JP7192519B2 - Ultra-pure boron-removed ultra-pure water production apparatus and ultra-pure boron-removed ultra-pure water production method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for producing ultrapure boron-removed ultrapure water in which boron is reduced to the limit and a method for producing ultrapure boron-removed ultrapure water. The present invention relates to an apparatus for producing ultrapure boron-removed ultrapure water and a method for producing ultrapure water from which ultrapure boron is removed, which can be used for blank water for analysis of

Semiconductor manufacturing plants use ultrapure water that has been purified to a high degree by removing impurities. Water quality control items for this ultrapure water include resistivity, fine particles, viable bacteria, TOC, dissolved oxygen, boron, silica, other cations and anions, and heavy metals.

Water quality analyzers for analyzing these water qualities are diluted and calibrated with blank water. If it is used, the measured and calibrated values will become abnormal, and it will not be possible to obtain stable and correct values.

Therefore, conventionally, the ultrapure water produced by ultrapure water production equipment is further processed in a column filled with ion exchange resin, or processed in a column filled with boron chelate resin and then processed in a column filled with ion exchange resin. By doing so, the ultrapure water was further purified.

Although high-purity blank water can be obtained by these methods, the method of producing blank water by treating ultrapure water in a column filled with ion-exchange resin only has a short column life of 2 to 3 weeks or less. Moreover, there is a risk that boron may break and leak into the blank water due to fluctuations in the boron concentration in the ultrapure water, so the blank water must be frequently sampled and analyzed. In addition, in the method of producing blank water by treating ultrapure water in a column filled with a boron chelate resin and then in a column filled with an ion exchange resin, the life until boron breaks is longer, but There is still a problem that the treated water must be frequently sampled and analyzed to monitor boron breakage.

Therefore, by using an electrodeionization device instead of a column filled with a boron chelate resin, it is possible to remove both boron and other ions and eliminate the need to monitor boron leakage. However, the Na concentration of the treated water of the electrodeionization apparatus capable of removing boron with high purity is at least 50 ppt, and the Na concentration of the ultrapure water, which is the treated water of the electrodeionization apparatus, is 10 ppt or less. It turned out that there exists a problem that Na concentration will increase sharply.

The present invention has been made in view of the above problems, and an ultra-pure boron removal type ultra-pure water production apparatus that can be used for blank water for ultra-pure water analysis, and ultra-pure boron using the same An object of the present invention is to provide a method for producing removed ultrapure water.

In view of the above object, the present invention firstly provides an ultrapure water production apparatus having a primary pure water apparatus and a subsystem for treating the primary pure water obtained from the primary pure water apparatus, and an electrodeionization apparatus is installed in the subsequent stage of the ultrapure water production apparatus. , and an ion exchange resin column using an H-type cation exchange resin in this order (Invention 1).

According to this invention (Invention 1), it is possible to stably produce ultrapure water from which boron has been removed to an ultrahigh purity level. This is for the following reasons. That is, as a result of investigation by the present inventors on the cause of the significant increase in Na concentration when ultrapure water is treated with an electrodeionization apparatus, the anion exchange resin and the cation exchange resin to be filled in the electrodeionization apparatus are each salt-type ( The deionization compartment and the concentration compartment are packed at a high density by reducing the volume as Na form and Cl form). It was found that the reason for this was that the exchange resin was converted to a regenerated type (H type), and Na was released along with this, resulting in an increase in the Na concentration in the treated water. Therefore, an ion exchange resin column using an H-type cation exchange resin can be provided in the subsequent stage of the electrodeionization apparatus to remove Na. Ion exchange resin columns can be used for a long time. These make it possible to stably supply ultrapure water from which boron has been removed with ultrahigh purity.

In the above invention (Invention 1), the electrodeionization apparatus comprises a cathode and an anode, a cation exchange membrane and an anion exchange membrane disposed between the cathode and the anode, and partitioned by the cation exchange membrane and the anion exchange membrane. desalting compartments and concentrating compartments are formed, wherein the desalting compartments and the concentrating compartments are filled with an ion exchanger, and the deionized water passed through the desalting compartments is desalted into the concentrating compartments. Preferably, the water is introduced into the concentrating chamber from the side of the chamber near the deionized water outlet, and is discharged from the side near the inlet of the demineralizing chamber (Invention 2).

