KR20190079851A - Electrodeionization with excellent boron removal efficiency - Google Patents

Abstract

The present invention relates to an electrodeionization (EDI) apparatus having excellent boron removal efficiency. More particularly, the present invention relates to an EDI module and system having excellent boron removal efficiency by producing ultrapure water by mixing boron-selective ion exchange resins in an appropriate ratio with ion exchange resins present in the EDI.

Description

[0001] The present invention relates to an electrodeionization apparatus having excellent boron removal efficiency,

The present invention relates to a module and system of an electrodeionization (EDI) device for removing high-efficiency boron, and more particularly, to an EDI module and system using boron-selective ion exchange resin, will be.

EDI stands for Electrodeionization and is called Electrodeionization Device. EDI is a water treatment technology that separates dissolved ions from water when electricity is applied by using ion exchange membrane and ion exchange resin. Chemical treatment for separate cleaning is not required, and is generally used for polishing at the end of the reverse osmosis (reverse osmosis).

The EDI system is a new technology that complements the disadvantages of the ion exchange resin tower system. The EDI system is filled with conductive materials such as ion exchange resins in the dilution chamber of the electrodialysis method, thereby reducing the generation of waste water and the resistance and current efficiency It is a process that can reduce.

The EDI module consists of a cation exchange membrane and an anion exchange membrane alternately arranged between the anode and the cathode, and consists of a dilution chamber, a concentration chamber and an electrode chamber. In general, the dilution chamber is filled with cation exchange resin and anion exchange resin. When the direct current power is applied to the anode and cathode of the module, the ions in the dilution chamber are moved to the concentration chamber through the ion exchange membrane by the applied direct current power, and the ion concentration of the dilution chamber gradually disappears and ultrapure water can be produced .

The cation exchange resin and the anion exchange resin used in the EDI module are generally composed of a strongly acidic cation exchange resin (SO3-H Type) and an anion exchange resin, a strongly basic anion exchange resin NH3 + OH Type) is used. Unlike other ion exchange resin processes, the ion exchange resin used in EDI does not require regeneration because, when a direct current power is applied to the EDI, the ion exchange resin - ion exchange resin, ion exchange resin - Ion is decomposed into H + and OH- ions, and the ion exchange resin is regenerated as H type and OH type through this water decomposition reaction.

In the semiconductor industry, boron dissolved in water can weaken the PN bond or lower the production yield. Therefore, there is a tendency that the production of ultrapure water having no boron is being strengthened in the semiconductor-grade ultrapure water production, Of boron content is required up to 50 ppt (parts per trillion) or less.

Japanese Unexamined Patent Application Publication No. 2004-261643 discloses a method for removing boron in semiconductor-grade ultrapure water production. For example, Japanese Unexamined Patent Publication (Kokai) No. 2004-261643 discloses a method of using a structure in which a concentrating chamber is passed through a desalting chamber in a direction opposite to the direction of water flow. Japanese Unexamined Patent Application Publication No. 2003-210946 discloses a method of using a structure in which the thicknesses of the inlet and outlet of the desalination chamber are adjusted differently. Korean Patent Laid-Open No. 2008-0113767 discloses a method in which a reverse osmosis membrane device and a water softener Structure is described.

Currently, the concentration of boron in ultrapure water is controlled by using a separate polishing process at the downstream of EDI to remove the boron in ultrapure water. However, in the polishing process after EDI, It is impossible to continuously produce the ion exchange resin for regeneration and input, and further, labor costs are required.

The present inventors have studied for the efficient removal of boron in semiconductor-grade ultrapure water. As a result, they have found that when EDI is mixed with a boron-selective ion exchange resin in an appropriate ratio to produce ultra pure water, EDI . In the case of boron-selective ion exchange resin, the regenerated OH type is used. It can be regenerated by EDI without additional chemical treatment, and it is confirmed that it is suitable for use as a resin to be filled in EDI Thereby completing the present invention.

An object of the present invention is to provide an EDI module and a system having excellent boron removal efficiency by mixing and filling a boron-selective ion exchange resin with an ion exchange resin existing in EDI (Electrodeionization) to improve the boron removal efficiency in ultrapure water .

In order to achieve the above object, the present invention provides a positive electrode, a negative electrode, a positive electrode and an anion exchange membrane alternately arranged between the positive electrode and the negative electrode, and a dilute chamber, a concentrate chamber, and an electrolytic chamber, Wherein the dilution chamber is filled with an anion exchange resin, a cation exchange resin, and a boron-selective ion exchange resin, wherein the dilution chamber is filled with an anion exchange resin, a boron selective ion exchange resin, and the like.

