JP3214724B2 - Fixed-bed type three-dimensional electrode type electrolytic cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed-bed tertiary-type tertiary water for electrochemically treating the water to be treated in order to suppress various performance deteriorations caused by the microorganisms. Regarding the former electrode type electrolytic cell, more specifically, photographic processing solution used in the photographic photosensitive material processing step, or pool water, papermaking washing water, heat exchanger cooling water, drinking water, water storage for cup type vending machines, fish farming Water to be treated that contains microorganisms such as service water, chemical dilution water, bath water, and circulating water for gas washing towers or that may generate microorganisms is electrochemically treated using a fixed-bed three-dimensional electrode electrolytic cell. The present invention relates to a fixed-bed type three-dimensional electrode type electrolytic cell for effectively controlling microorganisms in each of the waters to be treated, sterilizing and sterilizing them in a stable state for a long period of time.

[0002]

2. Description of the Related Art Conventionally, various kinds of aqueous solutions and single water in which other substances are not dissolved have been used for various purposes. These aqueous solutions and the like provide appropriate nutrients in the solute, or when the temperature of the aqueous solution is a relatively high temperature that is favorable for propagation,
Microorganisms such as bacteria proliferate, and the microorganisms often deteriorate the performance of the aqueous solution or the like, adversely affect products, float or accumulate in the processing apparatus, and often impair the function of the processing apparatus. Therefore, a method is proposed in which a water to be treated such as the aqueous solution is supplied to an electrolytic cell provided with a three-dimensional electrode made of a carbonaceous material or the like, and the water to be treated is brought into contact with the electrode to which an electric potential is applied, thereby performing sterilization. ing. In the electrolytic sterilization method of the water to be treated, it is desirable to perform sterilization efficiently at a relatively low voltage and current, and for that purpose, it is necessary that the water to be treated contacts the electrode surface as much as possible. In order to improve the contact efficiency, as described above, the electrode is made porous having a large number of micropores, or a fixed bed type three-dimensional electrode type electrolytic cell configured by laminating a plurality of the electrodes is used. It has been proposed to carry out water treatment.

When water to be treated containing microorganisms is supplied to this electrolytic cell, it comes into contact with the surface of the layered three-dimensional electrode and further contacts the electrode to which a sufficient voltage has been applied through the micropores in the electrode. Sterilization is carried out and flows further downstream from the other surface of the electrode, the same treatment is carried out by the other electrode, and the water is taken out of the electrolytic cell as sufficiently sterilized water to be treated.

However, in water to be treated containing a large amount of insoluble suspended components, the insoluble suspended components may adhere to the surface of the electrode or the inner surface of the micropores in the electrode. The adhesion of the undissolved suspended components on the electrode causes the electrode to be covered and clogged, thereby inhibiting the contact between the electrode and the water to be treated, thereby reducing the sterilization efficiency. This insoluble suspended component can be removed by installing a filter, but causes problems such as an increase in pressure loss in the system, an increase in cost, and a complicated maintenance.
In order to continue the electrolytic treatment, it is necessary to disassemble the electrolytic cell and replace it with a new electrolytic cell without clogging, resulting in reduced workability and an economic burden.

[0005]

Problems to be Solved by the Invention Electrolytic treatment of water to be treated containing microorganisms is a very useful method which does not use any chemicals and therefore does not have any drawbacks caused by residual medicines and the use of expensive chemicals. However, if a three-dimensional porous electrode is used to further improve the efficiency, as described above, there is a problem that the electrode is clogged, which is one of the causes of a decrease in processing efficiency.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixed-bed three-dimensional electrode type electrolytic cell which solves the above-mentioned problems of the prior art and minimizes the reduction in processing efficiency due to clogging. And

[0006]

SUMMARY OF THE INVENTION The present invention relates to a fixed-bed type tertiary electrode provided with a three-dimensional porous electrode for contacting water to be treated containing microorganisms to perform electrochemical treatment of the water to be treated. A fixed bed type three-dimensional electrode type electrolytic cell, wherein a through-hole communicating the upstream side and the downstream side of the electrode is formed in the three-dimensional porous electrode in the original electrode type electrolytic cell. In the present invention, the apparatus of the present invention should be referred to as an electrochemical treatment apparatus because an electrochemical reaction such as a substantial oxidation-reduction reaction may not occur on the electrode surface. Name. Hereinafter, the present invention will be described in detail.

