Preparation method and application of melamine modified collagenous fiber iodine adsorbent

Abstract

The invention discloses a preparation method and application of a melamine modified collagenous fiber iodine adsorbent, and relates to the technical field of nuclear medical radioactive waste treatment. The preparation method comprises the following steps: activating collagen fibers and modifying melamine; wherein the melamine modification comprises the following steps: taking the activated collagenous fiber, adding water, melamine and a dialdehyde cross-linking agent, and stirring at 35-45 DEG C for 6-8 hours to obtain the melamine modified collagenous fiber iodine adsorbent. According to the application, the prepared melamine modified collagenous fiber iodine adsorbent is used for adsorbing radioactive iodine. After melamine grafting, the nitrogen content of the collagenous fiber is remarkably increased, the collagen fiber has more prominent adsorption capacity on iodine steam and iodine in a solution, and an effective strategy is provided for removal and collection of radioactive iodine such as medical wastewater and radioactive waste liquid.

Description

Technical Field

[0001] This invention relates to the field of nuclear medical radioactive waste management technology, specifically to a method for preparing and applying a melamine-modified collagen fiber iodine adsorbent. Background Technology

[0002] 131 Ionic acid (I) is one of the important radionuclides for treating diseases such as cancer, and its demand and usage are both high. However, the preparation of... 131 The wastewater discharged from the reactor cooling system and the medical waste generated during the I process contain large amounts of highly radioactive iodine. Direct discharge would cause serious pollution to water and air, posing a severe threat to human health. Therefore, production and medical institutions decay and store the radioactive wastewater and medical waste until... 131 I will be released after it is no longer radioactive, but the waste volume is large, storage space is limited, and the potential hazards are significant. Therefore, 131 Centralized collection to improve space utilization is currently the most effective solution.

[0003] In recent years, studies have reported on the use of adsorbents for collection. 131 Common adsorbents include covalent organic frameworks (COFs), metal-organic frameworks (MOFs), and zeolite imidazole frameworks (ZIFs), all of which share common characteristics such as porous structures, open nanoscale channels, and tunable frameworks. Porous structures increase specific surface area, providing more adsorption sites. Open nanoscale channels allow for rapid mass transfer of iodine molecules, ensuring efficient adsorption kinetics. Furthermore, tunable structures allow researchers to modify and optimize adsorbents according to specific requirements, such as adjusting functional groups on the framework to enhance the affinity for iodine. Although these adsorbents have demonstrated outstanding iodine adsorption capacity in numerous experimental studies, the preparation methods of most adsorbents are cumbersome and complex, the raw material costs are expensive, the yield of the target product is low, and some adsorbents even contain harmful substances and metal elements, which still pollute water resources and threaten the human living environment when discharged as waste. Therefore, developing an environmentally friendly, simple, and low-cost collagen fiber iodine adsorbent is crucial.

[0004] Currently, there are reports on the preparation of iodine adsorbents using collagen fibers as raw materials. For example, by immobilizing myricetin on collagen fibers (CFs) and then chelating silver with the carboxyl groups of collagen and the hydroxyl groups of myricetin, iodine-active silver nanoparticles were constructed. Although this method provides an effective strategy for capturing iodine vapor, the loading capacity of tannin and silver nanoparticles is limited because the collagen fibers are not activated and a large number of functional groups are masked, resulting in a less than outstanding adsorption effect on iodine vapor (WANG B, ZHU H, DUAN T, et al. Multi-layer active interface construction with polyphenols and nano-silver on nano collagen fiber for efficient capturing iodine vapor [J]). .Applied Surface Science, 2022, 596:153585. In addition, there are reports of methods that activate collagen fibers before modification. For example, assembling plant polyphenols (catechins) onto activated collagen fibers (ACF) can further enhance the capture performance of collagen fiber-based adsorbents for iodine vapor and iodine in solution. However, its adsorption effect in alkaline environments is not ideal (ZHU H, WANG B, ZHU W, et al. Interface assembly of specific recognition gripper wrapping on activated collagen fiber for synergistic capture effect of iodine [J]. Colloids and Surfaces B-Biointerfaces, 2022, 210: 112216). In addition, composite adsorbents coated with plant polyphenols and chelated with metal ions on ACF for the adsorption of iodine in wastewater can only show relatively excellent iodine removal effects in acidic environments, and cannot meet the requirements for iodine removal in alkaline medical wastewater (ZHU H, CAO L, CHENG X, et al. In-site interface growth of bismuth-based hydrothermal carbon using collagen fiber for selective removal of iodide ion from wastewater [J]. Colloids and Surface A-Physiochemical and Engineering Aspects, 2023, 664: 131177).

