We are now realizing fantastic properties of tiny bubbles; microbubble can contribute to wastewater treatment and semiconductor cleaning, and nanobubbles activate fishes and plants. Microbubbles are gas bubbles less than 50 micrometer in diameter and shrink underwater due to the rapid dissolution of the interior gas. And it has been demonstrated that the bubbles can generate free radicals during the collapsing process under water. This is a very effective property of the tiny bubbles for surface cleaning in a wide variety of technical fields, including semiconductor manufacturing and textile industries. And we are also recognizing fantastic properties of nanobubbles. Nanobubbles may be defined as microbubble residues stabilized by the effect of condensed ionic cloud around the gas-water interface at the final stage of the collapsing process. In this article the author also introduces an example of cleaning by nanobubbles. In the cutting and polishing industry they are now trying to use a new type of cutting fluid containing nanobubble water, and it has turned out that the cutting machines was cleaned by the effect of scattered cutting fluid. For further development as a new cleaning technology, it is necessary to clarify the functional mechanism of nanobubble water.

Fine bubble (“FB” hereafter) water, an aqueous solution containing gases such as ozone and oxygen, is able to contain more gas when it is in the supersaturated state. This characteristic lends promise as a revolutionary kind of functional water with applications in the washing field. In particular, ozone FB water, which reported to provide powerful antiseptic effects, has entered real-world use to replace chlorine-based agents for washing vegetables and cleaning toilets. The present report explains the detergency effects of FB water by measuring cleanliness and detergency rates of the selected model soiling, using the removal of ATP (adenosine triphosphate) as an index, as part of efforts to advance the application of FB water to water-based washing. In addition, we will introduce the effects of varying ozone concentrations and effects when combined with surfactants and the soil removal capacity of ozone FB water. In addition, we will introduce the effects of varying ozone concentrations, and effects when combined with surfactants and compared the soil removal capacity of ozone FB water.

Fine bubble and ozone fine-bubble were used for textile dyeing process. Dyeing of woolen fabric using fine-bubble water showed shortening of dyeing time and darkening, though slightly. In the scouring of woolen fabric, ozone fine bubble water was used to lower the treatment temperature and shorten the processing time. In cotton fabric, ozone fine-bubble water can be used for bleaching. Ozone gas is easy to dissolve in low-temperature water, but maintaining the pH at 5 even at room temperature and adding the electrolyte component at about 0.03 mol / L makes it possible to obtain the same degree of whiteness as that of conventional method. Bleaching with ozone fine-bubbles does not require heating the treated water. In addition, the amount of chemicals to be used can be greatly reduced. The use of ozone fine-bubble technique can be said to be an environmentally friendly treatment method.

Characteristics of flow behavior of fine-bubble (microbubble and nanobubble) mixture water were studied. A reduction of pressure losses was observed for under the sheer flow and the vertical flow of fine-bubble mixture waters compared with ion-exchanged water. These results were very similar to surfactant solutions, so both liquids were increased mobility through the small spaces such as between clothing threads, as a result to these drag-reducing characteristics. And application of fine-bubble mixture water to dye the cloths, especially vegetable (herb) dyeing, it was more useful for deep color using of fine-babble mixture water compared with ion-exchanged water. Then, fine-bubble mixture waters are contribute to the efficient use of water, low energy, and low environmental loads.