JP2002143642A - Method for decomposing contaminated gas and equipment used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an equipment for decomposing gaseous organic chlorine compounds which suppresses a release to environment and efficiently utilizes chlorine. SOLUTION: This contaminated substance decomposition and purification method has a process which decomposes contaminated substances by irradiating the gas to be treated, which is made by incorporating air with chlorine introduced from functional water I, II and the contaminated substances, with light from a photoirradiation means. Further, the contaminated substance decomposition and purification method has a process which allows the air after decomposition treatment to contact with an alkaline aqueous solution and makes a chlorine-containing alkaline aqueous solution and a regeneration process which supplies at least a part of the chlorine-containing alkaline aqueous solution and the waste liquid of functional water from the solution for generating chlorine in the chlorine generation region to a functional water forming means by means of electrolysis, regenerates the same and produces the functional water II, and an equipment used therefor is also 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 decomposing a gaseous organochlorine compound and a decomposition apparatus used for the method.

[0002]

2. Description of the Related Art With the development of industrial technology up to recent years, organochlorine compounds (eg, chlorinated ethylene, chlorinated methane, etc.) have been used enormously, and their disposal has become a serious problem. In addition, these gases used have caused environmental problems such as polluting the natural environment, and great efforts have been made to solve them.

As a method of treating these, there is, for example, a method of decomposing chlorinated ethylene using an oxidizing agent or a catalyst, and specifically, a method of decomposing it with ozone (JP-A-3-38).
No. 297) 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. 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. 7-141373).

[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, a method in which an exhaust gas containing an organic halogen compound is subjected to ultraviolet irradiation treatment to make it into an acidic decomposition gas, and then washed with alkali to make it harmless (Japanese Patent Application Laid-Open No. 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. Also,
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.

Further, 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.

As described above, various methods for decomposing organic chlorine compounds have been conventionally proposed. However, according to the study of the present inventors, a complicated apparatus for decomposition is required, In many cases, further detoxification treatment of the product is required, and there are fewer problems and it is environmentally friendly.
It was concluded that a technique for decomposing organic chlorine compounds was necessary. That is, to provide a simpler and more efficient method for decomposing pollutants and a contaminant decomposer to be used therefor. Also, it does not require treatment with activated carbon or microorganisms, and is efficient and has a low level of secondary pollution. no problem,
There is also a need to provide a decomposition method capable of decomposing pollutants with a small amount of wastewater and an efficient pollutant decomposition apparatus using the method.

[0007] As an example of an apparatus for solving the above-mentioned problems, a gaseous organic chlorine compound in which a gas containing chlorine gas is mixed with a gaseous organic chlorine compound to be decomposed, and the mixed gas is irradiated with light. Has been proposed.

Here, as a simple and safe means for obtaining gas containing chlorine gas, chlorine gas generated from a solution containing chlorine (chlorine solution) is used.

FIG. 1 is a schematic view of one embodiment of the present invention. Reference numeral 11 denotes a means for generating air containing chlorine gas, a water tank 12 for storing a chlorine solution, a pipe 13 for blowing air into the solution, and an amount of air. A valve 14 is provided. Then, the air that has passed through the chlorine solution becomes air containing chlorine gas, and is led to the reaction tank 5. Reference numeral 1 denotes a device for supplying a gas to be decomposed, which is led to a reaction tank 5, mixed with air containing chlorine gas in the reaction tank 5, and irradiates the mixed gas with light for a predetermined time by a light irradiation means 4; The decomposition target gas is decomposed. The decomposed gas is discharged from the exhaust pipe 6.

The chlorine solution put in the water tank 12 has a hydrogen ion concentration (pH value) of 1-4 and a residual chlorine concentration of 5-150.
A solution having a characteristic of mg / L is used. Such a solution can be obtained, for example, by dissolving hypochlorite (sodium hypochlorite or potassium hypochlorite) in water. When an inorganic acid or the like is contained in this solution, chlorine gas can be efficiently generated.

By placing a pair of electrodes in water containing an electrolyte and applying a potential between them, a solution having the above properties can be generated near the anode. Water generated by such electrolysis is called electrolyzed water, functional water, or the like, and the generator is commercially available for sterilization or the like.

Although it can be understood whether a solution containing chlorine (chlorine solution) prepared by dissolving hypochlorite or the like in water and having the same properties as electrolyzed water is called functional water, it can be understood from discussion. In the specification, both the electrolyzed water and the chlorine solution are collectively referred to as functional water.

As shown in FIG. 2, functional water formed on the anode 23 side by a functional water generator 21 comprising an electrolyzer 22 is continuously supplied to a chlorine gas generation tank 11 at a desired flow rate by a pump 25 and a pipe 26. Is supplied via In the figure, 2
4 is a cathode, and 27 is a partition separating the anode side and the cathode side. The gas to be aerated is continuously supplied to the chlorine gas generation tank 11 at a desired flow rate through the supply pipe 13 and the pump 15. As a result, gas containing chlorine gas is discharged from the discharge pipe 3. The gas containing chlorine is introduced into the reaction tank 5,
Thereafter, the compound to be decomposed is decomposed by the method described above.
The functional water used in the treatment is discharged from the chlorine gas generation tank 11 to the tank 8. As described above, the method of generating air containing chlorine gas by passing air through the chlorine solution does not require a chlorine cylinder or the like, and can supply chlorine safely, simply, and stably.

[0014]

However, the above-mentioned apparatus for decomposing gaseous organochlorine compounds may have the following disadvantages. That is, in the decomposition apparatus, the decomposition reaction is started by mixing chlorine gas supplied from water containing chlorine, ie, functional water, and a gaseous organic chlorine compound as a decomposition target substance under light irradiation.

However, not all chlorine gas is consumed by the decomposition reaction, but rather, most of the chlorine gas is discharged as it is and may be released into the environment.
The fact that most of the chlorine is released means that chlorine used for decomposition is a small amount of the total chlorine and inefficient in the whole system.

An object of the present invention is to provide an apparatus for decomposing gaseous organic chlorine compounds which suppresses release into the environment and efficiently utilizes chlorine.

[0017]

The present invention solves the above-mentioned problems by recovering the discharged chlorine and subjecting it to a decomposition reaction again.

That is, the method for decomposing and purifying a gaseous organochlorine compound according to one embodiment of the present invention, which can achieve the above object, comprises the steps of: introducing chlorine introduced from functional waters (I) and (II); And contaminant decomposition and purification method having a step of decomposing the contaminant by irradiating light from the light irradiation means to the gas to be treated contained in the air, the functional water (I) and ( II) a step of generating chlorine, a step of contacting the gas after the decomposition treatment with an alkaline aqueous solution to form a chlorine-containing alkaline aqueous solution, and at least one of the chlorine-containing alkaline aqueous solution and the functional water waste liquid used for introducing the chlorine. And regenerating the functional water by means of electrolysis to obtain the functional water (II) .The functional water (II) from the regenerating step is sent to the chlorine generating step again. Can be , The functional water (I) and (I
I) is capable of generating air containing chlorine by aeration, and the functional water (I) does not include the functional water waste liquid or the chlorine-containing alkaline aqueous solution in a forming solution thereof, and the functional water ( II) relates to a method for decomposing and purifying pollutants, characterized in that at least a part of the forming solution contains the functional water waste liquid or the chlorine-containing alkaline aqueous solution.

