Preparation method of self-supporting polymolecular cage adsorption material and application of self-supporting polymolecular cage adsorption material in treatment of pertechnetate in radioactive wastewater

Abstract

The invention discloses a preparation method of a self-supporting polymolecular cage adsorption material and an application of the self-supporting polymolecular cage adsorption material in treatment of pertechnetate radicals in radioactive wastewater. The preparation method comprises the step of performing quaternization reaction on a porous organic molecular cage and dihaloalkane to form a porous ionic polymer material. The molecular cage has the beneficial effects that the molecular cage can be subjected to ion exchange with pertechnetate radicals in radioactive waste water, a molecular cage framework carries a large number of positive charges, a formed strong anode attracts a center, and pertechnetate radical anions can be adsorbed and limited in molecular cage pores through electrostatic interaction, so that purification of low-concentration pertechnetate radicals in low-emission waste liquid is realized; the material is fast in adsorption kinetics, high in adsorption capacity, good in recycling performance, mild in preparation condition, simple in process and easy to produce in batches; the material can be applied to purification treatment of pertechnetate radicals in complex low-level radioactive waste liquid generated during nuclear medicine research and development and production, the treatment effect is excellent, and the removal rate is still high under the condition that other high-concentration anions coexist.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer organic porous materials, and in particular relates to a preparation method of a self-supporting polymer cage adsorption material and an application of the material in treating pertechnetate in radioactive wastewater. Background Art

[0002] With the development of modern medicine, the application of nuclear medicine in hospital diagnosis and treatment is becoming more and more common. Promoting the high-quality development of the nuclear medicine industry is of great significance to building a healthy China. On June 24, 2021, my country issued the first programmatic document for the field of nuclear medicine, "Medium- and Long-Term Development Plan for Medical Isotopes (2021-2035)", which clearly pointed out that the actual demand for medical isotopes will show an explosive increase in the future, and it is conservatively estimated that it will increase by more than 10 times by 2030. This means that the research and development and production of nuclear medicine will develop rapidly, and the resulting radioactive waste liquid will also increase significantly. In addition to short-half-life radionuclides such as F-18, I-131, Lu-177, etc., the waste liquids generated by the nuclear medicine production end also contain medium- and long-half-life radionuclides, especially the radionuclide technetium-99 ( 99 Tc), making the waste liquid difficult to handle. 99 Tc is highly water soluble and will dissolve in wastewater immediately once produced, as pertechnetate anion (TcO4 - ) exists in the form of. At the same time, 99 Tc is a long-lived fission product with a half-life of 2.13×10 5 The migration ability in the natural environment is very strong and almost unobstructed. The existing nuclear medical waste liquid treatment method mainly adopts the storage decay method, that is, the waste liquid is stored in a separate collector and left to wait for the nuclide to decay until the radioactivity concentration drops below the standard value. This method is not suitable for radioactive substances containing long half-life nuclide ions TcO4 - In addition, during the spent fuel reprocessing process, 99 Tc is also one of the most difficult radionuclides. Therefore, the design and synthesis of TcO4 - Adsorption materials with improved removal performance are of great significance for protecting human health and the natural environment.

[0003] In TcO4 - In the removal of TcO4, ion exchange is currently the main method, including anion exchange resin adsorbent materials that have been used on a large scale. However, they have slow adsorption rates, limited adsorption capacity, and are not suitable for lower concentrations of TcO4. - The adsorption effect is poor, which greatly restricts its practical application. Organic cationic framework materials have been proven to be highly effective in removing TcO4 from water. -Its three-dimensional porous effect combined with ion exchange in the pores can achieve TcO4 - Highly selective adsorption.

