JPH03224681A - Electrochemical treatment of liquid to be treated - Google Patents

Abstract

PURPOSE:To efficiently sterilize pool water, etc., and to improve performance by supplying liquid to be treated to a double electrode type three-dimensional electrode type electrolytic cell at >=1/hour space velocity and bringing the liquid to be treated into contact with three-dimensional electrodes, thereby making the electrochemical treatment of the liquid. CONSTITUTION:The rear surfaces of respective fixed beds 5 are polarized positive and the front surfaces negative and a potential is generated in and between the fixed beds 5 when the electrodes are energized while the pool water or washing water for paper making or the like is supplied from below to the electrolytic cell as shown by arrows. The pool water or the like flowing in the electrolytic cell comes into contact with the fixed beds 5 polarized positive or negative by this potential, by which the reforming treatment, such as sterilizing of underwater fungi and bacteria, in the pool water, etc., is executed. This water is taken out of the upper part of the electrolytic cell. to be inoculated in the pool, etc. Plural pieces of the fixed beds 5 are laminated between an anode 3 for power feeding and a cathode 4 for power feeding and the respective fixed beds 5 are tightly adhered to the inside walls of the electrolytic cell body 2.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an electrochemical treatment method for sterilizing and improving the performance of water used in relatively large amounts, such as pool water and paper processing water. In detail, the pool water and paper manufacturing water that require carpenter's water treatment are electrochemically treated using a three-dimensional electrode type electrolytic cell suitable for large-volume water treatment, thereby sterilizing and improving performance. Regarding the method for.

(Prior Art) Swimming, the most common summer sport, remains popular and is enjoyed by people of a wide range of age groups. Pools are now being used to enjoy swimming, rather than having to travel to remote beaches.

The pool water used for this pool is inhabited by a large number of bacteria that are harmful to the human body, and the pool water can cause diseases if it comes into direct contact with the eyes of users. In order to prevent the occurrence of diseases, chemicals are introduced and sterilized in advance.However, chlorine-based reagents such as hypochlorous acid and trihalomethane, which have a strong sterilizing effect, are used as the chemicals.The chlorine The system reagents themselves or their decomposition products are irritating, and even if the reagents have a sterilizing effect, they can cause side effects such as eye pain and skin irritation, especially for young children who have a weak immune system. In addition, the amount of pool water used in the boules is enormous, and the cost of the chemicals used is also a big burden.

Furthermore, with the recent development of the information society, the demand for various types of paper, especially high-quality paper, is increasing. This paper is manufactured from a papermaking valve through various processes, including a step of cleaning the valve before papermaking to wash away unnecessary components. Since the bulb is maintained at a moderate temperature and contains proper nutrients,
Mold and bacteria easily breed, and if large amounts of mold and bacteria remain in the final product, performance deterioration such as discoloration of the paper will occur. Therefore, the enormous amount of washing water used in this washing process contains antifungal agents and bactericidal agents to prevent deterioration of the performance of the final product as much as possible. However, with this method, not only does the cost of the anti-mold agent and bactericide increase, but also the anti-mold agent and bactericide remain in the product, causing performance deterioration that is different from the deterioration caused by mold and bacteria. The problem is that it can sometimes occur.

(Problems to be Solved by the Invention) As described above, the conventional method for sterilizing and preventing mold from water that is used in large quantities, such as pool water and paper washing water, involves the injection of chemicals. Since a large amount of chemicals are required, the treatment cost is enormous, and the chemicals added may remain in the treated water, causing problems other than mold and bacteria. There is a need for a water treatment method that does not rely on water. Furthermore, in addition to the pool water and paper manufacturing washing water, there are many liquids to be treated that are used in relatively large quantities and require sterilization.

(Objective of the Invention) An object of the present invention is to provide an electrochemical method capable of processing a large amount of liquid to be processed relatively easily and without using chemicals.