According to another aspect of the present invention, there is provided an EDI module comprising an anode, a cathode, a cation and an anion exchange membrane alternately arranged between the anode and the cathode, the dilution chamber, the concentration chamber, and the electrolyte chamber, There is provided a method of removing or reducing boron in ultrapure water using an EDI module, which comprises mixing and charging a cation exchange resin and a boron-selective ion exchange resin.

The present invention also relates to a pure water generating module for filtering raw water supplied from the outside to generate pure water; An EDI module in which a boron-selective ion exchange resin is mixed and filled in an ion exchange resin present in the EDI according to the present invention for purifying purified water generated in the pure water generating module; A storage tank module for storing ultrapure water from which ions have been removed from the EDI module; And a dispenser module for discharging the ultrapure water generated in the ultrapure water generation module to the outside. The present invention also provides an EDI system for eliminating or reducing boron.

The EDI module and system according to the present invention can reduce the boron concentration present in the ultrapure water to about 1/4 to 1/3 level while maintaining the resistivity of ultrapure water as compared with EDI using only the existing ion exchange resin, Can be improved by about 4 to 3 times.

The present invention also provides a method for preparing EDI, which comprises mixing an ion exchange resin present in EDI with a boron-selective ion exchange resin and establishing optimum conditions for mixing ratio and installation position of the boron-selective ion exchange resin, The boron removal efficiency can be maximized.

1 is a plan view of an EDI internal cell according to the present invention.
2 is a photograph of EDI according to the present invention.
3 is a plan view of an EDI cell according to Embodiment 1 of the present invention:
① Mixed ion exchange resin: strong acid cation exchange resin, strong basic ion exchange resin; And
② Boron-selective ion exchange resin.
4 is a plan view of an EDI cell according to a second embodiment of the present invention:
① Mixed ion exchange resin: strong acid cation exchange resin, strong basic ion exchange resin; And
② Boron-selective ion exchange resin.

Hereinafter, the present invention will be described in detail.

The present invention

A positive electrode, a negative electrode, and a cation and an anion exchange membrane alternately arranged between the positive electrode and the negative electrode to form a dilute chamber, a concentrate chamber, and an electrolytic chamber,

Wherein the dilution chamber is filled with an anion exchange resin, a cation exchange resin and a boron selective ion exchange resin,

And an EDI (Electrodeionization) module for boron removal or abatement.

The anion exchange resin and the cation exchange resin are preferably mixed in a volume ratio of 7: 3 to 5: 5, more preferably a volume ratio of 7: 3.

The boron-selective ion exchange resin is preferably 1 to 10% (v / v), more preferably 3 to 10% (v / v) of the total mixed ion exchange resin.

Preferably, the EDI module is a top-down module comprising a deionized bed at the top of the EDI and a polishing bed at the bottom.

The mixed ion exchange resin in which the anion exchange resin, the cation exchange resin and the boron selective ion exchange resin are mixed is filled only in the upper part or the lower part of the inside of the EDI, and the mixed ion exchange of the anion exchange resin and the cation exchange resin It is preferable that the resin is filled, and it is more preferable that the mixed ion exchange resin mixed with the boron-selective ion exchange resin is filled in the lower part of the EDI.

The present invention is directed towards according to the principles of the when boron is removed from the inside EDI, typically boron is present in the form of H ₃ BO ₃ in water, and hardly ttiji ionic, the water H ₃ BO ₃ is encountered with OH B (OH) ^{4 -} , which is transferred to the concentrating chamber through the ion exchange resin and the ion exchange membrane inside the EDI.

EDI can be divided into two main areas, one is deionized bed where ions are removed and the other is a polishing bed. In deionized bed, ions contained in water are removed. Since there is almost no ion in Polishing bed, water decomposition occurs between ion exchange membrane - ion exchange resin and ion exchange resin - ion exchange resin, and regeneration of resin is performed. In this polishing bed, the OH ^- ion generated by the water decomposition meets H ₃ BO ₃ , which is a boron in water, and is ionized into B (OH) ^{4 -} to enable the treatment of boron through EDI.

The present invention also provides an EDI module comprising an anode, a cathode, a cation and an anion exchange membrane alternately arranged between the anode and the cathode, the dilution chamber, the concentration chamber, and the electrolyte chamber,

Mixing a dilution chamber of the EDI module with an anion exchange resin, a cation exchange resin and a boron selective ion exchange resin,

EDI module to remove or reduce boron in ultrapure water.

