A metal organic framework rectification filler, a preparation method thereof and application thereof in treating deuterium-containing wastewater and tritium-containing wastewater

Abstract

The application provides a metal organic framework rectification filler, a preparation method and application thereof in treatment of deuterium-containing wastewater and tritium-containing wastewater, and belongs to the field of chemical industry. The application is based on metal organic framework materials (MOFs), excellent MOF materials are synthesized by selection of metal centers and organic ligands, and the MOF materials are applied to the treatment process of deuterium-containing wastewater and tritium-containing wastewater in a granulation mode; meanwhile, due to the unique crystal properties of the MOF materials, the MOF materials are endowed with unique separation properties, and the theoretical plate number can be effectively improved. The application introduces the metal organic framework materials into the field of tritium-containing wastewater rectification, thereby expanding the material types in the field, and providing a brand-new vision and method for research and development of a new tritium-containing wastewater filler.

Description

Technical Field

[0001] This invention belongs to the field of chemical engineering, and particularly relates to a metal-organic framework distillation packing material and its preparation method, as well as its application in the treatment of deuterium-containing wastewater and tritium-containing wastewater. Background Technology

[0002] Nuclear energy, as a clean energy source in the 21st century, has played a significant role alongside human technological advancements. The rapid development of nuclear power, in particular, has enabled people to access clean and inexpensive electricity. However, with the increasing importance of nuclear power in human life, especially in coastal areas, the vigorous development of nuclear power has generated a large amount of radioactive waste during operation. The discharge of tritium-containing wastewater has attracted widespread attention. The traditional treatment method is to dilute and discharge it into the ocean. Tritium, as an isotope of hydrogen, readily enters the human body through respiration, ingestion, and skin. Its biological half-life is approximately 8 to 10 days, but its long half-life (12.26 years) poses a certain degree of internal radiation hazard. Furthermore, the human body's absorption capacity for tritium-containing water (HTO) is four orders of magnitude greater than that for tritium-containing gas (HT), resulting in a more pronounced biological effect. Therefore, tritized water poses a more serious threat to human health. Studies have shown that tritium-containing water is 520 times more toxic than the radionuclide tritium and can affect biological genetic material. Long-term, low-activity ingestion of tritium-containing water can induce carcinogenic, teratogenic, and mutagenic biological effects, and may even lead to leukemia and other malignant tumors. Therefore, the treatment of tritium-containing wastewater urgently needs to be addressed.

[0003] Currently, the main methods for treating tritium-containing wastewater include electrolysis, catalytic exchange, cryogenic distillation, and water distillation. Water electrolysis technology is relatively mature, and its advantages lie in its high separation coefficient and relatively low overall cost for concentrating high-activity tritized water, making it one of the most effective methods for tritium isotope separation. However, for low-activity tritized water, it preferentially electrolyzes H2O, resulting in lower efficiency and higher energy consumption. Furthermore, the β-decay of tritium can cause radiation damage to materials, and the system generates oxygen and hydrogen, posing an explosion risk. Cryogenic distillation is an effective method for large-scale separation of hydrogen isotopes and one of the main industrial methods for hydrogen isotope separation. Its advantages lie in its large throughput and high separation factor. However, it also faces several limitations in its application to the separation of low-activity tritium in water: To keep hydrogen and other isotopes in a liquid state, cryogenic equipment is needed to lower the temperature below their boiling point. Therefore, the entire system must be composed of distillation, refrigeration, and vacuum equipment, and relatively uniform cooling must be achieved. This results in technical complexity, large system size, and high cost. Simultaneously, it is necessary to reduce the significant tritium retention in the separation column. Furthermore, since the system contains flammable and explosive gas H2 (its explosion limit in air is 4%), the system's sealing and safety are also significant challenges for cryogenic distillation technology. Water distillation has a relatively small separation factor, thus requiring a high number of theoretical plates to achieve the desired separation effect. This necessitates a large separation equipment size and high energy consumption. Therefore, improving the separation efficiency of water distillation hinges on the packing material within the separation column. In summary, compared with several common methods for removing tritium-containing wastewater, water distillation is the most economical way to treat large-volume tritium-containing wastewater, and the most crucial aspect lies in the performance of the packing material used for distillation. Water distillation packing materials play a vital role in the treatment of tritium-containing wastewater during the rapid development of nuclear energy. Nuclear power plants generate large amounts of tritium-containing wastewater during operation. Due to its low activity and high flow rate, the treatment of this wastewater is energy-intensive and time-consuming, making water distillation a suitable treatment method.

