TWI814710B - Water quality management system and operation method of water quality management system - Google Patents

Abstract

A water quality management system 10, which includes: a regenerative ion exchange device 1; a water quality measuring device 2 having an ion concentration meter 22; a first discharge pipe 3 for circulating treated water W1 discharged from the regenerative ion exchange device 1; and a first discharge pipe 3. 2. The discharge pipe 4 branches from the first discharge pipe 3 via the automatic valve 5 and supplies the treated water W1 to the water quality measuring device 2. According to the water quality management system, the concentration of sodium ions (Na ⁺ ) or chloride ions (Cl ^- ) in the treated water discharged from the regenerative ion exchange device of the primary pure water system used in the ultrapure water production device can be stably reduced. , and can suppress short-term fluctuations in the sodium ion (Na ⁺ ) concentration or the chloride ion (Cl ^- ) concentration in the treated water discharged from the non-regenerative ion exchange device used in the subsequent subsystem.

Description

Water quality management system and operation method of water quality management system

The present invention relates to a water quality management system and an operation method of the system, which are used in a primary pure water system of a self-regeneration ion exchange device, especially an ultrapure water manufacturing device used in the process of manufacturing electronic products, etc. Manage the quality of the treated water discharged from the regenerative ion exchange device.

Ultrapure water manufacturing equipment usually includes a pre-treatment system, a primary pure water system, and a secondary pure water system (subsystem). The pre-treatment system includes coagulation, pressurized flotation (sedimentation), filtration (membrane filtration) devices, etc., and removes suspended substances or colloidal substances in raw water. During the treatment process of the pre-treatment system, polymeric organic matter, hydrophobic organic matter, etc. can also be removed. The primary pure water system basically includes a reverse osmosis (RO (Reverse osmosis)) membrane separation device and a regenerative ion exchange device (mixed bed type or 4-bed, 5-tower type, etc.). In the RO membrane separation device, salts are removed, and ionic and colloidal total organic carbon (TOC) components are removed. In the regenerative ion exchange device, salts are removed, and TOC components adsorbed or ion exchanged by the ion exchange resin are also removed.

The subsystem basically includes a low-pressure ultraviolet (UV) oxidation device, a non-regenerative mixed-bed ion exchange device and an ultrafiltration (UF) membrane separation device, and further improves the purity of primary water to create ultrapure water. water. In the low-pressure UV oxidation device, the TOC component is decomposed into organic acids and further into CO ₂ using ultraviolet light of 185 nm irradiated from a low-pressure ultraviolet lamp. The organic matter and CO ₂ generated by decomposition are removed using the non-regenerative mixed-bed ion exchange device in the subsequent stage. In the UF membrane separation device, fine particles are removed, and the outflow particles of the ion exchange resin are also removed.

In the above-mentioned ultrapure water production device, the regenerative ion exchange device used in the primary pure water system includes one tower or multiple towers including degassing devices according to the required water quality of the treated water, usually in the front stage. Equipped with reverse osmosis (RO) membrane device. Furthermore, a subsystem including a non-regenerative ion exchange device is provided at the rear of the regenerative ion exchange device.

Previously, in the above-mentioned regenerative ion exchange device, water intake and regeneration were repeated while ions in the water were electrochemically removed. Furthermore, regeneration means that when the ion exchange function of the ion exchange device is reduced, an ion exchange resin such as an anion exchange resin or a cation exchange resin filled in the ion exchange device is mixed with hydrochloric acid (HCl) or sodium hydroxide (NaOH). Wait for regeneration chemicals to come into contact for regeneration. The ion concentration of the treated water treated with an ion exchange device that mainly removes ions from the treated water is determined by the ion concentration of the supplied treated water and the amount of treated water (space velocity and linear velocity). Therefore, it is usually as described above. In the regenerative ion exchange device, a threshold value is set for the resistivity (or conductivity) of the treated water, and the ion exchange resin is regenerated by regeneration chemicals when the threshold value is exceeded. However, due to the regeneration chemicals remaining in the regenerated ion exchange resin, sodium ions (Na ⁺ ) or chloride ions (Cl ⁻ ) are present in the treated water when taking water after removing ions.

Recently, it has been found that there is a concern that short-term fluctuations in the concentration of sodium ions (Na ⁺ ) or chloride ions (Cl ^- ) in the treated water are becoming more and more obvious in non-regenerative ion exchange devices used in subsystems, and in When the treated water of the non-regenerative ion exchange device is used for cleaning semiconductor products, the yield of the manufactured semiconductor products is reduced.

Therefore, the present inventors studied the causes of changes in the concentration of sodium ions (Na ⁺ ) or chloride ions (Cl ^- ) in the treated water discharged from the above-mentioned regenerative ion exchange device. As a result, it was found that primary pure water The sodium ion (Na ⁺ ) concentration or chloride ion (Cl ^- ) concentration of the treated water of the regenerative ion exchange device used in the system affects the quality of the treated water of the non-regenerative ion exchange device used in the subsequent subsystem. Make an impact.

The present invention was made in view of the above problems, and its object is to provide a water quality management system and an operation method of the water quality management system that can stably reduce the cost of a regenerative ion exchange device in a primary pure water system used in an ultrapure water production device. The concentration of sodium ions (Na ⁺ ) or chloride ions (Cl ^- ) in the discharged treated water can be suppressed, and the sodium ions (Na ⁺ ) in the treated water discharged from the non-regenerative ion exchange device used in the subsequent subsystem can be suppressed. Concentration or short-term changes in chloride ion (Cl ^- ) concentration.

In order to solve the above problems, first, the present invention provides a water quality management system, which includes: a regenerative ion exchange device; a water quality measuring device having an ion concentration meter; and a first discharge pipe for discharge from the regenerative ion exchange device. of treatment flow and a second discharge pipe branched from the first discharge pipe to supply the treated water to the water quality measuring device (Invention 1).

According to the invention (Invention 1), the water quality measuring device can measure not only the resistivity of the treated water discharged from the regenerative ion exchange device, but also the ion concentration. Therefore, the ion exchange resin can be managed based on the measured value. Whether the regeneration is appropriate or not, the ion concentration in the treated water can be stably reduced, and short-term fluctuations in the ion concentration in the treated water discharged from the non-regenerative ion exchange device used in the subsequent subsystem can be suppressed. In addition, the water quality measuring device is connected to the second discharge pipe branched from the first discharge pipe via an automatic valve, for example, instead of being provided on the first discharge pipe. This allows the water quality measuring device to be easily connected at the necessary timing according to the switching operation of the automatic valve. Determine the quality of treated water.

In the invention (Invention 1), when the regenerative ion exchange device has a plurality of regenerative ion exchange towers, it is preferable that the regenerative ion exchange tower from the last stage of the regenerative ion exchange device The effluent water flowing out is the treated water (invention 2).

When the regenerative ion exchange device has a plurality of regenerative ion exchange towers, in order to reduce the ion concentration in the treated water flowing into the subsequent subsystem, it is only necessary to reduce the ion concentration in the treated water of the last regenerative ion exchange tower. That’s it. According to the invention (Invention 2), the effluent of the last stage regenerative ion exchange tower is used as treated water, the ion concentration (and resistivity) is measured, and the appropriateness and regeneration of the ion exchange resin are managed based on the measured values. No, this can stably reduce the ion concentration in the treated water and suppress non-regenerative ion exchange from the subsystem used in the subsequent stage. Short-term changes in ion concentration in the treated water discharged from the device.