[0004] Related technologies include Chinese invention patents CN116874698A, "A covalent organic framework material, preparation method and application for removing pertechnetate", and CN113214480B, "A synthesis method and adsorption application of a cationic framework material". The cationic organic framework materials designed in the above patents show a high pertechnetate exchange ratio and can be used as an adsorbent to adsorb and separate TcO4 in spent fuel. - However, the preparation conditions of covalent organic framework materials are harsh, requiring long-term correction crystallization at high temperatures and nitrogen atmosphere protection, making it difficult to achieve large-scale mass production. In addition, toxic volatile reagents such as tetrahydrofuran are used, which can easily cause secondary environmental pollution.

[0005] Another example is the Chinese invention patent CN106732481B, "A pertechnetate adsorbent, its synthesis method and application in the treatment of radioactive wastewater". It uses silver nitrate and tetrakis[4-(1-imidazolyl)phenyl]methane as raw materials to prepare an ionic organic material with a porous three-dimensional infinitely extended structure, and the free nitrate in its pores can effectively exchange pertechnetate to achieve adsorption. However, its hydrothermal reaction temperature is 80-140°C, and it is necessary to repeatedly slowly heat up and slowly cool down to obtain the crystalline material. At the same time, the silver nitrate used is expensive, resulting in high cost of the adsorbent. High temperature preparation conditions, refined preparation process and high cost make it difficult to apply on an industrial scale.

[0006] In addition, these existing patents are mainly aimed at removing TcO4 in the spent fuel reprocessing system. - In the radioactive waste liquid generated during the research and development and production of nuclear medicine, TcO4 - The concentration is very low (<1mg / L), the interference media are also different (including a large number of inorganic anions and cations, ligand organic matter, nitrogen / sulfur compounds, etc.), COD (chemical oxygen demand) and SS (solid suspended matter) are relatively high. Currently used for extremely low concentration TcO4 in wastewater in nuclear medicine research and development and production - There are no relevant research reports and technical precedents for the selective and rapid removal of pertechnetate. For example, in the invention patent CN115350731B, "Application of macroporous N-methylimidazolyl strong basic anion exchange resin as a pertechnetate adsorbent", the pore size of the material reported is 400-1000nm. However, the ion radius of pertechnetate is only 0.2-0.3nm, and the size difference between the two is nearly 5000 times, which means that the material cannot nano-confine pertechnetate, that is, due to chemical equilibrium limitations, it is impossible to achieve a high adsorption capacity of extremely low concentration pertechnetate.

[0007] Therefore, a method is needed to solve the problem of extremely low concentration of TcO4 in complex wastewater of nuclear medicine. - Problematic adsorbent materials that are difficult to remove accurately. Summary of the invention

[0008] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0009] In order to achieve these purposes and other advantages according to the present invention, a self-supporting polymer cage adsorption material is provided, characterized in that its structural formula is shown in the following formula I:

[0010]

[0011] Wherein, n is an integer from 1 to 8; X - Represents Cl - Br - ,I - 、NO3 - PF6 - Z is one or a combination of CH, N.

[0012] Preferably, the self-supporting polymer cage adsorption material is a porous ionic polymer material formed by a quaternization reaction of a porous organic molecular cage and a dihalogenated alkane, and the structural formulas of the porous organic molecular cage and the dihalogenated alkane are shown in Formula II and Formula III, respectively:

[0013]

[0014] Wherein, n is an integer of 1 to 8, R is F, Cl, Br or I; and Z is one or a combination of CH and N.

[0015] A method for preparing a self-supporting molecular cage adsorption material, comprising:

[0016] S1. Preparation of imine molecular cage CC6: 1,3,5-triphenyl compound and 1,5-diaminopentane are slowly mixed in a reaction solvent in a certain proportion, and the mixed solution is placed in a ventilated place at room temperature for a certain period of time. The obtained solid product is filtered, washed, and dried to obtain the CC6 imine molecular cage product in formula II; the synthesis equation is as follows:

[0017]

[0018] Wherein, Z is one or a combination of CH and N;

