KR20190039886A - Regenerative ion exchange apparatus and method of operating the same - Google Patents

Abstract

The upper portion of the regenerative ion exchange column 1 is connected to the supply pipe 3 of the pretreating water W for performing the ion exchange treatment while the lower portion of the ion exchange water W1 is connected to the discharge pipe 4 have. A NaOH solution supply pipe 5 and a hydrochloric acid (HCl) supply pipe 6, which are regenerated chemical solutions, are connected to the supply pipe 3 and the discharge pipe 4, respectively. Further, a discharge pipe 7 for regenerating wastewater is connected to the side of the tower main body 1A. A sodium ion electrode 9 for measuring the sodium ion (Na ⁺ ) concentration of the resistivity meter 8 and the ion exchange water W1 is formed in the discharge pipe 4. According to such a regenerative ion exchange apparatus, it is possible to suppress short-term fluctuations in the concentrations of sodium ions (Na ⁺ ) and chloride ions (Cl ^- ) in the treated water of the secondary pure water system (subsystem) .

Description

Regenerative ion exchange apparatus and method of operating the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative ion exchange apparatus used in a primary pure water system in an ultrapure water production facility used in the process of manufacturing electronic products and the like, The present invention relates to a regenerative ion exchanger capable of suppressing short-term fluctuation of ion concentration in the treated water of a non-material ion exchanger used in the ion exchanger.

The ultrapure water producing apparatus is generally constituted by a pretreatment system, a primary pure water system, and a secondary pure water system (subsystem). The pretreatment system is composed of coagulation, pressurization (sedimentation), filtration (membrane filtration), etc., and removes suspended substances and colloidal substances in raw water. In this process, polymer-based organic substances, hydrophobic organic substances, and the like may be removed. The primary pure water system is basically equipped with a reverse osmosis (RO) membrane separation device and a regenerative ion exchange device (mixed bed type or four-phase five-column type or the like) And removes ionic and colloidal TOC. In the regenerative ion exchanger, the salt is removed and the TOC component adsorbed or ion-exchanged by the ion exchange resin is removed.

Further, the subsystem basically includes a low-pressure ultraviolet (UV) oxidizing device, a non-regenerative mixed-bed ion exchange device, and an ultrafiltration (UF) membrane separator to further increase the purity of the primary pure water to ultrapure water. In the low-pressure UV oxidation apparatus, TOC is decomposed to organic acids, and thus CO ₂ , by ultraviolet rays of 185 nm emitted from a low-pressure ultraviolet lamp. Then, the organic matter and CO ₂ produced by the decomposition are removed by the non-regenerating mixed-bed type ion exchange apparatus at the subsequent stage. In the UF membrane separation apparatus, the fine particles are removed, and the outflow particles of the ion exchange resin are also removed.

In the above-described ultrapure water producing apparatus, the regenerative ion exchange apparatus of the primary pure water system is constituted by a plurality of towers including one tower or a degassing apparatus, whereby a water treatment apparatus And it is also common to have a reverse osmosis (RO) membrane device at the front end. In addition, ultrapure water can be produced at the downstream end of the regenerative ion exchanger by disposing a secondary pure water system (subsystem) equipped with a non-raw ion exchanger.

The concentration of the treated water ion in the ion exchange apparatus which mainly removes the ion flow in the water is determined by the water ion concentration and the treatment amount (space velocity and linear velocity). Conventionally, the regenerative ion exchange apparatus sets a threshold value to the resistivity (or electric conductivity) of the treated water and removes ions in water while repeating regeneration and water sampling. Since the ion exchange resin charged in such an ion exchange apparatus electrochemically removes ions in the water but has a capacity, the regeneration type ion exchange apparatus periodically regenerates the drug and regenerates its ability I have to.

In order to regenerate the ion exchange resin charged in the regenerative ion exchange apparatus, it is necessary to add chemicals such as hydrochloric acid (HCl) or sodium hydroxide (NaOH) according to the ion exchange resin filled with anion exchange resin or cation exchange resin However, sodium ions (Na ⁺ ) or chloride ions (Cl ^- ) are detected in the treated water after these regenerated drugs remain in the ion exchange resin after regeneration and ions in the water are removed.

In recent years, the sodium ion (Na ⁺ ) concentration and the chloride ion (Cl ^- ) concentration in the treated water of the non-cultured ion exchange apparatus of the sub-system (secondary pure water apparatus) And it is found that there is a problem in that the yield of semiconductor products produced by washing with water is affected.

As a result of the present inventors' investigation into the cause of the fluctuation of the sodium ion (Na ⁺ ) concentration and the chloride ion (Cl ^- ) concentration in the treated water of this nonporous ion exchange apparatus, The sodium ion (Na ⁺ ) concentration or the chloride ion (Cl ^- ) concentration remaining in the treated water of the exchanger affects the quality of the treated water of the non-cultured ion exchanger of the downstream subsystem, The yield of the semiconductor product produced by the method of the present invention is affected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a regeneration type ion exchange apparatus capable of suppressing short-term fluctuations in the concentration of sodium ions (Na ⁺ ) or chloride ions (Cl ^- ) in the treated water of the secondary pure water system And a method of operating the same.

In view of the above objects, the present invention provides a regenerative ion exchange apparatus having a regenerative ion exchange column alone, wherein the regenerative ion exchange apparatus comprises an ion electrode for measuring the ion concentration of the treated water alone of the regenerative ion exchange column Thereby providing a regenerative ion exchange apparatus (Invention 1).

According to the present invention (Invention 1), when the regenerative ion exchange apparatus constituting the primary pure water system is a regenerative ion exchange column alone, the resistivity of the treated water at the regeneration of the regenerated ion exchange column alone Since the concentration of ions introduced into the subsequent stage subsystem can be controlled by measuring the ion concentration (measured value by the ion electrode) and managing the adequacy of regeneration based on the measured ion concentration, Short-term fluctuation of the ion concentration of the treated water of the ion exchange apparatus can be suppressed, and the ion concentration itself can be suppressed to be low.

The present invention also provides a regenerative ion exchange apparatus comprising a plurality of regenerable ion exchange columns and a plurality of columns including a deaerator, wherein the ion concentration of the treated water in the column at the rearmost end of the plurality of regenerative ion exchange columns (I) of the present invention.

