JP6337933B2 - Water quality management system and operation method of water quality management system - Google Patents

Description

  The present invention manages the quality of treated water discharged from a regenerative ion exchange apparatus used in a primary deionized water system of a regenerative ion exchange apparatus, in particular, an ultrapure water production apparatus used in the process of manufacturing electronic products and the like. The present invention relates to a water quality management system and a method for operating the system.

  The ultrapure water production apparatus is generally composed of a pretreatment system, a primary pure water system, and a secondary pure water system (subsystem). The pretreatment system includes agglomeration, pressurized flotation (precipitation), filtration (membrane filtration) devices, and the like, and removes suspended substances and colloidal substances in raw water. In the treatment process by the pretreatment system, high molecular organic substances, hydrophobic organic substances, and the like can be removed. The primary pure water system basically includes a reverse osmosis (RO) membrane separation device and a regenerative ion exchange device (such as a mixed bed type or a four-bed five-column type). In the RO membrane separation apparatus, salts are removed and ionic and colloidal TOC components are removed. In the regenerative ion exchange apparatus, salts are removed and the TOC component adsorbed or ion exchanged by the ion exchange resin is also removed.

The sub-system is basically equipped with a low-pressure ultraviolet (UV) oxidizer, a non-regenerative mixed-bed ion exchanger, and an ultrafiltration (UF) membrane separator, and ultrapure by further increasing the purity of primary pure water. Produce water. In the low-pressure UV oxidizer, the TOC component is decomposed into an organic acid and further to CO ₂ by 185 nm ultraviolet rays emitted from a low-pressure ultraviolet lamp. Organic substances and CO ₂ produced by the decomposition are removed by a non-regenerative mixed bed ion exchange apparatus 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 ultrapure water production apparatus as described above, the regenerative ion exchange apparatus used in the primary pure water system is composed of one tower or a plurality of towers including a deaeration device depending on the required water quality of the treated water, It is common to have a reverse osmosis (RO) membrane device upstream. A sub-system provided with a non-regenerative ion exchange device is provided at the subsequent stage of the regenerative ion exchange device.

Conventionally, in a regenerative ion exchange apparatus as described above, ions in water are removed electrochemically while repeating sampling and regeneration. Regeneration refers to an ion exchange resin such as anion exchange resin or cation exchange resin filled in the ion exchange device when hydrochloric acid (HCl) or sodium hydroxide is used when the ion exchange function of the ion exchange device is reduced. Regeneration by contacting with a regenerative chemical such as (NaOH). Since the ion concentration of treated water treated with an ion exchange device that mainly removes ions in the treated water is determined by the ion concentration of the treated water and the amount of treated water (space velocity and linear velocity), In the regenerative ion exchange apparatus as described above, a threshold is set for the resistivity (or electrical conductivity) of the treated water, and when this threshold is exceeded, the ion exchange resin is regenerated with the regenerative chemical. However, due to the regenerated chemicals remaining in the regenerated ion exchange resin, sodium ions (Na ⁺ ) or chloride ions (Cl ⁻ ) are present in the treated water at the time of sampling after removing the ions. End up.

Recently, in a non-regenerative ion exchange apparatus used in a subsystem, short-term fluctuations in sodium ion (Na ⁺ ) concentration and chloride ion (Cl ⁻ ) concentration in treated water have become apparent, and this non-regenerative ion exchange apparatus It has been found that when the treated water is used for cleaning semiconductor products, the yield of manufactured semiconductor products may be reduced.

Therefore, as a result of the study by the present inventor on the cause of fluctuations in the sodium ion (Na ⁺ ) concentration and chloride ion (Cl ⁻ ) concentration in the treated water discharged from the regenerative ion exchange apparatus as described above, the primary purity The sodium ion (Na ⁺ ) concentration and chloride ion (Cl ⁻ ) concentration of the treated water of the regenerative ion exchanger used in the water system are the quality of the treated water of the non-regenerative ion exchanger used in the subsequent subsystem. It has been found that this has an effect.

This invention is made | formed in view of the said subject, The sodium ion (Na ^<+> ) and chloride ion (Cl) in the treated water discharged | emitted from the regenerative ion exchange apparatus used for the primary pure water system of an ultrapure water manufacturing apparatus. ⁻ )) Can be stably reduced, so that the concentration of sodium ions (Na ⁺ ) and chloride ions (Cl ⁻ ) in the treated water discharged from the non-regenerative ion exchanger used in the subsystem at the later stage An object of the present invention is to provide a water quality management system capable of suppressing short-term fluctuations in concentration and a method for operating the water quality management system.

  In order to solve the above problems, firstly, the present invention provides a regenerative ion exchange device, a water quality measuring device having an ion concentration meter, and a first discharge that distributes treated water discharged from the regenerative ion exchange device. A water quality management system comprising a pipe and a second discharge pipe branched from the first discharge pipe and supplying the treated water to the water quality measuring device is provided (invention 1).

  According to this invention (Invention 1), not only the resistivity of the treated water discharged from the regenerative ion exchange device but also the ion concentration can be measured by the water quality measuring device, so that the ion exchange resin is regenerated based on this measured value. The ion concentration in the treated water can be stably reduced by managing the suitability of the process, so that the short-term fluctuation of the ion concentration in the treated water discharged from the non-regenerative ion exchanger used in the subsequent subsystem can be reduced. It becomes possible to suppress. In addition, the water quality measuring device is not provided on the first discharge pipe, but is connected to the second discharge pipe branched from the first discharge pipe via, for example, an automatic valve, thereby switching the automatic valve. By the operation, it is possible to easily measure the quality of the treated water at a timing as required.

  In the above invention (Invention 1), when the regenerative ion exchange apparatus has a plurality of regenerative ion exchange towers, the effluent water flowing out from the regenerative ion exchange tower at the last stage of the regenerative ion exchange apparatus is It is preferable to use treated water (Invention 2).

  When the regenerative ion exchange apparatus has a plurality of regenerative ion exchange towers, in order to reduce the ion concentration in the treated water flowing into the downstream subsystem, What is necessary is just to reduce ion concentration. According to this invention (Invention 2), the ion concentration (and low efficiency) is measured using the effluent of the last-stage regenerative ion exchange tower as treated water, and the appropriateness of regeneration of the ion exchange resin is determined based on this measured value. By managing it, the ion concentration in the treated water can be stably reduced, thereby suppressing short-term fluctuations in the ion concentration in the treated water discharged from the non-regenerative ion exchanger used in the subsequent subsystem. Is possible.

