JP2002153750A - Pollutant decomposition method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pollutant decomposition method by ultraviolet radiation capable of efficiently carrying out decomposition at a low operation and initial cost and provide an apparatus suitable for the method. SOLUTION: The pollutant decomposition method comprises at least a step of decomposing a pollutant contained in a polluted gas, a gas containing the pollutant, by radiating ultraviolet rays from an ultraviolet ray radiation means. In the method, a decomposition treatment route having an introduction region for the polluted gas and a discharge region is formed, the polluted gas is passed through the decomposition treatment route, and an occupation region (a) of the ultraviolet ray radiation means and a non-occupation region (b) are arranged in this order from the upstream to the downstream side in the polluted gas flow direction in the decomposition treatment route so as to decompose the pollutant in the occupation region a and the non-occupation region b of the ultraviolet ray radiation means. The invention also provides a pollutant decomposition apparatus for the method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decomposing contaminants, for example, organic halogen compounds, especially organic chlorine compounds, and a decomposer used for the method.

[0002]

2. Description of the Related Art With the recent development of industrial technology, organic chlorine compounds (eg, chlorinated ethylene, chlorinated methane, etc.)
, And its disposal is becoming a serious problem. In addition, there is an environmental problem that these used pollutants pollute the natural environment, and great efforts have been made to solve the problem.

As a method for treating these, there is, for example, a method of decomposing chlorinated ethylene using an oxidizing agent or a catalyst.
No. 8297) and a method of irradiating ultraviolet rays in the presence of hydrogen peroxide (JP-A-63-218293). It has also been suggested to use sodium hypochlorite as an oxidizing agent (US Pat. Nos. 5,525,008 and 5,611,642), and a method of combining sodium hypochlorite with ultraviolet irradiation has been proposed (US Pat.
No. 582741). Furthermore, a method is also known in which a photocatalyst composed of oxide semiconductor fine particles such as titanium oxide and liquid chlorinated ethylene are suspended under alkaline conditions and decomposed by light irradiation (Japanese Patent Application Laid-Open No. 7-14137).

[0004] In addition to the above, a photolysis method of irradiating ultraviolet rays in a gas phase without using an oxidizing agent has already been attempted. For example, an exhaust gas containing an organic halogen compound is subjected to ultraviolet irradiation treatment to make it into an acidic decomposition gas, then washed with an alkali and detoxified (JP-A-62-191025). A device for performing aeration treatment, irradiating the discharged gas with ultraviolet rays, and then washing with alkali (Japanese Patent Application Laid-Open No. 62-191095) has been proposed.
Decomposition of chlorinated ethylene by iron powder is also known (Japanese Patent Application Laid-Open No. 8-257570), and in this case, it is presumed that probably reductive decomposition has occurred. As for the decomposition of tetrachloroethylene (hereinafter abbreviated as PCE) using silicon fine particles, reductive decomposition has also been reported.

In addition, trichloroethylene (hereinafter, TCE)
It is known that chlorinated aliphatic hydrocarbons such as PCE and chlorinated aliphatic hydrocarbons are decomposed aerobically or anaerobically by microorganisms. Attempted.

[0006]

Among such techniques, a method of decomposing contaminants by ultraviolet irradiation is considered to be one of useful techniques, but there is room for improvement in the cost associated with ultraviolet irradiation. was there.

An object of the present invention is to provide a method for decomposing contaminants by irradiating ultraviolet rays, which can be decomposed efficiently and which can reduce the power consumption related to ultraviolet irradiation, and an efficient method for this method. It is an object of the present invention to provide an apparatus for decomposing pollutants. It is also an object of the present invention to reduce the cost of the apparatus at the same time.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and have found that the number of ultraviolet lamps, which occupy a large part of the price of an ultraviolet irradiation type decomposition apparatus, has been reduced. In order to reduce the size of the quartz glass UV-transmitting part and reduce the power consumption, which accounts for a large part of the running cost of the UV irradiation type decomposition device, by half, not all but the entire reaction field is irradiated with ultraviolet rays. It was found that this was important, and led to the present invention.

