A deg-PTD ligand, a preparation method and application thereof, and a method for separating lanthanide and actinide elements from waste liquid

Abstract

The application provides a DEG-PTD ligand and a preparation method and application thereof, and a method for separating lanthanide elements and actinide elements from waste liquid, and belongs to the technical field of extraction separation. The application starts from the design of a ligand molecular structure, develops a new DEG-PTD ligand by designing the structure of the ligand, and ensures high distribution ratio for Eu, and meanwhile, the introduction of the water-soluble ligand also ensures efficient stripping for Am, 99% of 241Am loaded in the TODGA ligand organic phase can be stripped into the water phase, and the lanthanide-actinide separation factor SF of the DEG-PTD ligand is 1.5*10<4> Eu / Am The separation effect is good above 200. In addition, the ligand has good water solubility and extraction kinetics, and the water solubility is extremely good, and equilibrium can be reached in 5 min. The application provides a new idea for in-depth understanding of lanthanide-actinide separation, and provides important support for sustainable development of nuclear energy, scientific treatment and safe management of existing radioactive waste.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of extraction separation, in particular to a DEG-PTD ligand, a preparation method and application thereof, and a method for separating lanthanide elements and actinide elements from waste liquid. BACKGROUND

[0002] The separation of lanthanide elements and actinide elements is very important in the safe management of nuclear waste and the sustainable development of nuclear energy. Due to the chemical complexity of these elements, the separation process is challenging.

[0003] Methods for separating lanthanide elements and actinide elements include physical methods and chemical methods. Physical methods include high-speed counter-current chromatography (HSCCC) and methods based on graphene oxide ion sieve membranes, wherein: HSCCC is a new separation method that combines the advantages of liquid-liquid extraction and partition chromatography, does not require a solid carrier, and shows potential in the field of radiochemistry, and methods based on graphene oxide ion sieve membranes use the layered structure of graphene oxide nanosheets and adjustable nanoscale interlayer channels to achieve the separation of lanthanide and actinide elements. Chemical methods include ion exchange chromatography and liquid-liquid extraction, wherein ion exchange chromatography separates lanthanide and actinide elements by taking advantage of their different adsorption capacities on ion exchange resins, and liquid-liquid extraction separates lanthanide and actinide elements by selecting an appropriate extractant to transfer them from one solvent to another. The liquid-liquid extraction method in the related art has the problems of low separation factor and poor separation effect. SUMMARY

[0004] Therefore, the present application aims to provide a DEG-PTD ligand, a preparation method and application thereof, and a method for separating lanthanide elements and actinide elements from waste liquid. The DEG-PTD ligand of the present application has a high separation factor SF Eu / Am for lanthanum and actinium, and good separation effect.

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

[0006] The present application provides a DEG-PTD ligand having the structure shown in Formula I:

[0007]

[0008] The present application also provides a preparation method of the DEG-PTD ligand described in the above technical solutions, comprising the following steps:

[0009] mixing 2,6-dibromopyridine, (trimethylsilyl)acetylene, CuI, Pd(PPh3)4 and a solvent to perform a first substitution reaction to obtain 2,6-di((trimethylsilyl)ethynyl)pyridine;

[0010] The second substitution reaction is carried out by mixing 2-(2-chloroethoxy)ethanol, sodium azide and water to obtain 2-(2-azidoethoxy)ethanol;

[0011] The click reaction is carried out by mixing the 2,6-di((trimethylsilyl)ethynyl)pyridine, 2-(2-azidoethoxy)ethanol, K2CO3, CuSO4, sodium ascorbate, pyridine and a solvent to obtain the DEG-PTD ligand.

[0012] Preferably, the first substitution reaction is carried out at a temperature of 40-60 DEG C for 15-20 hours.

[0013] Preferably, the second substitution reaction is carried out at a temperature of 70-90 DEG C for 12-20 hours.

[0014] Preferably, the click reaction is carried out in a protective atmosphere for 70-80 hours.

[0015] The application also provides the DEG-PTD ligand of the above technical solution for separating lanthanides and actinides.