According to this invention (invention 2), in the case where the regenerative ion exchanger constituting the primary pure water system is composed of a plurality of towers including a regenerative ion exchange column and a degassing apparatus, the regenerative ion exchange column It is possible to control not only the resistivity of the treated water at the time of regeneration of the regenerated water but also the ion concentration introduced into the downstream subsystem by measuring the ion concentration (measured value by the ion electrode) , It is possible to suppress short-term fluctuations in the ion concentration of the treated water of the non-cultured ion exchange apparatus constituting the subsystem, and to suppress the ion concentration itself to a low level.

In the above invention (Inventions 1 and 2), the regeneration type ion exchange column for measuring the ion concentration by the ion electrode is filled with at least an anion exchange resin, and the ion electrode is treated with sodium ion (Na ⁺ ), It is preferable to be a sodium ion electrode for measuring the concentration (invention 3).

According to this invention (invention 3), anion exchange resins resistivity of the treated water at the time of reproduction of the regenerative ion-exchange column filled, as well as a, and sodium ions (Na ⁺⁾ measuring a sodium ion (Na ⁺⁾ concentration by an electrode , It is possible to control the short-term fluctuation of the sodium ion (Na < ⁺ & gt ^; ) concentration of the treated water in the non-cultured ion exchange apparatus of the downstream subsystem by controlling the adequacy of regeneration based on the measured value, .

Secondly, the present invention relates to a method of regenerating a reformed ion exchange apparatus having a regenerative ion exchanger having a regenerative ion exchange column, And a regeneration type ion exchange apparatus for regenerating the ion exchange column (Invention 4). Further, the present invention is characterized in that the ion concentration of the treated water after the regeneration of the column at the rearmost end of the regenerative ion exchange apparatus comprising a plurality of regenerable ion exchange columns and a plurality of columns including the degassing apparatus is measured by the ion electrode, And the regeneration type ion exchange column is regenerated based on the ion concentration measured by the ion electrode (Invention 5).

According to the invention (inventions 4 and 5), not only the resistivity of the treated water at the time of regeneration but also the ion concentration (measured value by the ion electrode) is measured while the regeneration type ion exchange column is regenerated and the water- The short-term fluctuation of the ion concentration in the treated water of the non-cultured ion exchange apparatus of the downstream subsystem can be suppressed and can be suppressed to a low level.

In the above invention (inventions 4 and 5), the regeneration type ion exchange column for measuring the ion concentration by the ion electrode is filled with at least an anion exchange resin, and the ion electrode measures the sodium ion (Na ⁺ ) concentration And the sodium ion concentration of the treated water after the regeneration of the anion exchange resin is measured by the sodium ion electrode to regenerate the regenerative ion exchange column (invention 6).

According to this invention (invention 6), anion exchange resins resistivity of the treated water at the time of reproduction of the regenerative ion-exchange column filled, as well as a, and sodium ions (Na ⁺⁾ measuring the (Na ⁺⁾ concentration of sodium ions, due to the electrode , It is possible to control the short-term fluctuation of the sodium ion (Na < ⁺ & gt ^; ) concentration of the treated water in the non-cultured ion exchange apparatus of the downstream subsystem by controlling the adequacy of regeneration based on the measured value, .

According to the present invention, since the regeneration type ion exchange column is managed not only by the resistivity of the treated water at the time of collecting water but also by the ion concentration (measured value by the ion electrode), the non-material ion exchange It is possible to suppress short-term fluctuation of the ion concentration in the treated water of the apparatus and to suppress the ion concentration to a low level. Especially, it is preferable to control the proper part of the regeneration of the anion exchange resin based on the sodium ion concentration by the sodium electrode. The yield of the semiconductor product produced by washing with the ultrapure water thus obtained can be kept high.

1 is a schematic diagram showing a regenerative ion exchange apparatus according to a first embodiment of the present invention.
2 is a schematic diagram showing a regenerative ion exchange apparatus according to a second embodiment of the present invention.
3 is a schematic diagram showing a regenerative ion exchanger according to a third embodiment of the present invention.
4 is a schematic diagram showing a regenerative ion exchanger according to a fourth embodiment of the present invention.
5 is a schematic diagram showing a regenerative ion exchange apparatus according to a fifth embodiment of the present invention.
6 is a schematic diagram showing a regenerative ion exchange apparatus according to a sixth embodiment of the present invention.

 Hereinafter, a first embodiment of the regenerative ion exchanger of the present invention will be described in detail with reference to Fig.

The regenerative ion exchanger shown in Fig. 1 is an embodiment in which the regenerative ion exchanger is composed of a regenerative ion exchanger alone. In the present embodiment, in the regenerative ion exchange column 1, an ion exchange resin layer 2 composed of a mixed resin of a cation exchange resin and an anion exchange resin is disposed in a cylindrical column body 1A . The upper portion of the tower main body 1A is connected to the supply pipe 3 of the pretreating water W for performing the ion exchange treatment while the discharge pipe 4 of the ion exchange treated water W1 is connected to the lower portion. An NaOH solution supply pipe 5 as an alkali and a hydrochloric acid (HCl) supply pipe 6 as an acid are connected to the supply pipe 3 and the discharge pipe 4, respectively. Further, a discharge pipe 7 for regenerating wastewater is connected to the side of the tower main body 1A. An unshown opening / closing valve is formed in each of the supply pipe 3, the discharge pipe 4, the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6 and the regeneration waste water discharge pipe 7. A sodium ion electrode 9 serving as an ion electrode for measuring the sodium ion (Na ⁺ ) concentration of the resistivity meter 8 and the ion exchange water W1 is formed in the discharge pipe 4. 1, reference numeral 10 denotes a heater (plate-type heat exchanger) formed in the NaOH solution supply pipe 5.

In the regenerated ion exchanger as described above, the cation exchange resin constituting the ion exchange resin layer (2) is preferably a strongly acidic cation exchange resin having a sulfone group as a cation exchanger, a weak acid cation exchanged with a carboxylic acid group It is general to use a gel resin because both of the exchange resin can be used and the elution of PSA is small. In the above-mentioned cation exchange resin, divinylbenzene serves as a crosslinking agent, and a chain structure is crosslinked to form a network structure. The more divinylbenzene is present, the more branches of the chain are formed and the dense structure is obtained. When the divinylbenzene content is small, a resin having a large number of branches is obtained. A resin used for ordinary water treatment has a degree of crosslinking of about 8% and is called a standard crosslinking resin. On the other hand, a cross-linking degree of 9% or more is called a high-degree cross-linking resin. In the present embodiment, all of them can be used, but a standard crosslinked resin is preferable.