That is, the present invention provides a method for decomposing contaminants, comprising the step of irradiating a contaminant gas, which is a gas containing at least contaminants, with ultraviolet light from ultraviolet irradiation means to decompose the contaminants. Forming a decomposition treatment path having an introduction area and a discharge area, flowing the contaminated gas through the decomposition treatment path, and irradiating the ultraviolet rays from upstream to downstream in the flow direction of the contaminant gas in the decomposition treatment path. A contaminant decomposing method characterized in that an installation area a and a non-installation area b of the means are provided in this order, and the contaminant is decomposed in the installation area a and the non-installation area b.

[0010] The present invention also includes an apparatus for performing the above contaminant decomposition method.

That is, the present invention provides a pollutant decomposition apparatus for decomposing a pollutant gas, which is a gas containing at least a pollutant gas, by irradiating the pollutant gas with ultraviolet rays from an ultraviolet irradiation means. A container for forming a decomposition treatment path having an introduction region and a discharge region of the contaminated gas for flowing, and an ultraviolet irradiation means; and in the decomposition treatment passage, from the upstream to the downstream in the flow direction of the contaminated gas. The installation region a and the non-installation region b of the ultraviolet irradiation means are provided in this order.

As the ultraviolet irradiation means, an artificial ultraviolet generator or a sunlight condensing device can be used.

[0013] The decomposition treatment path is formed by a container for flowing the contaminated gas therein, and has an introduction area for introducing the contaminated gas. The introduction region can be formed by an opening of the container when a contaminated gas is supplied to the container from the outside. When a substance other than gas containing pollutants (for example, liquid, slurry or solid) is supplied into the container from the outside, and a gas such as air is brought into contact with the substance to obtain a pollutant gas, the substance other than the gas in the container is used. The boundary between the region composed of and the gas phase (contaminated gas) region is the introduction region. The discharge area is for discharging pollutant gas from the decomposition treatment path, and can be formed by an opening of the container.

The installation area of the ultraviolet irradiation means is an area where the ultraviolet irradiation means is disposed along the decomposition treatment path, and ultraviolet rays are irradiated here. The non-installation area of the ultraviolet irradiation means is an area where the ultraviolet irradiation means in the decomposition treatment path is not provided, and may or may not be completely shielded from ultraviolet light. Ultraviolet rays leaking from the means, ultraviolet rays scattered from the apparatus or its surroundings, or ultraviolet rays included in natural light are allowed to hit.

In the disassembly processing path, the installation area and the non-installation area are provided one by one in this order, and a and b are respectively provided.
In this case, it is preferable that the volume ratio of the installation area a in the decomposition process path be 1/6 to 1/2, and 1/4 to 1
/ 3 is more preferable. This is because if the ratio of the installation area a is too large, the difference from a general decomposition processing apparatus that irradiates light to the whole becomes small, and the efficiency is reduced depending on the power consumption of the light irradiation unit, which is disadvantageous. It is. On the other hand, if the proportion of the installation area a is too small,
This is because it is disadvantageous in that it is necessary to irradiate intense light to a narrow area, a special light source needs to be prepared, and a problem exceeding the advantages of the present invention may occur.

Further, an installation area a 'of the light irradiation means can be provided further downstream of the non-installation area b in the decomposition processing path. In this case, the total decomposition processing path of the light irradiation areas a and a' Is preferably 1/6 to 1/2, more preferably 1/4 to 1/3.

Further, a plurality of areas where the light irradiating means are installed and areas where the light irradiating means are not installed may be provided alternately in the decomposition processing path. That is, downstream of the installation part a ′,
Further, a non-installed portion b 'can be provided, and an installed portion and a non-installed portion can be alternately provided. In any case, it is preferable that the volume ratio of the light irradiation area in the total decomposition processing path be 1/6 to 1/2, and 1/4 to 1/2.
More preferably, it is set to 1/3.

According to the present invention, a contaminant gas such as air containing a substance to be decomposed (contaminant) is moved into the reaction vessel,
A device that decomposes substances to be decomposed by irradiating ultraviolet rays.Instead of irradiating ultraviolet rays uniformly to the entire reaction field, instead of irradiating relatively strong ultraviolet rays to the first part of the container where contaminated gas flows, By irradiating a plurality of portions of the container with ultraviolet rays, an equivalent decomposition rate can be obtained with less power than uniformly irradiating the entire reaction field with ultraviolet rays.

The operation is as follows.

