Urban and rural waste resource recycled zero-carbon composite material, preparation method, and use

Abstract

Disclosed in the present invention are an urban and rural waste resource recycled zero-carbon composite material, a preparation method, and a use. The raw materials of the material include, in parts by weight, 5-90 parts of paper pulp and 10-95 parts of urban and rural waste. The urban and rural waste includes at least two of plant fibers, food processing residues, sludge waste, or algae. The preparation method for the urban and rural waste resource recycled zero-carbon composite material comprises: using a pulp board to perform pulping to obtain paper pulp; crushing plant fibers, then pulping same, and performing treatment by means of a bioenzyme; crushing food processing residues, then pulping same, and performing treatment by means of a bioenzyme; subjecting sludge waste to a high-temperature and high-pressure oxidation reaction in the presence of an oxidizing agent, and then adding an amylase for reaction; crushing algae and then performing enzymatic hydrolysis; mixing the paper pulp with at least two of the pulps, adding a protein bioenzyme for grafting modification, adding water to make the concentration of the pulp reach a target value, and performing forming to obtain the urban and rural waste resource recycled zero-carbon composite material. The present invention solves the problems of low yield, instability and low physical properties of a single raw material by mixing and pulping two or more urban and rural waste resources, improves the fiber utilization rate and material mechanical properties, and achieves conversion of urban and rural solid waste to resources.

Description

A zero-carbon composite material for urban and rural waste resource recycling, its preparation method and application Technical Field

[0001] This invention relates to a recycled composite material, its preparation method, and its application, and more particularly to a zero-carbon composite material for the recycling of urban and rural waste resources, its preparation method, and its application. Background Technology

[0002] The production of paper products consumes a large amount of scarce natural carbon sink resources. Currently, the amount of urban and rural waste is enormous, including byproducts from agricultural and forestry production and processing (such as straw, wood chips, and bamboo strips), urban waste collected by sanitation departments (such as waste paper, dead branches from urban and rural green belts, straw, reeds, old bamboo and wooden furniture, algae, tailings from municipal water supply plants, organic sludge from sewage treatment plants, riverbed sediment, and reservoir sediment), and residues from food processing (such as medicinal residues, fruit pulp, coffee grounds, and distiller's grains). These wastes have low utilization rates, and existing treatment and disposal methods mainly rely on incineration, hindering the recycling of natural resources and increasing the burden of incineration. As there are few closed-loop resource utilization pathways for urban solid waste, improving the utilization rate of waste resources and the proportion of recycled resources is one of the main paths to building a waste-free city.

[0003] Fiber materials in urban and rural waste resources are not effectively utilized due to low and unstable yields, significant differences in pulping methods, inconsistent fiber quality, and low physical and mechanical properties. Currently, urban and rural waste resources are mainly disposed of by municipal departments, requiring substantial government expenditure. Therefore, recycling technologies are a sustainable development direction for achieving dual-carbon goals.

[0004] Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a zero-carbon composite material for the recycling of urban and rural waste resources by using a complex hybrid material and a bio-enzymatic synthesis method to solve the problem of converting low-strength fiber and non-fiber urban and rural solid waste into resources.

[0006] The second objective of this invention is to provide a method for preparing the above-mentioned zero-carbon composite material for urban and rural waste resource recycling;

[0007] The third objective of this invention is to provide the application of the above-mentioned zero-carbon composite material for urban and rural waste resource recycling.

[0008] Technical solution: The zero-carbon composite material for urban and rural waste resource recycling described in this invention comprises, by weight, 50-90 parts of pulp and 10-95 parts of urban and rural waste; the urban and rural waste includes at least two of the following: plant fiber, food processing residue, sludge waste, or algae.

[0009] The pulp is obtained by pulping using at least one type of pulp board, such as wood pulp board, bamboo pulp board, sugarcane pulp board, or straw pulp board.

[0010] The plant fibers include at least one of the following: straw, cotton stalks, wheat straw, bamboo strips, wood blocks, old bamboo and wooden furniture, rice straw, reeds, mulberry branches and leaves, and dead branches in urban and rural green belts; the food processing residues include at least one of the following: medicinal residues, fruit residues, coffee grounds, distiller's grains, and sugarcane bagasse; the sludge includes at least one of the following: tailings sludge from municipal water supply plants, organic sludge from sewage treatment plants, riverbed sediment, and reservoir sediment; and the algae include at least one of the following: seaweed, seagrass, pistache, and cyanobacteria.

