JP2016135464A - Ion exchange resin regeneration method, ion exchange resin regeneration apparatus, and spent dialysis liquid regeneration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel regeneration method and apparatus for an ion exchange resin.SOLUTION: The ion exchange resin regeneration method is an ion exchange resin regeneration method in which, as a result of contact with a treatment liquid 22 comprising an object substance to be removed which is an organic compound having a polarity, an ion exchange resin 80 to which the object substance to be removed is adhering is regenerated. The method includes a regeneration step for desorbing the object substance to be removed adhering to the ion exchange resin 80 by bringing an organic solvent 32 into contact with the ion exchange resin 80; and the ion exchange resin regeneration apparatus includes regeneration means capable of implementing said regeneration step.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ion exchange resin regeneration method, an ion exchange resin regeneration device, and a used dialysate regeneration method.

  An ion exchange resin which is a kind of synthetic resin has a functional group having a structure capable of being ionized in a part of a molecular structure. By bringing the treatment liquid into contact with the ion exchange resin, the substance to be removed contained in the treatment liquid adheres to the ion exchange resin, and the substance to be removed is removed from the treatment liquid. When a certain amount of the substance to be removed adheres to the ion exchange resin, the ion exchange capacity is reduced or lost. However, it is known that the ion exchange resin can be regenerated by subsequently detaching the substance to be removed attached to the ion exchange resin.

As a method for regenerating an ion exchange resin, a method is generally known in which an acidic or alkaline chemical solution is injected into an ion exchange resin to desorb a substance to be removed attached to the ion exchange resin. Specifically, an aqueous hydrochloric acid solution or an aqueous sulfuric acid solution is used as the chemical solution for the cation exchange resin, and an aqueous sodium hydroxide solution is used for the anion exchange resin (for example, Patent Document 1).
Patent Document 2 will be described later.

JP 2000-254524 A Japanese Patent Laid-Open No. 2001-199918

For example, by injecting an acidic chemical into a cation exchange resin to which the substance to be removed is attached, it is possible to release the substance to be removed and to incorporate hydrogen ions into the functional group. It is widely known that can be reproduced.
The conventionally known methods for regenerating an ion exchange resin described above are methods that are substantially appropriate theoretically in view of the ion exchange ability of the ion exchange resin. For this reason, there has been almost no proposal for a novel method for regenerating ion exchange resins.

  The present invention proposes a novel regeneration method and regeneration apparatus for an ion exchange resin, and a spent dialysate regeneration method using the regeneration method.

  An ion exchange resin regeneration method of the present invention is an ion exchange resin regeneration method for regenerating an ion exchange resin to which the substance to be removed is adhered by contacting with a treatment liquid containing the substance to be removed which is an organic compound having polarity. And a regeneration step of desorbing the substance to be removed attached to the ion exchange resin by bringing the organic solvent into contact with the ion exchange resin.

  The ion exchange resin regeneration apparatus of the present invention is an ion exchange resin regeneration apparatus for carrying out the ion exchange resin regeneration method of the present invention, and the substance to be removed adheres to the treatment liquid containing the substance to be removed. Regeneration means for desorbing the substance to be removed by bringing an organic solvent into contact with the ion exchange resin is provided.

  Further, the used dialysate regeneration method of the present invention is the ion exchange resin regeneration method of the present invention, wherein the substance to be removed is contained in the treatment liquid by bringing the ion exchange resin into contact with the treatment liquid. After removing the step of attaching the ion exchange resin to the ion exchange resin and the separation step of separating the treated liquid obtained by bringing the treatment liquid into contact with the ion exchange resin from the ion exchange resin. A substance to be removed, which includes an ion exchange resin regeneration method for performing a regeneration step, and is brought into contact with a strongly acidic cation exchange resin and a first used dialysate to be contained in the first used dialysate A removal step of removing urea by attaching it to the strong acid cation exchange resin, and a regenerated dialysate which is a treated solution obtained by bringing the first used dialysate into contact with the strong acid cation exchange resin Strong acid cation exchange resin And then separating the urea adhering to the strongly acidic cation exchange resin by bringing the alcohol into contact with the strongly acidic cation exchange resin, Using the strongly acidic cation exchange resin regenerated in the regeneration step, the removal step and the separation step are performed using a second used dialysate different from the first used dialysate. And

  The ion exchange resin regeneration method and ion exchange resin regeneration apparatus of the present invention are a novel method and apparatus using an organic solvent as a chemical solution for an ion exchange resin. The present invention relates to regeneration of an ion exchange resin, reveals that an organic solvent can be used as a chemical solution, broadens the choice of chemical solution, and improves the convenience and efficiency of the ion exchange resin regeneration method.

  Moreover, according to the used dialysate regeneration method of the present invention, it is possible to repeatedly regenerate and use the used dialysate that has been discarded.

It is a conceptual diagram of the ion exchange resin reproduction | regeneration apparatus concerning 1st embodiment of this invention. It is a conceptual diagram of the ion exchange resin reproduction | regeneration apparatus concerning 2nd embodiment of this invention.

Hereinafter, embodiments of the present invention will be described. In all the drawings used for the description of the present invention, the same components are denoted by the same reference numerals, and redundant description will be appropriately omitted.
The various constituent elements of the ion exchange resin regeneration apparatus of the present invention do not have to be independent of each other, but a plurality of constituent elements are formed as one member, and one constituent element is a plurality of members. It is allowed to be formed, a certain component is a part of another component, a part of a certain component overlaps a part of another component, and the like.

The ion exchange resin regeneration method of the present invention (hereinafter, also simply referred to as the method of the present invention) is a method in which an ion exchange resin to which a substance to be removed has adhered is brought into contact with a treatment liquid containing the substance to be removed, which is a polar organic compound. Reproduce. The method of the present invention includes a regeneration step of desorbing a substance to be removed attached to an ion exchange resin by bringing an organic solvent into contact with the ion exchange resin.
In the present invention, the contact between the ion exchange resin and the treatment liquid includes both an aspect in which the ion exchange resin and the treatment liquid are in direct contact and an aspect in which the ion exchange resin is in indirect contact. Examples of the mode in which the ion exchange resin and the processing liquid are in direct contact include a column system in which the processing liquid is dropped onto a column filled with the ion exchange resin, or a batch system in which the ion exchange resin and the processing liquid are stirred and mixed. can do. As an aspect in which the ion exchange resin and the treatment liquid are in contact with each other, a method of confronting the ion exchange resin and the treatment liquid through a membrane through which urea contained in the treatment liquid or the treatment liquid can pass is exemplified. it can. The treatment liquid or the urea that has passed through the membrane and moved to the ion exchange resin side comes into direct contact with the ion exchange resin. The membrane may be in various forms such as a film or a tube such as a hollow fiber.

