JPWO2007058285A1 - Fluid purification method and purification device - Google Patents

Abstract

To provide a fluid purification method and a fluid purification device capable of easily purifying a fluid. A method for purifying a substance, which purifies the substance by irradiating the solution containing nitrous oxide with ultraviolet light in a state where the solution is in contact with the substance contained in the fluid.

Description

  The present invention relates to a method for purifying a fluid such as gas or liquid and an apparatus therefor.

  A fluid is a general term for gases and liquids, and is a substance whose shape can be freely changed. In general, a large number of impurities are mixed in the fluid, causing various adverse effects in each field.

  For example, gases and liquids contain a lot of organic substances such as oil and protein. Organic substances contained in the gas may cause an unpleasant odor, and oil contained in the liquid may cause environmental pollution. Therefore, when purifying such a fluid, it is important to decompose and remove organic substances contained in the fluid. As a method for purifying organic substances, a method for decomposing organic substances by causing an oxidation reaction is known (see Non-Patent Documents 1 and 2).

Naotoshi Yamanouchi, Mitsuo Takeda, “Nitrous Oxide”, High Pressure Gas, Vol. 13 No. 3 (1976) p105-111 “Photochemical reaction in the gas phase”, edited by Chemical Society of Japan, Chemical Review Inorganic Photochemical Society Publication Center No. 39, (1983) p14-38

  By the way, at present, purification of gas is required in various situations. For example, when circulating air in a building, taking outside air into a room, or releasing gas generated by industrial activities to the outside.

  Similarly, liquid purification is required in various situations. For example, when processing used to return used liquid used in various human activities to nature, or when processing to obtain liquid for a predetermined use from used liquid or liquid existing in nature, etc. is there.

  The need for such fluid purification is now increasing, and there is a need for a simple method for purifying liquids.

The present inventors are diligently researching a method for purifying fluids. Regarding the oxidation method using nitrous oxide (N ₂ O), from Non-Patent Document 1, nitrous oxide is stable at normal temperature and normal pressure. It was found that it is a gas and does not decompose by visible light. However, during further research, even when nitrous oxide was used, it was found that the gas was difficult to handle when oxidation was performed in the gas phase.

Further, from Non-Patent Document 2, the knowledge that nitrous oxide is decomposed into nitrogen molecules (N ₂ ) and atomic oxygen (O) when nitrous oxide is irradiated with light having a wavelength shorter than 240 nm is obtained. It was. However, in order to suppress the generation of ozone, a sealing device such as a processing chamber is required, and the temperature in the processing chamber must be increased as necessary, which increases the cost of oxidation with nitrous oxide. There was a problem. Non-Patent Document 2 did not disclose an optimum wavelength for causing an oxidation reaction using N ₂ O.

  This invention is made | formed in view of such a problem, and makes it a subject to provide the fluid purification method and its apparatus which can purify | clean a fluid easily.

  As described in the previously filed [Japanese Patent Application No. 2005-146361], the present inventors irradiate light to nitrous oxide dissolved in the liquid, whereby the conventional problem can be solved at once. The inventors have come up with the invention of the purification method and apparatus. That is, in the present invention, a method for purifying a substance that purifies the substance by irradiating the solution with nitrous oxide in contact with the substance contained in the fluid is irradiated with ultraviolet light.

  In this invention, it was set as the purification method of the fluid which irradiates an ultraviolet light in the state which made nitrous oxide gas contact the substance contained in the fluid.

  In the present invention, the fluid purifying method described above is characterized in that the fluid is a gas.

  In the present invention, the fluid purifying method according to any one of the above, wherein the fluid is a liquid.

  In the present invention, the fluid purification method according to any one of the above, wherein the nitrous oxide gas is dissolved in the fluid.

  In the present invention, the fluid purification method according to any one of the above, wherein the ultraviolet light source is a krypton-iodine (KrI) excimer lamp.

  In the present invention, a fluid comprising a contact unit for bringing a substance contained in a fluid into contact with a solution containing nitrous oxide, and a light source for irradiating the substance in contact with the nitrous oxide with ultraviolet light. A purification device was obtained.

  In the present invention, the contact unit is the fluid purification device described above including a storage unit that stores the fluid and the solution containing the nitrous oxide.

  In the present invention, the fluid according to the above, comprising a contact unit for bringing a substance contained in the fluid into contact with nitrous oxide, and a light source for irradiating the substance in contact with the nitrous oxide with ultraviolet light. The purification device.

  In the present invention, the contact unit includes the container for bringing a substance contained in the fluid into contact with nitrous oxide dissolved in the fluid.

  In the present invention, the fluid purification device according to any one of the above, wherein the ultraviolet light source is a krypton-iodine (KrI) excimer lamp.

  According to the present invention, the substance is purified by irradiating the solution containing nitrous oxide with ultraviolet light in a state where the solution is in contact with the substance contained in the fluid. For this reason, it is easy to control the oxidation reaction, and it is possible to easily purify the fluid to be treated, that is, gas or liquid. Nitrous oxide undergoes a separation reaction when irradiated with ultraviolet light having a wavelength that does not normally exist in nature. Therefore, for example, even if the treatment waste liquid is allowed to flow into the sewer as it is, there is no harmful effect on the natural world.

  According to the present invention, since the ultraviolet light is irradiated while the nitrous oxide gas is in contact with the substance contained in the fluid, the fluid can be easily purified. Further, when the fluid is a liquid, the liquid to be processed can be recovered without changing the concentration of the liquid to be processed. Further, since no solvent for dissolving nitrous oxide is required, purification can be performed economically.

  In the present invention, since the fluid is a gas, the gas can be easily purified by oxidizing an organic substance or the like contained in the gas.

  In the present invention, since the fluid is a liquid, the liquid can be easily purified by oxidizing an organic substance or the like contained in the liquid.

  According to the present invention, since the ultraviolet light source is a krypton-iodine (KrI) excimer lamp, it is possible to create ultraviolet light having an optimum light source wavelength region in the wet etching method according to the present invention. In addition, since the excimer lamp has a good rise and fall, etching can be performed only at a predetermined time by turning the lamp on and off. Further, if the irradiation with ultraviolet light is stopped, the object to be processed is hardly dissolved. Furthermore, the excimer lamp has an excellent characteristic that ozone is not generated due to light emission, so that it is possible to reduce the environmental load.

  According to the fluid purification device of the present invention, an oxidant contained in a gas to be treated is brought into contact with nitrous oxide or a solution containing nitrous oxide by a contact unit, and a light source is supplied to the oxidant in contact with nitrous oxide. The fluid to be treated can be easily purified simply by irradiating the ultraviolet light from.

It is a schematic diagram which shows the structure of the apparatus used with the fluid purification | cleaning method of this embodiment. It is a graph which shows the result of purification in Example 1 of a fluid purification method. It is a graph which shows the result of purification in comparative example 1 of a fluid purification method. It is a graph which shows the result of purification in comparative example 2 of a fluid purification method. It is a graph which shows the result of purification in Example 2 of a fluid purification method. It is a graph which shows the experimental result performed by changing the wavelength and irradiation time of an ultraviolet light using the apparatus of the Example of the fluid purification method. It is a graph which shows the UV absorption spectrum of a nitrous oxide solution. It is a graph which shows the UV absorption spectrum of oxygen. It is a schematic diagram which shows the structure of the gas purification apparatus in Example 1 of a gas purification apparatus. It is a schematic diagram which shows the structure of the gas purification apparatus in Example 2 of a gas purification apparatus. It is a schematic diagram which shows the structure of the gas purification apparatus of another Example. It is a schematic diagram which shows the structure of the gas purification apparatus of other Example. It is a schematic diagram which shows the structure of the gas purification apparatus of other Example. It is a schematic diagram which shows the structure of the gas purification apparatus of other Example. It is a schematic diagram which shows the structure of the gas purification apparatus of other Example. It is a schematic diagram which shows the structure of the gas purification apparatus of other Example. It is a schematic diagram which shows the structure of the liquid purification apparatus in Example 1 of a liquid purification apparatus. It is a schematic diagram which shows the structure of the liquid purification apparatus in Example 2 of a liquefying apparatus. It is a schematic diagram which shows the structure of the liquid purification apparatus in Example 3 of a liquefying apparatus. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example. It is a schematic diagram which shows the structure of the liquid purification apparatus of another Example.

Explanation of symbols

20, 30, 40, 70, 80, 90 Gas purification device 21 Treatment tank (container)
22 Processed gas supply pipe 23 Tank 24 Nitrous oxide supply pipe 25 Lamp (light source)
31 Chamber 32 Tank 33 Nitrous oxide supply pipe 34 Spout 61, 62 Tube-shaped container 71 Circulator 83 Stirrer 120, 130, 140, 170, 180, 191, 192, 193 Liquid purification device 121 Treatment tank (container)
122 Processed liquid supply pipe 123 Tank 124 Nitrous oxide supply pipe 125 Lamp (light source)
131 Gas cylinder 132 Ejector 141 Chamber 142 Gas cylinder 143 Gas supply pipe part 144 Liquid ejector 151 Groove-shaped container 161, 162 Pipe-shaped container 171 Circulator 181 Groove-shaped container 183 Stirring tool 184 Diluent supply pipe A Processed gas Ac treated gas F treated gas M treated liquid M mixed fluid Na nitrous oxide gas Nw nitrous oxide-containing aqueous solution (nitrous oxide-containing solution)

  As described above, fluid is a general term for gas and liquid. Here, the solution containing nitrous oxide refers to a solution obtained by dissolving nitrous oxide gas in a solvent such as water.

  The gas to be treated refers to a gas that is a target of the purification method according to the present invention.

  Moreover, an oxide refers to a target substance to be oxidized.

  Below, the purification method of the fluid concerning this invention is demonstrated.

  Here, a methylene blue solution was used as an object to be processed. The concentration of methylene blue in the aqueous solution was 10 ppm.

  The methylene blue aqueous solution has a blue color, and when purified by oxidation, the blue color disappears and becomes colorless. In the evaluation of the oxidizing power of a photocatalyst, the change in absorbance at 665 nm of a methylene blue (10 ppm) aqueous solution is generally measured. Further, in order for the absorbance at 665 nm of a methylene blue (10 ppm) aqueous solution to decrease to about 10% of the initial value, it usually takes a time of several tens of minutes to several hundred minutes for a photocatalyst.

<Example 1 of fluid purification method>
In this example, a purification device 11 as shown in FIG. 1 was prepared. The purification device 11 includes a container 12 whose upper surface is open, and a lamp (light source) 13 that emits ultraviolet light. The container 12 was a Teflon (registered trademark) processed inner surface of the container. The light source 13 is installed immediately above the container 12 and in a position close to the container 12, and can irradiate ultraviolet light into the container 12. The light source was a high-pressure mercury lamp, and its output was 1200 watts.

  Moreover, the nitrous oxide aqueous solution used for purification | cleaning of methylene blue aqueous solution was prepared. The nitrous oxide concentration in the solution was 1000 ppm.

  In the purification treatment, a methylene blue aqueous solution and a nitrous oxide aqueous solution were put into the container 12 and mixed to obtain a mixed solution 14. Then, the light source 13 was turned on, and the mixed liquid 14 in the container 12 was irradiated with ultraviolet light to perform purification treatment. The ambient temperature at the place where the purification device 11 was installed was 24 ° C.

  FIG. 2 is a graph showing the results of purification according to this example. The horizontal axis of this graph is the light irradiation time (minutes), and the vertical axis is the 665 nm absorbance of the methylene blue aqueous solution. The following formula 1 is a formula for obtaining the light transmittance (T). In this equation, the symbol “Ii” is the intensity of light incident on a certain substance, and the symbol “Io” is the intensity of light emitted therefrom. Formula 2 is a formula for obtaining absorbance.