[0005] Based on the above analysis, it can be seen that current modified collagen fiber adsorbents for capturing iodine vapor and solution suffer from several drawbacks during preparation. Firstly, the collagen fibers are not fully activated, failing to adequately expose active functional groups and limiting the loading of functional materials. Secondly, the performance of the loaded functional materials is not suitable for the actual environment. Furthermore, the excessively large molecular weight and variety of the loaded functional materials significantly affect the adsorption performance of the collagen fiber adsorbents. Therefore, the reported adsorption capacity, adsorption performance, iodine removal rate, and capture rate of collagen fiber iodine adsorbents currently available do not meet practical application requirements, thus greatly limiting their application in the adsorption field. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing a specific adsorption material for iodine ions and iodine vapor, which can improve the removal efficiency of iodine ions in nuclear medical waste, achieve the removal of I-131 nuclide from nuclear medical waste, and ensure that the total α activity of the final radioactive waste is <1 Bq / L and the total β activity is <10 Bq / L.

[0007] Therefore, in a first aspect, the present invention provides a method for preparing a melamine-modified collagen fiber iodine adsorbent, comprising: Activation of collagen fibers; Melamine modification: Take activated collagen fibers, add water, melamine and dialdehyde crosslinking agent, stir at 35~45℃ for 6~8 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0008] Further, the activation of the collagen fibers includes: dispersing the collagen fibers in water, gradually adding an alkaline solution to adjust the pH to 10-13, stirring at 25-50°C for 4-8 hours, washing with water until neutral, centrifuging to collect, and obtaining the activated collagen fibers.

[0009] Furthermore, the collagen fibers are dispersed in water, wherein the mass ratio of the collagen fibers to water is 1:(10~50).

[0010] Furthermore, the collagen fiber is any one of bovine collagen fiber, sheepskin collagen fiber, goatskin collagen fiber, and pigskin collagen fiber; the alkali used to activate the collagen fiber is any one of sodium hydroxide and potassium hydroxide.

[0011] Furthermore, in the melamine modification, the mass ratio of the activated collagen fiber to water is 1:(10~50), and the mass ratio of the activated collagen fiber to melamine is 1:(0.33-3).

[0012] Furthermore, the dialdehyde crosslinking agent is selected from any one of glutaraldehyde, glyoxal, dialdehyde carboxymethyl cellulose, or dialdehyde starch.

[0013] Furthermore, in the melamine modification, when the dialdehyde crosslinking agent is glutaraldehyde or glyoxal, the volume concentration of the dialdehyde crosslinking agent in the entire reaction system is controlled to be 2%~12%; when the dialdehyde crosslinking agent is dialdehyde carboxymethyl cellulose or dialdehyde starch, the mass concentration of the dialdehyde crosslinking agent in the entire reaction system is controlled to be 4%~24%.

[0014] In a second aspect, the present invention provides an application of a melamine-modified collagen fiber iodine adsorbent, wherein the collagen fiber iodine adsorbent prepared by the aforementioned preparation method is used for the adsorption of radioactive iodine.

[0015] Furthermore, the collagen fiber iodine adsorbent is used for I3 - When adsorbing into solution, the method is as follows: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] - The collagen fiber iodine adsorbent was added to the solution, and adsorption was carried out at a temperature of 20~60℃ and a pH of 7~9. Furthermore, when the collagen fiber iodine adsorbent is used for iodine vapor adsorption, the method is as follows: in a sealed container, the collagen fiber iodine adsorbent is subjected to adsorption with iodine vapor at 60~80°C.