According to this invention (Invention 2), the electrodeionization apparatus having such a configuration passes the deionized water that has passed through the desalting chambers through the concentration chambers, thereby reducing the ionic components of the desalted water itself to a very small amount. Therefore, the difference in ion concentration between the concentrating compartment and the demineralizing compartment can be reduced, so that the boron removal rate can be increased.

In the above inventions (inventions 1 and 2), it is preferable that the H-type cation exchange resin is substantially 100% H-type cation exchange resin (invention 3).

According to this invention (Invention 3), ultrapure water is treated with an electrodeionization apparatus and then treated with an ion exchange resin column using an H-type cation exchange resin. Since the H type is substantially 100% cation exchange resin, it removes Na and does not itself release Na, so it is possible to stably produce ultrapure water from which boron with a low concentration of Na is removed with ultrahigh purity. supply becomes possible.

Secondly, according to the present invention, an ultrapure water production apparatus having a primary pure water apparatus and a subsystem for processing the primary pure water obtained from the primary pure water apparatus is used to electrolyze ultrapure water produced by the ultrapure water production apparatus. Provided is a method for producing ultrapure boron-removed ultrapure water, in which water is passed through an ion device and then treated with an ion exchange resin column using an H-type cation exchange resin (Invention 4).

According to this invention (invention 4), ultrapure water is treated with an electrodeionization device to remove boron to a high degree, and then an ion exchange resin column using an H-type cation exchange resin removes the increased Na. Therefore, it is possible to stably supply ultrapure water from which boron has been removed at an ultrahigh purity.

According to the present invention, ultrapure water is treated with an electrodeionization apparatus to remove boron to a high degree. Therefore, it is possible to stably supply ultrapure water from which boron has been removed with ultrahigh purity.

1 is a flow chart showing a boron ultrapure removal type ultrapure water production apparatus according to a first embodiment of the present invention; FIG. FIG. 2 is a schematic cross-sectional view showing the configuration of an electrodeionization apparatus used in the ultrapure boron removal type ultrapure water production apparatus of the first embodiment. FIG. 3 is a system diagram showing the electrodeionization apparatus of FIG. 2; FIG. 4 is a flow diagram showing a boron ultrapure removal type ultrapure water production apparatus according to a second embodiment of the present invention.

Hereinafter, a boron ultrapure removal type ultrapure water production apparatus according to a first embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a flowchart showing a boron ultrapure removal type ultrapure water production apparatus according to a first embodiment of the present invention. In FIG. 1, the boron ultrapure removal type ultrapure water production apparatus 1 basically includes an ultrapure water production apparatus 1A with an electrodeionization device 21 and an ion exchange resin column 22 using an H-type cation exchange resin. It has a configuration in order. The ultrapure water production apparatus 1A is composed of a pretreatment device 2, a primary pure water device 3, and a subsystem (secondary pure water device) 4. The primary pure water device 3 includes a tank 5 for pretreated water W1 and a pump 6. , an ultraviolet (UV) oxidation device 7 , a regenerative ion exchange device (mixed bed type, 4-bed 5-tower type, etc.) 8 , and a membrane deaerator 9 .

The sub-system 4 includes a sub-tank 11 for storing the primary pure water W2 produced by the primary pure water apparatus 3 and an ultraviolet oxidation device for treating the primary pure water W2 supplied from the sub-tank 11 via a pump (not shown). 12, a platinum group metal catalyst resin column 13, a membrane deaerator 14, a non-regenerative mixed bed ion exchange device 15, and an ultrafiltration (UF) membrane 16 as a membrane filtration device. Ultrapure water (secondary pure water) W3 treated by the UF) membrane 16 is supplied to a point of use (POU) 17 .

Part of the ultrapure water W3 treated with the ultrafiltration (UF) membrane 16 of the ultrapure water production apparatus 1A as described above is passed through an electrodeionization apparatus 21 and an ion exchange resin column 22 using an H-type cation exchange resin. are processed in order.

As the electrodeionization device 21, one having a configuration as shown in FIGS. 2 and 3 can be preferably used.

In FIG. 2, the electrodeionization apparatus 21 alternately arranges a plurality of anion exchange membranes 33 and cation exchange membranes 34 between electrodes (anode 31 and cathode 32) to alternate between concentration compartments 35 and deionization compartments 36. The desalting chamber 36 is filled with ion exchangers (anion exchangers and cation exchangers) made of ion exchange resins, ion exchange fibers, graft exchangers, or the like in a mixed or multi-layered form. . The concentrating compartment 35, the anode compartment 37 and the cathode compartment 38 are also filled with ion exchangers.

