A composite membrane for in-situ loading of UIO-66-NH2 onto a shallow static cultured mycelium membrane, its preparation and application

Abstract

This invention discloses a composite membrane for in-situ loading of UIO-66-NH2 onto a shallow static cultured mycelium membrane, as well as its preparation and application. This invention uses a shallow static cultured mycelium membrane as a self-supporting carrier and polydopamine as a mediating layer to in-situ load UIO-66-NH2 to prepare a composite membrane. This solves the problems of existing mycelial carriers requiring secondary molding, weak MOF bonding, and difficulty in recovering adsorbent materials, achieving efficient adsorption and convenient recovery of tetracycline in water.

Description

Technical Field

[0001] This invention belongs to the field of biomimetic mineralization and nanoporous composite material technology, specifically involving a method for preparing metal-organic framework materials by in-situ synthesis on mycelial membranes mediated by polydopamine, and the application of the resulting composite membrane in the adsorption and removal of tetracycline from water. Background Technology

[0002] Tetracycline (TC) is a broad-spectrum antibiotic widely used in medicine, veterinary medicine, and agriculture due to its excellent antibacterial activity. Antibiotics in aquatic environments mainly originate from aquaculture wastewater, hospital wastewater, and domestic sewage. High concentrations of TC residues have been detected in rivers in many parts of my country. The persistent presence of TC residues in water bodies not only poses potential risks to aquatic ecosystems but also induces drug resistance in environmental microorganisms and may even promote the spread of drug-resistant genes, thereby threatening human health. Therefore, the efficient removal of tetracycline from water bodies has become an urgent problem to be solved in the field of water environment management.

[0003] Adsorption is widely used for the removal of tetracycline from water due to its low cost, high efficiency, ease of operation, and environmental friendliness. Currently, commonly used adsorbents include activated carbon, carbon nanotubes, clay minerals, ion exchange resins, and biomass materials. Activated carbon is inexpensive but has poor adsorption selectivity; carbon nanotubes and graphene-based materials have high adsorption capacity but are complex and expensive to prepare; biomass materials have good renewability but relatively low adsorption capacity. Therefore, developing novel adsorbents that combine high adsorption capacity, low cost, and easy recyclability is a key research focus. Metal-organic frameworks (MOFs) possess ultra-high specific surface area and tunable pore structure, showing excellent potential in tetracycline adsorption. The UIO-66 series MOFs, in particular, are especially suitable for aqueous adsorption systems due to their excellent chemical and water stability. However, UIO-66-NH2 usually exists in the form of nano or micron-sized powder, which poses serious challenges in actual water treatment: (1) it is difficult to quickly separate and recover from water after adsorption, requiring high-speed centrifugation or microporous membrane filtration, which is energy-intensive and inefficient; (2) the powder is easily lost with the water flow, causing secondary pollution and material loss; (3) when the powder is directly used in fixed beds or filter cartridges, it is prone to clogging and pressure drop, making it difficult to scale up in engineering. Therefore, loading UIO-66-NH2 onto a suitable macroscopic carrier is the key to overcoming its practical application bottleneck.

[0004] To overcome these problems, researchers have attempted to load these materials onto synthetic polymer membranes, inorganic fibers, sponges, and other carriers. For example, Ren et al. used lightweight porous polyurethane foam (PUF) as a carrier and loaded UiO-66-NH2 through in-situ growth, achieving macroscopic shaping. However, PUF is difficult to degrade, posing a risk of secondary pollution. Biomass materials such as bacterial cellulose, lignin, and cotton fiber have attracted attention due to their renewability, low cost, and rich functional groups. Fungal mycelium, as a special biomass material, possesses a natural three-dimensional network structure, abundant surface functional groups, and good flexibility, making it a potentially ideal carrier. However, existing mycelium is mostly in the form of loose mycelial balls cultured in shake flasks, requiring filtration and pressing to form membranes. The resulting membranes have a dense and uneven structure with high mass transfer resistance; simultaneously, the bonding force between the mycelium and MOF crystals is weak, and the MOF is prone to detachment, failing to meet the requirements for multiple recycling. In summary, the existing technology lacks a technical solution that can directly obtain a continuous self-supporting mycelial membrane without relying on secondary molding, and can firmly and uniformly load UIO-66-NH2 onto the membrane in situ, while the composite membrane has both high adsorption performance and easy recyclability. Summary of the Invention