[0004] In the field of water distillation, almost no new material systems have emerged in the past few decades. This is detrimental to the development of the field. Traditional water distillation materials, to avoid flooding during distillation, primarily use hydrophobic packings. This results in a small gas-liquid contact area when the hydrophobic packings encounter tritium-containing wastewater, and the low water retention rate of the hydrophobic packings also affects the overall distillation efficiency, leading to resource waste.

[0005] Existing water distillation packing materials mainly consist of copper mesh and stainless steel systems, with common specifications such as 2×2 (cm), 4×4 (cm), and 6×6 (cm). The 6×6 (cm) copper mesh packing material has a theoretical plate number of 10 (N / m) under test conditions. [Theoretical plate number (N): The number of plates required for sufficient contact time between the gas and liquid phases to reach phase equilibrium, and for the relationships between the components on the plates to conform to the equilibrium curve. A higher theoretical plate number is better.] In the field of water distillation, packing materials used for water distillation have a relatively low theoretical plate number in the treatment of tritium-containing wastewater, which is detrimental to the rapid development of nuclear power.

[0006] Traditional water distillation packing materials, such as 6×6 (cm) stainless steel packing, have a low number of separation plates in the treatment of tritium-containing wastewater. In practical applications, their smaller theoretical number of plates results in higher energy consumption and poor economic efficiency when separating the same amount of tritium-containing wastewater.

[0007] Therefore, based on the international research background and my country's urgent need to treat tritium-containing wastewater, we seek efficient distillation packing materials for removing tritium-containing wastewater to meet the urgent need for its removal during the rapid development of nuclear power.

[0008] Metal-organic frameworks (MOFs), as an emerging type of porous material, consist of multiple metal centers and various organic ligands, possessing tunable structures and finding wide applications in gas adsorption, separation, catalysis, energy, and radiation detection. MOFs also show promise in distillation separation due to their high specific surface area, good stability, and structural variability; however, their application in the distillation of tritium-containing wastewater remains relatively limited.

[0009] Therefore, there is an urgent need to develop a new type of distillation packing material that can reduce energy consumption while improving separation capacity during the separation process. Thus, introducing MOF materials into water distillation packing systems is of great significance. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a metal-organic framework (MOF) distillation packing material and its preparation method, along with its application in treating deuterium- and tritium-containing wastewater. This invention primarily solves the problems of low separation efficiency and high energy consumption in the treatment of tritium-containing wastewater using traditional materials, while introducing a new water distillation packing material system, providing a new direction for the expansion of materials in the field of water distillation packing materials. This invention mainly addresses the research on using MOF as a novel water distillation packing material for the removal of tritium-containing wastewater, and provides a new packing material direction for the treatment of tritium-containing wastewater.

[0011] This invention is achieved through the following technical solution:

[0012] The first objective of this invention is to provide a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0013] (1) A soluble metal salt and a ligand are mixed in a solvent and heated to react, thereby obtaining a metal-organic framework material;

[0014] (2) The metal-organic framework material obtained in step (1) is mixed with the binder and granulated to obtain the distillation packing based on the metal-organic framework.

[0015] In one embodiment of the present invention, in step (1), the soluble metal salt is selected from one or more of lead nitrate, barium nitrate, bismuth nitrate, calcium nitrate, gadolinium nitrate, zinc nitrate, europium nitrate, chromium nitrate, zirconium nitrate and terbium nitrate.

[0016] In one embodiment of the present invention, in step (1), the ligand is a compound containing a carboxyl group on a benzene ring; the ligand is selected from one or more of 2-methyl terephthalic acid, 2,5-dimethyl terephthalic acid, 2,6-dimethyl terephthalic acid, 2-hydroxy terephthalic acid, terephthalic acid, 2,5-dihydroxy terephthalic acid, methyl terephthalic acid, and 4-methyl-2,6-naphthalenedicarboxylic acid.

[0017] In one embodiment of the present invention, in step (1), the solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, ethanol and water.

[0018] In one embodiment of the present invention, in step (1), the molar ratio of the soluble metal salt to the ligand is 1:10-10:1.

