Active oxygen treatment device, treatment method using active oxygen, and ozone UFB-containing liquid production device

Abstract

This active oxygen treatment device can more surely treat a surface of an object to be treated using active oxygen. The present invention comprises: an ozone UFB-containing liquid production unit that produces an ozone UFB-containing liquid in which UFBs including ozone are contained in a liquid; a first storage unit that stores the ozone UFB-containing liquid; an energy imparting device that imparts, to the ozone UFB-containing liquid stored in the first storage unit, energy necessary for decomposing at least part of ozone included in the UFBs into active oxygen to decompose at least part of ozone into active oxygen; and an active oxygen UFB-containing liquid supplying device that decomposes at least part of ozone in the UFBs into active oxygen by imparting the energy, thereby supplying, to an object to be treated, an active oxygen UFB-containing liquid which is generated in the first storage unit and in which UFBs including active oxygen are contained in a liquid.

Description

Active oxygen treatment device, active oxygen treatment method, and ozone UFB-containing liquid manufacturing device

[0001] The present disclosure relates to an active oxygen treatment device and an active oxygen treatment method using ultra-fine bubbles containing ozone, and also to an ultra-fine bubble generator containing ozone.

[0002] Patent Document 1 relates to a disinfectant generating device and a disinfectant generating method that generate a disinfectant that can provide sufficient disinfecting and sterilizing effects using a liquid containing ozone ultrafine bubbles (hereinafter also referred to as "UFB").

[0003] Patent Document 1 discloses a disinfectant generating device including an ozone-UFB-containing liquid producing unit that produces an ozone-UFB-containing liquid containing ozone UFB in a liquid, a mist generating unit that generates a mist of the ozone-UFB-containing liquid, and an energy irradiating unit that irradiates the mist of the ozone-UFB-containing liquid. Patent Document 1 also discloses a disinfectant generating method that includes an ozone-UFB-containing liquid preparation step that prepares an ozone-UFB-containing liquid containing ozone UFB in a liquid, a mist generating step that generates a mist of the ozone-UFB-containing liquid, and an energy irradiating step that irradiates the mist of the ozone-UFB-containing liquid with energy.

[0004] Paragraph

[0048] of Patent Document 1 describes that by irradiating a mist of ozone UFB-containing liquid with ultraviolet light, the ultrafine ozone bubbles contained in the mist particles are broken down, accelerating the decomposition of ozone and generating hydroxyl radicals. It also describes that the mist disinfectant containing these hydroxyl radicals is supplied to a target, and disinfection or sterilization is carried out by the oxidizing action of the hydroxyl radicals.

[0005] Furthermore, Patent Document 2 describes a method for producing an ozone-containing ultra-fine bubble-containing liquid, which includes a step of irradiating an ultra-fine bubble liquid with ultraviolet light.

[0006] JP 2022-036815 A JP 2023-058216 A

[0007] The present inventors have studied the disinfectant generated by the disinfectant generator disclosed in Patent Document 1. As a result, the disinfecting effect of this disinfectant is limited, and there is still room for improvement. Furthermore, according to the study by the present inventors, the disinfecting effect of the ozone-containing ultra-fine bubble liquid disclosed in Patent Document 2 is also limited.

[0008] At least one aspect of the present disclosure is directed to providing an active oxygen treatment device that can more reliably treat the surface of a workpiece with active oxygen. Also, at least one aspect of the present disclosure is directed to providing an active oxygen treatment method that can more reliably treat the surface of a workpiece with active oxygen.

[0009] According to at least one aspect of the present disclosure, there is provided an active oxygen treatment apparatus comprising: an ozone-UFB-containing liquid production unit that produces an ozone-UFB-containing liquid in which ultrafine bubbles containing ozone are contained in a liquid; a first storage unit that stores the ozone-UFB-containing liquid; an energy imparting device that imparts to the ozone-UFB-containing liquid stored in the first storage unit energy required to decompose at least a portion of the ozone contained in the ultrafine bubbles into active oxygen, thereby decomposing at least a portion of the ozone into active oxygen; and an active oxygen-UFB-containing liquid supplying device that supplies to a workpiece the active oxygen-UFB-containing liquid in which ultrafine bubbles containing active oxygen are contained in a liquid, the active oxygen-UFB-containing liquid having been produced in the first storage unit by decomposing at least a portion of the ozone in the ultrafine bubbles into active oxygen through the imparting of energy.

[0010] According to at least one aspect of the present disclosure, there is provided a treatment method using active oxygen, comprising: (1) an ozone-UFB-containing liquid production step of producing an ozone-UFB-containing liquid containing ozone-UFB-containing ultrafine bubbles contained in a liquid; (2) a storage step of storing the produced ozone-UFB-containing liquid in a first storage unit; (3) a step of applying energy to the ozone-UFB-containing liquid stored in the first storage unit to decompose at least a portion of the ozone contained in the ultrafine bubbles into active oxygen, thereby decomposing at least a portion of the ozone into active oxygen, thereby preparing an active oxygen-UFB-containing liquid containing ultrafine bubbles containing the active oxygen contained in the liquid; and (4) an active oxygen-UFB-containing liquid supply step of supplying the active oxygen-UFB-containing liquid stored in the first storage unit to an object to be treated.

[0011] According to at least one aspect of the present disclosure, there is provided an ozone UFB-containing liquid generating apparatus for generating an ozone UFB-containing liquid in which ultrafine bubbles containing ozone are contained in a liquid, the ozone UFB-containing liquid generating apparatus comprising: a liquid storage section for storing a liquid, the liquid storage section comprising: a UFB generating apparatus for producing a UFB-containing liquid in which the liquid stored in the liquid storage section contains the ultrafine bubbles; and a plasma actuator, the plasma actuator having a first electrode and a second electrode sandwiching a dielectric, and generating an induced flow containing the ozone by applying a voltage between the first electrode and the second electrode, and the plasma actuator being positioned so that the induced flow flows inside the liquid storage section.

[0012] According to at least one aspect of the present disclosure, it is possible to obtain an active oxygen treatment device that can more reliably treat the surface of a workpiece with active oxygen. Also, according to at least one aspect of the present disclosure, it is possible to obtain an active oxygen treatment method that can more reliably treat the surface of a workpiece with active oxygen.

[0013] FIG. 1 is a schematic diagram of an active oxygen treatment device according to one embodiment of the present disclosure. FIGS. 2A and 2B are schematic diagrams of an active oxygen treatment device according to one embodiment of the present disclosure. FIG. 3 is a schematic diagram of an active oxygen treatment device according to one embodiment of the present disclosure. FIGS. 4A and 4B are schematic diagrams showing the configuration of a plasma actuator. FIG. 5 is an explanatory diagram of a plasma actuator. FIGS. 6A and 6B are schematic diagrams of an active oxygen treatment device according to one embodiment of the present disclosure. FIG. 7 is a schematic diagram of an active oxygen treatment device according to one embodiment of the present disclosure. FIG. 8 is a schematic diagram of an ozone UFB-containing liquid production apparatus according to one embodiment of the present disclosure. FIG. 9 is a schematic diagram of an active oxygen treatment device according to one embodiment of the present disclosure. FIGS. 10A and 10B are schematic diagrams of an active oxygen treatment device in an example. FIG. 11 is a schematic diagram of an ultraviolet lamp. FIG. 12 is a schematic diagram of an active oxygen treatment device in Comparative Example 2. FIG. 13 is a schematic diagram of an active oxygen treatment device in Comparative Example 3. FIG. 14 is an ESR spectrum of the active oxygen UFB-containing liquid in Example 1.

[0014] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined arbitrarily. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ.

[0015] In this disclosure, "ultrafine bubbles" refers to minute bubbles contained in a liquid with a diameter of less than 1 μm, particularly with a diameter of about 10 to 500 nm. Hereinafter, "ultrafine bubbles" may be referred to as "UFB." In this disclosure, active oxygen refers to, for example, ozone (O ３ ) is decomposed to produce superoxide (.O ２ － ), including free radicals such as the hydroxyl radical (.OH).

[0016] In the present disclosure, the "treatment" of an object to be treated with active oxygen includes any treatment that can be achieved with active oxygen, such as surface modification of the surface to be treated of the object to be treated with active oxygen (hydrophilization treatment), sterilization, deodorization, and bleaching.

[0017] Furthermore, the term "bacteria" as used herein to refer to microorganisms to be sterilized refers to microorganisms, including fungi, bacteria, unicellular algae, viruses, protozoa, and the like, as well as animal or plant cells (including stem cells, dedifferentiated cells, and differentiated cells), tissue cultures, fused cells (including hybridomas) obtained by genetic engineering, dedifferentiated cells, and transformants (microorganisms). Examples of viruses include norovirus, rotavirus, influenza virus, adenovirus, coronavirus, measles virus, rubella virus, hepatitis virus, herpes virus, and HIV virus. Examples of bacteria include Staphylococcus aureus, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Vibrio cholerae, Shigella, Bacillus anthracis, Mycobacterium tuberculosis, Clostridium botulinum, Clostridium tetani, and Streptococcus. Examples of fungi include Trichophyton, Aspergillus, and Candida.

[0018] The inventors speculate that the reason for the insufficient performance of the disinfectant disclosed in Patent Document 1 in disinfection and sterilization processes is as follows: The disinfectant disclosed in Patent Document 1 is generated by irradiating a mist of ozone-UFB-containing liquid with energy. However, even when energy is irradiated onto the mist of ozone-UFB-containing liquid, it is believed that sufficient energy is not necessarily imparted to each particle of the mist of ozone-UFB-containing liquid. Therefore, the decomposition of ozone contained in UFB into hydroxyl radicals is insufficient, and a significant portion of the treatment effect of the disinfectant disclosed in Patent Document 1 is believed to be due to ozone. Therefore, it is believed that the treatment performance of the disinfectant disclosed in Patent Document 1 was limited.

[0019] Based on these considerations, the inventors of the present invention have conducted further studies and found that by storing an ozone-UFB-containing liquid containing ozone-containing UFB in a storage section and applying energy to the stored ozone-UFB-containing liquid, the ozone trapped in the UFB can be more reliably decomposed into active oxygen. Here, the stored state refers to a state in which there is no inflow of liquid into the storage section or outflow of liquid from the storage section.

[0020] By imparting energy to the ozone-UFB-containing liquid stored in the storage section, the ozone contained in the UFB can be more reliably decomposed into active oxygen, and the concentration of the active oxygen UFB can be increased. When imparting energy to the stored ozone-UFB-containing liquid, it is preferable to flow the ozone-UFB-containing liquid in the storage section by stirring or the like to the extent that the UFB is not excessively destroyed, because this allows sufficient energy to be imparted to each of the ozone-UFB.

[0021] Furthermore, the ozone UFB liquid generator described in paragraphs

[0037] to

[0038] and Figure 6 of Patent Document 2 includes a gas dissolution tank, a UFB generation unit, an ultraviolet light, a recovery unit, and a storage unit. In this ozone UFB liquid generator, the UFB liquid discharged from the UFB generation unit is recovered in the recovery unit and sent to the storage unit, and ultraviolet light is irradiated onto the UFB liquid stored in the storage unit. The document describes that ozone is thereby generated in the UFB liquid in the storage unit, turning it into an ozone-containing UFB liquid.

