Preparation and application of a full-silica zeolite confined imidazole adsorbent

Abstract

The application discloses a preparation method of a full-silicon zeolite limited imidazole adsorbent, and comprises the following steps: mixing tetraethyl orthosilicate, tetrapropylammonium hydroxide, ammonium fluoride and water and stirring to perform a pre-crystallization reaction, then transferring the mixture into a stainless steel autoclave lined with Teflon to perform a crystallization reaction, filtering a solid product obtained after naturally cooling to room temperature, and performing water washing, drying and calcination to obtain full-silicon zeolite; heating and degassing the full-silicon zeolite, then loading the full-silicon zeolite into a container, placing the container in a container with imidazole at the bottom and sealing and heating to obtain the full-silicon zeolite limited imidazole adsorbent. The imidazole is limited in the full-silicon zeolite through a simple gas phase adsorption method, that is, the inherent structure and good stability of the zeolite are maintained, and the thermal stability of the imidazole is improved, and the prepared full-silicon zeolite limited imidazole adsorbent is applied to capture gaseous iodine and methyl iodine, and has high iodine capture capacity and recyclability.

Description

Technical Field

[0001] This invention belongs to the field of preparation technology of adsorbent materials for treating radioactive elements. More specifically, this invention relates to the preparation and application of an all-silica zeolite confined imidazole adsorbent. Background Technology

[0002] Volatile and radioactive iodine isotopes released during nuclear fuel reprocessing and nuclear leak accidents ( 129 I and 131 I) It usually exists in the form of elemental iodine and organic iodine (such as methyl iodine). These compounds can cause great harm to the ecological environment, for example... 129 I has a half-life of approximately 1.57 × 10⁻⁶. 7 In addition, it can severely affect human metabolism by damaging the thyroid gland. Therefore, effectively capturing volatile radioactive iodine is very important.

[0003] Currently, various methods exist for removing radioactive iodine pollutants from waste gas, broadly categorized into two types: wet scrubbing and solid-state adsorption. Compared to wet scrubbing using highly corrosive solutions, solid-state adsorption based on porous materials as adsorbents is more environmentally friendly, easier to operate, and has lower maintenance costs. To date, various porous materials have been widely used for capturing radioactive iodine, such as activated carbon, zeolites, aerogels, covalent organic frameworks (COFs), and metal-organic frameworks (MOFs). These materials possess structural and performance advantages due to their high specific surface area, uniformly dispersed active sites, and modifiability, significantly improving the mass transfer efficiency of gaseous molecules and enabling rapid adsorption of gaseous radioactive iodine. Among various adsorbents, inorganic microporous zeolites exhibit considerable iodine capture potential due to their high stability and ease of large-scale preparation. However, most zeolites have low adsorption capacity for intrinsic iodine and weak interactions with I2 and CH3I molecules, limiting their iodine capture capacity. Summary of the Invention

[0004] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0005] To achieve these objectives and other advantages of the present invention, a method for preparing an all-silica zeolite confined imidazole adsorbent is provided, comprising the following steps:

[0006] Step 1: Mix tetraethyl orthosilicate, tetrapropylammonium hydroxide, ammonium fluoride and water, heat and stir to carry out pre-crystallization reaction, then transfer to a stainless steel autoclave lined with Teflon to carry out crystallization reaction. After naturally cooling to room temperature, filter to obtain solid product, wash with water, dry and calcine to obtain all-silica zeolite.

[0007] Step 2: Heat the all-silica zeolite to degas it and remove guest molecules. Then, put it into a container and place it in a container with imidazole at the bottom. Seal and heat to obtain the all-silica zeolite confined imidazole adsorbent.

[0008] Preferably, in step one, the molar ratio of tetraethyl orthosilicate, tetrapropylammonium hydroxide, ammonium fluoride and water is 1:0.1-0.2:0.8-1.2:80-120.

[0009] Preferably, in step one, the temperature of the pre-crystallization reaction is 80–100°C, and the time is 24–48 h.

[0010] Preferably, in step one, the temperature of the crystallization reaction is 110–130°C and the time is 72–96 h.

[0011] Preferably, in step one, the drying temperature is 60–80°C and the drying time is 20–28 hours.

[0012] Preferably, in step one, the calcination temperature is 500–600°C and the calcination time is 4–6 hours.

