JP3340831B2 - Ultrapure water production equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrapure water producing apparatus for producing ultrapure water used in a semiconductor device manufacturing process and the like, and more particularly to an ultrapure water producing apparatus having a reduced TOC concentration.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional ultrapure water producing apparatus includes a pretreatment apparatus for performing coagulation and filtration, and a regenerating cation exchange column K for performing a primary treatment on pretreated water. ,
Decarbonation tower D, regeneration type anion exchange tower A, reverse osmosis membrane device R
O, a primary treatment system including a regenerative mixed-bed ion exchange column MB, etc., and an ultraviolet sterilizer UV _ST for further secondary treatment of the primary pure water obtained from the primary treatment system, and H in the column.
A non-regenerative mixed-bed ion exchange device filled with a mixed resin of a highly acidic cation exchange resin and a strongly basic anion exchange resin, an ultrafiltration membrane device UF, and a secondary tank TK Usually, it is composed of a processing system.

[0003] Ultrapure water produced using these apparatuses contains almost no impurities, but with the recent increase in the degree of integration of semiconductor devices, higher water quality is required. However, a very small amount of organic matter (T
At present, it is difficult to reduce OC) more easily.
One of the reasons is the elution of TOC from a non-regenerative mixed-bed type ion exchange device that is a constituent unit of the secondary treatment system. The strongly acidic cation exchange resin and the strongly basic anion exchange resin filled in the ion exchange device are made of an organic polymer compound, and have a large contact surface area with water. Elution of TOC from In a conventional non-regenerative mixed-bed ion exchange apparatus, the TOI is reduced by mixing a strongly acidic cation exchange resin and a strongly basic anion exchange resin.
Although the elution of C is considerably reduced, it has been proposed in recent years to further suppress the elution of TOC by setting the mixing ratio thereof so that the ratio of the strongly acidic cation exchange resin is increased. (Japanese Unexamined Patent Publication No. 1-224090
issue). However, as described above, the reduction of TOC in ultrapure water is further desired, and it is not sufficient to suppress the elution of TOC in such a conventional non-regenerative type mixed-bed ion exchange apparatus. .

[0004]

As a result of various studies to solve the above-mentioned problems, the present inventors have found that an anion exchange resin is provided downstream of a conventional non-regenerative mixed-bed ion exchange apparatus in a secondary treatment system. By installing a single-bed ion exchange device or as a non-regenerating mixed-bed ion exchange device, a mixed resin obtained by mixing a strongly acidic cation exchange resin and a strongly basic anion exchange resin, and an anion By filling and stacking the exchange resin in the same column, by using a mixed bed type ion exchange apparatus configured to pass water to be treated from the layer of the mixed resin to the layer of the anion exchange resin in order. The inventors have found that TOC eluted from a non-regenerative mixed-bed type ion exchange device of a secondary treatment system, in particular, a strongly acidic cation exchange resin used in the device can be efficiently removed, and have completed the present invention. That Where the target is to provide a very TOC concentration low ultrapure water production system.

[0005]

In order to achieve the above object, the present invention provides a mixed bed type ion exchange apparatus and an ultrafiltration membrane apparatus which further comprises at least a non-regenerating type mixed-bed ion exchange apparatus for treating water treated in a primary treatment system. In an ultrapure water production apparatus that performs treatment in a secondary treatment system having
A non-regenerative type anion exchange resin single bed type ion exchange device is installed between the mixed bed type ion exchange device and the ultrafiltration membrane device. This includes setting the flow SV of the exchange device to be larger than the flow SV of the non-regenerative mixed-bed ion exchange device.

[0006] Further, the present invention provides an ultra oxidizing apparatus comprising an ultraviolet oxidizing apparatus installed in a flow path between the non-regenerating type mixed bed type ion exchanger and the non-regenerating type anion exchange resin single bed type ion exchanger. Pure water production equipment.

[0007] The present invention further at least non-regenerative type mixed bed ion exchanger and ultrafiltration water treated in the primary treatment system
In the ultrapure water production apparatus for processing in a secondary treatment system having a filtration membrane device , the mixed bed type ion exchange device is obtained by mixing a strongly acidic cation exchange resin and a strongly basic anion exchange resin. A mixed-bed ion exchange apparatus in which the mixed resin and the anion exchange resin are stacked and filled in the same tower, and the water to be treated flows through the mixed resin layer in the order from the anion exchange resin layer. The present invention provides an ultrapure water production apparatus using the same.