  The method of the present invention enables the implementation of a novel ion exchange resin regeneration method. More specifically, the method of the present invention uses an organic solvent as a chemical solution for the regeneration of the ion exchange resin. According to the present invention, with respect to ion exchange resin regeneration, the range of selection of chemicals is expanded, and convenience and versatility are expanded.

  In the present invention, the ion exchange resin can remove the substance to be removed from the treatment liquid by adhering the substance to be removed contained in the treatment liquid, and the resin is generally understood as an ion exchange resin. It is selected appropriately. The ion exchange resins are roughly classified into cation exchange resins and anion exchange resins. The cation exchange resin includes a strong acid cation exchange resin and a weak acid cation exchange resin, and the anion exchange resin includes a strong base anion exchange resin and a weak base anion exchange resin.

  In the present invention, the regeneration of the ion exchange resin means that a part or all of the substance to be removed is desorbed from the ion exchange resin to which the substance to be removed contained in the treatment liquid adheres. The regenerated ion exchange resin can be used again for removing the substance to be removed contained in the treatment liquid.

  The substance to be removed in the present invention is not particularly limited as long as it is an organic compound having a polarity, and examples thereof include urea and glucose. In other words, the substance to be removed is a compound having an electrical bias in the molecule and containing carbon. The substance to be removed can be attached to a functional group having an ionizable structure provided in the ion exchange resin by having polarity. Here, the term “adhesion” widely includes that the substance to be removed temporarily increases around the ion exchange resin. For example, the ion exchange between the ion exchange resin and the substance to be removed, or the ion exchange resin and the substance to be removed. Including hydrogen bonding. In the ion exchange, ions are released from an ion exchange resin (particularly a functional group having ion exchange ability of the ion exchange resin), and a compound contained in the treatment liquid is ionized and taken into the ion exchange resin. Means ion exchange. The hydrogen bond means that the substance to be removed is electrostatically intermolecularly bonded to an ion exchange resin (particularly a functional group having ion exchange ability of the ion exchange resin).

  The treatment liquid is a liquid containing a substance to be removed. The liquid that can be included in the treatment liquid is not particularly limited, and widely includes a solvent or a dispersion medium. The treatment liquid may contain any other compound other than the substance to be removed.

  The organic solvent used in the present invention may be any solvent that can remove the substance to be removed from the ion exchange resin, and examples thereof include alcohols such as methanol or ethanol, benzene, and acetone. It is not limited to. In the method of the present invention, as the organic solvent, for example, it is preferable to select an organic solvent whose solubility in the substance to be removed is larger than that in the ion exchange resin to which the substance to be removed is attached.

  The organic solvent used in the method of the present invention preferably contains an alcohol. In particular, it is preferable that the organic solvent consists essentially of alcohol. This is because alcohol is generally easy to handle among organic solvents.

As the alcohol, one containing methanol or ethanol is preferably selected.
In particular, as the organic solvent, it is preferable to use an organic solvent mainly containing methanol, an organic solvent mainly containing ethanol, or an organic solvent mainly containing a mixed alcohol of methanol and ethanol. Here, the main component means that 60% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, particularly preferably 95% by mass or more is contained as a main component with respect to 100% by mass of the organic solvent. . For example, the alcohol has a concentration of 70% or higher, preferably 80% or higher, more preferably 90% or higher, more preferably 95% or higher, and a concentration of 99%. The above is particularly preferable. More specifically, in the present invention, an alcohol having a purity of 99.5% which is a reagent grade 1 or an alcohol having a purity of 99.8% which is a reagent special grade is particularly preferably used.

  By using methanol or ethanol as the main component of the organic solvent, it is possible to regenerate an ion exchange resin in which a substance to be removed having a high solubility is attached to these alcohols. As a specific example, the substance to be removed can be detached from the ion exchange resin by bringing an alcohol such as methanol or ethanol into contact with the ion exchange resin to which the substance to be removed such as urea or glucose is attached. is there.

For example, when a urea-containing liquid is brought into contact with a strong acid cation exchange resin, it is known that urea can be removed by adhering to the strong acid cation exchange resin. Conventionally, for regeneration of strongly acidic cation exchange resins to which substances to be removed are attached, it has been common technical knowledge to use hydrochloric acid or an acidic aqueous solution such as sulfuric acid as a chemical solution.
On the other hand, by selecting alcohol (for example, methanol or ethanol) as a chemical solution and bringing it into contact with a strongly acidic cation exchange resin to which urea is attached, urea can be desorbed from the strongly acidic cation exchange resin with high efficiency. it can. The reason for this is not clear, but urea has a high solubility in alcohol, such as about 167 g dissolved in 1 liter of methanol having a concentration of 99.8% or more and about 50 g dissolved in 1 liter of ethanol having a concentration of 99.8% or more. . Therefore, it is considered that urea can be desorbed from the strongly acidic cation exchange resin not by regeneration by ion exchange as in the prior art but by desorption by dissolution.

Therefore, when the substance to be removed contains urea, the ion exchange resin is well regenerated by the method of the present invention. That is, when the ion exchange resin regenerated in the method of the present invention is an ion exchange resin obtained by treating a treatment liquid containing urea as a substance to be removed, the effects of the present invention are exhibited very well. The treatment liquid containing urea as a substance to be removed (that is, a urea-containing liquid) may be industrial waste or the like, or may be a used dialysis liquid used for artificial dialysis.
More specifically, in the method of the present invention, the alcohol is brought into contact with the strongly acidic cation exchange resin to which urea is attached, which is generated by bringing the urea-containing liquid into contact, thereby efficiently removing the strong acid cation exchange resin. It is possible to desorb urea. Therefore, it is possible to regenerate the strongly acidic cation exchange resin used in the removing step for removing urea from the used dialysate, for example, by contacting with an organic solvent. By using the method of the present invention, it is possible to regenerate a strong acid cation exchange resin once used in the regeneration of used dialysate and repeatedly use it for regeneration of used dialysate. In particular, methanol has a very high urea solubility as described above. Therefore, the strongly acidic cation exchange resin regenerated using methanol can be regenerated to a level close to the adhesion capability before use (before urea adhesion), and has high reliability in reuse after regeneration.

