JPH10267838A - Method for evaluating performance of ion-exchange resin and method for managing water-treating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To grasp a cause and a state of contamination and enable estimation of a use limit, etc., by carrying out identification, determination, etc., to impurities of a surface part of an ion-exchange resin by a surface analysis method. SOLUTION: In evaluating an ion-exchange resin being used in various kinds of water-treating apparatuses, preferably, a surface analysis is carried out by the Fourier transform infrared total reflection analysis method (ATR method), thereby identifying a contaminant. Moreover, a degree of contamination is obtained from an intensity ratio of the natural absorption originated from the ion-exchange resin and the absorption originated from the contaminant. For example, an anion exchange resin used in a condensation desalination tower of a power plant is detected to be contaminated with polystyrene sulfonic acid eluted from a cation exchange resin by the ATR method, so that a quantitative working curve can be formed from a standard sample. A time when the anion exchange resin should be exchanged is judged, for example, from a mass-transfer coefficient(MTC). A quantitative value of the contaminant obtained by the ATR method is correlated to the MTC, and therefore can be utilized to judge the exchange time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating the performance of an ion exchange resin used in various water treatment apparatuses, and a method for managing a water treatment system using the method. A method for evaluating the performance of an ion exchange resin used in various water treatment devices such as a condensate desalination device and a general pure water production device (desalination device) used in a power plant, and using the method. The present invention relates to a method for managing a water treatment system for judging / determining a time for replacing an ion exchange resin.

[0002]

2. Description of the Related Art In a thermal power plant or a nuclear power plant, steam generated after driving a power generation turbine is cooled and condensed, and the condensed water is heated and used again as steam to drive the power generation turbine to generate power. The cycle is repeating. For this reason, condensate is highly sophisticated from the viewpoint of preventing corrosion of boilers, steam generators, nuclear reactors, etc., and reducing radioactivity (especially, accumulated through iron as impurities), which causes worker exposure. Various condensate purification devices such as a mixed-bed condensate desalination device, a powdered ion exchange resin filter, and a hollow fiber filter are used alone or in combination.

[0003] The mixed bed type condensate desalination apparatus generally includes a water flow system including a plurality of condensate desalination towers (hereinafter abbreviated as "desalination towers") and an ion exchange system used in the desalination towers. And a regeneration system for regenerating the resin. In the desalination tower, generally, H-form or N-form is used.
It is filled with a strongly acidic cation exchange resin in H ₃ form and a strongly basic anion exchange resin in OH form.

[0004] In such a condensate desalination apparatus, condensate treatment is performed as follows. That is, the condensate is passed in parallel to a plurality of desalination towers, and impurity ions contained in the condensate are removed by adsorption by ion exchange,
Metal oxides such as iron oxide are removed by filtration and physical adsorption to obtain purified treated water.

[0005] The ion exchange resin in such a desalination tower is
Usually, when a certain amount of water is treated, a regeneration step is started. In the regeneration step, the ion exchange resin in the desalting tower is transferred to a regeneration tower (regeneration facility), and a metal oxide attached to the surface of the ion exchange resin is removed by air scrubbing. Separation process to separate resin and anion exchange resin.Furthermore, after separation, pass hydrochloric acid or sulfuric acid through cation exchange resin and pass sodium hydroxide through anion exchange resin to desorb impurities. Then, there is a desorption step of regenerating both ion exchange resins. The ion-exchange resin whose regeneration has been completed is usually transferred to a storage tank, and is kept on standby until the ion-exchange resin in another desalination tower reaches the end point of water flow. The ion exchange resin that has reached the end point of water passing is taken out in the another desalination tower, and instead, the waiting ion exchange resin is transferred to the other desalination tower, and the cation exchange resin and the anion exchange resin are mixed. Used as a floor for condensate treatment. The mixing of the cation exchange resin and the anion exchange resin is usually performed by preliminary pre-mixing and post-mixing in a desalting tower to form a mixed bed.