[0016] The application also provides a method for separating lanthanides and actinides from waste liquid, comprising the following steps:

[0017] The solvent extraction is carried out by mixing the waste liquid with an extractant, wherein the extractant is the DEG-PTD ligand of the above technical solution, and the waste liquid contains lanthanides and actinides.

[0018] Preferably, the lanthanides include europium, and the actinides include americium.

[0019] Preferably, the acidity of the waste liquid is 0.005-4 M.

[0020] Preferably, the concentration of the DEG-PTD ligand in the system during the solvent extraction is 2.5-100 mM.

[0021] The application provides a DEG-PTD ligand with a structure shown in formula I, and the application has the following beneficial effects compared with the prior art:

[0022] The application designs the structure of the ligand, develops a new DEG-PTD ligand by designing the structure of the ligand, and ensures high distribution ratio of Eu, and the introduction of the water-soluble ligand also ensures high stripping efficiency of Am, 99% of 241Am loaded in the TODGA ligand organic phase can be stripped into the water phase, and the lanthanide-actinide separation factor SF of the DEG-PTD ligand is 2.5. Eu / AmThe separation effect is good above 200. In addition, the ligand water solubility and extraction kinetics are good, and the water solubility is very good, and the equilibrium can be reached in 5 min. The present application provides a new idea for in-depth understanding of lanthanide and actinide separation, and provides important support for sustainable development of nuclear energy, scientific treatment and safe management of existing radioactive waste.

[0023] The present application also provides a preparation method of the DEG-PTD ligand. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A reaction principle diagram for preparing the DEG-PTD ligand of the embodiment;

[0025] Figure 2 An acidity test curve of DEG-PTD;

[0026] Figure 3 A ligand concentration extraction curve of DEG-PTD;

[0027] Figure 4 A kinetics test curve of DEG-PTD. DETAILED DESCRIPTION

[0028] The present application provides a DEG-PTD ligand, which has a structure shown in formula I:

[0029]

[0030] The present application also provides a preparation method of the DEG-PTD ligand.

[0031] The 2,6-di((trimethylsilyl)ethynyl)pyridine is obtained by mixing 2,6-dibromopyridine, (trimethylsilyl)acetylene, CuI, Pd(PPh3)4 and a solvent to carry out a first substitution reaction;

[0032] The 2-(2-azidoethoxy)ethanol is obtained by mixing 2-(2-chloroethoxy)ethanol, sodium azide and water to carry out a second substitution reaction;

[0033] The DEG-PTD ligand is obtained by mixing the 2,6-di((trimethylsilyl)ethynyl)pyridine, 2-(2-azidoethoxy)ethanol, K2CO3, CuSO4, sodium ascorbate, pyridine and a solvent to carry out a click reaction.

[0034] In the present application, the raw materials used are commercially available in the art without special instructions.

[0035] The present application carries out a first substitution reaction by mixing 2,6-dibromopyridine, (trimethylsilyl)acetylene (acetylene TMS), CuI, Pd(PPh3)4 and a solvent to obtain 2,6-bis((trimethylsilyl)ethynyl)pyridine.

[0036] In the present application, the solvent is preferably a mixture of diisopropylamine (DIPA) and tetrahydrofuran (THF), and the volume ratio of diisopropylamine to tetrahydrofuran in the mixture is preferably 1:1.

[0037] In a specific embodiment of the present application, the dried diisopropylamine and tetrahydrofuran are added to a Schlenk flask and degassed using the "freeze-pump-thaw" method before use.

[0038] In the present application, the molar ratio of 2,6-dibromopyridine to (trimethylsilyl)acetylene is preferably 21.11:84.427.

[0039] In the present application, the molar ratio of 2,6-dibromopyridine to CuI is preferably 1:0.1.

[0040] In the present application, the molar ratio of 2,6-dibromopyridine to Pd(PPh3)4 is preferably 1:0.05.

[0041] In the present application, the amount ratio of 2,6-dibromopyridine to solvent is preferably 21.11 mmol:200-280 mL, and more preferably 21.11 mmol:240 mL.

[0042] In the present application, the temperature of the first substitution reaction is preferably 40-60°C, and can be specifically 40, 45, 50, 55 or 60°C, and the time is preferably 15-20 h, and can be specifically 15, 16, 17, 18, 19 or 20 h.

