JP3247611B2 - Hazardous substance remover and harmful substance removal method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a harmful substance removing agent for removing harmful substances in a liquid or a gas, a harmful substance removing method using the same, and a method for regenerating the harmful substance removing agent.

[0002]

2. Description of the Related Art In recent years, there has been an increasing awareness of problems with the global environment and living environment, and harmful substances such as nitrogen oxides and organic halogen compounds emitted from various factories and automobiles, and malodorous components in living spaces have been removed. Is an important issue. In addition, since ethylene gas released from fruits and vegetables or flowers has an effect of reducing the freshness thereof, there is also a problem that storage cannot be performed for a long period of time unless ethylene gas is removed. To remove these harmful substances, there is a method using an adsorbent such as activated carbon or zeolite.However, this method only adsorbs harmful substances. Harmful substances are no longer adsorbed,
Further, there is a problem that the adsorbed harmful substance is desorbed again with a change in state. For this reason, a method has been proposed in which a harmful substance is oxidized and decomposed by photocatalysis of an optical semiconductor such as titanium oxide to make it harmless.

[0003]

When an optical semiconductor such as the above-mentioned titanium oxide is used in the form of a powder, harmful substances can be efficiently detoxified by its photocatalytic activity, but separation from a liquid to be treated and a gas to be treated is difficult.・ There is a problem that collection is difficult. On the other hand, when the optical semiconductor is used in a granulated or molded state, separation and recovery are facilitated, but the liquid to be treated, the gas to be treated and the contact between the granules or the compacts are easily broken, and Since only the photo-semiconductor present on the surface of the granulated or molded article can contribute to the detoxification reaction, there are problems such as low photocatalytic activity. There is also a method in which the optical semiconductor is used while being supported on the surface of a carrier such as glass or ceramic. However, in this method, separation / recovery becomes easy, and although the optical semiconductor on the surface of the carrier can be effectively used, the optical semiconductor is separated from the carrier due to contact with the liquid to be treated or the gas to be treated, and the photocatalytic activity is reduced. Cannot be maintained over a long period of time, and the photocatalytic activity of the optical semiconductor itself decreases due to firing during the supporting treatment.

[0004]

Means for Solving the Problems The present inventors have searched for a harmful substance removing agent which has excellent photocatalytic activity, has high strength and can be used for a long period of time, and has good handleability such as separation and recovery. As a result, the present inventors have found that a granulated body comprising at least an optical semiconductor, a clay mineral, and an organic binder or a molded body thereof has a desired effect and can be applied to various uses as a harmful substance remover. Was completed. That is, an object of the present invention is to provide a harmful substance remover that has excellent ability to remove harmful substances such as malodorous components and is easy to handle. Still another object of the present invention is to provide a method for removing harmful substances using the above harmful substance remover. Another object of the present invention is to provide a method for regenerating and activating a harmful substance remover whose adsorption ability has been deactivated.

The present invention is a harmful substance remover characterized by being a granulated product comprising at least an optical semiconductor, a clay mineral and an organic binder or a molded product thereof. When an optical semiconductor is granulated or molded using a clay mineral as a binder, a granulated body or molded body having high strength, excellent photocatalytic activity and excellent adsorption performance can be obtained. Furthermore, when an optical semiconductor is granulated or molded using an organic binder as a binder together with a clay mineral, the strength of the granulated or molded body can be further increased. The shape of the granulated product or the formed product can be appropriately designed according to the use scene, and examples thereof include shapes such as a sphere, a column, a ring, a plate, and a honeycomb. Further, an irregular shape obtained by pulverizing a granulated body or a molded body may be used. In the present invention, a structure having a honeycomb shape is preferable because the contact area with the harmful substance can be increased and the pressure loss can be reduced. The structure having a honeycomb shape is a structure in which a large number of through-holes having a cross section of a triangle, a quadrangle, a hexagon, a circle, an ellipse, or the like exist. The size of the granulated product or formed product can be appropriately designed according to the use scene.