[0006] The quality of water required for the treated water treated by the above condensate desalination apparatus has been increasing in recent years from the viewpoint of preventing corrosion damage to boilers, steam generators, nuclear reactors and the like and preventing scale adhesion. Purity tends to be required. For example, the target of Na ion, Cl ion, and SO ₄ ion is 0.01 ppb or less.
Such impurities are usually captured by the ion exchange resin in the condensate desalination tower, but when the performance of the ion exchange resin is reduced, such impurities are transferred to boilers, steam generators, nuclear reactors, and the like. Inflow, causing obstacles such as corrosives formation and scale adhesion. For this reason, conventionally, the performance evaluation of ion exchange resins has been emphasized for safety management of power plants,
At present, a reaction rate test is employed for anion exchange resins.

[0007] The same applies to ion exchange resins used in general pure water production apparatuses other than the above-mentioned power plants. Normally, they are used in a mixed-bed type or a double-bed type, and when a certain amount of water is collected, regeneration is performed.
Further, depending on the use of the treated water, highly purified treated water is required, and after a certain amount of water is collected, the ion exchange resin may be replaced with a new ion exchange resin without regeneration. From the viewpoint of water quality management, it is important to maintain the performance of the ion exchange resin soundly and properly replace it.However, the performance evaluation and replacement time of the ion exchange resin are controlled by the specific resistance value of the ion exchange resin tower outlet water. That is the current situation.

[0008]

According to recent research,
Regarding the ion exchange resin used in the condensate desalination unit of the power plant, it has become clear that the reaction rate of the anion exchange resin decreases due to the influence of the cation exchange resin. In other words, the cation exchange resin adsorbing Fe ions and Cu ions in water undergoes oxidative decomposition, albeit very slight, due to the catalytic action of these heavy metal ions and contact with dissolved oxygen in water and oxygen in air. As a result, decomposed products composed of oligomers or low-molecular polymers of styrene sulfonic acid (hereinafter, these are referred to as “polystyrene sulfonic acids”), which are part of the parent structure of the cation exchange resin, are generated and decomposed. The substance is adsorbed on the surface of the anion exchange resin and contaminates it, which is a major cause for reducing the reactivity of the anion exchange resin. When the reactivity of the anion exchange resin decreases, the eluate from the cation exchange resin is not captured by the anion exchange resin but remains in the treated water treated by the condensate desalination apparatus, and the boiler, the steam generator, It flows into nuclear reactors, etc., and pyrolyzes at high temperature to produce CO ₂ and SO ₄ ^2- , increasing the amount of ions, and also failing to cope with leakage of seawater to the condenser. As a result, the quality of the treated water treated by the condensate desalination apparatus decreases. These decomposition products cannot be easily desorbed from the anion exchange resin by a normal ion exchange resin regeneration method.

The performance evaluation of an anion exchange resin used in a condensate desalination apparatus is generally based on a decrease in the reaction rate as an index. However, in an actual plant, the reaction rate of the anion exchange resin is not necessarily the same as the use period. Since it does not decrease gradually, but rather decreases more rapidly than a certain period, it is not possible to predict the service limit of the anion exchange resin simply by measuring the reaction rate. In addition, when a standard substance of polystyrene sulfonic acid (standard polystyrene sulfonic acid) is added to a new anion exchange resin, the reaction rate of the anion exchange resin rapidly decreases after adsorption of a certain amount of standard polystyrene sulfonic acid. Has also become apparent. It is not possible to predict such a rapid decrease in the reaction rate of the anion exchange resin just by measuring the reaction rate of the anion exchange resin as in the related art. Further, as a method for predicting such a rapid decrease in the reaction rate of the anion exchange resin, standard polystyrene sulfonic acid is added to the anion exchange resin, and then the reaction rate of the anion exchange resin and the standard polystyrene sulfonic acid are added. There is also a test method for measuring the amount of adsorption, but the standard polystyrene sulfonic acid used is difficult to adsorb to the anion exchange resin, and the standard polystyrene sulfonic acid adsorption amount is calculated by subtracting the unadsorbed amount from the added amount. For a reason, analysis takes time.

