Low-nucleation pollution decontaminant containing DTPA derivative and preparation method of low-nucleation pollution decontaminant

Abstract

The invention discloses a DTPA derivative-containing low-nucleation pollution detergent and a preparation method thereof.The DTPA derivative is prepared by the steps that diethylenetriamine pentaacetic acid and ethanolamine are put into an enamel reaction kettle with a distillation device, an 18-crown ether-6 catalyst is added, constant-temperature stirring reaction is conducted under vacuum protection, condensation reflux dehydration is conducted, and the DTPA derivative is obtained after the reaction is completed. The preparation method of the low-nucleation-pollution decontaminant comprises the following steps: mixing the DTPA derivative, the nonionic surfactant, the bio-based surfactant, the coordination adsorbent and water, and adjusting the pH value to 5-9 by using citric acid or diethylenetriamine to obtain the low-nucleation-pollution decontaminant containing the DTPA derivative. According to the invention, raw materials which do not contain halogen and harmful elements such as sulfur, sodium, silicon, lead, mercury, arsenic, antimony and copper are selected as synergistic components of the decontaminant, so that the problem that the harmful elements cause serious damage to equipment is avoided, and corrosion inhibitor components which are generally required to be added in a conventional nuclear pollution decontaminant are omitted by optimizing the raw materials.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear pollution cleaning and decontamination, and more specifically, relates to a low-foaming nuclear pollution decontamination agent containing a DTPA derivative and a preparation method thereof. Background Art

[0002] Traditional nuclear pollution decontamination agent patent publication number CN107629894A, CN107828524A, CN117987214A, CN116948751A, CN117604535A, CN111363635A, CN116574569A, WO2013065744, JP2013-83533A, EP1471135 A1. US20210174981A1. Radioactive nuclear pollution decontamination technology "Northern Environment", Research on the synergistic removal of uranium radioactive contamination by chemistry and ultrasound, The decontaminants recorded in "Atomic Energy Science and Technology" and other papers contain a large amount of sodium-based or potassium-based chelating agents, which are used to chelate heavy metal ions. Since ordinary chelating agents such as sodium-based or potassium-based chelating agents have limited chelating ability for radioactive heavy metal ions, they often cannot achieve excellent decontamination effects. The reason is that ordinary chelating agents have a simple structure and few coordinated atoms, resulting in limited coordination ability with high-valent heavy metal ions. In addition, since the components contain a certain amount of metal ions such as sodium and potassium, they also contain a large amount of halogen elements (such as fluorine, chlorine, and bromine) and anions such as sulfur, the risk of corrosion increases, which will cause corrosion to metals in the nuclear industry. In addition, the residual low-melting-point metal ions may also form new fission products after neutron activation, which can easily cause irreversible damage to the metal material of the equipment.

[0003] In addition, the preparation and production methods of cleaning and decontamination products have always been based on the compounding of conventional raw materials, which is essentially a physical mixing. The obvious disadvantage of this method is that only low-cost mainstream raw materials can be selected, and the result is that the decontamination effect cannot be optimal, especially in the field of nuclear cleaning. Decontaminants are used for different pollution sources and materials (such as stainless steel, carbon steel, plastic, paint, lead glass, etc.), and radioactive nuclides and conventional pollution must be removed. If pollutants are to be effectively removed, decontaminants with specific measures must be used in this decontamination work. Hazards to personnel and corrosion of materials must be eliminated. In addition, the radioactive liquid effluents generated during the decontamination process can be handled without any problems, and it cannot cause difficulties in the treatment of waste liquid and concentrate. It should be fully compatible with the waste liquid treatment system for evaporation concentration, filtration, and drying processes, and the subsequent incorporation of concentrated waste into cement, asphalt or glass. In the development of decontaminants, in addition to high decontamination efficiency, key indicators such as thermal stability, low foaming ability and low volatility should also be considered, and it does not contain halogens, sulfur and low melting point metals. In this context, it is urgent to develop a thermally stable, low-foaming and low-volatile decontaminant that does not contain halogens (fluorine, chlorine, bromine), sulfur, sodium, silicon, lead, mercury, arsenic, antimony, and copper harmful elements for cleaning and decontamination of in-service components in the nuclear industry. Summary of the invention

[0004] 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.

[0005] In order to achieve these purposes and other advantages according to the present invention, a DTPA derivative is provided, the structural formula of which is shown as follows:

[0006]

[0007] A method for synthesizing a DTPA derivative comprises the following steps:

[0008] Diethylenetriaminepentaacetic acid and ethanolamine are put into an enamel reaction kettle with a distillation device, 18-crown ether-6 catalyst is added, and the reaction is stirred at a constant temperature under vacuum protection, and condensed and refluxed for dehydration, so that the reaction is completed to obtain the DTPA derivative.

[0009] Preferably, the molar ratio of diethylenetriaminepentaacetic acid to ethanolamine is 1:5; and the added amount of 18-crown ether-6 is 0.1% to 1.0% of the total mass of diethylenetriaminepentaacetic acid and ethanolamine.

[0010] Preferably, the reaction temperature of the constant temperature stirring reaction is 95 to 130° C., and the reaction time is 4 to 6 hours.

[0011] The reaction conditions can ensure that the acid value of the reaction system remains unchanged during the reaction, that is, the reaction is completed to obtain the product DTPA derivative.

[0012] A method for synthesizing a DTPA derivative comprises the following steps:

[0013] Diethylenetriaminepentaacetic acid, dichloromethane and thionyl chloride are mixed and reacted at 38-42°C, then the solvent is removed, and the residue is added for redissolution to obtain solution A; then ethanolamine and triethylamine are dissolved in the solvent, the temperature is controlled at 0-5°C, solution A at 0-5°C is added, and then the temperature is raised to 25±5°C for reaction to obtain the DTPA derivative.

[0014] Preferably, the molar ratio of diethylenetriaminepentaacetic acid, ethanolamine and triethylamine is 1:5:5, the solvent is dichloromethane, and the mass volume ratio of diethylenetriaminepentaacetic acid to the solvent is 1kg:4L; the dosage ratio of diethylenetriaminepentaacetic acid, dichloromethane and thionyl chloride is 1kg:6L:1kg.

[0015] A low-foaming nuclear contamination detergent containing a DTPA derivative, comprising, by weight percentage:

[0016] 10% to 25% DTPA derivatives, 8% to 12% nonionic surfactants, 2% to 4% bio-based surfactants, 0.8% to 2% coordination adsorbents, and 57% to 79.2% water;

[0017] The pH value of the low-foaming nuclear pollution detergent containing the DTPA derivative is 5-9.