[0011] The above-mentioned method for preparing zero-carbon composite materials from urban and rural waste resources includes the following steps:

[0012] (1) Pulp is obtained by using a pulp board;

[0013] (2) Plant fiber is crushed and ground into pulp, then biological enzymes are added for reaction and then ground into pulp; food processing residue is crushed and ground into pulp, then biological enzymes are added for reaction; sludge waste is subjected to high temperature and high pressure oxidation reaction under the condition of adding oxidant, and then amylase is added for reaction; algae are crushed and then subjected to enzyme hydrolysis treatment.

[0014] (3) The pulp from step (1) is mixed with at least two of the treated products from step (2), and protein bio-enzymes are added for grafting modification. Water is then added to make the pulp concentration reach the molding target value. After molding, a zero-carbon composite material of urban and rural waste resource recycling is obtained.

[0015] In step (2), the plant fiber is crushed and ground into pulp, mechanically disintegrated, and then protein bioenzymes are added for reaction. The pH value during the reaction is 5-8.5, the temperature is 50-85℃, and the time is 1-36h. The pulp concentration is greater than 10%, and then the pulp is ground again.

[0016] In step (2), the food processing residue is crushed and then ground into fiber pulp, mechanically disintegrated, and then biological enzymes are added for reaction. The pH value during the reaction is 5-8.5, the temperature is 50-85℃, and the time is 1-36h; the pulp concentration is greater than 10%.

[0017] In step (2), when the sludge waste is treated with an oxidant, the reaction is carried out at a temperature of 160-260°C and a pressure of 0.5-8MPa for 15-180 minutes. After the reaction, the solid and liquid are separated, and the solid containing 50-60% tbsp is activated with amylase at a temperature of 65-80°C for 30 minutes to 3 hours. The pH value during activation is 5-7, which makes the powder surface rich in hydrophilic groups and makes the powder surface charge positive. The oxidant is at least one of air, oxygen, H2O2, and O3. The separated liquid is used as a carbon source for protease production.

[0018] In step (2), when the algae are crushed and then subjected to enzymatic hydrolysis, the pH value is 5-6, the temperature is 50-80℃, and the time is 0.5-12h.

[0019] The separated liquid is used as a carbon and nitrogen source and added to the preparation process of the protein bio-enzyme solution in step (3) above. The preparation method of the protein bio-enzyme solution is as follows: First, the protein bio-enzyme flora is fermented and isolated from fiber waste, mainly Trichoderma and Aspergillus; Trichoderma and / or Aspergillus flora are selected for seed culture, and the strains are inoculated into starch solution culture medium. The temperature is set to 25-30℃ and the pH value is 5-7 for pre-culture to allow the strains to expand to a certain number and obtain a pre-prepared protease solution; The separated liquid is used as a carbon and nitrogen source and added to the pre-prepared protease solution. The fermentation environment temperature is controlled at 25-30℃ and the pH value is 5-7. Fermentation is carried out in a fermenter for 48-96 hours to obtain the protein bio-enzyme solution. The strains are pre-cultured to expand to 0.001-0.003 mg / L; then transferred to the sludge separation liquid, and after fermentation, the protein bio-enzyme solution is obtained with a strain content of 0.01-0.03 mg / L. This invention utilizes a prepared protein-based enzyme solution to conduct a continuous reaction on a mixture of materials.

[0020] In step (3), protein bio-enzymes are added for activation for 30 min-8 h, with a pH of 5-8.5 and a temperature of 50-85℃.

[0021] The above-mentioned zero-carbon composite materials derived from urban and rural waste resources are used in packaging materials.