[0005] To address the shortcomings and deficiencies of existing technologies, the primary objective of this invention is to provide a method for preparing a composite membrane using a shallow static cultured mycelium membrane as a self-supporting carrier and polydopamine as a mediator layer to in situ load UIO-66-NH2. This method aims to solve problems such as the need for secondary molding of existing mycelium carriers, weak MOF bonding, and difficulty in recovering adsorbent materials, thereby achieving efficient adsorption and convenient recovery of tetracycline in water.

[0006] Another objective of this invention is to provide a composite membrane in situ loaded with UIO-66-NH2 on a shallow static cultured mycelium membrane prepared by the above-described method.

[0007] Another object of the present invention is to provide the application of the above-mentioned composite membrane with UIO-66-NH2 loaded in situ on a shallow static cultured mycelium membrane in the adsorption and removal of tetracycline from water.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for preparing a composite membrane in situ loaded with UIO-66-NH2 from a shallow static cultured mycelium membrane, comprising the following steps:

[0010] (1) Shallow static culture: Prepare the culture medium, add the culture medium into the container, control the height of the culture medium layer, inoculate the activated strain, and let it stand for culture. After the culture is completed, take out the mycelial membrane, wash it, dry it and set it aside for later use.

[0011] (2) Loading polydopamine: Immerse the mycelial membrane obtained in step (1) in a dopamine buffer solution, stir and react. After the reaction is complete, take it out, wash and dry it to obtain a polydopamine-modified mycelial membrane.

[0012] (3) In-situ loading of UIO-66-NH2: The polydopamine-modified mycelium membrane obtained in step (2) was immersed in Zr salt solution, ultrasonically treated, and acetic acid and 2-aminoterephthalic acid (NH2-H2BDC) were added for solvothermal reaction. After the reaction was completed, the composite membrane material was taken out, washed, and dried to obtain UIO-66-NH2 / mycelium membrane composite membrane.

[0013] Preferably, the container in step (1) is at least one of a petri dish, a tissue culture flask, and a glass culture box.

[0014] Preferably, the culture medium in step (1) is prepared by mixing glucose, maltose, yeast powder, magnesium sulfate, potassium dihydrogen phosphate and water in a mass ratio of (2-2.5):(1.5-2):(1-1.2):(0.04-0.05):(0.08-0.1):100.

[0015] Preferably, the culture medium in step (1) needs to be sterilized by high-pressure steam; the temperature of the high-pressure steam sterilization is 120±5 ℃ and the time is 30±5 min.

[0016] Preferably, the height of the culture medium layer in step (1) is 5 to 6 mm.

[0017] Preferably, the bacterial strain in step (1) is Inonotus hispidus.

[0018] Preferably, the inoculation of activated bacteria in step (1) refers to a bacterial suspension with an inoculation concentration of 9-11 g / L, and the inoculation amount of the bacterial suspension is 15-25% of the total volume of the culture medium.

[0019] Preferably, the static culture conditions in step (1) are: static culture at a constant temperature of 30±1 ℃ for 6 to 8 days.

[0020] Preferably, the washing in step (1) refers to washing with water.

[0021] Preferably, in the dopamine buffer solution in step (2), the concentration of dopamine is 1 to 3 g / L.

[0022] Preferably, the solvent of the dopamine buffer solution in step (2) is a Tris-HCl buffer solution with a pH of 8 to 8.5.

[0023] Preferably, the ratio of mycelial membrane to dopamine buffer solution in step (2) is 0.2-0.3g:100mL.