[0013] Preferably, in step two, the heating and degassing temperature is 100–140°C, and the time is 10–14 hours.

[0014] Preferably, in step two, the mass ratio of all-silica zeolite to imidazole is 1:1.5 to 2.5.

[0015] Preferably, in step two, the temperature of the sealing heating is 110–130°C, and the time is 48–96 hours.

[0016] Preferably, the method further includes: mixing and stirring the all-silica zeolite obtained in step one with manganese chloride solution and zinc chloride solution, then ultrasonically treating it for 10-30 minutes to obtain a homogeneous mixed solution, heating it to 60-80°C for 1-3 hours, drying it at 100-120°C for 8-12 hours, and then calcining it at 500-600°C for 4-6 hours to obtain manganese and zinc modified all-silica zeolite; and placing the manganese and zinc modified all-silica zeolite into a low-temperature plasma treatment instrument for 1-3 minutes to obtain modified all-silica zeolite.

[0017] Preferably, the gas used in the low-temperature plasma processor is oxygen or hydrogen, with a frequency of 30–50 kHz, a power of 300–500 W, and a gas flow rate of 10–20 L / min; the concentrations of the manganese chloride solution and zinc chloride solution are 0.5–2 mol / L, and the mass-to-volume ratio of the all-silica zeolite, manganese chloride solution, and zinc chloride solution is 1 g: 10–30 mL: 10–30 mL; the ultrasonic power is 100–200 W, and the ultrasonic frequency is 20–30 kHz.

[0018] The application of a fully silicate zeolite-confined imidazole adsorbent prepared by the method described above in the capture of radioactive iodine is characterized by the following steps: a container containing the fully silicate zeolite-confined imidazole adsorbent is placed in a container containing iodine or methyl iodine and sealed. The container is then heated to 70–80°C. After capture is completed, the fully silicate zeolite-confined imidazole adsorbent containing iodine is removed, heated to 180–220°C, and kept at this temperature for 20–28 hours to desorb the imidazole and the captured gaseous iodine or methyl iodine. The adsorbent is then placed in a container with imidazole at the bottom and sealed and heated again to obtain the fully silicate zeolite-confined imidazole adsorbent, which is then recycled.

[0019] This invention offers at least the following beneficial effects: By confining imidazole within all-silica zeolite using a simple gas-phase adsorption method, the invention enhances the capture capacity for gaseous iodine and methyl iodine. This not only maintains the inherent structure and good stability of the zeolite but also, compared to an open system, effectively suppresses the volatilization of imidazole molecules through confinement, significantly improving its thermal stability within the temperature range of 75–130°C. This invention selects imidazole functional groups with high affinity for gaseous iodine and methyl iodine and introduces them into microporous zeolite. Utilizing the sieving effect of the pores and the synergistic effect of imidazole molecule coordination, efficient simultaneous capture of gaseous iodine and methyl iodine is achieved. The prepared all-silica zeolite confined imidazole adsorbent achieves adsorption capacities of 2.394 g / g for gaseous iodine and 0.639 g / g for methyl iodine, respectively. Furthermore, the high-temperature heating process for adsorption-desorption of imidazole molecules and captured gaseous iodine or methyl iodine gives the all-silica zeolite confined imidazole adsorbent good recyclability. The preparation method provided by this invention is simple, low-cost, and applicable to other porous material systems.

[0020] This invention utilizes manganese and zinc to modify all-silica zeolite, uniformly coating the surface with manganese oxide and zinc oxide, increasing the specific surface area of ​​the zeolite. Simultaneously, the abundant hydroxyl active groups on the manganese oxide surface enhance the adsorption capacity of the zeolite, thereby improving the adsorption capacity of the confined imidazole adsorbent for gaseous iodine and methyl iodine. Furthermore, this invention employs a low-temperature plasma treatment device to modify the surface of the zeolite, increasing the active sites on the zeolite surface and enhancing its imidazole loading capacity, further improving the adsorption capacity of the confined imidazole adsorbent for gaseous iodine and methyl iodine.

[0021] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0022] Figure 1 The XRD patterns of the all-silica zeolite confined imidazole adsorbent prepared in Example 2 and the all-silica zeolite prepared in Comparative Example 1 are shown.