In the invention (Invention 1, Invention 2), it is preferable to include an automatic switching control mechanism that automatically switches an operation mode including a water intake mode for fetching the treated water, and a water intake mode for using the treated water. In the regeneration mode of the regeneration type ion exchange device, the automatic switching control mechanism performs automatic switching control of the operation mode in accordance with the measured value of the water quality measuring device (Invention 3).

According to the invention (Invention 3), the ion concentration (and resistivity) of the treated water discharged from the regenerative ion exchange device can be measured using a water quality measuring device, and the operation mode of the regenerative ion exchange device can be determined in accordance with the measured value. Automatically switches to water intake mode or regeneration mode, so the regeneration of the regenerative ion exchange device can be appropriately managed, and the ion concentration of the treated water flowing into the subsequent subsystem can be controlled.

In the invention (Invention 1 to Invention 3), it is preferable to include N (N is an integer of 2 or more) of the regenerative ion exchange devices arranged in parallel, and N or less of the water quality measuring devices arranged in parallel. , and is configured so that each treated water discharged from each of the N regenerative ion exchange devices can be supplied to each of the N or less water quality measuring devices (Invention 4).

Conventional ion concentration meters that measure ion concentrations have deviations in their measured values within a concentration range of hundreds of ng/L due to individual differences. Therefore, when a plurality of regenerative ion exchange devices are installed in parallel, if an ion concentration meter is installed to measure the ion concentration of the treated water for each series, the following situation will arise: Calibration and cross-checking of each ion concentration meter It takes time, making it impossible to properly manage the quality of the treated water at the required timing. According to the invention (Invention 4), it is possible to parallel When N (N is an integer of 2 or more) regenerative ion exchange devices are installed, one water quality management system can be used to select a specific regenerative ion exchange device at the necessary timing to measure the water quality. Compared with the case where an ion concentration meter (water quality measuring device) is provided for each regenerative ion exchange device, the management of the water quality of the treated water can be simplified, and the treated water with suppressed ion concentration can flow stably into the subsequent subsystem. In addition, one water quality management system can be used to manage the water quality of multiple regenerative ion exchange devices, so there is no need to install an ion concentration meter (water quality measuring device) for each regenerative ion exchange device. In this regard, the economical effect is Also large. This effect is particularly noticeable when the number of water quality measuring devices is smaller than the number of regenerative ion exchange devices.

Secondly, the present invention provides an operation method of a water quality management system, which is the operation method of the water quality management system described in any one of the inventions 1 to 4. The operation method of the water quality management system includes: The step of using the ion concentration meter to measure the ion concentration of the treated water; and based on the measured value of the measured ion concentration, automatically switching and controlling a water drawing mode for drawing the treated water, and a water drawing mode for drawing the treated water. A regeneration mode step for regenerating the regenerative ion exchange device (Invention 5).

According to the invention (Invention 5), not only the resistivity of the treated water discharged from the regenerative ion exchange device can be measured, but also the ion concentration can be measured. Therefore, the operation mode can be automatically switched to the water intake mode or the water intake mode based on the measured value. Regeneration mode. Therefore, even when the regenerative ion exchange device has a plurality of regenerative ion exchange towers, or when a plurality of regenerative ion exchange towers are installed in parallel, the quality of the treated water can be appropriately managed, and Furthermore, short-term fluctuations in the ion concentration of the treated water discharged from the non-regenerative ion exchange device used in the subsequent subsystem can be suppressed.

According to the present invention, the water quality measuring device can measure not only the resistivity of the treated water discharged from the regenerative ion exchange device, but also the ion concentration. Therefore, the appropriateness and regeneration of the ion exchange resin can be managed based on the measured value. No, the ion concentration in the treated water can be stably reduced, and short-term fluctuations in the ion concentration in the treated water discharged from the non-regenerative ion exchange device used in the subsequent subsystem can be suppressed. In addition, the water quality measuring device is connected to the second discharge pipe branched from the first discharge pipe via the automatic valve instead of being provided on the first discharge pipe. This allows simple measurement at the necessary timing according to the switching operation of the automatic valve. Treat water quality.

1: Regenerative ion exchange device

1A: The first regenerative ion exchange device

1B: The second regenerative ion exchange device

1C: The third regenerative ion exchange device

2:Water quality measuring device

2A: No. 1 water quality measuring device

2B: Second water quality measuring device

3: 1st discharge pipe

4: 2nd discharge pipe

4a, 4c, 4e: Branch 1

4b, 4d, 4f: 2nd branch pipe

5. 5a~5f: automatic valve

6: Supply pipe

7: 1st liquid medicine supply tube

8: 2nd liquid medicine supply tube

9: Regeneration wastewater discharge pipe

10, 10': Water quality management system

11: Regenerative ion exchange tower

11A: Regenerative anion exchange resin tower (OH tower) (first regenerative anion exchange resin tower (OH1 tower))

11A': The second regenerative anion exchange resin tower (OH2 tower)

11B: Regenerative cation exchange resin tower (H tower) (first regenerative cation exchange resin tower (H1 tower))

11B': The second regenerative cation exchange resin tower (H2 tower)

12: Ion exchange resin layer

12A: Anion exchange resin layer

12a: Weak anion exchange resin layer

12a':Strong anion exchange resin layer

12B: Cation exchange resin layer

12b: Weak cation exchange resin layer

12b': Strong cation exchange resin layer

13A, 13B: Shielding plate

20: Degassing device

21: Resistivity meter

22: Ion concentration meter

23: 1st automatic valve

24: 2nd automatic valve

25: 3rd automatic valve

26: 1st wastewater discharge pipe

27: 2nd wastewater discharge pipe

30:Pump

71: Heater (plate heat exchanger)

91: 1st regeneration wastewater discharge pipe

92: 2nd regeneration wastewater discharge pipe

93:Waste pipe for NaOH regeneration wastewater

94: Waste pipe for hydrochloric acid regeneration wastewater

111: Exchange tower body

W: pre-treatment water

W1: Ion exchange treated water

FIG. 1 is a schematic system diagram showing the water quality management system according to the first embodiment of the present invention. In Figure 1, the water quality management system includes a first example of a regenerative ion exchange device.

FIG. 2 is a schematic system diagram showing a water quality management system according to a second embodiment of the present invention. In FIG. 2 , the representation of each series of regenerative ion exchange devices is omitted.

3 is a schematic system diagram showing a second example of a regenerative ion exchange device included in the water quality management system of the present invention.

4 is a schematic system diagram showing a third example of a regenerative ion exchange device included in the water quality management system of the present invention.

Figure 5 shows the regenerative ion exchange included in the water quality management system of the present invention. Schematic system diagram of the fourth example of the device.

6 is a schematic system diagram showing a fifth example of a regenerative ion exchange device included in the water quality management system of the present invention.

7 is a schematic system diagram showing a sixth example of a regenerative ion exchange device included in the water quality management system of the present invention.

Hereinafter, embodiments of the water quality management system of the present invention will be described with reference to the drawings. The embodiments described below are provided to facilitate understanding of the present invention and do not limit the present invention in any way.

