Three-dimensional porous mycelium membrane and preparation method of three-dimensional porous mycelium membrane

Abstract

This application provides a three-dimensional porous mycelial membrane and a method for preparing a three-dimensional porous mycelial membrane, belonging to the field of membrane materials. The preparation method includes: cultivating Ganoderma lucidum mycelia on a Sabouraud dextrose agar medium as a nutrient source and a birchwood board as a carrier, allowing the Ganoderma lucidum mycelia to grow into an initial mycelial membrane with a three-dimensional porous mesh structure on the birchwood board; subjecting the initial mycelial membrane to alkaline treatment, converting chitin in the initial mycelial membrane into chitosan, obtaining an intermediate membrane; immersing the intermediate membrane in a mixed solution composed of PEI solution and TA solution for a first specified time; after the reaction, adjusting the pH of the mixed solution to 2-4; adjusting the pH of the mixed solution to 6-7, and continuing to immerse the intermediate membrane in the mixed solution for a second specified time, obtaining a three-dimensional porous mycelial membrane. The preparation method provided by this application is simple, low-cost, and can produce a high-performance hydrophilic and oleophobic three-dimensional porous mycelial membrane.

Description

Technical Field

[0001] This application relates to the field of membrane materials technology, and in particular to a three-dimensional porous mycelium membrane and a method for preparing a three-dimensional porous mycelium membrane. Background Technology

[0002] In the field of water treatment technology, membrane separation technology occupies a pivotal position, playing a key role in purifying water quality and separating different substances.

[0003] Currently, electrospinning, freeze-drying, and 3D printing are common methods for preparing porous membranes. Electrospinning technology can precisely control the porous structure of membrane materials through one-step or coaxial methods, and is widely used in the synthesis of membranes for water treatment. Freeze-drying technology can be used to prepare hydrophilic cellulose-based membranes, and has unique advantages in membrane material preparation. 3D printing technology utilizes materials such as nano-graphene oxide to manufacture membranes with specific properties, and has also made some progress in the field of membrane material preparation.

[0004] However, these commonly used techniques typically require the use of organic solvents, which not only increases preparation costs but may also cause secondary pollution problems such as environmental contamination. Secondly, these techniques often rely on complex equipment and have stringent operating conditions, further increasing the difficulty and cost of preparation. Therefore, developing a simple and inexpensive porous membrane for application in oil-water separation is of great significance. Summary of the Invention

[0005] In view of this, this application provides a three-dimensional porous mycelium membrane and a method for preparing a three-dimensional porous mycelium membrane, which can provide a hydrophilic and oleophobic three-dimensional porous mycelium membrane with simple preparation process, low cost and excellent performance.

[0006] Specifically, this application is implemented through the following technical solution:

[0007] The first aspect of this application provides a method for preparing a three-dimensional porous mycelial membrane, the method comprising:

[0008] Ganoderma lucidum mycelium was cultured on Sabouraud dextrose agar medium as nutrient source and birch board as carrier, so that the Ganoderma lucidum mycelium grew into an initial mycelial membrane with a three-dimensional porous grid structure on the birch board;

[0009] The initial mycelial membrane is subjected to alkaline treatment to convert chitin in the initial mycelial membrane into chitosan, thereby obtaining an intermediate membrane;

[0010] The intermediate membrane is immersed in a mixed solution composed of PEI solution and TA solution and reacted for a first specified time. After the reaction is completed, the pH value of the mixed solution is adjusted to 2-4.

[0011] The pH of the mixed solution is adjusted to 6-7, and the intermediate membrane is soaked in the mixed solution for a second specified time to obtain the three-dimensional porous mycelial membrane.

[0012] The second aspect of this application provides a three-dimensional porous mycelial membrane, which is prepared based on a method for preparing a three-dimensional porous mycelial membrane.

[0013] The third aspect of this application provides an application of a three-dimensional porous mycelial membrane, which is applied in the fields of water purification, oil-in-water emulsion separation, and oil-water mixture separation.

[0014] The three-dimensional porous mycelial membrane and its preparation method provided in this application use Sabouraud dextrose agar medium and birch boards as the nutrient source and carrier for the growth of Ganoderma lucidum mycelia. These materials are widely available and inexpensive. Sabouraud dextrose agar medium is a common microbial culture medium, and birch boards are also readily available, reducing production costs. Furthermore, they are natural materials, making them more environmentally friendly compared to the organic solvents and complex equipment used in traditional porous membrane preparation, reducing environmental pollution and potential harm to human health. The entire preparation process mainly includes three steps: mycelial cultivation, alkaline treatment, and roughness modification (roughness modification involves immersing the intermediate membrane in a mixed solution composed of PEI and TA solutions for a first specified time, adjusting the pH of the mixed solution to 2-4 after the reaction, adjusting the pH of the mixed solution to 6-7, and then immersing the intermediate membrane in the mixed solution for a second specified time). This process requires no complex equipment or processes and is relatively simple to operate. During the mycelial culture stage, the natural growth characteristics of Ganoderma lucidum mycelium are utilized to allow it to self-assemble into a three-dimensional porous structure under suitable conditions. The alkaline treatment and roughness modification steps are also mild, easy to control, and do not introduce harmful chemicals, conforming to the concept of green chemistry and facilitating large-scale production. Furthermore, the prepared three-dimensional porous mycelial membrane achieves a balance between hydrophilicity and underwater oleophobicity, enabling it to perform excellently in oil-water separation. The underwater oil contact angle, membrane flux, and separation efficiency of the three-dimensional porous mycelial membrane remain stable under various environmental conditions and after multiple cycles, allowing the membrane to operate stably and continuously in complex practical application scenarios, resulting in a long service life and reducing the cost and hassle of frequent membrane material replacement. This membrane exhibits a high removal rate of heavy metal ions in emulsions, providing a new approach to solving the problem of heavy metal-contaminated wastewater treatment. Attached Figure Description

[0015] Figure 1 A flowchart of Example 1 of the method for preparing the three-dimensional porous mycelial membrane provided in this application;

[0016] Figure 2This is a schematic diagram showing the results of scanning electron microscopy tests on the surface and cross-section of OR-MM, NaOH-MM, and MM@N-PT as presented in this application.

[0017] Figure 3 ATR-FTIR spectra of OR-MM, NaOH-MM, and MM@N-PT;

[0018] Figure 4 X-ray photoelectron spectra of OR-MM, NaOH-MM, and MM@N-PT;

[0019] Figure 5 High-resolution C1S, O1S, and N1S spectra of OR-MM;

[0020] Figure 6 High-resolution C1S, O1S, and N1S spectra of NaOH-MM;

[0021] Figure 7 High-resolution C1S, O1S, and N1S spectra of MM@N-PT;

[0022] Figure 8 The separation effect of MM@N-PT on oil-in-water emulsions obtained at different growth times is shown in the figure.

[0023] Figure 9 The separation effect of MM@N-PT on oil-in-water emulsion after soaking in NaCl solution (3.5wt%) for 0–48 h is shown in the figure.

[0024] Figure 10 The underwater oil contact angle of the MM@N-PT membrane after immersion in NaCl solution (3.5wt%) for 0–48 h;

[0025] Figure 11 The separation effect of MM@N-PT on oil-in-water emulsion after soaking at different pH values ​​for 4 hours is shown in the figure.

[0026] Figure 12 This is a schematic diagram of the circulation separation of pure water by MM@N-PT;

[0027] Figure 13 This is a schematic diagram of the cyclic separation of methyl silicone oil-water mixture by MM@N-PT;

[0028] Figure 14 This is a process diagram of using MM@N-PT membranes to separate oil-water mixtures;

[0029] Figure 15 Graphs showing membrane flux and separation efficiency for MM@N-PT in separating different types of oil-water mixtures;

[0030] Figure 16This is a process diagram of MM@N-PT used to separate methylene blue solution;

[0031] Figure 17 The absorbance spectra of methylene blue solution before and after separation by MM@N-PT are shown.

[0032] Figure 18 The experimental process and microscopic images of oil-in-water emulsion separation;

[0033] Figure 19 A pore size distribution diagram of MM@N-PT;

[0034] Figure 20 The figure shows the results of the cyclic separation of oil-in-water emulsion using NaOH-MM.

[0035] Figure 21 The graph shows the cyclic separation results of oil-in-water emulsions using MM@N-PT.

[0036] Figure 22 Graphs showing membrane flux and separation efficiency for MM@N-PT in separating different types of oil-in-water emulsions;

[0037] Figure 23 The particle size distribution of oil droplets in the oil-in-water emulsion before and after separation is shown in the diagram.