[0022] Furthermore, the ozone UFB liquid generator described in paragraphs

[0040] to

[0042] and Figure 7 of Patent Document 2 also includes a gas dissolution tank, a UFB generation unit, an ultraviolet light, a recovery unit, and a storage unit. In this ozone UFB liquid generator, an ultraviolet light is provided in the recovery unit, and the UFB liquid discharged from the UFB generation unit and recovered in the recovery unit is irradiated with ultraviolet light by the ultraviolet light within the recovery unit. As a result, the ozone-containing UFB liquid in which ozone has been generated is sent to the storage unit and stored therein.

[0023] According to the study by the present inventors, the active oxygen UFB-containing liquid according to one embodiment of the present disclosure has a significantly superior sterilization performance compared to the ozone-containing UFB liquid according to Patent Document 2. The reasons for this are considered to be as follows.

[0024] That is, in the ozone UFB liquid production method according to Patent Document 2, it is described that by irradiating the UFB liquid with ultraviolet light, oxygen in the oxygen atmosphere and in the liquid absorbs the ultraviolet light, dissociates into oxygen atoms, and the oxygen atoms combine with oxygen molecules to generate ozone, which is then recovered as an ozone-containing UFB liquid (see paragraph

[0018] of Patent Document 2). In other words, in the method according to Patent Document 2, it is believed that ozone is produced in the UFB for the first time by irradiating it with ultraviolet light.

[0025] On the other hand, in at least one aspect of the present disclosure, an ozone-UFB-containing liquid containing ozone-encapsulated UFB is prepared in advance, and energy is imparted to the ozone-UFB-containing liquid while the ozone-UFB-containing liquid is stored in a storage section. This is thought to produce an active oxygen-UFB-containing liquid in which a higher concentration of active oxygen is encapsulated in the UFB. As a result, the active oxygen-UFB-containing liquid according to one aspect of the present disclosure is thought to be able to exhibit higher sterilization performance than the ozone-containing UFB liquid according to Patent Document 2.

[0026] Hereinafter, specific examples of embodiments for carrying out this disclosure will be described with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in these embodiments can be changed as appropriate depending on the configuration of the member to which the disclosure is applied and various conditions. In other words, it is not intended to limit the scope of this disclosure to the following embodiments.

[0027] FIG. 1 is a schematic diagram of an active oxygen treatment apparatus 100 according to at least one embodiment of the present disclosure. The active oxygen treatment apparatus 100 includes an ozone-UFB-containing liquid production unit 101 (hereinafter also referred to as the "production unit") that produces a liquid (hereinafter also referred to as an "ozone-UFB-containing liquid") containing UFB with ozone trapped therein (hereinafter also referred to as "ozone-UFB"). The active oxygen treatment apparatus 100 includes an opening / closing device 102 that allows the flow of liquid from a liquid supply source (not shown) to the production unit 101 through a flow path connecting the production unit 101 to the supply source and blocks the flow of liquid. The active oxygen treatment apparatus 100 also includes a first storage unit 103 that stores the ozone-UFB-containing liquid produced in the production unit 101, and an energy application device 104 for the ozone-UFB-containing liquid stored in the first storage unit 103.

[0028] The energy imparting device imparts energy to the ozone UFB-containing liquid stored in the first storage section 103, decomposing at least a portion of the ozone contained in the UFB into active oxygen, thereby generating a liquid (hereinafter also referred to as an "active oxygen UFB-containing liquid") containing UFB (hereinafter also referred to as an "active oxygen UFB-containing liquid") containing active oxygen therein. The active oxygen treatment device 100 further includes an active oxygen UFB-containing liquid supply device (hereinafter also referred to as a "supply device") 105 that supplies the active oxygen UFB-containing liquid generated in the first storage section 103 toward the workpiece (not shown).

[0029] An opening / closing device 107-1 that allows the liquid to flow between the production unit 101 and the first storage unit 103 and blocks the flow of the liquid is provided in the flow path connecting the production unit 101 and the first storage unit 103. In addition, an opening / closing device 107-2 that allows the liquid to flow between the first storage unit 103 and the supply unit 105 and blocks the flow of the liquid is provided in the flow path connecting the first storage unit 103 and the supply unit 105.

[0030] These opening and closing devices 107-1 and 107-2 make it possible to control the inflow of liquid into first storage section 103 and the outflow of liquid from first storage section 103. Specifically, they are configured to be able to individually stop the outflow of liquid into first storage section 103 and the outflow of liquid from first storage section 103. Therefore, it is possible to store liquid in first storage section 103.

[0031] An example of a treatment method using the active oxygen treatment apparatus shown in Fig. 1 will be described. First, the opening and closing device 102 is opened, and liquid is introduced into the production section 101 from the liquid supply source. Next, with the opening and closing device 102 and the opening and closing device 107-1 closed, a liquid containing ultrafine bubbles (UFB-containing liquid) is generated in the presence of ozone in the production section 101. This generates a liquid containing ozone UFB, which contains ozone in UFB (ozone UFB-containing liquid) in the production section 101.

[0032] Next, with the opening and closing device 107-2 closed, the opening and closing device 107-1 is opened to move a predetermined amount of the ozone UFB-containing liquid produced in the production unit 101 to the first storage unit 103. Thereafter, the opening and closing device 107-1 is closed to store the ozone UFB-containing liquid in the first storage unit 103.

[0033] Next, the energy imparting device 104 built into the first storage unit 103 is operated to decompose at least a portion of the ozone contained in the UFB into active oxygen, thereby generating a liquid containing the active oxygen-containing UFB (active oxygen-containing UFB-containing liquid). Here, it is important to impart sufficient energy to the ozone UFB-containing liquid stored in the storage unit 103 to reliably convert the ozone UFB into active oxygen UFB.

[0034] Next, the opening and closing device 107-2 is opened to supply the active oxygen UFB-containing liquid to the supply device 105, and the supply device 105 is operated to apply the active oxygen-containing UFB-containing liquid in the storage section 103 to the object to be treated (not shown). Then, the object to be treated to which the active oxygen-containing UFB-containing liquid has been supplied is treated by the active oxygen in the UFB.

[0035] <Specific Configuration of Active Oxygen Treatment Device> A more specific configuration example of the active oxygen treatment device 100 according to one embodiment of the present disclosure will be described with reference to Figures 2A and 2B. The ozone UFB-containing liquid production unit (hereinafter also simply referred to as the "production unit") 101 of the active oxygen treatment device 100 shown in Figures 2A and 2B includes a UFB generator 109 that produces a UFB-containing liquid from a liquid 113, such as water, stored therein, and an ozone generator 111 that supplies ozone to the production unit 101. The active oxygen treatment device also includes an openable / closable device 102 that can block a liquid supply path 102-1 from a liquid supply source (not shown) to the inside of the production unit 101. As shown in Figure 2A, the production unit 101 is capable of storing the liquid 113 therein, and includes the UFB generator 109 and the ozone generator 111 therein.

[0036] The UFB generator 109 is not particularly limited, and any device capable of generating UFB in a liquid by known means such as ultrasonic waves, shearing, or pressure dissolution may be used. The UFB generator 109 preferably includes an ultrasonic vibrator capable of spraying a mist containing UFB in a liquid into the internal space of the production section 101. Specifically, the UFB generator 109 may be, for example, an ultrasonic atomizer equipped with an ultrasonic vibrator. The ultrasonic atomizer includes, for example, a control board and an ultrasonic vibrator connected to the board by wiring. The ultrasonic vibrator is made of a material such as ABS resin, silicone resin, or ceramics. As an example, the ceramic ultrasonic vibrator portion is a disc-shaped sheet having a diameter of preferably 10 to 1000 mm, particularly preferably 10 to 100 mm, and a thickness of preferably 0.5 to 10 mm, and is provided with countless minute holes, for example, with a diameter of approximately 1 to 10 μm, that are connected in the thickness direction. This ceramic ultrasonic vibrator is made of a piezoelectric material, so when a voltage is applied, ultrasonic vibrations are generated.

[0037] When ultrasonic waves are generated with the back surface of the ultrasonic vibrator in contact with the liquid surface, the liquid is sucked up into the micropores, passes through the micropores, and is ejected as fine droplets (mist) from the top surface of the ultrasonic vibrator. Furthermore, as the liquid passes through the micropores, pressure is applied to the liquid by the vibration of the ultrasonic vibrator, and the surrounding gas is taken in by the liquid, so that the ejected droplets contain the fine gas. In other words, the droplets contain UFB.

[0038] The resonant frequency of the ultrasonic vibrator is not particularly limited, but is preferably 50 kHz or higher, more preferably 100 kHz or higher. The upper limit is also not particularly limited, but is preferably 3 MHz or lower, more preferably 2 MHz or lower. A preferred range for the resonant frequency of the ultrasonic vibrator is 50 kHz or higher and 3 MHz or lower, particularly 100 kHz or higher and 3 MHz or lower. By setting the resonant frequency to 50 MHz or higher, the droplets sprayed into the internal space of the production section 101 can be converted into a nano-sized to micron-sized mist having a droplet diameter of, for example, 10 nm to 10 μm. By converting the droplets formed in the internal space into a nano-sized mist, the time during which the droplets can exist as droplets in the internal space can be extended, thereby further increasing the ozone concentration in the UFB. Note that, as the resonant frequency increases, the size of the mist can be reduced and the number concentration of the mist can be increased. The input intensity to the ultrasonic vibrator is also not particularly limited, but can be, for example, 0.1 to 10.0 W / cm. ２ It is preferable that the input intensity is increased. By increasing the input intensity, the number concentration of the mist can be increased. As the ultrasonic atomizer, a commercially available product can also be used.

[0039] In addition, when the bubbles in the droplets are relatively large, the bubbles are unstable and the gas is easily released from the droplets. However, when the bubbles in the droplets exist as UFB, the UFB is stable and remains incorporated into the droplets, and is ejected as a UFB-containing mist. In addition, for example, when adjacent sprayed fine droplets come into contact with each other and aggregate, they can incorporate bubbles of the same diameter as the droplets themselves, thereby forming a UFB-containing mist. The process of forming the UFB-containing mist is not limited.

[0040] The ozone generator 111 will now be described. The ozone generator generates ozone (O ３ There are no particular limitations on the ozone generator as long as it can generate ozone, and a commercially available ozone generator can be used. The ozone generator 111 may be arranged inside the production unit 101 as shown in FIG. 2A, and ozone may be generated inside the production unit 101 to supply ozone to the production unit. Alternatively, as shown in FIG. 3, the ozone generator may be arranged outside the production unit 101, and ozone generated outside the production unit 101 may be supplied to the production unit 101. A commercially available ozone generator 111 may be used.

[0041] It is preferable to use a plasma actuator (hereinafter, also referred to as "PA") as the ozone generator 111. The plasma actuator will be described later.