In the above method, the anion exchange resin and the cation exchange resin are preferably mixed in a volume ratio of 7: 3 to 5: 5, and more preferably a volume ratio of 7: 3.

In the above method, the boron-selective ion-exchange resin is preferably 1 to 10% (v / v), more preferably 3 to 10% (v / v) of the total mixed ion-exchange resin.

In the above method, the EDI module is preferably a top-down module including a Deionized bed at the top of the EDI and a polishing bed at the bottom.

In this method, the mixed ion exchange resin in which the anion exchange resin, the cation exchange resin and the boron selective ion exchange resin are mixed is filled only in the upper part or the lower part of the EDI, and the anion exchange resin and the cation exchange resin It is more preferable that the mixed ion exchange resin of the resin is filled and the mixed ion exchange resin mixed with the boron selective ion exchange resin is filled in the lower part of the EDI.

The present invention also relates to a pure water generating module for filtering raw water supplied from the outside to generate pure water;

An EDI module in which a boron-selective ion exchange resin is mixed and filled in an ion exchange resin present in the EDI according to the present invention for purifying purified water generated in the pure water generating module;

A storage tank module for storing ultrapure water from which ions have been removed from the EDI module; And

And a dispenser module for discharging the ultrapure water generated in the ultrapure water generation module to the outside.

In the EDI system, the pure water generating module may include a filter for removing the particles by filtering the raw water, and / or an reverse osmosis filter for producing pure water by pressurizing and filtering the impurities of the filtered raw water filtered by the filter .

In the reverse osmosis filter, a discharge channel for discharging pure water may be connected, if necessary, and a drain valve may be provided on the discharge channel.

In the EDI system, the EDI module may be arranged by stacking a plurality of cells.

The EDI system may further include an ultrapure water filtering module located between the storage tank module and the dispenser module, for filtering ultrapure water supplied from the storage tank module.

In the EDI system, the operation is as follows. First, the raw water flowing into the pure water generating module is filtered while passing through a reverse osmosis filter, and pure water is generated. The pure water generated in the pure water generation module flows into the EDI module. When the EDI module 200 is galvanized, the ions of the pure water flowing into the EDI module 200 are moved from the dilution chamber to the concentration chamber, and pure water from which ions are removed from the dilution chamber can be produced. The concentrated water concentrated in the concentrating chamber can be drained to the outside or reused as raw water flowing into the reverse osmosis filter. The ultrapure water generated in the EDI module is stored in the storage tank module. The ultra pure water stored in the storage tank module is supplied to an additional filtering module or to a dispenser module.

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

However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

< Example  1>

The ion exchange resin volume ratio in the EDI dilution chamber was changed to anion exchange resin: cation exchange resin 7: 3, and CRB03 of boron-selective ion exchange resin Mitsubishi Chemical Co. was added 1, 3, 5, 10 and 20% of the total volume ratio And the three kinds of ion exchange resins were uniformly mixed. The resistivity and boron concentration of ultrapure water produced through EDI were measured. In this case, the EDI module used was a top-down module.

Strongly basic anion exchange resin was used for the anion exchange resin used in the above experiment. Strongly acidic cation exchange resin was used for the cation exchange resin, and ion exchange resin of Dow chemical was used for the two kinds of resin.

The EDI module used is directly designed and used, and the structure of the EDI is shown in FIG.

The resistivity measurement was performed using Ultrameter II 4P product manufactured by Myron L Company, and Ultrameter II 4P product was used to express the resistance value of water by discharging the voltage of water and measuring the value of current flowing.

The measurement of the boron concentration was performed using a 7700x ICP-MS manufactured by Agilent Technologies. In the ICP-MS measurement method, a mixture of an inert gas such as argon and a spray sample was flowed along the axis of a co- And the luminescence by this was used as a light source.

Resistivity (M.OMEGA.cm) Boron concentration (ppb) Tap water 0.0020 to 0.0040 155 Ro processing 0.01 to 0.20 130 EDI processed number CRB03-00 15.5 51.6 CRB03-01 15.5 44.2 CRB03-03 15.4 15.4 CRB03-05 15.1 12.1 CRB03-10 14.3 12.4 CRB03-20 8.6 33.8

As a result, the boron-selective ion exchange resin showed a similar resistivity to 1 to 5%, while the boron concentration gradually decreased. When the boron-selective ion exchange resin ratio was 10%, the resistivity And the boron concentration was slightly increased (Table 1).