[0016] Furthermore, under the conditions of 60℃ and adsorption for 72 hours, I3 with an initial concentration of 3 g / L was treated. - In solution, when the dosage of the collagen fiber iodine adsorbent is 10 g / L, I3 - The removal rate can reach over 90%; under the conditions of 70℃ and adsorption for 30 hours, each gram of the collagen fiber iodine adsorbent can adsorb iodine vapor with a capacity of over 2.5g.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: The present invention provides a method for preparing a melamine-modified collagen fiber iodine adsorbent. Using collagen fiber and melamine as the main raw materials, a dialdehyde is added for cross-linking. Melamine is grafted onto the collagen fiber via a Schiff base reaction, thus synthesizing the melamine-modified collagen fiber iodine adsorbent. Melamine contains a large number of nitrogen atoms, and the grafting significantly increases the nitrogen content of the collagen fiber, resulting in a more prominent adsorption capacity for iodine vapor and iodine in solution. This provides an effective strategy for the removal and collection of radioactive iodine from medical wastewater, radioactive waste liquid, and other sources. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a schematic diagram illustrating the preparation mechanism of the melamine-modified collagen fiber iodine adsorbent provided in an embodiment of the present invention.

[0020] Figure 2 The melamine-modified collagen fiber iodine adsorbent provided in this embodiment of the invention has the effect of removing I3 from the solution. - A schematic diagram of the adsorption mechanism; Figure 3 This is a schematic diagram illustrating the adsorption mechanism of iodine vapor by the melamine-modified collagen fiber iodine adsorbent provided in this embodiment of the invention. Detailed Implementation

[0021] To better understand the above technical solutions, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0022] A first aspect of this invention provides a method for preparing a melamine-modified collagen fiber iodine adsorbent, comprising: Activation of collagen fibers; Melamine modification: Take activated collagen fibers, add water, melamine and dialdehyde crosslinking agent, stir at 35~45℃ for 6~8 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0023] See Figure 1 The melamine-modified collagen fiber iodine adsorbent provided by this invention is prepared by using activated collagen fibers and melamine as the main raw materials, adding dialdehyde for cross-linking, and grafting melamine onto collagen fibers via a Schiff base reaction to synthesize the melamine-modified collagen fiber iodine adsorbent. The activated collagen fibers expose a large number of active functional groups, which can interact with I2 and I3 through hydrogen bonds and lone pair electrons. - Adsorption occurs, and melamine contains a large number of nitrogen atoms. Melamine grafting significantly increases the nitrogen content of collagen fibers, affecting I2 and I3. - Its load-bearing capacity is also more outstanding; furthermore, melamine has excellent thermal stability, therefore, melamine-modified collagen fiber iodine adsorbents exhibit good thermal stability. In summary, melamine-modified collagen fiber iodine adsorbents demonstrate outstanding adsorption capacity for iodine vapor and iodine in solution, providing an effective strategy for the removal and collection of radioactive iodine from medical wastewater, radioactive waste liquids, and other sources.

[0024] This melamine-modified collagen fiber iodine adsorbent, see [link to relevant documentation]. Figure 2 and Figure 3 Iodine is adsorbed in two ways: (1) The abundant carboxyl and hydroxyl groups in collagen amino acids bind to I2 and I3 through electrostatic interaction and hydrogen bonding. - Adsorption occurs. In addition, collagen fibers contain benzene ring π bonds that achieve π-π stacking. Furthermore, according to the Lewis acid-base theory, I₂ acts as a Lewis acid, while nitrogen with its lone pair of electrons acts as a Lewis base. A strong interaction occurs between them, resulting in electron transfer from the lone pair of nitrogen to I₂ (N…I₂→N). + I - ), leading to the formation of iodide anions (I3).- and I5 - (2) Because melamine has abundant N atoms and lone pair electrons, grafting melamine through Schiff base reaction greatly increases the nitrogen content of collagen fibers, providing a large number of iodine adsorption sites for the adsorbent, making the collagen fiber adsorbent material more effective at adsorbing I2 and I3. - Its adsorption capacity is significantly improved.

[0025] In some embodiments, the activation of collagen fibers includes: dispersing collagen fibers in water, gradually adding an alkaline solution to adjust the pH to 10-13, stirring at 25-50°C for 4-8 hours, washing with water until neutral, centrifuging to collect, and obtaining the activated collagen fibers.

[0026] Specifically, activated collagen fibers possess a large number of active functional groups, providing numerous active sites for melamine grafting and modification. Alkali activation, a classic method for activating collagen fibers, is economically inexpensive and technologically mature. Furthermore, since maintaining a perfect natural triple helix structure is not necessary during modification, alkali activation effectively dissociates the fibers, fully exposing the reaction sites for binding with melamine. In contrast, enzyme activation is costly and inefficient, and physical activation methods do not achieve satisfactory activation results.