[0042] The method for obtaining the ozone UFB-containing liquid is not particularly limited. For example, by allowing ozone generated from the ozone generator 111 to exist in the space inside the production unit 101 where the UFB generator 109 is present, an ozone UFB-containing liquid containing ozone in the UFB can be obtained. Specifically, for example, when the above-mentioned ultrasonic sprayer is used as the UFB generator 109, the ozone from the ozone generator 111 is present in the internal space of the production unit 101, and droplets (mist) of the UFB-containing liquid are generated in the internal space where the ozone exists, thereby producing the ozone UFB-containing liquid. The reason for this is thought to be that by allowing the mist of the UFB-containing liquid to exist in the space inside the production unit 101 containing ozone, ozone is taken into the UFB. As mentioned above, when droplets are generated from the ultrasonic vibrator, the liquid absorbs the surrounding gas and is converted into droplets, and since this gas contains ozone, it is thought that the UFB in the droplets generated by the operation of the ultrasonic vibrator already contains ozone. Furthermore, the droplets of the ozone UFB-containing liquid generated in the internal space of the production section 101 are mixed with water stored in the lower part of the production section 101 and are repeatedly sprayed as droplets into the internal space by an ultrasonic sprayer, thereby making it possible to produce an ozone UFB-containing liquid containing ozone at a higher concentration.

[0043] Furthermore, for example, a particularly preferred embodiment of the method for producing an ozone UFB-containing liquid is a method in which a plasma actuator (described later) is disposed in the internal space of the production unit 101, and an induced flow from the plasma actuator is arranged to flow through the space, thereby causing droplets of the UFB-containing liquid generated by the ultrasonic vibrator to be taken into the induced flow. Details will be described later.

[0044] The type of liquid used as a raw material for the UFB-containing liquid is not particularly limited, but it preferably contains water, and water is more preferred. When using water, pure water or ultrapure water that does not contain impurities that may affect the size of the droplets can also be used. In addition to water, additives such as pH adjusters and surfactants, as well as organic solvents, may be added within a range that does not impair the effects of the present disclosure. Examples of organic solvents include alcohols such as ethanol. When water is used as the liquid, the pH is preferably 1.0 to 7.0, and more preferably 1.0 to 5.0. By keeping the pH within the above range, UFB can be stably maintained in the ozone UFB-containing liquid for a longer period of time. As a result, the processing capacity using active oxygen can be further improved.

[0045] The content of UFB with a bubble diameter of 500 nm or less per unit volume in the ozone UFB-containing liquid is preferably 1.0 × 10 ６ ~1.0 x 10 １０ cells / mL, more preferably 1.0 x 10 ７ ~1.0 x 10 ９ cells / mL, and more preferably 1.0 x 10 ８ ~1.0 x 10 ９ When the concentration is in the above range, the processing ability of active oxygen can be further improved.

[0046] The content of UFB in the ozone UFB-containing solution can be increased, for example, by increasing the partial pressure of ozone in the region where ozone is present in the internal space of the production section 101, or by increasing the input intensity to the ultrasonic vibrator to reduce the size of the mist. The content of ultrafine bubbles can be measured using a nanoparticle size distribution measuring device that uses laser scattering and diffraction. This will be described in detail later.

[0047] The number-average bubble diameter of UFB in the ozone-UFB-containing solution is preferably 10 to 300 nm, more preferably 20 to 200 nm. The above range contributes to further improving the stability of UFB in the ozone-UFB-containing solution. For example, when an ultrasonic vibrator is used for production, the number-average bubble diameter of ultra-fine bubbles can be increased by using one with a low resonant frequency. For example, when an ultrasonic vibrator is used for production, the number-average bubble diameter of UFB can be reduced by using one with a high resonant frequency to reduce the mist size, thereby also reducing the UFB contained in the mist. The preferred resonant frequency of the ultrasonic vibrator is as described above. The number-average bubble diameter of ultra-fine bubbles can be measured using a nanoparticle size distribution measurement device that utilizes laser scattering and diffraction. Specific details will be described later.

[0048] The pH of the ozone UFB-containing solution is preferably 1.0 to 7.0, more preferably 1.0 to 5.0. By keeping the pH in this range, the ozone UFB can be easily retained, and as a result, the treatment capacity by active oxygen can be further improved.

[0049] The ozone concentration in the ozone UFB-containing solution is preferably 0.1 to 20.0 mg / L, more preferably 0.5 to 15.0 mg / L, and even more preferably 2.0 to 15.0 mg / L. By keeping the ozone concentration in the above range, the treatment capacity by active oxygen can be further improved.

[0050] It is preferable to use at least a plasma actuator as the ozone generator 111. The plasma actuator will be described below.

[0051] <Plasma Actuator> A plasma actuator has a first electrode and a second electrode sandwiching a dielectric, and is capable of generating an induced flow containing ozone by applying a voltage between the two electrodes.

[0052] FIG. 4A shows the cross-sectional structure of one embodiment of a plasma actuator 400. The plasma actuator is a so-called dielectric barrier discharge (DBD) plasma actuator (hereinafter, sometimes simply referred to as a "DBD-PA"), in which a first electrode 203, which is an exposed electrode with an end face exposed on one surface (hereinafter, also referred to as the "first surface") of a dielectric 201, is provided, and a second electrode 205 is provided on the surface opposite the first surface (hereinafter, also referred to as the "second surface"). In FIGS. 4A and 4B, reference numeral 206 denotes a dielectric substrate for burying the second electrode 205 in the thickness direction of the plasma actuator so as to prevent induced current from occurring from the end face of the second electrode. Furthermore, a voltage can be applied to the first electrode and the second electrode by a power source 207.

[0053] In the plasma actuator 400, a first electrode 203 and a second electrode 205 are disposed on either side of a dielectric 201, and are arranged diagonally offset from each other. By applying a voltage from a power source 207 between the first electrode 203 and the second electrode 205 (between the two electrodes), a dielectric barrier discharge is generated from the first electrode 203 toward the second electrode 205, and a jet-like flow of surface plasma 202 is induced from the edge 204 of the first electrode 203 along the exposed portion 201-1 of the first surface of the dielectric 201 (the portion not covered by the first electrode). A suction flow of air is also generated from the surrounding space toward the electrode 203. Electrons in the surface plasma 202 collide with oxygen molecules in the air, dissociating the oxygen molecules and generating oxygen atoms. The resulting oxygen atoms collide with undissociated oxygen molecules, generating ozone. Therefore, due to the action of the jet-like flow caused by the surface plasma 202 and the suction flow of air, an induced flow 209 containing a high concentration of ozone is generated from the edge 204 of the first electrode 203 along the exposed portion 201-1 of the surface of the dielectric 201.

[0054] That is, the PA 400 is formed by laminating a first electrode 203, a dielectric 201, and a second electrode 205 in this order, and the first electrode 203 is an exposed electrode provided on a first surface, which is one surface of the dielectric 201. When a voltage is applied between the first electrode 203 and the second electrode 205, the PA generates a dielectric barrier discharge from the first electrode 203 to the second electrode 205, and ejects an induced flow, which is a unidirectional jet, from the first electrode 203 along a first direction (the direction of arrow X in FIG. 4A ), which is a direction along the first surface 201-1 of the dielectric 201.

[0055] In addition, in one cross section of the PA in the thickness direction, the second electrode 205 is present extending in the blowing direction (first direction) of the induced flow. More specifically, in a cross section of the PA in the direction along the first direction-thickness direction of the PA, the first electrode 203 and the second electrode 204 are arranged diagonally offset from each other with the dielectric 201 interposed therebetween. The first electrode 203 is provided so as to cover a part of the first surface of the dielectric 201, and at least a part of the first surface of the dielectric 201 constitutes an exposed portion 201-1 that is not covered by the first electrode 203.

[0056] 4B is a perspective view of the plasma actuator from the first surface side of the dielectric. At least a portion of exposed portion 201-1 overlaps with second electrode 205, which is shown by the dashed line. Therefore, the overlap is the region formed by the upper, lower, and right sides of the dashed line indicating electrode 205 in FIG. 4B and edge portion 204.

[0057] <Electrodes and Dielectrics> The materials constituting the first electrode and the second electrode are not particularly limited as long as they are materials with good conductivity. For example, metals such as copper, aluminum, stainless steel, gold, silver, platinum, etc., and their plated or vapor-deposited counterparts, conductive carbon materials such as carbon black, graphite, and carbon nanotubes, and composite materials obtained by mixing these with resins, etc., can be used. The materials constituting the first electrode and the second electrode may be the same or different.

[0058] Among these, from the viewpoint of avoiding electrode corrosion and achieving uniform discharge, the material constituting the first electrode is preferably copper, aluminum, stainless steel, or silver, and for the same reason, the material constituting the second electrode is preferably copper, aluminum, stainless steel, or silver.

[0059] The shapes of the first electrode and the second electrode can be flat, wire-like, needle-like, or the like, without any particular limitations. Preferably, the first electrode is flat. Preferably, the second electrode is flat. When at least one of the first electrode and the second electrode is flat, the aspect ratio (length of long side / length of short side) of the flat plate is preferably 2 or more. The dielectric is not particularly limited as long as it is a material with high electrical insulation. For example, resins such as polyimide, polyester, fluororesin, silicone resin, acrylic resin, and phenolic resin, glass, ceramics, and composite materials obtained by mixing these with resins, etc., can be used. Among these, ceramics and glass, which exhibit excellent flame retardancy, are preferred.

[0060] 5 is an explanatory diagram of the overlap between the first electrode 203 and the second electrode 205 of the plasma actuator 400, which is an ozone generator. It is a cross-sectional view of the plasma actuator. When viewed from above in the cross-sectional view, the first electrode 203 and the second electrode 205 are arranged diagonally opposite each other, and the edge of the first electrode may be present in the portion where the second electrode is formed, with a dielectric sandwiched between them. In other words, the first electrode and the second electrode may be arranged to overlap with the dielectric sandwiched between them. In this case, it is preferable to prevent dielectric breakdown when a voltage is applied in the portion where the first electrode and the second electrode overlap with the dielectric sandwiched between them.

[0061] Furthermore, when the first electrode and the second electrode are spaced apart as viewed from above in the cross section, it is preferable to increase the voltage to compensate for the weakening of the electric field caused by the increased distance between the electrodes. It is more preferable that the overlap between the edge of the first electrode and the edge of the second electrode is −100 μm to +1000 μm as viewed from above in the cross section, assuming that the overlap length is positive.

[0062] The thickness of the electrodes is not particularly limited for either the first electrode or the second electrode, but can be 10 μm to 1000 μm. If the thickness is 10 μm or more, the resistance is low and plasma generation becomes easier. If the thickness is 1000 μm or less, electric field concentration occurs easily, making plasma generation easier.

[0063] The width of the electrodes is not particularly limited for both the first electrode and the second electrode, but can be 1000 μm or more.

[0064] Furthermore, if the edge of the second electrode is exposed, plasma may also be generated from the edge of the second electrode, resulting in an induced flow in the opposite direction to the induced flow 209 originating from the first electrode. In the active oxygen supplying device according to this embodiment, it is preferable to keep the ozone concentration in the internal space of the active oxygen supplying device, other than the surface region of the workpiece, as low as possible. It is also preferable to prevent a gas flow that would disrupt the induced flow 209 from being generated within the container. Therefore, it is preferable to prevent an induced flow originating from the second electrode from being generated. Therefore, it is preferable that the second electrode 205 be covered with a dielectric such as a dielectric substrate 206, as shown in FIGS. 4A and 5 , or embedded in a dielectric 201, to prevent plasma generation from the edge of the second electrode.

