A Scintillation Resin of Fe-55, Its Preparation Method and Application

Abstract

The present invention provides a scintillation resin for Fe-55, a preparation method thereof and an application thereof, belonging to the technical field of separation and detection. The scintillation resin for Fe-55 provided by the present invention is obtained by a polymerization reaction from a polymerization monomer, a scintillator, a wavelength shifter, an extractant, a dispersant, an initiator, an organic solvent and water. The scintillator can convert the energy of received α or β rays into fluorescence, while the wavelength shifter transfers the energy released by the scintillation group to the wavelength range suitable for a photomultiplier tube, reducing the self-absorption effect. The extractant can specifically interact with 55 Fe, so that the resin has excellent adsorption and detection effects on 55 Fe, has good detection accuracy and stability, and after separation or detection is completed, can be separated by simple filtration.

Description

Technical Field

[0001] The present invention belongs to the technical field of separation and detection, and particularly relates to a scintillation resin for Fe-55, a preparation method thereof, and an application thereof. Background Art

[0002] The decommissioning of nuclear facilities marks the end of their life cycle, is a key link in the whole-life cycle management of nuclear facilities, and is also an important measure for environmental protection. Its core goal is to safely handle and dispose of radioactive substances, and transform the nuclear facility site into an unrestricted open green space or for other purposes. In the context of nuclear facility decommissioning, it is crucial to accurately analyze and evaluate the concentration levels of radionuclides, which is of great significance for environmental protection and human health. Among many radionuclides, 55 Fe, due to its long half-life and decay by K-capture mode, emitting soft X-rays, has become an important research object in the context of nuclear facility decommissioning.

[0003] In the prior art, radioactive nuclides are mainly detected by liquid scintillation. A liquid scintillation solution is prepared by mixing a scintillator with a solvent, additives, etc., and then the radioactive nuclides are detected. However, a large amount of organic radioactive waste liquid will be generated after this method of detection, which has always been a technical problem faced by liquid scintillation measurement technology, and at the same time, its detection sensitivity still needs to be improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a scintillation resin for Fe-55, a preparation method thereof, and an application thereof. The scintillation resin for Fe-55 provided by the present invention can be used for liquid scintillation measurement, is easy to separate, and has high detection sensitivity.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a scintillation resin for Fe-55, which is obtained by a polymerization reaction of a polymerization monomer, a scintillator, a wavelength shifter, an extractant, a dispersant, an initiator, an organic solvent, and water; the extractant includes at least one of bis(2,4,4-trimethylpentyl)phosphonic acid, 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester, and bis(2-ethylhexyl)phosphate.

[0007] Preferably, the scintillator includes at least one of 2,5-diphenyloxazole and p-terphenyl.

[0008] Preferably, the wavelength shifter includes at least one of 1,4-bis(2-(5-phenyloxazolyl))benzene and diphenylmethane.

[0009] The present invention also provides a preparation method of the scintillation resin for Fe-55 as described in the above technical solution, including the following steps:

[0010] (1) Mix water and a dispersant to obtain an aqueous phase;

[0011] (2) Mix a polymerization monomer, a scintillator, a wavelength shifter, an initiator, an extractant, and an organic solvent to obtain an organic phase;

[0012] (3) Mix the aqueous phase obtained in step (1) and the organic phase obtained in step (2), and carry out a polymerization reaction to obtain a scintillation resin of Fe-55;

[0013] There is no chronological order between steps (1) and (2).

[0014] Preferably, the dispersant in step (1) includes at least one of polyvinyl alcohol, gelatin, and calcium chloride.

[0015] Preferably, the mass ratio of the dispersant to the volume of water in step (1) is (0.4 - 1) g : (200 - 250) mL.

[0016] Preferably, the polymerization monomer in step (2) includes styrene and divinylbenzene.

