Application of sludge, sludge-hypha bio-based material and preparation method of sludge-hypha bio-based material

Abstract

The invention discloses application of sludge, a sludge-hypha bio-based material and a preparation method of the sludge-hypha bio-based material, and relates to the technical field of biopolymer materials, and the preparation method comprises the following steps: S1, performing innocent treatment on the sludge, then drying to constant weight, then grinding, and performing sterilization treatment on the ground sludge powder; s2, tearing mycelia into small particles, performing mixed inoculation on the mycelia particles and the sterile sludge matrix prepared in the S1 in a sterile environment to obtain a sludge-mycelia mixture, and loading the sludge-mycelia mixture into a mold for sealing; s3, placing the sludge-hypha mixture in a constant-temperature and constant-humidity box, and culturing in a dark place at the temperature of 20-30 DEG C and the relative humidity of 60-70%; and S4, after the hyphae are fully distributed, demolding, and air-drying and inerting in a drying oven at 35-45 DEG C for 72 hours to obtain the required sludge-hypha bio-based material. According to the method, the municipal sludge is used as a nutrient source and a growth substrate of the mycelium, so that a stable raw material source is provided for a mycelium bio-based material, and a recycling path of the municipal sludge is expanded and innovated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological macromolecular materials, and particularly relates to a sludge-mycelium bio-based material and a preparation method thereof. BACKGROUND

[0002] In recent years, mycelium bio-based material as a new green material has attracted more and more attention, which is a kind of degradable porous material manufactured by combining fungi with substrates by using the growth characteristics of fungal mycelium. The material can be made into different shapes by using different molds, and can replace foamed polystyrene (EPS) in the fields of packaging, heat preservation, sound insulation and the like. All raw materials are green and environmentally friendly and non-toxic, which greatly reduces environmental pollution. Moreover, the production process is simple, energy consumption is low, and cost is low. At present, the production of mycelium bio-based material mainly uses agricultural and forestry organic wastes such as corn cobs, cottonseed hulls, rice hulls and straw as growth substrates. These agricultural and forestry organic wastes are rich in lignocellulose components required for mycelium growth, such as cellulose, hemicellulose, lignin and other polysaccharides. However, due to the seasonality of agricultural by-products and the limitation of raw material acquisition by region, the continuous supply of substrates limits the stable production of mycelium bio-based material.

[0003] At the same time, with the acceleration of urbanization, the production of municipal sludge continues to rise, and traditional disposal methods such as landfill and incineration not only occupy land resources, but also have secondary environmental risks such as greenhouse gas emissions and heavy metal pollution. It is worth noting that sludge contains a large amount of organic matter (including cellulose, protein, etc.) and rich nutrients such as nitrogen and phosphorus, which are similar to agricultural by-products in theory and can be used as a high-quality culture medium for fungal growth to promote mycelium growth and form mycelium bio-based material.

[0004] Therefore, it is urgent to develop a mycelium bio-based material that can use sludge as a substrate. SUMMARY

[0005] The present application aims at the above-mentioned problems, and provides an application of sludge, a sludge-mycelium bio-based material and a preparation method thereof. Municipal sludge is used as a growth substrate for mycelium, and the organic components in the sludge are converted into mycelium growth nutrients, and the inorganic components participate in the construction of the material structure. The prepared sludge-mycelium bio-based material exhibits excellent properties such as light weight, high resilience, good cushioning performance and high compressive strength, and the material is degradable and has no secondary pollution, which can replace petroleum-derived products such as EPS. Not only does it provide a stable raw material source for mycelium bio-based material and overcome the bottleneck of agricultural and forestry organic waste supply, but also expands and innovates the resource utilization path of municipal sludge.

[0006] The technical scheme adopted by the present application is as follows: an application of sludge, and the sludge is used as a substrate for the preparation of mycelium bio-based material.

[0007] A preparation method of a sludge-mycelium bio-based material, comprising the following steps: S1, substrate preparation: harmless treatment is performed on sludge, and then the sludge is dried to constant weight, ground, and subjected to sterilization treatment to form a sterile sludge substrate for standby; S2, inoculation: the mycelium is torn into small particles, and the mycelium particles are mixed with the sterile sludge substrate prepared in S1 under a sterile environment to obtain a sludge-mycelium mixture, which is sealed in a mold; S3, cultivation: the sludge-mycelium mixture is placed in a constant-temperature and constant-humidity box, and cultivated in the dark at 20 DEG C to 30 DEG C and a relative humidity of 60% to 70%; S4, shaping: after the mycelium spreads, the sludge-mycelium bio-based material is obtained by demolding, drying and inertizing the sludge-mycelium mixture in an oven at 35 DEG C to 45 DEG C for 72 hours.

