JPH0686981A - Electrolytic treatment of water containing microb - Google Patents

Abstract

PURPOSE:To sterilize water completely and provide drinking water which contains an effective chlorine component in excessive of the set amount by bringing water containing microbs and an effective chlorine component into contact with a fixed bed type three dimensional electrode to carry out electrolytic treatment and sterilization and then bringing the resulting water into contact with a flat type electrode. CONSTITUTION:When water is supplied to a three dimensional electrode chamber 6 in an electrolytic bath from the lower side and electricity is applied to the electrode chamber, each fixed bed three dimensional electrode is polarized to positive in the lower side and negative in the upper side, a porous positive pole is formed in the lower side, the water is brought into contact with the porous positive pole, and thus sterilization of the microbes is carried out. Further, the water is brought into contact with the porous negative pole in the upper side to convert Ca, Mg, and iron ions into hydroxides which are precipitated and removed and to convert an effective chlorine component such as chlorine gas, etc., into chloride ion and the resulting water with scarcely containing microbes and effective chlorine component is supplied to a flat type electrode chamber 7 through a hole 4. In the flat type electrode chamber 7, the chloride ion produced in the three dimensional electrode chamber 6 is oxidized or reduced to chlorine gas and drinking water containing effective chlorine component which satisfies the standard of a regulation is taken out of a taking outlet 2.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to various kinds of water to be treated containing a microorganism and an effective chlorine component, in particular electrolytic treatment of the water to be treated in order to suppress various performance deteriorations caused by the microorganism in drinking water. Regarding the method, more specifically, only the effective chlorine component which is obliged to remain in the drinking water out of the microorganisms and effective chlorine components in the treated water such as the drinking water which is electrolytically treated with the treated water such as drinking water. And a method for providing clear drinking water and the like.

[0002]

2. Description of the Related Art Drinking water is supplied to households, restaurants, etc. through tap water after filtering the water stored in a water source such as a reservoir at a water purification plant and sterilizing it with a bactericide. The above-mentioned sterilization of drinking water is generally treated with chlorine gas, but sterilization of drinking water is relatively good according to the chlorine treatment, while foreign substances are mixed in the treated drinking water due to the influence of residual chlorine. It is also reported that such a discomfort occurs and the mellowness of natural water is impaired, or an organic chlorine compound represented by trihalomethane is generated, which is not preferable for human health. Drinking water is directly related to human health, and it is indispensable to sterilize bacteria contained therein and prevent the growth of mold, that is, kill most or all of microorganisms. Although the method using chlorine is the mainstream, sterilization methods other than the chlorine method have been proposed in order to eliminate the above-mentioned drawbacks of the chlorine method.

For example, a method has been proposed in which the drinking water is subjected to ozone addition treatment or activated carbon adsorption treatment to be reformed, but when the drinking water to be treated is, for example, water from a water purification plant, the treatment amount is enormous. Therefore, there are drawbacks such as not being economically viable. Further, even if treated at a water purification plant, there is a problem that the microorganisms will regenerate before reaching the end faucet. However, in tap water sterilization in urban areas, the raw water, such as river water and lake water, is contaminated with various organic substances, so it is necessary to add more chlorine than necessary for sterilizing microorganisms. The harmful effect of producing an organic halide etc. has arisen. In order to prevent these phenomena, conventionally, various chemicals such as antifungal agents and precipitation inhibitors have been put into the water to be treated and various filters have been installed in the middle of the piping. It has been pointed out that adverse effects on the water to be treated due to residual chemicals and problems in terms of the cost of using chemicals. Furthermore, there is a problem that antibacterial action against the added drug occurs after a while, and it becomes necessary to consider the next drug or supply a larger amount of drug than necessary. In addition, some drinking water is temporarily stored in a water storage tank or the like, such as water stored in a cup-type vending machine, and water is supplied as needed. This kind of drinking water may be stored in a storage tank for several days, and during this time, when the fungus propagates and is served for drinking, it may be unsuitable as drinking water.
However, such water storage does not take appropriate measures against the reproduction of the above-mentioned fungi, and soft drinks and the like that are unfavorable to human health may be sold or provided.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described above, drinking water such as tap water or stored water in a cup type vending machine may contain microorganisms. A method of sterilizing the drinking water by treatment has been proposed. According to this method, the microorganisms in the drinking water are sterilized at an efficiency of almost 100%, and the effective chlorine component often contained in the drinking water is also converted into chlorine ions, so that the so-called chlorine odor in the drinking water can be removed. It is an excellent method for treating drinking water and the like. However, according to the law, drinking water, especially tap water, must contain 0.1 ppm or more of available chlorine. When drinking water or the like is treated by the electrolysis, microorganisms are almost completely sterilized, and effective chlorine components are almost completely removed. Therefore, there is a problem that drinking water conforming to the law cannot be provided.

