JPH10272355A - Improved harmful substance-removing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a harmful substance-removing member having good harmful substance removing and purifying capacities and suitable for protecting environment. SOLUTION: This harmful substance-removing member is a hydrated coagulated substance obtained from a mixture consisting of a hydraulic compd., aggregate, a photocatalyst and water and at least either one of slaked lime, a water- soluble salt of a strong base and weak acid, a high capacity water reducing agent and an adsorbable substance is further added to the mixture. The photocatalyst is a certain kind of a semiconductor substance, that is, titanium dioxide. The water-soluble salt is sodium carbonate, sodium bicarbonate, sodium acetate, sodium hypochlorite or a bleaching powder and the high capacity water reducing agent is a sodium salt of naphthalenesulfonic acid formaldehyde high condensate and the adsorbable substance is activated carbon zeolite, magadite or petalite. A harmful substance capable of being removed by this harmful substance removing member is NOx, mercaptans, ammonia, hydrogen sulfide, amines or ethylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved harmful substance removing member, and more particularly to a harmful substance removing member having improved purification performance.

[0002]

2. Description of the Related Art In recent years, as the destruction of the global environment has been regarded as a problem, it has been noticed that photocatalysts or photocatalytic substances are useful for preventing or purifying the global environment. Development of products applied to purification of _X , purification of water, antibacterial / antifungal, deodorizing, etc. is being promoted.
As the photocatalyst, a semiconductor, for example, a photoconductor such as titanium dioxide is used. Specifically, JP-A-2-273514 discloses a remover for harmful substances obtained by kneading a titanium dioxide semiconductor with clay and drying the clay. Is disclosed. JP-A-6-327965 discloses a dispersion of a specific semiconductor in a hydrated aggregate of a hydraulic compound as an agent for removing harmful substances such as ethylene.

[0003]

However, as described above, the harmful substance removing agent described in Japanese Patent Application Laid-Open No. Hei 2-273514 requires a large amount of the harmful substance removing agent because the harmful substance removing speed is low. There is another problem, and the harmful substance removing agent described in JP-A-6-327965 has been improved in its removal efficiency, but further improvement is desired. Therefore, the present inventors have conducted various studies on the point of improving the removal rate or removal efficiency of the harmful substance removing agent as described above. As a result, a structure of a harmful substance removing member capable of improving the light absorption rate of the photocatalyst was obtained. The present inventors have found that an excellent environment for removing harmful substances can be obtained by forming an environment for improving the absorptivity, and the present invention has been made based on this finding. Therefore, an object of the present invention is to provide a harmful substance removing member having good harmful substance removal performance or purification performance and preferable for environmental protection.

[0004]

The above objects of the present invention are attained by the following inventions.

(1) A harmful substance removing member characterized by being a hydrated aggregate obtained from a mixture of a hydraulic compound, an aggregate, a photocatalyst and water. (2) The harmful substance removing member according to (1), wherein the mixture contains slaked lime. (3) The harmful substance removing member according to (1) or (2), wherein the mixture contains a water-soluble salt of a strong base and a weak acid. (4) The harmful substance removing member according to any one of (1) to (3), wherein the mixture contains a high-performance water reducing agent. (5) The harmful substance removing member according to any one of (1) to (4), wherein the mixture contains an adsorptive substance.

As described above, the harmful substance removing member of the present invention
A hydrated aggregate obtained from a mixture of a hydraulic compound, an aggregate, a photocatalyst, and water.Especially, when the aggregate is mixed, voids are formed, thereby increasing the degree of exposure of the photocatalyst and improving the light absorption rate. As a result, excellent harmful substance removal performance or purification performance can be obtained. Further, since the harmful substance removing member further contains slaked lime, pH is improved, and as a result, harmful substances, in particular, NO _X are discharged as a soluble salt out of the photocatalyst system, thereby improving the purification efficiency of the photocatalyst. At the same time, a harmful substance removing member suitable for protecting the natural environment can be obtained. When the substrate is concrete, acidification of the concrete with the passage of time can be prevented.

In the present invention, since the mixture contains a water-soluble salt of a strong base and a weak acid, nitrate ions generated by the decomposition of NOx are neutralized by the water-soluble salt having a pH buffering action to form NOx. It is possible to prevent the purification function from lowering.

