on Cleaning and Purification Using Fine Bubbles (ファインバブルを用いた洗浄・浄化に関する研究)

  Summary

  The study covered washing oil from polypropylene surfaces and salt from aluminum foil with fine-bubble water, and the effect on bottom sediments in a model river channel.

  Key findings

  In the model river channel, an oxidized layer formed on the sediment surface and phosphorus release decreased.

  Gas used

  Air

  Bibliographic information

  Hata et al. · 2018 · 混相流 (Japanese Journal of Multiphase Flow) 32(1): 4-11 · DOI 10.3811/jjmf.32.4

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• Cleaning with bulk nanobubbles

  Reported that nanobubble water of about 100 nm prevented proteins from adhering to surfaces and also cleaned surfaces that were already fouled.

  Paper details · Study conditions · Detailed results

  Original title

  Cleaning with Bulk Nanobubbles

  Summary

  Nanobubble water made by electrolysis (lasting about 24 hours) was examined for preventing and cleaning protein (BSA, lysozyme) fouling on hydrophilic and hydrophobic surfaces.

  Key findings

  The authors proposed that nanobubbles act in the same way detergents keep detached soils suspended in water. This is a mechanistic study explaining the potential of nanobubbles to disperse contaminants and inhibit their redeposition.

  Gas used

  Oxygen, hydrogen (electrolysis)

  Bibliographic information

  Zhu et al. · 2016 · Langmuir 32(43): 11203-11211 · DOI 10.1021/acs.langmuir.6b01004

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• Cleaning protein-coated surfaces with nanobubbles: a quartz crystal microbalance (QCM) study

  Reported that electrochemically generated nanobubbles completely removed protein fouling in 2 cycles on hydrophobic surfaces and 4 cycles on hydrophilic surfaces.

  Paper details · Study conditions · Detailed results

  Original title

  Cleaning of protein-coated surfaces using nanobubbles: An investigation using a Quartz Crystal Microbalance

  Summary

  Nanobubbles were generated for 10 seconds at a time on electrode surfaces with adsorbed protein (BSA), and protein detachment was tracked with a quartz crystal microbalance (QCM).

  Key findings

  Cleaning efficiency compared well with 20 minutes of surfactant (SDS) treatment. The nanobubbles were generated directly on the surface, and the method applies only to conductive substrates.

  Gas used

  Electrochemically generated gas

  Bibliographic information

  Liu et al. · 2008 · Journal of Physical Chemistry C 112(43): 16748-16753 · DOI 10.1021/jp805143c

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Neutral studies 1

• Combined effect of nanobubbles and surfactant in cleaning protein fouling

  Reported that nanobubbles alone did not sufficiently remove surface-bound protein, but combined with surfactant they removed it completely from hydrophilic surfaces.

  Paper details · Study conditions · Detailed results

  Original title

  Improved cleaning of hydrophilic protein-coated surfaces using the combination of nanobubbles and SDS

  Summary

  Hydrophobic and hydrophilic surfaces fouled with protein (lysozyme) were cleaned with nanobubbles, surfactant, or both, and the remaining amounts were compared.

  Key findings

  On hydrophobic surfaces, considerable protein remained even after 10 nanobubble treatments, while surfactant removed about 90%. On hydrophilic surfaces, neither alone removed the protein, but together they removed it completely in 6 cycles.

  Gas used

  Gas generated electrochemically

  Bibliographic information

  Liu, Craig · 2009 · ACS Applied Materials & Interfaces 1(2), 481-487 · DOI 10.1021/am800150p

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Industrial & Precision Cleaning

Positive studies 3

• Cleaning with nanobubbles: removal of fouling by electrochemical bubble generation

  Reported that nanobubbles produced by electrolysis reduced protein fouling on stainless steel and graphite surfaces, and pretreatment reduced fouling itself by 26–34%.

  Paper details · Study conditions · Detailed results

  Original title

  Cleaning using nanobubbles: Defouling by electrochemical generation of bubbles

  Summary

  Nanobubbles were produced by electrolysis before and after protein (BSA) was applied to graphite and stainless steel surfaces, comparing prevention and removal of fouling.

  Key findings

  Protein coverage on graphite fell from 100 to 82% with 50 seconds of treatment, and residual protein on stainless steel fell about 20% with 3 minutes of treatment, with more removed by repeated treatment. Significance was not reported.

  Gas used

  Gas produced by electrolysis

  Bibliographic information

  Wu et al. · 2008 · Journal of Colloid and Interface Science 328(1): 10-14 · DOI 10.1016/j.jcis.2008.08.064

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• Development of wafer cleaning equipment using nanobubbles and megasonics

  Reported that wafer cleaning equipment combining nanobubbles with megasonic ultrasound removed more than 97% of simulated contaminant particles.

  Paper details · Study conditions · Detailed results

  Original title

  Development of Wafer Cleaning Equipment Using Nano Bubble and Megasonic Ultrasound

  Summary

  Alumina and latex particles were applied to silicon wafers, and cleaning equipment combining nanobubble water with megasonic ultrasound was developed and its removal rate evaluated.

  Key findings

  Because the results were obtained together with ultrasound, the contribution of nanobubbles alone cannot be separated, and they were not validated on a production line. The study was published in a Korean journal.

  Gas used

  Not stated

  Bibliographic information

  Kim et al. · 2023 · Korean journal (KCI ART003039069)

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• Microbubbles for chemical-free cleaning of metal surfaces

  Reported oil removal of 78.5% on carbon steel and 49.8% on stainless steel after 15 minutes of cleaning with air microbubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Microbubbles for Effective Cleaning of Metal Surfaces Without Chemical Agents

  Summary

  Oil was washed from carbon steel and stainless steel surfaces with air microbubbles produced by hydrodynamic cavitation and compared with bubble-free water.

  Key findings

  Without bubbles, removal was 6.5% on carbon steel and 9.9% on stainless steel. Combined with ultrasound, removal reached 85.5% after 3 minutes, versus 69.0% with ultrasound alone. This is a microbubble study.

  Gas used

  Air

  Bibliographic information

  Li et al. · 2022 · Langmuir 38(2), 769-776 · DOI 10.1021/acs.langmuir.1c02769

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Textile cleaning

Positive studies 3

• Cleaning effect of nanobubble and surfactant mixtures under alternating flow

  Reported that nanobubble water had a cleaning rate about 5% higher than ion-exchanged water, and combined with surfactant about 10% higher than surfactant alone.

  Paper details · Study conditions · Detailed results

  Original title

  Investigation on Washing Effects for Nano-Bubble/Surfactant Mixtures in an Alternating Flow (交番流におけるナノバブル/界面活性剤混合液の洗浄効果の検討)

  Summary

  Fabrics were washed in a laundry test apparatus that alternates the direction of water flow, comparing the cleaning rates of nanobubble water, ion-exchanged water and anionic surfactant solution.

  Key findings

  Nanobubble water was reported to have lower surface tension than water. The effect was on the order of 5–10%, and the paper is in Japanese.

  Bibliographic information

  Ushida et al. · 2011 · 日本機械学会論文集 B編 77(777), 1219-1228 · DOI 10.1299/kikaib.77.1219

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• Evaluation of the cleaning power of micro-nanobubbles using ATP measurement

  Reported that micro-nanobubble water, alone and with surfactant, washed protein soil from fabrics and glass.

  Paper details · Study conditions · Detailed results

  Original title

  Evaluating the detergency affects of micro/nanobubble by the ATP testing method (ATP測定法を用いたマイクロ・ナノバブルの洗浄力評価)

  Summary

  Cotton, polyester and glass slides soiled with gelatin protein were washed with micro-nanobubble water, and cleaning power was evaluated from the ATP luminescence of the wash water.

  Key findings

  ATP luminescence rose under both conditions and was interpreted as indicating a cleaning effect.

  Gas used

  Not stated

  Bibliographic information

  Yamaguchi et al. · 2015 · 共立女子短期大学生活科学科紀要 58: 57-65

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• A sustainable cotton pretreatment process using nanobubble technology

  Reported that using nanobubble water in cotton pretreatment achieved quality similar to the conventional process with 30% less water, though compositional analysis showed no significant difference attributable to nanobubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Sustainable cotton pre-treatment processes with nanobubble technology

  Summary

  Nanobubble water was applied to cotton pretreatment (desizing, scouring, bleaching) in several recipes, comparing desizing, absorbency, whiteness, tear strength and wastewater COD with the conventional process.