[0005]

It is an object of the present invention to solve the above-mentioned drawbacks of the prior art, to sterilize microorganisms almost completely, and to produce drinking water or the like containing an effective chlorine component of a predetermined value or more. It is an object of the present invention to provide a method for electrolytic treatment of.

[0006]

According to the present invention, the water to be treated containing a microorganism and an effective chlorine component is brought into contact with a fixed bed type three-dimensional electrode for electrolytic treatment to sterilize the microorganism, and thereafter This is an electrolytic treatment method for water to be treated containing microorganisms, which comprises treating the treated water by contacting it with a flat plate type electrode.

The present invention will be described in detail below. In the electrolytic treatment using the fixed bed type three-dimensional electrode according to the present invention, microorganisms in the water to be treated such as tap water can be sterilized to provide water to be treated containing almost no microorganisms. The effective chlorine components of are also converted into substances having no sterilizing power such as chlorine ions. Since microorganisms are not contained in the water to be treated, there is no problem even if there is no effective chlorine component, but the legal requirements stipulate that drinking water must contain a certain value or more of effective chlorine component. Therefore, even drinking water that is practically unproblematic cannot be used as it is in the general public. In the present invention, in order to solve this problem, treated water such as drinking water containing microorganisms and effective chlorine components is treated with a fixed bed type three-dimensional electrode and treated water containing no microorganisms and effective chlorine components. After that, the water to be treated is brought into contact with a flat plate type electrode to convert the residual chlorine ions into effective chlorine components having a prescribed value or more to provide drinking water or the like conforming to the law.

The microorganisms of the present invention include bacteria (bacteria), fungi, filamentous fungi (molds), Escherichia coli, yeasts, morphogens, unicellular algae, protozoa, viruses, etc. Chlorate ions, chlorine gas, etc. are included. Further, the water to be treated of the present invention is intended for drinking water to be ingested by the human body, food treatment water, water storage of a water supply device, etc. Including tap water, etc., the food treatment water includes water contained in washing water for fresh food and water-containing food such as tofu, etc., and the water in the water dispenser is stored in a cup-type vending machine, a lobby of a bank, Includes water storage for foot-operated water dispensers installed on platforms, trains, ships, etc. In the present invention, it is necessary that the microorganisms and effective chlorine components in the water to be treated are first brought into contact with the fixed bed type three-dimensional electrode and then with the flat plate type electrode. The fixed bed type three-dimensional electrode and the flat plate type electrode may be housed in the same electrolytic cell or installed in separate electrolytic cells, but in the former case, both electrodes are separated by an appropriate insulating member. It is necessary to prevent electrical short circuit.

When the water to be treated is brought into contact with the fixed bed type three-dimensional electrode, the microorganisms in the water to be treated come into contact with the fixed bed type three-dimensional electrode, that is, the dielectric and particles for forming fixed beds, which will be described later, by liquid flow. However, it is considered that a strong redox reaction is generated in the microbial cells by receiving high-potential energy supply on their surface, the activity is weakened, or the microorganisms themselves die and sterilization is performed. Simultaneous with the sterilization of the microorganisms, the effective chlorine components in the water to be treated are converted into chlorine ions on the cathode surface of the three-dimensional electrolytic cell. The hypochlorite ion, which is the main component of the effective chlorine component in the water to be treated, is converted into chlorine ion and water according to the following equation (1). ClO ⁻ + 2H ⁺ + 2e ⁻ → Cl ⁻ + H ₂ O (1)