[0019] S2. Preparation of reduced molecular cage RCC6: dissolve the CC6 imine molecular cage in a solvent, add a certain amount of sodium borohydride under vigorous stirring, react at room temperature for a certain time, then add deionized water, continue stirring and react for a certain time, and filter, wash and dry the obtained product to obtain the reduced RCC6 molecular cage product; the reduction equation is as follows:

[0020]

[0021] Wherein, Z is one or a combination of CH and N;

[0022] S3. Preparation of self-supporting polymer cage adsorption material P-RCC6: dissolve the reduced RCC6 molecular cage in the reaction solvent, slowly add a certain amount of dihaloalkane in formula III under stirring and mix well, place the mixed solution at a certain temperature to react for a certain time to obtain a self-supporting polymer cage adsorption material of formula I.

[0023] Preferably, in S1, the 1,3,5-triphenyl compound is one or more of 1,3,5-tri(4-formylphenyl)benzene, 4,4',4"-(1,3,5-triazine-2,4,6-triyl)tribenzaldehyde, and 4,4,4-(pyridine-2,4,6-triylpyridine)tribenzaldehyde, the molar ratio of the 1,3,5-triphenyl compound to 1,5-diaminopentane is 2:2.5-3.5, the reaction solvent is one or more of methanol, ethanol, acetonitrile, dichloromethane, chloroform, and N,N-dimethylformamide, and the reaction time is 6-72 hours.

[0024] Preferably, in S1, the reaction process uses or does not use a catalyst. If a catalyst is used, the catalyst is trifluoroacetic acid or acetic acid, and the amount of the catalyst is 10 to 20 μL.

[0025] Preferably, in S2, the molar ratio of CC6 imine molecular cage to sodium borohydride is 1:5-10, the reaction solvent is one or more of dichloromethane, methanol, ethanol, acetonitrile and chloroform, and the reaction time is 8-36 hours.

[0026] Preferably, in S3, the molar ratio of the reduced RCC6 molecular cage and the dihalogenated alkane is 1:1 to 6, the reaction solvent is one or more of acetonitrile, methanol, ethanol, chloroform, toluene, N,N-dimethylformamide, ethyl acetate, and isopropanol, the reaction temperature is 45 to 120°C, and the reaction time is 12 to 96 hours.

[0027] The invention discloses an application of a self-supporting polymer cage adsorption material for the adsorption of pertechnetate.

[0028] A self-supporting polymer cage adsorption material is used for the adsorption of pertechnetate in medical radioactive wastewater generated during the research and development, production and use of medical isotopes.

[0029] Preferably, it is characterized in that, when treating radioactive wastewater containing pertechnetate, the mass ratio of the self-supporting polymolecular cage adsorbent material to the wastewater is 100-1000:1, the treatment time is 10-24h, and the self-supporting polymolecular cage adsorbent material after adsorbing pertechnetate can be reused after desorption, and the specific steps of desorbing pertechnetate are: the self-supporting polymolecular cage adsorbent after adsorption is soaked and washed with 3-5M hydrochloric acid for multiple times, then washed with deionized water, filtered and dried at 60-120°C.

[0030] The present invention includes at least the following beneficial effects: the present invention prepares a self-supporting polymolecular cage adsorption material for the first time, and the material is formed by connecting several ionic porous molecular cages with a three-dimensional spatial structure. The free chloride ions, bromide ions and other anions in the pores can undergo ion exchange with pertechnetate in radioactive wastewater. At the same time, the molecular cage skeleton carries a large amount of positive charge, and the strong anode attraction center formed by it can adsorb and confine the pertechnetate anions in the molecular cage pores through electrostatic interaction, thereby achieving the purification of low-concentration pertechnetate in low-level waste liquid. The polymolecular cage adsorption material disclosed in the present invention is synthesized and applied to the removal of pertechnetate pollutants for the first time. Compared with the existing disclosed adsorbents, the material has faster adsorption kinetics and high adsorption capacity, good recycling performance, mild preparation conditions, simple process, and easy batch production. In addition, the present invention applies the polymolecular cage adsorption material to the purification of pertechnetate in complex low-level waste liquid generated during nuclear medicine research and development and production for the first time, with excellent treatment effect, and still maintains a high removal rate even under the condition of coexistence of other high-concentration anions.