[0017] Preferably, the mass ratio of styrene, divinylbenzene, scintillator, wavelength shifter, initiator, and extractant in step (2) is (12 - 14) : (2 - 4) : (0.03 - 0.6) : (0.005 - 0.1) : (0.2 - 0.4) : (2 - 4).

[0018] Preferably, the temperature of the polymerization reaction in step (3) is 60 - 70 °C, and the time of the polymerization reaction is 5 - 6 h.

[0019] The present invention also provides the scintillation resin of Fe-55 described in the above technical solution or the scintillation resin of Fe-55 prepared by the preparation method described in the above technical solution in 55 the application of Fe separation and detection.

[0020] The present invention provides a scintillation resin of Fe-55, which is obtained by a polymerization reaction from a polymerization monomer, a scintillator, a wavelength shifter, an extractant, a dispersant, an initiator, an organic solvent, and water; the extractant includes at least one of bis(2,4,4-trimethylpentyl) phosphonic acid, 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester, and bis(2-ethylhexyl) phosphate. The scintillator in the scintillation resin provided by the present invention can convert the energy of received α or β rays into fluorescence, and the wavelength shifter transfers the energy released by the scintillation group to the wavelength range suitable for the photomultiplier tube, reducing the self-absorption effect. The extractant can specifically interact with 55 Fe, so that the resin has 55Fe has excellent adsorption and detection effects, thus having good detection accuracy and stability. After separation or detection is completed, it can be separated by simple filtration. The results of the examples show that the detection limit of the Fe-55 scintillation resin provided by the present invention is 0.11 Bq, and the detection efficiency after multiple measurements is above 5%. Description of the Drawings

[0021] Figure 1 SEM image of the resin prepared in Comparative Example 1;

[0022] Figure 2 SEM image of the Fe-55 scintillation resin prepared in Example 1;

[0023] Figure 3 Infrared spectra of the resins prepared in Comparative Example 1 and Example 1;

[0024] Figure 4 Fluorescence spectrum of the Fe-55 scintillation resin prepared in Example 1 after adsorbing 16 mg / g of Fe 3+ ;

[0025] Figure 5 Adsorption amount of the Fe-55 scintillation resin prepared in Example 1 for iron ions under different solid-liquid ratios;

[0026] Figure 6 Adsorption amount of the Fe-55 scintillation resin prepared in Example 1 for iron ions under different pH values;

[0027] Figure 7 Adsorption rate of the Fe-55 scintillation resin prepared in Example 1 for iron ions at different times;

[0028] Figure 8 Comparison chart of the adsorption amounts of the Fe-55 scintillation resins prepared in Examples 1 to 4 for iron ions;

[0029] Figure 9 Liquid scintillation test results of three batches of Fe-55 scintillation resins prepared according to the preparation method of Example 1 for 55 Fe;

[0030] Figure 10 Liquid scintillation test results of the Fe-55 scintillation resin prepared in Example 1 for 55 Fe at 1d, 5d, 10d and 20d; Detailed Embodiments

[0031] The present invention provides a Fe-55 scintillation resin, which is obtained by a polymerization reaction of a polymerization monomer, a scintillator, a wavelength shifter, an extractant, a dispersant, an initiator, an organic solvent and water.

[0032] In the present invention, the scintillator preferably includes at least one of 2,5-diphenyloxazole and p-terphenyl, and more preferably is 2,5-diphenyloxazole (PPO). In the present invention, the scintillator can convert the received energy of α or β rays into fluorescence.

[0033] In the present invention, the wavelength shifter preferably includes at least one of 1,4-bis(2-(5-phenyloxazolyl))benzene and diphenylmethane, and more preferably is 1,4-bis(2-(5-phenyloxazolyl))benzene (POPOP). In the present invention, the wavelength shifter transfers the energy released by the scintillation group to the wavelength range suitable for the photomultiplier tube, reducing the self-absorption effect.