In addition to the above-mentioned microorganisms and effective chlorine components, a small amount of ions such as calcium ions and magnesium ions and dissolved substances are present in the tap water as clusters having hydration water around them, and the hydration water is drinking water. It is one of the causes of losing the mellowness of the above. When the drinking water or the like is electrolytically treated by the method of the present invention, in addition to sterilization of microorganisms and decomposition of effective chlorine components, ions in the drinking water migrate or move at high speed in the liquid according to a potential gradient, and the clusters can move. Instead, the huge clusters are destroyed, or as described above, the ions having hydration water come into contact with the cathode side and are destroyed, and the number of the hydration water is greatly reduced, and the effect of modifying drinking water and the like is also produced. Further, calcium ions and magnesium ions also contribute to the taste of drinking water, but when the drinking water is subjected to the electrolytic treatment of the present invention, these ions are deposited on the cathode side as hydroxides or the like. Since it is removed from the drinking water, the taste of the drinking water is further improved. The electrode used for sterilizing microorganisms and decomposing effective chlorine components in the method of the present invention is a fixed bed type three-dimensional electrode, and since the electrode has a huge surface area, it increases the contact area between the electrode surface and the water to be treated. This is advantageous in that the device size can be reduced, and the efficiency of the electrolytic treatment can be increased. The fixed bed type three-dimensional electrode may be incorporated as a bipolar electrode in the electrolytic cell to form a bipolar electrode type electrolytic cell, or may be incorporated as a single electrode to configure a monopolar type electrolytic cell.

When the fixed bed type three-dimensional electrode in the method of the present invention is incorporated in an electrolytic cell, the electrolytic cell generally includes a power feeding electrode in addition to the three-dimensional electrode which causes a polarization phenomenon and functions as an electrode. Has a shape corresponding to the electrolytic cell used above, when using a fixed bed type bipolar electrode electrolytic cell,
A porous material that is permeable to the water to be treated, for example, activated carbon having a shape such as granular, spherical, felt-like, woven cloth-like, porous block-like, carbon-based material such as graphite, carbon fiber, or the like. A metal material having nickel, copper, stainless steel, iron, titanium or the like, and a plurality of preferably granular, spherical, fibrous, felt-like, woven cloth-like, formed from a material obtained by applying a coating of a noble metal to these metal materials. A DC voltage is applied between the power supply electrodes consisting of a porous block, porous plate, or sponge-like dielectric placed in a DC electric field, and flat plates, expanded mesh, or perforated plates installed at both ends. Or 10
A fixed bed type bipolar electrode electrolytic cell containing a three-dimensional electrode formed by applying an AC voltage of Hz or less to polarize the dielectric and forming an anode and a cathode at one end and the other end of the dielectric, respectively. In addition to this, a three-dimensional material that independently functions as an anode or a cathode can be installed so as not to be short-circuited alternately and electrically connected to form a fixed-bed type bipolar electrode electrolytic cell.

As the dielectric, activated carbon, graphite,
When carbon-based materials such as carbon fibers are used and the water to be treated is treated while generating oxygen gas from the anode, the dielectric may be oxidized by oxygen gas and dissolved as carbon dioxide gas. In order to prevent this, a porous metal material that is usually used as an insoluble metal electrode by coating a substrate such as titanium with a platinum group metal oxide such as iridium oxide or ruthenium oxide on the positively polarized side of the dielectric May be placed in contact with each other so that oxygen generation mainly occurs on the metal material. When a carbon-based material (carbonaceous three-dimensional electrode) is used as the dielectric (three-dimensional electrode), it is desirable that the average opening diameter is 25 to 125 μm. When treating the water to be treated by accommodating the carbonaceous three-dimensional electrode in the electrolytic cell,
The property of the carbonaceous three-dimensional electrode affects the ease of circulation of the water to be treated or the electrolytic voltage. The opening diameter of the carbonaceous three-dimensional electrode also has a relatively strong effect, and if the opening diameter of the carbonaceous three-dimensional electrode is large, it becomes easier for the water to be treated to pass through the electrolytic cell without coming into contact with the electrode, so that the current flows. Efficiency is reduced. On the other hand, if the pore size is too small, the water to be treated cannot flow through the carbonaceous three-dimensional electrode, resulting in an increase in electrolysis voltage and pressure loss of the liquid flow in the electrolytic cell.