[0024] Preferably, the stirring reaction time in step (2) is 12 to 24 hours.

[0025] Preferably, the washing in step (2) refers to washing with water.

[0026] Preferably, in step (3), the Zr salt is at least one of ZrCl4 and ZrOCl2·8H2O.

[0027] Preferably, in step (3), the molar ratio of Zr salt, 2-aminoterephthalic acid and acetic acid is 1:(1.45-1.65):(95-105).

[0028] Preferably, in the Zr salt solution of step (3), the molar ratio of Zr salt to solvent is 1:600-670; the solvent is N,N-dimethylformamide.

[0029] Preferably, the ratio of the polydopamine-modified mycelial membrane to the Zr salt solution in step (3) is 0.2-0.3 g: 30 mL.

[0030] Preferably, the ultrasonic treatment in step (3) takes 1 to 2 hours.

[0031] Preferably, the temperature of the thermodynamic reaction in step (3) is 120±5 ℃ and the time is 24±1 h.

[0032] Preferably, the washing step (3) refers to washing with DMF, ethanol and water 1 to 5 times in sequence.

[0033] Preferably, the drying in step (3) refers to freeze drying for 24±1 h and then vacuum drying at 60±5 ℃ for 6±1 h.

[0034] Secondly, the present invention provides a composite membrane in situ loaded with UIO-66-NH2 on a shallow static cultured mycelium membrane prepared by the above preparation method.

[0035] Thirdly, the present invention provides the application of the above-mentioned composite membrane in which UIO-66-NH2 is loaded in situ on a shallow static culture mycelium membrane.

[0036] Preferably, the composite membrane with UIO-66-NH2 loaded in situ on the shallow static culture mycelium membrane is used for the adsorption and removal of tetracycline from water.

[0037] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0038] (1) The present invention adopts a shallow static culture method to directly obtain a continuous and self-supporting mycelial membrane without the need for secondary forming processes such as filtration and pressing. The membrane structure is loose and uniform with low mass transfer resistance, which is conducive to the full penetration and uniform distribution of reactant molecules in the subsequent in-situ loading process.

[0039] (2) In this invention, a polydopamine layer is preloaded on the surface of the mycelium membrane. The abundant catechol and amino functional groups of polydopamine effectively enhance the interfacial bonding force between the mycelium and the UIO-66-NH2 crystals, solving the problem of weak direct bonding force between the mycelium and MOF and easy detachment, and significantly improving the structural stability and recyclability of the composite membrane.

[0040] (3) This invention uses renewable natural biomass material - coarse fiber Fomitopsis mycelium membrane as macroscopic carrier to replace the difficult-to-degrade synthetic polymer foam material, thus avoiding the risk of secondary pollution and showing outstanding environmental friendliness.

[0041] (4) The UIO-66-NH2 / mycelium membrane composite membrane preparation process provided by the present invention has good controllability and low raw material cost. The composite membrane obtained has high adsorption performance, good flexibility and easy recycling characteristics, and has broad application prospects in the adsorption treatment of wastewater containing antibiotics such as tetracycline. Attached Figure Description

[0042] Figure 1 These are photographs of mycelial membranes prepared by different methods of the present invention: (a) Mycelial membrane obtained by shallow static culture in Example 1; (b) Mycelial membrane obtained by Comparative Example 4 (traditional shake flask culture-filtration method).

[0043] Figure 2 This is a photograph of the mycelial membrane loaded with UIO-66-NH2 in Example 1 of the present invention.

[0044] Figure 3 These are SEM images of the samples obtained in Example 1 of this invention: (a) morphology of the mycelial membrane before loading UIO-66-NH2; (b-d) morphology of the composite membrane after loading UIO-66-NH2 at different magnifications.

[0045] Figure 4 This is an EDS diagram of the mycelial membrane loaded with UIO-66-NH2 in Example 1 of the present invention.