  As shown in FIG. 2, about 50% of methylene blue was decomposed when irradiated with ultraviolet light for 1 minute, and about 90% of methylene blue was decomposed when irradiated for 3 minutes. As a result, it was confirmed that the liquid could be purified and the gas to be treated could be purified.

<Comparative example 1 of fluid purification method>
In this comparative example, the same purification device 11 as in Example 1 was used. However, in this comparative example, an aqueous solution of helium (He) was prepared instead of the nitrous oxide aqueous solution. This helium aqueous solution is obtained by forcibly dissolving helium in water, and air components (N ₂ , O ₂ , CO _2, etc.) dissolved in water by forcibly dissolving helium. ) Was kicked out. Helium is a well-known inert gas and does not absorb light with a wavelength of 665 nm. The concentration of helium was 16 ppm.

  Then, a methylene blue aqueous solution and a helium aqueous solution were mixed in the same procedure as in Example 1 to purify the methylene blue aqueous solution.

  FIG. 3 is a graph showing the results of purification according to this comparative example. The format of the graph is the same as in FIG.

  As shown in FIG. 3, methylene blue was hardly decomposed even when irradiated with ultraviolet light for 1 minute, and methylene blue was not decomposed much even after irradiation for 3 minutes. This result is significantly different from the results of the examples. As a result, it was confirmed that the gas purification method according to the present invention is excellent as a purification method.

<Comparative example 2 of fluid purification method>
In this comparative example, the same purification device 11 as in Example 1 was used. All conditions were the same as in Example 1 except that the light source 13 was not turned on. The methylene blue aqueous solution was purified by the same procedure as in Example 1.

  FIG. 4 is a graph showing the results of purification according to this comparative example. The format of the graph is the same as in FIG.

  As shown in FIG. 4, methylene blue and nitrous oxide are dissolved in the mixed solution 14 obtained by mixing. However, in a state in which light having a wavelength of 240 nm or less is not irradiated, the mixture 14 is left at 665 nm even if left for 60 minutes. It was confirmed that the absorbance did not change. That is, it was confirmed from a comparison between FIG. 2 and FIG. 4 that methylene blue is not oxidatively decomposed unless light is irradiated to nitrous oxide.

<Example 2 of fluid purification method>
In this example, the same purification device 11 as in Example 1 was used. All the conditions were the same as in the example except that the light source 13 was temporarily turned off during the process. The methylene blue aqueous solution was purified by the same procedure as in Example 1. In this example, the lamp was turned off when 0.5 minutes had elapsed since the lamp was turned on, and the lamp was turned on again when 1.5 minutes had elapsed since the lamp was turned on. That is, the turn-off time was 1 minute.

  FIG. 5 is a graph showing the results of purification according to this example. The format of the graph is the same as in FIG.

  As shown in FIG. 5, the decomposition of methylene blue started with the start of irradiation with ultraviolet light, and the decomposition of methylene blue stopped when the irradiation with ultraviolet light was stopped. Thereafter, when irradiation with ultraviolet light was resumed, decomposition of methylene blue started simultaneously. As a result, according to the gas purification method of this embodiment using nitrous oxide, it was confirmed that the oxidation time of the substance can be controlled by controlling the irradiation time of ultraviolet light. Atomic oxygen generation started at the same time as the start of irradiation of nitrous oxide with ultraviolet light, and atomic oxygen generation was considered to stop at the same time as the irradiation of ultraviolet light was stopped. Is extremely short, so that the oxidation can be substantially started and stopped by starting and stopping the irradiation with ultraviolet light.

  As can be understood from the above description, in the gas purification method according to the present invention, an oxidation reaction occurs only when ultraviolet light is irradiated, and the gas to be treated is purified. Therefore, it is easy to control the oxidation reaction. Further, since the oxidation reaction occurs only during the irradiation with ultraviolet light, the corrosion of the equipment used for the purification treatment can be minimized. Therefore, there is an advantage that a countermeasure against corrosion is not necessary for a device such as a gas purification device used for the purification treatment, or a simple device can be used even when necessary.

Here, the result of measuring the absorbance (absorption spectrum) of nitrous oxide (N ₂ O) used in the gas purification method according to the present invention will be described. In the measurement, only the aqueous nitrous oxide solution (nitrogen oxide content of about 1000 ppm) was placed in the container of the purification apparatus used in the above example, and ultraviolet light was irradiated to absorb the absorbance (absorption) of nitrous oxide (N ₂ O). Spectrum).

  FIG. 6 shows the result. In addition, the horizontal axis in FIG. 6 is a wavelength range of a measurement range of 200 to 340 nm, and the vertical axis is absorbance. Curve C1 is the absorbance when not irradiated with ultraviolet light, curve C2 is the absorbance when irradiated with ultraviolet light for 1 minute, and curve C3 is the absorbance when irradiated with ultraviolet light for 3 minutes. As is apparent from the graph, the light having a wavelength of 240 nm or more has zero absorbance and no light was absorbed. In other words, nitrous oxide was not dissociated by light energy irradiation.

  Table 1 shows the change in the concentration of nitrous oxide determined from the absorbance at a wavelength of 205 nm shown in FIG. In addition, the density | concentration with zero irradiation time is made into a saturated density | concentration (value at the water temperature of 25 degreeC), and the relative value of each light absorbency is computed by multiplication. It can be seen that the concentration of nitrous oxide is considerably reduced by irradiation for 3 minutes.

As can be seen from the experimental results shown in FIG. 6, substantially no ozone (O ₃ ) by-product was detected. That is, the maximum wavelength (λmax) of ozone is 260 nm, but the absorbance at that is below the detection limit.

  As described above, according to the method using the nitrous oxide-containing solution, since ozone is hardly generated, there is an advantage that it is not always necessary to install a device for countermeasures against ozone in the gas purification device. Therefore, it is not necessary to provide an ozone countermeasure device, the structure of the gas purification device can be simplified, and the device can be miniaturized. In addition, there is an advantage that the degree of freedom in device design is increased.

  The KrI excimer lamp will be described in detail.

  The KrI excimer lamp was developed by the present inventors based on the characteristics of the UV absorption spectrum (cited from Brit. J. Anaesth., 44, 310 (1972)) of the nitrous oxide aqueous solution shown in FIG. . In FIG. 7, the horizontal axis represents wavelength and the vertical axis represents absorbance. The UV absorption spectrum in the figure represents the absorption spectrum of water that has reached equilibrium with 100% nitrous oxide, and water that has been equilibrated with helium is used as a reference cell.

  As shown in FIG. 7, the UV absorption spectrum of the aqueous nitrous oxide solution shows a peak exceeding 0.7 in the vicinity of 190 nm.

  For example, the emission wavelength of the low-pressure mercury lamp 16 is centered on 185 nm, and the absorbance at the wavelength of 185 nm is about 0.05, which is well below 0.7, which is the peak of the UV absorption spectrum of the aqueous nitrous oxide solution. Therefore, the efficiency is extremely low.

  On the other hand, there is a lamp that emits light at a wavelength centering around 190 nm where the UV absorption spectrum of the aqueous nitrous oxide solution shows a peak. As such a lamp, for example, an electrolytic coupling type high frequency discharge lamp using argon-fluorine, a so-called excimer lamp is known. The fluorinated excimer lamp emits light at a wavelength centered at 193 nm.

  In general, excimer lamps have characteristics suitable for the oxidation reaction according to the present invention, such as good rise and fall.

  However, in the fluorinated excimer lamp, the quartz tube is easily deteriorated by fluorine enclosed therein. That is, the excimer lamp has a problem that the compatibility between fluorine and the quartz tube is poor and the life is short. Further, as is clear from FIG. 7, the UV absorption spectrum of the aqueous nitrous oxide solution is steep near the peak. Therefore, even at a wavelength of 193 nm, the absorbance is greatly reduced compared to the peak value even though it is close to 190 nm. .

  Accordingly, the present inventors have developed a KrI excimer lamp that emits light at an ultraviolet wavelength of 191 nm, which is extremely close to 190 nm, and adopted this lamp as a light source for the gas purification method and the gas purification apparatus according to the present invention. The KrI excimer lamp is manufactured by a method in which solid iodine is vaporized and a predetermined amount is measured and sealed in a quartz tube.

  Since the absorbance of the nitrous oxide aqueous solution having an emission wavelength of 191 nm of the KrI excimer lamp L is about 0.65, which is close to the absorbance at the peak of the UV absorption spectrum of the nitrous oxide aqueous solution, the efficiency is good. Therefore, considering the generation of oxygen atoms due to the photodissociation of nitrous oxide, for example, the KrI excimer lamp L is less than the low pressure mercury lamp 16 because the absorbance at the emission wavelength of 185 nm of the low pressure mercury lamp 16 is about 0.05. It is possible to generate oxygen atoms with an efficiency exceeding 10 times, and the generation efficiency of oxygen atoms is extremely high compared to conventional light sources.

  KrI excimer lamps have the general characteristics of excimer lamps suitable for the oxidation reaction according to the present invention, such that the rise and fall are good, and the quartz tube is not easily deteriorated by the enclosed iodine. Since the compatibility with the quartz tube is good, there is an advantage that the life is long.

  In addition, the ultraviolet light with a wavelength of 191 nm emitted by the KrI excimer lamp L has substantially the same energy as the ultraviolet light with a wavelength of 185 nm emitted by the low-pressure mercury lamp, which is sufficiently large to decompose nitrous oxide and perform an oxidation reaction. .

  Furthermore, it has been found that the KrI excimer lamp L has an excellent characteristic that less ozone is generated due to light emission.

  FIG. 8 shows the UV absorption spectrum of oxygen (cited from J. Chem. Phys., 21, 1206 (1953)). In such a spectrum, in the region from the wavelength of about 175 nm to the wavelength of about 200 nm, a very fine periodic variation of the absorption coefficient is observed. Such a region is called the Schumann Runge band.

  The wavelength of 191 nm emitted by the KrI excimer lamp L is included in the Schumann Runge band, corresponds to a so-called valley portion between the 5-0 band and the 4-0 band, and has a small absorption coefficient. Therefore, there is little absorption by oxygen molecules, and there is little dissociation of oxygen molecules and subsequent generation of ozone. Since the generation of ozone, which is an environmental load, is small, the KrI excimer lamp L is easy to handle.

  In this respect, for example, the wavelength 185 nm of the ultraviolet light emitted by the low-pressure mercury lamp is located on the 8-0 band in the Schumann-Lunge band and has a large absorption coefficient. Therefore, if air exists between the low-pressure mercury lamp and the nitrous oxide solution, the energy of ultraviolet light is easily absorbed by oxygen molecules, and a large amount of ozone is generated. The efficiency of the reaction is low, resulting in a complicated structure, a design problem, an increase in size, and an increase in price of an apparatus equipped with the reaction.

  In contrast, the KrI excimer lamp L has the following advantages. That is, even if the atmosphere exists between the KrI excimer lamp L and the nitrous oxide solution, the energy of the ultraviolet light emitted from the KrI excimer lamp L is not easily absorbed by the oxygen molecules, so that the ultraviolet light is not absorbed by the nitrous oxide solution. Nitrous oxide can be decomposed with high efficiency.

  Therefore, the purification performance can be improved by using a KrI excimer lamp instead of the high-pressure mercury lamp as the light source of the gas purification apparatus of the above embodiment.

  Further, since the influence by the atmosphere is small, the degree of freedom of the arrangement position of the KrI excimer lamp L is high. A sealing device such as a processing chamber for measures against ozone can be omitted or simplified. Therefore, it is possible to provide a gas purification device having high oxidation reaction efficiency, a simple structure, a high degree of design freedom, a small size, and a low cost.

  Below, the gas purification method in the purification method of the fluid which concerns on this invention is demonstrated.

The gas purification method of this embodiment irradiates the light to be treated with ultraviolet light in a state where nitrous oxide (N ₂ O) contained in the nitrous oxide-containing solution is in contact with the material to be oxidized contained in the gas to be treated. Thus, the gas is purified by oxidizing the substance to be oxidized and decomposing and removing it.