Further, the apparatus for decomposing and purifying gaseous organochlorine compounds according to one embodiment of the present invention, which can achieve the above object, comprises chlorine introduced by functional waters (I) and (II), and pollutants. In a contaminant decomposition and purification device that decomposes the contaminant by irradiating the gas to be treated containing air with light from a light irradiation unit, the functional water
(I) and (II) are supplied, a chlorine generating region and a chlorine generating means for generating the chlorine to be introduced, a means for performing the light irradiation, a decomposition treatment region for decomposing the pollutant, and a function by electrolysis Water forming / regenerating means, and contacting the air after the decomposition treatment with an alkaline aqueous solution to form a chlorine-containing alkaline aqueous solution and a functional water waste liquid from the chlorine-containing alkaline aqueous solution and the chlorine-generating solution in the chlorine-generating region. Means for supplying at least a part of the functional water forming / regenerating means by the electrolysis, and means for supplying functional water (II) regenerated by the functional water forming / regenerating means to the chlorine generation region, The functional waters (I) and (II) are capable of generating air containing chlorine by ventilation, and the functional water (I) contains the functional water waste liquid or the chlorine-containing alkaline aqueous solution in a forming solution thereof. Not something Ri, the functional water (II) is related pollutant decomposition purifying apparatus, characterized in that comprising the functional water waste liquor or the chlorine-containing aqueous alkaline solution at least a portion of its forming solution.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic structure of an embodiment of the decomposition apparatus according to the present invention will be described below with reference to FIG.

[Decomposition Reaction] (Equipment Configuration) In FIG. 3, reference numeral 5 denotes a reaction apparatus, which is a mixture of air containing chlorine from a chlorine gas generation tank 11 and a gaseous organic chlorine compound to be decomposed. It is a container to store,
Light irradiation is performed in the reactor 5. The gaseous organic chlorine compound to be decomposed is supplied from the decomposition target substance supply means 1.

Water containing chlorine (functional water) is continuously supplied at a desired flow rate to the chlorine gas generation tank 11 via a pipe 26 and discharged to the storage tank 8 via a pipe 39. Water containing chlorine is produced on the anode 23 side of the 21 functional water generators. The gas to be aerated is continuously supplied at a desired flow rate through the supply pipe 13 and the means 14 for controlling the aeration to the chlorine generating tank 11.
To supply. As a result, gas containing chlorine gas is discharged
Is discharged from The chlorine-containing gas is introduced into the reaction tank 5 and mixed with the substance to be decomposed. Then, light is applied to the inside of the reaction apparatus 5 by means of irradiating light 4 to decompose the compound to be decomposed.

(Regarding chlorine solution or functional water) The chlorine solution that can be used in the present invention has, for example, a hydrogen ion concentration (pH value) of 1 to 4 and preferably 2 to 3 and a residual chlorine concentration of 5 mg / g. It should have properties of L or more and 300 mg / L or less, preferably 30 mg / L or more and 120 mg / L or less.

An electrolyte (eg, sodium chloride, potassium chloride, etc.) is dissolved in raw water, and this water is subjected to electrolysis in a water tank having a pair of electrodes, whereby a chlorine solution having the above properties is supplied from the anode side. Obtainable.

The concentration of the electrolyte in the raw water before the electrolysis is, for example, preferably 20 mg / L to 2000 mg / L for sodium chloride, more preferably 200 mg / L to 1000 mg / L.

When the diaphragm 27 is arranged between the pair of electrodes at this time, it is possible to prevent mixing of acidic water generated near the anode and alkaline water generated near the cathode.

As the diaphragm, for example, an ion exchange membrane is preferably used. As a means for obtaining such functional water, commercially available strongly acidic electrolyzed water generator (for example, trade name: Oasis Bio Half; manufactured by Asahi Glass Engineering Co., Ltd., trade name: strong electrolyzed water generator (Model FW- 200; Amano
Etc.) can be used.

This solution is called electrolyzed water, electrolyzed functional water, functional water, etc., and is used for the purpose of sterilization.

The chlorine solution having the above properties, that is, functional water, can be prepared from a reagent using hypochlorous acid or the like. For example, hydrochloric acid 0.001mol / L-0.1mol / L,
It can be obtained by adjusting the concentration to 0.005 mol / L to 0.02 mol / L for sodium chloride and 0.0001 mol / L to 0.01 mol / L for sodium hypochlorite.

It is also possible to prepare 2000 mg / L functional water having a pH of 4.0 or less and a chlorine concentration of 2 mg / L or more using hydrochloric acid and hypochlorite. For example, hydrochloric acid 0.001mol / L ~ 0.1
mol / L and sodium hypochlorite 0.0001 mol / L to 0.01
mol / L.

Other inorganic or organic acids can be used in place of the above hydrochloric acid. Examples of the inorganic acid include hydrofluoric acid, sulfuric acid, phosphoric acid, and boric acid, and examples of the organic acid include acetic acid, formic acid, malic acid, citric acid, and oxalic acid. Functional water can also be produced using N ₃ C ₃ O ₃ NaCl ₂ or the like, which is commercially available as a weakly acidic water powder generator (for example, Quinosan 21X (trade name, manufactured by Clean Chemical Co., Ltd.)).

Here, the raw water used for the preparation of the functional water includes tap water, river water, seawater and the like. PH of these waters
Is usually between 6 and 8 and the chlorine concentration is at most 1 mg / L
And such raw water does not have the resolution of organochlorine compounds as described above.

(Concentration of Chlorine Gas and Means of Generating Chlorine Gas) From the above-mentioned chlorine solution, ie, functional water, it is possible to generate chlorine gas necessary for decomposition. As the gas containing chlorine gas, for example, air containing chlorine gas obtained by passing air through functional water can also be used. The contaminants can be decomposed by mixing this with a decomposition target gas and performing light irradiation.

Alternatively, a mixed gas of a gas to be decomposed and chlorine gas may be obtained by passing air containing pollutants instead of passing air through functional water. In this case, a relatively high concentration of chlorine gas can be obtained.

With respect to the mixing ratio between the decomposition target gas and the gas containing chlorine gas, the concentration of chlorine gas in the gas is as follows:
It is preferable to adjust the concentration to be 20 ppmV to 500 ppmV or less, and it depends on the concentration of the decomposition target gas.
When the pressure is set to 200 ppmV, the decomposition efficiency of the decomposition target gas becomes particularly remarkable.