A carbonaceous three-dimensional electrode having a desired aperture diameter can be manufactured as follows. For example, when sintering a carbon-based particle to form a three-dimensional electrode, by adjusting the particle size of the carbon-based particle used, the open diameter of the prepared three-dimensional electrode can be adjusted to an arbitrary open diameter. And a sintering temperature of 1000 to 4000 ° C., preferably about 3800 ° C. In the case of a felt-like three-dimensional carbonaceous electrode, a three-dimensional electrode having an arbitrary average pore diameter can be obtained by adjusting the pressure during molding and the diameter of the carbon fiber used. In these cases, the relationship between the carbon-based particles and the opening diameter and the relationship between the molding pressure and the opening diameter can be obtained empirically. Further, as another type of fixed bed type bipolar electrode electrolytic cell, for example, an anode and a cathode for power feeding are installed in a cylindrical electrolytic cell body, and a large number of conductive materials functioning as a three-dimensional electrode are provided between both electrodes for power feeding. There is an electrolytic cell in which fixed bed forming particles and a smaller number of insulating particles made of a synthetic resin or the like having an electrically insulating property than the fixed bed forming particles are mixed almost uniformly. When a potential is applied by energizing between both electrodes for supplying electricity in the electrolytic cell, the fixed bed forming particles are polarized in the same manner as the dielectric material, and one end thereof is positively charged and the other end is negatively charged to form each fixed bed. An electric potential is generated in the particles for use, and each particle is given a function of sterilizing microorganisms in the water to be treated. The insulating particles have a function of preventing both of the power feeding electrodes from being electrically connected by the electrically conductive particles for forming the fixed bed to cause a short circuit.

When a monopolar fixed bed type electrolytic cell is used, the electrolytic cell described above or one of each of the three-dimensional materials each of which functions as an anode or a cathode by itself, with or without a diaphragm, is used. Or a plurality of dielectrics or the three-dimensional materials are placed in a single electrolytic cell at the same electrolytic potential. Regardless of which type of electrode is used, the treatment efficiency of the water to be treated decreases if there is a void that allows the liquid to flow without contacting the electrodes, dielectrics or particles in the electrolytic cell through which the water to be treated flows. Therefore, it is desirable to arrange the electrodes and the like so that the flow of the water to be treated in the electrolytic bath does not come into contact with the electrodes and does not short-pass.

Even if the inside of the electrolytic cell is partitioned by a diaphragm to form an anode chamber and a cathode chamber, it is possible to carry on the current without using the diaphragm, but without using the diaphragm and the distance between the electrodes. Alternatively, when the distance between the dielectric and the electrode or between the dielectrics is narrowed, an electrically insulating spacer such as a mesh spacer made of an organic polymer material is inserted between both electrodes or between the dielectrics to prevent short circuit. can do. Further, when using a diaphragm, it is desirable to use a porous material, for example, having an opening ratio of 10% or more and 95% or less, preferably 20% or more and 80% or less so as not to interfere with the movement of the water to be circulated. The diaphragm must have fine pores having a pore size that allows at least the water to be treated to permeate. The water to be treated, which has been subjected to electrolytic treatment in contact with such a fixed bed type three-dimensional electrode and sterilization of microorganisms and decomposition of the effective chlorine component, is then brought into contact with the flat plate type electrode to decompose the effective chlorine component. The effective chlorine components such as hypochlorite ion and chlorine gas are regenerated from the chlorine ions. As the material of the flat plate type electrode, those conventionally used may be used as they are. For example, a plate-shaped platinum group oxide-coated titanium material (dimensional stability electrode) or nickel material may be used as the anode and a plate-shaped material may be used as the cathode. A stainless material, a carbon material, or the like can be used.

As described above, this flat plate type electrode may be installed in the same electrolytic cell as the fixed bed type three-dimensional electrode or in a separate electrolytic cell. The electrical conductivity of tap water, groundwater, etc.
When the amount of water to be treated is about 500 μS / cm, and both electrodes are installed in the same electrolytic cell, a short circuit may occur between both electrodes and a leakage current may flow. Therefore, in this case, it is desirable to take measures to prevent the generation of the leakage current, for example, an opening that does not hinder the flow of the water to be treated, preferably an insulating material having an opening ratio of 30% or less. Isolate the electrodes to prevent short circuits. The flat plate type electrode has a small surface area, and the current density thereof is 1.0 A / dm ² or more, which is larger than the current density of the fixed bed type three-dimensional electrode. At this current density, the reverse reaction of the formula (1) occurs at the anode. Effective chlorine components such as hypochlorite ions are generated again. At this time, it is possible to appropriately set the concentration of the effective chlorine component to be generated by controlling the current flowing within the range of the current density, and to provide the water to be treated with the optimum concentration according to the legal value.