  Key findings

  With 30% less water, desizing, whiteness and tear strength were similar to the conventional process. Infrared spectroscopy confirmed starch removal but showed no significant difference due to nanobubbles. The result is equal cleaning quality with less water.

  Bibliographic information

  Anış et al. · 2026 · Cellulose 33(8), 4883-4905 · DOI 10.1007/s10570-026-07076-2

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Food washing

Positive studies 8

• Decontamination of apples using air micro-nanobubbles and ε-polylysine

  Reported that washing apples with air micro-nanobubbles combined with an antimicrobial reduced bacteria and yeast by more than 3 log and removed 77.3% of pesticide.

  Paper details · Study conditions · Detailed results

  Original title

  Decontamination of fresh apples using air micro-nanobubbles with epsilon-poly-lysine

  Summary

  Apples inoculated with Listeria, spoilage yeast and a pesticide (trichlorfon) were washed with air micro-nanobubble water combined with an antimicrobial (ε-polylysine 250 mg/L) and compared with each treatment alone.

  Key findings

  The pesticide removal of 77.3% was significantly higher than with either treatment alone, and quality after 20 days of storage did not differ. This removal rate was obtained with nanobubbles and the antimicrobial combined; the contribution of each was not evaluated separately.

  Gas used

  Air

  Bibliographic information

  Lu et al. · 2025 · Food Innovation and Advances 4(4), 446-453 · DOI 10.48130/fia-0025-0038

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• Inhibitory efficacy of air and oxygen micro-nanobubble water against Colletotrichum gloeosporioides and effects on postharvest quality of 'Fan Retief' guava

  Reported that surface microbes on guavas washed with air or oxygen micro-nanobubble water fell to less than one-hundredth, with quality retention similar to chlorine sanitizing.

  Paper details · Study conditions · Detailed results

  Original title

  Efficacy of Air and Oxygen Micro-nano Bubble Waters Against Colletotrichum gloeosporioides and Impacts on Postharvest Quality of 'Fan Retief' Guava Fruit

  Summary

  Guavas were washed for 15 or 30 minutes with tap water, sodium hypochlorite or air/oxygen bubble water and stored for 21 days at 13 ℃, comparing quality. In vitro tests against the anthracnose fungus were also carried out.

  Key findings

  Bubble water washing was similar to chlorine in maintaining firmness and delaying changes in color and sugar content, and reduced surface microbes by more than 2 log (p<0.05). In vitro, fungal survival was lowest after 60 minutes of exposure to air bubbles.

  Gas used

  Air, oxygen

  Bibliographic information

  Malahlela et al. · 2025 · Journal of Food Protection 88(1): 100437

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• Optimizing inactivation of aerobic bacteria and extending shelf life of tilapia fillets with carbon dioxide micro-nanobubbles

  Reported that tilapia fillets washed with carbon dioxide micro-nanobubbles stayed below the acceptable bacterial limit even after 7 days of refrigerated storage.

  Paper details · Study conditions · Detailed results

  Original title

  The Optimization of Aerobic Bacteria Inactivation in Tilapia (Oreochromis niloticus) Fillets using Micro-Nano Bubbles of Carbon Dioxide and Shelf-Life Extension

  Summary

  Conditions for washing tilapia fillets with brine and carbon dioxide micro-nanobubbles after dipping in chlorinated water were optimized by response surface methodology.

  Key findings

  Under optimal conditions (32-minute wash), aerobic bacteria fell by 1.5 log (5.623 → 4.120 log CFU/g), while untreated fillets exceeded the limit (6 log) after 7 days of storage. Because chlorine and salt were used together, the contribution of bubbles alone cannot be separated.

  Gas used

  Carbon dioxide

  Bibliographic information

  Naewkanya et al. · 2025 · Applied Science and Engineering Progress 18(1) · DOI 10.14416/j.asep.2024.08.002

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• Reduction of pesticide residues on curly chili using ozone fine-bubble technology

  Reported that a 10-minute wash with ozone fine-bubble water reduced pesticide residues (profenofos) on chili by up to 89.8% without loss of quality.

  Paper details · Study conditions · Detailed results

  Original title

  Pesticide Residue Reduction on Curly Chili (Capsicum annum L.) Using Ozone Fine Bubble Technology

  Summary

  Chili peppers with pesticide residues were washed for 10 minutes with ozone fine-bubble water (1 mg/L), and quality changes during storage at room temperature were examined.

  Key findings

  There was no loss of quality after washing, and marketability began to decline from day 6–8 of storage at room temperature. Bubble size was not measured, and the effect relative to ordinary ozonated water falls outside the scope of this result.

  Gas used

  Ozone

  Bibliographic information

  Levianny et al. · 2024 · jTEP Jurnal Keteknikan Pertanian 12(3): 340-351 · DOI 10.19028/jtep.012.3.340-351

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• Effect of ozone micro-nanobubbles on extending the shelf life of longan

  Reported that longans dipped in ozone micro-nanobubble water showed slower weight loss, peel browning and mold development than those washed with water.

  Paper details · Study conditions · Detailed results

  Original title

  Effect of ozone micro-nano bubbles on longan shelf life extension

  Summary

  Longans were dipped in distilled water (5 minutes) or ozone micro-nanobubble water (10, 20 or 30 minutes) and stored at 5 ℃ for 15 days (4 treatments × 4 replicates).

  Key findings

  The control lost the most weight, with peel browning after 9 days and mold after 12 days. This storage test was compared against the stated control, not directly against ordinary ozonated water.

  Gas used

  Ozone

  Bibliographic information

  Kidtuengkun et al. · 2023 · Journal of Science and Agricultural Technology 4(2): 46-52 · DOI 10.14456/jsat.2023.12

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• Effect of gas micro-nanobubbles on the efficacy of antimicrobials commonly used in the food industry

  Reported that adding carbon dioxide micro-nanobubbles to food sanitizers greatly increased the kill of E. coli O157 and Listeria.

  Paper details · Study conditions · Detailed results

  Original title

  Impact of gas micro-nano-bubbles on the efficacy of commonly used antimicrobials in the food industry

  Summary

  The bactericidal effect of peracetic acid, chlorine, citric acid and lactic acid sanitizers with and without air, carbon dioxide or nitrogen micro-nanobubbles was compared in culture suspensions.

  Key findings

  Reductions were 5.2 log with chlorine plus CO₂ bubbles vs. 3.8 log without bubbles for E. coli, and 4.4 log vs. 1.7 log with peracetic acid plus CO₂ bubbles for Listeria. These were suspension tests, not food surfaces, and the authors noted that validation on food is needed.

  Gas used

  Air, carbon dioxide, nitrogen

  Bibliographic information

  Singh et al. · 2021 · Journal of Applied Microbiology 130(4): 1092-1105 · DOI 10.1111/jam.14840

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• Effect of ozone micro-nanobubble treatment on maintaining postharvest freshness of spinach

  Reported that spinach treated with ozone micro-nanobubbles (4 mg/L, 5 minutes) showed slower loss of chlorophyll and vitamin C during storage.

  Paper details · Study conditions · Detailed results

  Original title

  Effect of Ozone Micro-nano-bubble Treatment on Postharvest Preservation of Spinach

  Summary

  Spinach was treated with ozone micro-nanobubbles and stored at 20 ℃ for 8 days, examining membrane damage, respiration, ethylene and antioxidant enzymes.

  Key findings

  Membrane damage indicators accumulated less, respiration and ethylene release were delayed, and antioxidant enzyme activity increased.

  Gas used

  Ozone

  Bibliographic information

  Wang et al. · 2020 · Food Science (食品科学) 41(23): 190-196 · DOI 10.7506/spkx1002-6630-20191102-014

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• Ozone microbubble technology for disinfecting alfalfa sprout seeds

  Reported that ozone microbubble water reduced bacteria on alfalfa seeds as much as chlorinated water without affecting germination or sprout growth.

  Paper details · Study conditions · Detailed results

  Original title

  An ozone micro-bubble technique for seed sterilization in alfalfa sprouts

  Summary

  Alfalfa seeds were treated for 5 minutes with tap water, microbubble water, ozonated water, ozone microbubble water or chlorinated water, comparing bacterial counts and germination and growth.

  Key findings

  Reductions in total bacteria were greatest with ozone microbubble water and chlorinated water, and chlorinated water lowered germination and sprout weight. E. coli was also removed by ordinary ozonated water, so the added effect of bubbles was confirmed only for total bacteria. This is a Korean microbubble study.