(Means for aerating the functional water) When a gas containing a contaminant and / or a gas for aeration is aerated in the functional water,
An air diffuser (bubble) can be used. The diffuser is
A normal apparatus used for blowing gas into a liquid may be used, but it is desirable that the size of the bubbles be selected so that the surface area is sufficient to diffuse chlorine.

It is desirable that a material that does not react with the functional water component be selected as the material of the air diffuser. For example, sintered glass, porous ceramic, sintered SUS31
6. A porous diffuser plate made of a net made of fibrous SUS316 or a sparger made of glass or a pipe made of SUS316 can be used.

(Main Reaction Field in Decomposition Step) In one embodiment of the present invention, air containing chlorine gas required for decomposition is generated by passing air through functional water. The part that passes air through the functional water basically plays the role of supplying chlorine gas required for decomposition.
Subsequent processing and gas phase reactions in a tank for performing the decomposition reaction are the main sites of the decomposition reaction.

Therefore, when the generation of chlorine and the decomposition reaction are integrated, the ratio between the gas phase and the liquid phase has a great influence on the decomposition ability. That is, if the volume of the functional water increases, the amount of chlorine that can be supplied increases, but the gas phase part decreases and the decomposition reaction field decreases. Conversely, if the gas phase increases, the reaction field increases and the decomposition reaction proceeds quickly, but the supply of chlorine is reduced because the liquid phase decreases.

Although there are various factors such as the speed of aeration and the supply speed of functional water, when the area for producing and decomposing chlorine-containing air (processing area) is integrated, the liquid phase in the processing tank is 5% to 30%, preferably 10% to 2%
It is good to make it 0%. Even in the case where they are not integrated, the ratio of the volume of the tank for generating the air containing chlorine to the volume of the tank for performing the decomposition reaction is desirably approximately 1: 2 to 1: 9.

(Decomposition target) Examples of the pollutants to be decomposed include chlorinated ethylene and chlorinated methane. Specifically, examples of the chlorinated ethylene include a 1 to 4 chlorine-substituted product of ethylene, that is, chloroethylene, dichloroethylene (DCE), trichloroethylene (TCE), and tetrachloroethylene (PCE). Further, as dichloroethylene, for example, 1,1-dichloroethylene (vinylidene chloride), cis-1,2-dichloroethylene, trans-
1,2-dichloroethylene can be mentioned. Examples of the chlorinated methane include chlorine-substituted methanes such as chloromethane, dichloromethane, and trichloromethane.

There are no particular restrictions on the pollutants containing organochlorine compounds to be decomposed, and the present invention can be applied to the purification of wastewater, exhaust gas, soil and groundwater contaminated with the above pollutants at paint factories and dry cleaning factories. it can. For example,
The present invention can be used for removing contaminants contained in gas generated during air stripping and vacuum extraction gas from contaminated soil.

(Light Irradiation Means) As the light irradiation means that can be used in the present invention, for example, light having a wavelength of 300 to 500 nm is preferable, and light having a wavelength of 350 to 450 nm is more preferable. As for the light irradiation intensity of the chlorine gas and the object to be decomposed, for example, a light source having a peak near a wavelength of 360 nm has an intensity of several hundred μW / cm ² (measured between 300 nm to 400 nm), and practically sufficient decomposition proceeds.

According to the present invention, light having a great effect on the human body 2
Since there is no need to use ultraviolet light having a wavelength of about 50 nm or less, glass, plastic, or the like can be used as a reaction tank.

As a light source for such light, natural light is used.
(For example, sunlight, etc.) or artificial light (mercury lamp, black light, color fluorescent lamp, short wavelength (500 nm or less) light emitting diode, etc.) can be used.

(Decomposition Reaction Mechanism) The present inventors have already found that the irradiation of light in the presence of chlorine gas causes the decomposition of the organic chlorine compound to proceed, but the reaction mechanism was largely unknown. However, it is already known that chlorine receives light of a specific range of wavelength and dissociates to produce radicals. In the present invention as well, it is considered that chlorine radicals are generated by light irradiation and react with a substance to be decomposed to break the bond.

In the reaction of the present invention, oxygen is indispensable, and it is sufficient that oxygen is present in the presence of oxygen radicals generated by the decomposition of chlorine and water and ordinary oxygen in the air.

[Chlorine trapping means: alkaline aqueous solution] In order to completely decompose the decomposition target in a short time, it is desirable to supply an excessive amount of chlorine exceeding the amount of chlorine required for decomposition. The purified gas discharged from the exhaust pipe contains chlorine. This chlorine is collected and recovered by means 31 for trapping the subsequent chlorine. In the means for trapping chlorine, the alkaline aqueous solution comes into contact with the purified gas containing chlorine discharged from 6, the chlorine is taken into the alkaline aqueous solution, and purified air containing no chlorine is exhausted from the 32 exhaust pipe. Is discharged.

The contact means between the alkaline aqueous solution and the discharged purifying gas containing chlorine may be in any form. For example, the purifying gas containing chlorine in the alkaline aqueous solution may be introduced or aerated to form a gas-liquid mixture. That increase the contact of

The alkaline aqueous solution used for collection is prepared by dissolving the above-mentioned electrolyte (eg, sodium chloride or potassium chloride) in raw water and subjecting this water to electrolysis in a water tank having a pair of electrodes. Alkaline water generated from the cathode side of the apparatus used can be used. This solution is called alkaline ionized water or the like, and is considered to be effective for health and beauty.

As the alkaline aqueous solution used for collection, a sodium hydroxide solution, a calcium carbonate solution, or the like can be used. The concentration may be set in accordance with the amount of chlorine to be captured, but it is desirable that the pH be 8 or more and 12 or less.

Means 3 for trapping chlorine when operation is continued
The pH of the alkaline water in 1 drops. The pH is desirably 8 or more.
Care must be taken not to be discharged from

When the operation is performed for a predetermined period, the residual chlorine concentration of the alkaline aqueous solution in the chlorine trapping means 31 increases.

[Reuse of Alkaline Aqueous Solution Trapping Chlorine / Regeneration of Waste Liquid] Using this solution, a chlorine solution that generates chlorine gas necessary for decomposition can be prepared again.

That is, the alkaline aqueous solution in the means 31 for trapping chlorine and the functional water waste liquid used for the generation of chlorine in the chlorine gas generation tank 11 are mixed in the storage tank 8 and the property of the solution 33 may be changed in some cases. The solution may be adjusted to desired properties by adjusting means. This mixed solution is sent again to the electrolytic device 22 to generate the functional water (II) by electrolysis.

Although the alkaline aqueous solution in the chlorine trapping means 31 and the functional water waste liquid used for generating chlorine are mixed, it is possible to adopt a form in which only one of them is introduced into the electrolytic cell to perform electrolysis.

The acidic solution containing chlorine generated on the anode side by the electrolysis is sent to eleven chlorine gas generating tanks to generate chlorine necessary for decomposition. Further, the alkaline water generated from the cathode side is sent to a means for trapping 31 chlorine and can be used again for collecting chlorine.

