JPH0824868A - Water treatment apparatus - Google Patents

Abstract

PURPOSE:To remove an oxidizing agent by electrolytic treatment without adding a reducing agent or applying activated carbon treatment by arranging a diaphragm type electrolytic apparatus on the front stage of an ion exchange device or a reverse osmosis membrane device and passing water to be treated containing an oxidizing agent through the cathode chamber of the diaphram type electrolytic apparatus to subject the same to electrolytic treatment. CONSTITUTION:Water to be treated containing an oxidizing agent is supplied to a clalifier 86 such as a flocculating filter device, a precise filter membrane device, an ultrafiltration membrane device or the like from piping 96 to be subjected to clarification treatment. The water to be treated come out from the clarifier 86 is introduced into the cathode chamber 88 of a two-chamber type diaphragm type electrolytic device 87 divided into cathode and anode chambers 88, 99 by a diaphragm 92 through piping 100 to reduce the oxidizing agent by electrolytic treatment. The water to be treated introduced into the anode chamber 90 from piping 98 is circulated to the introducing piping 96 through piping 99 and introduced into a desalting part 94 through piping 102 to be subjected to desalting treatment and discharged from piping 104.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment device for performing desalination treatment, softening treatment, etc. of water to be treated by using an ion exchange device or a reverse osmosis membrane device. The present invention relates to a water treatment device used when an agent is contained.

[0002]

2. Description of the Related Art Conventionally, there has been used a water treatment device which performs desalination treatment, softening treatment and the like of water to be treated using an ion exchange device and a reverse osmosis membrane device. However, when water to be treated containing an oxidant is introduced into an ion exchange device or a reverse osmosis membrane device in such a water treatment device, the oxidant in the water to be treated causes oxidative deterioration of the ion exchange resin or the reverse osmosis membrane. Therefore, when water to be treated containing an oxidant is treated with a water treatment device using an ion exchange device or a reverse osmosis membrane device, the ion exchange device or the reverse osmosis membrane is used for the purpose of preventing oxidative deterioration of the ion exchange resin or the like. The oxidizer is removed from the water to be treated by subjecting the water to be treated to activated carbon treatment to decompose the oxidizer or adding a reducing agent to the water to reduce the oxidizer at the front side of the equipment. ing.

[0003] For example, in a water treatment device which performs demineralization treatment of industrial water or city water and then desalination treatment by a reverse osmosis membrane device or an ion exchange device, the water to be treated contains an oxidizer such as chlorine. In this case, in order to prevent oxidative deterioration of the reverse osmosis membrane, ion exchange resin, etc., the water to be treated is passed through an activated carbon tower or a reducing agent is added to the water to be treated in the upstream side of the reverse osmosis membrane device or the ion exchange device. It is being added.

FIG. 6 shows an example of such a water treatment device. In FIG. 6, 2 is an activated carbon tower, 4 is a safety filter,
6 is a reverse osmosis membrane device, 8 is a mixed bed type ion exchange device, 10 is a treated water introducing pipe connected to the activated carbon tower 2, 12 is a connecting pipe between the activated carbon tower 2 and the safety filter 4, and 14 is a safety filter 4 And 16 are connection pipes of the reverse osmosis membrane device 6, 16 is a connection pipe of the reverse osmosis membrane device 6 and the ion exchange device 8, and 18 is a treated water discharge pipe.

Water treatment by the apparatus of FIG. 6 is performed as follows. Treated water containing an oxidizing agent such as chlorine (for example, city water such as tap water) is introduced into the activated carbon tower 2 through the treated water introducing pipe 10 and the oxidizing agent is removed from the treated water by the activated carbon treatment. The water to be treated that has exited the activated carbon tower 2 is introduced into the safety filter 4 through the pipe 12, where large particles such as iron are removed. The water to be treated that has left the safety filter 4 is introduced into the reverse osmosis membrane device 6 through the pipe 14, and the permeated water of the reverse osmosis membrane device 6 is introduced into the ion exchange device 8 through the pipe 16. Thereby, the desalination treatment of the water to be treated is performed. Demineralized water (treated water) is discharged from the pipe 18. In addition, in FIG.
Reference numeral 7 denotes a pipe for taking out the concentrated water of the reverse osmosis membrane device 6.