[0022] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects: (1) The present invention uses two or more urban and rural waste resources to mix and pulp, thereby solving the problems of low yield and unstable yield of single raw materials. The method of grafting and modifying multiple raw materials with protein bioenzymes solves the problem of low physical properties, improves the utilization rate of multiple urban and rural wastes and the mechanical properties of materials, realizes the transformation of multiple urban and rural solid wastes from waste to resources and the transformation into high-value pulp substitute raw materials, realizes high-value resource utilization, improves the utilization rate of waste resources and the proportion of recycled resources, helps the construction of waste-free cities, and reduces waste. (2) Using two or more urban and rural waste resources to mix and pulp can improve the strength of paperboard through the coordination of different materials through functional groups, improve the chemical bond interaction rate between fibers through the combination of fibers and particles, reduce porosity, and improve the surface smoothness of materials. (3) The present invention uses different enzymes to surface activate and modify various raw materials, which can effectively change the physicochemical structure of the raw material surface, thereby promoting the continuous reaction between the mixed materials. (4) By utilizing urban and rural solid waste, traditional wood pulp can be significantly replaced, reducing the use of traditional forest resources and thus protecting forest resources and carbon sinks; and since urban and rural waste is handled by municipal funds, recycling waste can alleviate fiscal expenditure. (5) The raw materials are widely available, have negative carbon properties, and after being composited, the material has better strength, lighter texture, better smoothness, and lower price, making it a superior low-carbon and environmentally friendly recycled material that can be widely used in packaging materials. Attached Figure Description

[0023] Figure 1 shows the XRD patterns of tailings from municipal water supply plants in Examples 1, 2, 3, and 7.

[0024] Figure 2 is a particle size distribution diagram of tailings from a municipal water supply plant in Example 1;

[0025] Figure 3 shows the SEM images of the slurries from Comparative Example 1, Example 7, and Example 3;

[0026] Figure 4 shows the SEM images of the tailings sludge from the municipal water supply plant at various stages according to the present invention. Detailed Implementation

[0027] The present invention will now be described in further detail.

[0028] Example 1

[0029] A zero-carbon composite material for recycling urban and rural waste resources, comprising the following raw materials by weight: 90 parts wood pulp board, 5 parts distiller's grains, and 5 parts organic sludge from wastewater treatment plants. Its preparation method includes the following steps:

[0030] (1) Wood pulp board is pulped in a hydraulic pulper for 20 minutes and then set aside; (2) Fibers from crushed distiller's grains are ground in a grinder, then mechanically decomposed, and then subjected to biological enzyme treatment. Treatment conditions: pH 7.5, temperature 50℃, time 8h, and then set aside. (3) The treatment process conditions for organic sludge from the sewage treatment plant are 260°C, 8MPa, reaction time 180min, oxygen as the oxidant, median particle size of the treated material is 40μm, organic matter content is about 19%, and the product is separated into solid and liquid after reaction; then the solid is treated with an appropriate amount of amylase at 80°C for 180min, treatment conditions pH 5, and then set aside; the separated liquid is used as the carbon and nitrogen source for the protein biological enzyme solution. (4) Ferment 30g / L of crushed wheat straw in an environment with humidity above 90% to avoid direct sunlight. The temperature is set at 25℃ and the pH value is 5. Trichoderma is cultivated and extracted for seed culture. Then, the strain is extracted and inoculated into starch solution medium for pre-culture to expand the strain to 0.003mg / L. Then, it is transferred into the separation liquid of sludge. The fermentation environment temperature is controlled at 25℃ and the pH value is 5. Fermentation is carried out in a fermenter for 48h to obtain protein bio-enzyme solution with a concentration of 0.01mg / L. (5) Mix the various slurries and add the protein bio-enzyme solution prepared in step (4) at a mass ratio of 1:2 for continuous reaction. The treatment conditions are: pH value 6, temperature 70℃, and time 8h. (6) Add water to the pretreated raw materials to make the slurry concentration reach 1.5%. The product is prepared by suction filtration and molding.