[0034] In the present invention, the extractant includes at least one of bis(2,4,4-trimethylpentyl)phosphonic acid, 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester, and bis(2-ethylhexyl)phosphate, and is preferably bis(2,4,4-trimethylpentyl)phosphonic acid (Cyanex272). In the present invention, the extractant can 55 specifically interact with Fe, thereby improving the detection sensitivity.

[0035] The scintillator in the scintillation resin provided by the present invention can convert the received energy of α or β rays into fluorescence, while the wavelength shifter transfers the energy released by the scintillation group to the wavelength range suitable for the photomultiplier tube, reducing the self-absorption effect. The extractant can 55 specifically interact with Fe, so that the resin has 55 excellent adsorption effect and detection effect on Fe, thereby having better detection accuracy and stability, and being a solid-phase material. After separation or detection, it can be separated by simple filtration, without generating a large amount of organic radioactive waste liquid, being more green and environmentally friendly, reducing the harm to the environment. The scintillation resin after detection can be recycled and reused, and can continuously monitor radionuclides in a complex environment.

[0036] The present invention also provides a preparation method of the scintillation resin of Fe-55 described in the above technical solution, including the following steps:

[0037] (1) Mix water and a dispersant to obtain an aqueous phase;

[0038] (2) Mix a polymerization monomer, a scintillator, a wavelength shifter, an initiator, an extractant, and an organic solvent to obtain an organic phase;

[0039] (3) Mix the aqueous phase obtained in step (1) and the organic phase obtained in step (2), and carry out a polymerization reaction to obtain the scintillation resin of Fe-55;

[0040] The steps (1) and (2) have no chronological order.

[0041] Unless otherwise specified, the present invention has no special limitation on the sources of the raw materials, and commercially available products well-known to those skilled in the art can be used.

[0042] The present invention mixes water and a dispersant to obtain an aqueous phase.

[0043] In the present invention, the dispersant preferably includes at least one of polyvinyl alcohol (PVA), gelatin, and calcium chloride, and more preferably polyvinyl alcohol (PVA). In the examples of the present invention, the polyvinyl alcohol is polyvinyl alcohol 1788 type, and the average molecular weight is 130.14.

[0044] In the present invention, the water is preferably deionized water.

[0045] In the present invention, the mass ratio of the dispersant to the volume of water is preferably (0.4 - 1) g : (200 - 250) mL. By controlling the mass ratio of the dispersant to the volume of water within the above range, the present invention can enable the dispersant to be fully dissolved.

[0046] In the present invention, the temperature of the mixing is preferably 50 - 70 °C, and more preferably 60 °C. The present invention has no special limitation on the mixing time, as long as the dispersant is fully dissolved in water.

[0047] The present invention mixes a polymerization monomer, a scintillator, a wave shifter, an initiator, an extractant, and an organic solvent to obtain an organic phase.

[0048] In the present invention, the polymerization monomer preferably includes styrene and divinylbenzene.

[0049] In the present invention, the initiator preferably includes at least one of azobisisobutyronitrile (AIBN) and benzoyl peroxide. In the present invention, the initiator is used to initiate the polymerization reaction of the monomer.

[0050] In the present invention, when the polymerization monomer includes styrene and divinylbenzene, the mass ratio of styrene, divinylbenzene, scintillator, wave shifter, initiator, and extractant is preferably (12 - 14) : (2 - 4) : (0.03 - 0.6) : (0.005 - 0.1) : (0.2 - 0.4) : (2 - 4). By controlling the mass ratio of each raw material within the above range, the present invention can further improve the detection accuracy.

[0051] In the present invention, the organic solvent preferably includes toluene, acetone, or kerosene.

[0052] In the present invention, the mass ratio of styrene to the organic solvent is preferably 14:(2 - 20). By controlling the mass ratio of styrene to the organic solvent within the above range, the present invention can ensure that all raw materials are fully dissolved.