[0018] Preferably, the nonionic surfactant is a mixture of N,N-dimethyl-decenamide (NADA) and a branched fatty alcohol polyoxyethylene ether with a carbon chain length of 11 or 13; and the bio-based surfactant is one or more of trehalose lipids, rhamnolipids, sophorolipids and tea saponins.

[0019] Among them, the models of branched fatty alcohol polyoxyethylene ether with a carbon chain length of 13 are TO-7 and TO-9, and the models of branched fatty alcohol polyoxyethylene ether with a carbon chain length of 11 are XP-5, XP-7, and XP-9.

[0020] Preferably, the coordination adsorbent is a mixture of chitosan and crown ether, wherein the crown ether is one of 18-crown-6, 15-crown-5, 12-crown-4, benzo-12-crown-4, phenylpropyl-15-crown-5 or 4'-aminobenzo-18-crown-6.

[0021] More preferably, the mass ratio of chitosan to crown ether is 1:2-4.

[0022] A method for preparing a low-foaming nuclear contamination detergent containing a DTPA derivative comprises the following steps: mixing a DTPA derivative, a nonionic surfactant, a bio-based surfactant, a coordination adsorbent and water, and adjusting the pH value to 5-9 by using citric acid or diethylenetriamine to obtain the low-foaming nuclear contamination detergent containing the DTPA derivative.

[0023] The present invention has at least the following beneficial effects:

[0024] The DTPA derivative (diethylenetriamine pentaacetic acid amide compound) synthesized by the present invention has a multidentate ligand with 8 Ns that can provide 8 metal ion coordination sites, and can be complexed with divalent, trivalent, tetravalent, pentavalent, and hexavalent (uranium, plutonium) metal nuclides to form a stable complex. Therefore, the problem of limited chelating ability of common chelating agents can be solved. In addition, the synthetic product DTPA derivative compound has non-ionic characteristics, which can greatly reduce the corrosion risk of the decontamination component and solve the corrosion and waste liquid post-treatment problems of common salt-containing, sulfur-containing, phosphorus-containing, and chlorine-containing chelating agents.

[0025] The surfactant components in the low-foaming nuclear pollution detergent containing DTPA derivatives have good synergistic effects with diethylenetriamine pentaacetic acid amide compounds. The reasonable combination of surfactant N, N-dimethyl-decenamide and branched fatty alcohols has strong permeability, emulsification, dispersibility, and low foaming tendency. It can quickly penetrate the pollution interface, reduce the interfacial tension between the polluting nuclide and the substrate, weaken the binding force between the nuclide and the substrate, and enable the arc pairs of electrons of the hydroxyl and amino functional groups in the coordination adsorbent to form coordination bonds with the empty orbitals of the metal ions to firmly bind the metal ions in the molecules and cooperate with the DTPA derivatives to achieve efficient chelation. The hole-like structure of the supramolecular crown ether plays a maximum role, adsorbs and wraps the nuclide ions and suspends them in the solution, and does not cause corrosion damage to the substrate.

[0026] The present invention avoids the problem of harmful elements causing serious damage to equipment by selecting raw materials that do not contain halogen (fluorine, chlorine, bromine, iodine), sulfur, sodium, silicon, lead, mercury, arsenic, antimony, and copper as the synergistic components of the decontamination agent. At the same time, the corrosion inhibitor component that is usually required to be added to the conventional nuclear pollution decontamination agent is omitted through the optimization of the raw materials.

[0027] 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

[0028] Figure 1 : is an infrared spectrum of the DTPA derivative generated by the reaction of DTPA in Example 1-2 of the present invention;

[0029] Figure 21H-NMR spectrum of the DTPA derivative prepared in Example 1;

[0030] Figure 3 13C-NMR spectrum of the DTPA derivative prepared in Example 1;

[0031] Figure 4 The negative ion mode mass spectrum of the DTPA derivative prepared in Example 1;

[0032] Figure 5 This is the positive ion mode mass spectrum of the DTPA derivative prepared in Example 1;

[0033] Figure 6 This is the positive ion mode mass spectrum of the DTPA derivative prepared in Example 1;

[0034] Figure 7 1H-NMR spectrum of the DTPA derivative prepared in Example 2;

[0035] Figure 8 13C-NMR spectrum of the DTPA derivative prepared in Example 2;

[0036] Fig. 9 The negative ion mode mass spectrum of the DTPA derivative prepared in Example 2;

[0037] Fig.10 This is the positive ion mode mass spectrum of the DTPA derivative prepared in Example 2;

[0038] Fig.11 This is the positive ion mode mass spectrum of the DTPA derivative prepared in Example 2;

[0039] Fig.12 It is the Nyquis diagram of Q235 carbon steel in two nuclear pollution decontaminants of Example 7 and Comparative Example 1;

[0040] Fig.13 It is a polarization curve diagram of Q235 carbon steel in two nuclear pollution decontaminants of Example 7 and Comparative Example 1;

[0041] Fig.14 This is a surface morphology of a Q235 steel plate after being corroded by the nuclear pollution decontaminant prepared in Example 7;

[0042] Fig.15 This is a surface morphology of a Q235 steel plate after being corroded by the nuclear pollution decontaminant prepared in Comparative Example 2;

[0043] Fig.16 The pictures are before and after the nuclear pollution decontamination agent prepared in Example 7 was used to decontaminate the sample of smeared nuclides and graphite mixed oil pollution;

[0044] Fig.17This is a graph showing the effect of the ratio of nonionic surfactant in the low-foaming nuclear pollution detergent containing DTPA derivatives on the foam height of the detergent in Example 8;

[0045] Fig.18 This is a graph showing the effect of the ratio of the coordination adsorbent in the low-foaming nuclear contamination detergent containing DTPA derivatives at different pH values ​​on the nuclide decontamination rate of the detergent in Example 9. DETAILED DESCRIPTION

[0046] 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.

[0047] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0048] Example 1

[0049] This embodiment provides a method for preparing a DTPA derivative, and the reaction formula is as follows:

[0050]

[0051] Here are the steps:

[0052] S1. Slowly put 472 kg (1200 mol) of diethylenetriaminepentaacetic acid and 367 kg (6000 mol) of ethanolamine in a molar ratio of 1:5 into a 1000-liter enamel reactor with a distillation device, control the stirring speed at 100 r / min, turn on the oil bath heating and keep the temperature at 100°C, and add 1.2 kg of 18-crown ether-6 catalyst.

