Purification method

Abstract

To provide a method for purifying a space where influence on a person present in the space is reduced as much as possible by reducing an amount of ozone that is generated by irradiated ultraviolet light and convects in the space.SOLUTION: A method for purifying partitioned space includes irradiating ultraviolet light whose peak wavelength falls within the range of 200-235 nm, into the space where an adsorbent having a specific surface area of 1 m2 / g or more is disposed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a purification method, and particularly to a purification method for a partitioned space.

Background Art

[0002] Conventionally, a technique of irradiating ultraviolet light to inactivate bacteria and viruses and purify a space is known. In recent years, since ultraviolet light having a wavelength of less than 240 nm is likely to be absorbed by the human skin surface (for example, the stratum corneum) and is difficult to penetrate into the skin, a purification method and an inactivating device for a space using ultraviolet light in this wavelength band have been proposed. For example, Patent Document 1 below describes an inactivating device that emits ultraviolet light belonging to the range of a peak wavelength of 190 nm or more and less than 240 nm.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, ultraviolet light belonging to the range of less than 200 nm can break the bond of oxygen atoms by irradiating oxygen molecules present in the air. And oxygen atoms whose bonds are broken in the air may react with oxygen molecules present in the vicinity to become ozone. Ozone is a gaseous substance at normal temperature and pressure that has a high oxidizing power and is harmful to the human body with a pungent odor. Also, it is known that even ultraviolet light belonging to the range of 200 nm or more and less than 240 nm may generate a small amount of ozone by being absorbed by oxygen molecules in the air.

[0005] The amount of ozone generated by irradiation with ultraviolet light in the wavelength range depends on the wavelength and radiation intensity of the ultraviolet light irradiated on the oxygen present in the air. Note that the inactivation device as described in Patent Document 1 above is solely aimed at inactivating bacteria, viruses, etc. in the space. Particularly, for ultraviolet light belonging to the range of 200 nm or more and less than 240 nm, the amount of ozone generated in the space hardly exceeds the allowable concentration in a general living space targeted for purification treatment.

[0006] However, as described above, ozone is a substance harmful to the human body. Therefore, even if the amount of ozone generated by the inactivation treatment is extremely small and hardly exceeds the allowable concentration in the space, it is desirable to take measures to further reduce the amount of ozone convecting in the space.

[0007] In addition, considering that the inactivation treatment using ultraviolet light in the above wavelength range is likely to be widely popularized in the future and may be used in an environment where the allowable concentration of ozone is set more strictly than in a general living space, it is extremely important to consider countermeasures against the generated ozone.

[0008] In view of the above problems, an object of the present invention is to provide a space purification method that suppresses the amount of ozone generated by the irradiated ultraviolet light and convecting in the space, and suppresses the influence on people present in the space as much as possible.

Means for Solving the Problems

[0009] The purification method of the present invention is a method for purifying a partitioned space, in the space where an adsorbent having concavo-convex portions on at least a part of its surface and a specific surface area of 1 m 2 / g or more is arranged, ultraviolet light belonging to the range of 200 nm to 235 nm in peak wavelength is irradiated.

[0010] The above purification method is The area of the region where the adsorbent is disposed is A [m 2 , and it is preferable to irradiate the space where the adsorbent is disposed, with the total luminous flux X [mW] of ultraviolet light satisfying the following formula (1), where the effective adsorption surface area of the adsorbent is B [m 2 .

[0011]

Equation

[0012] Furthermore, in the above purification method, it is preferable to irradiate the space where the adsorbent is disposed, with the ultraviolet light, where the effective adsorption surface area B [m 2 is 10 [m 2 or more.

[0013] In this specification, the "area of the region where the adsorbent is disposed" refers to the area of the region exposed in the space in the installed adsorbent. As a specific example of the "area of the region where the adsorbent is disposed", when the adsorbent is a poster attached to the inner wall surface of the space, it corresponds to the area of the surface on the side not in contact with the wall of the poster (that is, the area of the region where the poster is attached), and when it is a poster suspended in the space like an in-train hanging advertisement, it corresponds to the total area of both sides of the poster. Also, in this specification, the "effective adsorption surface area" is the area obtained from the product of the specific surface area [m 2 / g] of the adsorbent and the mass [g] of the adsorbent.

