JP2005218890A - Radical processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the decomposition efficiency of hardly decomposable organic matter dissolved in water by positively using radicals generated from electric discharge. <P>SOLUTION: In a radical processing system comprising a reaction vessel 3 for storing water 4 to be treated, a power supply part 1 for generating high voltage, and an electrode 2 connected to the power supply part 1 and generating the electric discharge to the water 4 to be treated, distance d (cm) between the water surface of the water 4 to be treated and the electrode 2, absolute temperature T (K), and pressure P (atm) of the reaction vessel 3 satisfy the relation that P×d<SP>2</SP>≤T<SP>5/4</SP>×10<SP>-6</SP>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radical treatment system for treating hardly decomposable organic substances contained in treated water by electric discharge.

In recent years, water treatment technology using the oxidation reaction of ozone (O ₃ ) has come to be used, but chlorination has been the mainstream until then. Both methods use chemically strong oxidizing power to decompose organic substances dissolved in water.

  Their oxidizing power is as high as 2.07 electron volts for ozone compared to 1.4 electron volts for chlorine. In addition, when chlorine reacts with organic substances formed from macromolecules, disinfection by-products such as chlorophenols, trihalomethanes, haloacetic acids, haloketones, and haloacetonitrile are produced, suggesting that some of these may be carcinogenic. Itself is also a harmful substance to the human body.

On the other hand, ozone is composed only of oxygen atoms, has a small burden on the environment, and is effective for the decomposition of off-flavor substances, so that it has been widely applied to water treatment including clean water. This is the reason why the water treatment method using O ₃ has become widespread in recent years.

  However, ozone has a slow reaction rate with difficult-to-decompose organic substances such as dioxins, agricultural chemicals, and environmental hormones, and it is difficult to decompose these substances, and there are concerns about the formation of aldehydes by reaction with organic substances.

In order to decompose a hardly decomposable organic substance using a chemical reaction, it is necessary to use a chemical species having a high oxidizing power. The higher the oxidizing power, the better the hydroxyl radical (OH radical) and oxygen atom radical (O radical) have an oxidizing power of 2.85 eV and 2.42 eV, respectively, which is higher than ozone and the reaction rate constant for organic substances is higher than ozone. The apparatus using these radicals is high and exists conventionally (refer patent document 1).
Basics and Applications of Ozone Mitsutoshi Hidetoshi Sugimitsu, published on February 10, 1996 (P18 Explanation of the oxidizing power of ozone and OH radicals, P21 Explanation of OH radicals having a high reaction rate, P26 O3 + H2O2, OH by O3 + UV Explanation of radical generation method)

  For this reason, it is possible to quickly decompose a hardly decomposable substance such as dioxin. This OH radical is obtained by generating a discharge in a gas with a lot of moisture, but since it has a very high reactivity with other particles, it immediately reacts with other particles and disappears.

  In order to decompose the hardly decomposable organic substance in which the OH radical is dissolved in water, it is necessary to dissolve in water immediately after generation, but the OH radical dissolved in water has a higher extinction probability. For this reason, the conventional radical treatment system which performs water treatment by electric discharge has a problem that efficiency is lowered.

  The present invention has been made to solve such problems, and it is possible to improve the decomposition efficiency of a hardly decomposable organic substance dissolved in water by actively using radicals generated from discharge. It aims at providing the radical processing system by electric discharge.

According to the first aspect of the present invention, a reaction vessel that stores treated water therein, a power supply unit that generates high voltage, and an electrode that is connected to the power supply unit and generates discharge to the treated water. In the radical treatment system provided, as a distance d (cm) between the surface of the treated water and the electrode, an absolute temperature T (K), and a pressure P (atm) in the reaction vessel, a value of P × d ² is ( T ^5/4 × 10 ⁻⁶ ) or less, which is a radical treatment system.

  According to such an invention, discharge is generated when a high voltage is applied to the electrode, and radicals are generated from this discharge. The generated radicals can be dissolved in the treated water to decompose the hard-to-decompose organic matter, but the radicals are highly reactive and the longer the distance between the treated water and the electrode, the more likely it will react with other materials, and the hard-to-decompose organic matter decomposition efficiency Decreases.