[0065] The induced flow 209 containing high-concentration ozone flows in the direction of a jet-like flow caused by surface plasma from the edge 204 of the first electrode 203 along the exposed portion 201-1 of the first surface of the dielectric 201, that is, in the direction from the edge 204 of the first electrode 203 along the exposed portion 201-1 of the first surface of the dielectric. This induced flow is a gas flow containing a high concentration of ozone, with a speed of several m / s to several tens of m / s. The voltage applied between the first electrode 203 and the second electrode 205 of the plasma actuator is not particularly limited as long as it can generate plasma in the plasma actuator. Furthermore, either a DC voltage or an AC voltage may be used, but an AC voltage is preferred. It is also a preferred embodiment that the voltage is a pulsed voltage.

[0066] Furthermore, the amplitude and frequency of the voltage can be appropriately set to adjust the flow rate of the induced flow and the ozone concentration in the induced flow, and in this case, the amplitude and frequency can be appropriately selected from the viewpoints of generating an ozone concentration in the induced flow required to generate an effective active oxygen concentration or amount of effective active oxygen according to the purpose of the treatment, and supplying the generated active oxygen to the surface region of the workpiece while maintaining the effective active oxygen concentration or amount according to the purpose of the treatment.

[0067] For example, the amplitude of the voltage can be 1 kV to 100 kV. Furthermore, the frequency of the voltage can be preferably 1 kHz or higher, more preferably 10 kHz to 100 kHz. When the voltage is an AC voltage, the waveform of the AC voltage is not particularly limited, and sine waves, square waves, triangular waves, etc. can be used, but a square wave is preferable from the viewpoint of the speed of the voltage rise. The duty ratio of the voltage can also be selected appropriately, but a fast voltage rise is preferable. Preferably, the voltage is applied so that the rise time of the voltage from the bottom to the peak of the wavelength amplitude is 4,000,000 V / second or more. The value obtained by dividing the amplitude of the voltage applied between the first electrode 203 and the second electrode 205 by the film thickness of the dielectric 201 (voltage / film thickness) is preferably 10 kV / mm or more.

[0068] By disposing a PA as an ozone generator 111 in the internal space of the production unit 101 of the active oxygen treatment apparatus according to one embodiment of the present disclosure so that an induced flow from the PA flows through the internal space, the production efficiency of the ozone UFB-containing solution can be significantly improved. The reason for this will be explained below.

[0069] 6A and 6B are schematic explanatory diagrams of an active oxygen treatment apparatus according to one aspect of the present disclosure, in which a plasma actuator 400 is disposed within the production unit 101 as the ozone generator 111. When the plasma actuator PA disposed within the production unit 101 is operated, an induced flow 209 generated from the PA is generated by sucking in air from the internal space of the production unit 101.

[0070] Then, by operating the ultrasonic vibrator, the internal space of the production section 101 is brought into a state in which mist of UFB-containing liquid is suspended, and the mist is also taken into the induced flow 209. As a result, it is considered that there is an extremely high probability that the mist containing UFB and ozone will come into contact with each other in the induced flow 209. As a result, it is considered that ozone will be taken into the UFB in the mist extremely efficiently. As a result, an ozone-UFB-containing liquid with a high concentration of ozone-containing UFB can be efficiently produced.

[0071] The PA is preferably arranged so that the induced flow 209 flows inside the production section 101. For example, the PA can be arranged as shown in Figures 6A and 6B. The PA is preferably arranged so that the induced flow 209 can circulate in the internal space of the production section 101. For this reason, it is preferable that no induced flow is generated from the second electrode 205.

[0072] When a commercially available ozone generator other than PA is used as the ozone generator 111, it is preferable to increase the ozone concentration in the production section 101 in order to increase the probability of contact between the mist of the UFB-containing liquid in the production section 101 and ozone. However, even if the ozone concentration in the production section 101 is increased, the probability of contact between the UFB and ozone is lower than the probability of contact between ozone and UFB in the induced flow, and it is thought that more ozone is actually taken into the UFB when PA is used.

[0073] On the other hand, when PA400 as the ozone generator 111 is placed in the manufacturing section 101, the high concentration of ozone in the induced flow 209 comes into contact with the UFB in the induced flow 209 due to the above-mentioned mechanism, and the ozone is efficiently absorbed into the UFB, so there is no need to fill the manufacturing section 101 with high concentration of ozone, which is also advantageous from an environmental perspective.

[0074] <Ozone Generation Capacity of PA> When a PA is used as an ozone generator, the ozone generation capacity of the PA can be expressed as the amount of ozone generated per unit time using the following formula (A) based on the time required for the ozone concentration in a container of a predetermined volume to reach saturation when the PA is operated in the container and the saturated ozone concentration (ppm) in the container. Specifically, for example, the gas in the container in which the PA is operated is collected at regular time intervals, and the ozone concentration of the gas is measured. The amount of ozone generated per unit time is then calculated from the time when the rate of change (rate of increase) between the ozone concentration of the gas measured immediately before and the ozone concentration at that time first becomes 5% or less. The ozone concentration in the gas can be measured using, for example, an ozone detector tube. An example of an ozone detector tube is the "182SA" (trade name, manufactured by Komyo Rikagaku Kogyo Co., Ltd.). The amount of ozone generated per unit time by the PA used as the ozone generator in the present disclosure is preferably 15 μg / min or more, particularly preferably 30 μg / min or more. The upper limit of the amount of ozone generated is not particularly limited, but is, for example, 1000 μg / min or less. That is, a preferred range is 15 μg / min or more and 1000 μg / min or less. Formula (A) Amount of ozone generated per unit time (μg / min) = Measured ozone concentration (ppm) × Molecular weight of ozone / 22.4 × 273 / (273 + Room temperature (°C)) × Gas volume in container (L)

[0075] <Active oxygen UFB production unit 103> The ozone UFB-containing liquid produced in the ozone UFB-containing liquid production unit 101 is moved to the first storage unit 103 by opening the opening / closing device 107-1 and closing the opening / closing device 107-2 (see FIG. 2A, etc.). After a predetermined amount of the ozone UFB-containing liquid in the production unit 101 is moved to the first storage unit 103, the opening / closing device 107-1 is closed and the ozone UFB-containing liquid is stored in the first storage unit 103 (put into a storage state).

[0076] Energy is applied to the ozone-UFB-containing solution stored in the first storage unit 103 by the energy application device 108, thereby decomposing at least a portion of the ozone contained in the UFB into active oxygen. As a result, an active-oxygen UFB-containing solution is obtained in the first storage unit 103, in which the active-oxygen UFB-containing solution is contained in the liquid. From the viewpoint of individually producing the ozone-UFB-containing solution and the active-oxygen UFB-containing solution and improving the production efficiency of the active-oxygen UFB-containing solution, it is preferable that the first storage unit 103 be a tank separate from the ozone-UFB-containing solution production unit 101, as shown in FIG. 2A . Furthermore, it is preferable that the distance between the energy application device and the ozone-UFB-containing solution is short. For example, the energy application device 108 may be provided so as to be able to contact the stored ozone-UFB-containing solution, or may be disposed in the first storage unit so as to be immersed in the ozone-UFB-containing solution stored in the first storage unit ( FIG. 6B ).

[0077] The energy applying device 108 is not particularly limited as long as it can decompose the ozone in the UFB contained in the stored ozone-UFB-containing liquid into active oxygen, and any known device can be used. The energy applying device 108 can be, for example, a heating device, an ultraviolet irradiation device, or a combination thereof. The ultraviolet irradiation device includes at least an ultraviolet light source. The ultraviolet irradiation device may be provided with a movable ultraviolet light source to uniformly apply energy to the first storage section.

[0078] <Ultraviolet Light Source and Ultraviolet Rays> The energy imparting device 108 is preferably an ultraviolet irradiating device equipped with an ultraviolet light source. The ultraviolet light source may be any light source capable of imparting the energy necessary to decompose at least a portion of the ozone contained in the UFB into active oxygen to the ozone-UFB-containing solution. That is, the ultraviolet light source is not particularly limited as long as it can irradiate ultraviolet rays capable of exciting ozone and generating active oxygen. Furthermore, the ultraviolet light source is not particularly limited as long as it has the wavelength and irradiance of ultraviolet rays necessary to excite ozone and obtain an effective active oxygen concentration or amount appropriate for the purpose of treatment.

[0079] For example, since the peak value of the optical absorption spectrum of ozone is 260 nm, the peak wavelength of the ultraviolet light is preferably within the range of 200 to 400 nm, more preferably within the range of 220 to 310 nm, particularly preferably within the range of 253 to 285 nm, and even more preferably within the range of 253 to 266 nm. Specific ultraviolet light sources that can be used include low-pressure mercury lamps in which mercury is sealed in quartz glass together with an inert gas such as argon or neon, cold-cathode ultraviolet lamps (UV-CCLs), and ultraviolet LEDs. The wavelength of the low-pressure mercury lamp or cold-cathode ultraviolet lamp may be selected from wavelengths such as 254 nm. On the other hand, the wavelength of the ultraviolet LED may be selected from wavelengths such as 265 nm, 275 nm, and 280 nm from the standpoint of output performance.

[0080] The ultraviolet irradiance is 0.2 to 8.0 mW / cm ２ is preferably 1.5 to 4.0 mW / cm ２ More preferably, it is 1.5 to 3.0 mW / cm ２ It is more preferable that the illuminance is 100% or less. This illuminance is a value measured by placing the illuminance detection unit of an ultraviolet illuminance meter adjacent to the emitting lamp. As the ultraviolet illuminance meter, an ultraviolet irradiation amount measuring device (product name: Data Logger Ultraviolet Intensity Meter UV-37SD, manufactured by Custom) can be used.

[0081] The amount of ultraviolet light irradiated per mL of the ozone UFB-containing liquid is preferably 5.0 to 200.0 mJ / mL, more preferably 25.0 to 200.0 mJ / mL, and even more preferably 40.0 to 80.0 mJ / mL. This amount of irradiation can be calculated from the area of ​​the irradiation surface of the ultraviolet lamp, the irradiation time, and the amount (liquid volume) of the ozone UFB-containing liquid to be irradiated, using the value obtained by measuring the ultraviolet light irradiance. Specifically, the ultraviolet light irradiance (mW / cm ２ ) × irradiation time (seconds) × area of ​​irradiated surface (cm ２ The irradiance can be calculated by dividing the volume of liquid (mL) adjacent to the irradiated surface. Note that the irradiance decreases only slightly within 3 cm of the irradiated surface, and it can be considered that the liquid is in contact with the irradiated surface of the ultraviolet lamp.

[0082] The irradiation time of the ozone UFB-containing solution with ultraviolet light is preferably 300 seconds or less, particularly preferably 200 seconds or less, and even more preferably 50 seconds or less. The lower limit of the irradiation time is not particularly limited, but is, for example, 3 seconds or more, particularly 5 seconds or more. A preferred range of the irradiation time is, for example, 3 to 300 seconds, particularly 3 to 200 seconds, or even 5 to 50 seconds. By adjusting the illuminance and area of ​​the ultraviolet lamp so as to achieve the above-mentioned irradiation amount within the above-mentioned irradiation time range, the ozone contained in the UFB can be more efficiently converted into active oxygen, and an active oxygen UFB-containing solution containing UFB with a higher concentration of active oxygen can be obtained. As a result, the treatment of the object to be treated with active oxygen can be more reliably performed.