  The substance to be oxidized here is, for example, an organic substance. Examples of organic substances include oils and proteins that are decomposed by an oxidation reaction.

  Therefore, according to the gas purification method according to the present invention, it is possible to purify various gases to be treated containing an oxidizable substance such as an organic substance. Examples of the gas to be treated include indoor air to be cleaned, outdoor air taken into the room, exhaust discharged from industrial activities such as factories, especially exhaust containing organic substances such as organic solvents, and decay caused by decay of organic substances such as living organisms. Examples thereof include organic substance-containing gas that originates from air, underground or cave, and organic substance-containing gas that is generated along with physiological phenomena of organisms that are active in dams, lakes, rivers, and the like.

  The purified gas obtained by the purification process can be used for various purposes and is useful. For example, purified indoor air or outdoor air can be used as room air.

  The oxidation reaction performed by irradiating an oxidizable material in contact with nitrous oxide with ultraviolet light has the following characteristics.

  When nitrous oxide is irradiated with ultraviolet light having a wavelength of 240 nm or less, dissociation of nitrous oxide occurs and atomic oxygen (O) is generated. When there is an oxidizable substance such as an organic substance, the oxidizable substance is oxidized by the generated atomic oxygen (O).

  Since the substance is oxidized only when irradiated with ultraviolet light, it can be said that nitrous oxide is stable unless irradiated with ultraviolet light. Therefore, if the light irradiation time is controlled, the oxidation time is controlled, and an oxidation reaction can be caused only for a desired time. Further, by controlling the light irradiation region, the oxidation region is controlled, and an oxidation reaction can be caused only in a desired region.

  Since the oxidation reaction is easily controlled, corrosion of equipment used for gas purification is minimized. In other words, the occurrence of equipment malfunctions due to corrosion is minimized. Therefore, there is an advantage that corrosion countermeasures are not required for equipment such as a gas purification device used when the gas purification method according to the present invention is performed.

  The gas purification method of the present embodiment uses atomic oxygen generated by irradiation with ultraviolet light for the oxidation reaction. Since the oxygen has an extremely high oxidizing power, there is an advantage that organic substances can be decomposed strongly.

  Nitrous oxide is relatively easy and inexpensive. Therefore, it is excellent both in terms of supply and cost, and is suitable as a gas purification method that is continuously used.

  In addition to the above-described characteristics, nitrous oxide, particularly a nitrous oxide-containing solution, simultaneously has excellent characteristics that are not seen in conventional oxidizing substances and are considered to be contradictory.

  For example, nitrous oxide has the property of being highly safe. Specifically, the aqueous nitrous oxide solution is harmless. Nitrous oxide with high safety has the advantage of being easy to handle with a low environmental burden. In addition, nitrous oxide having high safety has an advantage that a step of removing nitrous oxide from the purified gas is not necessarily required, and is preferable in terms of device fabrication. If a removal step such as a decomposition treatment is unnecessary, it is preferable because the gas purification step can be simplified. In addition, nitrous oxide having excellent stability is easy to store for a long time. Nitrous oxide is capable of causing an oxidation reaction in a liquid, but has a characteristic that generation of ozone can be suppressed when an oxidation reaction is caused in a liquid. Since the oxidation reaction occurs simultaneously in the entire ultraviolet light irradiation region, a rapid purification process by oxidation is realized.

  The superiority of the gas purification method using nitrous oxide becomes clearer by comparing with the properties of other substances used for purification. For example, hydrogen peroxide is a substance used for purification, but has the property of remaining in the treated gas for a relatively long time. Therefore, in order to reduce the environmental load, there is a problem of the complexity that the decomposition process is necessary and the cost required for the decomposition process. In addition, ozone water is harmful even at a low concentration, and there is a problem that the load applied to materials such as piping equipment is large, and decomposition treatment is necessary and processing costs are increased. In addition, the gas purification method using nitric acid, which is a strong acid as an oxidant, has a problem that costs are taken for countermeasures against corrosion of the apparatus and costs for reducing the risk during production. According to the gas purification apparatus of the present invention, these points do not become a problem.

  By the way, in order to purify the gas to be treated by the gas purification method according to the present invention, as described above, the oxidant contained in the gas to be treated is brought into contact with the nitrous oxide in the nitrous oxide-containing solution. There is a need to.

  Examples of the contacting step of bringing nitrous oxide into contact with the substance to be oxidized include a step of mixing a gas to be treated and a nitrous oxide-containing solution, and a step of causing nitrous oxide to exist in the gas to be treated.

  As a method of mixing the gas to be treated and the nitrous oxide-containing solution, for example, a method of containing the gas to be treated and the nitrous oxide-containing solution in the same container, or agitation of the fluid in the container after the accommodation. Can be mentioned.

  Examples of the method for causing nitrous oxide to be present in the gas to be treated include a method for releasing the nitrous oxide-containing solution into the gas to be treated, a method for releasing the gas to be treated into the nitrous oxide-containing solution, and the like. Can do.

  As a method for releasing the nitrous oxide-containing solution into the gas to be treated, for example, a so-called jetting method in which the nitrous oxide solution is discharged, jetted, jetted or sprayed into the gas to be treated can be mentioned.

  As a method for releasing the gas to be processed into the nitrous oxide-containing solution, for example, a so-called jetting method in which the gas to be processed is discharged, jetted or jetted into the nitrous oxide-containing solution can be mentioned. More specifically, a bubbling method can be mentioned.

  The light source used in the gas purification method according to the present invention is preferably one that generates light having a wavelength of 240 nm or less. Examples thereof include a high-pressure mercury lamp and a krypton-iodine (KrI) excimer lamp (hereinafter referred to as a KrI excimer lamp). The lamp output is not particularly limited. In general, when the same lamp is used, the rate of oxidative decomposition is affected by the output. In other words, when the lamp output is small, the oxidative decomposition rate decreases, and conversely, when the lamp output is large, the oxidative decomposition rate increases. The lamp output can be appropriately selected according to the desired oxidative decomposition rate.

  In the gas purification method according to the present invention, a pretreatment step for improving the irradiation efficiency of ultraviolet light may be performed.

  Examples of the pretreatment step include a dilution step for diluting the gas to be treated. As a dilution process, the process which adds the processed gas and clean air which were purified previously can be mentioned. In the diluted gas to be treated, the oxidative decomposition reaction at the time of ultraviolet light irradiation is promoted, and the purification rate and the purification rate are improved.

<Example of gas purification method>
In this example, gas purification was performed using a gas purification device. The gas purification apparatus is generally configured as the gas purification apparatus shown in FIG. That is, this gas purification apparatus will be described with reference to FIG. 9. A treatment tank 21 to which an aqueous nitrous oxide solution Nw is supplied, and an ejector 27 that injects the gas A to be treated into the treatment tank 21 by so-called bubbling. The structure corresponding to the lamp 25 that irradiates ultraviolet light toward the inside of the processing tank 21 is provided. The lamp 25 was an electrolytically coupled high-frequency discharge lamp using krypton-iodine, that is, a KrI excimer lamp, and the output of the lamp 25 was 1200 watts. Details of the device configuration will be described later.

  When such a device was used to purify a gas containing formaldehyde gas, the treated gas released from the upper end opening of the treatment tank 21 did not have a so-called formaldehyde odor.

  Next, the gas purification apparatus in the fluid purification apparatus according to the present invention will be described.

  The gas purification apparatus of the present embodiment includes a contact unit for bringing an oxidant contained in a gas to be treated into contact with nitrous oxide contained in a nitrous oxide-containing solution, and the oxidant in contact with the nitrous oxide. And a light source for irradiating the substance with ultraviolet light.

  In the gas purification device, nitrous oxide in a nitrous oxide-containing solution is brought into contact with an oxidizable substance such as an organic substance in a contact unit, and ultraviolet light from a light source is applied to the oxidized substance in a state where the nitrous oxide is in contact. Irradiation oxidizes the non-oxide, thereby oxidizing and decomposing the substance to be oxidized to purify the gas to be treated.

  The contact unit includes a container for bringing the substance to be oxidized into contact with nitrous oxide in the nitrous oxide-containing solution. Examples of the container include an open container having an opening and a sealed container used in a sealed state in terms of whether or not the container is open to the outside.

  In addition, from the viewpoint of whether or not to flow the mixed fluid when the fluid to be treated and the nitrous oxide-containing solution (hereinafter referred to as a mixed fluid) are irradiated with ultraviolet light, the storage container And fluid type containers.

  Examples of the open container include a batch processing tank having an opening at the upper end and a groove-shaped container having an upper end opened. Examples of the sealed container include a tube-shaped container such as a sealed chamber and a pipe. Further, examples of the storage container include the above-described batch processing tank and chamber. Examples of the fluid-type container include the above-described groove-shaped container and tube-shaped container.

  The flow-through container preferably has a shape that ensures a wide ultraviolet light irradiation area. Specifically, those having a wide flow passage are preferable. Here, the wide flow passage refers to a flow passage having a structure in which the flow passage width is wider than the depth of the mixed fluid flowing through the flow passage in the case of a flow-type and open container, for example. In this case, the ultraviolet light from the light source is applied to the mixed fluid in the container from the opening of the flow path. In addition, in the case of a flow-type and sealed container such as a tube, the wide flow path is, for example, a width of a side corresponding to a surface irradiated with stronger ultraviolet light when the cross-sectional shape of the flow path is a square. It is a flow passage having a structure in which the thickness dimension of the cross section of the flow path intersecting the irradiation direction is shorter than the dimension.

  More specifically, examples of the sealed container include a container having a plurality of or many thin tubes, a flat cross-sectional tube having an elongated cross-sectional shape, and the like. If it does in this way, even if a channel cross-sectional area is the same, an ultraviolet light irradiation area will become large and ultraviolet light irradiation efficiency will improve. In addition, as a material for a sealed container such as a tube, an ultraviolet light transmissive material such as glass is preferable, and a material having a high ultraviolet light transmittance is more preferable.

  When an open container is employed, the gas to be processed can be supplied from the opening or the processed gas can be recovered from the opening, which is suitable for performing such processing. The hermetic container is suitable as a container used in an apparatus in which a processing target is a gas, such as a gas purification apparatus. The storage-type container is suitable for purifying a large amount of gas to be processed, for example. The fluid type container is suitable for the case where purification is performed while circulating the gas to be processed and the mixed fluid.

  In the purification of the gas to be treated, it is necessary to ensure that the substance to be oxidized contained in the gas to be treated and nitrous oxide are brought into contact with each other. Accordingly, the contact unit is preferably one having a mixing means for positively contacting the oxidant contained in the gas to be treated and nitrous oxide.

  Examples of the mixing means include a liquid supply unit that supplies a nitrous oxide-containing solution into the gas to be processed and a process gas supply unit that supplies the gas to be processed into the nitrous oxide-containing solution. It is preferable to have at least one of these.

  As the liquid supply unit, for example, a liquid feeder such as a liquid supply pipe for pouring a nitrous oxide-containing solution such as an aqueous nitrous oxide solution into a container, or a liquid discharger that discharges a nitrous oxide-containing solution into a gas to be treated Can be mentioned. Examples of the liquid discharger include a discharger, a sprayer, a sprayer, or a sprayer of a nitrous oxide-containing container.

  As a to-be-processed gas supply part, the to-be-processed gas discharge device which discharge | releases to-be-processed gas in a nitrous oxide containing solution can be mentioned, for example. Examples of the gas discharger include a gas discharger or an ejector for the gas to be processed.

  The contact unit may include an agitation unit such as an agitator for agitating the mixed fluid in order to ensure that the oxidant contained in the gas to be treated and the nitrous oxide come into contact with each other.