In the present invention, since the mixture further contains a high-performance water reducing agent, the mixture can be uniformly dispersed. Therefore, the photocatalyst is also present uniformly and contributes to the light absorbing action. be able to. Furthermore, by containing the adsorbing substance in the mixture, harmful substances are decomposed and removed in the daytime and in a state of light, and at night, the harmful substances are adsorbed and removed by the adsorbing substance. . Furthermore, when light strikes in the daytime, the harmful substances adsorbed by the adsorptive substance are released and decomposed and removed by the light. Therefore, it has an excellent purification performance that enables harmful substances to be removed day and night.
Further, in the present invention, not only the purification of the NO _X in the air from the characteristics of the semiconductor, prevention of surface dirt, water purification, antibacterial,
It can prevent mold, deodorize, etc., and therefore can be used not only for multiple purposes but also for specific purposes.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited thereto.

The harmful substance removing member of the present invention is used after adding at least one kind of aggregate, slaked lime, high-performance water reducing agent or adsorbent substance to a mixture comprising a hydraulic compound and a photocatalyst, and kneading the mixture. Various hydrated aggregates produced by the above method. According to the embodiment, the harmful substance removing member of the present invention is a hydrated aggregate obtained from a mixture of a hydraulic compound, an aggregate, a photocatalyst, and water. The compound is an inorganic compound having a property of forming a hydrate by reacting with water and aggregating, and is not particularly limited. Specific examples of the hydraulic compound include cements, for example, ordinary Portland cement,
Examples include early-strength Portland cement, moderately heated Portland cement, ultra-high-strength Portland cement, sulfate-resistant Portland cement, white Portland cement, blast furnace cement, fly ash cement, silica cement, alumina cement, and ultra-rapid hardening cement. In addition,
Calcium sulfate, calcium silicate, calcium aluminate, calcium ferrate, celite, celite, gehlenite, anorthite, dolomite and the like. Preferably, the cements, especially white Portland cement, calcium sulfate and calcined gypsum are used.

The photocatalyst used in the present invention is a kind of semiconductor substance, and specifically, a metal such as tin dioxide, zinc oxide, tungsten trioxide, cerium oxide, titanium dioxide, barium titanate, and ferric oxide. Oxides: zinc sulfide,
Metal chalcogenites such as cadmium sulfide, lead sulfide, zinc selenide, and cadmium selenide; Group IV metals such as silicon and germanium; and compounds of Group III elements and Group V elements such as gallium phosphide, gallium arsenide, and indium phosphide Polyacetylene, polypyrrole, polythiophene,
Organic semiconductors such as polyaniline and polyvinyl carbazole are exemplified. Of these, semiconductors such as titanium dioxide, zinc oxide, selenium oxide, tungsten trioxide, and polyvinyl carbazole are more preferable. In addition, by using a metal such as zinc, iron and vanadium or a noble metal such as gold and platinum together with the semiconductor, the performance of removing harmful substances can be improved. The semiconductor used in the present invention is used as a powder, and the semiconductor powder is mixed and dispersed in a hydraulic compound.

The semiconductor substance used in the present invention is used in an amount of 5 to 800 parts by weight, preferably 1 to 100 parts by weight of the hydraulic compound.
The amount is 0 to 600 parts by weight, and more preferably 10 to 300 parts by weight based on 100 parts by weight of the hydraulic compound. This is an excellent effect that the purification performance can be improved by blending the aggregate, so that the amount can be relatively reduced as compared with the one containing no aggregate.

In the present invention, slaked lime may be further added to the mixture, and by adding the slaked lime, acidification of wastewater can be prevented. Particularly when the hydrated agglomerates hydraulic compound is a cement, but the cement is degraded loses alkaline by neutralization in time, not only alkalinity is maintained by slaked lime, such as of the NO _X toxic substances photocatalyst When it is changed to an acidic substance by the above, it can be neutralized and made harmless. In the present invention, the mixture contains a water-soluble salt of a strong base and a weak acid. Examples of the water-soluble salt include sodium carbonate, sodium hydrogen carbonate, sodium acetate, sodium hypochlorite, bleached powder, and the like. Can be Since these are water-soluble salts of a strong base and a weak acid, they have a pH buffering action.