[0046] Figure 5 These are the XRD patterns of samples prepared at each stage in Example 1 of this invention: (a) the mycelial membrane obtained in step (1); (b) the polydopamine-modified mycelial membrane obtained in step (2); (c) the UIO-66-NH2 / mycelial membrane composite membrane obtained in step (3); and (d) the simulated XRD pattern of UIO-66-NH2.

[0047] Figure 6The images shown are SEM and EDS images of ZIF-8 loaded mycelial membranes in Comparative Example 6 of this invention. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0049] Unless otherwise specified in the embodiments of this invention, the conditions shall be performed according to conventional conditions or conditions recommended by the manufacturer. All raw materials and reagents used, unless otherwise specified, are commercially available conventional products.

[0050] Example 1

[0051] (1) Shallow static culture

[0052] Weigh out each component (glucose, maltose, yeast powder, magnesium sulfate, potassium dihydrogen phosphate, and water) in a mass ratio of 2.5:2:1.2:0.05:0.1:100 to prepare 100 mL of culture medium. Pour the medium into an Erlenmeyer flask, seal with sealing film, and autoclave at 120 °C for 30 min. After sterilization, dispense the culture medium into petri dishes, maintaining a liquid level of 6 mm. Inoculate 20% of the total culture medium volume with activated *Inonotus hispidus* strain (activated *Inonotus hispidus* strain is added as a bacterial suspension with a concentration of 10 g / L, amounting to 20% of the total culture medium volume; *Inonotus hispidus* strain preservation number CGMCC3.15188), and incubate at 30 °C for 7 days. After incubation, remove the mycelial membrane, wash repeatedly with deionized water, dry, and set aside.

[0053] (2) Polydopamine-loaded

[0054] Dissolve 0.2 g of dopamine in 100 mL of Tris-HCl buffer solution with pH 8.5 and stir until homogeneous. Take the mycelial membrane obtained in step (1), weigh 0.2 g of the mycelial membrane and immerse it in the above dopamine solution, stirring continuously for 12 h. After the reaction is complete, remove the membrane, wash thoroughly with deionized water, and dry to obtain the polydopamine-modified mycelial membrane.

[0055] (3) In-situ load UIO-66-NH2

[0056] Weigh 0.14 g ZrCl4 and dissolve it in 30 mL DMF, stirring until completely dissolved. Immerse the polydopamine-modified mycelial membrane obtained in step (2) into the above ZrCl4 / DMF solution and sonicate for 1 h. Then add 3.6 mL acetic acid, stir evenly, and then add 0.16 g NH2-H2BDC. Transfer the reaction system to a high-pressure reactor and carry out a solvothermal reaction at 120 ℃ for 24 h. After the reaction is completed, allow it to cool naturally to room temperature, remove the composite membrane material, and wash it three times each with DMF, ethanol, and water. Finally, freeze-dry the sample for 24 h, and then activate it under vacuum at 60 ℃ for 6 h to obtain the UIO-66-NH2 / mycelial membrane composite membrane.

[0057] Example 2

[0058] (1) Shallow static culture

[0059] Same as step (1) in Example 1.

[0060] (2) Polydopamine-loaded

[0061] Dissolve 0.1 g of dopamine in 100 mL of Tris-HCl buffer solution with pH 8.5 and stir until homogeneous. Take the mycelial membrane obtained in step (1), weigh 0.2 g of the mycelial membrane and immerse it in the above dopamine solution, stirring continuously for 12 h. After the reaction is complete, remove the membrane, wash thoroughly with deionized water, and dry to obtain the polydopamine-modified mycelial membrane.

[0062] (3) In-situ load UIO-66-NH2

[0063] Same as step (3) in Example 1.

[0064] Example 3

[0065] (1) Shallow static culture

[0066] Same as step (1) in Example 1.

[0067] (2) Polydopamine-loaded

[0068] Dissolve 0.3 g of dopamine in 100 mL of Tris-HCl buffer solution with pH 8.5 and stir until homogeneous. Take the mycelial membrane obtained in step (1), weigh 0.2 g of the mycelial membrane and immerse it in the above dopamine solution, stirring continuously for 12 h. After the reaction is complete, remove the membrane, wash thoroughly with deionized water, and dry to obtain the polydopamine-modified mycelial membrane.