As the anion exchange resin, a gel resin is used because the elution of PSA is small. Styrene-divinylbenzene copolymers and the like are used as the base, strong basic anion exchange resins having a quaternary ammonium group such as trimethylammonium group or dimethylethanolammonium group, styrene-divinylbenzene copolymer, and the like. Or a weakly basic anion exchange resin having a primary or tertiary amino group as a functional group in a polyacrylate ester skeleton can be used, but strongly basic anion exchange resins can be preferably used. The exchanger 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 2 is 30:70 to 70:30, particularly 30: 70 to 50:50, it is preferable to mix a large amount of anion exchange resin.

A method of operating the regenerative ion exchanger as described above will be described. First, in the water sampling mode, the supply pipe (3) and the discharge pipe (4) are opened, and the pretreated water (W) is supplied while the NaOH solution supply pipe (5), the hydrochloric acid supply pipe (6) The pretreatment water W is supplied as the ion-exchanged water W1 after the cationic component and the anionic component are removed from the ion-exchange resin layer 2 by the mixed resin Is discharged from the discharge pipe 4, and is supplied to a subsystem not shown. The water flow condition at this time can be the same as the treatment by the ordinary ion exchange, and the flow rate of the ion exchange resin in the ion exchange resin layer 2 is 5 to 100 h ^-1 , particularly 5 to 50 h ^-1 .

When the resistivity of the ion exchange water W1 by the resistivity meter 8 exceeds a predetermined value, it is regarded that the ion exchange capacity of the ion exchange resin layer 2 is lowered, The regeneration of the mixed resin in the ion exchange column 1 is carried out. In this regeneration mode, first, the ion exchange water W1 is supplied from the discharge pipe 4 and discharged from the supply pipe 3 to back up the mixed resin constituting the ion exchange resin layer 2. [ In this backwash, the anionic exchange resin is separated upward by the difference in specific gravity of the anion exchange resin and the cation exchange resin, and the cation exchange resin is separated downward.

Then, in the state where the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6 and the regeneration waste water discharge pipe 7 are formed, an aqueous sodium hydroxide solution is supplied from the NaOH solution supply pipe 5 to regenerate the anion exchange resin , And hydrochloric acid is supplied from the hydrochloric acid supply pipe (6) to regenerate the cationic exchange resin distributed on the lower side. At this time, in order to efficiently regenerate the anion exchange resin, the sodium hydroxide aqueous solution is preferably heated to about 30 to 50 캜 by the heater 10. The wastewater after the regeneration of these aqueous sodium hydroxide solution and hydrochloric acid is discharged from the discharge pipe 7 of the regenerated wastewater.

Subsequently, in the state where the supply pipe 3 and the discharge pipe 4 are made separate and the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6 and the regeneration waste water discharge pipe 7 are closed, (Aqueous solution of sodium hydroxide and hydrochloric acid) used for regeneration is extruded by feeding the water W1 and discharging the water W1 from the discharge pipe 4. If the resistivity of the ion-exchanged water W1 is low or the sodium concentration is high, the regeneration operation so far is preferably performed two or more times.

Next, when the separated ion exchange resin constituting the ion exchange resin layer 2 is mixed, the pretreated water W is supplied from the supply pipe 3 and discharged from the discharge pipe 4 to manufacture the ion exchange treated water W1 Whereby the ion exchange resin is circulated and cleaned. The sodium ion (Na ⁺ ) concentration of the ion-exchanged water W1 is measured by the sodium-ion electrode 9 without supplying the ion-exchanged water W1 produced here to the subsystem. If the circulating washing is insufficient, the sodium ion is contained in the ion-exchanged water W1 largely because of the NaOH solution used for regeneration. Therefore, the regeneration is judged to be suitable when the sodium ion concentration becomes a predetermined value or less, And returns to the sampling mode. At this time, it is also possible to judge whether the regeneration is proper at both the resistivity meter 8 and the resistivity of the ion-exchanged water W1. When the sodium ion concentration exceeds the predetermined value, the circulating washing may be continued. The regeneration type ion exchange apparatus can be operated by alternately repeating the water sampling mode and the regeneration mode.

Based on the sodium ion concentration, it is judged whether or not the regeneration of the anion exchange resin is proper, and after the regeneration is judged to be suitable, the ion exchange water W1 is supplied to the subsystem, The sodium ion (Na < ⁺ & gt ^; ) concentration can be stabilized by keeping it low to a desired value.

Next, a second embodiment of the regenerative ion exchanger of the present invention will be described with reference to Fig. In this embodiment, the same reference numerals are assigned to the same components as those in the first embodiment, and a detailed description thereof will be omitted.

The regenerative ion exchanger shown in Fig. 2 is a mode in which the regenerative ion exchanger is composed of a regenerative ion exchanger alone. In the present embodiment, the regenerative ion exchange column 1 is of a type in which the water flows in an upward flow, and an anion exchange resin layer 2A and a cation exchange resin layer 2B are separated from each other. In the lower part of the tower main body 1A, a supply pipe 3 for pretreating water W for performing an ion exchange treatment is connected. On the other hand, an ion exchange treatment And the discharge pipe 4 of the number W1 is connected. An NaOH solution supply pipe 5 as an alkaline regeneration solution is connected to the discharge pipe 4 and a discharge pipe 7A for NaOH regeneration waste water is connected to the side of the tower main body 1A. On the other hand, a hydrochloric acid (HCl) supply pipe 6 as an acid communicates with the side of the tower main body 1A, and a discharge pipe 7B for hydrochloric acid waste water is connected to the supply pipe 3. An unshown opening / closing valve is formed in each of the supply pipe 3, the discharge pipe 4, the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6, the NaOH regeneration waste water discharge pipe 7A and the hydrochloric acid waste water discharge pipe 7B . A sodium ion electrode 9 for measuring the sodium ion (Na ⁺ ) concentration of the resistivity meter 8 and the ion exchange water W1 is formed in the discharge pipe 4. Reference numeral 10 denotes a heater (plate type heat exchanger) formed in the NaOH solution supply pipe 5 and 1B denotes a shield plate having a plurality of holes smaller than the anion exchange resin constituting the anion exchange resin layer 2A.