By repeating the above steps, it is possible to realize a decomposition and purification treatment using chlorine effectively.

[0059]

Embodiments will be described below with reference to embodiments of the present invention.

(Example 1) An example in which the present invention was experimentally confirmed with reference to FIG. A 400 mL glass column was used as the reactor 5. From the anode side of the functional water generator 21, a chlorine-containing solution was supplied to the 11 chlorine gas generation tanks at a rate of 2 mL / min.
And drained from the 39 drainage pipes to 8 storage tanks at 2 mL / min.

The chlorine solution has a pH of 2.5 and a residual chlorine concentration of 5
It was 0-70 mg / L.

Light was irradiated by a black light fluorescent lamp (FL20S · BLB; 20W, manufactured by Toshiba Corporation) as the light irradiation means 4. The irradiation light amount was set to 0.4 to 1.2 mW / cm ² .
Although it is in the reactor in the figure, in the experiment, irradiation was performed from outside the glass column into the reactor.

Simultaneously with the light irradiation, 100 mL of TCE having a concentration of 160 ppmV and air containing PCE of 20 ppmV, which were assumed to be contaminated air sucked from the contaminated soil generated by a permeator (manufactured by Gastec) from the bottom of the reactor 5, were used. / min
Air was supplied at a flow rate of Further, air is supplied to the chlorine gas generation tank 11.
Air was sent at a flow rate of 100 mL / min, and air containing chlorine was sent to the reactor 5.

For 30 minutes after starting the operation of this device,
The TCE and PCE concentrations in the exhaust air from the reactor
Sampling is periodically performed using a gas tight syringe at the sampling port 35, and the concentration of TCE and PCE is measured by gas chromatography (GC-14B manufactured by Shimadzu Corporation with a FID detector, and the column is DB-624 manufactured by J & W). Measured but not always detected. After completion, the TCE and PCE concentrations in the functional water were measured in the same manner, but were not detected.
This indicated that TCE and PCE could be decomposed.

When a chlorine solution, that is, functional water was prepared using a commercially available strongly acidic electrolyzed water generator (trade name: Strongly electrolyzed water generator (Model FW-200; manufactured by Amano Corporation)), a cathode cell was prepared. The alkaline water (pH 11.1) generated in the step was stored in 31. The purified gas discharged from 6 was jetted into the alkaline aqueous solution in 31. The chlorine concentration in the discharge pipe of 32 was detected by a detector tube (manufactured by Gastech Co., Ltd.). No. 8H) several times.

After the operation for a predetermined period, the cock 34 was opened, and the alkaline aqueous solution containing chlorine in 31 was sent to 8. In the storage tank of No. 8, the functional water is mixed with the waste water, and then the cathode and anode tanks of the functional water generator 21 are filled with the mixed liquid. By performing the electrolysis, functional water (chlorine solution) containing chlorine necessary for decomposition is generated again on the anode side, and water containing chlorine (functional water) is continuously supplied at a desired flow rate through the pipe 26. Is done. At this time, the pH of water containing chlorine (functional water) is 1.
8. The residual chlorine concentration was 64mg / L.

Further, alkaline water having a pH of 12.0 is generated on the cathode side, and the alkaline water is sent to a means 31 for trapping chlorine. At this time, the cock 34 is closed.

The supply of gas from the permeator and the supply of air containing chlorine are started again, and the decomposition reaction is performed using functional water generated by electrolyzing a mixed solution of the solution recovered from the chlorine trap and the waste water of functional water. As a result, the same decomposition ability as before was maintained.

It was also found that alkaline water produced by electrolyzing a mixed solution of a solution newly collected from a chlorine trap and a functional water waste liquid has a sufficient chlorine trapping ability.

Even if the above steps are repeated, the decomposition ability does not decrease, and the chlorine contained in the purified gas is collected with an alkaline aqueous solution, mixed with the functional water waste liquid, and electrolyzed again to decompose. It was confirmed that a chlorine solution having the ability to generate air containing chlorine required for the preparation of the solution could be prepared. Further, it was confirmed that decomposition was continuously progressed using chlorine generated from this solution.

(Embodiment 2) In Embodiment 1, the supply of the gas to be decomposed and the ventilation to water containing chlorine (functional water) were separately performed. Ventilation to water.

That is, in FIG. 4, reference numeral 5 denotes a reactor, in which functional water is stored in the lower part of the reactor, and in the gas phase, which is the upper part of the reactor 5, decomposes with air containing chlorine. Is mixed with the gaseous organochlorine compound to be made.
Light irradiation is performed in the reaction device 5 by the four light irradiation means.

The gaseous organic chlorine compound to be decomposed is supplied from the decomposition target substance supply means 1. The functional water is continuously supplied at a desired flow rate to the lower part of the reactor 5 via the pipe 26 and discharged to the storage tank 8 via the pipe 39.
Functional water is created by 21 functional water generators. The gas to be aerated contains a gaseous organochlorine compound to be decomposed and is continuously supplied at a desired flow rate to the lower portion of the reactor 5. As a result, the gas containing chlorine gas and the gaseous mixture containing the gaseous organic chlorine compound to be decomposed are discharged to the gas phase portion at the upper part of the reactor 5. The mixed gas in the reaction device 5 is irradiated with light by the means for irradiating light 4 to decompose the compound to be decomposed.

In order to completely decompose the decomposition target, it is desirable to supply an excessive amount of chlorine exceeding the amount of chlorine necessary for the decomposition. Therefore, the purified gas discharged from the exhaust pipe 6 is chlorine. Contains. This chlorine is collected and recovered by means 31 for trapping the subsequent chlorine. In the means for trapping chlorine, the alkaline aqueous solution comes into contact with the purified gas containing chlorine discharged from 6, the chlorine is taken into the alkaline aqueous solution, and purified air containing no chlorine is exhausted from the 32 exhaust pipe. Is discharged.

Means 3 for trapping chlorine when operation is continued
The pH of the alkaline water in 1 drops. The pH is desirably 8 or more.
Care must be taken not to be discharged from When the operation is performed for a predetermined period, the residual chlorine concentration of the alkaline aqueous solution in the chlorine trapping means 31 increases.

Using this solution, a chlorine solution that generates chlorine gas necessary for decomposition can be prepared again.

That is, the alkaline aqueous solution in the chlorine trapping means 31 and the functional water used for the generation of chlorine are mixed in the storage tank 8 and, if necessary, adjusted to the desired properties by the means 33 for adjusting the properties of the solution. The solution may be adjusted. This mixed solution is again sent to means for generating 22 functional waters, and functional water is generated by electrolysis.

Although the alkaline aqueous solution in the chlorine trapping means 31 and the functional waste water used for the generation of chlorine are mixed, it is possible to adopt a mode in which only one of them is introduced into the electrolytic cell to perform electrolysis.

