JP2023056155A - Inactivation device and inactivation method - Google Patents

Abstract

To provide an inactivation device and inactivation method, capable of simply inactivating adverse microorganisms and viruses existing in an environment in which fishes and shellfishes exist without exerting a bad influence on the fishes and shellfishes.SOLUTION: An inactivation device inactivates microorganisms and/or viruses by radiating ultraviolet light. The inactivation device comprises: a light source unit having a light source for radiating ultraviolet light having a wave length equal to or longer than 200 nm and equal to or shorter than 240 nm; and a support body for supporting the light source unit so that ultraviolet light to be radiated from the light source is to be radiated to an inner surface of a section unit that stores fishes and shellfishes and water and has a side surface and a bottom surface.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to an inactivation device and an inactivation method for inactivating harmful microorganisms and viruses.

Traditionally, fish and shellfish have been artificially farmed or bred. For example, fish and shellfish that are consumed as food are artificially bred in aquaculture tanks or in a predetermined area in the sea surrounded by nets and put on the market. In addition, depending on the type of fish and shellfish, it is temporarily kept in a fish tank when it is served to retailers and restaurants. In addition, fish and shellfish such as ornamental fish are raised in domestic water tanks and aquarium tanks.

If pathogenic bacteria (microorganisms, viruses, etc.) occur in the environment where the above fish and shellfish are artificially cultivated and reared, many fish and shellfish living in the same environment will be infected with the pathogen, and in the worst case, be annihilated.
In addition, algae tend to adhere to aquaculture nets for cultivating fish and shellfish and the inner surfaces (sides and bottoms) of tanks for breeding fish and shellfish, and these algae can serve as hotbeds for pathogenic bacteria. Therefore, in order to suppress the growth of pathogenic bacteria, it is necessary to remove algae that can serve as hotbeds for pathogenic bacteria.

For example, Patent Literature 1 discloses a water purifier that removes blue-green algae by irradiating blue-green algae-containing water containing blue-green algae (blue-green algae) with ultraviolet rays. This water purifier has a configuration in which water containing blue-green algae is taken with a hose and a pump, a coagulant is mixed with the taken-in water containing blue-green algae to coagulate and precipitate the blue-green algae, and ultraviolet rays having a wavelength of 200 to 280 nm are irradiated. . In this patent document 1, the ultraviolet rays to be irradiated to water containing blue-green algae are preferably ultraviolet rays having a wavelength of about 270 nm, which matches the absorption wavelength of the DNA of cells such as algae. The point of use is disclosed.

JP 2020-99846 A

In an environment where fish and shellfish live (e.g., in an aquarium), in order to effectively suppress the infection of pathogenic bacteria to fish and shellfish, the water itself in which the fish and shellfish live and the tanks that form the environment in which the fish and shellfish live It is preferable to inactivate pathogenic bacteria present in the entire environment, such as the inner surface of the body, and to kill algae that can serve as hotbeds for the pathogenic bacteria.
As described in Patent Document 1, by irradiating the entire environment with ultraviolet rays having a wavelength (for example, a wavelength of 253.7 nm) that has a strong bactericidal effect and effectively destroys cells such as algae, the above It is possible to inactivate pathogenic bacteria present in the environment and to kill algae that can serve as hotbeds for pathogenic bacteria.

However, when irradiating the entire environment where fish and shellfish exist as described above, it is almost impossible to irradiate only the water and the inner surface of the tank with UV light without irradiating the fish and shellfish existing in the environment with UV light. Impossible. When fishes and shellfishes are also irradiated with the ultraviolet rays, the cells of the fishes and shellfishes are also damaged, and in some cases, the fishes and shellfishes die.
If the seafood is evacuated from the environment and stored in another area, and the entire environment is irradiated with ultraviolet rays, a suitable effect can be obtained, but evacuating the seafood from the environment is a large-scale task. is not practical because

Therefore, the present invention provides an inactivation device and an inactivation method that can easily inactivate pathogenic bacteria (microorganisms, viruses, etc.) without adversely affecting fish and shellfish in an environment where fish and shellfish exist. is an issue.

In order to solve the above problems, one aspect of the inactivation device according to the present invention is an inactivation device that emits ultraviolet rays to inactivate microorganisms and/or viruses, and emits ultraviolet rays having a wavelength of 200 nm or more and 240 nm or less. a light source unit having a light source, a support supporting the light source unit so as to irradiate the ultraviolet rays emitted from the light source to the inner surface of a compartment containing fish and shellfish and water and having a side surface and a bottom surface; Prepare.

In this way, by irradiating the inner surface of the compartment containing seafood and water with ultraviolet rays having a wavelength of 200 nm or more and 240 nm or less, algae that can become a hotbed for pathogenic bacteria (microorganisms, viruses, etc.) attached to the inner surface are killed. can be algae. At this time, at least a portion of the water contained in the compartment can also be irradiated with ultraviolet rays, so pathogenic bacteria present in the water can be inactivated.
Here, the ultraviolet rays with a wavelength of 200 nm or more and 240 nm or less are ultraviolet rays that do not generate ozone, are absorbed by the protein components on the surface of the fish and shellfish, and do not penetrate inside the fish and shellfish. Therefore, it is possible to inactivate pathogenic bacteria present in the environment where seafood exists and to kill algae that can serve as hotbeds for the pathogenic bacteria without damaging the seafood.

Moreover, in the inactivation device described above, the light source section may be arranged in water in a region partitioned by the partition section.
In this case, desired ultraviolet irradiation can be realized more efficiently. For example, when ultraviolet rays are irradiated from above a region partitioned by partitions, part of the ultraviolet rays may be absorbed by water and the ultraviolet rays may not reach the bottom surface. By arranging the light source part in the water, it is possible to reliably irradiate the ultraviolet rays to the bottom surface and the like. Furthermore, even when the partition is made of a material that does not or does not easily transmit ultraviolet rays, the inside of the partition can be appropriately irradiated with ultraviolet rays.

Further, in the inactivation device described above, the light source unit includes a housing containing the light source therein and having a light emitting surface for emitting the ultraviolet rays, and the housing defines a closed space for housing the light source. may be formed.
In this case, since the light source can be housed in a waterproof housing, the light source can be immersed in water to appropriately irradiate ultraviolet rays in the water. Therefore, for example, it is not necessary to use a light guide member or the like to guide the ultraviolet rays emitted from the light source arranged outside into the water.