[0008] Alternatively, the harmless treatment is a hydrothermal oxidation technology, that is, the water content of the sludge is diluted to 90%, pyrolysis is performed at a temperature of 180 DEG C for 20 min to 40 min, pure oxygen is introduced, and the sludge solid phase is separated by precipitation after oxidation at 2 MPa for 10 min to 30 min.

[0009] Alternatively, the harmless treatment is a freeze-thaw technology, that is, the sludge is frozen at -15 DEG C to -20 DEG C for 10 hours, taken out and thawed at room temperature, and the sludge solid phase is separated by precipitation.

[0010] Alternatively, the sludge in S1 is ground to a particle size of less than 0.6 mm.

[0011] Alternatively, the sterilization method in S1 is to place the sludge powder in a high-temperature sterilization pot at 121 DEG C and 0.5 MPa for steam pressure for 0.5 hours, and then cool to room temperature in an ozone sterilization cabinet.

[0012] Alternatively, the mycelium is a medium-high temperature fungus, Pleurotus ostreatus.

[0013] Alternatively, the amount of the sterile sludge substrate incorporated in S2 when inoculation is 10% to 40% of the mass of the mycelium particles.

[0014] A sludge-mycelium bio-based material prepared by the preparation method of the sludge-mycelium bio-based material.

[0015] Alternatively, the sludge-mycelium bio-based material has a porous structure.

[0016] As described above, due to the adoption of the technical solutions, the present application has the following advantages: 1. The present invention provides an application of sludge, a sludge-mycelium bio-based material and its preparation method. Sludge is used as a matrix in the preparation of mycelium bio-based materials. It can not only provide energy for mycelial germination, extension and metabolism without the need for additional carbon and nitrogen sources, but also promote the rapid formation of a three-dimensional network with cementing effect by mycelia. Moreover, the inorganic components such as non-enzymatically biodegradable silica in sludge can be dispersed in the matrix as physical fillers to adjust the pore structure of the material and improve the structural stability.

[0017] 2. The sludge application, sludge-mycelium bio-based material and preparation method provided by the present invention do not require the addition of cementing materials during the preparation process, resulting in low energy consumption and low carbon emissions. The sludge-mycelium bio-based material has a porous structure and exhibits excellent properties such as light weight, high resilience, good buffering performance and high compressive strength. Moreover, the material is degradable, has no secondary pollution, and can replace petroleum-derived products such as EPS.

[0018] 3. The present invention provides an application of sludge, a sludge-mycelium bio-based material and its preparation method, which innovatively uses municipal sludge as a nutrient source and growth substrate for mycelium. This not only provides a stable source of raw materials for mycelium bio-based materials and overcomes the bottleneck of agricultural and forestry organic waste supply, but also expands and innovates the resource utilization path of municipal sludge, thereby achieving a coordinated unity of environmental and economic benefits. Attached Figure Description

[0019] The present invention will be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 This is a production flow diagram of the sludge-mycelium bio-based material of the present invention; Figure 2 SEM images of the bio-based materials prepared in Examples 1 (a, b), 3 (c, d), and 6 (e, f). Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings.

[0021] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0022] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is merely one example of a series of equivalent or similar features.

[0023] An application of sludge, in which sludge is used as a substrate in the preparation of mycelial bio-based materials.

