Method for sterilizing water by ultraviolet light

Abstract

To provide a method for sterilizing water by emitting ultraviolet light having sterilization action.SOLUTION: There is provided a method for sterilizing water W by ultraviolet light UV in which a light emitting body 1 emitting ultraviolet light UV is input into water W after waterproof treatment is performed, and water W is sterilized by ultraviolet light UV emitted from the light emitting body 1. Further, the light emitting body 1 emitting ultraviolet light UV is arranged in the vicinity of a housing container 5 housing water W, and water W inside the housing container 5 is sterilized by the ultraviolet light UV emitted from the light emitting body 1. Further, a tube 6 through which water W can pass is disposed in a wound state around the light emitting body 1 emitting ultraviolet light UV, water W is allowed to pass through the tube 6, and water W flowing through the tube 6 is sterilized by ultraviolet light UV emitted from the light emitting body 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for disinfecting water using ultraviolet light. [Background technology]

[0002] In recent years, due to the impact of the global coronavirus pandemic, devices that disinfect airborne bacteria and viruses have been attracting attention. For example, the present inventors have come up with a method shown in FIG. This involves placing a light emitting device 10 that emits ultraviolet rays UV in an indoor space, and using the ultraviolet rays UV to sterilize bacteria and the like present in the air (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-167884 Summary of the Invention [Problem to be solved by the invention]

[0004] The sterilization method described in Patent Document 1 can effectively eliminate bacteria in the air, which is highly effective in preventing the spread of airborne infectious diseases such as COVID-19. However, bacteria exist not only in the air but also in water, which poses the risk of infectious diseases spreading from there. For example, if the water in a bathtub at a hot spring facility is contaminated with bacteria, users could become infected with the bacteria. The same is true for water tanks and other water sources. Taking these circumstances into consideration, the present inventors have worked to develop a method for sterilizing water, which has now been completed.

[0005] Therefore, an object of the present invention is to provide a method for sterilizing water by emitting ultraviolet light having a sterilizing effect. [Means for solving the problem]

[0006] In order to achieve the above object, the ultraviolet water disinfection method of the present invention is a method for disinfecting water (W) by ultraviolet (UV), The light-emitting body (1) that emits ultraviolet (UV) rays is waterproofed, and then placed in the water (W), and the water (W) is sterilized by the ultraviolet (UV) rays emitted from the light-emitting body (1).

[0007] The ultraviolet water disinfection method of the present invention is a method for disinfecting water (W) by ultraviolet (UV) rays, The light-emitting body (1) that emits ultraviolet (UV) rays is placed near a storage container (5) that stores water (W), and the water (W) in the storage container (5) is sterilized by the ultraviolet (UV) rays emitted from the light-emitting body (1).

[0008] The ultraviolet water disinfection method of the present invention is a method for disinfecting water (W) by ultraviolet (UV) rays, A tube (6) through which water (W) can pass is wound around the illuminant (1) that emits ultraviolet (UV) light, The water (W) is passed through the tube (6), and the water (W) flowing through the tube (6) is sterilized by the ultraviolet light (UV) emitted from the light-emitting body (1).

[0009] The present invention is also characterized in that the water (W) is passed through the tube (6) only once.

[0010] The present invention is also characterized in that the water (W) is circulated through the tube (6) multiple times.

[0011] Furthermore, the present invention is characterized in that the light emitter (1) is a light emitting diode (LED) that emits UV-A ultraviolet light among the ultraviolet (UV) rays.

[0012] Furthermore, the present invention is characterized in that the light emitter (1) is a light emitting diode (LED) that emits UV-C ultraviolet light out of the ultraviolet (UV) rays.

[0013] Here, the symbols in parentheses indicate corresponding elements or items shown in the drawings and in the detailed description to be described later. [Effects of the Invention]

[0014] According to the ultraviolet water disinfection method of the present invention, an ultraviolet-emitting illuminant is waterproofed, then placed in water, and the water is disinfected by the ultraviolet light emitted from the illuminant, so that water can be reliably disinfected by the ultraviolet light having a disinfecting effect. Furthermore, since the light emitter is placed in the water, all of the ultraviolet light emitted from the light emitter can be made to act on the water.

