Polypeptide-containing multifunctional organic-inorganic composite material as well as preparation method and application thereof

Abstract

The invention discloses a polypeptide-containing multifunctional organic-inorganic composite material as well as a preparation method and application thereof. The composite material is prepared by compounding organic matters such as waste containing lignin and water-insoluble polysaccharide, waste containing protein and the like and inorganic matters containing nitrogen, phosphorus and potassium through certain steps. The material has multiple functions of promoting plant growth, controlling nutrient release, absorbing and retaining water, reducing damage of saline-alkali soil to plants, passivating heavy metal ions and the like. The method has the advantages of easily available and cheap raw materials, no pollution in the production process, diversified product functions, convenience in use, high production efficiency, low cost, easiness in large-scale production and application and the like. The method is a new method for high-valued and large-scale utilization of wastes such as straws, can solve the problem of straw utilization, promotes agricultural production, protects the ecological environment, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural production and ecological management, and in particular to a multifunctional organic-inorganic composite material containing polypeptides, and a preparation method and application thereof. Background Art

[0002] Take straw as an example. my country produces nearly 1 billion tons of straw every year. After the ban on straw burning, most of the straw is directly returned to the fields. Although it can supplement organic matter for arable land, the straw decomposes slowly and the harmful pests and diseases it carries are not killed. Directly returning the straw to the fields has a series of adverse effects on agricultural production. Straw utilization has become a major challenge facing my country's agricultural production and ecological environment. On the other hand, these wastes are rich in various nutrients necessary for plant growth. Therefore, it is urgent to develop new technologies to recycle these wastes and make the best use of them while reducing environmental pollution.

[0003] In addition, there are still many problems in global agricultural production and ecological environment:

[0004] 1. The area of ​​desertified land is large and has a tendency to expand, which compresses the habitable space for humans;

[0005] 2. The saline-alkali land is widely distributed and covers a large area, while the arable land area is small;

[0006] 3. The area of ​​cultivated land polluted by heavy metals continues to expand, affecting food safety;

[0007] 4. Agricultural production consumes 60% of the world's fresh water resources. Abnormal drought weather has become normalized. There is an urgent need to develop new water-saving planting technologies to alleviate water shortages, cope with climate anomalies, and ensure food production.

[0008] 5. Excessive use of chemical fertilizers has led to increasingly obvious trends of land acidification, compaction, salinization and desertification, soil degradation, and reduced crop yields and quality, affecting the sustainable development of agriculture.

[0009] To meet the above challenges, researchers have developed a series of technologies including controlled-release fertilizers, synthetic polymer agricultural water-retaining agents, heavy metal pollution remediation agents, soil improvement conditioners, bio-fermented organic fertilizers, and direct return of straw to the field. Although these technologies can partially solve the above problems, they still have the following obvious drawbacks:

[0010] 1. The production process is complicated, the production and use costs are high, and it is difficult to promote and apply on a large scale;

[0011] 2. The product effect is not outstanding and the function is single. When it is required to complete the diversified tasks of modern agriculture and ecological management such as crop growth, nutrient management, water conservation and drought resistance, improving soil fertility, increasing yield and quality, improving the environment, and reducing costs at the same time, multiple products need to be used;

[0012] 3. The product contains difficult-to-degrade ingredients or synthetic polymer materials, which degrade slowly or are difficult to degrade completely in the soil, leaving residues, leading to secondary pollution and having an adverse effect on crop growth.

[0013] Currently, there is no material that can solve the above problems, and the field is in urgent need of developing new multifunctional materials to overcome the drawbacks of the existing technology. Summary of the invention

[0014] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a multifunctional organic-inorganic composite material containing polypeptides and a preparation method and application thereof. The multifunctional organic-inorganic composite material containing polypeptides of the present invention is mainly prepared from organic matter such as waste containing lignin and water-insoluble polysaccharides, waste containing proteins, and inorganic matter containing nitrogen, phosphorus, and potassium. The multifunctional organic-inorganic composite material containing polypeptides of the present invention has multiple functions such as promoting plant growth, improving soil structure, increasing soil organic matter content, controlling nutrient release, enhancing soil water absorption and water retention, and absorbing heavy metal ions and saline-alkali ions in the soil.

[0015] To achieve the above purpose, the technical solution designed by the present invention is as follows:

[0016] The present invention provides a method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, comprising the following steps:

[0017] (1) Preparation of polypeptides: After the protein-containing waste is crushed, a potassium hydroxide solution is added, and then a protease is added for enzymolysis to obtain a polypeptide liquid;

[0018] (2) Preparation of graft-block copolymer: After the waste containing lignin and water-insoluble polysaccharide is crushed, a potassium hydroxide solution is added, and the lignin is dissolved in the potassium hydroxide solution. After filtering, a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharide are obtained;

[0019] The clear liquid containing lignin is added with formaldehyde solution to carry out lignin hydroxymethylation reaction, and after the reaction is completed, the pH is adjusted to 8.0-9.0, and urea and formaldehyde solution are added to carry out reaction; the pH is adjusted to 3.5-5.5, and the polypeptide liquid obtained in step (1) is added to carry out reaction, and after the reaction is completed, a mixed liquid containing graft-block copolymer is obtained;

[0020] (3) Carboxymethylation of water-insoluble polysaccharides: diluting the solid residue containing water-insoluble polysaccharides obtained in step (2) with water, adding potassium hydroxide to carry out an alkalization reaction, and adding chloroacetic acid to carry out a carboxymethylation reaction to obtain a carboxymethylated polysaccharide liquid;

[0021] (4) The mixed liquid containing the graft-block copolymer is added with stirring to the carboxymethylated polysaccharide liquid obtained in step (3), mixed, the pH value is adjusted to 4.5-7.5, and evaporated to obtain a concentrated liquid, which is a multifunctional organic-inorganic composite material containing polypeptides.