[0053] S2. Raise the temperature to 130°C and keep the temperature constant, turn on the vacuum pump (vacuum degree is 0.1Mpa), control the stirring speed at 400r / min, and the stirring time is 4h; use a container to collect the condensed recovered water.

[0054] S3. During the reaction, the acidity of the DTPA and ethanolamine reaction solution was tested every 1 hour. The acid value remained unchanged after 4 hours. Testing method: Take the reaction solution and prepare a 1% aqueous solution by mass, and titrate it with 0.01 mol / L hydrochloric acid. When the volume of 0.01 mol / L hydrochloric acid consumed does not increase, it indicates that the reaction is complete.

[0055] S4, discharge the material, which is the DTPA derivative.

[0056] The DTPA derivative prepared in this example was subjected to infrared spectroscopy testing using a potassium bromide (KBr) tableting method. 1 mg of the DTPA derivative and 100 mg of spectrally pure potassium bromide crystals were ground and mixed evenly in an agate mortar, and the mixed powder was pressed into a round sheet using a tablet press and placed in an infrared spectrometer sample holder for transmission testing.

[0057] Take 1 mg DTPA and 100 mg spectrally pure potassium bromide crystals and grind them in an agate mortar until they are evenly mixed. Use a tablet press to press the mixed powder into round slices and put them into the infrared spectrometer sample holder for transmission test as a comparison. The infrared spectra of the purified DTPA derivative and the raw material DTPA are shown in Figure 1 ,from Figure 1 It can be seen that the 1731cm -1 、1686cm -1 The absorption peak at 1635 cm is the stretching vibration signal of the carboxyl C=O, which is a characteristic peak of DTPA. -1 、1563cm -1 The characteristic peaks are amide group I and amide group II, indicating that obvious amidation reaction occurred between DTPA and ethanolamine.

[0058] The structure of the purified DTPA derivative was further confirmed using a nuclear magnetic resonance spectrometer and a mass spectrometer.

[0059] Example 1 Preparation of DTPA derivatives 1 H-NMR spectrum is shown in Figure 2 .

[0060] Example 1 Preparation of DTPA derivatives 13 C-NMR spectrum is shown in Figure 3 .

[0061] 1 HNMR(500MHz,D2O)δ3.61(10H,m,H-6),3.53-3.41(10H,m,H-3),3.32(10H,m,H-5),3.10(8H,d,J=9.6Hz,H-1,2).

[0062] 13 CNMR(126MHz,D2O)δ164.5(C-4),59.9(C-6),57.8(C-3),51.2(C-2),50.6(C-1),40.1(C-5).

[0063] The negative ion mode mass spectrum of the DTPA derivative prepared in Example 1 is shown in Figure 4 .

[0064] The positive ion mode mass spectrum of the DTPA derivative prepared in Example 1 is shown in Figure 5 .

[0065] The positive ion mode mass spectrum of the DTPA derivative prepared in Example 1 is shown in Figure 6 .

[0066] Figure 4 In the mass spectrometry negative ion peak results, 76.8 is the (M-5H) / 5 peak of DTPA, indicating that DTPA loses 5 charges when it is completely dissociated; Figure 5 In the mass spectrometry positive ion peak results, 62 is the M+H peak of monoethanolamine; Figure 6 In the mass spectrum positive ion peak results, 609 is the M+H peak of the DTPA derivative.

[0067] The above infrared spectrum, nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum show that the structural formula of the DTPA derivative prepared in Example 1 is as follows:

[0068]

[0069] Example 2

[0070] This embodiment provides a method for preparing a DTPA derivative, the steps are as follows:

[0071] Add diethylenetriaminepentaacetic acid (80.0kg, 1 equivalent) to a 1000L clean reactor, and add dichloromethane (480L). Then add thionyl chloride (80.0kg) to the reactor. Heat the reactor to 38°C and keep the temperature for 5 hours. After the reaction is completed, reduce the pressure and concentrate to remove the solvent (dichloromethane), add dichloromethane (160L) to dissolve the residue, transfer it for later use, and mark it as A.

[0072] Add ethanolamine (62.1 kg, 5 equivalents) into a 1000 L clean reactor, add dichloromethane (320 L) to dissolve, then add triethylamine (103.0 kg, 5 equivalents). Cool the reaction solution to 2 ° C, then keep the above prepared A solution at 0-5 ° C and add it dropwise to the reaction solution. After adding, warm to room temperature (25 ° C) and react for 2 hours.

[0073] After the reaction was completed, water (160 L) was added to the reactor to wash and separate the layers, and the aqueous layer 1 was separated. A 5% hydrochloric acid aqueous solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 2 was separated. A 5% sodium bicarbonate solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 3 was separated. Saturated brine (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 4 was separated. Magnesium sulfate (20.0 kg) was added to the organic layer, stirred and dried for 0.5 hours, filtered, and the filtrate was concentrated to dryness to obtain 112.3 kg of the product (yield: 90.7%).

[0074] The structure of the product isolated in Example 2 was confirmed by referring to the method in Example 1.

[0075] The infrared spectra of the DTPA derivative prepared in Example 2 and the raw material DTPA are shown in Figure 1 ,from Figure 1 It can be seen that the 1731cm -1 、1686cm -1 The absorption peak at 1635 cm is the stretching vibration signal of the carboxyl C=O, which is a characteristic peak of DTPA. -1 、1563cm -1 The characteristic peaks are amide group I and amide group II, indicating that obvious amidation reaction occurred between DTPA and ethanolamine.

[0076] Example 2 Preparation of DTPA derivatives 1 H-NMR spectrum is shown in Figure 7 .

[0077] Example 2 Preparation of DTPA derivatives 13 C-NMR spectrum is shown in Figure 8 .

[0078] 1 HNMR(500MHz,D2O)δ3.61(10H,m,H-6),3.53-3.41(10H,m,H-3),3.32(10H,m,H-5),3.10(8H,d,J=9.6Hz,H-1,2).

[0079] 13 CNMR(126MHz,D2O)δ164.5(C-4),59.9(C-6),57.8(C-3),51.2(C-2),50.6(C-1),40.1(C-5).