[0038] Figure 24 The NaOH-MM membrane and MM@N-PT membrane shown in this application are used to treat Pb under different environments. 2+ The removal efficiency graph. Detailed Implementation

[0039] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0040] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used herein are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0041] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0042] The following specific embodiments are given to illustrate the technical solution of this application in detail.

[0043] Example 1

[0044] Figure 1 This is a flowchart of Example 1 of the method for preparing the three-dimensional porous mycelial membrane provided in this application. Please refer to... Figure 1 The method provided in this embodiment may include:

[0045] S101. Ganoderma lucidum mycelium is cultured using Sabouraud dextrose agar medium as the nutrient source and birch board as the carrier, so that the Ganoderma lucidum mycelium grows on the birch board to form the initial mycelial membrane.

[0046] The porous structure of the birch board provides growth channels for the generation of Ganoderma lucidum hyphae. The Ganoderma lucidum hyphae grow along the surface and pores of the birch board based on their branching and expansion capabilities. The Ganoderma lucidum hyphae self-grow and entwine on the birch board, self-assembling to form an initial hyphal membrane with a three-dimensional porous mesh structure.

[0047] It should be noted that Ganoderma lucidum hyphae possess a high degree of branching and expansion capabilities. In the early stages of growth, the hyphae rapidly extend from the inoculation point to the surrounding birchwood surface and pores. Their branching structure continuously differentiates and expands, quickly occupying available growth space. This branching growth pattern allows the hyphae to form a large-area coverage in a short time, increasing the contact area with nutrients and the environment. Based on its inherent growth characteristics, Ganoderma lucidum hyphae undergo self-growth, winding, and self-assembly on the birchwood. During growth, the hyphae secrete sticky substances, such as polysaccharides, which help the hyphae adhere and fix each other. As the hyphae continue to grow and wind, an initial hyphal membrane with a three-dimensional porous mesh structure gradually forms. This self-assembly process is a natural and orderly biological process that does not require additional complex technological intervention, demonstrating the unique advantages of biomaterial preparation.

[0048] The growth and twining patterns of Ganoderma lucidum hyphae determine the initial three-dimensional porous mesh structure of the mycelial membrane. The growth of hyphae on birchwood is not uniform and flat, but rather exhibits a three-dimensional, interwoven state. The gaps between hyphae form pores of varying sizes, which are interconnected, constituting a three-dimensional porous network. For example, during growth, hyphae continuously branch and fuse, forming a network-like structure, where the size and shape of the pores are influenced by factors such as hyphal growth rate, branching angle, and density. In subsequent membrane applications, such as water purification or oil-water separation, this three-dimensional porous mesh structure provides a large specific surface area, which is beneficial for the adsorption and filtration of substances. Simultaneously, the connectivity of the pores ensures the smooth transport of liquids or gases within the membrane, improving membrane flux and separation efficiency.

[0049] It should be noted that before preparing the three-dimensional porous mycelial membrane, the experimental materials must be prepared first. Specifically, the experimental materials include: D(+) glucose, monohydrate (C6H2O) 12 O6·H2O (AR), potassium dihydrogen phosphate (KH2PO4 (AR), magnesium sulfate (MgSO4 (AR), sodium hydroxide (NaOH (AR)), anhydrous sodium sulfate (Na2SO4 (AR), hexadecyltrimethylammonium bromide (CTAB (AR)), and methylene blue (MB) were purchased from Sinopharm Chemical Reagent Co., Ltd. Cyclohexane (C6H2O) 12 ), tetrachloroethylene (C2C) l4 The following were purchased: Yeast powder from Shanghai Aladdin Biochemical Technology Co., Ltd.; Sabouraud dextrose agar (SDA) from Beijing Hongrun Baoshun Technology Co., Ltd.; Sudan III, polyethyleneimine (PEI, MW1800, 99%), and tannic acid (TA, AR) from Shanghai Maclean Biochemical Technology Co., Ltd.; Corn flour, methyl silicone oil, lubricating oil, sunflower oil, and vacuum pump oil from local supermarkets; Birch boards and Ganoderma lucidum mycelium stock. All chemical products were not further processed.

[0050] In practice, Ganoderma lucidum mycelium is cultured using Sabouraud dextrose agar as the nutrient source and birchwood as the carrier, allowing the mycelium to grow into an initial mycelial membrane on the birchwood. This process includes: preparing mycelial suspension spores; subjecting birchwood of a specified size to high-temperature and high-pressure sterilization, and placing the treated birchwood in a petri dish containing sterilized Sabouraud dextrose agar; inoculating the mycelial suspension spores onto the edge of the birchwood under aseptic conditions to obtain a petri dish inoculated with spores; incubating the petri dish at 28°C for a specified number of days, and after the incubation period, peeling off the Ganoderma lucidum mycelial membrane formed on the birchwood with tweezers; and rinsing the Ganoderma lucidum mycelial membrane with deionized water to obtain the initial mycelial membrane.

[0051] It should be noted that Sabouraud dextrose agar (SDA), as a nutrient source, is rich in various nutrients required for the growth of Ganoderma lucidum mycelia, such as carbon sources, nitrogen sources, minerals, and vitamins. It provides sufficient energy and material basis for mycelial growth, ensuring normal metabolism and proliferation. Birch planks, as a carrier, have unique advantages. On the one hand, the natural porous structure of the birch plank surface provides growth space and physical support for the mycelia. These pores allow the mycelia to penetrate deep into them and grow along the pore walls, helping them form a stable attachment and growth structure. On the other hand, the material properties of birch planks are compatible with mycelial growth and will not inhibit or adversely affect it.

[0052] It should be noted that the preparation of mycelial suspension spores includes: preparing a liquid culture medium using corn flour, deionized water, glucose, yeast powder, potassium dihydrogen phosphate, and magnesium sulfate; dispensing the liquid culture medium into Erlenmeyer flasks and subjecting the Erlenmeyer flasks to high-temperature and high-pressure sterilization; inoculating the Erlenmeyer flasks with mycelial sheets in a clean bench; allowing the inoculated Erlenmeyer flasks to stand for two days, and after the stand for two days, placing the Erlenmeyer flasks in a constant temperature incubator and continuously culturing them for a specified number of days at a first specified temperature and a specified rotation speed to obtain the mycelial suspension spores. Preferably, the first specified temperature can be 28°C, the specified rotation speed can be 150 rpm, and the specified number of days can be 3 days.

[0053] Specifically, add 5g of corn flour to 100ml of deionized water and heat while stirring constantly. Remove the filtrate, then add 15g of glucose, 2.5g of yeast powder, 1g of potassium dihydrogen phosphate, and 0.5g of magnesium sulfate, and bring the volume to 500ml with deionized water to prepare a liquid culture medium. Stir the liquid culture medium thoroughly, allow it to stand and clarify, then aliquot the supernatant into Erlenmeyer flasks and autoclave for 30 minutes (this effectively kills any contaminating bacteria, ensuring the purity of subsequent cultures). On a clean bench, use an inoculation needle to cut the mother culture fungus from the test tube into 0.6×0.6×0.3cm pieces. 3 Mycelial discs of approximately the same size were placed in a liquid Erlenmeyer flask and allowed to stand for two days to allow the mycelium to initially adapt to the environment and begin to grow. Then, they were placed in a constant temperature incubator and cultured for 3 days at 28°C and 150 rpm. By controlling the temperature and rotation speed, suitable temperature, humidity, and oxygen conditions were provided for the growth of the mycelium, promoting its rapid growth and reproduction, and ultimately forming mycelial suspension spores.

[0054] Cut the birch planks into 4×5×0.3cm pieces. 3The birchwood boards were then subjected to a 30-minute high-temperature, high-pressure sterilization process to thoroughly kill any microorganisms that might be present on or inside the boards, preventing contamination of the Ganoderma lucidum mycelium culture. The treated birchwood boards were then placed in petri dishes containing sterilized SDA medium, allowing the boards to fully absorb the nutrients and providing a stable support and nutrient supply interface for mycelial growth. Under aseptic conditions, mycelial suspension spores were inoculated onto the edge of the birchwood boards (adding a small amount of liquid culture medium promotes faster mycelial growth). The inoculated petri dishes were then incubated at 28°C for approximately 6 days. Finally, the Ganoderma lucidum mycelial membrane grown on the birchwood boards was gently peeled off with tweezers and rinsed with deionized water to obtain the initial mycelial membrane. The resulting sample was named OR-MM.

