JP2002301470A - Activated carbon cartridge and pure water making apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an activated carbon cartridge having no problem of the elution of ions at the start-up of an operation and capable of immediately using the pure water with prescribed quality, and a pure water making apparatus using the same. SOLUTION: In the pure water making apparatus equipped with an organic matter removing means using activated carbon and the desalting means provided to the post-stage of the organic matter removing means, the activated carbon cartridge 1 is used as the organic matter removing means. The activated carbon cartridge 1 is filled with a mixture 7 of activated carbon and an in exchange resin. The pure water making apparatus using the activated carbon cartridge 1 is also disclosed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an activated carbon cartridge used as an organic substance removing means in a pure water producing apparatus comprising an organic substance removing means using activated carbon and a desalting means provided at a stage subsequent to the organic substance removing means. And a pure water producing apparatus using the activated carbon cartridge.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, a silicon wafer manufacturing process, a liquid crystal manufacturing process, an inspection water manufacturing process, etc., a large amount of highly purified water or pure water having a specific resistivity is used. A large amount of used pure water is discharged from the process. Conventionally, used pure water discharged from these processes is recovered and desalted to increase its purity and reused. However, TOC components are mixed as impurities in the system. In some cases, they are often discarded without reuse.

[0003] However, in recent years, there has been a demand for a reduction in environmental load and a reduction in water treatment cost, and it has been practiced to collect and reuse used pure water mixed with TOC components. .

Conventionally, as a process for removing TOC components in water, there is a combination of a reverse osmosis membrane separator, an ultraviolet ray decomposer, an electrolyzer, an ozone oxidizer, etc., all of which have initial costs and running costs. Because it is expensive, the removal of TOC components in the used pure water (hereinafter referred to as "recovered water") uses activated carbon with a simple mechanism or a combination of activated carbon and other equipment. Is increasing.

[0005]

The activated carbon filled in the activated carbon cartridge as a means for removing the TOC component is subjected to a washing treatment with an acid in the production process, so that not only the surface but also the internal pores are removed. Ions are adsorbed. In order to remove these ions, in the finishing step of activated carbon, immersion cleaning with pure water and circulation cleaning incorporating a non-regenerative mixed-bed type ion-exchange packed column are performed. Such cleaning removes adsorbed ions. However, the purity can be increased to a specific resistance of activated carbon of 1 MΩ · cm or more. However, even with activated carbon that has been subjected to such washing, it is not possible to completely remove the ions adsorbed in the internal pores.
Residual ions in the pores are gradually released.

Therefore, when a new activated carbon cartridge supplied as a product is used as a TOC component removing means in a process of collecting and recycling used pure water,
In the initial stage of use, there is a problem that ions released in the activated carbon cartridge eluted into the treated water during the standing period after production, storage, transportation, and the start of use, leading to a decrease in the quality of the treated water.

For this reason, conventionally, when the activated carbon cartridge is replaced with a new activated carbon cartridge, a start-up operation is performed to collect the effluent of the activated carbon cartridge at the initial stage of water supply, and that the residual ions in the activated carbon are sufficient. After the water that reaches the target water quality is obtained, the water discharged from the activated carbon cartridge is sampled and sent to the next process. In addition, during the water sampling suspension period, a plurality of activated carbon cartridges are arranged in parallel so that the process is not stopped, and continuous processing is enabled by switching the water flow.

[0008] However, the activated carbon cartridge which cannot collect water at the start of use as described above has poor treatment efficiency and is unsuitable for a process of collecting and recycling used pure water for treating a large amount of recovered water.

As a method of solving the problem of the outflow of ions at the initial stage of passing water, it is conceivable to use a more advanced cleaning method during the production of activated carbon and to use activated carbon having a specific resistance higher than 1 MΩ · cm. However, such advanced cleaning requires a great deal of labor and time, and is not preferable because the cost of activated carbon rises.

The present invention solves the above-mentioned conventional problems, and uses an activated carbon cartridge capable of immediately collecting treated water of a target water quality without a problem of ion outflow at the beginning of use, and using the activated carbon cartridge. The purpose of the present invention is to provide a pure water producing apparatus.

[0011]

SUMMARY OF THE INVENTION An activated carbon cartridge according to the present invention is used as an organic substance removing means in a pure water production apparatus comprising an organic substance removing means using activated carbon and a desalting means provided at a stage subsequent to the organic substance removing means. The activated carbon cartridge used is characterized by being filled with a mixture of activated carbon and an ion exchange resin.

Since the activated carbon cartridge of the present invention is filled with the ion exchange resin together with the activated carbon, residual ions liberated from the activated carbon are converted into ions during the standing period before use during transportation or storage after being made into a product. Captured by the exchange resin. For this reason, in the initial stage of water supply at the beginning of use, there is almost no problem of water quality deterioration due to the outflow of ions released during the standing period, and water can be collected immediately from the beginning of water supply or only by a very short start-up operation. It becomes possible.