  In the said invention (invention 1 and 2), the automatic which switches the operation mode automatically including the sampling mode for sampling the said treated water, and the regeneration mode for regenerating | regenerating the said regenerative ion exchange apparatus It is preferable that switching control means is provided, and that the automatic switching control means performs automatic switching control of the operation mode according to the measurement value of the water quality measuring device (Invention 3).

  According to this invention (invention 3), the ion concentration (and low efficiency) of the treated water discharged from the regenerative ion exchange device is measured by the water quality measuring device, and according to this measured value, the regenerative ion exchange device Since the operation mode can be automatically switched to the water sampling mode or the regeneration mode, it is possible to appropriately manage the regeneration of the regenerative ion exchange device, and thus the ions in the treated water flowing into the subsystem at the subsequent stage can be managed. It is possible to control the concentration.

  In the said invention (invention 1-3), the said regenerative ion exchange apparatus provided in parallel with N pieces (N is an integer of 2 or more) and the water quality measuring apparatus provided in parallel with N pieces or less, It is preferable that each 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 (invention 4).

  Conventional ion concentration meters that measure the ion concentration cause variations in the measured value in a concentration range of several hundred ng / L level due to individual differences. Therefore, when a plurality of regenerative ion exchange devices are provided in parallel, if an ion concentration meter is provided to measure the ion concentration of treated water for each series, it takes time to calibrate and cross-check each ion concentration meter. However, there was a situation where the quality of the treated water could not be properly managed at the timing required. According to this invention (invention 4), even when N regenerative ion exchange devices are provided in parallel (N is an integer of 2 or more), one water quality management system at a timing as required. Since water quality can be measured by selecting a specific regenerative ion exchange device, the quality of treated water can be controlled compared to the case where an ion concentration meter (water quality measurement device) is provided for each regenerative ion exchange device. Is simple, and it becomes possible to stably flow the treated water with suppressed ion concentration into the subsystem at the subsequent stage. Moreover, since the water quality of a plurality of regenerative ion exchangers can be managed by one water quality management system, it is economical in that it is not necessary to provide an ion concentration meter (water quality measuring device) for each regenerative ion exchanger. Great effect. This effect is particularly remarkable when the number of water quality measuring devices is smaller than the number of regenerative ion exchange devices.

  Secondly, the present invention is an operation method of the water quality management system according to any one of the first to fourth aspects, wherein the ion concentration meter measures the ion concentration of the treated water, and the measurement is performed. An operation of a water quality management system comprising: a step of automatically switching between a water collection mode for collecting the treated water and a regeneration mode for regenerating the regenerative ion exchange device based on a measured value of ion concentration A method is provided (Invention 5).

  According to this invention (invention 5), not only the resistivity of the treated water discharged from the regenerative ion exchange apparatus but also the ion concentration can be measured. It is possible to switch to the playback mode. Therefore, even when the regenerative ion exchange apparatus has a plurality of regenerative ion exchange towers or a plurality of regenerative ion exchange towers are provided in parallel, the quality of the treated water can be appropriately managed. It is possible to suppress short-term fluctuations in the ion concentration in the treated water discharged from the non-regenerative ion exchange apparatus used for the process.

  According to the present invention, not only the resistivity of the treated water discharged from the regenerative ion exchange device but also the ion concentration can be measured by the water quality measuring device, so that the appropriateness of regeneration of the ion exchange resin is managed based on the measured value. By doing so, the ion concentration in the treated water can be stably reduced, and therefore, 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. It becomes possible. In addition, the water quality measuring device is not provided on the first discharge pipe, but is connected to the second discharge pipe branched from the first discharge pipe via the automatic valve, thereby switching the automatic valve. Therefore, it is possible to easily measure the quality of the treated water at a timing as required.

1 is a schematic system diagram showing a water quality management system according to a first embodiment of the present invention. In FIG. 1, the water quality management system is provided with a regenerative ion exchange device of the first example. It is a schematic system diagram which shows the water quality management system which concerns on 2nd embodiment of this invention. In FIG. 2, the display of the regenerative ion exchange apparatus of each series is omitted. It is a schematic system diagram which shows the 2nd example of the regenerative ion exchange apparatus with which the water quality management system of this invention is provided. It is a schematic system diagram which shows the 3rd example of the regenerative ion exchange apparatus with which the water quality management system of this invention is provided. It is a schematic system diagram which shows the 4th example of the regenerative ion exchange apparatus with which the water quality management system of this invention is provided. It is a schematic system diagram which shows the 5th example of the regenerative ion exchange apparatus with which the water quality management system of this invention is provided. It is a schematic system diagram which shows the 6th example of the regenerative ion exchange apparatus with which the water quality management system of this invention is equipped.

  Hereinafter, embodiments of a water quality management system of the present invention will be described with reference to the drawings as appropriate. The embodiment described below is for facilitating the understanding of the present invention, and does not limit the present invention.

[First embodiment]
FIG. 1 is a schematic system diagram showing a water quality management system 10 according to the first embodiment of the present invention. In FIG. 1, the water quality management system 10 includes a regenerative ion exchange device 1, a water quality measurement device 2 having a resistivity meter 21 and an ion concentration meter 22, and ion exchange treated water W <b> 1 discharged from the regenerative ion exchange device 1. And a second discharge pipe 4 for supplying the ion exchange treated water W1 to the water quality measuring device 2, and the second discharge pipe 4 is connected to the first discharge pipe 3 via the automatic valve 5. It is the structure branched from. In addition, the water quality management system 10 automatically switches between operation modes including a sampling mode for sampling the ion exchange treated water W1 and a regeneration mode for regenerating the regenerative ion exchange device 1. Control means (not shown) are provided. In the first embodiment, the regenerative ion exchange device 1 provided in the water quality management system 10 is a first example of the regenerative ion exchange device.

<Regenerative ion exchanger>
In this embodiment, the regenerative ion exchange tower 11 constituting the regenerative ion exchange apparatus 1 includes an ion exchange resin layer 12 made of a mixed resin of a cation exchange resin and an anion exchange resin in a cylindrical exchange tower body 111. It is arranged. A supply pipe 6 for supplying pretreated water W for performing ion exchange treatment is connected to the upper part of the exchange tower body 111, while a first discharge pipe 3 for discharging ion exchange treated water W1 is connected to the lower part. The second discharge pipe 4 is connected to the first discharge pipe 3 via an automatic valve 5. The first discharge pipe 3 is connected to a downstream subsystem (not shown). The pretreated water W is subjected to removal of ion components by the regenerative ion exchanger 1 and supplied to the subsystem through the first discharge pipe 3 as the 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 producing electronic products and the like.

