JP3137831B2 - Membrane processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane processing apparatus for producing pure water, demineralized water and the like used in semiconductor manufacturing, pharmaceutical manufacturing, food manufacturing and the like by reverse osmosis membrane processing.

[0002]

2. Description of the Related Art When a conventional membrane treatment device equipped with a reverse osmosis membrane device is operated for a long period of time, a hardness component, silica, aluminum, etc. in feed water gradually precipitates in the membrane device, and the membrane permeation resistance increases. However, there is a problem that the differential pressure of water flow increases. In addition, there is also a problem that bacteria and the like are generated, which causes an increase in membrane permeation resistance and an increase in differential pressure of water flow. In this case, for example, a chemical such as hydrochloric acid or caustic soda is prepared, and pH 2 to 4 or pH 9 to
These problems were addressed by adjusting the solution to 11 and performing chemical film cleaning.

Further, in order to prevent the precipitation of hardness components and silica, etc., the pH of the water to be treated is also adjusted by adding chemicals such as hydrochloric acid and caustic soda to the feed water of a reverse osmosis membrane device or the like. Have been.

That is, many chemicals are required to operate the membrane device, and as a result, many of the used chemicals are discharged into rivers or the like in some form.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, what the present inventors propose is the effective use of various components dissolved in feed water.

That is, among components dissolved in industrial water and city water, a considerable proportion of neutral salts such as salt, which is a raw material of chemicals such as hydrochloric acid and caustic soda, is contained. If these can be converted into chemicals such as hydrochloric acid and caustic soda by any method, or chemicals having the same effect, the operation of the membrane treatment equipment without external supply of chemicals or in almost no need Can be performed. By inventing a novel combination of a reverse osmosis membrane device and an electrolysis device, the present inventor can convert the neutral salt into a chemical and enable efficient operation of the reverse osmosis membrane device with high water utilization. Thus, the present invention has been completed.

Accordingly, it is an object of the present invention to provide a membrane treatment apparatus which requires little supply of chemicals such as acids and alkalis and has a high water utilization rate.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method for treating a feedwater by a reverse osmosis membrane to form a first permeate and a first permeate.
A first reverse osmosis membrane device for separating into a concentrated water, a second reverse osmosis membrane device for performing a reverse osmosis treatment on the first concentrated water to separate into a second permeate and a second concentrated water, Electrolytic apparatus for producing acidic and alkaline liquids by electrolyzing permeated water, and electrolytic apparatus
The acidic solution and / or the alkaline solution produced in
Supply to the reverse osmosis membrane device and / or the second reverse osmosis membrane device
Liquid supply means and / or alkaline liquid supply for
And a supply unit for supplying the acidic liquid to the feed water of the first reverse osmosis membrane device, and a supply unit for supplying the alkaline liquid with the second concentrated water. And an alkaline liquid feeding means for feeding the liquid to the apparatus.

[0009] The present invention also provides a first reverse osmosis membrane device for separating feed water into a first permeate and a first concentrated water by reverse osmosis membrane treatment, and an intermediate treatment by subjecting the first concentrated water to reverse osmosis membrane treatment. An intermediate reverse osmosis membrane device comprising a circulating means for separating permeated water and intermediate concentrated water and sending at least a part of the intermediate permeated water to feed water of a first reverse osmosis membrane device; A second reverse osmosis membrane device for treating and separating into a second permeate and a second concentrated water, an electrolyzer for electrolyzing the second permeate to produce an acidic solution and an alkaline solution, A membrane processing apparatus comprising: an acidic liquid feeding means for feeding the first concentrated water; and an alkaline liquid feeding means for sending the alkaline liquid to the second concentrated water.

Further, the present invention is a membrane processing apparatus comprising the above-mentioned membrane processing apparatus and an advanced processing apparatus for further processing the first permeated water of the membrane processing apparatus to obtain high-purity pure water. This includes that the treatment device is any one of a reverse osmosis membrane device, an electric deionized water production device, and a non-regenerative ion exchange device, or a combination thereof.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flowchart showing an example of the configuration of a film processing apparatus according to the present invention. In FIG. 1, reference numeral 11 denotes a pretreatment device water supply,
Specific examples include industrial water and city water. Water supply 1
In 1, pretreatment is performed by a pretreatment device 10, and fine particles, organic matter, residual chlorine, and further dissolved carbon dioxide gas and the like in the raw water are removed, and a pretreatment water 12 is obtained.