[0069] (3) In-situ load UIO-66-NH2

[0070] Same as step (3) in Example 1.

[0071] Example 4

[0072] (1) Shallow static culture

[0073] Weigh out each component (glucose, maltose, yeast powder, magnesium sulfate, potassium dihydrogen phosphate, and water) in a mass ratio of 2.5:2:1.2:0.05:0.1:100 to prepare 100 mL of culture medium. Pour the medium into an Erlenmeyer flask, seal with sealing film, and autoclave at 120 °C for 30 min. After sterilization, dispense the culture medium into petri dishes, maintaining a liquid level of 5 mm. Inoculate 20% of the total culture medium volume with activated *Inonotus hispidus* strain (activated *Inonotus hispidus* strain is added as a bacterial suspension with a concentration of 10 g / L, amounting to 20% of the total culture medium volume; *Inonotus hispidus* strain preservation number CGMCC3.15188), and incubate at 30 °C for 7 days. After incubation, remove the mycelial membrane, wash repeatedly with deionized water, dry, and set aside.

[0074] (2) Polydopamine-loaded

[0075] Same as step (2) in Example 1.

[0076] (3) In-situ load UIO-66-NH2

[0077] Same as step (3) in Example 1.

[0078] Comparative Example 1

[0079] Shallow static culture

[0080] Weigh out each component (glucose, maltose, yeast powder, magnesium sulfate, potassium dihydrogen phosphate, and water) in a mass ratio of 2.5:2:1.2:0.05:0.1:100 to prepare 100 mL of culture medium. Pour the medium into an Erlenmeyer flask, seal with sealing film, and autoclave at 120 °C for 30 min. After sterilization, dispense the culture medium into petri dishes, maintaining a liquid level of 2 mm. Inoculate 20% of the total culture medium volume with activated *Inonotus hispidus* (activated *Inonotus hispidus* strain added as a 10 g / L suspension, 20% of the total culture medium volume; *Inonotus hispidus* strain preservation number CGMCC3.15188), and incubate at 30 °C for 7 days. After incubation, remove the mycelial membrane, wash repeatedly with deionized water, dry, and set aside.

[0081] Comparative Example 2

[0082] Shallow static culture

[0083] Weigh out each component (glucose, maltose, yeast powder, magnesium sulfate, potassium dihydrogen phosphate, and water) in a mass ratio of 2.5:2:1.2:0.05:0.1:100 to prepare 100 mL of culture medium. Pour the medium into an Erlenmeyer flask, seal with sealing film, and autoclave at 120 °C for 30 min. After sterilization, dispense the culture medium into petri dishes, maintaining a liquid level of 4 mm. Inoculate 20% of the total culture medium volume with activated *Inonotus hispidus* (activated *Inonotus hispidus* strain added as a 10 g / L suspension, 20% of the total culture medium volume; *Inonotus hispidus* strain preservation number CGMCC3.15188), and incubate at 30 °C for 7 days. After incubation, remove the mycelial membrane, wash repeatedly with deionized water, dry, and set aside.

[0084] Comparative Example 3

[0085] Preparation of UIO-66-NH2 powder

[0086] Weigh 0.14 g ZrCl4 and dissolve it in 30 mL DMF, stirring until completely dissolved. Then add 3.6 mL acetic acid, stir well, and then add 0.16 g NH2-H2BDC. Transfer the reaction system to a high-pressure reactor and carry out a solvothermal reaction at 120 °C for 24 h. After the reaction is complete, allow it to cool naturally to room temperature, remove the material, wash it three times each with DMF, ethanol, and water, and centrifuge it. Finally, freeze-dry the sample for 24 h, and then activate it under vacuum at 60 °C for 6 h to obtain UIO-66-NH2 powder.