[0027] In some embodiments, when collagen fibers are activated, the collagen fibers are dispersed in water, and the mass ratio of collagen fibers to water is controlled to be 1:(10~50); preferably, the mass ratio of collagen fibers to water is controlled to be 1:(15~30).

[0028] Specifically, under the above-mentioned mass ratio of collagen fibers to water, the collagen fibers are well dispersed; if the mass fraction of water is too low, the collagen fibers are not dispersed evenly enough, and a good oscillation effect cannot be achieved during the reaction; if the mass fraction of water is too high, the collagen fibers are over-dispersed, resulting in an increase in the amount of reagent required and increasing costs.

[0029] In some embodiments, the collagen fiber is any one of bovine collagen fiber, sheepskin collagen fiber, goatskin collagen fiber, and pigskin collagen fiber; the alkali used to activate the collagen fiber is any one of sodium hydroxide and potassium hydroxide.

[0030] Specifically, the embodiments of the present invention can select different types of collagen fibers from the skin. These collagen fibers are natural and green materials, readily available, and low in cost, exhibiting excellent environmental friendliness and biocompatibility. The alkali activating reagent, melamine, and dialdehyde crosslinking agent used in the embodiments of the present invention are also common chemical raw materials, resulting in a simple formulation and easy operation. Therefore, the preparation method of the embodiments of the present invention for preparing melamine-modified collagen fiber iodine adsorbents can be easily industrialized.

[0031] In some embodiments, during melamine modification, the mass ratio of activated collagen fibers to water is 1:(10~50), preferably controlled at 1:(15~30); the mass ratio of activated collagen fibers to melamine is 1:(0.33-3), preferably controlled at 1:(0.6~1).

[0032] Specifically, under the above-mentioned mass ratio of collagen fibers to water, the activated collagen fibers are well dispersed. If the mass fraction of water is too low, the activated collagen fibers are not dispersed evenly, and a good oscillation effect cannot be achieved during the reaction, and melamine is also not easy to separate. If the mass fraction of water is too high, the activated collagen fibers are over-dispersed, resulting in an increase in the amount of reagent required, increasing costs. Furthermore, if the density of melamine and activated collagen fibers is too low, it is not conducive to their contact, and the reaction efficiency is reduced.

[0033] Under the above-mentioned mass ratio of activated collagen fiber to melamine, it is beneficial to modify the activated collagen fiber; too little melamine will lead to insufficient modification of the activated collagen fiber and poor adsorption effect; however, too much melamine will not only lead to a lot of unreacted melamine remaining in the activated collagen fiber, blocking the adsorption channel, but also cause reagent waste and increased cost.

[0034] In some embodiments, the dialdehyde crosslinking agent is selected from any one of glutaraldehyde, glyoxal, dialdehyde carboxymethyl cellulose, or dialdehyde starch; preferably, the dialdehyde crosslinking agent is glutaraldehyde.

[0035] Specifically, dialdehyde crosslinking agents can undergo Schiff base reactions with amino groups, thereby enabling the grafting of melamine onto activated collagen fibers. Among them, glutaraldehyde has the highest crosslinking efficiency, high stability after forming a Schiff base, and is also more inexpensive; dialdehyde carboxymethyl cellulose and dialdehyde starch are biodegradable; and all of the above-mentioned dialdehyde crosslinking agents are readily available.

[0036] In some embodiments, during melamine modification, when the dialdehyde crosslinking agent is glutaraldehyde or glyoxal, the volume concentration of the dialdehyde crosslinking agent in the entire reaction system is controlled to be 2%~12% (v / v), preferably 4%~10% (v / v); when the dialdehyde crosslinking agent is dialdehyde carboxymethyl cellulose or dialdehyde starch, the mass concentration of the dialdehyde crosslinking agent in the entire reaction system is controlled to be 4%~24% (wt / v), preferably 8%~20% (wt / v).

[0037] Specifically, the concentration of the dialdehyde crosslinking agent directly affects the modification effect. If the concentration is too low, the activated collagen fibers will not be modified enough, and the amount of melamine grafted will be too small, thus affecting the adsorption effect. If the concentration is too high, the activated collagen fibers and melamine will undergo self-crosslinking, resulting in a reduction in the amount of melamine grafted, and even a reduction in the adsorption capacity, ultimately affecting the adsorption effect.

