JP2017121611A - Electric deionization apparatus, and operation method of electric deionization apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric deionization apparatus capable of suppressing proliferation of fungi, microorganisms or the like in the apparatus.SOLUTION: An electric deionization apparatus 1 has concentration chambers 15 and desalination chambers 16 formed alternately by arranging alternately a plurality of anion exchange membranes 13 and cation exchange membranes 14 between electrodes (anode 11 and cathode 12). An ion exchanger is filled in the desalination chambers 16, the concentration chambers 15, an anode chamber 17, and a cathode chamber 18. The cation exchange membrane 14 and anion exchange membrane 13 are made of an ion exchange membrane containing a vinyl acetate component. The ion exchange membrane is especially made of a polymer composed of the vinyl acetate component and a component having an anionic group or a cationic group.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrodeionization apparatus and an operation method thereof, and more particularly to an electrodeionization apparatus capable of suppressing the growth of microorganisms and the like generated in the apparatus and an operation method thereof.

  The electrodeionization apparatus generally arranges a cation exchange membrane and an anion exchange membrane alternately between a cathode and an anode, and forms a demineralization chamber and a concentration chamber by partitioning these cation exchange membrane and anion exchange membrane, The desalting chamber and the concentration chamber are filled with an ion exchange resin. In a conventional electrodeionization apparatus, as an ion exchange membrane such as a cation exchange membrane or an anion exchange membrane, a heterogeneous membrane formed by adding a binder such as polystyrene to a powdered ion exchange resin, styrene- Homogeneous membranes formed by polymerization of divinylbenzene or the like, and those obtained by graft polymerization of monomers having various anion exchange functions or cation exchange functions are used.

  In the electrodeionization apparatus as described above, when raw water is allowed to pass through the desalting chamber and concentrated water is allowed to pass through the concentrating chamber, and an electric current is passed between the cathode and the anode along with this, the deionizing chamber passes through the ion exchange resin. Then, ions move through the anion exchange membrane and the cation exchange membrane to the concentration chamber, so that deionized water (pure water) is obtained from the demineralization chamber. The concentrated water enriched with ions flowing through the concentration chamber is discarded or partially recycled. Such an electrodeionization apparatus is used as a pure water production apparatus used in various industries such as semiconductor chip production, power plant operation, petrochemical use, pharmaceutical production, and the like.

  However, when deionized water is produced by the operation of the electrodeionization apparatus, fungi and microorganisms are propagated and contaminated. In particular, breeding is likely to occur in the concentrating chamber and a line communicating therewith, and in the worst case, the concentrating chamber may be blocked. Thus, as a method of sterilizing the electrodeionization apparatus, it is conceivable to circulate heated water or sterilize with chemicals. However, in heat sterilization, it is necessary to provide a means for producing and supplying heated water separately. is there. In the case of disinfection with a chemical, the chemical may be reactive with the ion exchange resin or ion exchange membrane in the electrodeionization apparatus, which may shorten the service life of the electrodeionization apparatus. There is a problem. In particular, it is desirable that the electrodeionization apparatus be cleaned as little as possible.

  This invention is made | formed in view of the said subject, and it aims at providing the electrodeionization apparatus which can suppress the proliferation of fungi, microorganisms, etc. which generate | occur | produce in an apparatus. Another object of the present invention is to provide a method for operating such an electrodeionization apparatus.

  In view of the above object, the present invention firstly provides a cathode and an anode, a cation exchange membrane and an anion exchange membrane disposed between the cathode and the anode, and a detachment formed by the cation exchange membrane and the anion exchange membrane. A salt chamber and a concentrating chamber, wherein the desalting chamber and the concentrating chamber are filled with an ion exchanger, and a concentrated water passing means for passing concentrated water through the concentrating chamber and raw water for the desalting chamber. An electrodeionization apparatus having means for passing deionized water by passing water, an electrodeionization apparatus comprising a vinyl acetate component as the cation exchange membrane and anion exchange membrane. (Invention 1).