[0024] The advantages of using sludge as a substrate are as follows: First, sludge can simultaneously achieve both nutritional and filling effects without the need for additional additives. On one hand, the organic components in sludge, such as proteins, lipids, and polysaccharides, can be broken down into small-molecule nutrients by proteases and lipases secreted by mycelia. This eliminates the need for additional carbon and nitrogen sources, providing energy for mycelial germination, extension, and metabolism, and promoting the rapid formation of a three-dimensional network with a cementing effect. On the other hand, the inorganic components in sludge, such as silica, cannot be enzymatically degraded and can be uniformly dispersed in the substrate as physical fillers, regulating the internal pore structure and improving structural stability. Meanwhile, agricultural and forestry organic waste is mainly composed of recalcitrant macromolecules such as cellulose and lignin, often requiring external carbon and nitrogen sources to support mycelial growth. Furthermore, agricultural and forestry organic waste lacks components that can act as physical fillers; if the material structure needs to be adjusted, glass particles, leather scraps, and natural polymer resins must be added to increase the material's density and strength. Secondly, sludge is an inevitable byproduct of municipal wastewater treatment. Using it as a mycelial substrate can efficiently absorb sludge volume, converting organic components into nutrients for mycelial growth, while inorganic components participate in the material's structural construction. There are no excess waste components. Compared to agricultural and forestry organic waste, it carries the additional environmental value of municipal sludge disposal, alleviating the pressure on urban environmental governance. Finally, the supply of sludge raw materials is highly stable. Sludge is continuously produced year-round by municipal wastewater treatment plants, with a stable source unaffected by seasons or regions. This provides a stable raw material guarantee for the industrial and large-scale production of mycelial bio-based materials, avoiding production stoppages due to raw material shortages. In contrast, agricultural and forestry organic waste (such as straw and bagasse) depends on seasonal production, is limited by region and climate, and has poor supply stability.

[0025] A method for preparing sludge-mycelium bio-based materials, such as Figure 1 As shown, it includes the following steps: S1. Matrix preparation: The sludge is rendered harmless, then dried to constant weight and ground. The ground sludge powder is then sterilized to form a sterile sludge matrix for later use. S2. Inoculation: Tear the mycelium into small particles, mix the mycelium particles with the sterile sludge substrate prepared in S1 under sterile conditions to obtain a sludge-mycelium mixture, and seal it in a mold. S3. Cultivation: Place the sludge-mycelium mixture in a constant temperature and humidity chamber at 20℃~30℃ and 60%~70% relative humidity in the dark for cultivation. S4. Shaping: After the mycelium has spread, demold and place in an oven at 35℃~45℃ for 72 hours to air dry and inert, thus obtaining the desired sludge-mycelium bio-based material.

[0026] The S1 process, through harmless treatment, disrupts the colloidal structure and cell wall integrity of extracellular polymers in the sludge, overcoming the dehydration challenge caused by its strong water-holding capacity. This significantly improves dehydration efficiency and reduces moisture content, creating suitable conditions for subsequent transportation, substrate preparation, and mycelial growth. Simultaneously, the harmless treatment destroys pathogens, heavy metals, and toxic organic matter in the sludge, facilitating subsequent resource utilization. Drying to constant weight removes residual moisture, preventing microbial growth and secondary activation of harmful substances due to moisture residue, thus consolidating the harmless treatment effect. Furthermore, stabilizing the moisture content provides a precise basis for subsequent nutrient ratio control when used as a mycelial growth substrate, ensuring the stability of the mycelial growth environment. Grinding increases the contact area between the sludge and mycelia, promoting the more efficient release and absorption of small-molecule nutrients (such as acetic acid and amino acids) by the mycelia. Sterilization treatment aims to completely kill miscellaneous bacteria, preventing them from competing with the target mycelium for nutrients and even secreting inhibitory substances, which would hinder mycelial growth and cause material formation failure. At the same time, it avoids the long-term accumulation of unsterilized sludge, which could lead to secondary pollution. It ensures that the sludge is safely transformed into a nutrient substrate that mycelium can utilize, which is a necessary prerequisite for the stable use of sludge as a mycelial substrate.

[0027] In S2, tearing the mycelium into small particles increases the inoculation sites and makes it easier for the mycelium to mix evenly with the substrate, ensuring uniform distribution. Smaller particles also have a larger contact area with the substrate, allowing for faster absorption of moisture and nutrients, thus promoting uniform mycelial growth. Aseptic inoculation helps prevent contamination by other microorganisms, which could prevent the production of mycelium-sludge bio-based materials.