Further, in the above deactivation device, the light source unit transmits ultraviolet rays having a wavelength of 200 nm or more and 240 nm or less between the light source and the light emitting surface inside the housing, and the wavelength is longer than 240 nm. may be provided with an optical filter that blocks the transmission of UV-C waves.
In this case, it is possible to irradiate only light in a wavelength range that has little adverse effect on fish and shellfish, human bodies, and animals. Also, since the optical filter is arranged in a sealed housing, the optical filter can be prevented from coming into contact with water.

In addition, in the inactivation device described above, the light source may be arranged above the region partitioned by the partition, and irradiate the ultraviolet rays toward the surface of the water.
In this case, it is not necessary to provide a waterproof mechanism in the light source section, and the device configuration can be simplified.

Further, in the inactivation device described above, the light source unit is arranged on the side of the area partitioned by the partitioning part made of a member that transmits the ultraviolet rays, and the ultraviolet rays are directed toward the outer surface of the partitioning part. may be irradiated.
In this case, the inner surface of the partition can be irradiated with ultraviolet rays from the vicinity of the inner surface. In addition, when ultraviolet rays are irradiated toward the outer surface of the partition, part of the ultraviolet rays may be diffusely reflected on the outer surface and irradiated to the person, but the ultraviolet rays with a wavelength of 200 nm to 240 nm are also effective for humans in principle. is safe, so there is no problem. In other words, even in an environment where people are present in the vicinity of the compartment such as a water tank, it is possible to inactivate pathogenic bacteria and kill algae by irradiating ultraviolet rays safely to people.

Furthermore, in the inactivation device described above, the light source may be arranged so as to be able to irradiate the ultraviolet rays over the entire length of the side surface of the partition in the up-down direction.
In this case, it is possible to evenly irradiate the side surfaces of the compartment with ultraviolet rays, and effectively suppress the propagation of algae.

Further, the deactivation device may include a scanning mechanism that moves at least one of the light source and the partition so that the ultraviolet rays scan the inner surface of the partition.
In this case, it is possible to evenly irradiate the side surfaces of the partition with ultraviolet rays with a small number of light sources, and to effectively suppress the propagation of algae.

Furthermore, in the above inactivation device, the light source may irradiate the inner surface of any one of the compartments, such as a water tank, a fish preserve, a net surrounding a specific sea area, or an artificial pond, with the ultraviolet rays.
In this case, in an environment where fish and shellfish are artificially bred, bred, and enjoyed, pathogenic bacteria can be inactivated from the entire environment where fish and shellfish exist, and algae that can serve as hotbeds for pathogenic bacteria can be killed.

In addition, one aspect of the inactivation method according to the present invention includes a step of radiating ultraviolet rays having a wavelength of 200 nm or more and 240 nm or less from a light source; to inactivate microorganisms and/or viruses that may be present on at least one of said water and said inner surface.

In this way, by irradiating the inner surface of the compartment containing seafood and water with ultraviolet rays having a wavelength of 200 nm or more and 240 nm or less, algae that can become a hotbed for pathogenic bacteria (microorganisms, viruses, etc.) attached to the inner surface are killed. can be algae. At this time, at least a portion of the water contained in the compartment can also be irradiated with ultraviolet rays, so pathogenic bacteria present in the water can be inactivated.
Here, the ultraviolet rays with a wavelength of 200 nm or more and 240 nm or less are ultraviolet rays that do not generate ozone, are absorbed by the protein components on the surface of the fish and shellfish, and do not penetrate inside the fish and shellfish. Therefore, it is possible to inactivate pathogenic bacteria present in the environment where seafood exists and to kill algae that can serve as hotbeds for the pathogenic bacteria without damaging the seafood.

INDUSTRIAL APPLICABILITY In the present invention, pathogens (microorganisms, viruses, etc.) can be easily inactivated in an environment where fish and shellfish are present, without adversely affecting the fish and shellfish.

It is a figure which shows the ultraviolet absorption spectrum of protein. It is a figure which shows an example of the application scene of the deactivation apparatus in this embodiment. It is a figure which shows another example of the application scene of the inactivation apparatus in this embodiment. It is a figure which shows another example of the application scene of the inactivation apparatus in this embodiment. It is a figure which shows another example of the application scene of the inactivation apparatus in this embodiment. It is a schematic diagram which shows the structural example of an ultraviolet irradiation unit. FIG. 4 is a schematic diagram showing another example of an ultraviolet irradiation unit; FIG. 4 is a schematic diagram showing another example of an ultraviolet irradiation unit; FIG. 4 is a schematic diagram showing another example of an ultraviolet irradiation unit; FIG. 4 is a schematic diagram showing another example of an ultraviolet irradiation unit; FIG. 4 is a schematic diagram showing another example of an ultraviolet irradiation unit; FIG. 4 is a schematic diagram showing another example of an ultraviolet irradiation unit;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
In this embodiment, an environment where seafood exists is irradiated with ultraviolet rays to inactivate pathogenic bacteria (microorganisms, viruses, etc.) present in the environment, and algae (microalgae such as moss) present in the environment. An inactivation device that kills algae will be described.
The term “inactivation” as used in the present embodiment refers to killing microorganisms or viruses (or losing their infectivity or toxicity).

Here, the environment in which the fish and shellfish exist is an environment that is partitioned by partitions having side surfaces and a bottom surface and contains water. The compartment may be a water tank, a fish preserve, a net surrounding a specific sea area, an artificial pond, or the like. The water tank can be, for example, a fish and shellfish farming site, a distribution vehicle, an aquarium, or a water tank used for home viewing. Also, the fish tank can be a fish tank used in stores, restaurants, food processing plants, markets, and the like, for example.
Further, in the present embodiment, the target fish and shellfish that can be irradiated with ultraviolet rays are fish and shellfish that have scales on the surface and body surface mucilage generally called "slimy" and that can live in water. and

The inactivation device in the present embodiment irradiates an environment where fish and shellfish exist with ultraviolet rays having a wavelength of 200 nm to 240 nm, which has little adverse effect on fish and shellfish. Inactivates microorganisms and viruses.
In practice, the wavelength range of ultraviolet rays used for decontamination (sterilization) is 200 nm to 320 nm, and in particular, nucleic acids (DNA, RNA) possessed by pathogenic bacteria (microorganisms, viruses, etc.) 260 nm has a large absorption. It is common to use near ultraviolet light. However, such ultraviolet rays in the wavelength region around 260 nm are strongly absorbed by nucleic acids in humans, animals, and fish and shellfish, and can have an adverse effect on humans, animals, and fish and shellfish.

