JPH0818039B2 - Method and apparatus for recycling pure water or ultrapure water - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling pure water or ultrapure water, and more particularly to cleaning water in a step of cleaning with pure water or ultrapure water in the electronics industry, precision machinery industry and the like. ,
The present invention relates to a recovery reuse method and device.

[0002]

2. Description of the Related Art Conventionally, the treatment of cleaning wastewater has been carried out by a method of removing harmful substances to the outside of the system, a method of removing the cleaning wastewater by ion removal, sterilization, and recycling after filtration. In recent years, the water used in the entire factory has been closed. This method divides the wastewater from various processes in the factory into the first wash water with high pollutant concentration and the second and subsequent wash water, and treats the first wastewater separately by means such as evaporation. The second and subsequent cleaning wastewater is reused as raw water of pure water for cleaning.

[0003]

According to the method of discharging the cleaning wastewater to the outside of the system, even after the removal of harmful substances such as heavy metal ions and cyan, the discharge to the outside of the factory is permitted depending on the location conditions of the factory. Sometimes you can't. There is also a problem in terms of effective use of water resources. Further, in the conventional method for recycling the cleaning waste water, since the ion removal step, the sterilization step and the fine particle removal step are generally recycled, an increase in organic substances in the cleaning water due to elution from the surface treatment equipment and the surface treated material, There was a problem such as increase or saturation of dissolved oxygen due to air release during cleaning. Particularly for dissolved oxygen, conventional methods for removing dissolved oxygen include vacuum degassing using a degassing tower, vacuum film degassing through a film, nitrogen aeration, addition of a reducing agent, etc., but the apparatus becomes large-scale. However, there is a problem that an excessive reducing agent and a reaction product remain, and it is difficult to use it in a small-sized closed apparatus.

In addition, in the method of closing the entire factory, due to an accident in the cleaning process or wastewater treatment process,
In some cases, the predetermined performance may not be maintained, which may cause an overload on the pure water production system, and in the worst case, may affect the entire factory. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art, and to provide a small-sized, high-purity pure water or ultrapure water recycling method and device capable of closing water.

[0005]

In order to solve the above-mentioned problems, the present invention provides a recycling method in which cleaning waste water in a cleaning step using pure water or ultrapure water is recycled and used.
In the regeneration treatment, (a) a step of passing cleaning wastewater through the ion-exchange resin layer, (b) passing treated water of (a) to the liquid contact side of the gas permeable membrane supporting palladium, and contacting the gas contact side. The step of supplying hydrogen to (a), (b) the step of irradiating the treated water with ultraviolet rays, and (d) the ion exchange resin layer obtained by mixing the H-type strongly acidic cation exchange resin and the OH-type anion exchange resin ( )
The method for recycling pure water or ultrapure water, which is characterized in that it is carried out by sequentially passing through each step of the step of passing the treated water of (4) and the step of (e) ultrafiltration of the treated water. It was done. In the above-mentioned regeneration treatment method, it is preferable that the regeneration treatment is further conducted through a heat exchange treatment step.

According to the present invention, there is provided an apparatus used in the above-mentioned method for recycling pure water, wherein the recycling processing apparatus is
(A) Ion exchange resin tower, (b) Palladium-supported gas permeable membrane, (c) UV irradiation tower, (d) Ion in which H-type strongly acidic cation exchange resin and OH-type anion exchange resin are mixed An ion exchange device having an exchange resin layer,
(E) An ultrafiltration device, and (f) a pipe and a pump for sequentially connecting the devices (a) to (e) to each other.
And pure water, or a tank, and a pipe for supplying reclaimed treated water from (e) to the cleaning device, and a pipe for supplying wastewater from the cleaning device to the regenerating device. This is a water recycling device. Further, in the above recycling apparatus, it is preferable to provide a heat exchange facility in any of the recycling processing device, the recycled treated water supply path, or the cleaning drainage supply path.