[0080] Figure 2 Example 1 Product 1 H-NMR, Figure 3 Example 1 Product 13 C-NMR and Figure 7 Example 2 Product 1 H-NMR, Figure 8 Example 2 Product 13C-NMR shows that the products formed by the two synthetic pathways are consistent. The hydrogen spectrum shows that δ3.61 (10H, m) corresponds to the overlapping signals of 5 methylene hydrogens connected to the hydroxyl group in the structure, δ3.53-3.41 (10H, m) corresponds to the overlapping signals of 5 methylenes connected to the nitrogen atom at one end and the carbonyl group at the other end in the structure, δ3.32 (10H, m) corresponds to the overlapping signals of 5 methylene hydrogens connected to the amide nitrogen atom in the structure, δ3.10 (8H, d, J = 9.6 Hz) corresponds to the overlapping signals of 4 methylene hydrogens between two nitrogen atoms in the structure, and a strong peak appears at δ8.01, which is the residual The carbon spectrum shows that δ164.5 corresponds to the carbonyl carbon signal of the amide in the structure, δ59.9, 57.8, 51.2, 50.6, and 40.1 correspond to the four methylene carbon signals at positions 6, 3, 2, 1, and 5 in the structure, respectively. A carbonyl signal can also be seen at position δ174.9 in the spectrum, which is the signal of the carboxyl carbon atom in the residual DTPA. A carbonyl signal appears at position δ166.6, which is confirmed to be the signal of residual formic acid. In summary, the H NMR spectrum and C NMR spectrum data are consistent with the target structure, indicating that the target product was successfully synthesized.

[0081] The negative ion mode mass spectrum of the DTPA derivative prepared in Example 2 is shown in Fig. 9 .

[0082] The positive ion mode mass spectrum of the DTPA derivative prepared in Example 2 is shown in Fig.10 .

[0083] The positive ion mode mass spectrum of the DTPA derivative prepared in Example 2 is shown in Fig.11 .

[0084] Fig. 9 In the mass spectrometry negative ion peak results, 76.9 is the (M-5H) / 5 peak of DTPA, indicating that DTPA loses 7 charges when it is completely dissociated; Fig.10 In the mass spectrometry positive ion peak results, 62 is the M+H peak of monoethanolamine; Fig.11 In the mass spectrum positive ion peak results, 609 is the M+H peak of the DTPA derivative.

[0085] The above infrared spectrum and mass spectrum show that the structural formula of the DTPA derivative prepared in Example 2 is as follows:

[0086]

[0087] Example 3

[0088] This embodiment provides a method for preparing a DTPA derivative, the steps are as follows:

[0089] Add diethylenetriaminepentaacetic acid (80.0kg, 1 equivalent) to a 1000L clean reactor, and add dichloromethane (480L). Then add thionyl chloride (160.0kg) to the reactor. Heat the reactor to 38°C and keep the temperature for 3 hours. After the reaction is completed, reduce the pressure and concentrate to remove the solvent (dichloromethane), add dichloromethane (160L) to dissolve the residue, transfer it for later use, and mark it as A.

[0090] Add ethanolamine (62.1 kg, 5 equivalents) into a 1000 L clean reactor, add dichloromethane (320 L) to dissolve, then add triethylamine (103.0 kg, 5 equivalents). Cool the reaction solution to 2 ° C, then keep the above prepared A solution at 0-5 ° C and add it dropwise to the reaction solution. After adding, warm to room temperature (25 ° C) and react for 2 hours.

[0091] After the reaction was completed, water (160 L) was added to the reactor to wash and separate the layers, and the aqueous layer 1 was separated. A 5% hydrochloric acid aqueous solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 2 was separated. A 5% sodium bicarbonate solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 3 was separated. Saturated brine (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 4 was separated. Magnesium sulfate (20.0 kg) was added to the organic layer, stirred and dried for 0.5 hours, filtered, and the filtrate was concentrated to dryness to obtain 108.2 kg of the product (yield: 87.4%).

[0092] Example 4

[0093] This embodiment provides a method for preparing a DTPA derivative, the steps are as follows:

[0094] Add diethylenetriaminepentaacetic acid (80.0kg, 1 equivalent) to a 1000L clean reactor, and add dichloromethane (480L). Then add thionyl chloride (80.0kg) to the reactor. React at room temperature (25°C) for 12 hours. After the reaction is completed, concentrate under reduced pressure to remove the solvent (dichloromethane), add dichloromethane (160L) to dissolve the residue, transfer it for later use, and mark it as A.

[0095] Ethanolamine (62.1 kg, 5 equivalents) was added to a 1000 L clean reactor, and dichloromethane (320 L) was added to dissolve it, and then triethylamine (103.0 kg, 5 equivalents) was added. The reaction solution was cooled to 2 ° C, and then the above prepared solution A was added dropwise to the reaction solution while maintaining it at 0 ° C. After the addition, the temperature was raised to room temperature (25 ° C) and the reaction was allowed to proceed for 2 hours.

[0096] After the reaction was completed, water (160 L) was added to the reactor to wash and separate the layers, and the aqueous layer 1 was separated. A 5% hydrochloric acid aqueous solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 2 was separated. A 5% sodium bicarbonate solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 3 was separated. Saturated brine (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 4 was separated. Magnesium sulfate (20.0 kg) was added to the organic layer, stirred and dried for 0.5 hours, filtered, and the filtrate was concentrated to dryness to obtain 104.2 kg of the product (yield: 84.2%).

[0097] Example 5

[0098] This embodiment provides a method for preparing a DTPA derivative, comprising:

[0099] Add diethylenetriaminepentaacetic acid (80.0kg, 1 equivalent) to a 1000L clean reactor, and add dichloromethane (480L). Then add thionyl chloride (80.0kg) to the reactor. Heat the reactor to 38°C and keep the temperature for 5 hours. After the reaction is completed, reduce the pressure and concentrate to remove the solvent (dichloromethane), add dichloromethane (160L) to dissolve the residue, transfer it for later use, and mark it as A.

[0100] Ethanolamine (99.4 kg, 8 equivalents) was added to a 1000 L clean reactor, and dichloromethane (320 L) was added to dissolve it, and then triethylamine (164.8 kg, 8 equivalents) was added. The reaction solution was cooled to 2 ° C, and then the above prepared solution A was added dropwise to the reaction solution at 0-5 ° C. After the addition, the temperature was raised to room temperature (25 ° C) and the reaction was carried out for 2 hours.