[0014] As a method for solving the above-described problems, the present inventor considered adsorbing ozone generated in the space by irradiation with ultraviolet light onto the surface of the adsorbent, and examined placing an adsorbent for adsorbing convective ozone in the space. Then, in this examination, the present inventor focused on the surface roughness of the adsorbent placed in the space (here, the "surface roughness" is intended to mean the "arithmetic mean roughness"), assuming that the total amount of ozone adsorbed would be related to the surface area of the adsorbent.

[0015] However, when various adsorbents with different surface roughnesses were arranged in the space and the change in ozone concentration was confirmed, no strong correlation that could be judged as effective was found between the surface roughness of the adsorbent and the ozone concentration in the space.

[0016] From the idea that the surface area of the adsorbent should be related to some extent from the principle of adsorption, the inventor was earnestly studying the parameters related to the surface area. As a result, it was confirmed that there is a correlation between the ozone adsorption amount and the specific surface area [m 2 / g] of the adsorbent, which is not seen in the surface roughness of the adsorbent.

[0017] And the inventor confirmed that according to the above method, a space purification method that further suppresses the influence on people existing in the space is realized.

[0018] When gas molecules come into contact with the uneven portions (pore portions) formed on the surface of the adsorbent, they adhere to the surface. And as the gas molecules that have gradually adhered increase, a molecular layer covered with gas molecules is formed on the surface. The adsorption amount V of gas molecules to this molecular layer depends on the adsorption amount V of gas molecules forming the layer (the layer closest to the surface of the adsorbent) that forms the molecular layer, as can be seen from the "BET equation" expressed as the following formula (2). m And it can be seen that the specific surface area is proportional to the product of this adsorption amount V m and the adsorption cross-sectional area. In the following formula (2), P is the adsorption equilibrium pressure, P0 is the saturated vapor pressure, C is a positive parameter related to the heat of adsorption, etc., and it is said that P / P0 accurately matches in the range of 0.05 to 0.35.

[0019]

Equation

[0020] Furthermore, through earnest research, the inventor found that when the specific surface area of the adsorbent is 1 m 2If it is / g or more, it was found that the effect of reducing the ozone concentration is relatively remarkable. Details of these will be described later together with verification experiments in the section "Embodiments for Carrying Out the Invention".

[0021] The above purification method may be a method of irradiating the ultraviolet light into the space where the adsorbent is fixed on the ceiling, wall surface, or floor surface.

[0022] Furthermore, in the above purification method, the adsorbent may be a member having cellulose as a base material.

[0023] Furthermore, in the above purification method, the adsorbent may be a sheet-like or plate-like member attached to the ceiling, wall surface, or floor surface.

[0024] The above purification method may be a method of directly irradiating at least a part of the ultraviolet light emitted from the light source device onto the adsorbent.

[0025] In the above purification method, the adsorbent may be arranged near the light source device that emits the ultraviolet light.

[0026] In this specification, "nearby" is used with the intention that the separation distance is within 300 mm.

[0027] Furthermore, the above purification method may be a method of irradiating the ultraviolet light that is emitted from the light source device and passes through the inside of the cylinder where the adsorbent is arranged on the inner wall surface into the space.

[0028] The amount of ozone generated is the largest near the light source device that emits ultraviolet light. Therefore, in order to adsorb more ozone generated by the irradiation of ultraviolet light, it is preferable to arrange an adsorbent for adsorption near the light source device.

[0029] The above purification method may be a method of irradiating the ultraviolet light into the space in which the adsorbent with the photocatalyst material attached thereto is disposed.

[0030] Furthermore, in the above purification method, the photocatalyst material may be configured such that particles of a metal oxide are dispersed in a base material.

[0031] According to the above method, since the ozone attached to the surface of the adsorbent is decomposed, the amount of ozone desorbing from the surface of the adsorbent is reduced. That is, since the method leads to further reduction of the ozone concentration in the space, it can be said that the method is more preferable from the viewpoint of further suppressing the influence on humans.

[0032] Note that the target product of the present invention does not cause erythema or keratitis on the skin or eyes of humans and animals, and can provide the original sterilization ability of ultraviolet light and the ability to inactivate viruses. In particular, different from conventional light source devices, taking advantage of the feature that it can be used in a manned environment, by installing it in a manned environment indoors and outdoors, the entire environment can be irradiated, and virus suppression and disinfection of the air and the surface of the installation members in the environment can be provided.

[0033] This corresponds to Goal 3 of the Sustainable Development Goals (SDGs) led by the United Nations, "Ensure healthy lives and promote well-being for all people of all ages", and also greatly contributes to Target 3.3, "By 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases, and combat hepatitis, waterborne diseases and other infectious diseases."

