A type of amyloid fiber hybrid membrane, its preparation method and application

Abstract

This invention belongs to the field of composite material preparation technology, specifically disclosing an amyloid cellulose hybrid membrane, its preparation method, and its application. The preparation method includes the following steps: adjusting the pH of a 10 wt% β-lactoglobulin solution, centrifuging, collecting the supernatant, filtering, dialyzing, and freeze-drying to obtain β-lactoglobulin monomer; dissolving the β-lactoglobulin monomer in ultrapure water, stirring evenly, adjusting the pH, and heating in a water bath to obtain an amyloid cellulose solution; adding bismuth nitrate to the amyloid cellulose solution, adjusting the pH, and shaking at a constant temperature to obtain amyloid cellulose-loaded bismuth hydroxide; mixing the amyloid cellulose-loaded bismuth hydroxide with activated carbon, stirring evenly, and vacuum filtering to obtain the amyloid cellulose hybrid membrane. This invention discloses an amyloid cellulose hybrid membrane, its preparation method, and its application. This hybrid membrane has high membrane flux, excellent adsorption selectivity, and cycling performance, and can remove iodine ions from complex radioactive medical waste.

Description

Technical Field

[0001] This invention belongs to the field of composite material preparation technology, specifically relating to an amyloid fiber hybrid membrane, its preparation method, and its application. Background Technology

[0002] Radioactive iodine isotopes have irreplaceable application value in the field of nuclear medicine. 131 As a core drug for treating hyperthyroidism and thyroid cancer, it controls the disease by targeting and destroying thyroid cells; 123 with I 124 It is a key tracer for single-photon emission computed tomography (SPECT) imaging, used for thyroid function assessment and tumor localization; I 125 Brachytherapy is used for precise treatment of solid tumors such as prostate cancer. However, all four isotopes have long half-lives and are highly radiotoxic. Once leaked from medical waste, they can rapidly migrate and spread through water bodies, accumulating in human thyroid tissue through the food chain and inducing cell carcinogenesis and genetic damage. Clinical data show that after hyperthyroid patients receive a radiation dose of 100–1000 MBq, approximately 70% of the radioactive iodine is excreted in urine, forming radioactive waste with high iodine concentration and complex composition.

[0003] To date, methods for removing iodide ions include adsorption, chemical precipitation, and ion exchange. Among these, adsorption has gained attention due to its simplicity and low secondary pollution. With further research, various adsorbents have been developed, such as carbon materials, nanomaterials, and metal oxides. In recent years, metal oxides such as Ag, Bi, and Cu have attracted widespread attention due to their excellent removal capabilities for iodides. These metals readily combine with iodide ions to form precipitates, thus achieving removal. However, some problems remain, such as the high price, toxicity, and scarcity of silver. Therefore, bismuth-based compounds such as Bi₂O₃ have become one of the most promising candidates for iodide removal. They are less toxic, stable, inexpensive, and readily available, and the iodide oxides formed by their reaction with iodide ions exhibit good thermodynamic stability. Nevertheless, a bismuth-based adsorbent capable of accurately capturing iodide ions in a large volume under conditions of multiple ion coexistence for a short period has not yet been developed. Summary of the Invention

[0004] This invention aims to provide an amyloid fiber hybrid membrane, its preparation method, and its application. The hybrid membrane has high membrane flux, excellent adsorption selectivity, and recycling performance. It can remove iodine ions from complex radioactive medical waste liquids without generating secondary waste during the treatment process, and has extremely broad market prospects.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing an amyloid fibrous hybrid membrane includes the following steps:

[0007] S1. Adjust the pH of the 10wt% β-lactoglobulin solution, centrifuge, collect the supernatant, filter, dialyze, and freeze-dry to obtain β-lactoglobulin monomer;

[0008] S2. Dissolve the β-lactoglobulin monomer obtained in S1 in ultrapure water, stir evenly, adjust the pH, and heat in a water bath to obtain a 2 wt% amyloid cellulose solution.

[0009] S3. Add bismuth nitrate to the amyloid fiber solution with a mass concentration of 2wt% obtained in S2, adjust the pH, and shake at a constant temperature to obtain amyloid fiber loaded with bismuth hydroxide.

[0010] S4. Mix the amyloid fibers loaded with bismuth hydroxide obtained in S3 with activated carbon, stir evenly, and vacuum filter to obtain an amyloid fiber hybrid membrane.

[0011] Preferably, in S1, hydrochloric acid with a mass fraction of 1% to 5% is used to adjust the pH of β-lactoglobulin with a mass concentration of 10 wt% to 4.6.