The electrodeionization apparatus 21 includes water passage means (not shown) for passing ultrapure water W3 through the deionization chamber 36 to take out treated water W4, and concentrating means for passing concentrated water W5 through the concentration chamber 35. A water passage means (not shown) is provided, and in this embodiment, the concentrated water W5 is introduced into the concentrating chamber 35 from the side near the outlet of the treated water W4 of the desalting chamber 36, and the desalting Concentrated water W5 is introduced into the concentration chamber 35 from the side near the inlet of the salting chamber 36, that is, from the direction opposite to the flow direction of the ultrapure water W3 in the demineralization chamber 36, and concentrated waste water W6 is discharged. there is

Specifically, as shown in FIG. 3, part of the treated water W4 obtained from the demineralization chamber 36 is introduced into the concentration chamber 35, and the treated water W4 is used as the concentrated water W5, thereby reducing the ion concentration. It is preferable to use the concentrated water W5.

The H-type cation exchange resin packed in the ion exchange resin column 22 using the H-type cation exchange resin is preferably a cation exchange resin in which substantially 100% of the H-type is used. Here, in the present embodiment, the cation exchange resin in which the H type is substantially 100% is defined as a cation exchange resin in which the H type is 99.999% or more. If the H type is 99.9%, the Na concentration is 1 ppb = 1000 ppt level, at 99.999% the Na concentration is 0.01 ppb = 10 ppt level, and at 99.999% the Na concentration is 0.001 ppb = 1 ppt level. Therefore, since the Na concentration of the ultrapure water W3 is 10 ppt or less, it is preferable that the H type is 99.999% or more. Regarding the upper limit of the ratio of the H type, it is necessary to increase the level of the cation exchange resin, which has been converted to the Na form with salt, from 99.999% or more of the H type to 1 year or more in regeneration by the electric current of the electrodeionization apparatus. It is not practical because it takes time for the water to pass through.

Next, a method for producing ultrapure boron-removed ultrapure water using the apparatus for producing ultrapure boron-removed ultrapure water having the configuration described above will be described. First, the raw water W is treated by a pretreatment device 2 comprising a flocculation, pressure flotation (sedimentation), filtration (membrane filtration) device, etc., thereby removing suspended solids and colloidal substances in the raw water W to obtain pretreated water. Get W1. In this process, it is also possible to remove polymeric organic substances, hydrophobic organic substances, and the like.

Next, the primary pure water device 3 removes most of the electrolytes, fine particles, etc. in the pretreated water W1 to produce primary pure water (pure water) W2.

This primary pure water W2 is then supplied to the subsystem 4, where the ultraviolet oxidizer 12 oxidizes and decomposes trace amounts of organic matter (TOC components) contained in the primary pure water W2 with ultraviolet rays. The resulting hydrogen peroxide is decomposed in the platinum group metal catalyst resin column 13, and dissolved gases such as DO (dissolved oxygen) are removed in the membrane deaerator 14 at the subsequent stage. Subsequently, the remaining carbonate ions, organic acids, anionic substances, metal ions and cationic substances are removed by ion exchange by treatment in the non-regenerative mixed bed ion exchange device 15 . Fine particles are removed by an ultrafiltration (UF) membrane 16 to obtain ultrapure water W3, which is supplied to a point of use (POU) 17, and unused ultrapure water is returned to the subtank 11.

The ultrapure water W3 obtained in this way has a resistivity of 18.1 MΩ cm or more, fine particles of 50 nm or more in diameter and 1000 particles/L or less, viable bacteria of 1 particle/L or less, and TOC (Total Organic Carbon). : 1 μg/L or less Total silicon: 0.1 μg/L or less Metals: 1 ng/L or less Ions: 10 ng/L or less Hydrogen peroxide: 30 μg/L or less Na concentration 10 ppt or less Boron concentration 10 ppt or less is.

Then, this ultrapure water W3 is fractionated and treated by the electrodeionization apparatus 21 to obtain treated water W4. The boron concentration of this treated water W4 is reduced to 5 ppt or less, while the Na concentration increases to about 100 ppt. Therefore, by performing continuous treatment in the ion exchange resin column 22 using an H-type cation exchange resin, it is possible to obtain ultrapure boron-removed ultrapure water W7 in which the Na concentration has been reduced to 5 ppt or less.