The method of filling the activated carbon and the ion exchange resin may be such that a layer of the ion exchange resin is formed on the outlet side of the water to be treated and a layer of the activated carbon is formed on the inlet side of the cartridge.
Filling in a mixed state is preferable because the above-described ion trapping effect is more easily obtained.

After the activated carbon cartridge is used, it is regenerated and reused. However, since the ion exchange resin is an organic substance, there is no adverse effect on the activated carbon regeneration treatment.

As described above, it is possible to prevent the outflow of ions at the start of use by performing advanced cleaning during the production of activated carbon, but such advanced cleaning requires
The price of activated carbon is soaring, which is not good. On the other hand, according to the present invention, it is possible to provide an inexpensive activated carbon cartridge that does not have a problem of outflow of ions at the start of use simply by filling both the ion exchange resin and the activated carbon together.

The amount of the ion exchange resin charged in the activated carbon cartridge is preferably determined based on the amount of ions initially eluted from the activated carbon in the activated carbon cartridge, that is, the amount of ions eluted from the activated carbon at the start of use.

The pure water producing apparatus according to the present invention is a pure water producing apparatus comprising an organic matter removing means using activated carbon and a desalting means provided at a stage subsequent to the organic matter removing means. Such an activated carbon cartridge of the present invention is used, and when the activated carbon cartridge is replaced, efficient pure water production can be performed without performing the startup operation of the activated carbon cartridge or only by a short startup operation.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the activated carbon cartridge and the pure water production apparatus according to the present invention will be described below in detail.

FIG. 1 is a schematic sectional view showing an embodiment of the activated carbon cartridge of the present invention, and FIG. 2 is a system diagram showing an embodiment of a pure water producing apparatus of the present invention.

In the activated carbon cartridge 1 shown in FIG. 1, a sprinkling pipe 5 for treated water and a collecting pipe 6 for treated water are inserted through a lid 4 provided in an upper opening 3 of a container 2. As the filler 7, a mixture of activated carbon and an ion exchange resin is filled.

The water sprinkling section 5A of the water sprinkling pipe 5 is located above the packed layer of the filler 7, and the water collecting section 6A of the water sprinkling pipe 6 is
To the lower layer of the packed bed.

The water to be treated is introduced into the activated carbon cartridge 1 from the water supply inlet 5B of the water sprinkling pipe 5, and sprinkled onto the filler 7 from the water sprinkling section 5A. The sprinkled water to be treated is filled 7
Flows down to reach the lower layer, during which the TOC component contained by contact with activated carbon is adsorbed and removed by the activated carbon. Then, the treated water is collected at the water collecting section 6A of the water collecting pipe 6, and discharged from the treated water outlet 6B.

According to the present invention, in such an activated carbon cartridge 1, since the ion exchange resin is mixed and charged together with the activated carbon, the ions eluted from the activated carbon at the start of use are adsorbed by the ion exchange resin, and the activated water is supplied to the treated water side. Elution is prevented. Therefore, the processing can be efficiently performed without the need for the start-up operation, or only by performing the start-up operation for a very short time.

It is preferable that the amount of the ion exchange resin to be filled together with the activated carbon is determined based on the initial amount of ions eluted from the activated carbon. That is, the activated carbon cartridge of the present invention
For the purpose of removing the TOC component, the activated carbon cartridge needs to be provided with a desalination function because it is disposed before the desalination means of the pure water production apparatus and ions in the water to be treated are removed by the subsequent desalination means. Absent. Therefore, the amount of the ion exchange resin to be filled in the activated carbon cartridge is small enough to obtain an ion exchange capacity commensurate with the initial amount of ions eluted from the activated carbon.

The ion exchange resin varies depending on the method of regenerating the activated carbon, the degree of washing during the regeneration, the type of the ion exchange resin, and the like.
If the activated carbon is washed to about 5.0 MΩcm,
1.0 to 10.0% by volume, particularly 2.0 to 5.0% by volume, and 0.5 to 50% by volume, particularly 1.0 to 2.5% by volume of the cation exchange resin based on the activated carbon. %, 1.5 to 1 in total of the anion exchange resin and the cation exchange resin
It is preferable to mix so as to be 5% by volume, particularly 3.0 to 7.5% by volume.

Activated carbon usually has an average particle size of 0.3-2.
Those having a thickness of about 0 mm are used. For such activated carbon, the ion-exchange resin keeps a uniform mixed state,
The average particle size of the ion exchange resin is preferably about 0.3 to 1.0 mm.