[0031] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a normal light microscope image of the self-supporting molecular cage P-RCC6 in Example 1;

[0033] Figure 2 This is a polarizing microscope image of the self-supporting molecular cage P-RCC6 in Example 1;

[0034] Figure 3 This is a graph showing the results of the pertechnetate adsorption experiment in Application Example 1;

[0035] Figure 4This is the result diagram of the adsorption of pertechnetate in the real low-level waste liquid from the nuclear medicine production end in Application Example 4;

[0036] Figure 5 This is the result diagram of the removal rate of pertechnetate in the real low-level waste liquid from the nuclear medicine production end in Application Example 4;

[0037] Figure 6 Schematic diagram of waste liquid flow in the configuration of three glass chromatography columns in Application Example 5

[0038] Figure 7 This is a structural diagram of the self-supporting molecular cage P-RCC6 of Example 1;

[0039] Figure 8 This is a structural diagram of the self-supporting molecular cage P-RCC6 of Example 2;

[0040] Fig. 9 This is a structural diagram of the self-supporting molecular cage P-RCC6 of Example 3;

[0041] Fig.10 This is a structural diagram of the self-supporting molecular cage P-RCC6 of Example 4;

[0042] Fig.11 This is a structural diagram of the self-supporting molecular cage P-RCC6 of Example 5;

[0043] Fig.12 This is a structural diagram of the self-supporting molecular cage P-RCC6 of Example 6. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0045] Example 1

[0046] A method for preparing a self-supporting molecular cage adsorption material, the specific steps are as follows:

[0047] S1. Add 20 mL of methanol solvent to 1.025 g (2.63 mmol) of 1,3,5-tri(4-formylphenyl)benzene and 0.402 g (3.94 mmol) of 1,5-diaminopentane, respectively, and slowly drop 1,5-diaminopentane into 1,3,5-tri(4-formylphenyl)benzene. Place the mixed solution in a ventilated place and react at room temperature for 24 h. Filter, wash and dry the obtained solid product to obtain the CC6 imine molecular cage product.

[0048] S2. Dissolve 0.5 g (0.51 mmol) CC6 in 25 mL of a mixed solvent of dichloromethane and methanol (v / v = 1 / 1), add 0.5 g (3.50 mmol) sodium borohydride (NaBH4) under vigorous stirring, and react the mixed solution at room temperature for 15 h. Subsequently, add 1 mL of deionized water as a solvent and continue to react at room temperature for 9 h. The obtained solid product can be filtered, washed, and dried to obtain the reduced RCC6 molecular cage product.

[0049] S3, 2.0g (2.02mmol) of RCC6 was dissolved in 30mL of ethyl acetate, and 1.39g (6.05mmol) of 1,5-dibromopentane (RCC6: 1,5-dibromopentane = 1:3) was added under stirring, and the mixed solution was reacted at 60°C for 32h. The obtained solid product was filtered, washed, and dried to obtain a self-supporting polymer cage P-RCC6 product, whose structure is as follows: Figure 7 shown.

[0050] Figure 1 This is a normal light microscope image of the self-supporting molecular cage P-RCC6 in Example 1. Figure 2 This is a polarizing microscope image of the self-supporting polymer cage P-RCC6 in Example 1. Figure 1-2 It can be seen that the obtained self-supporting molecular cage P-RCC6 has bright birefringence, indicating good crystallinity.

[0051] Example 2

[0052] A method for preparing a self-supporting molecular cage adsorption material, the specific steps are as follows:

[0053] S1. Add 20 mL of methanol solvent to 1.025 g (2.63 mmol) of 1,3,5-tris(4-formylphenyl)benzene and 0.470 g (4.60 mmol) of 1,5-diaminopentane, respectively, and slowly drop 1,5-diaminopentane into 1,3,5-tris(4-formylphenyl)benzene. Place the mixed solution in a ventilated place and react at room temperature for 24 h. Filter, wash and dry the obtained solid product to obtain the CC6 imine molecular cage product.