[0031] Example 2

[0032] A zero-carbon composite material for recycling urban and rural waste resources, comprising the following raw materials by weight: 90 parts wood pulp board, 5 parts municipal water treatment plant tailings sludge, and 5 parts cyanobacteria. Its preparation method includes the following steps:

[0033] (1) Pulp the wood board in a hydraulic pulper for 20 minutes and set aside; (2) The treatment process conditions for tailings sludge from the municipal water supply plant are 160°C, 0.5MPa, reaction time of 15 minutes, oxidant is air, median particle size of the treated material is 39μm, organic matter content is about 10%, solid-liquid separation of the product after reaction; then the solid is treated with an appropriate amount of amylase at 65°C for 30 minutes, treatment condition pH value is 7, set aside; the separated liquid is used as the carbon and nitrogen source for the protein bio-enzyme solution. (3) Ferment 30g / L of wood flour in the dark at an ambient humidity of more than 90%, temperature is set at 30°C, pH value is 7, Aspergillus is cultivated and extracted for seed culture, then the strain is extracted and inoculated into starch solution culture medium for pre-culture, so that the strain expands to 0.003mg / L; then transferred to the sludge separation liquid, the fermentation environment temperature is controlled at 30°C, pH value is 7, fermentation in fermenter for 48 hours, to obtain protein bio-enzyme solution with a concentration of 0.03mg / L. (4) The cyanobacteria undergo cellulase hydrolysis reaction under the following conditions: pH 5, temperature 50℃, time 0.5h. (5) Mix the various slurries to achieve a uniform slurry concentration of approximately 13%, then add the self-made protein bio-enzyme solution for continuous reaction under the following conditions: pH 5.5, temperature 60℃, time 2h. (6) Add water to the pretreated raw materials to achieve a slurry concentration of 1.5%, then cast and filter press to prepare the product.

[0034] Example 3

[0035] A zero-carbon composite material for recycling urban and rural waste resources, comprising the following raw materials by weight: 25 parts bamboo pulp board, 25 parts sugarcane pulp board, 30 parts municipal waterworks tailings, and 20 parts straw. Its preparation method includes the following steps:

[0036] (1) Bamboo pulp board and sugarcane pulp board are pulped in a hydraulic pulper for 20 minutes and set aside. (2) The treatment process conditions for tailings sludge from municipal water supply plants are 180°C, 1MPa, and 30 minutes of reaction time. The oxidant is oxygen. The median particle size of the treated material is 40μm, and the organic matter content is about 10%. The product is separated into solid and liquid after reaction. Then, the solid is treated with an appropriate amount of amylase at 65°C for 30 minutes. The treatment conditions are pH 7 and set aside. The separated liquid is used as the carbon and nitrogen source for the protein bio-enzyme solution. (3) Straw is mechanically crushed to 10-50mm. The treated fiber is ground in a pulper, then mechanically decomposed, and then treated with protein bio-enzymes. The treatment conditions are pH 5, temperature 50°C, and time 1 hour and set aside. The pulp concentration is greater than 10%. (4) Mix the various slurries to a uniform slurry concentration of approximately 13%, then add a protein bio-enzyme solution for a continuous reaction. The treatment conditions are: pH 5.5, temperature 60℃, and time 3 hours. The protein bio-enzyme solution is prepared using the same method as step (3) in Example 2. (5) Add water to the pretreated raw materials to achieve a slurry concentration of 1.5%, then filter and mold to prepare the product. The material strength of the product prepared from this material is shown in Table 1, and it has the best strength among all examples.

[0037] Example 4

[0038] A zero-carbon composite material for recycling urban and rural waste resources, comprising the following raw materials by weight: 25 parts bamboo pulp board, 25 parts sugarcane pulp board, 30 parts municipal waterworks tailings, and 20 parts straw. Its preparation method includes the following steps:

[0039] (1) Bamboo pulp board and sugarcane pulp board are pulped in a hydraulic pulper for 20 minutes and set aside; (2) The treatment process conditions for tailings sludge from municipal water supply plants are 200°C, 3MPa, reaction time of 90 minutes, oxidant is O3, median particle size of treated material is 10μm, organic matter content is about 10%, solid-liquid separation of reaction product; then the solid is treated with an appropriate amount of amylase at 80°C for 30 minutes, treatment condition pH value is 7, set aside; the separated liquid is used as carbon and nitrogen source for protein bio-enzyme solution. (3) The straw is mechanically crushed to 10-50mm. The treated fibers are then ground in a pulper, mechanically loosened, and subsequently treated with protein bio-enzymes. The treatment conditions are: pH 5, temperature 50℃, time 1h, and ready for use; pulp concentration is greater than 10%. (4) Various pulps are mixed to a uniform pulp concentration of about 13%. A self-made protein bio-enzyme solution is added for continuous reaction. The treatment conditions are: pH 5, temperature 60℃, time 3h. The preparation method of the protein bio-enzyme solution is the same as step (3) in Example 2. (5) Water is added to the pretreated raw materials to make the pulp concentration reach 1.5%. The product is prepared by suction filtration. The material strength of the product prepared by this material is shown in Table 1. The strength is the best among all examples.