The fixed-bed type three-dimensional electrode type electrolytic cell according to the present invention is a fixed-bed type three-dimensional electrode-containing electrolytic cell for controlling, sterilizing or sterilizing microorganisms in water to be treated such as a photographic processing solution. The fixed bed type three-dimensional electrode of the floor type three-dimensional electrode electrolytic cell is characterized in that a through-hole for reducing the resistance of the flow of the water to be treated is formed. The microorganism of the present invention includes bacteria (bacteria), fungi, molds (fungi), Escherichia coli,
Includes yeast, deformed fungi, unicellular algae, protozoa, viruses and the like. The water to be treated in the present invention includes photographic processing solution, pool water, paper washing water, heat exchanger cooling water, drinking water,
Includes water storage for cup-type vending machines, fish farming water, chemical dilution water, bath water and circulating water for gas washing towers. When the water to be treated is supplied to the fixed-bed type three-dimensional electrode electrolytic cell, microorganisms in the water to be treated come into contact with an anode or a cathode of the electrolytic cell or a dielectric material described later by a liquid flow and have a high potential on their surface. It is considered that a strong redox reaction occurs in the microbial cells upon receiving the energy supply, and the activity is weakened or the microorganism itself is killed and sterilization is performed.

[0008] The fixed bed type three-dimensional electrode type electrolytic cell of the present invention comprises:
In general, it includes a fixed-bed type three-dimensional electrode that functions as an electrode that causes a polarization phenomenon and a power supply electrode, and the fixed-bed type three-dimensional electrode has a shape according to the electrolytic cell used above, and is a fixed-bed type bipolar electrode. When using an electrolytic cell, a porous material through which the water to be treated can pass, such as felt, woven cloth, activated carbon having a shape such as a porous block, graphite, carbon-based material such as carbon fiber, etc. Or a plurality of preferably felt-like, woven-like, and porous materials formed of a metal material having the same shape, such as nickel, copper, stainless steel, iron, and titanium, and a material obtained by coating the metal material with a noble metal. A block, perforated, or sponge-like dielectric is placed in a DC electric field, and the power is supplied from a perforated plate, such as a flat plate, expanded mesh, or perforated plate, installed at both ends. A fixed bed containing a fixed-bed type three-dimensional electrode formed by applying a DC voltage or an AC voltage of 10 Hz or less between the electrodes to polarize the dielectric and form an anode and a cathode at one end and the other end of the dielectric, respectively. It is also possible to use a fixed-bed type bipolar cell in which a three-dimensional material that functions as an anode or a cathode alone is installed so as not to be short-circuited alternately and electrically connected. It can also be a type electrolytic cell.

When a monopolar fixed-bed electrolytic cell is used, the above-mentioned dielectric or one of the three-dimensional materials which independently function as an anode or a cathode can be used with or without a diaphragm. Or a plurality of dielectrics or the three-dimensional material are placed in a single electrolytic cell at the same electrolytic potential. Regardless of which type of electrode is used, the efficiency of the water to be treated decreases if there is a gap in the electrolytic cell through which the water to be treated flows without allowing the liquid to come into contact with the electrode, dielectric or fine particles. Therefore, it is desirable to arrange the electrodes and the like so that the flow of the water to be treated in the electrolytic cell does not contact the electrodes and does not cause a short path.

Even if the anode chamber and the cathode chamber are formed by partitioning the inside of the electrolytic cell with a diaphragm, energization can be carried out without using a diaphragm, but without using a diaphragm and the distance between the electrodes. Alternatively, when the distance between the dielectric material and the electrode or between the dielectric materials is reduced, a net-like spacer made of an organic polymer material or the like is inserted as an electrically insulating spacer between both electrodes or between the dielectric materials to prevent a short circuit. can do. When a diaphragm is used, it is desirable to use a porous material having an opening ratio of 10% or more and 95% or less, preferably 20% or more and 80% or less, so as not to hinder the movement of the water to be circulated. The diaphragm must have at least micropores with a pore size that allows the water to be treated to permeate. When a carbon-based material such as activated carbon, graphite, or carbon fiber is used as the dielectric and water to be treated is treated while generating oxygen gas from the anode, the dielectric is oxidized by oxygen gas and dissolved as carbon dioxide. May be. In order to prevent this, a porous material which is usually used as an insoluble metal electrode by coating a platinum group metal oxide such as iridium oxide or ruthenium oxide on a base material such as titanium on the side where the dielectric material is positively polarized is used. What is necessary is just to install in a contact state, and to generate | occur | produce oxygen mainly on this porous material.