[First Embodiment]

FIG. 1 is a schematic system diagram showing the water quality management system 10 according to the first embodiment of the present invention. In Figure 1, the water quality management system 10 includes: a regenerative ion exchange device 1; a water quality measuring device 2, including a resistivity meter 21 and an ion concentration meter 22; a first discharge pipe 3 for ions discharged from the regenerative ion exchange device 1 The exchange treated water W1 circulates; and the second discharge pipe 4 supplies the ion exchange treated water W1 to the water quality measuring device 2. The second discharge pipe 4 is branched from the first discharge pipe 3 via the automatic valve 5. In addition, the water quality management system 10 includes an automatic switching control mechanism (not shown) that automatically switches operation modes including a water intake mode for fetching ion-exchange treated water W1 and a regenerative ion-exchange mode. Regeneration mode of device 1 regeneration. Furthermore, in the first embodiment, the regenerative ion exchange device 1 included in the water quality management system 10 is a first example of the regenerative ion exchange device.

<Regenerative ion exchange device>

In this embodiment, the regenerative ion exchange tower 11 constituting the regenerative ion exchange device 1 has an ion exchange resin layer 12 formed of a mixed resin of a cation exchange resin and an anion exchange resin disposed in a cylindrical exchange tower body 111 . A supply pipe 6 for supplying pre-processed water W for ion exchange treatment is connected to the upper part of the exchange tower body 111. On the other hand, a first discharge pipe 3 for discharging the ion exchange treated water W1 is connected to the lower part. The first discharge pipe 3 The second discharge pipe 4 is connected via the automatic valve 5 . Furthermore, the first discharge pipe 3 is connected to a subsequent subsystem (not shown). The pretreated water W has ion components removed by the regenerative ion exchange device 1 and is supplied to the subsystem through the first discharge pipe 3 as ion exchange treated water W1. The ultrapure water produced by the subsystem is supplied to the use-point and used for cleaning in the process of manufacturing electronic products and the like.

The supply pipe 6 is connected to a first chemical solution supply pipe 7 that supplies a sodium hydroxide (NaOH) aqueous solution as an alkali for the regeneration chemical solution. The first discharge pipe 3 is connected to a second chemical solution supply pipe 8 on the upstream side of the automatic valve 5 for supplying hydrochloric acid (HCl) as an acid of the regeneration chemical solution. A regeneration wastewater discharge pipe 9 for discharging wastewater during regeneration is connected to the side of the exchange tower body 111 . On-off valves (not shown in the figure) are respectively provided on the first discharge pipe 3, the second discharge pipe 4, the supply pipe 6, the first chemical liquid supply pipe 7, the second chemical liquid supply pipe 8 and the regeneration wastewater discharge pipe 9. ). In this embodiment, a heater (plate heat exchanger) 71 is provided in the first chemical solution supply pipe 7 .

(cation exchange resin)

In the regenerative ion exchange device 1, as the cation exchange resin constituting the ion exchange resin layer 12, a strongly acidic resin having a styrene group attached as a cation exchange group can be used. As for any of the cation exchange resins and weakly acidic cation exchange resins having carboxylic acid groups attached thereto, gel-type resins are generally used in terms of less elution of PSA. In addition, divinylbenzene in the cation exchange resin serves as a cross-linking agent, and the chain structure is cross-linked to form a resin with a network structure. Therefore, the more divinylbenzene there is, the more branches the chain will have, forming a dense structure. If the vinylbenzene content is small, a resin with small branches and a large mesh can be obtained. The cross-linking degree of resin commonly used in water treatment is about 8%, and it is called standard cross-linked resin. In contrast, those with a cross-linking degree of 9% or more are called high-cross-linking degree resins. In this embodiment, either a standard cross-linked resin or a highly cross-linked resin can be used, but a standard cross-linked resin can be preferably used.

(Anion exchange resin)

As an anion exchange resin constituting the ion exchange resin layer 12, a gel-type resin is used in terms of less elution of PSA. Strongly basic anion exchange resins based on styrene-divinylbenzene copolymers and the like and having quaternary ammonium groups such as trimethylammonium groups or dimethylethanol ammonium groups on the styrene skeleton can be used. Any weakly basic anion exchange resin having primary to tertiary amine groups as functional groups on a styrene skeleton or a polyacrylate skeleton, such as divinylbenzene copolymer, etc., but a strong strong anion exchange resin can be preferably used. Basic anion exchange resin. The exchange group of the anion exchange resin is preferably of the OH type.

The mixing ratio of the cation exchange resin and the anion exchange resin in the mixed resin constituting the ion exchange resin layer 12 is preferably 30:70~70:30, particularly preferably 30:70~ A large amount of anion exchange resin is mixed in a 50:50 ratio. Furthermore, regarding the composition of the ion exchange resin layer The physical properties of the ion exchange resin of 12 are not particularly limited as long as it is in granular form.

(Regenerative ion exchange tower)

The material of the regenerative ion exchange tower 11 is not particularly limited as long as it is resistant to the regeneration chemical of the ion exchange resin.

<Water quality measuring device>

In this embodiment, the water quality measuring device 2 has a resistivity meter 21 and an ion concentration meter 22 in this order. The water quality measuring device 2 has a second automatic valve 24 on the pipe between the resistivity meter 21 and the ion concentration meter 22 . The pipe between the resistivity meter 21 and the second automatic valve 24 is branched through the first automatic valve 23 and provided with a first wastewater discharge for discharging the wastewater after the resistivity measurement by the resistivity meter 21 to the outside of the system. tube 26. In addition, a second wastewater discharge pipe 27 for discharging the wastewater discharged from the water quality measuring device 2 to the outside of the system is provided on the downstream side of the ion concentration meter 22 via the third automatic valve 25 .

(resistivity meter)

The resistivity meter 21 constituting the water quality measuring device 2 measures the resistivity of the ion-exchange treated water W1. The type of the resistivity meter 21 is not particularly limited. For example, a commercially available resistivity meter can be used to measure the resistivity of the ion-exchange treated water W1. In addition, when pure water is passed through at 1 L/min, the material of the measurement unit of the resistivity meter 21 is not particularly limited as long as the ion concentration of the measurement target does not elute 20 ng/L or more.

(ion concentration meter)

The ion concentration meter 22 constituting the water quality measuring device 2 measures the ion concentration of the ion-exchange treated water W1. The type of ion concentration meter 22 is not particularly limited. In this embodiment, the ion concentration of the ion-exchange treated water W1 is measured using a sodium ion electrode. In addition, when pure water is passed through at 1 L/min, the material of the measurement unit of the ion concentration meter 22 is not particularly limited as long as the ion concentration of the measurement target does not elute 20 ng/L or more.

<Automatic switching control mechanism>

The automatic switching control mechanism is a controller that switches the operation mode in accordance with the measured value of the water quality measuring device 2 . Specifically, in the water intake mode, the resistivity meter 21 is used to measure the resistivity of the ion-exchange treated water W1, and when the measured value exceeds a threshold value preset in the resistivity meter 21, it is determined that the ion exchange resin layer 12 The ion exchange energy decreases and the system switches to the regeneration mode. Furthermore, in the regeneration mode, the ion concentration meter 22 is used to measure the sodium ion (Na ⁺ ) concentration contained in the ion-exchange treated water W1, and the measured value becomes less than or equal to the threshold value preset in the ion concentration meter 22 , the regeneration is judged to be better, the regeneration process is ended, and the water intake mode is switched.

(recycled chemicals)

In this embodiment, sodium hydroxide (NaOH) and hydrochloric acid (HCl) are used as chemicals used to regenerate the ion exchange resin filled in the exchange tower body 111 of the regenerative ion exchange tower 11. The ion exchange resin is not limited to those that can be regenerated due to its performance.