[0022] Furthermore, the preparation method further comprises the following steps:

[0023] Preparation of chitosan and calcium nitrate: Chitosan-containing waste is crushed and diluted with water, nitric acid is added for decalcification, and a calcium nitrate-containing liquid and a chitosan-containing solid residue are obtained after filtration; a potassium hydroxide solution is added to the chitosan-containing solid residue for deacetylation to obtain a chitosan-containing liquid;

[0024] The mixed liquid containing the graft-block copolymer is added to the carboxymethylated polysaccharide liquid obtained in step (3), the liquid containing chitosan and the liquid containing calcium nitrate in sequence under stirring, mixed, the pH value is adjusted to 4.5-7.5, and evaporated and concentrated to obtain a concentrated liquid, which is a multifunctional organic-inorganic composite material containing polypeptides.

[0025] Furthermore, the multifunctional organic-inorganic composite material containing polypeptides can be spray-dried to obtain a powdered solid, or the multifunctional organic-inorganic composite material containing polypeptides can be wet-granulated to obtain a granular solid; the solid forms a gel after absorbing water.

[0026] Furthermore, in step (1), the concentration of the potassium hydroxide solution is 1-5%, and the mass volume ratio of the protein-containing waste to the potassium hydroxide solution is 1:3-10;

[0027] The protease is one or a combination of alkaline protease and neutral protease. The mass ratio of protease to protein-containing waste is 0.1-1:100. The enzymolysis conditions are 40-60°C for 2-6 hours. After the enzymolysis is completed, the temperature is raised to 90°C and maintained for 0.5 hours to inactivate the protease.

[0028] Furthermore, the protease is alkaline protease, and the enzymatic activity of the alkaline protease is 50,000 to 200,000 U / g;

[0029] Alternatively, the protease is a combination of alkaline protease and neutral protease, wherein the enzymatic activity of the alkaline protease is 50,000 to 200,000 U / g, the enzymatic activity of the neutral protease is 50,000 to 200,000 U / g, and the mass ratio of the alkaline protease to the neutral protease is 1 to 5:1.

[0030] Furthermore, the concentration of the potassium hydroxide solution is 1-2%, the mass volume ratio of the protein-containing waste to the potassium hydroxide solution is 1:5; and the mass ratio of the protease to the protein-containing waste is 0.45-0.58:100.

[0031] Furthermore, in step (1), the protein-containing waste is one or more combinations of livestock and poultry aquatic product processing scraps, oil cakes from oil mills, microbial fermentation broth and / or residues.

[0032] Furthermore, the protein-containing waste is one or more combinations of soybean meal, corn meal, sesame meal, rice bran meal, peanut meal, rapeseed meal, and animal hair, skin, viscera, and blood.

[0033] Furthermore, the protein-containing waste is soybean meal;

[0034] Alternatively, when the protein-containing waste is a combination of soybean meal, corn meal and peanut meal, the mass ratio of soybean meal, corn meal and peanut meal is 3:1:1;

[0035] Alternatively, the protein-containing waste is a combination of sesame oil cakes, fish viscera, and chicken and duck viscera, and the mass ratio of sesame oil cakes, fish viscera, and chicken and duck viscera is 6:3:1;

[0036] Alternatively, the protein-containing waste is a combination of soybean meal and rapeseed meal cake, and the mass ratio of the soybean meal to the rapeseed meal cake is 1:1;

[0037] Alternatively, the protein-containing waste is a combination of rice bran meal, peanut meal and fish viscera, and the mass ratio of the rice bran meal, peanut meal and fish viscera is 5:3:2;

[0038] Alternatively, the protein-containing waste is a combination of soybean meal, corn yellow powder and duck feathers, and the mass ratio of the soybean meal, corn yellow powder and duck feathers is 3:1:1.

[0039] Furthermore, in the step (2), the mass ratio of the waste containing lignin and water-insoluble polysaccharides to the waste containing protein is 1:0.05-0.3; the concentration of the potassium hydroxide solution is 1-10%; the mass volume ratio of the waste containing lignin and water-insoluble polysaccharides to the potassium hydroxide solution is 1:3-10; the lignin dissolution reaction conditions are 80-160°C and 2-4 hours;

[0040] The concentration of the formaldehyde solution is 37%, the mass ratio of the waste containing lignin and water-insoluble polysaccharides to the first added formaldehyde solution is 1:0.1-0.4; the mass ratio of the waste containing lignin and water-insoluble polysaccharides to the second added formaldehyde solution is 1:0.1-0.35; the mass ratio of the waste containing lignin and water-insoluble polysaccharides to urea is 1:0.1-0.5;

[0041] The conditions for the hydroxymethylation of lignin are: pH 11-12, 70-90°C, 2-4 hours; the conditions for the reaction with urea and formaldehyde are: 90-100°C, 2-4 hours; the conditions for the reaction with the polypeptide liquid are: 90-100°C, 1-3 hours;

[0042] Phosphoric acid was used to adjust the pH.

[0043] Furthermore, the mass ratio of the waste containing lignin and water-insoluble polysaccharides to the waste containing protein is 1:0.1-0.24; the concentration of the potassium hydroxide solution is 2-3%; the mass volume ratio of the waste containing lignin and water-insoluble polysaccharides to the potassium hydroxide solution is 1:5;

[0044] The mass ratio of the waste containing lignin and water-insoluble polysaccharides to the first added formaldehyde solution is 1:0.1-0.22; the mass ratio of the waste containing lignin and water-insoluble polysaccharides to the second added formaldehyde solution is 1:0.15-0.2; the mass ratio of the waste containing lignin and water-insoluble polysaccharides to urea is 1:0.32-0.45.

[0045] Furthermore, in step (2), the waste containing lignin and water-insoluble polysaccharides is one or more combinations of straw, tail vegetables, fruit shells, peels, weeds, fallen leaves, pruned branches and leaves, forestry processing residues, biological extraction residues, bagasse, algae, konjac peels, kitchen waste, and livestock and poultry manure.