[0087] Comparative Example 4

[0088] (1) Submerged shake flask culture

[0089] Weigh out each component (glucose, maltose, yeast powder, magnesium sulfate, potassium dihydrogen phosphate, and water) in a mass ratio of 2.5:2:1.2:0.05:0.1:100 to prepare 100 mL of culture medium. Pour the medium into an Erlenmeyer flask, seal with sealing film, and autoclave at 120 °C for 30 min. After sterilization, add the culture medium to the Erlenmeyer flask, maintaining a liquid level of approximately 20 mm. Inoculate 2% (2% of total culture medium volume) with activated *Inonotus hispidus* strain (activated *Inonotus hispidus* strain is added as a bacterial suspension with a concentration of 10 g / L; *Inonotus hispidus* strain preservation number CGMCC3.15188). Incubate at 30 °C in a shaker for 7 days. After incubation, remove the mycelium, filter and wash with deionized water, perform slight shearing and dispersion treatment, filter to form a membrane of a certain thickness, dry, and set aside.

[0090] (2) Polydopamine-loaded

[0091] Dissolve 0.2 g of dopamine in 100 mL of Tris-HCl buffer solution with pH 8.5 and stir until homogeneous. Take the mycelial membrane obtained in step (1), weigh 0.2 g of the mycelial membrane and immerse it in the above dopamine solution. Shake the membrane on a shaker (stirring may damage the membrane) for 12 h. After the reaction is complete, remove the membrane, wash it thoroughly with deionized water, and dry it to obtain the polydopamine-modified mycelial membrane.

[0092] (3) In-situ load UIO-66-NH2

[0093] Weigh 0.14 g ZrCl4 and dissolve it in 30 mL DMF, stirring until completely dissolved. Immerse the polydopamine-modified mycelial membrane obtained in step (2) into the above ZrCl4 / DMF solution and sonicate for 1 h. Then add 3.6 mL acetic acid, stir evenly, and then add 0.16 g NH2-H2BDC. Transfer the reaction system to a high-pressure reactor and carry out a solvothermal reaction at 120 ℃ for 24 h. After the reaction is completed, allow it to cool naturally to room temperature, remove the composite membrane material, and wash it three times each with DMF, ethanol, and water. Finally, freeze-dry the sample for 24 h, and then activate it under vacuum at 60 ℃ for 6 h to obtain the UIO-66-NH2 / post-treated mycelial membrane composite membrane.

[0094] Comparative Example 5

[0095] (1) Shallow static culture

[0096] Same as step (1) in Example 1.

[0097] (2) Polydopamine-loaded

[0098] Same as step (2) in Example 1.

[0099] (3) Unloaded MOFs materials

[0100] The polydopamine-modified mycelial membrane obtained in step (2) was immersed in 30 mL of DMF and sonicated for 1 h. Then, 3.6 mL of acetic acid was added. The reaction system was transferred to a high-pressure reactor and subjected to a solvothermal reaction at 120 °C for 24 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The composite membrane material was then removed and washed three times each with DMF, ethanol, and water. Finally, the sample was freeze-dried for 24 h and then activated under vacuum at 60 °C for 6 h to obtain the mycelial membrane composite membrane without MOF loading.

[0101] Comparative Example 6

[0102] (1) Shallow static culture

[0103] Same as step (1) in Example 1.

[0104] (2) Polydopamine-loaded

[0105] Same as step (2) in Example 1.

[0106] (4) In-situ load ZIF-8

[0107] Prepare 50 ml of a 0.1 mol / L methanol solution of zinc nitrate hexahydrate [Zn(NO3)2·6H2O]. Immerse the polydopamine-modified mycelial membrane obtained in step (2) in the above solution for 1 h. Prepare 50 ml of a 0.5 mol / L methanol solution of 2-methylimidazole (Hmim). After zinc adsorption is complete, quickly remove the mycelial membrane from the zinc solution, gently shake off excess liquid, and wash it three times with methanol solution to remove unstabilized adsorbed zinc ions. Transfer it to the 2-methylimidazole methanol solution. Let the mycelial membrane undergo ultrasonic reaction in the Hmim solution in an ice bath for 1 h. Take out the composite membrane material and wash it three times each with methanol and water. Finally, freeze-dry the sample for 24 h, and then activate it by vacuum drying at 60 ℃ for 6 h to obtain the composite membrane.