Examples of the pretreatment performed by the pretreatment device 10 include coagulation filtration, membrane filtration, decarboxylation, and activated carbon treatment. The feedwater 11 is desalinated water obtained from the membrane treatment apparatus of the present invention, for example, used as various types of cleaning water, and is mixed with recovered water and the like collected for reuse of relatively high-quality cleaning wastewater. It may be done. The pretreatment water 12 is then pressurized by a high-pressure pump (not shown) through a safety filter (not shown), and supplied to the first reverse osmosis membrane device 20 as feed water 21 of the first reverse osmosis membrane device 20. Here, the water is separated into a first permeated water 22 and a first concentrated water 23. The first permeated water 22 is used as it is as demineralized water, or after further advanced treatment, for various uses. Therefore, the reverse osmosis membrane device 20 is a membrane having a high rejection rate, for example, Toray SU-72.
0, Nitto Denko NTR-759HR, Filmtec FT
It is desirable to use -30 or the like.

A part or the whole amount of the first concentrated water 23 is supplied to the second reverse osmosis membrane device 30 as the water supply 31 of the second reverse osmosis membrane device 30. In this case, the application of the reverse osmosis pressure required for the reverse osmosis membrane treatment may use a new high-pressure pump,
The pressure of the first concentrated water 23 may be used.

When a part of the first concentrated water 23 is supplied to the second reverse osmosis membrane device 30, the other part of the first concentrated water 23 is branched off as extracted water 24.

The feed water 31 of the second reverse osmosis membrane device is separated into a second permeate 32 and a second concentrated water 33 by the second reverse osmosis membrane device 30, and the second permeate 32 is supplied to the electrolysis device 40.
Further, the second concentrated water 33 is discharged out of the system.

The reverse osmosis membrane used in the second reverse osmosis membrane device 30 has a low monovalent ion rejection and a high divalent ion rejection, that is, a so-called loose RO membrane, for example, Toray SU-220.
S, Nitto Denko NTR-7250, Filmtec NF-
70 is desirable.

As a result of the second reverse osmosis membrane treatment using such a reverse osmosis membrane, among the neutral salts contained in the feed water 31, monovalent neutral salts suitable for being converted into an acid or alkali by electrolysis. Part of the electrolysis device 40 selectively passes through the reverse osmosis membrane.
On the other hand, the hardness component or silica, which causes scale or the like in the electrolytic treatment, is blocked by the reverse osmosis membrane,
Since it shifts to the second concentrated water 33 side, it is hardly supplied to the electrolytic device 40 side.

A part 34 of the second concentrated water 33 is circulated to the feedwater 31 of the second reverse osmosis membrane device, and the salt concentration in the feedwater 31, especially the monovalent neutral salt concentration is increased to increase the permeated water. 1 in 32
The concentration of the neutral salt can be increased.

As the electrolysis device 40, a normal electrolysis device using an ion exchange membrane or the like as a diaphragm, an electrolysis device using a bipolar membrane to increase electrolysis efficiency, or the like can be used. FIG. 3 shows the basic structure of the electrolysis apparatus. Electrolysis device 40
Is internally partitioned by diaphragms 45, 46, 47. As the diaphragm, a microfiltration membrane (MF), an ultrafiltration membrane (UF), a reverse osmosis membrane (RO), a ceramic membrane, or the like can be used in addition to the ion exchange membrane.

The permeated water 32 of the second reverse osmosis membrane device 30 is branched and supplied to each chamber of the electrolysis device 40, where it is electrolyzed and converted into an acidic solution 41 and an alkaline solution 42, and stored in tanks 100 and 110. And used as needed.

Although not shown in FIG. 1, in more detail, as shown in FIG. 3, the permeated water 32 is divided into four parts and separated by three diaphragms 45, 46, 47 as shown in FIG. Device 4
It is sent to four flow paths within 0, and electrolysis is performed. Then, a diaphragm 45 composed of a fluorine-based ion exchange membrane or the like,
Electrode solution 43, 4 discharged from the electrode chamber partitioned by 46
4 is used separately or released outside the system.