(Means for Solving the Problems) The present invention supplies a liquid to be treated to a bipolar three-dimensional electrode type electrolytic cell at a space velocity of 1/hour or more, and brings the liquid to be treated into contact with the three-dimensional electrode. This is an electrochemical treatment method for a liquid to be treated. In addition, in the present invention, since an electrochemical reaction such as a substantial redox reaction may not occur on the electrode surface, the tank used in the method of the present invention should be called an electrochemical processing device, but the general name is Accordingly, it is called an electrolytic cell.

The present invention will be explained in detail below.

The present invention involves supplying a liquid to be treated that requires sterilization, such as pool water or paper manufacturing washing water, to a two-dimensional electrode type electrolytic cell at a space velocity of 1/hour or more, applying a voltage to the electrolytic cell, and performing electrolysis. This method is characterized in that the pool, paper manufacturing washing water, etc. are sterilized with or without gas. Although the reason why pool water or the like is modified by the voltage application is not necessarily clear, it can be inferred as follows.

Paper manufacturing washing water has an appropriate temperature and appropriate nutrients, so it is an environment where mold and bacteria can easily breed, and pool water and other treated liquids that are the subject of the present invention also contain many bacteria such as Escherichia coli. is inhabited.

According to the present invention, when a voltage is applied to pool water, paper manufacturing washing water, etc., mold and bacteria in the pool water, etc. are transferred to the anode and cathode of a three-dimensional electrode electrolytic cell, or to the tertiary electrodes such as dielectrics and particles described later. It is thought that when it comes into contact with the original electrode, it undergoes a strong oxidation reaction on the surface, which weakens its activity or kills itself. Therefore, it is possible to produce the same bactericidal or antifungal effect without using conventional bactericidal or antifungal agents.

In the present invention, the single electrolytic sliding voltage applied between the anode and cathode is IV
Electrolytic treatment in which the voltage is preferably 7 V or less, and a current flows according to the voltage value and gas generation occurs on the electrode surface;
Alternatively, sterilization can be performed by electrochemical treatment, which does not involve the flow of current and does not generate gas on the electrode surface.
When carrying out the method of the present invention, it is desirable to conduct the electrolytic treatment while passing an electric current and generating a small amount of gas in order to confirm that the treatment is actually being carried out efficiently.

The sterilization efficiency of the liquid to be treated depends on the contact efficiency of the cough liquid to the electrode, but when sterilizing a relatively large amount of liquid to be treated, conventional plate-shaped or porous electrodes may be used. The surface area of the electrode is not large enough, making it impossible to achieve satisfactory sterilization efficiency. Therefore, in the present invention, a relatively large layer of the liquid to be treated, that is, a liquid supplied to the electrolytic cell at a space velocity of 1/hour or more, is difficult to achieve. The treatment solution is processed using a three-dimensional electrode with a very large surface area.
A three-dimensional electrode type electrolytic cell having electrodes is used to sterilize the relatively large amount of liquid to be treated with high efficiency.

The space velocity in the present invention is [supply rate of liquid to be treated (ff
/hour)] ÷ [Volume of electrolytic cell (7 ri)], and in the present invention, a space velocity of 1 or more means that an amount of treated material equal to or greater than the volume of the electrolytic cell can be electrolyzed in one hour. It means that it is supplied to the tank.

The gases generated by water electrolysis, that is, oxygen gas and hydrogen gas, are usually generated at a mixing ratio within the explosive limit, so it is desirable to dilute them with an inert gas such as air to avoid the risk of explosion. It is possible to install means for separating the electrolytic gas generated during the separation and means for diluting the separated TL electrolytic gas with air so that the electrolytic gas concentration becomes 4% by volume or less.

The water treated by the present invention is pool water, paper manufacturing washing water, etc., and since these need to be treated in large amounts, the amount of electricity required for treatment often accounts for a large portion of the treatment cost.

The amount of power is expressed as C power] = [voltage] x [current], and T
When the L flow does not flow and no gas is generated, the amount of electric power is small, but if a current flows that causes gas to be generated, the amount of water to be treated is enormous, so the amount of power consumed is also enormous. Therefore, it is important to perform electrochemical processing that does not involve gas generation as much as possible in order to reduce power consumption.