[0015] Furthermore, according to the ultraviolet water disinfection method of the present invention, an ultraviolet-emitting light-emitting body is placed near a storage container containing water, and the water in the storage container is disinfected by the ultraviolet light emitted from the light-emitting body, so that water can be reliably disinfected by ultraviolet light that has a disinfecting effect. Furthermore, since the light emitter is disposed near the container, there is an advantage that waterproofing is not required.

[0016] Furthermore, according to the ultraviolet water disinfection method of the present invention, a tube through which water can pass is wound around an ultraviolet-emitting light-emitting body, and water is passed through the tube, and the water flowing through the tube is disinfected by the ultraviolet light emitted from the light-emitting body.Therefore, for example, water that is continuously supplied to a bathtub can be disinfected while it is being supplied.

[0017] Furthermore, according to the present invention, water is passed through the tube only once, so that the water can be sterilized quickly and efficiently.

[0018] Furthermore, according to the present invention, the water is circulated through the tube multiple times, so that the water can be sterilized more reliably.

[0019] Furthermore, the present invention is safe and economical because the light emitter is a light emitting diode (LED) that emits UV-A ultraviolet light from among ultraviolet rays. In other words, UV-A ultraviolet rays are the only type of ultraviolet light that does not have the properties to damage nucleic acids (DNA, RNA) in living organisms, so they do not have any adverse effects on the human body.In addition, light-emitting diodes (LEDs) use less electricity than mercury lamps and have a longer lifespan, making them more economical.

[0020] Furthermore, in the present invention, the light emitter is a light emitting diode (LED) that emits UV-C ultraviolet light, which is a type of ultraviolet light, and therefore the disinfecting effect is high and economical. UV-C ultraviolet light has the strongest disinfecting power of all ultraviolet rays, so it can reliably disinfect water. Also, as mentioned above, light-emitting diodes (LEDs) are economical because they use less power and have a long lifespan. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view showing an apparatus for carrying out an ultraviolet water disinfection method according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 10 is a perspective view showing an apparatus for carrying out an ultraviolet water disinfection method according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a perspective view showing an apparatus for carrying out an ultraviolet water disinfection method according to a third embodiment of the present invention. [Figure 4] 1 is a graph showing experimental results of the ultraviolet water disinfection method according to the present invention. [Figure 5] 1 is a table showing experimental results of the ultraviolet water sterilization method according to the present invention. [Figure 6] FIG. 1 is a perspective view showing a conventional light-emitting device that emits ultraviolet light into an indoor space. DETAILED DESCRIPTION OF THE INVENTION

[0022] Referring to FIG. 1, an ultraviolet water sterilization method according to a first embodiment of the present invention will be described. In the ultraviolet water disinfection method according to this embodiment, a light emitter 1 that emits ultraviolet light UV is waterproofed, and then the waterproofed light emitter 1 is placed in a water tank 3 that stores water W. Then, an electric current is passed through the light emitter 1 via a power cord 8, and the water W in the water tank body 3 is sterilized by ultraviolet light UV emitted from the light emitter 1.

[0023] Although there is no limitation on the method of waterproofing the light-emitting body 1, in this embodiment, waterproofing is performed by placing the light-emitting body 1 in a tightly sealed airtight container 2. This airtight container 2 is made of a transparent material that allows ultraviolet light (UV) to pass through more easily, but a colored, opaque material can also be used.

[0024] The type of ultraviolet light UV in this embodiment is not particularly limited, and UV-A (wavelength 380 to 315 nm), UV-B (315 to 280 nm), or UV-C (280 to 200 nm) can be used. UV-A is preferred because it does not adversely affect the human body, but if increased sterilization power is desired, UV-C or UV-B can be used.

[0025] The type of light emitter 1 may be a mercury lamp, a metal halide lamp, or a gallium lamp, but from the standpoint of economy, a light emitting diode (LED) is preferable. The water tank body 3 for storing water W is not limited to this, and may be, for example, a bathtub in a hot spring facility, or a water tank in an apartment building.