A method of operating the regenerative ion exchanger as described above will be described. First, in the water sampling mode, the supply pipe 3 and the discharge pipe 4 are made separate, and the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6, the NaOH regeneration waste water discharge pipe 7A and the hydrochloric acid waste water discharge pipe 7B are closed The preprocessed water W is supplied to the cation exchange resin layer 2B from the supply pipe 3 at the lower portion of the tower main body 1A and flows in the upward flow, And then the anion component is removed from the anion exchange resin layer 2A and then supplied to the subsystem (not shown) from the discharge tube 3 as the ion exchange water W1. The water flow condition at this time can be the same as the treatment by the usual ion exchange, and the space velocity is 5 to 100 h ^-1 , particularly 5 to 50 h ^-1 for the ion exchange resin.

Then, when the resistivity of the ion exchange water W1 by the resistivity meter 8 exceeds a predetermined value, the mode is switched to the regeneration mode, and the anion exchange resin layer 2A and the catheter The exchange resin layer 2B is regenerated. This regeneration is carried out by supplying an aqueous solution of sodium hydroxide from the NaOH solution supply pipe 5 with the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6, the NaOH regeneration waste water discharge pipe 7A and the hydrochloric acid waste water discharge pipe 7B, To regenerate the anion exchange resin layer 2A, and to discharge the regenerated chemical liquid from the discharge pipe 7A of the NaOH regeneration wastewater. At this time, in order to efficiently regenerate the anion exchange resin, the sodium hydroxide aqueous solution is preferably heated to about 30 to 50 캜 by the heater 10. On the other hand, hydrochloric acid is supplied from the hydrochloric acid feed pipe 6 connected to the side of the tower main body 1A to regenerate the cation exchange resin layer 2B, and the regenerated medicinal liquid is discharged from the hydrochloric acid waste water discharge pipe 7B.

Subsequently, the ion exchange water W1 is supplied from the NaOH solution supply pipe 5 and discharged from the discharge pipe 7A of the NaOH regeneration wastewater to extrude the NaOH solution used for regeneration, while being discharged from the hydrochloric acid supply pipe 6 The ion exchange water W1 is supplied and discharged from the discharge pipe 7B of the hydrochloric acid wastewater, whereby hydrochloric acid used for regeneration is extruded in a single operation. If the resistivity of the ion exchange water W1 is low or the sodium concentration is high, the regeneration up to this point is preferably carried out two or more times continuously. In the state where the supply pipe 3 and the discharge pipe 4 are opened and the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6, the NaOH regeneration waste water discharge pipe 7A and the hydrochloric acid waste water discharge pipe 7B are closed, The ion-exchange resin is circulated and cleaned by supplying the pretreatment water W from the supply pipe 3 and discharging it from the discharge pipe 4 to produce ion-exchange water W1.

The sodium ion (Na ⁺ ) concentration of the ion-exchanged water W1 is measured by the sodium-ion electrode 9 without supplying the ion-exchanged water W1 produced here to the subsystem. If the circulating washing is insufficient, the sodium ion is contained in the ion-exchanged water W1 largely because of the NaOH solution used for regeneration. Therefore, the regeneration is judged to be suitable when the sodium ion concentration becomes a predetermined value or less, And returns to the sampling mode. At this time, it is also possible to judge whether the regeneration is proper at both the resistivity meter 8 and the resistivity of the ion-exchanged water W1. When the sodium ion concentration exceeds the predetermined value, the circulating washing may be continued. The regeneration type ion exchange apparatus can be operated by alternately repeating the water sampling mode and the regeneration mode.

Based on the sodium ion concentration, it is judged whether or not the regeneration of the anion exchange resin is proper, and after the regeneration is judged to be suitable, the ion exchange water W1 is supplied to the subsystem, The sodium ion (Na < ⁺ & gt ^; ) concentration can be stabilized by keeping it low to a desired value.

Next, a third embodiment of the regenerative ion exchanger of the present invention will be described with reference to Fig. In this embodiment, the same reference numerals are assigned to the same components as those in the first embodiment, and a detailed description thereof will be omitted.

The regenerative ion exchanger shown in Fig. 3 is a mode in which the regenerative ion exchanger is composed of a regenerative ion exchanger alone. In the present embodiment, the regeneration type ion exchange column 1 is of a type that flows in an upward flow, and a cation exchange resin layer 2B and an anion exchange resin layer The ion exchanger 2 is a two-layered ion exchange column formed by separating the ion exchange membranes 2A and 2A from each other. The lower portion of the tower main body 1A is connected to a supply pipe 3 for pretreating water W for ion exchange treatment, And the discharge pipe 4 of the number W1 is connected. A hydrochloric acid (HCl) supply pipe 6 is connected to the discharge pipe 4 as an acid as a regenerant solution. A drain pipe 7B for discharging hydrochloric acid wastewater is connected to the side of the main body 1A. An NaOH solution supply pipe 5 as an alkali is connected to the side of the tower main body 1A and a discharge pipe 7A for the NaOH waste water is connected to the supply pipe 3. [ An unshown opening / closing valve is formed in each of the supply pipe 3, the discharge pipe 4, the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6, the NaOH waste water discharge pipe 7A and the hydrochloric acid waste water discharge pipe 7B have. A chlorine ion electrode 9A for measuring the chlorine ion (Cl ^- ) concentration of the resistivity meter 8 and the ion exchange water W1 is formed in the discharge pipe 4. Reference numeral 10 denotes a heater (plate type heat exchanger) formed in the NaOH solution supply pipe 5 and 1B is a shield plate having a plurality of holes smaller than the cation exchange resin constituting the cation exchange resin layer 2B.