The electrolysis voltage in a normal electrolytic cell is [voltage drop due to resistance between the anode terminal and anode] 10 [theoretical electrolysis voltage of the anode] + [overvoltage of the anode] ]−←[Theoretical electrolysis voltage of cathode]−←[
Cathode overvoltage] + [voltage drop due to resistance between cathode terminal and cathode] Of these, the theoretical electrolytic voltage and overvoltage do not change, and the resistance between the terminal and the electrode can be reduced by making the conductor thicker, but this is not an effective method, and the only way to reduce the electrolytic voltage is to It is most desirable to reduce the electrolytic sliding voltage. There are methods to reduce the single electrolytic sliding voltage, such as increasing the conductivity of the solution and reducing the distance between the two electrodes. It is not realistic to raise it. Therefore, in the present invention, it is preferable to reduce the distance between the two electrodes to reduce the single electrolytic sliding voltage.

The electrolytic cell used in the present invention is a bipolar fixed bed three-dimensional electrode electrolytic cell. Since the amount of water to be treated in the present invention is enormous, for example, several tons per hour, it is essential to use a bipolar fixed bed electrolytic cell that has a high processing capacity per unit volume. When used, the contact area with pool water, paper manufacturing washing water, etc. to be treated can be increased.
This is advantageous in that the device size can be reduced and the efficiency of electrolysis can be increased.

The three-dimensional electrode in the three-dimensional electrode electrolytic cell of the present invention is made of a porous material through which the pool water, paper manufacturing washing water, etc. can permeate, such as granular, spherical, felt, woven fabric, porous block, or a large number of porous materials. Carbon-based materials such as activated carbon, graphite, carbon fiber, etc. that have the shape of a solid body with through holes, or metal materials such as nickel, copper, stainless steel, iron, titanium, etc. that have the same shape, and precious metals in these metal materials. Preferably, the two-dimensional electrode is made of a plurality of dielectric bodies made of a material coated with A direct current voltage is applied between the anode and cathode for power supply made of a porous plate body, etc. to polarize the dielectric, and positive and negative charges are formed at one end and the other end of the dielectric, respectively, and the dielectric is polarized. In addition to this, R
Is it possible to install and electrically connect three-dimensional materials that can function alternately so that they do not short-circuit? It can be made into an electrode type fixed bed electrolytic cell. In addition, when using the aforementioned solid body with a large number of through holes as a three-dimensional electrode, what happens? , +L, so as not to obstruct the movement of pool water, etc. passing through, the porosity ratio should be 10% or more and 95% or less, preferably 20% or more and 80% or less, and a
It is preferable that the size of the through hole is a micropore having a diameter that allows the liquid to be treated to pass therethrough.

When a carbon-based material such as activated carbon, graphite, or carbon fiber is used as the dielectric and pool water is treated while generating oxygen gas from the anode, the dielectric is oxidized by the oxygen gas and dissolved as carbon dioxide. It becomes easier to do. To prevent this, a platinum group totally flexible oxide such as iridium oxide or ruthenium oxide is coated on a base material such as titanium on the anodic polarization side of the dielectric, and a porous material is usually used as an insoluble totally flexible electrode. The materials may be placed in contact such that oxygen evolution occurs primarily on the porous material.

When it is intended to lower the voltage by bringing the anode and cathode close to each other between the dielectric material or the power feeding anode and cathode, an electrically insulating spacer such as an organic polymer material may be used to prevent short circuits.
It is preferable to insert a net-like spacer or the like made in .

If there is a relatively large gap in the electrolytic cell through which the pool water, etc. to be treated flows, through which the pool water, etc. can flow without coming into contact with the dielectric, the anode or the cathode, the treatment efficiency of the pool water, etc. will decrease. It is desirable that the dielectric material etc. be arranged so that the flow of pool water, etc. in the electrolytic cell does not take a short path.