[0055] S102. The initial mycelial membrane is subjected to alkaline treatment to convert the chitin in the initial mycelial membrane into chitosan, thereby obtaining an intermediate membrane.

[0056] It should be noted that the alkaline treatment of the initial mycelial membrane to convert chitin in the initial mycelial membrane into chitosan to obtain an intermediate membrane includes: placing the initial mycelial membrane in a NaOH solution and treating it at a second specified temperature for a specified time; after alkaline treatment, washing away the NaOH on the surface of the treated initial mycelial membrane with deionized water to obtain the intermediate membrane, wherein the intermediate membrane is named NaOH-MM. Preferably, the second specified temperature here is 40°C and the specified time is 2 hours.

[0057] It should be noted that chitin is an important component in the initial mycelial membrane (OR-MM). Chitin undergoes a chemical reaction under alkaline conditions; the acetyl group (–COCH3) in its molecular structure reacts with hydroxide ions (OH-) in the presence of NaOH solution. - A reaction occurs. Specifically, in a 1M NaOH solution, OH- - It attacks the acetyl groups in chitin molecules, causing them to hydrolyze and lose the acetyl group to generate an amino group (-NH2), thus partially converting chitin into chitosan. This conversion not only changes the chemical composition of the membrane but also has a significant impact on its performance. Chitosan has better hydrophilicity than chitin because its molecular structure contains more hydrophilic groups (such as amino and hydroxyl groups), which significantly improves the hydrophilicity of the membrane and is more beneficial for subsequent applications such as water purification.

[0058] The 1M NaOH solution concentration was determined through experimental optimization. Lower concentrations of NaOH solution may not effectively facilitate the deacetylation of chitin, leading to incomplete conversion and affecting the final membrane performance. Conversely, excessively high concentrations of NaOH solution may cause excessive damage to the overall structure of the mycelial membrane, reducing its mechanical strength and integrity.

[0059] At a processing temperature of 40℃, the chemical reaction rate is moderate, ensuring smooth conversion of chitin to chitosan without triggering unnecessary side reactions or accelerating membrane degradation due to excessively high temperatures. Furthermore, the 2-hour processing time was determined by comprehensively considering conversion efficiency and production efficiency. Too short a time would result in incomplete chitin conversion; too long a time might increase production costs and pose potential risks to the membrane structure.

[0060] Furthermore, after alkaline treatment, rinsing the initial mycelial membrane surface with deionized water to remove NaOH is an essential step. Residual NaOH can affect subsequent treatment steps and membrane performance. For example, when subsequently mixed with PEI and TA solutions, residual NaOH may alter the pH of the solution, thus affecting the reaction between PEI and TA and their binding to the membrane surface. In addition, residual NaOH may gradually leach out during membrane use, contaminating the treated liquid environment or affecting membrane stability. Thorough rinsing yields a pure intermediate membrane (NaOH-MM), providing a good foundation for subsequent modification treatments.

[0061] S103. The intermediate membrane is immersed in a mixed solution composed of PEI solution and TA solution and reacted for a first specified time. After the reaction is completed, the pH value of the mixed solution is adjusted to 2-4.

[0062] It should be noted that polyethyleneimine (PEI) is a polymer containing a large number of amino functional groups, while tannic acid (TA) has a polyphenolic structure. When PEI and TA solutions are mixed, electrostatic attraction occurs between the positive charges of PEI and the negative charges of TA, along with hydrogen bonding, leading to self-assembly of PT nanoparticles. These nanoparticles can adhere to the surface of an alkaline-treated intermediate membrane (NaOH-MM), increasing the membrane's surface roughness. This increased surface roughness effectively increases the membrane's specific surface area, thereby improving its filtration efficiency and separation performance. For example, in the separation of oil-in-water emulsions, a rough surface can better capture and retain oil droplets, promoting the rapid passage of the aqueous phase and increasing the separation flux.

[0063] The choice of a 2 mg / ml PEI solution mixed with a 1.5 mg / ml TA solution was determined through experimental optimization. This appropriate concentration ratio ensures the formation of a suitable amount of PT nanocomplexes, enabling them to effectively adhere to the membrane surface for roughness modification without negatively impacting the overall membrane performance due to excessively high or low concentrations. If the PEI or TA concentration is too high, it may lead to excessive aggregation of the nanocomplexes or the formation of an uneven coating on the membrane surface, affecting membrane stability and permeability; conversely, if the concentration is too low, the expected roughness modification effect and functional improvement may not be achieved.

[0064] The intermediate membrane was immersed in the mixed solution for 25 minutes (a first specified time). This time was to ensure that PEI and TA had sufficient time to interact and form a stable nanocomplex adhesion layer on the membrane surface. During the reaction, the pH of the mixed solution was adjusted to 2-4 (preferably pH 3) using hydrochloric acid. This acidic environment promotes the electrostatic complexation reaction between PEI and TA, accelerating the formation of nanoparticles (in an acidic environment, the electrostatic attraction between the positive charge of PEI and the negative charge of TA is enhanced, promoting the self-assembly of PT nanoparticles). Simultaneously, suitable acidic conditions help the nanoparticles adhere better to the surface of the intermediate membrane, increasing the surface roughness of the membrane.

[0065] It should also be noted that after immersing the intermediate membrane in the PEI and TA mixed solution for 25 minutes, the pH value is adjusted with hydrochloric acid. An effective reaction can be achieved within a pH range of 2-4. When the pH value is below 2, the solution is too acidic, which may cause structural changes in PEI and TA, affecting the formation and adhesion of nanoparticles. When the pH value is above 4, the electrostatic complexation reaction rate decreases, which is not conducive to the self-assembly of nanoparticles and their adhesion to the membrane surface. In this application, a pH value of 3 is chosen, which effectively promotes the electrostatic complexation reaction between PEI and TA, accelerating the formation of nanoparticles.

[0066] S104. Adjust the pH of the mixed solution to 6-7, and continue to soak the intermediate membrane in the mixed solution for a second specified time to obtain the three-dimensional porous mycelium membrane.

[0067] It should be noted that the pH of the mixed solution can be adjusted to 6.5 using NaOH. This step is to neutralize the acidic environment, making the chemical environment on the membrane surface more stable, and also helps to further stabilize and solidify the NaOH-MM network structure. Immersing the intermediate membrane at pH 6.5 for another 30 minutes (the second specified time) allows the nanocomplexes to adhere more firmly to the membrane surface, enhancing the membrane's durability and stability, ultimately yielding a high-performance three-dimensional porous mycelial membrane (MM@N-PT).

[0068] It should also be noted that adjusting the pH of the mixed solution to around 6.5 with NaOH for subsequent soaking is actually effective, as a pH range of 6-7 generally yields good membrane performance optimization. When the pH is below 6, the chemical environment on the membrane surface is not stable enough, and the binding of PT nanoparticles to the membrane surface is not strong enough. When the pH is above 7, it may cause changes in the charge distribution on the membrane surface, affecting the balance between the membrane's hydrophilicity and underwater oleophobicity. In this application, a pH of 6.5 was determined to allow the nanocomplexes to adhere more firmly to the membrane surface, enhancing membrane stability.

[0069] It should also be noted that during the pH adjustment process, when using PEI and TA solutions to modify the roughness of the intermediate membrane, the specific timing of pH adjustment is as follows: After immersing the intermediate membrane in the mixed solution (a mixture of 2 mg / ml PEI solution and 1.5 mg / ml TA solution) for 25 minutes, the pH of the mixed solution is adjusted to 3 using hydrochloric acid. Immediately after this adjustment, the pH of the mixed solution is adjusted to 6.5 using NaOH. The intermediate membrane is then immersed in the mixed solution for another 30 minutes, thus completing the entire roughness modification process and obtaining a three-dimensional porous mycelial membrane (MM@N-PT). This precise timing ensures the accuracy and repeatability of the pH adjustment process, guaranteeing the preparation of a stable three-dimensional porous mycelial membrane.

[0070] It should also be noted that the hydrophilicity and underwater oleophobicity of the three-dimensional porous mycelial membrane are balanced. The underwater oil contact angle, membrane flux, and separation efficiency of the three-dimensional porous mycelial membrane remain stable under various environmental conditions and after multiple cycles. Specifically, water droplets can rapidly wet the three-dimensional porous mycelial membrane within 1 second; the underwater oil contact angle of the three-dimensional porous mycelial membrane is greater than 150°; the underwater oil contact angle of the three-dimensional porous mycelial membrane is greater than 150° under various environmental conditions and after multiple cycles; and the membrane flux of the three-dimensional porous mycelial membrane is greater than 300 μm under various environmental conditions and after multiple cycles. -2 h -1 The separation efficiency of the three-dimensional porous mycelial membrane is greater than 99% under various environmental conditions and after multiple cycles. Furthermore, the three-dimensional porous mycelial membrane removes more than 70% of heavy metal ions from the emulsion.