As the electrolysis device, in addition to the basic structure shown in FIG. 3, an electrolysis device having a multi-layered basic structure or a bipolar membrane having a structure in which an anion exchange membrane and a cation exchange membrane are bonded to a diaphragm is used. For example, an electrolyzer for performing an electrode reaction more efficiently, an electrolyzer for inverting the polarity of an electrode at an appropriate time interval, and removing scale on the electrode can be used.

The acidic liquid 41 produced in the electrolytic device 40
And the alkaline liquid 42 is used for various applications as described above. In FIG. 1, for example, the acidic liquid 41 is used for adjusting the pH of the water supplied to the first reverse osmosis membrane device 20 as one example.
An example in which the alkaline liquid 42 is used for neutralizing the second concentrated water 33 of the second reverse osmosis membrane device 30 is shown.

That is, the acidic solution 41 produced by the electrolytic device 40 is sent from the tank 100 to the water supply 21 of the first reverse osmosis membrane device 20 through the pipe 101 by an acidic solution feeding means (not shown) such as a pump. Thereby, the pH of the water supply 21 is controlled to be acidic. When the feed water 21 of the first reverse osmosis membrane device 20 is controlled to the acidic side in this manner, most of the added acid passes through the first concentrated water side of the first reverse osmosis membrane device 20 to the second reverse osmosis membrane device. Since the second concentrated water 33 of the osmosis membrane device 30 is concentrated in the second concentrated water 33, and the second concentrated water 33 becomes acidic, the alkaline liquid 42 produced in the electrolytic device 40 is neutralized from the tank 110 to neutralize the second concentrated water 33. The alkaline liquid is supplied to the second concentrated water 33 via a pipe 111 by an alkaline liquid supplying means (not shown). In this case, since the acidic liquid 41 and the alkaline liquid 42 are originally produced by the electrolysis apparatus 40 in equivalent amounts, the neutralization is naturally performed without any excess and deficiency, and the second concentrated water 33 is substantially naturally produced. It is neutralized and discharged out of the system.

As described above, the first reverse osmosis membrane device 20
The pH of the feed water 21 is controlled to be acidic because calcium, magnesium, etc., in the first reverse osmosis membrane device 20 or the second reverse osmosis membrane device 30 is improved with the improvement of the water utilization rate of the whole membrane treatment device. This is for preventing the precipitation of a hardness component, aluminum hydroxide, silica, or the like, which will be described in more detail in the following configuration examples.

FIG. 2 is a flowchart showing another example of the configuration of the film processing apparatus of the present invention. In this configuration example, the first permeated water 2 of the first reverse osmosis membrane device 20 is added to the configuration shown in FIG.
As an advanced treatment apparatus 200 for further treating the wastewater treatment apparatus 2, an electric deionized water production apparatus 60 and a non-regenerative ion exchange apparatus 70 are provided, and the first and second reverse osmosis membrane apparatuses 20, 3 are provided.
That is, the intermediate reverse osmosis membrane device 50 is provided between 0.

That is, the first permeated water 22 of the first reverse osmosis membrane device 20 is first sent to an electric deionized water producing device 60, where the ions are electrically removed, and the deionized water 61
Becomes

In the above-mentioned electric deionized water producing apparatus, a gap formed by an anion exchange membrane and a cation exchange membrane is basically filled with, for example, a cation exchange resin and an anion exchange resin, if necessary, to form a desalination chamber. And, while passing the water to be treated into the desalting chamber, a DC current is applied in a direction perpendicular to the flow of the water to be treated through the both ion exchange membranes, and flows outside the both ion exchange membranes. Deionized water is produced while electrically removing ions in the water to be treated from the concentrated water.Even if the deionization chamber is filled with an ion exchanger such as an ion exchange resin, regeneration of acids, alkalis, etc. Deionized water can be produced without using any chemicals. The concentration chamber 17 through which the concentrated water flows may be filled with an ion exchanger in the same manner as the desalting chamber.

As the electric deionized water producing apparatus,
Known (for example, JP-A-4-71624, JP-A-4-4-1)
No. 66215) can be used as it is.

The use of the deionized water producing apparatus 60 removes trace amounts of ions remaining in the first permeated water 22.

The deionized water 61 is then sent to a non-regenerative ion exchange device 70 where the remaining ions are further removed to produce pure water 71 of high purity. Examples of the non-regenerating type ion exchange device 70 include a mixed bed type ion exchange device and a column in which a mixed resin of an H type cation exchange resin and an OH type anion exchange resin which has been regenerated in another place is filled in a column. An anion exchange apparatus or the like in which only an OH type anion exchange resin is filled can be used.