[0043] In a specific embodiment of the present application, 2,6-dibromopyridine is added to a round-bottom flask, CuI is transferred to the flask, the mixture is transferred from the Schlenk flask to the reaction flask using a syringe and a long needle, Pd(PPh3)4 is weighed into a sample bottle in a glove box, and then Pd(PPh3)4 is transferred to the round-bottom flask, and finally acetylene TMS is injected into the flask using a syringe and a long needle to carry out the first substitution reaction.

[0044] After the first substitution reaction is completed, the present application stops the reaction and cools to room temperature, the resulting reaction mixture is filtered with a short silica gel chromatography column, the filtrate is evaporated with a rotary evaporator to obtain a primary product, the primary product is purified with a chromatography column, the product is collected and evaporated with a rotary evaporator to obtain the 2,6-bis((trimethylsilyl)ethynyl)pyridine.

[0045] In the present application, the length of the short diatomite chromatographic column is preferably 5-10 cm.

[0046] In the present application, the stationary phase used in the chromatographic column purification is silica, and the mobile phase is a mixture of dichloromethane (DCM) and polyethylene (PE), and the volume ratio of DCM to PE in the mixture is preferably 1:1.

[0047] In the present application, 2-(2-chloroethoxy)ethanol, sodium azide and water are mixed to carry out a second substitution reaction to obtain 2-(2-azidoethoxy)ethanol.

[0048] In the present application, the molar ratio of 2-(2-chloroethoxy)ethanol to sodium azide is preferably 46.416:116.04.

[0049] In the present application, the amount ratio of 2-(2-chloroethoxy)ethanol to water is preferably 46.416 mmol:20-40 mL, and more preferably 46.416 mmol:30 mL.

[0050] In the present application, the temperature of the second substitution reaction is preferably 70-90°C, and specifically can be 70, 75, 80, 85 or 90°C, and the time is preferably 12-20 h, and specifically can be 12, 13, 14, 15, 16, 17, 18, 19 or 20 h.

[0051] In a specific embodiment of the present application, 2-(2-chloroethoxy)ethanol and sodium azide are added to a round-bottom flask, water is then added, and the second substitution reaction is carried out by heating.

[0052] After the second substitution reaction is completed, the reaction mixture is naturally cooled, NaOH solution is added, the aqueous phase is extracted with dichloromethane, the dichloromethane phase is dried with anhydrous MgSO4, filtered, and the solvent is evaporated to obtain the 2-(2-azidoethoxy)ethanol.

[0053] In the present application, the mass concentration of the NaOH solution is preferably 5%.

[0054] In the present application, the amount ratio of 2-(2-chloroethoxy)ethanol to NaOH solution is preferably 46.416 mmol:80-120 mL, and more preferably 46.416 mmol:100 mL.

[0055] In the present application, the number of times of extracting the aqueous phase with dichloromethane is preferably 3.

[0056] After obtaining 2,6-bis((trimethylsilyl)ethynyl)pyridine and 2-(2-azidoethoxy)ethanol, the present application mixes 2,6-bis((trimethylsilyl)ethynyl)pyridine, 2-(2-azidoethoxy)ethanol, K2CO3, CuSO4, sodium ascorbate, pyridine and a solvent to carry out a click reaction, thereby obtaining the DEG-PTD ligand.

[0057] In the present application, the molar ratio of 2,6-bis((trimethylsilyl)ethynyl)pyridine to 2-(2-azidoethoxy)ethanol is preferably 9.22:23.61.

[0058] In the present application, the molar ratio of 2,6-bis((trimethylsilyl)ethynyl)pyridine to K2CO3 is preferably 9.22:58.802.

[0059] In the present application, the molar ratio of 2,6-bis((trimethylsilyl)ethynyl)pyridine to CuSO4 is preferably 9.22:7.01.

[0060] In the present application, the molar ratio of 2,6-bis((trimethylsilyl)ethynyl)pyridine to pyridine is preferably 9.22:98.941.

[0061] In the present application, the CuSO4 is preferably used in the form of CuSO4·5H2O.

[0062] In the present application, the molar ratio of 2,6-bis((trimethylsilyl)ethynyl)pyridine to sodium ascorbate is preferably 9.22:14.108.