(pre-treated water)

The quality of the pre-processed water W is not particularly limited because the raw water treatment method differs depending on the required water quality of ultrapure water used in the process of manufacturing electronic products and the like. In addition, the raw water of the pre-processed water W is not particularly limited.

(Piping)

When pure water is circulated at 1 L/min, the material of the first discharge pipe 3 and other pipes used in the water quality management system 10 does not matter as long as the ion concentration to be measured does not elute 20 ng/L or more. Specially limited.

(automatic valve)

When flowing pure water at 1 L/min, the specifications of the automatic valve used in the water quality management system 10 are not particularly limited as long as the ion concentration to be measured does not elute 20 ng/L or more.

[How to operate the water quality management system]

Next, the operation method of the water quality management system 10 of the first embodiment will be described. In addition, the so-called "water intake mode" in the following refers to the operation mode when the ion-exchange treated water W1 discharged from the regeneration-type ion exchange device 1 is withdrawn, and the so-called "regeneration mode" refers to the ion exchange of the regeneration-type ion exchange device 1. Operation mode when the resin layer 12 is regenerated.

<Water dispensing mode>

In the water dispensing mode, you can open the supply pipe 6 and the first discharge pipe 3, close the first chemical liquid supply pipe 7, the second chemical liquid supply pipe 8 and the regenerated wastewater discharge pipe 9, and then set the first discharge pipe 3 to Water is passed through the automatic valve 5 to the second discharge pipe 4. In this state, the pretreated water W is supplied from the supply pipe 6 to the regenerative ion exchange tower 11 in a downward flow manner. The supplied pretreatment water W removes cationic components and anionic components from the ion exchange resin layer 12 as the mixed resin filled in the regenerative ion exchange tower 11 (ion exchange step). The pretreated water W from which ion components have been removed is supplied as ion-exchange treated water W1 to the subsequent subsystem through the first discharge pipe 3 and is simultaneously supplied to the water quality measuring device 2 through the second discharge pipe 4 . In addition, the water flow conditions at this time can be set to the same level as those of ordinary ion exchange processing, as long as the space velocity is set to 5h ^-1 to 100h ^-1 with respect to the volume of the ion exchange resin of the ion exchange resin layer 12 , especially set it to 5h ^-1 ~50h ^-1 .

In the water quality measuring device 2 , with the first automatic valve 23 open and the second automatic valve 24 closed, the ion-exchange treated water W1 flows from the second discharge pipe 4 to the resistivity meter 21 . The resistivity of the passed ion-exchange treated water W1 is measured using the resistivity meter 21 (resistivity measurement step). The ion-exchange treated water W1 after the resistivity measurement is discharged to the outside of the system through the first wastewater discharge pipe 26 . When the resistivity of the ion-exchange treated water W1 exceeds a preset threshold value, the automatic switching control mechanism determines that the ion exchange energy of the ion-exchange resin layer 12 is reduced, and switches to the regeneration mode. Furthermore, the flow rate of the ion-exchange treated water W1 discharged from the regenerative ion exchange device 1 toward the water quality measuring device 2 is preferably 1 L/min or more, and more preferably 1.5 L/min.

<Regeneration mode>

In the regeneration mode, first, the ion exchange treated water W1 is supplied to the regeneration type ion exchange tower 11 from the first discharge pipe 3 in an upward flow manner, and is discharged from the supply pipe 6, whereby the ion exchange resin layer constituting the ion exchange resin layer 12 is Mix the resin and perform backwash (backwash step). Through this backwashing step, the anion exchange resin is separated into the upper side of the exchange tower body 111 due to the slight difference in specific gravity between the anion exchange resin and the cation exchange resin. The cation exchange resin is separated into the lower side of the exchange tower body 111 .

Next, with the first chemical solution supply pipe 7 , the second chemical solution supply pipe 8 and the regeneration wastewater discharge pipe 9 open, the sodium hydroxide aqueous solution is supplied from the first chemical solution supply pipe 7 in a downward flow to the regeneration system. type ion exchange tower 11, and hydrochloric acid is supplied to the regeneration type ion exchange tower 11 in an upward flow manner from the second chemical solution supply pipe 8 (regeneration treatment step). Thereby, the anion exchange resin that is biased on the upper side of the exchange tower body 111 is regenerated, and the cation exchange resin that is biased on the lower side of the exchange tower body 111 is regenerated. At this time, in order to efficiently regenerate the anion exchange resin, the sodium hydroxide aqueous solution is preferably heated to approximately 30°C to 50°C using the heater 71 provided in the first chemical solution supply pipe 7 . The regenerated sodium hydroxide aqueous solution and hydrochloric acid wastewater are discharged from the regenerated wastewater discharge pipe 9.

Then, after opening the supply pipe 6 and the first discharge pipe 3, closing the first chemical liquid supply pipe 7, the second chemical liquid supply pipe 8 and the regeneration wastewater discharge pipe 9, the first discharge pipe 3 stops flowing towards the automatic valve 5. Water flows through the second discharge pipe 4. In the above state, the ion exchange treated water W1 is supplied from the supply pipe 6 to the regenerative ion exchange tower 11 in a downward flow manner, and is discharged from the first discharge pipe 3, thereby The one-pass self-regenerating ion exchange tower 11 extrudes the chemical solution (sodium hydroxide aqueous solution and hydrochloric acid) used for regeneration (extrusion step). At this time, the ion-exchange treated water W1 discharged from the first discharge pipe 3 is not supplied to the subsequent subsystem. Furthermore, the regeneration operations (backwash step, regeneration treatment step, and extrusion step) up to this point are preferably performed continuously when the resistivity of the ion-exchange treated water W1 decreases or the sodium ion concentration described below increases significantly. times or more.

The separated ion exchange resin constituting the ion exchange resin layer 12 is mixed with After closing, the first discharge pipe 3 is configured to pass water to the second discharge pipe 4 through the automatic valve 5. In addition, in the same opening/closing state of the pipe as in the extrusion step, the supply pipe 6 The pretreated water W is supplied to the regenerative ion exchange tower 11 in a downward flow manner, and the ion exchange treated water W1 is discharged from the first discharge pipe 3, whereby the ion exchange resin is circulated and cleaned (circulation cleaning step). At this time, the ion-exchange treated water W1 discharged from the first discharge pipe 3 is not supplied to the subsequent subsystem. At the same time, the ion-exchange treated water W1 produced in the circulation cleaning step is supplied to the water quality measuring device 2 through the second discharge pipe 4 . Furthermore, the flow rate of the ion-exchange treated water W1 discharged from the regenerative ion exchange device 1 toward the water quality measuring device 2 is set to 1 L/min or more, preferably 1.5 L/min.

In the water quality measuring device 2, with the second automatic valve 24 and the third automatic valve 25 opened and the first automatic valve 23 closed, the ion-exchange treated water W1 is passed through the second discharge pipe 4 to the ion concentration meter 22. The sodium ion (Na ⁺ ) concentration of the passed ion-exchange treated water W1 is measured using the sodium ion electrode of the ion concentration meter 22 (ion concentration measurement step). When the circulation cleaning step is insufficient, a large amount of sodium ions (Na ⁺ ) originating from the sodium hydroxide aqueous solution used for the regeneration treatment are contained in the ion-exchange treated water W1. Therefore, when the sodium ion (Na ⁺ ) concentration of the ion-exchange treated water W1 becomes below the preset threshold value, the automatic switching control mechanism determines that regeneration is better, ends the regeneration process, and switches to the water intake mode. Furthermore, the ion-exchange treated water W1 whose ion concentration has been measured passes through the second wastewater discharge pipe 27 and is discharged outside the system.

