JP2001017971A - Oxidation-decomposition device for trace harmful substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently oxidize, decompose and remove soluble COD, ammonia and nitrate type nitrogen and also organic harmful substances such as phenol. SOLUTION: This device has a structure in which a metal integrally arranged with an electrically conductive oxide on the surfaces is used as anodes 1A, 2A and porous ceramic or a resin is made as a partitioning wall and inner walls at the both sides are formed of metallic plates bonded with noble metal by fusing and the metallic plates are used as cathodes 1B, 2B. Two symmetrically faced spaces 1, 2 are formed with the partitioning walls 20 of the anodes and trace harmful substances contained in contaminated water in the spaces 1, 2 is oxidized and decomposed in the device. In this case, the device is provided with a rectangular wave discharge device to the spaces and the contaminated water is allowed to flow in the one space 1 and is irradiated under an electric field, and later, its supernatant is irradiated under the electric field in the other space (2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for oxidizing and decomposing trace harmful substances. More specifically, the invention of this application is intended to separate and decompose algae bred by eutrophication of ponds and lakes, small animals and fungi that prey on the algae, and harmful substances called environmental hormones such as trihalomethane and tributyltin. The present invention relates to an apparatus for oxidatively decomposing trace harmful substances in polluted water or exhaust gas, which is useful for decomposing compounds and the like, and to a decomposition method using the same.

[0002]

2. Description of the Related Art Various methods and means for separating and decomposing various harmful substances in polluted water and exhaust gas have been studied. There are various types.

In these methods, a chemical agent is added or
Alternatively, a chemical method of decomposing by contact with these agents, a biological method having a characteristic treatment by a microorganism, and an electrochemical decomposition method are known as main ones.

However, a large amount of polluted water such as ponds, lakes and marshes, and river water is efficiently treated, and furthermore, propagated algae and small animals and fungi that prey on the algae are completely separated and decomposed. In terms of decomposing and decomposing organic compounds called environmental hormone substances such as trihalomethane and tributyltin, which have become serious problems in recent years, all of the conventional methods have advantages and disadvantages, common means, There was a problem that it could not be applied as a method.

More specifically, for the decomposition of polyphenols and trihalomethanes, an oxygen radical treatment technique using titanium oxide and UV light has been developed, but there is a problem that the running cost is high due to low light efficiency of UV light. . In addition, pressure flotation methods have been developed for removing cyanobacteria that live in wastewater, but there are problems in terms of running costs, such as the need for coagulating sedimentation agents,
There are technical limitations such as the removal rate not exceeding 95%, and the situation is not yet a comprehensive technique for removing soluble COD.

In such a situation, the inventors of the present application have found that it is effective to carry out oxidative decomposition treatment by high electric field pulse discharge, and have described a desirable method and an apparatus for applying this oxidative decomposition method. We have been considering.

[0007] The invention of this application has been made in view of the above background, solves the problems of the conventional method, enables more efficient large-scale processing, and provides various processing targets. It is an object of the present invention to provide an apparatus for oxidative decomposition of trace harmful substances in polluted water or exhaust gas, which can be applied to a wider range and which is more versatile, and a decomposition method using the same.

Further, the invention of this application is that the removal of algae floating in polluted water is of an energy input type by a pressure flotation method or the like, and it is impossible to completely remove soluble COD. Substances are ozone and UV
To provide a new oxidative decomposition apparatus and a decomposition method using the same, which can solve the conventional problem that the decomposition efficiency is 40 to 50% because ring cleavage cannot be achieved in a short time by oxygen radical oxidation by oxidizing. That is also a specific issue.