[0010] In addition to the oxidative degradation products from the cation exchange resin, rust preventives, auxiliary materials, and the like, which are used during periodic inspections of power plants, affect the reaction rate of the anion exchange resin. . At the start-up after the periodic inspection, water is usually passed through the condensate desalination tower to purify the circulation system water.In this case, impurities such as auxiliary materials contaminate the anion exchange resin as impurities in the circulation system. However, the reaction rate may decrease. Actually, there are many phenomena in which the reaction rate of the anion exchange resin temporarily decreases immediately after the regular inspection and immediately after startup. In the measurement of the reaction rate (for example, the mass transfer coefficient “MTC”) of the conventional anion exchange resin, it is determined whether the reaction rate of the anion exchange resin is reduced due to the above-described effect of the cation exchange resin. Indistinguishable from other factors. In addition, in a general water treatment apparatus such as a pure water production apparatus, an anion exchange resin affects a cation exchange resin, and is opposite to a phenomenon in a condensate desalination apparatus of a power plant. It has been confirmed that the reaction speed of the compound decreases.

In a condensate desalination unit and a general pure water production unit of a power plant, etc., the purity of the treated water is required to be improved year by year depending on the use of the treated water. Management is required. Therefore, the conventional performance evaluation management based on the reaction rate of the ion exchange resin alone is not sufficient for safety management, and more appropriate performance evaluation of the cation exchange resin and the anion exchange resin and determination of the replacement time are becoming important.

It is an object of the present invention to provide a method for evaluating the performance of an ion-exchange resin and a method for managing a water treatment system capable of predicting the limit of use of the ion-exchange resin, which can meet the demands of such an era.

[0013]

According to the present invention, there is provided an ion-exchange resin wherein the surface of the ion-exchange resin is subjected to surface analysis to identify and measure and / or quantify impurities on the surface of the ion-exchange resin. Resin performance evaluation method,
In addition, by performing the surface analysis of the ion exchange resin to identify impurities in the surface portion of the ion exchange resin and measure and / or quantify the distribution state, the cause of contamination and the contamination state of the ion exchange resin are grasped, and the ion exchange resin is contaminated. An object of the present invention is to provide a method for managing a water treatment system, which is characterized by predicting a tendency of a subsequent reduction in the reaction rate of a resin and determining a replacement time of an ion exchange resin.

The present invention relates to a method for evaluating the performance of an ion-exchange resin by a surface analysis method and a method for managing a water treatment system that determines the time for exchanging the ion-exchange resin using the method. Examples of the method include infrared spectroscopy, photoelectron spectroscopy, photoacoustic spectroscopy, secondary ion mass spectroscopy, and the like. In particular, ATR using infrared spectroscopy is useful. The ATR method is a method of analyzing a surface region up to a depth of several μm. Photoacoustic spectroscopy is also effective for analysis of a deeper region, and photoelectron spectroscopy or secondary ion mass spectrometry is used for analysis of a shallower region. Analytical methods are also effective (references: “Solid Surface Analysis I” and “Solid Surface Analysis II” published by Kodansha Scientific, Tokyo Chemical Dojin Publishing “F
T-IR Fundamentals and Practice "). Note that these surface analysis methods are particularly effective for measuring a sulfonic acid component (polystyrene sulfonic acid component) on the surface of an anion exchange resin in a thermal power plant or a nuclear power plant. By such a surface analysis method, for example, the surface of an ion exchange resin used in various water treatment apparatuses such as a condensate desalination apparatus is analyzed, and impurities present on the resin surface are directly identified and quantified. By this, the cause of contamination of ion exchange resin, which could not be elucidated in the past, is clarified, the contamination status of ion exchange resin is grasped, more accurate performance evaluation of ion exchange resin and prediction of future reaction rate decrease tendency Therefore, it is possible to judge and determine an appropriate replacement time.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an actual method for measuring impurities and a method for evaluating the performance of an ion exchange resin according to the embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments. Not.