[0008] According to the apparatus of the present invention having the above structure, the TOC eluted from the mixed resin layer of the H-type strongly acidic cation exchange resin and the OH-type strongly basic anion exchange resin, in particular, TOC eluted from the cation exchange resin is removed. It can be effectively adsorbed and removed by the subsequent layer of the OH-type anion exchange resin alone.

In addition, an ultraviolet oxidizing device is installed in a flow path between the non-regenerative type mixed bed type ion exchange device and the non-regenerative type anion exchange resin single bed type ion exchange device. Both the TOC component eluted from the cation exchange resin and the TOC component eluted from the anion exchange resin of the type ion exchange device can be decomposed into low molecular organic acids and CO ₂ , and these organic acids can be decomposed. And CO ₂
Can be easily removed by the subsequent anion exchange resin single bed type ion exchange device, so that ultrapure water having a lower TOC concentration can be obtained.

Hereinafter, the present invention will be described in detail.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the present embodiment, the ultrapure water production apparatus includes a pretreatment apparatus, a regeneration type cation exchange tower K, a decarbonation tower D, a regeneration type anion exchange tower A, a reverse osmosis membrane apparatus RO, and a regeneration type mixed bed ion A primary treatment system including an exchange tower MB, an ultraviolet sterilizer UV _ST , and an H-type strongly acidic cation exchange resin and OH
Non-regenerative mixed-bed ion exchange device filled with a mixed resin with a strong basic anion exchange resin in the form, a non-regenerative anion exchange resin single-bed ion exchange device, an ultrafiltration membrane device UF,
And a secondary processing system including a storage tank TK.

In this configuration, the pretreatment device is constituted by an appropriate combination of techniques such as coagulation sedimentation and filtration according to the purity of raw water, and these are configurations known to those skilled in the art.

Also, as the primary processing system, known components can be used as they are.

In the secondary treatment system, the primary treatment water in the storage tank TK is supplied from an ultraviolet sterilizer UV _ST , a non-regenerative mixed-bed ion exchanger, a non-regenerative anion exchange resin single-bed ion exchanger, and UF. After each processing, it is repeatedly taken out and used at the course point, and the rest is returned to the storage tank TK. That is, in the secondary treatment system, the secondary treatment water is configured to always circulate in the flow path.

Here, the storage tank TK and the ultraviolet sterilizer U
V _ST, non-regenerative mixed bed ion exchanger, UF is known ones all can be used.

[0016] The ultraviolet sterilizer UV _ST, irradiation wavelength of ultraviolet light is preferably one containing mainly those near 254 nm.

The non-regenerative mixed-bed type ion exchange apparatus comprises a strongly acidic cation exchange resin of H type and a strongly basic anion exchange resin of OH type in a volume ratio of 2: 1 to 1: 2. It is preferable that the mixture is filled with the mixture.

The non-regenerative anion exchange resin single bed type ion exchange apparatus is one in which an OH type strongly basic anion exchange resin and / or an OH type weakly basic anion exchange resin are filled. In addition, as the anion exchange resin to be used, a strongly basic resin is preferable because of its high ability to remove TOC.

It is preferable that the water flow SV of the non-regenerative anion exchange resin single-bed ion exchanger is set to be larger than the water SV of the non-regenerative mixed-bed ion exchanger. It is preferable that the water flow SV of the mixed ion exchange device: the water flow SV of the mixed bed ion exchange device be 3: 1 to 30: 1.

The reason is that the TOC concentration eluted from the resin layer is almost inversely proportional to the water flow SV, so that the water flow SV of the single-bed ion exchange device is different from that of the mixed-bed ion exchange device.
If the ratio to is smaller than 3, the increase in the amount of TOC eluted from the single-bed ion exchange device cannot be ignored. Note that the upper limit of the above ratio is limited to about 30: 1 in the water flow SV ratio because of the restriction that the speed must not interfere with the actual water flow operation.

The non-regenerative mixed-bed ion exchange device and the non-regenerative anion exchange resin single-bed ion exchange device are as follows:
Normally, the operation is performed with the same flow rate of water. In such a case, the ratio of the flow-through SV is inversely proportional to the volume ratio of the ion-exchange resin charged inside each ion-exchange device. Therefore, as described above, the water flow SV of the single-bed ion exchange device: the water flow SV of the mixed-bed ion exchange device =
In order to control the ratio from 3: 1 to 30: 1, the ratio of the volume of the anion exchange resin charged in the single-bed ion exchange device to the volume of the mixed resin charged in the mixed-bed ion exchange device is 1 /.
The ratio may be set to 3: 1 to 1/30: 1.