Decomposition of halogenated aliphatic compounds by irradiation with ultraviolet light is caused by the fact that these compounds are 185 nm or 254 nm.
A reaction in which ultraviolet rays having a central wavelength of m are excited and excited to become unstable and cause a dehalogenation reaction, thereby generating a halogen radical, and a reaction in which the generated radical attacks another halogenated aliphatic compound. It consists of two. Although these two reactions occur simultaneously in a general ultraviolet irradiation decomposition reaction vessel, the former dehalogenation reaction by ultraviolet excitation and the latter decomposition reaction need not always occur in the same place.

Since these two reactions occur sequentially, it is useless to irradiate the entire region in which the latter decomposition reaction occurs with ultraviolet light, but rather irradiate the ultraviolet light more strongly before the latter decomposition reaction starts. It is more efficient to generate halogen radicals of

In addition, once ultraviolet rays are irradiated to generate chlorine radicals and subsequently a decomposition reaction is carried out, the regions where the halogen radicals that can contribute to the reaction have been reduced are again irradiated with ultraviolet rays to generate halogen radicals again. Performing the decomposition reaction is more efficient. [Embodiment 1] FIG. 1 shows a basic configuration of an embodiment of a gaseous pollutant decomposition apparatus.

In FIG. 1, reference numeral 101 denotes a decomposition tank, which is a vessel made of a material that transmits ultraviolet light such as quartz glass and forms a decomposition processing path.
From 03, it is supplied to the decomposition treatment tank and discharged from the exhaust gas pipe 104. The whole area in the decomposition tank is a gas phase area. Here, the opening to the contaminated gas supply pipe of the container is an introduction area of the contaminated gas, and the opening to the exhaust gas pipe is a discharge area. The inside of the processing tank is irradiated with ultraviolet rays by ultraviolet irradiation means 106 installed along the lower side surface of the decomposition processing tank,
Decompose substances (contaminants) in the gas phase region that rises in the gas phase region 1.

In FIG. 1, the ultraviolet irradiation means 106 is installed outside the decomposition treatment tank 101,
Ultraviolet irradiation means may be provided inside 1. Similarly, the ultraviolet irradiation means 106 may have a ring shape, and a decomposition treatment tank 101 may be provided at the center thereof to irradiate the lower part of the decomposition treatment tank 101 from all directions. Conversely, a type in which the decomposition treatment tank 101 is a spiral column and a part thereof is irradiated by the ultraviolet irradiation means 106 may be used.

Also, as shown in FIG.
Is installed outside, depending on the strength and scale of the main body, the entire decomposition treatment tank 101 does not need to be made of a material that transmits ultraviolet light such as quartz glass, and only the portion irradiated with ultraviolet light is made of quartz glass. The other part may be made of an opaque material such as metal.

The air containing the substance to be decomposed is decomposed into
Immediately after the air is supplied to the first, that is, the most upstream part (section A in FIG. 1) of the decomposition treatment path is irradiated with ultraviolet rays from the ultraviolet irradiation means 106, that is, this area is set as the installation area a of the ultraviolet irradiation means, and the downstream part ( (Blocks B, C and D in FIG. 1)
Is a non-installation area b, thereby decomposing the substance to be decomposed.

The volume of the section A for irradiating the ultraviolet rays and the intensity of the ultraviolet rays are 1/6 to 2 times smaller than the case of the uniform irradiation for uniformly irradiating the entire reactor with the ultraviolet rays.
One-fourth, more preferably one-fourth to one-third is preferable (that is, the remaining portion is not irradiated with ultraviolet rays of the reactor but contributes to decomposition), and the intensity of ultraviolet rays per unit area is 1.5 times. Above, more preferably twice or more. By doing so, the same or better decomposition effect can be obtained with less power consumption than in the case of uniform irradiation. [Embodiment 2] In this embodiment, an ultraviolet irradiation means is provided along a portion (section A in FIG. 1) immediately after air containing a substance to be decomposed is supplied to 101, and the installation area a is provided. Ultraviolet rays of the same intensity as in the case of uniform irradiation in which ultraviolet rays are evenly irradiated are applied here. Figure 1 downstream of Section A
In section B, no ultraviolet irradiation means is provided alongside, that is, an area b where no ultraviolet irradiation means is provided. Here, the contaminant gas is not irradiated with ultraviolet light. In the section C in FIG. 1 downstream of the section B, an ultraviolet irradiating means (not shown) is arranged along the ultraviolet ray irradiating section, and an ultraviolet ray of the same intensity is again irradiated on the contaminated gas. D in FIG. 1 downstream of section C
No ultraviolet irradiation means is provided along the section, that is, this area is a non-installation area b 'of the ultraviolet irradiation means, and the contaminated gas passes again through the area not irradiated with ultraviolet light.

