JPS61101292A - Apparatus for making pure water - Google Patents

Abstract

PURPOSE:To conserve power consumption, by connecting a plurality of apparatus units each consisting of an ultraviolet ray irradiation apparatus and an ion exchange apparatus in series. CONSTITUTION:Raw water is introduced into a first ultraviolet ray irradiation apparatus 11a and irradiated with ultraviolet rays to oxidize the greater part of the org. substance therein to an org. acid. The treated water is introduced into a first ion exchange apparatus 12a to remove the org. acid and subsequently passes through a second ultraviolet ray irradiation apparatus 11b and a second iron exchange apparatus 12b or treated plural times by these apparatuses to perfectly remove the org. substance, to obtain pure water with high purity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pure rice production device, and particularly to a water treatment device that combines an ultraviolet irradiation device and an ion exchange device. The present invention relates to a pure water production device that has been improved to reduce power consumption in an ultraviolet irradiation device.

[Prior Art] In recent years, the development and mass production of LSIs and super LSIs have been actively carried out. In the manufacturing of LSI and aLSI, pure water is used in many cleaning processes, and various studies have been conducted on pure water production technology. Water) production technology has been developed.

Pure water usually coagulates, il! It is manufactured by filtration, ion exchange treatment, etc. However, with this method, it is impossible to remove bacteria, and organic substances, especially trace amounts of organic substances, remain in the treated water, which is insufficient to meet the required water quality of ultrapure water used in semiconductor manufacturing, for example. .

That is, natural water generally contains organic substances derived from decayed animals and plants, such as tannin and lignin, and microorganisms such as Pseudomonas and Achromobacter.

Contains Aerobacter, etc. These organic substances cannot be completely removed by coagulation filtration, treatment with reverse osmosis membranes, treatment with ultrafiltration membranes, ion exchange methods, or treatment methods that combine these, and trace amounts of organic substances still remain in the treated water. It remains.

As a treatment method to reduce the concentration of residual organic matter in pure water,
A method is known in which primary treated water that has been subjected to ion exchange treatment or reverse osmosis treatment is irradiated with ultraviolet rays and then subjected to finishing treatment in a mixed bed consisting of a cation exchange resin and an anion exchange resin (for example, , 56-28191).

According to such a pure water production process that includes an ultraviolet irradiation step, trace amounts of organic substances remaining in the primary treated water are ionized, and the generated ionized substances are removed in the mixed ion exchange resin bed, so that the organic substances are reduced accordingly. Pure water with low concentration is produced.

[Conventional problems] However, in the conventional pure water production process that includes an ultraviolet irradiation process, in order to reduce the concentration of residual organic matter, an extremely large amount of ultraviolet rays must be irradiated, and the power consumption of the ultraviolet irradiation equipment is high. I had no choice but to do it.

That is, by irradiating ultraviolet rays, organic substances are oxidized and decomposed into ionized substances, and as the amount of ultraviolet rays is increased, more organic substances can be ionized. However,
Due to the energy of the irradiated ultraviolet rays, the ionized substance is further decomposed into low-molecular compounds, and a considerable portion of the energy of the irradiated ultraviolet rays is used for low-molecular-weight reactions other than ionization reactions. That's what happens. (For example, organic substances derived from tannins and lignins are converted to formic acid by ultraviolet light.

Decomposed into organic acids such as acetic acid. And if further UV energy is supplied to the system.

It is decomposed into CO2, N2, and H20. ) If the amount of ultraviolet irradiation is reduced in order to suppress such wasteful consumption of ultraviolet energy, the amount of ionized substances produced will decrease and the concentration of residual organic substances will increase.

As described above, in conventional equipment, when the equipment is operated to increase the oxidative decomposition rate of organic matter in raw water in order to obtain high-purity treated water, ultraviolet irradiation causes *
Not only is the organic material fermented and decomposed into organic acids, but also C
This results in oxidative decomposition to O2, N2, H2O, etc., so to speak, excessive oxidation, resulting in a problem of poor power efficiency.

[Means for Solving the Problems] In order to solve the above-mentioned conventional problems, the present invention is configured so that one treatment step of ultraviolet irradiation and removal of the ionized substances generated thereby can be performed multiple times. There is a pure ice production equipment unit consisting of an ultraviolet irradiation device that irradiates water to be treated with ultraviolet rays, and an ion exchange device that treats the treated water from the ultraviolet irradiation device.

The gist of the present invention is a pure water production device characterized by having a plurality of J6 connected in series.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to FIG. 1, which shows an embodiment of a pure water production apparatus according to the present invention.