Effects of the Invention

[0034] According to the above configuration, a space purification method is realized that suppresses the amount of ozone generated by the irradiated ultraviolet light and convecting in the space, and suppresses the influence on the people existing in the space as much as possible.

Brief Description of the Drawings

[0035]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0036] Hereinafter, the purification method of the present invention will be described with reference to the drawings. Regarding the purification system described as an embodiment of the purification method of the present invention, each of the following drawings is schematically illustrated, and the dimensional ratios and numbers on the drawings do not necessarily match the actual dimensional ratios and numbers.

[0037] [First Embodiment] FIG. 1 is a drawing schematically showing the configuration of the first embodiment of the purification system 1. FIG. 2 is an enlarged cross-sectional view of the surface of the adsorption sheet material 3. FIG. 3 is a perspective view schematically showing the configuration of the light source device 10, and FIG. 4 is a drawing when the light source device 10 of FIG. 3 is viewed toward the light emitting portion 12. As shown in FIG. 1, the purification system 1 includes an adsorption sheet material 3 as an adsorbent installed on the wall surface 2b of the space 2 and a light source device 10 installed on the ceiling 2a of the space 2.

[0038] As shown in Fig. 1, the purification system 1 is a system that irradiates ultraviolet light L1 emitted from the light source device 10 into the space 2 where the adsorption sheet material 3 is installed on the wall surface 2b. Note that the adsorption sheet material 3 may be installed not on the wall surface 2b of the space 2 but on the ceiling 2a, the floor surface 2c, or on an article (for example, a table 4, etc.) installed in the space 2. Further, the light source device 10 may be installed not on the ceiling 2a of the space 2 but on the wall surface 2b, the floor surface 2c, or on an article (for example, a table 4, etc.) installed in the space 2.

[0039] The space 2 in the first embodiment has a floor area of 9 m 2 However, the size of the space 2 is not particularly limited. The space 2 is not limited to, for example, a living space, and for example, a space inside an automobile, a hall where many people gather, etc. are also assumed. Note that the light distribution angle, radiation intensity, etc. of the ultraviolet light L1 emitted from the light source device 10 are appropriately adjusted according to the size of the space 2. However, due to the relationship with the distance that the ultraviolet light L1 reaches while maintaining the intensity sufficient to break the bonds of oxygen molecules, the ozone concentration in the size (volume) of the space 2 will saturate at a certain concentration.

[0040] The adsorption sheet material 3 in the first embodiment is a poster with a specific surface area of 1.75 m 2 / g, in which ink is applied to the surface of the cellulose-based base material 3a to form uneven portions 3b for adsorbing ozone on the surface. Note that the adsorption sheet material 3 is not limited to a poster as long as the specific surface area is 1 m 2 / g or more, and for example, cardboard, painting, cloth, wallpaper, mat, etc. may also be used. Also, the arrangement method of these adsorption sheet materials 3 is arbitrary. For example, it may be attached to the inner wall surface of the space 2, or may be suspended at an arbitrary position in the space 2 by a dedicated gripping member provided on the ceiling 2a.

[0041] Furthermore, the adsorption sheet material 3 may be a portable member and may be a member that is temporarily installed in the space 2 when performing the purification process. When such an adsorption sheet material 3 is adopted, a more suitable adsorption sheet material 3 can be arbitrarily selected according to conditions such as the environment and structure of the space 2 to be treated. Also, if the adsorption sheet material 3 is installed on the ceiling 2a or the wall surface 2b of the space 2, there is no risk of being stepped on or dragged by people coming and going in the space 2. For this reason, it is more desirable that the adsorption sheet material 3 be installed on the ceiling 2a or the wall surface 2b of the space 2.

[0042] Furthermore, if a portion capable of adsorbing ozone with a specific surface area of 1 m 2 / g or more is formed on at least a part of the surface, a member having a shape other than a sheet shape or a plate shape may be arranged in the space 2 as an adsorbent instead of or together with the adsorption sheet material 3.

[0043] Whether the specific surface area is 1 m 2 / g or more is measured using a dedicated device (for example, Belsorp MAXII manufactured by MicrotracBEL).

[0044] As shown in FIG. 3, the light source device 10 includes a housing 11 and a light emitting portion 12 provided on one side surface of the housing 11. And, as shown in FIG. 4, an excimer lamp 13 that emits ultraviolet light with a peak wavelength of 222 nm is mounted inside the housing 11 of the light source device 10.