[0028] The purpose of maintaining a constant temperature and humidity in the S3 incubator, while avoiding light, is to provide an optimal environment for mycelial growth. 20℃–30℃ is the suitable temperature range for most fungal mycelial growth; at this temperature, the enzyme activity of the mycelium is at its peak, efficiently decomposing nutrients in the substrate and accelerating cell proliferation and mycelial extension. A relative humidity of 60%–70% keeps the substrate moist, providing a medium for mycelial absorption of water and soluble nutrients. It also prevents excessive humidity from causing substrate hypoxia or the growth of moisture-resistant bacteria, and avoids excessively low humidity from causing the substrate to dry and harden, hindering mycelial penetration and expansion. Constant temperature and humidity conditions eliminate the interference of environmental fluctuations on mycelial growth. The purpose of light-protected cultivation is to inhibit excessive fruiting body formation. If mycelial growth is stimulated by light, reproductive growth is easily initiated prematurely, resulting in a large number of fruiting bodies. This consumes nutrients in the substrate that should be used for mycelial growth, leading to hindered mycelial spread, a sparse network, and ultimately affecting the material's density and mechanical properties.

[0029] The role of air drying and inerting in S4 is to inactivate the mycelium through moderate dehydration and gentle treatment, thereby terminating metabolism. Simultaneously, it fixes the structural morphology of the mycelium-sludge bio-based material and regulates the moisture content to a reasonable range. The air drying temperature should not be too high, otherwise the mycelium-sludge bio-based material will lose water too quickly, resulting in significant deformation and shrinkage, and ultimately warping. The air drying time should not be too short to ensure sufficient internal moisture loss, reducing the risk of increased density, decreased thermal insulation performance, and the growth of miscellaneous bacteria during use due to residual moisture. Ultimately, this results in a structurally stable bio-based material that meets performance standards.

[0030] In summary, this invention utilizes sludge to promote mycelial growth, relying on the fungi's own metabolism to produce mycelia with a cementing effect. Simultaneously, the mycelia interweave and bind loose sludge particles into a mycelial network, which can be considered natural cement. No cementing materials are needed during the preparation process, resulting in low energy consumption and low carbon emissions. The resulting sludge-mycelial bio-based material has a porous structure, exhibiting excellent properties such as light weight, high resilience, good buffering performance, and high compressive strength. Furthermore, the material is biodegradable, produces no secondary pollution, and can replace petroleum-derived products such as EPS. This invention not only provides a stable raw material source for mycelial bio-based materials, breaking through the bottleneck of agricultural and forestry organic waste supply, but also innovatively expands the resource utilization pathway of municipal sludge, organically combining sludge treatment and green building material production, ultimately achieving a synergistic unity of environmental and economic benefits.

[0031] One alternative implementation involves hydrothermal oxidation technology for the harmless treatment. This involves diluting the sludge to 90% moisture content, pyrolyzing it at 180°C for 20-40 minutes, then oxidizing it with pure oxygen at 2 MPa for 10-30 minutes, followed by sedimentation to separate the sludge solid phase. Diluting the sludge to a uniform fluid or semi-fluid state optimizes heat conduction and mass transfer efficiency, preventing incomplete local reactions. The high-temperature, high-pressure water environment efficiently disrupts the extracellular polymer colloidal structure and microbial cell walls, releasing bound water to enhance dehydration. Simultaneously, it kills pathogens and oxidizes and decomposes recalcitrant toxic organic matter during the treatment process. It also degrades large organic molecules (such as cellulose and protein) into smaller molecules, and the resulting intermediate products, such as acetic acid, provide ample carbon and nitrogen sources for mycelial growth, laying a good substrate foundation for the preparation of mycelial bio-based materials. Separating the sludge solid phase removes excess water and soluble impurities generated during the oxidation reaction, resulting in a sludge solid phase with suitable moisture content and stable composition.

[0032] One alternative implementation involves freeze-thaw treatment, whereby the sludge is frozen at -15°C to -20°C for 10 hours, then thawed at room temperature, allowing the sludge solid phase to precipitate and separate. During the freeze-thaw process, a large amount of water in the sludge forms ice needles. These ice needles continuously grow and pierce the network structure of the sludge flocs, causing the solid particles to compact tightly. This releases a large amount of water from the sludge, thus improving dewatering performance. The mechanical action of the ice needles also destroys intracellular polymers and harmful substances in the sludge flocs, causing them to dissolve in large quantities, significantly improving the degree of sludge neutralization and creating favorable conditions for subsequent resource utilization. The precipitation and separation of the sludge solid phase can remove soluble substances, free water, and some bound water.