[0009]

Means for Solving the Problems According to the invention of the present application, first, as a solution to the above-mentioned problems, first, a metal having a surface on which a conductive oxide is disposed and integrated is used as an anode, and a porous material is used. Contaminated water with ceramics or resin as partitions, and a structure in which the inner walls on both sides are surrounded by a metal plate welded with a noble metal, and this metal plate is used as a cathode. A device for oxidizing and decomposing trace harmful substances contained in, wherein a rectangular wave discharge device is provided for the space, polluted water is flowed into one space and irradiated with an electric field, and then the supernatant is irradiated with an electric field in another space. A device for oxidatively decomposing trace harmful substances, characterized in that:

Secondly, in this device, the space between the anode partition wall and the cathode is spaced at a distance of 1 to 10 cm, and the rectangular wave discharge to this space has a frequency of 10 to 20 cm.
0 kHz, line voltage 200 V / cm to 10 kV / cm,
Oxidation is performed under the condition of a current of 0.5 to 50 mA, and the polluted water is oxidized and decomposed at a flow rate of 0.01 to 0.1 m / s in the first space. The conductive oxide provided and integrated is one or more of titanium oxide, tin oxide, and ruthenium oxide, and the noble metal deposited on the metal plate is platinum.

Fourth, the invention of the present application is different from the first to third inventions in that a thin film made of conductive oxide particles is provided on both surfaces and integrated to form a molecular component. A porous metal plate with permselectivity and a box-shaped container made of metal or metal on both sides to form a space, with the porous metal plate as the anode and the box-shaped container as the cathode A device for oxidizing and decomposing trace harmful substances contained in polluted water, which is equipped with a voltage applying device for the anode and the cathode, and has a space on one side surrounded by a porous metal plate and a box-shaped container. Circulating under pressure, applying a voltage to the anode and the cathode, and performing ultrafiltration in the space on the other side.

Fifth, the porous metal plate has a particle size
Thickness due to conductive oxide particles of 0.001 to 0.01 μm
It has a thin film of 10-20 μm, and its selective permeability is 50
× 10 ^Four~ 2 × 10^FourThe molecular fraction of Dalton,
The polluted water is pressurized and circulated at 0.2 to 6.0 MPa.
Between the anode and the cathode, a frequency of 10 to 200 kHz.
z, a line voltage between 200 V / cm and 10 kV / cm
Sixth, the oxidative decomposition device adapted to be applied
Oxide thin film is made of titanium oxide, tin oxide, ruthenium oxide
The box-shaped container is composed of at least one of
Acids made of stainless steel or having a platinum surface
A chemical decomposition device is provided.

Further, the invention of this application is, in the seventh aspect, arranged such that a metal rod coated with a conductive oxide is disposed at the center of an electrically insulated cylindrical container, and this is used as an anode, and the outside thereof is porous. Concentrically surrounded by a metal plate, this is used as a cathode, and a metal cylinder coated with a conductive oxide on the outside and inside of the cylinder is housed, and the inflow portion and the discharge portion of the gas into the cylindrical container A device for oxidatively decomposing harmful substances in exhaust gas, comprising: a line voltage of 0.4 kV /
An oxidative decomposer for trace harmful substances, characterized by comprising a transmitter for applying a current of 1 to 50 mA, a frequency of 50 to 150 kHz, and a current of 1 to 50 mA. An oxidative decomposition device provided with a partition orthogonal to a direction is provided.

Ninth, a metal rod or a metal rod having platinum disposed on its surface is placed as a cathode in the center of an electrically insulated cylindrical container, and this is electrically insulated with ceramics or resin. Then, wind and attach a spiral strip coated on the surface with a conductive oxide, further house the outer wall of which is covered with a stainless steel plate or a titanium plate as the anode, and connect it to the gas inflow section into the cylindrical container. An oxidative decomposition device for harmful substances in exhaust gas comprising the discharge section, wherein a line voltage between the anode and the cathode is 0.4 kV / cm to 7 kV / cm,
A device for oxidizing and decomposing trace harmful substances, comprising a transmitting device for applying a frequency of 50 to 150 kHz and a current of 1 to 50 mA. Tenth, a metal cylinder coated with a conductive oxide or platinum on the inside. The multiple bundled structure is used as the anode, and the metal is placed in each metal cylinder with the center at the center, and this is used as the cathode.These are housed in an electrically insulated cylinder or square cylinder, An apparatus for oxidatively decomposing harmful substances in exhaust gas, comprising an inflow portion and an exhaust portion, wherein a line voltage between an anode and a cathode is 0.4 kV / cm to 7 kV / c.
m, frequency 50-150kHz, current 0.5-50mA
And a transmitter for oxidizing and decomposing trace toxic substances.