[0046] Furthermore, the waste containing lignin and water-insoluble polysaccharides is one or more combinations of corn straw, wheat straw, rice straw, soybean straw, rape straw, sorghum straw, cotton straw, mulberry branches, tea tree pruning leaves, wood chips, bagasse, Chinese medicine residues, enteromorpha, kitchen waste, pig manure, cow manure and chicken manure.

[0047] Furthermore, the waste containing lignin and water-insoluble polysaccharides is corn stalks;

[0048] Alternatively, the waste containing lignin and water-insoluble polysaccharides is a combination of corn straw, wheat straw, rice straw and pig manure, and the mass ratio of the corn straw, wheat straw, rice straw and pig manure is 3:2:2:3;

[0049] Alternatively, the waste containing lignin and water-insoluble polysaccharides is a combination of wheat straw, bagasse, kitchen waste, soybean straw, Chinese herbal medicine residue, enteromorpha, cow dung and chicken dung, and the mass ratio of wheat straw, bagasse, kitchen waste, soybean straw, Chinese herbal medicine residue, enteromorpha, cow dung and chicken dung is 1:1:1:1:1:3:1:1;

[0050] Alternatively, the waste containing lignin and water-insoluble polysaccharides is a combination of soybean straw, rape straw and tea tree pruning leaves, and the mass ratio of the soybean straw, rape straw and tea tree pruning leaves is 1:1:1;

[0051] Alternatively, the waste containing lignin and water-insoluble polysaccharides is a combination of corn straw, wheat straw, mulberry branches and peanut shells, and the mass ratio of corn straw, wheat straw, mulberry branches and peanut shells is 3:2:2:3;

[0052] Alternatively, the waste containing lignin and water-insoluble polysaccharides is a combination of corn straw, wheat straw, rice straw, wheat husk and cow dung, and the mass ratio of the corn straw, wheat straw, rice straw, wheat husk and cow dung is 4:1:2:2:1;

[0053] Alternatively, the waste containing lignin and water-insoluble polysaccharides is a combination of corn stalks, walnut shells, walnut green peels, mushroom sticks and enteromorpha, and the mass ratio of corn stalks, walnut shells, walnut green peels, mushroom sticks and enteromorpha is 6:1:1:1:1.

[0054] Furthermore, in the step (3), the mass ratio of the waste containing lignin and water-insoluble polysaccharides, potassium hydroxide and chloroacetic acid is 1:0.05-0.2:0.1-0.6;

[0055] Alkalization reaction conditions: 50-70°C, 1-2 hours; carboxymethylation reaction conditions: 50-80°C for 2-4 hours, then heated to 90-100°C for 1-8 hours.

[0056] Furthermore, the mass ratio of the waste containing lignin and water-insoluble polysaccharides, potassium hydroxide and chloroacetic acid is 1:0.05-0.15:0.1-0.22.

[0057] Furthermore, in the step (4), phosphogypsum is used to adjust the pH; and triple-effect evaporation is used to concentrate to 35-45° Brix.

[0058] Further, the chitosan-containing waste is one or a combination of crayfish shells and crab shells;

[0059] The mass ratio of waste containing chitin to waste containing lignin and water-insoluble polysaccharide is 0.1-0.3:1; water is added to dilute to 3-10 times; nitric acid is added to a concentration of 1-5%; the decalcification reaction conditions are 50-80°C and 1-4 hours;

[0060] The concentration of the potassium hydroxide solution is 40-50%, the mass ratio of the chitosan-containing waste to the potassium hydroxide solution is 1-3:1-3, and the deacetylation reaction conditions are 80-100° C. and 1-4 hours.

[0061] Furthermore, the chitosan-containing waste is crayfish shells;

[0062] Alternatively, the waste containing chitosan is a combination of crayfish shells and crab shells, and the mass ratio of the crayfish shells to the crab shells is 2:1.

[0063] Furthermore, the mass ratio of the waste containing chitosan to the waste containing lignin and water-insoluble polysaccharides is 0.1-0.2:1; water is added to dilute to 5 times; nitric acid is added to a concentration of 1.5-3%;

[0064] The concentration of the potassium hydroxide solution is 45-50%, and the mass ratio of the waste containing chitosan to the potassium hydroxide solution is 1-1.5:1-1.2.

[0065] The present invention also provides a multifunctional organic-inorganic composite material containing polypeptides prepared by the preparation method, wherein the multifunctional organic-inorganic composite material containing polypeptides is mainly prepared from waste containing lignin and water-insoluble polysaccharides, waste containing protein, and inorganic substances containing nitrogen, phosphorus, and potassium;

[0066] Polypeptides are obtained from protein-containing wastes, and lignin / urea acetal / polypeptide graft-block copolymers and carboxymethylated polysaccharides are obtained from wastes containing lignin and water-insoluble polysaccharides, respectively. The two are cross-linked to form a three-dimensional network structure that can store water and nitrogen, phosphorus, and potassium nutrients.

[0067] Furthermore, the multifunctional organic-inorganic composite material containing polypeptides has multiple functions of promoting plant growth, controlling the release of nitrogen, phosphorus and potassium, improving soil water absorption and water retention performance, reducing the damage of saline-alkali land to plants, and passivating heavy metal ions.

[0068] The present invention also provides an application of a multifunctional organic-inorganic composite material containing polypeptides prepared by the preparation method in promoting plant growth, controlling the release of nitrogen, phosphorus and potassium, improving saline-alkali soil, improving soil water absorption and retention performance, and repairing heavy metal-contaminated soil.

[0069] Principle of the present invention:

[0070] 1. Waste containing lignin and water-insoluble polysaccharides is treated with KOH to obtain lignin. Lignin, formaldehyde, urea and polypeptide are subjected to lignin hydroxymethylation, acetalization, amidation and polycondensation to obtain a series of complex lignin / urea acetal / polypeptide graft-block copolymers.