  Connected to the supply pipe 6 is a first chemical liquid supply pipe 7 that supplies an aqueous solution of sodium hydroxide (NaOH) as an alkali that is a regenerated chemical liquid. A second chemical liquid supply pipe 8 for supplying hydrochloric acid (HCl) as an acid as a regenerated chemical liquid is connected to the first discharge pipe 3 upstream of the automatic valve 5. A regeneration waste water discharge pipe 9 for discharging waste water at the time of regeneration is connected to the side of the exchange tower main body 111. Each of 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 recycled wastewater discharge pipe 9 is provided with an open / close valve (not shown). . In the present embodiment, the first chemical liquid supply pipe 7 is provided with a heater (plate type heat exchanger) 71.

(Cation exchange resin)
In the regenerative ion exchange apparatus 1, the cation exchange resin constituting the ion exchange resin layer 12 is a strong acid cation exchange resin having a sulfone group as a cation exchange group or a weak acid cation exchange resin having a carboxylic acid group. Any of them can be used, and a gel-type resin is generally used in that PSA is hardly eluted. In the cation exchange resin, divinylbenzene serves as a cross-linking agent, and the chain structure is cross-linked to form a network-structured resin. Therefore, the more divinylbenzene, the more chain branches and the denser the structure. Thus, when the amount of divinylbenzene is small, a resin having a large network with few branches can be obtained. The resin used for normal water treatment has a degree of crosslinking of about 8% and is called a standard crosslinked resin. On the other hand, those having a crosslinking degree of 9% or more are called highly crosslinked resins. In the present embodiment, either a standard crosslinked resin or a highly crosslinked resin can be used, but a standard crosslinked resin can be suitably used.

(Anion exchange resin)
As the anion exchange resin constituting the ion exchange resin layer 12, a gel type resin is used in that the elution of PSA is small. A strongly basic anion exchange resin having a styrene skeleton based on a styrene-divinylbenzene copolymer or the like and a quaternary ammonium group such as a trimethylammonium group or a dimethylethanolammonium group, a styrene-divinylbenzene copolymer, etc. Any weakly basic anion exchange resin having a primary to tertiary amino group as a functional group can be used for the styrene skeleton or polyacrylate ester skeleton, but a strongly basic anion exchange resin can be suitably used. The exchange group of the anion exchange resin is preferably 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 such that the ratio of the cation exchange resin to the anion exchange resin is 30:70 to 70:30, particularly 30. : It is preferable to mix a lot of anion exchange resins with 70-50: 50. In addition, if the physical property of the ion exchange resin which comprises the ion exchange resin layer 12 is granular, there will be no restriction | limiting in particular.

(Regenerative ion exchange tower)
The material of the regenerative ion exchange column 11 is not particularly limited as long as it is resistant to the regenerative chemicals of the ion exchange resin.

<Water quality measuring device>
In the present embodiment, the water quality measuring device 2 includes 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 in a pipe between the resistivity meter 21 and the ion concentration meter 22. A pipe between the resistivity meter 21 and the second automatic valve 24 is provided with a first wastewater discharge pipe 26 for discharging the wastewater after the resistivity measurement by the resistivity meter 21 to the outside of the system. Branching through 23 is provided. A second wastewater discharge pipe 27 for discharging wastewater discharged from the water quality measuring device 2 to the outside of the system is provided via the third automatic valve 25 on the downstream side of the ion concentration meter 22.

(Resistivity meter)
The resistivity meter 21 constituting the water quality measuring device 2 measures the resistivity of the ion exchange treated water W1. The kind of resistivity meter 21 is not specifically limited, For example, you may measure the resistivity of the ion exchange treated water W1 with a commercially available electrical resistivity meter. The material of the measurement cell of the resistivity meter 21 is not particularly limited as long as the ion concentration of the measurement target does not elute more than 20 ng / L when pure water is passed at 1 L / min.

(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. Although the kind of ion concentration meter 22 is not specifically limited, In this embodiment, the ion concentration of the ion exchange treated water W1 is measured by a sodium ion electrode. The material of the measurement cell of the ion concentration meter 22 is not particularly limited as long as the ion concentration of the measurement target does not elute more than 20 ng / L when pure water is passed at 1 L / min.

<Automatic switching control means>
The automatic switching control means performs switching control of the operation mode according to the measurement value of the water quality measuring device 2. Specifically, in the water sampling mode, the resistivity of the ion exchange treated water W1 is measured by the resistivity meter 21, and when this measured value exceeds a threshold value preset in the resistivity meter 21, the ion exchange resin layer. Therefore, it is determined that the ion exchange capacity has decreased, and the regeneration mode is switched. And at the time of regeneration mode, the sodium ion (Na ⁺ ) density | concentration contained in the ion exchange treated water W1 is measured with the ion concentration meter 22, When this measured value becomes below the threshold value preset to the ion concentration meter 22, It is determined that the regeneration is suitable, the regeneration process is terminated, and switching to the water sampling mode is performed.

(Recycled chemicals)
In the present embodiment, sodium hydroxide (NaOH) and hydrochloric acid (HCl) are used as chemicals used for regeneration of the ion exchange resin filled in the exchange column main body 111 of the regenerative ion exchange column 11. As long as it can regenerate without significantly reducing the performance of the ion exchange resin, it is not limited to these.

(Pretreatment water)
The quality of the pretreated water W is not particularly limited since the raw water treatment method differs depending on the required quality of ultrapure water used in the process of manufacturing electronic products and the like. Moreover, there is no restriction | limiting in particular also about the raw water of the pre-treatment water W.

(Plumbing)
The material of the piping such as the first discharge pipe 3 used in the water quality management system 10 is particularly limited as long as the ion concentration of the measurement target does not elute more than 20 ng / L when pure water is passed at 1 L / min. Not.

(Automatic valve)
The specification of the automatic valve used in the water quality management system 10 is not particularly limited as long as the ion concentration of the measurement target does not elute 20 ng / L or more when pure water is passed at 1 L / min.

[Operation method of water quality management system]
Next, an operation method of the water quality management system 10 of the first embodiment will be described. In the following, the “water sampling mode” means an operation method at the time of sampling the ion exchange treated water W1 discharged from the regenerative ion exchange device 1, and the “regeneration mode” means the regenerative ion exchange device 1. The operation method at the time of regeneration of the ion exchange resin layer 12 is meant.