FIG. 1 is a diagram showing ultraviolet absorption spectra of proteins.
As shown in FIG. 1, protein has an absorption peak at a wavelength of 200 nm, and it can be seen that ultraviolet rays are hardly absorbed at a wavelength of 240 nm or longer.
The surface of seafood (especially fish) is covered with scales composed of keratin, collagen, calcium phosphate, etc., and body surface mucilage (slimy) containing a large amount of glycoprotein, generally called mucin.

In other words, ultraviolet light with a wavelength of 240 nm or longer easily penetrates body surface mucilages and scales, which are protein components on the surface of fish and shellfish, and penetrates deep into the body surface of fish and shellfish. Therefore, the cells inside the body surface of fish and shellfish are easily damaged. On the other hand, ultraviolet rays with a wavelength of around 200 nm are absorbed by glycoproteins, which are the main components of body surface mucilage on the surface of fish and shellfish, and proteins that constitute part of scales, and do not permeate inside the body surface of fish and shellfish. Therefore, it is safe for the body surface of fish and shellfish.
In addition, ultraviolet light with a wavelength of 240 nm or more easily penetrates the skin of humans and animals, and penetrates deep into the skin. Therefore, the cells in the human skin are easily damaged. On the other hand, ultraviolet light with a wavelength of around 200 nm is absorbed by the human skin surface (for example, the stratum corneum) and does not penetrate into the skin. Therefore, it is safe for human and animal skin.

On the other hand, ultraviolet rays with a wavelength of less than 200 nm can generate ozone (O ₃ ). This is because when ultraviolet rays with a wavelength of less than 200 nm are irradiated in an oxygen-containing atmosphere, oxygen molecules are photodecomposed to generate oxygen atoms, and ozone is generated by a bonding reaction between the oxygen molecules and the oxygen atoms. be.
Therefore, it can be said that the wavelength range of 200 nm to 240 nm is a safe wavelength range for fish and shellfish, humans and animals. The safe wavelength range for fish and shellfish, humans and animals is preferably 200 nm to 237 nm, more preferably 200 nm to 235 nm, even more preferably 200 nm to 230 nm.
For example, ultraviolet rays with a wavelength of 222 nm emitted from a KrCl excimer lamp and ultraviolet rays with a wavelength of 207 nm emitted from a KrBr excimer lamp are both safe for fish, shellfish, humans, and animals, and do not kill pathogenic bacteria (microorganisms, viruses, etc.). It is the light that can do the inactivation.

Application scenes of the inactivation device according to the present embodiment will be described below.
[Example 1]
In FIG. 2, the environment in which the fish and shellfish 200 exist is a water tank 311, and the water 312 in the water tank 311 and the inner surface of the water tank 311 are irradiated with ultraviolet rays, and the water 312 in the water tank 311 and the inner surface of the water tank 311 contain ultraviolet rays. It is a figure which shows the structural example of 100 A of inactivation apparatuses which inactivate pathogenic microbes.
Here, the water tank 311 can be, for example, a water tank installed in a transport vehicle for distributing fish and shellfish, a fish tank at a transportation destination, a water tank at an aquaculture site, a water tank in which fish and shellfish for appreciation are bred, and the like.

In FIG. 2, only the ultraviolet light source 110 and the wavelength selection filter (optical filter) 111 provided in the light source unit constituting the deactivation device 100A are shown, and other configurations are omitted. .
The light source part of the inactivation device 100A is supported by a support (not shown) so that the inner surface of the water tank 311 is irradiated with the ultraviolet rays emitted from the ultraviolet light source 110 . The support is attached to, for example, a ceiling, wall, water tank, or other structure to support the light source.
The ultraviolet light source 110 is arranged above the water tank 311 and irradiates the water surface of the water 312 contained in the water tank 311 with ultraviolet rays (UV). The ultraviolet rays irradiate the inner surface (side surface, bottom surface) of the water tank 311 , the water 312 in the water tank 311 , and the fish and shellfish 200 in the water tank 311 .

The ultraviolet light source 110 emits, as the ultraviolet rays, ultraviolet rays in a wavelength range of 200 nm to 240 nm which has little adverse effect on fish and shellfish. The ultraviolet light source 110 can be, for example, a KrCl excimer lamp that emits ultraviolet rays with a central wavelength of 222 nm, or a KrBr excimer lamp that emits ultraviolet rays with a central wavelength of 207 nm.
The ultraviolet light source 110 is not limited to the excimer lamp described above, and may be an LED light source, an LD light source, or a coherent light source that converts the wavelength of laser light emitted from laser light to emit ultraviolet light in the above wavelength range. There may be.

However, depending on the ultraviolet light source, in addition to the above-mentioned ultraviolet rays with a wavelength of 200 nm to 240 nm, light containing wavelengths that are not considered safe for fish, humans, and animals may also be emitted. Therefore, in order to cut light of such wavelengths, for example, as shown in FIG. A wavelength selection filter 111 that cuts light in the UV-C region (200 nm to 280 nm) may be provided.
As a result, ultraviolet rays with a wavelength of 200 nm to 240 nm can be selected by the wavelength selection filter 111 from light including ultraviolet rays emitted from the ultraviolet light source 110, and the surface of the living fish 200 can be irradiated with the selected ultraviolet rays.
In this embodiment, a case where the deactivation device 100A includes the wavelength selection filter 111 will be described, but the wavelength selection filter 111 may be separate from the deactivation device 100A.

Ultraviolet rays with a wavelength of 200 nm to 240 nm emitted from the light source unit are irradiated to the inner surface (side surface and bottom surface) of the water tank 311, and can kill algae (moss, etc.) adhering to the inner surface.
Moreover, the ultraviolet rays irradiate the water 312 in the water tank 311 and can inactivate pathogenic bacteria present in the water 312 .
The ultraviolet rays may also irradiate the seafood 200 in the water tank 311, but the seafood 200 is not damaged. The term "damage" as used herein includes threatening the survival of seafood, impairing the flavor of seafood, and the like.