After use, the activated carbon cartridge of the present invention is removed from the deionized water producing apparatus and is regenerated at a recycle plant or the like. The activated carbon is regenerated by heating to 900 ° C., and then the regenerated ion exchange resin is filled. When activated carbon is reduced by regeneration, new activated carbon is replenished accordingly.

As shown in FIG. 2, the pure water production apparatus of the present invention has an organic substance removing means 11 and a desalting means 12 at the subsequent stage, and the activated carbon cartridge 1 as shown in FIG. Is used.

In addition, in front of the activated carbon cartridge 1 as the organic substance removing means 11, a pretreatment means such as various filters for removing fine particles such as SS and a membrane separation device may be provided. Such a filter can be activated carbon cartridge 1
It can also be provided at the subsequent stage.

The desalting means 12 is not particularly limited.
An ion exchange resin tower, a reverse osmosis membrane separation device, an electrodeionization device, or the like can be used.

In the subsequent stage of the desalting means 12, a sterilizing means using ultraviolet rays, ozone or the like, or other post-processing means may be provided.

Further, a plurality of organic substance removing means and desalting means may be provided in parallel for continuous processing.

The activated carbon cartridge and the pure water producing apparatus of the present invention are suitable for a process of recovering and reusing highly pure water used in a semiconductor producing process, a silicon wafer producing process, a liquid crystal producing process, and a test water producing process. is there.

[0034]

The present invention will be described more specifically below with reference to examples and comparative examples.

Example 1 Activated carbon having a specific resistance of 1.0 MΩ · cm by washing was filled with 80 liters of a mixture of an anion exchange resin and a cation exchange resin at the following ratios, and the mixture was filled with the mixture according to the present invention shown in FIG. An activated carbon cartridge was used. [Mixing ratio] Activated carbon (Kuraray Chemical Co., Ltd. "Kuraray Coal", average particle size 1.0 mm): 76 L Anion exchange resin (Mitsubishi Chemical Corporation "Diaion SA10A", average particle size 0.5 mm): 2. 5L cation exchange resin ("Diaion SK1B" manufactured by Mitsubishi Chemical Corporation, average particle size 0.5mm): 1.5L

The collected water having the following water quality was passed through this activated carbon cartridge under the condition of 4 m ³ / h, and the amount of water flow until the effluent having the following target water quality was obtained was examined. , And startup operation was not required at all. [Recovered water quality] TOC: 5 ppm Specific resistance: 0.5 MΩ · cm [Target water quality] TOC: 1 ppm Specific resistance: 1.0 MΩ · cm

Comparative Example 1 An activated carbon cartridge was prepared in the same manner as in Example 1, except that the anion exchange resin and the cation exchange resin were not mixed and only 80 l of activated carbon was filled. When the amount of water flow until the effluent with the target water quality was obtained was examined,
It required a flow rate of 00 liters and a start-up operation of 2.0 hours.

[0038]

As described above in detail, in the case of the activated carbon cartridge of the present invention, the residual ions released from the activated carbon are captured by the ion exchange resin during the standing period before use. In the above, there is almost no problem of a decrease in water quality due to the outflow of ions released during the standing period. Therefore, water can be collected immediately from the beginning of water flow or only by a very short start-up operation.

The pure water producing apparatus of the present invention uses such an activated carbon cartridge of the present invention as an organic substance removing means. When the activated carbon cartridge is replaced, the activated carbon cartridge does not need to be started up. Alternatively, pure water production can be performed efficiently only by a short start-up operation.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of an activated carbon cartridge of the present invention.

FIG. 2 is a system diagram showing an embodiment of a pure water production apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Activated carbon cartridge 2 Container 5 Sprinkling pipe 6 Water collecting pipe 7 Filler (mixture of activated carbon and ion exchange resin) 11 Organic substance removing means 12 Desalting means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D006 GA03 KA01 KB04 KB11 KB12 KB30 PA01 PB02 PC03 4D024 AA03 AB04 AB14 BA02 BA17 BB01 CA04 DB05 DB09 DB10 DB19 DB24 4D025 AA03 AB02 BA08 BA13 BA24 BB04 BB07 DA03 DA04 DA05 DA06

Claims (3)

[Claims] 1. An activated carbon cartridge used as said organic substance removing means in a pure water production apparatus comprising an organic substance removing means using activated carbon and a desalting means provided at a stage subsequent to said organic substance removing means. An activated carbon cartridge filled with a resin. 2. The activated carbon cartridge according to claim 1, wherein a filling amount of the ion exchange resin in the activated carbon cartridge is determined based on an amount of ions initially eluted from the activated carbon in the activated carbon cartridge. 3. A pure water production apparatus comprising: an organic substance removing means using activated carbon; and a desalting means provided at a stage subsequent to the organic substance removing means, wherein the organic substance removing means is activated carbon according to claim 1 or 2. A pure water production apparatus characterized by being a cartridge.