[0045] The light emitting portion 12 is a window portion equipped with an optical filter (not shown) that substantially transmits ultraviolet light with a wavelength of 200 nm to 235 nm and does not substantially transmit ultraviolet light with a wavelength longer than 240 nm on the main surface of a quartz glass plate material. From the light emitting portion 12, the light that has passed through the optical filter among the light emitted from the excimer lamp 13 is radiated to the outside of the housing 11 as ultraviolet light L1.

[0046] As shown in FIG. 4, the excimer lamp 13 is an ultraviolet light source including a light-emitting tube 13a extending in one direction, and a pair of electrodes (13b, 13b) on which the light-emitting tube 13a is placed and which are spaced apart in the tube axis direction of the light-emitting tube 13a to supply power to the light-emitting tube 13a. Note that as shown in FIG. 4, the excimer lamp 13 of the first embodiment includes a plurality of light-emitting tubes 13a, but the number of light-emitting tubes 13a may be one.

[0047] The light-emitting tube 13a has krypton (Kr) gas and chlorine (Cl) gas sealed therein as a light-emitting gas, and is configured to emit ultraviolet light with a peak wavelength of 222 nm when an AC voltage is applied between the pair of electrodes (13b, 13b).

[0048] Note that the ultraviolet light source mounted on the light source device 10 may be an excimer lamp in which krypton (Kr) gas and bromine (Br) gas are sealed inside the light-emitting tube 13a, and ultraviolet light with a peak wavelength of 207 nm is emitted when an AC voltage is applied between the pair of electrodes (13b, 13b). Further, the ultraviolet light source may be any light source that can emit ultraviolet light belonging to the range of 200 nm to 235 nm in peak wavelength, and is not limited to an excimer lamp, and may be a light source including an LED, a laser light source, or further a light source equipped with a UVC phosphor, a wavelength conversion element, or the like.

[0049] [Second Embodiment] The configuration of the second embodiment of the purification system 1 of the present invention will be described centering on the points different from the first embodiment.

[0050] FIG. 5 is a drawing schematically showing the configuration of the second embodiment of the purification system 1. As shown in FIG. 5, the purification system 1 is configured such that the ultraviolet light L1 emitted from the light source device 10 is directly irradiated onto the adsorption sheet material 3. Further, on the surface of the adsorption sheet material 3 in the second embodiment, a photocatalyst material carrying metal oxide particles is formed. At this time, the adsorption sheet material 3 on which the photocatalyst material is formed has a specific surface area of 1 m 2If it is / g or more, the effect of reducing the ozone concentration will not be impaired. As the photocatalyst material, for example, Fe2O3, Cu2O, In2O3, WO3, Fe2TiO3, PbO, V2O5, FeTiO3, Bi2O3, Nb2O3, TiO2 (rutile type), TiO2 (anatase type), SrTiO3, ZnO3, BaTiO3, CaTiO3, KTaO3, SnO2, ZrO2 can be used. Since the photocatalyst material is dispersed on the surface of the adsorption sheet material 3, when the adsorption sheet material 3 is irradiated with ultraviolet light L1, the photocatalyst material can be activated, and the inactivation effect of bacteria and viruses present in the environment where the adsorption sheet material 3 is installed can be enhanced. Further, a deodorizing effect in the environment can be obtained by the photocatalyst material activated by the ultraviolet light L1. Thereby, in the space 2, reduction of the ozone concentration, deodorization treatment, and inactivation treatment of bacteria and the like are realized, and a higher purification effect can be obtained.

[0051] In addition, in FIG. 5, as shown by the dashed arrow, the light source device 10 may be configured to be able to irradiate the ultraviolet light L1 in an arbitrary direction. Further, the direct irradiation of the ultraviolet light L1 on the adsorption sheet material 3 may be irradiation on at least a part of the adsorption sheet material 3, and may be temporary irradiation.

[0052] Further, the light source device 10 may be configured to be able to control the light distribution angle of the emitted ultraviolet light L1. Furthermore, the purification system 1 may include a human detection unit for detecting whether or not a person is present in the space 2. The human detection unit is, for example, a human sensor, a camera, or the like.

[0053] If the direction of irradiating the ultraviolet light L1 is arbitrary, the purification system 1 can control the direction and area of irradiating the ultraviolet light L1 according to the situation such as the size and shape of the space 2 and whether or not a person is present in the space 2.