[0054] S2. Dissolve 0.5 g (0.51 mmol) CC6 in 25 mL of a mixed solvent of dichloromethane and methanol (v / v = 1 / 1), add 0.1 g (2.64 mmol) sodium borohydride (NaBH4) under vigorous stirring, and react the mixed solution at room temperature for 20 h. Subsequently, add 1 mL of deionized water as a solvent and continue to react at room temperature for 9 h. The obtained solid product can be filtered, washed, and dried to obtain the reduced RCC6 molecular cage product.

[0055] S3, 1.50g (1.51mmol) RCC6 was dissolved in 30mL ethyl acetate, 1.71g (9.10mmol) 1,2-dibromoethane (RCC6: 1,2-dibromoethane = 1:6) was added under stirring, and the mixed solution was reacted at 40°C for 24h. The obtained solid product was filtered, washed, and dried to obtain a self-supporting polymer cage P-RCC6 product, whose structure is as follows: Figure 8 shown.

[0056] Example 3

[0057] A method for preparing a self-supporting molecular cage adsorption material, the specific steps are as follows:

[0058] S1. Add 20 mL of methanol solvent to 1.025 g (2.61 mmol) of 4,4',4"-(1,3,5-triazine-2,4,6-triyl) benzaldehyde and 0.399 g (3.90 mmol) of 1,5-diaminopentane, respectively, and slowly drop 1,5-diaminopentane into 1,3,5-tri(4-formylphenyl)benzene. Place the mixed solution in a ventilated place and react at room temperature for 12 h. Filter, wash and dry the obtained solid product to obtain the CC6 imine molecular cage product.

[0059] S2. Dissolve 0.5 g (0.51 mmol) CC6 in 25 mL of a mixed solvent of dichloromethane and methanol (v / v = 1 / 1), add 0.3 g (7.92 mmol) sodium borohydride (NaBH4) under vigorous stirring, and react the mixed solution at room temperature for 15 h. Subsequently, add 1 mL of deionized water as a solvent and continue to react at room temperature for 9 h. The obtained solid product can be filtered, washed, and dried to obtain the reduced RCC6 molecular cage product.

[0060] S3, 2.0g (2.02mmol) of RCC6 was dissolved in 30mL of ethyl acetate, and 0.63g (9.10mmol) of 1,6-dichlorohexane (RCC6: 1,6-dichlorohexane = 1:2) was added under stirring, and the mixed solution was reacted at 80°C for 6h. The obtained solid product was filtered, washed, and dried to obtain a self-supporting polymer cage P-RCC6 product, whose structure is as follows: Fig. 9 shown.

[0061] Example 4

[0062] A method for preparing a self-supporting molecular cage adsorption material, the specific steps are as follows:

[0063] S1. Add 20 mL of methanol solvent to 1.025 g (2.62 mmol) of 4,4,4-(pyridine-2,4,6-triylpyridine) tribenzaldehyde and 0.401 g (3.92 mmol) of 1,5-diaminopentane, and slowly drop 1,5-diaminopentane into 1,3,5-tri(4-formylphenyl)benzene. Place the mixed solution in a ventilated place and react at room temperature for 12 h. Filter, wash and dry the obtained solid product to obtain the CC6 imine molecular cage product.

[0064] S2. Dissolve 0.5 g (0.51 mmol) CC6 in 25 mL of a mixed solvent of dichloromethane and methanol (v / v = 1 / 1), add 0.35 g (7.93 mmol) sodium borohydride (NaBH4) under vigorous stirring, and react the mixed solution at room temperature for 15 h. Subsequently, add 1 mL of deionized water as a solvent and continue to react at room temperature for 9 h. The obtained solid product can be filtered, washed, and dried to obtain the reduced RCC6 molecular cage product.