In this embodiment, as in the case of the first embodiment, a decomposition rate substantially equal to that in the case of uniform irradiation can be obtained with half the power consumption in the case of uniform irradiation.

It is to be noted that the section D is not always necessary, and there may be only the sections A and C to be irradiated with ultraviolet rays and the section B located between them and not irradiated with ultraviolet rays.

In the decomposition method of the present invention, it is preferable to use ultraviolet rays having a center wavelength of 185 nm or 254 nm from the viewpoint of resolution. Glass or transparent Teflon (registered trademark) is preferred. (Decomposition target substances) The pollutants to be decomposed in the present invention include halogenated aliphatic hydrocarbons, particularly chlorinated aliphatic hydrocarbons, and specific examples include chloroethylene, 1,1-dichloroethylene, and cis. Organic chlorine compounds such as -1,2-dichloroethylene, trans-1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, chloromethane, dichloromethane, trichloromethane and 1,1,1-trichloroethane can be exemplified. (Ultraviolet irradiation means)
It is preferable to use ultraviolet rays having a central wavelength of 185 nm or 254 nm, which has a high sterilizing effect. As a light source that generates such ultraviolet rays, a high-pressure and low-pressure mercury lamp, a xenon lamp, a halogen lamp, an excimer lamp, a deuterium lamp, and a metal halide lamp can be used. Among these, a low-pressure mercury lamp has a high ultraviolet irradiation efficiency and can be particularly preferably used. In addition, energy consumption can be reduced by using sunlight.

The irradiation amount of the ultraviolet rays is 10 μW / cm in the portion of the gas phase region to be irradiated which is closest to the light source.
^{2 to} 10 mW / cm ² , further 50 μW / cm ^{2 to 5} m
W / cm ² is preferred.

[0032]

EXAMPLES The present invention will be described in detail with reference to the following Examples, which do not limit the present invention in any way.

Example 1 Gas, 254 nm, Initial UV Irradiation The decomposition apparatus shown in FIG. 1 was prepared.

The decomposition bath 101 is a sealed container made of quartz glass having a height of 40 cm and a volume of 500 mL.

The decomposition treatment tank 101 was irradiated with ultraviolet rays as ultraviolet irradiation means 106 using a sterilizing lamp (GL4, 4W, manufactured by Toshiba Lighting & Technology Corp.) which irradiates ultraviolet rays of 253.7 nm. However, this lamp has a tube length of 13.
In contrast to 5 cm, here the irradiation area is 10 cm.
About 2 cm above and below the lamp by aluminum foil 1
07 and a germicidal lamp with a lamp tube length of 10 cm.
At this time, the irradiation light amount is 0.2 to 0.3 mW / at the position closest to the light irradiation means 106 on the surface of the decomposition treatment tank 101.
cm ² .

Contaminated gas supply pipe 1
03, TCE, which was regarded as contaminated air sucked from contaminated soil generated by a permeator (Gastec)
100 m of air containing 100 ppm each of
Air was supplied at a flow rate of L / min.

Exhaust gas from the exhaust gas pipe 104 is periodically sampled with a gas tight syringe after the decomposition process of this apparatus is started, and the TCE and PCE concentrations are analyzed by gas chromatography (trade name: GC-14B (FID detection). Instrument); Shimadzu Corporation).

This decomposition treatment tank 101 is divided into 10 cm sections from the bottom to form A section, B section, C section, and D section, and each section is irradiated with ultraviolet light by one or two lamps for 5 minutes. After 10 minutes and 15 minutes, the concentrations of TCE and PCE in the exhaust gas were measured, and the average decomposition rate was determined. [Experiment 1] A total of 4 germicidal lamps were installed in each of the compartments, and a total of 4 germicidal lamps were installed in each of the compartments A, B, C, and D of the decomposition treatment tank 101. Irradiated. The average decomposition rate at this time was 98.8%.