[0033] Hydrothermal oxidation technology involves pyrolysis at 180℃, resulting in lower energy consumption and better removal of heavy metals. It requires less investment per ton of sludge and is applicable year-round, making it more versatile. Freeze-thaw technology, on the other hand, has a weaker ability to remove recalcitrant substances from sludge and is primarily used for solid-liquid phase separation. It facilitates dewatering pretreatment and is more suitable for low-temperature regions or scenarios with available natural cooling sources, thus reducing energy consumption.

[0034] In one alternative implementation, the sludge in step S1 is ground to a particle size of less than 0.6 mm. Refining the sludge particles increases the specific surface area, making it easier for the organic matter in the sludge to contact the enzymes secreted by the mycelium, accelerating degradation efficiency, providing a more sufficient nutrient source for mycelial growth, promoting rapid mycelial extension and branching, and shortening the cultivation time.

[0035] In one alternative implementation, the sterilization process in S1 involves placing the sludge powder in a high-temperature sterilizer at 121°C and 0.5 MPa for 0.5 hours, followed by cooling to room temperature in an ozone disinfection cabinet. High-temperature, high-pressure sterilization thoroughly kills all residual microorganisms in the sludge powder. Ozone, with its strong oxidizing properties, continues to exert a secondary sterilization effect during the cooling process, effectively preventing the sludge powder from being recontaminated by environmental microorganisms during the cooling phase, thus ensuring the long-lasting sterilization effect.

[0036] In one alternative implementation, the mycelium is a thermophilic oyster mushroom. This thermophilic oyster mushroom has strong environmental adaptability, can absorb organic components from sludge, and can serve as a carbon and nitrogen source, promoting mycelial growth.

[0037] In one alternative implementation, during inoculation in S2, the amount of sterile sludge substrate incorporated is 10% to 40% of the mass of the mycelial particles. Adjusting the amount of sterile sludge substrate incorporated can optimize nutrient supply, thereby achieving optimal mycelial growth. Too low a concentration may limit mycelial germination and extension rates, resulting in slow network formation and low material strength; too high a concentration may lead to a dense substrate and poor material uniformity.

[0038] A sludge-mycelium bio-based material is prepared using the aforementioned method. The material's formation mechanism involves utilizing sludge to promote the growth of *Pleurotus ostreatus* mycelium. The fungus's own metabolism produces mycelium with a cementing effect, and simultaneously, the mycelium interweaves and binds loose sludge particles into a mycelial network. Ultimately, this composite structure of "mycelial network-sludge particles" forms a bio-based material possessing both lightweight and mechanical properties. The density range of the sludge-mycelium bio-based material is 0.3 g / cm³. 3 ~0.5g / cm 3 Its low density makes the material lightweight, which can significantly reduce the load on building structures and facilitate transportation, installation and construction. It is especially suitable for high-rise buildings or lightweight walls, partitions and other scenarios. Its compressive strength is over 600kPa, and its mechanical properties will increase with the amount of mycelium added and the density of the molding. This strength can meet the basic mechanical requirements of non-load-bearing scenarios, such as wall partitions and insulation layer filling.

[0039] Alternatively, the sludge-mycelium bio-based material has a porous structure. This porous structure significantly reduces the material's bulk density, achieving lightweight properties and reducing building load. Simultaneously, the mycelial network supports and maintains mechanical strength, preserving compressive and flexural strength while reducing density. Furthermore, the air trapped in the pores blocks heat conduction, giving the material excellent thermal insulation properties and contributing to building energy conservation. The porous structure also absorbs environmental noise, reduces sound reflection, and improves the material's sound insulation and noise reduction performance, allowing it to be applied to acoustic barriers, indoor sound-absorbing panels, and other scenarios.

[0040] Example 1 Medium- and high-temperature oyster mushrooms were selected as the mycelium, and sugarcane bagasse was used as the substrate.