A method of operating the regenerative ion exchanger as described above will be described. First, in the water sampling mode, the supply pipe 3 and the discharge pipe 4 are made separate and the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6, the NaOH waste water discharge pipe 7A and the hydrochloric acid waste water discharge pipe 7B are closed The pretreatment water W is supplied to the anion exchange resin layer 2A from the anion exchange resin layer 2A by removing the anion component from the anion exchange resin layer 2A by supplying the pretreated water W from the supply tube 3 in the lower part of the column body 1A, Then, after removing the cationic component from the cation exchange resin layer 2B, the ion exchange water W1 is discharged from the discharge tube 3 and supplied to a subsystem (not shown). The water flow condition at this time can be the same as the treatment by the usual ion exchange, and the space velocity is 5 to 100 h ^-1 , particularly 5 to 50 h ^-1 for the ion exchange resin.

Then, when the resistivity of the ion exchange water W1 by the resistivity meter 8 exceeds a predetermined value, the mode is switched to the regeneration mode, and the anion exchange resin layer 2A of the regenerative ion exchange column 1A, The exchange resin layer 2B is regenerated. This regeneration is carried out in such a manner that the NaOH solution supply pipe 5 connected to the side of the tower main body 1A is connected to the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6, the NaOH waste water discharge pipe 7A and the hydrochloric acid waste water discharge pipe 7B, The anion exchange resin layer 2A is regenerated by supplying an aqueous solution of sodium hydroxide from the aqueous solution 5 and the regenerated chemical liquid is discharged from the discharge pipe 7A of the NaOH waste water. At this time, in order to efficiently regenerate the anion exchange resin, the sodium hydroxide aqueous solution is preferably heated to about 30 to 50 캜 by the heater 10. On the other hand, hydrochloric acid is supplied from the acid supply pipe 6 at the upper part of the tower main body 1A to regenerate the cation exchange resin layer 2B, and the regenerated chemical liquid is discharged from the hydrochloric acid waste water discharge pipe 7B.

Subsequently, the ion exchange water W1 is supplied from the NaOH solution supply pipe 5 and is discharged from the NaOH waste water discharge pipe 7A to extrude the NaOH solution used for regeneration, And the hydrochloric acid used for regeneration is extruded one by one by supplying the exchange treatment water W1 and the discharge pipe 7B for the hydrochloric acid wastewater. If the resistivity of the ion exchange water W1 is low or the sodium concentration is high, the regeneration to this point is preferably performed two or more times continuously. In the state where the supply pipe 3 and the discharge pipe 4 are opened and the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6, the NaOH regeneration waste water discharge pipe 7A and the hydrochloric acid waste water discharge pipe 7B are closed, The ion-exchange resin is circulated and cleaned by supplying the pretreatment water W from the supply pipe 3 and discharging it from the discharge pipe 4 to produce ion-exchange water W1. The chloride ion (Cl ^- ) concentration of the ion-exchanged water W1 is measured by the chloride ion electrode 9A without supplying the ion-exchanged water W1 produced here to the subsystem. If the circulating washing is insufficient, chlorine ions are contained in the ion-exchanged water W1 largely due to the hydrochloric acid solution used for regeneration, so that the regeneration is judged to be suitable when the chlorine ion concentration becomes a predetermined value or less, And returns to the sampling mode. The regeneration type ion exchange apparatus can be operated by alternately repeating the water sampling mode and the regeneration mode.

As described above, the ion exchange water W1 is not limited to the sodium ion concentration but is determined based on the chloride ion concentration of the chloride ion electrode 9A. (Cl ^- ) concentration of ultrapure water (subsystem treated water) can be kept low to a desired value and stabilized.

A fourth embodiment of the regenerative ion exchanger of the present invention will be described in detail with reference to Fig.

The regenerative ion exchange apparatus shown in Fig. 4 is a so-called two-phase three-column ion exchange apparatus. The regenerative ion exchanger includes a two-layer type regenerated cation exchange resin column (H tower) 11, An apparatus 12, and a two-layer type regenerative anion exchange resin tower (OH tower) 13. The H tower 11 is connected to a supply pipe 14 for supplying pretreatment water W to be subjected to ion exchange treatment and an outlet pipe 15 for ion exchange water W1 is connected to the OH tower 13, And a sodium ion electrode 17 for measuring the sodium ion (Na ⁺ ) concentration of the resistivity meter 16 and the ion exchange water W1 is formed in the discharge pipe 15. [ A hydrochloric acid (HCl) supply pipe 18 as an acid is connected to the upper side of the H tower 11 and a hydrochloric acid (HCl) wastewater is supplied to the supply pipe 14 of the pretreatment water W under the H tower 11 Is connected to the discharge pipe (19). An NaOH solution supply pipe 20 as an alkali is connected to the upper side (discharge side) of the OH tower 13 and a discharge pipe 21 of NaOH solution is connected to the lower side (supply side) of the OH tower 13. Reference numeral 22 denotes a heater (plate type heat exchanger) formed in the NaOH solution supply pipe 20 and 23 denotes a pump for supplying the treated water treated by the degassing apparatus 12 to the OH tower 13. [

In this two-phase three-column ion exchange apparatus, the H tower 11 has a two-layer structure of a weak cation exchange resin layer 11A and a strong cation exchange resin layer 11B, Layer structure of a cation exchange resin layer 13A and a strong cation exchange resin layer 13B. Between the weak cation exchange resin layer 11A and the strong cation exchange resin layer 11B, the weak cation exchange resin layer 13A and the strong cation exchange resin layer 13B, (Not shown) having a plurality of holes smaller than the heat exchange resin.

Next, a method of operating the regenerative ion exchange apparatus as described above will be described. First, in the water collection mode, the pre-treatment water W is passed from the supply pipe 14, and in the H tower 11, the weakly acidic cation component in the weak cation exchange resin layer 11A, The cationic component of the neutral salt is removed from the pretreated water W by the deaerator 12 and the gas such as carbon dioxide dissolved in the pretreated water W is removed by the deaerator 12, The ion-exchanged water W1 can be produced by removing the weakly acidic anion component in the resin layer 13A and the anion component of the neutral salt in the strongly ion-exchanged resin layer 13B, respectively. The ion exchange water W1 is further supplied to the subsystem after various treatments and fine particles are removed as required.