[0053] The present invention has no special limitation on the operation of mixing the polymerization monomer, scintillator, wavelength shifter, initiator, extractant and organic solvent. The raw materials can be mixed evenly by adopting the technical scheme of material mixing well-known to those skilled in the art.

[0054] After obtaining the aqueous phase and the organic phase, the present invention mixes the aqueous phase and the organic phase to carry out a polymerization reaction to obtain the scintillation resin of Fe-55.

[0055] In the present invention, the mass ratio of the aqueous phase to the organic phase is preferably (10 - 12):1. By controlling the ratio of the aqueous phase to the organic phase within the above range, the present invention can make the products of the polymerization reaction more fully dispersed and have better detection sensitivity and accuracy.

[0056] The present invention has no special limitation on the operation of mixing the aqueous phase and the organic phase. The two can be mixed evenly by adopting the technical scheme of material mixing well-known to those skilled in the art.

[0057] In the present invention, the temperature of the polymerization reaction is preferably 60 - 70°C; the time of the polymerization reaction is preferably 5 - 6 h; the polymerization reaction is preferably carried out under stirring conditions. The present invention has no special limitation on the stirring method and rate, and the technical scheme of stirring well-known to those skilled in the art can be adopted. By controlling the temperature and time of the polymerization reaction within the above range, the present invention can ensure that the polymerization reaction proceeds fully.

[0058] After the polymerization reaction is completed, the present invention preferably washes and dries the product of the polymerization reaction in sequence to obtain the scintillation resin of Fe-55.

[0059] The present invention has no special limitation on the operation of the water washing, and the technical scheme of water washing well-known to those skilled in the art can be adopted.

[0060] In the present invention, the drying is preferably freeze-drying. The present invention has no special limitation on the operation of the freeze-drying, and the technical scheme well-known to those skilled in the art can be adopted.

[0061] The present invention obtains a matrix by crosslinking polymerization of styrene and divinylbenzene, and then modifies it with a scintillator, a wavelength shifter and an extractant and controls reaction parameters such as the dosage of each component. The scintillator can convert the energy of the received α or β ray into fluorescence, while the wavelength shifter transfers the energy released by the scintillation group to the wavelength range suitable for the photomultiplier tube to reduce the self-absorption effect. The extractant can react with 55Specific interactions occur with Fe, enabling the resin to 55 have excellent adsorption and detection effects on Fe, thus having good detection accuracy and stability. After separation or detection, it can be separated by simple filtration.

[0062] The present invention also provides the application of the scintillation resin of Fe-55 described in the above technical solution or the scintillation resin of Fe-55 prepared by the preparation method described in the above technical solution in 55 the separation and detection of Fe.

[0063] The scintillation resin of Fe-55 provided by the present invention can be used for liquid scintillation measurement to achieve the 55 separation and detection of Fe.

[0064] The present invention has no special limitation on the operation of the above application, and the technical solutions of the applications well-known to those skilled in the art can be adopted.

[0065] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts belong to the scope of protection of the present invention.

[0066] Example 1

[0067] A preparation method of a scintillation resin of Fe-55: (1) Mix water and polyvinyl alcohol (polyvinyl alcohol type 1788, with an average molecular weight of 130.14) to obtain an aqueous phase, and the mass ratio of polyvinyl alcohol to the volume of water is 0.7 g: 250 mL;

[0068] (2) Mix styrene, divinylbenzene, scintillator 2,5-diphenyloxazole, wavelength shifter 1,4-bis(2-(5-phenyloxazolyl))benzene, initiator azobisisobutyronitrile, extractant bis(2,4,4-trimethylpentyl)phosphonic acid and toluene to obtain an organic phase. The mass ratio of styrene, divinylbenzene, scintillator 2,5-diphenyloxazole, wavelength shifter 1,4-bis(2-(5-phenyloxazolyl))benzene, initiator azobisisobutyronitrile and extractant bis(2,4,4-trimethylpentyl)phosphonic acid is 14: 2: 0.6: 0.1: 0.2: 2, and the mass ratio of styrene to toluene is 14: 2;

[0069] (3) Mix the aqueous phase obtained in step (1) and the organic phase obtained in step (2) (the mass ratio of the aqueous phase to the organic phase is 12: 1), carry out a polymerization reaction at 60 °C for 5 h, wash with water and freeze-dry to obtain the scintillation resin of Fe-55, denoted as PSresin.