[0041] S1. Matrix Preparation: First, the sugarcane bagasse is cleaned to remove dust and other impurities. Then, the sugarcane bagasse is treated with hydrothermal oxidation technology to render it harmless. The moisture content of the sugarcane bagasse is diluted to 90%, and it is pyrolyzed at 180℃ for 20-40 minutes. Pure oxygen is introduced, and it is oxidized at 2MPa for 10-30 minutes. The sugarcane bagasse solid phase is separated by precipitation. The separated sugarcane bagasse solid phase is dried to constant weight and then ground to a particle size of less than 0.6mm. The ground sugarcane bagasse is placed in a high-temperature sterilizer at 121℃ and 0.5MPa for 0.5 hours and then placed in an ozone disinfection cabinet to cool to room temperature to form a sterile sugarcane bagasse matrix for later use. S2. Inoculation: Tear the mycelium into small particles and mix them in an aseptic environment at a ratio of 8% of the mass of the mycelium particles to obtain a sugarcane bagasse-mycelium mixture. Then, pack the mixture into a mold and seal it. S3. Cultivation: Place the sugarcane bagasse-mycelium mixture in a constant temperature and humidity chamber at 20℃~30℃ and relative humidity of 60%~70% in the dark for cultivation. S4. Shaping: After the mycelium has spread, demold and place in an oven at 35℃~45℃ for 72 hours to air dry and inert, thus obtaining the desired sugarcane bagasse-mycelium bio-based material.

[0042] Example 2 Medium- and high-temperature oyster mushrooms were selected as the mycelium, and sugarcane bagasse and sludge were used as the substrate.

[0043] S1. Matrix Preparation: First, the bagasse is cleaned to remove dust and other impurities. Then, the bagasse and sludge are treated with hydrothermal oxidation technology to render them harmless. The moisture content is diluted to 90%, and the mixture is pyrolyzed at 180℃ for 20-40 minutes. Pure oxygen is then introduced, and the mixture is oxidized at 2MPa for 10-30 minutes. The solid phase is then separated by precipitation. The separated solid phase is dried to constant weight and then ground to a particle size of less than 0.6 mm. The ground bagasse and sludge powder are placed in a high-temperature sterilizer at 121℃ and 0.5MPa for 0.5 hours and then placed in an ozone disinfection cabinet to cool to room temperature, forming sterile bagasse matrix and sterile sludge matrix for later use. S2. Inoculation: Tear the mycelium into small particles and mix them in a sterile environment at a ratio of 8% of the mass of the mycelium particles to 10% of the mass of the mycelium particles to obtain a sugarcane bagasse-sludge-mycelium mixture. The mixture is then placed into a mold and sealed. S3. Cultivation: Place the sugarcane bagasse-sludge-mycelium mixture in a constant temperature and humidity chamber at 20℃~30℃ and relative humidity of 60%~70% in the dark for cultivation. S4. Shaping: After the mycelium has spread, demold and place in an oven at 35℃~45℃ for 72 hours to air dry and inert, thus obtaining the desired sugarcane bagasse-sludge-mycelium bio-based material.

[0044] Example 3 Medium- and high-temperature oyster mushrooms were selected as the mycelium, and sugarcane bagasse and sludge were used as the substrate.

[0045] S1. Matrix Preparation: First, the bagasse is cleaned to remove dust and other impurities. Then, the bagasse and sludge are treated with hydrothermal oxidation technology to render them harmless. The moisture content is diluted to 90%, and the mixture is pyrolyzed at 180℃ for 20-40 minutes. Pure oxygen is then introduced, and the mixture is oxidized at 2MPa for 10-30 minutes. The solid phase is then separated by precipitation. The separated solid phase is dried to constant weight and then ground to a particle size of less than 0.6 mm. The ground bagasse and sludge powder are placed in a high-temperature sterilizer at 121℃ and 0.5MPa for 0.5 hours and then placed in an ozone disinfection cabinet to cool to room temperature, forming sterile bagasse matrix and sterile sludge matrix for later use. S2. Inoculation: Tear the mycelium into small particles and mix them in a sterile environment at a ratio of 16% of the mass of the mycelium particles to 20% of the mass of the mycelium particles to obtain a sugarcane bagasse-sludge-mycelium mixture. The mixture is then placed into a mold and sealed. S3. Cultivation: Place the sugarcane bagasse-sludge-mycelium mixture in a constant temperature and humidity chamber at 20℃~30℃ and relative humidity of 60%~70% in the dark for cultivation. S4. Shaping: After the mycelium has spread, demold and place in an oven at 35℃~45℃ for 72 hours to air dry and inert, thus obtaining the desired sugarcane bagasse-sludge-mycelium bio-based material.

[0046] Example 4 Medium- and high-temperature oyster mushrooms were selected as the mycelium, and sludge was used as the substrate.