[0006] Surface water (river water, lake water, etc.) and industrial water are clarified by using a microfiltration membrane, an ultrafiltration membrane, etc., and then desalted by a reverse osmosis membrane to obtain pure water. In the water treatment equipment to be obtained, in order to prevent operation failures due to accumulation of organic substances and microorganisms in the raw water on the membrane surface of the microfiltration membrane or ultrafiltration membrane, the preceding stage of the microfiltration membrane equipment or ultrafiltration membrane equipment On the side, an oxidizer such as sodium hypochlorite is added to the water to be treated as a bactericide, and therefore the water to be treated contains the oxidant.

In such a water treatment device, when desalination treatment is performed by a reverse osmosis membrane device using a synthetic composite membrane of, for example, polyamide type, aramid type, etc. in the subsequent stage of the microfiltration membrane device or the ultrafiltration membrane device. If the water to be treated contains an oxidant, the reverse osmosis membrane will be oxidatively deteriorated and the separation performance will be deteriorated.
Therefore, a reducing agent such as sulfite is added to the water to be treated on the upstream side of the reverse osmosis membrane device to reduce the oxidizing agent, and then the water to be treated is supplied to the reverse osmosis membrane device.

FIG. 7 shows an example of such a water treatment device. In FIG. 7, 20 is a hollow fiber type ultrafiltration membrane device,
22 is a decarbonation tower, 24 is an air introduction mechanism to the decarbonation tower 22, 26 is a reverse osmosis membrane device using a reverse osmosis membrane composed of a synthetic composite membrane, and 28 is a treated object connected to the ultrafiltration membrane device 20. Water introducing pipe, 30 is an oxidizing agent adding mechanism connected to the introducing pipe 28, 32 is a circulation pipe for circulating the concentrated water of the ultrafiltration membrane device 20 to the treated water side, 45 is a concentrated water blow pipe, and 34
Is a connecting pipe for introducing permeated water of the ultrafiltration membrane device 20 to the decarbonation tower 22, 36 is an acid addition mechanism connected to the pipe 34,
38 is a connecting pipe between the decarbonation tower 22 and the reverse osmosis membrane device 26,
Reference numeral 40 is a reducing agent addition mechanism connected to the pipe 38, 42 is a neutralizing agent addition mechanism connected to the downstream side of the reducing agent addition mechanism 40 connection point of the pipe 38, and 44 is a treated water discharge pipe.

The processing by the apparatus of FIG. 7 is performed as follows. NaClO is added from the oxidant addition mechanism 30 to the water to be treated (surface water or industrial water) flowing through the treated water introducing pipe 28. The amount of NaClO added is, for example, 1 mgCl / liter. The water to be treated to which the oxidizing agent has been added is introduced into the ultrafiltration membrane device 20 and subjected to a turbidity treatment. The turbid water to be treated (permeated water of the ultrafiltration membrane device 20) is introduced into the decarbonation tower 22 through the pipe 34 and is subjected to decarbonation treatment. At this time, in the pipe 34, H
Cl is added, and the decarbonation tower 2 is used for the progress of the decarbonation process.
The water to be treated is adjusted to be acidic on the upstream side of 2. In addition, a part of the concentrated water of the ultrafiltration membrane device 20 is circulated to the treated water side through the pipe 32, and the rest of the concentrated water is blown out of the system through the blow pipe 45. The water to be treated (decarbonated water) leaving the decarbonation tower 22 is piped 38
It is introduced into the reverse osmosis membrane device 26 through and is desalted. At this time, in the pipe 38, Na ₂ SO ₃ is first added to the water to be treated from the reducing agent addition mechanism 40, the oxidizing agent (NaClO) is reduced and removed by this reducing agent, and then the neutralizing agent addition mechanism 42 is used. NaOH is added to neutralize the water to be treated. The permeated water (demineralized water) is discharged from the pipe 44. In FIG. 7, 27 is a reverse osmosis membrane device 26.
The piping for taking out the concentrated water of is shown.