[0063] In the present application, the solvent is preferably degassed dichloromethane and degassed water, and the amount ratio of 2,6-bis((trimethylsilyl)ethynyl)pyridine, degassed dichloromethane and degassed water is preferably 9.22 mmol: 100-120 mL: 100-120 mL, more preferably 9.22 mmol: 114 mL: 114 mL.

[0064] In the present application, the click reaction is preferably carried out in a protective atmosphere, which is preferably nitrogen, for a time of preferably 70-80 h, specifically 70, 72, 75 or 80 h, and at a temperature of preferably room temperature, i.e. without additional heating or cooling.

[0065] In a specific embodiment of the present application, 2,6-di((trimethylsilyl)ethynyl)pyridine (main ring), K2CO3, CuSO4·5H2O, 2-(2-azidoethoxy)ethanol (branch), sodium ascorbate and a stirring rod are added into a Schlenk tube, then deaerated dichloromethane and deaerated water are added, followed by adding pyridine into the Schlenk tube, and the resulting reaction mixture is subjected to the click reaction at room temperature under a nitrogen atmosphere.

[0066] After the completion of the click reaction, the reaction mixture is preferably evaporated, ethylenediaminetetraacetic acid (EDTA) is dissolved in H2O, the pH value is adjusted to 7 with a NaOH solution, and then all the solutions are added into a flask, the mixture is stirred for 1 h, then evaporated, and then the product is dissolved in methanol and adsorbed on silica in a flask, and chromatography is performed with a methanol-dichloromethane mixture as the mobile phase to obtain the DEG-PTD ligand.

[0067] In the present application, the volume percentage of methanol in the methanol-dichloromethane mixture is preferably 10%.

[0068] The present application also provides the use of the DEG-PTD ligand as described in the above technical solution in the separation of lanthanide elements and actinide elements.

[0069] The present application also provides a method for separating lanthanide elements and actinide elements from waste liquid, comprising the following steps:

[0070] The waste liquid is mixed with an extractant for solvent extraction, and the extractant is the DEG-PTD ligand as described in the above technical solution, and the waste liquid contains lanthanide elements and actinide elements.

[0071] In the present application, the waste liquid is preferably high-level waste liquid, which refers to radioactive waste liquid with a radioactivity greater than 3.7×10 10 Bq / L, which is preferably raffinate aqueous phase from the co-decontamination circulation section of a spent fuel reprocessing plant, and the acidity of the high-level waste liquid is preferably 3-4 M.

[0072] In the present application, the lanthanide elements include europium (Eu), and the actinide elements include americium (Am).

[0073] In the present application, the acidity of the waste liquid is preferably 0.005-4 M, and can be specifically 0.005, 0.01, 0.05, 0.10, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 3 or 4 M. The present application preferably uses nitric acid to adjust the acidity of the waste liquid.

[0074] In the present application, the concentration of DEG-PTD ligand in the system during the solvent extraction is 2.5-100 mM, and specifically can be 2.5, 5, 10, 20, 25, 30, 40, 60, 80 or 100 mM.

[0075] In the present application, the temperature of the solvent extraction is preferably normal temperature, and the time is preferably 5-60 min, and specifically can be 5, 10, 15, 30, 45 or 60 min.

[0076] In the present application, the solvent extraction is preferably carried out under stirring, and the stirring speed is preferably 3000 rpm.

[0077] The technical solutions in the present application will be described clearly and completely below in combination with the embodiments in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0078] Figure 1 The principle diagram for preparing DEG-PTD ligand for the embodiments of the present application.