[0071] The following analysis and testing were conducted on samples prepared using three-dimensional porous mycelial membrane preparation methods (such as OR-MM, NaOH-MM, MM@N-PT, etc.) to understand their physical and chemical properties. The specific measurement methods and instruments used are as follows:

[0072] Scanning electron microscopy (SEM): The surface morphology of the samples was observed using a ZEISS Sigma 300 (Germany). SEM allows for direct visualization of the microstructure of the mycelial membrane at different preparation stages, such as the entangled filament network membrane formed by Ganoderma lucidum mycelia on a birchwood substrate in OR-MM, the retention of the micronetwork structure after alkaline treatment in NaOH-MM, and the nanoparticles attached to MM@N-PT due to chemical treatment. This helps in analyzing the structural characteristics and changes of the membrane.

[0073] Fourier transform infrared spectroscopy (FTIR): The functional groups of the sample were detected using a Thermo Fisher Scientific Nicoleti S20 (USA). By analyzing the position and intensity changes of different absorption peaks in the FTIR spectrum, the presence of components such as chitin, chitosan, and PT nanoparticles in the sample, as well as changes in their chemical structures, can be determined. Examples include the -OH stretching vibrations of some polysaccharide fragments in chitin and chitosan, and the appearance of new absorption peaks due to the attachment of PT nanoparticles. This provides a basis for studying the interactions between different components.

[0074] X-ray photoelectron spectroscopy (XPS): Utilizing Thermo Scientific K-Alpha (USA), the surface chemical composition of samples is tested. X-ray photoelectron spectroscopy can further verify changes in the elemental composition and chemical state of the sample surface. For example, after OR-MM is treated with an alkaline substrate and combined with PT nanoparticles, changes in characteristic peaks such as C1S, O1S, and N1S reflect changes in the surface chemical composition, including increases or decreases in the number of functional groups such as hydroxyl and amino groups, as well as the formation of new chemical bonds. This helps to gain a deeper understanding of the chemical properties and composite structure of the film.

[0075] Contact angle measurement: The water and oil contact angles of the samples were measured using a JY-82 contact angle meter (Chengde Dingsheng Co., Ltd., China). The water contact angle reflects the hydrophilicity of the membrane, while the oil contact angle is used to evaluate the underwater oleophobicity of the membrane. By measuring these contact angles, it is possible to determine the changes in the surface wettability of the membrane at different stages, such as the hydrophobicity of OR-MM, the improvement in hydrophilicity of NaOH-MM after alkaline treatment, and the superhydrophilicity and underwater superoleophobicity of MM@N-PT. This is crucial for performance evaluation in applications such as oil-water separation.

[0076] Other tests included: determining the oil concentration in the solution using an infrared oil content analyzer (JC-OIL-8, Qingdao Juchuang Instrument Co., Ltd.) to evaluate the membrane's oil separation effect; testing the specific surface area and pore size distribution of MM@N-PT using a fully automated specific surface area and porosity analyzer (Micromeritics ASAP2460, USA) to understand its porous structure characteristics; observing the distribution of oil droplets in the filtrate and permeate using a biological microscope (XD-303LEDCOLDLIGHTSOURCE, China) to visually verify the membrane's separation effect; analyzing dynamic light scattering (DLS) using a Malvern Zetasizer Nano ZS90 (UK); and testing Pb using a UV-Vis spectrophotometer (Shanghai Unico Instrument Co., Ltd., China). 2+ The concentration of these ions was used to study the membrane's ability to remove heavy metal ions. These methods comprehensively analyzed the properties of the samples from multiple perspectives, providing important data support for research on membrane preparation processes, performance optimization, and applications.

[0077] The experimental principles involved in this application are described below:

[0078] Separation experiments of oil-in-water emulsions, oil-water mixtures, and methylene blue solutions:

[0079] To prepare a series of surfactant-stabilized oil-in-water emulsions, 0.3 g of oil, 0.015 g of CTAB, and 150 mL of deionized water were mixed and stirred at 1500 rpm for 3 h. To prepare oil-water mixtures, 20 g of oil and 20 g of water were mixed. The oil was stained with Sudan Red. The separation effect of MB was observed using a spectroscopic instrument (FT-IR, VECTOR22, Bruker, Germany). In the experiment, a standard glass filter kit was used to separate the oil-in-water emulsions and oil-water mixtures, maintaining a separation height of 15 cm by gravity and an effective separation radius of 5 mm. The filtration flux was calculated using the following formula:

[0080] ;

[0081] Where J represents the filtration flux, in Lm. -2 h -1 V represents the liquid volume after passing through the MM@N-PT membrane, in L. A represents the effective filtration area, in m². 2 △t represents the effective separation time, in hours (h).

[0082] The separation efficiency of oil-in-water emulsions and oil-water mixtures is calculated using the following formula:

[0083] 100%;

[0084] Where R represents the separation efficiency, Cf C indicates the oil content of the filtrate. p This indicates the oil content of the permeate.

[0085] Durability test of MM@N-PT:

[0086] The durability of MM@N-PT was evaluated based on its salt resistance, acid and alkali resistance, etc. After immersion in a 3.5 wt% NaCl solution for different times, the filtration flux, separation efficiency, and underwater oil contact angle of MM@N-PT were measured. After immersion at different pH values ​​for 4 hours, the filtration flux and separation efficiency of MM@N-PT were tested. Furthermore, the reusability of the samples was evaluated by separating oil-water mixtures and oil-in-water emulsions for 10 cycles, with each cycle lasting 2 minutes.

[0087] Pb 2+ Removal experiment:

[0088] To evaluate the effect of MM@N-PT on Pb in oil-in-water emulsions 2+ The removal capacity of Pb was used to prepare Pb 2+ Mixed emulsions with concentrations ranging from 50 mg / L to 300 mg / L were analyzed by measuring the initial Pb in the filtrate. 2+ Concentration and residual Pb in the permeate 2+ Concentration, calculate Pb 2+ Removal efficiency. In the removal of Pb 2+ In the solution experiment, a standard glass filter kit was used, maintaining a separation height of approximately 2 cm by gravity, with an effective separation radius of 5 mm. The formula for calculating the removal efficiency is as follows:

[0089] ;

[0090] Where R represents the removal efficiency, and C0 represents Pb 2+ Initial concentration, C 60 This indicates the Pb content in the permeate after 60 minutes of filtration. 2+ Concentration. Different concentrations of Pb were removed using the same batch of MM@N-PT. 2+ .

[0091] The specific experimental process and results of this application are described below:

[0092] Figure 2 This is a schematic diagram illustrating the results of scanning electron microscopy tests on the surface and cross-section of OR-MM, NaOH-MM, and MM@N-PT, as shown in this application. Figure 2The sub-figures (a1) and (a2) show the top surface morphology of OR-MM; (b1) and (b2) show the top surface morphology of NaOH-MM; (c1) and (c2) show the top surface morphology of MM@N-PT; (a3) ​​shows the cross-sectional morphology of OR-MM; (b3) shows the cross-sectional morphology of NaOH-MM; and (c3) shows the cross-sectional morphology of MM@N-PT. Figure 2 As shown in (a1), Ganoderma lucidum hyphae can form an intertwined network of fine filaments on birchwood substrate, and the sticky substance (polysaccharide) secreted by the hyphae allows some hyphae to adhere together. The naturally controllable porous structure of the OR-MM membrane is beneficial for applications in water treatment. Furthermore, the cross-sectional SEM image shows that the hyphae self-growth and intertwine to form a three-dimensional porous structure. In addition, the hyphae possess a porous structure composed of tubular hyphae. The hollow tubular morphology of the Ganoderma lucidum hyphae facilitates water transport and increases the specific surface area, which is beneficial for the adsorption of heavy metal ions. The formation of the porous structure of the hyphae may be due to the degeneration or apoptosis of cells in the internal part as the hyphae increase in volume, leading to a hollow structure; on birchwood substrate, the hyphae may grow and branch in different ways, forming a unique hollow tubular structure. Figure 2 As shown in (a2), the SEM image of the OR-MM film reveals cubic particles, which may be due to powder particles left over from sawing birch planks. Since the OR-MM film surface naturally possesses hydrophobic properties, it is unfavorable for the preparation of superhydrophilic / underwater superoleophobic films. Therefore, its surface hydrophobicity can be adjusted by treating it with an appropriate concentration of sodium hydroxide. Figure 2 As shown in (b1) and (b2), after OR-MM alkaline treatment, the membrane's microstructure remains intact, and the wood chip particles on the surface are also removed. Furthermore, an appropriately high surface roughness can effectively increase the filtration area of ​​the NaOH-MS membrane, thereby promoting faster water permeation through the membrane. Figure 2 As shown in (c2), a large number of nanoparticles are attached to the mycelium. This is due to the electrostatic complexation of TA and PEI under acidic conditions to form nano-couplers. At the same time, the subsequent weakly acidic conditions neutralize the alkaline-treated Ganoderma lucidum mycelial membrane, which can further stabilize and solidify the NaOH-MM network structure. This results in the final MM@N-PT having good mechanical strength and being able to effectively separate oil-in-water emulsions over a long period of time.