[0065] S3, 2.0g (2.02mmol) of RCC6 was dissolved in 30mL of ethyl acetate, and 0.77g (6.05mmol) of 1,4-dichlorobutane (RCC6: 1,4-dichlorobutane = 1:3) was added under stirring, and the mixed solution was reacted at 50°C for 35h. The obtained solid product was filtered, washed, and dried to obtain a self-supporting polymer cage P-RCC6 product, whose structure is as follows: Fig.10 shown.

[0066] Example 5

[0067] A method for preparing a self-supporting molecular cage adsorption material, the specific steps are as follows:

[0068] S1. Add 20 mL of methanol solvent to 1.025 g (2.63 mmol) of 1,3,5-tri(4-formylphenyl)benzene and 0.335 g (3.28 mmol) of 1,5-diaminopentane, respectively, and slowly drop 1,5-diaminopentane into 1,3,5-tri(4-formylphenyl)benzene. Place the mixed solution in a ventilated place and react at room temperature for 12 h. Filter, wash and dry the obtained solid product to obtain the CC6 imine molecular cage product.

[0069] S2. Dissolve 0.5 g (0.51 mmol) CC6 in 25 mL of a mixed solvent of dichloromethane and methanol (v / v = 1 / 1), add 0.5 g (3.50 mmol) sodium borohydride (NaBH4) under vigorous stirring, and react the mixed solution at room temperature for 12 h. Subsequently, add 1 mL of deionized water as a solvent and continue to react at room temperature for 9 h. The obtained solid product can be filtered, washed, and dried to obtain the reduced RCC6 molecular cage product.

[0070] S3, 2.0g (2.02mmol) of RCC6 was dissolved in 30mL of ethyl acetate, and 0.74g (2.02mmol) of 1,8-diiodooctane (RCC6: 1,8-diiodooctane = 1:1) was added under stirring, and the mixed solution was reacted at 80°C for 72h. The obtained solid product was filtered, washed, and dried to obtain a self-supporting polymer cage P-RCC6 product, whose structure is as follows: Fig.11 shown.

[0071] Example 6

[0072] The difference between this embodiment and embodiment 5 is that the solid product obtained in S3 was filtered and then treated with 3 mol L -1 The product was immersed in HNO3 solution for 3 h for ion exchange, and finally filtered, washed and dried to obtain the nitrate-based self-supporting polymer cage P-RCC6 product.

[0073] The remaining steps are consistent with Example 5, and its structure is as follows Fig.12 shown.

[0074] Application Example 1

[0075] A self-supporting polymer cage adsorption material is used to simulate the removal of pertechnetate in wastewater. The specific steps are as follows:

[0076] Sodium pertechnetate was prepared into a 100 ppm aqueous solution, and the adsorption capacity of the P-RCC6 polymer cage adsorbent prepared in Example 1 was tested. 20 mg of P-RCC6 adsorbent was weighed, 50 mL of sodium pertechnetate aqueous solution (100 ppm) was added, and the adsorption experiment was carried out at pH = 7 and temperature of 25°C and stirred for 12 hours. The concentration of pertechnetate in the solution before and after adsorption was measured.

[0077] Figure 3 The results of the pertechnetate adsorption experiment in Application Example 1. As shown in the figure, the concentration of pertechnetate in the solution was measured to be 0.36 mg / L, and the removal rate of pertechnetate in the water sample by the adsorbent was calculated to be 99.7%. At the same time, two commercial ion exchange materials were selected for the same adsorption experiment, and it was found that the removal efficiency of P-RCC6 was much higher than that of conventional ion exchange materials.