The surface of the fish and shellfish 200 growing in water is covered with scales and body surface mucilage (slimy) containing a large amount of glycoprotein. The ultraviolet rays irradiated at 200 are absorbed by glycoproteins, which are the main components of body surface mucilage on the surface of fish and shellfish, and proteins constituting a part of scales, and can be prevented from penetrating into the inside of fish and shellfish.
Therefore, even if the entire environment in which the fish and shellfish 200 exist (the entire water tank 311) is irradiated with ultraviolet rays, even if the ultraviolet rays are irradiated to the fish and shellfish 200 existing in the environment, the inside of the fish and shellfish will not be damaged. It is possible to inactivate pathogenic bacteria contained in the water tank 312 and kill algae adhering to the inner surface of the water tank 311 .

[Modification 1]
In Example 1 shown in FIG. 2, the inactivation device 100A is arranged above the water tank 311, and the water 312 stored in the water tank 311 and the inner surface (of the water tank 311) are emitted from the ultraviolet light source 110 arranged above the water tank 311. and fish and shellfish in water), but the arrangement of the inactivation device 100A is not limited to this.
For example, when the water tank 311 is made of a material having ultraviolet transmittance such as quartz glass, the inactivation device 100B may be arranged on the side of the water tank 311 as shown in FIG. In this case, the inactivation device 100B may have the same configuration as the inactivation device 100A.

When algae (moss-like algae) 313 adhere to and proliferate on the inner side (the side in contact with water 312) of the side wall that constitutes the water tank 311, the visibility of ornamental fish and the like raised in the water tank 311 deteriorates. In addition, the algae 313 themselves can also serve as a hotbed for the pathogenic bacteria described above.
As shown in FIG. 3, the deactivation device 100B is arranged to face the outer surface of the water tank 311, and the ultraviolet light source 110 irradiates the outer surface of the water tank 311 with ultraviolet rays, thereby making the water tank 311 transparent to ultraviolet rays. , the ultraviolet rays pass through the sidewall of the water tank 311 and irradiate the algae 313 adhering to the inner surface (inner surface) of the water tank 311 . In this case, since the ultraviolet rays can be irradiated from the vicinity of the algae 313, it is possible to efficiently kill the algae 313 and inactivate pathogenic bacteria in the vicinity of the algae 313.

In addition, when ultraviolet rays are irradiated from the side of the water tank 311 toward the outer surface of the water tank 311 , part of the ultraviolet rays may be irregularly reflected by the surface of the water tank 311 . For example, when the water tank 311 is an ornamental water tank or an aquarium tank, there are many chances that people are present near the water tank 311, and the diffusely reflected ultraviolet rays may irradiate the people. Further, even when the water tank 311 is a water tank for aquaculture, a fish tank, or the like, a worker in the vicinity thereof may be irradiated with irregularly reflected ultraviolet rays.

However, as described above, ultraviolet rays with a wavelength of 200 nm to 240 nm are in principle safe for humans, and if the allowable irradiation dose is not exceeded, the skin of the person who watches the fish and shellfish in the aquarium and the worker. There is no problem even if it hits your eyes.
In addition, the illuminance of the ultraviolet rays that are diffusely reflected and irradiated to the person as described above is relatively small, and the ultraviolet irradiation time to the person who is watching or working is not so long. Therefore, during normal viewing or working, the amount of UV irradiation to a person hardly reaches the allowable amount of irradiation. Therefore, even in a space where people exist, inactivation and algicide treatment by ultraviolet irradiation can be performed safely for people.

In addition, as shown in FIG. 3, the inactivation device 100C may be placed in the water 312 contained in the water tank 311 . Note that FIG. 3 shows only the ultraviolet light source 110 of the inactivation device 100C and omits other configurations. This inactivation device 100C has a waterproof mechanism that can be immersed in water. The mechanism will be described later. Note that the inactivation devices 100A to 100C may have the same configuration.
In this way, even when the inactivation device 100C is placed in water and the ultraviolet light source 110 in water irradiates the inside (for example, the center) of the water tank 311 with ultraviolet rays, the inner surface of the water tank 311 and the water in the water tank 311 312 , the ultraviolet rays are applied to the fish and shellfish 200 in the water tank 311 .

For example, in an aquarium used for cultivating fish and shellfish, seawater is often used as water to be stored in the aquarium. When the water in the water tank is seawater, part of the ultraviolet rays having a wavelength of about 220 nm is absorbed by the seawater.
By arranging an ultraviolet light source in water and irradiating ultraviolet rays from water, ultraviolet rays are emitted from the ultraviolet light source 110 arranged outside the water tank 311 (above or on the side of the water tank 311) like the inactivation devices 100A and 100B. Pathogens (microorganisms, viruses, etc.) contained in the water 312 can be inactivated more efficiently than in the case of

The number and positions of the inactivation devices 100A, 100B, and 100C are not limited to those shown in FIG.
For example, the arrangement position of the inactivation device 100C is not limited to the vicinity of the side wall of the water tank 311 as shown in FIG. For example, the inactivation device 100C may be arranged in the center of the water tank 311, depending on the size and use of the water tank 311 (whether it is for ornamental purposes or for aquaculture).

[Modification 2]
In Modification 1 shown in FIG. 3, the inactivation device 100B irradiates the algae 313 adhering to the inner surface of the water tank 311 from the outside of the water tank 311 with ultraviolet rays. The ultraviolet irradiation of the algae 313 adhering to the surface is not limited to this.
For example, as shown in FIG. 4, an inactivation device 100D may be placed in water, and the algae 313 adhering to the inner surface of the water tank 311 may be irradiated with ultraviolet rays from the ultraviolet light source 110 in the water. In this case, even if the water tank 311 is made of a material such as acrylic that does not transmit ultraviolet rays, the inner surface of the water tank 311 can be appropriately irradiated with ultraviolet rays. Also, at this time, by arranging the inactivation device 100D in the vicinity of the inner surface of the water tank 311 in the water, it is possible to irradiate the algae 313 adhering to the inner surface of the water tank 311 with ultraviolet rays from the vicinity of the inner surface of the water tank 311 .

Moreover, as shown in FIG. 4, the inactivation device 100D may be configured to be capable of irradiating ultraviolet rays in a plurality of directions. As a result, even the water 312 in the water tank 311 can be sufficiently irradiated with the ultraviolet rays.
Here, the deactivation device 100D is provided with a waterproof mechanism capable of being immersed in water, like the deactivation device 100C. Note that FIG. 4 shows only the ultraviolet light source 110 of the inactivation device 100D, and omits other configurations.