[0071] The representative molecular structure of lignin / urea acetal / polypeptide graft-block copolymer is as follows Figure 1As shown in A, B, C, D, and E: the graft-block copolymer "fixes" urea and polypeptides in the polymer chain, which can reduce the solubility of urea and polypeptides in water, slow down the release rate of urea and polypeptides, and reduce the loss of nutrients in the soil in the early stage of plant growth; in the later stage of plant growth, as the polypeptides are degraded by soil microorganisms and proteases, on the one hand, the release of polypeptides in the soil increases, and on the other hand, the depolymerization of urea acetal in the graft-block copolymer is accelerated, and the nitrogen release rate is accelerated. At the same time, polypeptides play an important role in plant growth, including promoting plant growth, improving plant stress resistance, and improving the quality of agricultural products. Therefore, the graft-block copolymer can better control the nutrient release rate for plants than traditional urea, coated controlled-release fertilizers, and urea-formaldehyde controlled-release fertilizers, provide more lasting and more nutrients, better promote plant growth and development, and reduce fertilizer usage and environmental pollution.

[0072] Furthermore, the lignin part of the lignin / urea acetal / polypeptide graft-block copolymer contains a large amount of hydrophilic -OH, the main chain contains amide and -NH- groups, and the polypeptide side chain contains negatively charged -COO - , positively charged -NH 3 + and -SH and other sulfur-containing functional groups, providing hydrogen bonding, electrostatics, ion exchange, and metal ion complexation, with strong water absorption and water retention properties, and can also adsorb and exchange inorganic nutrients and salt-alkali ions (Na + , Cl - OH - , HCO 3 - 、SO 4 2- , CO 3 2- ). The -SH, -SS-, -SCH contained in the polypeptide 3 The groups can combine with the effective heavy metal ions in the soil and transform them into insoluble metal sulfides, or the -COO-, -OH, -NH 2 It can chelate with available heavy metal ions. Both can reduce the content of available heavy metal ions in the soil and passivate heavy metal ions.

[0073] 2. The multifunctional organic-inorganic composite material containing polypeptides of the present invention is a multi-component mixture, and each component is cross-linked to form a three-dimensional network structure through hydrogen bonds, electrostatics, and metal ion complexation to become a gel-type material. Specifically, lignin / urea acetal / polypeptide graft-block copolymer, carboxymethylated polysaccharide, calcium ions are cross-linked through hydrogen bonds between polymers, electrostatic interactions between positive and negative ions, intermolecular van der Waals forces, and Ca 2+ The cross-linking effect of ion complexation forms a three-dimensional network structure, such as Figure 2As shown. The three-dimensional network structure can absorb and store a large amount of water and nitrogen, phosphorus and potassium nutrients, and the water absorption and water retention and controlled release effects are further improved compared to the simple lignin / urea acetal / polypeptide graft-block copolymer. The polypeptide components contained in it also have the functions of absorbing and exchanging inorganic nutrients and salt-alkali ions, passivating heavy metal ions and promoting plant growth.

[0074] 3. Furthermore, the multifunctional organic-inorganic composite material containing polypeptides of the present invention can also be a multi-component mixture containing chitosan, wherein chitosan is a natural polymer containing -NH2, which is positively charged in an acidic environment to become a polycationic polymer, and has physiological effects such as antibacterial, improving plant immunity, and promoting plant growth. Each component forms a three-dimensional network structure through mutual hydrogen bonding, static electricity, and metal ion complexation to form a gel-type material. Specifically, lignin / urea acetal / polypeptide graft-block copolymer, carboxymethylated polysaccharide, calcium ions and chitosan form a three-dimensional network structure through hydrogen bonding between polymers, electrostatic interactions between positive and negative ions, intermolecular van der Waals forces and Ca 2+ The cross-linking effect of ion complexation forms a three-dimensional network structure, such as Figure 3 As shown. The three-dimensional network structure can absorb and store a large amount of water and nitrogen, phosphorus and potassium nutrients, and the water absorption and water retention and controlled release effects are further improved compared to the simple lignin / urea acetal / polypeptide graft-block copolymer. The contained polypeptide and chitosan components also have the functions of absorbing and exchanging inorganic nutrients and salt-alkali ions, passivating heavy metal ions and promoting plant growth.

[0075] Beneficial effects of the present invention:

[0076] 1. The carboxymethylation reaction step of water-insoluble polysaccharides such as cellulose of the present invention does not use organic solvents, does not need to separate and purify the products, avoids the recovery of organic solvents and complicated post-treatment processes, simplifies the traditional carboxymethylation reaction production process, reduces production costs, and has competitive advantages.

[0077] 2. The raw materials of the present invention are various domestic and industrial and agricultural production wastes. The raw materials are easy to obtain, inexpensive, and the organic matter is renewable. No complex, high-performance, and high-cost raw materials are used, so that the best use of materials is achieved, pollution is reduced, the construction of "zero-waste cities" is promoted, and the ecological environment is protected. Fundamentally, a series of difficult problems faced in the fields of waste resource utilization, straw returning to the field, ecological restoration, and sustainable agricultural development are solved, achieving multiple goals at one stroke.

[0078] 3. The production process of the present invention is simple, does not require fermentation, has a short production cycle, does not occupy a large amount of land, does not generate waste gas, has a waste utilization rate of 100%, has cost advantages, and is easy to mass produce and apply.

[0079] 4. The raw materials of the present invention are biomass materials, which are completely degraded in the soil, leaving no residue, no pollution, being environmentally friendly, ecologically sustainable, and conforming to the concept of sustainable agriculture.