Optical semiconductors exhibit a so-called photocatalytic action, and can oxidize and decompose harmful substances by the strong oxidizing power that develops when irradiated with light, thereby rendering them harmless. For example, known optical semiconductors such as titanium oxide, zinc oxide, tungsten oxide, iron oxide, strontium titanate, molybdenum sulfide, and cadmium sulfide can be used alone or in combination of two or more. In particular, titanium oxide which has high photocatalysis, is chemically stable, and is harmless is preferable. The titanium oxide includes, in addition to so-called titanium oxide, hydrous titanium oxide, hydrated titanium oxide, titanium hydroxide, metatitanic acid, and orthotitanic acid. Among them, titanium oxide having an anatase-type crystal form has excellent photocatalytic activity, and more preferably, one having a small particle diameter of 1 to 50 nm. A more preferred particle size is 1 to 30 nm. The particle diameter of an optical semiconductor such as titanium oxide is calculated from the half width of a peak obtained by powder X-ray diffraction using the following Scherrer equation. Lc = 0.9λ / (w · cos θ) (Lc is the particle diameter (nm), and λ is the wavelength (n
m) and w is the half width (rad) of the peak, θ
Is the angle of the peak position. In addition, an optical semiconductor such as titanium oxide may contain another metal or a compound of another metal such as iron, cobalt, nickel, copper, zinc, ruthenium, rhodium, palladium, silver, gold, and platinum. Titanium oxide supporting zinc oxide and / or zinc hydroxide has both the ability to adsorb harmful substances and the ability to decompose by photocatalysis.
More preferred.

The optical semiconductor used in the present invention can be obtained by a known method. For example, titanium oxide is a method of thermally hydrolyzing titanium compounds such as titanyl sulfate, titanium sulfate, titanium chloride and organic titanium compounds, and adding alkali to titanium compounds such as titanyl sulfate, titanium sulfate, titanium chloride and organic titanium compounds. And neutralization method, titanium chloride, a method of vapor-phase oxidation of organic titanium compounds, etc.,
The titanium oxide obtained by the above method can be obtained by firing at a temperature of about 800 ° C. or lower.

[0008] In the present invention, the clay mineral exhibits tackiness when containing water, and acts as a binder for a granulated or molded article. The clay minerals are aggregates of fine hydrated silicate minerals, for example, kaolin minerals such as nacrite, deckite, kaolinite, halloysite, hydrohaloysite, sericite, illite, mica clay minerals such as chlorite, Montmorillonite minerals such as montmorillonite, nontronite and saponite; chlorite minerals such as pennin and thulingite; vermiculite and attapulgite can be used.
In the present invention, it is preferable to use a kaolin mineral or a montmorillonite mineral since the strength of the obtained granulated or molded product is improved. In the present invention, the content of the clay mineral in the harmful substance remover is preferably 5 to 30% by weight,
Further, 10 to 20% by weight is more preferable. If the content of the clay mineral is less than the above range, it is not preferable because the binding force is insufficient and the strength of the granulated body or the molded body is weakened. It is not preferable because the adsorbing ability and the photocatalytic activity are hardly exhibited, and the strength of the granulated or molded article is rather weakened.

In the present invention, when an organic binder is blended in addition to the clay mineral, a harmful substance remover which is more robust and excellent in water resistance can be obtained. As the organic binder, commonly used organic binders can be used, for example, starches such as sweet potato, potato, tapioca, wheat, constarch, seaweed, seaweed such as galactan (agar), sodium alginate, trolloalloy, tragacanth gum , Gums such as gum arabic, gums such as gum, gelatin, casein, collagen, viscose, methylcellulose, ethylcellulose, hydroxyethylcellulose,
Water-soluble organic binders such as cellulose such as carboxycellulose, starches such as soluble starch, carboxymethyl starch and dialdehyde starch, and synthetic products such as polyvinyl alcohol, sodium polyacrylate, polyethylene oxide, urea-based polymers, and phenol-based polymers; Vinyl acetate, vinyl acetate / ethylene copolymer,
Vinyl acetate / acrylic copolymer, vinyl acetate / Veova copolymer, other vinyl acetate / polymerizable vinyl monomers, acrylic emulsion polyacrylate, acrylic / Veo
Va copolymers, vinyl acetate / Veova / acrylic type, ethylene / vinyl acetate / acrylic type, acrylic / styrene type, polyvinyl chloride, vinyl chloride / vinylidene chloride copolymer, emulsion polymers such as synthetic rubber latex and the like. In the present invention, it is more preferable to incorporate an emulsion polymer, since a harmful substance remover with even less disintegration due to moisture can be obtained. The content of the organic binder is 0.5 to the harmful substance remover.
-20% by weight is preferable, and 1-10% by weight is more preferable. When the content of the organic binder is less than the above range, it is not preferable because the effect of adding the organic binder is not easily recognized, and when the content is more than the above range, the adsorptive ability and photocatalytic activity of the optical semiconductor are exhibited. It is not preferable because it becomes difficult to be performed.

