JPH11342316A - Method of preventing environmental pollution and product having function of preventing environmental pollution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of preventing environmental pollution due to a product containing components having the possibility of giving off harmful materials into an environment and a product having the function of preventing the environmental pollution. SOLUTION: This is a method of decomposing and making harmless, by a photocatalyst, material such as dioxin having the possibility of diffusing into environment to cause environmental pollution. Particularly, a method of giving a mechanism for decomposing the harmful material even when discharged into the environment by previously incorporating the photocatalyst into a product in which the harmful material is contained or from which it is generated and the product are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing environmental pollution by products containing components that generate harmful substances and may diffuse into the environment, and a product having a function of preventing environmental pollution.

[0002]

2. Description of the Related Art Environmental pollution of substances harmful to the human body has become serious, and in recent years, the diffusion of hormone-like chemical substances (endocrine disrupting substances) into the environment, which affects various functions of ecology even in a very small amount, has been increasing. Is in question. Hormones are naturally secreted chemicals in the ecology, but it is suspected that some chemicals act like hormones and cause reproductive abnormalities in birds, mammals, and shellfish. Examples of such studies are the genitalization of the genitalia found in the snail, Ibonyshi, the morphological and behavioral femaleization of male seagulls, and the inhabitants of Lake Apopka, Florida Crocodiles' reproductive organs have also been reported to be due to pesticide contamination. Regarding effects on humans, a decrease in sperm count (reported to be halved from 1938 to 1990) and an increase in malformations have been remarkably observed in recent years, suggesting that the relationship with hormone-like chemicals is suspected. ing.

At present, suspected hormone-like chemicals include pesticides such as atrazine, DDT, and dicophor, phenols used in resins, and dioxins discharged during the processing of wastes. In particular, dioxin generated during the incineration of resins containing chlorine such as vinyl chloride is highly toxic, such as carcinogenic, and is always generated when burning incinerated materials containing chlorine. It is very problematic. Dioxin remains in the exhaust gas discharged from the incinerator and in the ash (incineration ash) remaining after incineration. The incineration ash is landfilled at the final disposal site, but dioxin contamination due to the scattered incineration ash has been detected above this disposal site.

[0004] Many of these environmental pollutants are relatively stable and cannot be expected to degrade microorganisms in the environment, and once discharged into the environment, it is difficult to remove them. For example, dioxin is relatively stable to heat, acids, and alkalis,
It has low water solubility and high persistence. Since dioxin is generated during the waste incineration process, there is a possibility that dioxin can be reduced by devising a dioxin adsorption filter in the incinerator.However, many products, such as agricultural materials, are burned in mountainous areas such as agricultural materials. Did not. Even better, there are no countermeasures for products spread in the environment, such as pesticides and pesticides.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for preventing environmental pollution by products containing components that generate harmful substances and may diffuse into the environment, and a product having a function for preventing environmental pollution. That is the task.

[0006]

Means for Solving the Problems The present inventors adsorb harmful substances which may be diffused into the environment to a photocatalyst having an adsorbing power before diffusing them as much as possible, and gradually adsorb the harmful substances such as sunlight. It was devised to decompose and detoxify by irradiating light. For example, by spraying an adsorbent such as activated carbon and a photocatalyst such as titanium oxide on the incineration ash at a final disposal site, dioxin is decomposed and contamination can be prevented.

The present inventors further incorporate a photocatalyst capable of adsorbing harmful substances into a product in advance, so that if the harmful substance can be adsorbed and held near the photocatalyst even after the product has diffused into the environment, the sunlight In addition, it was considered that light from various light sources, such as, can be gradually decomposed by photocatalyst, so that it does not remain in the environment, and that environmental pollution can be prevented.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Photocatalysts usable in the present invention include titanium oxide, zinc oxide, tin oxide, strontium titanate, tungsten oxide, bismuth oxide and iron oxide. Titanium oxide has the highest decomposition ability. It is desirable because it is stable and safe. Regarding the decomposition ability of titanium oxide, it can cover almost all organic substances and can be mineralized by changing to water and inorganic substances such as carbon dioxide and hydrochloric acid. The photocatalyst used in the present invention needs to have a property of adsorbing and holding harmful substances so that it does not escape. As such a photocatalyst, colloidal titanium oxide (titanium oxide sol) dispersed in a solvent or water or fine powder is desirable. In order to enhance the adsorptivity, it is effective to mix activated carbon, zeolite, activated alumina and the like with a photocatalyst or to coat photocatalyst particles.

In the case of mixing in a vinyl chloride resin or the like in order to suppress the generation of dioxin during combustion, further characteristics of a photocatalyst are required. That is, the photocatalytic activity does not work during normal use and does not oxidatively decompose the product, but after the product has accumulated heat during combustion, the activity of the photocatalyst develops and the adsorption power is maintained even after the heat treatment process Must be done. As an example of such a photocatalyst, an amorphous titanium oxide sol having a low crystallinity can be used. That is, titanium oxide having low crystallinity has low photocatalytic activity, and there is no fear of causing photocatalytic degradation even when kneaded with vinyl chloride or the like. However, once heat-treated at a temperature in the range of several hundred degrees to 800 ° C., photocatalytic activity increases and desired decomposition occurs. Forces arise. As a result, the dioxin contained in the ash after the vinyl chloride has been incinerated is decomposed and detoxified when exposed to light on the photocatalyst.