The chlorine solution generated by the electrolysis is supplied to the reactor 5
Sent to the lower part of the furnace to generate chlorine necessary for decomposition. Further, the alkaline water generated from the cathode side is sent to a means for trapping 31 chlorine and can be used again for collecting chlorine.

An example in which the present invention is experimentally confirmed based on FIG.

A 400 mL glass column was used as the reactor 5. The chlorine solution is transferred from the functional water generator 21 to 2
The solution was supplied to the lower part of the reactor 5 at a rate of mL / min, and was discharged from a drainage pipe of 39 to a storage tank of 8 at 2 mL / min. The pH of the chlorine solution was 2.5, and the residual chlorine concentration was 50 to 70 mg / L.

Light was irradiated by a black light fluorescent lamp (FL20S / BLB; 20 W, manufactured by Toshiba Corporation) as the light irradiation means 4. The irradiation light amount was set to 0.4 to 1.2 mW / cm ² .
Although it is in the reactor in the figure, in the experiment, irradiation was performed from outside the glass column into the reactor.

Simultaneously with the light irradiation, 200 mL of TCE at a concentration of 80 ppm and air containing PCE at a concentration of 20 ppm were applied from the bottom of the reactor 5 to the contaminated air sucked from the contaminated soil generated by the permeator (manufactured by Gastech Co.). Air was supplied at a flow rate of / min.

For 30 minutes after starting the operation of this device,
The TCE and PCE concentrations in the exhaust air from the reactor
Sampling is periodically performed using a gas tight syringe at the sampling port 35, and the concentration of TCE and PCE is measured by gas chromatography (GC-14B manufactured by Shimadzu Corporation with a FID detector, and the column is DB-624 manufactured by J & W). Measured but not always detected. After completion, the TCE and PCE concentrations in the functional water were measured in the same manner, but were not detected.
This indicated that TCE and PCE could be decomposed.

When a chlorine solution, ie, functional water, was prepared using a commercially available strongly acidic electrolyzed water generator (trade name: Strongly electrolyzed water generator (Model FW-200; manufactured by Amano Corporation)), a cathode cell was prepared. The alkaline water (pH 11.1) generated in the step was stored in 31. The purified gas discharged from 6 was jetted into the alkaline aqueous solution in 31. The chlorine concentration in the discharge pipe of 32 was detected by a detector tube (manufactured by Gastech Co., Ltd.). No. 8H) several times.

After the operation for a predetermined period, the cock 34 was opened and the alkaline aqueous solution containing chlorine in 31 was sent to 8. In the storage tank of No. 8, the functional water is mixed with the waste water, and then the cathode and anode tanks of the functional water generator 21 are filled with the mixed liquid. By performing the electrolysis, functional water (chlorine solution) containing chlorine necessary for decomposition is generated again on the anode side, and water containing chlorine (functional water) is continuously supplied at a desired flow rate through the pipe 26. Is done. At this time, the pH of water containing chlorine (functional water) is 1.
8. The residual chlorine concentration was 64mg / L.

Further, alkaline water having a pH of 12.0 is generated on the cathode side, and the alkaline water is sent to a means 31 for trapping chlorine. At this time, the cock 34 is closed.

The supply of gas from the permeator was started again, and a decomposition reaction was carried out using functional water generated by electrolyzing a mixed solution of the solution newly collected from the chlorine trap and the wastewater of functional water. Similar decomposition capacity was maintained.

It was also found that alkaline water produced by electrolyzing a mixed solution of a solution newly collected from a chlorine trap and a functional water waste solution has a sufficient chlorine trapping ability.

Even if the above steps are repeated, the decomposition ability does not decrease, and the chlorine contained in the purified gas is recovered with an alkaline aqueous solution, mixed with the functional water waste liquid, and electrolyzed again to decompose. It was confirmed that a chlorine solution having the ability to generate air containing chlorine required for the preparation of the solution could be prepared. Further, it was confirmed that decomposition was continuously progressed using chlorine generated from this solution.

(Embodiment 3) In Embodiments 1 and 2, the chlorine-containing gas was generated by passing gas through chlorine-containing water. However, in this embodiment, water containing chlorine, that is, functional water was supplied by small droplets. In this way, the generation of gas containing chlorine is promoted, the gas-liquid contact efficiency is increased, and the decomposition reaction is performed.

That is, in FIG. 5, reference numeral 5 denotes a reaction device, and a nozzle 2 for ejecting functional water into small droplets is provided above the reaction device 5. Functional water is continuously supplied at a desired flow rate into the reactor 5 via the nozzle 2. The decomposition target substance is supplied from the lower part of the reactor 5 from one decomposition target substance supply means. In the reactor 5, air containing chlorine generated from functional water and a gaseous organic chlorine compound to be decomposed are mixed. Also, the functional water comes into contact with the gaseous organochlorine compound to be decomposed. Light irradiation is performed in the reaction device 5 by the four light irradiation means.

The chlorine solution that can be used in the present invention, ie, the functional water, has a hydrogen ion concentration (pH value) of 1 or more and 4 or less, preferably 2 or more and 3 or less, and a residual chlorine concentration of 5 m or less.
g / L or more and 300 mg / L or less, preferably 30 mg / L or more and 120 m
It is good to have the property of g / L or less.

An electrolyte (for example, sodium chloride or potassium chloride) is dissolved in raw water, and this water is subjected to electrolysis in a water tank having a pair of electrodes, whereby the functional water having the above-mentioned properties is discharged from the anode side. Obtainable.

In order to completely decompose the decomposition target, it is desirable to supply an excessive amount of chlorine exceeding the amount of chlorine required for decomposition. For this reason, the purified gas discharged from the exhaust pipe 6 is chlorine. Contains. This chlorine is collected and recovered by means 31 for trapping the subsequent chlorine. In this means for collecting chlorine, the alkaline aqueous solution comes into contact with a purified gas containing chlorine discharged from 6, the chlorine is taken into the alkaline aqueous solution, and purified air containing no chlorine is exhausted from the 32 exhaust pipe. Is discharged.

The alkaline aqueous solution used for collection is obtained by dissolving the above-mentioned electrolyte (for example, sodium chloride or potassium chloride) in raw water and subjecting this water to electrolysis in a water tank having a pair of electrodes. Alkaline water generated from the cathode side of the apparatus used can be used. This solution is called alkaline ionized water or the like, and is considered to be effective for health and beauty.

Further, as an alkaline aqueous solution used for collection, a sodium hydroxide solution, a calcium carbonate solution, or the like can be used. The concentration may be set in accordance with the amount of chlorine to be captured, but it is desirable that the pH be 8 or more and 12 or less.

When the operation is performed for a predetermined period, the residual chlorine concentration of the alkaline aqueous solution in the chlorine trapping means 31 increases. Using this solution, a chlorine solution that generates chlorine gas necessary for decomposition can be prepared again.