The flow rate of the water to be treated supplied to the electrolytic cell is as follows:
It suffices that the water to be treated is regulated so as to be able to efficiently contact the surface of the electrode or the like.Because complete laminar flow causes less lateral movement and less contact with the electrode, dielectric and fine particle surfaces, It is preferable to form a turbulent state,
Particularly preferred is a turbulent flow having a Reynolds number of 500 or more. If the desired sterilization efficiency is not achieved only by the treatment using the electrolytic cell described above, a sterilizing agent may be added to the water to be treated continuously or intermittently to perform more complete sterilization. Even in this case, unlike the conventional sterilization treatment using only a sterilizing agent, a small amount of sterilizing agent may be added, so that the cost burden is small and almost no residue remains in the water to be treated, and the composition of the water to be treated changes. There are few things. The sterilant may be dissolved in the water to be treated from the beginning or may be injected into the piping or the water without the electrolytic tank.

In the case of a fixed-bed type three-dimensional electrode comprising the above derivative, the average pore diameter of the fine pores is usually about 25 to 125 μm. Since the micropores meander rather than extend the electrode linearly from the upstream side to the downstream side, clogging of the micropores caused by the sterilization process due to dead bodies and insoluble suspended components is liable to occur. . Therefore, in the present invention, a through hole having a diameter larger than the fine hole is formed in the fixed bed type three-dimensional electrode. In order to facilitate the flow of the water to be treated, the through holes are desirably formed substantially parallel to the flow direction of the water to be treated, unlike the fine holes. If the diameter of the through-hole is too large, the amount of water to be treated that does not come into contact with the fixed-bed type three-dimensional electrode is undesirably increased. If the diameter of the through-hole is too small, the resistance is slightly reduced and the electrode is clogged. disconnection is not preferable because it can not sufficiently prevent the total cross-sectional area of the through holes of the orthogonal three-dimensional porous electrode in the flowing direction of the water to be treated
It is desirable to determine the diameter and the number of the through-holes so as to be 0.05 to 5.0% of the area , and the diameter of the through-holes is made larger than that of the fine holes.

This through-hole is desirably formed in the fixed-bed type three-dimensional electrode in parallel with the flow direction of the water to be treated from the viewpoint of reducing the resistance of the flow of the water to be treated. If the diameter is too large, the contact efficiency between the water to be treated and the electrode is reduced as described above. Therefore, when it is desired to increase the cross-sectional area of the through-hole, it is desirable to form a plurality of relatively small-diameter through-holes. . In order to improve the processing efficiency, a plurality of the fixed-bed type three-dimensional electrodes may be installed in the electrolytic cell so as to overlap with each other. In this case, if the positions of the through-holes of the adjacent fixed-bed type three-dimensional electrodes match, the water to be treated that has passed through the upstream-side electrode immediately enters the downstream-side through-hole, and the water with the fixed-bed-type three-dimensional electrode intersects. When a plurality of fixed-bed type three-dimensional electrodes are used, they are installed in the electrolytic cell so that the positions of the through-holes are shifted from each other. Even if the treated water is guided from the through-hole of the upstream electrode to the through-hole of the downstream electrode, it is desirable to provide an opportunity to move laterally between the two electrodes and to make sufficient contact with the electrode surface during that time.