  When an adult weighing 50 to 80 kg is subjected to an artificial dialysis treatment for one day, the amount of urea excluded from the adult is about 20 g to about 32 g, and the dialysate used is about 100 L to about 150 L. is there. Thus, spent dialysate typically contains urea at a concentration of about 133 mg / l to about 320 mg / l.

  The aspect of this invention which selects alcohol as a chemical | medical solution may further have the distillation process which distills the used alcohol isolate | separated from the ion exchange resin after the regeneration process mentioned above, and refine | purifies used alcohol. Thus, by selecting alcohol as the chemical solution, the chemical solution can be easily purified, and the alcohol can be reused as the chemical solution.

The above-described method of the present invention can be carried out using the ion exchange resin recycling apparatus of the present invention (hereinafter also referred to as the apparatus of the present invention).
That is, the apparatus of the present invention includes a regenerating unit that contacts an ion exchange resin to which a substance to be removed has adhered due to contact with a treatment liquid containing the substance to be removed to desorb the substance to be removed. The apparatus of the present invention, together with the method of the present invention, realizes the regeneration of a new ion exchange resin.

  The regeneration means may be any means that can bring the ion exchange resin to which the substance to be removed is attached into contact with the organic solvent. Various conditions such as a specific method or time for performing the contact in the reproducing means can be determined as appropriate. Examples of regeneration means include means for filling a column with an ion exchange resin and passing an organic solvent through the column, means for bringing the organic solvent into contact with the ion exchange resin with the substance to be removed, stirring and mixing, or A means for spraying an organic solvent with a shower or the like on the ion exchange resin to which the removal substance is attached can be exemplified. However, the specific configuration of the reproducing means is not limited to these. The apparatus of the present invention may have any other means such as a distillation means for performing the above-described distillation step in addition to the regeneration means.

The method and apparatus of the present invention include a removing step (removing means) for removing a substance to be removed by bringing a treatment liquid containing the substance to be removed into contact with the ion exchange resin, and a regeneration step (reproducing means) for the ion exchange resin. May be performed by different apparatuses or by the same apparatus.
Hereinafter, an embodiment of the present invention in which the removal step (removal unit) and the regeneration step (regeneration unit) are performed in the same apparatus will be described.

(First embodiment)
A first embodiment of the method and apparatus of the present invention will be described below with reference to FIG. FIG. 1 is a conceptual diagram of an ion exchange resin regeneration device 100 (hereinafter also simply referred to as device 100) according to the first embodiment of the present invention.

  The apparatus 100 includes the following configuration in addition to the reproduction unit described above. That is, the apparatus 100 brings the ion exchange resin 80 and the treatment liquid 22 into contact with each other and removes a substance to be removed (not shown) contained in the treatment liquid 22 by attaching it to the ion exchange resin 80. And separation means for separating the treated liquid 52 obtained by bringing the treatment liquid 22 into contact with the ion exchange resin 80 from the ion exchange resin 80. According to the apparatus 100, in one apparatus, the treatment liquid 22 can be treated and the ion exchange resin 80 used for the treatment can be regenerated. Therefore, the treatment liquid 22 can be treated continuously or repeatedly.

In addition, by using the apparatus 100, the method of the present invention including a removal process and a separation process in addition to the above-described regeneration process can be performed in one apparatus. Here, the removing step is a step in which the ion exchange resin 80 and the treatment liquid 22 are brought into contact with each other to remove a substance to be removed contained in the treatment liquid 22 by attaching it to the ion exchange resin 80. The separation step is a step of separating the treated liquid 52 obtained by bringing the treatment liquid 22 into contact with the ion exchange resin 80 from the ion exchange resin 80. For example, the regeneration process is performed after the removal process and the separation process.
However, the apparatus 100 is only an example for carrying out the method of the present invention including a regeneration step, a removal step, and a separation step, and the method of the present invention performs each step using two or more devices. It does not exclude doing.

Details of the apparatus 100 will be described below with reference to FIG.
The apparatus 100 includes a removal tank 10 filled with an ion exchange resin 80. In the present embodiment, the apparatus 100 including one removal tank 10 will be described as an example, but the number of the removal tanks 10 can be changed as appropriate. The removal tank 10 is filled with an ion exchange resin 80 capable of adhering a substance to be removed contained in the treatment liquid 22 described later. The ion exchange resin 80 may be one kind of ion exchange resin, two or more kinds of ion exchange resins having different chemical structures, or a mixed bed of a cation exchange resin and an anion exchange resin.

  The removal tank 10 is connected to the treatment liquid tank 20 in which the treatment liquid 22 is accommodated by a flowable line 112, and the treatment liquid 22 is appropriately fed from the treatment liquid tank 20 to the removal tank 10. In the description of the present specification, the term “line” means a flow path through which a liquid material can flow unless otherwise specified. The treatment liquid tank 20 may contain a urea-containing liquid such as a used dialysate, but is not limited thereto. When the urea-containing liquid is stored as the processing liquid 22 in the processing liquid tank 20, it is desirable that the ion exchange resin 80 contains a strong acid cation exchange resin, and the ion exchange resin 80 is substantially a strong acid. It may be composed of a cationic cation exchange resin. For example, the processing liquid 22 may be sent to the processing liquid tank 20 from another apparatus such as an artificial dialysis apparatus through a line not shown.

  Examples of the removal tank 10 include, but are not limited to, a column filled with the ion exchange resin 80 or a mixing device capable of stirring and mixing the ion exchange resin 80 and the treatment liquid 22.

  The treatment liquid 22 is sent from the line 112 to the removal tank 10, the ion exchange resin 80 and the treatment liquid 22 come into contact, and the substance to be removed contained in the treatment liquid 22 adheres to the ion exchange resin 80. As a result, the removing step is performed in the apparatus 100.