When the resistivity of the ion exchange water W1 by the resistivity meter 16 exceeds a predetermined value, the regeneration mode is switched to open and close the flow path of the H tower 11 appropriately, The cation exchange resins 11A and 11B are regenerated by supplying hydrochloric acid from the hydrochloric acid wastewater 18 and discharged from the discharge pipe 19 of hydrochloric acid wastewater. On the other hand, the flow path of the OH column 13 is suitably opened and closed, and the NaOH solution is supplied from the NaOH solution supply pipe 20 so that the anion exchange resins 13A and 13B are regenerated while being discharged from the discharge pipe 21 of the NaOH solution. In order to efficiently regenerate the anion exchange resins 13A and 13B at this time, the sodium hydroxide aqueous solution is preferably heated to about 30 to 50 DEG C by the heater 22. [

Subsequently, the ion exchange water W1 is supplied from the hydrochloric acid supply pipe 18 to the H tower 11 to extrude the hydrochloric acid used for regeneration from the hydrochloric acid waste water discharge pipe 19 while the OH tower 13 The ion exchange water W1 is supplied from the upper side and the NaOH solution used for the regeneration is extruded from the discharge pipe 21 of the NaOH solution. The HCl column 11 and the deaerator 12 and the OH tower 13 are connected to each other so that the hydrochloric acid supply pipe 18 and the NaOH solution supply pipe 20 are closed and the pretreated water W is passed through the supply pipe 14. [ Circulating washing of the water. The sodium ion (Na ⁺ ) concentration of the ion exchange treated water W1 is measured by the sodium ion electrode 17 without supplying the ion exchange treated water W1 manufactured here to the subsystem. If the circulating washing is insufficient, the sodium ion is contained in the ion-exchanged water W1 largely because of the NaOH solution used for regeneration. Therefore, the regeneration is judged to be suitable when the sodium ion concentration becomes a predetermined value or less, And returns to the sampling mode. The regeneration type ion exchange apparatus can be operated by alternately repeating the water sampling mode and the regeneration mode.

The ion exchange treatment water (W1) of the regenerated anion exchange resin column (OH column) 13, which is the top column of the two or more regenerative ion exchange columns, ) Of the anion exchange resin (13A, 13B) is determined based on the sodium ion concentration, and the ion exchange water (Na ⁺ ) concentration of ultrapure water (subsystem treated water) can be controlled to a desired value by supplying the wastewater (W1) to the subsystem.

Next, a fifth embodiment of the regenerative ion exchanger of the present invention will be described in detail with reference to Fig.

The regenerative ion exchanger shown in Fig. 5 is a so-called three-phase four-column ion exchanger. In this embodiment, the regenerative ion exchange apparatus comprises a two-layered first regenerated cation exchange resin column (H1 column) 31, a degassing unit 32, a two-layer regenerative anion exchange resin (OH tower) 33, and a second regenerated cation exchange resin tower (H2 tower) 34 of a single layer type. A supply pipe 35 for the pretreatment water W for performing the ion exchange treatment is connected to the lower side of the H1 column 31 while a discharge pipe 36 for the ion exchange treated water W1 is connected to the lower side of the H2 column 34, And a chlorine ion electrode 38 for measuring a chlorine ion (Cl ^- ) concentration of the resistivity meter 37 and the ion-exchanged water W1 is formed in the discharge pipe 36. A hydrochloric acid (HCl) supply pipe 39 as an acid is connected to the upper side of the H2 tower 34. A discharge pipe 40 for the hydrochloric acid waste water is connected to the discharge pipe 36. [ The discharge pipe 40 for the hydrochloric acid waste water is connected to the upper side (discharge side) of the H1 tower 31. A waste tube 41 of hydrochloric acid (HCl) waste water is connected to the lower side (supply side) have. An NaOH solution supply pipe 42 as an alkali is connected to the upper side (discharge side) of the OH tower 33 and a drain pipe 43 for the NaOH waste water is connected to the lower side (supply side) of the OH tower 33. Reference numeral 44 denotes a heater (plate type heat exchanger) formed in the NaOH solution supply pipe 42. Reference numeral 45 denotes a pump for supplying the treated water treated by the degassing apparatus 12 to the OH tower 13. [

In this three-phase four-column ion exchange apparatus, the H1 column 31 has a two-layer structure of a weak cation exchange resin layer 31A and a strong cation exchange resin layer 31B, Layer structure of a cation exchange resin layer 33A and a strong cation exchange resin layer 33B. A shielding plate (not shown) having a plurality of holes smaller than the anion exchange resin and the cation exchange resin is formed between the weak cation exchange resin layer 31A and the strong cation exchange resin layer 31B.

The ion-exchanged water W1 is produced by supplying the pretreated water W from the H1 column 31 and discharging it from the H2 column 34 even in the case of the three-phase four-column type ion exchange apparatus as described above, It can be reproduced in the same manner as in the first to fourth embodiments. The chlorine ion electrode 38 for measuring the chloride ion concentration of the ion-exchanged water W1 of the H2 tower 34 at the rearmost column of the two or more regenerative ion exchange columns is formed, Thus, it is possible to control the chlorine ion concentration of the ultrapure water (subsystem treated water) to a desired value by judging the adequacy of regeneration of the cation exchange resin and supplying the ion exchange water W1 to the subsystem.

The sixth embodiment of the regenerative ion exchanger of the present invention will be described in detail with reference to Fig. In the present embodiment, the same reference numerals are assigned to the same components as those in the above-described fifth embodiment, and a detailed description thereof will be omitted.

The regenerative ion exchange apparatus shown in Fig. 6 is a so-called four-phase five-column type ion exchange apparatus and basically comprises a regenerated cation exchange resin column (H2 And a second regenerative anion exchange resin tower (OH2 tower) 46 of a single layer type is formed at the rear end of the tower (34). A drain pipe 36 for the ion exchange water W1 is connected to the lower part of the OH2 column 46. A sodium ion (Na (Na)) of the resistivity meter 37 and the ion- ⁺ & Lt ^{; /} RTI > concentration. An NaOH solution supply pipe 47 as an alkali is connected to the upper side of the OH2 column 46 and a drain pipe 48 for NaOH solution is connected to the lower discharge pipe 36. [ The outlet pipe 48 is connected to the upper side (discharge side) of the first regenerative anion exchange resin tower (OH1 column) 33 as a NaOH solution supply pipe. On the lower side (supply side) of the OH1 column 33, And a waste organs 49 of wastewater are connected.