[0012] Preferably, in S1, the centrifugation is performed three times at a speed of 8000 rpm, each time for 15 minutes, with a 12-hour interval between each centrifugation.

[0013] Preferably, in S1, a 0.45μm filter is used for filtration, and dialysis is performed for 5 to 7 days using an 8000Da dialysis bag. The dialysis solution is ultrapure water, and the solution is freeze-dried at -50℃ to -60℃ for 48 hours to obtain β-lactoglobulin monomer, which is then stored at 4℃.

[0014] Preferably, in step S2, 5% hydrochloric acid is added to adjust the pH to 2, the water bath heating temperature is 90°C, and the heating time is 5 hours.

[0015] Preferably, in step S3, 1% NaOH is added to adjust the pH to 4.25, and the mixture is placed in a water bath shaker and shaken at 160 rpm and 25°C for 12 hours.

[0016] Preferably, in S4, the mass ratio of the amyloid fiber-loaded bismuth hydroxide to activated carbon is 1:9.

[0017] The present invention also provides an amyloid fiber hybrid membrane prepared by the preparation method described above.

[0018] The present invention also provides the application of the amyloid fibrous hybrid membrane as described above or the amyloid fibrous hybrid membrane prepared by the preparation method above in the removal of iodine ions from radioactive medical waste liquid.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects:

[0020] (1) This invention discloses an amyloid fiber hybrid membrane, its preparation method and application. The hybrid membrane uses β-lactoglobulin and activated carbon as core raw materials to construct a green and environmentally friendly composite adsorption system. The raw materials are widely available and no toxic reagents are added during the preparation process. Through the synergistic effect of the multi-level channels of amyloid fibers and the high porosity structure of activated carbon, high membrane flux is achieved, which can quickly treat large volumes of radioactive waste liquid and significantly improve the treatment efficiency per unit time. By regulating the coordination chemical effect of amino and carboxyl groups on the surface of amyloid fibers with nano-bismuth hydroxide, the material is endowed with excellent adsorption selectivity. Furthermore, the hybrid membrane has excellent cycling performance and adsorption capacity.

[0021] (2) The preparation process does not require high temperature and high pressure conditions, the operation is simple and the equipment requirements are low, which reduces the production cost. During the process, iodine ions are fixed through physical adsorption and coordination reaction, and no secondary waste is generated. The membrane material after adsorption saturation can achieve long-term stable storage of radionuclides through safe curing process, which fundamentally avoids the leakage risk of storage decay method and has broad industrial application prospects.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a process flow diagram of the synthesis of amyloid fiber hybrid membrane according to the present invention;

[0024] Figure 2 Infrared image of the functional groups of the amyloid fibrous hybrid membrane provided in Example 1;

[0025] Figure 3 The distribution coefficient (Kd) of Example 1 is compared with that of the comparative example;

[0026] Figure 4 The cycling performance results of the amyloid fiber hybrid membrane provided in Example 1 under iodine ion solution. Detailed Implementation

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0029] Source of experimental materials:

[0030] In this invention, unless otherwise specified, all other test materials and instruments are conventional test materials in the field and can be purchased through commercial channels.

[0031] The process flow diagram for synthesizing amyloid fiber hybrid membranes in the embodiments is as follows: Figure 1 As shown.

[0032] Example 1

[0033] A method for preparing an amyloid fibrous hybrid membrane includes the following steps:

[0034] S1. Adjust the pH of 10wt% β-lactoglobulin to 4.6 using 1% hydrochloric acid. Centrifuge three times at 8000 rpm for 15 min each time with a 12-h interval between centrifugations. Collect the supernatant, filter it using a 0.45 μm filter, dialyze it for 7 days using an 8000 Da dialysis bag with ultrapure water as the dialysate, and freeze-dry it at -60℃ for 48 h to obtain β-lactoglobulin monomer. Store it at 4℃.

[0035] S2. Dissolve 2g of the β-lactoglobulin monomer obtained in S1 in 98mL of ultrapure water, stir well, add 5% hydrochloric acid to adjust the pH to 2, heat in a 90℃ water bath for 5h to obtain a 2wt% amyloid cellulose solution.

[0036] S3. Add 3.153 g of bismuth nitrate to the 2 wt% amyloid fiber solution obtained in S2, add 1% NaOH to adjust the pH to 4.25, place in a water bath shaker, and shake at 160 rpm and 25°C for 12 h to obtain amyloid fiber loaded with bismuth hydroxide.

[0037] S4. Mix 0.01g of amyloid cellulose loaded with bismuth hydroxide obtained in S3 with 0.09g of activated carbon, stir evenly, and vacuum filter for 3min, wherein the vacuum degree is 0.01MPa, to obtain 100mg of amyloid cellulose hybrid membrane AC-βFs-Bi(OH)3.