In the method of the present invention, the surface analysis of the ion exchange resin is preferably performed by infrared spectroscopy. Infrared total reflection spectroscopy (ATR, ATR
= Attenuated Total Reflectance) is particularly preferable to perform the surface analysis of the ion exchange resin. In the ATR method, an ion exchange resin is brought into contact with a crystal plate inactive with infrared light, and infrared light is made incident through the crystal plate to identify and quantify contaminants on the resin surface. A
According to the TR method, it is possible to analyze the surface portion of the ion-exchange resin to a depth of several μm. For example, the polystyrene sulfonic acid (as described above, “styrene, which is a decomposition product of a cation-exchange resin, Sulfonic acid oligomers and low molecular weight polymers ”), although the depth of the adsorbent layer varies depending on the molecular weight and the amount of adsorption, at a level that causes contamination, about 1 to about 1 to about the surface of the anion exchange resin. Since it is considered that the substance is adsorbed to a depth of 2 μm, it is sufficient if the analysis can be performed to a depth of several μm.

As the infrared spectrometer, a dispersion type or a Fourier transform type can be used, but a Fourier transform type is particularly preferable.
The ATR method includes a method in which a crystal plate is placed in the optical path of an infrared spectroscope used for ordinary infrared spectroscopy, and a method in which this method is combined with the use of a microscope, and either method may be used.

The ion exchange resin used for the measurement may be either in a dry state or a water-containing state, but the water-containing state is more effective in that the peak of the infrared absorption spectrum becomes sharp. A sample ion-exchange resin is brought into contact with a crystal plate and irradiated with infrared light. As the material of the crystal plate, it can be used as long as it has no absorption in a target infrared region and has a sufficiently large refractive index. However, Ge and ZnSe are particularly preferable. When the ion exchange resin is in a dry state, KRS-5 ( A mixed crystal of thallium iodide TlI and thallium bromide TlBr) is also effective. As the shape of the crystal plate, various shapes such as a trapezoid, a rhombus, and a hemisphere can be used. The angle of incidence of the infrared light is not particularly limited as long as it is equal to or larger than the critical angle. For example, any of 30 degrees, 45 degrees, and 60 degrees commonly used in commercially available infrared spectrometers can be used. The depth that can be analyzed can be changed depending on the combination of the material of the plate and the incident angle. For example, in the analysis of a relatively deep surface region, ZnSe or KRS-
In the analysis of the crystal plate No. 5 and the incident angle of 45 degrees, and the relatively shallow surface area, the combination of the Ge crystal plate and the incident angle of 60 degrees is effective.

For example, by analyzing the absorption originating from the contaminant in comparison with the absorption originating from the ion exchange resin, the contaminant is identified, and based on the intensity ratio of the absorption originating from the ion exchange resin and the absorption originating from the contaminant, ion exchange is performed. The degree of resin contamination can be determined. Furthermore, it is also possible to prepare a calibration curve using standard contaminants and quantify the amount of contaminants.

FIG. 1 shows an example of an infrared absorption spectrum by the ATR method. The sample is a standard sample ("MW 50,000" in Table 1 of Example 1) consisting of a resin obtained by adsorbing a fixed amount (294 mg / L-resin) of standard polystyrene sulfonic acid (molecular weight: 50,000) on an anion exchange resin. Standard Product Column ”). In this infrared absorption spectrum, the absorption of the anion exchange resin is detected in a wave number 977Cm ^-1, wavenumber 1009cm ^-1, 1035cm ^-1, 112
Absorption derived from standard polystyrenesulfonic acid as a contaminant is detected at 6 cm ^-1 and 1182 cm ^-1 (wide peak). (The absorption peak position is slightly shifted depending on the state of the sample, measurement conditions, and the like. The peak position is not always the above position).

FIG. 2 shows another example of the infrared absorption spectrum by the ATR method. The sample is an anion exchange resin (actual anion exchange resin No. 1 in Table 3 of Example 1) used in a condensate desalination tower of a certain power plant. This is an example showing the contamination of the anion exchange resin by a decomposition product eluted from the cation exchange resin. In this infrared absorption spectrum, the wave number is 977 cm ⁻¹ , similarly to the infrared absorption spectrum of the standard sample. , The wave numbers of 1009 cm ⁻¹ , 1035 cm ⁻¹ , 1126 cm ⁻¹ ,
Absorption derived from the cation exchange resin is detected at 1182 cm ^-1 (wide peak), and it can be seen that the decomposition product is mainly polystyrene sulfonic acid (the absorption peak position depends on the state of the sample, the measurement conditions, and the like). , The absorption peak position is not always the above position). From the intensity ratio of the absorption derived from the cation exchange resin to the absorption of the anion exchange resin, it is possible to determine the degree of contamination of the surface of the anion exchange resin due to elutes such as decomposition products of the cation exchange resin as contaminants. it can.
In this case, any of the above-mentioned absorption wave numbers may be used as the absorption wave number derived from the contaminant.