The present invention will be described in detail below. Figure 1
It is explanatory drawing of the flow which shows an example of the embodiment of this invention.
The recycling method and apparatus of the present invention will be described in more detail with reference to FIG. In FIG. 1, the water used in the cleaning device 12 is supplied from the cleaning drainage tank 14 in the cleaning device via the cleaning drainage line 15 and the pump 16 to the ion exchange resin tower 1
Introduce to. Then, the treated water is introduced to the liquid contact side of the dissolved oxygen removing device 2 having the gas permeable membrane 3 supporting palladium. The gas contacting side of this time the device for supplying hydrogen gas to the water head difference hydrogen water sealed tube 4 so that the 0 to 100 c MAQ. Then, the treated water is supplied to the tank 6. From the tank 6, water to be treated having a flow rate corresponding to 1 to 3 times the flow rate of washing water is introduced into the ultraviolet irradiation tower 8 via the pump 7. Then, the ultraviolet-treated water is introduced into the ion-exchange tree tower 9, and then into the ultrafiltration device 10. Then, the treated water is supplied to a circulation line 11 including a cleaning device 12,
The unused water returns to the tank 6 via the heat exchange device 13.

Here, the ion exchange resin tower 1 may be any one capable of removing the ions contained in the cleaning wastewater, and it varies depending on the substance to be cleaned, the cleaning agent, etc., but is a weakly basic or strongly basic anion exchange. A mixed resin of a resin and a strongly acidic cation exchange resin can be used. Whichever resin is used, it is desirable that it be highly regenerated and thoroughly washed with water before use. The dissolved oxygen removing device 2 has a gas permeable membrane 3 supporting palladium.
The gas permeable film 3 may be any film that is permeable to hydrogen but impermeable to liquid and has palladium supported thereon, and hydrogen is supplied 5 to the gas contact side. The loading of palladium on the gas permeable membrane 3 has been already proposed by the present inventors, but it can be carried out according to a plating method on plastics or a loading method on ion exchange resins or the like. Hydrogen supply to gas contact side 5
Is preferably supplied from an equivalent amount to about 3 times the equivalent amount of oxygen dissolved in the inflowing water to the dissolved oxygen removing device 2.

The tank 6 corresponds to the amount of cleaning water used and its fluctuation, and when the amount of water used or its fluctuation is large, the tank 6 needs to be enlarged. The light source in the ultraviolet irradiation tower 8 may be any one that irradiates ultraviolet rays having a wavelength of 400 nm or less, and has a wavelength of about 260 nm which is a germicidal ray and a wavelength of 200 nm which is considered to be effective for organic substances.
Those which can be irradiated with the following ultraviolet rays are particularly desirable. A low pressure mercury lamp using artificial quartz for the lamp and the protective tube can be preferably used. The mixed bed type ion exchange resin tower 9 is
It is a mixed resin of H type strongly acidic cation exchange resin and OH type strongly basic anion exchange resin, which is highly regenerated before mixing,
It is desirable to wash thoroughly with water. Wash with water here is 4
It is desirable to use ultrapure water or pure water heated to about 0 ° C. As the ultrafiltration device 10, it is desirable to use an external pressure type hollow fiber ultrafiltration membrane. The heat exchange device 13
It is a device that prevents the rise in water temperature due to the amount of heat supplied by a pump, an ultraviolet lamp, or the like, and may be a multi-tube type, a plate type, or the like.

[0010]

The operation of the present invention will be described according to each processing step.
The ion exchange resin removes metal ions and inorganic ions such as cyanide in the cleaning waste water. In addition, ionic organic substances such as organic acids are also removed. Next, in a dissolved oxygen removing apparatus having a gas permeable membrane supporting palladium and supplying hydrogen to the gas contact side, in the presence of palladium, the reaction represented by the formula O ₂ + 2H ₂ → 2H ₂ O Done to remove oxygen. At this time, hydrogen comes into contact with oxygen in the form of being dissolved in palladium, so that hydrogen reacts efficiently, and since the product is water, impurities do not increase. Although a small amount of hydrogen remains in this treatment step, it can be removed by a membrane degassing device or the like if necessary.