In the ion concentration measurement step, when the sodium ion (Na ⁺ ) concentration of the ion-exchange treated water W1 exceeds a preset threshold value, the cycle cleaning step only needs to be continued.

Furthermore, the automatic switching control mechanism may be configured based on the measured value of the resistivity of the ion-exchange treated water W1 obtained by the resistivity meter 21 and the ion-exchange treated water W1 obtained by the sodium ion electrode of the ion concentration meter 22 The measured value of the sodium ion (Na ⁺ ) concentration is used to determine whether the regeneration is appropriate.

In this way, by using the automatic switching control mechanism to alternately repeat the water intake mode and the regeneration mode, it is possible to measure the water quality based on the measured value obtained by the water quality measuring device 2, especially the sodium ion (Na ⁺ ) concentration of the ion-exchange treated water W1. It is judged whether the regeneration of the ion exchange resin layer 12 is appropriate or not, and the ion exchange treated water W1 judged to be better regenerated is supplied to the subsequent subsystem. Therefore, the sodium ions (Na) of the ultrapure water (subsystem treated water) can be ⁺ ) concentration is maintained low to the desired value to stabilize it.

[Second Embodiment]

FIG. 2 is a schematic system diagram showing the water quality management system 10' according to the second embodiment of the present invention. The water quality management system 10' in FIG. 2 includes three regenerative ion exchange devices 1 (first example) arranged in parallel, and two water quality measuring devices 2 arranged in parallel, and is configured from three regenerative ion exchange devices 1 Each discharged treated water can be supplied to each of the two water quality measuring devices 2 . In addition, the illustration of each series of regenerative ion exchange devices 1 (1A, 1B, 1C) is omitted in FIG. 2 . In addition, in FIG. 2 and the following description, the same reference numerals are used for devices having the same configuration or the same functions as those in the first embodiment, and detailed descriptions thereof are omitted.

In this embodiment, as the water quality measuring device 2, two first water quality measuring devices 2A and 2B are arranged in parallel, and as the regenerative ion exchange device 1, three first regenerative ion exchange devices 1A are arranged in parallel. With the second regenerative ion exchange device 1B and the third regenerative ion exchange device 1C. The second discharge pipe 4 of the first regenerative ion exchange device 1A branches into a first branch pipe 4a and a second branch pipe 4b. The first branch pipe 4a is connected to the first water quality measuring device 2A via the automatic valve 5a, and the second branch pipe 4b is connected to the second water quality measuring device 2B via the automatic valve 5b.

The second discharge pipe 4 of the second regenerative ion exchange device 1B branches into a first branch pipe 4c and a second branch pipe 4d. The first branch pipe 4c merges with the first branch pipe 4a via the automatic valve 5c, and the second branch pipe 4d merges with the second branch pipe 4b via the automatic valve 5d. The second discharge pipe 4 of the third regenerative ion exchange device 1C branches into a first branch pipe 4e and a second branch pipe 4f. The first branch pipe 4e joins the first branch pipe 4a through the automatic valve 5e on the downstream side of the meeting point of the first branch pipe 4a and the first branch pipe 4c, and the second branch pipe 4f joins the second branch pipe 4b through the automatic valve 5f. The further downstream side of the merging point of the branch pipe 4d merges with the second branch pipe 4b.

[How to operate the water quality management system]

Next, the operation method of the water quality management system 10' of the second embodiment will be described. In addition, in the following description, the first series using the first regenerative ion exchange device 1A and the second series using the second regenerative ion exchange device 1B are taken as the water intake mode, and the third series using the third regenerative ion exchange device 1C is used as the water intake mode. The case where the 3rd series is in regeneration mode will be explained as an example.

(Series 1 - Water Dispensing Mode)

The first series is in a state in which the ion-exchange treated water W1 discharged from the first regenerative ion exchange device 1A after the ion exchange step passes through the first discharge pipe 3 and is supplied to the subsequent subsystem, and simultaneously passes through the second discharge pipe 4 and The first branch pipe 4a passes water to the first water quality measuring device 2A. Furthermore, in the first water quality measuring device 2A, the resistivity of the ion-exchange treated water W1 is measured using the resistivity meter 21 (resistivity measurement step). The ion-exchange treated water W1 after the resistivity measurement is discharged to the outside of the system through the first wastewater discharge pipe 26 . When the measured resistivity exceeds a preset threshold value, an automatic switching control mechanism is used to switch to the regeneration mode.

(Series 2 - Regeneration Mode)

The second series is in a state in which the sodium hydroxide aqueous solution is supplied from the first chemical solution supply pipe 7 to the regenerative ion exchange tower 11 of the second regenerative ion exchange device 1B after the backwash step, and the second chemical solution is supplied from The supply pipe 8 supplies hydrochloric acid (regeneration treatment step). In addition, the regenerated sodium hydroxide aqueous solution and hydrochloric acid wastewater in the second regenerative ion exchange device 1B are discharged from the regenerated wastewater discharge pipe 9 .

(Series 3 - Regeneration Mode)

The third series is in a state in which the ion-exchange treated water W1 discharged from the third regenerative ion exchange device 1C after the circulation step is discharged through the first discharge pipe 3 and simultaneously passes through the second discharge pipe 4 and the second branch pipe 4f. water to the second water quality measuring device 2B. Furthermore, in the second water quality measuring device 2B, the ion concentration of the ion-exchange treated water W1 is measured using the ion concentration meter 22 (ion concentration measurement step). At this time, the first water quality measuring device 2A is used to measure the resistivity of the ion-exchange treated water W1 of the first regenerative ion exchange device 1A. Therefore, the ion-exchange treated water W1 discharged from the third regenerative ion exchange device 1C can be used. The automatic valve 5e is automatically controlled so that water is not passed to the first branch pipe 4e but is passed to the second branch pipe 4f. Therefore, the unused second water quality measuring device 2B can be selected to measure the sodium ions (Na ⁺ ) concentration determination.

In this way, even when three regenerative ion exchange devices 1 are installed in parallel, one water quality management system 10' can be used to select a specific regenerative ion exchange device 1 at the necessary timing to measure the water quality. Compared with the case where the water quality measuring device 2 is provided for each regenerative ion exchange device 1 (1A, 1B, 1C), the quality of the treated water can be easily managed and the treated water with suppressed ion concentration can stably flow into the subsequent subsystem.

[Other examples of regenerative ion exchange devices]

Next, the regenerative ion exchange device 1 of the second to sixth examples shown in FIGS. 3 to 7 will be described respectively. In the following example, when the regenerative ion exchange device 1 includes a plurality of regenerative ion exchange towers 11, the ion exchange treated water W1 discharged from the regenerative ion exchange tower 11 at the last stage of the regenerative ion exchange device 1 is , the water quality (resistivity, sodium ion (Na ⁺ ) concentration) may be measured based on the first embodiment or the second embodiment. That is, it may be configured such that the second discharge pipe 4 of the regenerative ion exchange tower 11 at the last stage of the regenerative ion exchange device 1 is connected to the water quality measuring device 2 . At this time, the water quality measuring device 2 is preferably installed in front of the automatic valve 5 . In addition, in FIGS. 3 to 7 and the following description, the same reference numerals are used for devices having the same configuration or the same function, and detailed descriptions thereof are omitted.