[0101] After the reaction was completed, water (160 L) was added to the reactor to wash and separate the layers, and the aqueous layer 1 was separated. A 5% hydrochloric acid aqueous solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 2 was separated. A 5% sodium bicarbonate solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 3 was separated. Saturated brine (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 4 was separated. Magnesium sulfate (20.0 kg) was added to the organic layer, stirred and dried for 0.5 hours, filtered, and the filtrate was concentrated to dryness to obtain 111.4 kg of the product (yield: 90.0%).

[0102] Example 6

[0103] This embodiment provides a method for preparing a DTPA derivative, the steps are as follows:

[0104] Add diethylenetriaminepentaacetic acid (80.0kg, 1 equivalent) to a 1000L clean reactor, and add dichloromethane (480L). Then add thionyl chloride (80.0kg) to the reactor. Heat the reactor to 38℃ and keep it warm for 5 hours. After the reaction is completed, reduce the pressure and concentrate to remove the solvent (dichloromethane), and add dichloromethane (320L) to dissolve the residue. Cool the above reaction solution to 0-5℃, then add triethylamine (103.0kg, 5 equivalents) precooled to 2℃, and then continue to add ethanolamine (62.1kg, 5 equivalents) precooled to 2℃. After adding, warm to room temperature (25℃) and react for 2 hours.

[0105] After the reaction was completed, water (160 L) was added to the reactor to wash and separate the layers, and the aqueous layer 1 was separated. A 5% hydrochloric acid aqueous solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 2 was separated. A 5% sodium bicarbonate solution (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 3 was separated. Saturated brine (160 L) was added to the organic layer to wash and separate the layers, and the aqueous layer 4 was separated. Magnesium sulfate (20.0 kg) was added to the organic layer, stirred and dried for 0.5 hours, filtered, and the filtrate was concentrated to dryness to obtain 92.3 kg of the product (yield: 74.6%).

[0106] Example 7

[0107] This embodiment provides a method for preparing a low-foaming nuclear contamination detergent containing a DTPA derivative, and the steps are as follows:

[0108] Prepare the following amounts of components in percentage by mass:

[0109] The DTPA derivative prepared in Example 1 is 25%, the nonionic surfactant NADA is 5%, the branched fatty alcohol polyoxyethylene ether TO-9 is 5%, the trehalose lipid is 3%, the chitosan is 0.4%, the 18-crown ether is 61%, and the water is 60.6%.

[0110] The above components are mixed and stirred evenly, and then the pH value is adjusted to 5 with citric acid to obtain a low-foaming nuclear pollution detergent containing a DTPA derivative.

[0111] The harmful components of the low-foaming nuclear contamination detergent containing DTPA derivatives prepared in Example 7 were detected. Referring to the EN14582:2016 standard, ion chromatography was used to detect harmful elements fluorine, chlorine, bromine, and sulfur; referring to USEPA30521996, inductively coupled plasma emission spectrometer was used to detect sodium, lead, antimony, and copper; referring to the ASTMD4004-06 (2017) standard, IEP-OES was used to detect silicon, arsenic, and mercury.

[0112] The test results are shown in Table 1.

[0113] Table 1

[0114]

[0115]

[0116] It can be seen from Table 1 that the content of harmful elements in the nuclear pollution decontaminant prepared in Example 7 of the present invention is extremely low, which complies with the provisions of Section 7.3.3 of NB / T20233-2013 "Cleanliness and Cleanliness Requirements for Nuclear Steam Supply System Equipment in Pressurized Water Reactor Nuclear Power Plants" on the surface of austenitic stainless steel or nickel-based alloy equipment, the maximum allowable content of chloride and fluoride should be 200 mg / kg, and the maximum allowable content of sulfur should be 200 mg / kg. In addition, the VOC content in the nuclear pollution decontaminant prepared in Example 7 was tested with reference to the volatile organic compound (VOC) content determination method in GB38508-2020, and the test result was 49 g / L, which has low organic volatile compounds. The thermal stability of Example 7 was analyzed by thermogravimetric analyzer (TGA) with reference to ISO11358-1:2014. The test conditions were 10°C / min in nitrogen, from room temperature to 600°C, and then 10°C / min in oxygen from 600 to 800°C. The results showed that the weight loss in stage I (90°C to 110°C) was about 62.5%, the weight loss in stage II (120 to 180°C) was about 13.8%, and the weight loss in stage III (190 to 220°C) was about 23.6%. The first stage was caused by the evaporation of water molecules, with a maximum decomposition temperature of 220°C, and had thermal stability.

[0117] Comparative Example 1

[0118] This comparative example provides a method for preparing a nuclear pollution decontaminant. Compared with Example 7, the only difference is that an equal mass of EDTA-2Na is used to replace the DTPA derivative.

[0119] Comparative Example 2

[0120] A nuclear pollution cleaning agent prepared according to the preparation method of Example 1 disclosed in the prior art "A universal nuclear pollution cleaning agent and its preparation method" CN201711005892.4.

[0121] Comparison of the Corrosiveness of the Nuclear Pollution Decontaminants Prepared in Example 7 and Comparative Example 1

[0122] The experiment used a CH660 electrochemical workstation for performance testing. The polarization curve and ELS were measured in a three-electrode tank. The reference electrode was a saturated calomel electrode, the auxiliary electrode was a platinum electrode, and the electrolyte solutions were Example 7 and Comparative Example 1. The polarization curve was measured between -0.7 and 0.7 relative to the open circuit potential, the impedance spectrum measurement frequency was 100kHz to 0.01Hz, and the test temperature was (25±1)°C. The electrochemical impedance spectra and polarization curves of Q235 carbon steel in different solutions were compared.

[0123] 1. AC impedance

[0124] Using Q235 carbon steel as the base material, the Nyquis diagrams of the two nuclear pollution decontaminants obtained by testing are shown in Fig.12 ,from Fig.12 It can be seen that the Nyquist plots of the two samples are composed of a capacitive reactance arc (high frequency area) and a straight line with a slope of about 45° (low frequency area), wherein the capacitive reactance arc radius of the sample in the solution of Example 7 is larger, indicating that the charge transfer resistance of the Q235 sample in the solution is larger, and its corrosion inhibition performance is better, and the corrosion process of the material is slowed down. In comparison, the capacitive reactance arc radius of the Q235 sample in the solution of Comparative Example 1 is smaller, which is about one order of magnitude different from the former, so the corrosion rate of the Q235 sample in the solution of Comparative Example 1 is larger, and the corrosion inhibition performance of the material is poor.