[0070] Example 2

[0071] A preparation method of Fe-55 scintillating resin: (1) Mix water and polyvinyl alcohol (polyvinyl alcohol type 1788, average molecular weight is 130.14) to obtain an aqueous phase, and the mass ratio of polyvinyl alcohol to the volume of water is 0.4 g: 250 mL;

[0072] (2) Mix styrene, divinylbenzene, scintillator 2,5-diphenyloxazole, wavelength shifter 1,4-bis(2-(5-phenyloxazolyl))benzene, initiator azobisisobutyronitrile, extractant bis(2,4,4-trimethylpentyl)phosphonic acid and toluene to obtain an organic phase. The mass ratio of styrene, divinylbenzene, scintillator 2,5-diphenyloxazole, wavelength shifter 1,4-bis(2-(5-phenyloxazolyl))benzene, initiator azobisisobutyronitrile and extractant bis(2,4,4-trimethylpentyl)phosphonic acid is 14:2:0.6:0.1:0.2:2, and the mass ratio of styrene to toluene is 14:20;

[0073] (3) Mix the aqueous phase obtained in step (1) and the organic phase obtained in step (2) (the mass ratio of the aqueous phase to the organic phase is 12:1), carry out a polymerization reaction at 60 °C for 5 h, wash with water and freeze-dry to obtain Fe-55 scintillating resin.

[0074] Example 3

[0075] A preparation method of Fe-55 scintillating resin: (1) Mix water and polyvinyl alcohol (polyvinyl alcohol type 1788, average molecular weight is 130.14) to obtain an aqueous phase, and the mass ratio of polyvinyl alcohol to the volume of water is 1 g: 250 mL;

[0076] (2) Mix styrene, divinylbenzene, scintillator 2,5-diphenyloxazole, wavelength shifter 1,4-bis(2-(5-phenyloxazolyl))benzene, initiator azobisisobutyronitrile, extractant bis(2,4,4-trimethylpentyl)phosphonic acid and toluene to obtain an organic phase. The mass ratio of styrene, divinylbenzene, scintillator 2,5-diphenyloxazole, wavelength shifter 1,4-bis(2-(5-phenyloxazolyl))benzene, initiator azobisisobutyronitrile and extractant bis(2,4,4-trimethylpentyl)phosphonic acid is 14:2:0.6:0.1:0.2:2, and the mass ratio of styrene to toluene is 14:15;

[0077] (3) Mix the aqueous phase obtained in step (1) and the organic phase obtained in step (2) (the mass ratio of the aqueous phase to the organic phase is 12:1), carry out a polymerization reaction at 60 °C for 5 h, wash with water and freeze-dry to obtain Fe-55 scintillating resin.

[0078] Example 4

[0079] A preparation method of a scintillation resin of Fe-55: (1) Mix water and polyvinyl alcohol (polyvinyl alcohol type 1788, with an average molecular weight of 130.14) to obtain an aqueous phase, and the mass ratio of polyvinyl alcohol to the volume of water is 1 g: 250 mL;

[0080] (2) Mix styrene, divinylbenzene, scintillator 2,5-diphenyloxazole, wavelength shifter 1,4-bis(2-(5-phenyloxazolyl))benzene, initiator azobisisobutyronitrile, extractant bis(2,4,4-trimethylpentyl)phosphonic acid, and toluene to obtain an organic phase. The mass ratio of styrene, divinylbenzene, scintillator 2,5-diphenyloxazole, wavelength shifter 1,4-bis(2-(5-phenyloxazolyl))benzene, initiator azobisisobutyronitrile, and extractant bis(2,4,4-trimethylpentyl)phosphonic acid is 14: 2: 0.6: 0.1: 0.2: 2, and the mass ratio of styrene to toluene is 14: 5;

[0081] (3) Mix the aqueous phase obtained in step (1) and the organic phase obtained in step (2) (the mass ratio of the aqueous phase to the organic phase is 12: 1), carry out a polymerization reaction at 60 °C for 5 h, wash with water, and freeze-dry to obtain a scintillation resin of Fe-55.

