JP2012210593A - Ultrapure water producing system and ultrapure water producing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrapure water producing system and ultrapure water producing method more simplified while maintaining the water quality of ultrapure water to be made.SOLUTION: The ultrapure water producing system comprises: a pretreatment unit to which water to be treated is introduced; and an ultrapure water producing unit including a pretreatment bath 14, a reverse osmosis membrane device 15 to which pretreated water is introduced from the pretreatment bath, and an electric deionization device 16, wherein: the pretreatment unit includes an active carbon filter device 13; the active carbon filter device includes a filter body having a sheet-shaped member wound in a spiral shape and a filtering bath through which water passes and in which the filter body is filled with its axis being in the direction of a water flow; the sheet-shaped member is formed by superposing a mesh sheet having holes through which water passes on a sheet surface of a sheet-shaped spacer through which water passes with more difficulty than through the mesh sheet; and at least portions of the mesh sheet and the spacer are formed of an active carbon fiber.

Description

  The present invention relates to an ultrapure water production system and an ultrapure water production method used in various industries such as the electronics industry, liquid crystal, pharmaceuticals, and food, and research facilities.

  Ultrapure water production systems that produce ultrapure water from treated water such as industrial water, city water, well water, river water, lake water, and factory wastewater are generally pretreatment units, primary pure water systems, It consists of a system and a terminal piping section. In the pretreatment section, treatments such as aggregation, precipitation, filtration, softening, iron removal, manganese removal, and adsorption are performed mainly for the purpose of removing insoluble substances so that the subsequent apparatus can be stably operated. The primary pure water system is for producing pure water by treating the pretreated water treated in the pretreatment unit, and is mainly an ion exchange device, an electrodeionization device, a degassing membrane device, or a reverse osmosis membrane device. It is configured. In addition, the subsystem further refines the pure water produced by the primary pure water system and finishes it into ultrapure water, and is composed of, for example, a sub tank, an ultraviolet oxidation device, an ion exchange device, and an ultrafiltration membrane device. Has been. Then, the ultrapure water produced by the subsystem is sent to the use point at the terminal piping section, and the excess ultrapure water that has not been used at the use point is returned to the sub tank of the subsystem and is circulated. For example, as shown in FIG. 10 which is a schematic system diagram showing a conventional ultrapure water production system, a raw water tank 41, a heat exchanger 42, a microfiltration (MF) membrane device 43, an activated carbon tower 44, a security filter 45, A pretreatment section provided between the activated carbon tower 44 and the safety filter 45 and having a chemical introduction means 46 for introducing a chemical such as sulfuric acid into the water to be treated, a pretreatment water tank 47, a reverse osmosis (RO) membrane device 48, deaeration (MD) membrane device 49, primary deionized water system having electrodeionization (EDI) device 50, subtank 51, heat exchange (H / E) device 52, ultraviolet sterilizer 53, terminal having terminal microfiltration membrane device 54 There is an ultrapure water production system or the like that has a piping part and that feeds treated water with a pump to produce ultrapure water. Such a conventional ultrapure water production system has an ideal device configuration in terms of stably supplying high-purity ultrapure water to the use point, but the equipment investment cost and operation from the user Due to demands for cost reduction and space saving, simplification of ultrapure water production system is strongly demanded.

  As a technology for these requirements, a pretreatment unit, an ultrapure water production unit into which pretreated water treated in the pretreatment unit is introduced, and ultrapure water produced in the ultrapure water production unit are used points. An ultrapure water production system comprising a terminal pipe unit that supplies excess ultrapure water to the ultrapure water production unit, wherein the ultrapure water production unit is introduced with at least pretreatment water. A tank and a reverse osmosis membrane device, a deaeration device, an electrodeionization means, and a filtration membrane device for treating water from the tank, and excess ultrapure water returned from the terminal pipe section are There is an ultrapure water production system introduced into a tank (see Patent Document 1). However, further simplification is required.

JP 2004-57935 A

  In view of the circumstances described above, an object of the present invention is to provide a more simplified ultrapure water production system and ultrapure water production method while maintaining the quality of the produced ultrapure water.

  The ultrapure water production system of the present invention that solves the above problems includes a pretreatment section into which treated water is introduced, a pretreatment water tank in which the treated water treated in the pretreatment section is stored, and the pretreatment water tank. A reverse osmosis membrane device into which water to be treated is introduced and an ultrapure water production unit having an electrodeionization device, the pretreatment unit has an activated carbon filtration device, and the activated carbon filtration device is a sheet-like member A filter body in which the filter body is wound in a spiral shape, and a filtration tank in which the water to be treated is passed and the filter body is filled in such a manner that the axial center of the filter body is along the water passing direction. The sheet-like member has a sheet-like mesh sheet having pores through which the water to be treated passes, and sheet surfaces of sheet-like spacers where the water to be treated is difficult to pass compared to the mesh sheet. A small amount of the mesh sheet and the spacer. And also characterized in that a part is one which is formed by activated carbon fibers.

It is preferable that the spacer is formed of activated carbon fibers having a diameter of 0.1 to 100 μm.
Moreover, you may have at least 1 or more decarbonation equipment in the upstream of the said electrodeionization apparatus.
And it is preferable that the said electrodeionization apparatus has a bipolar membrane.
Or it is preferable that the thickness of the demineralization chamber of the said electrodeionization apparatus is 2-5 mm.
Moreover, it is preferable to have a terminal piping part which sends the ultrapure water discharged | emitted from the said ultrapure water manufacturing part to a use point, and returns excess ultrapure water to the said pre-treatment water tank.

  In the method for producing ultrapure water of the present invention, treated water that has been subjected to activated carbon filtration treatment by an activated carbon filtration device is stored in a pretreatment water tank, and the treated water stored in the pretreatment water tank is treated with a reverse osmosis membrane device using a reverse osmosis membrane device. After that, the method for producing ultrapure water in which deionization processing is performed with an electrodeionization apparatus, wherein the activated carbon filtration device includes a filter body in which a sheet-like member is wound in a spiral shape and water to be treated is passed. A filtration tank in which the filter body is filled so that the shaft core of the filter body is along the direction of water flow, and the sheet-like member has a hole through which water to be treated passes. The sheet-like mesh sheet and the sheet surface of the sheet-like spacer in which the water to be treated is difficult to pass compared to the mesh sheet are overlapped, and at least a part of the mesh sheet and the spacer is activated carbon fiber. Is formed And wherein the door.

  ADVANTAGE OF THE INVENTION According to this invention, the quality of the ultrapure water manufactured is favorable and can provide the simplified ultrapure water manufacturing system. Therefore, it is possible to obtain ultrapure water with good water quality while reducing the capital investment cost and operation cost and saving space.