[0093] Chemical composition analysis:

[0094] Figure 3 ATR-FTIR spectra of OR-MM, NaOH-MM, and MM@N-PT; Figure 4 X-ray photoelectron spectra of OR-MM, NaOH-MM, and MM@N-PT; Figure 5High-resolution C1S, O1S, and N1S spectra of OR-MM; Figure 6 High-resolution C1S, O1S, and N1S spectra of NaOH-MM; Figure 7 High-resolution C1S, O1S, and N1S spectra of MM@N-PT.

[0095] like Figure 3 As shown, the FTIR spectra of OR-MM, NaOH-MM, and MM@N-PT all exhibit a wavelength of ~3270 cm⁻¹. -1 A broad absorption band centered on the chitin and chitosan moieties is attributed to the -OH stretching vibrations of the polysaccharide fragments. At 2920 cm⁻¹... -1 The nearby absorption peaks are mainly related to the stretching vibrations of CH in the alkyl chains, which are typically hydrophobic. NaOH-MM and MM@N-PT show absorption peaks near 2920 cm⁻¹. -1 The peak absorbance gradually decreases at ~1630 cm⁻¹, because the denaturation of hydrophobic proteins on the membrane surface leads to a reduction in the exposure of hydrophobic regions. Furthermore, at ~1630 cm⁻¹... -1 The peak value at this point is due to the C=O functional group in acetamide. The absorption intensity decreases with increasing deacetylation, indicating that more chitin is converted into hydrophilic chitosan. The MM@N-PT membrane absorbs at ~1320 cm⁻¹. -1 A new absorption peak appeared at ~1200 cm⁻¹, originating from CO stretching vibrations, confirming TA adhesion to the membrane. Simultaneously, a new absorption peak appeared at ~1200 cm⁻¹. -1 and ~1540cm -1 Absorption peaks for CN and NH molecular deformation vibrations were found at the , indicating that PT nanoparticles have been successfully introduced into NaOH-MM, thus forming an MM@N-PT film.

[0096] X-ray photoelectron spectroscopy can further verify the changes in the surface chemical composition of OR-MM after alkaline treatment and composite with PT nanoparticles. For example... Figure 4As shown, X-ray photoelectron spectroscopy was used to analyze the C1S, O1S, and N1S of OR-MM, NaOH-MM, and MM@N-PT. The O1S characteristic peak of NaOH-MM exhibited the highest binding energy at approximately 532 eV. This is attributed to the formation of numerous hydroxyl groups and other hydrophilic groups on the surface of the OR-MM film after NaOH treatment. The O1S characteristic peak of MM@N-PT was lower than that of NaOH-MM, likely due to the PT nanoparticles covering the film surface, reducing the exposed hydrophilic oxygen groups. Furthermore, the C1S characteristic peak of MM@N-PT was higher than that of NaOH-MM, possibly because the groups in the PT nanoparticles (such as the amino groups of PEI and the hydroxyl groups of TA) underwent new chemical interactions with the carbon atoms in the film, thus increasing the binding energy. In addition, the atomic ratios and the contents of O, N, and C elements in each sample were tested, indicating that the PT nanoparticles successfully adhered to the surface of the MM@N-PT film.

[0097] exist Figure 5 In the high-resolution C1S spectrum, the C=O peak in the NaOH-MM sample was caused by oxidation with sodium hydroxide. CN bonds appeared in the MM@N-PT sample, indicating that PEI was introduced into the film. The increased OC=O peak at approximately 288 eV was due to the reaction of the phenolic hydroxyl groups of TA with functional groups such as amino or carboxyl groups on the surface of the NaOH-MM film. Simultaneously, both PEI and TA contain a large number of C-C bonds, thus the C-C peak in the X-ray photoelectron spectrum of the MM@N-PT film also increased. These phenomena indicate that the composite nanostructure coating PT effectively covers the surface of the NaOH-MM film through electrostatic complexation. Figure 6 The increase in the number of oxygen-containing hydrophilic functional groups in MM@N-PT can prove that the membrane material has good hydrophilicity. Figure 7 The N1S spectra of the X-ray photoelectron spectroscopy of all samples showed -NC and -NH2 bonds, mainly attributed to the inherent protein and amino acid structures in the membrane, and possibly also related to the presence of amino compounds and adsorbed nitrogen compounds on the surface. Figure 7 As shown, NaOH treatment may lead to the degradation of nitrogen compounds, thereby weakening the signal of nitrogen groups in the NaOH-MM film in X-ray photoelectron spectroscopy, resulting in a decrease in peak value. Furthermore, the characteristic peak of the MM@N-PT film at approximately 401 eV is -NH3. + This is because the weakly acidic conditions lead to the protonation of the amino groups introduced into the PEI. These amino groups can form hydrogen bonds with water molecules, thereby enhancing the hydrophilicity of the MM@N-PT membrane.

[0098] Synthesis mechanism of MM@N-PT:

[0099] It should be noted that the OR-MM membrane was prepared using a controlled self-growth strategy by allowing Ganoderma lucidum mycelia and spores to grow on birchwood, thereby forming a three-dimensional porous membrane structure. The formation of this structure is mainly due to the following factors: First, Ganoderma lucidum mycelia have a high degree of branching and expansion ability, enabling them to grow rapidly along the surface and pores of the birchwood; second, the natural microporous structure of the birchwood provides growth channels for the mycelia, allowing them to expand in both upward and downward directions; in addition, the SDA medium provides sufficient nutrients for the mycelia; finally, the mycelia can self-assemble into a complex three-dimensional porous network during growth, further promoting the formation of the OR-MM membrane structure. To enable the prepared OR-MM membrane to be applied to wastewater treatment research, the following chemical treatment was performed: NaOH treatment deacetylates the main chitin component in the OR-MM membrane, converting it into chitosan. In the deacetylation reaction, the acetyl group (–COCH3) in the chitin molecule is converted into a hydroxyl group (OH-) in the NaOH solution. - Under the action of α, the chitin is removed, and through alkaline hydrolysis, a higher proportion of amino groups (-NH2) is generated, thereby converting the chitin portion into chitosan. Furthermore, NaOH treatment can increase the number of -OH groups in the chitin molecules, thus improving the hydrophilicity of the OR-MM membrane. However, the hydrophilicity of the formed NaOH-MM membrane is still insufficient. To further improve the hydrophilicity of the membrane, PT nanoparticles are self-assembled through the electrostatic attraction and hydrogen bonding between the positive charge of PEI and the negative charge of TA to increase the surface roughness of the NaOH-MM membrane, thereby further enhancing its hydrophilicity. Although nanoparticles are usually prone to detachment from the membrane surface, the -NH2 and -OH groups in the chitosan formed after NaOH treatment can react with the -OH groups of TA in the PT nanoparticles to form stable hydrogen bonds. Therefore, the PT nanoparticles can firmly adhere to the surface of the MM@N-PT membrane, enhancing its durability. Ultimately, the strong hydrogen bond network formed by the MM@N-PT membrane not only enhances the hydrophilicity of the membrane but also improves its stability. In addition, MM@N-PT membranes, rich in hydrophilic groups (-NH2, -OH, etc.), can not only achieve efficient oil-water separation, but also effectively remove heavy metal ions.