[0010]

As described above, conventionally, when the water to be treated containing the oxidant is treated by the water treatment device using the ion exchange device or the reverse osmosis membrane device,
In order to prevent oxidative deterioration of the ion exchange resin and reverse osmosis membrane, etc.
The oxidizing agent is removed from the water to be treated by a reducing treatment using a reducing agent or an activated carbon treatment.

However, the means for removing the oxidizing agent in the water to be treated by adding the reducing agent increases the types of chemicals used in the operation of the apparatus, the amount of chemicals, and increases the chemical cost.
There is a problem that the salt concentration in the water to be treated increases and the salt load on the ion exchange device and the reverse osmosis membrane device increases.

Further, the means for removing the oxidizer in the water to be treated by the activated carbon treatment requires securing the installation space of the activated carbon tower, periodical cleaning and replacement of the activated carbon,
There is a problem in that it is disadvantageous in terms of cost and maintenance, pulverized coal leaks into the water to be treated, and the water recovery rate decreases due to activated carbon cleaning.

The present invention has been made in view of the above circumstances. In a water treatment device using an ion exchange device or a reverse osmosis membrane device, when the water to be treated contains an oxidant, the ion exchange device is used. The oxidizing agent can be removed from the water to be treated without adding a reducing agent or treating with activated carbon on the upstream side of the reverse osmosis membrane device, thus eliminating the disadvantages of adding the reducing agent or treating with activated carbon described above. An object is to provide a water treatment device.

[0014]

Means and Action for Solving the Problems The present inventors have
As a result of intensive studies to achieve the above-mentioned object, in a water treatment apparatus using an ion exchange device or a reverse osmosis membrane device, a diaphragm-type electrolysis device is installed on the upstream side of the ion exchange device or the reverse osmosis membrane device, When water to be treated containing an oxidant is passed through the cathode chamber of a diaphragm electrolyzer for electrolytic treatment, the oxidant in the water to be treated is reduced by a reduction reaction that receives electrons. The inventors have found that the water to be treated from which the oxidant has been removed by the electrolytic treatment can be supplied to the ion exchange device or the reverse osmosis membrane device without the need to complete the present invention.

Therefore, according to the present invention, in a water treatment device for treating water to be treated by an ion exchange device or a reverse osmosis membrane device, a diaphragm electrolysis device is installed in front of the ion exchange device or the reverse osmosis membrane device. Together with this, the water to be treated containing an oxidant is introduced into the cathode chamber of the diaphragm electrolyzer, and the water to be treated containing the oxidant is electrolyzed in the cathode chamber, and then the water to be treated is exchanged with an ion exchange device or reverse osmosis. Provided is a water treatment device configured to supply to a membrane device.

The present invention will be described in more detail below. There is no limitation on the structure of the diaphragm type electrolyzer used in the water treatment apparatus of the present invention, which is provided with a cathode chamber and an anode chamber partitioned by a diaphragm, and a cathode chamber and an anode by flowing a direct current between the cathode and the anode. Although any water can be used as long as it can electrolyze the water flowing through the chamber, for example, the two-chamber electrolysis device shown in FIG. 1 or the three-chamber electrolysis device shown in FIG. 2 (Japanese Patent Laid-Open No. 5-339769). No.) can be preferably used.