[0047] S1. Matrix Preparation: The sludge is treated with hydrothermal oxidation technology to render it harmless. The moisture content of the sludge is diluted to 90%, pyrolyzed at 180℃ for 20-40 minutes, pure oxygen is introduced, and it is oxidized at 2MPa for 10-30 minutes. The sludge solid phase is then separated by precipitation. The separated sludge solid phase is dried to constant weight and then ground to a particle size of less than 0.6 mm. The ground sludge powder is placed in a high-temperature sterilizer at 121℃ and 0.5MPa for 0.5 hours and then placed in an ozone disinfection cabinet to cool to room temperature to form a sterile sludge matrix for later use. S2. Inoculation: Tear the mycelium into small particles and mix them in a sterile environment at a ratio of 10% of the mass of the mycelium particles to obtain a sludge-mycelium mixture, which is then placed into a mold and sealed. S3. Cultivation: Place the sludge-mycelium mixture in a constant temperature and humidity chamber at 20℃~30℃ and 60%~70% relative humidity in the dark for cultivation. S4. Shaping: After the mycelium has spread, demold and place in an oven at 35℃~45℃ for 72 hours to air dry and inert, thus obtaining the desired sludge-mycelium bio-based material.

[0048] Example 5 Medium- and high-temperature oyster mushrooms were selected as the mycelium, and sludge was used as the substrate.

[0049] S1. Matrix Preparation: The sludge is treated with hydrothermal oxidation technology to render it harmless. The moisture content of the sludge is diluted to 90%, pyrolyzed at 180℃ for 20-40 minutes, pure oxygen is introduced, and it is oxidized at 2MPa for 10-30 minutes. The sludge solid phase is then separated by precipitation. The separated sludge solid phase is dried to constant weight and then ground to a particle size of less than 0.6 mm. The ground sludge powder is placed in a high-temperature sterilizer at 121℃ and 0.5MPa for 0.5 hours and then placed in an ozone disinfection cabinet to cool to room temperature to form a sterile sludge matrix for later use. S2. Inoculation: Tear the mycelium into small particles and mix them in a sterile environment at a ratio of 20% of the mass of the mycelium particles to obtain a sludge-mycelium mixture, which is then placed into a mold and sealed. S3. Cultivation: Place the sludge-mycelium mixture in a constant temperature and humidity chamber at 20℃~30℃ and 60%~70% relative humidity in the dark for cultivation. S4. Shaping: After the mycelium has spread, demold and place in an oven at 35℃~45℃ for 72 hours to air dry and inert, thus obtaining the desired sludge-mycelium bio-based material.

[0050] Example 6 Medium- and high-temperature oyster mushrooms were selected as the mycelium, and sludge was used as the substrate.

[0051] S1. Matrix Preparation: The sludge is treated with hydrothermal oxidation technology to render it harmless. The moisture content of the sludge is diluted to 90%, pyrolyzed at 180℃ for 20-40 minutes, pure oxygen is introduced, and it is oxidized at 2MPa for 10-30 minutes. The sludge solid phase is then separated by precipitation. The separated sludge solid phase is dried to constant weight and then ground to a particle size of less than 0.6 mm. The ground sludge powder is placed in a high-temperature sterilizer at 121℃ and 0.5MPa for 0.5 hours and then placed in an ozone disinfection cabinet to cool to room temperature to form a sterile sludge matrix for later use. S2. Inoculation: Tear the mycelium into small particles and mix them in a sterile environment at a ratio of 40% of the mass of the mycelium particles to obtain a sludge-mycelium mixture, which is then placed into a mold and sealed. S3. Cultivation: Place the sludge-mycelium mixture in a constant temperature and humidity chamber at 20℃~30℃ and 60%~70% relative humidity in the dark for cultivation. S4. Shaping: After the mycelium has spread, demold and place in an oven at 35℃~45℃ for 72 hours to air dry and inert, thus obtaining the desired sludge-mycelium bio-based material.

[0052] Conclusion: The compressive strength of Example 1 was 443 kPa, Example 2 was 437 kPa, Example 3 was 440 kPa, Example 4 was 577 kPa, Example 5 was 643 kPa, and Example 6 was 690 kPa. When using sludge as a substrate to prepare mycelial bio-based materials, the compressive strength of the materials significantly increased. Meanwhile, from... Figure 2 It can be seen that when sludge was used as a substrate to prepare mycelial bio-based material in Example 6, the width of the mycelium increased significantly. This indicates that sludge can significantly improve the compressive strength of the material through the dual effects of strengthening the structure with inorganic fillers and promoting mycelial thickening with readily available nutrients.