The advanced treatment apparatus 200 is not limited to the above configuration. For example, an ultraviolet oxidizing apparatus (not shown) may be provided in front of the electric deionized water producing apparatus 60, and the first permeated water 22 may be treated by the ultraviolet oxidizing apparatus. After reducing the TOC, water can be passed through an electric deionized water producing apparatus or a non-regenerative ion exchange apparatus. In this case, high-purity pure water having a lower TOC can be obtained. Further, a reverse osmosis membrane device or the like can be additionally provided.

That is, in order to improve the purity of the first permeated water 22, an advanced treatment apparatus 200 composed of any of the above apparatuses or a combination of a plurality of these apparatuses is provided. Specific examples of the advanced treatment apparatus 200 include: (1) an electric deionized water producing apparatus-a non-regenerative ion exchange apparatus; and (2) an ultraviolet oxidizing apparatus-an electric deionized water producing apparatus-a non-regenerative ion exchange apparatus. 3) Reverse osmosis membrane device-Non-regenerative ion exchange device (4) Ultraviolet oxidizer-Non-regenerative ion exchange device (5) Electric deionized water production device-Ultraviolet oxidizer-Non-regenerative ion exchange device Further, a membrane processing device such as a microfiltration membrane device or an ultrafiltration membrane device may be arranged at a stage subsequent to the device having the above-described configuration (1) to (5).

Further, in the present configuration, an intermediate reverse osmosis membrane device 50 is provided between the first and second reverse osmosis membrane devices 20 and 30, and the intermediate permeated water 52 of the intermediate reverse osmosis membrane device 50 is supplied to the first reverse osmosis membrane device 50. 1 The water is circulated to the water supply of the reverse osmosis membrane device 20, thereby improving the water utilization rate of the entire membrane treatment device. In this case, precipitation of hardness components such as calcium and magnesium which may be generated inside the intermediate reverse osmosis membrane device 50 or the second reverse osmosis membrane device 30 or aluminum hydroxide with the improvement of the water utilization rate. In order to prevent precipitation of silica, silica, etc., the acid solution 4
1 is sent from the tank 100 to the first concentrated water 23 of the first reverse osmosis membrane device 20 through a pipe 101 by an acidic liquid feeding means (not shown), whereby the intermediate water supply 51 of the intermediate reverse osmosis membrane device 50 is supplied. Control the pH to acidic. In this case, the pH control in this case is preferably performed so that the pH of the intermediate concentrated water 53 of the intermediate reverse osmosis membrane device 50 is maintained at 5.5 to 4.5.

It has been discovered by the present inventor that the acidification not only prevents the precipitation of scale due to the hardness component but also the precipitation of silica. This technology is currently being patent-pended (Japanese Patent Application No. 5-315708).

If necessary, a small amount of an organic phosphate-based or acrylic polymer-based dispersant may be added to the intermediate reverse osmosis membrane device 50.
Can be added to the intermediate water supply 51.

The intermediate concentrated water 53 is sent to the second reverse osmosis membrane device 30 as the water supply 31 of the second reverse osmosis membrane device 30.

Further, in this configuration, the alkaline liquid 4
2 is a pipe 11 by an alkaline liquid supply means (not shown).
After passing through 1, the water is sent to the second concentrated water 33 of the second reverse osmosis membrane device 30, and after mixing with the second concentrated water 33, is discharged to the outside as a discharge water 35.

Since the acidic liquid 41 is mixed with the intermediate feed water 51, the intermediate concentrated water 53 and, consequently, the second concentrated water 33 are acidic. However, the intermediate concentrated water 53 is neutralized by the alkaline liquid to be mixed. As described above, the liquid and the alkaline liquid are originally produced by the electrolysis apparatus 40 in an equivalent amount, so that the neutralization is naturally performed without any excess and deficiency, and the discharged water 35 discharged to the outside of the system is naturally almost completely. It is neutral.

