JP2008023414A - Method for evaluating performance of anion exchange resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for evaluating the performance of an anion exchange resin contained in ion exchange resins used in a mixed-bed demineralizer, in which the performance of the anion exchange resin is evaluated by particularly measuring the deterioration of the ionic reactivity of the anion exchange resin and an evaluated result is prevented from becoming unstable to surely obtain the evaluated result having high reliability. <P>SOLUTION: The method for evaluating the performance of the anion exchange resin comprises the steps of: sampling the ion exchange resins used in the mixed-bed demineralizer; keeping a mixed state of the anion exchange resin with a cation exchange resin in the sampled ion exchange resins for a predetermined period of time; separating the anion exchange resin from the cation exchange resin after the predetermined period of time; and evaluating the performance of the separated anion exchange resin within three days after the anion exchange resin is separated. The performance of the anion exchange resin is preferably evaluated under such time management that the evaluation is performed within three days after the anion exchange resin is separated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for evaluating the performance of an anion exchange resin in an ion exchange resin used in a mixed bed desalting apparatus.

  Ion exchange resins are widely used to remove various ions that are dissolved impurities in water. In particular, it plays an important role in fields where water quality is required in which the amount of impurities in the water is reduced as much as possible, such as cleaning of electronic components and condensate desalination of power plants. In such applications, in order to obtain a higher-purity treated water quality, it is necessary to maintain the characteristics of the ion exchange resin high, but the ion exchange performance of the ion exchange resin gradually deteriorates over a long period of use. As a result, the quality of the treated water is deteriorated. In the field where treated water is used, deterioration of treated water causes deterioration of product quality and corrosion of plant equipment. Therefore, grasp the performance of ion-exchange resin in water treatment facilities and maintain it at a high level. Has become an important task for daily management.

  Conventionally, as an index for evaluating the performance of an ion exchange resin, for example, there are methods of measuring the total exchange capacity indicating the maximum capacity capable of ion exchange and the particle size distribution for examining the degree of crushing of resin particles. It is in a situation where it is not possible to adequately cope with recent improvements in the quality of requested treated water.

  Therefore, in actual equipment, the ion exchange resin should be replaced after the quality of the treated water has deteriorated, or the ion exchange resin that has been used for a certain period of time can be changed regularly with a margin in ion exchange performance. It corresponds by exchanging it automatically. However, the method of exchanging the ion exchange resin after the deterioration of the treated water quality cannot prevent the deterioration of the treated water quality in advance, but on the other hand, the ion exchange resin should be periodically replaced with a margin in ion exchange performance. In the exchange method, the cost of the ion exchange resin is high.

  In recent years, deterioration of ion exchange resins, which has been a problem particularly in mixed bed desalting apparatuses, is an event in which a very small amount of cation exchange resin is dissolved and irreversibly adsorbed on an anion exchange resin. In other words, the dissolved cation exchange resin is called polystyrene sulfonic acid, and it is usually known that its molecular weight ranges from about 1,000 to 1 million. Since it is comparatively huge, it adsorbs so that it may remain on the surface part of an anion exchange resin. When this adsorption occurs, even if chloride ions or sulfate ions that should be ion-exchanged by the anion exchange resin are present in the vicinity of the anion exchange resin, they are present at a slightly higher concentration than the surroundings on the surface of the anion exchange resin. It is considered that the surface of the anion exchange resin is difficult to reach due to polystyrene sulfonic acid, and as a result, chloride ions and sulfate ions in the water are not adsorbed by the anion exchange resin and easily leak into the treated water.

  Therefore, as a method for evaluating the performance of such an anion exchange resin, a method for measuring the degree of ion reactivity of the anion exchange resin, for example, measuring the reaction rate at which impurity ions are adsorbed to the anion exchange resin under certain conditions. Alternatively, a method of measuring the impurity ion removal rate is being adopted.

  However, when evaluating the performance of an anion exchange resin that has actually generated an event such as deterioration of treated water by such a performance evaluation method, the evaluation result is almost the same as an anion exchange resin that has not deteriorated in performance. Therefore, such a method of measuring the reaction rate and the removal rate of impurity ions has been considered to have low reliability as a method for evaluating the performance of anion exchange resins.