[0054] [Verification experiment] Here, when performing the purification treatment of the space 2 using the light source device 10 of the first embodiment, a verification experiment was conducted to confirm how much the ozone concentration in the space 2 changes depending on the adsorbent placed in the space 2, and the details thereof will be described.

[0055] Using each sample shown in Table 1 below as an adsorbent, after turning on the light source device 10 so that the total luminous flux becomes 140 mW in the experimental BOX, the ozone concentration in the experimental BOX was measured and compared at the time of continuous irradiation for 60 minutes. The size of the experimental BOX was 0.27 m in floor area 2 , 0.73 m in height, and 0.198 m in volume 3 .

[0056]

Table 1

[0057] Note that as the photocatalyst material, one in which metal oxide particles are supported on a base material can be adopted. In the samples using the photocatalyst material in Table 1 above, a photocatalyst material in which titanium dioxide (TiO2) particles are supported in the resin serving as the base material was adopted.

[0058] [Results] Regarding each of the above samples, the measurement results of the ozone concentration were as shown in Table 2 below. For the determination, for the samples having an ozone concentration smaller than 0.05 ppm, which is half of the result of Reference Example 1 with nothing, the determination was made as "〇". Regarding the allowable concentration of ozone, the standards vary slightly in each country in the world. However, since the allowable concentration determined by the U.S. Food and Drug Administration (FDA), which is widely referred to in the formulation of standards in each country, is 0.05 ppm, it can be said that it is reasonable to use the fact that it is below 0.05 ppm as a standard even in the light of world standards.

[0059]

Table 2

[0060] As shown in Table 2 above, all of Examples 1 to 3 have a judgment of "〇", and all of Comparative Examples 1 to 5 have a judgment of "×". For Reference Example 2, under the condition that the specific surface area of the adsorbent is slightly smaller than 1 m 2 / g, the judgment is "〇". This indicates that if the specific surface area of the adsorbent is 1 m 2 / g or more, it can be said that the ozone concentration in Space 2 is sufficiently reduced.

[0061] Figure 6A is a graph plotting the time change of the ozone concentration in Space 2 during the purification process. In Figure 6A, for convenience of illustration, only the results of Example 1 and Comparative Example 2 are shown. As shown in Figure 6A, when the light source device 10 is continuously lit for 60 minutes, it is confirmed that the ozone concentration in Space 2 is saturated. That is, it can be confirmed that the results in Table 2 above are not the results of observing the state during the change of the ozone concentration in Space 2, but the results of observing the saturated state.

[0062] Here, the amount of ozone adsorbed per unit area of the adsorbent (hereinafter referred to as "adsorption amount") [μg / m 2 , and the relationship with the effective adsorption surface area B [m 2 will be described. Here, the adsorption amount is the total amount of ozone adsorbed by the adsorbent divided by the area A [m 2 of the region where the adsorbent is arranged.

[0063] Regarding Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Reference Example 2, the specific surface area [m 2 / g], the effective adsorption surface area B [m 2 , and the adsorption amount per size of the adsorbent were as shown in Table 3 below.

[0064]

Table 3

[0065] Figure 6B shows the effective adsorption surface area B [m 2and the amount of adsorbed ozone per unit size [μg / m 2 It is a graph plotting the relationship with. In FIG. 6B, an approximate straight line (y = 18.5x × 193.1) is drawn for the plot. Here, the condition that the adsorbent can sufficiently adsorb the ozone generated in space 2 is that the area A [m 2 of the amount of ozone that can be adsorbed in is larger than the amount of ozone generated by the total luminous flux X [mW] of the ultraviolet light L1 emitted from the light source device 10. According to such a condition and the approximate straight line of the graph in FIG. 6B, the relationship of the following formula (3) is derived. Note that "2.14" on the right side is a coefficient derived from 300 [μg] / 140 [mW] ≒ 2.14 [μg / mW] based on the fact that the maximum amount of ozone generated when the light source device with a total luminous flux of 140 mW is lit for 1 hour was approximately 300 μg. A·(18.5·B + 193.1) ≧ 2.14·X (3)

[0066] And the above formula (1) is derived by transforming the above formula (3). For the sake of caution, the above formula (1) is reproduced.

[0067]

Equation

[0068] That is, the above formula (1) is a relational expression derived such that the area A [m 2 is equal to or greater than the area required to adsorb the maximum amount of ozone assumed to be generated in space 2 in the purification process. Also, as can be seen from Table 3 above, the effective adsorption surface area B [m 2 is preferably 10 m 2 or more.