<Water sampling mode>
In the water sampling mode, the supply pipe 6 and the first discharge pipe 3 are opened, the first chemical liquid supply pipe 7, the second chemical liquid supply pipe 8 and the recycled wastewater discharge pipe 9 are closed, and then in the first discharge pipe 3, In a state where water can be passed through the second discharge pipe 4 by the automatic valve 5, the pretreated water W is supplied from the supply pipe 6 to the regenerative ion exchange column 11 in a downward flow. In the ion-exchange resin layer 12 which is a mixed resin filled in the regenerative ion exchange tower 11, the cationic component and the anionic component are removed from the supplied pretreated water W (ion exchange step). The pretreated water W from which the ionic components have been removed is supplied as ion exchange treated water W1 to the downstream subsystem via the first discharge pipe 3 and simultaneously to the water quality measuring device 2 via the second discharge pipe 4. The In addition, the water flow conditions at this time can be set to the same level as the treatment by normal ion exchange, and the space velocity is 5 to 100 h-1, particularly 5 to 5 with respect to the volume of the ion exchange resin of the ion exchange resin layer 12. It may be 50h-1.

  In the water quality measuring device 2, the ion exchange treated water W <b> 1 is passed from the second discharge pipe 4 to the resistivity meter 21 with the first automatic valve 23 opened and the second automatic valve 24 closed. The resistivity is measured by the resistivity meter 21 with respect to the ion exchange treated water W1 that has been passed through (resistivity measurement step). The ion exchange treated water W1 after the resistivity measurement is discharged out of the system through the first wastewater discharge pipe 26. The automatic switching control means determines that the ion exchange capacity of the ion exchange resin layer 12 has decreased when the resistivity of the ion exchange treated water W1 exceeds a preset threshold value, and switches to the regeneration mode. The flow rate of the ion exchange treated water W1 discharged from the regenerative ion exchange device 1 to the water quality measurement device 2 is preferably 1 L / min or more, and more preferably 1.5 L / min.

<Playback mode>
In the regeneration mode, first, the ion exchange treated water W1 is supplied from the first discharge pipe 3 to the regenerative ion exchange tower 11 in an upward flow and discharged from the supply pipe 6 to form the ion exchange resin layer 12. The mixed resin is backwashed (backwashing step). By this backwashing step, the anion exchange resin is separated on the upper side of the exchange tower body 111 and the cation exchange resin is separated on the lower side of the exchange tower body 111 due to a slight difference in specific gravity between the anion exchange resin and the cation exchange resin.

  Next, with the first chemical solution supply pipe 7, the second chemical solution supply pipe 8 and the regeneration waste water discharge pipe 9 opened, a regenerative ion exchange column 11 is flowed downward with a sodium hydroxide aqueous solution from the first chemical solution supply pipe 7. In addition, hydrochloric acid is supplied from the second chemical solution supply pipe 8 in an upward flow to the regenerative ion exchange column 11 (regeneration process step). Thereby, the anion exchange resin unevenly distributed on the upper side of the exchange tower main body 111 is regenerated, and the cation exchange resin unevenly distributed on the lower side of the exchange tower main body 111 is regenerated. At this time, in order to efficiently regenerate the anion exchange resin, the aqueous sodium hydroxide solution is preferably heated to about 30 to 50 ° C. by the heater 71 provided in the first chemical solution supply pipe 7. The recycled sodium hydroxide aqueous solution and hydrochloric acid wastewater are discharged from the recycled wastewater discharge pipe 9.

  Subsequently, the supply pipe 6 and the first discharge pipe 3 are opened, the first chemical liquid supply pipe 7, the second chemical liquid supply pipe 8 and the recycled wastewater discharge pipe 9 are closed. In a state where water flow to the second discharge pipe 4 is stopped by the valve 5, the ion exchange treated water W <b> 1 is supplied from the supply pipe 6 to the regenerative ion exchange tower 11 in a downward flow and discharged from the first discharge pipe 3. By doing so, the chemical | medical solution (sodium hydroxide aqueous solution and hydrochloric acid) used for reproduction | regeneration is extruded from the regenerative ion exchange tower 11 by a transient type (extrusion process). At this time, the ion-exchanged water W1 discharged from the first discharge pipe 3 is not supplied to the subsequent subsystem. In addition, the regeneration operation so far (back washing process, regeneration process process and extrusion process) is continuously performed twice or more when the resistivity of the ion exchange treated water W1 decreases significantly or the sodium concentration described later increases greatly. Preferably.

  After mixing the separated ion exchange resins constituting the ion exchange resin layer 12, the first discharge pipe 3 is the same as the extrusion step except that the automatic valve 5 allows water to pass through the second discharge pipe 4. Ion exchange is performed by supplying pretreatment water W to the regenerative ion exchange tower 11 in a downward flow from the supply pipe 6 and discharging the ion exchange treated water W1 from the first discharge pipe 3 in the open / closed state of the pipe. The resin is circulated and washed (circulation washing process). 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 W <b> 1 produced in the circulation cleaning process is supplied to the water quality measuring device 2 through the second discharge pipe 4. The flow rate of the ion exchange treated water W1 discharged from the regenerative ion exchange device 1 to the water quality measurement device 2 is 1 L / min or more, and preferably 1.5 L / min.

In the water quality measuring device 2, the ion exchange treated water W 1 is passed from the second discharge pipe 4 to the ion concentration meter 22 with the second automatic valve 24 and the third automatic valve 25 opened and the first automatic valve 23 closed. Watered. The sodium ion (Na ⁺ ) concentration is measured by the sodium ion electrode of the ion concentration meter 22 with respect to the ion exchange treated water W1 that has been passed (ion concentration measurement step). When the circulation washing process is insufficient, a large amount of sodium ions (Na ⁺ ) resulting from the sodium hydroxide aqueous solution used for the regeneration treatment is contained in the ion exchange treated water W1. Therefore, when the sodium ion (Na ⁺ ) concentration of the ion exchange treated water W1 is equal to or lower than a preset threshold value, the automatic switching control unit determines that the regeneration is suitable, ends the regeneration process, and selects the water sampling mode. Switch to. In addition, the ion exchange treated water W1 after the ion concentration measurement is discharged out of the system through the second wastewater discharge pipe 27.

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 circulation cleaning step may be continued.

The automatic switching control means measures the resistivity value of the ion exchange treated water W1 by the resistivity meter 21 and the sodium ion (Na ⁺ ) concentration of the ion exchange treated water W1 by the sodium ion electrode of the ion concentration meter 22. The propriety of reproduction may be determined based on both measured values.