  For example, the performance evaluation method for anion exchange resins reported in International Water Conference 86-54 is based on polystyrene sulfonic acid, in which part of the cation exchange resin is dissolved, and the anion exchange resin strongly adsorbs, This is a method to evaluate and evaluate the phenomenon in which the ability of anion exchange resin to remove sulfate ions decreases. However, when this method is used to evaluate the anion exchange resin that is actually used, the removal performance of sulfate ions is certainly reduced. However, a phenomenon that does not necessarily result in deterioration of the performance of the resin used for a long period of time occurs.

  By the way, when evaluating the performance of an ion exchange resin conventionally used in a mixed bed type desalinator, for evaluating the performance of the ion exchange resin in all the sites where water treatment is performed in the mixed bed type desalinator. Since it is difficult to prepare an analytical instrument, in order to evaluate the performance of the ion exchange resin, it is necessary to send it to a place where the environment for performance evaluation is prepared. Therefore, first, an ion exchange resin is collected from an arbitrary pipe of a mixed bed type desalination apparatus (usually provided with a plurality of desalting towers, a regeneration tower, a regeneration resin storage tank, etc.) and accommodated in a container. The collected ion exchange resin is stored, packed, and shipped to the performance evaluation site. The ion exchange resin sent to the performance evaluation site is stored, and if it is a mixed resin, it is separated into an anion exchange resin and a cation exchange resin, and used for analysis. There are various cases, such as when the ion exchange resin is collected by the user of the desalting apparatus, by the desalinating apparatus administrator, or by the evaluator. Sometimes it is a week. Further, the analysis on the side of receiving the sent resin at the performance evaluation site may be the next day or one week later for the convenience of work setup. In addition, the anion exchange resin and the cation exchange resin may be separated before the shipment or after the received resin is received. It may be stored to some extent.

Thus, in the past, the actual situation is that the storage state and storage period of the collected resin from the collection of the ion exchange resin to the analysis for performance evaluation were hardly managed.
International Water Conference 86-54

  In the present invention, the evaluation result becomes unstable when evaluating the performance of the anion exchange resin in the ion exchange resin used in the mixed bed desalting apparatus, particularly by measuring the decrease in the ion reactivity. It is an object of the present invention to provide a method for reliably obtaining a highly reliable evaluation result.

  As a result of earnestly examining the performance evaluation method of the anion exchange resin in the ion exchange resin used in the mixed bed type desalination apparatus, the inventors have stored the ion exchange resin in a state close to the use conditions in the actual machine, It has been found that the above-mentioned problems can be solved by performing performance evaluation within a predetermined period after separating the anion exchange resin from the ion exchange resin.

  That is, the substance causing the performance deterioration of the anion exchange resin in the ion exchange resin used in the mixed bed desalination apparatus is polystyrene sulfonic acid which is eluted by oxidation of the cation exchange resin, and this is irreversible to the anion exchange resin. Has been confirmed to be adsorbed. Therefore, even if a certain amount of polystyrene sulfonic acid is artificially adsorbed on the anion exchange resin, the performance of the anion exchange resin deteriorates. It is also known that the relationship between polystyrene sulfonic acid loading and sulfate ion removal performance is complex, and the degree of influence varies depending on the molecular weight. Phenomena such as recovery with progress are also observed.

  As a result of examining the cause of the performance recovery of the anion exchange resin over time, the present inventors have found that the adsorption of polystyrene sulfonic acid to the anion exchange resin is strong, but since polystyrene sulfonic acid exists as a polymer, its molecular diameter It was estimated that polystyrene sulfonic acid was adsorbed on the surface portion of the anion exchange resin and then gradually diffused into the anion exchange resin particles.

  On the other hand, if the amount of polystyrene sulfonic acid present on the surface of the anion exchange resin particle is large, the degree of inhibition of the removal performance of impurity ions such as sulfate ion of the anion exchange resin is also large. It was considered that when the polystyrene sulfonic acid concentration on the surface of the anion exchange resin was decreased by diffusing into the resin grains, the performance of removing impurity ions such as sulfate ions was recovered.

  For this reason, the performance of the anion exchange resin recovers over time from the time when it is collected from the mixed bed desalting apparatus for the performance evaluation and separated from the cation exchange resin. For this reason, it is desirable to evaluate the performance immediately after collecting a resin sample and separating the anion exchange resin and the cation exchange resin, but in the past, the storage state and storage period of the collected resin are hardly controlled. In general, since a period of about two weeks is required from the collection of the resin to the analysis for the performance evaluation, the correct performance evaluation cannot be performed.

