JP2005235607A - Optical processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide optical irradiation equipment which is capable of mineralizing a test piece S comprising small-sized organic contaminants, and has a simple structure. <P>SOLUTION: In the optical irradiation equipment using as a light source an excimer lamp (1), a container (10) is filled up with discharging gas for producing excimer molecules by a discharge generated between a pair of electrodes (12, 13) where a dielectric material is interposed, and a test piece (S) comprising organic material is mineralized by irradiation processing passing through thin passages (2, 20) which form portions of the container wall of the excimer lamp (1) too. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a light irradiation apparatus using an excimer lamp. In particular, the present invention relates to a light irradiation apparatus for completely mineralizing a water-soluble or gaseous analysis sample containing an organic substance by oxidative decomposition.

  Conventionally, several methods have been proposed for oxidative decomposition of organic substances (contaminants), many of which are based on photochemical reactions. These oxidation technologies are large-scale technological developments, mostly developed for the treatment of toxic contaminated water, prior to the final waste in biological treatment plants.

In addition, there is an oxidation technique based on a photochemical reaction using an excimer lamp using a dielectric barrier discharge. However, satisfactory irradiation treatment has not always been possible.
US Patent 5,173,638 JP-A-1-144560

  The problem to be solved by the present invention is to provide a light irradiation device having a small and simple structure and to mineralize a sample containing an organic contaminant.

  In order to solve the above problems, a light irradiation apparatus according to the present invention uses an excimer lamp in which a discharge gas for generating excimer molecules by discharge with a dielectric material interposed between a pair of electrodes is filled in a container as a light source. The light irradiation apparatus is characterized in that a sample containing an organic substance is mineralized by irradiation while passing through a thin sample channel that also serves as a part of a container wall of an excimer lamp.

  Furthermore, the light irradiation apparatus according to claim 2 is characterized in that a cooling channel for the excimer lamp is formed in a part of a container wall of the excimer lamp.

  Furthermore, the light irradiation apparatus according to claim 3 is characterized in that the excimer lamp has a substantially cylindrical shape, and the sample channel is formed in a part of an outer peripheral wall of the excimer lamp.

  Furthermore, in the light irradiation device according to claim 4, the excimer lamp has a substantially double cylindrical shape in which an inner tube and an outer tube are arranged coaxially, and the sample channel is formed inside the inner tube. It is characterized by.

  Furthermore, the light irradiation apparatus according to claim 5 is characterized in that the inside of the sample flow path is 1 mm or less.

The light irradiation apparatus of the present invention uses a oxidative decomposition reaction that is photochemically induced by vacuum ultraviolet rays (light having a wavelength of 200 nm or less) under the condition that a gas or liquid sample flows continuously in one direction. Is to do.
As a result, the light irradiation apparatus of the present invention can be processed only by the emitted light from the excimer lamp without adding an auxiliary oxidizing agent or catalyst. In particular, since highly concentrated OH and HO ₂ radicals can be generated locally, reliable irradiation treatment can be achieved with a small apparatus.

FIG. 1 shows a schematic configuration of an excimer light irradiation apparatus and peripheral devices according to the present invention.
The excimer lamp 1 has a sample flow path 2 passing through the inside thereof, and a cooling means 3 and a power feeding device 4 are connected to each other. The cooling device 3 cools the excimer lamp 1 by flowing a cooling medium such as cooling water through the excimer lamp 1, and supplies power necessary for light emission from the power supply device 4 to the excimer lamp 1. Yes. Moreover, in this invention, the excimer lamp 1, the cooling means 3, and the electric power feeder 4 are used as the excimer light irradiation apparatus.
The input side end of the sample channel 2 is connected to the container 5, and the sample S contained in the container 5 is sucked into the sample channel 2 by the pump 6. The pump 6 is also connected to an oxygen cylinder 7 and oxygen is mixed in the sample flow path 2. Accordingly, the sample S mixed with oxygen continuously flows inside the sample flow path 2, and light emitted from the excimer lamp 1 when flowing through the excimer lamp 1, particularly vacuum ultraviolet rays. You will be irradiated with light.
The sample S that has been irradiated with light passes through the cooling container 8 and accumulates in the storage container 9.

FIG. 2 shows another configuration of the excimer light irradiation apparatus and peripheral devices of the present invention.
In the sample channel 2, the oxygen cylinder 7 and the nitrogen cylinder 7 'are connected, oxygen is sent from the oxygen cylinder 7 with saturated water vapor, the sample vapor is carried from the nitrogen cylinder 7', and both are mixed. Sent to the excimer lamp 1. The gas irradiated with the excimer lamp 1 is directly analyzed by gas chromatography and HPLC. A valve having six holes is attached to the gas chromatography, and the gas is carried to the gas chromatography at the time of measurement, and is discharged outside at other times. The sample is also appropriately discharged from the bulbs connected before and after the excimer lamp 1.