Furthermore, as shown in FIG. 4, multiple inactivation devices 100C may be placed in the water. At this time, the irradiation directions of the ultraviolet rays of the plurality of deactivation devices 100C may be different from each other.
For example, ultraviolet rays may be irradiated toward the bottom surface of the water tank 311 from the deactivation device 100C placed underwater. As a result, the algae 314 existing on the bottom surface of the water tank 311 can be appropriately irradiated with ultraviolet rays.

The ecology of algae is diverse, and in addition to mossy algae 313 adhering to the inner surface of the water tank 311, there are algae 314 that grow like threads on the bottom surface of the water tank 311, and algae that float in water (not shown). If such algae grow in an environment where fishes and shellfishes live, the oxygen in the water in the environment becomes deficient, and the putrefaction of the algae produces offensive odors.
In addition, in household aquariums for viewing fish and shellfish, aquarium tanks, and the like, the occurrence of such algae may cause problems such as reduced visibility of the fish and shellfish in the water. Furthermore, even such algae can become hotbeds for pathogenic bacteria present in water, as described above.

As shown in FIG. 4, in addition to the configuration in which ultraviolet rays are irradiated from above the water tank 311 toward the water surface of the water tank 311, ultraviolet rays are emitted from the water in the water tank 311 toward the inside of the water tank 311 and the inner surface (inner side surface and bottom surface) of the water tank 311. By irradiating the ultraviolet rays on the entire environment where the fish 200 exist (the water 312 in the water tank 311 and the inner surface (the inner side surface and the bottom surface) of the water tank 311), the ultraviolet rays can be irradiated. This makes it possible to inactivate pathogenic bacteria contained in the entire environment, and to kill algae (including mossy algae 313 and filamentous algae 314) contained in the entire environment.

The number and positions of the inactivation devices 100A, 100C, and 100D are not limited to those shown in FIG.
Also, in the example shown in FIG. 4, two types of inactivation devices 100C and 100D are placed in water, but only one of them may be placed in water.

[Example 2]
FIG. 5 shows that the environment in which the fish and shellfish 200 exist is a specific area in the sea (specific sea area) partitioned by a net 321, and the seawater 322 in the specific sea area and the inner surface of the net 321 that defines the specific sea area. is a diagram showing a configuration example of an inactivation device that inactivates pathogenic bacteria contained in seawater 322 and a net 321 by irradiating with .
Specifically, it includes an inactivation device 100A that is arranged above a specific sea area and irradiates ultraviolet rays toward the sea surface 323, and a plurality of inactivation devices 100D that are arranged in the sea and irradiate ultraviolet rays from underwater. Here, the inactivation devices 100A and 100D may have the same configuration as the above-described inactivation devices 100A and 100D, respectively.

Ultraviolet rays (UV) emitted from the inactivation device 100A are irradiated to the inner surface (side surface) of the net 321, the seawater 322 in the specific sea area partitioned by the net 321, and the fish and shellfish 200 in the specific sea area.
Here, the vertical length of the net 321 is longer than the height of the water tank 311 as in the first embodiment, for example. Therefore, near the lower end of the net 321, the distance from the sea surface 323 is long, and even if the UV light source 110 of the deactivation device 100A irradiates the UV rays toward the sea, there is a possibility that the UV rays will not reach them.
Also, the density of fish and shellfish cultured in the specific sea area partitioned by the net 321 is generally high. Therefore, when ultraviolet rays are irradiated from above the sea surface 323, the ultraviolet rays are blocked by the fish 200 positioned above the specific sea area, and the ultraviolet rays frequently do not reach the seawater 322 positioned below the specific sea area. sell. In that case, there is a high possibility that the inactivation of pathogenic bacteria contained in the seawater 322 below the specific sea area will be insufficient.

Furthermore, it is difficult to irradiate the entire net 321 with ultraviolet rays from above the sea surface 323 . Therefore, there is a high possibility that the inactivation of pathogenic bacteria adhering to the net 321 and the algae killing of algae adhering to the net 321 will be insufficient.

Therefore, as shown in FIG. 5, a plurality of inactivation devices 100D are arranged vertically in water. As a result, it is possible to irradiate ultraviolet rays over the entire length in the vertical direction of the specific area partitioned by the mesh 321 . In other words, it is possible to irradiate the seawater 322 below the specific area partitioned by the net 321 and the entire net 321 with the ultraviolet rays.
As a result, the ultraviolet light is blocked by the fish 200 located above the specific sea area as described above, and the ultraviolet light emitted from the ultraviolet light source 110 installed above the sea surface 323 does not reach the seawater 322 below the specific sea area. Problems are avoided, and pathogenic bacteria contained in the seawater 322 located below the specific sea area can be appropriately inactivated.
In addition, since the entire net 321, which can be a breeding ground for pathogens, can be irradiated with ultraviolet rays, pathogens attached to the net 321 or present in the vicinity of the net 321 can be sufficiently inactivated.

The number and positions of the inactivation devices 100D are not limited to those shown in FIG. The number and positions of the deactivation devices 100D can be appropriately set according to the size (depth, etc.) of the specific sea area partitioned by the net 321.
Further, instead of the inactivation device 100D capable of irradiating ultraviolet rays in a plurality of directions, an inactivation device 100C capable of irradiating ultraviolet rays in a predetermined direction as shown in FIGS. 3 and 4 may be used.

The configurations of the inactivation devices 100C and 100D having a waterproof mechanism will be specifically described below.
FIG. 6 is a schematic diagram showing a configuration example of the inactivation device 100C.
FIG. 6 shows an ultraviolet irradiation unit 10A, which is a portion related to ultraviolet irradiation of the light source section.
The ultraviolet irradiation unit 10A includes, for example, a housing 11 made of conductive metal, and an ultraviolet light source 12 housed inside the housing 11 .