  As described above, the treated liquid 52 is obtained by bringing the treatment liquid 22 into contact with the ion exchange resin 80 and performing the removing step. The treated liquid 52 is separated from the ion exchange resin 80 by the separation means in the apparatus 100. The separation means in the apparatus 100 is not particularly limited as long as the treated liquid 52 and the ion exchange resin 80 can be separated. For example, as the separating means, the treated liquid 52 obtained by carrying out the removing step may be discharged from the removing tank 10 which is a column filled with the ion exchange resin 80 by applying its own weight or pressure. As another separation means, after the removal step, the ion exchange resin 80 is selectively removed from the mixture of the treated liquid 52 and the ion exchange resin 80 to separate them, and then the treated liquid 52 is removed from the removal tank 10. You may take it out. As described above, the separation process is performed in the apparatus 100.

  The treated liquid 52 separated from the ion exchange resin 80 by performing the separation step is sent to the treated liquid tank 50 through the line 114 and stored therein, for example. The line 114 connects the removal tank 10 and the processed liquid tank 50. In the present embodiment, the line 114 is provided with an on-off valve 125. The on-off valve 125 is opened in the apparatus 100 when the removal step and the separation step are being performed, and is closed when the regeneration step described later is performed. In the present embodiment, the ion exchange resin 80 to which the substance to be removed is attached exists in the removal tank 10 after the removal process and the separation process are completed as described above.

The apparatus 100 has a regeneration means for bringing the substance to be removed into contact with the ion exchange resin 80 to which the substance to be removed is attached by bringing the organic solvent 32 as a chemical solution into contact therewith. Thereby, the regeneration process can be performed in the apparatus 100. By carrying out the regeneration process, the ion exchange resin 80 is regenerated and the ability to attach the substance to be removed is recovered.
The regeneration means is not particularly limited as long as the ion exchange resin 80 to which the substance to be removed is attached and the organic solvent 32 can be brought into contact with each other. For example, the apparatus 100 includes a line 118 that connects the chemical tank 30 filled with the organic solvent 32 and the removal tank 10 as the regeneration means, and injects the organic solvent 32 into the removal tank 10 through the line 118, The solvent 32 and the ion exchange resin 80 can be brought into contact with each other. Note that FIG. 1 shows an example in which the line 118 and the line 112 are independently connected to the removal tank 10, but the line 118 and the line 112 merge at an intermediate portion and serve as a single flow passage. 10 (not shown).

  As another example of the regenerating means not shown, the ion exchange resin 80 to which the substance to be removed is attached is taken out from the removal tank 10 and the organic solvent 32 and the organic solvent 32 are brought into contact with each other in a different environment from the removal tank 10. You may implement a reproduction | regeneration process by the reproduction | regeneration means by the thing.

  In the apparatus 100, after the regeneration process is performed by the regeneration means, the organic solvent 32 containing the substance to be removed desorbed from the ion exchange resin 80 is separated from the ion exchange resin 80. The separation means here is not particularly limited, and the description of the separation means (separation step) for separating the treated liquid 52 from the ion exchange resin 80 is appropriately referred to.

  The apparatus 100 of the present embodiment includes a distillation unit 60 and / or a waste liquid tank 70, and the organic solvent 32 separated from the ion exchange resin 80 is sent to the distillation unit 60 or the waste liquid tank 70. For example, when the separated organic solvent 32 is regenerated, the organic solvent 32 is discharged from the removal tank 10 through a line 122 which is a discharge path provided in the removal tank 10 and flows through a line 128 connected to the line 122. Then, it is sent to the distillation unit 60. Further, when the separated organic solvent 32 is discarded, the organic solvent 32 may be discharged from the removal tank 10 through the line 122 and may be sent to the waste liquid tank 70 through the line 126 connected to the line 122.

  The apparatus 100 according to the present embodiment has a three-way valve 124 at a branch point between the line 122, the line 126, and the line 128, and selectively circulates the liquid material flowing from the line 122 to the line 126 or line 128. be able to. For example, the three-way valve 124 can be electromagnetically or manually switched to completely shut off the liquid flowing from the line 132, to flow to the line 128, or to flow to the line 126.

When the organic solvent 32 is alcohol, the apparatus 100 preferably includes a distillation unit 60. In the distillation unit 60, the apparatus 100 including the distillation unit 60 distills the organic solvent 32 (spent alcohol) separated from the ion exchange resin 80 after the regeneration step, and the organic solvent 32 (substantially free of a substance to be removed) ( Alcohol) can be purified. That is, a distillation step of distilling the organic solvent 32 in the distillation unit 60 is performed. The distillation unit 60 includes, for example, an evaporator that can recover the organic solvent 32 purified by distilling the organic solvent 32 under reduced pressure. In the present embodiment, as shown in FIG. 1, the distillation unit 60 is connected to the chemical tank 30 by a line 150. The organic solvent 32, which is alcohol distilled by the distillation unit 60, is discharged from the distillation unit 60, circulated through the line 150, sent to the chemical tank 30, and can be used again in a regeneration process for regenerating the ion exchange resin 80.
Conventionally, as a recovery method for recovering alcohol with high yield from an aqueous solution containing an organic compound or the like and alcohol, as described in Patent Document 2, an appropriate additive is added to the aqueous solution, methanol, A method for recovering organic compounds and the like has been proposed. On the other hand, in the present embodiment, no special additive is required, and the organic solvent 32 (used alcohol) separated from the ion exchange resin 80 after the regeneration step can be distilled and recovered in the distillation unit 60. In particular, by using an alcohol having a preferable concentration range described above, the alcohol can be recovered with a high yield without using an additive. More specifically, for example, the organic solvent 32, which is used methanol containing urea as a substance to be removed, is discharged from the removal tank 10, and it is not necessary to add a special additive. 60 can be recovered with high efficiency (for example, 70% or more). As a result, high-purity methanol can be recovered from the spent methanol.

  After the regeneration process is performed and then the ion exchange resin 80 and the organic solvent 32 are separated, a cleaning process may be further performed to clean the regenerated ion exchange resin 80. For example, the apparatus 100 includes a cleaning liquid tank 40 in which a cleaning liquid 42 such as pure water is accommodated, as shown in FIG. The cleaning liquid tank 40 is connected to the removal tank 10 by a line 116 and a line 118, and a cleaning liquid 42 such as pure water is fed into the removal tank 10 at an appropriate timing. The cleaning liquid 42 fed into the removal tank 10 can come into contact with the ion exchange resin 80 and wash away and wash the organic solvent 32 remaining in the removal tank 10. The line 118 is provided with a pump 120, and when the organic solvent 32 or the cleaning liquid 42 is circulated through the removal tank 10, pressure can be applied to the organic solvent 32 or the cleaning liquid 42 in a predetermined direction as appropriate.