[0080] 5. The organic-inorganic composite material of the present invention is multifunctional and general, easy to use, labor-saving, and reduces the cost of use, and can simultaneously meet the diverse needs of modern agriculture and ecological management. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 It is a schematic diagram of the molecular structure of lignin / urea acetal / polypeptide graft-block copolymer;

[0082] In the figure, A is molecular structure formula 1, B is molecular structure formula 2, C is molecular structure formula 3, D is molecular structure formula 4, and E is molecular structure formula 5;

[0083] Figure 2 Schematic diagram of the three-dimensional network structure formed by the interaction between lignin / urea acetal / polypeptide graft-block copolymer and carboxymethylated polysaccharide;

[0084] Figure 3 Schematic diagram of the three-dimensional network structure formed by the interaction of lignin / urea acetal / polypeptide graft-block copolymer, carboxymethylated polysaccharide, calcium ions and chitosan;

[0085] Figure 4 This is a total nitrogen cumulative release curve of the multifunctional organic-inorganic composite material containing polypeptides obtained in Example 1;

[0086] Figure 5 This is a cumulative release curve of total phosphorus of the multifunctional organic-inorganic composite material containing polypeptide obtained in Example 1;

[0087] Figure 6 This is a cumulative total potassium release curve of the multifunctional organic-inorganic composite material containing polypeptides obtained in Example 1;

[0088] Figure 7 This is a water retention curve of the multifunctional organic-inorganic composite material containing polypeptide obtained in Example 3;

[0089] Figure 8 This is a curve diagram of the improved soil water absorption rate of the multifunctional organic-inorganic composite material containing polypeptides obtained in Example 3;

[0090] Fig. 9 This is a curve diagram of improved soil water retention rate of the multifunctional organic-inorganic composite material containing polypeptides obtained in Example 3. DETAILED DESCRIPTION

[0091] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand.

[0092] Example 1

[0093] This embodiment provides a method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, and the specific steps are as follows:

[0094] (1) Preparation of polypeptides: 150 kg of soybean meal was crushed by a crusher, and 5 times the amount of 2% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a reactor. 750 g of alkaline protease (the activity of alkaline protease is 50,000 U / g) was added and enzymolyzed at 55° C. for 4 hours. The temperature was raised to 90° C. and maintained for 0.5 hour to inactivate the protease, thereby obtaining a liquid containing polypeptides, which was the polypeptide feed liquid and was set aside.

[0095] (2) Preparation of chitosan and calcium nitrate: 100 kg of dried crayfish shells were crushed with a crusher and diluted 5 times with water, homogenized with a colloid mill for 1 hour, fully mixed and ground, and nitric acid was added to a concentration of 2%. The shells were transferred to an enameled reactor and decalcified at 60°C for 2 hours to generate calcium nitrate. After plate and frame filtration, a clear liquid and a solid residue containing chitosan were obtained. The clear liquid was marked as the liquid containing calcium nitrate and set aside.

[0096] The solid residue containing chitosan was added with 100 kg of 45% potassium hydroxide solution, homogenized by colloid mill for 1 hour, fully mixed and ground, transferred to a stainless steel reactor, and deacetylated at 95° C. for 2 hours to obtain a chitosan-containing liquid for later use.

[0097] (3) Preparation of graft-block copolymer: 1000 kg corn stalks were crushed by a crusher and added with 5 times the amount of 2% potassium hydroxide solution, colloid milled for 2 hours, fully mixed and ground, transferred to a 10 cubic meter stainless steel reactor, dissolved at 140° C. for 2 hours, lignin dissolved in the potassium hydroxide solution, cooled, and filtered through a plate and frame to obtain a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharides.

[0098] The clear liquid containing lignin is transferred to a 12 cubic meter stainless steel reactor, and 200 kg of a 37% formaldehyde solution is added, and the hydroxymethylation reaction of lignin is carried out at pH 11.5 and 80° C. for 2 hours; phosphoric acid is added to adjust the pH to 8.5, 400 kg of urea and 150 kg of a 37% formaldehyde solution are added, and the temperature is raised to 95° C. for reaction for 2 hours. Phosphoric acid is added to adjust the pH to 4.5, and the polypeptide solution obtained in step (1) is added, and the reaction is carried out at 95° C. for 2 hours; a mixed solution containing a graft-block copolymer is obtained.

[0099] (4) Carboxymethylation of water-insoluble polysaccharides: The solid residue containing water-insoluble polysaccharides was diluted 5 times with water, 50 kg of potassium hydroxide was added, and the slurry was homogenized by a colloidal mill for 2 hours. The mixture was fully mixed and ground, and then transferred to a stainless steel reactor. The mixture was alkalized at 50°C for 1 hour, 100 kg of chloroacetic acid was added, and the carboxymethylation reaction was carried out at 70°C for 3 hours. The temperature was raised to 95°C and the reaction was continued for 2 hours to obtain a carboxymethylated polysaccharide liquid for use.

[0100] (5) The mixed liquid containing the graft-block copolymer is transferred to a stainless steel reactor, and the carboxymethylated polysaccharide liquid, the chitosan-containing liquid, and the calcium nitrate-containing liquid are added in sequence under stirring, and the mixture is mixed evenly. The pH value is adjusted to 6.5 by adding phosphogypsum, and the mixture is stirred and mixed evenly. The mixture is homogenized by a colloid mill, and concentrated to 35° Brix by triple-effect evaporation to obtain a concentrated liquid, and the concentrated liquid is spray-dried to obtain 2149.5 kg of a powdered solid; or the concentrated liquid is wet-granulated to obtain a granular solid; the concentrated liquid, the powdered solid, and the granular solid are all multifunctional organic-inorganic composite materials containing polypeptides. The powdered solid re-forms a gel after absorbing water, and this process is reversible and repeatable.

[0101] Example 2

[0102] This embodiment provides a method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, and the specific steps are as follows:

[0103] (1) Preparation of polypeptides: 200 kg of protein-containing waste (including soybean meal: corn meal: peanut meal in a mass ratio of 3:1:1) was crushed by a pulverizer, and then 5 times the amount of 2% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a reactor. 900 g of alkaline protease (the activity of alkaline protease was 100,000 U / g) was added and enzymolyzed at 50°C for 4 hours. The temperature was raised to 90°C and maintained for 0.5 hour to inactivate the protease, thereby obtaining a polypeptide-containing liquid, which was the polypeptide feed liquid and was set aside.