  Gas used

  Ozone

  Bibliographic information

  Kwack et al. · 2014 · Horticultural Science and Technology (원예과학기술지) 32(6): 901-905 · DOI 10.7235/hort.2014.14129

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Neutral studies 2

• Evaluation of the effect of ozone nanobubble treatment on the postharvest quality of fresh peaches

  Reported that dipping peaches in high-concentration ozone nanobubble water caused peel burn and decay, while oxygen nanobubble water did not differ from chlorine sanitizing.

  Paper details · Study conditions · Detailed results

  Original title

  Evaluating the Effects of Ozone Nanobubble Treatments on Postharvest Quality of Fresh Peaches

  Summary

  Two peach varieties (3,200 fruits in total) were dipped for 30 minutes in oxygen nanobubble water (dissolved oxygen 10, 20 or 30 mg/L), ozone-saturated water (about 8 mg/L) or chlorinated water (50 mg/L) and stored for 28 days.

  Key findings

  Firmness did not differ among treatments, and oxygen nanobubble water had no effect on decay. Ozone-saturated treatment caused white-spot peel burn within 7 days that led to decay, reaching about 20% in one variety (0% with chlorinated water). The study indicates an upper limit for ozone concentration.

  Gas used

  Oxygen, ozone

  Bibliographic information

  Giannopoulos et al. · 2025 · HortTechnology 35(1) · DOI 10.21273/HORTTECH05557-24

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• Effect of ultrasound and surfactant on bacterial reduction by nanobubbles: bacterial suspensions and produce surfaces

  Reported that oxygen nanobubbles alone did not reduce bacteria on spinach surfaces, but did so substantially when combined with ultrasound.

  Paper details · Study conditions · Detailed results

  Original title

  The Effect Ultrasound and Surfactants on Nanobubbles Efficacy against Listeria innocua and Escherichia coli O157:H7, in Cell Suspension and on Fresh Produce Surfaces

  Summary

  Two bacteria in suspension and on spinach leaves were treated with oxygen nanobubbles, ultrasound, both combined, and with added surfactant.

  Key findings

  In suspension, nanobubbles alone or ultrasound alone produced no significant reduction even after 15 minutes. Combined, they removed more than 2 log of Listeria and more than 4 log of E. coli from spinach. Adding surfactant did not significantly increase the effect.

  Gas used

  Oxygen

  Bibliographic information

  Rafeeq, Ovissipour · 2021 · Foods 10(9), 2154 · DOI 10.3390/foods10092154

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Equipment & pipe interior cleaning

Positive studies 8

• Effect of micro-nanobubbles on emitter clogging in drip irrigation systems

  Reported that adding micro-nanobubbles to drip irrigation lines delayed emitter clogging by 20–130%.

  Paper details · Study conditions · Detailed results

  Original title

  Influence of micro/nanobubbles on clogging in drip irrigation systems

  Summary

  In a drip irrigation system recirculating groundwater, five emitter types were run for 430 hours, comparing lines with and without micro-nanobubbles (200 nm–4 μm).

  Key findings

  The time for mean flow to fall to 75% was delayed by 20–130% depending on the emitter (e.g., from 306 to 422 hours). The bubble effect was statistically significant but much smaller than the effect of operating time. Microbes and mechanisms were not measured.

  Bibliographic information

  Li et al. · 2020 · RSC Advances 10(64), 38912-38922 · DOI 10.1039/D0RA07782H

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• Potential of air micro-nanobubbles and carbon dioxide bubbles to remove and prevent biofouling of seawater reverse osmosis membranes

  Reported that bubble-based cleaning of biofilm on seawater reverse osmosis membranes recovered 49–56% of the pressure drop, similar to chemical cleaning (51%).

  Paper details · Study conditions · Detailed results

  Original title

  The potential of air micro-nano bubbles and nucleated CO2 bubbles as curative and preventive strategies for SWRO biofouling removal

  Summary

  Biofilm on seawater reverse osmosis membranes was evaluated with air micro-nanobubbles and carbon dioxide bubbles formed in water, used both for cleaning and as a daily preventive treatment. The indicator was pressure drop.

  Key findings

  Recovery with water flushing alone was 24%. With daily treatment, the onset of performance loss was delayed by 123% with carbon dioxide bubbles and 95% with air micro-nanobubbles. Recovery was not complete.

  Gas used

  Air, carbon dioxide

  Bibliographic information

  Alvarez Sosa et al. · 2025 · Desalination 610, 118865 · DOI 10.1016/j.desal.2025.118865

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• Micro-nanobubbles for removing foulants from nanofiltration membranes used in drinking water treatment

  Reported that cleaning nanofiltration membranes with micro-nanobubbles for 90 minutes or more fully restored water permeability.

  Paper details · Study conditions · Detailed results

  Original title

  Micro-nanobubbles for removing membrane foulants from the surface of nanofiltration membranes in drinking water applications

  Summary

  A submerged nanofiltration membrane treating surface water directly was operated for 49 days and cleaned once a week with micro-nanobubbles.

  Key findings

  In the first four filtration cycles, transmembrane pressure returned to its initial value, but cleaning efficiency declined thereafter. Dissolved organic carbon removal remained at 74% or higher.

  Bibliographic information

  Son et al. · 2025 · Separation and Purification Technology 377, 134259 · DOI 10.1016/j.seppur.2025.134259

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• Performance of micro-nanobubbles for controlling combined inorganic and colloidal fouling in reverse osmosis

  Reported that with combined inorganic and colloidal fouling of reverse osmosis membranes, adding micro-nanobubbles reduced the flux decline from 76.3% to 18.5%.

  Paper details · Study conditions · Detailed results

  Original title

  Evaluation of the Performance of Micro–Nano Bubbles to Control the Simultaneous Inorganic and Colloidal Foulings in Reverse Osmosis

  Summary

  A reverse osmosis membrane was operated with feed water containing both gypsum and colloidal silica, comparing operation with and without air micro-nanobubble injection.

  Key findings

  Without bubbles, a dense fouling layer formed and flux fell 76.3% and salt rejection 4%; with bubbles, these declines were reduced to 18.5% and about 1%. Fouling was not completely prevented, and the study was laboratory-scale.

  Gas used

  Air

  Bibliographic information

  Dahrazma et al. · 2024 · Journal of Environmental Engineering 150(8) · DOI 10.1061/JOEEDU.EEENG-7648

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• Evaluation of the antifouling effect of micro-nanobubbles on reverse osmosis membrane performance

  Reported that adding micro-nanobubbles to reverse osmosis made the colloidal fouling layer more loosely packed and improved flux by 21–40%.

  Paper details · Study conditions · Detailed results

  Original title

  Evaluation of the Anti-Fouling Effects of Micro-Nano Bubbles on the Performance of Reverse Osmosis Membrane

  Summary

  A reverse osmosis membrane was operated with synthetic feed water at different colloidal silica concentrations, comparing operation with and without air micro-nanobubble injection.

  Key findings

  Without bubbles, flux fell 24–56%. With bubbles, the fouling layer formed as a porous structure, improving flux and salt rejection, and was easily removed by cleaning-in-place (CIP). The study was laboratory-scale, and energy costs were not evaluated.

  Gas used

  Air

  Bibliographic information

  Authors · 2023 · Journal of Environmental Engineering 149(4) · DOI 10.1061/JOEEDU.EEENG-7072

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• Effect and mechanism of micro-nanobubbles on membrane antifouling performance

  Reported that introducing micro-nanobubbles raised the antifouling performance of separation membranes by 165.9% and slowed the decline in flux.

  Paper details · Study conditions · Detailed results

  Original title

  Effects of micro-/nanobubble on membrane antifouling performance and the mechanism insights

  Summary

  Micro-nanobubbles were introduced into membrane filtration, and antifouling performance and changes in foulant particles were analyzed.

  Key findings

  Foulants were observed to aggregate into larger particles, and the authors interpreted the bubbles as preventing adhesion between foulants and the membrane surface.

  Gas used

  Not stated

  Bibliographic information

  Fan et al. · 2022 · Journal of Cleaner Production 376

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• Scaling inhibition with nanobubbles in membrane distillation of hypersaline brine

  Reported that a single dose of air nanobubbles in membrane distillation of hypersaline brine reduced scaling and allowed 98 hours of operation.

  Paper details · Study conditions · Detailed results

  Original title

  Nanobubble-assisted scaling inhibition in membrane distillation for the treatment of high-salinity brine

  Summary

  A 100 g/L brine was treated by membrane distillation, comparing operation with and without air nanobubbles averaging 128.81 nm.