It is a schematic system diagram which shows an example of the ultrapure water manufacturing system of this invention. It is a longitudinal cross-sectional view which shows the structure of an activated carbon filtration apparatus. It is a cross-sectional view which shows the structure of an activated carbon filtration apparatus. It is a perspective view which shows the filter body of an activated carbon filtration apparatus. It is a principal part enlarged view of a mesh sheet. It is a schematic block diagram which shows the example of 1 structure of an electrodeionization apparatus. It is a schematic block diagram which shows the structural example of the electrodeionization apparatus which has a bipolar membrane. It is a schematic system diagram which shows the other example of the ultrapure water manufacturing system of this invention. It is a figure which shows the measuring method of the differential pressure | voltage of a reverse osmosis membrane. It is a schematic system diagram which shows the ultrapure water manufacturing system of a prior art.

Hereinafter, the present invention will be described in detail based on embodiments.
The ultrapure water production system of the present invention includes a pretreatment unit into which treated water is introduced, a pretreatment water tank in which treated water treated in the pretreatment unit is stored, and treated water from the pretreatment water tank. A reverse osmosis membrane device and an ultrapure water production unit having an electrodeionization device. And the pretreatment part has an activated carbon filtration device, and this activated carbon filtration device has a filter body whose sheet-like member is wound in a spiral shape, water to be treated is passed, and the shaft core of the filter body is The filter body has a filtration tank filled therein so that the water passage direction is along, and the sheet-like member is a sheet-like mesh sheet having pores through which the water to be treated passes, and the mesh sheet The sheet surfaces of the sheet-like spacers to which the water to be treated is difficult to pass are overlapped, and at least a part of the mesh sheets and the spacers are formed of activated carbon fibers.

  Specifically, as shown in FIG. 1 which is a schematic system diagram illustrating an example of the ultrapure water production system of the present invention, the ultrapure water production system 10 includes a raw water tank 11 into which treated water (raw water) is introduced. And a pre-treatment unit having a heat exchanger 12 provided on the downstream side of the raw water tank 11 for heating the water to be treated, and an activated carbon filtration device 13 for subjecting the water to be treated heated by the heat exchanger 12 to an activated carbon filtration treatment. It has. Note that the heat exchanger 12 may not be provided if it is not necessary to heat the water to be treated. Moreover, the pretreatment water tank 14 which stores the to-be-processed water processed by the pretreatment part, the reverse osmosis membrane apparatus 15, the electrodeionization apparatus 16, and the microfiltration membrane apparatus 17 provided in order in the downstream of the pretreatment water tank 14 are provided. It has an ultrapure water production department. Then, the ultrapure water discharged from the ultrapure water production department, that is, the pipe for feeding the ultrapure water discharged from the microfiltration membrane device 17 to the use point, and the excess ultrapure water are returned to the pretreatment water tank 14. The terminal piping part which consists of piping is comprised. Note that a pump P is appropriately provided between the devices as means for feeding the water to be treated. Further, in FIG. 1, a reducing agent introduction means 18 for introducing a reducing agent such as sodium hydrogen sulfite into the raw water tank 11 is provided.

An example of the activated carbon filtration device 13 will be specifically described with reference to FIGS. FIG. 2 is a longitudinal sectional view of the direction of water to be treated showing the configuration of the activated carbon filtration device, FIG. 3 is a transverse sectional view showing the configuration of the activated carbon filtration device, and FIG. It is a perspective view which shows a filter body.
As shown in FIGS. 2 and 3, the activated carbon filtration device 13 includes a cylindrical filtration tank 1 through which water to be treated is passed and a filter body 2 that captures turbidity in the water to be treated. Have. The filter body 2 includes a core body 3 connected to both ends of the filtration tank 1 in the water flow direction, and a filter body main body 4 including a sheet-like member wound around the core material 3 in a spiral shape. The sheet-like member includes a sheet-like mesh sheet 5 having pores through which the water to be treated passes, and a sheet-like spacer 6 formed of activated carbon fibers through which the water to be treated is difficult to pass compared to the mesh sheet 5. The faces are overlapped.

  In addition, a circular plate 7 made of resin or the like provided with a plurality of holes to the extent that water to be treated containing turbidity (suspension material) or the like can freely pass is provided at both ends of the filtration tank 1 in the water flow direction. The both ends of the core material 3 are fixed to the center of each plate 7. And as for the filter body 2, the filter body 2 is filled into the filtration tank 1 whole inside so that the axial center of the filter body main body 4 may follow the water flow direction of to-be-processed water. Further, the gap between the inner wall of the filtration tank 1 and the outer periphery of the filter body 4 and the gap near the core 3 are filled with a water-impermeable member 8 through which the water to be treated such as an adhesive does not pass. Cannot pass through. The shaft core of the filter body 4 is the center of the spiral of the filter body 4 wound in a spiral shape, and the core material 3 corresponds to this embodiment.

  When water to be treated is passed through such an activated carbon filtration device 13, the spacer 6 is less likely to pass the water to be treated than the mesh sheet 5, so that most of the water to be treated passes through the pores of the mesh sheet 5. The mesh sheet 5 is substantially longitudinally cut, that is, passes through the mesh sheet 5 in the surface direction, and turbidity contained in the water to be treated is trapped in the mesh sheet 5, and the water to be treated from which the turbidity has been removed is removed from the filtration tank 1. Discharged. In this way, the water to be treated is passed through the mesh sheet 5 having pores through which the water to be treated passes and capable of trapping turbidity, not vertically across the thickness direction, but longitudinally. By using the activated carbon filtration device 13 having a structure, clear treated water can be obtained. Therefore, the activated carbon filtration device 13 can suppress clogging or deterioration of the reverse osmosis membrane device 15 and deterioration of the electrodeionization device 16. Further, the activated carbon filtration device 13 is not filtered using a membrane as in the case of an ultrafiltration membrane device or a microfiltration membrane device, so it is difficult to block and is inexpensive.

  Since the spacer 6 is made of activated carbon fiber, when the water to be treated comes into contact with the spacer 6, the oxidizing agent such as hypochlorous acid contained in the water to be treated reacts with the activated carbon fiber and is reduced. Is done. Therefore, the water to be treated discharged from the activated carbon filtration device 13 can be one in which the oxidizing agent has been almost completely removed.

  Here, the mesh sheet 5 is not particularly limited as long as the mesh sheet 5 has pores through which the water to be treated can pass and can remove the turbidity contained in the water to be treated to a desired extent. For example, FIG. Such a woven fabric formed of warp yarns 9a and weft yarns 9b. FIG. 5 is an enlarged plan view of the main part of the mesh sheet 5 (FIG. 5A) and a cross-sectional view taken along the line AA ′ of FIG. 5A (FIG. 5B).

  The distance between adjacent warp yarns 9a and adjacent weft yarns 9b of the mesh sheet 5, that is, the opening (indicated by OP in FIG. 5) is preferably about 200 to 4000 μm. ), That is, the space ratio (opening area) of the mesh sheet 5 in plan view is preferably about 40 to 98%, and the height of the intersection (thickness indicated by T in the figure) Is preferably 500 to 1200 μm. As a specific product, for example, a product of about 100th to 8th (NBC) may be used. If it is this range, a turbidity can be removed especially suitably. Further, in the reverse osmosis membrane device 15, for example, a spiral type reverse osmosis membrane device having a shape in which a reverse osmosis membrane is wound, a mesh sheet having an intersection portion height of usually about 0.65 to 1.2 mm is used as a raw water flow path spacer. This is because it is preferable to use a mesh sheet having a lower intersection portion than the reverse osmosis membrane device. For example, it is preferable to use a mesh sheet having a height of the intersection portion of 2/3 times or less than the reverse osmosis membrane device 15.