Eleventh, the present invention provides the oxidative decomposition apparatus according to any one of the seventh to tenth aspects, wherein the conductive oxide is at least one of titanium oxide, tin oxide, and ruthenium oxide.

Further, the present invention relates to a twelfth invention,
A thirteenth method for oxidative decomposition of trace harmful substances using any of the first to third devices, a thirteenth method for oxidative decomposition of trace toxic substances using any of the fourth to sixth devices, Provides an oxidative decomposition method for trace harmful substances using any one of the seventh to eleventh devices.

As described above, the invention of this application exposes algae to electric field pulse irradiation, decomposes cells by electroporation, oxidatively decomposes the contents, and removes CO2 dissolved in water.
Oxidative decomposition of D component, ammonia or nitrate nitrogen can be performed in a short time.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The invention of this application has the features as described above, and embodiments thereof will be described below.

First, the main principle of the oxidative decomposition on which the devices of the first to seventh aspects of the present invention rely is as follows. That is, when electrons enter the surface of a cavity formed by a conductive oxide such as titanium oxide, ruthenium oxide, or tin oxide particles, oxygen radicals or hydroxyl radicals are mainly generated on the surface for 10 to 100 μs. It is known that these oxygen radicals and hydroxyl radicals oxidize soluble components, and that hydroxyl radicals play a significant role in cleavage of aromatic phenolic substances. The apparatus of the present invention is a wastewater treatment apparatus utilizing the characteristics of the high electric field pulse irradiation.

Further, the ecological cell membrane is penetrated by electron irradiation,
The cell particles will be perforated. Since the cell constituents are discharged into the liquid, it is effective for sterilization. For example, cyanobacteria are destroyed with a line voltage of 1 kv / cm and a current of 1 mA.

Since the ^* O and ^* OH radicals leave H ⁺ ions in the liquid after oxidation, the electroporated cells are degassed if the air bubbles have oxygen. On the other hand, the cell membrane is quickly charged and has cohesive properties, and thus precipitates easily. Thus, it is useful for decomposing and removing living cells.

The oxidative decomposition apparatus for harmful substances in polluted water according to the first to third inventions (claims 1 to 3) is most suitable for separating and removing algae. Basically, the structure of this device is such that a metal with conductive oxide disposed and integrated on the surface is used as the anode, porous ceramics or resin is used as the partition, and the inner walls on both sides are surrounded by a metal plate welded with noble metal. Having a structure in which the metal plate is used as a cathode, the partition walls of the anode are plane-symmetrical to form two chambers, and a rectangular wave discharge device for the space is provided. The supernatant is irradiated with an electric field, and then the supernatant is irradiated with an electric field in another space.

In this configuration, the space between the anode partition and the cathode is spaced at a distance of 1 to 10 cm, and the rectangular wave discharge to this space has a frequency of 10 to 200 kHz.
z, the line voltage is 200 V / cm to 10 kV / cm, and the current is 0.5 to 50 mA. The polluted water is caused to flow in the first space at a flow rate of 0.01 to 0.1 m / s. And that the conductive oxide disposed and integrated on the surface is at least one of titanium oxide, tin oxide and rubidium oxide, and that the noble metal deposited on the metal plate is platinum. This is also a preferred embodiment.

FIG. 1 of the accompanying drawings shows an example of the configuration in this case.

In this example, the first chamber (1) has an anode (1A) and a cathode (1B), and the second chamber (2) has an anode (2).
A) and a cathode (2B) are provided, and an anode (1A)
A partition (20) is disposed between the anode and the anode (2A).