  Key findings

  Without nanobubbles, severe scaling brought flux to zero after 13 hours; with nanobubbles, flux decline was limited to 63% even after 98 hours. Scaling was delayed rather than eliminated, and the study was laboratory-scale.

  Gas used

  Air

  Bibliographic information

  Farid et al. · 2022 · Water Research 209: 117954 · DOI 10.1016/j.watres.2021.117954

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• Membrane fouling control by micro-nanobubbles in vacuum membrane distillation of high-salinity organic wastewater

  Reported that micro-nanobubble aeration effectively controlled combined organic and salt fouling in vacuum membrane distillation of high-salinity organic wastewater.

  Paper details · Study conditions · Detailed results

  Original title

  Study on micro-nanobubble control of membrane fouling in vacuum membrane distillation of high salt organic wastewater

  Summary

  Vacuum membrane distillation was run with feed water containing humic acid, protein, sodium alginate and salts, examining fouling patterns and the effect of bubble aeration.

  Key findings

  Combined fouling by humic acid and salts was the most severe, with relative flux falling to 20.59–36.33% after 7 hours. These flux decline rates describe the combined fouling condition itself, not the improvement achieved with nanobubbles.

  Gas used

  Not stated

  Bibliographic information

  Huang et al. · 2022 · 环境工程技术学报 (Journal of Environmental Engineering Technology) 12(4): 1333-1341 · DOI 10.12153/j.issn.1674-991X.20220100

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Neutral studies 2

• Microbubble-assisted CIP process and environmental performance of an ultrafiltration system

  Reported that adding microbubbles to CIP of ultrafiltration membranes raised flux recovery, but protein removal did not differ.

  Paper details · Study conditions · Detailed results

  Original title

  Microbubble-Assisted Cleaning-in-Place Process for Ultrafiltration System and Its Environmental Performance

  Summary

  On pilot-scale ultrafiltration membranes used to filter whole milk, air microbubbles (mean about 4 μm) were added to the rinse, alkaline and acid steps of a 7-step CIP and compared with conventional CIP.

  Key findings

  Flux recovery was 31–72% higher than conventional, and protein removal did not differ significantly. A life cycle assessment estimated 29% less cleaning power and 34% lower global warming impact. This is a microbubble study.

  Gas used

  Air

  Bibliographic information

  Chung et al. · 2023 · Membranes 13(4), 424 · DOI 10.3390/membranes13040424

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• Effect of nanobubbles on ultrafiltration membrane performance and properties of model cheese whey

  Reported that in ultrafiltration of cheese whey, adding nanobubbles raised early-stage flux by up to 34% and shortened concentration time by 28%.

  Paper details · Study conditions · Detailed results

  Original title

  Effect of Nanobubbles on Ultrafiltration Membrane Performance and Properties of Model Cheese Whey

  Summary

  Model cheese whey was concentrated by ultrafiltration with and without air nanobubbles (3 runs per treatment).

  Key findings

  Time to reach 3× concentration was 79.77 vs. 111.40 minutes. The flux advantage appeared only from 20 to 60 minutes, however, and at 120 minutes flux was lower than the control. Nanobubble size and concentration were not measured, and this is a filtration performance study, not a cleaning study.

  Gas used

  Air

  Bibliographic information

  Akshit et al. · 2025 · Foods 14(24): 4224 · DOI 10.3390/foods14244224

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Wastewater treatment & reuse

Positive studies 8

• Enhanced ammonia removal in ozonation using nanobubble technology

  Reported that at the same ozone flow, ammonia removal after 30 minutes was 82.5% with ozone nanobubbles and 44.2% with ordinary bubbles.

  Paper details · Study conditions · Detailed results

  Original title

  Nanobubble Technology Enhanced Ozonation Process for Ammonia Removal

  Summary

  Using 10 L of synthetic wastewater high in ammonia, ozone supplied as nanobubbles was compared with ozone supplied through a ceramic diffuser at the same flow rate, in triplicate.

  Key findings

  The reaction rate constant was 0.064 vs. 0.017 min⁻¹ (3.78×), and the proportion of bubbles below 200 nm was 87.1% vs. 33.3%. The water was synthetic, and the generator's energy consumption was not measured.

  Gas used

  Ozone

  Bibliographic information

  Wu et al. · 2022 · Water 14(12), 1865 · DOI 10.3390/w14121865

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• How ozone micro-nanobubbles enhance the oxidation of tetracycline in wastewater

  Reported that ozone micro-nanobubbles produced higher hydroxyl radical and dissolved ozone concentrations than conventional ozone diffusion and removed 96.25% of an antibiotic (tetracycline) in 120 seconds.

  Paper details · Study conditions · Detailed results

  Original title

  Mechanisms of Enhancing Tetracycline Oxidation in Wastewater by Ozone Micro-Nano Bubbles

  Summary

  Using 5 L of synthetic solution containing tetracycline (40 mg/L), ozone micro-nanobubbles (50–1,200 nm) were compared with conventional ozone diffusion.

  Key findings

  Mean hydroxyl radical concentration was 117% higher than with conventional diffusion, and peak dissolved ozone (27.9 mg/L) 85.5% higher. Total organic carbon (TOC) removal averaged only 11.01%, so the compound was not fully mineralized. Real wastewater was not tested.

  Gas used

  Ozone

  Bibliographic information

  Li et al. · 2026 · Processes 14(7), 1093 · DOI 10.3390/pr14071093

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• Design and development of a nanobubble-assisted modified advanced oxidation process (M-AOP) for high-efficiency wastewater treatment

  Reported that an advanced oxidation process combined with nanobubbles removed 92–98% of the COD of municipal sewage effluent in 15 hours, higher than conventional advanced oxidation (70.6%).

  Paper details · Study conditions · Detailed results

  Original title

  Design and development of a modified nanobubble-assisted advanced oxidation process (M-AOP) for high-efficiency wastewater treatment

  Summary

  Five liters of sewage effluent with an initial COD of about 921 mg/L were treated by ordinary aeration, conventional advanced oxidation and nanobubble-assisted advanced oxidation and compared (3 replicates).

  Key findings

  The study evaluated pollutant removal by the combined application of nanobubbles and advanced oxidation. Removal rates should be compared with the test conditions and evaluation time points kept distinct.

  Gas used

  Not stated

  Bibliographic information

  Shakouri et al. · 2025 · Scientific Reports 15: 41368 · DOI 10.1038/s41598-025-25407-4

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• Degradation of tetracycline in wastewater by ozone nanobubble advanced oxidation: nanobubble formation, kinetics, mechanisms and effects of water matrix

  Reported tetracycline removal after 45 minutes of 95.73% with ozone nanobubbles, 83.85% with ozone microbubbles and 76.75% with conventional ozone diffusion.

  Paper details · Study conditions · Detailed results

  Original title

  Tetracycline degradation for wastewater treatment based on ozone nanobubbles advanced oxidation processes (AOPs) - Focus on nanobubbles formation, degradation kinetics, mechanism and effects of water composition

  Summary

  Tetracycline dissolved in ultrapure water (100–400 mg/L) was treated with ozone nanobubbles (mean 230–260 nm), ozone microbubbles, conventional ozone diffusion and oxygen microbubbles and compared.

  Key findings

  Mass transfer coefficients were 0.150 for nanobubbles, 0.113 for microbubbles and 0.0085 min⁻¹ for diffusion. Conditions used high concentrations in ultrapure water, and TOC and COD were not measured. Replicates and statistics were not reported.

  Gas used

  Ozone (comparison: oxygen)

  Bibliographic information

  Koundle et al. · 2024 · Chemical Engineering Journal 501, 156236 · DOI 10.1016/j.cej.2024.156236

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• Combining ozone-based advanced oxidation with nanobubble generation for textile wastewater reuse

  Reported that combining ozone advanced oxidation with nanobubble generation removed 81.1% of textile wastewater COD in 300 minutes, far higher than ozone alone (about 10%).

  Paper details · Study conditions · Detailed results

  Original title

  Combination of ozone-based advanced oxidation process and nanobubbles generation toward textile wastewater recovery

  Summary

  Primary effluent from a textile mill (COD 114.30 mg/L) was treated in a 570 L/min recirculation loop with four nanobubble generators, ozone and ultraviolet light.

  Key findings

  Ammonia fell 30.81% and suspended solids 41.98%, and the peak bubble size was 216.9 nm. This was a single experiment without replicates or statistical tests, and some authors are affiliated with a related company.