When a through-hole is formed in the fixed-bed type three-dimensional electrode, the flow rate of the water to be processed flowing through the through-hole becomes greater than the flow rate of the water to be processed flowing through the fine holes, and the entire flow rate of the water to be processed is increased. Water passage resistance is reduced. Therefore, the flow of the to-be-treated water in the fixed-bed type three-dimensional electrode becomes smooth, the accumulation of dead microorganisms decreases, and clogging hardly occurs. On the other hand, the contact velocity between the water to be treated and the electrode is reduced due to the increased flow velocity, but the clogging does not occur, so there is no need to replace the electrode and disassemble or assemble the electrolytic cell. And economy is greatly improved. Even when the electrolytic cell configured as described above is used, dead microorganisms and hydroxides of calcium and magnesium adhere to the fixed-bed type three-dimensional electrode. In order to remove these deposits, the polarity of the three-dimensional electrode is reversed, and the dead microorganisms and the like that have adhered are redissolved on the anode surface having a high hydrogen ion concentration of the water to be treated and removed from the electrode surface, Thereby, clogging of the fixed-bed type three-dimensional electrode can be further suppressed. The time ratio for reversing the polarity varies depending on the amount of dead microorganisms and the like, and it is not necessary that all of the dead microorganisms and the like be removed by one polarity reversal. Normally, it is desirable that the time ratio between energization in which the polarity is in the positive direction and energization in which the polarity is reversed (inverted) is in the range of 1: 1 to 10: 1.

Next, preferred examples of the electrolytic cell of the present invention will be described with reference to the accompanying drawings, but the electrolytic cell of the present invention is not limited to these electrolytic cells. FIG. 1 is a schematic longitudinal sectional view showing an example of a monopolar fixed-bed electrolytic cell that can be used as the electrolytic cell of the present invention. Treatment water supply port 1 in the center of the bottom plate
In the lower part of the short cylindrical electrolytic cell body 3 having the water outlet 2 to be treated at the center of the top plate, a short cylindrical porous body formed of a carbonaceous material or a metal sintered body is provided. The fixed-bed type three-dimensional cathode 4 is accommodated so as to form a small gap with the inner wall of the main body 3 so that substantially no liquid flow occurs, and the cathode 4 has a large number of small-diameter penetrations in the vertical direction. A hole 5 is formed. The electrolytic cell main body 3 is preferably formed of an electrically insulating material that can withstand long-term use or re-use. Particularly, synthetic resins such as polyepichlorohydrin, polyvinyl methacrylate, polyethylene, polypropylene, polyvinyl chloride, and polyvinyl chloride Ethylene, phenol-formaldehyde resin, polyacrylonitrile resin and the like can be preferably used.

The electrolytic cell main body 3 having such a structure is installed, for example, in the middle of a water supply pipe or at a water tap.
When treated water containing microorganisms is supplied from the treated water supply port 1 to the treated water, the treated water contacts the lower surface of the cathode 4 and partially penetrates the micropores in the cathode 4 and Portion penetrates through the through hole 5 relatively quickly and reaches the upper surface of the cathode 4. During this time, the water to be treated comes into contact with the cathode 4 such as a carbonaceous material, and the microorganisms in the water to be treated are killed. Since the diameter of the micropores is smaller than the diameter of the through-holes 5 and the resistance is large and the flow velocity is low, the dead microorganisms generated in the micropores are difficult to be taken out to the upper surface of the cathode 4 together with the water to be treated, and clogging occurs relatively quickly. . On the other hand, since the diameter of the through-hole 5 is larger than the diameter of the fine hole, the resistance is small and the flow rate is high, the dead microorganisms generated in the through-hole 5 are taken out to the upper surface of the cathode 4 together with the water to be treated. Almost no clogging. Therefore, even if electrolytic sterilization of the water to be treated is performed using the electrolytic cell 3 of FIG. 1, the through-hole 5 having a relatively large diameter hardly clogs, and the cathode 4 is replaced for a long period of time. Processing can be continued.