The ultraviolet light source 12 corresponds to the ultraviolet light source 110 described above, and can be, for example, a KrCl excimer lamp that emits ultraviolet light with a central wavelength of 222 nm. The ultraviolet light source 12 is not limited to the KrCl excimer lamp, and may be any light source that emits ultraviolet light within a wavelength range of 200 nm to 240 nm.
The ultraviolet irradiation unit 10A, which is a light source, irradiates ultraviolet rays emitted from an ultraviolet light source (excimer lamp) 12 toward the inner surface of a compartment (water tank 311, net 321, etc.) containing fish and shellfish and water. It is supported by a support (not shown). For example, the support is attached to the water tank 311, the net 321, or other structures to support the light source.

The ultraviolet irradiation unit 10A also includes a power supply unit 16 such as a battery that supplies power to the excimer lamp 12, and a control unit 17 that controls irradiation and non-irradiation of the excimer lamp 12, the amount of ultraviolet light emitted from the excimer lamp 12, and the like. , provided. The excimer lamp 12 is fixed inside the housing 11 by a lamp fixing member 18 .

The housing 11 is formed with an opening 11a serving as a light exit window. The housing 11 is configured to seal the inside except for the portion where the opening 11a is provided.
The opening 11a is provided with a transmission window 11b corresponding to the above-described light emitting surface, and is sealed by a sealing member (not shown). Here, the transmissive window portion 11b is made of an ultraviolet ray transmissive member such as quartz glass.
As described above, since the housing 11 forms a sealed space containing the excimer lamp 12, even if the ultraviolet irradiation unit 10A is immersed in water, water (seawater, etc.) does not enter its interior.

An optical filter 13 is arranged inside the housing 11 between the excimer lamp 12 and the transmission window portion 11b. This optical filter 13 is held by a filter holding member 14 . The optical filter 13 corresponds to the wavelength selection filter 111 described above, and blocks unnecessary light among the light emitted from the excimer lamp 12 .

As the optical filter 13, for example, a wavelength selection filter that transmits light in the wavelength range of 200 nm to 240 nm and cuts light in the other UV-C wavelength range (light of 241 nm to 280 nm) can be used.
Here, as the wavelength selection filter, for example, a dielectric multilayer filter with HfO ₂ layers and SiO ₂ layers can be used.
As the wavelength selection filter, an optical filter having a dielectric multilayer film of SiO ₂ layers and Al ₂ O ₃ layers can also be used.

In this way, by providing the optical filter 13, the light transmitted through the transmission window 11b and emitted to the outside of the housing 11 is in the UV-C wavelength range of 241 nm or more, which damages people and fish and shellfish. Light is not included.
This optical filter 13 is arranged in a sealed housing 11 . Therefore, even when the deactivation device 100C is immersed in water, the optical filter 13 can be prevented from coming into contact with water, and the filter characteristics can be appropriately maintained.
When the optical filter 13 is a dielectric multilayer filter, the transmission wavelength range shifts to the short wavelength side when the incident angle of light is greater than 0 degrees. As close as possible is preferable.

FIG. 7 is a schematic diagram showing a configuration example of the inactivation device 100D.
FIG. 7 shows an ultraviolet irradiation unit 10B, which is a portion related to ultraviolet irradiation of the light source section.
This ultraviolet irradiation unit 10B has the same configuration as the ultraviolet irradiation unit 10A shown in FIG.
By configuring in this way, it becomes possible to irradiate ultraviolet rays in a plurality of directions (horizontal direction in FIG. 7), respectively.

6 and 7 show an example in which the power supply unit 16 and the control unit 17 are provided inside the housing 11, but as shown in FIGS. can be separated from By configuring in this way, it becomes possible to supply power to a plurality of ultraviolet light sources (excimer lamps, etc.) 12 from one power supply unit 16 and to control these plurality of ultraviolet light sources 12 by one control unit 17.
Here, FIG. 8 is a schematic diagram of an ultraviolet irradiation unit 10C having one transmission window 11b of the housing 11, and FIG. 9 is a schematic diagram of an ultraviolet irradiation unit 10D having two transmission windows 11b of the housing 11. It is a schematic diagram.

As shown in FIGS. 8 and 9, the power supply unit 16 and the control unit 17 are arranged in the power supply/control unit case 21 . A feeder line connecting the excimer lamp 12 and the feeder section 16 is housed inside a waterproof tube 22 . Connector portions are provided at both ends of the waterproof tube 22, one end is connected to the receptacle portion 11c provided in the housing 11, and the other end is connected to the receptacle portion 21a provided in the housing 21 for power supply/control unit. connected with
Here, the connecting portions between the connector portion of the tube 22 and the receptacle portions 11c and 21a are configured so that water (such as seawater) does not enter from the outside.
Further, each power supply line is surrounded by an insulating member (not shown). Therefore, even if the feeders come into contact with each other inside the tube or the like, no electrical short circuit occurs.

The ultraviolet irradiation units 10A to 10D shown in FIGS. 6 to 9 are provided with a transmission window portion 11b made of plate-shaped quartz glass in the opening portion 11a of the housing 11, and an ultraviolet light source (excimer lamp) is provided in the housing 11. 12, but the configuration of the ultraviolet irradiation unit is not limited to the above.
For example, as shown in FIG. 10, an ultraviolet-transmitting quartz glass tube (cylindrical tube or rectangular tube) 11b' arranged to surround the ultraviolet light source 12 may be used as the transmission window. In this case, a plurality of optical filters 13 are also arranged side by side so as to surround the ultraviolet light source 12 .

The ultraviolet irradiation unit 10E shown in FIG. 10 includes a quartz glass tube 11b' one end of which is closed, and a support housing 11' that supports the quartz glass tube 11b'.
Inside the quartz glass tube 11b', an excimer lamp 12 arranged coaxially and a plurality of (here, four) optical filters 13 arranged so as to surround it are arranged.
The excimer lamp 12 is fixed by a lamp fixing member 18 inside the quartz glass tube 11b'. The optical filter 13 is fixed to the quartz glass tube 11b' by, for example, welding the end of the optical filter 13 to the inside of the quartz glass tube 11b'. That is, the optical filter 13 is fixed by the welded portion 14a inside the quartz glass tube 11b'.

The opening of the quartz glass tube 11b' in which the excimer lamp 12 and the optical filter 13 are fixed is connected to the support housing 11', and the connection is sealed by a sealing member (not shown).
As a result, the housing of the ultraviolet irradiation unit 10E made up of the support housing 11' and the quartz glass tube 11b' has a structure in which the inside is sealed. water (seawater, etc.) does not enter.