A sample obtained by adsorbing an equal amount of benzenesulfonic acid on a strongly basic anion exchange resin and a pulverized sample, and a pulverized product of the ion exchange resin not adsorbed to the pulverized sample are mixed at different ratios. A calibration curve can be created using the obtained sample as a standard sample. Since benzene sulfonic acid is a simple compound similar to styrene sulfonic acid, if excess benzene sulfonic acid is added to the anion exchange resin, benzene sulfonic acid is also adsorbed to the inside of the resin by ion bonding, and the resulting resin is washed with water. Then, a resin sample having an equal amount of benzenesulfonic acid adsorbed thereon can be easily obtained. In this case, benzene sulfonic acid is a simple compound similar to styrene sulfonic acid, while polystyrene sulfonic acid generated by decomposition of the cation exchange resin in actual use is, as described above, "polystyrene sulfonic acid. Oligomers and low-molecular-weight polymers ", so in using the above calibration curve, the correlation between the model case of the calibration curve creation due to such a difference and the actual case should be grasped in advance by accumulating actual machine use data. Need to be kept.

Further, a calibration curve can be prepared using a sample obtained by adsorbing the amount of standard polystyrene sulfonic acid on the surface of an anion exchange resin as a standard sample. In this case as well, when using this calibration curve, it is preferable to grasp in advance the correlation between the model case for creating the calibration curve and the actual case by stacking the actual machine use data. The calibration curve is almost the same even if the molecular weight of the acid is different. A calibration curve was prepared in this manner, and polystyrenesulfonic acid (hereinafter referred to as a contaminant on the surface of the anion exchange resin) (hereinafter referred to as “contaminant”) was determined from the absorption intensity ratio (intensity ratio of the absorption derived from the cation exchange resin to the absorption of the anion exchange resin). , Sometimes abbreviated as "PSS"). FIG. 3 shows an example of such a calibration curve. FIG. 3 shows that the standard polystyrene sulfonic acid (standard PSS,
The amount of adsorption on the surface of the anion exchange resin having a molecular weight of “MW”: 50,000) and the wave number of the standard PSS adsorbed to the absorption of the wave number of 977 cm ⁻¹ of the anion exchange resin in the infrared absorption spectrum by the ATR method of 1126 cm ⁻¹ FIG. 3 is a diagram showing a calibration curve (created based on the data in Table 1 of Example 1) showing a correlation with the intensity ratio of absorption (absorption peak height ratio). Note that the standard PSS adsorption amount in FIG. 3 is obtained by immersing the anion exchange resin in an aqueous solution having a predetermined standard PSS concentration and shaking for a predetermined time, adsorbing the standard PSS on the anion exchange resin, and separating the resin and the aqueous solution. It is calculated from the difference between the standard PSS concentration of the separated aqueous solution and the standard PSS concentration of the first aqueous solution.

In carrying out the method for managing a water treatment system of the present invention, identification of contaminants of the ion exchange resin as described above,
It is necessary to grasp the correlation between the results of quantification and the like and the reaction rate of the ion exchange resin. As an example, a case in which the determination and determination of the replacement time of the anion exchange resin used in the actual condensate desalination apparatus as a water treatment system will be described.

The measurement of the reaction rate of the anion exchange resin is performed, for example, by measuring the mass transfer coefficient “MTC” (mass transfer coefficient).
cient) or a known method such as a shallow betting method. In the shallow betting method, NaCl is added to an ion exchange resin layer having a resin layer height of about 10 mm.
Alternatively, it is a method of flowing a salt-containing water such as sodium sulfate and measuring the ion removal rate. On the other hand, the mass transfer coefficient “MT
The method based on the measurement of "C" is convenient, and an outline of an example of the measurement method is as follows.