(Second example of regenerative ion exchange device)

The regenerative ion exchange device 1 shown in FIG. 3 includes a separate regenerative ion exchange tower 11 . In this embodiment, the water flow mode of the regenerative ion exchange tower 11 is an upward flow, and an anion exchange resin layer 12A and a cation exchange resin are formed separately from the upper side in the cylindrical exchange tower body 111. Layer 12B of the two-layer ion exchange tower. A supply pipe 6 for pre-processed water W for ion-exchange treatment is connected to the lower part of the exchange tower body 111, and on the other hand, a first discharge pipe 3 for ion-exchange treated water W1 is connected to the upper part. The second discharge pipe 4 is branch-connected via the automatic valve 5 . Furthermore, a first chemical solution supply pipe 7 for supplying an alkali NaOH solution as a regeneration chemical solution is connected to the first discharge pipe 3 on the upstream side of the automatic valve 5, and a discharge pipe for discharging is connected to the side of the exchange tower body 111. The first regeneration wastewater discharge pipe 91 for NaOH regeneration wastewater. On the other hand, a second chemical liquid supply pipe 8 for supplying hydrochloric acid (HCl) as the acid of the regeneration chemical liquid is connected to the side of the exchange tower body 111, and a second chemical liquid supply pipe 8 for discharging the hydrochloric acid regeneration wastewater is connected to the supply pipe 6. Regenerate wastewater discharge pipe 92. In the first discharge pipe 3, the second discharge pipe 4, the supply pipe 6, the first chemical liquid supply pipe 7, the second chemical liquid supply pipe 8, the first regeneration waste water discharge pipe 91 and the second regeneration waste water discharge pipe 92 There are on-off valves (not shown) respectively. In addition, in FIG. 3 , 71 is a heater (plate heat exchanger) provided in the first chemical solution supply pipe 7 , and 13A is an anion exchange resin having a plurality of smaller holes than the anion exchange resin constituting the anion exchange resin layer 12A. shielding board.

(Regenerative ion exchange device of the third example)

The regenerative ion exchange device 1 shown in Figure 4 includes a separate regenerative ion The appearance of the exchange tower 11. In this embodiment, the water flow mode of the regenerative ion exchange tower 11 is an upward flow, and a cation exchange resin layer 12B and an anion exchange resin are formed separately from the upper side in the cylindrical exchange tower body 111. Two-layer ion exchange tower with layer 12A. A supply pipe 6 for pre-processed water W for ion-exchange treatment is connected to the lower part of the exchange tower body 111, and on the other hand, a first discharge pipe 3 for ion-exchange treated water W1 is connected to the upper part. The second discharge pipe 4 is connected via the automatic valve 5 . Furthermore, a second chemical solution supply pipe 8 for supplying hydrochloric acid (HCl) as an acid of the regeneration chemical solution is communicated with the first discharge pipe 3 on the upstream side of the automatic valve 5, and is useful for being connected to the side of the exchange tower body 111. The second regeneration wastewater discharge pipe 92 discharges the hydrochloric acid regeneration wastewater. In addition, a first chemical solution supply pipe 7 for supplying an alkali NaOH solution as a regeneration chemical solution is connected to the side of the exchange tower body 111, and a first regeneration wastewater discharge pipe for discharging NaOH regeneration wastewater is connected to the supply pipe 6. 91. In the first discharge pipe 3, the second discharge pipe 4, the supply pipe 6, the first chemical liquid supply pipe 7, the second chemical liquid supply pipe 8, the first regeneration waste water discharge pipe 91 and the second regeneration waste water discharge pipe 92 There are on-off valves (not shown) respectively. In addition, in Fig. 4, 71 is a heater (plate heat exchanger) provided in the first chemical solution supply pipe 7, and 13B is a cation exchange resin having a plurality of smaller holes than the cation exchange resin constituting the cation exchange resin layer 12B. shielding board.

(Regenerative ion exchange device of the fourth example)

The regenerative ion exchange device 1 shown in FIG. 5 is a so-called two-bed, three-tower type ion exchange device, and includes a two-layer regenerative cation exchange resin tower (H tower) 11B, a degassing device 20, and two Layered regenerative anion exchange resin tower (OH Tower) 11A appearance. A supply pipe 6 for pretreated water W subjected to ion exchange treatment is connected to the lower side of the H tower 11B. On the other hand, a first discharge pipe 3 for the ion exchange treated water W1 is connected to the upper side of the OH tower 11A. The discharge pipe 3 is connected to the second discharge pipe 4 via the automatic valve 5 . Furthermore, the second chemical solution supply pipe 8 for supplying hydrochloric acid (HCl) as the acid of the regeneration chemical solution is connected to the upper side of the H tower 11B, and is connected to the supply pipe 6 of the pretreated water W on the lower side of the H tower 11B. There is a second regeneration wastewater discharge pipe 92 for discharging hydrochloric acid regeneration wastewater. Furthermore, a first chemical solution supply pipe 7 for supplying an alkali NaOH solution as a regeneration chemical solution is connected to the first discharge pipe 3 on the upper side (discharge side) of the OH tower 11A on the upstream side of the automatic valve 5. A first regeneration wastewater discharge pipe 91 for discharging NaOH regeneration wastewater is connected to the lower side (supply side) of the tower 11A. In addition, in FIG. 5 , 71 is a heater (plate heat exchanger) provided in the first chemical solution supply pipe 7 , and 30 is for supplying the treated water processed by the degassing device 20 to the OH tower 11A. of pump. The specifications of the degassing device 20 and the pump 30 provided at the rear stage of the degassing device 20 are not particularly limited. The same applies to the fifth and sixth examples below.

In this 2-bed, 3-tower ion exchange device, the ion exchange resin layer 12 filled in the H tower 11B has a two-layer structure of a weak cation exchange resin layer 12b and a strong cation exchange resin layer 12b', and the ion exchange resin layer 12 filled in the OH tower 11A The exchange resin layer 12 has a two-layer structure of a weak anion exchange resin layer 12a and a strong anion exchange resin layer 12a'. Furthermore, a plurality of relatively anion exchange resins and cation exchange resins are respectively provided between the weak cation exchange resin layer 12b and the strong cation exchange resin layer 12b', the weak anion exchange resin layer 12a and the strong anion exchange resin layer 12a'. smaller holes Shielding plate (not shown).

(Regenerative ion exchange device of the fifth example)

The regenerative ion exchange device 1 shown in FIG. 6 is a so-called 3-bed, 4-tower type ion exchange device, and includes a two-layer first regenerative cation exchange resin tower (H1 tower) 11B, a degassing device 20, A two-layer type regenerative anion exchange resin tower (OH tower) 11A, and a single-layer type second regenerative cation exchange resin tower (H2 tower) 11B'. A supply pipe 6 for pre-processed water W subjected to ion exchange treatment is connected to the lower side of the H1 tower 11B. On the other hand, a first discharge pipe 3 for the ion-exchange treated water W1 is connected to the lower side of the H2 tower 11B'. The second discharge pipe 4 is connected to the first discharge pipe 3 via an automatic valve 5 . Furthermore, a second chemical solution supply pipe 8 for supplying hydrochloric acid (HCl) as an acid for the regeneration chemical solution is connected to the upper side of the H2 tower 11B', and a second chemical solution supply pipe 8 is connected to the first discharge pipe 3 on the upstream side of the automatic valve 5. The second regeneration wastewater discharge pipe 92 discharges the hydrochloric acid regeneration wastewater. The second regeneration wastewater discharge pipe 92 is connected to the upper side (discharge side) of the H1 tower 11B, and a waste pipe 94 for hydrochloric acid regeneration wastewater is connected to the supply pipe 6 on the lower side (supply side) of the H1 tower 11B. Furthermore, a first chemical solution supply pipe 7 for supplying a NaOH solution as an alkali is connected to the upper side (discharge side) of the OH tower 11A, and a third chemical liquid supply pipe 7 for discharging NaOH regeneration wastewater is connected to the lower side (supply side) of the OH tower 11A. 1. Regeneration wastewater discharge pipe 91. Furthermore, 71 is a heater (plate heat exchanger) provided in the first chemical solution supply pipe 7, and 30 is a pump for supplying the treated water processed by the degassing device 20 to the OH tower 11A.