[0100] Surface wettability test:

[0101] The surface wettability, oil adhesion resistance, self-cleaning properties, and underwater oil resistance of MM@N-PT are key indicators for treating oily wastewater. OR-MM exhibits a water contact angle (WCA) of 150° in air, and water droplets can remain embedded for 60 seconds without penetrating, indicating strong hydrophobicity. This high water contact angle is related to the hydrophobicity of the outermost hydrophobic proteins of the fungal hyphae cell wall. Sodium hydroxide denatures the hydrophobic proteins in the OR-MM membrane and converts its chitin into chitosan, thus achieving hydrophilic modification of the OR-MM surface. Specifically, water droplets can wet the NaOH-MM membrane within 2 seconds, indicating that alkaline treatment can significantly improve the hydrophilicity of OR-MM. Furthermore, MM@N-PT exhibits superhydrophilicity, with water droplets rapidly wetting the MM@N-PT membrane within 1 second. This is due to the introduction of PT nanocomplexes onto the NaOH-MM membrane surface, increasing the surface roughness and hydrophilic groups. It should also be noted that the underwater oil contact angles of both NaOH-MM and MM@N-PT are greater than 150°, indicating that even simple alkaline treatment can impart underwater superoleophobic properties to the membranes. To further test the oil adhesion resistance of NaOH-MM and MM@N-PT, tetrachloroethylene solvent stained with Sudan Red was used as the oiling agent. Specifically, oil droplets could fall and bounce off the membrane surface with the needle without adhering, indicating that the NaOH-MM and MM@N-PT membranes have excellent oil adhesion resistance. Furthermore, when MM@N-PT was immersed in a large amount of red oil and then cleaned with water, no red oil adhered to its surface. Moreover, when a large amount of oil was dropped onto the MM@N-PT membrane immersed in water, the oil droplets quickly slid off without adhering. The experiments clearly show that the MM@N-PT membrane was not contaminated by oil droplets. These findings demonstrate that MM@N-PT possesses excellent self-cleaning properties and underwater oil resistance.

[0102] Controllable self-growth, stability, and durability:

[0103] The filtration flux and separation efficiency of the final three-dimensional porous mycelial membrane are controlled by the growth time of the Ganoderma lucidum mycelium; the generation time of the Ganoderma lucidum mycelium is related to the pore size and surface hydrophobic protein content of the initial mycelial membrane; the step of incubating the culture dish at 28°C for a specified number of days includes: incubating the culture dish at 28°C for 6 days.

[0104] As the growth time of Ganoderma lucidum mycelium extends, its growth on birch boards gradually becomes denser. In the early stages of growth, the mycelium is relatively sparse, and the resulting initial mycelial membrane (OR-MM) has larger pores and a relatively uneven distribution. Over time, the mycelium branches, expands, and intertwines, gradually filling the originally larger pore spaces, making the pores smaller and more evenly distributed. For example, after 4 days of growth, the membrane pores are relatively large, which may allow some smaller impurities or particles to pass through during filtration, affecting separation efficiency. However, when the growth time reaches 6 days or longer, the smaller and more uniform pores can more effectively trap impurities, improving filtration efficiency. This change in pore size directly affects the filtration flux of the three-dimensional porous mycelial membrane. Smaller and more uniform pores increase the resistance of liquid passing through the membrane, thus reducing the filtration flux. In practical applications, it is necessary to balance the relationship between pore size and filtration flux while ensuring a certain separation efficiency, and to select an appropriate mycelial growth time.

[0105] The content of hydrophobic proteins on the surface of Ganoderma lucidum mycelia changes during growth. In the early stages of mycelial growth, the content of hydrophobic proteins is relatively low, but as the mycelia mature, the concentration of hydrophobic proteins may increase. This increase in surface hydrophobic protein content enhances the hydrophobicity of the three-dimensional porous mycelial membrane surface. In water purification or oil-water separation applications, excessive hydrophobicity may affect the membrane's affinity for the aqueous phase and its repulsion of the oil phase, hindering efficient separation. Therefore, it is necessary to regulate the content of surface hydrophobic proteins by controlling the mycelial growth time to obtain optimal membrane surface wettability and separation performance.

[0106] Extensive experimental research and data analysis revealed that a 6-day static culture at 28℃ effectively balanced the filtration flux and separation efficiency of the three-dimensional porous mycelial membrane. At this point, the initial mycelial membrane's pore size and surface hydrophobic protein content reached a relatively suitable state. Compared to a 4-day growth period, the 6-day culture time resulted in a more stable membrane structure and a moderate pore size, ensuring both sufficient filtration flux and high separation efficiency. Compared to a 9-day growth period, it avoided the problems of excessively small pores and low filtration flux caused by excessive mycelial growth, while also preventing the negative impact of excessively high surface hydrophobic protein content on membrane performance. Therefore, considering various factors, a 6-day static culture at 28℃ was ultimately determined to obtain a high-performance initial mycelial membrane, thereby enabling the preparation of a three-dimensional porous mycelial membrane that meets application requirements.

[0107] Figure 8 The separation effect of MM@N-PT on oil-in-water emulsions obtained at different growth times is shown in the figure. Figure 9The separation effect of MM@N-PT on oil-in-water emulsion after soaking in NaCl solution (3.5wt%) for 0–48 h is shown in the figure. Figure 10 The underwater oil contact angle of the MM@N-PT membrane after immersion in NaCl solution (3.5wt%) for 0–48 h; Figure 11 The images show the separation effect of MM@N-PT on oil-in-water emulsions after soaking at different pH values ​​for 4 hours. Specifically, controlling the mycelial growth time is crucial for adjusting the pore size and surface hydrophobic protein content of the OR-MM membrane. By controlling the growth time of the OR-MM membrane, the flux and separation efficiency of the MM@N-PT membrane were improved. After the OR-MM membranes grew for 4, 6, and 9 days, they were removed from the birchboard and modified to obtain MM@N-PT membranes. The MM@N-PT membranes were then used to filter oil-in-water emulsions, yielding separation fluxes of 1756.07, 496.56, and 267.38 Lm, respectively. -2 h -1 The separation efficiencies were 99.82%, 99.99%, and 99.85%, respectively. Figure 8 As shown above, the results indicate that with prolonged hyphal growth, the OR-MM membrane network becomes denser, with smaller and more uniform pores, leading to a gradual decrease in the flux of the MM@N-PT membrane. Secondly, the content of surface hydrophobic proteins also changes with hyphal growth time. As the hyphae mature, the concentration of hydrophobic proteins may increase, enhancing the hydrophobicity of the MM@N-PT membrane surface. Considering both the flux and separation efficiency of the MM@N-PT membrane, the OR-MM membrane grown for six days was ultimately selected as the target for modification in oil-water separation experiments.

[0108] Furthermore, to test the adaptability of the MM@N-PT membrane under various environmental conditions, the MM@N-PT membrane was first immersed in a 3.5% NaCl solution for 0h, 6h, 12h, 24h, and 48h. Then, the membrane was removed and its underwater oleophobic angle, flux, and efficiency in separating oil-in-water emulsions were tested. Figure 9 As shown, the membrane flux of MM@N-PT stabilizes at 400 μm. -2 h -1 The separation efficiencies are 99.98%, 99.99%, 99.95%, 99.96%, and 99.98%, respectively. And from... Figure 10 It can be seen that after immersion in 3.5% NaCl solution for 0-48 hours, the underwater oleophobic angle of the MM@N-PT membrane remained at approximately 150°. These results indicate that MM@N-PT exhibits excellent salt tolerance. Furthermore, the separation effect of MM@N-PT on oil-in-water emulsions was tested after immersion in solutions with pH values ​​ranging from 3 to 11 for 4 hours. Figure 11The results showed that MM@N-PT maintained a separation efficiency higher than 99.90% even under extreme acidic and alkaline conditions. Furthermore, the MM@N-PT membrane retained its integrity after being immersed in an environment with pH values ​​ranging from 3 to 11 for 7 days. In addition, the MM@N-PT membrane possesses a dense mycelial network fiber structure, allowing it to continue to be used after being folded and bent. Therefore, these research results demonstrate that MM@N-PT exhibits excellent durability and stability, and can efficiently purify oily wastewater even under harsh acidic, alkaline, and high-salt conditions.