As described above, the automatic switching control means is operated by alternately repeating the water sampling mode and the regeneration mode, whereby the measured value by the water quality measuring device 2, particularly the sodium ion (Na ⁺ ) concentration of the ion exchange treated water W1. Therefore, it is possible to determine whether or not the ion exchange resin layer 12 is regenerated and to supply the ion exchange treated water W1 after the regeneration is determined to be suitable to the subsystem in the subsequent stage. It is possible to stabilize the sodium ion (Na ⁺ ) concentration of the subsystem treated water) by keeping it low to a desired value.

[Second Embodiment]
FIG. 2 is a schematic system diagram showing a water quality management system 10 ′ according to the second embodiment of the present invention. The water quality management system 10 ′ of FIG. 2 includes three regenerative ion exchange devices 1 (first example) provided in parallel and two water quality measurement devices 2 provided in parallel. Each type of treated water discharged from each of the ion exchange devices 1 is configured to be able to be supplied to each of the two water quality measuring devices 2. In FIG. 2, the display of the regenerative ion exchange devices 1 (1A, 1B, 1C) of each series is omitted. Further, in FIG. 2 and the following description, the same reference numerals are used for the devices having the same configuration or the same function as those of the first embodiment, and the detailed description thereof is omitted.

  In the present embodiment, as the water quality measuring device 2, the first water quality measuring device 2A and the second water quality measuring device 2B are provided in two stages in parallel, and the regenerative ion exchange device 1 is the first regenerative ion exchange. The apparatus 1A, the second regenerative ion exchange apparatus 1B, and the third regenerative ion exchange apparatus 1C are provided in three stages in parallel. The second discharge pipe 4 of the first regenerative ion exchange apparatus 1A is branched into a first branch pipe 4a and a second branch pipe 4b. A first water quality measuring device 2A is connected to the first branch pipe 4a via an automatic valve, and a second water quality measuring device 2B is connected to the second branch pipe 4b via an automatic valve.

  The second discharge pipe 4 of the second regenerative ion exchange apparatus 1B is branched 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 an automatic valve, and the second branch pipe 4d merges with the second branch pipe 4b via an automatic valve. The second discharge pipe 4 of the third regenerative ion exchange device 1C is branched into a first branch pipe 4e and a second branch pipe 4f. The first branch pipe 4e is joined to the first branch pipe 4a downstream from the joining point of the first branch pipe 4a and the first branch pipe 4c via an automatic valve, and the second branch pipe 4f is an automatic valve. The second branch pipe 4b joins the second branch pipe 4b downstream of the junction of the second branch pipe 4b and the second branch pipe 4d.

[Operation method of water quality management system]
Next, the operation method of the water quality management system 10 ′ of the second embodiment will be described. In the following description, the first series by the first regenerative ion exchange apparatus 1A and the second series by the second regenerative ion exchange apparatus 1B are the water sampling mode, and the third series by the third regenerative ion exchange apparatus 1C. A case where is in the reproduction mode will be described as an example.

(First series-sampling mode)
In the first series, the ion exchange treated water W1 discharged from the first regenerative ion exchange device 1A after the ion exchange step is supplied to the subsequent subsystem via the first discharge pipe 3, and at the same time the second discharge. The water is passed through the first water quality measuring device 2A through the pipe 4 and the first branch pipe 4a. In the first water quality measuring apparatus 2A, the resistivity of the ion exchange treated water W1 is measured by the resistivity meter 21 (resistivity measurement step). The ion exchange treated water W1 after the resistivity measurement is discharged out of the system through the first wastewater discharge pipe 26. When the measured resistivity exceeds a preset threshold value, the automatic switching control means switches to the reproduction mode.

(Second series-playback mode)
In the second series, an aqueous sodium hydroxide solution is supplied from the first chemical solution supply pipe 7 to the regenerative ion exchange column 11 of the second regenerative ion exchange device 1B after the backwashing process, and the second chemical solution In this state, hydrochloric acid is supplied from the supply pipe 8 (regeneration process step). The regenerated sodium hydroxide aqueous solution and hydrochloric acid waste water in the second regenerative ion exchange apparatus 1B are discharged from the regenerated waste water discharge pipe 9.

(3rd series-playback mode)
In the third series, 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 at the same time, the second discharge pipe 4 and the second branch. In this state, water is passed through the second water quality measuring device 2B through the pipe 4f. In the second water quality measuring device 2B, the ion concentration of the ion exchange treated water W1 is measured by the ion concentration meter 22 (ion concentration measurement step). At this time, since the first water quality measuring device 2A is used for measuring the resistivity of the ion exchange treated water W1 of the first regenerative ion exchange device 1A, the ions discharged from the third regenerative ion exchange device 1C. The exchanged water W1 is automatically controlled so as not to pass through the first branch pipe 4e but through the second branch pipe 4f by the automatic valve, so the second water quality measuring device 2B that is not used is selected. Thus, the sodium ion (Na ⁺ ) concentration of the ion exchange treated water W1 can be measured.

  Thus, even when three regenerative ion exchange apparatuses 1 are provided in parallel, a specific regenerative ion exchange apparatus 1 is selected by one water quality management system 10 ′ at a timing as required. Water quality can be measured, and the water quality management of the treated water is simpler than when the water quality measuring device 2 is provided for each regenerative ion exchange device 1 (1A, 1B, 1C), and In addition, it is possible to stably flow the treated water with suppressed ion concentration into the subsequent subsystem.

[Other examples of regenerative ion exchange equipment]
Next, the second example-sixth example regenerative ion exchange apparatus 1 shown in FIGS. 3 to 7 will be described. In the following example, when the regenerative ion exchange apparatus 1 includes a plurality of regenerative ion exchange towers 11, ion exchange treated water discharged from the regenerative ion exchange tower 11 at the last stage of the regenerative ion exchange apparatus 1. About W1, based on 1st embodiment or 2nd embodiment, what is necessary is just to measure a water quality (resistivity, sodium ion (Na ^<+> ) density | concentration). That is, the second discharge pipe 4 of the regenerative ion exchange tower 11 at the last stage of the regenerative ion exchange apparatus 1 may be configured to be connected to the water quality measurement apparatus 2. At this time, the water quality measuring device 2 is preferably provided in the immediate vicinity of the automatic valve 5. 3 to 7 and the following description, devices having the same configuration or the same function are denoted by the same reference numerals, and detailed description thereof is omitted.