FIG. 2 is a schematic longitudinal sectional view showing another example of a monopolar fixed bed type electrolytic cell which can be used as the electrolytic cell of the present invention. The inside of an electrolytic cell body 13 having a cylindrical shape having a treated water supply port 11 in the center of the bottom plate and a treated water outlet 12 in the center of the top plate, and having an inner wall surface functioning as an anode, has an upper surface. A baffle plate 14 accommodates a cylindrical porous fixed-bed type three-dimensional cathode 15 which is integrally installed such that a slight gap is formed between the baffle plate 14 and the inner upper surface of the main body 13. A cut 16 is cut from the center of the lower surface of the baffle, and the cut 16 extends slightly below the baffle plate 14. The cathode 15 has a through hole 17 formed in the lateral direction from the cut 16 toward the periphery, and an O-ring is provided between the lower surface of the cathode 15 and the inner lower surface of the main body 13.
18 is provided to prevent water to be treated from leaking into the gap. When water to be treated is supplied from the water supply port 11 to the electrolytic cell body 13 having such a configuration, the water to be treated passes through the gap between the inner lower surface of the body 13 and the lower surface of the cathode 15 by the O-ring 18. Because it is suppressed, after rising in the cut 16, a part of the perforation passes through the fine holes of the cathode 15, and the other part flows through the through hole 17 and reaches the outer peripheral surface of the cathode 15. It rises and passes through the gap on the upper surface of the baffle plate 14 and is taken out of the tank from the water outlet 12 for treatment. In the electrolytic cell of FIG. 2, similarly to the electrolytic cell of FIG. 1, clogging of the through holes 17 does not occur, and the electrolytic sterilization of the water to be treated is continued without replacing the cathode 15 for a long period of time. be able to.

FIG. 3 is a schematic vertical sectional view showing one example of a bipolar fixed-bed type electrolytic cell usable as the electrolytic cell of the present invention. A meshed power supply anode terminal 23 and a power supply cathode terminal 24 are provided near the inner upper end and the lower end of a cylindrical electrolytic cell main body 22 having upper and lower flanges 21, respectively. A plurality of sponge-like fixed beds 25 are stacked between the two electrode terminals 23 and 24 in the illustrated example,
Further, four mesh diaphragms or spacers 26 are sandwiched between the fixed bed 25 and between the fixed bed 25 and the two electrode terminals 23 and 24. Each fixed bed 25 is in close contact with the inner wall of the electrolytic cell main body 22 and does not pass through the inside of the fixed bed 25.
It is arranged so that the leakage flow of the water to be treated flowing between the side walls of the pipe 22 is as small as possible.

A plurality of through holes 27 are formed in each of the three fixed floors 25, and the through holes of the fixed floor 25 adjacent vertically are formed.
27 are staggered in the horizontal direction. When current is supplied to the electrolytic cell having such a configuration while supplying water to be treated from below as indicated by the arrow, each fixed bed 25 is polarized such that its lower surface is positive and its upper surface is negative, as shown in the figure. A porous cathode is formed on the upper surface of the floor 25, and the water to be treated contacts the porous cathode to sterilize microorganisms.
The treated water supplied to the electrolytic cell is partially transmitted through the fine holes in the fixed bed 25 and the other part is circulated through the through holes 27 as in the electrolytic cells of FIGS. 1 and 2. Electrolytic sterilization of the water to be treated can be continued without exchanging the fixed bed 25 for a long period of time without clogging the through holes 27.

FIG. 4 shows another example of the bipolar fixed-bed type electrolytic cell of the present invention. The electrolytic cell is a fixed bed of the electrolytic cell of FIG.
A mesh-like insoluble metal electrode 28 is placed in close contact with the power supply cathode terminal 24 on the side of the power supply cathode terminal 24, that is, on the side to be positively polarized, and instead of the large number of small-diameter through holes 27 in FIG. A relatively large through hole 30a near the left edge of 29a
A relatively large diameter through hole near the right edge of the middle fixed floor 29b.
30b has a relatively large diameter through hole 30c formed near the left edge of the lowermost fixed floor 29c, and the other members are the same as those in FIG. .