An electrolytic cell with such a configuration is located close to the pool.
Alternatively, it can be installed at important points in the paper manufacturing process or other processes to circulate part of the pool water and return it to the pool after being sterilized in the electrolytic cell, or to circulate all or part of the paper manufacturing washing water, etc. After the treatment in the electrolytic bath! I! It can be used as washing water in paper processing.

Note that if the pool water, etc. supplied to the electrolytic cell is a laminar flow, it may pass through the electrolytic cell without making sufficient contact with the surface of the dielectric material, etc. It is preferable that the turbulent flow has a Reynolds number of 500 or more and is passed through the electrolytic cell while sufficiently moving in the lateral direction.

In addition, in the electrolytic cell of the present invention, a leakage current occurs in the electrolytic cell, and the leakage current T flows from the electrolytic cell through pool water to be treated, paper manufacturing washing water, etc., to metallic members of the pond, such as the inner wall of the pool, and various parts of the paper manufacturing process. It may flow into the tank or the like, causing electrochemical corrosion such as elution to the members or electrocuting pool users.

Therefore, a member with higher conductivity than pool water, etc. is installed at the back of the electrode where the power feeding anode and cathode do not face each other in the electrolytic cell and/or in the inlet/outlet piping of the electrolytic cell so that one end thereof can be grounded. Leakage current can be cut off.

Next, a preferred example of an electrolytic cell that can be used in the present invention will be described based on the accompanying drawings, but the electrolytic cell used in the method of the present invention is not limited to this electrolytic cell.

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

A mesoche-shaped power feeding anode 3 and a power feeding cathode 4 are provided near the upper and lower ends of a cylindrical electrolytic cell body 2 having flanges 1 on the upper and lower sides, respectively. Electrolytic cell body 2
is preferably made of an electrically insulating material that can withstand long-term use or reuse, and is particularly made of synthetic resins such as polyevik-1 corhydrin and polyvinyl methacrylate-1.
, polyethylene, polypropylene, polyvinyl chloride, polyethylene chloride, phenol-formaldehyde resin, etc. can be preferably used. The power feeding anode 3 that provides a positive DC voltage is made of, for example, a carbon material (such as activated carbon, charcoal, coke, coal, etc.), a graphite material (such as carbon fiber, carbon cloth, graphite, etc.), or a carbon composite material (such as carbon and metal). (mixed and sintered in powder form, etc.), activated carbon fiber nonwoven fabric (e.g. K E-1000 felt, Toyobo Co., Ltd.), or materials in which this supports platinum, platinum, baradium, or nickel, and dimensionally stable electrodes. (platinum group oxide coated titanium material), platinum coated titanium material, nickel material, stainless steel material, iron material, etc. The power supply cathode 4, which faces the power supply opening 3 and receives a negative DC voltage, is coated with, for example, platinum, stainless steel, titanium, nickel, Hastelloy, Grapheye I, carbon material, mild steel, or platinum group metal. It is formed from a metal material or the like.

A plurality of fixed beds 5, three in the illustrated example, are stacked between the repowering electrodes 3.4, and between the fixed beds 5 and between the fixed beds 5 and the repowering electrodes 3.4. Four porous diaphragms or spacers 6 are sandwiched between them. Each fixed bed 5
is placed in close contact with the inner wall of the electrolytic cell main body 2 so as not to pass through the inside of the fixed bed 5, and so that the leakage flow of the photographic processing solution flowing between the fixed bed 5 and the side wall of the electrolytic cell main body 2 is minimized. There is. When a diaphragm is used, a woven fabric, an unglazed plate, a particle sintered plastic, a porous plate, an ion exchange membrane, etc. are used as the diaphragm, and a woven fabric, a perforated plate, or a mesh made of an electrically insulating material are used as the spacer. , rod-shaped materials, etc. are used.