For example, an anion exchange resin sampled from a condensate desalination unit at a power plant is regenerated using NaOH, and the regenerated resin and a new H-form of the cation exchange resin are regenerated with the regenerated anion exchange resin / cation. Mix at an exchange resin volume ratio = 1/2 and pack into a column. Subsequently, ammonium ions (aqueous ammonia) and sodium sulfate are passed through the upper part of the column at a flow rate of 70 L / hr (liter / hour) in the form of an aqueous solution having a predetermined concentration. The column inlet water and outlet water are collected during the passage of water, the sulfate ion concentration is measured, and after the passage of water, the porosity and the anion exchange resin particle size are measured. The mass transfer coefficient “MTC” is calculated according to the following equation. It can be said that the higher the value, the higher the reaction rate of the anion exchange resin, and the sounder the performance. Usually, the MTC value of a new anion exchange resin is about 2.0 (× 10 ⁻⁴ m / sec).

[0027] Here, K: mass transfer coefficient “MTC” (m / sec), ε: porosity, R: volume ratio of anion exchange resin / cation exchange resin,
F: water flow rate (m ³ / sec), A × L: resin amount (m ³ ), d: resin particle size (m), C ₀ : inlet water SO ₄
^2- concentration, C: SO ₄ ^2- concentration of outlet water.

If the MTC is low, the reaction rate is low, and the general exchange time of the anion exchange resin is, for example, MTC
= 1 (× 10 ⁻⁴ m / sec), but the degree of contamination at which the anion exchange resin should be replaced is
It changes depending on the operating conditions of the equipment and the required performance of the water quality.
It should be determined individually and specifically.

The amount of the standard PSS having a different molecular weight was changed and added to a new anion exchange resin.
The relationship between the adsorption amount of Mn and the MTC at that time is shown with one axis as standard PS.
The amount of S adsorbed and the other axis plotted in a table with MTC, and plotted by molecular weight to draw a line
Create an adsorption sample curve. On the other hand, for example, the adsorption amount (A) of PSS to the surface of the anion exchange resin used in the actual condensate desalination apparatus was determined by the method of the present invention, and the MTC was determined by the above method. It is plotted as a point B (MTC and A for the anion exchange resin used in the actual condensate desalination apparatus) in the chart depicting the PSS adsorption sample curve.

By comparing each standard PSS adsorption sample curve with point B, the average molecular weight of PSS adsorbed on the surface of the anion exchange resin used in the actual condensate desalination apparatus was estimated. Based on the adsorption sample curve, the MTC with the subsequent increase in the amount of PSS adsorbed on the anion exchange resin surface
Predict the downward trend of In the subsequent measurements,
By measuring the amount of PSS adsorbed on the anion exchange resin used in the actual machine by the method of the present invention, the MTC of the anion exchange resin used in the actual machine is estimated based on the standard PSS adsorption sample curve closest to the point B. be able to. Furthermore, for example, the allowable amount of PSS adsorption until the MTC reaches 1 (× 10 ⁻⁴ m / sec) is read from the above chart,
It will be used as a reference for the ion exchange resin exchange time.

[0031]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 New anion exchange resin Amberlite IRA900 manufactured by Rohm and Haas Co. (in the column of "Standard MW 50,000" in Table 1), and a resin having a molecular weight "MW" of 50,000 was added to this resin.
00 standard PSS aqueous solution,
5 types of anion exchange resin which reduced the reaction rate by adsorbing
) And four types of anion exchange resins in use in the actual condensate demineralization tower (actual anion exchange resins Nos. 1-4 in Table 3).
These four types of anion exchange resins were collected from condensate and desalination units at different power plants. )
Was measured for its infrared absorption spectrum. The measurement conditions were as follows. The calibration curve of FIG. 3 was created based on the data of Table 1.