[0023] Figure 2 Thermogravimetric curves of the all-silica zeolite confined imidazole adsorbent prepared in Example 2 and the all-silica zeolite prepared in Comparative Example 1 are compared.

[0024] Figure 3 The graph shows the comparison of the imidazole retention rates of the all-silica zeolite confined imidazole adsorbent and imidazole at different temperatures (75℃, 100℃, 130℃) after 24 to 72 hours.

[0025] Figure 4 A comparison chart showing the adsorption capacity of gaseous iodine and methyl iodine by the all-silica zeolite confined imidazole adsorbents prepared in Examples 1-3 and the all-silica zeolite prepared in Comparative Example 1.

[0026] Figure 5 A comparison of the adsorption capacity of gaseous iodine and methyl iodine by the all-silica zeolite confined imidazole adsorbents prepared in Examples 2, 4 and 5;

[0027] Figure 6 The graph shows the adsorption efficiency of the all-silica zeolite confined imidazole adsorbent prepared in Example 2 for gaseous iodine and methyl iodine in three cycles. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0029] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0030] Example 1

[0031] A method for preparing an all-silica zeolite confined imidazole adsorbent includes the following steps:

[0032] Step 1: Tetrapropylammonium hydroxide, ammonium fluoride and water are mixed in a molar ratio of 1:0.15:1:100 and stirred at 90°C for 24 hours. Then the mixture is transferred to a stainless steel autoclave lined with Teflon and crystallized at 120°C for 96 hours. After naturally cooling to room temperature, the solid product is filtered, washed with water, dried at 70°C for 24 hours, and calcined at 550°C for 5 hours to obtain all-silica zeolite.

[0033] Step 2: Degas the all-silica zeolite at 120℃ for 12 hours to remove guest molecules, then put it into a glass bottle, place it in a wide-mouth bottle with imidazole at the bottom and seal it, wherein the mass ratio of all-silica zeolite to imidazole is 1:2, and heat it in an oven at 120℃ for 48 hours to obtain the all-silica zeolite confined imidazole adsorbent.

[0034] Example 2

[0035] A method for preparing an all-silica zeolite confined imidazole adsorbent includes the following steps:

[0036] Step 1: Tetrapropylammonium hydroxide, ammonium fluoride and water are mixed in a molar ratio of 1:0.15:1:100 and stirred at 90°C for 24 hours. Then the mixture is transferred to a stainless steel autoclave lined with Teflon and crystallized at 120°C for 96 hours. After naturally cooling to room temperature, the solid product is filtered, washed with water, dried at 70°C for 24 hours, and calcined at 550°C for 5 hours to obtain all-silica zeolite.

[0037] Step 2: Degas the all-silica zeolite at 120℃ for 12 hours to remove guest molecules, then put it into a glass bottle, place it in a wide-mouth bottle with imidazole at the bottom and seal it, wherein the mass ratio of all-silica zeolite to imidazole is 1:2, and heat it in an oven at 120℃ for 72 hours to obtain the all-silica zeolite confined imidazole adsorbent.

[0038] Example 3

[0039] A method for preparing an all-silica zeolite confined imidazole adsorbent includes the following steps:

[0040] Step 1: Tetrapropylammonium hydroxide, ammonium fluoride and water are mixed in a molar ratio of 1:0.15:1:100 and stirred at 90°C for 24 hours. Then the mixture is transferred to a stainless steel autoclave lined with Teflon and crystallized at 120°C for 96 hours. After naturally cooling to room temperature, the solid product is filtered, washed with water, dried at 70°C for 24 hours, and calcined at 550°C for 5 hours to obtain all-silica zeolite.

[0041] Step 2: Degas the all-silica zeolite at 120℃ for 12 hours to remove guest molecules, then put it into a glass bottle, place it in a wide-mouth bottle with imidazole at the bottom and seal it, wherein the mass ratio of all-silica zeolite to imidazole is 1:2, and heat it in an oven at 120℃ for 96 hours to obtain the all-silica zeolite confined imidazole adsorbent.

[0042] Example 4

[0043] A method for preparing an all-silica zeolite confined imidazole adsorbent includes the following steps:

[0044] Step 1: Tetrapropylammonium hydroxide, ammonium fluoride and water are mixed in a molar ratio of 1:0.15:1:100 and stirred at 90°C for 24 hours. Then the mixture is transferred to a stainless steel autoclave lined with Teflon and crystallized at 120°C for 96 hours. After naturally cooling to room temperature, the solid product is filtered, washed with water, dried at 70°C for 24 hours, and calcined at 550°C for 5 hours to obtain all-silica zeolite.