  Gas used

  Ozone

  Bibliographic information

  Hutagalung et al. · 2023 · Frontiers in Environmental Science 11: 1154739 · DOI 10.3389/fenvs.2023.1154739

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• Treatment of organically contaminated wastewater by ozone micro-nanobubbles

  Reported that ozone micro-nanobubbles reduced the COD of high-salinity industrial wastewater by 63% and removed more than 95% of benzene and chlorobenzene from contaminated groundwater in 30 minutes.

  Paper details · Study conditions · Detailed results

  Original title

  Treatment of Organics Contaminated Wastewater by Ozone Micro-Nano-Bubbles

  Summary

  Ozone micro-nanobubbles averaging 265 nm were used in the laboratory (20 L) to treat dye solutions, high-salinity industrial wastewater and contaminated groundwater from a chemical plant site.

  Key findings

  Dyes were more than 90% removed in 30 minutes across pH 3–11, and removal was faster at higher salinity. Nitrobenzene removal reached only 67% and nitrochlorobenzene about 35%. There was no direct comparison with conventional ozone, and byproducts were not analyzed.

  Gas used

  Ozone

  Bibliographic information

  Xia et al. · 2019 · Water 11(1): 55 · DOI 10.3390/w11010055

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• High-performance ozone nanobubble-based advanced oxidation for degrading organic pollutants under high pollutant loads

  Reported that ozone nanobubbles completely degraded high-concentration dyes within 300 seconds, with faster kinetics than ozone microbubbles.

  Paper details · Study conditions · Detailed results

  Original title

  High Performance Ozone Nanobubbles Based Advanced Oxidation Processes (AOPs) for Degradation of Organic Pollutants under High Pollutant Loading

  Summary

  High-concentration solutions of two dyes were treated with ozone nanobubbles and ozone microbubbles, comparing reaction rates and the contribution of radicals.

  Key findings

  Complete degradation of both dyes was observed within 300 seconds under acidic conditions and with some additives. Reaction rates varied with test conditions.

  Gas used

  Ozone (5 L/min)

  Bibliographic information

  Koundle et al. · 2025 · Journal of Environmental Management 374: 124107 · DOI 10.1016/j.jenvman.2025.124107

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• Effectiveness of ozone micro-nanobubbles in removing infectious pathogens from contaminated water: E. coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus

  Reported that ozone micro-nanobubbles killed all four pathogens in 2–8 minutes, much faster than conventional ozone (60–120 minutes).

  Paper details · Study conditions · Detailed results

  Original title

  Effect of Ozone Micronano Bubbles on the Removal of Infectious Pathogens in Contaminated Water: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis

  Summary

  Water contaminated with E. coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus was treated with ozone micro-nanobubbles and conventional ozone bubbles at the same ozone dose (5 g/h).

  Key findings

  Time to 100% kill was 8 vs. 120 minutes for Pseudomonas aeruginosa, 5 vs. 90 minutes for Staphylococcus aureus, 3 vs. 60 minutes for E. coli and 2 vs. 60 minutes for Enterococcus.

  Gas used

  Ozone

  Bibliographic information

  Dehrazma et al. · 2024 · Journal of Environmental Engineering 150(3) · DOI 10.1061/JOEEDU.EEENG-7481

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Neutral studies 2

• Wastewater aeration with a ceramic membrane nanobubble generator: experimental validation and modeling of oxygen transfer

  Reported that aerating wastewater with a ceramic membrane nanobubble generator gave low oxygen transfer and energy efficiency.

  Paper details · Study conditions · Detailed results

  Original title

  Aeration of wastewater with a ceramic membrane nanobubble generator: Experimental validation and modelling of its oxygen transfer

  Summary

  Demineralized water, buffer solution and activated sludge from a sewage treatment plant were aerated with a ceramic membrane nanobubble generator, and oxygen transfer was measured and compared with a model. This was a short-term test in a 10 L laboratory unit.

  Key findings

  Standard oxygen transfer efficiency was about 20–54% in demineralized water and about 2–8% in wastewater, and standard aeration efficiency was below 0.01 kg O₂/kWh. The authors concluded that nanobubbles are not the main carrier of oxygen and that oxygen transfer comes mainly from microbubbles and turbulence.

  Gas used

  Air

  Bibliographic information

  Messina, Christensen · 2025 · Chemical Engineering Journal 524, 169390 · DOI 10.1016/j.cej.2025.169390

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• Are microbubbles magic or just small? A direct comparison of hydroxyl radical generation in microbubble and conventional bubble ozonation under typical operating conditions

  Reported no evidence that ozone microbubbles generate more hydroxyl radicals than ordinary bubbles at the same effective ozone dose.

  Paper details · Study conditions · Detailed results

  Original title

  Are microbubbles magic or just small? a direct comparison of hydroxyl radical generation between microbubble and conventional bubble ozonation under typical operational conditions

  Summary

  In a 100 L reactor, ozone was supplied as 37 μm microbubbles or 5.4 mm ordinary bubbles, and hydroxyl radical generation was compared directly at pH 6–8.

  Key findings

  The ratio of radical generation was 0.73–1.12 depending on pH, none significant (p=0.16–1.0), and radical levels were governed by effective ozone dose and pH. The authors suggested that the microbubble advantage reported in other studies may reflect laboratory conditions.

  Gas used

  Ozone

  Bibliographic information

  John et al. · 2022 · Chemical Engineering Journal 435: 134854 · DOI 10.1016/j.cej.2022.134854

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Water body management

Positive studies 8

• Micro-nanobubble-enhanced treatment for efficient volume reduction of contaminated sediment: dewatering characteristics and mechanism

  Reported that pretreatment of dredged lake sediment with micro-nanobubbles reduced dewatering time by 89%.

  Paper details · Study conditions · Detailed results

  Original title

  Micro-Nano Bubbles Conditioning Treatment of Contaminated Sediment for Efficient Reduction: Dehydration Characteristic and Mechanism

  Summary

  Dewatering pretreatment conditions combining a flocculant (PAM) with micro-nanobubbles were tested on dredged lake sediment with 90% water content.

  Key findings

  Under optimal conditions (1 μm bubbles, air 30 L/min, 90 seconds), the dewatering index (CST) fell from 1,500 to 160.6 seconds, and filter cake water content was 65.2% (78.2% with flocculant alone). This is pretreatment of dredged sediment, not treatment of a water body, and replicates and statistics were not reported.

  Gas used

  Air

  Bibliographic information

  Zhang et al. · 2023 · Water 15(11): 1985 · DOI 10.3390/w15111985

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• Multifunctional materials for eutrophication restoration: simultaneous control of internal nutrient loading and hypoxia

  Reported that in a field experiment in a eutrophic lake, bottom water dissolved oxygen reached 6.2 mg/L with a material loaded with oxygen nanobubbles, higher than without it (about 1.5 mg/L).

  Paper details · Study conditions · Detailed results

  Original title

  Exploring a multifunctional geoengineering material for eutrophication remediation: simultaneously control internal nutrient load and tackle hypoxia

  Summary

  Eight field enclosures were set up in a shallow eutrophic lake to compare, over 35 days, no treatment, natural zeolite, modified zeolite and modified zeolite loaded with oxygen nanobubbles.

  Key findings

  The sediment shifted from releasing phosphorus to absorbing it. The additional reduction attributable to the oxygen nanobubble loading was 57.3% for phosphorus and 56.1% for ammonia nitrogen. Bubbles were not injected directly into the water but carried on a solid material that settled to the bottom.

  Gas used

  Oxygen

  Bibliographic information

  Zhang et al. · 2021 · Chemical Engineering Journal 406, 127206 · DOI 10.1016/j.cej.2020.127206

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• Experimental application of micro-nanobubbles to reduce phosphorus release from lake sediments and separate phosphorus particles

  Reported that in a lake sediment experiment, micro-nanobubbles raised bottom water dissolved oxygen from 1 to 5 mg/L and lowered phosphorus release by up to 3 times compared with the untreated case.

  Paper details · Study conditions · Detailed results

  Original title

  Experimental application of micro/nano bubbles to control P release and separate P particles from benthic lake sediment

  Summary

  Lake bottom sediment was placed in laboratory tanks and injected with air micro-nanobubbles, examining phosphorus release from the sediment and flotation separation of phosphorus particles.

  Key findings

  Dissolved oxygen rose and then gradually declined. Separation efficiency for phosphorus particles was 12% with nanobubbles, 44% with microbubbles and 62% with both combined. The study was laboratory-scale, and significance was mostly not reported.