[0104] (2) Preparation of chitosan and calcium nitrate: 200 kg of waste containing chitosan (wherein the mass ratio of dried crayfish shell to crab shell is 2:1) was crushed by a grinder, diluted 5 times with water, homogenized by a colloid mill for 1 hour, fully mixed and ground, and nitric acid was added to a concentration of 3%. The mixture was transferred to an enameled reactor and decalcified at 80°C for 1 hour to generate calcium nitrate. The mixture was filtered on a plate and frame to obtain a clear liquid and a solid residue containing chitosan. The clear liquid was marked as the liquid containing calcium nitrate and set aside.

[0105] The solid residue containing chitosan was added with 200 kg of 50% potassium hydroxide solution, homogenized by colloid mill for 1 hour, fully mixed and ground, transferred to a stainless steel reactor, and deacetylated at 90° C. for 1 hour to obtain a chitosan-containing liquid for later use.

[0106] (3) Preparation of graft-block copolymers: 1000 kg of waste containing lignin and water-insoluble polysaccharides (wherein the mass ratio of corn straw: wheat straw: rice straw: pig manure = 3:2:2:3) was crushed by a pulverizer, and then 5 times the amount of 3% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1.5 hours, fully mixed and ground, and transferred to a 10 cubic meter stainless steel reactor and dissolved at 90° C. for 2 hours to dissolve the lignin in the potassium hydroxide solution. The mixture was cooled and filtered through a plate and frame to obtain a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharides.

[0107] The clear liquid containing lignin is transferred to a 12 cubic meter stainless steel reactor, and 220 kg of a 37% formaldehyde solution is added, and the lignin is subjected to a hydroxymethylation reaction at pH 11.0 and 75° C. for 2 hours; phosphoric acid is added to adjust the pH to 8.0, 450 kg of urea and 180 kg of a 37% formaldehyde solution are added, and the temperature is raised to 90° C. for reaction for 2 hours. Phosphoric acid is added to adjust the pH to 5.0, and the polypeptide solution obtained in step (1) is added, and the reaction is carried out at 90° C. for 2.5 hours; a mixed solution containing a graft-block copolymer is obtained.

[0108] (4) Carboxymethylation of water-insoluble polysaccharides: The solid residue containing water-insoluble polysaccharides was diluted 5 times with water, 90 kg of potassium hydroxide was added, and the slurry was homogenized by a colloidal mill for 2 hours. The mixture was fully mixed and ground, and then transferred to a stainless steel reactor. The mixture was alkalized at 60°C for 1 hour, 130 kg of chloroacetic acid was added, and the carboxymethylation reaction was carried out at 50°C for 3 hours. The temperature was raised to 95°C and the reaction was continued for 2 hours to obtain a carboxymethylated polysaccharide liquid for use.

[0109] (5) The mixed liquid containing the graft-block copolymer is transferred to a stainless steel reactor, and the carboxymethylated polysaccharide liquid, the chitosan-containing liquid, and the calcium nitrate-containing liquid are added in sequence under stirring, and the mixture is uniformly mixed. The pH value is adjusted to 5.2 by adding phosphogypsum, and the mixture is uniformly mixed. The mixture is homogenized by a colloid mill, and evaporated and concentrated to 40° Brix to obtain a concentrated liquid. The concentrated liquid is spray-dried to obtain 2690.6 kg of a powdered solid; or the concentrated liquid is wet-granulated to obtain a granular solid; the concentrated liquid, the powdered solid, and the granular solid are all multifunctional organic-inorganic composite materials containing polypeptides. The powdered solid re-forms a gel after absorbing water, and this process is reversible and repeatable.

[0110] Example 3

[0111] This embodiment provides a method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, and the specific steps are as follows:

[0112] (1) Preparation of polypeptides: 100 kg of protein-containing waste (wherein the mass ratio of sesame oil cake: fish viscera: chicken and duck viscera is 6:3:1) was crushed by a pulverizer, and then 5 times the amount of 1% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a reactor. 580 g of a mixture of alkaline protease and neutral protease (wherein the enzymatic activity of the alkaline protease is 50,000 U / g, the enzymatic activity of the neutral protease is 100,000 U / g, and the mass ratio of the alkaline protease to the neutral protease is 3:1) was added. The mixture was enzymolyzed at 53° C. for 4 hours, and then the temperature was raised to 90° C. and maintained for 0.5 hour to inactivate the protease, thereby obtaining a polypeptide-containing liquid, which was the polypeptide feed liquid and was set aside.

[0113] (2) Preparation of chitosan and calcium nitrate: 120 kg of dried crayfish shells were crushed in a crusher and diluted 5 times with water, homogenized in a colloid mill for 1 hour, fully mixed and ground, and nitric acid was added to a concentration of 1.5%. The shells were transferred to an enameled reactor and decalcified at 70°C for 1.5 hours to generate calcium nitrate. After plate and frame filtration, a clear liquid and a solid residue containing chitosan were obtained respectively; the clear liquid was marked as the liquid containing calcium nitrate and set aside.

[0114] The solid residue containing chitosan was added with 100 kg of 50% potassium hydroxide solution, homogenized by colloid mill for 1 hour, fully mixed and ground, transferred to a stainless steel reactor, and deacetylated at 80° C. for 1 hour to obtain a chitosan-containing liquid for later use.

[0115] (3) Preparation of graft-block copolymers: 1000 kg of waste containing lignin and water-insoluble polysaccharides (wherein the mass ratio of wheat straw: bagasse: kitchen waste: soybean straw: Chinese medicine residue: enteromorpha: cow dung: chicken dung is 1:1:1:1:1:3:1:1) was crushed by a pulverizer, and then 5 times the amount of 3% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a 10 cubic meter stainless steel reactor and dissolved at 100° C. for 2 hours to dissolve the lignin in the potassium hydroxide solution. The mixture was cooled and filtered through a plate and frame to obtain a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharides.