Further, the support housing 11' is provided with a receptacle portion 11c in the same manner as the housing 11 shown in FIGS. The structure of the power supply line connecting the excimer lamp 12 and the power supply part 16 is the same as that shown in FIGS.

In addition, in the ultraviolet irradiation unit 10E shown in FIG. 10, the quartz glass tube 11b' is a cylindrical tube, but the quartz glass tube 11b' is not limited to a cylindrical tube. For example, like the ultraviolet irradiation unit 10F shown in FIG. 11, a rectangular quartz glass tube 11b'' may be used.

Furthermore, in the ultraviolet irradiation unit 10E shown in FIG. 10, a plurality of flat optical filters 13 are arranged inside the quartz glass tube 11b', but the shape of the optical filters 13 is not limited to flat. For example, as in an ultraviolet irradiation unit 10G shown in FIG. 12, a cylindrical optical filter 13a may be used.
When the optical filter is a dielectric multilayer film filter, the dielectric multilayer film is generally provided on the light incident side of the substrate. Therefore, when the substrate is cylindrical, the dielectric multilayer film is applied to the inner side of the cylinder. However, it is difficult to form a dielectric multilayer film inside a cylindrical substrate by vapor deposition or the like.
Therefore, for example, a cylindrical substrate is divided into a plurality of members to form a plurality of gutter-shaped substrates, a dielectric multilayer film is formed on the concave surface side of each gutter-shaped substrate, and then these are combined to form a cylindrical optical device. It may be used as a filter. FIG. 12 shows an example in which four dielectric multilayer filters (optical filters) 13a formed by dividing a cylindrical substrate into four are combined.

As described above, the inactivation device according to the present embodiment includes a light source unit having the ultraviolet light source 110 that emits ultraviolet light with a wavelength of 200 nm or more and 240 nm or less, and the ultraviolet light emitted from the ultraviolet light source 110 is used to separate fish and shellfish and water. a support for receiving and supporting the light source unit for illuminating the inner surface of the compartment having side and bottom surfaces. Here, the division part for storing fish and shellfish and water can be a water tank, a fish tank, a net surrounding and dividing a specific sea area, an artificial pond, or the like.
In this way, in an environment where fish and shellfish are artificially cultivated and reared, since the inner surface of the compartment containing the fish and shellfish and water is irradiated with ultraviolet rays, pathogenic bacteria (microorganisms, viruses, etc.) adhering to the inner surface It can kill algae that can be hotbeds of At this time, at least a portion of the water contained in the compartment can also be irradiated with ultraviolet rays, so pathogenic bacteria present in the water can be inactivated. Therefore, the risk of fish and shellfish being infected with pathogens can be reduced.

The area occupied by the environment in which fish and shellfish are artificially cultivated and bred is generally narrower than the natural environment (rivers, seas, etc.) in which fish and shellfish are nurtured. Therefore, in the above artificial living environment of fish and shellfish, the density of fish and shellfish is high, and there are many opportunities for fish and shellfish to come into contact with each other. Therefore, if a pathogen occurs in such an artificial environment and even one fish is infected with the pathogen, a large number of fish and shellfish are immediately infected with the pathogen, and in the worst case, they are completely destroyed.
In addition, algae tend to adhere to nets that partition specific areas in the sea and to the inner walls (walls in contact with water) of aquariums in which ornamental fish are bred, and these algae can become hotbeds for pathogenic bacteria.

In this embodiment, by irradiating with ultraviolet rays in the artificial environment as described above, it is possible to inactivate pathogenic bacteria present in the environment and to kill algae that can serve as hotbeds for pathogenic bacteria. In this way, it is possible to inactivate pathogens floating in the water between fish and shellfish. In addition, it is possible to suppress the growth of pathogenic bacteria that make a hotbed in the environment containing water (the inner wall of the tank, the bottom surface of the tank, the surface of the net, etc.) near the fish and shellfish. Therefore, in an environment where fish and shellfish exist in high density, it is possible to efficiently suppress infection of fish and shellfish with pathogens.
Furthermore, for example, in the case of an aquarium in which ornamental fish are bred, by killing algae adhering to the walls of the aquarium, it is possible to maintain good visibility of ornamental fish and the like raised in the aquarium.

By the way, it is necessary to periodically replace the water in the aquarium with water that does not contain pathogens or that has inactivated pathogens, and remove algae (moss, etc.) adhering to the walls of the aquarium. By doing so, it is thought that the risk of pathogen infection in the environment where fish and shellfish live can be reduced.
However, even if the amount of pathogenic bacteria is temporarily drastically reduced by operations such as water exchange, it is difficult to completely remove the pathogenic bacteria remaining in the water tank. Therefore, it is difficult to completely suppress the infection of fish and shellfish with pathogenic bacteria through water.
In addition, the work of removing algae adhering to the walls of water tanks, the nets of marine farms, etc. is troublesome, and it is difficult to remove them thoroughly. Particularly in a water tank or the like, algae spores in the air are likely to be mixed in, and the replacement water itself may also be contaminated with spores. Therefore, algae grow in the water tank in a relatively short period of time, and it is necessary to remove the algae frequently.

In the present embodiment, since the inner surface of the compartment containing seafood and water is irradiated with ultraviolet rays having a wavelength of 200 nm or more and 240 nm or less, pathogenic bacteria (microorganisms, viruses, etc.) present in the environment where seafood is present can be easily removed. In addition to being able to inactivate, it is possible to appropriately remove algae that can serve as hotbeds for the pathogenic bacteria.

Here, the ultraviolet rays with a wavelength of 200 nm or more and 240 nm or less are ultraviolet rays that do not generate ozone, are absorbed by the protein components on the surface of the fish and shellfish, and do not penetrate inside the fish and shellfish. Therefore, as a result of irradiating the environment with ultraviolet rays, even if at least some of the fish and shellfish present in the environment are irradiated with the ultraviolet rays, the fish and shellfish are not damaged.
Therefore, there is no need for large-scale work such as evacuating the fish and shellfish from the environment, storing them in a separate area, and irradiating the entire environment with ultraviolet rays. The area can be irradiated with UV light. At this time, an incidental effect of inactivating microorganisms and viruses existing on the surface of fish and shellfish can also be obtained.
In addition, ultraviolet light with a wavelength of 200 nm or more and 240 nm or less is light that has little effect on humans and animals. Therefore, there is no problem even if a person near a water tank or the like is irradiated with ultraviolet light diffusely reflected by the water tank or the like.