Although the present invention has been described above based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications are possible. For example, as shown in FIG. 4, the primary pure water apparatus 3 includes a tank 5 for pretreated water W1, a pump 6, a reverse osmosis membrane apparatus 7A, a membrane degassing apparatus 8A, and an electrodeionization apparatus 9A. It can be applied to various ultrapure water production apparatuses.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

[Example 1]
Using the apparatus shown in FIG. 1, raw water W was treated by pretreatment apparatus 2, primary pure water apparatus 3 and subsystem 4 to produce ultrapure water W3. This ultrapure water W3 had a boron concentration of 10 ppt and a Na concentration of 10 ppt.

This ultrapure water W3 was treated with an electrodeionization device (KCDI-UPz manufactured by Kurita Water Industries Ltd.) 21 of the type shown in FIGS. 2 and 3, and the treated water W4 had a boron concentration of 1 ppt and a Na concentration of 100 ppt. . This treated water W4 was passed through an ion-exchange resin column 22 filled with a cation exchange resin of 99.9999% or more H form at SV=50/h to obtain ultrapure boron-removed ultrapure water W7.

This ultra-pure boron-removed ultrapure water W7 had both a boron concentration and a Na concentration of 1 pp level, and was able to obtain boron-free water suitable for various precision analyses. In addition, since the Na load of the ion exchange resin column 22 packed with a cation exchange resin having an H form of 99.9999% or more is as low as about 10 ppt, it is possible to secure a service life of 1 to 2 years or more, and it is possible to secure a life of 1 to 2 years or more. Leak management is also unnecessary.

1 Boron ultrapure removal type ultrapure water production device 1A Ultrapure water production device 2 Pretreatment device 3 Primary pure water device 4 Subsystem (secondary pure water device)
21 Electrodeionization device 22 Ion exchange resin column W using H type cation exchange resin Raw water W1 Pretreated water W2 Primary pure water W3 Ultrapure water (secondary pure water)
W4 Treated water W5 Concentrated water W6 Concentrated waste water W7 Ultra-pure boron-removed ultrapure water

Claims (3)

An electrodeionization device and an ion exchange resin column using only an H-type cation exchange resin as an ion exchange resin are provided in this order ,
The electrodeionization device has a primary pure water device and a sub-system for processing the primary pure water obtained from the primary pure water device to produce ultrapure water. A portion of the ultrapure water flowing through the
The H-type cation exchange resin is substantially 100% H-type cation exchange resin,
The primary pure water device comprises, in order, an ultraviolet (UV) oxidation device, a regenerative ion exchange device, and a membrane degassing device,
The sub-system comprises, in order, an ultraviolet oxidizer, a platinum group metal catalyst resin tower, a membrane deaerator, a non-regenerative mixed bed ion exchange device, and a membrane filtration device. Ultrapure water production equipment. The electrodeionization apparatus comprises a cathode and an anode, a cation exchange membrane and an anion exchange membrane disposed between the cathode and the anode, and a desalting chamber and a concentration chamber partitioned by the cation exchange membrane and the anion exchange membrane. wherein the deionization compartments and the concentration compartments are filled with an ion exchanger, and the deionized water passed through the deionization compartments into the concentration compartments is close to the deionized water outlet of the deionization compartments. 2. The apparatus for producing ultrapure boron-removing ultrapure water according to claim 1, wherein the water is introduced into the concentrating chamber from the side and is discharged from the side near the inlet of the demineralizing chamber. Part of the ultrapure water flowing between the point of use and the ultrapure water production device having a primary pure water device and a subsystem for producing ultrapure water by processing the primary pure water obtained from the primary pure water device to an electrodeionization apparatus ; and
treating a portion of the ultrapure water with the electrodeionization device;
treating the treated water treated by the electrodeionization apparatus with an ion- exchange resin column using only an H-type cation exchange resin as the ion-exchange resin ;
The H-type cation exchange resin is substantially 100% H-type cation exchange resin,
The primary pure water device comprises, in order, an ultraviolet (UV) oxidation device, a regenerative ion exchange device, and a membrane degassing device,
The subsystem comprises, in sequence, an ultraviolet oxidation device, a platinum group metal catalyst resin tower, a membrane degasser, a non-regenerative mixed bed ion exchange device, and a membrane filtration device. A method for producing pure water.

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