[0079] Embodiment 1

[0080] 1.1 Main ring synthesis (a): 2,6-bis((trimethylsilyl)ethynyl)pyridine

[0081]

[0082] DIPA, dry THF and DIPA (1 :1 by volume) were added to a Schlenk flask and degassed using the "freeze-pump-thaw" method. Then, 5 g (21.11 mmol) of 2,6-dibromopyridine was added to a 500 mL round bottom flask. 402.4 mg (2.11 mmol, 10 mol%) of CuI was quantitatively transferred to the flask. 240 mL of degassed DIPA / THF mixture was transferred from the Schlenk flask to the reaction flask using a syringe and a long needle. Then, 1.207 g (1.055 mmol, 5 mol%) of Pd(PPh3)4 was weighed into a sample bottle in the glove box, and then the PdPd(PPh3)4 was transferred to the round bottom flask. Finally, 11.935 mL (84.427 mmol) of ethynyl TMS was injected into the flask using a syringe and a long needle. The reaction mixture was stirred at reflux at 50 °C for 16 h. After 16 h, the reaction was stopped and cooled to room temperature. The reaction mixture was filtered with a short silica gel chromatography column (10 cm), and the filtrate was evaporated with a rotary evaporator to obtain the primary product, which was purified with a chromatography column (400 g of silica, mobile phase: DCM:PE = 1 :1 by volume). The product was collected and evaporated with a rotary evaporator to obtain 5.95 g (100%) of the pure product as a solid.

[0083] 1 H NMR (400 MHz, CDC13) δ (ppm): 7.59-7.55 (m, 1H), 7.36-7.34 (m, 2H), 0.24-0.22 (m, 18H);13C NMR (400 MHz, CDC13) δ (ppm): 143.45 (2C), 136.35 (1C), 126.78 (2C), 103.21 (2C), 95.53 (2C), 0.21 (6C); MS (ESI + )m / z calcd. for [M+H] + : 272.13, found: 272.1235; MS (ESI + )m / z calcd. for [2M+H] + : 543.25, found: 543.2414; MS (ESI + )m / z calcd. for [2M+Na] + : 565.23, found: 565.2228.

[0084] 1.2 Branched synthesis (b): 2-(2-azidoethoxy)ethanol

[0085]

[0086] To a 100 mL round bottom flask was added 5 mL of 2-(2-chloroethoxy)ethanol (46.416 mmol) and 7.54 g of sodium azide (116.04 mmol) followed by 30 mL of pure water, the reaction was heated to 80 °C, after 16 h of reaction, the reaction mixture was cooled, 100 mL of 5 wt% NaOH solution was added, the aqueous phase was extracted with dichloromethane (3 x 100 mL) after which the dichloromethane phase was dried over anhydrous MgS04, filtered, and the solvent was evaporated to yield 6.06 g (99%) of pure product.

[0087] 1 H NMR (400 MHz, D20) δ (ppm): 3.77-3.74 (m, 4H), 3.70-3.67 (m, 2H), 3.56-3.52 (m, 2H);13C NMR (400 MHz, D20) δ (ppm): 71.70 (1C), 69.19 (1C), 60.44 (1C), 50.29 (1C); MS (ESI + )m / z calcd. for [M+Na] 154.06, found: 154.0567; FT-IR (KBr disc): v max 3535 (s), 2566 (w), 2164 (m), 1837 (s), 1511 (s), 1380 (s), 1014 (m), 507 (w). +

[0088] 1.3 DEG-PTD Ligand Synthesis (c)

[0089]

[0090] ​In a 250 mL Schlenk tube, add 2.5 g (9.22 mmol) of 2,6-bis((trimethylsilyl)ethynyl)pyridine (main ring), 8.127 g of K₂CO₃ (58.802 mmol), 1.750 g of CuSO₄·5H₂O (7.01 mmol), 3.094 g (23.61 mmol) of 2-(2-azidoethoxy)ethanol (branched chain), 2.795 g (14.108 mmol) of sodium ascorbate, and a stir bar. Then add 100 mL of degassed dichloromethane and 100 mL of degassed water. Next, add 8.01 mL (98.941 mmol) of pyridine to the Schlenk tube. The reaction mixture is stirred at room temperature under a nitrogen atmosphere for 76 h. After 76 h, the reaction mixture is evaporated. Dissolve 5 g of EDTA in H₂O and adjust the pH to 7 with NaOH solution. Then add all the solutions to a flask. The mixture was stirred for 1 hour and then evaporated. The product was dissolved in 100 mL of methanol, and 50 g of silica was added to the flask for adsorption. Purification was performed by chromatography using 400 g of silica as the stationary phase and 10 vol% methanol in dichloromethane as the mobile phase, with an Rf of 0.35. Finally, 2.44 g of pure, dried product was obtained, with a yield of 80%.