The fixed beds 29a to 29c to which a DC voltage is applied are most strongly polarized at both ends, and when gas is generated, gas is easily generated at both ends. Therefore, the fastest and most intense oxidation reaction and the dissolution reaction of the electrode base material take place at the ends of the fixed beds 29a to 29c, which are the most strongly anodic polarized, that is, generate the most intense oxygen gas, toward the power supply cathode terminal 24. As shown, the insoluble metal electrode 28
Is installed, most of the oxygen gas is generated from the insoluble metal electrode 28 because the oxygen generating overvoltage of the insoluble metal electrode 28 is lower than the overvoltage of the carbon-based material forming the fixed beds 29a to 29c. Ｃc hardly comes into contact with oxygen gas, so that the dissolution of the fixed beds 29a〜c is effectively suppressed. The water to be treated supplied to the electrolytic cell 22 is treated in the same manner as in the case of FIG. 3, but the through holes 30a to 30c formed in the fixed beds 29a to 29c have the uppermost and lowermost fixed beds 29a. And c are formed near the left edge, and the middle fixed floor 29b is formed near the right edge, so that the water to be treated passes through the through holes 30a to 30a.
Even if only c flows, the water to be treated flows laterally between the adjacent fixed beds 29a to 29c and contacts the upper and lower surfaces of the fixed beds 29a to 29c, so that the treatment is reliably performed.

[0022]

EXAMPLES Examples of the treatment of water to be treated using the apparatus of the present invention are described below, but the examples do not limit the present invention.

Example 1 Transparent rigid polyvinyl chloride resin height 25
The electrolytic cell 22 shown in FIG. 3 which is a cylinder having a diameter of 0 mm and an inner diameter of 205 mm and shown in FIG. 3 was installed close to the heat exchanger, and six electrolytic cell and heat exchanger systems were prepared.

In the electrolytic cell, a porous fixed bed (manufactured by Tokai Carbon Co., Ltd.) having a diameter of 200 mm and a thickness of 10 mm made of carbon fiber formed with 0 to 200 through-holes having a hole diameter of 3 mm.
Each piece is sandwiched between 11 polyethylene resin membranes having an aperture ratio of 80% and having a diameter of 205 mm and a thickness of 5 mm. Platinum is plated on the upper and lower ends of the membrane by platinum on the surface thereof, each having a diameter of 200 mm and a thickness of 1 mm. The mesh-type power supply anode terminal and the power supply cathode terminal were placed in contact with each other.
The cooling water for the heat exchanger is supplied to the electrolytic cell at a rate of 50 liters / minute, and a DC constant voltage of 60 V is applied between the power supply electrode terminals. The general bacterial colonies in the water to be treated before and after the electrolytic treatment were cultivated by a direct smear method using a standard agar medium, and the number of colonies was measured by changing each electrolytic bath as shown in Table 1. The results are shown in Table 1.

[0024]

[Table 1]

From Table 1, when a fixed bed having 10 to 200 3 mm-diameter through-holes is used, that is, the total cross-sectional area of the through-holes is defined by the cross-section of the three-dimensional porous electrode perpendicular to the flow direction of the water to be treated.
It can be seen that a low bacterial count can be maintained for a long period of time when the content is 0.05 to 5.0%. If the number of through-holes is zero, clogging of the fixed bed occurs, so that it is estimated that sterilization cannot be performed after one month because the water to be treated cannot contact the fixed bed. If the number of cells is 300, that is, if it is 5.0% or more, the clogging of the fixed bed begins to occur over time, and the water to be treated flows only through the holes and does not come into contact with the fixed bed. It is estimated that the number will increase.

[0026]

Example 2 The number of through holes formed in the fixed bed number was fixed to 25, and the hole diameter was 1 mm, 2 mm, 3 m as shown in Table 2.
The water to be treated was treated under the same conditions using the same electrolytic cell as the electrolytic cell of Example 1 except that m, 5 mm and 20 mm were used. The results are shown in Table 2.

[0027]

[Table 2] From Table 2, it can be seen that the electrode cross- section of the total cross-sectional area of the through hole formed in the fixed floor is shown.
It can be seen that the ratio to the area is desirably 0.05 to 5.0%.

[0028]

Example 3 The number of through holes formed in the fixed bed was fixed to one, and the hole diameters were 5 mm, 20 mm, 40 mm and 40 mm as shown in Table 3.
The treatment of the water to be treated was carried out under the same conditions using the same electrolytic cell as in Example 1 except that the fixed bed was 60 mm and the through holes in the fixed bed were arranged in a staggered manner (see FIG. 4). Was. Table 3 shows the results.