  Examples of the gas purification device further include a dilution liquid supply unit that supplies a gas for dilution that improves the transparency of the gas to be processed into the gas to be processed. Examples of the gas for dilution include treated gas and clean air. The diluent supply unit supplies at least one of these dilution gases. When the gas to be treated is diluted in this way, the transmission efficiency of ultraviolet light is improved and the irradiation efficiency is improved.

  Moreover, as a gas purification apparatus, especially a gas purification apparatus provided with a flow-through container, there may be mentioned one provided with a circulation device that circulates a processed gas such as a mixed fluid or a gas to be processed once purified. By circulating, the purification gas can be repeatedly subjected to purification treatment.

  Examples of the gas purification apparatus according to the present invention may further include a heating unit that heats the fluid to be processed and a cooling unit that cools the fluid to be processed. Moreover, what is provided with the condenser which liquefies the water | moisture content in the processed gas of to-be-processed gas can be mentioned.

  And the gas purification apparatus which concerns on this invention is equipped with the light source which irradiates an ultraviolet light.

  As the light source, a light source that generates light having a wavelength of 240 nm or less is preferable. For example, a high pressure mercury lamp and a KrI excimer lamp can be mentioned.

  Among these, the ultraviolet light irradiated by the KrI excimer lamp is easily absorbed by nitrous oxide, but is not easily absorbed by oxygen and has excellent nitrous oxide resolution. Therefore, the oxidation reaction is performed efficiently, and the gas purification is performed with high efficiency. In addition, since ozone generation is small, it is not always necessary to install a device for countermeasures against ozone, which contributes to simplifying and downsizing the structure of the gas purification device used when carrying out the gas purification method according to the present invention. . In addition, there is an advantage that the degree of freedom in device design is increased.

  The gas purification apparatus may include a controller that controls the output of the lamp. An example of the controller is one that controls the output (illuminance) of ultraviolet light. Examples of the output control method include on / off control.

  Examples of the lamp for the light source that emits ultraviolet light include an external lamp installed outside the contact unit and an internal lamp installed inside the contact unit. More specifically, examples of the lamp include an external lamp installed outside the container of the contact unit and an internal lamp installed inside the container of the contact unit.

  When the container is an open container and the lamp is an external lamp, ultraviolet light is irradiated into the container from the opening of the container. In addition, if an open container has a part which consists of ultraviolet light transmissive materials, such as glass, an ultraviolet light can be irradiated in the container from the part.

  When the container is a sealed container and the lamp is an external lamp, the container needs to have a portion made of an ultraviolet light transmissive material. Ultraviolet light is irradiated into the container from this portion.

  When the lamp is an internal lamp, the material of the container does not need to be an ultraviolet light transmissive material regardless of whether the lamp is an open type or a sealed type. Rather, a material that does not transmit ultraviolet light is preferred.

  Moreover, as a lamp | ramp, the fixed lamp fixed with respect to the contact unit or the container, and the movement lamp installed so that movement is possible can be mentioned. An example of the moving lamp is one that is integrated with a stirring device that stirs the fluid to be treated.

  The contact unit may be provided with a plurality of containers for bringing the substance to be oxidized contained in the gas to be treated into contact with nitrous oxide. When a plurality of containers are provided, it is not necessary to irradiate all the containers with ultraviolet light from the light source, and it is sufficient that one or more selected containers are irradiated with ultraviolet light. Specifically, the first container for mixing the gas to be treated and the nitrous oxide-containing material, and the flow destination of the mixed fluid from the first container, for irradiating the mixed fluid that has flowed with ultraviolet light The thing provided with the 2nd container of this can be mentioned.

  Embodiments of a gas purification apparatus according to the present invention will be described below with reference to the drawings.

<Example 1 of a gas purification apparatus>
As shown in FIG. 9, the gas purification apparatus 20 of the present embodiment includes a treatment tank (contact unit container) 21 to which a treatment gas A to be purified is supplied, and a treatment gas A to the treatment tank 21. A gas supply pipe 22 to be processed, a tank 23 of a nitrous oxide aqueous solution Nw, a nitrous oxide supply pipe 24 for supplying the nitrous oxide aqueous solution Nw from the tank 23 to the treatment tank 21, and a treatment tank 21 The lamp 25 which irradiates ultraviolet light toward the inside, and the collection | recovery device 26 which collect | recovers the gas which exists near the opening of the processing tank 21 by suction | inhalation are provided.

  The processing tank 21 is an open container having an opening at the upper end. And the processing tank 21 is equipped with the discharge port 21a for discharging | emitting the liquid in the processing tank 21 in the side surface. The inner surface of the processing tank 21 is subjected to Teflon (registered trademark) processing.

  The to-be-processed gas supply pipe 22 includes an ejector 27 that ejects the to-be-processed gas on the downstream side. The ejector 27 includes a large number of ejection ports 27 a for ejecting a gas to be treated. The ejection port 27 a communicates with the inside of the processing tank 21 through a vent 21 b formed in the bottom surface of the processing tank 21. Yes. Therefore, the gas to be processed supplied from the gas to be processed supply pipe 2 is ejected from the ejector 27 into the processing tank 21.

  The lamp 25 is an electrolytically coupled high-frequency discharge lamp using krypton-iodine, that is, a KrI excimer lamp. The output of the lamp 25 was 1200 watts.

  The recovery device 26 is installed in a state where the suction port 26 a is directed to the opening at the upper end of the processing tank 21. The suction port 26a may be installed so as to cover the processing tank 21 or may be installed in a state of being connected to the opening of the processing tank.

  When purifying the gas A to be treated with such a gas purification device 20, first, the nitrous oxide aqueous solution Nw is caused to flow into the treatment tank 21 from the nitrous oxide supply pipe 24. And the to-be-processed gas A is supplied to the ejector 27 by the to-be-processed gas supply pipe 22, and the to-be-processed gas A is ejected from the ejector 27 to the processing tank 21. Then, the gas A to be treated is released in a so-called bubbled state in the aqueous nitrous oxide solution Nw. Thereby, an oxidizable substance such as an organic substance in the gas to be treated A comes into contact with the nitrous oxide dissolved in the nitrous oxide aqueous solution Nw.

  In this state, the lamp 25 is turned on, and ultraviolet light is irradiated into the processing tank 21. Then, nitrous oxide dissolved in the nitrous oxide aqueous solution Nw is dissociated to generate atomic oxygen (O), and this atomic oxygen strongly oxidizes organic substances (oxidized substances) such as oil and protein. The gas to be treated A is purified. That is, the organic substance is removed from the gas A to be processed by being decomposed into water, carbon dioxide and the like by oxidation. The purified gas, that is, the treated gas Ac of the gas to be treated A is released from the water surface of the nitrous oxide aqueous solution Nw. Then, the released processed gas Ac is sucked into the recovery device 26 and recovered.

<Example 2 of the gas purification device>
A gas purification apparatus according to the next embodiment will be described. In addition, about the structure same as the said gas purification apparatus 20 (Example 1 of a gas purification apparatus), suppose that the same code | symbol is attached | subjected and the description is abbreviate | omitted. The same applies to the embodiments described below.

  As shown in FIG. 10, the gas purification apparatus 30 of the present embodiment supplies a sealed chamber 31, a tank 32 of an aqueous nitrous oxide solution Nw, and an aqueous nitrous oxide solution Nw in the tank 32 to the chamber 31. A nitrous oxide supply pipe 33, an ejector 34 that ejects the aqueous nitrous oxide solution Nw from the supply pipe 33, a gas supply pipe 22 to be processed, and a lamp 25 that irradiates the chamber 31 with ultraviolet light I have.

  The chamber 31 includes a drain port 31 a for discharging the liquid in the chamber 31 and an exhaust port 31 b for discharging the gas in the chamber 31. Moreover, the chamber 31 is provided with a glass transmission part 31c having excellent ultraviolet light transmission performance as a part thereof. Therefore, ultraviolet light can be irradiated into the chamber 31 from the transmission part 31c.

  When purifying the gas to be processed A with such a gas purification device 30, the nitrous oxide aqueous solution Nw is ejected into the chamber 31 by the ejector 34 and the gas to be processed is introduced into the chamber 31 from the gas supply pipe 22 to be processed. A is ejected. Thereby, the state which the nitrous oxide in the nitrous oxide aqueous solution Nw contacts the to-be-oxidized substance in the to-be-processed gas A is obtained.

  In this state, the lamp 25 is turned on to irradiate the chamber 31 with ultraviolet light. Thereby, the to-be-oxidized substance contained in to-be-processed gas A is decomposed | disassembled by oxidation reaction, and to-be-processed gas A is purified. The gas obtained by purification, that is, the processed gas Ac of the gas to be processed A is discharged from the exhaust port 31b of the chamber 31 to the outside of the chamber 31 and collected.

  Here, two types of gas purification devices have been described, but each gas purification device can be used with various modifications.

  Hereinafter, modified examples of the gas purification apparatus according to the present invention will be described.

  The gas purification apparatus 20 according to the first embodiment can irradiate ultraviolet light into the treatment tank 21 from the opening at the upper end of the treatment tank 21. Therefore, the material of the processing tank 21 is not necessarily a material excellent in ultraviolet light transmittance. However, as the treatment tank 21, a material in which a material having a high transmittance of ultraviolet light, particularly light having a wavelength of 190 nm is used in part or in whole may be used. If such a processing tank 21 is used, ultraviolet light is irradiated not only from the opening of the upper end of the processing tank 21 but also from the side or the lower side of the processing tank 21 to purify the gas A to be processed in the processing tank 21. Can be promoted.

  Although the container of the gas purification apparatus 20 of Example 1 is the processing tank 21 which is what is called an open type container, an airtight type container may be sufficient. An example of the sealed container is a chamber 31 shown in FIG. Moreover, it may consist of the container of the gas purification apparatus 40 shown in FIG. 11, that is, the processing tank 21, and the lid 21c that closes the upper end opening thereof. In this case, a part or all of the processing tank 21 and / or its lid 21c is made of a material having ultraviolet light transmission so that the processing tank 21 can be irradiated with ultraviolet light. In this embodiment, the lid 21c is made of glass.

  The containers 21 and 31 used in the gas purification apparatuses 20 and 30 of the above embodiment are storage-type containers, but may be fluid-type containers. That is, a tube-shaped container 61 as shown in FIG. The container 61 is composed of a plurality of tubes 61a having a circular cross section, and a mixed fluid of the gas to be processed A and the nitrous oxide aqueous solution Nw is circulated in each tube 61a. Each tube 61a is made of glass so that the mixed fluid in the tube 61a can be irradiated with ultraviolet light from the outside. Therefore, the gas A to be treated is purified by being irradiated with ultraviolet light when flowing through the tube 61a. Various methods are conceivable as a method for recovering the gas obtained by purification, that is, the treated gas Ac of the gas to be treated A. For example, as shown in FIG. 12, the gas is disposed downstream of the outlet 61b. A storage tank 61c for liquid separation is provided, the processed gas Ac of the gas to be processed A is recovered from the exhaust port 61d connected to the storage tank 61c, and the used liquid of the nitrous oxide aqueous solution Nw is recovered from the drain port 61e. You may make it do.

  Further, the sealed and fluid type container may be the container 62 shown in FIG. The container 62 is made of a so-called flat tube 62a having an elongated cross-sectional shape inside the tube, and is made of a resin having ultraviolet light permeability.

  In the containers 61 and 62 shown in FIG. 12 or FIG. 13, a wider ultraviolet light irradiation area is ensured even if the flow path cross-sectional area is the same. Further, since the flow channel thickness is thin, it becomes easy to transmit ultraviolet light to the mixed fluid flowing in the tubes 61a and 62a. For example, even if the mixed fluid is cloudy, the entire gas to be processed can be irradiated with ultraviolet light. If the irradiated ultraviolet light passes through the mixed fluid, it is preferable that the entire mixed fluid flowing therethrough can be irradiated with ultraviolet light. Thus, if these containers 61 and 62 are used, the ultraviolet light irradiation efficiency can be improved.