(Regenerative ion exchange device according to the second example)
The regenerative ion exchange apparatus 1 shown in FIG. 3 is an embodiment configured by a single regenerative ion exchange column 11. In the present embodiment, the regenerative ion exchange column 11 is a system in which water flows in an upward flow, and the anion exchange resin layer 12A and the cation exchange resin layer 12B are separated from each other in the cylindrical exchange column body 111 from above. It is a two-layer type ion exchange tower formed as described above. A supply pipe 6 for pretreatment water W for performing ion exchange treatment is connected to the lower part of the exchange tower body 111, while a first discharge pipe 3 for ion exchange treatment water W1 is connected to the upper part of the exchange tower main body 111. A second discharge pipe 4 is branched and connected to the discharge pipe 3 via an automatic valve 5. The first discharge pipe 3 is connected to the upstream side of the automatic valve 5 with a first chemical liquid supply pipe 7 for supplying a NaOH solution as alkali as a regenerated chemical liquid, and is connected to the exchange tower main body 111 side. A first regeneration waste water discharge pipe 91 for discharging NaOH regeneration waste water is connected to the section. On the other hand, a second chemical liquid supply pipe 8 for supplying hydrochloric acid (HCl) as an acid, which is a regenerated chemical liquid, communicates with the side of the exchange tower main body 111, and hydrochloric acid regenerated waste water is discharged to the supply pipe 6. The 2nd reproduction | regeneration waste water discharge pipe 92 for doing is connected. 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 are respectively An open / close valve (not shown) is provided. In FIG. 3, reference numeral 71 denotes a heater (plate type heat exchanger) provided in the first chemical liquid supply pipe 7, and 13A has many holes smaller than the anion exchange resin constituting the anion exchange resin layer 12A. It is a shielding plate.

(Regenerative ion exchanger according to the third example)
The regenerative ion exchange apparatus 1 shown in FIG. 4 is an embodiment configured with a single regenerative ion exchange column 11. In the present embodiment, the regenerative ion exchange column 11 is a system in which water flows in an upward flow, and the cation exchange resin layer 12B and the anion exchange resin layer 12A are separated from each other in the cylindrical exchange column body 111 from above. It is a two-layer type ion exchange tower formed as described above. A supply pipe 6 for pretreatment water W for performing ion exchange treatment is connected to the lower part of the exchange tower body 111, while a first discharge pipe 3 for ion exchange treatment water W1 is connected to the upper part of the exchange tower main body 111. A second discharge pipe 4 is connected to the discharge pipe 3 via an automatic valve 5. The first discharge pipe 3 communicates with the second chemical liquid supply pipe 8 for supplying hydrochloric acid (HCl) as an acid as a regenerated chemical liquid to the upstream side of the automatic valve 5. A second regeneration waste water discharge pipe 92 for discharging hydrochloric acid regeneration waste water is connected to the side of the second side. Further, a first chemical solution supply pipe 7 for supplying a NaOH solution as an alkali, which is a regenerated chemical solution, is connected to a side portion of the exchange tower main body 111, and NaOH regeneration waste water is discharged to the supply pipe 6. The 1st regeneration waste water discharge pipe 91 of this is connected. 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 are respectively An open / close valve (not shown) is provided. In FIG. 4, reference numeral 71 denotes a heater (plate type heat exchanger) provided in the first chemical liquid supply pipe 7, and 13B has many holes smaller than the cation exchange resin constituting the cation exchange resin layer 12B. It is a shielding plate.

(Regenerative ion exchanger according to the fourth example)
The regenerative ion exchange apparatus 1 shown in FIG. 5 is a so-called two-bed / three-column type ion exchange apparatus, which is a two-layer type regenerative cation exchange resin tower (H tower) 11B, a degassing apparatus 20, and a two-layer type. And a regenerative anion exchange resin tower (OH tower) 11A. A supply pipe 6 for pretreatment water W for performing ion exchange treatment is connected to the lower side of the H tower 11B, while a first discharge pipe 3 for ion exchange treatment water W1 is connected to the upper side of the OH tower 11A. The second discharge pipe 4 is connected to the first discharge pipe 3 via the automatic valve 5. And the 2nd chemical | medical solution supply pipe 8 for supplying hydrochloric acid (HCl) as an acid which is a regenerated chemical | medical solution is connected to the upper side of H tower 11B, and the pre-treatment water W of the lower side of H tower 11B is connected. The supply pipe 6 is connected to a second recycled wastewater discharge pipe 92 for discharging hydrochloric acid recycled wastewater. Further, a first chemical solution supply pipe 7 for supplying an NaOH solution as alkali as a regenerated 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 recycled wastewater discharge pipe 91 for discharging NaOH recycled wastewater is connected to the lower side (supply side) of the OH tower 11A. In FIG. 5, 71 is a heater (plate type heat exchanger) provided in the first chemical liquid supply pipe 7, and 30 is for supplying the treated water treated by the deaerator 20 to the OH tower 11A. It is a pump. There is no restriction | limiting in particular about the specification of the deaeration apparatus 20, and the pump 30 provided in the back | latter stage of the deaeration apparatus 20. FIG. The same applies to the following fifth and sixth examples.

  In this two-bed / three-column type ion exchange apparatus, 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 ′. The ion exchange resin layer 12 filled in 11A has a two-layer structure of a weak anion exchange resin layer 12a and a strong anion exchange resin layer 12a ′. In addition, between the weak cation exchange resin layer 12b and the strong cation exchange resin layer 12b ′, and the weak anion exchange resin layer 12a and the strong anion exchange resin layer 12a ′, there are many pores smaller than the anion exchange resin and the cation exchange resin. A shielding plate (not shown) is provided.

(Regenerative ion exchanger according to the fifth example)
The regenerative ion exchange apparatus 1 shown in FIG. 6 is a so-called three-bed / four-column ion exchange apparatus, which is a two-layer first regenerative cation exchange resin tower (H1 tower) 11B, a degassing apparatus 20, This is an embodiment composed of a two-layer type regenerative anion exchange resin tower (OH tower) 11A and a single-layer second regenerative cation exchange resin tower (H2 tower) 11B ′. A supply pipe 6 for pretreatment water W for performing ion exchange treatment is connected to the lower side of the H1 tower 11B, while a first discharge pipe 3 for ion exchange treatment 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. A second chemical solution supply pipe 8 for supplying hydrochloric acid (HCl) as an acid as a regenerative chemical solution is connected to the upper side of the H2 tower 11B ′, and an automatic valve 5 is connected to the first discharge pipe 3. A second regeneration waste water discharge pipe 92 for discharging hydrochloric acid regeneration waste water is connected to the upstream side. The second regeneration waste water discharge pipe 92 is connected to the upper side (discharge side) of the H1 tower 11B, and the hydrochloric acid regeneration waste water waste pipe 94 is connected to the supply pipe 6 on the lower side (supply side) of the H1 tower 11B. ing. Further, a first chemical liquid supply pipe 7 for supplying an NaOH solution as an alkali is connected to the upper side (discharge side) of the OH tower 11A, and NaOH is connected to the lower side (supply side) of the OH tower 11A. A first recycled wastewater discharge pipe 91 for discharging recycled wastewater is connected. In addition, 71 is a heater (plate type heat exchanger) provided in the 1st chemical | medical solution supply pipe 7, 30 is a pump for supplying the treated water processed with the deaeration apparatus 20 to OH tower 11A.