[0019] In one embodiment of the present invention, in step (1), the heating temperature is 180℃-220℃; the heating time is 1 day-5 days.

[0020] In one embodiment of the present invention, in step (2), the adhesive is selected from one or more of polyvinylpyrrolidone, sodium alginate, sodium carboxymethyl cellulose and carboxypropyl cellulose.

[0021] In one embodiment of the present invention, in step (2), the mass ratio of the metal-organic framework material to the adhesive is 1-10:10-1.

[0022] A second objective of this invention is to provide a metal-organic framework-based distillation material obtained by the aforementioned preparation method.

[0023] A third objective of this invention is to provide the application of the aforementioned metal-organic framework-based distillation material in the treatment of deuterium-containing wastewater and tritium-containing wastewater; wherein the mass concentration of deuterium water in the deuterium-containing wastewater is 0.1%-1.5%; and the activity of tritium water in the tritium-containing wastewater is 1×10⁻⁶. 7 Bq / L-8×10 8 Bq / L.

[0024] This method primarily involves dissolving metal salts and organic ligands in a specific ratio (molar ratio of ligands: 1:10-10:1) in a 20 mL high-pressure reactor filled with deionized water. After ultrasonic vibration (33 kHz-40 kHz) for 5 minutes, the solution is removed to obtain a suspension with an initial pH of 2.60. This suspension is then placed in an oven at 180℃-220℃ and allowed to react for 1-5 days to obtain a metal-organic framework (MOF). The obtained MOF is then granulated with a binder at a specific mass ratio (MOF: binder = 1-10:10-1), with an appropriate amount of water added for mixing and molding. The resulting mixture is granulated, frozen in liquid nitrogen, and finally freeze-dried in a refrigeration unit for 24 hours to obtain a distillation packing material based on a metal-organic framework.

[0025] The main innovations of this invention are: 1. Expanding the scope of water distillation packing systems by introducing metal-organic frameworks (MOFs) into the field of water distillation, which will inevitably broaden the application scenarios and scope of water distillation packings. Simultaneously, the structural designability of MOFs provides a wider range of choices for water distillation packings. 2. As a type of organic-inorganic hybrid material, the ordered crystal structure of MOFs provides a more intuitive representation for the visualization of mechanistic explanations. Furthermore, compared to traditional mechanistic explanation methods, using MOFs as water distillation packings allows for explanations of mechanisms at the molecular level and even more in-depth levels. This provides a simple and clear design approach and method for designing water distillation materials for subsequent practical applications.

[0026] The technical solution of the present invention has the following advantages:

[0027] (1) This invention is based on metal-organic frameworks (MOFs). By selecting the metal center and organic ligands, MOF materials with excellent performance were synthesized and applied to the treatment of tritium-containing wastewater through granulation. Simultaneously, due to the unique crystal properties of MOFs, they possess unique separation properties, effectively increasing the theoretical step number. This invention expands the types of materials in the field of tritium-containing wastewater distillation by introducing metal-organic frameworks, providing a new perspective and method for the development of novel packing materials for tritium-containing wastewater.

[0028] (2) Compared with the high specific surface area, high designability, and selectivity of MOF, traditional distillation packings lack reasonable design methods, which is detrimental to the development of the water distillation field. This invention, through the tunability of the metal center and organic ligands, identifies a packing material with high separation performance in the treatment of tritium-containing wastewater. At the same time, its high designability opens up new avenues for the development of the water distillation field.

[0029] (3) In this invention, the separation effect of hydrophilic distillation packing is better for tritium-containing wastewater. Hydrophilic distillation packing can significantly increase the gas-liquid exchange process during distillation and increase the gas-liquid contact area, thereby greatly improving the distillation effect. During the distillation process, it is only necessary to control the gas-liquid transfer rate, the hydrophilicity of the hydrophilic packing, and the distillation temperature and pressure, etc., and the flooding problem can be avoided with a high probability. Attached Figure Description

[0030] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0031] Figure 1 This is a diagram showing the separation of deuterium-containing wastewater and tritium-containing wastewater using a metal-organic framework-based distillation packing and a conventional packing in the test examples of this invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0033] Example 1

[0034] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0035] 0.1 mmol of bismuth nitrate and 0.1 mmol of terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, yielding a suspension with an initial pH of 2.60. The suspension was then placed in an oven at 200 °C and allowed to stand for 3 days to obtain a metal-organic framework (MOF) material. Subsequently, the MOF was granulated with a binder (sodium alginate) at a specific mass ratio (MOF: binder = 2:1), with 15 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried for 24 h to obtain a metal-organic framework-based distillation packing.