In the case of this configuration, the reverse osmosis membrane devices 20 and 50
The reverse osmosis membrane used in the above is a membrane having a high rejection rate, for example, Toray SU-
720, Nitto Denko NTR-759HR, and Filmtec FT-30 are preferred. On the other hand, what is used for the reverse osmosis membrane device 30 has a low rejection rate of monovalent ions and a high rejection rate of divalent ions, a so-called loose RO membrane, for example, Toray SU-
220S, Nitto Denko NTR-7250, Filmtec NF-70 and the like are desirable.

In order to obtain an acidic solution and an alkaline solution having the concentrations required for adjusting the pH of the intermediate condensed water 53 of the intermediate reverse osmosis membrane device 50 to the above-mentioned preferable pH range, in the above-mentioned configuration, It is necessary to increase the concentration of the monovalent neutral salt in the second permeated water 32 supplied to the electrolysis device 40 accordingly, so that the water utilization rate should be 80% or more, preferably 90% or more. desirable. Here, the water utilization rate is defined as 22 first permeated water / 11 × 100 (supplied water). <Example 1> Water film treatment was performed using the apparatus shown in FIG. As the pretreatment feedwater 11, Toda City industrial water was used, and as pretreatment, coagulation filtration and decarbonation treatment using a decarbonation tower were performed. For the reverse osmosis membrane, Nitto Denko NTR759HR is used for the reverse osmosis membrane device 20, and NT is also used for the reverse osmosis membrane device 30.
R7250 was used. As the electrolysis device, an electrolysis unit of a commercially available alkaline ionized water production device (manufactured by Nippon Intec Co., Ltd.) was used. A part of the concentrated water of the first reverse osmosis membrane device 20 is supplied to the second reverse osmosis membrane device 30, and a certain amount (5
L / h) was subjected to electrolytic treatment. The current required for the electrolytic treatment was about 0.5 A and 20 V. As a result, the properties of the obtained acidic liquid and alkaline liquid are shown in Table 1. The water utilization rate here is 22 permeate / 11 × 100 (%) feed water. As this value is larger, the concentration of neutral salt in the feed water 31 of the second reverse osmosis membrane device 30 is higher, and as a result, the concentration of neutral salt in the permeated water 32 supplied to the electrolytic device 40 is higher. It was found that the pH of the obtained acidic solution and alkaline solution was affected.

[0043]

[Table 1] Water supply 11: pH 6.3, Water supply 21: pH 6.6 Practically, in order to carry out chemical cleaning of the reverse osmosis membrane, p
A chemical solution with H <3 or pH> 10 is desirable. Therefore, although it is affected by the quality of the raw water, the separation performance of the membrane, and the electrolysis conditions, it was found that the water utilization rate in the case of the configuration of this embodiment is desirably 80% or more.

An acidic liquid obtained in an experiment with a water utilization of 80%,
The alkaline liquid was used for cleaning the membrane device. That is, the obtained acidic solution and alkaline solution were each stored in 100 L, and the membrane device was washed once / weekly. The cleaning method is
The method was performed by a method of filling the above acidic solution or the like in the flow path of the present membrane processing apparatus. First, the substrate was immersed and washed in an acidic solution for 1 hour, washed with deionized water, treated in the same manner with an alkaline solution, and finally washed with demineralized water and then returned to a normal operation. The above-mentioned water membrane treatment and washing were continued for two months, but no decrease in the amount of permeated water and no increase in the pressure difference in water passage were observed.

On the other hand, when the cleaning treatment was not performed at all, the pressure difference in water flow increased after 1.5 months, and the amount of permeated water decreased. This phenomenon was recovered by washing the channel with a solution adjusted to pH 10 with sodium hydroxide. Therefore,
It is considered that the slime due to the generation of microorganisms accumulated in the membrane device, causing an increase in the differential pressure.

As described above, according to the present invention, stable operation was achieved without supplying a chemical such as caustic soda from the outside. In view of the present embodiment, it is estimated that a longer cleaning interval is effective. <Example 2> In Example 1, the higher the water utilization rate was, the more effective in the present invention, and the effect of the washing was clarified. However, since silica and hardness components in raw water precipitate, it is often not always possible to simply increase the water utilization rate. Therefore, in a second embodiment, an example in which the present invention is used for the purpose of increasing the water utilization rate will be described. The apparatus of the present invention having a configuration excluding the non-regenerative ion exchange apparatus 70 from the apparatus configuration shown in FIG.
The acidic solution No. 6 was added to the intermediate feed water 51 of the intermediate reverse osmosis membrane device 50, and the alkaline solution having a pH of 10.4 was added to the second concentrated water 33 of the second reverse osmosis membrane device 30. In addition, water supply 11
As a pre-treatment, a coagulation filtration and a decarbonation treatment by a decarbonation tower are performed, and the concentrated water (not shown) of the electric deionized water producing device 60 (EDI) is supplied to the feed water 21 of the first reverse osmosis membrane device 20.
Used to circulate.