[Experiment 2] One section A One section of the decomposition treatment tank 101 was covered with aluminum foil so that only section A was exposed to ultraviolet rays, and one germicidal lamp was placed beside section A. Irradiated with ultraviolet light. The average decomposition rate at this time was 97.1%.

[Experiment 3] Two compartments A Two compartments other than compartment A of the decomposition tank 101 were covered with aluminum foil so that only compartment A was exposed to ultraviolet rays, and two germicidal lamps were installed beside compartment A. Irradiated with ultraviolet light. The average decomposition rate at this time was 98.9%.

[Experiment 4] One section B One section of the decomposition tank 101 was covered with aluminum foil so that only section B was exposed to ultraviolet rays, and one germicidal lamp was set up next to section B. Irradiated with ultraviolet light. The average decomposition rate at this time was 94.4%.

[Experiment 5] Two B compartments The other than the B compartment of the decomposition tank 101 was covered with aluminum foil so that only the B compartment was exposed to ultraviolet rays, and two sterilizing lamps were installed beside the B compartment. Irradiated with ultraviolet light. The average decomposition rate at this time was 98.1%.

[Experiment 6] One C section The other than the C section of the decomposition tank 101 was covered with aluminum foil so that only the C section was irradiated with ultraviolet rays, and one germicidal lamp was installed beside the C section. Irradiated with ultraviolet light. The average decomposition rate at this time was 90.5%.

[Experiment 7] Two C compartments The other than the C compartment of the decomposition treatment tank 101 was covered with aluminum foil so that only the C compartment was irradiated with ultraviolet rays, and two sterilizing lamps were installed beside the C compartment. Irradiated with ultraviolet light. The average decomposition rate at this time was 94.6%.

[Experiment 8] One D section The other than the D section of the decomposition tank 101 was covered with aluminum foil so that only the D section was irradiated with ultraviolet rays, and one germicidal lamp was installed beside the D section. Irradiated with ultraviolet light. The average decomposition rate at this time was 71.2%.

[Experiment 9] Two compartments D Two parts of the decomposition tank 101 were covered with aluminum foil so that only the D compartment was exposed to ultraviolet rays, and two germicidal lamps were installed beside the D compartment. Irradiated with ultraviolet light. The average decomposition rate at this time was 77.6%.

[Experiment 10] Decomposition tank 10 except for one compartment and one compartment (10 cm) in length.
Using the same decomposition treatment tank as in Example 1, one sterilization lamp was installed beside the decomposition treatment tank and irradiated with ultraviolet rays. The average decomposition rate at this time was 69.5%.

[Experiment 11] Decomposition tank 10 except for one compartment and two compartments (10 cm) in length.
Using the same decomposition treatment tank as in No. 1, two sterilization lamps were installed beside the decomposition treatment tank and were irradiated with ultraviolet rays. The average decomposition rate at this time was 75.3%. Comparison of Experiments 2, 4, 6, and 8 and Comparison of Experiments 3, 5, 7, and 9 show that when different positions of the decomposition treatment tank are irradiated with ultraviolet light, the decomposition rate of the entire device differs even with the same amount of ultraviolet light. I understood. From comparison of these with Experiments 10 and 11, TCE and PCE
It has been found that it is preferable to provide a decomposition reaction region in which the ultraviolet ray is not irradiated (downstream) after irradiating the ultraviolet ray containing air with the ultraviolet ray.

Further, according to the comparison between Experiments 1 and 2 and 3, the total irradiation amount of the ultraviolet rays is 1/4 and the unit irradiation area is 1/4 when the irradiation area of the ultraviolet rays is 1/4 as compared with the case of the uniform irradiation. Irradiating the same amount of UV light alone reduces the decomposition rate of the entire apparatus by almost 1%, but the total amount of UV light is halved and twice the amount of UV light per unit area is required. It was found that almost the same decomposition rate could be obtained.

From the above results, compared with the case of uniform irradiation in which the entirety of the decomposition treatment tank is uniformly irradiated with ultraviolet light, the first quarter of the decomposition treatment tank through which air containing the substance to be decomposed flows flows. It has been found that, when the total irradiation amount is one half and the irradiation amount per unit area is twice as large as that of the ultraviolet irradiation, the power consumption of the ultraviolet irradiation device is half and the same device decomposition efficiency can be obtained. [Example 2] Low pressure mercury lamp irradiating ultraviolet rays of 184.9 nm and 253.7 nm instead of a germicidal lamp irradiating ultraviolet rays of 185 nm and 253.7 nm instead of gas, 185 nm, initial ultraviolet ray (Ushio Electric Co., Ltd. UL0-6DQ ,
6W) and using a filter that does not transmit light of 230 nm or more, the same experiment as in Example 1 was performed except that the decomposition treatment apparatus 101 was irradiated with ultraviolet light of 184.9 nm, and the concentrations of TCE and PCE in the exhaust gas were measured. The average decomposition rate was examined.