[0083] The content of UFB with bubbles having a diameter of 500 nm or less in the active oxygen UFB-containing solution is preferably 1.0 × 10 ６ ~1.0 x 10 １０ cells / mL, more preferably 1.0 x 10 ７ ~1.0 x 10 ９ cells / mL, and more preferably 1.0 x 10 ８ ~1.0 x 10 ９ The concentration is in the range of 1 / mL. The processing ability by active oxygen can be further improved. The content of UFB in the active oxygen UFB-containing solution can be increased, for example, by increasing the amount of UFB when producing ozone UFB using the method described above.

[0084] After the ozone UFB-containing liquid is stored and energy is imparted to obtain an active-oxygen-containing UFB-containing liquid, the open / close device 107-2 is opened ( FIG. 2B ) and the supply device 105 is operated, thereby applying the active-oxygen-containing UFB-containing liquid in the first storage section 103 to an object to be treated (not shown). The supply device 105 is not particularly limited as long as it can apply a liquid to an object to be treated, and a known device may be used. The supply device 105 may be, for example, a spray device that sprays the active-oxygen UFB-containing liquid, an injection device that sprays the active-oxygen UFB-containing liquid, or an application device that applies the active-oxygen UFB-containing liquid. When spraying or spraying the active-oxygen UFB-containing liquid, a known propellant such as carbon dioxide gas may be used.

[0085] The supply device 105 preferably includes a spray device that sprays the active oxygen UFB-containing liquid onto the object to be treated. Any known spray device may be used, but an ultrasonic sprayer is preferred. The ultrasonic sprayer may be the same as the one described above as the UFB generator. The active oxygen UFB-containing liquid is brought into contact with the rear surface of the vibrator, the liquid is sucked up through the micropores, and a mist is generated from the vibrator surface and sprayed onto the object.

[0086] As shown in Figure 7, another embodiment of the active oxygen treatment device further includes a second reservoir. The second reservoir is configured to be able to receive the active oxygen UFB-containing liquid generated in the first reservoir. The active oxygen treatment device 700 includes a second reservoir 115 that can receive the active oxygen UFB-containing liquid from the first reservoir 103. The opening and closing device 107-3 allows the liquid to flow from the first reservoir 103 into the second reservoir 115. The opening and closing devices 107-2 and 107-3 also allow the liquid to be stored in the second reservoir 115.

[0087] Furthermore, the active oxygen UFB-containing liquid supplying device 105 is configured to be able to supply the active oxygen UFB-containing liquid stored in the second storage section 115 to the object to be treated. By providing such a second storage section 115, it becomes possible to select a means suitable for supplying the active oxygen UFB-containing liquid to the object regardless of the configuration of the first storage section, i.e., its relative position with respect to the ozone UFB-containing liquid production section, the shape of the energy imparting device, etc. Furthermore, it becomes possible to continuously produce the active oxygen UFB-containing liquid while treating the object to be treated with the active oxygen UFB-containing liquid supplying device 105.

[0088] In the active oxygen treatment apparatus, the production section 101 can also serve as the first storage section 103. That is, the active oxygen treatment apparatus 900 shown in FIG. 9 has a UFB generator 109 and an ozone generator 111 disposed in the internal space of the production section 101. It also includes an energy imparting device 108 for the ozone UFB-containing liquid stored in the internal space. This active oxygen treatment apparatus 100 is provided with an opening / closing device 102 that allows liquid to flow from a liquid supply source (not shown) into the internal space of the production section 101 and blocks the inflow of liquid. A flow path connecting the internal space of the production section 101 and the active oxygen UFB-containing liquid supply device 105 is also provided with an opening / closing device 107-2 that allows the active oxygen UFB-containing liquid stored in the internal space of the production section 101 to be supplied to the supply device 105 and can also block the supply.

[0089] A treatment method using active oxygen using this active oxygen treatment device 900 will be described. First, with the opening and closing device 107-2 closed, the opening and closing device 102 is opened to introduce liquid into the internal space of the production section 101. Next, with the opening and closing device 102 and the opening and closing device 107-2 closed, the ultrasonic vibrator 109 is operated to produce an ozone UFB-containing liquid, and the ozone UFB-containing liquid 113 is stored in the internal space of the production section 101 (which also serves as the storage section 103). Next, with the opening and closing devices 102 and 107-2 closed, i.e., with the ozone UFB-containing liquid stored in the internal space of the production section 101, the energy imparting device 108 is operated. In this way, energy is imparted to the ozone UFB-containing liquid stored in the internal space of the production section 101, and at least a portion of the ozone contained in the UFB is decomposed into active oxygen, thereby generating an active oxygen UFB-containing liquid. Next, the active oxygen UFB-containing liquid produced in the internal space of the production section 101 is supplied to the object to be treated (not shown) by the active oxygen UFB-containing liquid supply device 105, and the object to be treated is treated with the active oxygen.

[0090] (Treatment method using active oxygen) At least one aspect of the present disclosure provides a treatment method using active oxygen. The treatment method for active oxygen includes the following steps (1) to (4): (1) an ozone-UFB-containing liquid production step of producing an ozone-UFB-containing liquid in which an ozone-UFB-containing UFB is contained in a liquid; (2) a storage step of storing the produced ozone-UFB-containing liquid in a first storage section; (3) a step of imparting to the ozone-UFB-containing liquid stored in the first storage section energy required to decompose at least a portion of the ozone contained in the ultrafine bubbles into active oxygen, thereby decomposing at least a portion of the ozone into active oxygen, thereby preparing an active oxygen-UFB-containing liquid in which the ultrafine bubbles containing the active oxygen are contained in the liquid; and (4) an active oxygen-UFB-containing liquid supply step of supplying the active oxygen-UFB-containing liquid stored in the first storage section to an object to be treated.

[0091] The production and storage of the ozone-UFB-containing liquid, as well as the preparation of the active oxygen-UFB-containing liquid and the supply of the active oxygen-UFB-containing liquid to the material to be treated, are the same as those in the active oxygen treatment device described above. For example, the treatment method may be performed using the active oxygen treatment device described above. From the viewpoint of more reliably performing the treatment with active oxygen, it is preferable that in step (3), energy is imparted to the ozone-UFB-containing liquid in the first reservoir without the ozone-UFB-containing liquid flowing into the first reservoir or the ozone-UFB-containing liquid flowing out of the first reservoir.

[0092] (Ozone UFB-containing liquid generator) The present disclosure also relates to an ozone UFB-containing liquid generator that generates an ozone UFB-containing liquid. Fig. 8 shows an example of an ozone UFB-containing liquid generator 800. The ozone UFB-containing liquid generator 800 includes a liquid reservoir 801 that stores a liquid.

[0093] The liquid storage unit 801 includes a UFB generator 109 that produces a UFB-containing liquid by adding ultrafine bubbles to the liquid 113 stored in the liquid storage unit 801, and a plasma actuator 400. The liquid storage unit 801 also includes an opening and closing device 102 that allows the liquid 113 to flow into the liquid storage unit 801 and blocks the inflow of the liquid, and an opening and closing device 107-6 that allows the ozone UFB-containing liquid to flow out from the liquid storage unit 801. By closing these opening and closing devices 102 and 107-6, the liquid can be stored in the liquid storage unit 801.

[0094] The plasma actuator has a first electrode and a second electrode sandwiching a dielectric, and generates an induced flow 209 containing ozone by applying a voltage between the first electrode and the second electrode. The plasma actuator is disposed so that the induced flow 209 flows inside the liquid storage portion 801. In the ozone UFB-containing liquid generating device 800, the induced flow 209 comes into contact with the UFB-containing liquid, thereby generating an ozone UFB-containing liquid.

[0095] The UFB generator 109 and the plasma actuator 400 are the same as those described above in the description of the active oxygen treatment device. The UFB generator 109 preferably includes an ultrasonic vibrator that contains UFB in a liquid and sprays the liquid, and an ultrasonic sprayer is more preferable. As described above, operation of the ultrasonic vibrator can cause droplets (mist) of the UFB-containing liquid to float inside the liquid storage section 801. This makes it easy to bring the UFB-containing liquid into contact with the induced flow 209, allowing for efficient production of an ozone UFB-containing liquid.

[0096] Hereinafter, the present disclosure will be described in more detail using examples and comparative examples, but the aspects of the present disclosure are not limited thereto.

[0097] The active oxygen treatment device shown in Figures 6A, 10A, and 10B was fabricated. Specifically, an ozone UFB-containing liquid production unit, an ozone generator, an energy imparting device, an ozone UFB-containing liquid storage tank as a first storage unit, and an active oxygen UFB-containing liquid supply device were provided as follows. Figures 10A and 10B are schematic diagrams of the active oxygen treatment device as seen from the left and right sides, respectively.

[0098] Ozone UFB-containing liquid production unit The ozone UFB-containing liquid production unit 101 was made of ABS resin, measuring 135 mm x 30 mm x 30 mm high. It was capable of storing water inside, and an ultrasonic sprayer equipped with an ultrasonic vibrator was installed as the UFB generator 109. An ultrasonic sprayer module (manufactured by REN HE) was used as the ultrasonic sprayer. The ultrasonic sprayer module included an electrically controlled printed circuit board and an ultrasonic vibrator connected to the board by wiring. The ultrasonic vibrator was made of ceramic and had a circular shape with a diameter of 16 mm and a thickness of 1 mm, and had numerous minute communicating holes with a diameter of approximately 5 μm that connected to the top and bottom surfaces.

[0099] The ultrasonic vibrator had a resonant frequency of 108 kHz, and the frequency of the generated ultrasonic waves was 108 kHz. The voltage applied to the ultrasonic vibrator to operate it was an AC voltage with a frequency of 108 kHz. An external DC voltage input to the printed circuit board was used as an AC voltage, and the 108 kHz AC voltage was input to the ultrasonic vibrator. The input intensity was 0.75 W / cm. ２ It was decided.

[0100] Ozone Generator; Plasma Actuator A plasma actuator 400 having the configuration shown in Fig. 4A was placed in the ozone UFB-containing liquid production unit 101 as shown in Fig. 6A. Specifically, the first electrode (exposed electrode) 203 was placed so as to be exposed to the internal space of the production unit 101 so that the induced flow 209 generated from the PA when the PA was operated would flow through the internal space of the production unit 101. The direction perpendicular to the paper surface of Fig. 4A (depth direction) is the longitudinal direction of the PA.

[0101] The PA was fabricated by hot pressing a 100 μm thick silicone film as dielectric 201 onto a glass epoxy substrate 206 (160 mm long, 10 mm wide, 1.0 mm thick) on which copper foil (150 mm long, 2 mm wide, 35 μm thick) was printed as an electrode (second electrode 205). Furthermore, a SUS plate (135 mm long, 80 μm thick) was placed as an electrode (first electrode 203) with its longitudinal direction parallel to the longitudinal direction of the lower electrode, and the distance between the closest points of the first electrode and second electrode was the thickness of the silicone film.

[0102] The dischargeable range was 135 mm in the longitudinal direction of the PA, and the PA was positioned so that its longitudinal direction coincided with the longitudinal direction of the ozone UFB-containing liquid production unit (Figure 10A). An AC voltage of 3.0 KVpp (frequency 75 KHz) was applied to the PA via a conversion board. The PA generated 96 μg / min of ozone per unit time when the AC voltage was applied. The method for measuring the amount of ozone generated was as described above.