  Moreover, the diameter D of the fiber used as the warp 9a or the weft 9b is preferably 0.1 to 0.6 mm, and more preferably about 0.1 to 0.4 mm. Depending on the turbidity and the amount of water to be treated, it is necessary to form holes that allow the water to be treated to pass through the fibers of a certain thickness in order to allow the water to be treated to be substantially vertically cut. Moreover, if the thickness is too large, the formed pores become too large, and the suspended matter cannot be removed.

  Examples of the material constituting the mesh sheet 5 include synthetic resins such as polyolefin, polyester, nylon, and polyvinylidene fluoride (PVDF), metal fibers, activated carbon fibers, and the like, from the viewpoint of chlorine resistance. Polyolefins are preferred. In addition, although the woven fabric was illustrated in FIG. 5, the nonwoven fabric which has a comparatively big void | hole formed with the fiber may be sufficient.

  Further, the spacer 6 is not particularly limited as long as the water to be treated is less likely to pass through than the mesh sheet 5. For example, the water impermeable sheet that has no pores and does not allow the water to be treated to pass therethrough. Or it may be a non-woven fabric formed of fibers having a diameter of 0.1 to 100 [mu] m, preferably about 0.5 to 30 [mu] m, or the like, or those laminated by integrally bonding them by heat fusion or the like. In addition, since the to-be-processed water can be made to contact the mesh sheet | seat 5 uniformly if the spacer 6 is a water-impermeable sheet which does not allow the to-be-processed water to pass through, the spacer 6 may have a water-impermeable sheet. preferable. And if a nonwoven fabric is used as the spacer 6, since the turbidity of to-be-processed water can be capture | acquired in the fluff site | part of the nonwoven fabric surface, the turbidity capture | acquisition property of the activated carbon filtration apparatus 13 can be improved, Therefore A spacer composed of a sheet is preferable.

  In addition, when at least one part of the mesh sheet 5 is formed using activated carbon fiber, the spacer 6 may be formed with materials other than activated carbon fiber. Examples of the material of the spacer 6 include polyolefin, polyester, nylon, polyvinylidene fluoride (PVDF), and metal fiber. Of these, polyolefins are preferred from the viewpoint of chemical resistance and economy.

  The form in which the mesh sheet 5 and the spacer 6 are overlapped is not particularly limited, and the sheet surfaces may be bonded together or integrally formed by heat fusion. In addition, although the magnitude | size of the mesh sheet 5 and the spacer 6 does not need to be the same, in order to process a to-be-processed water uniformly, it is preferable that it is substantially the same. The length of the mesh sheet or the spacer 6 in the water passing direction depends on the turbidity of the water to be treated, the amount to be treated, the quality of the ultrapure water (treated water) to be obtained, etc., but may be, for example, about 200 to 1000 mm. .

  The material of the core material 3 around which the sheet member on which the mesh sheet 5 and the spacer 6 are superimposed is wound is not particularly limited, and plastic, metal, or the like can be used, but from the economical viewpoint, vinyl chloride piping (CVP piping) ) Is preferable. Further, the shape 3 of the core material is not particularly limited, and may be, for example, a cylindrical shape or a prismatic shape. The method for winding the sheet member around the core member 3 is not particularly limited. For example, the end of the sheet member is fixed to the core member 3 with an adhesive or the like, and the sheet member is wound around the core member 3. It is sufficient to wind the film to have an arbitrary diameter according to the amount of water to be treated and the turbidity.

  And there is no limitation in the filtration tank 1, For example, a material can be made from stainless steel or a fiber reinforced plastic (FRP), and if a magnitude | size is a hollow cylindrical shape (cylinder shape), it will be 100-1000 mm in diameter. The height can be 200 to 1000 mm. Moreover, although it was set as the cylindrical filtration tank 1 in FIG. 2, it does not need to be a cylinder and may be the shape which can permeate | transmit water, ie, what is hollow, for example, the shape which provided the cavity in the prism.

  In FIG. 2, the filter body 2 having the filter body 4 wound around the core material 3 is used, but the number of windings is not limited, and the amount of water to be treated and the turbidity What is necessary is just to adjust suitably according to the quality etc. of the ultrapure water to require. The filter body 2 may be the filter body 2 wound only once. However, as the number of times of winding is increased, the shape of the mesh sheet 5 becomes easier to be held by the spacer 6, and the water to be treated is uniformly distributed to the treated water. This is preferable because the water treatment can be stabilized because it can be longitudinally cut.

  In FIG. 2, a filter body 2 in which a filter body main body 4 is wound around a core material 3 is used as the filter body 2, but the core material 3 may be omitted. For example, the mesh sheet 5 may be passed by a spacer 6 or the like. If the shape at the time of water is hold | maintained and the to-be-processed water can pass the mesh sheet 5 to a surface direction (vertical cut), it is good also as the filter body 2 which consists only of the filter body main body 4. FIG.

  Moreover, in FIG. 2, although it was set as the activated carbon filter 13 which filled the filter body 2 in the hollow cylindrical filter tank 1, the sheet | seat, such as FRP, is wound around the filter body 2 so that to-be-processed water may not leak. It may be joined. Alternatively, the spacer 6 may be made of a water-impermeable material so that the water to be treated does not leak, so that the spacer 6 also serves as the filtration tank 1.

  In addition, the activated carbon filtration device 13 is treated water discharged from the activated carbon filtration device 13 in a direction opposite to the water flow direction of the treated water, a cleaning liquid, a mixed liquid of cleaning liquid and air, or treated water (raw water). ) It is preferable to perform so-called backwashing by passing water and discharging it outside the system. Thereby, contaminants, such as a turbidity adhering to members, such as the filter body 2 which the activated carbon filtration apparatus 13 has, can be removed. In the ultrapure water treatment apparatus of FIG. 1, the water to be treated stored in the pretreatment water tank 14 is supplied to the activated carbon filtration device 13 in the direction opposite to the water flow direction of the treated water to reverse the activated carbon filtration device 13. The structure is washable.

Further, the reverse osmosis membrane device 15 has a reverse osmosis membrane and performs membrane separation treatment by passing water to be treated so that ions such as HCO ₃ ⁻ contained in the water to be treated, total organic carbon (TOC), etc. The cross-sectional area of the water passage of the treated water is larger than the cross-sectional area of the mesh sheet 5 in the direction of water flow of the water to be treated. What has the width | variety of a raw | natural water flow path larger than the height of the intersection part of the mesh sheet | seat 5 is preferable. And although there is no particular limitation on the form of the reverse osmosis membrane device 15, for example, a so-called spiral type of a shape obtained by winding a reverse osmosis membrane bound on a bag around a hollow core member having a water passage hole on its side surface This is preferable because it can easily cope with an increase in size. In particular, a spiral reverse osmosis membrane device having the same diameter as the activated carbon filtration device 13 is preferable. When a spiral type reverse osmosis membrane device is used, treated water whose impurities have been subjected to membrane separation treatment by the reverse osmosis membrane is discharged from the hollow core material, and membrane separation treatment is performed by the reverse osmosis membrane from other than the core material. So-called concentrated water containing a lot of impurities is discharged. In addition to the spiral type, any structure such as a flat membrane or a hollow fiber may be used.