As a result, almost the same results as in Example 1 were obtained, and even if the ultraviolet light of 184.9 nm was used, the ultraviolet light having twice the initial intensity was compared to the case where the ultraviolet light was evenly applied to the entire decomposition treatment tank. It was found that by irradiating, the power consumed by the ultraviolet irradiation device was reduced to half and the same device decomposition efficiency was obtained. [Example 3] Gas, 254 nm, partial ultraviolet irradiation The B and D sections of the decomposition tank 101 were covered with aluminum foil so that only the A and C sections were exposed to ultraviolet rays.
The same experiment as in Example 1 was performed by arranging two sterilizing lamps one by one next to the sections A and C and irradiating ultraviolet rays. The average decomposition rate at this time was 98.7%.

By comparing this result with the experiment 1 of Example 1, the first quarter region and the third quarter region of the decomposition treatment tank through which the air containing the substance to be decomposed flows. In comparison with the case where ultraviolet rays are evenly applied to the entire decomposition tank, if the total amount of ultraviolet rays is halved and the same amount of ultraviolet light is irradiated per unit area, the power consumed by the ultraviolet irradiation device is reduced. It was found that the same device decomposition efficiency was obtained in half. [Example 4] Gas, 254 nm, partial ultraviolet irradiation The B and C sections of the decomposition tank 101 were covered with aluminum foil so that only the A and D sections were exposed to ultraviolet rays.
The same experiment as in Example 1 was performed by installing two germicidal lamps one by one next to the A and D compartments and irradiating them with ultraviolet rays. The average decomposition rate at this time was 98.3%.

By comparing this result with Experiment 1 of Example 1, it was found that the first quarter region and the fourth quarter region of the decomposition treatment tank through which the air containing the substance to be decomposed flows. In comparison with the case where ultraviolet rays are evenly applied to the entire decomposition tank, if the total amount of ultraviolet rays is halved and the same amount of ultraviolet light is irradiated per unit area, the power consumed by the ultraviolet irradiation device is reduced. It was found that the same device decomposition efficiency was obtained in half.

[0054]

According to the present invention, in a method of decomposing pollutants by irradiating ultraviolet rays, the power consumption associated with the decomposed ultraviolet rays can be reduced, and thus the running cost can be reduced. Provided is an efficient pollutant decomposition method and a pollutant decomposition apparatus that can reduce costs.

[Brief description of the drawings]

FIG. 1 is a schematic view of a decomposition apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 101: Decomposition treatment tank 103: Contaminated gas supply pipe 104: Exhaust gas pipe 106: Ultraviolet irradiation means 107: Aluminum foil for sterilizing lamp upper and lower light shielding

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 19/05 C07C 19/05 21/04 21/04 21/073 21/073 21/10 21/10 21 / 12 21/12 (72) Inventor Masahiro Kawaguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2E191 BA15 BD11 BD17 4G075 AA03 AA37 BA01 BA04 BA05 BD04 CA32 CA33 DA01 EA01 EB21 EB31 EE31 FB02 FB06 FC04 4H006 AA05 AC13 BA95 BC13 BC18 EA02 EA03

Claims (26)