In the present invention, when an adsorbent is contained in the harmful substance removing agent, the ability to adsorb harmful substances can be enhanced, which is a more preferable embodiment. As the adsorbent, a commonly used adsorbent can be used, and specific examples thereof include silica, alumina, zeolite and activated carbon, and it is preferable to use at least one selected from them. The content of the adsorbent in the harmful substance remover of the present invention is preferably from 1 to 70% by weight, more preferably from 1 to 60% by weight, based on the harmful substance remover. At this time, the content of the optical semiconductor is preferably 20 to 90% by weight. When the content of the adsorbent is less than the above range,
The effect of adding the adsorbent is not preferable because it is difficult to recognize the effect, and when the amount is more than the above range, the content of the optical semiconductor decreases, the photocatalytic activity decreases, and the content of the clay mineral or the organic binder decreases. Is decreased, and the binding force is reduced.

The harmful substance removing agent of the present invention may contain various reinforcing materials and fillers as necessary. As the reinforcing material, titanium oxide fiber, potassium titanate fiber, crystalline cellulose, or the like can be used.

Next, in order to produce the harmful substance removing agent of the present invention, a method (1) in which a mixture of an optical semiconductor, a clay mineral, an organic binder, and water is granulated or molded, and then dried. In order to perform the above-mentioned granulation and molding, for example, using a machine such as a rolling granulator, an extrusion granulator, a stirring granulator, a crusher, a compression molding machine, a spray granulator, and a mold molding machine. Granules and compacts obtained by a rolling granulator, extrusion granulator or compression molding machine are preferable because of their relatively high strength. The obtained granulated body or molded body is dried at a temperature of about 50 to 200 ° C. to obtain a harmful substance removing agent. The harmful substance removing agent thus obtained may be fired at a temperature of 200 to 800 ° C, if necessary. By this calcination, the strength of the granulated body or the molded body can be increased, and the water resistance can be improved.
However, if the firing temperature is higher than 800 ° C., the photocatalytic activity and the adsorptive capacity of the optical semiconductor are reduced, which is not preferable.
The granules or the compact before drying may be subjected to a rolling granulator such as a Roche granulator or a marmellaizer, if necessary, to adjust the granules into spherical granules, and then dried.

In order to produce the harmful substance removing agent of the present invention, a method (2) of drying a mixture of an optical semiconductor, a clay mineral, an organic binder, and water and then coarsely pulverizing or granulating or molding is used. preferable. Dry the mixture at 50-200 ° C
It can be performed at a temperature of the order. The coarse pulverization can be performed using a commonly used pulverizer, and the obtained one may be sieved as necessary. The harmful substance removing agent obtained in this manner is optionally used at 200 to 800 ° C.
May be baked at the above temperature. By this calcination, the strength of the granulated body or the molded body can be increased, and the water resistance can be improved. However, if the firing temperature is higher than 800 ° C., the photocatalytic activity and the adsorptive capacity of the optical semiconductor are reduced, which is not preferable. The granulated or shaped body after the coarse pulverization may be subjected to a rolling granulator such as a Roche granulator or a marmellaizer, if necessary, to form a spherical granulated body, and then dried. .

An adsorbent can be blended with the mixture of the photosemiconductor, clay mineral, organic binder and water used in the above methods (1) and (2). A mixture containing an adsorbent in addition to the optical semiconductor, the clay mineral, the organic binder, and water is granulated or molded by the methods (1) and (2) to obtain a harmful substance remover. The harmful substance removing agent thus obtained may be fired at a temperature of 200 to 800 ° C, if necessary. By this calcination, the strength of the granulated body or the molded body can be increased, and the water resistance can be improved. However, if the firing temperature is higher than 800 ° C., the photocatalytic activity of the optical semiconductor and the adsorbing ability of the adsorbent decrease, which is not preferable.