Further, in the present invention, an aggregate is used,
Examples of the aggregate include sand, crushed stone, silica sand, and glass. Usually, the size of the aggregate is preferably the size of sand, but is not limited thereto, and the particle size is 0.1 mm to
A particle size in the range of 10 mm may be sufficient. In the present invention, a high-performance water reducing agent is preferably added to the mixture. Examples of the high-performance water reducing agent include a sodium salt of a naphthalenesulfonic acid formaldehyde polycondensate, a sodium salt of a creosote oil sulfonic acid condensate, and the like. Can be By adding the high-performance water reducing agent, the mixture can be uniformly dispersed, and as a result, the photocatalyst can be uniformly illuminated with light and the purification performance can be improved.

In the present invention, an adsorbing substance can be further added to the mixture, and specific examples include activated carbon, silica gel, zeolite, magadiite, petalite and the like. Magadiite is Na ₂ Si ₁₄ O ₂₉ nH ₂
It has the chemical formula of O and is effective as an adsorptive substance. Further, petalite is a white or gray mineral similar in appearance to quartz, and is a silicate mineral (Li ₂ OAl ₂
O ₃ 8SiO ₂ ). Excellent adsorption performance. All of these adsorbing substances have excellent adsorption performance and can be removed by absorbing harmful substances. The action of the adsorbent substance will be described in more detail. Not only is the harmful substance such as NO _x not only purified and removed by daylight (ultraviolet rays contained therein) but also at night, This is decomposed by ultraviolet light during the day to purify harmful substances. Activated carbon is preferred among these adsorptive substances.

In the present invention, the harmful substance removing member is produced by uniformly kneading a mixture of a hydraulic compound, an aggregate, a photocatalyst and water, but the order of adding these components is not particularly limited. . Preferably, the aggregate, a part of the water, the hydraulic compound, the photocatalyst and the remainder of the water are added and mixed in this order. After kneading the mixture, the mixture is used in an appropriate form. The first form is that the hydrated aggregate of the kneaded product is pulverized and used as granules. When used as an apparatus, this granular material can be used for purification of a contaminated medium by putting it in a transparent container as it is and passing the contaminated medium through the container while irradiating light. A second form of the method is a method of molding the kneaded material into various shapes using a molding means. By irradiating light by forming a plate-shaped body by this method, air purification,
Water can be purified. Furthermore, it can be used for applications such as antibacterial, antifungal and antifouling. In addition, by increasing the amount of the photocatalyst, it can be used for applications such as antibacterial, antifungal, and antifouling even if it is not exposed to light. Further, the kneaded material can be applied to the surface of the plate-like body, whereby the cost of the photocatalyst can be reduced, and it is more economical.

The weight ratio of each component of the harmful substance removing member of the present invention may be a weight ratio at the time of forming a hydrated aggregate of a normal hydraulic compound, but is preferably 100 parts by weight of the hydraulic compound. , 50 to 500 parts by weight of aggregate, photocatalyst 5
Parts by weight to 200 parts by weight and water 10 parts by weight to 300 parts by weight. More preferably, the amount is 100 parts by weight to 300 parts by weight of the aggregate, 10 parts by weight to 100 parts by weight of the photocatalyst, and 20 parts by weight to 150 parts by weight of water with respect to 100 parts by weight of the hydraulic compound. If the ratio exceeds these ranges, not only is there substantially no harmful substance removal performance, but it is not preferable in terms of cost. In the harmful substance removing member of the present invention, the amount of slaked lime is 1 to 50 parts by weight based on 100 parts by weight of the hydraulic compound, and preferably 5 to 30 parts by weight based on 100 parts by weight of the hydraulic compound.
Weight. When the amount of slaked lime is less than 1 part by weight with respect to 100 parts by weight of the hydraulic compound, it does not contribute to improvement in the purification performance of harmful substances. On the other hand, if the amount of slaked lime exceeds 50 weight, the amount of photocatalyst is relatively reduced and purification performance is lowered, which is not preferable.

In the present invention, the amount of the water-soluble salt of the strong base and the weak acid is 0.5 to 30 parts by weight, preferably 100 parts by weight of the hydraulic compound. The weight is 1 to 10% by weight. When the amount of the water-soluble salt is less than 0.5 part by weight with respect to 100 parts by weight of the hydraulic compound, it does not contribute to the improvement of harmful substance purification performance. Further, if the amount of the water-soluble salt exceeds 30 weight, it adversely affects the hydration reaction, which is a curing reaction of cement, and not only does not obtain a cured body strength, but also the amount of photocatalyst is relatively reduced and purification performance is lowered. Not preferred.