[0108] Comparative experiment explanation:

[0109] The synthesis results are as follows Figure 6 As shown, it should be noted that ZIF-8 material exhibits poor structural stability in aqueous solutions. Its framework is prone to hydrolytic collapse, leading to a rapid loss of specific surface area and pore structure, making it unable to maintain effective adsorption performance in aqueous adsorption systems. Therefore, ZIF-8 was not included in the tetracycline adsorption comparison test in this embodiment.

[0110] Test case

[0111] 1. Physicochemical property characterization

[0112] The thickness and density of the mycelial membranes prepared in Examples 1 and 4, and Comparative Examples 2 and 4 were tested. Thickness was measured using a thickness gauge, and density was determined using the mass-volume method. Comparative Example 1 was not included in the thickness and density comparison because the membrane formation was difficult and a complete self-supporting membrane could not be obtained. The test results are shown in Table 1.

[0113] Table 1. Physicochemical property characterization

[0114]

[0115] 2. Tetracycline Adsorption Performance Test

[0116] 0.02 g of the materials prepared in Examples 1-4 and Comparative Examples 3-5 were weighed and placed in 20 ml of a 100 mg / L tetracycline (TC) aqueous solution, respectively. Static adsorption was performed for 6 h at pH 5 and 30°C. The absorbance of TC in the supernatant was measured at 357 nm using a UV-Vis spectrophotometer, and the TC concentration was calculated using a standard curve. Adsorption capacity (q) e ) and removal rate (R e The results are calculated according to formulas (1) and (2) respectively, and the test results are shown in Table 2.

[0117] (1)

[0118] (2)

[0119] R e Removal rate (%); q e Adsorption capacity (mg / g); C0: Initial concentration (mg / L); C e V: Equilibrium concentration (mg / L); V: Volume of adsorption solution (mL); M: Mass of adsorbent (g)

[0120] Table 2 Tetracycline Adsorption Performance Test

[0121]

[0122] 3. Characterization of the UIO-66-NH2 / mycelium membrane composite membrane structure of the present invention

[0123] (1) The surface morphology of the UiO-66-NH2 / mycelial membrane composite membrane obtained in Example 1 was characterized by scanning electron microscopy (SEM). The results are shown in the figure. Figure 3 .Depend on Figure 3As shown in (d), the particles loaded on the film exhibit the typical octahedral morphology of the UiO-66 series materials, with clear crystal outlines and distinct edges, indicating that the synthesized UiO-66-NH2 has good crystallinity. The crystal particle size distribution is relatively uniform, with individual crystal sizes ranging from approximately 20 to 40 nm, belonging to nanoscale crystals, which is consistent with the size range of UiO-66-NH2 reported in the literature for solvothermal synthesis.

[0124] (2) Figure 5 The XRD patterns of the samples prepared in each stage of Example 1 are shown. The mycelial membrane obtained in step (1) and the polydopamine-modified mycelial membrane obtained in step (2) both exhibit amorphous characteristics and no obvious crystal phase diffraction peaks. The XRD pattern of the UiO-66-NH2 / mycelial membrane composite membrane obtained in step (3) shows characteristic diffraction peaks at corresponding positions that are completely consistent with the simulated UiO-66-NH2 pattern, belonging to the (111), (200), (222), (400), (442), and (711) crystal planes, respectively. The peaks are sharp and without significant shift. These results indicate that the method of this invention successfully achieved the in-situ synthesis and loading of UiO-66-NH2 on the mycelial membrane. The obtained MOF has good crystallinity, and neither the mycelial membrane carrier nor the polydopamine modification layer has adversely affected the crystal structure of the MOF, providing a good crystal phase basis for the subsequent adsorption application of the composite membrane.