[0045] Step 2: Mix the all-silica zeolite obtained in Step 1 with 1 mol / L manganese chloride solution and 1 mol / L zinc chloride solution, stir, and treat under ultrasonic treatment at 150 W and 25 kHz for 20 min to obtain a homogeneous mixed solution. Heat to 70 °C and react for 2 h, then dry at 110 °C for 10 h, and then calcine at 550 °C for 5 h to obtain modified all-silica zeolite; wherein the mass-volume ratio of all-silica zeolite, manganese chloride solution and zinc chloride solution is 1 g: 20 mL: 20 mL.

[0046] Step 3: The modified all-silica zeolite obtained in Step 2 is heated at 120℃ for 12 hours to remove guest molecules. Then it is placed in a glass bottle, placed in a wide-mouth bottle containing imidazole at the bottom and sealed. The mass ratio of modified all-silica zeolite to imidazole is 1:2. The mixture is heated in an oven at 120℃ for 72 hours to obtain the all-silica zeolite confined imidazole adsorbent.

[0047] In this embodiment, manganese and zinc are used to modify the all-silica zeolite. Manganese oxide and zinc oxide are uniformly coated on the surface of the all-silica zeolite, which increases the specific surface area of ​​the all-silica zeolite. At the same time, the surface of manganese oxide has abundant hydroxyl active groups, thereby enhancing the adsorption capacity of the all-silica zeolite and improving the adsorption capacity of the all-silica zeolite confined imidazole adsorbent for gaseous iodine and methyl iodine.

[0048] Example 5

[0049] A method for preparing an all-silica zeolite confined imidazole adsorbent includes the following steps:

[0050] Step 1: Tetrapropylammonium hydroxide, ammonium fluoride and water are mixed in a molar ratio of 1:0.15:1:100 and stirred at 90°C for 24 hours. Then the mixture is transferred to a stainless steel autoclave lined with Teflon and crystallized at 120°C for 96 hours. After naturally cooling to room temperature, the solid product is filtered, washed with water, dried at 70°C for 24 hours, and calcined at 550°C for 5 hours to obtain all-silica zeolite.

[0051] Step 2: The all-silica zeolite obtained in Step 1 is mixed and stirred with 1 mol / L manganese chloride solution and 1 mol / L zinc chloride solution. The mixture is then treated under ultrasonic treatment at a power of 150 W and a frequency of 25 kHz for 20 min to obtain a homogeneous mixed solution. The solution is heated to 70 °C and reacted for 2 h. After that, it is dried at 110 °C for 10 h and then calcined at 550 °C for 5 h. The resulting product is then placed in a low-temperature plasma treatment instrument for 2 min to obtain modified all-silica zeolite. The gas used in the low-temperature plasma treatment instrument is oxygen, with a frequency of 40 kHz, a power of 400 W, and a gas flow rate of 15 L / min. The mass-to-volume ratio of all-silica zeolite, manganese chloride solution, and zinc chloride solution is 1 g: 20 mL: 20 mL.

[0052] Step 3: The modified all-silica zeolite obtained in Step 2 is heated at 120℃ for 12 hours to remove guest molecules. Then it is placed in a glass bottle, placed in a wide-mouth bottle containing imidazole at the bottom and sealed. The mass ratio of modified all-silica zeolite to imidazole is 1:2. The mixture is heated in an oven at 120℃ for 72 hours to obtain the all-silica zeolite confined imidazole adsorbent.

[0053] In this embodiment, a low-temperature plasma treatment instrument is used to further modify the surface of manganese and zinc-modified all-silica zeolite, increasing the active sites on its surface, improving its loading capacity for imidazole, and further enhancing the adsorption capacity of the all-silica zeolite confined imidazole adsorbent for gaseous iodine and methyl iodine.