When the electrolytic cell configured as described above is energized while supplying pool water, paper manufacturing washing water, etc. from below as shown by the arrow, each of the fixed beds 5 is polarized with the lower surface being positively polarized and the upper surface being negatively polarized as shown in the figure. As a result, a potential is generated within the fixed bed 5 and between the fixed beds 5, and the pool water flowing through the electrolytic cell comes into contact with the fixed bed 5, which is polarized positively or negatively due to this potential, and mold and other substances in the pool water are generated. After undergoing a reforming process such as sterilization of bacteria, the pool water is taken out from above the electrolytic cell, and the sterilized pool water is circulated into the pool. ! If paper slag is purified water, it will be supplied to the paper manufacturing process.

FIG. 2 shows another example of a bipolar fixed bed electrolytic cell that can be used in the present invention. A mesoche-like insoluble metal material 7 is installed in close contact with the side to be positively polarized, and since the other members are the same as those in FIG. 1, they are given the same reference numerals and their explanation will be omitted.

The fixed bed 5 to which a DC voltage is applied is most polarized at both ends thereof, and when gas is generated, the most intense gas generation occurs at both ends. Therefore, dissolution occurs fastest at the end of the fixed bed 5 facing the power supply cathode 4 where the polarization is strongest, that is, where oxygen gas is most intensely generated. As shown in the figure, if the insoluble metal material 7 is installed in this part, most of the oxygen gas will be removed from the insoluble metal material 7 because the overvoltage of the insoluble metal material 7 is lower than the overvoltage of the carbon-based material forming the fixed bed 5. Since the fixed bed 5 hardly comes into contact with oxygen gas, the dissolution of the fixed bed 5 is effectively suppressed. Moreover, the pool water etc. supplied to the electrolytic cell 2 is treated and sterilized in the same manner as in the case of FIG.

FIG. 3 shows another example of a bipolar fixed bed electrolytic cell that can be used in the present invention.

A mesoche-shaped power feeding anode 13 and a power feeding cathode 14 are provided near the upper and lower ends of the cylindrical electrolytic cell body 12 having flanges 11 on the upper and lower sides, respectively. The electrolytic seed book (*12) is preferably made of an electrically insulating material, especially synthetic resin, that can withstand long-term use or repeated use.

Between the repowering electrodes 13 and 14, there are a large number of fixed bed forming particles 15 made of a conductive material such as a carbon-based material and a smaller number of insulating particles 18 made of synthetic resin, for example, than the fixed bed forming particles 15. are almost evenly mixed. The insulating particles 18 have a function of preventing the power feeding anode 13 and the power feeding cathode 14 from being completely short-circuited.

When an electric current is supplied to the electrolytic cell constructed as shown in FIG. 1 while supplying pool water, paper manufacturing washing water, etc. from below as shown by the arrow, each of the fixed bed forming particles 15 is caused to have an anode 13 side facing negative. The power supply negative Ifi 14 side is positively polarized and functions as a three-dimensional electrode with a huge surface area, and can be used for modification such as sterilization of mold and fine particles in the pool water etc. in the same manner as the electrolytic cells shown in Figs. 1 and 2. After treatment, it is removed from the top of the electrolytic cell.

(Example) Examples of the treatment liquid modification treatment according to the method of the present invention will be described below, but the examples are not intended to limit the present invention.

The electrolytic cell shown in Figure 1, which is made of transparent hard polyvinyl chloride resin and has a flanged cylindrical shape with a height of 600 fins and an inner diameter of 500 μ, is installed in front of the equipment that filters and cleans the pool water and returns it. did. Inside the electrolytic cell, a diameter 500 shaft made of carbon fiber,
30 fixed beds with a thickness of 101 m, with an opening ratio of 80% and a diameter of 5
It is sandwiched between 31 polyethylene resin diaphragms with a diameter of 480 mm and a thickness of 1.00 fins and a thickness of 1.2 m, and the upper and lower membranes are made of titanium with platinum coated on their surfaces.
, 0 mm mesoche-like power feeding anode and power feeding cathode were placed in contact with each other.

Pool water was supplied to the electrolytic cell at a rate of 5 tons/min (space velocity approximately 2560/hr), and the electrolytic voltage shown in Table 1 was applied between the electrodes to treat the pool water. Table 1 summarizes the presence or absence of gas generated by visual observation during the treatment operation, the number of bacteria in the pool water around 1 m of the electrolytic cell, and the amount of power consumed.