[0103] First Storage Chamber The first storage chamber 103 was 135 mm long x 16 mm wide x 8 mm high and was made of ABS resin.

[0104] Energy application device; ultraviolet lamp As shown in FIG. 6A, a cylindrical cold cathode ultraviolet lamp (product name: UW / 9F89 / 9, manufactured by Stanley Electric Co., Ltd., cylindrical with a diameter of 9 mm, peak wavelength = 254 nm) was used as the energy application device 108 so that ultraviolet light was irradiated into the internal space of the first storage chamber 103. The portion of this ultraviolet lamp capable of stable ultraviolet irradiation is the 135 mm long portion of the cylindrical portion, and this portion was arranged along the longitudinal direction of the first storage chamber 103 (the direction perpendicular to the paper surface in FIG. 6A). FIG. 11 is a cross-sectional view of the ultraviolet lamp in a direction perpendicular to the longitudinal direction. The ultraviolet lamp is capable of irradiating ultraviolet light with a wavelength of 254 nm over a portion with a longitudinal length of 135 mm. The lower half of the cross section of FIG. 11 is the irradiable surface 1101 capable of ultraviolet irradiation. The upper half is the non-irradiated surface 1102, with aluminum foil attached to the inside. When the UV irradiation surface faces the ozone UFB-containing liquid storage tank, the area of ​​the irradiation surface is 19.1 cm ２ It was.

[0105] The ultraviolet lamp is composed of an ultraviolet irradiating portion and a quartz tube exterior, with aluminum foil installed on the inner half of the quartz tube. In other words, the semi-cylinder is the non-irradiated surface and the other semi-cylinder is the irradiated surface in the circumferential direction of the ultraviolet lamp. This ultraviolet lamp can move in the circumferential direction while installed in the ozone UFB-containing liquid storage tank, meaning that both the ultraviolet irradiating surface and the irradiated surface can be directed toward the inside of the ozone UFB-containing liquid storage tank. The first storage chamber 103 is adjacent to the production section 101 via an opening / closing door, and liquid can flow in by opening the opening / closing door.

[0106] Active oxygen UFB-containing liquid supply device 105 An ultrasonic sprayer (manufactured by REN HE) was placed in the center of the surface of the first storage chamber 103 opposite to the surface having the connection part with the production part 101. This ultrasonic sprayer was the same as the ultrasonic sprayer used in the UFB generator 109 placed in the internal space of the production part 101. The liquid stored in the internal space of the first storage chamber 103 came into contact with the back surface of the ultrasonic vibrator, and a mist of the active oxygen UFB-containing liquid was generated from the surface of the ultrasonic vibrator, so that it could be supplied to the object to be treated.

[0107] (Introduction of Liquid and Preparation of Ozone UFB-Containing Liquid) Treatment with active oxygen was performed using the active oxygen treatment device prepared as described above. First, 15 mL of tap water was introduced into the internal space of the production section 101 by opening the opening / closing device 102, and the water was stored in the internal space of the production section 101. A DC voltage of 20 V was applied to the power supply conversion board connected to the PA, and an AC voltage of 3.0 KVpp (frequency 75 KHz) was applied between the first and second electrodes of the PA, generating an induced flow containing ozone from the PA.

[0108] In addition, in an ultrasonic sprayer serving as the UFB generator 109 placed in the internal space of the production section 101, a DC voltage of 5 V was applied to a power application converter board connected to an ultrasonic vibrator, generating a mist of water containing UFB stored in the internal space of the production section 101. The ultrasonic sprayer and plasma actuator were operated for 20 minutes and then stopped. After that, they were left to stand for 5 minutes, allowing the mist of ozone-UFB-containing liquid floating in the internal space of the production section 101 to settle to the bottom of the internal space of the production section 101. In this way, 20 mL of ozone-UFB-containing liquid was stored in the internal space of the production section 101.

[0109] (Conversion of ozone into activated oxygen by ultraviolet lamp) Next, valve 107-1 between production unit 101 and first storage unit 103 was opened, and valve 107-2 between first storage unit 103 and supply device 105 was closed to allow 15 mL of ozone UFB-containing liquid to flow into first storage unit 103. Thereafter, valve 107-1 was closed, and the ozone UFB-containing liquid was stored in first storage unit 103. Next, the irradiable surface of the ultraviolet lamp was irradiated with ultraviolet light for 20 seconds onto the internal space of the first storage unit, i.e., the ozone UFB-containing liquid.

[0110] The ultraviolet irradiation dose was measured by contacting the detection part of an ultraviolet irradiation amount measuring device (product name: Data Logger Ultraviolet Intensity Meter UV-37SD, custom-made) with the irradiable surface outside the ozone UFB-containing liquid storage tank during the warm-up operation of the ultraviolet lamp before irradiation of the ozone UFB-containing liquid. Just before the warm-up operation was completed, i.e., just before irradiation of the ozone UFB-containing liquid, the ultraviolet irradiation dose was 2.0 mW / cm. ２ The measured value was stable. The cumulative amount of ultraviolet irradiation was 760 mJ, and the amount of irradiation to the ozone-UFB-containing solution was 50.7 mJ / ml. In this way, at least a portion of the ozone contained in the UFB in the ozone-UFB-containing solution was decomposed into active oxygen in the internal space of the first storage section 103, to produce an active oxygen-UFB-containing solution.

[0111] (Treatment of object to be treated with active oxygen) The object to be treated with active oxygen was placed in the direction of the mist ejected from the ultrasonic vibrator, which is the active oxygen UFB-containing liquid supply device. The amount of liquid supplied can be controlled by measuring the amount of spray with a precision balance. In this example, the amount of liquid supplied by the mist at a distance of 5 cm was 3 μg per second, so it was controlled from the spray time.

[0112] (Evaluation 1: Measurement of the amount of ozone generated per unit time in the plasma actuator (ozone generation capacity of the PA)) To calculate the amount of ozone generated from the PA, before producing the ozone-UFB-containing liquid, i.e., before introducing tap water into the internal space of the production unit 101, the PA placed in the internal space was operated for 2 minutes under the above-mentioned conditions for producing the ozone-UFB-containing liquid. The volume of the internal space of the production unit 101 was 0.122 L = 135 mm × 30 mm × 30 mm. 50 ml of gas from the internal space was sampled every 30 seconds from the start of operation of the PA, and the sampled gas was drawn into an ozone detector tube (product name: 182SA, manufactured by Komyo Rikagaku Kogyo Co., Ltd.), and the measured ozone concentration (ppm) contained in the induced flow from the plasma actuator was measured. Then, one minute after the start of PA operation, the rate of change of the ozone concentration in the gas in the internal space relative to the ozone concentration in the gas in the internal space 30 seconds after the start of PA operation became 5% or less for the first time, and therefore it was determined that the ozone concentration in the gas in the internal space reached saturation one minute after the start of PA operation. Therefore, using the ozone concentration value in the internal space one minute after the start of PA operation, the amount of ozone generated per unit time by PA was calculated using the following formula. The room temperature was 25°C. Formula (A) Amount of ozone generated per unit time (μg / min) = Measured ozone concentration (ppm) x Molecular weight of ozone 48 / 22.4 x 273 / (273 + Room temperature (°C)) x Gas volume in container (L) = Measured ozone concentration (ppm) x 48 / 22.4 x 273 / (273 + 25) x 0.122

[0113] (Evaluation 2-1: Measurement of ozone concentration in ozone-UFB-containing liquid) The ozone concentration in the ozone-UFB-containing liquid was measured using Pack Test (trade name: Digital Pack Test and Pack Test model WAK-O3, manufactured by Kyoritsu Chemical Research Institute), a colorimetric method using an enzyme. The measurement method involved measuring 1.5 mL of the ozone-UFB-containing liquid and mixing it with dye powder to produce a purple color, and then calculating the ozone concentration from the degree of color development. A sample was taken from the ozone-UFB-containing liquid in the first reservoir just before applying energy for active oxygen generation. The measurement range was 0.2 to 5 mg / L, and if the concentration exceeded this range, the solution was diluted to within the measurable range to obtain a value, and the ozone concentration before dilution was calculated from the dilution ratio.

[0114] (Evaluation 2-2: Measurement of Acidity pH of Ozone-UFB-Containing Solution) The pH of the ozone-UFB-containing solution was measured using a pH meter (product name: Twin pH Meter II LAQUA Twin, manufactured by AS ONE). 0.2 ml of the solution was introduced into the device, and the output value was used as the pH value.

[0115] (Evaluation 2-3: Number-average bubble diameter of UFB in ozone-UFB-containing solution) (Evaluation 3-1: Measurement of the amount of UFB in ozone-UFB-containing solution) (Evaluation 3-2: Measurement of the amount of UFB in active oxygen-UFB-containing solution) The amount of UFB per unit volume (number / mL) in the ozone-UFB-containing solution and the active oxygen-UFB-containing solution was measured. The measurement device used was a nanoparticle size distribution measurement device (product name: SALD 7500, manufactured by Shimadzu Corporation) that utilizes laser scattering and diffraction. Specifically, the liquid to be evaluated was placed in a 5 ml sample cell, and the sample cell was inserted into the nanoparticle size distribution measurement device to measure the bubble diameter and number of bubbles in the cell. The number and number-average diameter (number-average bubble diameter) of bubbles with a bubble diameter of 500 nm or less were then calculated. In this evaluation, the above procedure was performed three times using different samples, and the arithmetic mean value was used as the value in this evaluation. The measurement by this device includes noise, and ５ When the number was less than 1 / ml, it was difficult to distinguish and the amount was not sufficient as UFB, so it was determined not to calculate.

[0116] (Evaluation 4: Bacterial elimination test) Using the active oxygen treatment device prepared in this example, an Escherichia coli sterilization test was carried out according to the following procedure. All instruments used in this sterilization test were subjected to high-pressure steam sterilization using an autoclave. First, Escherichia coli (trade name "KWIK-STIK (Escherichia coli) ATCC8739)", manufactured by Microbiology) was placed in an Erlenmeyer flask containing LB medium (4 tablets of LB medium raw material pellets, a total of 25 g (trade name "LB Broth (Lennox)", manufactured by Sigma-Aldrich), to which 200 mL of distilled water was added). Next, the Erlenmeyer flask was shaken and cultured at 37°C for 48 hours at 80 rpm using a shaking incubator (TA-25R-3F, ​​manufactured by Takasaki Scientific Instruments Co., Ltd.) to obtain an Escherichia coli solution. The viable cell count of the resulting E. coli solution was 9.2 x 10 ９ (CFU / mL).

[0117] <Control Experiment> 0.01 mL of the above E. coli solution was poured into a 10 mL test-tube-shaped plastic tube. 0.2 mL of distilled water was poured into this plastic tube. The opening of the plastic tube was then capped, and the mixture was stirred for 15 seconds using a shaker mixer (product name: Mini Test Tube Mixer MVM-10; manufactured by AS ONE Corporation). 0.1 mL of sodium thiosulfate was then poured into the mixture, and the mixture was stirred for 15 seconds using the shaker mixer.