[0053] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention provides an application of sludge, a sludge-mycelium bio-based material and its preparation method. Sludge is used as a matrix in the preparation of mycelium bio-based materials. It can not only provide energy for mycelial germination, extension and metabolism without the need for additional carbon and nitrogen sources, but also promote the rapid formation of a three-dimensional network with cementing effect by mycelia. Moreover, the inorganic components such as non-enzymatically biodegradable silica in sludge can be dispersed in the matrix as physical fillers to adjust the pore structure of the material and improve the structural stability.

[0054] 2. The sludge application, sludge-mycelium bio-based material and preparation method provided by the present invention do not require the addition of cementing materials during the preparation process, resulting in low energy consumption and low carbon emissions. The sludge-mycelium bio-based material has a porous structure and exhibits excellent properties such as light weight, high resilience, good buffering performance and high compressive strength. Moreover, the material is degradable, has no secondary pollution, and can replace petroleum-derived products such as EPS.

[0055] 3. The present invention provides an application of sludge, a sludge-mycelium bio-based material and its preparation method, which innovatively uses municipal sludge as a nutrient source and growth substrate for mycelium. This not only provides a stable source of raw materials for mycelium bio-based materials and overcomes the bottleneck of agricultural and forestry organic waste supply, but also expands and innovates the resource utilization path of municipal sludge, thereby achieving a coordinated unity of environmental and economic benefits.

[0056] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. An application of sludge, characterized in that: Sludge is used as a substrate in the preparation of mycelial bio-based materials.

2. A method for preparing a sludge-mycelium bio-based material, characterized in that: Includes the following steps: S1. Matrix preparation: The sludge is rendered harmless, then dried to constant weight and ground. The ground sludge powder is then sterilized to form a sterile sludge matrix for later use. S2. Inoculation: Tear the mycelium into small particles, mix the mycelium particles with the sterile sludge substrate prepared in S1 under sterile conditions to obtain a sludge-mycelium mixture, and seal it in a mold. S3. Cultivation: Place the sludge-mycelium mixture in a constant temperature and humidity chamber at 20℃~30℃ and 60%~70% relative humidity in the dark for cultivation. S4. Shaping: After the mycelium has spread, demold and place in an oven at 35℃~45℃ for 72 hours to air dry and inert, thus obtaining the desired sludge-mycelium bio-based material.

3. The method for preparing sludge-mycelium bio-based materials as described in claim 2, characterized in that: The harmless treatment is a hydrothermal oxidation technology, which involves diluting the sludge to 90% moisture content, pyrolyzing it at 180℃ for 20-40 minutes, introducing pure oxygen, oxidizing it at 2MPa for 10-30 minutes, and then precipitating and separating the sludge solid phase.

4. The method for preparing sludge-mycelium bio-based materials as described in claim 2, characterized in that: The harmless treatment is a freeze-thaw process, in which the sludge is frozen at -15℃ to -20℃ for 10 hours, then taken out and thawed at room temperature, and the sludge solid phase is separated by precipitation.

5. The method for preparing sludge-mycelium bio-based materials as described in claim 2, characterized in that: In S1, the sludge is ground to a particle size of less than 0.6 mm.

6. The method for preparing sludge-mycelium bio-based materials as described in claim 2, characterized in that: The sterilization process in S1 involves placing the sludge powder in a high-temperature sterilizer at 121°C and 0.5 MPa for 0.5 hours, and then cooling it to room temperature in an ozone disinfection cabinet.

7. The method for preparing sludge-mycelium bio-based materials as described in claim 2, characterized in that: The mycelium is a medium-to-high temperature oyster mushroom.

8. The method for preparing sludge-mycelium bio-based materials as described in claim 2, characterized in that: During inoculation in S2, the amount of sterile sludge substrate incorporated is 10% to 40% of the mass of the mycelial particles.

9. A sludge-mycelium bio-based material, characterized in that: It is prepared by the method of any one of claims 2-8 for preparing sludge-mycelium bio-based materials.

10. The sludge-mycelium bio-based material as described in claim 9, characterized in that: The sludge-mycelium bio-based material has a porous structure.

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