[0038] In a second aspect, the present invention provides an application of a melamine-modified collagen fiber iodine adsorbent, wherein the collagen fiber iodine adsorbent prepared by the above preparation method is used for the adsorption of radioactive iodine.

[0039] Specifically, collagen fiber iodine adsorbents are used for I3 - During adsorption, the methods include: (1) Preparation of experimental solutions: Prepare two concentration series of I3. - Solutions; among which, high concentration series: 1, 2, 3, 4, 5 g / L; low concentration series: 40, 60, 80, 100 mg / L.

[0040] (2) Adsorption experiment: The effect of concentration on the amount of collagen fiber iodine adsorbent was investigated: 10 mL of each high-concentration series solution was taken, and 0.1 g of collagen fiber iodine adsorbent was added to each. 25 mL of each low-concentration series solution was taken, and 0.05 g of collagen fiber iodine adsorbent was added to each.

[0041] Investigating the effects of temperature and pH: using 100 mg / L I3 - The solution was subjected to adsorption experiments at 25, 30, 40, 50, and 60 °C and different pH values ​​(7, 8, and 9). The results showed that the collagen fiber iodine adsorbent achieved the optimal adsorption effect at 60 °C and pH 8.

[0042] (3) Testing and Calculation The solution was measured at regular intervals using ultraviolet absorption spectroscopy, and the residual I3 in the solution was analyzed using a standard curve. - The amount is calculated, and the adsorption capacity and removal rate are calculated.

[0043] When collagen fiber iodine adsorbents are used for iodine vapor adsorption, the methods include: First, 1g of elemental iodine was weighed and placed in a wide-mouthed bottle. Then, 0.1g of collagen fiber iodine adsorbent was weighed and placed in a crucible. The crucible was then placed inside the wide-mouthed bottle containing elemental iodine and sealed. The bottle was then placed in a 70℃ oven. The weight of the collagen fiber iodine adsorbent and the iodine vapor adsorption capacity were recorded every 2 hours. The maximum adsorption capacity of the collagen fiber iodine adsorbent at adsorption equilibrium was calculated using a time-weighted method. The experimental results show that the collagen fiber iodine adsorbent basically reaches adsorption equilibrium after 25-30 hours of adsorption.

[0044] In some embodiments, collagen fiber iodine adsorbents are used for I3 - When adsorbing into solution, the method is as follows: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] - Collagen fiber iodine adsorbent was added to the solution, and adsorption was carried out under conditions of 20-60℃ and pH 7-9; among which, the high concentration series was 10mL I3 - Add 0.1g of collagen fiber iodine adsorbent to the solution, and then add a low-concentration series of I3. - Add 0.05g of collagen fiber iodine adsorbent to 25mL of solution.

[0045] In some embodiments, when collagen fiber iodine adsorbent is used for iodine vapor adsorption, the method is as follows: in a closed container, the collagen fiber iodine adsorbent and iodine vapor are adsorbed at 60~80℃ for 25~30h to reach adsorption equilibrium.

[0046] In some embodiments, I3 with an initial concentration of 3 g / L was treated at 60°C for 72 hours. - In solution, when the dosage of collagen fiber iodine adsorbent is 10 g / L, I3 - The removal rate can reach over 90%; under the conditions of 70℃ and adsorption for 30 hours, the adsorption capacity of each gram of collagen fiber iodine adsorbent for iodine vapor can reach over 2.5g.

[0047] Example 1: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse bovine collagen fibers in water (the mass ratio of bovine collagen fibers to water is 1:20), gradually add sodium hydroxide solution to adjust the pH to 12, stir at 45℃ for 6 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers; Step 2: Disperse activated collagen fibers in water (the mass ratio of activated bovine collagen fibers to water is 1:20), then add melamine (the mass ratio of melamine to activated collagen fibers is 1:1) and glutaraldehyde (the volume concentration of glutaraldehyde in the entire reaction system is 8%) in sequence. Stir at 45°C for 6 hours, then filter and dry to obtain melamine-modified collagen fiber iodine adsorbent.

[0048] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 1 was used for adsorbing I3 in solution. - Removal of initial I3 in solution -The concentration of collagen fiber iodine adsorbent was 100 mg / L, and 2 g of collagen fiber iodine adsorbent was added per liter of solution. The solution was treated at 60℃ and pH 7.5 for 72 h. The removal rate of iodine ions in the solution by the adsorbent was then characterized by UV-Vis spectrophotometry. For the removal of iodine vapor, 0.1 g of collagen fiber iodine adsorbent and 1 g of elemental iodine (solid) were added (excess to ensure that the adsorbent could be saturated). The adsorption was carried out at 70℃ for 30 h under sealed conditions. The iodine vapor adsorption capacity of the collagen fiber iodine adsorbent was then determined by gravimetric method. The results are shown in Table 1.