The two-chamber electrolysis apparatus of FIG. 1 has a cathode chamber 54 in which a cathode 52 is installed and an anode chamber 58 in which an anode 56 is installed.
And are separated by a diaphragm 60. 6 in FIG.
Reference numerals 2 and 63 are cathode-side water flow paths, and 64 and 65 are anode-side water flow paths. The three-chamber electrolysis apparatus of FIG. 2 is provided between the cathode chamber 68 in which the cathode 66 is installed, the anode chamber 72 in which the anode 70 is installed, and between the cathode chamber 68 and the anode chamber 72. And the intermediate chamber 74 filled with the solid electrolyte of
And 78. In FIG. 2, 80, 8
1 is a cathode side water flow channel, 82 and 83 are anode side water flow channels, 84,
Reference numeral 85 indicates an intermediate chamber water flow path.

In the apparatus shown in FIGS. 1 and 2, as the cathode and the anode of the electrolysis apparatus, those made of platinum, platinum black, carbon or the like can be used. Further, as the diaphragm, it is possible to use one that allows an electric current to pass but restricts free movement of water. For example, an ion exchange membrane, a microfiltration membrane (MF), an ultrafiltration membrane (UF), a reverse osmosis membrane ( RO),
A ceramic film or the like can be used. In such a diaphragm type electrolyzer, while water to be treated containing an oxidant is caused to flow in the cathode chamber and a direct current is caused to flow between the cathode and the anode, the electrochemical reduction reaction in the cathode chamber causes a reduction in the water to be treated. Since the oxidant can be reduced, the water to be treated is then supplied to the ion exchange device or the reverse osmosis membrane device, whereby the oxidative deterioration of the ion exchange resin or the reverse osmosis membrane can be reliably prevented. .

An electrolytic apparatus applying this principle is, for example, an alkaline ionized water generator (Japan Intec Co., Ltd.). Further, as the electrolysis device, it is also possible to use a diaphragm type electrolysis device in which a plurality of electrodes and diaphragms are alternately arranged and a large number of electrolysis chambers are provided.

The type of ion exchange device used in the water treatment device of the present invention is not limited, and various ion exchange devices can be used. Specifically, for example, a mixed bed type ion exchange device,
A two-bed, three-column type ion exchange device, a softening device, an electric deionized water production device, etc. can be used. The mixed bed type ion exchange apparatus is one in which a cation exchange resin and an anion exchange resin are mixed and packed in one ion exchange resin tower. Two
The three-bed floor ion exchange apparatus is one in which a cation exchange resin tower and an anion exchange resin tower are installed in the front and rear stages of the decarbonation tower, respectively. The softening device softens hard water with Na-type cation exchange resin.

The electric deionized water producing apparatus is for desalting by an electrodialysis method, and basically, an anion exchange resin such as an anion exchange resin is provided in a gap formed by the cation exchange membrane and the anion exchange membrane. One or more pairs of individual cation-exchange resin layers are alternately laminated, or a mixed ion-exchange resin layer of anion-exchange resin and cation-exchange resin is filled into a desalting chamber, and the ion-exchange resin layer is treated. Along with passing water, a direct current is applied in a direction perpendicular to the flow of the water to be treated through the both ion exchange membranes so that the concentrated water flowing in the concentration chamber formed outside the both ion exchange membranes is exposed to The deionized water is produced while electrically removing the ions in the treated water.

The type of reverse osmosis membrane device used in the water treatment apparatus of the present invention is not limited, and various types of reverse osmosis membrane devices can be used. For example, reverse osmosis composed of a synthetic composite membrane of polyamide type, aramid type, etc. A reverse osmosis membrane device using a membrane can be used. Also, as a reverse osmosis membrane device, a spiral type,
Any type such as hollow fiber type and tubular type may be used.

In the water treatment apparatus of the present invention, both the ion exchange apparatus and the reverse osmosis membrane apparatus may be installed in the latter stage of the diaphragm type electrolysis apparatus, or only one of them may be installed. It can be arbitrarily selected according to the purpose of the water treatment device.