Next, preferred examples of the electrolytic cell that can be used in the present invention will be described based on the attached drawings, but the electrolytic cell that can be used in the present invention is not limited to this electrolytic cell. FIG. 1 is a schematic vertical cross-sectional view showing an example of a single electrolytic cell containing a bipolar electrode fixed bed type electrode and a plate type electrode which can be used as the electrolytic cell of the method of the present invention. The treated water supply port 1 is located at the center of the bottom plate.
Further, the cylindrical electrolytic cell main body 3 having the treated water outlet 2 in the center of the top plate has a lower three-dimensional electrode by a separator plate 5 made of an insulating material in which a through hole 4 for circulating the treated water is formed in the center. It is partitioned into a chamber 6 and an upper flat plate electrode chamber 7.
The electrolytic cell body 3 is preferably formed of an electrically insulating material that can withstand long-term use or re-use, and in particular, it is a synthetic resin such as polyepichlorohydrin, polyvinyl methacrylate, polyethylene, polypropylene, polyvinyl chloride, or polychloride. Ethylene, phenol-formaldehyde resin, polyacrylonitrile resin and the like can be preferably used. A mesh-shaped power feeding anode 8 and a power feeding cathode 9 are provided near the upper end and the lower end inside the three-dimensional electrode chamber 6, respectively.
Is provided. Between the two feeding electrodes 8 and 9, a plurality of three sponge-like fixed bed type three-dimensional electrodes are provided in the illustrated example.
10 are stacked, and between the three-dimensional electrodes 10 and the three-dimensional electrodes
Four mesh-shaped diaphragms or spacers 11 are sandwiched between 10 and the power feeding electrodes 8 and 9. Each three-dimensional electrode 10 is in close contact with the inner wall of the electrolytic cell body 3 and does not pass through the inside of the three-dimensional electrode 10, and the leakage flow of the water to be treated flowing between the three-dimensional electrode 10 and the side wall of the electrolytic cell body 3 should be as small as possible. It is arranged to be less. Reference numeral 12 is a porous metal material such as an insoluble electrode, which is installed in close contact with the side of the three-dimensional electrode 10 that undergoes positive polarization.

A flat plate type anode 13 and a flat plate type cathode 14 which are vertically positioned are installed in the flat plate type electrode chamber 7, and the effective current density thereof becomes larger than that of the fixed bed type electrode 10 when energized. To do so. The fixed bed type three-dimensional electrode 10 and the flat plate type electrodes 13 and 14 may be energized by separate power sources, or a single power source may be used by common wiring to energize both electrodes. When current is supplied from below to the three-dimensional electrode chamber 6 of the electrolytic cell having such a structure as shown by the arrow, each fixed bed type three-dimensional electrode 10 has a positive bottom surface as shown in the drawing. The upper surface of the three-dimensional electrode 10 is negatively polarized to form a porous anode on the lower surface of each three-dimensional electrode 10. The water to be treated is brought into contact with the porous anode to sterilize microorganisms. Further, the water to be treated comes into contact with the porous cathode on the upper surface and calcium, magnesium, iron ions, etc. are deposited and removed as hydroxides thereof, and effective chlorine components such as hypochlorite ions and chlorine gas are removed. According to the above formula (1), it is converted into chlorine ions and supplied to the flat plate type electrode chamber 7 through the through hole 4 in a state in which microorganisms and effective chlorine components are hardly contained. In the flat plate type electrode chamber 7, the chlorine ions generated in the fixed bed type three-dimensional electrode chamber 6 are oxidized or reduced to be converted to hypochlorite ion or chlorine gas, and an effective chlorine component conforming to the regulations of the law is obtained. It is taken out from the water to be treated 2 as drinking water and the like and is used for a predetermined purpose.

FIG. 2 relates to the improvement of the electrolytic cell of FIG. 1, and the same members as those of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. The three-dimensional electrode chamber 6 and the flat plate type electrode chamber 7 are partitioned by a separator plate 5'made of an insulating material in which a through hole 4'for treating water distribution having a diameter larger than that of the through hole 4 in FIG. A cylindrical connecting rod 15 is inserted into the through hole 4 '. The lower end of the connecting rod 15 is connected to the power-supplying anode 8 in the three-dimensional electrode chamber 6, and the upper end of the rod 16 is in the form of a mesh or a plate installed in parallel in the flat plate type electrode chamber 7. It is connected to the lower cathode 14 'of the anode 13' and the cathode 14 '. When this electrolytic cell is used, the water to be treated comes into contact with the porous anode of the three-dimensional electrode 10 to sterilize the microorganisms, as in the case of FIG. Further, the water to be treated passes through the porous cathode on the upper surface in a state in which calcium and the like are precipitated and removed as hydroxides thereof and are removed, and effective chlorine components such as hypochlorite ions are hardly contained. 4 '
Through the flat plate type electrode chamber 7. In this flat plate type electrode chamber 7 as well, electrolysis of the water to be treated is carried out in the same manner, and it is taken out from the water to be treated 2 as drinking water or the like having an effective chlorine component conforming to the regulations of the law and used for a predetermined purpose. .