  After collecting an anion exchange resin for performance evaluation, the present inventors maintain this in a state where it is used, and after separation from the cation exchange resin, perform time management to provide performance evaluation, and thus I found that I could solve the legal problem.

  The present invention has been achieved based on such knowledge, and the method for evaluating the performance of an anion exchange resin according to the present invention (Claim 1) is an anion in an ion exchange resin used in a mixed bed desalting apparatus. In the method for evaluating the performance of the exchange resin, the ion exchange resin is collected, and after the collection, the anion exchange resin and the cation exchange resin are separated and separated through a period of holding the mixed state. The performance of the separated anion exchange resin is evaluated within 3 days after the separation.

  The method for evaluating the performance of an anion exchange resin according to claim 2 is a method for evaluating the performance of an anion exchange resin in an ion exchange resin used in a mixed bed desalination apparatus. After a period of holding the exchange resin and the cation exchange resin in a mixed state, the anion exchange resin and the cation exchange resin are separated, and after 3 days from the separation, the separated anion exchange resin is again added to the cation exchange resin. Are mixed and kept in a mixed state and then separated, and the performance of the separated anion exchange resin is evaluated within 3 days after the separation.

  The method for evaluating the performance of an anion exchange resin according to claim 3 is characterized in that, in claim 1 or 2, the cation exchange resin is a cation exchange resin used in the mixed bed desalting apparatus.

  The performance evaluation method for an anion exchange resin according to claim 4 is the method according to any one of claims 1 to 3, wherein the mixed state of the anion exchange resin and the cation exchange resin is an anion exchange resin in the mixed bed desalting apparatus. And the cation exchange resin are mixed at substantially the same mixing ratio.

  The method for evaluating the performance of an anion exchange resin according to claim 5 is characterized in that in any one of claims 1 to 4, the anion exchange resin is evaluated under a time management evaluated within 3 days after the separation. And

  According to the present invention, the ion exchange resin collected from the mixed bed desalting apparatus is stored in a mixed state of the anion exchange resin and the cation exchange resin, and after the anion exchange resin and the cation exchange resin are separated, the separation is performed. In order to use the anion exchange resin for performance evaluation within 3 days later, after the anion exchange resin is separated from the cation exchange resin, the performance evaluation can be performed before the performance recovers over time. The performance of the exchange resin can be accurately grasped (claim 1).

  Even after 3 days or more have passed after the separation of the anion exchange resin and the cation exchange resin, the separated anion exchange resin is mixed with the cation exchange resin, and then the anion exchange resin is separated to evaluate the performance. Similarly, the performance of the anion exchange resin in the use state can be accurately grasped (claim 2).

  In the present invention, in order to accurately evaluate the performance in the state where the anion exchange resin is actually used, the cation exchange resin mixed with the anion exchange resin is a mixed bed type desalination apparatus that collects the anion exchange resin. (Claim 3), and the anion exchange resin and the cation exchange resin may be mixed so as to be equivalent in the mixing ratio in the mixed bed desalting apparatus. Preferred (claim 4).

  In the present invention, it is preferable to perform time management for evaluation within 3 days after separation of the anion exchange resin.

  Embodiments of the performance evaluation method for an anion exchange resin of the present invention will be described in detail below.

  The anion exchange resin subject to performance evaluation in the present invention is an anion exchange resin used in a mixed bed desalting apparatus, and in particular, the total exchange capacity showing the maximum capacity capable of ion exchange and the degree of crushing of the resin particles The present invention is effective in evaluating the performance of an anion exchange resin in a mixed bed desalting apparatus producing high-purity treated water, which cannot be sufficiently evaluated by evaluation such as particle size distribution. Examples of such a mixed bed desalting apparatus include, but are not limited to, a mixed bed desalting apparatus installed in a semiconductor manufacturing factory, a thermal power plant, or a nuclear power plant.

  In order to collect the ion exchange resin used in actual mixed-bed desalination equipment such as power plants, it is installed in the resin transfer pipe when the resin is transferred from the desalting tower to the regeneration tower for resin regeneration. The resin can be collected from the existing resin sampling pipe. Further, when the regenerated resin is transferred from the regeneration tower to the desalting tower, the resin may be collected from a resin sampling pipe installed in the resin transfer pipe.