Next, using the harmful substance removing agent of the present invention,
To remove harmful substances in the fluid, a harmful substance remover
Contacting a fluid containing a harmful substance to adsorb and remove the harmful substance, or contacting a fluid containing a harmful substance with light while irradiating the harmful substance removing agent, and harmful substance by photocatalysis. Can be decomposed, rendered harmless and removed. For this reason, the harmful substance removing agent of the present invention is, for example, in a place where a fluid containing a harmful substance exists,
It may be simply placed in a living space such as a toilet, a living room, a kitchen, a refrigerator, a car, a shoe box, or the like in a factory or a place adjacent thereto so as to come in contact with harmful substances. Toxic substances in the fluid include odorous components such as ammonia, aldehydes, mercaptans, amines, hydrogen sulfide, and methyl sulfide,
Nitrogen oxides, hydrocarbons, organic halogen compounds, COD
Load substances, microorganisms, bacteria, fungi, algae and the like can be targeted. In particular, the harmful substance removing agent of the present invention can efficiently remove malodorous components. The light applied to the harmful substance removing agent may include ultraviolet light having a wavelength of 400 nm or less. Examples of the light source include a mercury lamp, a xenon lamp, a mercury-xenon lamp, and a germicidal lamp.
An artificial light source such as a black light and a white fluorescent lamp and natural light of sunlight can be used. Further, the above artificial light source or natural light may be used in combination, or light radiated from them may be collected and used. Light irradiation to the harmful substance removing agent is not necessarily performed continuously, but may be performed intermittently. When a fluid containing a harmful substance is brought into contact with the harmful substance removing agent, it can be forcibly brought into contact with a blower or a liquid feeder, so that the harmful substance remover can be efficiently removed. Further, an air purifying device can be provided by incorporating the harmful substance removing agent of the present invention, a light source and a blower. Specifically, the harmful substance removing agent of the present invention is filled into a box of an arbitrary shape made of a net-like base material, and this is provided in a gas flow path in an air cleaning device, and the harmful substance removing agent is illuminated with light. By arranging the light sources so that the air purifies, an air purifying device can be obtained.

Next, when the harmful substance is attached to the harmful substance removing agent of the present invention and the harmful substance removing ability is lowered, the harmful substance removing agent is irradiated with light to remove the attached harmful substance. It can be removed to restore the ability to remove harmful substances and be regenerated. As the light source used in this reproduction method, the above-described light source can be used. This regenerating method is particularly effective as a regenerating method when the adsorption ability of the harmful substance removing agent used in a place where it is usually difficult to reach light or a place where a light source is difficult to be installed is deactivated.

[0017]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

1. Preparation of Sample Example 1 Titanium sulfate was thermally hydrolyzed, and the resulting precipitate was filtered, washed, dried, and pulverized to obtain a titanium oxide hydroxide (Sample A). As a result of X-ray diffraction, Sample A was an anatase-type titanium oxide, and the X-ray particle size was 7 nm. 80 parts by weight of this sample A, 15 parts by weight of a commercially available kaolin (manufactured by Kyoritsu Ceramic Industry Co., Ltd., clay containing kaolin such as kaolin and kaolinite) and an acrylic emulsion polyacrylate as an organic binder in terms of resin. 60 parts by weight of water was added to 5 parts by weight, and the mixture was kneaded for 5 minutes with a kneading machine (a batch kneader manufactured by Fuji Paudal Company, KDH-20). This mixture is subjected to a wet pre-extrusion granulator (pellet double, EXDF-100 manufactured by Fuji Paudal)
And granulated with a spherical sizing machine (Malmerizer, Q-400 manufactured by Fuji Paudal Co., Ltd.), and dried to obtain a spherical granulated product having an average particle size of 2 to 3 mm (sample P). ) Got.

Example 2 The sample A described in Example 1 was dispersed in pure water, and after dissolving zinc chloride, neutralized with an aqueous sodium hydroxide solution, followed by filtration, washing, drying and pulverization. Thus, a titanium oxide-supported hydrous titanium oxide (sample B) was obtained. The supported amount of zinc hydroxide was Zn: Ti = 15: 85 in molar ratio. As a result of X-ray diffraction, Sample B contained anatase-type titanium oxide and had an X-ray particle size of 7 nm. Next, an average particle diameter of 2 to 3 was obtained in the same manner as in Example 1 except that Sample B was used instead of Sample A of Example 1.
mm spherical granules (sample Q) were obtained.