[0036] Example 2

[0037] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0038] 0.15 mmol of barium nitrate and 0.1 mmol of terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain a suspension. The suspension was then placed in an oven at 210 °C and allowed to stand for 5 days to synthesize a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (sodium alginate and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 2:1.5), with 15 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried in a refrigeration unit for 24 h to obtain a metal-organic framework-based distillation packing.

[0039] Example 3

[0040] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0041] 0.2 mmol lead nitrate and 0.1 mmol terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL N,N-dimethylformamide. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 180 °C and allowed to stand for 2 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (povidone and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 3:1), with 20 mL of water added for mixing and molding. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried for 24 h to obtain a metal-organic framework-based distillation packing.

[0042] Example 4

[0043] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0044] 0.1 mmol of calcium nitrate and 0.1 mmol of terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to react for 4 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (povidone) at a specific mass ratio (MOF: binder = 3:1), with 20 mL of water added for mixing and plasticity. The resulting mixture was then granulated, frozen in liquid nitrogen, and finally freeze-dried in a refrigeration unit for 24 h to obtain a metal-organic framework-based distillation packing.

[0045] Example 5

[0046] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0047] 0.1 mmol of zinc nitrate and 0.1 mmol of terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of ethanol. The mixture was ultrasonically vibrated (33-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 210 °C and allowed to react for 4 days to obtain a metal-organic framework (MOF). Subsequently, the MOF was granulated with a binder (sodium carboxymethyl cellulose) at a specific mass ratio (MOF: binder = 2:1), with 10 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried in a refrigeration unit for 24 h to obtain a metal-organic framework-based distillation packing.

[0048] Example 6

[0049] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0050] 0.2 mmol europium nitrate and 0.1 mmol terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL N,N-dimethylformamide. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to stand for 3 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 1.5:1), with 15 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried for 24 h to obtain a metal-organic framework-based distillation packing.

[0051] Example 7

[0052] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0053] 0.15 mmol of terbium nitrate and 0.15 mmol of terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of LDM (N,N-dimethylterephthalic acid). The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 210 °C and allowed to react for 1-3 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (sodium alginate and sodium carboxymethyl cellulose) at a specific mass ratio (MOF: binder = 1.5:1), with 10 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried for 24 h to obtain a metal-organic framework-based distillation packing.

[0054] Example 8

[0055] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0056] 0.1 mmol zirconium nitrate and 0.1 mmol terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to react for 2 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (povidone, sodium carboxymethyl cellulose, and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 3:1). 20 mL of water was added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried for 24 h to obtain a metal-organic framework-based distillation packing.

[0057] Example 9

[0058] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0059] 0.1 mmol of terbium nitrate and 0.1 mmol of 2-hydroxyterephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to stand for 1 day to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (sodium alginate and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 3:1), with 20 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried in a cryogenic apparatus for 24 h to obtain a metal-organic framework-based distillation packing.

[0060] Example 10

[0061] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0062] 0.1 mmol zinc nitrate and 0.1 mmol 2,5-dihydroxyterephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to stand for 2 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (povidone and sodium carboxymethyl cellulose) at a specific mass ratio (MOF: binder = 3:1), with 20 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried in a refrigeration unit for 24 h to obtain a metal-organic framework-based distillation packing.

[0063] Example 11

[0064] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0065] 0.1 mmol of zirconium nitrate and 0.1 mmol of 2,5-dimethylterephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to stand for 5 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (sodium carboxymethyl cellulose and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 3:1), with 20 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried in a refrigeration unit for 24 h to obtain a metal-organic framework-based distillation packing.

[0066] Example 12

[0067] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0068] 0.1 mmol of calcium nitrate and 0.1 mmol of tetramethyl-p-toluenedicarboxylic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to react for 2.5 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (sodium carboxymethyl cellulose) at a specific mass ratio (MOF: binder = 3:1), with 20 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried in a refrigeration unit for 24 h to obtain a metal-organic framework-based distillation packing.