[0091] 1 H NMR (400MHz, CDCl3) δ (ppm): 8.43 (s, 2H), 7.98-7.96 (d, J = 7.8Hz, 2H), 7.78-7.74 ( m,1H),4.56-4.54(m,4H),3.85-3.83(m,4H),3.71-3.68(m,6H),3.55-3.53(m,4H).

[0092] 13 C NMR (400MHz, CDCl3) δ (ppm): 149.98 (2C), 148.10 (2C), 137.91 (1C), 123.93 (2C), 119.23 (2C), 72.69 (2C), 69.27 (2C), 61.51 (2C), 50.41 (2C).

[0093] MS(ESI+)m / z calcd.for[M+Na] + :412.17,found:412.1723;MS(ESI+)m / zcalcd.for[2M+Na] + :801.35,found:801.3514; HRMS(ESI+)m / z calcd.for[M+Na] + :412.17,found:412.1704.

[0094] 2. Solvent extraction test

[0095] 2.1 Stock solutions

[0096] The organic phase for all solvent extraction experiments was prepared using the tracer loaded organic phase (TLOP) - protocol.

[0097] A ligand stock solution was prepared by dissolving 674.2 mg of ligand in 10 mL of pure water, resulting in a concentration of 160 mM.

[0098] 241Am(N03)3stock solution containing 0.01 M nitric acid.

[0099] 152 / 154Eu(N03)3stock solution containing 0.01 M nitric acid.

[0100] HNO3stock solutions were 0.1 M, 1 M and 4 M.

[0101] NaNO3stock solution was 4 M.

[0102] 2.2 Tracer loaded organic phase (TLOP) - protocol

[0103] I. Preparation of the irradiated aqueous phase

[0104] 100 mL of 3 M HNO3was prepared into a clean conical flask and 10 mL of 3 M HNO3was added to a polypropylene centrifuge tube. To the centrifuge tube was added 20 pL of241Am tracer and 20 pL of 152 / 154Eu.

[0105] II. Preparation of TODGA

[0106] 0.2 M TODGA (N,N,N',N'-tetraoctyl-3-oxapentanediamide) organic phase: 3.521 g of TODGA was dissolved in 30 mL of kerosene / n-octanol (95:5, v / v) solution.

[0107] III. Loading

[0108] 20 mL of organic phase was added to the centrifuge tube containing the aqueous phase and 20 pL of241Am tracer and 20 pL of 152 / 154Eu, the centrifuge tube was closed appropriately. The centrifuge tube was then mounted on an orbital shaker and shaken for 60 min. After this time, the aqueous phase was centrifuged at 3000 rpm for 2 min and the aqueous phase was carefully removed into a radioactive waste bottle.

[0109] IV. Washing (removal of HNO3dissolved in the organic phase)

[0110] Add 10 mL of 0.5 M HNO3 to the centrifuge tube containing the organic phase of the tracer, close the centrifuge tube and shake for 15 min. Centrifuge at 3000 rpm for 2 min, and carefully transfer the aqueous phase to a radioactive waste bottle.

[0111] Then, an organic phase sample was taken for LSC to measure the initial 241Am and 152 / 154Eu counts.

[0112] Prepared TLOPs should be safely stored in a refrigerator to minimize solvent evaporation and maintain the same counting ratio over many days. Use 1 mL of organic phase for each sample tube.

[0113] 2.3 Three types of tests:

[0114] 2.3.1 Acidity test to determine the effect of nitric acid concentration on the partition ratio and SF. Eu / Am The impact.

[0115] For the ligand DEG-PTD, acidity studies were conducted at nitric acid concentrations of 0.005, 0.01, 0.05, 0.10, 0.15, 0.20, 0.30, 0.50, and 1.00 M, with the standard concentration of the ligand being 80 mM sodium nitrate.

[0116] 2.3.2 Kinetic studies were conducted to determine the kinetics of the extraction process.

[0117] The aqueous phase contained a constant concentration of ligand (80 mM) and 0.5 M nitric acid, with a sodium nitrate concentration of 0.5 M. Tests were performed at 5, 10, 15, 30, 45 and 60 min.