In this 3-bed 4-tower ion exchange device, the ion exchange resin layer 12 filled in the H1 tower 11B is a weak cation exchange resin layer 12b and a strong cation exchange tree. The two-layer structure of the lipid layer 12b' and the ion exchange resin layer 12 filled in the OH tower 11A is a two-layer structure of a weak anion exchange resin layer 12a and a strong anion exchange resin layer 12a'. Furthermore, a plurality of relatively anion exchange resins and cation exchange resins are respectively provided between the weak cation exchange resin layer 12b and the strong cation exchange resin layer 12b', the weak anion exchange resin layer 12a and the strong anion exchange resin layer 12a'. A shielding plate with smaller holes (not shown).

(Regenerative ion exchange device of the sixth example)

The regenerative ion exchange device 1 shown in FIG. 7 is a so-called 4-bed, 5-tower ion exchange device, and basically includes the regenerative cation exchange resin in the 3-bed, 4-tower ion exchange device 1 of the fifth example. The rear stage of the tower (H2 tower) 11B' is further provided with a single-layer type second regenerative anion exchange resin tower (OH2 tower) 11A'. The first discharge pipe 3 of the ion-exchange treated water W1 is connected to the lower side of the OH2 tower 11A', and the second discharge pipe 4 is connected to the first discharge pipe 3 via the automatic valve 5 . Furthermore, a first chemical solution supply pipe 7 for supplying a NaOH solution as an alkali is connected to the upper side of the OH2 tower 11A', and a first discharge pipe 3 on the lower side is connected to the downstream side of the automatic valve 5 for discharging NaOH for regeneration. The first regeneration wastewater discharge pipe 91 of wastewater. The first regenerated wastewater discharge pipe 91 serves as a NaOH solution supply pipe and is connected to the upper side (discharge side) of the first regenerative anion exchange resin tower (OH1 tower) 11A, and NaOH regeneration is connected to the lower side (supply side) of the OH1 tower 11A. Wastewater disposal pipe 93.

As mentioned above, the present invention has been described with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments and can be modified in various ways. For example, the number of regenerative ion exchange devices 1 installed in parallel is different from the number of water quality measuring devices 2 installed in parallel. The ratio of the number of water quality measuring devices 2 is not limited to 3 to 2 as long as the number of water quality measuring devices 2 is equal to or smaller than the number of regenerative ion exchange devices 1 . In addition, a known water treatment element such as a reverse osmosis membrane separation device may be installed in the front stage of the regenerative ion exchange device 1 . Furthermore, in the above-described embodiment, switching to the regeneration mode is performed when the resistivity of the ion-exchange treated water W1 obtained by the resistivity meter 21 exceeds a preset threshold value. However, the regeneration mode may be switched to the predetermined volume. The ion-exchange treated water W1 is operated so as to switch to the regeneration mode, and the timing of switching to the regeneration mode can also be measured externally with a resistivity meter.

[Example]

Hereinafter, the present invention will be described in further detail based on Examples, but the present invention is not limited to the following Examples.

[Example]

Two stages of the regenerative ion exchange device 1 of the first example shown in Figure 1 are arranged in parallel, and the water quality management system 10' shown in Figure 2 is used to sequentially perform four switching operations between the regeneration mode and the water intake mode. Normally, the first series (the first regenerative ion exchange device 1A) is in the water intake mode, and the second series (the second regenerative ion exchange device 1B) is in the regeneration mode and standby.

In both the first water quality measuring device 1A and the second water quality measuring device 1B, MX-3 (manufactured by Kurita Industrial Co., Ltd.) is used as the resistivity meter 21, and swan AMI Soditrace (manufactured by T&C Technical Co., Ltd.) is used as the resistivity meter using sodium ions. Electrode ion concentration meter 22.

As the ion exchange resin filled in the ion exchange tower 11, use Porous type PK228L (manufactured by Mitsubishi Chemical Corporation) is a cation exchange resin, and porous PA312L (manufactured by Mitsubishi Chemical Corporation) is an anion exchange resin.

(Series 1)

First, the first regenerative ion exchange device 1A that takes in water at a space velocity (Space Velocity, SV) of 40 h ^-1 with respect to the ion exchange resin filled with a mixture of cation exchange resin and anion exchange resin at a volume ratio of 1:2 is used. The ion-exchange treated water W1 before regeneration is passed to the first water quality measuring device 2A, and the resistivity and sodium ion (Na ⁺ ) concentration in the ion-exchange treated water W1 are measured.

Next, the operation mode of the first regenerative ion exchange device 1A is switched from the water intake mode to the regeneration mode, and the regeneration operation of filling the ion exchange resin layer 12 of the regenerative ion exchange tower 11 is performed. The detailed steps of the regeneration operation are as follows.

Initially, with the water flow to the first water quality measuring device 2A stopped, the ion exchange resin layer 12 filled in the regenerative ion exchange tower 11 is backwashed with the ion exchange treated water W1 to separate the cation exchange resin and anions. Exchange resin separation (backwash step).

Next, while the water flow to the first water quality measuring device 2A is stopped, an aqueous solution of industrial hydrochloric acid (HCl) adjusted to 5% is used as a regeneration solution to regenerate the separated cation exchange resin, and at the same time, the separated cation exchange resin is regenerated. The water heated to 40° C. by the heater 71 was adjusted to a 4% industrial sodium hydroxide (NaOH) aqueous solution as a regeneration solution to regenerate the separated anion exchange resin (regeneration treatment step).

Next, in a state where the water flow to the first water quality measuring device 2A is stopped, the ion-exchange treated water W1 is supplied in a downward flow to the regeneration chemical liquid. Each of the regenerated cation exchange resin and the anion exchange resin is extruded through one-pass extrusion (extrusion step).

Furthermore, in a state where the water flow to the first water quality measuring device 2A is stopped, the pretreatment water W is supplied to the regeneration type ion exchange tower 11 in a downward flow manner, whereby the cation exchange resin after extruding the regeneration chemical solution is Mix it with anion exchange resin, and use pre-treatment water W to circulate and clean the mixed ion exchange resin (circulation cleaning step).

At the same time, the circulated treated water of the first regenerative ion exchange device 1A is passed to the first water quality measuring device 2A, and the resistivity and sodium ion (Na ⁺ ) concentration of the circulated treated water are measured. The resistivity becomes 18.0MΩ. cm or more and when the sodium ion (Na ⁺ ) concentration becomes 300 ng/L or less, water flow to the first water quality measuring device 2A is stopped, and the regeneration process is completed.