  The collected ion exchange resin is sent to a resin performance evaluation place and analyzed for evaluation of the resin performance. At this time, the ion exchange resin filled as the mixed bed resin in the mixed bed desalting apparatus is separated into an anion exchange resin and a cation exchange resin. In order to perform this separation, for example, it is convenient and preferable to place the sample in a column, pass water in an upward flow, and separate the two using the difference in specific gravity between the cation exchange resin and the anion exchange resin. is there.

  In the present invention, the performance of the anion exchange resin is evaluated within 3 days after such resin separation. If this performance evaluation time is not within 3 days from the separation of the resin, the polystyrene sulfonic acid eluted from the cation exchange resin and adsorbed on the anion exchange resin when packed in the mixed bed desalting apparatus as a mixed bed resin. In order to recover the performance of the anion exchange resin by diffusing into the grains of the anion exchange resin over time, an accurate performance evaluation result cannot be obtained.

  The shorter the period from resin separation to performance evaluation (hereinafter sometimes referred to as “storage period after separation”) is preferably as short as possible, particularly preferably within 72 hours, and particularly preferably within 50 hours. However, industrially, it is generally difficult to set the storage period after separation to 0 hour, and usually about 6 hours are required.

  If the performance evaluation cannot be performed within 3 days after separating the anion exchange resin and the cation exchange resin from the mixed bed resin, the anion exchange resin is mixed again with the cation exchange resin and mixed bed resin. The anion exchange resin and the cation exchange resin are separated again, and the performance of the anion exchange resin may be evaluated within 3 days after the separation. That is, when the storage period after separation exceeds 3 days, the performance of the anion exchange resin is restored by the intragranular diffusion of polystyrene sulfonic acid, but it is eluted from the cation exchange resin by mixing it with the cation exchange resin again. The polystyrene sulfonic acid thus adsorbed on the anion exchange resin can return the performance of the anion exchange resin to the original state (the state immediately after use).

  In addition, after this remixing, when the resin is separated again and the performance evaluation is performed within 3 days, if the period from remixing to reseparation is too short, the performance recovery of the anion exchange resin by remixing is not sufficient Therefore, it is preferable to store the resin as a mixed bed resin for 3 days or more after remixing, for example 3 to 7 days, and then separate the resin, and then perform the performance evaluation within 3 days.

  In the present invention, the cation exchange resin used as the mixed bed resin with the anion exchange resin to be evaluated is the cation exchange resin mixed with the anion exchange resin in the mixed bed desalting apparatus in which the anion exchange resin was used. Moreover, it is preferable that the mixing ratio is substantially the same as the mixing ratio of the mixed bed resin in the mixed bed desalting apparatus. Here, “substantially the same” means a ratio within ± 20% with respect to the mixing ratio (cation exchange resin amount / total resin amount) of the mixed bed resin in the mixed bed desalting apparatus. By doing so, polystyrene sulfonic acid is constantly present in the vicinity of the anion exchange resin, although the amount thereof is small, but is constantly eluted from the cation exchange resin. It can be stored, and a more accurate performance evaluation result can be obtained.

  Thus, in the present invention, in the period from the collection of the ion exchange resin from the mixed bed desalting apparatus to the performance evaluation of the anion exchange resin, the storage period after separation is within 3 days. While obtaining an evaluation result close to the performance of the anion exchange resin, as described above, by collecting the ion exchange resin at the installation location of the mixed bed type desalination apparatus and performing the performance evaluation at the performance evaluation location, A storage period of about one week is usually required for sending sample resin, preparation for analysis, etc., and about one month if it is long. Therefore, in the present invention, it is preferable to perform time management so that the storage period after separation is within 3 days in this storage period.

As this time management,
(1) For example, a method of recording the collection date of the ion exchange resin from the mixed bed desalting apparatus, the separation date of the mixed bed resin, and the date of analysis on an arbitrary recording medium. (2) Separation of the mixed bed resin (3) Method of creating a schedule to be analyzed within 3 days after mixing (including re-separation after mixing) (3) Method of listing these dates in the resin evaluation test report (4) Separation (after re-mixing) (Including re-separation), and a method for describing a mechanism for analysis within 3 days after the above.