As shown in FIG. 1, the pure water production apparatus of the present invention comprises an ultraviolet irradiation device and an ion exchange device. It is formed by connecting a plurality of C4 units 1.2 (two in the diagram!lI's1) in series.

In the pure water production apparatus shown in FIG. 1, raw water is first introduced into the first ultraviolet irradiation device 11a and irradiated with ultraviolet rays, thereby oxidizing most of the organic substances contained therein into organic acids.

The liquid containing the organic acid is then introduced into the first ion exchange device 12a, where the organic acid is removed. The liquid that has passed through the first ion exchange device 12a still contains a small amount of organic matter, but this residual organic matter is irradiated with ultraviolet rays in the second ultraviolet irradiation device 11b and is almost completely decomposed into organic acids. The organic acids are removed in a second ionic culture exchanger 2tlZb.

In this way, the liquid that has been subjected to ultraviolet irradiation and ion exchange treatment multiple times becomes highly purified water containing almost no organic matter, but as shown in FIG. By passing the water through this mixed bed type ion exchange device 13, it is possible to obtain pure water with higher purity.

Although FIG. 1 shows an apparatus having two pure water production apparatus units, the apparatus of the present invention may have three or more of these units.

The number of units installed may be appropriately selected based on the composition and concentration of organic matter in the raw water, the TOC concentration of the target treated water, etc., so that the most efficient treatment can be performed.

Further, in order to further complete the oxidative decomposition of the organic matter at the amount of ultraviolet irradiation f14, it is preferable to add hydrogen peroxide as an oxidizing agent and perform the treatment by irradiating ultraviolet rays in the presence of hydrogen peroxide.

In this case, it is preferable that the ion exchange device is filled with a catalyst resin capable of decomposing hydrogen peroxide, and the liquid from the ultraviolet irradiation device is brought into contact with the catalyst resin to remove hydrogen peroxide.

As the catalyst resin, an ion exchange resin supported with palladium is used, and the amount supported is preferably about 0.1-10% based on the ion exchange resin.

It is preferable to use an anion exchange resin as the ion exchange resin used in this catalyst resin because it exhibits an excellent effect with a small amount of supported palladium. Polymer anion exchange resins are preferred. The ionic form of the anion exchange resin may be either the C1 type or the OH type, but the OH type has a higher processing capacity and is more preferable. It is better to pass the alkaline liquid through it.

In order to support palladium on an anion exchange resin, it is preferable to fill a column with the anion exchange resin and then pass water through an acidic solution of palladium chloride.

At that time, the amount of palladium supported was (12~LOg-Pd/
It is preferable that the amount is about l-resin.

Specifically, the catalyst resin is Lewait QC-LO.
45 (C1 type strongly basic 7 anion exchange resin supporting palladium, manufactured by Bayer) or its OH type.

As shown in Figure 1, when installing a mixed bed type ion exchanger i13, the resins constituting this hotbed are H type of strongly acidic cation exchange resin and O type of strongly basic anion exchange resin.
Used in combination with H type. Specifically, Diamond Aeon ■P
A312 (manufactured by Mitsubishi Chemical Industries, Ltd.) and Diaion @PK
228 (manufactured by the same company) is suitable.

[Function] According to the pure water production apparatus of the present invention, the treatment consisting of the oxidation treatment by ultraviolet irradiation and the ion exchange treatment is performed multiple times.

That is, in the apparatus of the present invention, the organic matter in the raw water is decomposed to the organic acid stage by the first stage of ultraviolet irradiation, and this aqueous acid is removed by the subsequent ion exchange device. Most of the organic matter still remaining in the liquid that has passed through the ion exchange device is decomposed into organic acids by ultraviolet irradiation in the second stage or later, and then removed by the second or subsequent ion exchange device. .

Therefore, in the device of the present invention, there is no need to increase the amount of ultraviolet irradiation in order to almost completely decompose organic matter in raw water in one ultraviolet irradiation device, unlike conventional devices, and it is possible to improve power efficiency and reduce power consumption. This makes it possible to reduce the Furthermore, since the raw water load on each ultraviolet irradiation device is significantly reduced, it is possible to downsize the device, and it is also possible to downsize the entire device.

[Examples] The present invention will be described in more detail with reference to comparative examples and examples, but the present invention is not limited to the following examples unless the gist thereof is exceeded.

The composition of raw water used in Examples and Comparative Examples.

The use of ultraviolet oxidation equipment and ion exchange equipment is as follows.