3 shows an enlarged structure of the excimer lamp 1 shown in FIGS. 1 and 2, wherein (a) is a transverse sectional view and (b) is an AA sectional view of (a).
The excimer lamp 1 has two cylindrical tubes arranged coaxially, and a disc-shaped glass member is welded to the end thereof, and has a substantially cylindrical shape composed of an outer tube portion 10a, an inner tube portion 10b, and an end portion 10c. The discharge vessel 10 is configured.
A discharge space 11 is formed inside the discharge vessel 10 to form excimer molecules by discharge (so-called dielectric barrier discharge) with a dielectric material interposed therebetween, and discharge that emits vacuum ultraviolet light from the excimer molecules. A working gas, such as xenon gas, is enclosed.
The material of the discharge vessel 10 is made of a material that functions as a dielectric and that transmits vacuum ultraviolet light well, such as synthetic quartz glass.
When the excimer lamp 1 is filled with xenon gas as a discharge gas, light having a wavelength of 172 ± 12 nm is generated.

  On the outer surface of the outer tube portion 10a, the first electrode 12 is disposed in almost the entire region. The first electrode 12 is, for example, a mesh-shaped light transmissive electrode, and radiated light generated in the discharge space 11 is radiated through the mesh. If the first electrode 12 has a configuration in which one metal wire is knitted seamlessly, the adhesion with the discharge vessel 10 is increased and the luminous efficiency can be increased.

A sample channel 20 and a cooling channel 30 through which the sample S (processed material) flows are formed on the outer surface of the inner tube portion 10b (the surface opposite to the discharge space 11). The sample channel 20 is formed so as to also serve as a part of the wall of the discharge vessel 10, specifically, the inner tube portion 10 b, and is configured to efficiently radiate light emitted from the discharge space 11.
The cooling flow path 30 is a pipe-like shape inserted into the through space inside the inner tube portion 10 b and is formed coaxially with the discharge vessel 10.
Further, the cooling flow path 30 is connected to the cooling means 3 shown in FIGS. 1 and 2, and has a structure in which a cooling medium such as water flows inside. Furthermore, the cooling flow path 30 is arranged so that the other electrode 13 made of, for example, a metal wire penetrates the inside. In this case, the cooling medium also functions as an electric conductor to serve as an electrode.

The first electrode 12 and the second electrode 13 are connected to the power feeding device 4 shown in FIG. 1, and when predetermined power necessary for light emission is supplied from the power feeding device 4, excimer molecules are generated inside the discharge space 11. Excimer emission occurs.
Incidentally, the current flow is as follows: power supply device 4 → first electrode 12 → outer tube portion 10a of discharge vessel 10 → discharge space 11 → inner tube portion 10b of discharge vessel 10 → sample channel 20 → cooling channel 30 → When the second electrode 13 is changed to the power feeding device 4 and an alternating current is applied, the polarity is reversed and a reverse path is formed.
For example, the excimer lamp 1 has an electric input of 1 kW or less, and more specifically, 10 W to 150 W is preferable.

FIG. 4 shows another structure of the excimer lamp 1.
The excimer lamp introduced in FIG. 3 is different from the excimer lamp in the structure of the sample channel 20, and the other structures are basically the same.
The sample channel 2 is formed in a spiral shape along the outer wall (inner tube) of the discharge vessel 10 in the inner space of the discharge vessel 10 (a space formed by the inner tube, not the discharge space 11). ing. Specifically, the partition wall 21 is spirally welded and formed on the outer peripheral surface of the pipe-shaped cooling flow path 30 so that the sample S flows while spirally turning.

FIG. 5 shows another structure of the excimer lamp 1.
The structures of the excimer lamp and the sample channel 2 shown in FIGS. 3 and 4, the structure of the cooling channel, and the forms of the first electrode and the second electrode are different.
The sample channel 20 is formed on the outer periphery of the discharge vessel 10 (the outer periphery of the outer tube), and has a spiral shape as in FIG. 4 in order to increase the light processing efficiency. The cooling water channel 14 is formed so as to cover the entire discharge vessel 10 and the sample channel 2.
In the present embodiment, the first electrode is preferably a planar metal member in order to have a reflecting function. This is because the processing efficiency can be increased by reflecting the radiated light from the discharge space 11 by the first electrode 13.
Further, the sample channel 20 does not have to be a spiral shape.

FIG. 6 shows another structure of the excimer lamp 1.
This structure is a combination of the structure shown in FIG. 4 and the structure shown in FIG. 5, and the sample S flows through the outer peripheral surface of the discharge vessel 10 after flowing through the through space inside the discharge vessel 10. It has a structure. In any channel, it is preferable to adopt a spiral structure from the viewpoint of processing efficiency, but the flow path is not limited to the spiral structure.
According to this structure, since the vacuum ultraviolet light radiated from the discharge space can be used effectively, there is an advantage that the light processing efficiency is remarkably improved.