  According to this invention (Invention 1), the present inventor has examined the cause of fungi and microorganisms easy to propagate in the concentration chamber of the electrodeionization apparatus and the line communicating therewith. Various ions are concentrated in the partitioned concentration chamber, but organic ions tend to adhere to general-purpose ion exchange membranes (anion exchange membranes and cation exchange membranes) such as heterogeneous membranes and homogeneous membranes. As a result, it was found that fungi and microorganisms were easy to propagate. Therefore, a film made of a polymer containing a vinyl acetate component is excellent in organic contamination resistance and hardly adheres to fungi and microorganisms. Therefore, a polymer comprising a vinyl acetate component and a component having an anionic group or a cationic group. The use of an ion exchange membrane using the material makes it possible to suppress the growth of fungi and microorganisms in the concentration chamber, avoid the blockage of the concentration chamber, and reduce the frequency of cleaning the electrodeionization apparatus.

  In the said invention (invention 1), it is preferable that the said concentrated water flow means passes the deionized water which flowed through the said demineralization chamber as concentrated water (invention 2). In particular, the concentrated water flow means introduces the concentrated water into the concentration chamber from the side near the deionized water outlet of the demineralization chamber and flows out from the side near the raw water inlet of the demineralization chamber. Preferred (Invention 3).

  According to the inventions (Inventions 2 and 3), by passing deionized water through deionized water and passing through deionized water into the concentrating chamber, the amount of ionic components per se is small, so that the growth of fungi and microorganisms can be suppressed. . Furthermore, in the electrodeionization apparatus, the ion concentration decreases toward the side closer to the deionized water outlet in the demineralization chamber. On the other hand, since concentrated water having a high ion concentration circulates in the concentrating chamber, the difference in ion concentration increases, so that the ion removal rate is less likely to increase as the purity of the deionized water increases. Therefore, by passing deionized water through the concentration chamber, the difference in ion concentration can be reduced and the ion removal rate can be improved. In particular, in the demineralization chamber, the ion concentration decreases toward the side closer to the deionized water outlet, and conversely, deionized water is supplied to the concentrating chamber from the side closer to the deionized water outlet. The difference in ion concentration between the salt chamber and the concentration chamber can be reduced over the entire area of the desalting chamber and the concentration chamber, and the effect of improving the ion removal rate is great. Furthermore, there is an effect that the concentrated components can be easily discharged out of the system.

  In the said invention (invention 1-3), it is preferable that the said cation exchange membrane contains the copolymer of the anionic monomer which has a sulfonate group in a molecule | numerator, and the monomer of vinyl acetate (invention 4). ).

  According to this invention (invention 4), such a cation exchange membrane has a cation exchange ability and is excellent in organic contamination resistance, so that it is possible to suppress the growth of fungi and microorganisms, and an electrodeionization apparatus. It is suitable as a cation exchange membrane constituting

  In the said invention (invention 1-4), it is preferable that the said anion exchange membrane contains the copolymer of the cationic monomer which has a quaternary ammonium group in a molecule | numerator, and the monomer of vinyl acetate ( Invention 5).

  According to this invention (invention 5), such an anion exchange membrane has anion exchange ability and is excellent in organic contamination resistance. Therefore, it is possible to suppress the growth of fungi and microorganisms and to provide an electrodeionization apparatus. It is suitable as a constituent anion exchange membrane.

  In addition, the present invention secondly, a cathode and an anode, a cation exchange membrane and an anion exchange membrane disposed between the cathode and the anode, a desalting chamber partitioned by these cation exchange membrane and anion exchange membrane, and A concentrating chamber, wherein the desalting chamber and the concentrating chamber are filled with an ion exchanger, and a concentrated water passage means for passing the concentrated water to the concentrating chamber and raw water to the desalting chamber. A means for taking out deionized water and using the membrane made of a polymer containing a vinyl acetate component as the cation exchange membrane and the anion exchange membrane, A method of operating an electrodeionization apparatus is provided, wherein a part of deionized water that has passed through the demineralization chamber is introduced (invention 6).

  According to this invention (Invention 6), since a film made of a polymer containing a vinyl acetate component is excellent in organic contamination resistance, the film formed by a vinyl acetate component and a polymerization component having an anionic group or a cationic group is used. By using a combined ion exchange membrane in an electrodeionization apparatus and introducing a portion of the deionized water that has passed through the demineralization chamber as concentrated water, the deionized water itself has a trace amount of ionic components. Therefore, high-purity deionized water that can suppress the growth of fungi and microorganisms can be produced.

  In the said invention (invention 6), while introducing the said concentrated water from the side near the deionized water taking-out port of the said demineralization chamber of the said concentration chamber, from the side near the raw | natural water inlet of the said demineralization chamber of the said concentration chamber It is preferable to let it flow out (Invention 7).