[0118] 2.3.3 Ligand concentration extraction studies were conducted to determine the ligand concentration-particulate ratio and SF. Eu / Am The impact.

[0119] The ligand DEG-PTD was tested at concentrations of 10, 20, 40, 60, 80, and 100 mM. The acidity was constant at 0.15 M nitric acid, and the sodium nitrate concentration was 0.5 M. 2.3.4

[0121] Mix 1 mL of aqueous phase and 1 mL of organic phase in a PP vial, vortex (standard 60 min), and then centrifuge (3000 rpm, 2 min) to completely separate the two phases. Samples from both the aqueous and organic phases are then collected, and the radioactivity in different channels is counted using LSC to distinguish between alpha radioactivity of 241Am and beta radioactivity of 152Eu / 154Eu. To ensure data accuracy, measurements are performed on each sample for at least 5 min. The count ratios in the two phases are then interpreted as extraction parameter D. Am and D Euand SF Eu / Am D is calculated as Eu D Am .

[0122] 2.4 solvent extraction results

[0123] Figure 2 is the acidity test curve of DEG-PTD, Figure 3 is the extraction curve of DEG-PTD ligand concentration, Figure 4 is the kinetics test curve of DEG-PTD, it can be known that the optimal acidity used by DEG-PTD is 0.05-0.2M, and the separation effect is good, SF Eu / Am is 200-240, and the equilibrium time is good, less than 5min.

[0124] In summary, the present application starts from the design of ligand molecular structure, develops a new DEG-PTD ligand by designing the structure of the ligand, and the ligand not only ensures the high distribution ratio of Eu, but also ensures the efficient stripping of Am by introducing the water-soluble ligand, 99% of 241Am loaded in the TODGA ligand organic phase can be stripped into the aqueous phase, and the lanthanide-actinide separation factor SF Eu / Am of DEG-PTD ligand is more than 200, and the separation effect is good. In addition, the water-solubility and extraction kinetics of the ligand are good, the water-solubility is very good, and the equilibrium can be reached in 5min. The present application provides a new idea for in-depth understanding of lanthanide-actinide separation, and provides important support for sustainable development of nuclear energy, scientific treatment and safe management of existing radioactive waste.

[0125] The above only describes the preferred embodiments of the present application, and does not limit the present application in any form. It should be noted that, for ordinary skilled persons in the technical field, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A DEG-PTD ligand, characterized in that, having a structure shown in Formula I: Formula I.

2. The method of producing a DEG-PTD ligand according to claim 1, characterized in that, comprising the following steps: mixing 2,6-dibromopyridine, (trimethylsilyl)acetylene, CuI, Pd(PPh3)4 and a solvent to perform a first substitution reaction to obtain 2,6-di((trimethylsilyl)ethynyl)pyridine; mixing 2-(2-chloroethoxy)ethanol, sodium azide and water to perform a second substitution reaction to obtain 2-(2-azidoethoxy)ethanol; mixing the 2,6-di((trimethylsilyl)ethynyl)pyridine, 2-(2-azidoethoxy)ethanol, K2CO3, CuSO4, sodium ascorbate, pyridine and a solvent to perform a click reaction to obtain the DEG-PTD ligand.

3. The production method according to claim 2, characterized by, The first substitution reaction is performed at a temperature of 40-60℃ for 15-20h.

4. The preparation method according to claim 2, characterized in that, The second substitution reaction is performed at a temperature of 70-90℃ for 12-20h.

5. The preparation method according to claim 2, characterized in that, The click reaction is performed in a protective atmosphere for 70-80h.

6. The DEG-PTD ligand of claim 1 is used in separating lanthanide elements including europium elements and actinide elements including americium elements.

7. A method for separating lanthanides and actinides from waste solutions, characterized in that, comprising the following steps: mixing a waste liquid containing lanthanide elements including europium elements and actinide elements including americium elements with the DEG-PTD ligand of claim 1 as an extractant to perform solvent extraction.

8. The method of claim 7, wherein, The waste liquid has an acidity of 0.005-4M.

9. The method of claim 7, wherein, The DEG-PTD ligand has a concentration of 2.5-100mM in the system during the solvent extraction.

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