[0118] Next, 0.2 mL of the bacterial solution in the plastic tube was added to 9 mL of buffer (phosphate-buffered saline) (trade name: Gibco PBS, manufactured by Life Technologies Japan). Using the resulting bacterial solution (hereinafter also referred to as "1 / 1 solution") as a reference, bacterial solutions were diluted 10-fold (1 / 10 dilution), 100-fold (1 / 100 dilution), 1000-fold (1 / 1000 dilution), and 10,000-fold (1 / 10,000 dilution) using the above buffer. Next, 0.05 mL was sampled from the 1 / 1 solution and smeared on a stamp medium (trade name: Petan Check II25 Standard Agar Medium, manufactured by Eiken Chemical). After spreading, the stamp medium was placed in an incubator (trade name: IS600; manufactured by Yamato Scientific Co., Ltd.) and cultured at 37°C for 24 hours. The number of colonies that emerged was counted. The "1 / 10 diluted solution," "1 / 100 diluted solution," "1 / 1000 diluted solution," and "1 / 10,000 diluted solution" were also smeared on stamp media and cultured in the same manner as above, and the number of colonies that appeared on the media was counted. The results are shown in Table 1 below.

[0119]

[0120] Since the detection error is small when the number of colonies is in the range of 10 to 100, when multiple dilutions are counted, data within the above range is used as the true value. From the results in Table 1 above, the number of colonies when the 1 / 10,000 diluted solution was cultured was 20, so this value is used. The number of E. coli present in 0.2 ml of bacterial solution added to the buffer solution is 20 x 10 ４ / 0.05 x 9.2 = 3.7 x 10 ７ The E. coli count thus obtained was designated as the reference E. coli count D0.

[0121] <Bacteria elimination test> 0.01 mL of the above-mentioned E. coli liquid was poured into a 10 mL test-tube-shaped plastic tube. The distance from the inlet of this plastic tube to the liquid surface of the E. coli liquid was 9.5 cm. An active oxygen treatment device was placed at the opening of the plastic tube so that the discharge portion of the ultrasonic vibrator serving as the active oxygen supply device 105 was in contact with the opening of the plastic tube. The opening / closing device 107-2 was opened to send the active oxygen UFB-containing liquid stored in the first storage section 103 to the active oxygen supply device, and the ultrasonic vibrator was operated to discharge the active oxygen UFB-containing liquid, which was then introduced into the plastic tube. Note that since the supply rate of the active oxygen UFB-containing liquid from the ultrasonic vibrator was 3 μm / sec, discharge was continued for approximately 33 seconds, and 0.1 mL of the active oxygen UFB-containing liquid was poured into the plastic tube. Thereafter, the opening of the plastic tube was capped, and the contents were stirred for 15 seconds using a shaker mixer (trade name: Mini Test Tube Mixer MVM-10; manufactured by AS ONE Corporation).

[0122] Next, the cap of the plastic tube was removed, and 0.1 mL of sodium thiosulfate was added to the plastic tube to eliminate the effects of active oxygen and ozone, followed by stirring for an additional 30 seconds. This operation ensured that the number of E. coli bacteria would not change over time. Next, 0.2 mL of the bacterial solution in the plastic tube was added to 9 mL of a buffer solution (phosphate buffered saline, product name: PBS, manufactured by Life Technologies Japan). The liquid obtained in this manner was designated the "treated base solution."

[0123] Subsequently, the treated base solution was diluted 10-fold, 100-fold, 1000-fold, and 10,000-fold with the buffer solution to prepare diluted solutions. The resulting diluted solutions are also referred to as "1 / 10 diluted solution," "1 / 100 diluted solution," "1 / 1000 diluted solution," and "1 / 10,000 diluted solution," respectively.

[0124] Next, 0.05 mL was sampled from the treated base solution and smeared on a stamp medium (product name: Petan Check II25 Standard Agar Medium, manufactured by Eiken Chemical). After spreading, the stamp medium was placed in an incubator (product name: IS600, manufactured by Yamato Scientific Co., Ltd.) and cultured at 37°C for 24 hours. The number of colonies that emerged was counted. The "1 / 10 diluted solution," "1 / 100 diluted solution," "1 / 1000 diluted solution," and "1 / 10,000 diluted solution" were also smeared on stamp medium and cultured in the same manner as above, and the number of colonies that emerged on the medium was counted. The results are shown in Table 2 below.

[0125]

[0126] As shown in the results in Table 2 above, the colony count was 0 even with the 1 / 100,000 diluted solution, but it is possible that if further dilutions were made, the number would have become countable, so here we will interpret it as being between 0 and 1, and consider the colony count to be 1 or less. Using this, the number of E. coli D present in 0.2 ml of bacterial solution added to the buffer solution was calculated as 1 x 10,000 / 0.05 x (9 + 0.2) = 1.8 x 10 ２ (CFU) or less.

[0127] As the sterilization effect of the active oxygen treatment device according to this example, the rate of change in the number of E. coli D relative to the reference number of E. coli D was calculated, and the logarithm of this rate, −Log10(D / D ０ ) is shown as the order of magnitude of reduction in the number of bacteria. The reference number of E. coli D0 was 3.7 x 10 as described above. ７ The number of E. coli bacteria was 5.3 or more, and the number of E. coli bacteria D was below the lower limit of evaluation, so the reduction was 5.3 or more.

[0128] (Evaluation 5: Evaluation of the Presence or Absence of Generation of Reactive Oxygen - ESR Analysis) Analysis by electron spin resonance (ESR) was carried out to confirm the generation of reactive oxygen. ESR is a spectroscopic analysis that observes the transition between levels that occurs when an unpaired electron is placed in a magnetic field, and is capable of analyzing short-lived free radicals, including reactive oxygen species such as hydroxyl radicals. Specifically, the short-lived radicals are captured with a spin trapping reagent to generate and detect relatively stable radical adducts. For reactive oxygen species such as hydroxyl radicals, radical adducts are detected using 5,5-Dimethyl-1-Pyrroline-N-Oxide (DMPO) as a spin trapping reagent.

[0129] In this evaluation, a 90 μL sample collected by spraying an active oxygen UFB-containing solution from an ultrasonic sprayer for 30 seconds was mixed with 10 μL of spin-trapping reagent DMPO (Fujifilm Wako Pure Chemical Industries) refrigerated at 5°C to prepare a DMPO mixture. The DMPO mixture was then injected into a glass capillary with an inner diameter of 1 mm. The capillary containing the DMPO mixture was then placed in an electron spin resonance (ESR) spectrometer (product name: JES-X310; manufactured by JEOL Ltd.) to acquire a spectrum. An Mn marker was also simultaneously acquired for data correction. ESR analysis yields a spectrum (hereinafter also referred to as the "ESR spectrum") in which the horizontal axis represents magnetic field strength and the vertical axis represents signal (peak) intensity.

[0130] The presence of the DMPO-OH radical adduct can be confirmed by the observation of periodic signals in the ESR spectrum, specifically, well-symmetrical peaks in the order of small-large-large at intervals of 1.49 mT between Mn marker signals. Figure 14 shows the ESR spectrum of the active oxygen UFB-containing solution prepared in Example 1. In the ESR spectrum shown in Figure 14, peaks (1) and (6) are peaks attributable to the Mn marker, and peaks (2) to (5) are peaks attributable to the DMPO-OH radical adduct.

[0131] The amount of OH radicals can be calculated from the peak intensity of the DMPO-OH radical adduct / peak intensity of the Mn marker (hereinafter also referred to as the "OH radical signal ratio"). As the peak derived from the DMPO-OH radical adduct used in calculating the OH radical signal ratio, the peak with the highest intensity is selected from peaks (2) to (5) derived from the DMPO-OH radical. As the peak derived from the Mn marker used in calculating the OH radical signal ratio, the peak on the low magnetic field side (peak (1) in FIG. 14) is used. Furthermore, as the peak intensities used in calculating the OH radical signal ratio, both amplitudes of the peaks used for calculation (A(Mn) and A(OH) in FIG. 14) are used.

[0132] The value of the OH radical signal ratio is at least 0.10 or more, preferably 0.20 or more, more preferably 0.30 or more, even more preferably 0.50 or more, and particularly preferably 1.00 or more. The upper limit of the OH radical signal ratio is not particularly limited, but is preferably, for example, 3.00 or less, particularly 2.50 or less. Preferred numerical ranges for the OH radical signal ratio are 0.10 to 3.00, 0.20 to 3.00, 0.30 to 3.00, 0.50 to 3.00, and even 1.00 to 2.50.

[0133] In the ESR spectrum, when the OH radical signal ratio was less than 0.10, and when a clear peak derived from the DMPO-OH radical adduct could not be confirmed because it was buried in measurement noise, it was determined that no OH radicals were present, and the result was recorded as "absent" for OH radicals in Table 4 shown below.

[0134] Further, examples of the present disclosure will be described. Unless otherwise specified, the same operations and evaluation methods as in Example 1 were carried out.

[0135] (Example 2) In Example 1, an ultrasonic vibrator with a resonance frequency of 1.7 MHz (product name: PZT Ultrasonic Mist Maker Ceramic Atomizing Disc KS-20-1.7, manufactured by Gazechimp) was used as the ultrasonic vibrator of the ultrasonic sprayer placed in the internal space of the production section 101. In addition, an external power source was used to operate this ultrasonic vibrator, and an AC voltage of 1.7 MHz and 48 Vpp was applied. Other than that, the active oxygen treatment was carried out in the same manner as in Example 1.

[0136] (Examples 3 to 6) The ultraviolet irradiance and irradiation time, or irradiation time, were as shown in Table 3. Otherwise, the active oxygen treatment was carried out in the same manner as in Example 1.

[0137] Example 7 Sodium bicarbonate was added as a neutralizing agent to the ozone UFB-containing solution transferred from the production unit 101 to the first storage unit 103, and the pH of the ozone UFB-containing solution was adjusted to 6.9. Otherwise, the active oxygen treatment was carried out in the same manner as in Example 1.

[0138] (Example 8) Nitric acid was added as a neutralizing agent to the ozone UFB-containing solution transferred from the production unit 101 to the first storage unit 103, and the pH of the ozone UFB-containing solution was adjusted to 1.2. Otherwise, the active oxygen treatment was carried out in the same manner as in Example 1.

[0139] Example 9 A commercially available ozone generator (product name: O3 Clear 3, manufactured by Ozone Mart Co., Ltd.) that was not a PA was prepared as the ozone generator 111. This ozone generator was placed outside the housing of the production section 101, as shown in Figure 3, and a flow rate adjustment pump 302 was interposed in the middle of the ozone supply path 301 from the ozone generator to adjust the amount of ozone supplied to the internal space of the production section 101, thereby adjusting the ozone concentration in the internal space of the production section 101 to the same ozone concentration as in Example 1. Otherwise, the active oxygen treatment was performed in the same manner as in Example 1.

[0140] The active oxygen treatment conditions for Examples 1 to 9 are summarized in Table 3 below.