[0049] Example 2: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse bovine collagen fibers in water (the mass ratio of bovine collagen fibers to water is 1:20), gradually add potassium hydroxide solution to adjust the pH to 13, stir at 35°C for 5 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers; Step 2: Disperse activated collagen fibers in water (the mass ratio of activated collagen fibers to water is 1:30), then add melamine (the mass ratio of melamine to activated collagen fibers is 1:1) and dialdehyde carboxymethyl cellulose (the mass concentration of dialdehyde carboxymethyl cellulose in the entire reaction system is 12%) in sequence, and stir at 35°C for 8 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0050] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 2 was used for adsorbing I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0051] Example 3: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse goat skin collagen fibers in water (mass ratio of goat skin collagen fibers to water is 1:35), gradually add sodium hydroxide solution to adjust the pH to 12, stir at 45℃ for 6 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers; Step 2: Disperse activated collagen fibers in water (mass ratio of activated collagen fibers to water is 1:40), then add melamine (mass ratio of melamine to activated collagen fibers is 2:1) and glyoxal (volume concentration of glyoxal in the entire reaction system is 6%) in sequence, stir at 45℃ for 6 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0052] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 3 was used for adsorbing I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0053] Example 4: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse goat skin collagen fibers in water (mass ratio of goat skin collagen fibers to water is 1:25), gradually add sodium hydroxide solution to adjust the pH to 10, stir at 35℃ for 8 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers; Step 2: Disperse activated collagen fibers in water (mass ratio of activated collagen fibers to water is 1:50), then add melamine (mass ratio of melamine to activated collagen fibers is 3:1) and glutaraldehyde (volume concentration of glutaraldehyde in the entire reaction system is 10%) in sequence, and stir at 40°C for 8 hours.

[0054] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 4 was used for the adsorption of I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0055] Example 5: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse pigskin collagen fibers in water (the mass ratio of pigskin collagen fibers to water is 1:50), gradually add potassium hydroxide solution to adjust the pH to 13, stir at 50℃ for 4 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers; Step 2: Disperse activated collagen fibers in water (mass ratio of activated collagen fibers to water is 1:25), then add melamine (mass ratio of melamine to activated collagen fibers is 1:2) and dialdehyde carboxymethyl cellulose (mass concentration of dialdehyde carboxymethyl cellulose in the entire reaction system is 14%) in sequence, stir at 35℃ for 8 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0056] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 5 was used for the adsorption of I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0057] Example 6: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse pigskin collagen fibers in water (the mass ratio of pigskin collagen fibers to water is 1:15), gradually add potassium hydroxide solution to adjust the pH to 13, stir at 30°C for 8 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers; Step 2: Disperse activated collagen fibers in water (mass ratio of activated collagen fibers to water is 1:35), then add melamine (mass ratio of melamine to activated collagen fibers is 1:3) and glutaraldehyde (volume concentration of glutaraldehyde in the entire reaction system is 5%) in sequence, and stir at 38°C for 7 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0058] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 6 was used for adsorbing I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0059] Example 7: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse pigskin collagen fibers in water (the mass ratio of pigskin collagen fibers to water is 1:40), gradually add sodium hydroxide solution to adjust the pH to 13, stir at 35°C for 5 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers; Step 2: Disperse activated collagen fibers in water (mass ratio of activated collagen fibers to water is 1:45), then add melamine (mass ratio of activated collagen fibers to water is 1:1) and glyoxal (volume concentration of glyoxal in the entire reaction system is 7%) in sequence, stir at 35℃ for 8 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0060] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 7 was used for adsorbing I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0061] Example 8: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse sheepskin collagen fibers in water (mass ratio of sheepskin collagen fibers to water is 1:30), gradually add potassium hydroxide solution to adjust the pH to 12, stir at 50℃ for 4 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers. Step 2: Disperse activated collagen fibers in water (mass ratio of activated collagen fibers to water is 1:10), then add melamine (mass ratio of melamine to activated collagen fibers is 2:1) and glutaraldehyde (volume concentration of glutaraldehyde in the entire reaction system is 8%) in sequence, and stir at 45℃ for 8 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0062] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 8 was used for the adsorption of I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0063] Example 9: Preparation method and application of a melamine-modified collagen fiber iodine adsorbent (I) Preparation method Includes the following steps: Step 1: Disperse sheepskin collagen fibers in water (mass ratio of sheepskin collagen fibers to water is 1:10), gradually add potassium hydroxide solution to adjust the pH to 13, stir at 35℃ for 5 hours, wash with water until neutral, centrifuge and collect to obtain activated collagen fibers. Step 2: Disperse activated collagen fibers in water (mass ratio of activated collagen fibers to water is 1:20), then add melamine (mass ratio of melamine to activated collagen fibers is 1:1.5) and glyoxal (volume concentration of glyoxal in the entire reaction system is 7%) in sequence, and stir at 35°C for 8 hours to obtain melamine-modified collagen fiber iodine adsorbent.