The water treatment device of the present invention comprises the above-mentioned diaphragm type electrolysis device and an ion exchange device or a reverse osmosis membrane device,
The water to be treated containing the oxidant is passed through the cathode chamber of the diaphragm electrolyzer before being supplied to the ion exchange device or the reverse osmosis membrane device. Agent may be included, but typically NaCl
Examples thereof include chlorine-based oxidizing agents such as O and chloramine, and oxygen-based oxidizing agents such as 0 ₃ and H ₂ O ₂ . For example, NaCl as an oxidizing agent
When water to be treated containing O is passed through the cathode chamber of the diaphragm type electrolysis apparatus, the oxidizing agent is reduced by the reduction reaction of the following formula in the cathode chamber. ClO ⁻ + H ₂ O + 2e ⁻ → Cl ⁻ + 2O
H ⁻ Also other oxidants are similarly reduced by the reduction reaction receiving electrons.

[0025]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to the following examples.

Embodiment 1 FIG. 3 shows an embodiment of the water treatment device of the present invention. In FIG. 3, 86 is a flocculating device such as a coagulation filtration device, a microfiltration membrane device, and an ultrafiltration membrane device, and 87 is a two-chamber diaphragm electrolysis in which a cathode chamber 88 and an anode chamber 90 are separated by a diaphragm 92. Device (Fig. 1
), 94 is a desalination unit equipped with an ion exchange device or a reverse osmosis membrane device, 96 is a treated water introduction pipe connected to the turbidity removal device 86, and 98 and 99 are treated water flowing through the introduction pipe 96. A circulation pipe which circulates water to the anode chamber 90 of the electrolysis device 87 and then circulates it through the introduction pipe 96, 100 is a connection pipe between the turbidity removal device 86 and the cathode chamber 88 of the electrolysis device 87, and 102 is the cathode chamber 88 and the desorption chamber. Reference numeral 104 denotes a connection pipe with the salt portion 94, and 104 denotes a treated water discharge pipe.

Water treatment by the apparatus shown in FIG. 3 is performed as follows. Treated water containing oxidants (industrial water, surface water, city water, etc.)
Is supplied from the pipe 96 to the turbidity-eliminating device 86, and the water to be treated is turbidized. The water to be treated which has flowed out of the turbidity removal device 86 is introduced into the cathode chamber 88 of the electrolysis device 87 through the pipe 100, where the electrolysis treatment is performed and the oxidant is reduced. The water to be treated introduced from the pipe 98 into the anode chamber 90 is circulated through the pipe 99 to the introduction pipe 96. The water to be treated that has left the cathode chamber 88 is introduced into the desalination unit 94 through the pipe 102, and the desalination treatment of the water to be treated is performed. The demineralized water is discharged from the pipe 104.

Embodiment 2 FIG. 4 shows another embodiment of the water treatment device of the present invention. The apparatus of this example is the conventional water treatment apparatus shown in FIG. 6, in which the oxidizing agent in the water to be treated is removed by a diaphragm electrolysis apparatus instead of being removed by activated carbon treatment. Therefore, in FIG. 4, the same components as those of the apparatus of FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted.
Further, since the diaphragm electrolysis device is the same as that used in the device of FIG. 3, in FIG. 4, parts having the same configurations as those of the device of FIG.

In the apparatus shown in FIG. 4, the water to be treated flowing through the water to be treated introducing pipe 10 first has the cathode chamber 8 of the electrolyzer 87.
8 and is subjected to an electrolytic treatment to remove the oxidant, and then supplied to the safety filter 4 through the connecting pipe 106. The water treatment by the apparatus of FIG. 4 is the same as that of FIG. 6 except that the water to be treated containing an oxidizing agent such as chlorine is introduced into the cathode chamber 88 of the electrolyzer 87 and the oxidizing agent in the water to be treated is removed by the electrolytic treatment. It is the same as the water treatment device of.

Embodiment 3 FIG. 5 shows still another embodiment of the water treatment device of the present invention.
The apparatus of this example is the conventional water treatment apparatus shown in FIG. 7, in which the oxidizing agent in the water to be treated is removed by a diaphragm electrolysis apparatus instead of being removed by adding a reducing agent. Therefore, in FIG. 5, the same components as those of the apparatus of FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted. Further, since the diaphragm type electrolysis device is the same as that used in the device of FIG. 3, the same reference numerals are given to the same components in FIG. 5 as those of the device of FIG. 3, and the description thereof will be omitted.