From Table 1, it can be seen that the number of bacteria in pool water is significantly reduced by treatment with an electrolytic cell, regardless of the magnitude of electrolysis voltage. It is also understood that when the electrolytic voltage per tank is about 2 V, a small amount of gas is generated and the power consumption does not become very large.

After 30 mouths had elapsed, 1J11 TL was stopped, the electrolytic cell was disassembled, and the state of the fixed bed was observed, and no change was observed in the electrolytic cell.

1. Using the electrolytic cell body and power supply cathode of Example 1, graphite particles with a particle size of 5 to 10 nv+ and insulating particles made of hard polyvinyl chloride resin with a particle size of 5 to 10 mm are placed between the power feeding TL electrodes. The electrolytic cell shown in FIG. 3 was constructed by filling mixed particles uniformly mixed at a weight ratio of 4:1.

This electrolytic cell is installed close to the paper manufacturing process, and paper manufacturing washing water before use is supplied to the electrolytic cell under the same conditions as in Example 1.
As in Example 1, the presence or absence of generated gas was visually observed during the treatment, and the number of bacteria and power consumption in the paper washing water before and after passing through the electrolytic bath were measured, and the results are summarized in Table 2.

From Table 2, it can be seen that the number of bacteria in the paper washing water is significantly reduced by treatment in the electrolytic bath, regardless of the magnitude of the electrolytic voltage. It is also understood that when the electrolytic voltage per tank is about 2V, a small amount of gas is generated and the power consumption does not increase so much.

Using the electrolytic cell of Example 1 in Table 1, the number of dead cells, electrolysis voltage, and power consumption of the pool water were measured by varying the supply layer of pool water to the electrolytic cell, that is, the space velocity. The results are summarized in Table 3. The number of bacteria in the pool water used before passing through the electrolytic tank was 32,150 per liter! The amount of gas generated was very small in each boule water treatment.

From Table 3, sterilization is defeated at a space velocity of 1/hour. 3 table No. table It can be seen that there is a significant change in sterilization efficiency.

The paper washing water was sterilized under the same conditions as in Example 3 except for the supply rate and space velocity shown in Table 4. The results are shown in Table 4.

In the case of this example, as in Example 3, it can be seen that there is a large change in the number of sterilizations, that is, the sterilization efficiency, when the space velocity reaches 1/hour.

Using the electrolytic cell of Example 1, the space velocity was fixed at 37.5/hour, and the pool water (the number of bacteria before passing through the electrolytic cell was 34/m1).
) was supplied to the electrolytic cell, the electrolysis voltage was varied, and the influence of the voltage change on the amount of generated gas, sterilization efficiency, and deterioration status of the anode was investigated. The results are summarized in Table 5.

As is clear from Table 5, if the electrolysis voltage per single electrolytic cell is less than 1V, the sterilization efficiency will be greatly reduced, and if it exceeds 7V, the deterioration of the anode will be significant. The electrolytic voltage is preferably 1 to 7 cm.

Table (Effects of the Invention) The method of the present invention involves supplying a liquid to be treated, which requires a relatively large amount of water treatment, to a bipolar three-dimensional electrode type electrolytic cell, and contacting the liquid to be treated with the three-dimensional electrode. There is also an electrochemical treatment method for a liquid to be treated in which the liquid to be treated is treated electrically.

For example, in the case of swimming pool water (Claim 2) and paper manufacturing washing water (Claim 3), where a huge amount of false processing occurs, bipolar electrodes have a high processing capacity per unit volume, which makes it possible to downsize the electrolytic cell and reduce the installation area. According to the type three-dimensional electrode type electrolytic cell, processing, especially sterilization, can be carried out efficiently without using conventional sealants or V'J fungicides, which can save a huge amount of costs for processing chemicals. Moreover, the inconvenience caused by the chemical remaining in treated pool water can be avoided. In particular, in the method for treating a liquid to be treated according to the present invention, there is a large difference in sterilization efficiency depending on the space velocity of the liquid to be treated, and the critical value is around 1/hour. It becomes possible to sterilize the liquid to be processed more efficiently each time it is supplied and processed.