Next, in the ultraviolet irradiation device, the organic substances remaining in the water to be treated and the organic substances eluted from the cleaning device itself and the recycling device are decomposed by the ultraviolet rays having a wavelength of 200 nm or less. In addition, sterilization is also performed by ultraviolet rays having a wavelength of around 260 nm, which is called sterilization line. Next, in the ion-exchange resin tower 9, ionic decomposition products due to ultraviolet decomposition and ions such as palladium, which are eluted in a very small amount from the gas permeable membrane supporting palladium, are removed. Next, fine particles are removed by an ultrafiltration device. The fine particles include not only those contained in the water to be treated but also bacteria killed by bacteria, dust generated by the pump, leaked from the ion exchange resin, the gas permeable membrane and the like. Next, the treated water is sent to the cleaning device 12 through the circulation line 11, and the unused water is returned to the tank 6.

Further, in a cleaning facility using cleaning water,
By circulating the cleaning water at least up to the branch point closest to the water supply valve, it is possible to minimize the water so-called dead in the pipe and prevent the propagation of bacteria and the like. Here, since the ultraviolet lamp, the circulation pump, and the like give energy to water, the water temperature rises. In a normal water purifier, etc., the used water is discharged and makeup water at room temperature is supplied,
The rise in water temperature is not significant. However, the rise in water temperature cannot be ignored when the system is closed with almost no water being discharged or replenished. Here, it is preferable that the washing water has a high water temperature because the washing effect is improved, but the ion-exchange resins and the like currently put into practical use lack heat resistance, and the performance deteriorates when the temperature exceeds about 40 ° C. Therefore, it is necessary to suppress the rise in water temperature, and a cooling facility having a cooling capacity equivalent to the energy used for the recycling facility is required.

[0013]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Example 1 FIG. 1 shows a schematic flow chart of the apparatus used in this example.
Wastewater from the cleaning device is introduced into the ion exchange resin tower 1 through the cleaning drainage line 15 and the drainage transfer pump 16, and then treated by the dissolved oxygen removing device 2 having the gas permeable membrane 3 carrying palladium, and then the tank. Supply to 6. From the tank 6, a pump 7 was supplied at a rate of 5 m ³ / h to the ultraviolet irradiation device 8, the cartridge type ion exchange resin tower 9, and the ultrafiltration membrane 10 for circulation treatment. Here, as the ion exchange resin 1, a cartridge type ion exchange resin tower in which 60 liters of a strongly basic anion exchange resin and 60 liters of a strongly acidic cation exchange resin were mixed was used. Then,
The dissolved oxygen removing device 2 is a gas permeable membrane module having a polyolefin-polyurethane-based hollow fiber composite membrane inside which is catalyzed and activated by palladium according to an electroless plating method and has a membrane area of 12 m ² . A module was used. Water to be treated is passed through the inside of this gas permeable membrane, and hydrogen gas of 0.1 kgf / cm ² , 100 ml / m is passed outside.
Supplied in.

Next, the effective volume of the ultraviolet irradiation device 8 is about 3
0 liters, 100 power consumption through artificial quartz tube
Seven W low-pressure mercury lamps were turned on. Next, the cartridge type ion exchange resin tower 9 was prepared by mixing 10 liters of sufficiently washed H-type strongly acidic cation exchange resin and 20 liters of OH type strongly basic anion exchange resin and filling it in a FRP container. I used a book. Next, the ultrafiltration device 10
Is an external pressure type hollow fiber membrane module (Asahi Kasei OLT-302
Two of 6) were used. Then, the treated water was supplied to the pure water line 11 including the inside of the cleaning device, and the unused water was circulated to the tank 6 via the heat exchange device 13 for circulation. The cleaning drainage transfer pump 16 performs operation control according to the amount of cleaning drainage,
Excessive supply of hydrogen was prevented by interlocking and controlling the automatic valve 17 for hydrogen. Table 1 shows the results.