[0078] Application Example 2

[0079] A self-supporting polymer cage adsorption material is used to simulate the removal of pertechnetate in wastewater. The specific steps are as follows:

[0080] Sodium pertechnetate was prepared into an aqueous solution with a concentration of 100ppm. At the same time, 0.31g of sodium chloride, 0.66g of sodium nitrate, 0.68g of sodium sulfate, and 0.42g of sodium phosphate were weighed and added to the above system, dissolved and mixed evenly, and the anti-interference adsorption capacity of the P-RCC6 polymolecular cage adsorption material prepared in Example 1 was tested. Weigh 20mg of the P-RCC6 adsorbent of Example 1, add 50mL of the mixed ion aqueous solution, stir for 8h at pH=7 and temperature of 25°C for adsorption experiment. The concentration of pertechnetate in the solution before and after adsorption was measured. The concentration of pertechnetate in the solution was measured to be 3.71mg / L, and the removal rate of pertechnetate in the water sample by the adsorbent was calculated to be 96.3%.

[0081] Application Example 3

[0082] This application example provides a self-supporting polymer cage adsorption material for the removal of pertechnetate in simulated wastewater, and then the self-supporting polymer cage adsorption material is recycled. The specific steps are as follows:

[0083] The P-RCC6 polymer cage adsorption material after adsorbing pertechnetate in Application Example 1 was desorbed: it was soaked and washed three times with 3M hydrochloric acid, then rinsed with deionized water, and dried at 80°C. The desorbed P-RCC6 was subjected to a desorption-adsorption experiment according to the adsorption process in Application Example 1, and the pertechnetate removal rate was determined to be 99.1%.

[0084] Application Example 4

[0085] A self-supporting polymer cage adsorption material is used to remove pertechnetate in real low-level wastewater. The specific steps are as follows:

[0086] 20 mg of the P-RCC6 polymolecular cage adsorption material prepared in Example 1 was added to 50 mL of real radioactive wastewater containing pertechnetate ions generated in the nuclear medicine production process (sourced from a nuclear medicine production company, with an initial activity of total α=121.7 Bq / L, total β=5392 Bq / L, pH=6.8), and the adsorption experiment was carried out at a temperature of 25°C and stirred for 12 hours. The total α and total β of the radioactivity concentration in the solution before and after adsorption were measured.

[0087] Figure 4 and Figure 5 This is the adsorption experimental result of pertechnetate in the real low-level waste liquid from nuclear medicine production in Application Example 4. As shown in the figure, the total α in the solution after adsorption is measured to be 0.178Bq / L, and the total β is 8.025Bq / L. The removal rate of pertechnetate in wastewater by the adsorbent is calculated to be total α=99.86%, and total β=99.85%.

[0088] Application Example 5

[0089] A self-supporting polymer cage adsorption material is used to remove the mobility of pertechnetate in low-level wastewater. The specific steps are as follows:

[0090] The self-supporting molecular cage adsorption material obtained in Example 1 was filled into three glass chromatography columns with a diameter of 5 cm and a tube length of 10 cm by a wet method, and then connected in series, as shown in FIG. Figure 6 As shown. With a mass ratio of wastewater to molecular cage adsorption material of 500:1 and a peristaltic pump flow rate of 5mL / min, radioactive wastewater containing pertechnetate is introduced in a bottom-in-top-out manner. The treated wastewater is collected from the column outflow section. The total α and total β of the radioactivity concentration in the wastewater solution before and after adsorption are measured, and the removal rate of pertechnetate in the wastewater by the adsorbent is calculated to be 99.43%.

[0091] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A self-supporting molecular cage adsorption material, characterized in that: Its structural formula is shown in the following formula I: Wherein, n is an integer from 1 to 8; X - Represents Cl - Br - ,I - 、NO3 - PF6 - Z is one or a combination of CH, N.

2. The self-supporting polymer cage adsorption material according to claim 1, characterized in that: The self-supporting polymer cage adsorption material is a porous ionic polymer material formed by a quaternization reaction between a porous organic molecular cage and a dihalogenated alkane. The structural formulas of the porous organic molecular cage and the dihalogenated alkane are shown in Formula II and Formula III, respectively: Wherein, n is an integer of 1 to 8, R is F, Cl, Br or I; and Z is one or a combination of CH and N.