FIG. 7 shows another structure of the excimer lamp 1.
The excimer lamp shown in FIGS. 3 to 6 is substantially cylindrical, but the excimer lamp shown in FIG. 7 is different in that it has a substantially flat plate shape.
The first electrode 12 and the second electrode 13 are provided on the outer surface of the discharge vessel 10, and a sample flow channel 20 is formed between the first electrode 12 and the discharge vessel 10. The sample channel 2 is formed in, for example, a spiral shape, and has a structure in which it is introduced from a part of the outer periphery, guided to the center along the spiral, and then discharged outward.
According to this structure, it is possible to maximize the volume of the sample channel with respect to the irradiated area of the processing object.

FIG. 8 shows another structure of the excimer lamp 1.
The excimer lamp 1 shown in this figure also has a flat plate shape, and the structure shown in FIG. In addition, what is shown in FIG. 7 is a spiral sample channel, whereas the sample channel shown in this figure has a meandering structure.

In all of the above embodiments, the sample S (processed product) made of liquid or gas receives the vacuum ultraviolet light emitted from the excimer lamp 1 while passing through the sample flow path (2, 20). Thereby, the sample S containing an organic substance is completely mineralized.
In particular, according to the structure of the present invention, it is possible to achieve complete mineralization of an organic substance only by passing a sample once through an excimer lamp. Further, according to the light irradiation device of the present invention, it is possible to produce a high local concentration of OH, HO ₂ radical, do not require the addition of supplemental oxidant and catalyst.

In the light irradiation apparatus of the present invention, it is desirable that the sample channel has a width of 1 mm or less in at least a region that receives the excimer light irradiation. As described above, this is because local high-concentration OH and HO ₂ radicals are generated and reacted efficiently.
Further, it is desirable that the sample flow channel 2 has a spiral structure as described above, for example, to make the sample turbulent or promote turbulent flow.
The sample channel 2 is preferably mixed with gas bubbles such as oxygen or air before light irradiation when the sample is liquid, and is mixed with water vapor when the sample is gas. It is preferable. This is because the transport amount of the sample can be increased.
Moreover, it is preferable to perform the mineralization process of the organic substance by light irradiation of the present invention under a reduced pressure of 6 bar or less, more preferably 1 bar or less.
Then, the treated product up to a concentration of at least 500 ppm C can be completely mineralized. In addition, it is possible to completely mineralize a gas processed product containing an organic substance having a volume ratio of 10% or less.

  Further, according to the light irradiation treatment of the present invention, carbon dioxide and water can be generated by completely mineralizing the hydrocarbon. Moreover, hydrochloric acid can be produced by mineralizing organic compounds combined with chlorine. In this way, an inorganic acid derived from the corresponding substituent can be generated.

The excimer lamp is also referred to as a dielectric barrier discharge lamp, and has an excellent feature that does not exist in conventional low-pressure mercury lamps or high-pressure discharge lamps.
The light of a single wavelength is determined by the sealed gas in the discharge vessel. As described above, the light of wavelength 172 nm is used for xenon gas (Xe), and the wavelength of 175 nm is used for argon gas (Ar) and chlorine gas (CL). Light, light with a wavelength of 191 nm for krypton (Kr) and iodine (I), light with a wavelength of 193 nm for argon (Ar) and fluorine (F), wavelength of 207 nm for krypton (Kr) and bromine (Br) In the case of krypton (Kr) and chlorine (CL), light having a wavelength of 222 nm is emitted. Further, it has a feature that it can be blinked and lighted instantaneously (within 1 second) as necessary.

  The voltage waveform supplied from the power supply device to the excimer lamp for excimer light emission is not limited to a sine wave, and may be a pulse waveform. In this case, instead of continuously supplying pulses, a pulse waveform providing an interval (rest period) is preferable in terms of light emission efficiency, and the pulse waveform is preferably applied in a steep rising waveform. This is because applying a voltage having a steep rising waveform approaches a state in which a voltage is directly applied to the gas itself in the discharge vessel as compared to applying a gentle voltage such as a sine wave voltage. The rest period is provided so that excimer molecules once generated are not destroyed.

Experimental Example 1 and Experimental Example 2 below were performed using the excimer lamp having the structure shown in FIG.
The excimer lamp has a discharge vessel 10 with a total length of 140 mm and an outer diameter of 14 mm. The sample channel 20 is formed as a space partitioned by a part of the wall of the discharge vessel 10 and the cooling channel 30, and the gap is 0.5 mm and the cross-sectional area is 5.5 mm ² . Shape. The voltage applied to the first electrode 12 and the second electrode 13 is a sine wave of 5 kV and 250 kHz.