[0040] Example 5

[0041] A zero-carbon composite material for recycling urban and rural waste resources, comprising the following raw materials by weight: 3 parts bamboo pulp board, 2 parts sugarcane pulp board, 50 parts tailings from municipal waterworks, and 40 parts straw. Its preparation method includes the following steps:

[0042] (1) Bamboo pulp board and sugarcane pulp board are pulped in a hydraulic pulper for 20 minutes and then set aside; (2) The treatment process conditions for tailings sludge from municipal water supply plants are 180°C, 1MPa, and 30 minutes of reaction time, with air as the oxidant. The median particle size of the treated material is 40μm, and the organic matter content is about 10%. The product is separated into solid and liquid after reaction. Then, the solid is treated with an appropriate amount of amylase at 80°C for 30 minutes, with a pH of 7, and then set aside. The separated liquid is used as the carbon and nitrogen source for the protein bio-enzyme solution. (3) The straw is mechanically crushed to 50mm, and the treated fibers are ground in a pulper, then mechanically loosened, and then subjected to protein bio-enzyme treatment. The treatment conditions are: pH 5, temperature 50℃, time 1h, and ready for use; pulp concentration is greater than 10%; (4) Mix the various pulps, and uniformly mix the pulp concentration to about 13%. Add the self-made protein bio-enzyme solution for continuous reaction. The treatment conditions are: pH 5, temperature 60℃, time 3h; wherein, the preparation method of the protein bio-enzyme solution is the same as step (3) in Example 2; (5) Add water to the pretreated raw materials to make the pulp concentration reach 1.5%, and filter and mold to prepare the product. The material strength of the product prepared by this material is shown in Table 1, and the strength is the best among all examples.

[0043] Example 6

[0044] A zero-carbon composite material for recycling urban and rural waste resources, comprising the following raw materials by weight: 10 parts wood pulp board, 20 parts straw pulp board, 30 parts fruit pomace, 15 parts riverbed sediment, and 25 parts water hyacinth. Its preparation method includes the following steps:

[0045] (1) Wood pulp board and straw pulp board are pulped in a hydraulic pulper for 20 minutes and set aside. (2) Fruit pomace is mechanically crushed to 10-50 mm, and the treated fibers are ground in a grinder, then mechanically decomposed, and then subjected to biological enzyme treatment. The treatment conditions are pH 7.5, temperature 80℃, and time 36 h. Set aside. (3) Riverbed sediment is reacted at 260°C and 8MPa for 180 min, with O3 as the oxidant. The median particle size of the treated material is 39 μm, and the organic matter content is about 15%. The product is separated into solid and liquid. The solid is then enzyme-activated at 80°C for 3 h. The treatment conditions are pH 5. Set aside. The separated liquid is used as the carbon and nitrogen source for the protein biological enzyme solution. (4) Phoenix tail is mechanically crushed to fragments <5 mm, and then subjected to enzymatic hydrolysis. The treatment conditions are pH 6, temperature 80℃, and time 12 h. Set aside. (5) Mix the various slurries to a uniform slurry concentration of about 13%, add the self-made protein bio-enzyme solution for continuous reaction, and process under the following conditions: pH 6, temperature 85℃, time 30min; wherein, the preparation method of the protein bio-enzyme solution is the same as step (4) in Example 1. (6) Add water to the pretreated raw materials to make the slurry concentration reach 1.5%, and prepare the product by casting and pressure filtration.