(a) Raw water composition Electric chamber conductivity 1.0 hiros/mmetal
5 sppm TOC 20 ppm (b) Ultraviolet irradiation device reaction tank capacity 12.5 mm Ultraviolet lamp 0, 4KW (c) Ion exchange device resin tower 215mmΦX500mmM Ion exchange resin 0C1045 Catalyst resin Lewait 200ml Regenerant
NaOH Comparative Example 1 Using the conventional equipment shown in Figure 2, H2027 was added to raw water 12.51.
1P pm (66% of the theoretical amount) was added and first irradiated with ultraviolet rays for 25 minutes in ultraviolet irradiation device 11, and then water was passed through ion exchange device 12 to obtain alimentized water.

Table 1 shows the results of measuring Toca degree, H2O2 concentration, electric type conductivity, and PH for the liquid and treated water before and after UV irradiation.

Table 1 Comparative Example 2 120 pP of H2H2O2 in raw water 12.51 theoretically required 1)
When TOC was removed using only an ultraviolet irradiation device without using an ion exchange device, the TOC of the treated water was
It took 60 minutes of ultraviolet irradiation to reach a concentration of 1.7 ppm.

Example 1 Raw water was treated using the example apparatus shown in FIG.

That is, 70 ppm of H2O was added to raw water 12.51 ml, irradiated with ultraviolet rays for 25 minutes in the first ultraviolet irradiation device, and then passed through the ion exchange device of FJ41. The liquid discharged from the second ion exchange device is irradiated with ultraviolet rays for 10 minutes in the second ultraviolet irradiation device, and then passed through the second ion exchange device, and then passed through the mixed bed type ion exchange device to treat the treated water. I got it. (In other words, the treatment in this example corresponds to the treatment in which the treated water obtained in Comparative Example 1 was further irradiated with ultraviolet rays for 10 minutes, and then subjected to catalytic resin bed and hot bed ion exchange.) Second ultraviolet rays Liquid before irradiation (corresponding to the treated water obtained in Comparative Example!), liquid after second ultraviolet irradiation, liquid at the outlet of the second ion exchanger, and liquid at the outlet of the mixed bed ion exchanger (treated water) Table 2 shows the results of measuring TOC concentration, H202 concentration, electrical type conductivity, and pH.

Table 2 Table 2 shows that by performing the treatment of ultraviolet ray irradiation and ion exchange twice with the pure water production apparatus of the present invention, TO in the treated water can be reduced.
C is 0. It is confirmed that the O content is reduced to 5 ppm or less, and ultrapure water with extremely high purity can be obtained. Also, the processing time is short.

Comparative Example 3 In Comparative Example 1.2, the TOC concentration of the treated water was 0. O5
Ultraviolet rays were irradiated so that the amount was ppm.

Table 3 shows the measurement results of the irradiation time and the power consumption of the ultraviolet irradiation device at that time.

Table 3 From Table 3, it is clear that the power consumption of the ultraviolet irradiation device in the example device is significantly lower than that in the comparative example.

[Effects] As detailed above, according to the pure water production apparatus of the present invention, the treatment consisting of ultraviolet irradiation and ion exchange can be performed multiple times. This treatment makes it possible to produce highly purified water with extremely low TOC concentration in a short time.

Moreover, wasteful consumption of power due to excessive oxidation of organic matter can be avoided, and the amount of power required for ultraviolet oxidation can be reduced. Furthermore, the amount of oxidizing agent required can be significantly reduced, and undecomposed oxidizing agent (H202) can be almost completely removed. Therefore, according to the device of the present invention.

The running cost of the equipment can be significantly reduced,
It also makes it possible to downsize the device, making it economical.

It is extremely advantageous industrially.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the pure water production apparatus of the present invention, and FIG. 2 is a system diagram showing a conventional apparatus. l, 2... Pure water production equipment unit, 11, lla
, llb... Ultraviolet irradiation device, 12.12&,
12b...Ion exchange device, 13...
Mixed bed ion exchange equipment.

Claims (2)

[Claims] (1) An ultraviolet irradiation device that irradiates the water to be treated with ultraviolet rays,
A pure water production device comprising a plurality of pure water production device units each comprising an ion exchange device for treating treated water from the ultraviolet irradiation device and connected in series. (2) Hydrogen peroxide is added to the water to be treated that is irradiated with ultraviolet rays, and an ion exchange resin capable of decomposing hydrogen peroxide is present in the ion exchange device. The pure water production equipment described in section.