  According to this invention (invention 7), in the demineralization chamber, the ion concentration decreases toward the side closer to the deionized water outlet, and conversely, deionized water is supplied from the side closer to the deionized water outlet. By supplying to the concentrating chamber, the difference in ion concentration between the desalting chamber and the concentrating chamber can be reduced throughout the desalting chamber and the concentrating chamber.

  According to the present invention, the cation exchange membrane and the anion exchange membrane constituting the electrodeionization apparatus comprise a polymer containing a vinyl acetate component, particularly a vinyl acetate component and an anionic group or a component having a cationic group. Since the ion exchange membrane is used, the propagation of fungi and microorganisms in the concentration chamber can be suppressed, the blockage of the concentration chamber can be avoided, and the frequency of cleaning the electrodeionization apparatus can be suppressed.

It is typical sectional drawing which shows the structure of the electrodeionization apparatus by one Embodiment of this invention. It is a systematic diagram which shows the electrodeionization apparatus by one Embodiment of this invention.

  Hereinafter, an electrodeionization apparatus according to a first embodiment of the present invention and an electrodeionization operation method using the same will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing a configuration of an electrodeionization apparatus according to an embodiment of the present invention. In FIG. 1, an electrodeionization apparatus 1 includes a plurality of anion exchange membranes between electrodes (anode 11 and cathode 12). 13 and the cation exchange membrane 14 are alternately arranged to form the concentration chamber 15 and the desalting chamber 16 alternately. The desalting chamber 16 is made of an ion exchange resin, an ion exchange fiber, a graft exchanger or the like. The ion exchangers (anion exchanger and cation exchanger) to be mixed or packed in multiple layers. The concentration chamber 15, the anode chamber 17 and the cathode chamber 18 are also filled with an ion exchanger.

  In the electrodeionization apparatus 1, a water supply means (not shown) for passing water to be treated (raw water) W through the demineralization chamber 16 and taking out the deionized water (treated water) W 1, and a concentration chamber 15 Concentrated water passing means (not shown) for passing the concentrated water W2 is provided, and in the present embodiment, the concentrated water W2 is concentrated from the side close to the deionized water W1 outlet of the desalting chamber 16. While being introduced into the chamber 15, the concentrated water W 2 flows into the concentrating chamber 15 from the side near the raw water inlet of the desalting chamber 16, that is, from the direction opposite to the flow direction of the treated water (raw water) W in the desalting chamber 16. It is the structure which introduces and discharges the concentrated waste water W3.

  Specifically, as shown in FIG. 2, by introducing a part of deionized water obtained from the desalting chamber 16 into the concentration chamber 15, and using the deionized water W1 as the concentrated water W2 in the concentration chamber 15, It is preferable that the concentrated water W2 has a reduced ion concentration.

  In this electrodeionization apparatus 1, as the ion exchange membrane constituting the cation exchange membrane 14 and the anion exchange membrane 13, one containing a vinyl acetate component is used. In particular, it is preferable to use an ion exchange membrane made of a polymer of a vinyl acetate component and a polymerization component having an anionic group or a cationic group. In the case of the cation exchange membrane 14, a film obtained by forming a copolymer of an anionic monomer having a sulfonate group in the molecule and a vinyl acetate monomer can be used. In the case of the anion exchange membrane 13, a film obtained by forming a copolymer of a cationic monomer having a quaternary ammonium group in the molecule and a vinyl acetate monomer can be used.

  By using a membrane made of a polymer containing a vinyl acetate component as the ion exchange membrane (anion exchange membrane 13 and cation exchange membrane 14), the growth of microorganisms and the increase in the number of bacteria in the concentration chamber 15 can be suppressed. Blockage can be prevented and the frequency of cleaning the electrodeionization apparatus 1 can be reduced.

  As an ion exchange membrane composed of a polymer composed of a vinyl acetate component as described above and a polymerization component having an anionic group or a cationic group, there is no particular limitation as long as it includes a polymer obtained by polymerizing these components. What was described in Unexamined-Japanese-Patent No. 2015-17419 etc. can be applied suitably.