[Claims] 1. A method for decomposing contaminants, comprising the step of irradiating a contaminant gas, which is a gas containing at least contaminants, with ultraviolet light from an ultraviolet irradiation means to decompose said contaminants, wherein said contaminant gas introduction region Forming a decomposition treatment path having a discharge area and discharging the contaminated gas in the decomposition treatment path, and installing the ultraviolet irradiation means in the decomposition treatment path from upstream to downstream in the flow direction of the contaminant gas. A method for decomposing a contaminant, comprising: providing an area a and a non-installation area b in this order, and decomposing the contaminant in the installation area a and the non-installation area b. 2. The method for decomposing pollutants according to claim 1, wherein the volume ratio of the installation area a in the decomposition process path is 1/6 to 1/2. 3. The method according to claim 2, wherein the volume ratio is 1/4 to 1/3. 4. The method for decomposing pollutants according to claim 1, wherein an installation area a ′ for the ultraviolet irradiation means is provided further downstream of the non-installation area b, and the contaminants are also decomposed in the installation area a ′. 5. The method for decomposing pollutants according to claim 4, wherein the total volume ratio of the installation areas a and a ′ in the decomposition process path is 1/6 to 1/2. 6. The method for decomposing contaminants according to claim 1, wherein a plurality of areas where the ultraviolet irradiation means are installed and a plurality of areas where the ultraviolet light is not installed are alternately provided. 7. The method for decomposing contaminants according to claim 1, wherein the ultraviolet rays include ultraviolet rays having a wavelength of 185 nm. 8. The method for decomposing pollutants according to claim 1, wherein the ultraviolet rays include ultraviolet rays having a wavelength of 254 nm. 9. The irradiation amount of the ultraviolet light is 10 μW / cm ² or more.
Pollutant decomposition method according to claim 1 which is 10 mW / cm ^2. 10. An irradiation amount of the ultraviolet ray is 50 μW / cm ^2.
Pollutant decomposition method according to claim 9 is ~5mW / cm ^2. 11. The method for decomposing pollutants according to claim 1, wherein said pollutants are halogenated aliphatic hydrocarbons. 12. The method according to claim 11, wherein the halogenated aliphatic hydrocarbon is a chlorinated aliphatic hydrocarbon. 13. The chlorinated aliphatic hydrocarbon is chloroethylene, 1,1-dichloroethylene, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, chloromethane, dichloromethane, trichloromethane and 13. The method for decomposing pollutants according to claim 12, which is at least one compound selected from the group consisting of 1,1,1-trichloroethane. 14. A pollutant decomposing apparatus for decomposing a pollutant gas, which is a gas containing at least a pollutant gas, by irradiating the pollutant gas with ultraviolet rays from an ultraviolet ray irradiating means. A container forming a decomposition treatment path having an introduction region and a discharge region of the contaminated gas, and an ultraviolet irradiation means, wherein the ultraviolet light is supplied from the upstream to the downstream in the flow direction of the contaminant gas in the decomposition treatment passage. A contaminant decomposing apparatus, wherein an installation area a and a non-installation area b of the irradiation unit are provided in this order. 15. The contaminant decomposition apparatus according to claim 14, wherein a volume ratio of the installation area a to the decomposition processing path is 1/6 to 1/2. 16. The contaminant decomposition apparatus according to claim 15, wherein the volume ratio is 1/4 to 1/3. 17. The pollutant decomposer according to claim 14, wherein an installation area a ′ of said ultraviolet irradiation means is provided further downstream of said non-installation area b. 18. The contaminant decomposition apparatus according to claim 17, wherein the total volume ratio of the installation areas a and a ′ to the decomposition processing path is 1/6 to 1/2. 19. The contaminant decomposing apparatus according to claim 14, wherein a plurality of the installation areas and the non-installation areas of the ultraviolet irradiation means are provided alternately. 20. The pollutant decomposer according to claim 14, wherein the ultraviolet light includes ultraviolet light having a wavelength of 185 nm. 21. The pollutant decomposer according to claim 14, wherein the ultraviolet light includes ultraviolet light having a wavelength of 254 nm. 22. An irradiation amount of the ultraviolet light is 10 μW / cm ^2.
Pollutant decomposition apparatus according to any one of claims 14 to 21 is ~10mW / cm ^2. 23. An irradiation amount of the ultraviolet light is 50 μW / cm ^2.
23. The pollutant decomposer according to claim 22, wherein the power is ５5 mW / cm ² . 24. The pollutant decomposition apparatus according to claim 14, wherein the pollutant is a halogenated aliphatic hydrocarbon. 25. The apparatus according to claim 24, wherein the halogenated aliphatic hydrocarbon is a chlorinated aliphatic hydrocarbon. 26. The chlorinated aliphatic hydrocarbon is chloroethylene, 1,1-dichloroethylene, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, chloromethane, dichloromethane, trichloromethane and The pollutant decomposition device according to claim 25, which is one or more compounds selected from the group consisting of 1,1,1-trichloroethane.