[0109] Separation of oil-water mixtures and purification of dyes:

[0110] Figure 12 This is a schematic diagram of the circulation separation of pure water by MM@N-PT; Figure 13 This is a schematic diagram of the cyclic separation of methyl silicone oil-water mixture by MM@N-PT; Figure 14 This is a process diagram of using MM@N-PT membranes to separate oil-water mixtures; Figure 15 Graphs showing membrane flux and separation efficiency for MM@N-PT in separating different types of oil-water mixtures; Figure 16 This is a process diagram of MM@N-PT used to separate methylene blue solution; Figure 17 The absorbance spectra before and after separation of methylene blue solution by MM@N-PT are shown. First, to investigate the anti-swelling performance of the MM@N-PT membrane, 10 water cycle tests were conducted. The membrane flux of MM@N-PT decreased with increasing cycle number, but remained at 400 μm. -2 h -1 above( Figure 12 This result demonstrates that the MM@N-PT membrane exhibits good anti-swelling properties, which is beneficial for its repeated use. To verify the reusability of MM@N-PT for separating methyl silicone oil-water mixtures, a ten-cycle test was conducted. Figure 13 As shown, the filtration flux of MM@N-PT can be maintained at 400 Lm. -2 h -1 The separation efficiency is above 99.99%. This result is likely due to the excellent mechanical properties and superior hydrophilicity of the MM@N-PT membrane, which prevents oil from adhering to its surface even under multiple filtration cycles. Figure 14 It can be observed that after the oil-water mixture is poured into the gravity separation device, the oil and water can quickly separate into layers. The water in the lower layer will permeate through the MM@N-PT membrane, while the oil in the upper layer is successfully intercepted and does not adhere to the membrane surface, indicating that the MM@N-PT membrane has excellent self-cleaning performance.

[0111] This application investigated the use of MM@N-PT membranes for the reaction of methyl silicone oil (MS), lubricating oil (LO), sunflower oil (SO), and cyclohexane (C6H). 12Five oil-water mixtures, including vacuum pump oil (VPO), were separated and tested. The results showed that the membrane filtration fluxes were 649.35, 763.94, 630.25, 687.55, and 725.75 Lm, respectively. -2 h -1 And the separation efficiency is greater than 99.99% ( Figure 15 The results of this study demonstrate that MM@N-PT membranes can effectively purify various oil-water mixtures and have broad application prospects.

[0112] In addition, this application also conducts purification tests on solutions containing methylene blue (MB), using ultraviolet-visible spectroscopy to test the absorbance of the original MB solution and the filtered solution to evaluate the separation efficiency of the MM@N-PT membrane for the dye (biomimetic high intensity). Figure 16 The process of filtering MB solution using an MM@N-PT membrane is demonstrated. The absorbance spectra of the MM@N-PT membrane before and after separation of the methylene blue solution are shown below. Figure 17 As shown in the figure, the original MB solution exhibits a specific peak at a wavelength of 660 nm, while the absorbance of the filtered solution approaches 0 in the wavelength range of 400-800 nm. This result indicates that MM@N-PT can effectively filter MB solutions. This is because the membrane, through its natural porous structure and abundant hydrophilic groups (such as hydroxyl, amino, and carboxyl groups), utilizes mechanisms such as physical adsorption, chemical adsorption, electrostatic interaction, and hydrophilicity-enhanced mass transfer to adsorb and bind with MB molecules, thereby achieving efficient removal of dyes from the solution.

[0113] Therefore, the novel porous membrane MM@N-PT, with its good anti-swelling properties and excellent hydrophilicity, can efficiently achieve the separation of oil-water mixtures and the purification of dyes in wastewater.

[0114] Separation of oil-in-water emulsions:

[0115] Because emulsified oil has small droplet size and high stability, it is quite difficult to purify. Figure 18 The experimental process and microscopic images of oil-in-water emulsion separation are shown. Figure 18 Figure (a) shows a microscopic image of the oil-in-water emulsion before separation, (b) shows the process of separating the oil-in-water emulsion using MM@N-PT, and (c) shows a microscopic image of the oil-in-water emulsion after separation. Figure 19 A pore size distribution diagram of MM@N-PT; Figure 20 The figure shows the results of the cyclic separation of oil-in-water emulsion using NaOH-MM. Figure 21 The graph shows the cyclic separation results of oil-in-water emulsions using MM@N-PT. Figure 22 Graphs showing membrane flux and separation efficiency for MM@N-PT in separating different types of oil-in-water emulsions; Figure 23The image shows the particle size distribution of oil droplets in the oil-in-water emulsion before and after separation. To further explore the application of MM@N-PT in oil-water separation, an oil-in-water emulsion was prepared using methyl silicone oil as a representative. A gravity separation device was employed. Figure 18 (b) A series of separation tests were conducted on oil-in-water emulsions. For example... Figure 18 As shown, the oil-water emulsion was effectively purified after gravity separation. Microscopic images revealed that the emulsion contained a large number of oil droplets before separation, while no oil droplets were found in the emulsion after separation, demonstrating that MM@N-PT can efficiently separate oil-in-water emulsions.

[0116] Furthermore, the average pore size of the MM@N-PT membrane is approximately 11 nm. Figure 19 This pore size facilitates membrane demulsification. The demulsification mechanism of the MM@N-PT membrane is as follows: The superhydrophilic properties of the MM@N-PT membrane lead to the formation of a stable hydration layer on its surface. Under gravity, this allows the aqueous phase to selectively pass through the membrane, while the oil phase is blocked on the membrane surface. This makes the emulsion unstable; the small droplets of the oil phase (dispersed phase) in the oil-in-water emulsion aggregate into large droplets, ultimately causing the oil and water phases to separate into two layers.

[0117] The cyclic separation of oil-in-water emulsions using NaOH-MM and MM@N-PT membranes, such as... Figure 20 , 21 As shown, after multiple oil-water separations, the filtration flux of the NaOH-MM membrane decreased from 267.38 Lm to 190.99 Lm. -2 h -1 However, the separation efficiency remained above 99.55%. In contrast, the filtration flux of the MM@N-PT membrane decreased from 477.46 μL to 324.68 μm after 10 cycles of separation. -2 h -1 The separation efficiency remained above 99.93%. These results demonstrate that the MM@N-PT membrane exhibits excellent repeatability during multiple cycles, primarily attributed to its superior superhydrophilicity, dense porous structure, and high surface roughness. Furthermore, to further verify the application potential of the MM@N-PT membrane in oil-in-water emulsions, its separation performance for various emulsions was tested. For example... Figure 22 As shown, the MM@N-PT membrane is effective against methyl silicone oil (MS), lubricating oil (LO), sunflower oil (SO), and cyclohexane (C6H). 12 The filtration fluxes of the five emulsions (including vacuum pump oil (VPO)) were 458.37, 485.10, 401.07, 439.27, and 477.46 Lm, respectively. -2 h -1The separation efficiency reached as high as 99.99%. To further verify the high efficiency of MM@N-PT in separating oil-in-water emulsions, the oil droplet size distribution before and after emulsion separation was tested. Figure 23 As shown, the oil droplet size ranged from 100 nm to 400 nm in the emulsion before separation, while the oil droplet size in the emulsion before separation was between 100 and 400 nm. No oil droplet distribution was found in the emulsion after separation. This result demonstrates that the MM@N-PT membrane can achieve efficient separation of oil-in-water emulsions. Furthermore, MM@N-PT can separate oily wastewater from ship bilges with a concentration of 5400 mg / L, achieving a separation efficiency of 99.85%. Therefore, this superhydrophilic / underwater superoleophobic porous mycelial membrane—MM@N-PT—which has a simple preparation method, low cost, and controllable self-growth characteristics, has broad application prospects in the field of oil-water separation and is expected to achieve large-scale application.

[0118] For Pb 2+ Removal:

[0119] Figure 24 The NaOH-MM membrane and MM@N-PT membrane shown in this application are used to treat Pb under different environments. 2+ The removal efficiency graph shows that in recent years, the use of fungi to remove heavy metal ions has attracted increasing attention from researchers (fungal detoxification). Figure 24 The sub-figures are (a) the effects of NaOH-MM film and MM@N-PT film on Pb. 2+ (a) Ion removal efficiency; (b) MM@N-PT membrane for different initial Pb concentrations 2+ (c) Removal efficiency of MM@N-PT membrane under different acid and alkaline conditions for Pb 2+ The removal efficiency is high. The charged functional groups such as hydroxyl and amino groups on the fungal cell wall make the cell wall surface electronegative, which is beneficial for fungi to purify metal ions in wastewater through ion exchange or electrostatic adsorption (modified microorganisms). This application mainly studies the removal of Pb from oil-in-water emulsions using MM@N-PT. 2+ .like Figure 24 As shown in (a), the NaOH-MS film on Pb 2+ The removal efficiency was 88.5%, while the MM@N-PT membrane showed a high removal efficiency of 88.5% for Pb. 2+ The removal efficiency was 92.8%. Among them, the NaOH-MS membrane showed the best removal efficiency for Pb. 2+ The removal effect mainly stems from the deacetylation reaction of chitin, which is abundant in the mycelium, to generate chitosan. The hydroxyl and amino groups in chitosan have a strong adsorption capacity for heavy metal ions (possessing heavy metal adsorption properties). To further enhance the membrane's ability to remove Pb from the emulsion... 2+To enhance the removal capacity of Pb, the NaOH-MM membrane was modified with a PT nanocomplex formed by PEI and TA, generating more -NH2 and -OH active groups, thereby improving the removal capacity of Pb. 2+ Its chelating ability.