In the apparatus of FIG. 5, a cathode chamber 88 of an electrolysis apparatus 87 is provided in a connecting pipe 38 connecting the decarbonation tower 22 and the reverse osmosis membrane apparatus 26. That is, the outflow end of the upstream portion 38a of the pipe 38 is connected to the inlet of the cathode chamber 88, and the inflow end and the outflow end of the downstream portion 38b are connected to the outlet of the cathode chamber 88 and the reverse osmosis membrane device 26, respectively. Further, the concentrated water of the reverse osmosis membrane device 26 is passed through the pipe 27 to the anode chamber 90 of the electrolysis device 87, and then circulated to the introduction pipe 28 through the pipe 110. Furthermore, in this apparatus, the reducing agent addition mechanism 40 and the neutralizing agent addition mechanism 42 shown in FIG. 7 are not provided. The reason why the neutralizing agent addition mechanism is not provided in this device is that N contained in the water to be treated is electrolytically reacted in the cathode chamber 88.
This is because an alkaline component such as NaOH is generated from cations such as a ⁺ and neutralization is naturally performed, which is as shown in the experimental example described later. In the water treatment by the apparatus of FIG. 5, water to be treated (decarbonated water) containing an oxidant (NaClO) is introduced into the cathode chamber 88 of the electrolysis apparatus 87,
The water treatment apparatus is the same as the water treatment apparatus in FIG. 7, except that the oxidizing agent in the water to be treated is removed by electrolytic treatment and the acid is neutralized at the same time.

In the water treatment apparatuses of Examples 1 to 3, after removing the oxidizing agent in the water to be treated by electrolytic treatment without adding a reducing agent or treating with activated carbon, the water is treated in an ion exchange apparatus or a reverse osmosis membrane apparatus. Since water is supplied, problems such as an increase in the chemical cost that occurs when the oxidizing agent is removed by adding the reducing agent, an increase in the salt load on the ion exchange device and the reverse osmosis membrane device, and oxidation due to activated carbon treatment It is possible to avoid problems such as disadvantages in cost and maintenance in removing the agent, leakage of pulverized coal into the water to be treated, and reduction in water recovery rate due to washing with activated carbon. In addition, the water treatment apparatus of Example 3 has an advantage that the neutralizing agent addition mechanism provided in the apparatus of FIG. 7 is unnecessary.

In the water treatment apparatuses of Examples 1 and 2, a part of the water to be treated flowing through the treated water introducing pipe is passed through the anode chamber of the electrolyzer and then circulated through the treated water introducing pipe. In the water treatment device of Example 3, the concentrated water of the reverse osmosis membrane device was made to pass through the anode chamber of the electrolysis device and then circulated through the treated water introduction pipe, but the water to be passed to the anode chamber was other water. It may be.

[Experimental Example 1] City water (treatment water) containing a chlorine-based oxidizing agent was desalted by using the water treatment apparatus shown in FIG. In this case, as the electrolysis device 87, a diaphragm 92 using Nafion 450 (trade name, an ion exchange membrane manufactured by DuPont) is used, and the current density is 0.6 A / dm ² , and the cathode chamber 8 is used.
The electrolysis treatment was performed under the condition that the water flow rate to 8 was 1 m ³ / h. Further, for comparison, the same desalination treatment of the water to be treated was performed using the water treatment apparatus of FIG. 6 which is a conventional apparatus. Table 1 shows the water quality of city water, which is the water to be treated, and the water quality of oxidant-removed water in both devices.
Shown in The oxidant-removed water is the outlet water of the cathode chamber 88 in the apparatus of FIG. 4 and the outlet water of the activated carbon tower 2 in the apparatus of FIG.