FIG. 3 is a schematic view showing a state in which the electrolytic cell of FIG. 1 is used for reforming the stored water of a cup type vending machine. Tap water or the like to be diluted water of the cup type vending machine is supplied to a box-shaped cup type vending machine storage tank 17 after solid impurities are removed by a filter 16 in advance. The tank
The stored water 18 in 17 circulates through a circulation line 19 connected to the electrolytic cell 3 to sterilize microorganisms and remove effective chlorine components in the three-dimensional electrode chamber 6 of the electrolytic cell 3 and to dispose in the flat plate type electrode chamber 7. After the fixed amount of available chlorine component is generated again, it is returned to the storage tank 17. Therefore, the stored water 18 in the tank 17 is water that does not always contain microorganisms and that complies with the law as drinking water containing a predetermined amount of available chlorine components. The water 18 stored in the storage tank 17 is supplied to the paper cup 21 by opening the cock 20, and is mixed with the concentrated stock solution supplied separately and sold as soft drink.

FIG. 4 is a schematic vertical sectional view showing another example of the electrolytic cell which can be used as the electrolytic cell of the method of the present invention. Treated water supply port 31 in the center of the bottom plate, and treated water outlet in the center of the top plate
Short cylindrical three-dimensional electrode type electrolytic cell 33 having 32 respectively
A fixed-bed type three-dimensional anode 34 and a flat-plate type cathode 35, which are the same as the fixed-bed type three-dimensional electrode of FIG. 1, are installed therein to form a single electrode type electrolytic cell. The treated water outlet 32 of the three-dimensional electrode type electrolytic bath 33 is provided with the treated water supply port 37 of the flat plate type electrode electrolytic bath 36.
Are connected to each other, and a flat plate type anode 38 and a flat plate type cathode 39 that are vertically positioned are installed in the flat plate electrode type electrolytic bath 36, and the water to be treated treated in the flat plate electrode type electrolytic bath 36 is not treated. It is taken out from the treated water outlet 40. Also in the illustrated example, similar to the case of FIG. 1, it is possible to produce drinking water or the like which does not contain microorganisms containing an effective chlorine component of a predetermined concentration, and the fixed bed type electrode 34 and the flat plate type electrodes 38, 39 are separate. Since it is installed in the electrolytic cell, no short circuit will occur.

[0022]

EXAMPLES Next, examples of treatment of water to be treated by the method of the present invention will be described, but these examples do not limit the present invention.

Example 1 Height 80 made of transparent hard polyvinyl chloride resin
mm, an inner diameter of 40 mm and a flanged cylindrical electrolytic bath shown in FIG. 1 were used to electrolyze the water to be treated. In the fixed-bed type electrode chamber of the electrolytic cell, three fixed-bed type three-dimensional electrodes with a diameter of 38 mm and a thickness of 10 mm, to which a porous metal material made of carbon fiber and titanium material coated with iridium oxide was adhered, were used. The diameter is made of titanium, which is sandwiched between four polyethylene resin diaphragms with a diameter of 38 mm and a thickness of 1.2 mm at 80%, and platinum is plated on the upper and lower diaphragms respectively.
A 38 mm thick 1.0 mm mesh power feeding anode and a power feeding cathode were placed in contact with each other.