[0125] 2. Polarization curve

[0126] Potentiodynamic polarization scanning was performed on two groups of specimens, and the electrochemical parameters corrosion potential Ecorr and corrosion current density Icorr were obtained by Tafel linear extrapolation. Ecorr is the stable potential measured by a specific corrosion system without the influence of an applied voltage, which can reflect the size of the metal corrosion tendency. The higher the Ecorr value, the smaller the corrosion tendency; the Icorr of the metal electrode is proportional to the corrosion rate, which can reflect the speed of the metal corrosion rate. The higher the Icorr value, the faster the corrosion rate of the metal. It can be seen that the higher the Ecorr value and the lower the Icorr value, the better the corrosion resistance of the alloy.

[0127] Fig.13 Table 2 is the polarization curve of Q235 carbon steel in two test solutions, and Table 3 is the electrochemical impedance spectroscopy fitting results. Fig.13 From the fitting parameters in Table 2, it can be found that the self-corrosion potential Ecorr of the Q235 sample in the solution of Example 7 is -0.700 V, and the self-corrosion current density Icorr is relatively large, which is 1.42×10 -6 A.cm -2 The self-corrosion potential Ecorr of the sample in the solution of Comparative Example 1 was reduced to -0.948V, and the self-corrosion current density Icorr increased to 6.75×10 -5A.cm -2 According to electrochemical theory, the Icorr of a metal electrode is proportional to the corrosion rate, which can reflect the speed of metal corrosion. The higher the Icorr value, the faster the metal corrodes. Therefore, the corrosion rate in the solution of Example 7 is relatively small, and the corrosion inhibition performance of the Q235 carbon steel material in this test environment is relatively good.

[0128] Table 2 Electrochemical impedance spectroscopy fitting results

[0129]

[0130]

[0131] Comparison of the Corrosiveness of the Nuclear Pollution Decontaminants Prepared in Example 7 and Comparative Example 2 on Q235 Steel Plate

[0132] Method: Degrease the surface of the test sample, wash it with water, and dry it; apply the above two test detergents to the clean surface of Q235 steel plate. After 48 hours, rinse the surface of the sample with anhydrous ethanol and observe it.

[0133] The surface morphology of the steel sample after 48h corrosion is shown in Fig.14 and Fig.15 .Depend on Fig.14 and Fig.15 The surface morphology diagram shows that after 48 hours of corrosion test on the sample surface of Example 7, only slight rust is formed on the metal surface. After 48 hours of corrosion test on the sample surface of the comparative example, the sample surface has serious corrosion phenomenon.

[0134] The weight loss of 304 stainless steel plate corroded by the nuclear pollution decontaminant prepared in Example 7 and Comparative Example 2 was further compared.

[0135] Method: The size of the pre-prepared sample was measured, and after accurate weighing, it was placed in the detergent prepared in Example 7 and Comparative Example 2 at room temperature. After 48 hours, it was taken out, cleaned, dried, and weighed again after removing the product, and the weight loss was calculated. The results are shown in Table 3.

[0136] Table 3 Corrosion weight loss test records

[0137]

[0138] According to NB / T20142-2012 Guidelines for Chemical Decontamination of Primary Circuit Systems and Equipment in Pressurized Water Reactor Nuclear Power Plants, 45 steel, martensitic stainless steel (0Cr 17 The corrosion rates of four material specimens, namely, Ni4Cu4Nb), austenitic stainless steel (316L) and nickel-based alloy (INCOEL718), in the nuclear pollution decontaminant prepared in Example 7.

[0139] Test process

[0140] All test pieces were polished with 320# sandpaper, cleaned, dried, and the specimen dimensions were measured and weighed;

[0141] Place the test pieces one by one into the sample rack and mark them on the sample rack;

[0142] 150 mL of detergent (mixed with distilled water in Example 7 at a volume ratio of 4:1) was placed in each beaker, and the beaker was sealed with plastic wrap;

[0143] Put it in a constant temperature water bath and keep the temperature at 80℃;

[0144] Put the test pieces in order, record the start time, and continue the test for 1 hour;

[0145] After the test, the test piece was taken out, cleaned, dried, weighed and the corrosion rate was calculated. The calculation results are shown in Table 4.

[0146] Table 4 Corrosion rates of four materials

[0147]

[0148] The decontamination effect of the nuclear pollution decontamination agent prepared in Test Example 7 on the simulated nuclide and graphite mixed oil pollution

[0149] Method: Mix 430 grams of REP anti-radiation grease, 50 grams of graphite and 20 grams of cesium chloride in a 1L wide-mouth jar, place it in a 200±5℃ forced air drying oven, insert a glass tube with a diameter of 6.4mm, and introduce air into the mixture at a flow rate of 8.5±0.5cm / s. The mixture is heated at 200±5℃ for 24 hours with ventilation, then cooled to room temperature and mixed evenly to form standard dirt for standby use.

[0150] The test plate should be ground with 0# fine sandpaper, then cleaned with lens paper soaked with toluene and then isopropyl alcohol, dried to constant weight, weighed to an accuracy of 0.0001g, and about 0.25g of standard dirt should be evenly brushed on the center area with a brush, then baked at 200±3℃ for 20min, and weighed after cooling to an accuracy of 0.0001g. The test plate with 0.10-0.20g of dirt should be selected for the test.

[0151] Prepare 1000mL of nuclear pollution decontamination agent with a volume fraction of 10wt.% in Example 7 and diluted with deionized water, and spray it onto the rotating test plate brushed with dirt through a nozzle (air gauge pressure is 0.07mpa). The flow rate of the solution is adjusted to 100±10mL / min, and then the test plate is rinsed in the same way with 100mL of distilled water. The decontamination equipment rotates vertically at a speed of 200r / min in front of the nozzle, and the nozzle is perpendicular to the plate. The nozzle is kept at a distance of 80±5㎜ from the test plate. The test plate after rinsing should be dried at 105℃ for 10min, then cooled to room temperature, and then weighed to an accuracy of 0.0001g. Pictures of the sample before and after decontamination are shown in Fig.16 The cleaning effect of the diluted nuclear pollution decontamination agent in Example 7 on the simulated nuclides and graphite mixed oil pollution is shown in Table 5.