However, when the atmospheric temperature is high, the diffusion rate of the substance is improved and the amount of dissolution in the treated water is increased. At this time, since the relationship between the distance d (m) between the treated water and the electrode, the ambient temperature T (K), and the pressure (P), P × d ² <(T ^5/4 × 10 ⁻⁶ ), it is generated by discharge. The radicals thus dissolved can be dissolved in the treated water, and the decomposition efficiency of the hardly decomposable organic matter contained in the treated water can be improved.

  According to the second invention of the present invention, a reaction vessel for storing treated water therein, a power supply unit for generating a high voltage, and an electrode connected to the power supply unit for generating discharge with respect to the treated water. And a gas flow device for discharging a gas for guiding the radical generated from the electrode part to the treated water.

  According to such an invention, radicals can be efficiently guided to the treated water by the gas discharged by the gas flow device.

  As described above in detail, according to the present invention, radicals generated from discharge can be positively used to improve the decomposition efficiency of a hardly decomposable organic substance dissolved in water.

  Hereinafter, a radical processing system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a radical processing system according to an embodiment of the present invention.

  In the figure, treated water 4 is stored in a reaction vessel 3 as waste water containing persistent organic matter and waste, leachate of final disposal site, dioxins, factory waste water, domestic waste water and the like. In the air, the electrode 2 to which a high voltage is applied is disposed with a space from the treated water 4. A plurality of the electrodes 2 may be arranged depending on the scale and the shape of the reaction vessel 3. A high voltage is applied to the electrode 2 from the high-voltage power supply 1. When a high voltage is applied to the electrode 2, a discharge 5 is generated from the electrode 2.

  A part of the electrode 2 has a needle shape or a rod shape. With such a shape, the electric field concentrates at the needle-like or bar-like portion, so that discharge can be generated at a low voltage. For this reason, radicals can be generated with less energy.

  In order to decompose the hard-to-decompose organic matter in the treated water with OH radicals generated from the discharge, it is necessary to dissolve the radicals generated by the discharge into the water. However, since radicals are rich in reactivity, they react with other particles in a short time, so it is necessary to dissolve them in water immediately after generation from discharge.

From the discharge, OH radicals are generated by the following reaction. When the discharge 5 is generated in an atmosphere containing water vapor and oxygen, the discharge 5 generates oxygen atoms O (3P) in the ground state and O atoms O (1D) in the excited state due to collision of electrons e with gas molecules. To do. That is,
e + O ₂ → O (1D) + O (3P) (1)
O (1D) reacts with water molecules to generate hydroxy radicals (hereinafter referred to as “OH radicals”). That is,
O (1D) + H ₂ O → 2OH. (2)
From O (3P) atoms, ozone O ₃ is generated by the three-body collision between the O 2 molecule and the neutral molecule M. That is,
_{O (3P) + O 2 +} M → O 3 + M (3)
In addition, H atoms and OH radicals are also generated by direct electron collision with water molecules. That is,
e + H ₂ O → H + OH (4)
The generated OH · has a moving speed depending on temperature and pressure and dissolves in the treated water. However, OH radicals have a very high oxidizing power and react with other particles in a short time. That is, in order to use OH radicals for water treatment, it is only necessary to dissolve in treated water after reacting with other particles after being generated by discharge.

  FIG. 3 shows the temperature dependence of the lifetime of the OH radical, where the lifetime from the generation to the reaction with other particles is defined as the lifetime. The maximum value of the concentration of OH radicals generated from discharge does not depend on temperature, but the higher the temperature, the longer the state of high concentration, that is, the lifetime of OH radicals increases in proportion to the temperature.

  In contrast, FIG. 2 shows the pressure dependence of the OH radical concentration change. The maximum value of the generated amount is larger as the pressure is higher, but the lifetime is longer as the pressure is lower. When generating the discharge, the discharge can be ignited with lower energy as the pressure is lower. For this reason, since OH radicals are generated with low energy, OH radicals can be expected to have a long life and high generation efficiency as the temperature is raised or the pressure is lowered.

  As shown in the equations (2) and (4), when discharge is ignited in a water vapor atmosphere, OH radicals are generated. When steam is generated by a boiler, etc., the limit is several thousand degrees Celsius, although it depends on the conditions.

  Further, when it is desired to generate a higher temperature, it is possible to raise the temperature to several thousand degrees Celsius by generating an arc discharge, and the temperature can be controlled by adjusting the power injected into the arc discharge. However, since the boiling of the treated water can be considered, the temperature cannot be increased too much. That is, when water is radically treated industrially, it can be said that the temperature is from room temperature to several hundreds of degrees Celsius depending on the treatment conditions.