[0141] The evaluation results for each example are shown in Table 4. In the table, for example, "3.1E+08" means "3.1 x 10 ８" indicates the number of ozone-containing liquids. The UFB amount in the active oxygen UFB-containing liquid is the amount of UFB in the active oxygen UFB-containing liquid used in the sterilization treatment test. The presence or absence of active oxygen generation indicates the results of the ESR analysis described above. D is the number of remaining Escherichia coli bacteria in the treatment of the active oxygen UFB-containing liquid. The number of digits of reduction is the number of digits of reduction in the number of bacteria due to the sterilization treatment. Comparing Example 1 and Example 9, although the ozone concentration in the internal space of the production section 101 was the same, as shown in Table 4, the ozone concentration in the ozone UFB-containing liquid in Example 1 was more than twice that of Example 9. This is thought to mean that by using a PA as an ozone generator, ozone was more efficiently absorbed into the UFB.

[0142] Comparative Example 1 Energy was not imparted (ultraviolet light irradiation) to the ozone UFB-containing liquid stored in the first storage section 103. Otherwise, the treatment object was treated in the same manner as in Example 1.

[0143] (Comparative Example 2) A treatment apparatus 1201 having the configuration shown in Fig. 12 was prepared. That is, an active oxygen supplying device 105 was attached to the side of the storage section 103 of the active oxygen treatment apparatus according to Example 9 opposite to the side where the valve 102 was provided, so that the ozone UFB-containing liquid stored in the internal space of the storage section 103 could be sprayed onto the object to be treated. In addition, an ultraviolet lamp 108 was arranged so that ultraviolet light could be irradiated onto the mist of the ozone UFB-containing liquid sprayed from the active oxygen supplying device 105. As the active oxygen treatment apparatus 105, an ultrasonic sprayer identical to the ultrasonic sprayer used in the active oxygen UFB-containing liquid supplying device of the active oxygen treatment apparatus according to Example 1 was used.

[0144] An ozone-UFB-containing liquid was then produced in the same manner as in Example 9, and the ozone-UFB-containing liquid stored in the internal space of the storage section 103 was sprayed from an ultrasonic sprayer so as to pass through the area irradiated with ultraviolet light. The mist that passed through the ultraviolet light irradiated area was collected and used for evaluation. The results are shown in Table 4. That is, the collected liquid contained UFB, but the presence of active oxygen could not be confirmed. The sterilization effect was also inferior to that of each example. From this, it is thought that in this comparative example, even if ultraviolet light was irradiated onto the mist of the ozone-UFB-containing liquid, the ozone in the UFB could not be converted into active oxygen.

[0145] Comparative Example 3 A processing apparatus having the configuration shown in FIG. 13 was prepared. Specifically, an ozone generator 1303 incorporating the PA prepared in Example 1 was prepared. The ozone generator 1303 was 135 mm deep, 30 mm wide, and 30 mm high and made of ABS resin. The ozone generated in the ozone generator 1303 could be transferred to the internal space of the production section 101 via the supply path 102-1 using a pump (not shown). Additionally, 60 mL of tap water was stored in the internal space of the production section 101 so that the water level was 1 cm above the top end of the opening of the supply path 102-1 for ozone-containing air from the ozone generator 1303 on the production section 101 side. Next, with the opening / closing device 102 closed, the PA400 was operated under the same conditions as in Example 1 to generate ozone in the internal space of the ozone generator 1303.

[0146] Next, the opening / closing device 102 was opened, and the ozone-containing air inside the ozone generation unit 1303 was moved to the production unit 101 using a pump (not shown), bringing the water stored in the production unit 101 into contact with the ozone-containing air (bubbling). Bubbling was continued until the ozone concentration in the water stored in the internal space of the production unit 101 reached 2.5 mg / L. Immediately after bubbling was stopped, 15 mL of liquid in the production unit 101 was moved to the first storage unit 103, with the opening / closing device 107-1 opened and the opening / closing device 107-2 closed. The opening / closing device 107-1 was then closed, leaving the liquid stored in the first storage unit. The liquid stored in the first storage unit was then irradiated with ultraviolet light under the same conditions as in Example 1. The liquid that had completed the ultraviolet irradiation treatment was then supplied to the workpiece in the same manner as in Example 1.

[0147] The results of Evaluations 1 to 5 of this comparative example are shown in Table 5. As shown in Table 5, in this comparative example, the formation of UFB and the generation of active oxygen were not confirmed, and no sterilization effect was obtained. It is believed that when water was bubbled with air containing ozone, UFB was not substantially formed, and only unstable coarse bubbles were formed. In other words, it is believed that ozone-containing bubbles could not stably exist in the water stored in the production section 101 after bubbling was completed, and the ozone that was taken into the water was immediately released as gas. Therefore, even when ultraviolet light was irradiated in the first storage section, it is believed that the water to be irradiated contained almost no ozone, and active oxygen was not generated.

[0148] (Comparative Example 4) An ozone-free UFB-containing solution was prepared, and then an ultraviolet emitting device with two peak wavelengths of 185 nm and 254 nm was placed above the surface of the UFB-containing solution at a distance from the surface, and irradiated with the ultraviolet light. The generation of an ozone UFB-containing solution and the generation of an active oxygen UFB-containing solution were confirmed. Specifically, the following procedure was performed.

[0149] In Example 1, the PA in the ozone-UFB-containing liquid production unit was not operated, and the ultrasonic vibrator was operated to produce an ozone-free UFB-containing liquid. The ultraviolet lamp disposed in the first reservoir was changed to an ultraviolet lamp (cold cathode ultraviolet lamp, product name: UW / 9E89 / 9, manufactured by Stanley Electric Co., Ltd., cylindrical, 9 mm diameter, peak wavelength = 185 nm + 254 nm) having the same shape as the ultraviolet lamp used in Example 1 and peak wavelengths of 185 nm and 254 nm. The portion of this ultraviolet lamp capable of stable ultraviolet irradiation was a 135 mm long cylindrical portion.

[0150] The amount of UFB in the ozone UFB-containing solution produced in the production section 101 was 3.1 × 10 ８ After confirming that the number of particles / mL was 15 mL of the ozone UFB-containing solution, 15 mL of the ozone UFB-containing solution was transferred to the first storage section 103. Then, the UFB-containing solution stored in the first storage section 103 was irradiated with ultraviolet light for 2 minutes using the ultraviolet lamp. Otherwise, evaluations 1 to 5 were performed in the same manner as in Example 1. The results are shown in Table 5.

[0151] As shown in Table 5, the generation of ozone UFB was confirmed, but the generation of active oxygen was not confirmed, and the sterilization performance was significantly lower than that of the Examples. It is presumed that the sterilization effect in this comparative example is due to the ozone generated in the liquid by ultraviolet irradiation in the first storage section. In this comparative example, the reason why the generation of active oxygen was not observed even by ultraviolet irradiation is thought to be because ozone was not taken in during the preparation of the UFB-containing liquid, and only air was contained in the UFB.

[0152]

[0153] The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the present disclosure. Therefore, the following claims are appended to clarify the scope of the present disclosure. This application claims priority based on Japanese Patent Application No. 2023-138429, filed August 28, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. An active oxygen treatment apparatus comprising: an ozone UFB-containing liquid production section for producing an ozone UFB-containing liquid in which ultra-fine bubbles containing ozone are contained in the liquid; a first storage section for storing the ozone UFB-containing liquid; an energy imparting device for imparting to the ozone UFB-containing liquid stored in the first storage section the energy required to decompose at least a portion of the ozone contained in the ultra-fine bubbles into active oxygen, thereby decomposing at least a portion of the ozone into active oxygen; and an active oxygen UFB-containing liquid supplying device for supplying to a workpiece the active oxygen UFB-containing liquid in which ultra-fine bubbles containing active oxygen are contained in the liquid, the active oxygen UFB-containing liquid having been produced in the first storage section by decomposing at least a portion of the ozone in the ultra-fine bubbles into active oxygen through the imparting of energy.

2. The active oxygen treatment device according to claim 1, further comprising a second storage section, the second storage section being configured to receive the active oxygen UFB-containing liquid generated in the first storage section.

3. The active oxygen treatment device according to claim 2, wherein the active oxygen UFB-containing liquid supply device is configured to be capable of supplying the active oxygen UFB-containing liquid stored in the second storage section to the object to be treated.

4. The active oxygen treatment device according to any one of claims 1 to 3, wherein the active oxygen UFB-containing liquid supply device comprises a spray device for spraying the active oxygen UFB-containing liquid onto the object to be treated.

5. The content per unit volume of the ultra-fine bubbles having a bubble diameter of 500 nm or less in the ozone UFB-containing liquid is 1.0 x 10 ６ ~1.0 x 10 １０ The active oxygen treatment device according to any one of claims 1 to 4, wherein the concentration of the active oxygen is 1 / mL.

6. The active oxygen treatment device according to any one of claims 1 to 5, further comprising an ozone generator that supplies the ozone to the ozone UFB-containing liquid production section, the ozone generator being a plasma actuator having a first electrode and a second electrode sandwiching a dielectric, and applying a voltage between the first electrode and the second electrode to generate an induced flow containing the ozone.

7. The active oxygen treatment device according to any one of claims 1 to 6, wherein the energy imparting device is an ultraviolet ray irradiation device equipped with an ultraviolet ray light source.

8. A treatment method using active oxygen, comprising: (1) an ozone UFB-containing liquid production process for producing an ozone UFB-containing liquid in which ultra-fine bubbles containing ozone are contained in the liquid; (2) a storage process for storing the produced ozone UFB-containing liquid in a first storage section; (3) a process for providing the ozone UFB-containing liquid stored in the first storage section with energy required for decomposing at least a portion of the ozone contained in the ultra-fine bubbles into active oxygen, thereby decomposing at least a portion of the ozone into active oxygen, thereby preparing an active oxygen UFB-containing liquid in which the ultra-fine bubbles containing the active oxygen are contained in the liquid; and (4) an active oxygen UFB-containing liquid supply process for supplying the active oxygen UFB-containing liquid stored in the first storage section to an object to be treated.

9. A method for treatment using active oxygen as described in claim 8, wherein the step (3) involves imparting energy to the ozone UFB-containing liquid in the first storage section without flowing the ozone UFB-containing liquid into the first storage section or outflowing the ozone UFB-containing liquid from the first storage section.

10. An ozone UFB-containing liquid generating device that generates an ozone UFB-containing liquid in which ultra-fine bubbles containing ozone are contained in the liquid, the ozone UFB-containing liquid generating device comprising: a liquid storage section for storing a liquid, the liquid storage section comprising: a UFB generating device that produces a UFB-containing liquid in which the liquid stored in the liquid storage section contains the ultra-fine bubbles; and a plasma actuator, the plasma actuator having a first electrode and a second electrode sandwiching a dielectric, and generating an induced flow containing the ozone by applying a voltage between the first electrode and the second electrode, the plasma actuator being positioned so that the induced flow flows inside the liquid storage section.

11. The ozone UFB-containing liquid manufacturing apparatus according to claim 10, wherein the UFB generator includes an ultrasonic vibrator that causes the liquid to contain and spray the ultra-fine bubbles.

12. The ozone UFB-containing liquid manufacturing device according to claim 10 or 11, wherein when the plasma actuator is installed in a container and operated to sample gas inside the container and measure the ozone concentration (ppm), the amount of ozone generated per unit time calculated by the following formula (A) is 15 μg / min or more. Formula (A) Ozone generation amount per unit time (μg / min) = Measured ozone concentration (ppm) x Molecular weight of ozone / 22.4 x 273 / (273 + Room temperature (°C)) x Gas volume in container (L)

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