The liquid containing algae transferred by the pump P1 is the first liquid.
After passing through the chamber (1), it is irradiated with an electric field, and is easily settled and separated in the settling tank (3). Further, the supernatant of the precipitation tank (3), that is, the supernatant containing cell lysates and soluble substances is sent to the second chamber (2) by the pump P2, where it is irradiated with an electric field. In the precipitation tank (4), fine particles precipitate. Most of the gas is discharged as CO ₂ or N ₂ gas at the upper part of the precipitation tanks (3) and (4). However, harmful gases such as hydrogen sulfide gas, NO _x , and SO _x are generated. The treatment of the gaseous substance or the treatment such as activated carbon adsorption of the seventh and eighth inventions can be performed.

Utilizing the activity of ^* O radicals generated in the cavities of the metal oxide, H generated by oxidative decomposition of oxygen radicals
^The problem is solved by a one-electrode two-chamber structure in order to promote agglomeration of cell fragments that have become dead cells by utilizing the chargeability of ⁺ , separate algae, and sufficiently oxidize cell contents.

Further, since aromatic substances such as dioxin and PCB contained in sludge water generate intermediate products during cleavage and oxidative decomposition, it is necessary to repeatedly irradiate the electric field. The device of the invention according to claims 4 to 6) is configured to easily decompose these hardly decomposable substances.

That is, basically, a porous metal plate in which a thin film made of conductive oxide particles is provided and integrated on both surfaces to give selective permeability to molecular fractionation, and both surfaces of which are made of metal,
Alternatively, a space is formed by surrounding a box-shaped container having a metal surface, a porous metal plate is used as an anode, and the box-shaped container is used as a cathode, and a voltage applying device for the anode and the cathode is provided, and the porous metal plate is provided. The contaminated water is pressurized and circulated in a space on one side surrounded by a box-shaped container, a voltage is applied to the anode and the cathode, and ultrafiltration is performed in the space on the other side.

In this configuration, the porous metal plate has a thin film of conductive oxide particles having a particle size of 0.001 to 0.01 μm and a thickness of 10 to 20 μm, and has a selective permeability of 50 × 10 ^4. ２2 × 10 ⁴ Dalton molecular fraction, polluted water is pressurized and circulated at 0.2-6.0 MPa, and a frequency of 10-20
0 kHz, a line voltage of 200 V / cm to 10 kV / cm was applied, and the conductive oxide thin film was made of one of titanium oxide, tin oxide, and ruthenium oxide.
In a preferred embodiment, the box-shaped container is made of stainless steel or has a platinum surface.

FIG. 2 shows an example of such a configuration. In FIG. 2, an upper space (8) formed by a porous metal plate (5) as an anode and box-shaped containers (6) and (7) as a cathode contains raw water to be treated, for example, a pressurized pump. P1 is pressurized to 0.2 to 5.0 MPa and circulated and circulated. In the metal oxide film on the surface of the porous metal plate (5) on the side of the upper space (8), voids exist as small holes having a diameter of, for example, 0.002 to 0.01 μm, and have a molecular weight of 200 Da (Dalton). It has the same properties as the so-called ultrafiltration and reverse osmosis membranes in the structure that blocks the permeation of the above molecules. Substances of 200 daltons or less pass through the metal oxide film, exude from the lower part of the porous metal plate (5), and enter the lower space (9). The filtered water is completely circulated by pumping two to three times to completely remove CO _2.
Or N ₂ .

The frequency, line voltage and current are changed depending on the molecular weight of the hardly decomposable substance and the strength of the molecular bond.
Since decomposed gas is emitted from the circulating water from the upper space (8) and the lower space (9), harmful gas must be treated using the apparatus of the present invention or by absorption of activated carbon. It is considered that dioxin and PCB can be easily decomposed in view of the chemical structure. Trihalomethane or N-
It has been confirmed that harmful substances in groundwater such as hexane isopropanol are decomposed by 100%.

[0033] Oxygen radicals, many occurring in the cavity of the oxidized electrode surface, the oxidizing power is not strong, when carefully selected metal oxide and the grain shape ^* O radicals than ^* OH
There are conditions under which radicals are generated, and these conditions can be confirmed by the coloring property of the chemical substance. By selecting these conditions, the aromatic ring can be cleaved by the ^* OH radical in a short time.