[0054] Comparative Example 1

[0055] A method for preparing all-silica zeolite includes: mixing tetraethyl orthosilicate, tetrapropylammonium hydroxide, ammonium fluoride and water in a molar ratio of 1:0.15:1:100, stirring and reacting at 90°C for 24 h, then transferring to a Teflon-lined stainless steel autoclave, crystallizing at 120°C for 96 h, naturally cooling to room temperature, filtering to obtain a solid product, washing with water, drying at 70°C for 24 h, and calcining at 550°C for 5 h to obtain all-silica zeolite.

[0056] Figure 1 The XRD patterns of the all-silica zeolite confined imidazole adsorbent prepared in Example 2 and the all-silica zeolite prepared in Comparative Example 1 show that no new characteristic peaks were observed in the all-silica zeolite confined imidazole adsorbent prepared in Example 2 compared with the all-silica zeolite prepared in Comparative Example 1, indicating that the all-silica zeolite confined imidazole adsorbent prepared in this invention still maintains the framework structure of all-silica zeolite.

[0057] Figure 2 The thermogravimetric curves of the all-silica zeolite confined imidazole adsorbent prepared in Example 2 and the all-silica zeolite prepared in Comparative Example 1 are compared. It can be seen that the all-silica zeolite confined imidazole adsorbent experienced mass loss in the range of 100-250℃. This is mainly attributed to the thermal decomposition of imidazole. Thus, the imidazole loading in the all-silica zeolite confined imidazole adsorbent prepared in Example 2 is calculated to be approximately 12 wt%.

[0058] Figure 3 The graph shows a comparison of the imidazole retention rates of the all-silica zeolite confined imidazole adsorbent and imidazole at different temperatures (75℃, 100℃, 130℃) after 24–72 hours. It can be seen that, compared with the open imidazole system, the imidazole retention rate of the all-silica zeolite confined imidazole adsorbent prepared in Example 2 is improved at different temperatures, indicating that the confinement effect of the all-silica zeolite effectively inhibits the volatilization of imidazole, thereby improving its thermal stability.

[0059] Iodine adsorption experiment: Weigh 50 mg of all-silica zeolite confined imidazole adsorbent or all-silica zeolite into a 5 mL glass vial and place it into a 250 mL glass vial containing 2 g of iodine or 3 mL of methyl iodine. Seal the vial and place it in a 75 °C forced-air drying oven. After 48 h, remove the adsorbent and weigh it. Determine the amount of iodine adsorbed (g / g) by the mass difference.

[0060] Figure 4 The graph shows a comparison of the adsorption capacities of gaseous iodine and methyl iodine by the all-silica zeolite confined to imidazole adsorbents prepared in Examples 1-3 and the all-silica zeolite prepared in Comparative Example 1. It can be seen that the adsorption capacities of gaseous iodine and methyl iodine by the all-silica zeolite confined to imidazole adsorbents prepared in Examples 1-3 are higher than those of all-silica zeolite. This indicates that imidazole confinement of all-silica zeolite significantly improves its adsorption capacity for iodine. Furthermore, as the reaction time (48-96 h) between all-silica zeolite and imidazole increases in Examples 1-3, its adsorption capacity for gaseous iodine and methyl iodine gradually increases. After 72 h, the increase is no longer significant, and the adsorption capacities for gaseous iodine and methyl iodine reach 2.394 g / g and 0.639 g / g, respectively.

[0061] Figure 5 The chart shows a comparison of the adsorption capacities of gaseous iodine and methyl iodine by the all-silica zeolite confined imidazole adsorbents prepared in Examples 2, 4, and 5. It can be seen that the all-silica zeolite confined imidazole adsorbent of Example 4 has a higher adsorption capacity for gaseous iodine and methyl iodine than that of Example 2, reaching 2.862 g / g and 0.927 g / g, respectively. This indicates that the modification of all-silica zeolite with manganese and zinc enhances the adsorption capacity of the all-silica zeolite confined imidazole adsorbent for gaseous iodine and methyl iodine. The all-silica zeolite confined imidazole adsorbent of Example 5 has the highest adsorption capacity for gaseous iodine and methyl iodine, reaching 3.171 g / g and 1.335 g / g, respectively. This indicates that the surface modification of the manganese and zinc-modified all-silica zeolite using a low-temperature plasma treatment device further enhances the adsorption capacity of the all-silica zeolite confined imidazole adsorbent for gaseous iodine and methyl iodine.