  As shown in FIG. 14, the gas purification device 70 may include a circulator 71 that circulates the mixed fluid in a container such as the processing tank 21 so that the mixed fluid can be introduced into the processing tank 21 a plurality of times. The circulator 71 includes a recovery pipe 71a, a three-way valve 71b installed in the middle thereof, a circulation pipe 71c connected to the recovery pipe 71a via the three-way valve 71b, and a circulation pipe 71c. The circulation pipe 71c is connected to the supply pipe 22 of the gas A to be processed. If such a circulator 71 is installed, the treated gas Ac can be irradiated with ultraviolet light repeatedly as necessary, and the gas A to be treated can be purified more reliably.

  In addition, you may provide the circulator 72 also about the nitrous oxide aqueous solution Nw. This circulator 72 is similar to the circulator 71 of the treated gas Ac, a recovery pipe 72a, a three-way valve 72b installed in the middle thereof, and a circulation connected to the recovery pipe 72a via the three-way valve 72b. Pipe 72c and a circulation pump 72d installed in the middle of the circulation pipe 72c. The downstream end of the circulation pipe 72c is connected to the tank 23 of the nitrous oxide aqueous solution Nw. If such a circulator 72 is installed, the aqueous nitrous oxide solution Nw can be used repeatedly as necessary.

  As the gas purification device, when the installed container is a sealed container such as the container 61 (see FIG. 12) including the chamber 31 (see FIG. 10) or the tube 61a, the mixed fluid in the container is made more homogeneous. As a means for mixing, a movable mechanism for swinging, vibrating or rotating the container may be provided. A more homogeneous mixed fluid can be obtained by moving the container by the movable mechanism.

  As shown in FIG. 15, the gas purification device 80 may include a stirring unit that stirs the mixed fluid in a container such as the processing tank 21. The gas purification apparatus 80 shown in FIG. 15 includes a stirring tool 83 as stirring means. The stirring tool 83 includes a stirring bar 83b extending in the horizontal direction at the tip of a bar-like support member 83a extending vertically. The support member 83a can move up and down and rotate. Therefore, when the support member 83a is operated, the stirring rod 83b moves up and down and / or rotates, and the mixed fluid in the processing tank 21 is stirred. Thereby, nitrous oxide can be made to contact an oxidizable substance about the whole mixed fluid. Moreover, the staying time in the liquid of the to-be-processed gas A will be extended by stirring, and purification of the to-be-processed gas A will be performed more reliably.

  Further, as shown in FIG. 16, the supply device for supplying the gas A to be processed may not be fixed to a container such as the gas purification device 90 or the processing tank 21, and may be mobile or portable. But you can. In the gas purification apparatus 90 shown in FIG. 16, an injector 94 that can be installed in or removed from the treatment tank 21 is used. This injector 94 is used. The injector 94 injects the gas to be processed A into the nitrous oxide aqueous solution Nw that has flowed into the processing tank 21, and includes a large number of injection holes 94a. Therefore, the gas A to be treated can be supplied into the nitrous oxide aqueous solution Nw by bubbling.

  The injector 94 may be formed integrally with another device. For example, you may form integrally in the part of the stirring rod 83b of the front-end | tip of the stirring tool 83 shown by FIG. With such a configuration, it is possible to supply the gas A to be processed into the nitrous oxide aqueous solution Nw while stirring the nitrous oxide aqueous solution Nw with the stirring tool 84.

  By the way, in the gas purification apparatuses 20 and 30 of the two embodiments described first, the lamp 25 is installed outside the container such as the processing tank 21 and the chamber 41. However, the installation position of the lamp 25 is not limited to the outside of the container, and may be inside the container such as the processing tank 21 as in the gas purification device 80 shown in FIG. If the installation position of the lamp 25 is in the container, the light source is installed very close to the gas A to be processed, and the ultraviolet light irradiation efficiency is improved.

  When the installation position of the lamp 25 is only in the container, the material of the container does not necessarily need to be a material that transmits ultraviolet light, but rather a material that does not transmit ultraviolet light. If a material that does not transmit ultraviolet light is used, the ultraviolet light irradiation efficiency is improved.

  And as the lamp | ramp 25, what is not fixed with respect to a gas purification apparatus or a container may be sufficient, and a mobile type and a portable type may be sufficient. For example, you may install a lamp | ramp in the front-end | tip of the stirring tool 83 shown by FIG. With such a structure, the mixed fluid can be homogeneously mixed by stirring, and the entire mixed fluid can be uniformly irradiated with ultraviolet light.

  The KrI excimer lamp is excellent in the light intensity rising performance at the start of irradiation and the light intensity falling performance at the end of irradiation. Therefore, the on / off control of the oxidation reaction can be easily performed by turning on / off the lamp 25. Therefore, the gas purification apparatus may include a controller that controls the execution and stop of the purification process by on / off control of the KrI excimer lamp.

  Next, the liquid purification method in the fluid purification method according to the present invention will be described.

The liquid purification method of the present embodiment irradiates the liquid to be treated with ultraviolet light in a state where nitrous oxide (N ₂ O) is in contact with the substance to be oxidized contained in the liquid to be treated. In this method, the liquid is purified by oxidizing and removing it.

  The substance to be oxidized here is, for example, an organic substance. Examples of organic substances include oils and proteins that are decomposed by an oxidation reaction.

  Therefore, according to the liquid purification method according to the present invention, it is possible to purify various liquids to be treated containing an oxidizable substance such as an organic substance. Examples of the liquid to be treated include domestic waste liquid, industrial waste liquid, rain water or ground water, water taken from a dam, lake, river or sea.

  The purified liquid obtained by the purification process can be used for various purposes and is useful. For example, the use as water for middle water used in what is called a middle water can be mentioned. More specifically, toilet water, cleaning water, dust-preventing water that is sprinkled to prevent dust scattering, water for squirting water, cooling water used in various devices equipped with heat generating parts, so-called miniature gardens and flowing water devices The water for running water etc. which are used can be mentioned.

  The oxidation reaction performed by irradiating an oxidizable substance in contact with nitrous oxide with ultraviolet light is as described in the embodiment of the gas purification method.

  According to the present invention, since the oxidation reaction is easily controlled, corrosion of equipment used for liquid purification is suppressed to a minimum. In other words, the occurrence of equipment malfunctions due to corrosion is minimized. Therefore, there is an advantage that a countermeasure against corrosion is unnecessary for equipment such as a liquid purification device used when the liquid purification method according to the present invention is performed.

  By the way, in order to purify the liquid to be treated by the liquid purification method according to the present invention, as described above, it is necessary to bring the oxidant contained in the liquid to be treated into contact with nitrous oxide. And as mentioned above, when suppression of generation | occurrence | production of ozone etc. is considered, the method of making the nitrous oxide dissolved in the liquid contact the to-be-oxidized substance contained in to-be-processed gas is preferable. For example, a method using a nitrous oxide-containing solution or a method having a step of dissolving nitrous oxide in the liquid to be treated is preferable.

  The state in which nitrous oxide is brought into contact with the substance to be oxidized can be obtained, for example, by performing the following contact process. As the contacting step, a step of mixing the liquid to be treated and nitrous oxide gas, a step of exposing the liquid to be treated to the nitrous oxide gas, a step of causing nitrous oxide to exist in the liquid to be treated, or containing nitrous oxide Examples include a step of causing an oxidizable substance to exist in the nitrous oxide gas.

  Here, the nitrous oxide gas is meant to include not only a gas composed of only nitrous oxide but also a gas containing nitrous oxide.

  Among these, as a method of mixing the liquid to be treated and nitrous oxide gas, for example, the liquid to be treated and at least one of the nitrous oxide gas or the nitrous oxide-containing solution are placed in the same container. The method of accommodating and the method of stirring further after accommodation can be mentioned.

  Examples of the method of exposing the liquid to be treated to nitrous oxide gas include a method of adding nitrous oxide gas to the atmosphere of the liquid to be treated.

  Examples of the method for causing nitrous oxide to be present in the liquid to be treated include a method for releasing nitrous oxide gas into the liquid to be treated, and a method for adding nitrous oxide-containing water to the liquid to be treated. .

  Examples of a method for releasing nitrous oxide gas into the liquid to be treated include a so-called jetting method in which nitrous oxide gas is discharged, jetted, or jetted into the liquid to be treated. More specifically, a bubbling method can be mentioned.

  Examples of the method for causing the substance to be oxidized to exist in the nitrous oxide gas include a method for releasing the liquid to be treated into the nitrous oxide gas. More specifically, a so-called jetting method in which the liquid to be treated is discharged, jetted, jetted or sprayed can be mentioned.

  In addition, the method of bringing nitrous oxide into contact with the oxidant contained in the liquid to be treated can be broadly classified by focusing on the state of the liquid to be treated. A method of contacting nitrogen, a method of bringing nitrous oxide into contact with an oxidant in the vaporized material of the liquid to be treated, and a suboxidation of an oxidant contained in a gas-liquid coexisting material in which a part of the liquid to be treated is vaporized It is roughly divided into methods of contacting nitrogen. That is, in the liquid purification method according to the present invention, the substance to be oxidized is brought into contact with nitrous oxide while the liquid to be treated remains in a liquid state, a gas state, or a gas-liquid two-phase state.

  Examples of suitable methods for bringing part or all of the liquid to be treated into a gas state include a spraying method, a method of vaporizing by heating, and a method of decompressing the liquid to be treated.

  The lamp (light source) used in the liquid purification method according to the present invention is preferably one that generates light having a wavelength of 240 nm or less. Examples thereof include a high-pressure mercury lamp and a krypton-iodine (KrI) excimer lamp (hereinafter referred to as a KrI excimer lamp). The lamp output is not particularly limited. In general, when the same lamp is used, the rate of oxidative decomposition is affected by the output. In other words, when the lamp output is small, the oxidative decomposition rate decreases, and conversely, when the lamp output is large, the oxidative decomposition rate increases. The lamp output can be appropriately selected according to the desired oxidative decomposition rate.

  In the liquid purification method according to the present invention, a pretreatment step for improving the irradiation efficiency of ultraviolet light may be performed.

  Examples of the pretreatment step include a dilution step for diluting the liquid to be treated. As a dilution process, the process of adding water and the process of adding nitrous oxide containing water can be mentioned. The diluted liquid to be processed has improved light transmittance. Therefore, the irradiation efficiency of ultraviolet light is improved.

<Example of liquid purification method>
In the present embodiment, the liquid purifier 11 having the same configuration as that of the first embodiment is used except that the lamp 13 is a KrI excimer lamp. A nitrous oxide aqueous solution used for purification was also prepared. The nitrous oxide concentration in the solution was 1000 ppm.

  Using such an apparatus and an aqueous nitrous oxide solution, the same methylene blue aqueous solution as that purified in Example 1 was purified. In the purification treatment, a methylene blue aqueous solution and a nitrous oxide aqueous solution were put into the container 12 and mixed to obtain a mixed solution 14. And the lamp | ramp 13 was turned on and the liquid mixture 14 in the container 12 was irradiated with ultraviolet light, and the purification process was performed. The ambient temperature of the place where the liquid purification apparatus 11 was installed was 24 ° C. As a result, the purification performance was equivalent to or better than that when the apparatus of Example 1 using a high-pressure mercury lamp was used. Moreover, the trichlorethylene concentration which existed in trace amount in the liquid mixture before ultraviolet light irradiation was falling in the solution after ultraviolet light irradiation.

  Next, the liquid purification apparatus in the fluid purification apparatus according to the present invention will be described.

  The liquid purification apparatus of the present embodiment includes a contact unit that makes an oxidant contained in a liquid to be treated come into contact with nitrous oxide, and a light source that irradiates the oxidant that comes into contact with the nitrous oxide with ultraviolet light. Is.