  Examples of the reverse osmosis membrane include a membrane made of aromatic polyamide.

The electrodeionization device 16 is not particularly limited as long as it can perform a deionization treatment that removes ions, CO ₂ , silica, and the like that are contained in the water to be treated and not removed by the reverse osmosis membrane device 15. In addition, a general electrodeionization apparatus can be used. A general electrodeionization apparatus is, for example, a schematic configuration diagram showing a configuration example of an electrodeionization apparatus, and a plurality of anion exchanges between a cathode (cathode) and an anode (anode) as shown in FIG. The concentration chamber 33 and the desalting chamber 34 are formed by alternately arranging the membrane 31 and the cation exchange membrane 32. The concentration chamber 33 and the desalting chamber 34 are each filled with an ion exchange resin in a mixed bed or a single layer. In such an electrodeionization apparatus, when the water to be treated is passed, the treated water that has been deionized is discharged from the desalting chamber 34, and ions, HCO ₃ ⁻ , CO ₃ ²⁻ are discharged from the concentration chamber 33. Then, concentrated water containing a large amount of silica or the like is discharged.

Among such electrodeionization apparatuses, it is preferable to use an electrodeionization apparatus in which a scale component hardly precipitates. For example, when the water to be treated contains high-concentration carbon dioxide CO ₂ , the carbon dioxide that has permeated from the demineralization chamber 34 on the anion exchange membrane 31 side to the concentration chamber 33 in the concentration chamber 33 of the electrodeionization apparatus. In some cases, hydrogen ions HCO ³⁻ and the like react with calcium ions Ca ^{2+ and the} like that have permeated from the desalination chamber 34 on the cation exchange membrane 32 side to the concentration chamber 33, and scale components (calcium carbonate, etc.) may be deposited. However, by using an electrodeionization apparatus having a bipolar membrane as shown in, for example, Japanese Patent Application Laid-Open No. 2001-198577 and Japanese Patent Application Laid-Open No. 2008-36486, scale components are hardly precipitated in the concentration chamber 33. The bipolar membrane is a kind of composite membrane having a structure in which a cation exchange membrane and an anion exchange membrane are bonded together, and as a diaphragm used for water electrolysis or an aqueous solution of a salt which is a neutralized product of acid and alkali It is a known ion exchange membrane that has been widely used as a separation membrane for regenerating acid and alkali.

Such an electrodeionization apparatus is a schematic configuration diagram showing an example of the structure of an electrodeionization apparatus having a bipolar membrane. As shown in FIG. 7, a plurality of electrodeionization apparatuses are provided between a cathode (cathode) and an anode (anode). By alternately arranging the anion exchange membrane 31 and the cation exchange membrane 32, a concentrating chamber 33 and a desalting chamber 34 are formed, and in each of the concentrating chamber 33 and the desalting chamber 34, an ion exchange resin is mixed. Alternatively, it is filled with a single layer. The concentration chamber 33 is partitioned into a cathode side and an anode side by providing the concentration chamber 33 with the bipolar membrane 35. The bipolar membrane 35 is provided so that the anion exchange membrane is located on the anode (anode) side and the cation exchange membrane is located on the cathode (cathode) side. In such an electrodeionization apparatus, when the water to be treated is passed, the treated water that has been deionized is discharged from the desalting chamber 34, and ions, HCO ₃ ⁻ , CO ₃ ²⁻ are discharged from the concentration chamber 33. Then, concentrated water containing a large amount of silica or the like is discharged. At this time, hydrogen carbonate ions HCO ³⁻ etc. permeate from the desalting chamber 34 on the anion exchange membrane 31 side to the concentrating chamber 33, and calcium ions Ca ²⁺ pass from the desalting chamber 34 on the cation exchange membrane 32 side to the concentrating chamber 33. However, since it is blocked by the cation exchange membrane and the anion exchange membrane of the bipolar membrane 35, it is possible to prevent the scale from being formed in the concentration chamber 33.

  In addition, since the amount of ions per desalting chamber 34 can be reduced by using an electrodeionization apparatus having a small thickness of the desalting chamber 34, it is difficult for the scale component to precipitate in the concentration chamber 33. For example, the thickness of the desalting chamber 34 is preferably 2 to 5 mm. If it is less than 2 mm, the members constituting the desalting chamber 34 are likely to be easily deformed and water leakage is likely to occur, and if it exceeds 5 mm, the load on the desalting chamber 34 is high and scale is likely to precipitate. However, in the case of the electrodeionization apparatus having the bipolar membrane, since no ions are associated even if the thickness exceeds 5 mm, no scale is generated.

  By using an electrodeionization device having such a bipolar membrane or having a small thickness of the desalting chamber 34, a degassing membrane device having a degassing membrane and capable of removing a gas such as carbon dioxide is provided. Even without this, precipitation of scale components such as calcium carbonate can be prevented, and the ultrapure water production system 10 can be stably operated.

  The microfiltration membrane device 17 has a microfiltration membrane that can remove fine particles, for example, a microfiltration membrane that can remove fine particles of 0.02 to 10 μm, and is used in conventional ultrapure water production systems. A microfiltration membrane device 17 can be used. Of course, depending on the quality of ultrapure water to be obtained, the microfiltration membrane device 17 may not be provided, or an ultrafiltration membrane with higher fine particle removal performance may be used. When such a microfiltration membrane device 17 or the microfiltration membrane device 17 is not provided, the water to be treated discharged from the electrodeionization device 16 or the like is the intended ultrapure water.

  As described above, the terminal piping section includes a terminal piping section that includes a pipe that supplies the obtained ultrapure water to the use point and a pipe that returns excess ultrapure water to the pretreatment water tank 14. Here, the ultrapure water sent to the use point is used in the user's washing machine or the like, but the water pressure to be used is, for example, about 0.1 to 0.3 MPa, and the terminal piping part increases to that pressure. It is preferable to have a pump.

  Furthermore, the ultrapure water production system 10 of the present invention has a reductant storage for introducing a reductant into the water to be treated in order to prevent the reverse osmosis membrane device 15 and the electrodeionization device 16 from being deteriorated by an oxidant or the like. You may have the reducing agent introduction means which consists of a tank, a pump, etc. In FIG. 1, a reducing agent introduction means 18 for introducing a reducing agent into the raw water tank 11 is provided.