^* OH radicals become ^* O radicals at the time of oxidation and release H ⁺ , which is also advantageous for the charge aggregation of particles. However, the generation time of ^* OH radical is 1 to 10 μs
Therefore, it is necessary to increase the transmission frequency, but it is difficult to obtain a large line voltage. Therefore, the generation of ^* OH radicals can be enhanced by bringing the electrode surfaces closer to each other. Thereby, for example, the decomposition of phenol as shown in FIG. 6 can be performed in a very short time.

The upper surface portion of the anode surface is formed into a film structure.
Batch processing is carried out by preventing more than 00 daltons, and the decomposition efficiency is increased by adopting a two-stage decomposition membrane composite structure in which the decomposed substance is decomposed again in the liquid part of the lower space (9).

The oxidative decomposition in the treatment of polluted water described above
Considering the generation of harmful gases such as O _x , SO _x , H ₂ S, it is desirable to re-decompose these gases. As a device for that, as in the seventh and eighth inventions,
A metal rod coated with a conductive oxide is disposed at the center of an electrically insulated cylindrical container, and this is used as an anode, and the outside thereof is concentrically surrounded by a porous metal plate, and this is used as a cathode,
A device for oxidizing and decomposing harmful substances in exhaust gas, further comprising a metal cylinder coated with a conductive oxide on the outside and inside of the cylinder, and having a gas inlet and a gas outlet into the cylindrical container. And the line voltage is 0.4 kV between the anode and the cathode.
/ Cm to 7 kV / cm, a frequency of 50 to 150 kHz, and a transmitter for applying a current of 1 to 50 mA.

In a preferred embodiment, the oxidative decomposition apparatus has a partition wall provided in the cylindrical container perpendicular to the central axis direction.

FIG. 3 shows an example of the configuration.

In FIG. 3, a round bar of titanium or stainless steel coated with a conductive oxide such as titanium oxide, tin oxide or ruthenium oxide is used as an anode (10), and a porous metal plate of stainless steel or titanium is used as a cathode ( As 11), the anode (10) is concentrically surrounded thereby, and a titanium or stainless steel cylinder (12) coated with a conductive oxide similar to the above is disposed on the outer inner wall. These are housed in an electrically insulated cylindrical container (not shown).

The gas enters through the inlet (13), flows in the axial direction while being hindered by the partition plate (14), and flows through the outlet (1).
5) More than one pass.

According to this device, the line voltage is 1 kV / c.
m, current 2 mA, frequency 50 kHz, NO _x , H ₂ S
Has been confirmed to be 70-80%.

According to the ninth aspect of the present invention, the device is configured such that a metal rod or a metal rod having platinum disposed on the surface is placed as a cathode in the center of an electrically insulated cylindrical container, and this is made of ceramics or resin. Helically wound with a conductive oxide coated on the surface and wound around it, and the outer wall of which is covered with a stainless steel plate or titanium plate is housed as an anode and placed in a cylindrical container. For oxidizing and decomposing harmful substances in exhaust gas, comprising a gas inlet and a gas outlet, wherein a line voltage of 0.4 kV /
It is characterized by having a transmitting device for applying a current of 1 to 50 mA at a frequency of 50 to 150 kHz, a frequency of 50 to 150 kHz, and a current of 1 to 50 mA.

FIG. 4 shows an example of the configuration.

In the example of FIG. 4, the shaft portion (16) is a cathode, the spiral surface (17) is an anode coated with metal oxide, and the inside of the outer cylindrical portion of the spiral surface (17) is also coated with metal oxide. The gas entered from the inflow port (13) flows along the spiral surface. If the pitch of the helix is made smaller, the efficiency of removing harmful gases increases, but the pressure loss increases. For example, when the pitch is 30 mm, the outer diameter of the spiral surface is 12 cm, and the length of the cylinder is 30 cm, the removal rate of NO _x and H ₂ S is 1 kV / cm for line voltage, ₂ mA for current, and 50 kHz for current.
Has been confirmed to be 90-95%.