  In a liquid purification device, nitrous oxide is brought into contact with an oxidizable substance such as an organic substance in a contact unit, and the non-oxide is oxidized by irradiating the oxidized substance in contact with the nitrous oxide with ultraviolet light from a light source. As a result, the material to be treated is oxidized and decomposed to purify the liquid to be treated.

  The contact unit for bringing the substance to be oxidized contained in the liquid to be treated into contact with nitrous oxide includes a container for bringing the substance to be oxidized into contact with nitrous oxide. Examples of the container include an open container having an opening and a sealed container used in a sealed state in terms of whether or not the container is open to the outside.

  In addition, a fluid (hereinafter referred to as a mixed fluid) in which a liquid to be treated and / or a vaporized product thereof and at least one of nitrous oxide gas, nitrous oxide gas, or a nitrous oxide-containing solution are mixed is referred to as an ultraviolet ray. From the viewpoint of whether or not to allow the mixed fluid to flow when irradiating light, a storage container and a fluid container can be mentioned.

  Examples of the open container include a batch processing tank having an opening at the upper end and a groove-shaped container having an upper end opened. Examples of the sealed container include a tube-shaped container such as a sealed chamber and a pipe. Further, examples of the storage container include the above-described batch processing tank and chamber. Examples of the fluid-type container include the above-described groove-shaped container and tube-shaped container.

  The flow-through container preferably has a shape that ensures a wide ultraviolet light irradiation area. Specifically, those having a wide flow passage are preferable. Here, the wide flow passage refers to a flow passage having a structure in which the flow passage width is wider than the depth of the mixed fluid flowing through the flow passage in the case of a flow-type and open container, for example. In this case, the ultraviolet light from the light source is applied to the mixed fluid in the container from the opening of the flow path. In addition, in the case of a flow-type and sealed container such as a tube, the wide flow path is, for example, a width of a side corresponding to a surface irradiated with stronger ultraviolet light when the cross-sectional shape of the flow path is a square. It is a flow passage having a structure in which the thickness dimension of the cross section of the flow path intersecting the irradiation direction is shorter than the dimension.

  More specifically, examples of the sealed container include a container having a plurality of or many thin tubes, a flat cross-sectional tube having an elongated cross-sectional shape, and the like. If it does in this way, even if a channel cross-sectional area is the same, an ultraviolet light irradiation area will become large and ultraviolet light irradiation efficiency will improve. In addition, as a material for a sealed container such as a tube, an ultraviolet light transmissive material such as glass is preferable, and a material having a high ultraviolet light transmittance is more preferable.

  The open container is suitable as a container used when the treatment liquid is subjected to purification treatment in a liquid state or when the purification treatment is performed using a nitrous oxide-containing solution. The hermetically sealed container is suitable as a container used when a purification process is performed on a vaporized liquid to be processed or when a purification process is performed using nitrous oxide gas. The storage container is suitable for purifying a large amount of liquid to be processed, for example. The fluid type container is suitable for purifying the liquid to be processed and the mixed fluid while circulating them.

  Furthermore, an open and fluid type container is suitable for the case of using a method in which the liquid to be treated is exposed to nitrous oxide gas, or for purifying while the liquid to be treated is circulated. Further, the sealed and sealed container is suitable for the case where the vaporized material to be treated is circulated or the case where nitrous oxide gas is used and the liquid to be treated or the vaporized material is purified while being circulated. Yes.

  In the purification of the liquid to be treated, it is necessary to reliably bring the oxidant contained in the liquid to be treated into contact with nitrous oxide. Therefore, the contact unit is preferably one having a mixing means for positively contacting the oxidant contained in the liquid to be treated with nitrous oxide.

  As a mixing means, a liquid supply unit for supplying a nitrous oxide-containing solution into the liquid to be processed or a vaporized liquid to be processed, and a gas supply for supplying nitrous oxide gas into the liquid to be processed or the vaporized liquid to be processed A liquid to be treated for supplying a liquid to be treated in a nitrous oxide-containing solution or nitrous oxide gas, a gas for supplying a vapor of the liquid to be treated in a nitrous oxide-containing solution or nitrous oxide gas A compound supply part can be mentioned. It is preferable to have at least one of these.

  As the liquid supply unit, for example, nitrous oxide is contained in a liquid feeder such as a liquid supply pipe for pouring a nitrous oxide-containing solution such as an aqueous nitrous oxide solution into a container, or in a liquid to be treated or a vaporized liquid to be treated. Mention may be made of a liquid discharger for discharging the solution. Examples of the liquid discharger include a discharger, a sprayer, a sprayer, or a sprayer of a nitrous oxide-containing container.

  Examples of the gas supply unit include a gas discharger that discharges nitrous oxide gas into the liquid to be processed and the vaporized liquid of the liquid to be processed. Examples of the gas discharger include a gas discharge device, an ejector, and an injector. More specifically, examples of the discharger that discharges gas into the liquid to be processed include so-called bubbling devices. Further, when the nitrous oxide gas is released toward the liquid to be processed, the liquid to be processed is placed in the nitrous oxide gas atmosphere.

  Examples of the processing liquid supply unit include a liquid supply device such as a processing liquid supply pipe for pouring the processing liquid into the container, and a processing liquid discharger that discharges the processing liquid into nitrous oxide gas. it can. Examples of the processing liquid discharger include a processing liquid discharger, an ejector, an injector, or a sprayer.

  As a vaporization supply part, the vaporizer discharge | release device which discharge | releases the vaporization material of a to-be-processed liquid in a nitrous oxide containing solution and nitrous oxide gas can be mentioned, for example. Examples of the vaporizer discharger include a sprayer of a liquid to be treated, a vaporizer ejector, or an injector. More specifically, examples of the discharger that discharges the vaporized material into the nitrous oxide-containing solution include a so-called bubbling device. Note that the vaporized substance supply unit includes not only those in which all of the substances to be supplied are vaporized substances to be treated, but also those in which at least a part is vaporized substances. Examples of means for vaporizing part or all of the liquid to be treated include a sprayer, a heater, and a decompressor.

  The contact unit may include an agitation unit such as an agitator for agitating the mixed fluid in order to ensure that the oxidant contained in the liquid to be treated and nitrous oxide come into contact with each other.

  As the liquid purification apparatus, a dilution liquid supply unit that supplies a dilution liquid that improves the transparency of the liquid to be processed can be further included in the liquid to be processed. Examples of the diluent include water and nitrous oxide-containing water. The diluent supply unit supplies at least one of these diluents. When the liquid to be treated is diluted in this way, the ultraviolet light transmission efficiency is improved and the irradiation efficiency is improved.

  Moreover, as a liquid purification apparatus, especially a liquid purification apparatus provided with a flow-through container, there may be mentioned one provided with a circulation device that circulates the liquid to be treated exposed to the mixed fluid or nitrous oxide gas. By circulating, it is possible to repeatedly purify the liquid to be treated.

  Examples of the liquid purification apparatus according to the present invention may further include a heating unit that heats the fluid to be processed and a cooling unit that cools the fluid to be processed. Moreover, when a to-be-processed fluid is gas, what is provided with the condenser which liquefies the said to-be-processed fluid can be mentioned.

  And the liquid purification apparatus which concerns on this invention is equipped with the light source which irradiates an ultraviolet light.

  As the light source, a light source that generates light having a wavelength of 240 nm or less is preferable. For example, a high pressure mercury lamp and a KrI excimer lamp can be mentioned.

  The liquid purification apparatus may include a controller that controls the output of the lamp. An example of the controller is one that controls the output (illuminance) of ultraviolet light. Examples of the output control method include on / off control.

  Examples of the lamp for the light source that emits ultraviolet light include an external lamp installed outside the contact unit and an internal lamp installed inside the contact unit. More specifically, examples of the lamp include an external lamp installed outside the container of the contact unit and an internal lamp installed inside the container of the contact unit.

  When the container is an open container and the lamp is an external lamp, ultraviolet light is irradiated into the container from the opening of the container. In addition, if an open container has a part which consists of ultraviolet light transmissive materials, such as glass, an ultraviolet light can be irradiated in the container from the part.

  When the container is a sealed container and the lamp is an external lamp, the container needs to have a portion made of an ultraviolet light transmissive material. Ultraviolet light is irradiated into the container from this portion.

  When the lamp is an internal lamp, the material of the container does not need to be an ultraviolet light transmissive material regardless of whether the lamp is an open type or a sealed type. Rather, a material that does not transmit ultraviolet light is preferred.

  Moreover, as a lamp | ramp, the fixed lamp fixed with respect to the contact unit or the container, and the movement lamp installed so that movement is possible can be mentioned. An example of the moving lamp is one that is integrated with a stirring device that stirs the fluid to be treated.

  The contact unit may be provided with a plurality of containers for bringing the substance to be oxidized contained in the liquid to be treated into contact with nitrous oxide. When a plurality of containers are provided, it is not necessary to irradiate the ultraviolet light from the light source into all the containers, and it is sufficient that one or more selected containers are irradiated with the ultraviolet light. Specifically, the first container for mixing the liquid to be treated and the nitrous oxide-containing material, and the flow destination of the mixed fluid from the first container, for irradiating the mixed fluid that has flowed with ultraviolet light The thing provided with the 2nd container of this can be mentioned.

  Embodiments of a liquid purification method and a purification apparatus according to the present invention will be described below with reference to the drawings.

<Example 1 of liquid purifier>
As shown in FIG. 17, the liquid purification apparatus 120 of the present embodiment includes a treatment tank (contact unit container) 121 to which a treatment liquid F to be purified is supplied and a treatment liquid F in the treatment tank 121. To-be-processed liquid supply pipe 122 for supply, nitrous oxide aqueous solution Nw tank 123 in which nitrous oxide is dissolved, and nitrous oxide supply pipe for supplying nitrous oxide aqueous solution Nw from tank 123 to treatment tank 121 124 and a lamp 125 that irradiates ultraviolet light into the processing tank 121.

  The processing tank 121 is an open container having an opening at the upper end. And the processing tank 121 is provided with the discharge port 121a for discharging | emitting the liquid in the processing tank 121. FIG. The inner surface of the processing tank 121 is subjected to Teflon (registered trademark) processing.

  The lamp 125 is an electrolytically coupled high-frequency discharge lamp using krypton-iodine, that is, a KrI excimer lamp. The output of the lamp 125 was 1200 watts.

  In the case where the liquid purification apparatus 120 purifies the liquid F to be treated such as domestic wastewater containing organic substances such as oil and protein, first, the liquid F to be treated is supplied to the treatment tank 121 from the liquid supply pipe 122 to be treated. In addition, the nitrous oxide aqueous solution Nw is caused to flow from the nitrous oxide supply pipe 124. Thereby, the to-be-processed liquid F and the nitrous oxide aqueous solution Nw are mixed in the processing tank 121, and the state which the nitrous oxide in the nitrous oxide aqueous solution Nw contacts the to-be-oxidized substance in the to-be-processed liquid F is obtained. . In this case, the mixed fluid M accommodated in the processing tank 121 is a liquid.

  In this state, the lamp 125 is turned on and ultraviolet light is irradiated toward the inside of the processing tank 121. Then, the nitrous oxide dissolved in the mixed fluid M in the ultraviolet light irradiation region is dissociated to generate atomic oxygen (O), and this atomic oxygen strongly urges organic substances (oxidized substances) such as oil and protein. The liquid F to be treated is purified by oxidation and decomposition. That is, the organic substance is removed from the liquid to be treated by being decomposed into water, carbon dioxide, or the like by oxidation.

  Thereby, the to-be-oxidized substance contained in the to-be-processed liquid F is decomposed | disassembled by oxidation reaction, and the to-be-processed liquid F is purified. Thereafter, the processed liquid in the processing tank 121 is discharged from the discharge port 121a, and the processed liquid is recovered.