  Further, depending on the quality of ultrapure water to be obtained, an ultrapure water production system having various devices such as an ion exchange resin tower, an ultraviolet irradiation oxidative decomposition apparatus, and an ultraviolet sterilization apparatus in the subsequent stage of the electrodeionization apparatus 16 may be used. When the microfiltration membrane device 17 or the like is installed for the purpose of removing fine particles, an ion exchange resin tower, an ultraviolet oxidative decomposition device, an ultraviolet sterilization device, or the like is interposed between the electrodeionization device 16 and the microfiltration membrane device 17. Usually placed.

  An example of a method for producing ultrapure water using such an ultrapure water production system will be described below. First, water to be treated (raw water) is introduced into the raw water tank 11.

  Examples of water to be treated include water containing a humic acid / fulvic acid organic substance, a biological metabolite such as sugar produced by algae, or a synthetic chemical substance such as a surfactant, specifically, industrial water. , City water, well water, river water, lake water, factory wastewater (especially biologically treated water obtained by biologically treating wastewater from the factory) and flocs (aggregates) formed by adding and aggregating flocculants to these Water that has been subjected to agglomeration treatment. Further, water added with an oxidizing agent such as sodium hypochlorite, hydrogen peroxide or ozone may be used for the purpose of suppressing the occurrence of troubles caused by microorganisms. The humic substance refers to a corrosive substance generated by the decomposition of plants and the like into microorganisms, and includes humic acid, and the water containing the humic substance is derived from humic substance and / or humic substance. It has a soluble COD component, suspended matter and chromaticity component. In addition, examples of the flocculant for performing the flocculant treatment include a polymer flocculant and an inorganic flocculant. Examples of the polymer flocculant include poly (meth) acrylic acid, a copolymer of (meth) acrylic acid and (meth) acrylamide, and anionic organic polymer flocculants such as alkali metal salts thereof, From nonionic organic polymer flocculants such as poly (meth) acrylamide, cationic monomers such as dimethylaminoethyl (meth) acrylate or quaternary ammonium salts thereof, dimethylaminopropyl (meth) acrylamide or quaternary ammonium salts thereof And a cationic organic polymer flocculant such as a copolymer of a nonionic monomer copolymerizable with the cationic monomer, and the anionic monomer, cationic monomer or copolymerized with these monomers. Amphoteric organic polymer co-polymers with possible nonionic monomers Agents. The amount of the polymer flocculant added is not particularly limited and may be adjusted according to the properties of the water to be treated, but is generally 0.01 to 10 mg / L in solid content with respect to the water to be treated. Examples of the inorganic flocculant include aluminum salts such as sulfuric acid band and polyaluminum chloride, and iron salts such as ferric chloride and ferrous sulfate. Moreover, there is no limitation in particular also in the addition amount of an inorganic flocculant, What is necessary is just to adjust according to the property of the to-be-processed water to process, but about 0.5-10 mg / L in conversion of aluminum or iron with respect to to-be-processed water. It is. Further, although depending on the properties of the water to be treated, when polyaluminum chloride (PAC) is used as the inorganic flocculant, the pH of the water to be treated to which the polymer flocculant and the inorganic flocculant are added is pH 5.0-7. If it is about 0.0, aggregation is optimal. The inorganic flocculant may be added before or after the polymer flocculant is added to the water to be treated, or may be added simultaneously with the polymer flocculant.

  Next, a reducing agent is added to the water to be treated as necessary. By adding the reducing agent, the oxidizing agent contained in the water to be treated is reduced by the reducing agent, so that deterioration due to the oxidizing agent in the reverse osmosis membrane device 15 and the electrodeionization device 16 in the subsequent stage can be suppressed. . Examples of the reducing agent include sodium bisulfite, sodium sulfite, sodium thiosulfate, hydrazine, and the like.

  Next, the water to be treated heated by the heat exchanger 12 is introduced into the activated carbon filtration device 13. And the muddy substance contained in to-be-processed water is removed when the to-be-processed water introduced into the activated carbon filtration apparatus 13 cuts the mesh sheet 5 longitudinally. Further, when the water to be treated comes into contact with the spacer 6 formed of the activated carbon fiber, the oxidizing agent contained in the water to be treated is reduced with the activated carbon fiber. Therefore, the water to be treated discharged from the activated carbon filtration device 13 is one in which the oxidant has been almost completely removed and the turbidity has also been removed. The treated water discharged from the activated carbon filtration device 13 is stored in the pretreatment water tank 14.

  Then, the water to be treated stored in the pretreatment water tank 14 is passed through the reverse osmosis membrane device 15 to be subjected to membrane separation treatment with the reverse osmosis membrane. The treated water (treated water) discharged from the reverse osmosis membrane device 15 is deionized by passing it through the electrodeionization device 16, and the concentrated water discharged from the reverse osmosis membrane device 15 is pretreated. When it returns to the water tank 14 or there are many impurities, it removes out of the system. Then, the water to be treated (treated water) discharged from the electrodeionization device 16 is passed through the microfiltration membrane device 17 to perform membrane separation treatment with the microfiltration membrane, and is discharged from the electrodeionization device 16. The concentrated water is returned to the pretreatment water tank 14. The treated water discharged from the microfiltration membrane device 17 in this way, that is, the intended ultrapure water is sent to the use point. In addition, surplus ultrapure water is returned to the pretreatment water tank 14 via the terminal piping section. In addition, when the to-be-processed water returned to the pretreatment water tank 14 contains dissolved oxygen, it is preferable to suppress reaction of microorganisms etc. by performing disinfection washing | cleaning of piping or introducing nitrogen gas.

  Here, in the ultrapure water production system 10 shown in FIG. 1 described above, the concentration of iron and aluminum in the water to be treated (raw water) is low (for example, 0.06 ppm or less), and the total organic carbon concentration (TOC concentration). ) Is an ultrapure water production system suitable for a high case, and operates at a neutral pH. This is because, when the pH is low, organic substances such as humic substances may be insolubilized and block the reverse osmosis membrane. In addition, when iron or aluminum is high in concentration, it may become a hydroxide and clog the reverse osmosis membrane. However, when the concentration of iron or aluminum is low, this problem hardly occurs. Can be made.

  On the other hand, when the concentration of iron or aluminum in the treated water (raw water) is high and the total organic carbon concentration (TOC concentration) is low, in addition to the ultrapure water production system shown in FIG. An ultrapure water production system having at least one decarbonation facility on the upstream side of the deionizer 16 is preferable. Thus, even if the concentration of iron or aluminum is high by operating an ultrapure water production system having a decarboxylation facility on a low pH (for example, pH 4 to 5), that is, on the acidic side, iron or aluminum Can be prevented from becoming ionized and blocking the reverse osmosis membrane, and can be operated stably. Regardless of the concentration of iron or aluminum in the water to be treated (raw water), if the total organic carbon concentration (TOC concentration) is high, the total organic matter such as agglomeration treatment before the activated carbon filtration device 13 of the pretreatment section. A treatment for reducing the carbon concentration is required.