The ion exchange water W1 is produced by supplying the pretreated water W from the H1 column 31 and discharging it from the OH2 column 44 even in the four-phase five-column type ion exchanger as described above, It can be reproduced in the same manner as in the first to fifth embodiments. By forming the sodium ion electrode 38A for measuring the sodium ion concentration of the ion-exchanged water W1 of the OH2 column 44, which is the topmost tower of the two or more regenerative ion exchange columns, Thus, it is possible to control the chlorine ion concentration of the ultrapure water (subsystem treated water) to a desired value by judging the adequacy of regeneration of the cation exchange resin and supplying the ion exchange water W1 to the subsystem.

While the present invention has been described with reference to the accompanying drawings, it is to be understood that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configuration of the regenerative ion exchanger is not limited to the above-described embodiments, and various modifications are possible. A known water treatment element such as a reverse osmosis membrane separation device can be formed at the front end of the regenerative ion exchanger. When the resistivity of the ion exchange water W1 by the resistivity meter exceeds a predetermined value, the mode is switched to the regeneration mode. However, the ion exchange water W1 of a predetermined volume may be regenerated by regeneration. Also, the timing of regeneration may be measured in addition to the resistivity meter.

Example

The present invention will be described in more detail with reference to the following specific examples.

[Example 1]

1, "PK228L" (Porous type) manufactured by Mitsubishi Chemical Corporation as a cation exchange resin and "PA312L" (Porous type) manufactured by Mitsubishi Chemical Corporation as anion exchange resin were mixed in a cation exchange resin: 2 (volume ratio) was charged to form an ion-exchange resin layer 2, whereby a one-tower type regenerative ion exchanger was constructed. "MX-3" manufactured by Kurita Kogyo Co., Ltd. and "swan AMI Soditrace" manufactured by Tee & Technical Co., Ltd. were used as the sodium ion (Na ⁺ ) electrode 9 as the resistivity meter 8, respectively.

The one-tower type regenerative ion exchanger is firstly passed through the pre-treatment water W in the water intake mode at a space velocity (SV) of 40 h ^-1 with respect to the volume of the ion exchange resin layer 2, (W1) and the sodium ion (Na ⁺ ) concentration were measured. Further, the ion exchange water W1 was supplied to a subsystem equipped with a non-raw material ion exchange device formed at the subsequent stage, and the sodium ion concentration of the subsystem treatment water was measured by ICP-MS ("7500cs" manufactured by Agilent Technologies, ). As a non-production type ion exchange apparatus, one filled with cation exchange resin: anion exchange resin = 1: 1.6 (volume ratio) was used and water was passed at SV = 80 h ^-1 .

When the resistivity of the ion exchange water W1 by the resistivity meter 8 is less than 18.0 M? 占 ㎝ m, the water supply is stopped and then the regeneration mode is switched to the ion exchange water W1 Was supplied and discharged from the supply pipe 3 to back up the mixed resin constituting the ion exchange resin layer 2 and to separate the cation exchange resin to the upper side and the anion exchange resin to the upper side.

Then, an aqueous sodium hydroxide solution adjusted to 4% was supplied from the NaOH solution supply pipe 5 in the state where the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6 and the regeneration waste water discharge pipe 7 were united, The exchange resin is regenerated and industrial-use hydrochloric acid (HCl) adjusted to 5% from the hydrochloric acid (HCl) supply pipe 6 is supplied to regenerate the cationic exchange resin distributed on the lower side. These sodium hydroxide aqueous solution and hydrochloric acid- (7). At this time, in order to efficiently regenerate the anion exchange resin, the sodium hydroxide aqueous solution was heated to 40 캜 by the heater 10.

Subsequently, in the state where the supply pipe 3 and the discharge pipe 4 are formed separately and the NaOH solution supply pipe 5, the hydrochloric acid supply pipe 6 and the regeneration waste water discharge pipe 7 are closed, The aqueous solution (sodium hydroxide solution and hydrochloric acid) used for regeneration is extruded by feeding the water W1 and discharged from the supply pipe 3, and then the pretreated water W is circulated to circulate the ion exchange resin Respectively. At this time, the resistivity of the treated water W1 was measured by a resistivity meter 8, and the sodium ion (Na ⁺ ) concentration was measured by the sodium ion electrode 9 to measure the resistivity of 18.0 MΩ · cm or more, Na ⁺ ) concentration became 300 ng / liter or less, the regeneration was completed and the regeneration operation was completed.

Next, the regenerative ion exchange apparatus is switched to the collection mode again, the pre-treatment water W is circulated to the regenerative ion exchange apparatus to restart the water supply, and the non-regenerated ion exchange And supplied to the subsystem equipped with the device. When the resistivity of the treated water of the ion-exchanged water W1 became less than 18.0 M? · Cm, the operation of stopping the water supply and regenerating and collecting water was repeated 8 times in the same manner. Table 1 shows the results of measuring the resistivity and sodium ion (Na < ⁺ & gt ^; ) concentration of the ion-exchanged water W1 12 hours after the start of water collection in this regenerative ion exchange apparatus. The sodium ion (Na ⁺ ) concentration in the treated water of the non-cultured ion exchanger of the subsystem formed at the rear end was measured. The results are shown in Table 2.

[Comparative Example 1]

The regeneration mode of the regenerative ion exchanger was terminated at a point when the resistivity of the resistivity meter 8 reached 18.0 M? 占 ㎝ m or more, and the mode was switched to the collection mode without forming the sodium ion electrode 9 in Example 1 , And the operation of regeneration and water sampling was repeated 8 times in the same manner except that the pretreated water W was circulated to the regenerative ion exchanger and the water supply was resumed. The results of measurement of the resistivity and sodium ion (Na ⁺ ) concentration of the ion-exchanged water W1 after 12 hours from the start of water collection of this regenerative ion exchange apparatus are shown in Table 1. The sodium ion (Na ⁺ ) concentration in the treated water of the non-cultured ion exchanger of the subsystem formed at the rear end was measured. The results are also shown in Table 2.