[0069] Note that the conditions of the above formula (1) and the effective adsorption surface area B [m 2 is 10 m 2The above is merely one of the preferred conditions set with the expectation of the above effects, and it is not an essential condition for achieving a "〇" judgment in this verification experiment.

[0070] From the above, according to the purification method as described above, the ozone concentration in the space 2 is reduced compared to the case where no adsorbent is arranged. Therefore, the above purification method can further suppress the influence on the people present in the space more than before.

[0071] [Another Embodiment] Hereinafter, another embodiment will be described.

[0072] 〈1〉 FIG. 7 is a perspective view schematically showing the configuration of the light source device 10 in another embodiment, and FIG. 8 is a drawing when the light source device 10 in FIG. 7 is viewed toward the light emitting portion 12. As shown in FIGS. 7 and 8, the light source device 10 is equipped with a cylindrical body 60 so as to cover the light emitting portion 12. An adsorbent 60a is arranged on the inner wall surface of the cylindrical body 60. The adsorbent 60a has a specific surface area of 1 m 2 / g or more in the state of being removed from the cylindrical body 60.

[0073] And the ultraviolet light L1 emitted from the light emitting portion 12 is radiated into the space 2 after passing through the inside of the cylindrical body 60.

[0074] With the above configuration, the adsorbent 60a can adsorb more ozone in the vicinity of the light emitting portion 12 where ozone is relatively easily generated, and the purification system 1 can be constructed with the light source device 10 alone.

[0075] In addition, as a method of adsorbing more ozone generated in the vicinity of the light emitting portion 12, it is preferable to mount the cylindrical body 60 with the adsorbent 60a arranged inside, but a method of separately arranging an adsorbent in the vicinity of the light source device 10 may also be adopted. Also, the shape of the cylindrical body 60 may be any shape such as a cylindrical shape, an elliptical cylindrical shape, or a polygonal cylindrical shape.

[0076] 〈2〉 The configuration of the purification system 1 described above and the method implemented by the purification system 1 are merely examples, and the present invention is not limited to each of the illustrated configurations and each of the described methods.

Explanation of Reference Numerals

[0077] 1: Purification system 2: Space 2a: Ceiling 2b: Wall surface 2c: Floor surface 3: Adsorption sheet material 3a: Base material 3b: Concavo-convex portion 4: Table 10: Light source device 11: Housing 12: Light emitting portion 13: Excimer lamp 13a: Discharge tube 13b: Electrode 60: Cylindrical body 60a: Adsorbent L1: Ultraviolet light

Claims

1. A method for purifying an enclosed space, comprising: irradiating the enclosed space in which an adsorbent having a specific surface area of 1 m 2 / g or more is disposed with ultraviolet light having a peak wavelength in the range of 200 nm to 235 nm.

2. irradiating the enclosed space in which the adsorbent is disposed with the ultraviolet light such that the total luminous flux X [mW] satisfies the following formula (1), where the area A [m 2 ] of the region where the adsorbent is disposed and the effective adsorption surface area B [m 2 ] of the adsorbent. The purification method according to claim 1, characterized in that: 【Equation 1】

3. irradiating the enclosed space in which the adsorbent having an effective adsorption surface area B [m 2 ] of 10 [m 2 ] or more is disposed with the ultraviolet light. The purification method according to claim 2, characterized in that:

4. irradiating the enclosed space in which the adsorbent is fixed to the ceiling, wall surface, or floor surface with the ultraviolet light. The purification method according to claim 1, characterized in that:

5. The purification method according to claim 4, characterized in that the adsorbent is a member having cellulose as a base material.

6. The purification method according to claim 5, characterized in that the adsorbent is a sheet-like or plate-like member attached to the ceiling, wall surface, or floor surface.

7. The purification method according to any one of claims 1 to 6, characterized in that at least a part of the ultraviolet light emitted from the light source device is directly irradiated onto the adsorbent.

8. The purification method according to any one of claims 1 to 6, characterized in that the adsorbent is disposed in the vicinity of the light source device that emits the ultraviolet light.

9. The purification method according to claim 8, characterized in that the ultraviolet light emitted from the light source device and passed through the inside of the cylinder in which the adsorbent is disposed on the inner wall surface is irradiated into the space.

10. The purification method according to any one of claims 1 to 6, characterized in that the ultraviolet light is irradiated into the space in which the adsorbent to which the photocatalyst material is attached is disposed.

11. The purification method according to claim 10, characterized in that the photocatalyst material is formed by dispersing metal oxide particles in a base material.

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