[0064] (II) Application The melamine-modified collagen fiber iodine adsorbent prepared in Example 9 was used for adsorbing I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0065] Comparative Example 1: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Bovine collagen fibers were dispersed in water (the mass ratio of bovine collagen fibers to water was 1:20), and sodium hydroxide solution was gradually added to adjust the pH to 12. The mixture was stirred at 45°C for 6 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers.

[0066] (II) Application The activated collagen fibers prepared in Comparative Example 1 were used to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0067] Comparative Example 2: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Bovine collagen fibers were dispersed in water (the mass ratio of bovine collagen fibers to water was 1:20), and potassium hydroxide solution was gradually added to adjust the pH to 13. The mixture was stirred at 35°C for 5 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers. (II) Application The activated collagen fibers prepared in Comparative Example 2 were used to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0068] Comparative Example 3: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Goat skin collagen fibers were dispersed in water (the mass ratio of goat skin collagen fibers to water was 1:35), sodium hydroxide solution was gradually added to adjust the pH to 12, the mixture was stirred at 45°C for 6 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers. (II) Application Comparative Example 3 prepared the above-mentioned activated collagen fibers and used them to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0069] Comparative Example 4: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Goat skin collagen fibers were dispersed in water (the mass ratio of goat skin collagen fibers to water was 1:25), sodium hydroxide solution was gradually added to adjust the pH to 10, the mixture was stirred at 35°C for 8 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers. (II) Application Comparative Example 4 prepared the above-mentioned activated collagen fibers and used them to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0070] Comparative Example 5: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Pigskin collagen fibers were dispersed in water (the mass ratio of pigskin collagen fibers to water was 1:50), potassium hydroxide solution was gradually added to adjust the pH to 13, the mixture was stirred at 50°C for 4 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers. (II) Application Comparative Example 5 prepared the above-mentioned activated collagen fibers and used them to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0071] Comparative Example 6: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Pigskin collagen fibers were dispersed in water (the mass ratio of pigskin collagen fibers to water was 1:15), potassium hydroxide solution was gradually added to adjust the pH to 13, the mixture was stirred at 30°C for 8 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers. (II) Application Comparative Example 6 prepared the above-mentioned activated collagen fibers and used them to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0072] Comparative Example 7: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Pigskin collagen fibers were dispersed in water (the mass ratio of pigskin collagen fibers to water was 1:40), sodium hydroxide solution was gradually added to adjust the pH to 13, the mixture was stirred at 35°C for 5 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers. (II) Application Comparative Example 7 prepared the above-mentioned activated collagen fibers and used them to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0073] Comparative Example 8: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Sheepskin collagen fibers were dispersed in water (the mass ratio of sheepskin collagen fibers to water was 1:30), potassium hydroxide solution was gradually added to adjust the pH to 12, the mixture was stirred at 50°C for 4 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers. (II) Application Comparative Example 8 prepared the above-mentioned activated collagen fibers and used them to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0074] Comparative Example 9: Preparation method and application of activated collagen fiber adsorbent (I) Preparation method Sheepskin collagen fibers were dispersed in water (the mass ratio of sheepskin collagen fibers to water was 1:10), potassium hydroxide solution was gradually added to adjust the pH to 13, the mixture was stirred at 35°C for 5 hours, washed with water until neutral, and collected by centrifugation to obtain activated collagen fibers. (II) Application Comparative Example 9 prepared the above-mentioned activated collagen fibers and used them to react with I3 in solution. - The removal of iodine vapor and the application method for removing iodine vapor are the same as in Example 1, and the results are shown in Table 1.