[0046] Example 7

[0047] A zero-carbon composite material for recycling urban and rural waste resources, comprising the following raw materials by weight: 25 parts bamboo pulp board, 15 parts rice straw, 15 parts old bamboo and wooden furniture, 15 parts reeds, 15 parts sugarcane bagasse, and 15 parts coffee grounds. Its preparation method includes the following steps:

[0048] (1) Pulp bamboo pulp board in a hydraulic pulper for 20 minutes and set aside; (2) Cut straw, old bamboo and wooden furniture, and reeds into pieces of 10-50mm in size and <8mm in thickness, and mechanically and physically extrude and loosen them to initially disperse and dissociate the fibers to 10mm. The treated fibers are then ground in a pulper and mechanically loosened to a freeness of 45SR. Subsequently, they are subjected to biological enzyme treatment at pH 8.5, temperature 85℃, and time 6h to further disperse and dissociate the fibers and set aside. (3) Sugarcane bagasse is further dispersed and dissociated in a pulper. The treated fibers are then ground in a pulper and mechanically loosened to a freeness of 45SR and set aside. (4) Coffee grounds are ground in a grinder, then mechanically decomposed, and then treated with bio-enzymes. The treatment conditions are pH 7.5, temperature 50℃, and time 3h. The median particle size of the treated material is 27μm, and the organic matter content is about 10%. It is then set aside. (5) Various slurries are mixed to a uniform slurry concentration of about 13%. A self-made protein bio-enzyme solution is added for continuous reaction. The treatment conditions are pH 5, temperature 60℃, and time 8h. The preparation method of the protein bio-enzyme solution is the same as step (4) in Example 1. (6) Water is added to the pretreated raw materials to make the slurry concentration reach 1.5%. The product is then prepared by casting and pressing.

[0049] Example 8

[0050] A zero-carbon composite material for recycling urban and rural waste resources, comprising the following raw materials by weight: 10 parts wood pulp board, 10 parts bamboo strips, 10 parts wood blocks, 10 parts cotton stalks, 10 parts mulberry branches and leaves, 10 parts dead branches from urban and rural green belts, 15 parts organic sludge from sewage treatment plants, 15 parts cyanobacteria, and 10 parts distiller's grains. Its preparation method includes the following steps:

[0051] (1) Pulp the wood pulp board in a hydraulic pulper for 20 minutes and set aside; (2) Cut bamboo chips, wood blocks, cotton stalks, mulberry branches and leaves, and dead branches from urban and rural green belts into pieces with a size of 30-50 mm and a thickness of <8 mm. Perform mechanical physical extrusion to initially disperse and dissociate the fibers to 10 mm, and further disperse and dissociate the fibers; grind the treated fibers in a pulper, and then perform mechanical dissociation with a beating degree of 55SR. Then perform biological enzyme treatment under the following conditions: pH 8.5, temperature 85℃, time 12h, and set aside. (3) The treatment process conditions for organic sludge from the sewage treatment plant are 260°C, 8MPa, reaction time 180 min, oxidant is H2O2, median particle size of the treated material is 24 μm, organic matter content is about 19%, and the product is separated into solid and liquid after reaction; then the solid is treated with an appropriate amount of amylase at 80°C for 180 min under the following conditions: pH 5.5, and set aside; the separated liquid is used as the carbon and nitrogen source for the protein biological enzyme solution. (4) Blue-green algae undergo enzymatic hydrolysis reaction. The treatment conditions are pH 5, temperature 50℃, and time 0.5h. (5) Distillers' grains are ground in a grinder, then mechanically loosened, and then subjected to biological enzyme treatment. The treatment conditions are pH 7.5, temperature 50℃, and time 8h. The mixture is then set aside. (6) Various slurries are mixed to a uniform slurry concentration of about 13%. A self-made protein biological enzyme solution is added for continuous reaction. The treatment conditions are pH 5, temperature 60℃, and time 8h. The protein biological enzyme solution is prepared in the same way as step (4) in Example 1. (7) Water is added to the pretreated raw materials to make the slurry concentration reach 1.5%. The mixture is then cast and filtered to form the product.

[0052] Comparative Example 1

[0053] A material, the raw materials comprising, by weight: 100 parts wood pulp board.