  Next, an operation method of the above-described electrodeionization apparatus will be described. First, water to be treated (raw water) W is introduced into the desalting chamber 16, and deionized water W <b> 1 is obtained from the desalting chamber 16. In the present embodiment, a part of the deionized water W1 is concentrated water W2, and the water is passed through the concentration chamber 15 in a countercurrent and transient manner in a direction opposite to the direction of water flow through the demineralization chamber 16. Concentrated waste water W3 is discharged out of the system. That is, in the electrodeionization apparatus 1 of the present embodiment, the concentration chambers 15 and the demineralization chambers 16 are alternately arranged in parallel, and serve as an inlet of the concentration chamber 15 on the side of the demineralization chamber 16 where the deionized water W1 is taken out. In addition, an outlet of the concentrating chamber 15 is provided on the raw water inflow side of the desalting chamber 16. Part of the deionized water W1 is supplied to the inlet side of the anode chamber 17, and the effluent water of the anode chamber 17 is supplied to the inlet side of the cathode chamber 18, and the effluent water of the cathode chamber 18 is drained. Is discharged outside the system.

  In this way, by passing deionized water W1 through the concentration chamber 15 in a counter-current and transient manner with the desalting chamber 16, the concentrated drainage in the concentration chamber 15 is closer to the desalting chamber 16 in the desalting chamber 16. The concentration of ions in W3 is low, and not only the growth of fungi and microorganisms itself is suppressed, but also the influence on the desalting chamber 16 due to concentration diffusion is reduced, and the ion removal rate, particularly the removal rate of silica and boron, is reduced. It can be improved dramatically. In addition, the concentrated component discharged from the desalting chamber 16 can be easily discharged out of the system.

  In the operation method of the electrodeionization apparatus 1, various ions are concentrated in the concentration chamber 15 from the demineralization chamber 16, and since organic ions are included in these, fungi and microorganisms are propagated. It's easy to do. However, as the ion exchange membrane (anion exchange membrane 13 and cation exchange membrane 14), a membrane made of a polymer containing the vinyl acetate component as described above is used, and the polymer containing the vinyl acetate component is resistant to organic contamination. Since it is excellent, the organic ions are not easily attached to the ion exchange membranes 13 and 14, and thus are efficiently discharged as the concentrated waste water W3. Thereby, propagation of microorganisms in the concentration chamber 15 and an increase in the number of bacteria can be suppressed, the blockage of the concentration chamber 15 can be prevented, and the frequency of cleaning the electrodeionization apparatus 1 can be reduced.

  As mentioned above, although one Embodiment of this invention has been demonstrated with reference to an accompanying drawing, if this invention uses the film | membrane which consists of a polymer containing a vinyl acetate component as the anion exchange membrane 13 and the cation exchange membrane 14, the said will be said. The present invention is not limited to the embodiment, and various modifications can be made. For example, in the embodiment, deionized water W1 is used as the concentrated water W2, but pure water may be separately prepared. Further, the water flow direction may be the same direction as the water to be treated W.

  The following specific examples further illustrate the present invention. In addition, this invention is not limited to the following Example.

[Example 1]
In an electrodeionization apparatus (KCDI-UPz · 20H, Kurita Kogyo Co., Ltd.), a cation exchange membrane containing a copolymer of an anionic monomer having a sulfonate group in its molecule and a vinyl acetate monomer (Kuraray) And anion exchange membrane (made by Kuraray Co., Ltd.) containing a copolymer of a cationic monomer having a quaternary ammonium group in the molecule and a vinyl acetate monomer. Configured the device.

Using this electrodeionization apparatus, raw water (200 μS / cm, TOC 3 ppm) of a semiconductor factory treated with a reverse osmosis (RO) membrane was passed through the electrodeionization apparatus as raw water (treated water W). The treatment conditions are such that the flow rate of deionized water (treated water) W1 is 2 m ³ / h, the flow rate of concentrated water W2 is 0.3 m ³ / h, and a portion of deionized water W1 is used as the concentrated water W2. Water was passed through the concentration chamber in a transient manner so as to counter flow with the salt chamber.

When such operation was continued for one year, the differential pressure of the concentrated water W2 was almost constant at 0.2 kg / cm ² , and no increase was observed.

[Comparative Example 1]
In the electrodeionization device (KCDI-UPz · 20H, Kurita Kogyo Co., Ltd.), the electrodeionization device is composed of a cation exchange membrane and anion exchange membrane using a general-purpose heterogeneous membrane with polystyrene as a binder. did.