[0069] Example 13

[0070] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0071] 0.1 mmol of gadolinium nitrate and 0.1 mmol of 2,6-dimethylterephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min to obtain an initial suspension. This suspension was then placed in an oven at 200 °C and allowed to react for 4.5 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (povidone, sodium alginate, sodium carboxymethyl cellulose, and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 3:1). 20 mL of water was added for mixing and shaping. The resulting mixture was then granulated, frozen in liquid nitrogen, and finally freeze-dried in a refrigeration unit for 24 h to obtain a metal-organic framework-based distillation packing.

[0072] Example 14

[0073] This embodiment provides a method for preparing packing material for distillation of tritium-containing wastewater, comprising the following steps:

[0074] 0.1 mmol of rubidium nitrate and 0.1 mmol of 2,6-naphthalenedicarboxylic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water and ethanol. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to react for 3 days to obtain a metal-organic framework (MOF) material. Subsequently, the synthesized MOF was granulated with a binder at a specific mass ratio (MOF: binder = 3:1), with 20 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried in a cryogenic apparatus for 24 h to obtain a metal-organic framework-based distillation packing.

[0075] Example 15

[0076] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0077] 0.1 mmol of rubidium nitrate and 0.1 mmol of 2,6-dihydroxyterephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water and N,N-dimethylacetamide. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min to obtain an initial suspension. This suspension was then placed in an oven at 210 °C and allowed to react for 3.5 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (sodium carboxymethyl cellulose and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 1.5:1), with 20 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried for 24 h to obtain a metal-organic framework-based distillation packing.

[0078] Example 16

[0079] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0080] 0.15 mmol of calcium nitrate and 0.1 mmol of 2,6-naphthalenedicarboxylic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to stand for 5 days to obtain a metal-organic framework (MOF) material. The synthesized MOF was then granulated with a binder (sodium carboxymethyl cellulose) at a specific mass ratio (MOF: binder = 3:1), with 20 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried in a cryogenic apparatus for 24 h to obtain a metal-organic framework-based distillation packing.

[0081] Example 17

[0082] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0083] 0.1 mmol of barium nitrate and 0.1 mmol of terephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of deionized water and N,N-dimethylacetamide. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to react for 4 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (sodium carboxymethyl cellulose and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 2:1). 20 mL of water was added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried for 24 h to obtain a metal-organic framework-based distillation packing.

[0084] Example 18

[0085] This embodiment provides a method for preparing a distillation packing material based on a metal-organic framework, comprising the following steps:

[0086] 0.1 mmol of calcium nitrate and 0.1 mmol of 2,6-dihydroxyterephthalic acid were mixed in a 20 mL reactor, followed by the addition of 10 mL of N,N-dimethylacetamide. The mixture was ultrasonically vibrated (33 kHz-40 kHz) for 5 min, and then removed to obtain an initial suspension. This suspension was then placed in an oven at 220 °C and allowed to react for 5 days to obtain a metal-organic framework (MOF). The synthesized MOF was then granulated with a binder (sodium alginate and carboxypropyl cellulose) at a specific mass ratio (MOF: binder = 1:1), with 20 mL of water added for mixing and shaping. The resulting mixture was granulated, frozen in liquid nitrogen, and finally freeze-dried for 24 h to obtain a metal-organic framework-based distillation packing.

[0087] Comparative Example

[0088] Traditional packing: The 6x6 traditional packing is copper mesh packing, purchased from Guanghan Xinrui Distillation Chemical Equipment Co., Ltd.

[0089] Test Example 1

[0090] The metal-organic framework-based distillation packing material prepared in Example 1 and the packing material in the comparative example were respectively packed into packed columns, and tested for low mass concentration (0.5%) deuterium water (D2O) and a concentration of 4 x 10⁻⁶ D₂O. 8 An experiment was conducted using Bq / L of tritium water (T₂O). The results are as follows: Figure 1As shown.

[0091] Test Example 2

[0092] The metal-organic framework-based distillation packing material prepared in Example 1 and the packing material in the comparative example were respectively packed into packed columns, and tested for low concentration (0.1%) deuterium water (D2O) and an activity of 5 x 10⁻⁶. 8 Experiments were conducted using Bq / L of tritium water (T2O).