[0054] (1) Pulp the wood pulp board in a hydraulic pulper for 20 minutes and set aside; (2) Add water to the pretreated raw material to make the pulp concentration reach 1%, and then cast and filter press to prepare the product.

[0055] Comparative Example 2

[0056] Based on Example 6, the difference from Example 6 is that the composite material contains, by weight, 50 parts of wood pulp board and 50 parts of lotus leaves.

[0057] (1) Pulp the wood pulp board in a hydraulic pulper for 20 minutes and set aside; (2) Crush the fern leaves mechanically to fragments <5mm, and then carry out an enzymatic hydrolysis reaction. The treatment conditions are pH 6, temperature 80℃, and time 12h. Set aside; (3) Mix the various pulps and mix them evenly to a pulp concentration of about 13%. Add the self-made protein bio-enzyme solution and react continuously. The treatment conditions are pH 6, temperature 85℃, and time 30min; (4) Add water to the pretreated raw materials to make the pulp concentration reach 1.5%. Cast and filter press to prepare the product.

[0058] Comparative Example 3

[0059] Based on Example 8, the difference is that in step (2), the reaction time is 30 min at 0.5 MPa. The median particle size of the treated material is 39 μm, and the organic matter content is about 8%. Then, an appropriate amount of amylase is added at 80°C for further treatment.

[0060] Comparative Example 4

[0061] Based on Example 8, the difference from Example 8 is that no pulp was added to the composite material. The raw materials, by weight, include: 10 parts bamboo strips, 15 parts wood blocks, 20 parts cotton stalks, 10 parts mulberry branches and leaves, 10 parts dead branches from urban and rural green belts, 10 parts organic sludge from sewage treatment plants, 10 parts cyanobacteria, and 15 parts distiller's grains.

[0062] Comparative Example 5

[0063] Based on Example 1, the difference from Example 1 is that step (4) is omitted.

[0064] The performance test results of each embodiment and comparative example are shown in Table 1 below; the performance analysis of the slurry obtained in Examples 1-3 and Example 7 is shown in Table 2.

[0065] As can be seen from Figure 1 and Table 2, the bonding area between the various fibers in Example 7 is the largest, and its mixed raw material composition is mainly plant fiber; the bonding strength between fibers in Example 3 is the highest, with more hydration swelling forming more intramolecular hydrogen bonds in the amorphous region.

[0066] As can be seen from the particle size distribution diagram of the sludge in Example 1 in Figure 2, the median epoch of the treated material is 40 μm, which is suitable for the preparation of composite materials.

[0067] Figure 3(a) is an electron microscope image of the slurry in Comparative Example 1, (b) is an electron microscope image of the slurry in Example 7, and (c) is an electron microscope image of the slurry in Example 3. As can be seen from the electron microscope images in Figure 3, the fiber bonding area after enzymatic hydrolysis is larger, i.e., in Example 7, the connection between the wastes is tighter after being connected by protease solution.

[0068] Figure 4(a) is a scanning electron microscope image of the original municipal water supply plant tailings used in each embodiment and comparative example, (b) is a scanning electron microscope image of the municipal water supply plant tailings after oxidation treatment in Example 2, and (c) is a scanning electron microscope image of the municipal water supply plant tailings after amylase activation in Example 2. As can be seen from Figure 4, the tailings of the water supply plant after oxidation treatment have smaller particle size and are more homogeneous, and the tailings after amylase activation have better surface affinity.

[0069] Table 1 Performance test results of each embodiment and comparative example

[0070] Table 2. Performance analysis of the final slurry obtained in Examples 1-3 and Example 7.

Claims

1. A zero-carbon composite material for recycling urban and rural waste resources, characterized in that, The raw materials, by weight, include: 5-90 parts pulp and 10-95 parts urban and rural waste; the urban and rural waste includes at least two of the following: plant fiber, food processing residue, sludge waste, or algae.