In the harmful substance removing member of the present invention, the amount of the high-performance water reducing agent may be an amount generally used in the technical field of cement, and is 0.1 to 10 parts by weight based on 100 parts by weight of the hydraulic compound. And preferably 0.5 to 5.0 parts by weight based on 100 parts by weight of the hydraulic compound. The amount of the high-performance water reducing agent is set to be 0.1 to 100 parts by weight of the hydraulic compound.
If it is less than 1 weight, the mixture cannot be uniformly dispersed. When the amount of the high performance water reducing agent exceeds 10 weight,
It is not preferable because the cost is increased. Further, in the harmful substance removing member of the present invention, the amount of the adsorptive substance is from 5 parts by weight to 100 parts by weight of the hydraulic compound, depending on the type.
The amount is 50 parts by weight, preferably 10 parts by weight to 30 parts by weight based on 100 parts by weight of the hydraulic compound. When the amount of the adsorptive substance is less than 5 parts by weight with respect to 100 parts by weight of the hydraulic compound, the harmful substance cannot be sufficiently adsorbed, so that the purification performance cannot be improved. On the other hand, if the amount of the adsorbing substance exceeds 50 parts by weight, the amount of the photocatalyst is relatively reduced and the purification performance is lowered, which is not preferable.

In using the harmful substance removing member of the present invention,
The light to be irradiated is preferably light containing ultraviolet light, and the wavelength range of the light is preferably 200 nm to 400 nm. Ultraviolet rays are particularly preferred, but when used outdoors, sunlight is sufficient. For indoor use, ultraviolet rays from an ultra-high pressure mercury lamp, a xenon lamp, or a low pressure mercury lamp are irradiated to the harmful substance removing member. At this time, it is preferable to use the harmful substance removing member as close as possible. The hazardous substance removing member in a removable harmful substances, NO _X, mercaptans, ammonia, hydrogen sulfide, amines, ethylene and the like are preferably removed. In the present invention, the usage amount of the harmful substance removing member can be determined in consideration of the type of harmful substance, light illuminance, and the like. However, in the present invention, since the removal or purification performance of the harmful substance removing member is high, the use amount thereof may be small.

[0021]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 100 parts by weight of white cement,
220 parts by weight of sand, 25 parts by weight of titanium dioxide powder and water 3
After kneading 0 parts by weight, the kneaded material was put in a mold frame of 10 × 20 cm and subjected to vibration molding to form a molded body. After curing, the specimen was pulverized to obtain a harmful substance removing member having a particle size of 1 to 10 mm. Next, this harmful substance removing member was placed in a transparent container having an entrance and an exit, and the NO removal rate was measured by the following test method. As a comparative example, a mixture obtained by kneading 100 parts by weight of white cement and 25 parts by weight of titanium dioxide powder with water was molded, cured, and pulverized in the same manner to produce a harmful substance removing member. When the harmful substance removing member of the comparative example was used, the NO removal rate was 65%, whereas in the case of the harmful substance removing member of the present invention, the NO removal rate was 73%, and the purification performance was high. Improvement was seen.

[NO Removal Test Method 1] In the test, a test sample was placed in a closed container, and a simulation gas containing 1 ppm of NO gas was flowed from the inlet. The concentration of the gas leaving the outlet was measured, from which the NO removal rate was measured. The test was conducted for 24 hours, 1
The numerical value obtained by averaging the removal rates every 0 minutes was used as the test result. In test method 1, 10 W × 3 ultraviolet lamps were
The test was performed with the lights on for 4 hours.

Example 2 The same harmful substance removing member as in Example 1 was manufactured. In the NO removal test method 1, the performance of the harmful substance removing member was examined in the same manner except that ethylene was used instead of NO gas. According to the harmful substance removing member of the present invention, the use of the harmful substance removing member of the comparative example resulted in an ethylene removal rate of 55%, whereas the harmful substance removing member of the present invention did not. In Example 1, the ethylene removal rate was 64%, and a product having an improved ethylene removal rate was obtained. The concentration at the outlet of ethylene was measured by gas chromatography. A product having an improved ethylene removal rate was obtained. Furthermore, in the present invention, the harmful substance removing member further absorbs harmful substances at night by adding any of activated carbon, zeolite, magadiite, and petalite as an adsorptive substance, and releases and decomposes them during the day. Further harmful substance removal performance can be improved.