  According to the method of the present invention of the first embodiment described above or the apparatus 100 of the present invention capable of performing the method of the present invention, the organic solvent 32 is used as the chemical solution and the treatment liquid 22 is treated to remove the substance to be removed. It is possible to regenerate the ion exchange resin 80 to which is attached. Since the organic solvent 32 used for such regeneration can be purified in the distillation unit 60 as necessary, it is returned again to the chemical tank 30 and can be reused for regeneration of the ion exchange resin 80. The organic solvent 32 may be appropriately purified in the distillation section 60 of the apparatus 100 as described above after being discharged from the removal tank 10, or may be treated as the waste liquid 72, or may be other than the apparatus 100. You may refine | purify with an apparatus.

  The treated liquid 52 treated with the ion exchange resin 80 can be reused because the substance to be removed has been removed. The apparatus 100 uses, for example, a spent dialysis solution in artificial dialysis as the treatment liquid 22 and processes it to obtain a reusable dialysis fluid (treated solution 52), and ions used for the treatment of the used dialysis fluid. The exchange resin 80 can be regenerated and used repeatedly. Therefore, from this point of view, the apparatus 100 can be used as a used dialysis fluid regenerating apparatus. Moreover, the used dialysis fluid regeneration apparatus can implement a regeneration method of the spent dialysis fluid.

That is, the present invention includes the following method for regenerating spent dialysate.
The used dialysate regeneration method of the present invention comprises a strong acid cation exchange resin and a first used dialysate in contact with each other, and urea that is a substance to be removed contained in the first used dialysate is a strong acid. A removal step of attaching to and removing the cationic cation exchange resin. After carrying out the removal step, a separation step of separating the regenerated dialysate, which is a treated solution obtained by bringing the first used dialysate into contact with the strong acid cation exchange resin, from the strong acid cation exchange resin is carried out. Next, a regeneration step is carried out in which urea adhering to the strong acid cation exchange resin is eliminated by bringing the alcohol into contact with the strong acid cation exchange resin. Using the strongly acidic cation exchange resin regenerated in the regeneration step, the above-described removal step and the above-described separation step are performed using a second used dialysate different from the first used dialysate. As a result, the used dialysate can be regenerated repeatedly.
Note that the difference between the first used dialysate and the second used dialysate means that these are not used dialysate discharged by a single artificial dialysis treatment. Therefore, the second used dialysate is, for example, a dialysate obtained by regenerating the first used dialysate, and the artificial dialysate performed at a different time from the artificial dialysis treatment from which the first used dialysate was discharged. It is the used dialysate discharged | emitted by the dialysis process.
From this point of view, the apparatus 100 or the apparatus 200 described later can be used as a used dialysate regeneration apparatus. In addition, the used dialysate regeneration method of the present invention is a method for producing an artificial dialysate that allows the used dialysate used in the artificial dialysis to be subjected to artificial dialysis again.
In addition, since the regenerated dialysate obtained by the used dialysate regenerating method of the present invention is reused as a dialysate, the composition and the like may be adjusted as appropriate by adding arbitrary components.

(Second embodiment)
Next, a second embodiment relating to the invention and apparatus of the present invention will be described with reference to FIG. FIG. 2 is a conceptual diagram of an ion exchange resin regeneration apparatus 200 (hereinafter also simply referred to as apparatus 200) according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in the following points. Of the configuration of the second embodiment, the description of the same configuration as the first embodiment will be omitted as appropriate.

Similar to the apparatus 100, the apparatus 200 according to the second embodiment brings the organic solvent 32 into contact with the ion exchange resin 80 to which the substance to be removed has adhered due to contact with the treatment liquid 22 containing the substance to be removed (not shown). And regenerating means for desorbing the substance to be removed.
In addition, the apparatus 200 has a plurality of removal tanks (first removal tank 130 and second removal tank 140) connected in series, and the treatment liquid 22 is removed from the plurality of removal tanks (first removal tank 130, second removal tank 140). There is a shared flow passage that circulates in series in the removal tank 140). The regeneration means in the present embodiment supplies the organic solvent 32 in parallel to each of a plurality of removal tanks (first removal tank 130 and second removal tank 140) in which the ion exchange resin 80 is accommodated, and the ion exchange resin 80. Is a means for reproducing.

  As described above, the apparatus 200 of the present embodiment regenerates the processing liquid 22 in series with respect to a plurality of removal tanks (first removal tank 130 and second removal tank 140) in the removal process. In carrying out the process, the organic solvent 32 is distributed in parallel. According to the apparatus 200, each of the plurality of removal tanks (the first removal tank 130 and the second removal tank 140) in which the ion exchange resin 80 used in the removal process is accommodated is not contaminated with the substance to be removed. Solvent 32 can be injected. Therefore, in any of the plurality of removal tanks, the substance to be removed attached to the ion exchange resin 80 can be desorbed with high efficiency.

Hereinafter, the features of the apparatus 200 will be specifically described with reference to FIG.
As shown in FIG. 2, the apparatus 200 includes a first removal tank 130 and a second removal tank 140 as a plurality of removal tanks. The first removal tank 130 is connected to the processing liquid tank 20 through a line 112, and is a first removal tank into which the processing liquid 22 is sent through the line 112.
The first removal tank 130 and the second removal tank 140 are connected by a line 113. The line 113 is a discharge path for discharging the treatment liquid 22 that has come into contact with the ion exchange resin 80 in the first removal tank 130, and the second treatment liquid 22 that has come into contact with the ion exchange resin 80 in the first removal tank 130. This is an injection path for injecting into the removal tank 140.
The second removal tank 140 is connected to the processed liquid tank 50 by a line 114. The treatment liquid 22 sent to the second removal tank 140 through the line 113 comes into contact with the ion exchange resin 80 accommodated in the second removal tank 140, is discharged from the line 114, and is treated as the treated liquid 52. Is sent to.