The voltage value per electrolytic cell affects the processing efficiency, and if the voltage is less than IV, sufficient sterilization efficiency cannot be obtained, and 7v
If the voltage exceeds the voltage, gas generation becomes noticeable and the positive FW deteriorates, so it is desirable that the voltage is in the range of IV to 7cm (Claim 4).

The method of the present invention may or may not involve gas generation on the three-dimensional electrode, but confirmation that the electrochemical treatment of the present invention is actually being performed can be done by observing gas generation with the naked eye. be. Therefore, in the present invention, it is preferable to apply a voltage of such an extent that a certain amount of gas is generated. However, the method of the present invention targets liquids to be treated that require relatively large amounts of treatment, and the power consumption (1) is 1.5% compared to the amount of gas generated. ; Since it is proportional to I', it is desirable to suppress the generated gas l as much as possible.

Furthermore, the electrolytic gas generated in the present invention is a mixed gas of oxygen gas and hydrogen gas within the explosive limit, and there is a risk of explosion if the process is carried out in a closed system. Therefore, by providing means for separating the gas generated by electrolysis and means for diluting the separated gas near the outlet of the electrolytic cell, it is possible to avoid the danger of explosion (Claim 6).

In addition, leakage TL flow may occur in the electrolytic cell of the present invention,
The leakage current flows from the electrolytic tank through the pool water to be treated and paper manufacturing washing water into the inner walls of the pool and into various tanks in the paper manufacturing process, causing electrochemical corrosion such as elution to the components and harming pool users. may cause electric shock. In order to avoid this, it is possible to ground one end of a member that is more conductive than pool water, etc., on the back of the electrode where the power feeding anodes and cathodes in the electrolytic cell do not face each other, and/or in the inlet and outlet piping of the electrolytic cell. The leakage current can be cut off by installing it as follows (Claim 7).

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a bipolar fixed bed electrolytic cell that can be used as the electrolytic cell of the present invention, and FIG. 2 is a longitudinal sectional view showing an example of another bipolar fixed bed electrolytic cell. FIG. 3 is a vertical cross-sectional view showing an example of yet another bipolar fixed bed electrolytic cell. 1.11...Flange 2.12...Electrolytic cell body 3.1
3...Anode for power supply 4.14...Cathode for power supply 5...Fixed bed 6...Spacer 7...Insoluble metal material 15...Particles for forming fixed bed 18...Insulating particles Part 1 Part 2 figure

Claims (1)

[Scope of Claims] (1) A liquid to be treated is supplied to a bipolar three-dimensional electrode type electrolytic cell at a space velocity of 1/hour or more, and the liquid to be treated is brought into contact with the three-dimensional electrode to electrochemically An electrochemical treatment method for a liquid to be treated. (2) The method according to claim 1, wherein the liquid to be treated is pool water. (3) The method according to claim 1, wherein the liquid to be treated is papermaking treated water. (4) The method according to any one of claims 1 to 3, wherein the single electrolytic sliding voltage between the anode and cathode of the three-dimensional electrode electrolytic cell is 1 V or more and 7 V or less. (5) The liquid to be treated is treated while applying a voltage between the anode and cathode of the three-dimensional electrode type electrolytic cell to generate oxygen gas at the anode and hydrogen gas at the cathode. the method of. (6) The method according to any one of claims 1 to 5, wherein an electrolytic cell is used, which is provided near the outlet with means for separating gas generated by electrolysis and means for diluting the separated gas. (7) A member with higher conductivity than the liquid to be treated can be grounded at one end on the back of the power supply electrode where the power supply anode and cathode in the three-dimensional electrode type electrolytic cell do not face each other and/or inside the inlet and outlet piping of the electrolytic cell. The method according to any one of claims 1 to 6, wherein the method is carried out by installing the method in a.