[0116] The clear liquid containing lignin is transferred to a 12 cubic meter stainless steel reactor, and 100 kg of a 37% formaldehyde solution is added, and the lignin is subjected to a hydroxymethylation reaction at pH 11.0 and 80° C. for 2 hours; phosphoric acid is added to adjust the pH to 8.5, and 320 kg of urea and 160 kg of a 37% formaldehyde solution are added, and the temperature is raised to 95° C. for reaction for 2 hours. Phosphoric acid is added to adjust the pH to 4.5, and the polypeptide solution obtained in step (1) is added, and the reaction is carried out at 95° C. for 2.5 hours; a mixed solution containing a graft-block copolymer is obtained.

[0117] (4) Carboxymethylation of water-insoluble polysaccharides: The solid residue containing water-insoluble polysaccharides was diluted 5 times with water, and 130 kg of potassium hydroxide was added. The mixture was homogenized with a colloidal mill for 2 hours, mixed and ground thoroughly, and transferred to a stainless steel reactor. The mixture was alkalized at 70°C for 1 hour, 180 kg of chloroacetic acid was added, and the mixture was carboxymethylated at 70°C for 2 hours. The mixture was heated to 95°C and the reaction was continued for 2 hours to obtain a carboxymethylated polysaccharide liquid for later use.

[0118] (5) The mixed liquid containing the graft-block copolymer is transferred to a stainless steel reactor, and the carboxymethylated polysaccharide liquid, the chitosan-containing liquid, and the calcium nitrate-containing liquid are added in sequence under stirring, and the mixture is uniformly mixed. The pH value is adjusted to 6.8 by adding phosphogypsum, and the mixture is stirred and uniformly mixed. The mixture is homogenized by a colloid mill, evaporated and concentrated to 40° Brix to obtain a concentrated liquid, and the concentrated liquid is spray-dried to obtain 2147.8 kg of a powdered solid; or the concentrated liquid is wet-granulated to obtain a granular solid; the concentrated liquid, the powdered solid, and the granular solid are all multifunctional organic-inorganic composite materials containing polypeptides. The powdered solid re-forms a gel after absorbing water, and this process is reversible and repeatable.

[0119] Example 4

[0120] This embodiment provides a method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, and the specific steps are as follows:

[0121] (1) Preparation of polypeptides: 240 kg of protein-containing waste (wherein the mass ratio of soybean meal to rapeseed oil cake is 1:1) was crushed by a pulverizer, and then 5 times the amount of 2% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a reactor. 1.2 kg of a mixture of alkaline protease and neutral protease (wherein the enzymatic activity of the alkaline protease is 50,000 U / g, the enzymatic activity of the neutral protease is 100,000 U / g, and the mass ratio of the alkaline protease to the neutral protease is 3:1) was added. The mixture was enzymolyzed at 60° C. for 2 hours, and then the temperature was raised to 90° C. and maintained for 0.5 hour to inactivate the protease, thereby obtaining a polypeptide-containing liquid, which was the polypeptide feed liquid and was set aside.

[0122] (2) Preparation of chitosan and calcium nitrate: 150 kg of dried crayfish shells were crushed in a crusher and diluted 5 times with water, homogenized in a colloid mill for 1 hour, fully mixed and ground, and nitric acid was added to a concentration of 3%. The shells were transferred to an enameled reactor and decalcified at 60°C for 1 hour to generate calcium nitrate. After plate and frame filtration, a clear liquid and a solid residue containing chitosan were obtained respectively; the clear liquid was marked as the liquid containing calcium nitrate and set aside.

[0123] The solid residue containing chitosan was added with 120 kg of 50% potassium hydroxide solution, homogenized by colloid mill for 1 hour, fully mixed and ground, transferred to a stainless steel reactor, and deacetylated at 80° C. for 1 hour to obtain a chitosan-containing liquid for later use.

[0124] (3) Preparation of graft-block copolymers: 1000 kg of waste containing lignin and water-insoluble polysaccharides (wherein the mass ratio of soybean straw: rape straw: tea tree pruning leaves = 1:1:1) was crushed by a pulverizer, and then 5 times the amount of 3% potassium hydroxide solution was added. The slurry was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a 10 cubic meter stainless steel reactor and dissolved at 100° C. for 2 hours to dissolve the lignin in the potassium hydroxide solution. The waste was cooled and filtered through a plate and frame to obtain a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharides.

[0125] The clear liquid containing lignin is transferred to a 12 cubic meter stainless steel reactor, and 150 kg of a 37% formaldehyde solution is added, and the lignin is subjected to a hydroxymethylation reaction at pH 11.0 and 80° C. for 2 hours; phosphoric acid is added to adjust the pH to 8.5, and 380 kg of urea and 200 kg of a 37% formaldehyde solution are added, and the temperature is raised to 95° C. for reaction for 2 hours. Phosphoric acid is added to adjust the pH to 4.3, and the polypeptide solution obtained in step (1) is added, and the reaction is carried out at 95° C. for 3 hours to obtain a mixed solution containing a graft-block copolymer.

[0126] (4) Carboxymethylation of water-insoluble polysaccharides: The solid residue containing water-insoluble polysaccharides was diluted 5 times with water, and 150 kg of potassium hydroxide was added. The mixture was homogenized with a colloidal mill for 2 hours, mixed and ground thoroughly, and transferred to a stainless steel reactor. The mixture was alkalized at 70°C for 1 hour, 220 kg of chloroacetic acid was added, and the mixture was carboxymethylated at 70°C for 2 hours. The mixture was heated to 95°C and the reaction was continued for 2 hours to obtain a carboxymethylated polysaccharide liquid for later use.

[0127] (5) The mixed liquid containing the graft-block copolymer is transferred to a stainless steel reactor, and the carboxymethylated polysaccharide liquid, the chitosan-containing liquid, and the calcium nitrate-containing liquid are added in sequence under stirring, and the mixture is uniformly mixed. Phosphoric acid is added to adjust the pH to 6.5, and the mixture is stirred and uniformly mixed. The mixture is homogenized by a colloid mill, evaporated and concentrated to 45° Brix to obtain a concentrated liquid, and the concentrated liquid is spray-dried to obtain 2627.6 kg of a powdered solid; or the concentrated liquid is wet-granulated to obtain a granular solid; the concentrated liquid, the powdered solid, and the granular solid are all multifunctional organic-inorganic composite materials containing polypeptides. The powdered solid re-forms a gel after absorbing water, and this process is reversible and repeatable.