[0082] Comparative Example 1

[0083] Omit the extractant in Example 1, and keep other parameters the same as in Example 1 to obtain scintillation resin microspheres, denoted as PSm.

[0084] Use a scanning electron microscope to observe the resins prepared in Comparative Example 1 and Example 1. The obtained SEM images are respectively as Figures 1 - 2 shown. It can be seen from Figures 1 - 2 that the PSm microspheres exhibit a plump shape and a smooth surface. This characteristic indicates that they have excellent physical properties and chemical stability. After introducing the functional group (extractant) onto the microsphere surface, although the microspheres remain spherical, their surface becomes no longer smooth. This phenomenon may be due to the introduction of the functional group, which causes changes in the chemical properties and physical structure of the resin surface. The introduction of the functional group may increase the surface roughness. By comparing and analyzing the morphological differences between the resins in Comparative Example 1 and Example 1, it can be preliminarily inferred that the functional group has been successfully introduced onto the microspheres, thereby achieving effective adsorption of Fe 3+ and marking the successful synthesis of a resin with Fe 3+ adsorption ability.

[0085] The infrared spectra of the resins prepared in Comparative Example 1 and Example 1 are as Figure 3 shown. It can be seen from Figure 3 that the infrared spectral characterizations of the PSm microspheres and PSresin reveal significant differences. Compared with the PSm microspheres, PSresin shows a peak at 2956 cm-1 showed an obvious absorption peak, which corresponded to the C-H stretching vibration in the alkyl chain of Cyanex 272. In addition, the absorption peak at 1171 cm -1 was the characteristic vibration peak of the phosphonic acid group and was associated with the P=O stretching vibration in Cyanex 272. The presence of these characteristic peaks clearly confirmed that the functional groups had been successfully introduced onto the surface of the microspheres.

[0086] The scintillation resin of Fe-55 prepared in Example 1 adsorbed ferric ions, and the Fe adsorbed was 16 mg / g 3+ The fluorescence spectrum of Fe-PSresin after that was as Figure 4 shown. As can be seen from Figure 4 it, Fe-PSresin after adsorbing 16 mg / g of Fe 3+ showed an obvious peak of fluorescence intensity at a wavelength of 416 nm. This phenomenon indicated that the material had a high fluorescence emission efficiency at this specific wavelength. Since the wavelength of 416 nm was within the optimal detection range of the photomultiplier tube (PMT), this indicated that the fluorescence characteristics of the Fe-PSresin material could be efficiently detected and applied.

[0087] Test Example 1

[0088] The scintillation resin of Fe-55 prepared in Example 1 was mixed with a ferric salt (ferric nitrate) solution (ferric ion concentration was 50 ppm), and the pH value was adjusted with nitric acid. Adsorption was carried out for 24 h at a pH value of 2 ± 0.05 and a temperature of 25 ± 0.5 °C. The adsorption amounts under different solid-liquid ratios were as Figure 5 shown. As can be seen from Figure 5 it, when the concentration of Fe 3+ was constant, the increase in the solid-liquid ratio led to a downward trend in the adsorption amount of the scintillation resin for Fe 3+ until a stable state was reached, and the adsorption amount at this time was the minimum value. Further increasing the solid-liquid ratio, the adsorption amount would no longer change. This phenomenon might be related to the saturation of the adsorption sites, that is, under high solid-liquid ratio conditions, the active sites on the resin surface were fully utilized, resulting in the adsorption amount tending to be stable.