2. The zero-carbon composite material for urban and rural waste resource recycling according to claim 1, characterized in that, The pulp is obtained by pulping at least one of wood pulp board, bamboo pulp board, sugarcane pulp board, straw pulp board, or recycled paperboard; the plant fiber includes at least one of straw, cotton stalk, wheat straw, bamboo strips, wood blocks, old bamboo and wood furniture, rice straw, reeds, mulberry branches and leaves, and dead branches in urban and rural green belts; the food processing residue includes at least one of medicinal residue, fruit residue, coffee grounds, distiller's grains, and sugarcane bagasse; the sludge includes at least one of municipal water supply plant tailings sludge, sewage treatment plant organic sludge, riverbed sediment, and reservoir sediment; the algae includes at least one of seaweed, seagrass, water hyacinth, and blue-green algae.

3. A method for preparing a zero-carbon composite material for urban and rural waste resource recycling as described in claim 1, characterized in that, Includes the following steps: (1) Pulp is obtained by using a pulp board; (2) After the plant fiber is crushed and ground into pulp, biological enzymes are added to react and then ground into pulp again. Food processing residues are crushed, ground into a paste, and then reacted with biological enzymes; sludge waste undergoes high-temperature and high-pressure oxidation under the condition of adding oxidant, followed by the addition of amylase; algae are crushed and then subjected to enzymatic hydrolysis. (3) The pulp from step (1) is mixed with at least two of the treated products from step (2), and protein bio-enzymes are added for grafting modification. Water is then added to make the pulp concentration reach the molding target value. After molding, a zero-carbon composite material of urban and rural waste resource recycling is obtained.

4. The method for preparing zero-carbon composite materials for urban and rural waste resource recycling according to claim 3, characterized in that, In step (2), the plant fiber is crushed and ground into pulp, mechanically disintegrated, and then biological enzymes are added to react. The pH value of the reaction is 5-8.5, the temperature is 50-85℃, and the time is 1-36h. Then the pulping is carried out again.

5. The method for preparing zero-carbon composite materials for urban and rural waste resource recycling according to claim 3, characterized in that, In step (2), the food processing residue is crushed and then the fiber is ground into a pulp, mechanically disintegrated, and then biological enzymes are added to react. The pH value of the reaction is 5-8.5, the temperature is 50-85℃, and the time is 1-36h.

6. The method for preparing zero-carbon composite materials for urban and rural waste resource recycling according to claim 3, characterized in that, In step (2), when the sludge waste is treated with the addition of an oxidant, the reaction is carried out at a temperature of 160-260°C and a pressure of 0.5-8MPa for 15-180 min. After the reaction, the solid and liquid are separated. The solid with a water content of 50-60% is activated with amylase at a temperature of 65-80°C for 30 min-3 h. The pH value during activation is 5-7, which makes the surface of the powder rich in hydrophilic groups and makes the surface charge of the powder positive. The separated liquid is used as a carbon source for the production of protease.

7. The method for preparing zero-carbon composite materials for urban and rural waste resource recycling according to claim 3, characterized in that, In step (2), when the algae are crushed and then subjected to enzymatic hydrolysis, the pH value is 5-6, the temperature is 50-80℃, and the time is 0.5-12h.

8. The method for preparing zero-carbon composite materials for urban and rural waste resource recycling according to claim 6, characterized in that, The separated liquid is used as a carbon and nitrogen source and added to the preparation process of the protein bio-enzyme solution in step (3) of claim 3. The preparation process of the protein bio-enzyme solution is as follows: First, the protein bio-enzyme flora is fermented and isolated from fiber waste. A flora containing Trichoderma and / or Aspergillus is selected for seed culture. The strain is inoculated into a starch solution culture medium, the temperature is set to 25-30℃, the pH value is 5-7, and pre-culture is carried out to allow the strain to expand to a certain number and obtain a pre-prepared protease solution. The separated liquid is used as a carbon and nitrogen source and added to the pre-prepared protease solution. The fermentation environment temperature is controlled to be set to 25-30℃, the pH value is 5-7, and fermentation is carried out in a fermenter for 48-96 hours to obtain the protein bio-enzyme solution.

9. The method for preparing zero-carbon composite materials for urban and rural waste resource recycling according to claim 3, characterized in that, Add protein bio-enzyme solution and carry out the activation reaction for 30 min-8 h, with a pH value of 5-8.5 and a temperature of 50-85℃.

10. The application of the zero-carbon composite material of urban and rural waste resource recycling as described in claim 1 in packaging materials.

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