<Example 2 of liquid purifier>
A liquid purification apparatus according to the next embodiment will be described. In addition, about the same structure as the said liquid purification apparatus 120 (Example 1 of a liquid purification apparatus), suppose that the same code | symbol is attached | subjected and the description is abbreviate | omitted. The same applies to the embodiments described below.

  As shown in FIG. 18, the liquid purification apparatus 130 according to the present embodiment includes a treatment tank 121, a treatment liquid supply pipe 122 that supplies a treatment liquid F, and a gas cylinder 131 that stores nitrous oxide gas Ng. , A gas ejector 132 for ejecting the nitrous oxide gas Ng in the gas cylinder 131, and a lamp 125 for irradiating the processing tank 121 with ultraviolet light.

  The processing tank 121 is provided with a vent hole 121b on the bottom surface thereof, and the gas ejector 132 is provided with a gas jet hole 132a connected to the vent hole 121b. Therefore, the nitrous oxide gas Ng can be supplied into the treatment tank 121 from the gas ejection holes 132a. The lamp 125 was a KrI excimer lamp.

  In order to purify the liquid F to be treated with such a liquid purification device 130, first, the liquid F to be treated flows into the treatment tank 121. Then, the nitrous oxide gas Ng is ejected from the gas ejector 132. Then, the nitrous oxide gas Ng is released into the liquid F to be processed in a so-called bubbling state. As a result, nitrous oxide is dissolved in the liquid F to be processed, and a state in which the nitrous oxide is in contact with the substance to be oxidized in the liquid F to be processed is obtained.

  In this state, the lamp 125 is turned on, and ultraviolet light is irradiated into the processing tank 121. Thereby, the to-be-oxidized substance contained in the to-be-processed liquid F is decomposed | disassembled by oxidation reaction, and the to-be-processed liquid F is purified. Thereafter, the mixed fluid M in the processing tank 121 is discharged from the discharge port 121a, and the processed liquid is recovered.

<Example 3 of liquid purifier>
Next, a liquid purification apparatus of Example 3 will be described.

  As shown in FIG. 19, the liquid purification apparatus 140 of the present embodiment includes a sealed chamber 141, a gas cylinder 142 in which nitrous oxide gas Ng is stored, and nitrous oxide gas Ng in the gas cylinder 142 in the chamber 141. A gas supply pipe portion 143 to be supplied to the chamber, a liquid supply pipe to be processed 122, a liquid ejector 144 for ejecting the liquid to be processed F into the chamber 141, and a lamp 125 for irradiating the chamber 141 with ultraviolet light. ing.

  The chamber 141 includes a discharge port 141 a for discharging the fluid in the chamber 141. The chamber 141 includes a glass transmission part 141b having excellent ultraviolet light transmission performance. Therefore, ultraviolet light can be irradiated into the chamber 141 from the transmission part 141b.

  When purifying the liquid F to be treated with such a liquid purification apparatus 140, first, the chamber 141 is filled with nitrous oxide gas Ng. Then, the liquid F to be treated is ejected from the liquid ejector 144 into the chamber 141. Thereby, the liquid F to be processed is ejected into the nitrous oxide gas Ng filled in the chamber 141. Thereby, the state which the nitrous oxide in nitrous oxide aqueous solution contacts the to-be-oxidized substance in the to-be-processed liquid F is obtained. In this case, the mixed fluid M accommodated in the chamber 141 is in a gas state or a gas-liquid mixed state.

  In this state, the lamp 125 is turned on to irradiate ultraviolet light into the chamber 141. Thereby, the to-be-oxidized substance contained in the to-be-processed liquid F is decomposed | disassembled by oxidation reaction, and the to-be-processed liquid F is purified. Thereafter, the mixed fluid M in the chamber 141 is discharged from the discharge port 141a. Thereby, the treated liquid is recovered.

  Here, three types of liquid purification devices have been described, but each liquid purification device can be used with various modifications.

  Hereinafter, modified examples of the liquid purification apparatus according to the present invention will be described.

  The liquid purification apparatuses 120 and 130 according to the first and second embodiments can irradiate ultraviolet light into the treatment tank 121 from the opening at the upper end of the treatment tank 121. Therefore, the material of the processing tank 121 is not necessarily a material excellent in ultraviolet light transmittance. However, as the processing tank 121, a material in which a material having a high transmittance of ultraviolet light, particularly light having a wavelength of 190 nm is used in part or in whole may be used. If such a processing tank 121 is used, ultraviolet light is irradiated not only from the opening of the upper end of the processing tank 121 but also from the side or lower side of the processing tank 121 to purify the liquid F to be processed in the processing tank 121. Can be promoted.

  The containers of the liquid purification apparatuses 120 and 130 according to the first and second embodiments are the treatment tank 121 which is a so-called open container, but may be a sealed container. An example of the sealed container is the chamber 141 according to the third embodiment. In addition, as shown in FIG. 20, a sealed container including a processing tank 121 and a lid 121c that closes the upper end opening thereof may be used. In this case, the treatment tank 121 and / or a part or all of the lid body thereof are made of a material having ultraviolet light transmission so that the treatment tank 121 can be irradiated with ultraviolet light. In this embodiment, the lid 121c is made of glass.

  In addition, a connection tool (not shown) that can removably connect the tips of the liquid supply pipe 122 and the nitrous oxide supply pipe 124 is attached to the lid 121c, and the lid 121c is attached to the treatment tank 121 and sealed. In this state, a nitrous oxide aqueous solution and a nitrous oxide gas may be supplied into the treatment tank 121. If the treatment tank 121 can be supplied in a sealed state, nitrous oxide does not leak and can be used effectively. Note that the case of using a sealed container such as the chamber 141 of the third embodiment has already been described in the third embodiment, and a description thereof will be omitted.

  The container used in the liquid purification apparatus of the above embodiment is a storage type container, but may be a fluid type container. That is, a groove-shaped container 151 as shown in FIG. 21 may be used. In the groove-shaped container 151, the liquid F to be treated and the aqueous nitrous oxide solution Nw that flowed in do not stay in the container but flow in the container toward the discharge portion 151a on the downstream side of the container 151.

  When such a container 151 is used, the mixed fluid M flowing in the container 151 can be irradiated with ultraviolet light, and the liquid F to be treated can be purified while irradiating the flowing mixed fluid M with ultraviolet light. In this way, since all the mixed fluid M can pass through the predetermined flow path portion, the entire mixed fluid M is surely irradiated with ultraviolet light by irradiating the predetermined flow path portion with ultraviolet light. Thus, the entire liquid to be treated F can be reliably purified.

  Note that the flow rate of the mixed fluid M flowing in the container 151 may be increased or decreased. If the flow rate can be adjusted, the ultraviolet light irradiation time can be adjusted. A container 151 shown in FIG. 21 is provided with a rotating shaft 151b extending in the horizontal direction on the side portion on the upstream side. The rotating shaft 151b is supported by a support member (not shown), and can move up and down the discharge portion 151a on the downstream side of the container 151. Therefore, when the discharge unit 151a is moved upward, the flow rate of the mixed fluid M in the container 151 is decreased, and when the discharge unit 151a is moved downward, the flow rate of the mixed fluid M is increased.

  The fluid type container may be an open container such as the groove-shaped container 151, but may be a closed fluid type container. That is, a tube-shaped container 161 as shown in FIG. 22 may be used. The container 161 is composed of a plurality of tubes 161a having a circular cross section, and the mixed fluid M is circulated in each tube 161a. Each tube 161a is made of glass so that the fluid in the tube can be irradiated with ultraviolet light from the outside.

  Further, as a sealed and fluid type container, a container 162 shown in FIG. 23 may be used. The container 162 is formed of a tube 162a having a so-called flat cross-sectional shape in which the cross-sectional shape in the tube is an elongated shape, and is formed of a resin having ultraviolet light permeability.

  In the containers 161 and 162 shown in FIG. 22 or FIG. 23, a wider ultraviolet light irradiation area is secured even if the flow path cross-sectional area is the same. Further, since the channel thickness is thin, it becomes easy to transmit the ultraviolet light to the mixed fluid M flowing in the pipes 161a and 162a. For example, even if the liquid to be processed F is turbid, the entire liquid to be processed can be irradiated with ultraviolet light. If the irradiated ultraviolet light passes through the mixed fluid M, it is preferable that the entire mixed fluid M flowing therethrough can be irradiated with ultraviolet light. Thus, if these containers 161 and 162 are used, the ultraviolet light irradiation efficiency can be improved.

  As shown in FIG. 24, the liquid purification apparatus 170 may include a circulator 171 that circulates the mixed fluid M in a container such as the processing tank 121 so that the mixed fluid M can be introduced into the processing tank 121 a plurality of times. The circulator 171 includes a recovery pipe 171a, a three-way valve 171b installed in the middle thereof, a circulation pipe 171c connected to the recovery pipe 171a via the three-way valve 171b, and a circulation pipe 171c. The circulation pipe 171c is connected to the supply pipe 122 of the liquid F to be processed. If such a circulator 171 is installed, the mixed fluid M can be repeatedly irradiated with ultraviolet light as necessary, and the liquid F to be treated can be purified more reliably.

  As shown in FIG. 25, the liquid purification apparatus 180 may include a plurality of containers, specifically, two containers. As illustrated, the liquid purification apparatus 180 includes a processing tank 121 and a groove-shaped container 181 into which the mixed fluid M discharged from the discharge port 121a flows. The groove-shaped container 181 has the same shape as the groove-shaped container 151 described in FIG. 21, and includes a rotation shaft 181a corresponding to the rotation shaft 151b. Therefore, detailed description is omitted.

  The liquid purification apparatus 180 mixes the liquid F to be treated and the nitrous oxide aqueous solution Nw in the upstream processing tank 121. The obtained mixed fluid M is poured into a groove-shaped container 181 on the downstream side, where it is irradiated with ultraviolet light to be purified. With such a configuration, the mixed fluid M can be reliably irradiated with ultraviolet light in the groove-shaped container 181, and the liquid F to be processed can be reliably purified. Moreover, it is not necessary to use an ultraviolet light transmissive material as the container material for both the processing tank 121 and the groove-shaped container 181.

  Further, as the liquid purification apparatus, when the installed container is a sealed container such as the container 161 (see FIG. 22) including the chamber 141 (see FIG. 19) or the pipe 161a, the mixed fluid M in the container is more homogeneous. As a means for mixing, a movable mechanism that swings, vibrates or rotates the container may be provided. A more homogeneous mixed fluid can be obtained by moving the container by the movable mechanism.

  As shown in FIG. 26, the liquid purification apparatus 191 may include a stirring unit that stirs the mixed fluid M in a container such as the processing tank 121. The liquid purification device 191 shown in FIG. 26 includes a stirring tool 183 as stirring means. The stirring tool 183 includes a stirring bar 183b extending in the horizontal direction at the tip of a bar-like support member 183a extending vertically. The support member 183a can move up and down and rotate. Therefore, when the support member 183a is operated, the stirring rod 183b moves up and down and / or rotates, and the mixed fluid M in the processing tank 121 is stirred. Thereby, about the whole mixed fluid M, a nitrous oxide can be made to contact an to-be-oxidized substance.

  As shown in FIG. 26, the liquid purification apparatus 191 may further include a diluent supply pipe 184 that supplies the diluent W of the liquid F to be processed. Here, the diluent is water, but in addition, an aqueous nitrous oxide solution can be mentioned. The diluent supply pipe 184 supplies at least one of these diluents. There may be a case where the ultraviolet light transmittance of the mixed fluid M is low, such as when the liquid F to be treated is cloudy. In such a case, when a diluent is introduced, the ultraviolet light transmittance of the mixed fluid M is improved by the dilution, and the purification efficiency is improved.

  The liquid purification apparatus may further include a heating unit that heats the mixed fluid M and a cooling unit that cools the mixed fluid M. Further, when the mixed fluid M is a gas, the liquid purification device preferably includes a condenser that liquefies the mixed fluid M after the purification treatment.