Examples of the decarboxylation facility include a decarboxylation tower and a device having a degassing membrane (degassing membrane device). When using a deaeration membrane apparatus, it is preferable to provide in the back | latter stage of the reverse osmosis membrane apparatus 15 at the point which can prevent the dirt of a deaeration membrane. In addition, when the electrodeionization device 16 is used, the load on the electrodeionization device can be reduced, and scale generation can be prevented. Therefore, the degassing membrane device is provided in front of the electrodeionization device. preferable.
Moreover, you may use a decarbonation tower as a decarboxylation equipment. An ultrapure water production system having a decarboxylation tower as such a decarboxylation facility will be described with reference to FIG. 8 which is a schematic system diagram showing another example of the ultrapure water production system of the present invention. The same devices as those in FIG. 1 are denoted by the same reference numerals, and the configuration thereof is the same as described above, and the description thereof is omitted.

  As shown in FIG. 8, an ultrapure water production system 10 </ b> A having a decarboxylation tower heats the water to be treated provided in the raw water tank 11 into which the water to be treated (raw water) is introduced, and downstream of the raw water tank 11. A pretreatment unit having a heat exchanger 12 and an activated carbon filtration device 13 that performs activated carbon filtration treatment of water to be treated heated by the heat exchanger 12 is provided. Note that the heat exchanger 12 may not be provided if it is not necessary to heat the water to be treated. Moreover, the pretreatment water tank 14 which stores the to-be-processed water processed by the pretreatment part, the reverse osmosis membrane apparatus 15, the electrodeionization apparatus 16, and the microfiltration membrane apparatus 17 provided in order in the downstream of the pretreatment water tank 14 are provided. It has an ultrapure water production department. Further, a decarboxylation tower 19 is provided immediately above the pretreatment water tank 14, and the treated water treated in the pretreatment section is stored in the pretreatment water tank 14 via the decarbonation tower 19. The decarboxylation tower 19 and the pretreatment water tank 14 are integrally configured. Of course, it is good also as an apparatus with which the decarboxylation tower 19 and the pretreatment water tank 14 were separated instead of the apparatus comprised integrally. Moreover, the decarboxylation tower 19 should just be provided one or more upstream in the electrodeionization apparatus 16, for example, between the heat exchanger 12 and the activated carbon filtration apparatus 13, or the pretreatment water tank 14 and reverse osmosis. It may be provided between the membrane device 15. Then, the ultrapure water discharged from the ultrapure water production department, that is, the pipe for feeding the ultrapure water discharged from the microfiltration membrane device 17 to the use point, and the excess ultrapure water are returned to the pretreatment water tank 14. The terminal piping part which consists of piping is comprised. Note that a pump P is appropriately provided between the devices as means for feeding the water to be treated. Further, in FIG. 8, a pH adjusting agent introducing means for introducing the pH adjusting agent into the water to be treated is provided immediately after the activated carbon filtration device 13.

  The decarboxylation tower 19 is not particularly limited as long as it is an apparatus capable of removing carbon dioxide contained in the water to be treated, and a decarboxylation tower used in a normal ultrapure water production system can be used. For example, a container filled with a filler, a spray nozzle for passing water to be treated from the upper part of the container, a gas introducing means for blowing air or nitrogen gas from the lower part of the container and discharging the gas from the upper part of the container, It is what has. Examples of the filler include ½ to 2 inch net rings and Raschig rings. If the size is less than ½ inch, although depending on the material and shape of the filler, the pressure loss becomes too large. If the size is more than 2 inches, sufficient carbon dioxide removal performance may not be obtained. Moreover, it is preferable to fill with a filler so that the volume flow rate SV of to-be-processed water may be 30-100. If the volume flow rate is too low, the flow of water to be treated will be unevenly distributed and may not contact carbon dioxide, and carbon dioxide removal performance may not be obtained. If it is too high, pressure loss will be high and gases such as air and nitrogen will not flow uniformly. This is because the carbon dioxide removal performance may not be obtained without contact.

  An example of a method for producing ultrapure water using such an ultrapure water production system 10A will be described below. First, water to be treated (raw water) is introduced into the raw water tank 11. Next, a reducing agent is added to the water to be treated as necessary.

  Next, the water to be treated heated by the heat exchanger 12 is introduced into the activated carbon filtration device 13. And the muddy substance contained in to-be-processed water is removed when the to-be-processed water introduced into the activated carbon filtration apparatus 13 cuts the mesh sheet 5 longitudinally. Further, when the water to be treated comes into contact with the spacer 6 formed of the activated carbon fiber, the oxidizing agent contained in the water to be treated is reduced with the activated carbon fiber. Therefore, the water to be treated discharged from the activated carbon filtration device 13 is one in which the oxidant has been almost completely removed and the turbidity has also been removed.

  And the pH adjuster is introduce | transduced into the to-be-processed water discharged | emitted from the activated carbon filtration apparatus 13 from a pH adjuster introduction means, and pH of to-be-processed water is adjusted to acidic desired value, for example, pH 4-5. Examples of the pH adjuster include sulfuric acid, hydrochloric acid, nitric acid, potassium hydroxide, and sodium hydroxide.

  Then, the water to be treated whose pH is adjusted is passed through the spray nozzle from the upper part of the decarboxylation tower 19 in which air or nitrogen gas is blown from the lower part of the container filled with the filler and discharged from the upper part of the container. To remove carbon dioxide. The treated water from which the carbon dioxide has been removed falls into the pretreatment water tank 14 provided immediately below and is stored.

  Next, the water to be treated stored in the pretreatment water tank 14 is passed through the reverse osmosis membrane device 15 to perform membrane separation treatment with the reverse osmosis membrane. The treated water (treated water) discharged from the reverse osmosis membrane device 15 is deionized by passing it through the electrodeionization device 16, and the concentrated water discharged from the reverse osmosis membrane device 15 is pretreated. When it returns to the water tank 14 or there are many impurities, it removes out of the system. Then, the water to be treated (treated water) discharged from the electrodeionization device 16 is passed through the microfiltration membrane device 17 to perform membrane separation treatment with the microfiltration membrane. The concentrated water discharged from the electrodeionization device 16 contains a large amount of inorganic carbonic acid, but the inorganic carbonic acid cannot be removed by the reverse osmosis membrane device 15 under pH acidic conditions. Therefore, in order to remove the inorganic carbonic acid contained in the concentrated water from the electrodeionization apparatus 16, it is necessary to return the concentrated water to a stage prior to the decarbonation facility, and in this embodiment, the configuration is returned to the raw water tank 11. did. The treated water discharged from the microfiltration membrane device 17 in this way, that is, the intended ultrapure water is sent to the use point. In addition, surplus ultrapure water is returned to the pretreatment water tank 14 via the terminal piping section. In addition, when the to-be-processed water returned to the pretreatment water tank 14 or the raw | natural water tank 11 contains dissolved oxygen, it is preferable to suppress reaction of microorganisms etc. by introduce | transducing the bactericidal property of piping or introducing nitrogen gas.

  Hereinafter, although it further explains in full detail based on an Example and a comparative example, the present invention is not limited at all by this example.