In Japan, the upper limit of the water utilization rate is generally determined by the deposition limit of silica (about 100 ppm at 25 ° C.). The industrial water of Toda used in the experiment also contained about 15 ppm of silica. Therefore, even if the water utilization rate is simply increased, the concentrated water can supply 6.7% of the supply water.
When the concentration is more than twice, the concentration of silica on the concentrated water side exceeds the precipitation limit to cause precipitation of silica, which may cause a decrease in the amount of permeated water.However, according to the present invention, there is no need for external supply of chemicals. The pH of the concentrated water side of the intermediate reverse osmosis membrane device 50 and the second reverse osmosis membrane device 30 having a high concentration rate could be kept low, and the precipitation of silica could be prevented. As the reverse osmosis membranes of the reverse osmosis membrane devices 20 and 50, NRT759HR was used, and as the electrolysis device 40, two devices used in Example 1 were used in parallel.

Table 2 shows the flow rate and silica concentration of each part. In the present embodiment, the intermediate reverse osmosis membrane device 50 is used.
The pH of the intermediate feed water 51 was about 6.9 at the beginning of the operation, but became about 5 one day after the start of the operation, and was stabilized. As a result, the intermediate concentrated water 53 and the second reverse water of the intermediate reverse osmosis membrane device 50 were obtained. The pH of the second concentrated water 33 of the osmosis membrane device 30 could be stably maintained at 5 or less. Further, the same washing as that described in Example 1 was performed at an interval of once / two weeks. In addition,
Acidic and alkaline liquids for cleaning are gradually stored in tank 10
The apparatus was operated while accumulating at 0,110. The operation was performed for two months, but no decrease in the amount of permeated water in each of the reverse osmosis membrane devices 20, 30, and 50 was observed.

On the other hand, when the water utilization rate was set to 90% in the apparatus shown in Example 1 and the pH of the water supply 21 was not adjusted with the acidic solution produced in the electrolytic apparatus 40, the reverse osmosis was performed after one month. The amount of permeated water of the membrane device 20 is reduced to about 85% of the initial value.
The amount of water permeated through the reverse osmosis membrane device 30 was reduced to 70%. In addition, these reverse osmosis membrane devices are set to pH 3 (hydrochloric acid) and pH 1
Chemical cleaning was performed with an aqueous solution of 0 (caustic soda), but the amount of permeated water recovered little. Therefore, it was presumed that the decrease in the amount of permeated water was caused by silica or the like which could not be washed with an acid or alkali.

[0050]

[Table 2] (*) Exactly 13 μg SiO ₂ / l.

As is clear from Table 2, since the pH of the intermediate concentrated water and the second concentrated water could be maintained at 5 or less, the silica concentration in the intermediate concentrated water 53 and the second concentrated water 33 was 1%.
The intermediate reverse osmosis membrane device and the second reverse osmosis membrane device could be operated stably even at a high concentration exceeding 00 ppm, thereby achieving a water utilization of 90%. The obtained deionized water 61 also has a silica concentration of 13 μg SiO ₂ / l and a resistivity of 16.
The purity was as high as 7 MΩ · cm.

As described above, according to the present embodiment, it was possible to stably perform the operation at a water utilization rate of 90% without externally supplying a chemical. <Embodiments 3 and 4> In the apparatus shown in FIG. 2, a non-regenerative ion exchange device 70 is removed, and a membrane treatment device in which an ultraviolet oxidation device (UV _OX ) is provided in front of an electric deionized water production device 60. And deionized water was produced under the same operating conditions as in Example 2.

The ultraviolet oxidation apparatus is TF manufactured by Chiyoda Kohan Co., Ltd.
L-1.

Table 3 shows the measured values of the water quality in each channel.

[0055]

[Table 3] In addition, for reference, Table 4 shows measured values of water quality in each flow path when deionized water was manufactured under the same operating conditions using an apparatus in which the ultraviolet oxidation apparatus was removed from the above configuration.