Example 3 30 parts by weight of the sample A described in Example 1, 15 parts by weight of the commercially available kaolin described in Example 1, and 50 parts of commercially available powdered activated carbon
55 parts by weight of water were added to 5 parts by weight of an acrylic emulsion polyacrylate as an organic binder in terms of resin, and then granulated in the same manner as in Example 1 to give an average particle size of 2 to 2 parts by weight. A 3 mm spherical granule (sample R) was obtained.

Example 4 30 parts by weight of sample B described in Example 2, 15 parts by weight of commercially available kaolin described in Example 1, and 50 parts of commercially available powdered activated carbon
55 parts by weight of water were added to 5 parts by weight of an acrylic emulsion polyacrylate as an organic binder in terms of resin, and then granulated in the same manner as in Example 1 to give an average particle size of 2 to 2 parts by weight. A 3 mm spherical granule (sample S) was obtained.

Example 5 30 parts by weight of the sample A described in Example 1, 15 parts by weight of a commercially available clay (Tokoname clay, Nagamine shale clay), 50 parts by weight of a commercially available powdered activated carbon, and an acrylic emulsion polyacrylate as an organic binder Was added to 5 parts by weight in terms of resin, and 55 parts by weight of water was added. Then, this was granulated in the same manner as in Example 1 to obtain a spherical granule having an average particle diameter of 2 to 3 mm (sample T). .

Example 6 30 parts by weight of the sample A described in Example 1, 15 parts by weight of a commercially available clay (Tokoname clay, Nagamine shale clay), 50 parts by weight of a commercially available powdered activated carbon, and an acrylic emulsion polyacrylate as an organic binder Was added to 5 parts by weight of resin and 50 parts by weight of water to obtain a mixture. The obtained mixture was molded with a compression molding machine and dried to obtain a honeycomb molded body (sample U) having a thickness of 15 mm, a hole diameter of 1 mm, and 200 mesh.

Comparative Example 1 A comparative sample (V) was obtained by granulating in the same manner as in Example 1 except that kaolin was not used.

Comparative Example 2 A comparative sample (W) was obtained by granulating in the same manner as in Example 1 except that no organic binder was used.

2. Characteristic evaluation of the sample Strength of the granulated product The sample obtained in the example was placed on a spring type
The weight value at which the powder collapses by pressing from above was measured, and the average value of 20 pieces was used as the strength of the granulated product. The obtained results are shown in Table 1. From these results, it was found that the harmful substance removing agent of the present invention has high strength and can withstand long-term use.

[0027]

[Table 1]

Evaluation of Water Resistance The samples obtained in the examples were put into water and examined for disintegration. As a result, the samples PQ, R, S, T and U of the examples did not disintegrate, but the samples of the comparative example did not disintegrate. Samples V and W were found to collapse easily. From this result, it was found that the harmful substance removing agent of the present invention has excellent water resistance and can be used for a long period of time.

Ability to remove harmful substances by adsorption action The sample obtained in the example was filled in a tube made of Pyrex glass, and in a state where light was blocked (in the dark), a harmful gas of a certain concentration was passed through one of the tubes. The harmful gas removal ability of the sample was evaluated by measuring the concentration of the gas emerging from the other (outlet). Here, the linear velocity of the harmful gas in the packed bed was set at 20 cm / sec, the space velocity was set at 10,000 hr ^-1 , and the removal ability was represented by the following equation. Removal capacity = (inlet concentration-outlet concentration) / inlet concentration × 100
(%) As harmful gases, ammonia and methyl mercaptan, which are typical examples of malodorous components, were used. As a comparative sample, a commercially available granular activated carbon (comparative sample AC) and an inorganic adsorbent mizucanite (comparative sample MZ) were used for comparison. Table 2 shows the obtained results. From this result, it was found that the harmful substance removing agent of the present invention was excellent in the ability to remove harmful substances by the adsorption action.

[0030]

[Table 2]

Ability to remove harmful substances by photocatalysis The sample obtained in the example was filled in a tube made of Pyrex glass, and light irradiation with black light was performed from the outside of the tube. Similarly to the above, the harmful gas removal ability of the sample was evaluated by flowing a certain concentration of harmful gas from one of the tubes and measuring the concentration of the gas coming out of the other (outlet). Table 3 shows the obtained results. From these results, it was found that the harmful substance removing agent of the present invention was excellent in the ability to remove harmful substances by photocatalysis.