Further, the plate type electrode chamber of the electrolytic cell has a vertical length of 30 mm,
Anode consisting of dimensionally stable electrodes 30 mm wide and 1.0 mm thick, and 30 mm long, 30 mm wide and 1.0 m thick made of titanium
m cathodes were placed 5.0 mm apart from each other. Both electrode chambers are made of vinyl chloride resin and have a diameter of 40 mm and a diameter of 10 m in the center.
It was partitioned by a separator plate having m through holes. Both electrodes are energized by separate power sources, a voltage of 16 V is applied to the fixed-bed electrode chamber so that the effective current density is 0.15 A / dm ^2, and a voltage of 2.5 V is applied to the flat electrode chamber. , Its effective current density was set to 3.5 A / dm ² . Microorganisms were added to tap water to make the number of microorganisms 3400 / milliliter, and 3.0 liters of test water was treated water, and the inside of the electrolyzer was a fixed bed type electrode chamber and a flat plate type electrode chamber at a flow rate of 1.2 liters / min. It was made to pass and electrolytic treatment was performed. After introducing the treated water taken out from the electrolysis tank into the storage tank, it was supplied to the electrolysis tank again and passed through the electrolysis cell multiple times to measure the number of microorganisms and the effective chlorine component in the storage tank after a predetermined time elapsed. However, the results are shown in Table 1.

[0024]

Example 2 Treated water was treated in the same manner as Example 1 except that the separator of the electrolytic cell was removed. The results are shown in Table 2. From Table 2, there is a slight increase in the number of microorganisms after passing through the electrolytic cell, which is presumed to be due to a short circuit of the electrolytic current between the fixed bed electrode and the flat plate electrode through the water to be treated.

[0025]

[Comparative Example 1] The treated water was treated under the same conditions as in Example 1 except that the flat plate electrode was not energized, and the numbers of microorganisms and effective chlorine components before and after passing through the electrolytic cell were measured. It was on the street. It can be seen from Table 3 that the effective chlorine component is scarcely contained in the water to be treated taken out from the electrolytic cell unless the flat plate type electrode is used.

[0026]

[0027]

Example 3 Using the electrolytic bath shown in FIG. 3, the water to be treated was electrolyzed. A cylindrical fixed-bed electrode electrolysis cell made of transparent transparent vinyl chloride resin with an inner diameter of 40 mm and a height of 30 mm has a fixed-bed three-dimensional anode made of carbon fiber with a diameter of 38 mm and a thickness of 20 mm and titanium. 38mm diameter and thickness 1.
A 0 mm plate-shaped cathode was installed. Also, the height is 15 m in a box-type flat plate electrode type electrolytic cell with a length of 20 mm, width of 40 mm and height of 40 mm.
m, width 35 mm and thickness 1.0 mm, an anode consisting of dimensionally stable electrodes, and titanium made 15 mm in length, 35 mm in width and thickness 1.
The 0 mm cathodes were placed well separated from each other. Both of the electrolyzers are energized by separate power sources, a voltage of 5.5 V is applied to the fixed bed type three-dimensional electrode type electrolyzer, and the effective current density is
0.25 A / dm ^2, and a voltage of 2.5 V was applied to the flat plate electrode type electrolytic cell, and the effective current density was 1.5 A / dm ^2.
It was set to dm ² . The same water to be treated as in Example 1 was passed through both electrolytic cells to carry out electrolytic treatment in the same manner as in Example 1. The water to be treated taken out of the electrolytic cell was supplied to the electrolytic cell again and passed through the electrolytic cell a plurality of times to measure the number of microorganisms and the effective chlorine component in the storage tank after a lapse of a predetermined time. It was

[0028]

[Table 4]

[0029]

According to the method of the present invention, the water to be treated containing microorganisms and effective chlorine components is brought into contact with a fixed bed type three-dimensional electrode for electrolytic treatment to sterilize the microorganisms, and then the treated water is flattened. A method for electrolytically treating water to be treated containing microorganisms, which comprises treating the treated water by contacting it with a mold electrode (claim 1). In the conventional method of electrochemically treating the water to be treated containing the microorganism, not only the sterilization of the microorganism but also the effective chlorine component contained in the water to be treated is decomposed. Since the treated water thus obtained contains almost no microorganisms, it does not cause any substantial harm even if it does not contain an effective chlorine component, but when the treated water after treatment is used as drinking water. Must contain more than a certain amount of available chlorine components as required by law.

Therefore, when a modification treatment is carried out using microorganisms and effective chlorine components as the water to be treated to produce drinking water, the microorganisms are completely sterilized and the effective chlorine components are partially decomposed to obtain a small amount of effective water. Ideally, the chlorine component should remain.
However, in reality, it is almost impossible to leave a desired amount of available chlorine component. The present invention is a method of electrolytically treating water to be treated containing microorganisms and effective chlorine components using a fixed bed type three-dimensional electrode to sterilize microorganisms and decompose effective chlorine components almost completely. A predetermined amount of effective chlorine component is again generated in the water to be treated by electrolyzing the water to be treated containing a chlorine ion or the like, which is a decomposition product of the components, with a flat plate type electrode, and drinking water etc. conforming to the stipulations of laws and regulations is obtained. It made it possible to obtain.