[0062] Iodine adsorption cycle experiments were conducted on the all-silica zeolite confined imidazole adsorbent prepared in Example 2: The all-silica zeolite confined imidazole adsorbent after iodine adsorption was heated to 200°C and kept at that temperature for 24 hours to desorb the imidazole and adsorbed gaseous iodine or methyl iodine. It was then placed in a wide-mouth bottle containing imidazole at the bottom and sealed, and heated in an oven at 120°C for 72 hours to obtain the all-silica zeolite confined imidazole adsorbent. The iodine adsorption experiment was repeated, and this process was repeated three times. The results are as follows: Figure 6 As shown in the figure, after three cycles, the adsorption efficiency of the all-silica zeolite confined imidazole adsorbent prepared in Example 2 for gaseous iodine or methyl iodine did not decrease significantly, indicating that the all-silica zeolite confined imidazole adsorbent of the present invention has good recyclability.

[0063] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing an all-silica zeolite confined imidazole adsorbent, characterized in that, Includes the following steps: Step 1: Mix tetraethyl orthosilicate, tetrapropylammonium hydroxide, ammonium fluoride and water, heat and stir to carry out pre-crystallization reaction, then transfer to a stainless steel autoclave lined with Teflon to carry out crystallization reaction. After naturally cooling to room temperature, filter to obtain solid product, wash with water, dry and calcine to obtain all-silica zeolite. Step 2: The all-silica zeolite is heated to degas and remove guest molecules. Then, it is placed in a container, which is then placed in a container with imidazole at the bottom and sealed and heated to obtain an all-silica zeolite confined imidazole adsorbent. The heating and degassing temperature is 100~140℃ and the time is 10~14h. The mass ratio of all-silica zeolite to imidazole is 1:1.5~2.

5. In step two, before using the all-silica zeolite, the all-silica zeolite is modified, including: mixing the all-silica zeolite obtained in step one with manganese chloride solution and zinc chloride solution, then ultrasonically treating it for 10-30 minutes to obtain a uniform mixed solution, heating it to 60-80℃ for 1-3 hours, then drying it at 100-120℃ for 8-12 hours, and then calcining it at 500-600℃ for 4-6 hours to obtain manganese and zinc modified all-silica zeolite; and then treating the manganese and zinc modified all-silica zeolite in a low-temperature plasma treatment instrument for 1-3 minutes to obtain modified all-silica zeolite.

2. The preparation method of the all-silica zeolite confined imidazole adsorbent as described in claim 1, characterized in that, In step one, the molar ratio of tetraethyl orthosilicate, tetrapropylammonium hydroxide, ammonium fluoride and water is 1:0.1~0.2:0.8~1.2:80~120.

3. The preparation method of the all-silica zeolite confined imidazole adsorbent as described in claim 1, characterized in that, In step one, the temperature of the pre-crystallization reaction is 80~100℃ and the time is 24~48h.

4. The preparation method of the all-silica zeolite confined imidazole adsorbent as described in claim 1, characterized in that, In step one, the temperature of the crystallization reaction is 110~130℃ and the time is 72~96h.

5. The preparation method of the all-silica zeolite confined imidazole adsorbent as described in claim 1, characterized in that, In step one, the drying temperature is 60~80℃ and the drying time is 20~28h.

6. The preparation method of the all-silica zeolite confined imidazole adsorbent as described in claim 1, characterized in that, In step one, the calcination temperature is 500~600℃ and the calcination time is 4~6h.

7. The preparation method of the all-silica zeolite confined imidazole adsorbent as described in claim 1, characterized in that, In step two, the temperature of the sealed heating is 110~130℃, and the time is 48~96h.

8. The application of a fully silica zeolite confined imidazole adsorbent prepared by the preparation method according to any one of claims 1-7 in the capture of radioactive iodine, characterized in that, A container containing all-silica zeolite confined imidazole adsorbent is placed in a container containing iodine or methyl iodine and sealed. The container is then heated to 70-80°C. After collection is complete, the all-silica zeolite confined imidazole adsorbent containing iodine is removed and heated to 180-220°C and kept at that temperature for 20-28 hours to desorb the imidazole and the collected gaseous iodine or methyl iodine. The adsorbent is then placed in a container with imidazole at the bottom and sealed and heated again to obtain the all-silica zeolite confined imidazole adsorbent, which can then be recycled.

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