[0032]

[Table 3]

Next, the samples U and T obtained in Examples 6 and 5 were placed in Pyrex glass cylindrical containers, respectively, and acetaldehyde of a predetermined concentration, which is a typical example of a malodorous component, was introduced. After the adsorption reached equilibrium, light irradiation with black light was performed, and the concentration of carbon dioxide generated by the decomposition of acetaldehyde was measured to evaluate the ability of the sample to remove harmful gases. Table 4 shows the obtained results. From this result, it was found that the harmful substance removing agent of the present invention was excellent in the ability to remove harmful substances by photocatalysis, and in particular, the performance was further improved by forming a honeycomb shape.

[0034]

[Table 4]

Regeneration Ability by Light Irradiation The sample obtained in the example was filled in a tube made of Pyrex glass, and in a state where light was first blocked (in a dark state), a harmful gas of a certain concentration was supplied from one side of the tube for a certain time. Then, the removal ability at that time was measured. Next, after light irradiation was performed for a certain period of time from the outside of the tube with black light, the light was blocked again, and the removal ability at that time was measured. When the value of the removal ability after light irradiation is larger than that before light irradiation, it indicates that there is a reproduction ability by light irradiation. Table 5 shows the obtained results.
From these results, it was found that the harmful substance removing agent of the present invention regained its ability to remove harmful substances by light irradiation.

[0036]

[Table 5]

[0037]

According to the present invention, there is provided a granulated product containing at least an optical semiconductor, a clay mineral, and an organic binder, or a molded product thereof, which has an excellent ability to remove harmful substances. Since it is capable of maintaining its capacity for a long period of time and has good handleability such as separation and recovery, it is useful as a harmful substance remover and applicable to a wide range of applications. Further, the present invention is a granulated body or a molded body thereof containing an optical semiconductor, a clay mineral, an adsorbent, and an organic binder, and can more efficiently remove harmful substances such as malodorous components. It is useful not only for industrial use but also for general household use. Furthermore, the method for removing harmful substances of the present invention is a simple method using the above-mentioned harmful substance remover, and therefore can be applied not only to industrial use but also to general household use. Furthermore, according to the regeneration method of the present invention, when the harmful substance removing agent is inactivated by the attachment of the harmful substance, the harmful substance removing agent can be easily regenerated, so that the harmful substance removing agent can be used repeatedly.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI B01J 2/28 B01D 53/36 H 21/16 53/34 116A (56) References JP-A-7-60132 (JP, A) JP-A-5-238843 (JP, A) JP-A-2-273514 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 21/00-38/74 B01D 53/86

Claims (11)

(57) [Claims] 1. A clay mineral comprising 5 to 30% by weight and 0.5 to 20% by weight.
% By weight of an organic binder as a binder, at least an optical semiconductor, a clay mineral, an organic binder, an adsorbent, and water.
Granulation and molding of the mixture obtained by mixing with a granulator or molding machine
Removing harmful substances agent, which is a granule or a molded body obtained by. 2. The harmful substance-removing agent according to claim 1, wherein the granulated material or a molded product thereof is a structure having a honeycomb shape. 3. The harmful substance removing agent according to claim 1, wherein the organic binder is an emulsion polymer. 4. The optical semiconductor has an anatase crystal form,
The harmful substance remover according to any one of claims 1 to 3, which is a titanium oxide having a particle diameter of 1 to 50 nm. 5. The agent for removing harmful substances according to claim 1, wherein the optical semiconductor is titanium oxide supporting zinc oxide and / or zinc hydroxide. 6. The harmful substance removing agent according to claim 1, wherein the adsorbent is at least one selected from the group consisting of silica, alumina, zeolite and activated carbon. 7. The harmful substance removing agent according to claim 1, wherein the content of the optical semiconductor is 20 to 90% by weight and the content of the adsorbent is 1 to 70% by weight. 8. A method for removing harmful substances, comprising contacting a fluid containing harmful substances with the harmful substance removing agent according to any one of claims 1 to 7 to remove the harmful substances. 9. A method for removing a harmful substance by contacting a harmful substance-containing fluid with the harmful substance removing agent according to claim 1 while irradiating the harmful substance with the light. Hazardous substance removal method. 10. The method for removing harmful substances according to claim 8, wherein the harmful substances are malodorous components. 11. The harmful substance removing agent according to any one of claims 1 to 7, wherein the harmful substance removing agent is irradiated with light when the harmful substance removing ability is reduced due to adhesion of the harmful substance. And removing adhering harmful substances.