That is, the alkaline aqueous solution in the means 31 for trapping chlorine and the functional water used for the generation of chlorine from 39 are mixed in the storage tank 8 and, if necessary, adjusted by the means 33 for adjusting the properties of the solution. The solution may be adjusted to the properties described in the above. This mixed solution is sent to the functional water generator 21 again, and functional water is generated by electrolysis.

Although the alkaline aqueous solution in the chlorine trapping means 31 and the functional water waste liquid used for the generation of chlorine are mixed, it is possible to adopt a mode in which only one of them is introduced into the electrolytic cell to perform electrolysis.

The chlorine solution generated by the electrolysis is sent to the reaction tank 5 again to generate chlorine necessary for decomposition. Further, the alkaline water generated from the cathode side is sent to a means for trapping 31 chlorine and can be used again for collecting chlorine.

When the supply of the contaminated gas was started and the decomposition reaction was carried out using functional water generated by electrolyzing a mixed solution of the solution newly collected from the chlorine trap and the wastewater of functional water, the decomposition capacity was the same as before. Was maintained.

It was also found that alkaline water generated by electrolyzing a mixed solution of a solution newly collected from a chlorine trap and a waste water of functional water has a sufficient chlorine trapping ability.

Even if the above steps are repeated, the decomposition ability does not decrease, and the chlorine contained in the purified gas is recovered with an alkaline aqueous solution, mixed with a functional water waste liquid, and electrolyzed again to decompose. In this embodiment, it was confirmed that a chlorine solution having an ability to generate air containing chlorine required for the above-mentioned process can be prepared. Further, it was confirmed that decomposition was continuously progressed using chlorine generated from this solution.

(Embodiment 4) In this embodiment, a device shown in FIG. 3 is used as a basic configuration, and a collecting device using an acidic aqueous solution is added thereto.
(Trap device).

The purified gas containing chlorine discharged from the exhaust pipe 6 may contain an acidic substance. This is mainly when the decomposition product is an acidic substance, which is discharged along with the flow of the purification gas. In such a case, when trapping chlorine, acidic substances are also trapped in the alkaline aqueous solution at the same time, and the hydrogen ion concentration (pH value) of the alkaline aqueous solution gradually decreases, eventually becoming an acidic aqueous solution and trapping chlorine. Lose ability.

To prevent this, a means for trapping an acidic substance is provided upstream of the means 31 for trapping chlorine. In this means of trapping acidic substances,
The acidic aqueous solution and the purified gas containing chlorine discharged from 6 come into contact with each other, and the water-soluble acidic substance is collected. At this time, chlorine contained in the purified gas is sent to the chlorine trapping means 31 without being trapped by the acidic solution, and is collected.

Means for trapping the acidic substance may be any solution as long as the acidic substance can be captured. For example, the hydrogen ion concentration (pH value) of the aqueous solution is desirably 4 or less, and particularly desirably 1 to 3. As such a solution, a solution of hydrochloric acid, sulfuric acid, or acetic acid can be used. However, the purpose of capturing an acidic substance can be achieved even in a form using an alkaline solution. In this case, a certain amount of chlorine is trapped in the alkaline solution at a certain time, and the pH of the alkaline solution decreases with the capture of the acidic substance, whereby chlorine is released again. In other words, it is possible to start with an alkaline solution as a solution for capturing an acidic substance, but as the operation is continued, the pH of the solution for capturing the acidic substance falls within the range of the preceding hydrogen ion concentration (pH value).

A means for trapping such an acidic substance may be provided between the exhaust pipe 6 and the means 31 for trapping chlorine as required.

[0110]

According to the method of the present invention, resources can be effectively used by reusing chlorine gas, and the effect of suppressing the discharge of chlorine gas to the outside and reducing the adverse effect on the environment can be seen. Was.

Further, the apparatus configuration for achieving the above object was established.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional apparatus for decomposing a gaseous organic chlorine compound using chlorine gas and light irradiation without reusing chlorine gas.

FIG. 2 is a diagram showing a case where acidic electrolyzed water is used as a chlorine-containing solution in a conventional apparatus for decomposing gaseous organic chlorine compounds using chlorine gas and light irradiation without reusing chlorine gas.

FIG. 3 shows a configuration of an embodiment of a gaseous organic chlorine compound decomposer for reusing chlorine gas by trapping using chlorine gas and light irradiation according to the present invention, that is, chlorine gas generated by aerating a chlorine solution. FIG. 3 is a diagram showing a configuration in which air containing a pollutant to be decomposed is mixed with air.

FIG. 4 shows a basic configuration of another embodiment of a gaseous organochlorine compound decomposing apparatus for reusing chlorine gas by trapping using chlorine gas and light irradiation according to the present invention, ie, air containing a pollutant to be decomposed. It is a figure which shows the structure in the case of directly obtaining air containing chlorine and a pollutant by directly aeration.

FIG. 5 is a configuration of still another embodiment of a gaseous organic chlorine compound decomposing apparatus for recycling chlorine gas by trapping using chlorine gas and light irradiation according to the present invention, that is, small droplets of water containing chlorine. FIG. 3 is a diagram showing a configuration for promoting generation of a gas containing chlorine and improving gas-liquid contact efficiency.

[Explanation of symbols]

 1: Decomposition target substance supply means 2: Nozzle (for jetting) 4: Light irradiation means 5: Reaction tank / reactor 6: Exhaust pipe (for decomposition gas discharge) 8: Storage tank (for waste liquid / trap discharge after absorbing chlorine / chlorine) 11: Means for generating air containing chlorine gas (chlorine gas generation tank) 12: Water tank (chlorine solution storage tank) 13: Pipe / supply pipe (for blowing air) 14: Valve (for adjusting air amount) 15: Pump ( 21: Functional water generator 22: Electrolyzer 23: Anode 24: Cathode 25: Pump 26: Pipe (for supplying functional water) 27: Partition wall 31: Means for trapping chlorine 32: Exhaust pipe (for purified air) 33: Means for adjusting solution properties 34: Cock (for controlling supply of alkaline aqueous solution containing chlorine) 35: Sampling port 39: Pipe (for waste liquid drainage)

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B01J 19/12 C02F 1/46 A 4G075 B09C 1/04 B01D 53/34 134E C02F 1/20 ZAB 1/46 134A B09B 5 / 00 S (72) Inventor Akira Kuriyama 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 4D002 AA18 AA21 AC10 BA02 BA09 CA01 CA06 CA13 CA20 DA02 DA05 DA12 DA16 DA53 DA70 EA02 GA01 GB09 GB20 4D004 AA41 AB06 CA50 4D037 AA01 AB14 BA23 BB05 4D061 DA02 DA03 DA04 DB08 DB10 EA02 EB01 EB04 EB12 ED12 ED13 FA03 FA11 4G068 DA10 DB01 DB03 DC10 4G075 AA03 AA05 AA15 AA37 BA01 BD04 BD03 BD03 EB01 EB21 EB31 EC01 FB02 FB04 FB06 FC04

Claims (66)