  The lifetime of OH radicals under these conditions is shown in FIG. From the figure, it can be seen that when the processing atmosphere temperature is 2,000 ° C., most of the OH radicals remain without being extinguished even after 10 milliseconds have elapsed from the discharge ignition.

  As described above, OH radicals are generated when a discharge is ignited in a high humidity atmosphere. In the state of 100% with the highest humidity, in the case of atmospheric pressure, the proportion of water molecules in the space is about 1% of the whole.

  FIG. 2 shows the pressure dependence of the lifetime of OH radicals when a discharge is generated with a gas having a humidity of 100% at atmospheric pressure. From the figure, it can be seen that when the pressure is reduced to about 0.01 atm, most of the OH radicals remain without being extinguished even after about 10 milliseconds have elapsed since the occurrence of discharge.

  By removing all but water molecules from a gas having a humidity of 100% at atmospheric pressure, all water molecules are obtained at a pressure of about 0.01 atm. Therefore, considering the pressure range that can be used industrially, the atmospheric pressure should be about 0.01 atm.

  As can be seen from the above, the lifetime of the OH radical is extended by raising the temperature and lowering the pressure. In order to perform water treatment with OH radicals, it is only necessary to dissolve in the treated water within the time when OH radicals are present.

  OH radicals generated from the discharge reach the treated water surface by diffusion. The movement distance δ of OH radicals by diffusion can be expressed by the following equation using the diffusion constant D, the movement time t, the temperature T, and the pressure P.

δ = (2Dt) ^1/2 (5)
D = 5.4 × 10 ⁻⁴ × T ^3/2 / P (6)
That is,
t = P × d ² / (T ^3/2 × 1.08 × 10 ⁻³ ) (7)
As can be seen from FIGS. 2 and 3, the OH radical has a longer extinction time as the pressure is lower and as the temperature is higher. Considering the extinction time obtained from FIGS. 2 and 3 in the equation (7), the following equation is obtained.

P × d ² <(T ^5/4 × 10 ⁻⁶ ) (8)
In equation (8):
1. The temperature T is normal temperature, the pressure P is 50 torr (0.065 atm), the inter-electrode distance d is 1.3 cm or less, and 2. 2. the temperature T is 1500 degrees, the pressure P is atmospheric pressure, the inter-electrode distance d is 1 mm or less; Preferably, the temperature T is 1500 degrees, the pressure P is 50 torr, and the inter-electrode distance d is 3.78 cm or less, so that the treatment water can be treated with OH radicals.

In the radical treatment apparatus having the distance d between the electrode and the treated water surface discovered by the formula (8), OH radicals generated from the discharge are dissolved in the treated water, react with the hardly decomposable organic matter, and water H ₂ O and Decomposes into carbon dioxide CO ₂ and hydrogen peroxide. That is,
OH · + R → H ₂ O + CO ₂ + H ₂ O ₂ (9)
Unlike conventional ozone treatment, radical treatment can completely mineralize persistent organic substances.

  The high voltage power supply 1 may be any of an AC power supply, a DC power supply, and a pulse power supply. When an AC power source is used as the power source, power can be efficiently injected into the discharge through the water layer, so that it is possible to improve the decomposition efficiency of the hardly decomposable organic matter. In addition, when a DC power source is used as the power source, discharge can be efficiently started in the gas phase, so that it is possible to improve the decomposition efficiency of hardly decomposable organic substances.

  Furthermore, when a pulsed power supply is used as the power supply, high energy can be injected into the discharge in a short time, thereby improving radical generation efficiency. Also, since the time for one discharge is short, the energy injected into the discharge is Joule heating in the discharge space. Since most of them are used for radical generation without being used for temperature rise due to, it is possible to improve the decomposition efficiency of hardly decomposable organic substances.

<First Modification>
FIG. 4 is a diagram showing a first modification of the radical processing system according to the embodiment of the present invention. Also in this embodiment, the treated water 4 is stored in the reaction vessel 3. In the air, the electrode 2 to which a high voltage is applied is disposed with a space from the treated water 4. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted here.

  The gas generated from the gas flow device 6 is sprayed from the gas spray device 17 to the discharge via the gas guide 8. This gas spraying device 17 is arranged so as to guide radicals generated from the electrode 5 to the treated water 4, and is constituted by, for example, a nozzle. In addition, the gas generated from the gas flow generator 6 is a gas containing oxygen, for example, water vapor.