[0026] In the ultraviolet water disinfection method of this embodiment, the light-emitting body 1 is placed in the water tank body 3 to disinfect the water W, so that all of the ultraviolet rays UV emitted from the light-emitting body 1 can act on the water W. Therefore, the water W can be disinfected efficiently.

[0027] Referring to FIG. 2, an ultraviolet water sterilization method according to a second embodiment of the present invention will be described. In the ultraviolet water disinfection method according to this embodiment, an illuminant 1 that emits ultraviolet rays UV is placed near a storage container 5 that stores water W, and then the water W in the storage container 5 is disinfected by the ultraviolet rays UV emitted from the illuminant 1 using current supplied through a power cord 8. The illuminant 1 in this embodiment is a light-emitting diode (LED) that emits UV-A ultraviolet rays, but as mentioned above, an LED or mercury lamp that emits UV-B ultraviolet rays or UV-C ultraviolet rays may also be used.

[0028] Unlike the first embodiment, this light-emitting body 1 does not need to be waterproofed, but it can be covered with a sealing member 4 that has sealing properties in consideration of the possibility of water W in the storage container 5 splashing during work. The number of storage containers 5 that store water W is not limited, and can be set appropriately taking into consideration the size of the light-emitting body 1 and the amount of ultraviolet light UV emitted. In addition, the distance between the storage container 5 and the light-emitting body 1 can also be determined depending on the size of the light-emitting body 1 and the amount of ultraviolet light UV emitted.

[0029] The ultraviolet water sterilization method of this embodiment can reliably sterilize water W by ultraviolet rays UV from light emitter 1 placed nearby inside storage container 5. Therefore, the light-emitting body 1 can be moved near the storage container 5, and vice versa, allowing for sterilization suitable for a variety of uses. Furthermore, the light-emitting body 1 does not necessarily need to be waterproofed, so its configuration can be simplified and is economical.

[0030] Referring to FIG. 3, an ultraviolet water sterilization method according to a third embodiment of the present invention will be described. In the ultraviolet water disinfection method according to this embodiment, a tube 6 through which water W can pass is wound around a light emitter 1 that emits ultraviolet light UV, and then water W is passed through the tube 6. The water W flowing through the tube 6 is sterilized by ultraviolet rays UV emitted from the light emitter 1 by current supplied via the power cord 8. In this embodiment, the light emitter 1 is a light emitting diode (LED) that emits UV-A ultraviolet rays, but an LED that emits UV-B ultraviolet rays or UV-C ultraviolet rays may also be used. Also, instead of an LED, another light source that emits ultraviolet rays UV may be used.

[0031] There are no particular limitations on the means for winding the tube 6 around the light emitter 1, but in this embodiment, the tube 6 is placed in a transparent seal container 7 that has sealability. The sealed container 7 is composed of a base 7a and a cover part 7b that is placed on the base 7a and has a generally cylindrical shape with a hemispherical shell-like top, and the light-emitting body 1 is placed on the base 7a. The tube 6 is wound around the outer periphery of the cover part 7b. The number of times that the tube 6 is wound around the cover portion 7b is not limited, and may be multiple times as shown in Figure 3, or may be only once. The tube 6 and the cover portion 7b are preferably transparent, but may also be opaque.

[0032] The ultraviolet water sterilization method of this embodiment involves passing water W through a tube 6 wound around the outer surface of the cover portion 7b of the sealed container 7, and sterilizing the water W flowing inside the tube 6 using ultraviolet light UV from the light-emitting body 1.Therefore, for example, when water W is continuously supplied to a bathtub, an apparatus that implements the method of this embodiment can be interposed in the middle of the supply. This allows sterilized water W to be continuously supplied to the bathtub.

[0033] In the ultraviolet water sterilization method according to the third embodiment, the water W may be passed through the tube 6 only once, or may be circulated multiple times. Passing only once means, for example, supplying water W from the water supply to a bathtub or the like by passing it once through the tube 6. Circulating multiple times means, for example, connecting the start end and end end of the tube 6 to make it endless, circulating the water W in the tube 6 multiple times using the power of a circulation pump or the like, and then opening the end end to supply the water to a bathtub or the like. When the water W is passed through only once, rapid and efficient sterilization is possible, and when the water W is circulated multiple times, sufficiently reliable sterilization is possible.