[Claims] 1. A method for irradiating a gas to be treated, which contains chlorine introduced from functional waters (I) and (II) and a contaminant with air, from a light irradiation means, thereby producing the contaminant. A chlorine generating step of generating the chlorine from the functional waters (I) and (II), and contacting the gas after the decomposition treatment with an alkaline aqueous solution to obtain a chlorine-containing alkaline aqueous solution. And a regeneration step in which at least a portion of the chlorine-containing alkaline aqueous solution and the functional water waste liquid used for introducing the chlorine are supplied to the functional water forming means by electrolysis and regenerated to obtain the functional water (II). Wherein the functional water (II) from the regeneration step is sent again to the chlorine generation step, and the functional waters (I) and (II) can generate chlorine-containing air by ventilation. And the functional water (I) is added to the solution for forming the functional water (I). It does not contain the functional water waste liquid or the chlorine-containing alkaline aqueous solution, and the functional water (II) is characterized in that at least a part of the forming solution contains the functional water waste liquid or the chlorine-containing alkaline aqueous solution. Pollutant decomposition purification method. 2. After the step of decomposing the contaminants, before bringing the air after the decomposition treatment into contact with an alkaline aqueous solution,
2. The air after the decomposition treatment is brought into contact with an acidic aqueous solution.
3. The method for decomposing and purifying contaminants described in 1. above. 3. The hydrogen ion concentration (pH value) of the acidic aqueous solution.
3. The method according to claim 2, wherein the number of contaminants is 4 or less. 4. A hydrogen ion concentration (pH value) of the acidic aqueous solution.
The method for decomposing and purifying pollutants according to claim 3, wherein 5. The method according to claim 1, wherein the alkaline aqueous solution is alkaline water generated by electrolysis of a solution containing an electrolyte. 6. The means for forming functional water by electrolysis,
Having a diaphragm between the cathode and the anode, the functional water (I) and (II)
And alkaline water are produced separately from each other.
The method for decomposing and purifying pollutants according to any one of claims 1 to 5. 7. The functional water (I) as the chlorine generating step.
And a step of blowing air to the surface of (II).
7. The method for decomposing and purifying pollutants according to any one of claims 6 to 6. 8. The functional water (I) as the chlorine generating step.
7. The method for decomposing and purifying contaminants according to any one of claims 1 to 6, further comprising the step of bringing small droplets of (II) and air into contact with each other. 9. The method according to claim 8, wherein the step of bringing the small droplets of the functional waters (I) and (II) into contact with air is performed by jetting the functional waters (I) and (II) from a nozzle. Pollutant decomposition and purification method. 10. The functional water as the chlorine generating step.
The method according to claim 1, further comprising the step of aerating (I) and (II) with air.
7. The method for decomposing and purifying pollutants according to any one of 6. 11. The method according to claim 10, wherein the step of aerating the functional waters (I) and (II) with air is performed by a bubbler. 12. The gas to be treated according to claim 1, wherein at least a part of the air containing the contaminant is directly sent to a decomposition treatment area where a step of decomposing the contaminant is performed.
12. The method for decomposing and purifying contaminants according to any one of 11 above. 13. The method for decomposing and purifying pollutants according to claim 1, wherein in the chlorine generation step, air supplied from the outside is used. 14. The method for decomposing and purifying pollutants according to claim 1, wherein in the chlorine generation step, air containing the pollutants is used. 15. A chlorine-generating region in which the chlorine-generating step is performed is a separately provided functional water aeration tank, and only a gas-phase portion containing generated chlorine is a decomposition treatment region in which a step of decomposing the pollutant is performed. The method for decomposing and purifying pollutants according to any one of claims 1 to 13, which is sent to a decomposition treatment tank comprising: 16. The method according to claim 1, wherein the chlorine generating region for performing the chlorine generating step constitutes a decomposition processing tank integrated with the decomposition processing region for performing the step of decomposing the contaminant, and exists below the chlorine processing region. The method for decomposing and purifying pollutants according to any one of the above. 17. The chlorine introduced into the gas to be treated,
The method for decomposing and purifying pollutants according to claim 1, wherein chlorine radicals are generated under the light irradiation. 18. The method according to claim 1, wherein the functional water (I) and / or (II) is acidic water generated by electrolysis of a solution containing an electrolyte. 19. The method according to claim 18, wherein the electrolyte is at least one of sodium chloride and potassium chloride. 20. The method according to claim 1, wherein the functional water (I) is a functional water containing hypochlorous acid or an aqueous solution of hypochlorite. 21. The method according to claim 20, wherein the hypochlorite is at least one of sodium hypochlorite and potassium hypochlorite. 22. The method according to claim 20, wherein the functional water (I) contains an inorganic acid or an organic acid. 23. The inorganic or organic acid is at least one acid selected from hydrochloric acid, hydrofluoric acid, oxalic acid, sulfuric acid, phosphoric acid, boric acid, acetic acid, formic acid, malic acid and citric acid. 23. The method for decomposing and purifying pollutants according to 22. 24. The functional waters (I) and (II) have a hydrogen ion concentration (pH value) of 1 to 4 and a dissolved chlorine concentration of 5 to 150 mg.
The method for decomposing and purifying pollutants according to any one of claims 1 to 23, having a characteristic of / L. 25. An irradiation light having a wavelength of 300 to 500 n.
The method for decomposing and purifying pollutants according to any one of claims 1 to 24, wherein the method includes light in a wavelength range of m. 26. An irradiation light having a wavelength of 350 to 450 n.
The method for decomposing and purifying pollutants according to claim 25, wherein the light is light in a wavelength range of m. 27. A light irradiation amount of 10 μW / cm ² to 10
The pollutant decomposition and purification method according to any one of claims 1 to 26, wherein the method is mW / cm ² . 28. A light irradiation amount of 50 μW / cm ^{2 to 5} m
W / cm ² a pollutant decomposition purification method according to claim 27, wherein. 29. The air containing the contaminants is air that is vacuum extracted from soil containing the contaminants.
9. The method for decomposing and purifying contaminants according to any one of 8. 30. The method for decomposing and purifying pollutants according to claim 1, wherein the air containing the pollutants is obtained by aerating groundwater containing the pollutants. 31. The method according to claim 1, wherein the pollutant is an organic chlorine compound. 32. The organic chlorine compound is a group consisting of chloroethylene, 1,1-dichloroethylene, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, chloromethane, dichloromethane and trichloromethane. 1 to be chosen from
32. The method for decomposing and purifying pollutants according to claim 31, which is at least one compound. 33. The method according to claim 1, wherein the steps are repeated.