FIG. 2 is a block diagram showing another embodiment of the present invention.

In this example, an ultraviolet oxidizer UV _OX is provided in a flow path between a non-regenerative mixed bed type ion exchanger and a non-regenerative anion exchange resin single bed ion exchanger. Has the same configuration as the above embodiment.

As the UV _OX , a known UV oxidizer can be used. This is to irradiate an ultraviolet ray containing a large number of wavelengths around 185 nm, and the irradiation amount is 100 to 500.
W · h / m ³ is preferred.

In each of the above embodiments, the primary processing system and the secondary processing system are configured as described above. However, the present invention is not limited to this, and can be applied to all known primary processing systems and all known secondary processing systems. The configuration can be appropriately changed according to the purpose of the present invention.

Further, in the above embodiment, a conventionally known mixed-bed type ion exchange apparatus comprising a column filled with a mixed resin of a strongly acidic cation exchange resin and a strongly basic anion exchange resin, A single-bed ion exchange device filled only with an anion exchange resin was separately configured, but is not limited to this.
For example, the above-mentioned mixed resin and anion exchange resin are stacked in two layers in one resin tower, filled and integrated, and water to be treated is passed from the layer of the mixed resin to the layer of the anion exchange resin alone. The configuration may be modified, and various changes may be made without departing from the scope of the present invention.

[0027]

【Example】

Example 1 After treating industrial water with a pretreatment device consisting of a coagulating sedimentation device and a sand filter, a regenerated cation exchange filled with a strongly acidic cation exchange resin Amberlite (registered trademark, the same applies hereinafter) IR-124. Tower, decarbonation tower, regenerated anion exchange tower packed with strong basic anion exchange resin Amberlite IRA-402BL, and then treated with water, and then equipped with a reverse osmosis membrane SU-710 manufactured by Toray Industries, Inc. Treated with a reverse osmosis membrane device, and further passed through a regenerative mixed-bed ion exchange device filled with Amberlite IR-124 and Amberlite IRA-402BL at a volume ratio of 1: 1 to be treated. Specific resistance 18.2MΩ · cm, TOC concentration 2.4p
Primary pure water of pb was obtained. This is the primary processing system.

The primary pure water is sterilized using an ultraviolet sterilizer SX-1 / 2 manufactured by Chiyoda Kohan Co., Ltd. using a high-pressure mercury lamp, and then special conditioning and regeneration are performed in advance. A mixed resin obtained by mixing the H-type strongly acidic cation exchange resin Amberlite IR-124 and the OH-type strongly basic anion exchange resin IRA-402BL at a volume ratio of 1: 1 was filled. Amberlite I, a strongly basic anion exchange resin in the OH form, which has been treated by passing water through a non-regenerative mixed bed type ion exchange device at a water flow rate of SV50, and which has been specially conditioned and regenerated in advance
Water was passed through a non-regenerative anion exchange resin single bed type ion exchange device filled with RA-402BL at SV = 150 to be treated.

At this time, the treated water TOC concentration at each point of the outlet of the ultraviolet sterilizer (UV _ST ), the outlet of the non-regenerative mixed bed type ion exchanger, and the outlet of the non-regenerative anion exchange resin single bed ion exchanger. Table 1 summarizes the measurement results.

The TOC was measured using a T
The measurement was performed using an OC meter and Olgatoc. Examples 2 and 3 The non-regenerating anion exchange resin in Example 1 was set to have a flow SV of 300 (Example 2) or 1 in the single bed type ion exchange device.
The processing was performed under the same conditions as in Example 1 except that 500 (Example 3) was used.

The treated water TOC at each point at this time
Table 1 summarizes the measurement results of the concentrations.

[0032]

[Table 1] Example 4 Between the non-regenerative mixed bed type ion exchange device and the non-regenerative anion exchange resin single bed type ion exchange device in Example 1,
TFL-4 manufactured by Chiyoda Corporation using a low-pressure mercury lamp
UV oxidizer (UV _OX ), non-regenerative anion-exchange resin single bed type treated with non-regenerative mixed-bed ion exchanger Water was passed in the order of the ion exchange apparatus for treatment.