COMPARATIVE EXAMPLE 1 Recovery of water was carried out by using the same apparatus as in Example except that the circulating water was not provided and the treated water was stored in the treated water tank and intermittently supplied to the cleaning device only when in use. It was reused. The results are shown in Table 1. Decrease in resistivity of feed water, increase in organic substances, increase in viable bacteria, etc. are observed. Especially for live bacteria,
A large increase was observed as compared to Example 1.

Comparative Example 2 Water was recovered and reused by a conventional device using an ion exchange resin and an ultrafiltration membrane. A schematic flow chart is shown in FIG. 2, and the results are shown in Table 1. The dissolved oxygen was almost saturated, and the number of viable bacteria was also increased as compared with the examples.

[0017]

[Table 1]

[0018]

As described above, by using the water recovery / reuse apparatus according to the present invention, (1) the amount of water used is greatly reduced as compared with the method of discharging washing wastewater, Effective use of resources is promoted. (2) Compared to the method of closing the whole factory,
Since only one process is closed, even if the performance of the processing equipment deteriorates due to an accident or the like, there is almost no effect on the entire factory. (3) There is no deterioration of water quality as compared with the method of recovery and reuse by ion exchange resin and filtration. And so on.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention.

FIG. 2 is a schematic diagram of a conventional recovery / reuse device.

[Explanation of symbols]

1: Ion-exchange resin column A, 2: Dissolved oxygen removal device, 3:
Palladium-supported gas permeable membrane, 4: hydrogen water sealing tube, 5: hydrogen supply line, 6: tank, 7: pump, 8: ultraviolet irradiation tower, 9: ion exchange resin tower B, 10: ultrafiltration device, 1
1: circulation line, 12: cleaning device, 13: heat exchange device,
14: Washing waste water tank, 15: Washing drain line, 16:
Wastewater transfer pump, 17: Automatic valve for hydrogen

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C02F 9/00 503 B 504 B B08B 3/14 2119-3B C02F 1/32 1/42 B 1 / 44 J 9538-4D 1/58 T (72) Inventor Ken Nakajima 4-2-1 Motofujisawa, Fujisawa City, Kanagawa Prefecture Ebara Research Institute Ltd. (72) Inventor Manabu Tsujimura 11 Haneda Asahi-cho, Ota-ku, Tokyo No. 1 in EBARA CORPORATION

Claims (4)

[Claims] 1. A recycling method in which cleaning wastewater in a cleaning step using pure water or ultrapure water is recycled and used, wherein (a) cleaning wastewater is passed through the ion-exchange resin layer. Step (b): Passing the treated water of (a) to the liquid contact side of the gas permeable membrane supporting palladium and supplying hydrogen to the gas contact side, (c) UV light to the treated water of (b) The step of irradiating, (d) the step of passing the treated water of (c) through the ion exchange resin layer obtained by mixing the H-type strongly acidic cation exchange resin and the OH type anion exchange resin, (e) the treated water of (d) The method for reusing pure water or ultrapure water, which comprises performing the steps of: 2. The method for recycling pure water or ultrapure water according to claim 1, wherein the recycled water is further passed through a heat exchange treatment step. 3. An apparatus used in the method for reclaiming pure water according to claim 1, wherein the regeneration processing apparatus comprises (a) an ion exchange resin tower and (b) a gas permeable membrane supporting palladium. And (c) an ultraviolet irradiation tower, (d) an ion exchange device having an ion exchange resin layer in which an H-type strongly acidic cation exchange resin and an OH-type anion exchange resin are mixed, and (v) an ultrafiltration device. And (f) a pipe, a pump, and a tank that sequentially connect the devices from (a) to (e), and a pipe that supplies the reclaimed treated water from (e) to a cleaning device, and a cleaning process. An apparatus for reusing pure water or ultrapure water, comprising a pipe for supplying wastewater from the apparatus to the reprocessing apparatus. 4. The apparatus for reusing pure water or ultrapure water according to claim 3, wherein a heat exchange facility is provided in any one of the regeneration treatment apparatus, the regeneration treatment water supply passage, and the cleaning drainage supply passage.