3. A method for preparing the self-supporting polymer cage adsorption material according to claim 1, characterized in that: include: S1. Preparation of imine molecular cage CC6: 1,3,5-triphenyl compound and 1,5-diaminopentane are slowly mixed in a reaction solvent in a certain proportion, and the mixed solution is placed in a ventilated place at room temperature to react for a certain period of time. The obtained solid product is filtered, washed, and dried to obtain the CC6 imine molecular cage product in formula II; S2. Preparation of reduced molecular cage RCC6: dissolve the CC6 imine molecular cage in a solvent, add a certain amount of sodium borohydride under vigorous stirring, react at room temperature for a certain time, then add deionized water, continue stirring and react for a certain time, and filter, wash and dry the obtained product to obtain the reduced RCC6 molecular cage product; S3. Preparation of self-supporting polymer cage adsorption material P-RCC6: dissolve the reduced RCC6 molecular cage in the reaction solvent, slowly add a certain amount of dihaloalkane in formula III under stirring and mix well, place the mixed solution at a certain temperature to react for a certain time to obtain a self-supporting polymer cage adsorption material of formula I.

4. The method for preparing the self-supporting polymer cage adsorption material according to claim 3, characterized in that: In S1, the 1,3,5-triphenyl compound is one or more of 1,3,5-tri(4-formylphenyl)benzene, 4,4',4"-(1,3,5-triazine-2,4,6-triyl)tribenzaldehyde, and 4,4,4-(pyridine-2,4,6-triylpyridine)tribenzaldehyde; the molar ratio of the 1,3,5-triphenyl compound to 1,5-diaminopentane is 2:2.5-3.5; the reaction solvent is one or more of methanol, ethanol, acetonitrile, dichloromethane, chloroform, and N,N-dimethylformamide; and the reaction time is 6-72 hours.

5. The method for preparing the self-supporting polymer cage adsorption material according to claim 3, characterized in that: In S1, the reaction process may or may not use a catalyst. If a catalyst is used, the catalyst is trifluoroacetic acid or acetic acid, and the amount of the catalyst is 10 to 20 μL.

6. The method for preparing the self-supporting polymer cage adsorption material according to claim 3, characterized in that: In S2, the molar ratio of CC6 imine molecular cage to sodium borohydride is 1:5-10, the reaction solvent is one or more of dichloromethane, methanol, ethanol, acetonitrile, and chloroform, and the reaction time is 8-36 hours.

7. The method for preparing the self-supporting polymer cage adsorption material according to claim 3, characterized in that: In S3, the molar ratio of the reduced RCC6 molecular cage and the dihalogenated alkane is 1:1-6, the reaction solvent is one or more of acetonitrile, methanol, ethanol, chloroform, toluene, N,N-dimethylformamide, ethyl acetate, and isopropanol, the reaction temperature is 45-120°C, and the reaction time is 12-96h.

8. An application of the self-supporting polymer cage adsorption material as claimed in claims 1 to 7, characterized in that: Used for the adsorption of pertechnetate.

9. An application of the self-supporting polymer cage adsorption material as claimed in claims 1 to 7, characterized in that: Used for the adsorption of pertechnetate in medical radioactive wastewater generated during the research and development, production and use of medical isotopes.

10. The use of the self-supporting molecular cage adsorption material according to claims 1 to 9, characterized in that: When treating radioactive wastewater containing pertechnetate, the mass ratio of the self-supporting polymolecular cage adsorbent material to the wastewater is 100-1000:1, the treatment time is 10-24 hours, and the self-supporting polymolecular cage adsorbent material after adsorbing pertechnetate can be reused after desorption. The specific steps of desorbing pertechnetate are: soaking and washing the adsorbed self-supporting polymolecular cage adsorbent with 3-5M hydrochloric acid for multiple times, then washing with deionized water, filtering and drying at 60-120°C.

Images