  As described above, the lifetime of OH radicals is short, and the distance traveled by diffusion is negligible. In order to solve this problem, the gas ejected from this gas flow device is for forcibly moving O radicals and OH radicals generated by discharge to the treated water surface, and the gas flow velocity V at this time is Considering the OH radical annihilation time obtained from FIGS. 2 and 3, by setting d / V to be 1 millisecond or less, in addition to the movement by diffusion, the movement of O radical and OH radical by the movement of radical by gas flow. Since it becomes possible to send out to treated water during the lifetime, it is possible to improve the decomposition efficiency of hardly decomposable organic substances.

  In the figure, a plurality of electrodes 2 may be arranged depending on the scale and the shape of the reaction vessel 3. A high voltage is applied to the electrode 2 from the high-voltage power supply 1. When a high voltage is applied to the electrode 2, a discharge 5 is generated from the electrode 2.

<Second Modification>
FIG. 5 is a cross-sectional view showing a second modification of the electrode of the radical processing system according to the embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted here.

  The electrode 2 is hollow, and the electrode 2 and the gas flow device 6 are connected via a gas guide 8. A gas containing oxygen generated from the gas flow device 6 flows into the electrode 8 through the gas guide 8. By flowing the gas inside the electrode 8, O radicals and OH radicals generated from the discharge 5 can be forcibly moved to the treated water surface. In addition, since the gas flows through the electrode 8, when the gas is water vapor, the amount of OH radicals generated is greatly improved, and the hardly decomposable organic matter decomposition treatment is performed.

  Therefore, according to the present embodiment, the electrode 2 is hollow, and the gas flows therein, so that most of the discharge energy can be injected into the gas, and the gas that is likely to generate OH radicals is used as the electrode. By flowing it inside, it is possible to increase the generation efficiency of OH radicals and improve the decomposition efficiency of refractory organic substances.

<Third Modification>
FIG. 6 is a cross-sectional view showing a third modification of the electrode of the radical processing system according to the embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted here.

  The feature of this modification is that the electrode 2 has a double tube structure as shown in FIG. Then, the inner tube 2a of the electrode 2 and a gas guide (not shown) are connected, and the gas generated from the gas flow device is passed through the inner tube 2a of the electrode 2.

  In addition, since the outer tube 2b is provided around the inner tube 2a in order to have a heat insulating effect from the outside of the electrode, the air supply gas temperature can be made constant, and as a result, the lifetime of radicals is extended and water treatment is effective. Can be done.

<Fourth Modification>
FIG. 7 is a cross-sectional view showing a fourth modification of the electrode of the radical processing system according to the embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted here.

  As shown in FIG. 7, the feature of this modification is that the shape of the electrode 2 is a linear electrode and is disposed opposite to the treated water 4. By setting the electrode in such a shape, the electric field concentrates along the electrode 2 and discharge is generated at a low voltage. Therefore, radical generation efficiency is high, and the length and shape of the electrode 2 are matched to the shape of the reaction vessel 3. Since it is possible to change this, it is effective for water treatment.

  Further, by providing the linear electrode 2 disposed opposite to the treated water, discharge can be generated over a wide range, so that the organic matter decomposition efficiency can be improved.

<Fifth Modification>
FIG. 8 is a cross-sectional view showing a fifth modification of the electrode of the radical processing system according to the embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted here.

  The feature of this modification is that the shape of the electrode 2 is a flat plate and is arranged in parallel with the treated water 4. Thus, by making the shape of the electrode 2 the flat plate 6, it is possible to generate a discharge in a wide area with respect to the treated water surface, improve the generation efficiency of O radicals and OH radicals, and obtain high water treatment efficiency. .

<Sixth Modification>
The feature of this modification is that the periphery of the electrode 2 is covered with a dielectric.

  FIG. 9 is a cross-sectional view showing a sixth modification of the electrode of the radical processing system according to the embodiment of the present invention. In the figure, the case where the surface of the hollow electrode 2 is covered with a dielectric 9 is shown. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted here.

  Thus, by covering the electrode 5 with the dielectric, not only can the secondary contamination of the treated water be prevented by the dissolution of the electrode material into the treated water by the discharge, but when an alternating voltage is applied, a pulsed microdischarge is generated. Since it occurs innumerably, a stable and uniform micro discharge can be obtained in the discharge space, and O radical and OH radical generation efficiency is improved. From this, the organic substance decomposition efficiency can be improved.