[Measurement conditions] Apparatus: Infrared spectrometer “DIAMON” sold by JEOL Ltd.
D20 "Attached device: ATR device Crystal plate: ZnSe Incident angle: 45 degrees Integration frequency: 1024

The evaluation of the reaction rate of these anion exchange resins was based on the mass transfer coefficient “MT” of the anion exchange resin.
C "was measured by the method described above. The new anion exchange resin has a molecular weight "MW" of 10,000.
For the five types of anion exchange resins (in the column of "MW 10,000 standard" in Table 2) in which the standard PSS aqueous solution was previously added and the standard PSS was adsorbed to reduce the reaction rate, the mass transfer coefficient " MTC ”was measured. The results are shown in Tables 2 and 3 and FIG. The concentration and molecular weight of the standard PSS were measured using gel permeation chromatography, and the amount of the standard PSS adsorbed on the anion exchange resin was determined by the method described above.

In the infrared absorption spectrum of each anion exchange resin used in the actual condensate demineralization tower, the wave number was 977 cm ⁻¹ , similarly to the infrared absorption spectrum of the anion exchange resin sample to which standard PSS was adsorbed. Absorption of the anion exchange resin was detected at a wave number of 1009 cm ^-1 , 1035 cm ^-1 , and 11
It was confirmed that absorption derived from PSS as a contaminant was detected at 26 cm ^-1 and 1182 cm ^-1 (wide peak).

Wave number 97 of each infrared absorption spectrum obtained
Was calculated intensity ratio of the absorption at a wavenumber of 1126cm ^-1 for absorption of 7 cm ^-1. The results are shown in Tables 1 and 3. In Tables 1 and 2, “MW 10,000 standard product” and “MW 50,000 standard product” refer to “molecular weight 1”, respectively.
It shows that "standard PSS of 000" or "standard PSS of molecular weight 50,000" was used for adsorption to a new anion exchange resin. In Tables 1 and 2, "PSS"
Represents the amount of PSS adsorbed on the anion exchange resin. In Table 3, “calculated PSS amount” represents the amount of PSS adsorbed on the anion exchange resin determined from the absorption intensity ratio using the calibration curve of FIG. FIG. 4 shows the relationship between the mass transfer coefficient “MTC” and the amount of PSS adsorbed on the surface of the anion exchange resin.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

From the curve of the adsorption sample of the standard PSS with a molecular weight of 10,000 and the curve of the adsorption sample of the standard PSS with a molecular weight of 50,000 in FIG. 4, the reduction in the reaction rate of each anion exchange resin in use in the actual condensate desalination tower (MTC Is the main cause of
This is the adsorption of the PSS eluate, which is a decomposition product of the cation exchange resin, to the anion exchange resin, and it is considered that the average molecular weight of the adsorbed PSS is about 10,000 to 50,000.

"Actual anion exchange resins No. 1 and No. 1
2 "has an MTC of 1.8 (× 10 ⁻⁴ m / sec)
c), the PSS adsorption amount was No. 1 is about 1
No. at 100 mg / L-resin. 2 is 200 mg / L-resin, which is different between the two. No. in FIG. Since point 1 is close to the curve of the 50,000-standard PSS adsorption sample, it is considered that the MTC will rapidly decrease in the future, and until the MTC reaches 1 (× 10 ⁻⁴ m / sec). Further, the amount of PSS allowed to be adsorbed can be estimated to be about 60 mg / L-resin. On the other hand, in FIG. Point 2 is close to the curve of the sample with a standard molecular weight of 10,000 PSS, so that the amount of PSS that allows further adsorption before the MTC reaches 1 (× 10 ⁻⁴ m / sec) is 100 mg / L. -Can be predicted as resin. No. in FIG. Point 3 is molecular weight 1
000 standard PSS adsorption sample curve and molecular weight 50,000
Since it is almost in the middle of the 0 standard PSS adsorption sample curve,
By the time the MTC reaches 1 (× 10 ⁻⁴ m / sec), the amount of PSS allowed to be further adsorbed can be estimated to be about 50 mg / L-resin. No. in FIG. Point 4 is less than the allowable limit of general MTC = 1 (× 10 ⁻⁴ m / sec), indicating that the anion exchange resin needs to be replaced.