  Gas used

  Air

  Bibliographic information

  Choi et al. · 2025 · Journal of Contaminant Hydrology 268, 104466 · DOI 10.1016/j.jconhyd.2024.104466

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• Removal of algae-derived taste and odor micropollutants by nanobubble-based foam fractionation

  Reported that nanobubble foam fractionation removed 83.2% of an odor compound (geosmin) from lake water.

  Paper details · Study conditions · Detailed results

  Original title

  Nanobubble-enabled foam fractionation to remove algogenic odorous micropollutants

  Summary

  Odor compounds produced by algae (geosmin, 2-MIB) were removed from synthetic water and actual lake water by foam fractionation using air nanobubbles and surfactant.

  Key findings

  Removal was 91.81% for geosmin and 85.0% for 2-MIB in synthetic water and 83.2% and 48.1% in actual lake water, with nanobubbles outperforming microbubbles. Because surfactant addition is a precondition, this is not an effect of nanobubbles alone.

  Gas used

  Air

  Bibliographic information

  Zhang et al. · 2024 · Water Research 267 · DOI 10.1016/j.watres.2024.122540

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• Effects of ozone nanobubbles on the microbial ecology of pond water and safety for jade perch

  Reported that ozone nanobubbles (0.15 mg/L) reduced bacteria in pond water by more than 90% with no effect on fish.

  Paper details · Study conditions · Detailed results

  Original title

  Effect of ozone nanobubbles on the microbial ecology of pond water and safety for jade perch (Scortum barcoo)

  Summary

  Pond water was treated with ozone nanobubbles and ordinary ozone bubbles, comparing bacterial communities and safety for fish (jade perch).

  Key findings

  Heterotrophic bacteria fell by 90.9–99.4%, and nanobubbles reached the target ozone concentration faster while also raising dissolved oxygen substantially. Bacterial communities recovered within 24 hours, however, which limits how long the effect lasts.

  Gas used

  Ozone

  Bibliographic information

  Huang et al. · 2023 · Aquaculture 576: 739866 · DOI 10.1016/j.aquaculture.2023.739866

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• A novel treatment of Microcystis aeruginosa with chitosan-modified nanobubbles

  Reported that positively charged chitosan-modified nanobubbles inactivated 73% of bloom-forming cyanobacteria in 24 hours with almost no toxin release.

  Paper details · Study conditions · Detailed results

  Original title

  Novel treatment of Microcystis aeruginosa using chitosan-modified nanobubbles

  Summary

  Chitosan-modified nanobubbles (255 nm, positively charged) were added to cyanobacteria (Microcystis) to evaluate inactivation, cell lysis and toxicity.

  Key findings

  Cell lysis was 0.25% or less, and no acute toxicity to Daphnia was observed. Inactivation was strongly proportional to reactive oxygen species generation (r²=0.97). Results are from laboratory culture conditions.

  Gas used

  Not stated

  Bibliographic information

  Nam et al. · 2022 · Environmental Pollution 292 · DOI 10.1016/j.envpol.2021.118458

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• Reducing arsenic toxicity with interfacial oxygen nanobubble technology for sediment remediation

  Reported that oxygen nanobubble treatment lowered dissolved arsenic above hypoxic sediment from 23.2 μg/L to below 10 μg/L.

  Paper details · Study conditions · Detailed results

  Original title

  Reducing arsenic toxicity using the interfacial oxygen nanobubble technology for sediment remediation

  Summary

  In tanks simulating the sediment-water interface made hypoxic by algae, the effect of oxygen nanobubble treatment on arsenic behavior was examined.

  Key findings

  65–75% of the more toxic trivalent arsenic was converted to the pentavalent form, and the sediment shifted from releasing arsenic to retaining it.

  Gas used

  Oxygen

  Bibliographic information

  Tang et al. · 2021 · Water Research 205: 117657 · DOI 10.1016/j.watres.2021.117657

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• Interfacial oxygen nanobubbles reduce methylmercury production potential in sediments of eutrophic waters

  Reported that oxygen nanobubbles lowered methylmercury production potential in eutrophic lake sediment by up to 48%.

  Paper details · Study conditions · Detailed results

  Original title

  Interfacial oxygen nanobubbles reduce methylmercury production ability of sediments in eutrophic waters

  Summary

  Mercury was added to columns containing sediment and water from Lake Taihu, comparing methylmercury production with and without oxygen nanobubble treatment.

  Key findings

  Overlying water dissolved oxygen rose from 0 to 2.1 mg/L, and the gene for methylmercury production (hgcA) fell by up to 86%. These are laboratory column results and should be distinguished from application conditions in actual water bodies.

  Gas used

  Oxygen

  Bibliographic information

  Ji et al. · 2020 · Ecotoxicology and Environmental Safety 188: 109888 · DOI 10.1016/j.ecoenv.2019.109888

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Neutral studies 2

• Effects of ozone nanobubble treatment on cyanobacterial blooms: mesocosm and field trials

  Reported that ozone nanobubbles reduced cyanobacteria by 98–99% in mesocosms but showed no effect in the lake field trial, and oxygen nanobubbles showed no effect.

  Paper details · Study conditions · Detailed results

  Original title

  Effectiveness of ozone nanobubble treatments on high biomass cyanobacterial blooms: A mesocosm experiment and field trial

  Summary

  In an Ohio (USA) lake with a major cyanobacterial bloom, ozone nanobubble treatment was tested in 2,000 L mesocosms and in an actual bay (about 47 million L).

  Key findings

  In the mesocosms, at moderate or higher doses, chlorophyll and cyanobacterial pigments fell by 98–99% and toxin (microcystin) by 62–92%. The field trial, with two treatments over 4 weeks, showed no effect; the dose was low and the treated water reached only a limited area. Nanobubbles containing only oxygen had no effect on chlorophyll or toxin.

  Gas used

  Ozone (comparison: oxygen)

  Bibliographic information

  Chaffin et al. · 2024 · Journal of Environmental Management 372, 123406 · DOI 10.1016/j.jenvman.2024.123406

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• Application of micro- and nano-sized bubbles to separate phosphorus nanoparticles released from sediment

  Reported that micro-nanobubble flotation removed 34% of phosphorus nanoparticles released from sediment, with limitations as a stand-alone process.

  Paper details · Study conditions · Detailed results

  Original title

  Application of micro- and nanosized bubbles for the separation of phosphorus nanoparticles released from sediments

  Summary

  The separation of phosphorus particles of 0.45 μm or smaller released from sediment was compared between flotation with microbubbles alone and with nanobubbles added.

  Key findings

  With nanobubbles added, 5 minutes of flotation removed 34.09% of total phosphorus and 18.91% of dissolved phosphorus, while microbubbles alone gave limited removal. The authors suggested combining pretreatment for higher removal. This is a Korean study.

  Gas used

  Air

  Bibliographic information

  Nguyen et al. · 2026 · Chemical Engineering Research and Design 229: 134-144 · DOI 10.1016/j.cherd.2026.03.042

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CCUS R&D

Positive studies 3

• Nanobubble flow in porous media: a review of numerical and experimental studies of nanobubble technology for enhanced oil recovery and carbon sequestration

  A review of numerical and experimental studies on nanobubble flow and interfacial behavior in porous media and their potential for carbon sequestration.

  Paper details · Study conditions · Detailed results

  Original title

  Nanobubbles-laden fluid flow in porous media: A review study of numerical and experimental insights of nanobubble technology for enhanced oil recovery and carbon sequestration

  Summary

  The review brings together experimental and numerical modeling studies on using nanobubbles for enhanced oil recovery and geological CO₂ sequestration.

  Key findings

  This is a literature review and does not demonstrate actual long-term storage for any specific system. The field is at the R&D stage.

  Gas used

  Carbon dioxide and others

  Bibliographic information

  Pal · 2026 · Advances in Colloid and Interface Science 355:103917 · DOI 10.1016/j.cis.2026.103917

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• Feasibility of a carbon dioxide nanobubble system for enhanced oil recovery in ultra-low-permeability reservoirs

  Oil recovery performance in ultra-low-permeability formations was evaluated in the laboratory using carbon dioxide nanobubbles stabilized with modified particles.

  Paper details · Study conditions · Detailed results

  Original title

  Investigating the Potential of CO2 Nanobubble Systems for Enhanced Oil Recovery in Extra-Low-Permeability Reservoirs

  Summary

  Particle-stabilized carbon dioxide nanobubbles were injected into cores simulating ultra-low-permeability reservoirs to test oil recovery performance.

  Key findings

  This is a laboratory core test combined with particle stabilization technology; the effect of an ordinary generator alone and long-term CO₂ storage were not verified. The field is at the R&D stage.