<Seventh Modification>
FIG. 10 is a diagram showing a seventh modification of the radical processing system according to the embodiment of the present invention. 1 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted here. The feature of this modification is that a humidifying device 10 for increasing the humidity in the reaction vessel 3 is provided.

  In the figure, treated water 4 is stored in a reaction vessel 3. In the air, the electrode 2 to which a high voltage is applied is disposed with a space from the treated water 4. Further, a humidifier 10 for increasing the humidity in the reaction vessel 3 is provided. This humidifier 10 humidifies the inside of the reaction vessel 3 so that the inside of the reaction vessel 3 is not condensed. As a result, the humidity during discharge is increased, the O radical and OH radical generation efficiency is improved, and the organic substance decomposition efficiency can be improved.

  In FIG. 10, the humidifier 10 is shown separately from the reaction vessel 3, but the structure of the humidifier 10 is not limited to this. FIG. 11 is a diagram illustrating an example of a humidifier. As shown in the figure, a gas guide 8 a for partitioning the inside of the reaction vessel 3 by a partition 11 and discharging the gas into the treated water 4 is provided. In addition, a gas guide 8 b is provided for passing the gas, which has been humidified by passing through the treated water 4, through the electrode 2.

  According to the humidifier having such a structure, since the reaction vessel 3 is shared, the radical processing system can be miniaturized.

<Eighth Modification>
FIG. 12 is a diagram showing an eighth modification of the radical processing system according to the embodiment of the present invention. 1, 4, and 10 are denoted by the same reference numerals, and detailed description thereof is omitted here. The feature of this modification is that a heating device 10 for increasing the temperature in the reaction vessel 3 is provided.

  In the figure, treated water 4 is stored in a reaction vessel 3. In the air, the electrode 2 to which a high voltage is applied is disposed with a space from the treated water 4. Moreover, the heating apparatus 11 for raising the temperature in the reaction container 3 is provided. This increases the temperature during discharge and improves the diffusion rate of O radicals and OH radicals. This improves the decomposition efficiency of the hardly decomposable organic matter.

<Ninth Modification>
FIG. 13 is a diagram showing a ninth modification example of the radical processing system according to the embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted here.

  In the figure, treated water 4 is stored in a reaction vessel 3. In the air, the electrode 2 to which a high voltage is applied is disposed with a space from the treated water 4. The reaction vessel 3 is also provided with an arc discharge electrode 12 and an arc discharge power source 13 for generating arc discharge.

  When arc discharge is generated in the reaction vessel 3, the temperature of the discharge part rises due to the heat generation effect of the arc discharge, and the diffusion rate of O radicals and OH radicals generated from the discharge 5 can be improved. In addition, since oxygen atoms are generated from arc discharge in an atmosphere containing oxygen, O radical and OH radical generation efficiencies are improved thereby, and the processing efficiency of hardly decomposable organic substances is improved.

<Tenth Modification>
FIG. 14 is a diagram showing a tenth modification of the radical processing system according to the embodiment of the present invention. 1 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted here.

  In the figure, treated water 4 is stored in a reaction vessel 3. In the air, the electrode 2 to which a high voltage is applied is disposed with a space from the treated water 4. In addition, a pressure reducing device 14 for reducing the pressure in the reaction vessel is provided, thereby increasing the diffusion rate of O radicals and OH radicals generated from the discharge. For this reason, since the dissolved amount of the generated radicals in the treated water increases, it is possible to improve the decomposition efficiency of the hardly decomposable organic matter.

<Eleventh Modification>
FIG. 15 is a diagram showing an eleventh modification of the radical processing system according to the embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted here. A feature of this modification is that a part of the electrode 2 is in the treated water 4.

  In the figure, treated water 4 is stored in a reaction vessel 3. The electrode 2 to which a high voltage is applied is disposed in the treated water 4, and the gas supplied through the gas guide 8 is ejected from the tip thereof.

  A part of the electrode 2 is disposed in the treated water 4, and bubbles 15 are generated in the water when gas is ejected from the electrode 2. The diameter of the bubbles generated at this time is such that d / V is 1 millisecond or less when the distance between the water surface of the treated water 4 and the electrode 2 is d (m) and the gas flow velocity is V (m / s). Adjusted to be. The gas fed at this time may be blown onto the electrode tip by an external gas blowing device. Thereby, a hardly decomposable organic substance process is attained.