32. The method for decomposing and purifying pollutants according to any of 32. 34. A method for irradiating a gas to be treated, which contains chlorine introduced by functional waters (I) and (II) and a pollutant in air, from a light irradiating means, thereby producing the pollutant. A chlorine generating region and a chlorine generating means for supplying the functional waters (I) and (II) and generating the chlorine to be introduced, a means for performing the light irradiation, A decomposition treatment area for decomposing substances, a means for forming and regenerating functional water by electrolysis, a means for bringing the air after the decomposition treatment into contact with an alkaline aqueous solution to form a chlorine-containing alkaline aqueous solution, the chlorine-containing alkaline aqueous solution and the chlorine generation Means for supplying at least a part of the functional water waste liquid from the chlorine generation solution in the region to the functional water forming / regenerating means by the electrolysis; and functional water (II) regenerated by the functional water forming / regenerating means. To the chlorine generation region, and the functional water (I) and (II) can generate air containing chlorine by ventilation, and the functional water (I) The solution does not contain the functional water waste liquid or the chlorine-containing alkaline aqueous solution, and the functional water (II) contains the functional water waste liquid or the chlorine-containing alkaline aqueous solution in at least a part of the forming solution thereof. Characteristic pollutant decomposition purification equipment. 35. A means for bringing the air after the decomposition treatment into contact with the acidic aqueous solution before the means for bringing the air after the decomposition treatment into contact with the alkaline aqueous solution to form the chlorine-containing alkaline aqueous solution. 3. A device for decomposing and purifying pollutants according to claim 1. 36. The hydrogen ion concentration (pH) of the acidic aqueous solution.
36. The pollutant decomposition and purification apparatus according to claim 35, wherein the value is 4 or less. 37. The hydrogen ion concentration (pH) of the acidic aqueous solution.
37) The pollutant decomposition / purification apparatus according to claim 36, wherein (value) is 1 to 3. 38. The method according to any one of claims 34 to 37, wherein alkaline water generated by electrolysis of a solution containing an electrolyte is brought into contact with an aqueous alkaline solution after the decomposition treatment, and introduced into a means for producing a chlorine-containing alkaline aqueous solution. The contaminant decomposing / purifying apparatus according to the above. 39. The functional water forming / regenerating means by electrolysis has a diaphragm between a cathode and an anode, and the functional water (I)
The pollutant decomposition / purification apparatus according to any one of claims 34 to 38, wherein (II) and the alkaline water are generated separately from each other. 40. The functional water as the chlorine generating means.
The pollutant decomposition and purification apparatus according to any one of claims 34 to 39, further comprising means for blowing air to the surfaces of (I) and (II). 41. The functional water as the chlorine generating means.
The pollutant decomposition / purification apparatus according to any one of claims 34 to 39, further comprising means for bringing the small droplets (I) and (II) into contact with air. 42. The nozzle according to claim 41, wherein the means for bringing the small droplets of the functional waters (I) and (II) into contact with air is a nozzle for jetting the functional waters (I) and (II). Pollutant decomposition and purification equipment. 43. The functional water as the chlorine generating means.
35. A means for aerating (I) and (II) with air.
40. The contaminant decomposition / purification apparatus according to any one of -39. 44. The apparatus according to claim 43, wherein the means for aerating the functional water (I) and (II) with air is a bubbler. 45. The apparatus for decomposing and purifying a pollutant according to claim 34, further comprising means for directly sending at least a part of the air containing the pollutant to the decomposition treatment area. 46. The apparatus for decomposing and purifying pollutants according to claim 34, further comprising means for introducing air supplied from outside to said chlorine generating means. 47. The apparatus for decomposing and purifying pollutants according to claim 34, wherein the air containing the pollutants is directly introduced into the chlorine generating means. 48. The chlorine generation region and the decomposition treatment region are provided in separate functional water aeration tanks and decomposition treatment tanks, respectively, and a gas phase portion containing chlorine from the chlorine generation region is separated by the decomposition treatment tank. 47. The contaminant decomposing / purifying apparatus according to any one of 34 to 46, further comprising means for introducing the gas to be treated and forming the gas to be treated. 49. The apparatus for decomposing and purifying pollutants according to any one of claims 34 to 47, wherein the chlorine generation region constitutes a decomposition treatment tank integrated with the decomposition treatment region and exists below the decomposition treatment tank. 50. The chlorine contained in the gas to be treated generates chlorine radicals under the light irradiation.
49. The pollutant decomposition and purification apparatus according to any one of 4 to 49. 51. The pollutant decomposition and purification apparatus according to claim 34, wherein the functional water (I) and / or (II) is acidic water generated by electrolysis of a solution containing an electrolyte. 52. The apparatus for decomposing and purifying pollutants according to claim 51, wherein the electrolyte is at least one of sodium chloride and potassium chloride. 53. The pollutant decomposition and purification apparatus according to claim 34, wherein the functional water (I) is a functional water containing hypochlorous acid or an aqueous solution of hypochlorite. 54. The pollutant decomposition and purification apparatus according to claim 53, wherein the hypochlorite is at least one of sodium hypochlorite and potassium hypochlorite. 55. The pollutant decomposition and purification apparatus according to claim 53, wherein the functional water (I) contains an inorganic acid or an organic acid. 56. The inorganic or organic acid is at least one acid selected from hydrochloric acid, hydrofluoric acid, oxalic acid, sulfuric acid, phosphoric acid, boric acid, acetic acid, formic acid, malic acid and citric acid. 56. The pollutant decomposition and purification apparatus according to 55. 57. The functional waters (I) and (II) have a hydrogen ion concentration (pH value) of 1 to 4 and a dissolved chlorine concentration of 5 to 150 mg.
57. The pollutant decomposition / purification apparatus according to any one of claims 34 to 56, having a characteristic of / L. 58. An irradiation light having a wavelength of 300 to 500 n.
The pollutant decomposition / purification apparatus according to any one of claims 34 to 57, wherein the apparatus includes light in a wavelength range of m. 59. Irradiation light having a wavelength of 350 to 450 n
The contaminant decomposition / purification apparatus according to claim 58, wherein the light is light in a wavelength range of m. 60. A light irradiation amount of 10 μW / cm ² -10
pollutant decomposition purifying apparatus according to any one of claims 34 to 59 is mW / cm ^2. 61. A light irradiation amount of 50 μW / cm ^{2 to 5} m
Pollutant decomposition purifying apparatus according to claim 60 is a W / cm ^2. 62. The air containing the contaminants, wherein the air is vacuum-extracted from soil containing the contaminants.
61. The contaminant decomposition / purification apparatus according to any of 61. 63. The apparatus for decomposing and purifying pollutants according to claim 34, wherein the air containing the pollutants is obtained by aerating groundwater containing the pollutants. 64. The pollutant decomposition / purification apparatus according to claim 34, wherein the pollutant is an organic chlorine compound. 65. The organic chlorine compound is a group consisting of chloroethylene, 1,1-dichloroethylene, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, chloromethane, dichloromethane and trichloromethane. 1 to be chosen from
65. The pollutant decomposition / purification apparatus according to claim 64, wherein the apparatus is at least one compound. 66. The method according to claim 34, wherein the steps are repeated.
65. The pollutant decomposition / purification apparatus according to any one of to 65.