  As described above, in the present embodiment, the treatment liquid 22 flows through the first removal tank 130 and the second removal tank 140 and comes into contact with the ion exchange resin 80 accommodated therein, so that the removal process is performed. That is, in the present embodiment, the line 112, the first removal tank 130, the line 113, the second removal tank 140, and the line 114 are connected in series in this order, and the shared circulation that distributes the processing liquid 22 in series. Make a road.

Next, the reproducing means in this embodiment will be described.
The apparatus 200 according to this embodiment includes a regeneration unit that regenerates the ion exchange resin 80 by supplying the organic solvent 32 in parallel to each of the first removal tank 130 and the second removal tank 140 in which the ion exchange resin 80 is accommodated. Prepare. That is, as shown in FIG. 2, the apparatus 200 includes a line 118 that connects the chemical tank 30 in which the organic solvent 32 is stored, the first removal tank 130, and the second removal tank 140. It branches into the 1st injection path 118A and the 2nd injection path 118B.
The first injection path 118 </ b> A is an injection path for injecting the organic solvent 32 sent from the chemical tank 30 into the first removal tank 130. The second injection path 118 </ b> B is an injection path for injecting the organic solvent 32 sent from the chemical tank 30 into the second removal tank 140. The apparatus 200 includes the first injection path 118A and the second injection path 118B, so that the organic solvent 32 that is a chemical solution that is not contaminated with the substance to be removed is supplied to the first removal tank 130 and the second removal tank 140, respectively. Can be injected. Therefore, each ion exchange resin 80 accommodated in the first removal tank 130 or the second removal tank 140 and to which the substance to be removed is attached is regenerated well by contacting the organic solvent 32 sent from the chemical solution tank 30. .

In the apparatus 200 of the present embodiment, each of the plurality of removal tanks (the first removal tank 130 and the second removal tank 140) individually has a discharge path for discharging the organic solvent 32. The organic solvent 32 is removed from each removal tank (first removal tank 130 and second removal tank 140) through a plurality of removal tanks (first removal tank 130, It is led downstream of the second removal tank 140).
Here, each removal tank individually has a discharge path means that one discharge path provided in one removal tank avoids merging with another removal tank. That is, the organic solvent 32 discharged from one removal tank is prevented from joining the organic solvent 32 flowing through the other removal tanks until reaching the downstream side of the plurality of removal tanks.

  Thereby, the organic solvent 32 discharged | emitted from the removal tank (1st removal tank 130) located in the upstream of several removal tanks (the 1st removal tank 130, the 2nd removal tank 140) continues downstream. Feeding into the removal tank (second removal tank 140) located on the side is avoided. Here, upstream and downstream mean the flow direction of the organic solvent 32 with the chemical tank 30 as the upstream side and the distillation unit 60 or the waste liquid tank 70 as the downstream side. Further, the downstream of the plurality of removal tanks refers to the downstream side of the removal tank (second removal tank 140) located on the most downstream side among the plurality of removal tanks provided in the apparatus 200.

  According to the apparatus 200 including a plurality of discharge paths, the organic solvent 32 that contains the substance to be removed by contacting the ion exchange resin 80 in one removal tank (for example, the first removal tank 130) It does not flow into the removal tank (for example, the second removal tank 140).

  For example, as shown in FIG. 2, the first discharge path 132 </ b> A and the second discharge path 132 </ b> B may merge downstream of the first removal tank 130 and the second removal tank 140 to form a line 132. The organic solvent 32 containing the substance to be removed and joined in the line 132 flows from the line 132 through the line 128 and is sent to the distillation unit 60, or flows through the line 126 and sent into the waste liquid tank 70. A modification of the second embodiment (not shown) includes a mode in which the first discharge path 132A and the second discharge path 132B do not merge with each other and continue to the distillation unit 60 or the waste liquid tank 70 in parallel.

Although the first embodiment and the second embodiment of the present invention have been described above, the present invention is not limited to the above-described embodiment, and various modifications, improvements, etc. as long as the object of the present invention is achieved. This embodiment is also included.
For example, in the first embodiment or the second embodiment, the treatment liquid tank 20, the removal tank 10, the first removal tank 130, the second removal tank 140, the treated liquid tank 50, the distillation unit 60, the waste liquid tank 70, the chemical liquid tank. 30 and the washing | cleaning liquid tank 40 were connected by the line, and the example which moves a liquid substance through the said line was demonstrated. However, the method or apparatus of the present invention is not limited to this, and any or all of the lines may be omitted, and the liquid material may be moved between each tank or section by other means including manual operation.
Further, the lines shown in FIG. 1 or FIG. 2 can be merged with each other to be a common line or can be independent from each other without departing from the spirit of the present invention.

  The Example and comparative example of this invention were implemented as follows. In each of the examples and comparative examples, after performing the first removal step for removing the substance to be removed contained in the treatment liquid, a regeneration step for regenerating the ion exchange resin used for this was performed. And in order to evaluate reproduction | regeneration of the ion exchange resin by implementation of a reproduction | regeneration process, the 2nd removal process was implemented using the regenerated ion exchange resin.

Example 1
Two columns filled with 10 g of strongly acidic cation exchange resin A were prepared, and used as a first column and a second column, respectively. The first column and the second column were connected in series so that the treatment liquid injected into the first column was continuously injected into the second column. As strongly acidic cation exchange resin A, Amberlyst-15 (DRY) provided by Organo Corporation was used. The column used was a chromatograph tube of 12φ (body inner diameter 12 mm) × 300 mm.
The urea-containing liquid that is the treatment liquid used in Example 1 was adjusted by adding commercially available urea to pure water to a urea concentration of 350 mg / l.
50 ml of the urea-containing liquid was injected into the first column, discharged from the second column side, and dropped, and the first removal step and separation step were performed. The urea-containing liquid was started to be injected into the first column, and the flow rate of the urea-containing liquid was adjusted so that the time until the entire amount of the urea-containing liquid was discharged from the second column side was 1 hour. As described above, the treated liquid discharged from the second column side was used as the first treated liquid.

  After obtaining the first treated liquid as described above, the connection between the first column and the second column is released, and 50 ml of reagent-grade methanol (purity 99.5%) is added to each column as a chemical over 2 hours. The regeneration process was carried out.

  The first column and the second column after the regeneration step are connected again in series, 100 ml of pure water is dropped and discharged over 1 hour, and methanol remaining in the column is replaced with pure water. The strongly acidic cation exchange resin was washed. And using the urea containing liquid prepared like the above-mentioned, the 2nd removal process and separation process were implemented by the method similar to the method of obtaining the 1st processed liquid, and the 2nd processed liquid was obtained.