In Experimental Example 1, 60 ppmC of 2,4-Dichlorophenol was used as a sample, and oxygen was saturatedly dissolved in the sample. The flow rate of the sample was 0.5 ml / min, and the excimer lamp was turned on with an input power of 50 W.
As a result, CO2 analysis with a TOC analyzer revealed a carbon mineralization degree of 98% or more, and analysis with ion chromatography revealed a chlorine separation degree of 98% or more.

In Example 2, 80 ppmC 2,4-Dichlorophenol was used as a sample, and oxygen was saturatedly dissolved in the sample. The flow rate in this case was 0.4 ml / min, and the excimer lamp was turned on with an input power of 50 W.
As a result, CO2 analysis with a TOC analyzer revealed a carbon mineralization degree of 98% or more, and analysis with ion chromatography revealed a chlorine separation degree of 98% or more.
That is, in both cases of Experimental Example 1 and Experimental Example 2, the values of TOC and TOX could be reduced to a range where the error could not be reproduced.

Next, Experimental Example 3 below was performed using an excimer lamp having the structure shown in FIG.
The sample channel 20 is formed in a spiral shape with a gap of 0.5 mm and a cross-sectional area of 2.1 mm ² . The voltage applied to the first electrode 12 and the second electrode 13 is a sine wave of 5 kV and 250 kHz.

In Example 3, a Cd {EDTA} ²⁻ (2 ppm Cd ²⁺ ) aqueous solution containing excess EDTA (20 ppmC) was used as a sample. In this case, the flow rate was 0.5 ml / min. It was lit at 50W.
As a result, when analyzed by ASV (Anodic Stripping Voltametry), the separation degree of cadmium was 99% or more. In addition, the completely suppressed signal of the stock solution in ASV was completely recovered by irradiation with vacuum ultraviolet rays in a single flow system.

Next, Experimental Example 4 using an excimer lamp having the structure shown in FIG. 5 was performed.
The sample channel 20s is formed in a spiral shape, and the gap is 0.5 mm and the cross-sectional area is 2.6 mm ² . The voltage applied to the first electrode 12 and the second electrode 13 is a sine wave of 5 kV and 250 kHz.

In Example 4, 170 ppmC 2,4-Dichlorophenol was used as a sample, and oxygen was saturatedly dissolved in the sample. The flow rate in this case was 0.5 ml / min, and the excimer lamp was turned on with an input power of 50 W.
As a result, when CO2 was analyzed with a TOC analyzer, the degree of mineralization of carbon was 98% or more, and when analyzed by ion chromatography, the degree of separation of chlorine was 98% or more.

Next, Experimental Example 5 was performed using an excimer lamp having the structure shown in FIG.
The applied voltage is 5 kV and the frequency is 250 kHz.

In Example 5, 230 ppmC 2,4-Dichlorophenol was used as a sample, and oxygen was saturatedly dissolved in the sample. The flow rate in this case was 0.5 ml / min, and the excimer lamp was turned on with an input power of 50 W.
As a result, when CO2 was analyzed with a TOC analyzer, the degree of mineralization of carbon was 98% or more, and when analyzed by ion chromatography, the degree of separation of chlorine was 98% or more.

The schematic structure of the excimer light irradiation apparatus of this invention and a peripheral device is shown. The other structure of the excimer light irradiation apparatus of this invention and a peripheral device is shown. The expansion structure of the excimer lamp of this invention is shown. The expansion structure of the excimer lamp of this invention is shown. The expansion structure of the excimer lamp of this invention is shown. The expansion structure of the excimer lamp of this invention is shown. The expansion structure of the excimer lamp of this invention is shown. The expansion structure of the excimer lamp of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excimer lamp 2 Sample flow path 3 Cooling means 4 Power supply means 10 Discharge vessel 11 Discharge space 12 First electrode 13 Second electrode 20 Sample flow path 30 Cooling flow path

Claims (5)

In a light irradiation apparatus using an excimer lamp filled with a discharge gas for generating excimer molecules by discharge with a dielectric material interposed between a pair of electrodes in a container,
A light irradiation apparatus characterized in that a sample containing an organic substance is mineralized by irradiation treatment while passing through a thin sample channel that also serves as a part of a container wall of an excimer lamp.   2. The light irradiation apparatus according to claim 1, wherein a cooling channel for the excimer lamp is formed in a part of a container wall of the excimer lamp.   2. The light irradiation apparatus according to claim 1, wherein the excimer lamp has a substantially cylindrical shape, and the sample channel is formed in a part of an outer peripheral wall of the excimer lamp.   2. The light irradiation apparatus according to claim 1, wherein the excimer lamp has a substantially double cylindrical shape in which an inner tube and an outer tube are coaxially arranged, and the sample channel is formed inside the inner tube. . The light irradiation apparatus according to claim 1, wherein the sample channel has an inside of 1 mm or less.

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