[0034] The present inventors conducted an experiment to confirm the effect of the ultraviolet water disinfection method according to the present invention. In this experiment, various test strains were mixed into purified water (water W from which mineral components, bacteria, etc. had been removed) to produce test water, and then UV-A ultraviolet light was emitted (irradiated) from a light-emitting element (light-emitting diode) 1 toward the test water.

[0035] The test strains used were S. aureus (Staphylococcus aureus), E. coli (Escherichia coli), P. aeruginosa (Pseudomonas aeruginosa), and L. pneumophila (Legionella pneumophila).

[0036] The reduction rates of various test strains in the test water were confirmed 4 and 7 hours after UV-A irradiation. The results are shown by the solid lines in Figure 4. The dotted lines in the same figure show the reduction rates of various test strains in test water prepared in the same way but left as is without UV irradiation.

[0037] The experimental results in Figure 4 show that in the test water exposed to UV-A, the number of test strains mixed in the water decreased significantly over time, whereas in the test water not exposed to UV, the number of test strains mixed in the water did not decrease. From this, it was confirmed that the ultraviolet water sterilization method according to this embodiment can reliably sterilize water W.

[0038] In addition to the above experiments, the inventors also prepared suspensions by mixing various test strains with physiological saline, not purified water, and then dropped the suspensions onto stainless steel pieces. After irradiating them with UV-A rays, they confirmed the reduction rates of the various test strains after 7 hours. The results are shown in Figure 5.

[0039] The test strains used here were V. parahaemolyticus (Vibrio parahaemolyticus), V. cholerae non-O-1 (Vibrio cholerae non-O-1), S. Typhilmurium (Salmonella typhimurium), E. coli (Escherichia coli), Y. enterocolitica (Yersinia enterocolitica), and L. monocytogenes (Listeria monocytogenes).

[0040] As shown in Figure 5, all of the various bacterial strains exposed to UV-A light showed a reduction rate of over 99 percent. This confirmed that UV-A light can effectively sterilize saline, which is water other than purified water. From this, it can be understood that the ultraviolet water sterilization method according to this embodiment can also be used as a sterilization method for water other than purified water or other liquids.

[0041] It should be noted that the above-mentioned patent documents do not describe at all a method for sterilizing water W using ultraviolet light UV. [Explanation of symbols]

[0042] 1. Light source 2. Airtight containers 3. Aquarium body 4 Sealing material 5. Storage container 6 tubes 7 Sealed container 7a Pedestal 7b Cover 8 Power cord 10. Light-emitting device UV ultraviolet light W water

Claims

1. A method for disinfecting water by ultraviolet light, comprising: The ultraviolet water sterilization method is characterized in that the illuminant that emits ultraviolet light is waterproofed, then placed in the water, and the water is sterilized by the ultraviolet light emitted from the illuminant.

2. A method for disinfecting water by ultraviolet light, comprising: An ultraviolet water sterilization method characterized by placing an ultraviolet-emitting light-emitting body near a storage container containing water, and sterilizing the water in the storage container by the ultraviolet light emitted from the light-emitting body.

3. A method for disinfecting water by ultraviolet light, comprising: a tube through which water can pass is wound around the illuminant that emits ultraviolet light; An ultraviolet water disinfection method, characterized in that water is passed through the tube and the water flowing through the tube is disinfected by the ultraviolet rays emitted from the light-emitting body.

4. The ultraviolet water disinfection method according to claim 3, wherein the water is passed through the tube only once.

5. The ultraviolet water disinfection method according to claim 3, wherein the water is circulated through the tube multiple times.

6. The ultraviolet water disinfection method according to any one of claims 1 to 3, characterized in that the light-emitting body is a light-emitting diode (LED) that emits UV-A ultraviolet rays among the ultraviolet rays.

7. The ultraviolet water disinfection method according to any one of claims 1 to 3, characterized in that the light-emitting body is a light-emitting diode (LED) that emits UV-C ultraviolet rays among the ultraviolet rays.

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