In particular, when 20% boron-selective ion exchange resin is used, excess ion exchange resin is injected compared to the space of the dilution chamber, so that the pressure drop of the EDI stack, the flow rate and the resistivity of ultrapure water decrease, Respectively. This is because the flow rate of the dilution chamber is reduced due to the excessive ion exchange resin injection and the flow of the flow path is not smooth (Table 1).

< Example  2>

In the EDI dilution chamber, an ion exchange resin volume ratio of anion exchange resin: cation exchange resin 7: 3 was prepared, and the two ion exchange resins were evenly mixed. The capacity of the mixed ion exchange resin was equally divided by two, The exchange resin, CRB03 from Mitsubishi Chemical Co., Ltd., was evenly mixed into an ion-exchange resin divided by 5% of the total volume ratio. The resin mixed with the boron-selective ion exchange resin was put into either the upper or lower part of the EDI dilution chamber, and the mixed ion exchange resin of the anion exchange resin and the cation exchange resin was placed in the upper or lower part of the EDI dilution chamber. The resistivity and boron concentration of ultrapure water produced through EDI were measured. In this case, the EDI module used was a top-down module.

Strongly basic anion exchange resin was used for the anion exchange resin used in the above experiment. Strongly acidic cation exchange resin was used for the cation exchange resin, and ion exchange resin of Dow chemical was used for the two kinds of resin.

The EDI module used is directly designed and used, and the structure of the EDI is shown in FIG.

The resistivity measurement and the boron concentration measurement were carried out in the same manner as in Example 1 above.

Resistivity (M.OMEGA.cm) Boron concentration (ppb) Tap water 0.0020 to 0.0040 155 Ro processing 0.01 to 0.20 130 EDI processed number CRB03-00 15.5 51.6 CRB03-top 15.6 43.1 CRB03-Lower 15.3 12.0

Since the EDI module used in the above is a top-down module, the upper part of the EDI is composed of a deionized bed and the lower part is composed of a polishing bed. As a result, the boron-selective resin is installed in a polishing bed inside the EDI, (Table 2).

Claims (10)

A positive electrode, a negative electrode, and a cation and an anion exchange membrane alternately arranged between the positive electrode and the negative electrode to form a dilute chamber, a concentrate chamber, and an electrolytic chamber,
Wherein the dilution chamber is filled with an anion exchange resin, a cation exchange resin and a boron selective ion exchange resin,
EDI (Electrodeionization) module for removing or reducing boron.
The method according to claim 1,
Wherein the anion exchange resin and the cation exchange resin are mixed in a volume ratio of 7: 3 to 5: 5.
The method according to claim 1,
Wherein the boron-selective ion exchange resin is 1 to 10% (v / v) of the total mixed ion exchange resin.
The method according to claim 1,
Wherein the EDI module is a top-down module comprising a deionized bed at the top of the EDI and a polishing bed at the bottom.
The method according to claim 1,
Mixed ion exchange resin in which an anion exchange resin, a cation exchange resin and a boron-selective ion exchange resin are mixed is filled in either the upper part or the lower part of EDI, and the mixed ion exchange resin of anion exchange resin and cation exchange resin Wherein the EDI module is filled with boron.
An EDI module comprising an anode, a cathode, a dilute chamber, a concentrate chamber, and an electrolyte chamber arranged alternately with positive and negative ion exchange membranes between the anode and the cathode,
Mixing a dilution chamber of the EDI module with an anion exchange resin, a cation exchange resin and a boron selective ion exchange resin,
Removal or reduction of boron in ultrapure water using EDI module.
The method according to claim 6,
Wherein the boron-selective ion exchange resin is 1 to 10% (v / v) of the total mixed ion exchange resin.
The method according to claim 6,
A mixed ion exchange resin in which an anion exchange resin, a cation exchange resin and a boron selective ion exchange resin are mixed is filled in either the upper part or the lower part of the EDI, and an anion exchange resin and a cation exchange resin mixed ion exchange resin Wherein the EDI module is used to fill or purge the boron in the ultrapure water.
A pure water generating module for filtering raw water supplied from the outside to generate pure water;
An EDI (Electrical De-ionization) module according to any one of claims 1 to 5 for purifying pure water generated in the pure water generating module;
A storage tank module for storing ultrapure water from which ions have been removed from the EDI module; And
And a dispenser module for discharging the ultrapure water generated in the ultrapure water generation module to the outside.
EDI system for boron removal or abatement.
10. The method of claim 9,
Further comprising an ultrapure water filtering module disposed between the storage tank module and the dispenser module for filtering ultrapure water supplied from the storage tank module.

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