[0075] Table 1. Effect of melamine-modified collagen fiber iodine adsorbent on I3 - Removal rate and adsorption capacity for iodine vapor

[0076] As shown in Table 1, the melamine-modified collagen fiber adsorbents (Examples 1-9) effectively treated I3. - The removal rate and adsorption capacity for iodine vapor were significantly higher than those of unmodified activated collagen fibers (Comparative Examples 1-9). Specifically, the melamine-modified collagen fiber iodine adsorbent prepared in Example 1 showed significantly higher adsorption capacity for I3. - It has a better adsorption capacity than elemental iodine.

[0077] It will be readily understood by those skilled in the art that the above-described advantageous methods can be freely combined and superimposed without conflict. The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A method for preparing a melamine-modified collagen fiber iodine adsorbent, characterized in that, include: Activation of collagen fibers; Melamine modification: Take activated collagen fibers, add water, melamine and dialdehyde crosslinking agent, stir at 35~45℃ for 6~8 hours to obtain melamine-modified collagen fiber iodine adsorbent.

2. The method for preparing the melamine-modified collagen fiber iodine adsorbent according to claim 1, characterized in that, The activation of the collagen fibers includes: dispersing the collagen fibers in water, gradually adding an alkaline solution to adjust the pH to 10-13, stirring at 25-50°C for 4-8 hours, washing with water until neutral, centrifuging and collecting to obtain the activated collagen fibers.

3. The preparation method of the melamine-modified collagen fiber iodine adsorbent according to claim 2, characterized in that, The collagen fibers are dispersed in water, wherein the mass ratio of the collagen fibers to water is 1:(10~50).

4. The method for preparing the melamine-modified collagen fiber iodine adsorbent according to claim 2, characterized in that, The collagen fiber is any one of bovine collagen fiber, sheepskin collagen fiber, goatskin collagen fiber, and pigskin collagen fiber; the alkali used to activate the collagen fiber is any one of sodium hydroxide and potassium hydroxide.

5. The method for preparing the melamine-modified collagen fiber iodine adsorbent according to claim 1, characterized in that, In the melamine modification, the mass ratio of the activated collagen fiber to water is 1:(10~50), and the mass ratio of the activated collagen fiber to melamine is 1:(0.33-3).

6. The method for preparing the melamine-modified collagen fiber iodine adsorbent according to claim 1, characterized in that, The dialdehyde crosslinking agent is selected from any one of glutaraldehyde, glyoxal, dialdehyde carboxymethyl cellulose, or dialdehyde starch.

7. The method for preparing the melamine-modified collagen fiber iodine adsorbent according to claim 6, characterized in that, In the melamine modification process, when the dialdehyde crosslinking agent is glutaraldehyde or glyoxal, the volume concentration of the dialdehyde crosslinking agent in the entire reaction system is controlled to be 2%~12%; when the dialdehyde crosslinking agent is dialdehyde carboxymethyl cellulose or dialdehyde starch, the mass concentration of the dialdehyde crosslinking agent in the entire reaction system is controlled to be 4%~24%.

8. The application of a melamine-modified collagen fiber iodine adsorbent, characterized in that, The collagen fiber iodine adsorbent prepared by any one of claims 1-7 is used for the adsorption of radioactive iodine.

9. The application according to claim 8, characterized in that: The collagen fiber iodine adsorbent is used for I3 - When adsorbing into solution, the method is as follows: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] - The collagen fiber iodine adsorbent was added to the solution, and adsorption was carried out at a temperature of 20~60℃ and a pH of 7~9. When the collagen fiber iodine adsorbent is used for iodine vapor adsorption, the method is as follows: in a closed container, the collagen fiber iodine adsorbent is subjected to adsorption with iodine vapor at 60~80℃.

10. The application according to claim 9, characterized in that, I3 was treated at an initial concentration of 3 g / L under the conditions of 60 °C and adsorption for 72 hours. - In solution, when the dosage of the collagen fiber iodine adsorbent is 10 g / L, I3 - The removal rate can reach over 90%; Under conditions of 70℃ and 30 hours of adsorption, each gram of the collagen fiber iodine adsorbent can adsorb more than 2.5g of iodine vapor.

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