[0042]

As described above, in order to maintain good water quality of the circulating system water of a power plant, it has been necessary to keep the ion exchange resin in the condensate desalination tower sound. The same applies to general water treatment equipment such as a pure water production equipment (desalination equipment). In any case, it is important for water quality management to accurately evaluate and judge the performance of the ion exchange resin. However, if only the performance evaluation based on the reaction rate measurement of the conventional ion exchange resin is performed, the cause of the contamination of the ion exchange resin is unknown, and it is difficult to cope with a rapid decrease in the reaction rate. Therefore, by introducing the method for evaluating an ion-exchange resin according to the present invention, it is possible to clarify the cause of contamination of the ion-exchange resin, and to predict a rapid decrease in the reaction rate of the ion-exchange resin in advance. Becomes Furthermore, in comparison with a conventional method for evaluating the performance of an ion exchange resin by measuring MTC, the method of the present invention is used for analysis because the performance of the ion exchange resin is evaluated by performing a surface analysis of the ion exchange resin. The amount of ion exchange resin is 1 to several 1
The analysis time can be as short as zero (several thousands or more in MTC measurement) and the analysis time can be as short as 1 to 20 minutes (several days in MTC measurement).

According to the management method of the present invention, the use limit is predicted before the ion exchange resin malfunctions,
The water treatment system can be managed stably. The control method of the present invention can be suitably used, for example, for an anion exchange resin used in a condensate desalination apparatus, and more preferably, a PWR (pressurized water reactor) or BWR
It can be used for anion exchange resins used in condensate desalination units of nuclear power plants (boiling water reactors).

[Brief description of the drawings]

FIG. 1 shows that an anion exchange resin is supplied with a fixed amount of standard polystyrene sulfonic acid (molecular weight: 50,000) (294).
(mg / L-resin) It is an infrared absorption spectrum figure by ATR method of one standard sample which consists of the resin adsorbed.

FIG. 2 shows an anion exchange resin No. used in the actual condensate demineralization tower in Example 1. FIG. 1 is an infrared absorption spectrum diagram of the No. 1 ATR method.

FIG. 3 is a graph showing the adsorption amount of standard polystyrene sulfonic acid (molecular weight: 50,000) on the surface of an anion exchange resin and the absorption at a wave number of 977 cm ⁻¹ of the anion exchange resin in an infrared absorption spectrum by an ATR method. FIG. 4 is a diagram showing a calibration curve showing a correlation with an absorption intensity ratio (absorption peak height ratio) of an adsorbed standard polystyrene sulfonic acid at a wave number of 1126 cm ⁻¹ .

FIG. 4 shows the results of Example 1, in which the mass transfer coefficient “MTC” versus PS on the surface of the anion exchange resin was measured.
It is a figure which shows the relationship of S adsorption amount.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G01N 29/00 501 G01N 29/00 501

Claims (8)

[Claims] 1. A method for evaluating the performance of an ion-exchange resin, comprising: identifying, measuring and / or quantifying the distribution of impurities on the surface of the ion-exchange resin by analyzing the surface of the ion-exchange resin. 2. The method according to claim 1, wherein the surface analysis is performed by infrared spectroscopy, photoelectron spectroscopy, photoacoustic spectroscopy or secondary ion mass spectrometry. . 3. The method according to claim 2, wherein the surface analysis is performed by infrared spectroscopy, preferably by Fourier transform infrared total reflection spectroscopy. 4. The method for evaluating the performance of an ion exchange resin according to claim 1, wherein the ion exchange resin is an anion exchange resin. 5. The surface analysis of the ion-exchange resin to identify and measure and / or quantify the impurities on the surface of the ion-exchange resin to grasp the cause of contamination and the state of the contamination of the ion-exchange resin. A method for predicting a subsequent tendency of the reaction rate of the ion exchange resin to decrease, and determining a replacement time of the ion exchange resin. 6. The method according to claim 5, wherein the surface analysis is performed by infrared spectroscopy, photoelectron spectroscopy, photoacoustic spectroscopy or secondary ion mass spectrometry. 7. The method for managing a water treatment system according to claim 6, wherein the surface analysis is performed by infrared spectroscopy, preferably by Fourier transform infrared total reflection spectroscopy. 8. The method for evaluating the performance of an ion exchange resin according to claim 5, wherein the ion exchange resin is an anion exchange resin.