When considering such applications, it is necessary that the distribution state of the photocatalyst particles in the product is as uniform as possible and that the harmful substances are efficiently adsorbed and captured and not released. When applied to vinyl chloride, it is desirable that the photocatalyst particles therein are dispersed as uniformly as possible. Also, when applied to insecticides and pesticides, it is desirable that the titanium oxide is uniformly dispersed in the liquid preparation. In order to increase the dispersibility in the solution, p
It is effective to adjust H and use an appropriate dispersant. For example, since the isoelectric point of titanium oxide is close to neutral, it can be stabilized by adjusting the pH of the solution to acidic or alkaline. Further, in order to change the stable pH range of titanium oxide, the isoelectric point can be changed by coating silica or the like around the titanium oxide particles.

Such applications include vinyl chloride, insecticides,
It can be applied to all products, not just pesticides. Surfactants also cause environmental pollution, but detergents, soaps, and postcards containing surfactants can be detoxified when they diffuse into the environment by mixing photocatalyst into titanium oxide, etc. I can do it.

[0012]

[Example 1] Photocatalytic titanium oxide sol (6 wt.
%, Alkali peptized type, manufactured by Taki Kagaku Co., Ltd.) spray-coated on an alumina substrate to a thickness of about 1 micron, heat-treated at various temperatures, and evaluated the decomposition activity of toxic gas methyl mercaptan. did. First 3 in the dark
ppm of methyl mercaptan gas was introduced into an 11 liter glass container containing the sample, and the BLB lamp 4W was turned on for 8 hours.
Irradiate at a distance of cm and evaluate the decomposition rate of gas. After 30 minutes, the concentration reduction rate is plotted on a graph as R30, as shown in FIG. 1. At the beginning, the photocatalytic activity is not so large, but the activity increases as the temperature rises, and the activity decreases when the temperature exceeds 800 ° C.

The decomposition activity of dioxin (DCDD: 2,7-dichloro-p-dibenzodioxin) was evaluated by gas chromatography of a heat treatment of such a titanium oxide sol at 700 ° C. assuming incineration and disposal. Has the ability to decompose.

[0014]

According to the present invention, when a product containing a harmful substance such as a hormone-like substance or the like which may cause environmental pollution or a product that generates a harmful substance in an incineration process or the like is discharged to the environment, Since harmful substances can be detoxified by decomposing with sunlight or the like, environmental pollution can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the photocatalytic activity of a titanium oxide sol and a heat treatment temperature.

Claims (11)

[Claims] 1. A method for decomposing and purifying harmful substances which may diffuse into the environment using a photocatalyst having an adsorption effect and a decomposition effect or a photocatalyst and an adsorbent. 2. A method for preventing environmental pollution caused by a product containing a component which may generate harmful substances and diffuse into the environment, comprising a photocatalyst or a photocatalyst having an effect of adsorbing and decomposing harmful substances in the product. Prevents environmental pollution by adsorbing harmful substances contained or generated when the product diffuses into the environment, and naturally decomposing and detoxifying by sunlight or lighting when the product diffuses into the environment Method. 3. A product containing a component that may generate harmful substances and diffuse into the environment, wherein a photocatalyst having a harmful substance adsorption effect and a decomposition effect and a photocatalyst and an adsorbent are previously contained in the product. Thus, when the product diffuses into the environment, the product has a function of adsorbing harmful substances contained or generated, and having a function of preventing environmental pollution, which is naturally decomposed and rendered harmless by sunlight or illumination light. 4. The harmful substance is dioxins generated when a vinyl chloride resin is burned, and the dioxins generated during the combustion are adsorbed by a photocatalyst or a photocatalyst and an adsorbent previously contained in vinyl chloride. 2. A method for preventing environmental pollution according to claim 1, wherein said method is followed by photocatalytic decomposition. 5. The harmful substance is a dioxin generated when a vinyl chloride resin is burned, and the dioxin generated during the combustion is adsorbed by a photocatalyst or a photocatalyst and an adsorbent previously contained in vinyl chloride. 3. A vinyl chloride product having a function of preventing environmental pollution according to claim 2, which has a function of causing photocatalytic decomposition. 6. The environmental pollution according to claim 1, wherein the harmful substance is a pesticide, which is dispersed in the environment, adsorbed on a photocatalyst or a photocatalyst and an adsorbent previously contained in the pesticide, and subsequently decomposed by photocatalyst. Prevention method. 7. The method according to claim 2, wherein the harmful substance is a pesticide, which has a function of being dispersed in the environment, adsorbed to a photocatalyst or a photocatalyst and an adsorbent previously contained in the pesticide, and subsequently decomposed by the photocatalyst. Pesticide products that have the function of preventing environmental pollution based on them. 8. The method according to claim 1, wherein the harmful substance is an insecticide, which is dispersed in the environment, adsorbed on a photocatalyst or a photocatalyst and an adsorbent previously contained in the insecticide, and subsequently decomposed by photocatalyst. How to prevent environmental pollution. 9. The method according to claim 1, wherein the harmful substance is an insecticide, which has a function of being dispersed in the environment, adsorbed on a photocatalyst or a photocatalyst and an adsorbent previously contained in the insecticide, and subsequently decomposed by photocatalyst. 2. An insecticide product having a function of preventing environmental pollution based on No. 2. 10. The harmful substance is a surfactant,
2. A method for preventing environmental pollution according to claim 1, wherein after being dispersed in the environment, the photocatalyst or a photocatalyst or a photocatalyst previously contained in a surfactant is adsorbed on an adsorbent, and subsequently photocatalytically decomposed. 11. The harmful substance is a surfactant,
3. A surfactant having a function of preventing environmental pollution according to claim 2, which has a function of adsorbing a photocatalyst or a photocatalyst and a photocatalyst and an adsorbent previously contained in a surfactant after being dispersed in the environment and subsequently decomposing the photocatalyst. Including products.