  In the present invention, the specific test method for evaluating the performance of the anion exchange resin is not particularly limited, but the present invention is particularly effective for the evaluation method for measuring the ion reactivity of the anion exchange resin. The method of measuring the ion movement speed mentioned in the section is preferable.

  Hereinafter, the present invention will be described more specifically with reference to experimental examples and examples.

In the following, the performance evaluation test of the anion exchange resin was carried out by the following ion migration rate measurement method using the apparatus shown in FIG. 1 improved from the method reported in International Water Conference 86-54. In the following, pure water having a specific resistance of 10 MΩ · cm ⁻¹ or more was used for washing the ion exchange resin and preparing the sodium sulfate aqueous solution.

<Measurement method of ion moving speed>
(1) Fill the glass column 3 with 50 mL of completely regenerated cation exchange resin and wash it thoroughly.
(2) Similarly, 50 mL of the sample anion exchange resin is filled in the glass column 2 and sufficiently washed.
(3) A sodium sulfate aqueous solution (10 mg-SO ₄ / L) is prepared.
(4) The prepared sodium sulfate aqueous solution is stored in the tank 1 and passed through the anion exchange resin column 2 to the cation exchange resin column 3 at a flow rate of 20 L / h, and the specific resistance value of the cation exchange resin galam effluent is measured. To do. In FIG. 1, reference numeral 4 is a pump, 5 is a flow meter, 6 is a valve, and 7 is a specific resistance meter.

The ion movement speed K is obtained by the following equation.
K = 1 / (6 × (1-ε)) · SV · d · ln (C0 / C)
K: Ion migration rate in anion exchange resin (m / sec)
ε: Porosity of anion exchange resin layer (−)
SV: Flow rate of ion exchange resin column (1 / sec)
d: particle size of anion exchange resin (m)
C ₀ : Sulfate ion concentration of sodium sulfate aqueous solution (μg / L)
C: Sulfate ion concentration calculated from the specific resistance value (μg / L)

Experimental example 1
In the case of an ion exchange resin used in a condensate demineralizer, the procedure of a conventional sampling method is as follows.
(1) The cation exchange resin and the anion exchange resin that have been regenerated and mixed in the regeneration tower and cleaned are stored in the resin storage tank in a mixed state. When the resin in the desalting tower used for sampling is saturated by ion exchange, the resin in the desalting tower is transferred to the regeneration tower for regeneration. The prepared recycled resin in the resin storage tank is transferred to the empty desalting tower.
(2) Normally, when it is necessary to evaluate the performance of the resin, the cation exchange resin sample and the anion exchange resin sample can be collected at the same time. Therefore, the sample is collected when the resin is transferred from the resin storage tank to the desalting tower. The main reason for collecting at this time is that the mixing operation is performed in advance and the collected resin is the average resin of the whole.
(3) The collected resin sample is sent to the laboratory.
(4) At the laboratory, considering the operation process, etc., the resin is separated as appropriate and the analysis operation is performed.
(5) In the past results, the number of days from the resin collection date to the completion of the analysis of the resin performance was 32 days at the maximum, 7 days at the shortest, and 13 days on the average.

  The resin used in the condensate demineralizer at a certain power plant was examined as shown in FIG. This result could not be said to be a measurement result in which the resin performance deteriorates with the years of use, but was a result in which the reliability of the measurement was suspected.

  Table 1 shows the results of examining the detailed schedule from resin collection to resin analysis for each of the measured values. Here, the data on the use month and month 0 is that the resin is in a new state only of the anion exchange resin, and therefore there is no resin separation operation. In addition, the data of 23 months of use is obtained by separating the cation exchange resin and the anion exchange resin in the power plant premises and sending the resin sample to the analysis laboratory.

  From the above results, it can not be said that the performance of the anion exchange resin has deteriorated with the years of use, and the performance measurement results of the long-term use resin especially for 17 months and 23 months are rather recovered. The value is shown.

  As described in Table 1, this measured value was examined focusing on the period during which the resin to be measured was stored as a mixed state of a cation exchange resin and an anion exchange resin, and the period from when the two resins were separated until the performance was measured. Then, when measuring performance after storing for about one week after resin separation, it can be seen that the measured value of the anion exchange resin tends to recover the performance.