[0089] Test Example 2

[0090] 5 mg and 10 mg of the scintillation resin of Fe-55 prepared in Example 1 were respectively mixed with a ferric salt (ferric nitrate) solution (ferric ion concentration was 50 ppm), the solid-liquid ratio was 2.0 g / L, and the pH values were adjusted to 1, 2, and 3 with nitric acid respectively. Adsorption was carried out for 24 h at 25 ± 0.5 °C. The adsorption amounts under different pH conditions were as Figure 6 shown. As can be seen from Figure 6 it, with the increase of pH, the resin's adsorption of Fe 3+The adsorption capacity gradually increases. The reason is that the functional groups in the resin are gradually deprotonated, which improves the adsorption ability of the resin for Fe 3+ , and the electronegativity on the resin surface is enhanced. The electrostatic interaction between the resin and Fe 3+ is strengthened, thus promoting the adsorption of Fe 3 + .

[0091] Test Example 3

[0092] Mix the Fe-55 scintillation resin prepared in Example 1 with a ferric salt (ferric nitrate) solution (ferric ion concentration is 20 ppm), with a solid-liquid ratio of 2.0 g / L. Adjust the pH value to 2 ± 0.05 using nitric acid, and perform adsorption at 25 ± 0.5 °C. The adsorption rates at different adsorption times are as Figure 7 shown. It can be seen from Figure 7 that the adsorption of this scintillation resin for Fe 3+ can reach 80% of the maximum adsorption rate at 200 min and basically reaches equilibrium after 4 h. In the initial stage of adsorption, the adsorption capacity of this scintillation resin for Fe 3+ increases rapidly because there are more adsorption sites provided by the adsorbent in the initial stage of adsorption and the adsorption rate is relatively high. Subsequently, the adsorption rate of this scintillation resin for Fe 3+ decreases slightly because as the adsorption proceeds, the adsorption sites provided by the adsorbent gradually decrease, and the concentration of Fe 3+ in the solution also gradually decreases, so the adsorption rate will decrease slightly, but the adsorption equilibrium can be reached in 4 h.

[0093] Test Example 4

[0094] Mix the Fe-55 scintillation resins prepared in Examples 1 to 4 with a ferric salt solution (ferric ion concentration is 20 ppm), with a solid-liquid ratio of 2.0 g / L. Adjust the pH value to 2 ± 0.05 using nitric acid, and perform adsorption for 24 h at 25 ± 0.5 °C. The adsorption amounts of different examples are as Figure 8 shown. It can be seen from Figure 8 that the scintillation resin prepared in Example 1 has the highest adsorption amount of iron.

[0095] Application Example 1

[0096] Put 1 g of the Fe-55 scintillation resin prepared in Example 1 into a plastic scintillation column, and pass 20 mL of a solution with pH = 2 containing 55 Fe ( 55 the activity of Fe is 42.34 Bq) through this plastic scintillation column at a flow rate of 0.25 mL / min to achieve 55 the effective adsorption of Fe, and then the adsorbed 55The plastic scintillation column of Fe was transferred into a liquid scintillation vial. Meanwhile, a liquid scintillation vial containing the same amount of scintillation resin and plastic scintillation column of Fe-55 but without 55 Fe solution was prepared as a blank sample. Using a liquid scintillation spectrometer, the blank sample and the scintillation resin of Fe-55 after adsorbing 55 Fe were scanned and analyzed, and the counting time for each sample was 60 min. The experimental data are shown in Table 1. By calculating the data in Table 1, the detection limit of the scintillation resin of this Fe-55 was obtained as 0.11 Bq.