  Gas used

  Carbon dioxide

  Bibliographic information

  Cai · 2024 · Nanomaterials 14(15):1280 · DOI 10.3390/nano14151280

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• Micro-nanobubble technology as a new frontier for CO₂ enhanced oil recovery and geological storage: a review

  The review examines the potential benefits and limits of micro-nanobubbles for CO₂ gas transfer, migration within formations and storage.

  Paper details · Study conditions · Detailed results

  Original title

  Micro and nanobubbles technologies as a new horizon for CO2-EOR and CO2 geological storage techniques: A review

  Summary

  A review summarizing micro-nanobubble research in CO₂ enhanced oil recovery and geological storage.

  Key findings

  These results were not validated at commercial storage facilities. The field is at the R&D stage.

  Gas used

  Carbon dioxide

  Bibliographic information

  Authors · 2023 · Fuel 341:127661 · DOI 10.1016/j.fuel.2023.127661

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Hygiene, disinfection & biosecurity

Positive studies 2

• Evaluation of the bactericidal effect of hydrogen- and ozone-charged ultrafine bubble water

  Reported that hydrogen and ozone ultrafine bubble water reduced E. coli and Staphylococcus aureus by more than 90% in 3–6 hours.

  Paper details · Study conditions · Detailed results

  Original title

  Evaluation of Bactericidal Effects of H2- and O3-filled Ultrafine Bubbles Water

  Summary

  Bacterial suspensions were exposed to hydrogen ultrafine bubble water and ozone ultrafine bubble water, and survival was measured.

  Key findings

  Survival fell by more than 90% after 6 hours of exposure for E. coli and 3 hours for Staphylococcus aureus. Because a 90% reduction (about 1 log) took several hours, this is insufficient evidence for short-contact disinfection. The paper is a 4-page short report.

  Gas used

  Hydrogen, ozone

  Bibliographic information

  Morishita et al. · 2022 · Biocontrol Science 27(3): 139-142 · DOI 10.4265/bio.27.139

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• Nanobubble ozone stored in hyaluronic acid-decorated liposomes: antibacterial and anti-SARS-CoV-2 effects and biocompatibility tests

  Reported that a liposome solution containing nanobubble ozone inhibited the growth of three bacteria and showed no toxicity in animal tests.

  Paper details · Study conditions · Detailed results

  Original title

  Nanobubble Ozone Stored in Hyaluronic Acid Decorated Liposomes: Antibacterial, Anti-SARS-CoV-2 Effect and Biocompatibility Tests

  Summary

  A solution of nanobubble ozone in hyaluronic acid liposomes was tested for bacterial inhibition, cytotoxicity, skin and mucosal irritation, and prevention of COVID-19 virus infection in mice.

  Key findings

  There was no cytotoxicity and no skin, oral, nasal or eye irritation, and viral RNA decreased when given intranasally to mice in advance. This is a liposome formulation, not ozone nanobubble water, and the authors noted that clinical validation is needed.

  Gas used

  Ozone (liposome formulation)

  Bibliographic information

  Sabanci et al. · 2022 · International Journal of Nanomedicine 17: 351-379 · DOI 10.2147/ijn.s328090

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Neutral studies 2

• Antibacterial effect of nanobubble water and potential application in healthcare-associated infection control

  Reported that nanobubble water without ozone did not reduce bacterial counts with exposures of 60 minutes or less.

  Paper details · Study conditions · Detailed results

  Original title

  Antibacterial Effects of Nanobubble Water and Its Potential Application in Healthcare-associated Infection Control

  Summary

  Nanobubble water made with four gases (bubbles 50–100 nm) was applied to E. coli and Staphylococcus aureus (including resistant strains) to examine antibacterial effects over time.

  Key findings

  Antibacterial effects grew with time and varied by gas and bacterial species. With no reduction at 60 minutes or less, the authors concluded it suits long-immersion uses rather than short-contact disinfection.

  Gas used

  Air, oxygen, nitrogen, carbon dioxide

  Bibliographic information

  Yoshida et al. · 2026 · In Vivo 40(2), 889-903 · DOI 10.21873/invivo.14245

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• Bactericidal effect of ozonated water produced with nanobubble technology after storage

  Reported that nanobubble ozonated water retained its bactericidal power when stored frozen, but ozone fell rapidly when stored at room temperature or refrigerated.

  Paper details · Study conditions · Detailed results

  Original title

  Microbicidal Effects of Stored Aqueous Ozone Solution Generated by Nano-bubble Technology

  Summary

  Commercial nanobubble ozonated water was stored at room temperature, refrigerated or frozen, comparing residual ozone and bactericidal activity against E. coli and a tuberculosis surrogate.

  Key findings

  After one week at room temperature, about 90% of the ozone had disappeared, and in refrigerated water about 60% of E. coli survived even after 60 minutes of exposure. Water stored frozen for one year killed more than 95% in 60 minutes. The study also serves as counter-evidence to claims of long-term stability of ozone nanobubble water.

  Gas used

  Ozone

  Bibliographic information

  Seki et al. · 2017 · In Vivo 31(4): 579-583

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Functional water production

Positive studies 3

• Effect of an oxygen nanobubble beverage on 16.1 km time trial and repeated sprint cycling performance: a double-blind, randomized, placebo-controlled pilot study

  Reported that 16.1 km completion time was 2.4% shorter after drinking an oxygen nanobubble beverage than after a placebo beverage.

  Paper details · Study conditions · Detailed results

  Original title

  A double-blind, randomized, placebo-controlled pilot study examining an oxygen nanobubble beverage for 16.1-km time trial and repeated sprint cycling performance

  Summary

  Ten male cyclists completed the same riding test after drinking an oxygen nanobubble beverage and a placebo beverage. Neither cyclists nor researchers knew which beverage was taken, and the order was randomized.

  Key findings

  Completion time was 2.4% shorter (p=0.010), mean power 4.1% higher (p=0.006) and mean peak power over four 30-second sprints 7.1% higher (p=0.002). This was a pilot study of 10 people, and the test beverage was provided by the beverage manufacturer.

  Gas used

  Oxygen

  Bibliographic information

  King et al. · 2023 · Journal of Dietary Supplements 21(2), 167-181 · DOI 10.1080/19390211.2023.2203738

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• Metagenomic analysis of the effect of nanobubble water on gut microbiota composition in mice

  Reported that mice drinking nitrogen or hydrogen nanobubble water for 5 weeks had higher gut microbial diversity than mice drinking deionized water.

  Paper details · Study conditions · Detailed results

  Original title

  Metagenomic insights into the effects of nanobubble water on the composition of gut microbiota in mice

  Summary

  Mice on a standard diet drank nitrogen nanobubble water, hydrogen nanobubble water or deionized water for 5 weeks, and their gut microbiota were analyzed.

  Key findings

  With nitrogen nanobubble water, the proportion of some bacteria (Clostridium, Coprococcus) rose 6.3–9.7 times, and with hydrogen nanobubble water, the proportion of some bacteria fell 60–86%. This animal study examined microbial composition only, not health indicators.

  Gas used

  Nitrogen, hydrogen

  Bibliographic information

  Guo et al. · 2020 · Food & Function 11(8): 7175-7182 · DOI 10.1039/d0fo01592j

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• Nanobubble water supplementation alleviates obesity-related indicators in high-fat-diet mice by modulating gut microbiota

  Reported that high-fat-diet mice drinking nitrogen nanobubble water for 10 weeks had lower serum total cholesterol than those drinking deionized water.

  Paper details · Study conditions · Detailed results

  Original title

  Supplementation with nanobubble water alleviates obesity-associated markers through modulation of gut microbiota in high-fat diet fed mice

  Summary

  High-fat-diet mice drank deionized water, nitrogen nanobubble water or hydrogen nanobubble water for 10 weeks, comparing serum indicators and gut microbiota.

  Key findings

  Mice drinking nitrogen nanobubble water had significantly lower serum total cholesterol, liver enzyme (ALT) and lipopolysaccharide. This animal study observed selected blood biochemistry indicators after nitrogen nanobubble water administration and is distinct from human efficacy data.

  Gas used

  Nitrogen, hydrogen

  Bibliographic information

  Guo et al. · 2020 · Journal of Functional Foods 67, 103820 · DOI 10.1016/j.jff.2020.103820

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Neutral studies 2

• Effect of ultrafine bubble water on gut microbiota composition and health indicators in rats

  Reported that rats drinking ultrafine bubble water for 12 weeks showed more gut metabolites and lower inflammatory markers, but no differences in body weight or intestinal tissue.