(Example 2)
Two columns filled with 20 g of strongly acidic ion exchange resin B (Diaion RCP160M manufactured by Mitsubishi Chemical Corporation) were prepared, and the same as in Example 1 except that these were used as the first column and the second column. The first removal step and the separation step were performed to obtain a first treated liquid.
Next, the regeneration process was performed in the same manner as in Example 1. Next, the first column and the second column were again connected in series, and methanol remaining in the column was replaced with pure water to wash the strongly acidic cation exchange resin. And using the urea containing liquid prepared like the above-mentioned, the 2nd removal process and separation process were implemented by the method similar to the method of obtaining the 1st processed liquid, and the 2nd processed liquid was obtained.

(Comparative Example 1)
In the same manner as in Example 2, the first removal step and the separation step were performed to obtain a first treated liquid.
Next, instead of using methanol as a chemical solution, 1N hydrochloric acid was used, and 200 ml of 1N hydrochloric acid was added dropwise to each of the first and second columns over 1 hour to perform a regeneration step.
After that, the first column and the second column after the regeneration step as described above are connected again in series, 200 ml of pure water is dropped over 1 hour, and the hydrochloric acid remaining in the column is replaced with pure water. The strongly acidic cation exchange resin was washed. And using the urea containing liquid prepared like the above-mentioned, the 2nd removal process and separation process were implemented by the method similar to the method of obtaining the 1st processed liquid, and the 2nd processed liquid was obtained.

  In each example and comparative example, the removal step was performed under the condition that the urea concentration of the treated liquid discharged from the second column reached equilibrium.

(Evaluation)
The urea concentration of the first treated liquid and the second treated liquid obtained in each example and comparative example was measured by the Kjeldahl method.
Specifically, each first treated solution, each second treated solution, and ammonium ion standard solution as samples were subjected to an ion chromatograph, and the ammonium ion concentration in each sample was determined by a calibration curve method. An ICS3000 type ion chromatograph manufactured by Nippon Dionex Co., Ltd. was used as the ion chromatograph.
Next, the nitrogen concentration in each sample was converted from the ammonium ion concentration obtained above, and the urea concentration (mg / l) was determined by the following formula 1 using this. Table 1 shows the urea concentrations of the first treated liquid and the second treated liquid obtained.
(Formula 1) Urea concentration (mg / l) = nitrogen concentration (mg / l) × (molecular weight of urea / molecular weight of nitrogen in urea)

Moreover, the urea removal rate by which urea was removed from the urea-containing liquid (urea concentration 350 mg / l) by carrying out the removal step in each example or comparative example was determined by the following formula 2. The urea removal rate obtained from Equation 2 is shown in Table 1.
(Expression 2) Urea removal rate (%) = [(Urea concentration of urea-containing liquid (mg / l) −Urea concentration of treated liquid (mg / l)) / Urea concentration of urea-containing liquid (mg / l)] × 100

  As shown in Table 1, the urea concentration of the first treated liquid in each example and comparative example was 2 mg / l or less, and the urea removal rate was 99% or more. From this, in the first removal step performed to obtain the first treated liquid, the urea contained in the urea-containing liquid almost completely adheres to the strongly acidic cation exchange resin and is very high. It was confirmed that an efficient urea removal treatment was performed.

  The urea concentrations of the second treated liquids of Example 1 and Example 2 were both 2 mg / l or less, and the urea removal rate was 99% or more. From this, it was confirmed that a very highly efficient urea removal treatment was performed in the second removal step performed to obtain the second treated liquid. From these results, it was confirmed that the ion exchange resin was regenerated to almost 100% by performing the regeneration step performed between the first removal step and the second removal step. Thus, it was confirmed that methanol was very excellent as a chemical solution for the regeneration process.

  On the other hand, the urea concentration of the second treated solution of Comparative Example 1 using hydrochloric acid as the chemical solution in the regeneration process was 23.5 mg / l, which was significantly higher than the urea concentration of the first treated solution. As a result, it was found that the ion exchange resin could not be regenerated to a level close to 100% in the regeneration step performed between the first removal step and the second removal step in Comparative Example 1. . The degree of such regeneration can be said to be a good range in view of the regeneration rate of conventional ion exchange resins, but the regenerative rate is not as high as in Examples 1 and 2 using methanol as the chemical solution in the regeneration process. It was. In other words, it was shown by this example that methanol can exhibit a regeneration capability that exceeds that of hydrochloric acid that has been conventionally used as a chemical solution in the regeneration process. In addition, it was suggested by this example that an organic solvent (for example, alcohol) can exhibit a regeneration capability equivalent to or higher than that of an acidic aqueous solution as a chemical solution in the regeneration process of the cation exchange resin.