In particular, the water of the cup-type vending machine, the lobby or platform, and the water supply device in the train or the ship is stored in the storage tank and is supplied as needed, so that it is often stored in the tank for a long period of time. Is likely to occur, and as described above, it is obligatory to contain an effective chlorine component in a specified amount or more. When the present invention is applied to the water storage of the cup type vending machine and the water storage of the water supply device of the lobby or platform (Claim 2), it is possible to sterilize the propagated microorganisms and produce the effective chlorine component at the same time, which complies with the law. It is possible to provide soft drinks and the like made from clear water.
The fixed bed type three-dimensional electrode and the flat plate type electrode may be installed in the same electrolytic cell or separate electrolytic cells, but they may be installed in the same electrolytic cell to reduce the installation area. Preferred (Claim 3). However, when both electrodes are installed in the same electrolytic cell, it is desirable to take measures to prevent both electrodes from short-circuiting. For example, an insulating separator having a through hole that does not impede the flow of the water to be treated may be used. An electrode chamber containing the electrode is defined.

Further, the decomposition of the effective chlorine component and the formation of the effective chlorine component from the decomposition product may occur simultaneously. In the present invention, the effective chlorine component is decomposed in the fixed bed type three-dimensional electrode chamber, and the flat plate type electrode is used. It is necessary to cause the production of available chlorine components in the chamber. The both reactions are greatly affected by the current density of the electrode, and the effective chlorine component is likely to be decomposed at a low current density and the effective chlorine component is easily generated at a high current density. In general, a fixed bed type three-dimensional electrode has a high surface area and a flat plate type electrode has a low surface area.
Therefore, if the ordinary fixed bed type three-dimensional electrode and flat plate type electrode are used as they are, the current density of the fixed bed type three dimensional electrode is low and the effective chlorine component is decomposed, and the current density of the flat plate type electrode is high and the effective chlorine component is generated. As a result (claim 4), it is possible to obtain drinking water or the like having a desired effective chlorine component concentration and containing almost no microorganisms.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an example of a single electrolytic cell containing a bipolar fixed bed type electrode and a plate type electrode which can be used as an electrolytic cell of the method of the present invention.

FIG. 2 is a schematic vertical sectional view showing an electrolytic cell relating to the improvement of the electrolytic cell of FIG.

FIG. 3 is a schematic view showing a state in which the electrolytic cell of FIG. 1 is used for reforming stored water of a cup type vending machine.

FIG. 4 is a schematic vertical sectional view showing another example of an electrolytic cell that can be used as the electrolytic cell of the method of the present invention.

[Explanation of symbols]

3 ... Electrolyzer body 4 ... Through hole 5 ... Separator
6 ... Three-dimensional electrode chamber 7 ... Flat plate type electrode chamber 8 ... Anode for feeding 9 ...
Power supply cathode chamber 10 ... Fixed bed type electrode 13 ... Plate type anode 14 ... Plate type cathode 17 ... Storage tank 18 ...
・ ・ Water storage 21 ・ ・ ・ paper cup 33 ・ ・ ・ three-dimensional electrode type electrolytic cell 34 ・ ・ ・ three-dimensional electrode 36 ・ ・ ・ plate type electrode electrolytic cell 38 ・ ・ ・ plate type anode 39 ・ ・ ・ plate type cathode

[Procedure amendment]

[Submission date] September 20, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

Claims (4)

[Claims] 1. The water to be treated containing a microorganism and an effective chlorine component is brought into contact with a fixed bed type three-dimensional electrode for electrolytic treatment to sterilize the microorganism, and then the water to be treated is brought into contact with a flat plate type electrode. A method for electrolytic treatment of water to be treated containing microorganisms, characterized in that 2. The method according to claim 1, wherein the water to be treated is water stored in a cup-type vending machine and / or water stored in a water dispenser. 3. The method according to claim 1, wherein the fixed bed type three-dimensional electrode and the plate type electrode are installed in a single electrolytic cell. 4. The method according to claim 1, wherein the effective current density of the fixed bed type three-dimensional electrode is smaller than that of the flat plate type electrode.