  Paper details · Study conditions · Detailed results

  Original title

  Effects of Ultrafine Bubble Water on Gut Microbiota Composition and Health Markers in Rats

  Summary

  Twenty-four rats drank ultrafine bubble water (mean about 168 nm) or ordinary water for 12 weeks, comparing gut microbiota and health indicators.

  Key findings

  Fecal butyrate +56.0% and inflammatory marker (TNF-α) −84.0%, among others, were significant, but major gut bacterial proportions and body weight did not differ. Bubble concentration was raised at week 7, confounding duration and concentration, and all authors are affiliated with a bubble technology supplier.

  Gas used

  Air

  Bibliographic information

  Jackowetz et al. · 2025 · Nanomaterials 15(15): 1193 · DOI 10.3390/nano15151193

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• Radioprotective effect and serum protein response of ultrafine bubble hydrogen water in mice exposed to whole-body irradiation

  Reported that mice drinking ultrafine bubble hydrogen water had higher survival after radiation exposure, while those drinking oxygen water did not differ from tap water.

  Paper details · Study conditions · Detailed results

  Original title

  Radio-protective effects of ultra-fine bubble hydrogen water and serum protein responses in whole-body radiation-exposed mice

  Summary

  Mice drank ultrafine bubble hydrogen water, ultrafine bubble oxygen water or tap water before whole-body X-ray irradiation, comparing 30-day survival and serum proteins.

  Key findings

  At 6.0 Gy, 30-day survival was 100% with hydrogen water and 37% with tap water (P=0.0158). Oxygen water gave 60% at 6.0 Gy and 20% at 6.5 Gy, not significantly different from tap water. Because there was no comparison with bubble-free hydrogen water, the effect of nanobubbles alone cannot be separated. This is an animal study.

  Gas used

  Hydrogen, oxygen

  Bibliographic information

  Yamaguchi et al. · 2025 · Scientific Reports 15(1), 4447 · DOI 10.1038/s41598-025-87963-z

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Skincare & body care

Positive studies 3

• Effect of oxygen nanobubble water on wound healing in WI-38 fibroblasts

  Reported that oxygen nanobubble water increased fibroblast proliferation and migration into the wound area in a concentration-dependent manner.

  Paper details · Study conditions · Detailed results

  Original title

  Oxygen nanobubble water affects wound healing of fibroblast WI-38 cells

  Summary

  Human fibroblasts (WI-38) were treated in vitro with oxygen nanobubble water at 0, 50 and 100% concentration, examining cell count, reactive oxygen species and recovery of scratch wounds.

  Key findings

  There was no cytotoxicity, cell count was highest at 100%, and reactive oxygen species generation was suppressed. Because these are in vitro results in lung fibroblasts, not skin cells, they are not evidence of clinical wound healing, and the authors described the work as a preliminary study.

  Gas used

  Oxygen

  Bibliographic information

  Sofyana et al. · 2023 · Bioscience, Biotechnology, and Biochemistry 87(6): 620-626 · DOI 10.1093/bbb/zbad026

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• Effect of nanobubbles on skin delivery of drugs and cosmetics

  Reported that nanobubbles in oil increased ingredient permeation through a skin-mimicking membrane by about 1.45 times.

  Paper details · Study conditions · Detailed results

  Original title

  Effects of Nanobubbles in Dermal Delivery of Drugs and Cosmetics

  Summary

  Nanobubbles generated in oil were used as a delivery medium for cosmetic ingredients, and their effect was evaluated with artificial membrane permeation tests and pigment cell tests.

  Key findings

  Permeation over 24 hours was 3.00 vs. 2.06 mM, the depigmenting effect of a whitening ingredient (α-bisabolol) was greater with nanobubbles, and there was no cytotoxicity. These are nanobubbles in oil, not water, and the results are not evidence of efficacy on human skin.

  Gas used

  Not stated

  Bibliographic information

  Park et al. · 2022 · Nanomaterials 12(19): 3286 · DOI 10.3390/nano12193286

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• Effect of ultrafine bubble showering on stratum corneum hydration and moisturization

  Reported that stratum corneum hydration after showering with ultrafine bubbles was significantly higher at 15 and 30 minutes than after a tap water shower.

  Paper details · Study conditions · Detailed results

  Original title

  ウルトラファインバブルを含むシャワーの角層水分量・保湿への影響

  English title

  Effect of ultrafine bubble showering on stratum corneum hydration and moisturization

  Summary

  Tap water and ultrafine bubble water at 40 ℃ were each sprayed for 20 seconds on the forearms of 16 healthy adult women, and stratum corneum hydration was measured for up to 30 minutes. Conditions were randomized within each participant.

  Key findings

  With tap water, hydration rose immediately and returned to baseline after 30 minutes, while with ultrafine bubble water it stayed higher at every time point. Two of the three authors are affiliated with the manufacturer of the water heater used in the test. Measurements were short-term, up to 30 minutes.

  Bibliographic information

  Hayasaka et al. · 2023 · 日本健康開発雑誌 44, 55-60 · DOI 10.32279/jjhr.202344G05

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Neutral studies 1

• Beneficial effects of ultrafine bubble showering in mouse models of atopic dermatitis

  Reported that ultrafine bubble showering lowered dermatitis scores in one atopic dermatitis mouse model, with no clear effect in the other.

  Paper details · Study conditions · Detailed results

  Original title

  Beneficial effects of ultrafine bubble shower on a mouse model of atopic dermatitis

  Summary

  Two atopic dermatitis mouse models received a 1-minute ultrafine bubble shower daily for 7–14 days, comparing dermatitis scores, scratching and skin barrier genes.

  Key findings

  In the mite-induced model, dermatitis scores fell (p=0.009) and barrier-related genes increased, but scratching frequency and epidermal thickness did not differ. The other model showed no clear effect. This is an animal study funded in part by a shower head manufacturer.

  Gas used

  Not stated

  Bibliographic information

  Matsumoto et al. · 2024 · Frontiers in Immunology 15: 1483000 · DOI 10.3389/fimmu.2024.1483000

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Others (soil washing, mineral processing, etc.) R&D

Positive studies 3

• Microbubble-assisted enhancement of cleaning diesel-contaminated sand

  Reported that microbubbles made with saline water cleaned 85% of diesel from contaminated sand in 30 minutes.

  Paper details · Study conditions · Detailed results

  Original title

  Enhanced microbubbles assisted cleaning of diesel contaminated sand

  Summary

  Diesel-contaminated sand was cleaned with microbubbles below 50 μm, evaluating the effects of ultrasound, temperature and salinity.

  Key findings

  Diesel removal in 30 minutes was 41–68% with microbubbles alone and 47–76% with ultrasound, and microbubbles made with saline water (599 mM) reached 85% in fine sand. This is a microbubble study in a field at the R&D stage.

  Gas used

  Air

  Bibliographic information

  Agarwal et al. · 2017 · Marine Pollution Bulletin 124(1): 331-335 · DOI 10.1016/j.marpolbul.2017.07.041

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• Flotation of apatite tailings with nanobubbles: a beneficiation approach

  Conditions under which nanobubble-assisted flotation could improve the recovery, grade and selectivity of apatite tailings were evaluated.

  Paper details · Study conditions · Detailed results

  Original title

  Nanobubble-Assisted Flotation of Apatite Tailings: Insights on Beneficiation Options

  Summary

  Air nanobubbles were combined with flotation of apatite tailings to examine changes in recovery and separation performance.

  Key findings

  Results depend heavily on particle size, collector and bubble generation conditions, and are not guaranteed performance in a continuous commercial process. The field is at the R&D stage.

  Gas used

  Air

  Bibliographic information

  Chipakwe et al. · 2021 · ACS Omega 6(21):13888–13894 · DOI 10.1021/acsomega.1c01551

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• Nanobubble generation and its application in froth flotation (Part IV): coal flotation in mechanical cells and a specially designed column

  Reported that coal flotation with nanobubbles raised coal recovery at the same grade by about 8–27%.

  Paper details · Study conditions · Detailed results

  Original title

  Nanobubble generation and its applications in froth flotation (part IV): mechanical cells and specially designed column flotation of coal

  Summary

  Coal was separated with nanobubbles in mechanical flotation cells and a specially designed column.

  Key findings

  Results are for specific coal and particle size conditions and cannot be applied directly to other minerals. The field is at the R&D stage.

  Gas used

  Air

  Bibliographic information

  Fan · 2010 · Mining Science and Technology (China) 20(5) · DOI 10.1016/S1674-5264(09)60259-3

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