[0097] Table 1 Liquid Scintillation Test Results

[0098]

[0099] The method of Example 1 was used to synthesize three batches of scintillation resin of Fe-55, and the batch stability was tested. First, the background of each batch of resin was measured. Subsequently, 40 Bq of 55 Fe activity in a 20 mL nitric acid system with pH = 2 was passed through three batches of resin. The amount of resin used was 1 g, and the flow rate was 0.25 mL / min, and counting measurements were carried out on it. The experimental results are as Figure 9 shown. It can be seen from Figure 9 that the resin showed good batch stability.

[0100] Using the same method, the stability of the scintillation resin of Fe-55 prepared in Example 1 was tested. The scintillation resin of Fe-55 prepared in Example 1 was subjected to a repeatability test, and it was tested once every 1 d, 5 d, 10 d, and 20 d, for a total of 4 tests. No post-treatment was carried out after each test. The experimental results are as Figure 10 shown. It can be calculated from Figure 10 that the detection efficiencies obtained were all above 5%.

[0101] In summary, the scintillation resin of Fe-55 prepared by the present invention has excellent stability and detection accuracy, avoids the use of organic scintillation liquid, and thus reduces the generation of radioactive organic waste liquid.

[0102] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A scintillating resin of Fe-55, characterized in that, It is obtained by a polymerization reaction of a polymerization monomer, a scintillator, a wavelength shifter, an extractant, a dispersant, an initiator, an organic solvent and water; the extractant is bis(2,4,4-trimethylpentyl)phosphonic acid; the scintillator is 2,5-diphenyloxazole; the wavelength shifter is 1,4-bis(2-(5-phenyloxazolyl))benzene; The preparation method of the scintillation resin of Fe-55 is the following steps: (1) Mix water and a dispersant to obtain an aqueous phase; the dispersant in step (1) is polyvinyl alcohol; the mass ratio of the dispersant to the volume of water in step (1) is 0.7 g: 250 mL; (2) Mix a polymerization monomer, a scintillator, a wavelength shifter, an initiator, an extractant and an organic solvent to obtain an organic phase; the polymerization monomer in step (2) is styrene and divinylbenzene; the mass ratio of styrene, divinylbenzene, scintillator, wavelength shifter, initiator and extractant in step (2) is 14:2:0.6:0.1:0.2:2; the organic solvent is toluene; the mass ratio of styrene to the organic solvent is 14:2; (3) Mix the aqueous phase obtained in step (1) and the organic phase obtained in step (2), and carry out a polymerization reaction to obtain the scintillation resin of Fe-55; the mass ratio of the aqueous phase to the organic phase is 12:1; There is no chronological order between steps (1) and (2).

2. The preparation method of the scintillation resin of Fe-55 according to claim 1 is the following steps: (1) Mix water and a dispersant to obtain an aqueous phase; the dispersant in step (1) is polyvinyl alcohol; the mass ratio of the dispersant to the volume of water in step (1) is 0.7 g: 250 mL; (2) Mix a polymerization monomer, a scintillator, a wavelength shifter, an initiator, an extractant and an organic solvent to obtain an organic phase; the polymerization monomer in step (2) is styrene and divinylbenzene; the mass ratio of styrene, divinylbenzene, scintillator, wavelength shifter, initiator and extractant in step (2) is 14:2:0.6:0.1:0.2:2; the organic solvent is toluene; the mass ratio of styrene to the organic solvent is 14:2; (3) Mix the aqueous phase obtained in step (1) and the organic phase obtained in step (2), and carry out a polymerization reaction to obtain the scintillation resin of Fe-55; the mass ratio of the aqueous phase to the organic phase is 12:1; There is no chronological order between steps (1) and (2).

3. The preparation method according to claim 2, characterized in that, The temperature of the polymerization reaction in step (3) is 60-70 °C, and the time of the polymerization reaction is 5-6 h.

4. The application of the scintillation resin of Fe-55 prepared according to the scintillation resin of Fe-55 described in claim 1 or the preparation method described in claim 2 or 3 in 55 the separation and detection of Fe.

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