Example 3 100 parts by weight of calcined gypsum, sand 22
After kneading 0 parts by weight, 50 parts by weight of titanium dioxide powder and 30 parts by weight of water, a harmful substance removing member was manufactured in the same manner as in Example 1. Depending on the presence or absence of sand, the harmful substance removing member of the present invention was obtained with an improved NO removal rate.

Example 4 The composition of the block base layer was 100 parts by weight of Portland cement, 195 parts by weight of crushed stone,
After kneading 240 parts by weight of sand and water 31, 10 × 20c
The kneaded product was placed in a m mold frame and subjected to vibration molding to form a concrete base layer. On this surface, white cement 10
A mixture obtained by kneading 0 parts by weight, 220 parts by weight of sand and 25 parts by weight of titanium dioxide powder with 30 parts by weight of water was poured and molded. The obtained molded body was cured. As a comparative example,
In the production of the above-mentioned molded product, the kneaded material from which sand was removed was molded and cured in the same manner to produce a harmful substance removing member. Each of these compacts was placed in a closed container, and the NO removal rate was measured in the same manner as in Example 1. When the harmful substance removing member of the comparative example was used, the NO removal rate was 60%, whereas in the case of the harmful substance removing member of the present invention, the NO removal rate was 60%.
The O removal rate was 72%, and the purification performance was improved. Improvement of purification performance even NO _X using Portland cement instead of the white cement was observed.

Example 5 As the kneaded material of the surface layer described in Example 4, 100 parts by weight of white cement, 220 parts by weight of sand, 25 parts by weight of titanium dioxide powder and 30 parts by weight of slaked lime were kneaded with 30 parts by weight of water. This was cast and molded. The obtained molded body was cured. As a comparative example, in the production of the above-mentioned molded body, the kneaded material from which sand was removed was similarly molded and cured to produce a harmful substance removing member. Each of these compacts was placed in a closed container, and the NO removal rate was measured in the same manner as in Example 1. At this time, water was sprinkled from above on the molded body like rain. When the harmful substance removing member of the comparative example was used, the NO removal rate was 60%, whereas in the case of the harmful substance removing member of the present invention, the NO removal rate was 74%, and the purification performance was high. Has been improved,
Further, in the comparative example, acidic water was obtained, whereas in the present invention, neutral to weakly alkaline water was obtained, which was preferable from the viewpoint of protecting the natural environment.

Example 6 A molded article of the present invention was prepared in the same manner as in Example 4 except that 0.6 parts by weight of a high-performance water reducing agent was further added to the kneaded product of the surface layer described in Example 4. A harmful substance removing member was manufactured, and the NO removal rate was measured in the same manner as in Example 4. The obtained compact was uniformly dispersed, and as a result, the NO removal rate was improved.

Example 7 A molded article of the present invention is obtained in the same manner as in Example 4, except that 25 parts by weight of activated carbon as an adsorbent is further added to the kneaded material of the surface layer described in Example 4. A harmful substance removing member was manufactured. The measurement of NO removal rate
The following NO removal test method 2 was used. In the comparative example, comparison was made with no added activated carbon. As a result, the NO removal rate was improved by 30% to 60% as compared with the comparative example. Even when zeolite, magadiite, and petalite were used as the adsorptive substance, a substance having excellent purification performance was similarly obtained.

[NO removal performance test method 2] When performing NO removal performance test method 1, the ultraviolet lamp was repeatedly turned on and off every two hours. Thus, during the 24 hour test period, the lamp was on for 12 hours.

Example 8 A molded article of the present invention is obtained in the same manner as in Example 5, except that 25 parts by weight of activated carbon is further mixed as an adsorbent with the kneaded material of the surface layer described in Example 5. A harmful substance removing member was manufactured. The measurement of NO removal rate
The following NO removal test method 2 was used. In the comparative example, comparison was made with no added activated carbon. As a result, the NO removal rate was improved by 30% to 60% as compared with the comparative example. Furthermore, since slaked lime is added, neutral or weakly alkaline water is obtained, which is preferable from the viewpoint of protecting the natural environment.

Example 9 The same harmful substance removing member as in Example 1 was manufactured. In the NO removal test method 1, the performance of this harmful substance removing member was examined in the same manner except that methyl mercaptan was used instead of NO gas. When the harmful substance removing member of the present invention is used according to the presence or absence of sand, the removal ratio of methyl mercaptan is 40% when the harmful substance removing member of the comparative example is used, whereas the harmful substance removing member of the present invention has a removal rate of 40%. In this case, the removal rate of methyl mercaptan was 55%, and a product having an improved removal rate of offensive odor was obtained. In addition,
Hydrogen sulfide and ammonia were similarly tested using the harmful substance removing member of the present invention. As a result, sufficient odor could be removed.