<Twelfth modification>
FIG. 16 is a diagram showing a twelfth modification of the radical processing system according to the embodiment of the present invention. 1 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted here. The feature of this modification is that a spraying device 16 for spraying the gas supplied from the gas flow device 6 through the gas guide 8 to the linear electrode 9 is provided.

  As a result, discharge can be generated in a wide range and the electrode shape can be easily changed, so that the electrode shape suitable for the shape of the reaction vessel can be obtained. Also by this, the O radicals and OH radicals generated from the discharge are dissolved in the treated water by the gas blown by the gas spraying device 16, so that it is possible to treat the hardly decomposable organic matter.

<Thirteenth Modification>
FIG. 17 is a diagram showing a thirteenth modification of the radical processing system according to the embodiment of the present invention. 1 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted here. The feature of this modification is that a spraying device 17 for spraying the gas supplied from the gas flow device 6 through the gas guide 8 to the flat electrode 9 is provided.

  As a result, discharge can be generated in a wide range and the electrode shape can be easily changed, so that the electrode shape suitable for the shape of the reaction vessel can be obtained. Also by this, the O radicals and OH radicals generated from the discharge are dissolved in the treated water by the gas blown by the gas spraying device 16, so that it is possible to treat hardly decomposable organic substances.

<14th modification>
FIG. 18 is a diagram showing a fourteenth modification of the radical processing system according to the embodiment of the present invention. 1, 4, and 10 are denoted by the same reference numerals, and detailed description thereof is omitted here. The feature of this modification is provided with a humidifier 10 for supplying steam for increasing the humidity in the reaction vessel 3 in addition to the gas flow device 6 for supplying gas to the gas guide 8.

  Steam is sent into the reaction vessel 3 to increase the humidity in the reaction vessel 3. At this time, by sending a gas containing oxygen gas together with the steam from the gas flow device 6, not only the OH radical but also the O radical generation efficiency is improved from the discharge. This improves the decomposition efficiency of the hardly decomposable organic matter.

<15th modification>
FIG. 19 is a diagram showing a fifteenth modification of the radical processing system according to the embodiment of the present invention. The feature of this modification is in the combination with the gas flow device 6 and the humidifier 10. The same parts as those in FIGS. 10 and 15 are denoted by the same reference numerals for description.

  As shown in the figure, the gas containing oxygen generated in the gas flow device 6 is discharged through the gas guide 8 into the liquid 18 stored in the humidifier 10. The humidified gas that has passed through the liquid 18 passes through the electrode 2 via the gas guide 8 and is discharged into the treated water 4.

  Thereby, the same effect as that of the fourteenth modification can be obtained.

<Sixteenth Modification>
In the above-described embodiment and its modifications, the radical processing system having one electrode is shown for convenience of explanation, but the number of electrodes for discharging is not limited to one.

  FIG. 20 is a cross-sectional view showing the structure of an electrode including an electrode unit that performs a plurality of discharges in the radical processing system according to the embodiment of the present invention. It should be noted that the same parts as those in FIG.

  As shown in the figure, the inside of the electrode 2 is hollow, and hollow electrodes 2a to 2h having the structure shown in FIG. 5 are provided in the hollow portion. In addition, in this modification, although shown about the case where there exist multiple hollow electrodes shown in FIG. 5, this is an illustration, and this modification is also applicable to the case where there are multiple electrodes shown in other modifications. include.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