[0125] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a composite membrane in situ loaded with UIO-66-NH2 from shallow static cultured mycelial membrane, characterized in that, Includes the following steps: (1) Shallow static culture: Prepare the culture medium, add the culture medium into the container, control the height of the culture medium layer, inoculate the activated strain, and let it stand for culture. After the culture is completed, take out the mycelial membrane, wash it, dry it and set it aside for later use. (2) Loading polydopamine: Immerse the mycelial membrane obtained in step (1) in a dopamine buffer solution, stir and react. After the reaction is complete, take it out, wash and dry it to obtain a polydopamine-modified mycelial membrane. (3) In-situ loading of UIO-66-NH2: The polydopamine-modified mycelium membrane obtained in step (2) was immersed in Zr salt solution, ultrasonically treated, acetic acid and 2-aminoterephthalic acid were added, and a solvothermal reaction was carried out. After the reaction was completed, the composite membrane material was taken out, washed, and dried to obtain UIO-66-NH2 / mycelium membrane composite membrane.

2. The preparation method according to claim 1, characterized in that, The height of the culture medium layer in step (1) is 5-6 mm; And / or, the container in step (1) is at least one of a petri dish, a tissue culture flask, and a glass culture box.

3. The preparation method according to claim 1 or 2, characterized in that, The bacterial strain mentioned in step (1) is *Fomitopsis coarseis*; And / or, the inoculation of activated bacteria in step (1) refers to a bacterial suspension with an inoculation concentration of 9 to 11 g / L, and the inoculation amount of the bacterial suspension is 15 to 25% of the total volume of the culture medium.

4. The preparation method according to claim 1 or 2, characterized in that, In step (2), the concentration of dopamine in the dopamine buffer solution is 1–3 g / L; And / or, the ratio of mycelial membrane to dopamine buffer solution in step (2) is 0.2-0.3 g: 100 mL.

5. The preparation method according to claim 1 or 2, characterized in that, In step (3), the molar ratio of Zr salt, 2-aminoterephthalic acid and acetic acid is 1:(1.45-1.65):(95-105); And / or, in the Zr salt solution described in step (3), the molar ratio of Zr salt to solvent is 1:600-670; And / or, the ratio of the polydopamine-modified mycelial membrane to the Zr salt solution in step (3) is 0.2–0.3 g: 30 mL.

6. The preparation method according to claim 1 or 2, characterized in that, The stirring reaction in step (2) takes 12 to 24 hours; And / or, the duration of the ultrasonic treatment in step (3) is 1 to 2 hours; And / or, the temperature of the thermodynamic reaction in step (3) is 120±5 ℃ and the time is 24±1 h.

7. The preparation method according to claim 1 or 2, characterized in that, The conditions for static culture in step (1) are: static culture at a constant temperature of 30±1 ℃ for 6 to 8 days; And / or, the culture medium in step (1) is prepared by mixing glucose, maltose, yeast powder, magnesium sulfate, potassium dihydrogen phosphate and water in a mass ratio of (2-2.5):(1.5-2):(1-1.2):(0.04-0.05):(0.08-0.1):100; And / or, the culture medium in step (1) needs to be sterilized by high pressure steam; the temperature of the high pressure steam sterilization is 120±5 ℃ and the time is 30±5 min.

8. The preparation method according to claim 1 or 2, characterized in that, The solvent for the dopamine buffer solution in step (2) is Tris-HCl buffer solution with a pH of 8 to 8.5; And / or, the solvent for the Zr salt solution in step (3) is N,N-dimethylformamide.

9. A composite membrane in situ loaded with UIO-66-NH2 on a shallow static culture mycelium membrane prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the composite membrane of shallow static culture mycelium membrane in situ loaded with UIO-66-NH2 as described in claim 9.

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