Using this electrodeionization apparatus, raw water (200 μS / cm, TOC 3 ppm) of a semiconductor factory treated with a reverse osmosis (RO) membrane was passed through the electrodeionization apparatus as raw water (treated water W). The treatment conditions are such that the flow rate of deionized water (treated water) W1 is 2 m ³ / h, the flow rate of concentrated water W2 is 0.3 m ³ / h, and the treated water W (RO membrane treated water) is used as the concentrated water W2. Then, water was passed through the concentration chamber in a transient manner so as to be in the same direction (cocurrent flow) as the desalting chamber.

Was continued such an operating one year, the differential pressure of the concentrated water W2 is increased from 0.2 kg / cm ² to 0.7 kg / cm ^2, concentrating compartments washing electrodeionization apparatus is needed.

[Comparative Example 2]
In the electrodeionization device (KCDI-UPz · 20H, Kurita Kogyo Co., Ltd.), the electrodeionization device is composed of a cation exchange membrane and anion exchange membrane using a general-purpose heterogeneous membrane with polystyrene as a binder. did.

Using this electrodeionization apparatus, raw water (200 μS / cm, TOC 3 ppm) of a semiconductor factory treated with a reverse osmosis (RO) membrane was passed through the electrodeionization apparatus as raw water (treated water W). The treatment conditions are such that the flow rate of deionized water (treated water) W1 is 2 m ³ / h, the flow rate of concentrated water W2 is 0.3 m ³ / h, and a portion of deionized water W1 is used as the concentrated water W2. Water was passed through the concentration chamber in a transient manner so as to counter flow with the salt chamber.

Was continued such an operating one year, the differential pressure of the concentrated water W2 is increased from 0.2 kg / cm ² to 0.9 kg / cm ^2, concentrating compartments washing electrodeionization apparatus is needed.

DESCRIPTION OF SYMBOLS 1 ... Electrodeionization apparatus 11 ... Anode 12 ... Cathode 13 ... Anion exchange membrane 14 ... Cation exchange membrane 15 ... Concentration chamber 16 ... Desalination chamber 17 ... Anode chamber 18 ... Cathode chamber W ... Water to be treated (raw water)
W1 ... Deionized water (treated water)
W2 ... Concentrated water W3 ... Concentrated drainage

Claims (7)

A cathode and an anode;
A cation exchange membrane and an anion exchange membrane disposed between the cathode and the anode;
A demineralization chamber and a concentration chamber partitioned by these cation exchange membrane and anion exchange membrane,
The desalting chamber and the concentration chamber are filled with an ion exchanger,
In an electrodeionization apparatus comprising a concentrated water flow means for passing concentrated water through the concentration chamber, and a means for passing raw water through the demineralization chamber and taking out deionized water,
An electrodeionization apparatus comprising a cation exchange membrane and an anion exchange membrane containing a vinyl acetate component.   2. The electrodeionization apparatus according to claim 1, wherein the concentrated water passage means passes deionized water that has passed through the demineralization chamber as concentrated water.   The concentrated water flow means introduces the concentrated water into the concentration chamber from the side near the deionized water outlet of the desalting chamber and flows out from the side near the raw water inlet of the desalting chamber. The electrodeionization apparatus according to claim 2.   4. The electrodeposition according to claim 1, wherein the cation exchange membrane comprises a copolymer of an anionic monomer having a sulfonate group in the molecule and a vinyl acetate monomer. Ion device.   The said anion exchange membrane contains the copolymer of the cationic monomer which has a quaternary ammonium group in a molecule | numerator, and the monomer of vinyl acetate, The Claim 1 characterized by the above-mentioned. Electrodeionizer. A cathode and an anode, a cation exchange membrane and an anion exchange membrane disposed between the cathode and the anode, and a desalting chamber and a concentrating chamber defined by the cation exchange membrane and the anion exchange membrane, A chamber and the concentration chamber are filled with an ion exchanger, and a concentrated water passage means for passing the concentrated water through the concentration chamber and a means for passing the raw water through the demineralization chamber and taking out the deionized water. And an operation method of an electrodeionization apparatus using a membrane made of a polymer containing a vinyl acetate component as the cation exchange membrane and the anion exchange membrane,
A method of operating an electrodeionization apparatus, wherein a part of deionized water that has passed through the demineralization chamber is introduced as the concentrated water.   The concentrated water is introduced from a side near the deionized water outlet of the demineralizing chamber of the concentrating chamber, and flows out from a side of the concentrating chamber near the raw water inlet. The operation method of the electrodeionization apparatus of 6.

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