[0093] Test Example 3

[0094] The metal-organic framework-based distillation packing material prepared in Example 1 and the packing material in the comparative example were respectively packed into packed columns, and tested for low mass concentration (0.2%) deuterium water (D2O) and a concentration of 6 x 10⁻⁶. 8 Experiments were conducted using Bq / L of tritium water (T2O).

[0095] Test Example 4

[0096] The metal-organic framework-based distillation packing material prepared in Example 1 and the packing material in the comparative example were respectively packed into packed columns, and tested for low mass concentration (0.3%) deuterium water (D2O) and a concentration of 8 x 10⁻⁶ D₂O. 8 Experiments were conducted using Bq / L of tritium water (T2O).

[0097] Test Example 5

[0098] The metal-organic framework-based distillation packing material prepared in Example 1 and the packing material in the comparative example were respectively packed into packed columns, and tested for low mass concentration (1%) deuterium water (D2O) and an activity of 5 x 10⁻⁶. 7 Experiments were conducted using Bq / L of tritium water (T2O).

[0099] Test Example 6

[0100] The metal-organic framework-based distillation packing material prepared in Example 1 and the packing material in the comparative example were respectively packed into packed columns, and tested for low mass concentration (1.2%) deuterium water (D2O) and a concentration of 6 x 10⁻⁶. 7 Experiments were conducted using Bq / L of tritium water (T2O).

[0101] Test Example 7

[0102] The metal-organic framework-based distillation packing material prepared in Example 1 and the packing material in the comparative example were respectively packed into packed columns, and tested for low mass concentration (1.5%) deuterium water (D2O) and a concentration of 8 x 10⁻⁶ D₂O. 7 Experiments were conducted using Bq / L of tritium water (T2O).

[0103] Test Example 8

[0104] The metal-organic framework-based distillation packing material prepared in Example 1 and the packing material in the comparative example were respectively packed into packed columns, and tested for low mass concentration (1.6%) deuterium water (D2O) and a concentration of 1x10⁻⁶ D₂O. 7 Experiments were conducted using Bq / L of tritium water (T2O).

[0105] Test examples show that, compared with traditional copper mesh packing, the metal-organic framework-based distillation packing (SA@MOF granulation packing) prepared in Example 1 improves the separation performance of deuterium by about 1.5-1.8 times; the improvement in the separation performance of tritium is even more significant. The results indicate that the metal-organic framework-based distillation packing prepared in this invention has good advantages.

[0106] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An application of a metal-organic framework-based water distillation packing material in the treatment of deuterium-containing or tritium-containing wastewater, characterized in that, The preparation method of the water distillation packing material based on the metal-organic framework includes the following steps: (1) A soluble metal salt and a ligand are mixed in a solvent and heated to react, thereby obtaining a metal-organic framework material; (2) The metal-organic framework material obtained in step (1) is mixed with a binder and granulated to obtain the water distillation packing based on the metal-organic framework; In step (1), the ligand is a compound containing a carboxyl group on a benzene ring; In step (1), the ligand is selected from one or more of 2-methyl terephthalic acid, 2,5-dimethyl terephthalic acid, 2,6-dimethyl terephthalic acid, 2-hydroxy terephthalic acid, terephthalic acid, 2,5-dihydroxy terephthalic acid methyl terephthalic acid and 4-methyl-2,6-naphthalenedicarboxylic acid; In step (1), the temperature of the heating reaction is 180℃-220℃; the heating reaction time is 1 day-5 days. In step (2), the adhesive is selected from one or more of polyvinylpyrrolidone, sodium alginate, sodium carboxymethyl cellulose, and carboxypropyl cellulose; In step (1), the soluble metal salt is selected from one or more of lead nitrate, barium nitrate, bismuth nitrate, calcium nitrate, gadolinium nitrate, zinc nitrate, europium nitrate, chromium nitrate, zirconium nitrate, and terbium nitrate; In step (1), the solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, ethanol and water.

2. The application according to claim 1, characterized in that, In step (1), the molar ratio of the soluble metal salt to the ligand is 1:10-10:

1.

3. The application according to claim 1, characterized in that, In step (2), the mass ratio of the metal-organic framework material to the adhesive is 1-10:10-1.

4. The application according to claim 1, characterized in that, The mass concentration of deuterium water in the deuterium-containing wastewater is 0.1%-1.5%; the activity of tritium water in the tritium-containing wastewater is 1×10⁻⁶. 7 Bq / L-8×10 8 Bq / L.

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