Further, in the apparatus according to the tenth aspect of the present invention, an anode having a structure in which a plurality of metal cylinders coated with a conductive oxide such as tin oxide or titanium oxide or platinum on the inner side are used as an anode. Each one is centered on metal, this is used as the cathode, and these are electrically insulated cylinders,
An apparatus for oxidizing and decomposing harmful substances in exhaust gas, which is housed in a square cylinder and has an inflow portion and a discharge portion of a gas,
Line voltage 0.4 kV / cm to 7 kV between anode and cathode
/ Cm, frequency 50-150kHz, current 0.5-50
It is characterized by having a transmitting device for giving mA.

FIG. 5 shows an example of this configuration.

The oxidative combustion of dioxins and a gas of an automobile engine hydrocarbons and CO, are taken into consideration black smoke and NO _X erasure of the diesel engine. Titanium of approximately 50φ is used for the cylinder (18), tin oxide is applied on the inside thereof, and a platinum wire (19) is arranged at the center. Saturated steam and synthesis gas with 1% CO concentration
Assuming that the frequency is 0 kHz (the duty ratio is 50% in each case) and the measured value of the line voltage is 1 kV / cm, the result as shown in FIG. 6 is obtained. It is possible to improve the oxidative decomposition rate by improving the honeycomb structure and the technique of depositing tin oxide or titanium oxide inside the cylindrical or rectangular honeycomb. Since the possibility of decomposition of dioxin in the combustion gas can be sufficiently read from FIG. 6, the diameter of the electrode is reduced, the length of the electrode is increased, and the frequency is set to 150 to 200 kHz.
It is considered that the removal efficiency can be increased by increasing the value to z. As far as NO _x and SO _x were tested with normal temperature gas,
Because of the oxidation treatment, the N
It is also considered useful for reducing O _x and SO _x .

For example, with respect to the above-mentioned oxidation treatment of harmful substances in a gas, for example, more practically, the following conditions can be considered in its execution. Counterparts: compost, exhaust sewage treatment plants, malodorous flue gas toilet etc., dioxins, NO _X SO _x automobile exhaust gas, hydrocarbons. Method: higher voltage 6-7 kV / cm, pulse width 20-25
μs, duty ratio 30-50% (gas velocity 1 m / s or less) Current 1-5 mA (lower).

Water is supplied by a gas spray method using an atomizer.

A temperature of 200 ° C. or lower (no decomposition of water) Therefore, an example will be shown below and will be described more specifically.

[0051]

EXAMPLES Example 1 Algae Separation and Recovery Apparatus A polluted water containing 50 μg / L of algae at a concentration of chlorophyll a was collected at 50 kHz by an apparatus shown in FIG. 1 equipped with an anode having titanium oxide and a stainless steel cathode. , Line voltage 4
When continuous processing was performed at a flow rate of 1 L / min at a current of 5 mA at a current of 00 v / cm, the results shown in Table 1 were obtained. Nitrogen gas,
It can be seen from the fact that the generation of N ₂ O gas is obtained and the mass balance of nitrogen and phosphorus shows that the nitrogen component is surely decomposed. On the other hand, it is clear that phosphorus precipitates and moves to the precipitate side.

[0052]

[Table 1]

(Example 2) Decomposition experiment of phenol Whether the cleavage of the benzene ring of phenol can be surely performed or not was determined by conducting a phenol decomposition experiment using the apparatus shown in FIG. 2 equipped with an anode having tin oxide and a stainless steel cathode. When carried out as an experiment, the results shown in FIG. 7 were obtained, and it was found that the decomposition was surely performed. During the decomposition, the presence of an intermediate product was observed, but disappeared over time. For a browning substance having a high molecular weight such as polyphenol, create a metal oxide film surface with a molecular fractionation of 20,000 daltons,
Operation at a pressure of 0.3 Mpa resulted in a very rapid decrease in turbidity D ₅₂₀ (FIG. 8). (Example 3) The apparatus shown in FIG. 2 equipped with an anode having tin oxide and a cathode made of stainless steel was used to carry out oxidative decomposition treatment for 1 hour using municipal waste water from which solids were removed with a 200-mesh sieve as test raw water. As an experiment,
The results as shown in Table 2 were obtained, and 70% to 80% of soluble COD and ammonia / nitrate nitrogen were removed.