The operation mode of the first regenerative ion exchange device 1A is switched from the regeneration mode to the water intake mode, and the intake of the ion exchange treated water W1 filled into the ion exchange resin layer 12 of the regenerative ion exchange tower 11 is started, and at the same time, the ion exchange treated water is W1 passes water to the first water quality measuring device 2A to measure resistivity and sodium ion (Na ⁺ ) concentration.

(Series 2)

Regarding the second regenerative ion exchange device 1B that takes in water, the resistivity and sodium ion (Na ⁺ ) concentration of the ion-exchange treated water W1 before the regeneration process is measured using the second water quality measuring device 2B. The operation mode of the second regenerative ion exchange device 1B is switched from the water intake mode to the regeneration mode, and filling of the ion exchange resin layer 12 of the regenerative ion exchange tower 11 is performed in the same manner as in the case of the first regenerative ion exchange device 1A. Regeneration processing.

In addition, in the water intake mode of each regenerative ion exchange device (1A, 1B), ICP-MS (manufactured by Agilent Technologies, 7500cs) was used to analyze the non-regenerative ion exchange in the subsystem installed at the back end. Sodium ion (Na ⁺ ) concentration of the treated water discharged from the device (capacity; cation exchange resin/anion exchange resin = 1/1.6, SV; 80 ^-h ).

[Comparative example]

Similar to the above embodiment, two sections of the regenerative ion exchange device 1 of the first example shown in Figure 1 are arranged side by side, and the water quality management system 10' shown in Figure 2 is used to sequentially perform four regeneration modes and water intake modes. Switch operation. Normally, the first series (the first regenerative ion exchange device 1A) is in the water intake mode, and the second series (the second regenerative ion exchange device 1B) is in the regeneration mode and standby.

The cation exchange resin separated by the backwash step was regenerated using a 5% by-product hydrochloric acid (HCl) aqueous solution as a regeneration chemical.

In addition, in the water intake mode of each regenerative ion exchange device (1A, 1B), ICP-MS (manufactured by Agilent Technologies, 7500cs) was used to analyze the non-regenerative ion exchange in the subsystem installed at the back end. Sodium ion (Na ⁺ ) concentration of the treated water discharged from the device (capacity; cation exchange resin/anion exchange resin = 1/1.6, SV; 80 ^-h ).

Furthermore, the resistivity of the ion-exchange treated water W1 of each regenerative ion exchange device (1A, 1B) in the water intake is 18.0 MΩ. cm below and the sodium ion (Na ⁺ ) concentration exceeds 500ng/L, repeat the regeneration process twice.

The resistivity and sodium ion (Na ⁺ ) concentration of the ion-exchange treated water W1 12 hours after the start of water intake in the first regenerative ion exchange device 1A (indicated by A in the table. The same applies below), and the second regeneration Table 1 shows a comparison between the resistivity of the ion-exchange treated water W1 and the sodium ion (Na ⁺ ) concentration (indicated by B in the table. The same applies below) 12 hours after the start of water intake in the ion exchange device 1B. It can be seen that by using the water quality management system 10' to manage the sodium ion (Na + ) concentration in the ion-exchange treated water W1 during regeneration and water intake, the sodium ions (Na ⁺ ) in the ion-exchange treated water W1 during water intake can be reduced to ⁺ ) concentration is controlled below 300ng/L.

Comparison of the sodium ion (Na ⁺ ) concentration of the treated water discharged from the non-regenerative ion exchanger of the subsequent subsystem when water is taken from the first regenerative ion exchanger 1A and the second regenerative ion exchanger 1B Shown in Table 2. Furthermore, it can be seen that by using the water quality management system 10' to manage the sodium ion (Na + ) concentration in the ion-exchange treated water W1 during regeneration and water intake of each regenerative ion exchange device (1A, 1B), it is possible to control the sodium ion (Na ⁺ ) concentration from the subsequent stage. Short-term changes in the sodium ion (Na ⁺ ) concentration in the treated water discharged from the non-regenerative ion exchange device.

As described above, it can be seen that not only the resistivity but also the sodium ion (Na ⁺ ) concentration is measured for the quality of the ion-exchange treated water W1 during regeneration and water extraction of the regenerative ion exchange device 1, and the ions are managed based on these measured values. Whether the regeneration of the exchange resin layer 12 is appropriate can be appropriately switched between the regeneration mode and the water intake mode, and the sodium ions (Na ^{+ )} in the treated water discharged from the non-regenerative ion exchange device of the subsequent subsystem can be controlled. ) short-term changes in concentration.

1‧‧‧Regenerative ion exchange device

2‧‧‧Water quality measuring device

3‧‧‧1st discharge pipe

4‧‧‧Second discharge pipe

5‧‧‧Automatic valve

6‧‧‧Supply pipe

7‧‧‧No.1 chemical liquid supply pipe

8‧‧‧Second chemical liquid supply pipe

9‧‧‧Regeneration wastewater discharge pipe

10‧‧‧Water quality management system

11‧‧‧Regenerative ion exchange tower

12‧‧‧Ion exchange resin layer

21‧‧‧Resistivity meter

22‧‧‧Ion concentration meter

23‧‧‧No. 1 automatic valve

24‧‧‧Second automatic valve

25‧‧‧3rd automatic valve

26‧‧‧No.1 wastewater discharge pipe

27‧‧‧Second wastewater discharge pipe

71‧‧‧Heater (plate heat exchanger)

111‧‧‧Exchange tower body

W‧‧‧Pre-treatment water

W1‧‧‧Ion exchange treated water

Claims (4)

A water quality management system, which includes: a regenerative ion exchange device; a water quality measuring device having a resistivity meter and an ion concentration meter; a first discharge pipe for circulating treated water discharged from the regenerative ion exchange device; a second discharge pipe a pipe branched from the first discharge pipe and supplying the treated water to the water quality measuring device; and an automatic switching control mechanism that automatically switches an operation mode, the operation mode including performing a step on the treated water. The automatic switching control mechanism is performed in correspondence with the measured value of the resistivity meter and the measured value of the ion concentration meter between the water intake mode and the regeneration mode for regenerating the regenerative ion exchange device. Automatic switching control of the operation mode. The water quality management system as described in claim 1 of the patent application, wherein when the regenerative ion exchange device has a plurality of regenerative ion exchange towers, the regenerative ion exchange tower from the last stage of the regenerative ion exchange device is The effluent water flowing out of the ion exchange tower is set as the treated water. The water quality management system described in Item 1 or Item 2 of the patent application includes: N of the regenerative ion exchange devices arranged in parallel, where N is an integer greater than 2; and N or less of the water quality measuring devices are arranged in parallel, and the treated water discharged from each of the N regenerative ion exchange devices is configured to be supplied to each of the N or less water quality measuring devices. An operation method of a water quality management system, which is an operation method of a water quality management system. The water quality management system includes: a regenerative ion exchange device; a water quality measuring device having a resistivity meter and an ion concentration meter; a first discharge pipe for The treated water discharged from the regenerative ion exchange device circulates; the second discharge pipe is branched from the first discharge pipe and supplies the treated water to the water quality measuring device; and automatic switching of the operation mode is automatically switched. A control mechanism, the operation mode includes a water intake mode for fetching the treated water, and a regeneration mode for regenerating the regenerative ion exchange device, and the operation method of the water quality management system includes: utilizing the The step of measuring the resistivity of the treated water with the resistivity meter; the step of measuring the ion concentration of the treated water with the ion concentration meter; and the measured value based on the measured resistivity and the measured value. The step of automatically switching the operation mode of the automatic switching control mechanism based on the measured value of the ion concentration.

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