  That is, after separating the anion exchange resin and the cation exchange resin, it is estimated that the storage period until the performance evaluation affects the reliability of the measurement value.

Experimental example 2
In order to confirm the estimation in Experimental Example 1, a new anion exchange resin (DiaionPA312LT manufactured by Mitsubishi Chemical Corporation) was added to polystyrene sulfonic acid (molecular weight 4400) manufactured by Polymer Standard Service, Inc. .2 mg / ml-resin was loaded, and the influence of the number of days left was examined by changing the number of days until the ion migration rate measurement after loading.

  As a result, as shown in FIG. 3, it is clear that the measured value of the ion migration speed tends to recover with time.

  From this tendency, the true ion migration rate value of the anion exchange resin is measured several times over time and is obtained by extrapolating the value of the number of elapsed days 0, or is always measured under a constant time condition. Can be assumed to be a technique for obtaining more reliable measurement results.

Example 1
Based on the results of the above experimental examples 1 and 2, the performance of actual samples actually used in the condensate demineralizer was evaluated by the following procedure.
a) Sample the regenerated resin of the actual apparatus in the state of the ratio of the cation exchange resin and the anion exchange resin actually used.
b) Pack and ship on the day of collection.
c) At the laboratory, the resin is separated on the day when the resin sample is received, and the ion transfer rate measurement is performed on the same day (0.5 days later).
d) For comparison, ion separation rate measurement is performed three times (2.5 days, 4 days, and 7 days) after the resin is separated for the purpose of comparison.
e) For comparison, the resin sample is separated from the date of receipt of the resin sample (3 days after resin collection, 7 days later), and ion migration rate measurement is performed in the same manner as in c) and d).

  The measurement results at this time are shown in Table 2 and FIG.

  As shown in Table 2 and FIG. 4, the period from the acquisition of the resin sample to the resin separation does not give a very large measurement error if the resin sample is in a mixed state, but until the measurement date after the resin separation. The period affects the measured value.

  Therefore, in order to accurately grasp the resin performance, it is important to carry out analytical operations such as resin separation within a certain period of time from the collection of the resin sample, in order to ensure the reliability of the measured value, In particular, if the measurement is within 3 days after the resin separation, there will be no large error in the measured value, but if it exceeds 3 days, the measurement error will be large. It can be seen that the measurement needs to be done within 3 days.

It is a systematic diagram of the apparatus for ion movement speed measurement. 6 is a graph showing the results of Experimental Example 1. 10 is a graph showing the results of Experimental Example 2. 3 is a graph showing the results of Example 1.

Explanation of symbols

2 Anion exchange resin packed column 3 Cation exchange resin packed column

Claims (5)

In the method for evaluating the performance of the anion exchange resin in the ion exchange resin used in the mixed bed desalting apparatus,
Collecting the ion exchange resin;
After a period of holding the anion exchange resin and the cation exchange resin in a mixed state after collection, the anion exchange resin and the cation exchange resin are separated,
A performance evaluation method for an anion exchange resin, wherein the performance of the separated anion exchange resin is evaluated within 3 days after the separation. In the method for evaluating the performance of the anion exchange resin in the ion exchange resin used in the mixed bed desalting apparatus,
Collecting the ion exchange resin;
After a period of holding the anion exchange resin and the cation exchange resin in a mixed state after collection, the anion exchange resin and the cation exchange resin are separated,
After 3 days have passed after the separation, the separated anion exchange resin is mixed with the cation exchange resin and kept in a mixed state, and then separated.
A performance evaluation method for an anion exchange resin, wherein the performance of the separated anion exchange resin is evaluated within 3 days after the separation.   3. The method for evaluating the performance of an anion exchange resin according to claim 1, wherein the cation exchange resin is a cation exchange resin used in the mixed bed desalting apparatus.   The mixed state of the anion exchange resin and the cation exchange resin according to any one of claims 1 to 3 is substantially the same as a mixing ratio of the anion exchange resin and the cation exchange resin in the mixed bed desalting apparatus. A method for evaluating the performance of an anion exchange resin, which is in a mixed state.   5. The method for evaluating the performance of an anion exchange resin according to claim 1, wherein the anion exchange resin is evaluated under a time management evaluated within 3 days after the separation.

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