[0152] Table 5 Decontamination effect of diluted nuclear pollution decontamination agent in Example 7 on mixed oil pollution of nuclides and graphite

[0153]

[0154] Comparison of the decontamination efficiency of the nuclear pollution decontaminants prepared in Example 7 and Comparative Example 2 on nuclides

[0155] Decontamination effect verification

[0156] This test method is designed according to GB / T14057.1-2008 "Decontamination of radioactively contaminated surfaces Part 1: Test methods for and evaluation of the difficulty of decontamination", GB / T14056-2008 "Determination of surface contamination" - Part 1: β emitters (maximum β energy greater than 0.15 MeV) and α emitters, and GB5202-2008 "α, β and α-β surface contamination measuring instruments and monitors".

[0157] A.1 Principle

[0158] Will 60 Co. 137 Cs, 238 The U mixed liquid is applied to the center of each stainless steel sheet fixed on the sample contamination positioner (the device complies with Appendix A and B of GB / T14057.1-2008), left for a specified time, and the nuclear contamination decontamination agents of Example 7 and Comparative Example 2 are configured under specified conditions to carry out a decontamination test and determine the decontamination efficiency.

[0159] A.2 Reagents and materials

[0160] Anhydrous ethanol, 0.1 mol / L nitric acid, radioactive standard solution: used in the experiment 60 Co. 137 Cs, 238U radioactive standard solution is used to prepare the test sample for radioactive contamination (mixing ratio is 2:2:1 by volume); the specific activity of the mixed radioactive solution is not less than 50 kBq / mL, and the expanded uncertainty is 5% (K=2); 60 Co. 137 Cs, 238 The medium of U standard solution is 0.1mol / L nitric acid and absorbent cotton.

[0161] A.3 Instruments and equipment

[0162] Thermometer and hygrometer, 100μL pipette, analytical balance, sensitivity 0.1mg, α, β surface contamination measuring instrument, dryer, 2000ml beaker, sample contamination locator, which should comply with the provisions of Appendix A of GB / T 14057.1, cage stirring decontaminant, which should comply with the provisions of Appendix B of GB / T 14057.1, fume hood, tweezers.

[0163] A.4 Experimental procedures

[0164] A.4.1 Test preparation

[0165] A.4.1.1 3mm thick 304 stainless steel is used for the test. This grade of stainless steel meets the requirements of the test steel plate in NB / T20133.4-2012 Specification for Protective Coatings for Pressurized Water Reactor Nuclear Power Plant Facilities and Equipment Part 4: Determination of Decontamination of Coating System, and the surface roughness is within 70μm. The size of the stainless steel used for the test is 50mm×50mm×3mm.

[0166] A.4.1.2 The test is carried out as follows: the net count rate is measured on a blank sample, the contamination count rate is measured after a radioactive solution is added to the test sample and allowed to stand for a period of time, decontamination is performed using the detergent of Example 7 or Comparative Example 2, the count rate of the radioactivity remaining in the sample is measured, and the decontamination efficiency is calculated.

[0167] A.4.1.3 Pre-treat the stainless steel sheet used in the test as follows: Apply absorbent cotton soaked in anhydrous ethanol to the surface of the sample, cover it with a petri dish for 10 minutes, remove the cotton ball, and clean the surface with distilled water. Dry it at room temperature, and select materials with similar appearance and color as test materials.

[0168] A.4.2 Measuring the net count rate on a blank sample

[0169] Place a blank sample on the measurement positioning frame, use an α or β surface contamination meter on the positioning frame to measure the blank background count rate, record the background count rate 10 times, and calculate the background average count rate. If the measuring instrument allows, the instrument can measure and record the background count rate, and then display the net count rate.

[0170] A.4.3 Measurement of radioactive contamination count rate of simulated samples

[0171] A.4.3.1 Simulated sample radioactive contamination

[0172] A.4.3.1.1 After applying the radioactive solution to the simulated sample, let it stand for 120 minutes. Prepare 5 simulated contaminated samples for each group.

[0173] A.4.3.1.2 Place the positioner horizontally in the fume hood, fix the samples one by one on the sample contamination positioner, take 50μL~100μL, and drop it on the center of the test piece to make the contaminated solution evenly distributed on the surface of the sample.

[0174] A.4.3.1.3 Let stand at room temperature for 120 minutes, then use absorbent cotton to absorb the surface moisture. Record the counting rate of each simulated sample three times and calculate the average value A1.

[0175] A.4.4 Decontamination of simulated contaminated samples using decontamination solution

[0176] A.4.4.1 Fix the simulated samples to the cage stirring decontaminator. Use rubber bands to fix the 5 simulated samples to the "window frame" of the cage stirring device. The sixth "window" contains an uncontaminated blank for material recontamination analysis. Make sure the simulated sample is placed in the center of the "window".

[0177] A.4.4.2 Add 1000 mL of detergent (50 mL of detergent, 950 mL of deionized water) at a temperature of about 25°C and a concentration of 5 wt.% in a 2L beaker. Place the bottom of the cage stirring detergent directly in contact with the bottom of the beaker. The liquid level in the beaker should not be lower than the 1500 mL mark.

[0178] A.4.4.3 Start decontamination, and rotate the cage stirrer at a speed of about 100 r / min for 2.5 minutes. Then take out the cage stirrer, put it into another beaker filled with clean water, and rotate it for another 10 seconds.

[0179] A.4.4.4 Remove the sample from the cage stirrer and place it in a fume hood at room temperature for 30 minutes.

[0180] A.4.5 Measurement of residual radioactivity in simulated samples

[0181] A.4.5.1 Place the surface contamination meter on the measurement positioning frame to measure the residual radioactivity count rate on the simulated sample after decontamination.

[0182] A.4.5.2 Record three measurements for each sample and calculate the average value.

[0183] Calculation method

[0184] The decontamination effect is expressed by the decontamination efficiency (Q), which is calculated according to the following formula:

[0185] Q=(A1-A2) / A1×100%

[0186] In the above formula, Q is the decontamination efficiency, %; A1 is the pollution counting rate before decontamination S -1 ; A2 is the pollution counting rate S after decontamination -1 .

[0187] The nuclide decontamination efficiency of the nuclear pollution decontamination agent prepared in Example 7 is shown in Table 6; the nuclide decontamination efficiency of the nuclear pollution decontamination agent prepared in Comparative Example 2 is shown in Table 7.

[0188] Table 6 Nuclide decontamination efficiency of the nuclear pollution decontaminant prepared in Example 7

[0189]

[0190]

[0191] Table 7 Nuclide decontamination efficiency of the nuclear pollution decontamination agent prepared in Comparative Example 2

[0192]

[0193]

[0194] Example 8

[0195] The effect of the ratio of nonionic surfactants on the foam height of low-foaming nuclear contamination detergents containing DTPA derivatives was investigated:

[0196] Compared with the solution of Example 7, the mass ratios of nonionic surfactant NADA and branched fatty alcohol polyoxyethylene ether TO-9 in the formula were adjusted to 1:0.5, 1:1, 1:1.5, 1:2 and 1:3 respectively, and the total amount remained 10wt.%.