Example 1
As treated water (raw water), city water, specifically, turbidity of 1.0 degree or less, residual chlorine (as.Cl ₂ ): 0.5 ppm, water temperature: 20 ° C., iron concentration: 0.01 ppm, aluminum Water having a concentration of 0.05 ppm and a TOC concentration of 0.5 ppm was treated with the ultrapure water production system shown in FIG. The configuration of each device is as follows. The raw water pH was 7.1.

<Reducing agent introduction means>
Tank: EWN-B11-VC1J-WPO manufactured by Iwaki Co., Ltd.
Pump: CT-U120N manufactured by Iwaki Co., Ltd.
Reducing agent: Sodium bisulfite

<Activated carbon filter>
Filtration tank: cylindrical container (vessel) with an inner diameter of 100 mm
Filter body: mesh sheet made of warp and weft made of polyethylene fibers having a diameter of 0.3 mm, 1 m × 10 m shown in FIG. 5, the height T of the intersection is 0.5 mm, opening 3000 μm, opening area 80% 1 m × 10 m × 0.3 mm thick activated carbon nonwoven fabric with spacers made of activated carbon fibers with a diameter of 15 μm and a 1 m × 10 m × 0.1 mm thick film made of PET (polyethylene terephthalate) (Water impermeable film) and a sheet-like member in which these were superposed and the four corners were heat-sealed. The sheet member is formed by wrapping 10 m around a pipe (core material) made of vinyl chloride having a diameter of 20 mm so that the water-impermeable film is on the outside, and a filter body having a diameter of 100 mm. and the gap between the outer periphery of the inner wall and the filter body, a gap around the core, passing water filtration devices that filled with an adhesive that does not pass through the water to be ^{treated: 1.6m 3 / h (LV =} 200m / h)

<Reverse osmosis membrane device>
Reverse osmosis membrane: Two spiral type (diameter 100 mm) connected using FILMTEC LE-4040 (the height of the intersection of raw water flow path spacers: 0.85 mm) manufactured by The Dow Chemical Company Water volume: 0.5m ³ / h
Concentrated water volume: 1.1 m ³ / h

<Electrodeionization equipment>
A concentration chamber and a desalination chamber are formed by alternately arranging a plurality of the following anion exchange membranes and cation exchange membranes between the cathode (cathode) and the anode (anode). The following ion exchange resin was filled, and the following bipolar membrane was provided in the concentration chamber, so that the concentration chamber was partitioned into a cathode side and an anode side. In addition, the thickness and membrane area of the desalting chamber and the concentration chamber are as follows.
Anion exchange membrane: Asahi Kasei Kogyo Co., Ltd. “Aciplex A501SB”
Cation exchange membrane: Asahi Kasei Kogyo Co., Ltd. “Aciplex K501SB”
Ion exchange resin: An anion exchange resin ("SA10A" manufactured by Mitsubishi Chemical Corporation) and a cation exchange resin ("SK1B" manufactured by Mitsubishi Chemical Corporation) mixed at a volume mixing ratio of 6: 4.
Bipolar membrane: A cation exchange membrane (CMB) manufactured by Tokuyama Soda is immersed in an aqueous ferrous chloride solution at 25 ° C. for 1 hour, washed thoroughly with ion exchange water, air-dried, and then cation exchange membrane by a polymer coating method. Made by applying a quaternized base-containing polymer containing amino groups to the surface. Desalination chamber: 10 mm thick
Concentration chamber: 4 mm thick
Membrane area: 300 cm ² (300 mm × 100 mm)
Treated water volume: 0.4 m ³ / hour Concentrated water volume: 0.1 m ³ / hour

<Microfiltration membrane device>
Microfiltration membrane: Advantech made hydrophilic PTFE (polytetrafluoroethylene) filter TCFH-050-S1FE

  About the to-be-processed water discharged | emitted from the microfiltration membrane, the electrical conductivity (specific resistance) in 25 degreeC was measured. Further, as shown in FIG. 9, the differential pressure of the reverse osmosis membrane device 15 at the time of processing is a difference between the pressure P1 at the inlet of the reverse osmosis membrane device 15 and the pressure P2 at the outlet of the concentrated water (P1−P2 (MPa)). Asked.

(Example 2)
As treated water (raw water), well water, specifically, turbidity of 1.0 degree or less, residual chlorine (as.Cl ₂ ): 0.0 ppm, water temperature: 10 ° C., iron concentration: 0.1 ppm, aluminum Water having a concentration of 0.03 ppm and a TOC concentration of 0.2 ppm was treated with the ultrapure water production system shown in FIG. The configuration of each device is as follows. Moreover, the pH of the to-be-processed water after addition of a pH adjuster was 5.0.

<PH adjuster introduction means>
Tank: EWN-B11-VC1J-WPO manufactured by Iwaki Co., Ltd.
Pump: CT-U120N manufactured by Iwaki Co., Ltd.
pH adjuster: 10% sulfuric acid

<Activated carbon filter>
Filtration tank: cylindrical container (vessel) with an inner diameter of 100 mm
Filter body: mesh sheet made of warp and weft made of polyethylene fibers having a diameter of 0.3 mm, 1 m × 10 m shown in FIG. 5, the height T of the intersection is 0.5 mm, opening 3000 μm, opening area 80% 1 m × 10 m × 0.3 mm thick activated carbon nonwoven fabric with spacers made of activated carbon fibers with a diameter of 15 μm and a 1 m × 10 m × 0.1 mm thick film made of PET (polyethylene terephthalate) (Water impermeable film) and a sheet-like member in which these were superposed and the four corners were heat-sealed. The sheet member is formed by wrapping 10 m around a pipe (core material) made of vinyl chloride having a diameter of 20 mm so that the water-impermeable film is on the outside, and a filter body having a diameter of 100 mm. The gap between the inner wall and the outer periphery of the filter body or the gap near the core is filled with an adhesive that does not allow the water to be treated to pass through. Water flow rate of the filtration device: 1.6 m ³ / h (LV = 200 m / h)

<Decarbonation device>
A cylindrical container having an inner diameter of 250 mm and a height of 1500 mm filled with a 3/4 inch net ring to a height of 1000 mm was used as a decarboxylation tower, and this was connected to the upper part of the pretreatment water tank.

<Reverse osmosis membrane device>
Reverse osmosis membrane: Two spiral type (diameter 100 mm) connected using FILMTEC LE-4040 (the height of the intersection of raw water flow path spacers: 0.85 mm) manufactured by The Dow Chemical Company Water volume: 0.5m ³ / h
Concentrated water volume: 1.1 m ³ / h

<Electrodeionization equipment>
Electrodeionization apparatus A plurality of the following anion exchange membranes and cation exchange membranes are alternately arranged between a cathode (cathode) and an anode (anode) to form a concentration chamber and a desalting chamber, and a desalting chamber. And what filled the following ion exchange resin into the concentration chamber was used. In addition, the thickness and membrane area of the desalting chamber and the concentration chamber are as follows.
Anion exchange membrane: Asahi Kasei Kogyo Co., Ltd. “Aciplex A501SB”
Cation exchange membrane: Asahi Kasei Kogyo Co., Ltd. “Aciplex K501SB”
Ion exchange resin: An anion exchange resin ("SA10A" manufactured by Mitsubishi Chemical Corporation) and a cation exchange resin ("SK1B" manufactured by Mitsubishi Chemical Corporation) mixed at a volume mixing ratio of 6: 4.
Desalination chamber: 5mm thick
Concentration chamber: 4 mm thick
Membrane area: 300 cm ² (300 mm × 100 mm)
Treated water volume: 0.4 m ³ / hour Concentrated water volume: 0.1 m ³ / hour

<Microfiltration membrane device>
Microfiltration membrane: Advantech made hydrophilic PTFE (polytetrafluoroethylene) filter TCFH-050-S1FE

(Comparative Example 1)
As water to be treated (raw water), water to be treated similar to that in Example 1 was treated with the ultrapure water production system shown in FIG. The configuration of each device is as follows. The pH of the raw water was 7.1.

<Microfiltration membrane device>
Microfiltration membrane: Asahi Kasei UNA-600A
Treated water volume: 2.5 m ³ / h

<Activated carbon tower>
Concatenation of two Kurita Industries CF-50 Treated water volume: 2.5 m ³ / h

<Security filter>
Loki Techno DIA (II) spool filter × 5 Treatment water volume: 2.5 m ³ / h

<Chemical introduction means>
Tank: CT-U120N made by Iwaki Co., Ltd.
Pump: EWN-B11-VC1J-WPO manufactured by Iwaki Co., Ltd.
Chemical: 10% sulfuric acid

<Reverse osmosis membrane device>
Reverse osmosis membrane: FILMTEC LE-4040 manufactured by The Dow Chemical Company (the height of the intersection of raw water flow path spacers: spiral type using 0.85 mm, diameter 100 mm) connected two treated water volume: 0.5m ³ / h
Concentrated water volume: 1.1 m ³ / h

<Deaeration membrane device>
Mitsubishi Rayon MHF1704
Treated water volume: 0.5m ³ / h

<Electrodeionization equipment>
A concentration chamber and a desalination chamber are formed by alternately arranging a plurality of the following anion exchange membranes and cation exchange membranes between the cathode (cathode) and the anode (anode). The one filled with the following ion exchange resin was used. In addition, the thickness and membrane area of the desalting chamber and the concentration chamber are as follows.
Anion exchange membrane: Asahi Kasei Kogyo Co., Ltd. “Aciplex A501SB”
Cation exchange membrane: Asahi Kasei Kogyo Co., Ltd. “Aciplex K501SB”
Ion exchange resin: An anion exchange resin ("SA10A" manufactured by Mitsubishi Chemical Corporation) and a cation exchange resin ("SK1B" manufactured by Mitsubishi Chemical Corporation) mixed at a volume mixing ratio of 6: 4.
Desalination chamber: 15mm thick
Concentration chamber: 15 mm thick
Membrane area: 300 cm ² (300 mm × 100 mm)
Treated water volume: 0.4 m ³ / h
Concentrated water volume: 0.1 m ³ / h

<Ultraviolet sterilizer>
Kurita Industrial NPX-1 / 2
Treated water volume: 0.4 m ³ / h

<Terminal microfiltration membrane device>
Advantech TCFH-050-S1FE
Treated water volume: 0.4 m ³ / h

(Comparative Example 2)
As water to be treated (raw water), water to be treated similar to that in Example 2 was treated with the ultrapure water production system shown in FIG. The configuration of each device is the same as that of Comparative Example 1. Moreover, the pH of the to-be-processed water after addition of a pH adjuster was 5.0.

  As a result, the specific resistances of the treated water obtained in Examples 1 and 2 and Comparative Examples 1 and 2 are both 16.5 MΩ · cm, and the treated water obtained in Examples 1 and 2 is Comparative Example 1. 2 and high quality water comparable to the treated water obtained in 2. The ultrapure water production system of Example 1 was 60% of the floor area of the ultrapure water production system of Comparative Example 1 and the production cost was 60%. The ultrapure water production system of Example 2 was 70% of the floor area of the ultrapure water production system of Comparative Example 2, and the production cost was 65%.

  DESCRIPTION OF SYMBOLS 1 Filtration tank, 2 Filter body, 3 Core material, 4 Filter body main body, 5 Mesh sheet, 6 Spacer, 7 Plate, 8 Water impervious member, 9a Warp, 9b Weft, 10, 10A Ultrapure water production system, 11 Water tank, 12 Heat exchanger, 13 Activated carbon filtration device, 14 Pretreatment water tank, 15 Reverse osmosis membrane device, 16 Electrodeionization device, 17 Precision filtration membrane device

Claims (7)

A pretreatment unit into which water to be treated is introduced; a pretreatment water tank in which the water to be treated treated in the pretreatment unit is stored; a reverse osmosis membrane device into which water to be treated is introduced from the pretreatment water tank; An ultrapure water production department having an ion device,
The pretreatment unit includes an activated carbon filtration device, and the activated carbon filtration device has a filter body having a sheet-like member wound in a spiral shape, water to be treated is passed, and an axis of the filter body has a shaft core. A filtration tank in which the filter body is filled so as to be along a water flow direction, and the sheet-like member is a sheet-like mesh sheet having pores through which water to be treated passes, and a mesh sheet The sheet surfaces of the sheet-like spacer that is difficult to pass the water to be treated are overlapped, and at least a part of the mesh sheet and the spacer is formed of activated carbon fibers. Ultrapure water production system.   2. The ultrapure water production system according to claim 1, wherein the spacer is formed of activated carbon fibers having a diameter of 0.1 to 100 [mu] m.   The ultrapure water production system according to claim 1 or 2, wherein at least one decarbonation facility is provided upstream of the electrodeionization apparatus.   The ultrapure water production system according to any one of claims 1 to 3, wherein the electrodeionization apparatus has a bipolar membrane.   The ultrapure water production system according to any one of claims 1 to 4, wherein the deionization chamber of the electrodeionization apparatus has a thickness of 2 to 5 mm.   The ultrapure water discharged from the ultrapure water production unit is sent to a use point, and at the same time, it has a terminal piping unit that returns excess ultrapure water to the pretreatment water tank. The ultrapure water production system described in one item. The treated water that has been subjected to the activated carbon filtration treatment by the activated carbon filtration device is stored in the pretreatment water tank, and the treated water stored in the pretreatment water tank is subjected to the reverse osmosis membrane treatment by the reverse osmosis membrane device, and then deionized by the electrodeionization device A method for producing ultrapure water,
The activated carbon filtration device includes a filter body in which a sheet-like member is wound in a spiral shape, water to be treated is passed, and the filter body is arranged such that an axis of the filter body is along a water passage direction. The sheet-like member has a sheet-like mesh sheet having pores through which the water to be treated passes, and a sheet-like material through which the water to be treated is difficult to pass compared to the mesh sheet. A method for producing ultrapure water, wherein sheet surfaces of spacers are overlapped, and at least a part of the mesh sheet and the spacers are formed of activated carbon fibers.