[0035]

[Table 1]

From Table 1, it is found that no residual chlorine is found in the outlet water of the cathode chamber 88 subjected to the electrolytic treatment, and the oxidation-reduction potential is lower than that of the activated carbon-treated water, which is in a reduced state. It can be seen that the ion-exchange resin does not cause oxidative deterioration.

[Experimental Example 2] Industrial water (water to be treated) was desalted by using the water treatment apparatus shown in FIG. In this case, the configuration of the electrolysis device 87 and the conditions of the electrolysis treatment were the same as in Experimental Example 1. For comparison, industrial water was desalted by using the conventional water treatment apparatus shown in FIG. In any of the apparatuses, the amount of NaClO added to the water to be treated from the oxidizing agent adding mechanism 30 was 1 mgCl / liter. Table 2 shows the results. The decarbonated water in Table 2 is the outlet water of the decarbonation tower 22, and its water quality is the same in both devices. The water to be desalinated in Table 2 is the outlet water of the cathode chamber 88 in the apparatus of FIG. 5, and the neutralizing agent addition mechanism 42 in the apparatus of FIG.
Water after the neutralizing agent has been added by.

[0038]

[Table 2]

From Table 2, no residual chlorine was found in the outlet water (water to be desalinated) of the cathode chamber 88 subjected to the electrolytic treatment, and the oxidation-reduction potential was lower than that of the desalinated water to which the reducing agent was added, which was in a reduced state. It is clear that the reverse osmosis membrane on the rear side does not cause oxidative deterioration. Further, it is understood that sodium ion and sulfate ion do not increase as in the conventional device because no chemicals are added, and the salt load on the reverse osmosis membrane device is reduced.

[0040]

According to the apparatus of the present invention, when the water to be treated contains an oxidizing agent, the water to be treated can be treated without addition of a reducing agent or activated carbon treatment before the ion exchange apparatus or the reverse osmosis membrane apparatus. Oxidizing agent can be removed from water, and therefore oxidative deterioration of ion exchange resin, reverse osmosis membrane, etc. can be prevented, and at the same time, the disadvantages of removing the oxidizing agent by adding a reducing agent or activated carbon treatment are eliminated. be able to.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a two-chamber diaphragm electrolysis device.

FIG. 2 is a schematic view showing an example of a three-chamber diaphragm electrolysis device.

FIG. 3 is a flowchart showing a water treatment device according to an embodiment of the present invention.

FIG. 4 is a flow chart showing a water treatment device according to an embodiment of the present invention.

FIG. 5 is a flow chart showing a water treatment device according to an embodiment of the present invention.

FIG. 6 is a flow chart showing an example of a conventional water treatment device using an ion exchange device or a reverse osmosis membrane device.

FIG. 7 is a flow chart showing an example of a conventional water treatment device using an ion exchange device or a reverse osmosis membrane device.

[Explanation of symbols]

 6 Reverse Osmosis Membrane Device 8 Ion Exchange Device 20 Ultrafiltration Membrane Device 22 Decarbonation Tower 26 Reverse Osmosis Membrane Device 30 Oxidizer Addition Mechanism 54 Cathode Chamber 58 Anode Chamber 60 Diaphragm 68 Cathode Chamber 72 Anode Chamber 76 Diaphragm 78 Diaphragm 86 Dispersion Device 87 Diaphragm type electrolysis device 88 Cathode chamber 90 Anode chamber 92 Diaphragm 94 Desalination section

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C02F 9/00 JM 503 A 504 B

Claims (1)

[Claims] 1. In a water treatment device for treating water to be treated by an ion exchange device or a reverse osmosis membrane device, a diaphragm type electrolytic device is installed in front of the ion exchange device or the reverse osmosis membrane device, and an oxidizer is used. Water to be treated is introduced into the cathode chamber of the diaphragm electrolyzer, and the water to be treated containing the oxidizing agent is electrolyzed in the cathode chamber, and then the treated water is supplied to the ion exchange device or the reverse osmosis membrane device. A water treatment device characterized in that