[0029]

According to the present invention, there is provided a fixed-bed type three-dimensional electrode type electrolytic cell provided with a three-dimensional porous electrode for contacting water to be treated containing microorganisms to perform an electrochemical treatment of the water to be treated. 3. The fixed-bed type three-dimensional electrode type electrolytic cell according to claim 1, wherein a through-hole communicating the upstream side and the downstream side of the electrode is formed in the three-dimensional porous electrode. When the water to be treated is subjected to electrolytic sterilization using a normal fixed-bed type three-dimensional electrode-type electrolytic cell, the three-dimensional electrode is porous, and dead microorganisms generated by sterilization close the micropores of the electrode. It causes clogging and inhibits contact between the microorganisms and the electrodes, greatly reducing sterilization efficiency.

[0030]

[Table 3]

On the other hand, in the fixed-bed type three-dimensional electrode type electrolytic cell of the present invention having the above-described structure, a through-hole is formed in the fixed-bed type three-dimensional electrode in the flow direction of the water to be treated. Due to the presence of the through-hole, the resistance of the water to be treated passing through the fixed-bed type three-dimensional electrode is reduced, and the water to be treated flows through the through-hole at a relatively high speed, and the dead microorganisms generated in the through-hole. Therefore, clogging of the through hole hardly occurs. Although the through-holes reduce the efficiency of contact between the microorganisms and the electrodes, they can avoid disassembly and assembly of the electrolytic cell and clogging of the electrodes which requires a new fixed-bed type three-dimensional electrode. In other words, the fixed-bed type three-dimensional electrode type electrolytic cell of the present invention prevents clogging of the electrode by partially sacrificing the contact efficiency between the water to be treated and the electrode.

The through-hole has a cross-sectional area of 0.05% of the cross-sectional area of the three-dimensional porous electrode perpendicular to the flow direction of the water to be treated.
Particularly desirable results can be obtained when it is set to ~ 5.0% (claim 2). When a bipolar fixed bed type three-dimensional electrode type electrolytic bath is used as the electrolytic bath (claim 3), the surface area of the fixed bed becomes enormous, and the processing efficiency is dramatically increased.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view showing an example of a monopolar fixed-bed electrolytic cell that can be used as an electrolytic cell of the present invention.

FIG. 2 is a schematic longitudinal sectional view showing another example of a monopolar fixed-bed electrolytic cell that can be used as the electrolytic cell of the present invention.

FIG. 3 is a schematic longitudinal sectional view showing an example of a bipolar fixed-bed type electrolytic cell that can be used as the electrolytic cell of the present invention.

FIG. 4 is a schematic longitudinal sectional view showing another example of a bipolar fixed-bed electrolytic cell that can be used as the electrolytic cell of the present invention.

[Explanation of symbols]

3 ・ ・ ・ Electrolyzer main body 4 ・ ・ ・ Fixed floor type 3D cathode 5
・ ・ ・ Through hole 6 ・ ・ ・ anode 13 ・ ・ ・ electrolyzer main body 15
・ ・ ・ Fixed bed type three-dimensional cathode 17 ・ ・ ・ Through hole 22 ・ ・ ・ Electrolyzer main body 25 ・ ・ ・ Fixed floor 27 ・ ・ ・ Through hole
29a-c: fixed floor 30a-c: through hole

────────────────────────────────────────────────── (5) References JP-A-4-18980 (JP, A) JP-A-4-78486 (JP, A) US Patent 3,910,962 (US, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) C02F 1/46 C02F 1/48 C25B 9/00 C25B 11/00

Claims (3)

(57) [Claims] 1. A fixed-bed type three-dimensional electrode type electrolytic cell provided with a three-dimensional porous electrode for contacting water to be treated containing microorganisms to perform electrochemical treatment of the water to be treated, A fixed-bed three-dimensional electrode type electrolytic cell, wherein a linear through-hole communicating the upstream side and the downstream side of the electrode is formed in the original porous electrode. 2. The fixed bed type three-dimensional electrode type electrolysis according to claim 1, wherein the total cross-sectional area of the through-hole is 0.05 to 5.0% of the cross-sectional area of the three-dimensional porous electrode perpendicular to the flow direction of the water to be treated. Tank. 3. The electrolytic cell according to claim 1, wherein the electrolytic cell is a bipolar fixed bed type three-dimensional electrode type electrolytic cell.