[0038] Comparative Example 1

[0039] Commercial activated carbon, purchased from Zhengzhou Zhongliao Environmental Protection Co., Ltd.

[0040] The effectiveness of the amyloid fiber hybrid membrane provided in Example 1 was verified through the following experiments.

[0041] 1. The functional groups of the amyloid fibrous hybrid membrane provided in Example 1 were characterized by infrared spectroscopy, and the results are as follows: Figure 2 .

[0042] Depend on Figure 2It can be seen that the Bi-O bonds were successfully loaded on the fiber, and the presence of Bi-O bonds was clearly observed on the membrane before adsorption of iodine ions; after filtration, the Bi-O bonds overlapped with the Bi-I bonds.

[0043] 2. The distribution coefficient (Kd) of the amyloid fiber hybrid membrane provided in Example 1 and the commercial activated carbon provided in Comparative Example 1 were compared. The experimental procedure is as follows: The amyloid fiber hybrid membrane prepared in Example 1 and the commercial activated carbon provided in Comparative Example 1 were tested with different concentrations of SO4. 2- Iodide ions were removed by filtration under ion presence conditions (0-500 mg / L), where the iodide ion concentration was 100 mg / L, 10 mL of solution was filtered, and vacuum filtration was performed for 3 min at a vacuum degree of 0.01 MPa. The hybridization membrane exhibited excellent selectivity, as shown in the results. Figure 3 As shown.

[0044] Depend on Figure 3 It can be seen that, even in the presence of high concentrations of sulfate ions, the amyloid cellulose hybrid membrane AC-βFs-Bi(OH)3 membrane still exhibits extremely high selectivity for iodide ions, with a Kd index 10 higher than that of commercial activated carbon. 6 times.

[0045] 3. The cycling performance of the amyloid fiber hybrid membrane provided in Example 1 in iodide ion solution was determined, and the volume of radioactive wastewater that could be treated per square meter of hybrid membrane was evaluated.

[0046] The experimental procedure is as follows: Prepare 1000 mL of a 4.2 mg / L solution, and circulate the carbon-based hybrid membrane prepared in Example 1 100 times to remove iodide ions. Each filtration cycle uses 10 mL of solution, and the vacuum filtration time is 3 min. The results are as follows. Figure 4 As shown.

[0047] Depend on Figure 4 It can be seen that the hybrid membrane exhibits excellent cycling performance and strong processing capacity.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an amyloid fibrous hybrid membrane, characterized in that, Includes the following steps: S1. Adjust the pH of the 10wt% β-lactoglobulin solution, centrifuge, collect the supernatant, filter, dialyze, and freeze-dry to obtain β-lactoglobulin monomer; S2. Dissolve the β-lactoglobulin monomer obtained in S1 in ultrapure water, stir evenly, adjust the pH, and heat in a water bath to obtain a 2 wt% amyloid cellulose solution. S3. Add bismuth nitrate to the amyloid fiber solution with a mass concentration of 2wt% obtained in S2, adjust the pH, and shake at a constant temperature to obtain amyloid fiber loaded with bismuth hydroxide. S4. Mix the amyloid fibers loaded with bismuth hydroxide obtained in S3 with activated carbon, stir evenly, and vacuum filter to obtain an amyloid fiber hybrid membrane. In S1, the pH of 10wt% β-lactoglobulin was adjusted to 4.6 using hydrochloric acid with a mass fraction of 1% to 5%. In S1, the centrifugation is performed three times at a speed of 8000 rpm, each time for 15 minutes and with an interval of 12 hours between each centrifugation. In S1, the sample was filtered using a 0.45μm filter and dialyzed for 5–7 days using an 8000Da dialysis bag. The dialysate was ultrapure water. The sample was freeze-dried at -50℃ to -60℃ for 48 hours to obtain β-lactoglobulin monomer, which was then stored at 4℃. In S2, 5% hydrochloric acid is added to adjust the pH to 2, the water bath heating temperature is 90℃, and the heating time is 5h; In S3, add 1% NaOH to adjust the pH to 4.25, place in a water bath shaker, and shake at 160 rpm and 25°C for 12 hours.

2. The preparation method according to claim 1, characterized in that, In S4, the mass ratio of amyloid fibers loaded with bismuth hydroxide to activated carbon is 1:

9.

3. The amyloid fiber hybrid membrane prepared by the preparation method according to any one of claims 1 to 2.

4. The application of the amyloid fiber hybrid membrane as described in claim 3 or the amyloid fiber hybrid membrane prepared by the preparation method according to any one of claims 1 to 2 in the removal of iodine ions from radioactive medical waste liquid.

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