[0054]

[Table 2]

[0055]

As described in detail above, conventionally,
For titanium dioxide and UV light treatment technology, which are difficult to decompose such as polyphenols, there are technical limitations such as low efficiency, high running cost, and the removal rate of cyanobacteria etc. does not exceed 95%. In the device of the invention of the present invention, the removal of soluble COD can be realized almost completely efficiently, and the high voltage and low current are applied to the surface of the metal oxide by a pulse wave, so that the duty is low, the power consumption is low, and the flocculant is low. The processing cost can be considerably reduced because the system is not used. ^* O radicals and ^* OH radicals are generated on the electrode surface by the action of the electromagnetic wave, and H ⁺ ions remain in the liquid. The organic matter in the waste water is oxidized (or burned) by such radicals, and CO ₂ and N ₂ are generated.
In addition, harmful substances such as trace amounts of environmental hormone substances such as trihalomethane and tributyltin can be oxidized to cleave aromatic rings and detoxify them. Furthermore, high electric field pulse irradiation destroys algal and fungal cells and is also effective for sterilization. In the case of blue-green algae, cells irradiated with electromagnetic waves are degassed of oxygen contained in air bubbles, and are charged quickly by the action of H ⁺ ions, and are easily aggregated and precipitated. on the other hand,
The oxide film surface remembering ultrafiltration action, it is possible to oxidative decomposition of exhaust gas of the harmful gas and automobiles, such as NO _X generated in the wastewater treatment process (NO _x, SO _x, etc.) by high electric field treatment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an oxidative decomposition treatment apparatus for polluted water of the present invention.

FIG. 2 is a schematic view showing another example of the oxidative decomposition treatment apparatus for polluted water.

FIG. 3 is a schematic view showing an example of a gas oxidative decomposition device.

FIG. 4 is a schematic diagram showing another example different from FIG.

FIG. 5 is a schematic diagram showing still another example.

FIG. 6 is a diagram illustrating a result of a CO ₂ increase rate by an oxidation treatment.

FIG. 7 is a diagram illustrating actual results of oxidative decomposition of phenol.

FIG. 8 is a diagram showing an example of polyphenol reduction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st chamber 1A anode 1B cathode 2 2nd chamber 2A anode 2B cathode 3,4 Precipitation tank 5 Porous metal plate 6,7 Box-shaped container 8 Upper space 9 Lower space 10 Anode 11 Cathode 12 Cylindrical 13 Inflow 14 Partition plate 15 Discharge port 16 Shaft part 17 Spiral surface 17A Insulating plate 18 Cylindrical body 19 Platinum wire 20 Partition wall

Claims (14)