At this time, the water flow rate of the non-regenerative mixed bed type ion exchange device was set to SV50, and the water flow SV of the non-regenerative anion exchange resin single bed type ion exchange resin was set to 150. Also,
The irradiation amount of the ultraviolet oxidation device was set to 300 W · h / m ³ .

The other conditions are the same as in the first embodiment.

Table 1 summarizes the measurement results of the treated water TOC concentration at each point.

According to each of the above embodiments, by installing a non-regenerative type anion exchange resin single bed type ion exchanger at the subsequent stage of the non-regenerative mixed bed type ion exchanger, ultrapure water having a further lower TOC concentration can be obtained. Obviously, you can.

Further, when an ultraviolet oxidizing apparatus is installed between the non-regenerative type mixed bed type ion exchanger and the non-regenerative type anion exchange resin single bed type ion exchanger, the TOC can be further reduced. .

In the above Examples 1 to 3, the conventional non-regenerative mixed-bed type, which was filled only with a mixed resin obtained by mixing a strongly acidic cation exchange resin and a strongly basic anion exchange resin, was used. An example in which a non-regenerative anion exchange resin single bed type ion exchange device was installed at the subsequent stage of the ion exchange device was shown. However, both of these ion exchange devices were integrated, that is, a strongly acidic cation exchange resin and a strong base. A mixed resin obtained by mixing an anion exchange resin, and an anion exchange resin are stacked and filled in the same tower, and the water to be treated is processed from the layer of the mixed resin to the layer of the anion exchange resin alone. The same effect was obtained by using a non-regenerative type mixed-bed ion exchange device having a configuration for passing water.

[0039]

According to the ultrapure water production apparatus of the present invention, in the secondary treatment system, a non-regenerative anion exchange resin single bed type ion exchange is provided downstream of a conventional non-regenerative mixed bed type ion exchanger. Since the apparatus is installed or a new non-regenerative mixed bed type ion exchange apparatus of a type integrating both of these apparatuses is used, the TOC concentration in the resulting ultrapure water can be greatly reduced. Further, when an ultraviolet oxidizer is provided in the flow path between the conventional mixed bed ion exchanger and the anion exchange resin single bed ion exchanger, the TOC can be further reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating an example of a conventional ultrapure water production apparatus.

[Explanation of symbols]

K regeneration type cation exchange tower D decarbonation tower A regeneration type anion exchange tower RO reverse osmosis membrane unit MB regeneration type mixed bed type ion exchange unit UV _ST ultraviolet sterilizer UF ultrafiltration membrane unit TK storage tank UV _OX ultraviolet oxidation equipment

Claims (5)

(57) [Claims] 1. The water treated in the primary treatment system is further reduced.
In the ultrapure water production apparatus for processing in a secondary treatment system including a non-regenerative type mixed bed type ion exchange device and an ultrafiltration membrane device, the mixed bed type ion exchange device and the ultrafiltration Between the membrane device
An ultrapure water production apparatus characterized in that a non-regeneration type anion exchange resin single bed type ion exchange apparatus is installed in the apparatus. 2. The non-regenerating type anion exchange resin having a single-bed type ion exchange device, wherein a water flow SV is set to be larger than that of a non-regeneration type mixed-bed type ion exchange device. The ultrapure water production apparatus according to claim 1, wherein 3. An ultraviolet oxidizing apparatus is provided in a flow path between the non-regenerative type mixed bed ion exchanger and the non-regenerative anion exchange resin single bed type ion exchanger. The ultrapure water production apparatus according to claim 1. 4. The amount of water treated in the primary treatment system is further reduced.
Also in the ultrapure water production apparatus for processing in a secondary treatment system equipped with a non-regenerating type mixed bed type ion exchange device and an ultrafiltration membrane device, the mixed bed type ion exchange device is strongly acidic A mixed resin obtained by mixing a cation exchange resin and a strongly basic anion exchange resin, and an anion exchange resin are stacked and filled in the same tower, and the water to be treated is anion-exchanged from the mixed resin layer. An ultrapure water production apparatus characterized by using a mixed-bed ion exchange apparatus configured to pass water in the order of layers of exchange resin. 5. The anion exchange resin according to claim 4, wherein a mixed resin obtained by mixing a strongly acidic cation exchange resin and a strongly basic anion exchange resin is mixed with the anion exchange resin. An ultrapure water production apparatus characterized by being filled so as to be smaller in volume.