  For example, in the liquid purification apparatuses 120, 130, and 140 according to the three embodiments described first, the lamp 125 is installed outside a container such as the processing tank 121 or the chamber 141. However, the installation position of the lamp 125 is not limited to the outside of the container, and may be inside the container such as the processing tank 121 as in the liquid purification device 192 shown in FIG. If the installation position of the lamp 125 is in the container, the light source is installed very close to the liquid F to be processed, and the ultraviolet light irradiation efficiency is improved.

  Further, when the lamp 125 is installed only in the container, the material of the container does not necessarily need to be an ultraviolet light transmissive material, but is preferably a material that does not transmit ultraviolet light. If a material that does not transmit ultraviolet light is used, the ultraviolet light irradiation efficiency is improved.

  As shown in FIG. 20, the lamp 125 may be one that is not fixed to the liquid purification device 193 or the container, or may be movable or portable. In the liquid purification apparatus shown in FIG. 20, the lamp 125 is installed at the tip of the stirring tool 183. With such a structure, the mixed fluid M can be uniformly mixed by stirring, and the entire mixed fluid M can be uniformly irradiated with ultraviolet light.

  As shown in FIG. 28, the supply device for supplying the nitrous oxide gas or the nitrous oxide aqueous solution may not be fixed to a container such as the liquid purification device 193 or the processing tank 121, and is mobile. It may be portable. In the liquid purification apparatus 193 shown in FIG. 28, the stirring tool 183 is also an injector 185 that supplies nitrous oxide gas Ng. That is, the stirrer 183 includes a hollow support member 183a and a hollow stirrer 183b, and allows nitrous oxide gas to flow through the support member 183a and the stirrer 183b. The stirring rod 183b is formed with a large number of injection holes (not shown) for injecting the nitrous oxide gas Ng. That is, the stirring tool 183 is also a bubbling device for the nitrous oxide gas Ng. Therefore, the nitrous oxide gas Ng can be supplied to the mixed fluid M by bubbling while stirring with the stirring tool 183.

  The KrI excimer lamp 125 is excellent in the light intensity rising performance at the start of irradiation and the light intensity falling performance at the end of irradiation. Therefore, the on / off control of the oxidation reaction can be easily performed by turning on / off the lamp 125. Therefore, the liquid purification apparatus may include a controller that controls the execution and stop of the purification process by the on / off control of the KrI excimer lamp.

  Next, the supply of nitrous oxide gas, the method of obtaining nitrous oxide aqueous solution by dissolving nitrous oxide, the concentration detection, etc. used in the fluid purification method and fluid purification apparatus according to the present invention will be described in detail.

  First, the supply of nitrous oxide gas will be described.

  The nitrous oxide gas can be supplied by a gas cylinder of compressed gas such as liquefied gas filled in the high pressure vessel, and can be installed in the vicinity of the fluid purification device. It can also be supplied from a large high-pressure vessel in a factory or factory using a centralized pipe. A small container such as a cassette type gas cylinder may be mounted and supplied to the fluid purification device, or a nitrous oxide generation device is provided in the fluid purification device, in the vicinity of the fluid purification device, or in the workplace, and the Nitrogen oxide may be directly supplied to a container such as a treatment tank in the fluid purification device.

  Nitrous oxide gas can be generated as follows. As an industrial method, (1) an ammonia oxidation method in which ammonia is heated at 200 ° C. to 500 ° C. in the presence of a metal oxide catalyst using oxygen or air, and (2) ammonium nitrate is thermally decomposed or nitric acid Practical scale of ammonium nitrate decomposition method that produces soda by heating ammonium sulfate mixture, (3) sulfamic acid and nitric acid react while supplying sulfamic acid divided into two or more stages or adding sulfuric acid Can be used.

  In the case of small-scale production, nitrous oxide can be generated by passing ozone gas and nitrogen gas through a glass capillary used for gas chromatography, etc., which is suitable for efficiently generating a small amount of nitrous oxide gas. ing.

  As a method of dissolving nitrous oxide gas in a solvent, (1) a gas diffusion plate or a gas diffusion tube made of a porous material made of plastic or ceramic is installed so as to be immersed in the solvent, and the above-described gas cylinder or generator A method of supplying nitrous oxide gas to the diffuser plate or diffuser tube and bubbling in the solvent from the above, (2) Using the ejector, the pressurized solvent is ejected from the nozzle of the ejector, and the generated negative Nitrous oxide gas and solvent are brought into contact with and dissolved by using pressure to absorb and dissolve nitrous oxide gas into the solvent, pressurized plate tower, packed tower, shower tower, bubble tower, etc. Stirring and dissolving the solvent in contact with the pressurized nitrous oxide gas in a pressure vessel, and stirring and mixing the pressurized solvent and nitrous oxide gas in a small pressure vessel (3) A porous membrane hollow fiber made of a hydrophobic resin such as polytetrafluoroethylene, utilizing the hydrophobicity of the resin and the gas permeability of the pores. By dissolving the gas in the liquid, or by dissolving the gas that has permeated the resin in the liquid using a non-porous gas permeable membrane hollow fiber using the gas dissolution / diffusion mechanism inside the resin, at any pressure There is a dissolution method using a hollow fiber membrane in which nitrous oxide gas is dissolved in a solvent without generating bubbles. These apparatus configurations can also be used as a configuration in which the gas A to be processed is ejected into the liquid or a configuration in which a gas such as nitrous oxide gas is ejected into the liquid such as the liquid F to be processed.

  Further, these methods can be used in combination with an ultrasonic wave or a magnetic field having a gradient to improve the amount of nitrous oxide gas dissolved in the solvent and the dissolution rate. Considering the concentration of nitrous oxide gas and the amount of nitrous oxide-containing liquid necessary for the fluid purification apparatus according to the present invention, the nitrous oxide gas can be used as a method for dissolving nitrous oxide gas in a solvent efficiently and in a short time. It is preferable to use a thread membrane.

  The concentration control and detection method of nitrous oxide in the solvent will be described.

  Nitrous oxide in the solvent can be maintained at a substantially constant concentration by dissolving the nitrous oxide gas in the solvent by the above-mentioned predetermined method and controlling the dissolution time and gas supply pressure. is there. Therefore, there is an advantage that it is not always necessary to detect, record and manage the nitrous oxide concentration in the solvent in the fluid purification device.

  However, when it becomes necessary to strictly control the concentration, the nitrous oxide concentration can be detected and managed as follows. (1) Electrolysis of nitrous oxide using an electrolytic cell having a working electrode and a counter electrode, if necessary, two or more electrolytic electrodes of a regenerative electrode, an ion exchange membrane that partitions the electrodes, and an electrolytic solution containing halogen ions (2) An ultraviolet light having a predetermined wavelength is irradiated to a cell stored in a nitrous oxide-containing solvent, and a light source is sandwiched between the cells. (3) TN (total nitrogen) analysis method defined in JIS K0102, (4) inert in nitrous oxide-containing solvent Nitrous oxide dissolved in the solvent is moved into the gas phase by, for example, supplying gas to the gas, and non-dispersive infrared absorption method, ultraviolet light absorption altitude method and oxygen ion conductive solid decomposition product Chemical measurement sensor How to measure the nitrous oxide concentration in the gas phase using, and the like can be used. The present invention can be used for management of a state before supply of a solution such as a nitrous oxide aqueous solution used in the fluid purification method and the fluid purification apparatus according to the present invention, solution management in a container such as a processing tank, and the like.

  Next, nitrous oxide waste liquid treatment will be described.

  Only about several hundred ppm of nitrous oxide remains in the solvent after the treatment, and the amount of nitrous oxide in the waste liquid is very small due to mixing with the rinse water after treatment and wastewater from other processes. Become. Therefore, basically, the fluid purification device does not need to have a device for decomposing and excluding nitrous oxide.

  Further, in the case where neutralization treatment, activated sludge treatment, electrolytic treatment, or the like is performed to treat components other than nitrous oxide in the waste liquid, nitrous oxide does not inhibit these treatments. Therefore, it is possible to carry out sludge treatment or the like without treating nitrous oxide in the treated liquid. Furthermore, nitrous oxide does not cause abnormal decomposition like oxidants such as hydrogen peroxide. Therefore, when the treated liquid containing nitrous oxide is transported to another work place or a waste disposal site, there is an advantage that it is not necessary to treat the nitrous oxide in the waste liquid before transportation.

  However, it may be necessary to reduce nitrous oxide emissions from the fluid purification device by decomposing nitrous oxide in the fluid purification device due to the relationship with other processes and the environmental management of the entire workplace. It is done. In this case, the following method can be used as a method for decomposing nitrous oxide in waste water. (1) A method of decomposing waste water by irradiating it with ultraviolet light for a certain period of time, (2) A method of electrolysis using a noble metal such as platinum as an anode, and (3) A method of reductive decomposition by reaction with hydrogen gas in the presence of a catalyst. (4) A method of decomposing microorganisms using microorganisms that breathe using oxygen in nitrous oxide in an anaerobic state. These methods can be applied as needed.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Deformation / change is possible.

  For example, the solvent of nitrous oxide is not limited to the above-mentioned water, and the function of generating atomic oxygen dissociated by ultraviolet light irradiation is not impaired, and methanol is not consumed unless the generated atomic oxygen is consumed. , Ethanol, isopropanol, methylcyclohexane, cyclohexane, acetonitrile, hexane, dioxane, glycerin, n-pentane, dichloromethane and the like may be used. The maximum soluble amount of nitrous oxide varies depending on the type of solvent. Since it is preferable that the maximum soluble amount is large, the maximum soluble amount is also considered in the selection of the solvent.

  From the viewpoint of miscibility with the liquid to be treated, a thickener for improving viscosity may be added to a nitrous oxide-containing solution such as an aqueous nitrous oxide solution. As the thickener, those that do not lose the function of generating atomic oxygen and do not consume the generated atomic oxygen are preferable.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

According to the present invention, the fluid to be treated can be easily purified by bringing the material to be treated contained in the fluid to be treated into contact with nitrous oxide or a solution containing nitrous oxide and irradiating with ultraviolet light in this state. .
Further, according to the fluid purification device of the present invention, the contacted unit causes the oxidized material contained in the fluid to be treated to contact nitrous oxide or a solution containing nitrous oxide, and the oxidized material contacted with the nitrous oxide. The fluid to be treated can be easily purified simply by irradiating with ultraviolet light from the light source.

Claims (11)

  A method for purifying a substance, which purifies the substance by irradiating the solution containing nitrous oxide with ultraviolet light in a state where the solution is in contact with the substance contained in the fluid.   A fluid purification method in which ultraviolet light is irradiated in a state where nitrous oxide is in contact with a substance contained in the fluid.   2. The fluid purification method according to claim 1, wherein the fluid is a gas.   3. The fluid purification method according to claim 1, wherein the fluid is a liquid.   The fluid purification method according to claim 2 or 4, wherein the nitrous oxide is dissolved in the fluid.   6. The fluid purification method according to claim 1, wherein the ultraviolet light source is a krypton-iodine (KrI) excimer lamp.   The fluid according to claim 2, further comprising: a contact unit for bringing a substance contained in the fluid into contact with a solution containing nitrous oxide; and a light source for irradiating the substance in contact with the nitrous oxide with ultraviolet light. Purification equipment.   The fluid purification device according to claim 7, wherein the contact unit includes a storage unit that stores the fluid and the solution containing the nitrous oxide.   A fluid purification apparatus comprising: a contact unit for bringing a substance contained in a fluid into contact with nitrous oxide; and a light source for irradiating the substance in contact with the nitrous oxide with ultraviolet light.   The fluid purification device according to claim 9, wherein the contact unit includes a container for bringing a substance contained in the fluid into contact with nitrous oxide dissolved in the fluid.   The fluid purification device according to claim 7 or 9, wherein the ultraviolet light source is a krypton-iodine (KrI) excimer lamp.

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