[Claims] A metal having a conductive oxide disposed and integrated on its surface is used as an anode, a porous ceramic or resin is used as a partition, and inner walls on both sides thereof are surrounded by a metal plate welded with a noble metal, and this metal plate is used as a cathode. A device for oxidizing and decomposing trace harmful substances contained in polluted water that forms at least two chambers with the partition wall of the anode being plane-symmetrical, comprising a rectangular wave discharge device for the space, An apparatus for oxidizing and decomposing trace toxic substances, characterized in that water is flowed into one space and irradiated with an electric field, and then the supernatant is irradiated with an electric field in another space. 2. The space between the partition wall of the anode and the cathode is 1 to
At a distance of 10 cm, a rectangular wave discharge into this space is performed at a frequency of 10 to 200 kHz and a line voltage of 200 V / c.
m to 10 kV / cm, and a current of 0.5 to 50 mA.
2. The oxidative decomposition apparatus according to claim 1, wherein the flow rate is 0.1 m / s. 3. The conductive oxide disposed and integrated on the surface is one of titanium oxide, tin oxide and ruthenium oxide.
3. The oxidative decomposition apparatus according to claim 1, wherein the noble metal, which is at least one kind and is deposited on the metal plate, is platinum. 4. A porous metal plate in which a thin film of conductive oxide particles is disposed and integrated on both sides to provide selective permeability for molecular fractionation, and a box made of metal on both sides and having a metal surface Oxidizing and decomposing a small amount of harmful substances contained in polluted water using a porous metal plate as an anode, a box-shaped container as a cathode, and a voltage applying device for the anode and the cathode. The contaminated water is pressurized and circulated in the space on one side surrounded by a porous metal plate and a box-shaped container, a voltage is applied to the anode and the cathode, and ultrafiltration is performed in the space on the other side. Oxidative decomposer for trace harmful substances. 5. The porous metal plate has a particle size of 0.001 to 0.1.
10 μm to 20 μm thick with conductive oxide particles of 01 μm
Having a permeability of 50 × 10 ^Four~ 2 × 1
0^FourThe molecular fraction of Daltons, where the polluted water is 0.2
Circulated under pressure of up to 6.0 MPa, and anode and cathode
Between 10 and 200 kHz frequency and 200 line voltage
V / cm to 10 kV / cm
The oxidative decomposition device according to claim 4. 6. The conductive oxide thin film is made of at least one of titanium oxide, tin oxide, and ruthenium oxide, and the box-shaped container is made of stainless metal or has a platinum surface. 4 or 5 oxidative decomposition apparatus. 7. A metal rod coated with a conductive oxide is disposed at the center of an electrically insulated cylindrical container, which is used as an anode, and its outside is concentrically surrounded by a porous metal plate.
This serves as a cathode, and further contains a metal cylinder coated with a conductive oxide on the outside and inside of the cylinder, and is provided with a gas inflow portion into the cylindrical container and a discharge portion thereof. An apparatus for oxidative decomposition of a substance, comprising a line voltage of 0.4 kV / cm to 7 kV / cm and a frequency of 50 to
An apparatus for oxidizing and decomposing trace harmful substances, comprising a transmitter for applying 150 kHz and a current of 1 to 50 mA. 8. The oxidative decomposition apparatus according to claim 7, wherein a partition wall orthogonal to the central axis direction is provided in the cylindrical container. 9. A metal rod or a metal rod having platinum disposed on its surface is placed as a cathode in the center of an electrically insulated cylindrical container, and this is electrically insulated with ceramics or resin to form a conductive oxide. A spiral-coated strip is wound around the object and attached, and the outer wall of the strip is covered with a stainless steel plate or titanium plate. A device for oxidizing and decomposing harmful substances in exhaust gas, comprising: a line voltage of 0.4 kV / cm to 7 kV / cm between an anode and a cathode;
A device for oxidizing and decomposing trace harmful substances, comprising a transmitting device for applying a current of 1 to 50 mA at kHz. 10. An anode having a structure in which a plurality of metal cylinders coated with a conductive oxide or platinum on the inside are used as an anode, and a metal is placed on each metal cylinder and used as a cathode. An oxidative decomposition device for harmful substances in exhaust gas, which is housed in an electrically insulated cylinder or a square cylinder, and has a gas inlet and a gas outlet, comprising a wire between an anode and a cathode. Voltage between 0.4 kV / cm-7 kV / cm, frequency 5
A device for oxidizing and decomposing trace harmful substances, comprising a transmitting device for applying a current of 0 to 150 kHz and a current of 0.5 to 50 mA. 11. The conductive oxide is at least one of titanium oxide, tin oxide and ruthenium oxide.
Oxidative decomposer according to any one of the above. 12. A method for oxidatively decomposing trace harmful substances, comprising using the apparatus according to claim 1. 13. A method for oxidatively decomposing trace harmful substances, comprising using the apparatus according to claim 4. 14. A method for oxidatively decomposing trace harmful substances, comprising using the apparatus according to claim 7. Description: