JP2011110515A - Method and apparatus for purifying ion exchange resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce an ion exchange resin exhibiting remarkably reduced boron elution in particular, by highly purifying the same. <P>SOLUTION: An ion exchange resin is purified by washing the same with water having been treated to contain boron at a concentration of 1 ppt or lower. The treated water is produced by treating raw water of a boron concentration of 100 ppt or lower by causing the same to flow through a reverse osmosis membrane device 1, a degassing membrane device 2, and an electric deionizer 3 one after another in that order, and subsequently causing the resulting water to flow through an oxidation device 4 employing an ultraviolet ray for oxidation, an ion exchange device 5 that is not to be reactivated, and an ultrafiltration device 6 one after another in that order. In the electric deionizer 3, a portion of the deionized water coming out of a desalination chamber is made to countercurrently flow through a concentration chamber, relative to the desalination chamber. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a purification method and a purification apparatus for highly purifying an ion exchange resin, and particularly to obtain an ion exchange resin with a significantly reduced boron elution amount.
The present invention also relates to a method and apparatus for producing water for purifying ion exchange resin used for purification of such ion exchange resin.

  In the semiconductor industry, ultrapure water is used for cleaning semiconductor products and other applications, but the demand for the quality of this ultrapure water is becoming stricter. In particular, boron ions in ultrapure water cause a significant hindrance to semiconductor manufacturing if they remain on the semiconductor substrate. Therefore, in ultrapure water used for semiconductor manufacturing, boron ions together with fine particles and TOC (total organic carbon). Reduction is required.

In the ultrapure water production system, ultrapure water is produced by combining different types of treatment equipment, such as deoxygenation equipment, reverse osmosis membrane equipment, primary deionization equipment, ultraviolet oxidation equipment, secondary deionization equipment, and ultrafiltration membrane equipment. It is manufactured.
In such an ultrapure water production system, a non-regenerative ion exchange resin tower (non-regenerative ion exchange device) installed as a terminal deionization device is new or has a relatively low use frequency of strongly acidic cation exchange. H-type strongly acidic cation exchange resins and OH-type strongly basic anion exchange resins obtained by purifying a resin and a strongly basic anion exchange resin are used. Usually, as this ion exchange resin tower, a mixed bed type ion exchange resin tower in which both ion exchange resins are mixed is adopted and designed to obtain a treated water quality of 18 MΩ · cm or more. In this non-regenerative ion exchange apparatus, it is necessary to reduce the leakage of impurities from the ion exchange resin itself as well as the ion removal performance by the ion exchange resin.

  Various proposals have been made regarding conditioning methods and treatment agents for suppressing leakage of impurities from ion exchange resins. For example, Patent Document 1 discloses ultrapure water as a conditioning method for ion exchange resins. A method has been proposed in which ion-exchange resin is washed with gas-dissolved water in which an inorganic gas is dissolved, and then washed with ultrapure water.

  In such ion-exchange resin conditioning, in the ion-exchange resin cleaning with ultrapure water in the final stage of conditioning, the longer the cleaning time, the lower the elution of impurities such as the TOC component of the ion-exchange resin. Therefore, in some cases, cleaning is performed over a long period of one week to one month.

However, according to the study of the present inventor, when the ion exchange resin is washed for a long period of time, elution of TOC components and the like is reduced, but boron in the ultrapure water used for washing is adsorbed and adsorbed on the ion exchange resin. Boron was desorbed during use of the ion exchange resin and mixed into the production water, and it was found that production water with a sufficiently reduced boron concentration could not be obtained.
This problem is promoted as the cleaning time with ultrapure water is increased. Especially when cleaning for a long period of 3 weeks or more, the problem of boron contamination of the ion exchange resin due to the cleaning is remarkable. For example, when producing ultrapure water using resin, it is not possible to collect water from the start of production of ultrapure water until boron does not elute in the production water. It takes a long time to start up the device until sampling.

  By the way, when removing boron in water, an ordinary electrodeionization apparatus has a low boron removal rate (for example, 50 to 70%) and cannot perform efficient boron removal. Moreover, even if a reverse osmosis membrane device is combined with an electrodeionization device, a sufficient boron removal rate cannot be achieved. On the other hand, in a non-regenerative ion exchange apparatus, since boron is saturated early, it is necessary to replace the ion exchange resin frequently, for example, every two weeks, which is uneconomical. Although a certain amount of boron removal efficiency can be obtained by frequently regenerating the ion exchange resin in a multi-bed type ion exchange resin apparatus, for example, the regeneration is performed periodically at a frequency of once a day. It is necessary to carry out, continuous water flow is not possible, and for continuous water flow, a preliminary series is necessary and operation is difficult, and high concentration acid and alkali are required for regeneration, Further, the treatment is complicated, for example, the recycled wastewater is discharged.

  On the other hand, in Patent Document 2, water having a lower boron concentration than raw water is passed through the concentration chamber of the electrodeionization device in the countercurrent direction with the demineralization chamber, thereby removing boron in the electrodeionization device. An invention is described that increases the rate and obtains water with a significantly reduced boron concentration.

  The electrodeionization apparatus disclosed in Patent Document 2 can highly remove boron in water, but the electrodeionization apparatus is generally preceded by a non-regenerative ion exchange apparatus in an ultrapure water production system. Even if the boron removal rate is increased by using such an electrodeionization apparatus, there is a problem of elution of boron from the ion exchange resin filled in the non-regenerative ion exchange apparatus at the subsequent stage. The final treated water is water mixed with boron.

JP 2009-240943 A Japanese Patent No. 3794268

  In the conventional cleaning with ultrapure water for the purification of ion exchange resin, the longer the cleaning time, the more elution of TOC components and ion components from the ion exchange resin can be reduced, but the longer cleaning time. Therefore, there is a problem that boron is adsorbed on the ion exchange resin and boron elution is improved.

  The present invention solves the problem of boron contamination of such an ion exchange resin, and can obtain an ion exchange resin in which not only the elution of TOC component and ion component but also the elution of boron is sufficiently reduced. It is an object of the present invention to provide a method and an apparatus for purifying an exchange resin and a method and an apparatus for producing purified water for ion exchange resin used for the purification of such an ion exchange resin.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a water having a significantly reduced boron concentration for a long time as the water used for the final purification process in the conditioning of the ion exchange resin. In order to obtain an ion exchange resin having no boron elution problem by preventing boron contamination of the ion exchange resin when washing is performed, for example, in order to obtain an ion exchange resin having a boron elution amount of 1 ppt or less, boron is used. It was found that it was necessary to wash with water having a concentration of 1 ppt or less.

  The present invention has been achieved on the basis of such findings, and the gist thereof is as follows.

  The method for purifying an ion exchange resin of the present invention (invention 1) is characterized in that the ion exchange resin is purified using water treated to a boron concentration of 1 ppt or less.

  The method for purifying an ion exchange resin according to claim 2 is the reverse osmosis membrane device, degassing membrane device, and electrodeionization device according to claim 1, wherein the water treated to have a boron concentration of 1 ppt or less is raw water having a boron concentration of 100 ppt or less. In that order, followed by passing through an ultraviolet oxidizer, a non-regenerative ion exchange device, and an ultrafiltration membrane device in this order. Part of the deionized water from the chamber is passed through the concentration chamber in a counter-current direction to the desalination chamber.

  The method for purifying an ion exchange resin according to claim 3 is the method according to claim 2, wherein the non-regenerative ion exchange device or the ultrafiltration membrane device has a boron concentration of treated water obtained by passing water to be treated into the device. The amount of increase of the water to be treated with respect to the boron concentration has a cleanliness of 1 ppt or less.

  According to a fourth aspect of the present invention, there is provided a method for purifying an ion exchange resin according to the second or third aspect, wherein the raw water contains all or part of the water used for the purification of the ion exchange resin.

  An apparatus for purifying an ion exchange resin according to the present invention (Claim 5) includes a water treatment device for treating raw water to obtain treated water having a boron concentration of 1 ppt or less, and ions into which treated water obtained by the water treatment device is introduced. And an exchange resin purification tower.

  An apparatus for purifying an ion exchange resin according to claim 6 is characterized in that, in claim 5, the concentration of boron in the raw water is 100 ppt or less, and the water treatment apparatus is a reverse osmosis membrane device, a degassing membrane device, or an electrodeionization device. A primary treatment system connected in order, and a secondary treatment system connected in the order of an ultraviolet oxidation device, a non-regenerative ion exchange device, and an ultrafiltration membrane device in the subsequent stage, and the electrodeionization The apparatus is characterized by having means for allowing a part of deionized water from the desalting chamber to flow through the concentration chamber in a counter-current direction to the desalting chamber.

  The apparatus for purifying an ion exchange resin according to claim 7 is the boron concentration of treated water obtained by passing the treated water through the apparatus according to claim 6, wherein the non-regenerative ion exchange apparatus or the ultrafiltration membrane apparatus is passed through the apparatus. The amount of increase of the water to be treated with respect to the boron concentration has a cleanliness of 1 ppt or less.

  The purification apparatus for an ion exchange resin according to claim 8 returns the whole or part of the water used for purification of the ion exchange resin in the ion exchange resin purification tower as raw water of the water treatment apparatus according to claim 6 or 7. It has the means to do.

  The method for producing purified water for ion exchange resin according to the present invention (Claim 9) is a method for producing water used for purification of an ion exchange resin, wherein raw water having a boron concentration of 100 ppt or less is converted into a reverse osmosis membrane device and a deaeration membrane device. , And the electrodeionization apparatus in order, and then processed by treatment, and then the ultraviolet oxidation apparatus, the non-regenerative ion exchange apparatus, and the ultrafiltration membrane apparatus in order of treatment and treatment with a boron concentration of 1 ppt or less. In the electrodeionization apparatus, a part of the deionized water from the demineralization chamber is passed through the concentration chamber in a countercurrent direction to the demineralization chamber.

  The method for producing purified water for ion exchange resin according to claim 10 is the treated water according to claim 9, wherein the non-regenerative ion exchange device or the ultrafiltration membrane device is obtained by passing water to be treated through the device. The amount of increase of the boron concentration with respect to the boron concentration of the water to be treated has a cleanliness of 1 ppt or less.

  The method for producing purified water for ion exchange resin according to claim 11 is characterized in that, in claim 9 or 10, the raw water contains all or part of the water used for purification of the ion exchange resin.

  The apparatus for producing purified water for ion exchange resin of the present invention (Claim 12) is an apparatus for producing water used for purification of ion exchange resin, in the order of reverse osmosis membrane device, deaeration membrane device, and electrodeionization device. A primary treatment system connected, a secondary treatment system connected in the order of an ultraviolet oxidation device, a non-regenerative ion exchange device, and an ultrafiltration membrane device in the subsequent stage, and a boron concentration of 100 ppt or less in the primary treatment system A means for supplying raw water, and the electrodeionization apparatus has means for passing a part of the deionized water from the desalting chamber to the concentrating chamber in a counter-current direction to the desalting chamber. It is characterized by.

  The apparatus for producing purified water for ion exchange resin according to claim 13 is the treated water according to claim 12, wherein the non-regenerative ion exchange apparatus or the ultrafiltration membrane apparatus is obtained by passing water to be treated through the apparatus. The amount of increase of the boron concentration with respect to the boron concentration of the water to be treated has a cleanliness of 1 ppt or less.

  The apparatus for producing purified water for ion exchange resin according to claim 14 has means for mixing the whole or part of the water used for purification of the ion exchange resin with the raw water according to claim 12 or 13. .

According to the present invention, it is possible to solve the problem of boron contamination when the ion exchange resin is purified by washing for a long time, so that the ion that has sufficiently reduced boron elution along with the TOC component and the ion component. An exchange resin can be obtained.
Since the ion exchange resin highly purified according to the present invention has no problem of boron elution, by using this ion exchange resin, for example, at the production site of ultrapure water, there is a problem of boron contamination from the beginning of operation. Water can be obtained, and the apparatus startup time until water sampling can be greatly shortened.

It is a systematic diagram which shows embodiment of the water treatment apparatus for the water manufacture for ion exchange resin refinement | purification of this invention. It is a schematic diagram which shows the structure of the electrodeionization apparatus used suitably in this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

In the present invention, there is no particular limitation on the instrument used for evaluating the water quality, but in the present invention, the value measured by the following water quality measuring device is adopted as the water quality item.
TOC: Anatel TOC meter “Anatel 1000XP”
Specific resistance: resistivity meter “MX-4” manufactured by Kurita Kogyo Co., Ltd.
Boron: Boron meter manufactured by Seaverse Co., Ltd. Number of fine particles: “KLAMIC-KS” manufactured by Kurita Industries Co., Ltd.

[Ion-exchange resin purification water]
In the present invention, water used for the purification of the ion exchange resin (hereinafter sometimes referred to as “purification water”) is water having a boron concentration of 1 ppt or less (ultra pure water).
When the boron concentration of this purification water exceeds 1 ppt, an ion exchange resin with a sufficiently reduced boron elution amount cannot be obtained.

  The boron concentration in the water for purification is preferably as low as possible, and the boron concentration in this water is particularly preferably 1 ppt or less, particularly preferably 0.5 ppt or less. However, the lower limit of the boron concentration of the purification water is usually about 1 ppt from the limit of the treatment for removing boron in the production of the purification water described later.

In addition, it is preferable that it is the following values as water quality components other than boron of this water for refinement | purification.
Specific resistance: 18.2 MΩ · cm or more TOC: 1 ppb or less Number of fine particles: 1 particle / l mL or less (the number of particles having a particle diameter of 0.05 μm or more present in 1 mL of water is 1 or less, and so on)

[Production of water for purification]
Hereinafter, a method for producing purification water having a boron concentration of 1 ppt or less will be described with reference to FIG. 1. However, the method for producing the purification water of the present invention is not limited to the method shown in FIG. Any other method may be used.

  FIG. 1 is a system diagram showing an example of an apparatus for producing purification water according to the present invention. In the figure, 1 is a reverse osmosis membrane apparatus, 2 is a degassing membrane apparatus, 3 is an electrodeionization apparatus, 4 Is an ultraviolet oxidation device, 5 is a non-regenerative ion exchange device, and 6 is an ultrafiltration membrane device. The primary treatment system is formed by the reverse osmosis membrane device 1, the deaeration membrane device, and the electrodeionization device 3, and the ultraviolet oxidation The apparatus, the non-regenerative ion exchange device 5 and the ultrafiltration membrane device 6 form a secondary processing system. A relay tank may be provided between the primary processing system and the secondary processing system as necessary.

  The purification water according to the present invention having a boron concentration of 1 ppt or less uses such a device, and the treated water (raw water) is converted into reverse osmosis membrane device 1, degassing membrane device 2, electrodeionization device 3, and ultraviolet oxidation device. 4. It can be produced by passing water through the non-regenerative ion exchange device 5 and the ultrafiltration membrane device 6 for processing, but in the production of this purification water, the raw water is a relatively low boron concentration of 100 ppt or less. It is preferable that the boron concentration is low. If the boron concentration of the raw water exceeds 100 ppt, water having a boron concentration of 1 ppt or less may not be obtained even if such an apparatus is used. Therefore, it is desirable to treat, as raw water, ultrapure water having a boron concentration of 100 ppt or less, for example, a boron concentration of about 5 to 50 ppt, manufactured by a normal general ultrapure water production apparatus. If the boron concentration is 100 ppt or less, the raw water for producing the purification water may contain water used for the ion exchange resin purification process described later. Reduction can be achieved.

For example, the following water quality is preferable as the water quality other than boron of the raw water used for producing the purification water.
Specific resistance: 10 MΩ · cm or more, for example, 15 to 18 MΩ · cm
TOC: 10 ppb or less, for example, 1 to 5 ppb
Number of fine particles: 1000 particles / 1 mL or less, for example, 100 to 500 particles / 1 mL

  In addition, in order to reliably obtain treated water having a boron concentration of 1 ppt or less from such boron-concentrated raw water, the electrodeionization apparatus 3 can be used from a demineralization chamber as described in the aforementioned Japanese Patent No. 3794268. It is preferable to use an electrodeionization apparatus configured to pass a part of the deionized water obtained through the concentrating chamber in a direction opposite to the flow direction of the desalting chamber.

  Below, this electrodeionization apparatus is demonstrated with reference to FIG.

  FIG. 2 is a schematic cross-sectional view showing an example of an electrodeionization apparatus suitable for the present invention. This electrodeionization apparatus includes a plurality of anion exchange membranes (electrodes 11 and 12) (an anode 11 and a cathode 12). A membrane) 13 and cation exchange membrane (C membrane) 14 are alternately arranged to form a concentration chamber 15 and a desalting chamber 16 alternately. In the desalting chamber 16, an ion exchange resin, an ion exchange An anion exchanger and a cation exchanger made of a fiber or a graft exchanger are mixed or packed in a multilayered manner.

  The concentration chamber 15, the anode chamber 17, and the cathode chamber 18 are also filled with an electric conductor (including a mesh electrode) such as an ion exchanger, activated carbon, or metal.

  The water to be treated is introduced into the desalting chamber 16, and deionized water is taken out from the desalting chamber 16. A portion of this deionized water is passed through the concentrating chamber 15 in a counter-current and transient manner in a direction opposite to the direction of water passing through the desalting chamber 16, and the outflow water from the concentrating chamber 15 is discharged out of the system. That is, in this electric deionization apparatus, the concentrating chambers 15 and the desalting chambers 16 are alternately arranged in parallel, and the inlet of the concentrating chamber 15 is provided on the deionized water take-out side of the desalting chamber 16. An outlet of the concentrating chamber 15 is provided on the treated water inflow side of the chamber 16. A part of the deionized water 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 used as drainage. It is discharged out of the system.

  In this way, by passing deionized water through the concentrating chamber 15 in a countercurrent and transient manner with the desalting chamber 16, the concentration of the concentrated water in the concentrating chamber 15 becomes lower toward the deionized water extraction side. The influence of the diffusion on the desalting chamber 16 is reduced, and the ion removal rate, particularly the boron removal rate, can be dramatically increased.

  Conventionally, concentrated water (flowing water from the concentration chamber) of the electrodeionization apparatus is circulated to the inlet side of the concentration chamber after being partially discharged to improve the water recovery rate. Was 80 m / hr or more.

  On the other hand, in the electrodeionization apparatus of FIG. 2, deionization performance can be ensured by filling the concentration chamber with an ion exchanger, even if the LV of the concentration chamber is 20 m / hr or less. This is because when the concentrating chamber is a spacer, it was necessary to diffuse the concentration of boron on the membrane surface of the concentrating chamber by a water flow, whereas by filling the concentrating chamber with an ion exchanger or the like, the ion exchanger This is probably because ions diffuse through the surface, so that a high water flow rate (LV) is not required.

  Since the water flow rate may be low in this way, even if the concentrated water is passed through in a transient manner, the water recovery rate can be improved as compared with the conventional one, and it is not necessary to use a circulation pump. It is more economical. In the present invention, it is preferable to pass the concentrated water in a transient manner by setting the water flow LV in the concentration chamber to 20 m / hr or less, for example, 10 to 20 m / hr, in order to highly remove boron.

  The concentrating chamber filling may be activated carbon or the like in order to secure the necessary current, but it is preferable to fill the ion exchanger from the viewpoint of the ion diffusion action.

  In the electrodeionization apparatus of FIG. 2, deionized water is also supplied to the electrode chambers 17 and 18, but in the electrode chambers 17 and 18, as in the concentration chamber 15, an ion exchanger or Filling with activated carbon, metal or mesh electrode, which is an electrical conductor, makes the power consumption constant regardless of the water quality, ensuring the necessary current even when passing high-quality water such as ultrapure water. It becomes possible.

In the electrode chamber, the generation of oxidizers such as chlorine and ozone occurs in the anode chamber in particular. Therefore, the packing material should be made of a metal such as a mesh electrode rather than using an ion exchange resin in the long term. Is preferred. Further, supplying deionized water to the electrode chamber as shown in FIG. 2 can prevent generation of chlorine because there is almost no Cl ^{− in} the electrode chamber supply water, so that long-term stabilization of the filling material and the electrode can be achieved. Is desirable.

  In addition, the electrode chamber may be made porous so that the water passage surface side of the electrode plate can be made porous without using the filler as described above, and in this case, the electrode water can be passed. Since the plate and the electrode chamber can be integrated, there are advantages such as easy assembly.

  In such an electrodeionization apparatus, in order to improve the boron removal rate, it is advantageous that the thickness of the demineralization chamber is smaller. The thickness of the desalting chamber is preferably 5 mm or less, and the smaller the thickness, the better. However, in consideration of water permeability, handling at the time of production, etc., it is preferably 2 mm or more in practice.

Further, it is preferable to improve the boron removal rate by securing the current and eliminating the influence of concentration diffusion. For securing the current, the concentration chamber, and further the electrode chamber as described above Although a device is required, the current required for achieving a high boron removal rate is preferably a current value in order to obtain a current value corresponding to 10% or less as a current efficiency, and further a boron removal rate of 99.9% or more. A current value corresponding to an efficiency of 5% or less is required. The current efficiency is expressed by the following formula.
Current efficiency (%) = 1.31 × flow rate per cell (L / min) × (treated water equivalent conductivity)
(ΜS / cm) −deionized water equivalent conductivity (μS / cm)) / current (A)

The flow rate per cell in this electrodeionization apparatus is preferably 130 L / hr or less, for example, 100 to 120 L / hr, and the water flow SV for the ion exchange resin in the cell is 130 hr ⁻¹ or less, for example 100. About 120 hr ⁻¹ is preferable, the current condition is 6 A or more, particularly 8 A or more, preferably about 8 to 10 A, and the water recovery rate is preferably 90% or less, particularly 80% or less, for example, 75 to 80%.

  Such an electrodeionization apparatus can secure a necessary current even when boron is further reduced from the water to be treated having a high specific resistance, so that the current does not flow through either the concentration chamber or the electrode chamber. Thus, the conventional problem that the current of the entire electrodeionization apparatus stops flowing can be solved.

  The ion exchange resin filled in the demineralization chamber and the concentration chamber of the electrodeionization apparatus is preferably a mixed resin of an anion exchange resin and a cation exchange resin, and the mixing ratio thereof is anion exchange resin: cation exchange resin = 5. : From the same ratio of 5 to 7: 3 (volume ratio), it is preferable in terms of removal of boron that the anion exchange resin is slightly excessive.

  With such an electrodeionization apparatus, it is possible to obtain water from which boron is highly removed with a boron concentration of 1 ppt or less from water to be treated having a boron concentration of about 10 to 100 ppt.

  In addition, by providing the deaeration membrane device 2 in the preceding stage of the electrodeionization device 3 and reducing the dissolved oxygen (DO) in the water to a DO concentration of 10 ppb or less, for example, the oxidative deterioration in the electrodeionization device 3 is prevented. Thus, the lifetime of the electrodeionization apparatus 3 can be extended.

  Although there are no particular restrictions on the specifications of other treatment apparatuses of the purification water production apparatus shown in FIG. 1, even if an electrodeionization apparatus having a high boron removal rate as shown in FIG. If there is a problem of boron contamination in the subsequent apparatus, the boron concentration of the resulting treated water cannot be sufficiently reduced, and purification water having a boron concentration of 1 ppt or less cannot be obtained. Non-regenerative ion exchange device 5 or ultrafiltration membrane device 6 in the latter stage, preferably both non-regenerative ion exchange device 5 and ultrafiltration membrane device 6 are treated water (device inlet) that is passed through the device. The degree of increase in the boron concentration of the treated water (device outlet water) obtained from this apparatus with respect to the boron concentration of water (that is, the apparatus outlet water boron concentration minus the apparatus inlet water boron concentration. Boron contamination ), That is, a highly clean apparatus in which the degree of boron contamination by passing through the apparatus is 1 ppt or less, particularly 0.5 ppt or less, for example, 0.1 to 0.5 ppt. Preferably there is. Examples of such a highly clean non-regenerative ion exchange apparatus include a non-regenerative ion exchange apparatus filled with an ion exchange resin purified by the method of the present invention. Moreover, as an ultrafiltration membrane apparatus, the apparatus wash | cleaned highly by the purified water used by this invention is mentioned.

  If the electrodeionization apparatus 3 shown in FIG. 1 is used as the electrodeionization apparatus 3, the boron concentration is 1 ppt or less, the specific resistance is 18.2 MΩ · cm or more, the TOC is 1 ppb or less, the number of fine particles It is possible to produce high-purity water such that it is 1 / mL or less.

  In the present invention, high-purity water produced in this way is used as purification water, but this high-purity water is not limited to ion-exchange resin purification water, but an ultrafiltration membrane device that requires high cleanliness, etc. It can also be used as washing water for cleaning the apparatus.

[Purification of ion exchange resin]
In the present invention, the ion exchange resin is washed and purified using the above-described purification water having a boron concentration of 1 ppt or less.

For washing the ion exchange resin, an appropriate column is filled with the ion exchange resin, and the water for purification is passed through.
Therefore, for example, a means for passing treated water taken out from the ultrafiltration membrane device 6 of the purification water production apparatus shown in FIG. 1 through this ion exchange resin packed column may be provided to purify the ion exchange resin.

  Conditions for this purification treatment vary depending on the degree of contamination of the ion exchange resin to be purified and the cleanliness of the target ion exchange resin, but the following conditions are usually preferred.

Water flow direction: Downstream water flow Water flow SV: 10 to 50 hr ⁻¹
Water flow LV: 30 to 150 m / hr

  The washing time is also appropriately determined according to the degree of contamination of the ion exchange resin used for purification, the cleanliness of the target ion exchange resin, and other washing conditions, but is usually about 4 to 5 to 10 to 30 days. In particular, the present invention is effective for long-term cleaning in which cleaning for 3 weeks or more is performed and boron adsorption from the cleaning water becomes a problem.

  In addition to setting the ion exchange resin cleaning time to a predetermined value, the water quality measuring instrument described above is provided in the cleaning drain discharge pipe of the ion exchange resin cleaning column, continuously or intermittently (for example, every 30 minutes). When the water quality of the cleaning wastewater is monitored and the value becomes a predetermined value, for example, when the boron concentration of the cleaning wastewater becomes 1 ppt or less, the cleaning can be automatically controlled to end.

[Reuse of washing wastewater]
Discarding the entire amount of the washing wastewater used for the purification treatment of the ion exchange resin is uneconomical because of the large amount of water used.
Accordingly, the washing wastewater used for washing the ion exchange resin can be used as the raw water of the above-described purification water production apparatus if the water quality does not cause any problems when the purification water having a boron concentration of 1 ppt or less is used as the raw water. Preferably it is processed and reused.

  Specifically, any cleaning wastewater having a TOC of 1 ppm or less, a specific resistance of 1 MΩ · cm or more, and a boron concentration of 100 ppt or less can be reused as raw water for production of purification water.

  Therefore, the above-mentioned water quality measuring instrument is provided in the washing drain discharge pipe of the washing column of the ion exchange resin, and the quality of the washing drainage is monitored continuously or intermittently (for example, every 30 minutes). In such a case, the flow path of the discharge pipe for cleaning waste water may be switched and returned to the inlet side of the reverse osmosis membrane device 1 of the above-described purification water production apparatus.

  Further, in this case, as described above, when the quality of the washing wastewater reaches a predetermined value, the washing is terminated, whereby the production of the purification water from the raw water and the ion exchange resin by the purification water are performed. It is efficient because refining and reuse of washing wastewater can be performed by continuous automatic operation.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

[Example 1]
Using the apparatus shown in FIG. 1, ion-exchange resin purification water was manufactured using ultrapure water having the following water quality obtained by another ultrapure water manufacturing apparatus as raw water.

<Raw water quality>
Boron: 20 ppb
Specific resistance: 15 MΩ · cm
TOC: 500ppb

  As shown in FIG. 2, as the electrodeionization apparatus, Kurita is an electrodeionization apparatus that circulates a part of the deionized water from the demineralization chamber into the concentrating chamber in the direction of water flow in the direction of water flow in the demineralization chamber. An industrial deionization apparatus “KCDI-UPz” was used. The demineralization chamber and the concentration chamber of this electrodeionization apparatus were filled with a mixture of an anion exchange resin and a cation exchange resin in a ratio of 6: 4 (volume ratio). The anode chamber and the cathode chamber were filled with activated carbon. The thickness of the desalting chamber is 5 mm, and the thickness of the concentration chamber is 5 mm.

  The operating conditions of this electrodeionization apparatus are as follows.

[Operating conditions]
Current: 10A (current efficiency 2%)
Desalination chamber SV: 115 hr ⁻¹
Concentration chamber LV: 15 m / hr
Deionized water volume: 25 m ³ / hr
Concentration chamber flow rate: 5 m ³ / hr
Electrode chamber flow rate: 200 L / hr
Water recovery rate: 80%

That is, through the water in a countercurrent transient expression concentrating chamber ^{5 m} 3 / hr in deionized water ^{25 m} 3 / hr, was passed through the cathode chamber was passed through a 200L / hr to the anode chamber.

  The specifications of other devices are as follows.

Reverse osmosis membrane device: “K-RO-A2031” manufactured by Kurita Kogyo Co., Ltd.
Deaeration membrane device: "X40" manufactured by Celgard
Ultraviolet oxidizer: “SUV-4800TOC-N” manufactured by Nippon Photo Science Co., Ltd.
Non-regenerative ion exchanger: “KR-FM1” manufactured by Kurita Kogyo Co., Ltd.
Ultrafiltration membrane device: Kurita Industry Co., Ltd. “KU-1510HS-H”

  The non-regenerative ion exchange apparatus and ultrafiltration membrane apparatus used were cleaned to a boron contamination rate of 1 ppt by cleaning with chemicals and then conditioning with ultrapure water.

  With this apparatus, the following treated water was obtained.

<Treatment water>
Boron: 1 ppt or less Specific resistance: 18.24 MΩ · cm
TOC: 1 ppb or less Number of fine particles: 1 particle / 1 mL or less

The obtained treated water was used as purification water, and a column packed with an ion exchange resin (“KR-FM1” manufactured by Kurita Kogyo Co., Ltd.) was subjected to a treatment by washing with downward flowing water at SV30hr ⁻¹ for 30 days. .

  About the ion exchange resin after washing | cleaning, the elution amount of each component was investigated and the result was shown in Table 1.

[Comparative Example 1]
In Example 1, the ion-exchange resin was washed in the same manner except that the following water quality water containing more than 1 ppt of boron was used as the purification water, and the elution amount of each component was similarly examined, and the results are shown in Table 1. It was shown in 1.
Boron: 30ppt
Specific resistance: 18.2 MΩ · cm
TOC: 1 ppb or less Number of fine particles: 1 particle / 1 mL or less

[Reference Example 1]
In Comparative Example 1, the ion exchange resin was washed in the same manner except that the washing time was shortened to 3 days. Similarly, the elution amount of each component was examined, and the results are shown in Table 1.

  From Table 1, it can be seen that according to the present invention, not only the TOC component but also a highly clean ion exchange resin with a small boron elution amount can be obtained.

On the other hand, in Comparative Example 1 where the boron concentration of the water for purification exceeds 1 ppt, there is a problem of elution of boron from the ion exchange resin.
Even if this purification water is used, there is no problem of boron elution when the washing time is short as in Reference Example 1, but in this case, TOC elution becomes a problem.

  In Example 1, the water quality of the washing wastewater used for washing the ion exchange resin was monitored, and after 1 day, the water quality became TOC 1 ppm or less, specific resistance 1 MΩ · cm or more, and boron concentration 100 ppt or less. When the raw water was produced in the same manner as in Example 1 using the subsequent washing waste water as the production raw water for purification, treated water having the same water quality as in Example 1 could be obtained.

DESCRIPTION OF SYMBOLS 1 Reverse osmosis membrane apparatus 2 Deaeration membrane apparatus 3 Electrodeionization apparatus 4 Ultraviolet oxidization apparatus 5 Non-regenerative ion exchange apparatus 6 Ultrafiltration membrane apparatus 11 Anode 12 Cathode 13 Anion exchange membrane (A membrane)
14 Cation exchange membrane (C membrane)
15 Concentration chamber 16 Desalination chamber 17 Anode chamber 18 Cathode chamber

Claims (14)

  A method for purifying an ion exchange resin, comprising purifying an ion exchange resin using water treated to a boron concentration of 1 ppt or less.   In claim 1, water treated to a boron concentration of 1 ppt or less is treated by passing raw water having a boron concentration of 100 ppt or less in the order of a reverse osmosis membrane device, a deaeration membrane device, and an electrodeionization device, and then ultraviolet rays. Water that has been treated by passing through an oxidizing device, a non-regenerative ion exchange device, and an ultrafiltration membrane device in this order, and in the electrodeionization device, a portion of the deionized water from the desalting chamber is dehydrated. A method for purifying an ion exchange resin, wherein water is passed through a concentration chamber in a counterflow direction with respect to a salt chamber.   3. The non-regenerative ion exchange device or the ultrafiltration membrane device according to claim 2, wherein the amount of increase in the boron concentration of the treated water obtained by passing the treated water through the device is 1 ppt. A method for purifying an ion exchange resin, characterized by having the following cleanliness.   The method for purifying an ion exchange resin according to claim 2 or 3, wherein the raw water contains all or part of the water used for the purification of the ion exchange resin.   An ion exchange resin comprising: a water treatment device for treating raw water to obtain treated water having a boron concentration of 1 ppt or less; and an ion exchange resin purification tower into which treated water obtained by the water treatment device is introduced. Purification equipment.   In Claim 5, The boron concentration of the said raw | natural water is 100 ppt or less, The said water treatment apparatus is a primary treatment system connected in order of the reverse osmosis membrane apparatus, the deaeration membrane apparatus, and the electrodeionization apparatus, Furthermore, the subsequent stage A secondary treatment system connected in the order of an ultraviolet oxidation device, a non-regenerative ion exchange device, and an ultrafiltration membrane device, and the electrodeionization device comprises deionized water from a demineralization chamber. An apparatus for purifying an ion exchange resin, comprising means for passing a part of water through a desalination chamber and a concentration chamber in a countercurrent direction.   7. The non-regenerative ion exchange apparatus or ultrafiltration membrane apparatus according to claim 6, wherein the amount of increase in the boron concentration of the treated water obtained by passing the treated water through the apparatus is 1 ppt. An apparatus for purifying an ion exchange resin, characterized by having the following cleanliness.   8. The ion exchange resin according to claim 6, further comprising means for returning all or part of the water used for the purification of the ion exchange resin in the ion exchange resin purification tower as raw water of the water treatment apparatus. Purification equipment.   In the method for producing water used for the purification of ion exchange resin, raw water having a boron concentration of 100 ppt or less is treated by passing water in the order of reverse osmosis membrane device, degassing membrane device, and electrodeionization device, and then UV oxidation. Apparatus, a non-regenerative ion exchange device, and an ultrafiltration membrane device are passed through the water in order to obtain treated water having a boron concentration of 1 ppt or less, in the electrodeionization device, from the demineralization chamber. A method for producing purified water for ion-exchange resin, wherein a portion of the deionized water is passed through the concentration chamber in a counter-current direction to the desalting chamber.   10. The non-regenerative ion exchange device or ultrafiltration membrane device according to claim 9, wherein the amount of increase in the boron concentration of the treated water obtained by passing the treated water through the device is 1 ppt. The manufacturing method of the purified water for ion exchange resins characterized by having the following cleanliness.   11. The method for producing purified water for ion exchange resin according to claim 9 or 10, wherein the raw water contains the whole or a part of the water used for purification of the ion exchange resin.   In an apparatus for producing water used for the purification of ion exchange resin, a primary treatment system connected in the order of a reverse osmosis membrane device, a deaeration membrane device, and an electrodeionization device, and an ultraviolet oxidation device, non-regenerative type in the subsequent stage A secondary treatment system connected in order of an ion exchange device and an ultrafiltration membrane device, and means for supplying raw water having a boron concentration of 100 ppt or less to the primary treatment system, and the electrodeionization device comprises: An apparatus for producing purified water for ion-exchange resin, comprising means for passing a part of deionized water from a desalting chamber through a concentration chamber in a counter-current direction to the desalting chamber.   13. The non-regenerative ion exchange device or ultrafiltration membrane device according to claim 12, wherein the amount of increase in the boron concentration of the treated water obtained by passing the treated water through the device is 1 ppt. An apparatus for producing purified water for ion-exchange resin, characterized by having the following cleanliness.   14. The apparatus for producing purified water for ion exchange resin according to claim 12 or 13, further comprising means for mixing all or part of the water used for purification of the ion exchange resin with the raw water.

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