It is a figure which shows the radical processing system which concerns on embodiment of this invention. It is a figure which shows the pressure dependence of OH radical density | concentration change. It is a figure which shows the lifetime of OH radical. It is a figure which shows the 1st modification of the radical processing system which concerns on embodiment of this invention. It is sectional drawing which shows the 2nd modification of the electrode of the radical processing system which concerns on embodiment of this invention. It is sectional drawing which shows the 3rd modification of the electrode of the radical processing system which concerns on embodiment of this invention. It is sectional drawing which shows the 4th modification of the electrode of the radical processing system which concerns on embodiment of this invention. It is sectional drawing which shows the 5th modification of the electrode of the radical processing system which concerns on embodiment of this invention. It is sectional drawing which shows the 6th modification of the electrode of the radical processing system which concerns on embodiment of this invention. It is a figure which shows the 7th modification of the radical processing system which concerns on embodiment of this invention. It is a figure which shows an example of a humidifier. It is a figure which shows the 8th modification of the radical processing system which concerns on embodiment of this invention. It is a figure which shows the 9th modification of the radical processing system which concerns on embodiment of this invention. It is a figure which shows the 10th modification of the radical processing system which concerns on embodiment of this invention. It is a figure which shows the 11th modification of the radical processing system which concerns on embodiment of this invention. It is a figure which shows the 12th modification of the radical processing system which concerns on embodiment of this invention. It is a figure which shows the 13th modification of the radical processing system which concerns on embodiment of this invention. It is a figure which shows the 14th modification of the radical processing system which concerns on embodiment of this invention. It is a figure which shows the 15th modification of the radical processing system which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the electrode provided with the electrode part which performs the some discharge of the radical processing system which concerns on embodiment of this invention.

Explanation of symbols

1 ... High voltage power supply,
2 ... Electrodes,
3 ... reaction container,
4 ... treated water,
5 ... discharge,
6 ... Gas flow device,
8, 8a, 8b ... gas guide,
9: Dielectric,
10 ... Humidifier,
11 ... heating device,
12 ... arc discharge electrode,
13: Arc discharge power supply,
14 ... decompression device,
15 ... Bubbles,
16 ... spraying device,
17 ... Gas spraying device,
18 ... Liquid.

Claims (15)

A reaction vessel for storing treated water inside;
A power supply that generates high voltage;
In a radical treatment system comprising an electrode connected to the power supply unit and generating discharge with respect to the treated water,
As a distance d (cm) between the water surface of the treated water and the electrode, an absolute temperature T (K), and a pressure P (atm) in the reaction vessel, a value of P × d ² is (T ^5/4 × 10 ^{− 6} ) A radical processing system characterized by: A reaction vessel for storing treated water inside;
A power supply that generates high voltage;
An electrode connected to the power supply unit and generating a discharge with respect to the treated water;
A radical treatment system comprising: a gas flow device that discharges a gas for guiding radicals generated from the electrode part to the treated water. A reaction vessel for storing treated water inside;
A power supply that generates high voltage;
An electrode connected to the power supply unit and generating a discharge with respect to the treated water;
A radical treatment system comprising a humidifier for increasing the humidity in the reaction vessel. A reaction vessel for storing treated water inside;
A power supply that generates high voltage;
An electrode connected to the power supply unit and generating a discharge with respect to the treated water;
A radical treatment system comprising a heating device for increasing the temperature in the reaction vessel. A reaction vessel for storing treated water inside;
A power supply that generates high voltage;
An electrode connected to the power supply unit and generating a discharge with respect to the treated water;
A radical treatment system comprising: a decompression device for decompressing the pressure in the reaction vessel.   The electrode has a hollow needle shape or a rod shape, and the gas generated by the gas flow device is allowed to pass through the inside of the electrode to guide radicals generated from the electrode portion to the treated water. The gas flow device according to claim 2.   The shape of the electrode is a double tube structure, and the gas generated by the gas flow device is passed through the tube inside the electrode, thereby leading the radical generated from the electrode part to the treated water. The gas flow device according to claim 2.   The gas flow device according to claim 6 or 7, wherein at least a part of the electrode is provided in the treated water. The gas flow device comprises:
A value d / V (seconds) obtained by dividing the distance d (m) between the electrode and the water surface of the treated water by the flow velocity V (m / s) of the discharged gas is 10 ⁻³ (seconds) or less. The radical processing system according to claim 2.   The radical processing system according to claim 4, wherein the heating device includes an arc discharge electrode for raising a temperature in the reaction vessel.   The radical processing system according to any one of claims 1 to 5, wherein a shape of a portion of the electrode that generates discharge is a needle shape or a rod shape.   The radical processing system according to any one of claims 1 to 5, wherein the electrode is a linear electrode disposed to face the treated water.   The radical processing system according to any one of claims 1 to 5, wherein the electrode is a flat electrode arranged in parallel to the treated water.   The radical processing system according to any one of claims 1 to 5, wherein a part of the electrode is covered with a dielectric material.   The radical processing system according to any one of claims 1 to 5, wherein the power supply unit is any one of an AC power supply, a DC power supply, and a pulse power supply.

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