[Reference Example]

In Example 1, the regeneration was stopped when the resistivity of the ion-exchanged water (W1) of the regenerative ion exchanger became less than 18.0 M? · Cm, and the regeneration was performed in the regeneration mode. This regeneration was carried out by regenerating the anion exchange resin separated by backwashing and the cation exchange resin in an aqueous solution of by-product hydrochloric acid (HCl) adjusted to 5%, and having a resistivity of 18.0 MΩ · cm or more , And the regeneration operation was terminated at the time when the sodium ion (Na ⁺ ) concentration became 300 ng / liter or less. In addition, the regeneration operation was repeated twice for the fifth and eighth times when the sodium ion (Na ⁺ ) concentration of the ion-exchanged water W1 at the time of collection was 500 ng / liter or more. The results of measurement of the resistivity and sodium ion (Na ⁺ ) concentration of the ion-exchanged water W1 after 12 hours from the start of water collection of this regenerative ion exchange apparatus are shown in Table 1. The sodium ion (Na ⁺ ) concentration in the treated water of the non-cultured ion exchanger of the subsystem formed at the rear end was measured. The results are also shown in Table 2.

[Comparative Example 2]

In the reference example, the regeneration mode of the regenerative ion exchanger is terminated at the time when the resistivity reaches 18.0 M? 占 ㎝ m or more and the mode is switched to the water intake mode without forming the sodium ion electrode 9, The operation of regeneration and water sampling was repeated 8 times in the same manner except that the pretreated water W was circulated and the water supply was resumed. The results of measurement of the resistivity and sodium ion (Na ⁺ ) concentration of the ion-exchanged water W1 after 12 hours from the start of water collection of this regenerative ion exchange apparatus are shown in Table 1. The sodium ion (Na ⁺ ) concentration in the treated water of the non-cultured ion exchanger of the subsystem formed at the rear end was measured. The results are also shown in Table 2.

As is apparent from Table 1, according to the operation method of the regenerative ion exchanger of Example 1, the rest of the regeneration of the ion-exchanged water W1 is performed with the sodium ion (Na ⁺ ) concentration measured by the sodium ion electrode 9 It is possible to control the concentration of sodium ions (Na ⁺ ) after 12 hours from the start of water sampling to 300 ng / liter or less, (Na ^< ⁺ & gt ^; ) concentration exceeded 300 ng / l. Further, when only the cation exchange water is regenerated as in the reference example, since the anion exchange resin is not regenerated, the sodium ion concentration is large.

As apparent from Table 2, according to the operation method of the regenerative ion exchanger of Example 1, the rest of the regeneration of the ion-exchanged water W1 is performed with the sodium ion (Na ⁺ ) concentration measured by the sodium ion electrode 9 It can be seen that the sodium (Na ⁺ ) concentration of the treated water of the non-cultured ion exchange apparatus of the downstream subsystem can be controlled to be low and the fluctuation width can be controlled to be small.

From these results, it is possible to reconsider the regeneration condition by managing the quality of the regenerated ion exchanger in regeneration with the sodium ion (Na ⁺ ) concentration measured by the sodium ion electrode 9, It can be seen that the short-term variation of the sodium ion (Na ⁺ ) concentration of the treated water of the ion exchange apparatus can be controlled.

1 regenerative ion exchange column
5 NaOH solution supply pipe
6 Hydrochloric acid (HCl) feed tube
7 Waste water discharge pipe
7A NaOH waste water discharge pipe
7B HCl wastewater discharge pipe
8, 16, 37 Resistivity meter
9, 17, 38A Sodium ion electrode (ion electrode)
9A, 38 Chlorine ion electrode (ion electrode)
11 Two-layer type regenerated cation exchange resin tower (H tower)
12, 32 Deaerator
13 2-layer type regenerative anion exchange resin tower (OH tower)
18 hydrochloric acid (HCl) feed tube
19 Hydrochloric acid (HCl) Wastewater discharge pipe
20 NaOH solution supply pipe
21 NaOH solution outlet pipe
31 Two-layered first regenerated cation exchange resin column (H1 tower)
33 Replaceable anion exchange resin top (OH top) (2nd regenerative anion exchange resin top (OH1 top))
34 Second regeneration type cation exchange resin tower (H2 tower)
39 hydrochloric acid (HCl) feed line
40 Hydrochloric acid (HCl) waste water discharge pipe
41 Lung organ of hydrochloric acid (HCl) wastewater
42 NaOH solution supply pipe
43 NaOH waste water discharge pipe
46 2nd regenerative anion exchange resin tower (OH2 tower)
47 NaOH solution supply pipe
48 NaOH solution outlet pipe
W preprocessing water
W1 ion exchange water treatment

Claims (6)

1. A regenerative ion exchanger having a regenerative ion exchange column alone, the regenerative ion exchange apparatus comprising an ion electrode for measuring the ion concentration of the treated water of the regenerative ion exchange column alone. A regeneration type ion exchange apparatus comprising a plurality of regenerative ion exchange columns and a plurality of columns including a degassing apparatus, characterized in that an ion electrode And an ion exchange device. 3. The method according to claim 1 or 2,
Wherein the regeneration type ion exchange column for measuring the ion concentration by the ion electrode is charged with at least an anion exchange resin and the ion electrode is a sodium ion electrode for measuring the sodium ion (Na ⁺ ) concentration of the treated water Ion exchange device. The ion concentration of the treated water after the regeneration of the regenerative ion exchanger having the regenerative ion exchanger alone is measured by the ion electrode and the regeneration of the regenerated ion exchanger is performed based on the ion concentration measured by the ion electrode Wherein the regeneration type ion exchange apparatus comprises: The ion concentration of the treated water after the regeneration of the column at the rearmost end of the regenerative ion exchange apparatus comprising a plurality of regenerative ion exchange columns and a plurality of columns including the degassing apparatus is measured by the ion electrode, And regeneration of the regenerative ion exchange column is controlled based on the ion concentration of the regenerated ion exchanger. The method according to claim 4 or 5,
A regeneration type ion exchange column for measuring the ion concentration by the ion electrode is filled with at least an anion exchange resin and the ion electrode is a sodium ion electrode for measuring a sodium ion (Na ⁺ ) concentration, Wherein the sodium ion concentration of the treated water after the regeneration of the regenerated ion exchange column is measured by the sodium ion electrode and regeneration of the regenerative ion exchange column is managed.

Images