Example 10 The harmful substance removing member of the present invention described in Example 4 and the harmful substance removing member of the comparative example were produced by changing the amount of titanium dioxide as shown in Table 1, and were produced in a place where no sunlight was exposed. And used as an outer wall material of a humid workplace,
Six months later, the state of the mold was investigated, and the results shown in Table 2 were obtained. The state of the mold was evaluated as slight when it was slightly adhered; good when not adhered at all.

[0034]

[Table 1]

Example 11 100 parts by weight of white cement, 220 parts by weight of sand, 25 parts by weight of titanium dioxide powder, 3 parts by weight of sodium carbonate and 30 parts by weight of water were kneaded.
The kneaded material was placed in a mold frame of 10 × 20 cm and subjected to vibration molding to form a molded body. After curing, the specimen was pulverized to a particle size of 1
A harmful substance removing member of 10 to 10 mm was used. Then, put this harmful substance removing member in a transparent container with an entrance and an exit,
The NO removal rate was measured by the NO removal test method 1 described in Example 1. When the harmful substance removing member of Example 1 was used, the NO removal rate was 73%, whereas in the case of the harmful substance removing member containing a salt of a strong base and a weak acid, NO was removed.
The removal rate was 78%, the purification performance was improved, and the durability was longer than that of Example 1.
In addition, not only NOx but also ethylene and mercaptan were similarly tested, and it was found that they could be decomposed with excellent decomposition efficiency.

EXAMPLE 12 125 parts by weight of a hydraulic mixture (white cement 4: titanium dioxide powder 1) obtained by mixing titanium dioxide and gypsum in a cement clinker, 220 parts by weight of sand, and 3 parts by weight of sodium carbonate Part and water 3
A harmful substance removing member was manufactured in the same manner as in Example 11 except that 0 parts by weight was kneaded. In the case of manufacturing by this method, the method of mixing the titanium dioxide powder with the cement has a higher N content.
The Ox purification function was excellent.

[0037]

The harmful substance removing member of the present invention is a hydrated aggregate obtained from a mixture of a hydraulic compound, an aggregate, a photocatalyst and water, and in particular, a void is formed by mixing the aggregate, The degree of exposure of the photocatalyst is increased, so that the light absorptivity can be improved. As a result, excellent harmful substance removal performance or purification performance can be obtained. The improved pH is due to contain the slaked lime to the hazardous substance removing member, as a result harmful substances in, in particular improves the purification efficiency of the photocatalyst by the NO _X discharged to the outside of the photocatalyst as a soluble salt A harmful substance removing member suitable for protecting the natural environment can be obtained.

In the present invention, since the mixture contains a water-soluble salt of a strong base and a weak acid, nitrate ions generated by the decomposition of NOx are neutralized by the water-soluble salt having a pH buffering action. A decrease in the NOx purification function can be prevented. Further, in the present invention, since the mixture contains the high-performance water reducing agent, the mixture can be dispersed uniformly, and therefore, the photocatalyst can be uniformly present and contribute to the light absorbing action. Furthermore, since the mixture contains activated carbon, harmful substances are decomposed and removed in the daytime under light, and at night, the harmful substances are adsorbed and removed by the adsorptive substance. Furthermore, when light strikes in the daytime, the harmful substances adsorbed by the adsorptive substance are released and decomposed and removed by the light.
Therefore, it has an excellent purification performance that enables harmful substances to be removed day and night.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI E01C 19/00 (72) Inventor Kiyoshi Kamiya 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Materials Corporation Cement Research Institute

Claims (5)

[Claims] 1. A member for removing harmful substances, which is a hydrated aggregate obtained from a mixture comprising a hydraulic compound, an aggregate, a photocatalyst and water. 2. The harmful substance removing member according to claim 1, wherein the mixture contains slaked lime. 3. The harmful substance removing member according to claim 1, wherein the mixture contains a water-soluble salt of a strong base and a weak acid. 4. The harmful substance removing member according to claim 1, wherein the mixture contains a high-performance water reducing agent. 5. The harmful substance removing member according to claim 1, wherein the mixture contains an adsorptive substance.