The above embodiment includes the following technical idea.
(1) An ion exchange resin regeneration method for regenerating an ion exchange resin to which the substance to be removed has adhered by contacting with a treatment liquid containing the substance to be removed that is an organic compound having polarity,
An ion exchange resin regeneration method comprising a regeneration step of desorbing the substance to be removed attached to the ion exchange resin by bringing an organic solvent into contact with the ion exchange resin.
(2) The method for regenerating an ion exchange resin according to (1), wherein the organic solvent contains an alcohol.
(3) The method for regenerating an ion exchange resin according to (2), wherein the alcohol contains methanol or ethanol.
(4) The method for regenerating an ion exchange resin according to the above (2) or (3), wherein after the regeneration step, the used alcohol separated from the ion exchange resin is distilled and the distillation step for purifying the used alcohol is performed. .
(5) The ion exchange resin regeneration method according to any one of (1) to (4), wherein the substance to be removed contains urea.
(6) The method for regenerating an ion exchange resin according to (5), wherein the treatment liquid is a used dialysis liquid used for artificial dialysis.
(7) A removal step of bringing the ion exchange resin and the treatment liquid into contact with each other and removing the substance to be removed contained in the treatment liquid by attaching it to the ion exchange resin;
After separating the treated liquid obtained by bringing the treated liquid into contact with the ion exchange resin from the ion exchange resin,
The method for regenerating an ion exchange resin according to any one of (1) to (6), wherein the regeneration step is performed.
(8) An ion exchange resin regeneration apparatus for performing the ion exchange resin regeneration method according to any one of (1) to (7) above,
Ion exchange resin regeneration, characterized by comprising regeneration means for contacting the ion exchange resin to which the substance to be removed has adhered by contacting the treatment liquid containing the substance to be removed to bring the substance to be removed into contact with the organic solvent. apparatus.
(9) A removal tank for contacting the ion exchange resin with the treatment liquid to remove the substance to be removed contained in the treatment liquid by attaching it to the ion exchange resin;
The ion exchange resin regeneration apparatus according to (8), further comprising separation means for separating the treated liquid obtained by bringing the treatment liquid into contact with the ion exchange resin from the ion exchange resin.
(10) having a plurality of the removal tanks connected in series;
Having a shared flow path for allowing the treatment liquid to flow in series to the plurality of removal tanks; and
(8) or (9), wherein the regeneration means is means for regenerating the ion exchange resin by supplying the organic solvent in parallel to each of the plurality of removal tanks containing the ion exchange resin. Ion exchange resin recycling equipment.
(11) Each of the plurality of removal tanks individually has a discharge path for discharging the organic solvent,
The said organic solvent is an ion exchange resin reproduction | regeneration apparatus as described in said (10) guide | induced to the downstream of the said several removal tank through the said discharge channel from the said removal tank.
(12) including the ion exchange resin regeneration method according to (7) above,
A strong acid cation exchange resin and a first used dialysate are brought into contact with each other, and urea to be removed contained in the first used dialysate is adhered to the strong acid cation exchange resin. A removal step to remove;
Separating the regenerated dialysate, which is a treated liquid obtained by bringing the first used dialysate into contact with the strong acid cation exchange resin, from the strong acid cation exchange resin, and
Next, a regeneration step of desorbing the urea adhering to the strong acid cation exchange resin by bringing the alcohol into contact with the strong acid cation exchange resin is performed,
The removal step and the separation step are performed using a second used dialysate different from the first used dialysate using the strongly acidic cation exchange resin regenerated in the regeneration step. A used dialysate regeneration method.

DESCRIPTION OF SYMBOLS 10 ... Removal tank 20 ... Processing liquid tank 22 ... Processing liquid 30 ... Chemical liquid tank 32 ... Organic solvent 40 ... Cleaning liquid tank 42 ... Cleaning liquid 50 ... Processed liquid tank 52 ... Processed liquid 60 ... Distillation section 70 ... Waste liquid tank 72 ... Waste liquid 80 ... Ion exchange resin 100, 200 ... Ion exchange resin regenerators 112, 113, 114, 116, 118, 122, 126, 128, 132, 150 ... line 118A ... first injection passage 118B ... second injection passage 120 ... pump 124 ... three-way valve 125 ... on-off valve 130 ..First removal tank 132A ... first discharge path 132B ... second discharge path 140 ... second removal tank

Claims (12)

An ion exchange resin regeneration method for regenerating an ion exchange resin to which the substance to be removed has adhered by contacting with a treatment liquid containing the substance to be removed, which is an organic compound having polarity,
An ion exchange resin regeneration method comprising a regeneration step of desorbing the substance to be removed attached to the ion exchange resin by bringing an organic solvent into contact with the ion exchange resin.   The method for regenerating an ion exchange resin according to claim 1, wherein the organic solvent contains an alcohol.   The method for regenerating an ion exchange resin according to claim 2, wherein the alcohol contains methanol or ethanol.   The ion exchange resin regeneration method of Claim 2 or 3 which implements the distillation process which distills the used alcohol isolate | separated from the said ion exchange resin after the said regeneration process, and refine | purifies the said used alcohol.   The ion-exchange resin regeneration method according to any one of claims 1 to 4, wherein the substance to be removed contains urea.   The method for regenerating an ion exchange resin according to claim 5, wherein the treatment liquid is a used dialysis liquid used for artificial dialysis. A removing step of contacting the ion exchange resin and the treatment liquid to remove the substance to be removed contained in the treatment liquid by attaching it to the ion exchange resin;
After separating the treated liquid obtained by bringing the treated liquid into contact with the ion exchange resin from the ion exchange resin,
The ion-exchange resin regeneration method as described in any one of Claim 1 to 6 which implements the said reproduction | regeneration process. An ion exchange resin regeneration apparatus for performing the ion exchange resin regeneration method according to any one of claims 1 to 7,
Ion exchange resin regeneration, characterized by comprising regeneration means for contacting the ion exchange resin to which the substance to be removed has adhered by contacting the treatment liquid containing the substance to be removed to bring the substance to be removed into contact with the organic solvent. apparatus. A removal tank for contacting the ion exchange resin and the treatment liquid to remove the substance to be removed contained in the treatment liquid by attaching it to the ion exchange resin;
The ion exchange resin regeneration apparatus according to claim 8, further comprising separation means for separating the treated liquid obtained by bringing the treatment liquid into contact with the ion exchange resin from the ion exchange resin. A plurality of the removal tanks connected in series;
Having a shared flow path for allowing the treatment liquid to flow in series to the plurality of removal tanks; and
The ion exchange according to claim 8 or 9, wherein the regeneration means is means for regenerating the ion exchange resin by supplying the organic solvent in parallel to each of the plurality of removal tanks in which the ion exchange resin is accommodated. Resin recycling equipment. Each of the plurality of removal tanks individually has a discharge path for discharging the organic solvent,
The ion-exchange resin regeneration apparatus according to claim 10, wherein the organic solvent is led from the removal tank to the downstream of the plurality of removal tanks through the discharge path. Including an ion exchange resin regeneration method according to claim 7,
A strong acid cation exchange resin and a first used dialysate are brought into contact with each other, and urea to be removed contained in the first used dialysate is adhered to the strong acid cation exchange resin. A removal step to remove;
Separating the regenerated dialysate, which is a treated liquid obtained by bringing the first used dialysate into contact with the strong acid cation exchange resin, from the strong acid cation exchange resin, and
Next, a regeneration step of desorbing the urea adhering to the strong acid cation exchange resin by bringing the alcohol into contact with the strong acid cation exchange resin is performed,
The removal step and the separation step are performed using a second used dialysate different from the first used dialysate using the strongly acidic cation exchange resin regenerated in the regeneration step. A used dialysate regeneration method.

Images