  In this three-bed / four-column type ion exchange apparatus, the ion exchange resin layer 12 filled in the H1 tower 11B has a two-layer structure of a weak cation exchange resin layer 12b and a strong cation exchange resin layer 12b ′. The ion exchange resin layer 12 filled in 11A has a two-layer structure of a weak anion exchange resin layer 12a and a strong anion exchange resin layer 12a ′. In addition, between the weak cation exchange resin layer 12b and the strong cation exchange resin layer 12b ′, and the weak anion exchange resin layer 12a and the strong anion exchange resin layer 12a ′, there are many pores smaller than the anion exchange resin and the cation exchange resin. A shielding plate (not shown) is provided.

(Regenerative ion exchanger according to the sixth example)
The regenerative ion exchange apparatus 1 shown in FIG. 7 is a so-called four-bed five-column ion exchange apparatus. Basically, the regenerative cation of the third-bed four-column ion exchange apparatus 1 of the fifth example described above. A single-layer second regenerative anion exchange resin tower (OH2 tower) 11A ′ is further provided at the rear stage of the exchange resin tower (H2 tower) 11B ′. A first discharge pipe 3 of the ion exchange treated water W1 is connected to the lower side of the OH2 tower 11A ′, and a second discharge pipe 4 is connected to the first discharge pipe 3 via an automatic valve 5. . And the 1st chemical | medical solution supply pipe | tube 7 for supplying the NaOH solution as an alkali is connected to the upper side of OH2 tower 11A ', and the lower 1st discharge pipe 3 is the downstream of the automatic valve 5, A first regeneration waste water discharge pipe 91 for discharging NaOH regeneration waste water is connected. The first regeneration waste water discharge pipe 91 is connected to the upper side (discharge side) of the first regenerative anion exchange resin tower (OH1 tower) 11A as an NaOH solution supply pipe, and to the lower side (supply side) of the OH1 tower 11A. Is connected to a waste pipe 93 for NaOH regeneration wastewater.

  Although the present invention has been described with reference to the accompanying drawings, the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the ratio between the number of regenerative ion exchange devices 1 provided in parallel and the number of water quality measurement devices 2 provided in parallel is the number of water quality measurement devices 2 equal to the number of regenerative ion exchange devices 1. Or it may be a smaller number and is not limited to 3 to 2. Further, a known water treatment element such as a reverse osmosis membrane separation device can be provided in the previous stage of the regenerative ion exchange device 1. Furthermore, in the said embodiment, although switching to the regeneration mode is performed when the resistivity of the ion exchange treated water W1 by the resistivity meter 21 exceeds a preset threshold, the ion exchange treated water W1 having a predetermined volume is switched. It may be operated so as to switch to the reproduction mode at the time of manufacturing the device, or the timing of switching to the reproduction mode may be measured by means other than the resistivity meter.

  EXAMPLES Hereinafter, although this invention is further explained in full detail based on an Example, this invention is not limited to a following example.

[Example]
A regenerative ion exchange apparatus 1 of the first example shown in FIG. 1 is provided in two stages in parallel, and the water quality management system 10 ′ shown in FIG. I went twice. Usually, the first series (first regenerative ion exchange apparatus 1A) is in the water collection mode, and the second series (second regenerative ion exchange apparatus 1B) is in the regeneration mode and standby.

  Both 1st water quality measuring device 1A and 2nd water quality measuring device 1B use MX-3 (made by Kurita Kogyo Co., Ltd.) as resistivity meter 21, and swan AMI Soditrace (as ion concentration meter 22 using a sodium ion electrode) Tea & Technical Co.) was used.

  As the ion exchange resin charged in the ion exchange tower 11, porous PK228L (manufactured by Mitsubishi Chemical Corporation) was used as the cation exchange resin, and porous PA312L (manufactured by Mitsubishi Chemical Corporation) was used as the anion exchange resin.

(First series)
First, the first regenerative ion exchange in which the space velocity (SV) is collected at 40 h ⁻¹ with respect to the ion exchange resin in which the cation exchange resin and the anion exchange resin are mixed and filled at a volume ratio of 1: 2. The ion exchange treated water W1 before regeneration of the device 1A was passed through the first water quality measuring device 2A, and the resistivity and sodium ion (Na ⁺ ) concentration in the ion exchange treated water W1 were measured.

  Next, the operation mode of the first regenerative ion exchange device 1A was switched from the water sampling mode to the regenerative mode, and the regenerative work of the ion exchange resin layer 12 filled in the regenerative ion exchange tower 11 was performed. The detailed process of the regeneration operation is as follows.

  First, 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 back-washed using the ion exchange treated water W1, The cation exchange resin and the anion exchange resin were separated (back washing step).

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

  Subsequently, in a state where 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 each of the cation exchange resin and the anion exchange resin regenerated with the regenerated chemical solution, The regenerative chemical solution in the regenerative ion exchange tower 11 and the ion exchange resin layer 12 was extruded in a transient manner (extrusion step).

  Then, the cation after the regenerated chemical solution is pushed out by supplying the pretreated water W to the regenerative ion exchange tower 1A in a downward flow while water flow to the first water quality measuring device 2A is stopped. The exchange resin and the anion exchange resin were mixed, and the mixed ion exchange resin was circulated and washed with the pretreatment water W (circulation washing process).

At the same time, the circulated treated water of the first regenerative ion exchange device 1A was passed through the first water quality measuring device 2A, and the resistivity and sodium ion (Na ⁺ ) concentration of the circulated treated water were measured. When the resistivity was 18.0 MΩ · cm or more and the sodium ion (Na ⁺ ) concentration was 300 ng / L or less, water flow to the first water quality measurement device 2A was stopped, and the regeneration process was terminated.