[0197] The prepared 5 groups of low-foaming nuclear contamination detergents containing DTPA derivatives were added with deionized water to prepare dilutions with a detergent concentration of 5 wt.%, and the foam height was measured with reference to the foam performance test of GB / T357595.8. The measurement results are shown in Fig.17 .

[0198] from Fig.17 It can be seen that the mass ratio of NADA to TO-9 is in the range of 1:0.5 to 1.5, and the foam volume of the prepared detergent after 5in is less than 20mm. When used for decontamination, it can effectively reduce the amount of liquid waste and is compatible with the waste liquid treatment system.

[0199] Example 9

[0200] The effect of the ratio of the coordination adsorbent in the low-foaming nuclear contamination decontamination agent containing DTPA derivatives on the radionuclide decontamination rate in different pH ranges was investigated:

[0201] Compared with the solution of Example 7, the mass ratios of chitosan and 18-crown ether-6 in the formula were adjusted to 1:0.5, 1:1, 1:2, 1:3 and 1:4 respectively, the total amount remained 1.4wt.%, and the pH value range was expanded to 5, 6, 7, 8, 9.

[0202] The prepared 25 groups of low-foaming nuclear contamination detergents containing DTPA derivatives were added with water to prepare a dilution with a detergent concentration of 5wt.%, and 100mgUO2(NO3)2·6H2O was weighed and dissolved in 20mL aqueous solution to prepare 5mg / ml. 75 304 stainless steel test pieces (3 pieces per group) were selected, the surface was polished with 320# sandpaper, cleaned with anhydrous ethanol and dried. 100μL of uranium contamination solution was taken with a 20mL pipette and dropped into the center area and dried at 105℃ for 4 hours.

[0203] Use a pipette to take 5mL of the decontaminant dilution solution and rinse the contaminated stainless steel for 4 times in total. Collect the rinse solution in a 200ml beaker and use ICP-MS to measure the uranium content as the removal content. Refer to HJ 700-2014 "Determination of 65 Elements in Water Quality by Inductively Coupled Plasma Mass Spectrometry" to determine the decontamination rate of the dilution solution for uranium. The results are shown in Fig.18 .

[0204] Removal rate = initial content - (initial content - removal content) / initial content × 100%

[0205] from Fig.18 It can be seen that when the mass ratio of chitosan and crown ether is in the range of 1:1 to 3, the prepared detergent has a radionuclide removal rate of not less than 99%, and has a good decontamination effect in the pH range of 5 to 9. However, when the mass ratio of chitosan and crown ether is too high or too low, it has an adverse effect on the radionuclide removal ability of the detergent.

[0206] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

[0207] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.

[0208] 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 DTPA derivative, characterized in that Its structural formula is shown below:

2. A method for synthesizing the DTPA derivative according to claim 1, characterized in that: The following steps are involved: Diethylenetriaminepentaacetic acid and ethanolamine are put into an enamel reaction kettle with a distillation device, 18-crown ether-6 catalyst is added, and the reaction is stirred at a constant temperature under vacuum protection, and condensed and refluxed for dehydration, so that the reaction is completed to obtain the DTPA derivative.

3. The method for synthesizing a DTPA derivative according to claim 2, characterized in that: The molar ratio of diethylenetriaminepentaacetic acid to ethanolamine is 1:5; the added amount of 18-crown ether-6 is 0.1% to 1.0% of the total mass of diethylenetriaminepentaacetic acid and ethanolamine.

4. The method for synthesizing a DTPA derivative according to claim 2, characterized in that: The reaction temperature of the constant temperature stirring reaction is 95-130° C., and the reaction time is 4-6 hours.

5. A method for synthesizing the DTPA derivative according to claim 1, characterized in that: The following steps are involved: Diethylenetriaminepentaacetic acid, dichloromethane and thionyl chloride are mixed and reacted at 38-42°C, then the solvent is removed, and the residue is added for redissolution to obtain solution A; then ethanolamine and triethylamine are dissolved in the solvent, the temperature is controlled at 0-5°C, solution A at 0-5°C is added, and then the temperature is raised to 25±5°C for reaction to obtain the DTPA derivative.

6. The method for synthesizing a DTPA derivative according to claim 5, characterized in that: The molar ratio of diethylenetriaminepentaacetic acid, ethanolamine and triethylamine is 1:5:5, the solvent is dichloromethane, the mass volume ratio of diethylenetriaminepentaacetic acid to the solvent is 1kg:4L; the usage ratio of diethylenetriaminepentaacetic acid, dichloromethane and thionyl chloride is 1kg:6L:1kg.

7. A low-foaming nuclear contamination detergent containing the DTPA derivative as claimed in claim 1, characterized in that: In terms of mass percentage, the components include: 10% to 25% DTPA derivatives, 8% to 12% nonionic surfactants, 2% to 4% bio-based surfactants, 0.8% to 2% coordination adsorbents, and 57% to 79.2% water; The pH value of the low-foaming nuclear pollution detergent containing the DTPA derivative is 5-9.

8. The low-foaming nuclear contamination detergent containing a DTPA derivative according to claim 7, characterized in that: The nonionic surfactant is a mixture of N,N-dimethyl-decenamide and branched fatty alcohol polyoxyethylene ether with a carbon chain length of 11 or 13; the bio-based surfactant is one or more of trehalose lipids, rhamnolipids, sophorolipids and tea saponin.

9. The low-foaming nuclear contamination detergent containing a DTPA derivative according to claim 7, characterized in that: The coordination adsorbent is a mixture of chitosan and crown ether, wherein the crown ether is one of 18-crown-6, 15-crown-5, 12-crown-4, benzo-12-crown-4, phenylpropyl-15-crown-5 or 4'-aminobenzo-18-crown-6.

10. A method for preparing a low-foaming nuclear contamination detergent containing a DTPA derivative according to claims 7 to 9, characterized in that: The method comprises the following steps: mixing DTPA derivatives, nonionic surfactants, bio-based surfactants, coordination adsorbents and water, and adjusting the pH value to 5-9 by using citric acid or diethylenetriamine to obtain the low-foaming nuclear pollution detergent containing the DTPA derivatives.

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