As described above, the inactivation device according to the present embodiment can easily inactivate pathogenic bacteria (microorganisms, viruses, etc.) in an environment where seafood exists, without adversely affecting the seafood.

In the above-described embodiment, the ultraviolet light source 110 is placed in the water, and the ultraviolet light source 110 is placed in the water. A light guide member such as a fiber may be used to guide the light into the water. In this case, the waterproof mechanism as shown in FIGS. 6 to 12 is not required, and the device configuration can be simplified.

In addition, in the above-described embodiment, the case where the ultraviolet light source 110 is fixed at a predetermined position has been described. A scanning mechanism may be provided. In this case, the inner surfaces of the water tank 311 and the net 321 can be evenly irradiated with ultraviolet rays with a small number of light sources, and the propagation of algae can be effectively suppressed.
In addition, when the compartment for storing the fish and shellfish and water is a movable storage container such as the water tank 311, the compartment is moved so that the ultraviolet rays scan the inner surface of the compartment such as the water tank 311. , the above scanning mechanism may be realized.

Moreover, in the above embodiment, the case of using an excimer lamp as the ultraviolet light source has been described, but an LED can also be used as the ultraviolet light source.
As the LED, for example, an aluminum gallium nitride (AlGaN)-based LED, an aluminum nitride (AlN)-based LED, a magnesium zinc oxide (MgZnO)-based LED, or the like can be employed.
Here, for the AlGaN-based LED, it is preferable to adjust the Al composition so that the center wavelength is within the range of 200 nm to 240 nm. AlN-based LEDs emit ultraviolet rays with a peak wavelength of 210 nm. Also, the MgZnO-based LED can emit ultraviolet light with a center wavelength of 222 nm by adjusting the composition of Mg.

The AlGaN-based LED and the MgZnO-based LED, which emit ultraviolet rays with a central wavelength of 222 nm, emit ultraviolet rays in a wavelength range that spreads to some extent from the central wavelength of 222 nm, and the light emitted from the LEDs contains a small amount of human energy. and UV wavelengths that are unsafe for animals. Therefore, as in the case where the ultraviolet light source is an excimer lamp, it is preferable to use a dielectric multilayer filter (optical filter) that cuts light in the UV-C wavelength range having wavelengths other than the wavelength range of 200 nm to 240 nm.

However, the above-mentioned AlN-LED emitting ultraviolet rays with a center wavelength of 210 nm does not require the above-mentioned optical filter.
Also, whether the ultraviolet light source is an excimer lamp or an LED, depending on the illuminance on the light emitting surface of the ultraviolet light source, the distance from the ultraviolet light source to the surface to be irradiated with ultraviolet rays, etc. and animal-unsafe wavelengths of UV light may fall below the permissible level. Therefore, in such a case, it is not necessary to provide the optical filter.

According to the inactivation device and the inactivation method according to the present invention, it is possible to provide the original sterilization and virus inactivation capabilities of ultraviolet rays without adversely affecting fish and shellfish and the human body due to ultraviolet irradiation. In particular, unlike conventional inactivation devices and inactivation methods, effective sterilization and inactivation by ultraviolet rays can be performed even in a space where people are present. This corresponds to Goal 3 of the United Nations-led Sustainable Development Goals (SDGs), "Ensure healthy lives and promote well-being for all at all ages", and also to Target 3.3. It will make a significant contribution to “by 2030, end epidemics such as AIDS, tuberculosis, malaria and neglected tropical diseases, and combat hepatitis, water-borne diseases and other communicable diseases”.

DESCRIPTION OF SYMBOLS 10... Ultraviolet irradiation unit 11... Housing 12... Excimer lamp 13... Optical filter 14... Filter holding member 16... Power supply part 17... Control part 18... Lamp fixing member 110... Ultraviolet light source 111... Wavelength selection filter 200 Fish 311 Aquarium 312 Water 313 Algae 321 Net 322 Sea water 323 Sea surface

Claims (10)

An inactivation device that emits ultraviolet rays to inactivate microorganisms and/or viruses,
a light source unit having a light source that emits ultraviolet light having a wavelength of 200 nm or more and 240 nm or less;
a support for supporting the light source so that the ultraviolet rays emitted from the light source are irradiated to the inner surface of a compartment containing fish and shellfish and water and having a side surface and a bottom surface. activation device. 2. The deactivation device according to claim 1, wherein the light source section is arranged in the water in the area partitioned by the partition section. The light source unit
A housing containing the light source inside and having a light emitting surface for emitting the ultraviolet rays,
3. The inactivation device according to claim 2, wherein the housing forms a sealed space that accommodates the light source. The light source unit
An optical filter is provided between the light source and the light emitting surface inside the housing, which transmits ultraviolet rays with a wavelength of 200 nm or more and 240 nm or less and blocks transmission of UV-C waves with a wavelength longer than 240 nm. The inactivation device according to claim 3, characterized in that: 2. The deactivation device according to claim 1, wherein the light source is arranged above the area partitioned by the partition, and irradiates the ultraviolet rays toward the water surface. The said light source part is arrange|positioned at the side of the area|region divided|segmented by the said division part which consists of the member which permeate|transmits the said ultraviolet-ray, and irradiates the said ultraviolet-ray toward the outer surface of the said division part. Item 1. The inactivation device according to item 1. 2. The deactivation device according to claim 1, wherein the light source unit is arranged so as to be able to irradiate the ultraviolet rays over the entire length in the vertical direction of the side surface of the partition unit. 2. The deactivation device according to claim 1, further comprising a scanning mechanism for moving at least one of said light source and said partition so that said ultraviolet rays scan the inner surface of said partition. 9. Any one of claims 1 to 8, wherein the light source unit irradiates the inner surface of any one of the water tank, the fish preserve, the net surrounding the specific sea area, and the artificial pond, which are the division units, with the ultraviolet rays. 3. Inactivation device according to paragraph. a step of emitting ultraviolet rays having a wavelength of 200 nm or more and 240 nm or less from a light source;
The ultraviolet rays emitted from the light source are irradiated toward the inner surface of a compartment containing fish and shellfish and water and having a side surface and a bottom surface, and microorganisms and/or viruses that may exist in at least one of the water and the inner surface. and inactivating.

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