When the operation mode of the first regenerative ion exchange apparatus 1A is switched from the regenerative mode to the water sampling mode and sampling of the ion exchange treated water W1 by the ion exchange resin layer 12 filled in the regenerative ion exchange tower 11 is started. At the same time, the ion exchange treated water W1 was passed through the first water quality measuring device 2A, and the resistivity and sodium ion (Na ⁺ ) concentration were measured.

(Second series)
With respect to the second regenerative ion exchange device 1B in the collected water, the resistivity and sodium ion (Na ⁺ ) concentration of the ion exchange treated water W1 before the regeneration treatment were measured by the second water quality measurement device 2B. The operation mode of the second regenerative ion exchange apparatus 1B is switched from the water sampling mode to the regenerative mode, and the regeneration process of the ion exchange resin layer 12 filled in the regenerative ion exchange tower 11 is performed by the first regenerative ion exchange apparatus. It carried out like the case of 1A.

In addition, when the regenerative ion exchange device (1A, 1B) is in the water sampling mode, a non-regenerative ion exchange device (capacity; cation exchange resin / anion exchange resin = 1 / 1.6, SV) provided in the subsequent subsystem. The concentration of sodium ions (Na ⁺ ) in the treated water discharged from 80 ^−h ) was analyzed using ICP-MS (manufactured by Agilent Technologies, 7500cs).

[Comparative example]
Similar to the above embodiment, the regenerative ion exchange apparatus 1 of the first example shown in FIG. 1 is provided in two stages in parallel, and the water quality management system 10 ′ shown in FIG. Switching operation was performed 4 times in this order. Usually, the first series (first regenerative ion exchange apparatus 1A) is in the water collection mode, and the second series (second regenerative ion exchange apparatus 1B) is in the regeneration mode and standby.

  About the cation exchange resin isolate | separated by the backwashing process, the byproduct hydrochloric acid (HCl) aqueous solution adjusted to 5% was regenerated | regenerated as a regenerative chemical.

In addition, when the regenerative ion exchange device (1A, 1B) is in the water sampling mode, a non-regenerative ion exchange device (capacity; cation exchange resin / anion exchange resin = 1 / 1.6, SV) provided in the subsequent subsystem. The concentration of sodium ions (Na ⁺ ) in the treated water discharged from 80 ^−h ) was analyzed using ICP-MS (manufactured by Agilent Technologies, 7500cs).

In addition, after the resistivity of the ion exchange treated water W1 of each regenerative ion exchange apparatus (1A, 1B) during sampling is 18.0 MΩ · cm or less and the sodium ion (Na ⁺ ) concentration exceeds 500 ng / L or more For reproduction, the reproduction process was repeated twice.

In the first regenerative ion exchange apparatus 1A, the resistivity and sodium ion (Na ⁺ ) concentration (shown as A in the table; the same applies hereinafter) of the ion exchange treated water W1 12 hours after the start of sampling, and the second regenerative type 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 hereinafter) 12 hours after the start of sampling in the ion exchange apparatus 1B. Playback and sodium ions ion-exchanged treated water in W1 during water sampling the (Na ⁺⁾ concentration, by managing the water quality management system 10 ', the sodium in the ion exchange treatment water W1 during water sampling ions (Na ⁺⁾ It can be seen that the concentration could be controlled to 300 ng / L or less.

The concentration of sodium ions (Na ⁺ ) in the treated water discharged from the non-regenerative ion exchange device provided in the subsequent subsystem during sampling of the first regenerative ion exchange device 1A and the second regenerative ion exchange device 1B. Table 2 shows the comparison. By managing the sodium ion (Na ⁺ ) concentration in the ion exchange treated water W1 at the time of regeneration and sampling of each regenerative ion exchange device (1A, 1B) by the water quality management system 10 ′, the subsequent non-regeneration It turns out that the short-term fluctuation | variation of the sodium ion (Na ^<+> ) density | concentration in the treated water discharged | emitted from a type | formula ion exchanger was able to be controlled.

As described above, not only the resistivity but also the sodium ion (Na ⁺ ) concentration is measured for the water quality of the ion exchange treated water W1 at the time of regeneration and sampling of the regenerative ion exchange device 1, and based on these measured values. By managing the appropriateness of regeneration of the ion exchange resin layer 12, it is possible to appropriately switch between the regeneration mode and the water sampling mode, and in the treated water discharged from the non-regenerative ion exchange device of the subsequent subsystem. It can be seen that short-term fluctuations in sodium ion (Na ⁺ ) concentration can be controlled.

DESCRIPTION OF SYMBOLS 10 Water quality management system 1 Regenerative ion exchange apparatus 11 Regenerative ion exchange tower 111 Exchange tower main body 12 Ion exchange resin layer 2 Water quality measuring device 21 Resistivity meter 22 Ion concentration meter 26 First waste water discharge pipe 27 Second waste water discharge pipe 3 First discharge pipe 4 Second discharge pipe 5 Automatic valve 6 Supply pipe 7 First chemical liquid supply pipe 8 Second chemical liquid supply pipe 9 Recycled wastewater discharge pipe W Pretreated water W1 Ion exchange treated water

Claims (4)

A regenerative ion exchanger;
And water quality measuring device having a resistivity meter and the ion concentration meter,
A first discharge pipe for circulating treated water discharged from the regenerative ion exchange device;
A second discharge pipe branched from the first discharge pipe and supplying the treated water to the water quality measuring device;
Automatic switching control means for automatically switching an operation mode including a sampling mode for sampling the treated water and a regeneration mode for regenerating the regenerative ion exchange device;
The automatic switching control means performs automatic switching control of the operation mode according to the measured value of the resistivity meter and the measured value of the ion concentration meter.
Water quality management system. In the case where the regenerative ion exchange apparatus has a plurality of regenerative ion exchange towers,
The water quality management system according to claim 1, wherein the outflow water flowing out from the regenerative ion exchange tower at the last stage of the regenerative ion exchange apparatus is the treated water. N regenerative ion exchange devices provided in parallel (N is an integer of 2 or more);
N or less water quality measuring devices provided in parallel,
The water quality management system according to claim 1 or 2 , wherein each 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. . A regenerative ion exchanger;
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 branched from the first discharge pipe and supplying the treated water to the water quality measuring device;
Operation of a water quality management system comprising an automatic switching control means that automatically switches an operation mode including a water collection mode for collecting the treated water and a regeneration mode for regenerating the regenerative ion exchange device A method,
Measuring the resistivity of the treated water with the resistivity meter;
Measuring the ion concentration of the treated water with the ion concentration meter;
And a step of automatically switching the operation mode of the automatic switching control means based on the measured resistivity measurement value and the measured ion concentration measurement value.

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