[0056]

[Table 4] Comparing Tables 3 and 4, the TOC was reduced from 49 ppb to 8 ppb by providing the ultraviolet oxidizer, and the effect of the ultraviolet oxidizer was confirmed. As for silica, water quality equivalent to that obtained by the conventional ion exchange method was obtained.

In the conventional method of directly supplying water such as city water or industrial water with an ion exchange device to obtain pure water as desalinated water, since the salt concentration in the water supply is high, a double-bed type usually equipped with a regeneration facility is used. And a mixed bed type ion exchange device is used, and naturally, chemical regeneration with acid and alkali is required, and many chemicals will be supplied from the outside, but according to the present invention, as described above, from the outside 90% water utilization without chemical replenishment,
And high-purity pure water could be produced.

[0058]

As described above, the membrane treatment apparatus of the present invention is an ideal one in which the amount of chemicals required for operation is extremely small and the water utilization rate is high, that is, the amount of drainage is small.

[Brief description of the drawings]

FIG. 1 is a flowchart showing one configuration example of the present invention.

FIG. 2 is a flowchart showing another configuration example of the present invention.

FIG. 3 is a conceptual diagram illustrating a configuration of an electrolysis device.

DESCRIPTION OF SYMBOLS 10 Pretreatment device 11 Pretreatment water supply 20 First reverse osmosis membrane device 21 Water supply of first reverse osmosis membrane device 22 First permeate water 23 First concentrated water 30 Second reverse osmosis membrane device 31 Second reverse Water supply to osmosis membrane device 32 Second permeate water 33 Second concentrated water 35 Drainage water 40 Electrolysis device 41 Acidic solution 42 Alkaline liquid 50 Intermediate reverse osmosis membrane device 51 Intermediate water supply to intermediate reverse osmosis membrane device 52 Intermediate permeate 53 Intermediate concentrated water Reference Signs List 60 Deionized water production device 70 Non-regenerative ion exchange device 200 Advanced treatment device

Claims (5)

(57) [Claims] 1. A first reverse osmosis membrane device for separating feed water into a first permeated water and a first concentrated water by reverse osmosis membrane treatment, and a second permeated water by subjecting the first concentrated water to reverse osmosis membrane treatment. When a second reverse osmosis membrane apparatus for separating and a second concentrated water, an electrolytic apparatus for producing an acidic solution and an alkaline solution by electrolysis of the second permeate, electrolysis instrumentation
Acid and / or alkaline liquids
Supply to the first reverse osmosis membrane device and / or the second reverse osmosis membrane device
Liquid supply means and / or alkaline liquid
A film processing apparatus comprising: a feeding unit . 2. An acidic solution feeding means for feeding an acidic solution produced by an electrolyzer to water supply of a first reverse osmosis membrane device, and an alkaline solution produced by said electrolyzer by a second reverse osmosis membrane device of a second reverse osmosis membrane device. 2. The membrane processing apparatus according to claim 1, further comprising an alkaline liquid feeding means for feeding the concentrated water. 3. A first reverse osmosis membrane apparatus for separating feed water by reverse osmosis membrane treatment into first permeated water and first concentrated water, and an intermediate permeated water by reverse osmosis membrane treatment of the first concentrated water. An intermediate reverse osmosis membrane device provided with a circulating means for separating at least a part of the intermediate permeate into feed water of the first reverse osmosis membrane device while separating the intermediate concentrated water from the intermediate concentrated water; A second reverse osmosis membrane device for separating the second permeated water and a second concentrated water, an electrolysis device for electrolyzing the second permeated water to produce an acidic solution and an alkaline solution, and a first concentration of the acidic solution. A membrane processing apparatus, comprising: an acidic liquid feeding means for feeding water, and an alkaline liquid feeding means for feeding the alkaline liquid to the second concentrated water. 4. A membrane processing apparatus comprising: the membrane processing apparatus according to claim 1; and an advanced processing apparatus that further processes first permeated water of the membrane processing apparatus to obtain high-purity pure water. apparatus. 5. The membrane treatment according to claim 4, wherein the advanced treatment apparatus is any one of a reverse osmosis membrane apparatus, an electric deionized water production apparatus, and a non-regenerative ion exchange apparatus, or a combination thereof. apparatus.