[0120] Pb 2+ The initial concentration affects the Pb concentration of the MM@N-PT membrane. 2+ Key factors for removal efficiency. For example... Figure 24 As shown in (b), when Pb in an oil-in-water emulsion... 2+ When the concentration is in the range of 50 mg / L to 250 mg / L, with the increase of Pb 2+ With increasing concentration, the MM@N-PT membrane affects the Pb content. 2+ The removal efficiency gradually improved. However, when Pb... 2+ When the lead concentration increased to 300 mg / L, the removal efficiency of the MM@N-PT membrane actually decreased (lead-induced). This may be because the higher concentration of lead ions enhanced the mass transfer driving force of lead, overcoming the mass transfer limitation between the bacterial cell surface and the liquid phase, thereby increasing the adsorption capacity of the filter membrane for lead. Furthermore, the higher lead ion concentration also increased the number of effective collisions between the filter membrane and lead ions, strengthening the adsorption capacity of the bacteria for lead (Optimizing fungal removal of lead ions: An explanation of the fungal adsorption mechanism). Therefore, when the lead ion concentration in the oil-in-water emulsion was 250 mg / L, the MM@N-PT membrane showed a higher removal efficiency for Pb. 2+ The removal efficiency reached its maximum (94.4%). However, when the lead ion concentration is too high, it will cause insufficient binding sites on the surface of the MM@N-PT membrane, leading to competitive adsorption between metal ions, thereby reducing the removal efficiency (biofilm).

[0121] In addition, the pH of the solution also affects the effect of MM@N-PT on Pb. 2+ Removal efficiency is a crucial factor. Therefore, the removal efficiency of the MM@N-PT membrane for lead ions under different pH conditions was tested when the lead ion concentration in the oil-in-water emulsion was 50 mg / L. For example... Figure 24 As shown in (c), when pH=5, MM@N-PT affects Pb 2+ The removal efficiency reached 77.1%, while under strong acid or strong alkaline conditions, MM@N-PT showed a lower removal efficiency for Pb. 2+ The removal efficiency is relatively low. This is because when the pH value is too low, the surface of the MM@N-PT membrane will be affected by H3O. + Due to electrostatic repulsion, metal ions have difficulty binding to adsorption sites on the membrane surface; when the pH value is too high, heavy metal ions will reach their precipitation equilibrium constant, and thus generate hydroxide precipitates, thereby affecting the removal effect (Optimizing the removal of lead ions by fungi: an explanation of the fungal adsorption mechanism).

[0122] MM@N-PT membrane for Pb removal 2+ The mechanism of action is that the membrane achieves successful Pb removal through the synergistic effect (maximum) of complexation, electrostatic adsorption, and hydrogen bonding. 2+ Highly efficient removal. The removal mechanism is as follows: First, after alkaline treatment, more active groups such as -OH and -NH2 are generated on the membrane surface. Simultaneously, the abundant -NH2 and -OH groups in the PT nanocomplex further enrich the types and number of active adsorption sites on the MM@N-PT membrane. These groups can bind to Pb through coordination. 2+ This process forms stable complexes, thereby achieving efficient removal of heavy metal ions; secondly, in acidic solutions, the -NH2 portion of PEI is protonated to -NH3. + This gives the MM@N-PT membrane a positive charge on its surface. At the same time, the membrane surface still retains some negatively charged groups (such as -COO- groups). - ), through electrostatic attraction with Pb 2+ They combine to become the main adsorption sites. -NH3 + By adjusting the surface charge distribution, Pb is indirectly enhanced. 2+ The adsorption efficiency is improved; furthermore, the formation of hydrogen bonds in the MM@N-PT film can enhance the adsorption efficiency of hydrogen-containing polar groups (such as -OH, -NH2, -COOH, etc.) and Pb. 2+ Therefore, MM@N-PT membranes can effectively remove Pb from oil-in-water emulsions due to their binding capacity. 2+ .

[0123] Corresponding to the aforementioned embodiment of the method for preparing a three-dimensional porous mycelial membrane, this application also provides a three-dimensional porous mycelial membrane, which is prepared based on the method for preparing a three-dimensional porous mycelial membrane. The hydrophilicity and underwater oleophobicity of the three-dimensional porous mycelial membrane are balanced, and the underwater oil contact angle, membrane flux, and separation efficiency of the three-dimensional porous mycelial membrane remain stable under various environmental conditions and after multiple cycles.

[0124] Corresponding to the aforementioned embodiment of a method for preparing a three-dimensional porous mycelial membrane, this application also provides an application of the three-dimensional porous mycelial membrane, which is applied in the fields of water purification, oil-in-water emulsion separation, and oil-water mixture separation.

[0125] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a three-dimensional porous mycelial membrane, characterized in that, The method includes: Ganoderma lucidum mycelium was cultured on Sabouraud dextrose agar medium as nutrient source and birch board as carrier, so that the Ganoderma lucidum mycelium grew into an initial mycelial membrane with a three-dimensional porous grid structure on the birch board; The initial mycelial membrane was placed in a 1M NaOH solution and treated at 40°C for 2 hours. After washing with deionized water, an intermediate membrane was obtained. The intermediate membrane was immersed in a mixed solution consisting of 2 mg / ml PEI solution and 1.5 mg / ml TA solution and reacted for 25 minutes. After the reaction is complete, adjust the pH of the mixed solution to 2-4; The pH of the mixed solution was adjusted to 6-7, and the intermediate membrane was soaked in the mixed solution for another 30 minutes to obtain the three-dimensional porous mycelium membrane.

2. The method according to claim 1, characterized in that, Using Sabouraud dextrose agar as the nutrient source and birchwood as the carrier, Ganoderma lucidum mycelia were cultured, allowing the mycelia to grow on the birchwood to form an initial mycelial membrane, including: Preparation of mycelial suspension spores; High-temperature and high-pressure sterilization was performed on birch boards of a specified size, and the treated birch boards were placed in petri dishes containing sterilized Sabouraud dextrose agar medium. Under aseptic conditions, the mycelial suspension spores were inoculated onto the edge of a birch board to obtain a culture dish inoculated with spores. The culture dish was incubated at 28°C, and after the incubation was completed, the Ganoderma lucidum mycelium membrane generated on the birch board was peeled off with tweezers. The Ganoderma lucidum mycelium membrane was rinsed with deionized water to obtain the initial mycelium membrane.

3. The method according to claim 2, characterized in that, The filtration flux and separation efficiency of the three-dimensional porous mycelial membrane are controlled by the growth time of the Ganoderma lucidum mycelium; the generation time of the Ganoderma lucidum mycelium is related to the pore size of the initial mycelial membrane and the content of surface hydrophobic proteins; the culture dish is incubated at 28°C for 6 days.

4. The method according to claim 2, characterized in that, The preparation of mycelial suspension spores includes: A liquid culture medium was prepared using corn flour, deionized water, glucose, yeast powder, potassium dihydrogen phosphate, and magnesium sulfate. The liquid culture medium is dispensed into Erlenmeyer flasks, and the Erlenmeyer flasks are subjected to high-temperature and high-pressure sterilization. In a clean bench, mycelial sheets are inoculated into the triangular conical flask; The triangular conical flask inoculated with mycelium was left to stand for two days. After the standing culture was completed, the triangular conical flask was placed in a constant temperature incubator and cultured for 3 days to obtain the mycelial suspension spores.

5. A three-dimensional porous mycelial membrane, characterized in that, The three-dimensional porous mycelium membrane is prepared based on the method described in any one of claims 1-4.

6. An application of a three-dimensional porous mycelial membrane, characterized in that, The three-dimensional porous mycelium membrane is applied in the fields of water purification, oil-in-water emulsion separation, and oil-water mixture separation.

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