[0128] Example 5

[0129] This embodiment provides a method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, and the specific steps are as follows:

[0130] (1) Preparation of polypeptides: 50 kg of protein-containing waste (wherein the mass ratio of soybean meal: corn yellow powder: duck feather is 3:1:1) was crushed by a pulverizer, and then 3 times the amount of 1% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a reactor. 50 g of a mixture of alkaline protease and neutral protease (wherein the enzymatic activity of the alkaline protease is 50,000 U / g, the enzymatic activity of the neutral protease is 200,000 U / g, and the mass ratio of the alkaline protease to the neutral protease is 5:1) was added. The mixture was enzymolyzed at 40°C for 6 hours, and then the temperature was raised to 90°C and maintained for 0.5 hour to inactivate the protease, thereby obtaining a polypeptide-containing liquid, which was the polypeptide feed liquid and was set aside.

[0131] (2) Preparation of chitosan and calcium nitrate: 100 kg of dried crayfish shells were crushed with a crusher and diluted 3 times with water, homogenized with a colloid mill for 1 hour, fully mixed and ground, and nitric acid was added to a concentration of 1%. The shells were transferred to an enameled reactor and decalcified at 50°C for 1 hour to generate calcium nitrate. After plate and frame filtration, a clear liquid and a solid residue containing chitosan were obtained. The clear liquid was marked as the liquid containing calcium nitrate and set aside.

[0132] The solid residue containing chitosan was added with 300 kg of 40% potassium hydroxide solution, homogenized by colloid mill for 1 hour, fully mixed and ground, transferred to a stainless steel reactor, and deacetylated at 80°C for 1 hour to obtain a chitosan-containing liquid for later use.

[0133] (3) Preparation of graft-block copolymers: 1000 kg of waste containing lignin and water-insoluble polysaccharides (wherein the mass ratio of corn straw: wheat straw: mulberry branch: peanut shell = 3:2:2:3) was crushed by a grinder, and then 3 times the amount of 10% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a 10 cubic meter stainless steel reactor and dissolved at 80° C. for 4 hours to dissolve the lignin in the potassium hydroxide solution. The mixture was cooled and filtered through a plate and frame to obtain a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharides.

[0134] The clear liquid containing lignin is transferred to a 12 cubic meter stainless steel reactor, and 250 kg of a 37% formaldehyde solution is added, and the lignin is subjected to a hydroxymethylation reaction at pH 11.0 and 70° C. for 2 hours; phosphoric acid is added to adjust the pH to 8, 100 kg of urea and 100 kg of a 37% formaldehyde solution are added, and the temperature is raised to 90° C. for reaction for 2 hours. Phosphoric acid is added to adjust the pH to 3.5, and the polypeptide solution obtained in step (1) is added, and the reaction is carried out at 90° C. for 1 hour; a mixed solution containing a graft-block copolymer is obtained.

[0135] (4) Carboxymethylation of water-insoluble polysaccharides: The solid residue containing water-insoluble polysaccharides was diluted 5 times with water, and 200 kg of potassium hydroxide was added. The mixture was homogenized by a colloid mill for 2 hours, mixed and ground thoroughly, and transferred to a stainless steel reactor. The mixture was alkalized at 50°C for 1 hour, 100 kg of chloroacetic acid was added, and the mixture was carboxymethylated at 50°C for 4 hours. The mixture was heated to 90°C and the reaction was continued for 8 hours to obtain a carboxymethylated polysaccharide liquid for later use.

[0136] (5) The mixed liquid containing the graft-block copolymer is transferred to a stainless steel reactor, and the carboxymethylated polysaccharide liquid, the chitosan-containing liquid, and the calcium nitrate-containing liquid are added in sequence under stirring, and the mixture is uniformly mixed. The pH value is adjusted to 4.5 by adding phosphogypsum, and the mixture is stirred and mixed uniformly. The mixture is homogenized by a colloid mill, evaporated and concentrated to 40° Brix to obtain a concentrated liquid, and the concentrated liquid is spray-dried to obtain 2321.5 kg of a powdered solid; or the concentrated liquid is wet-granulated to obtain a granular solid; the concentrated liquid, the powdered solid, and the granular solid are all multifunctional organic-inorganic composite materials containing polypeptides. The powdered solid re-forms a gel after absorbing water, and this process is reversible and repeatable.

[0137] Example 6

[0138] This embodiment provides a method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, and the specific steps are as follows:

[0139] (1) Preparation of polypeptides: 300 kg of protein-containing waste (wherein the mass ratio of soybean meal: corn yellow powder: peanut meal = 3:1:1) was crushed by a pulverizer, and then 10 times the amount of 5% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a reactor. 3000 g of a mixture of alkaline protease and neutral protease (wherein the enzymatic activity of the alkaline protease was 200,000 U / g, the enzymatic activity of the neutral protease was 50,000 U / g, and the mass ratio of the alkaline protease to the neutral protease was 1:1) was added. The mixture was enzymolyzed at 60°C for 2 hours, and then the temperature was raised to 90°C and maintained for 0.5 hour to inactivate the protease, thereby obtaining a polypeptide-containing liquid, which was the polypeptide feed liquid and was set aside.

[0140] (2) Preparation of chitosan and calcium nitrate: 300 kg of waste containing chitosan (wherein the mass ratio of dried crayfish shell to crab shell is 2:1) was crushed by a grinder, diluted 10 times with water, homogenized by a colloid mill for 1 hour, fully mixed and ground, and nitric acid was added to a concentration of 5%. The mixture was transferred to an enameled reactor and decalcified at 80°C for 4 hours to generate calcium nitrate. After plate and frame filtration, a clear liquid and a solid residue containing chitosan were obtained. The clear liquid was marked as the liquid containing calcium nitrate and set aside.

[0141] The solid residue containing chitosan was added with 100 kg of 50% potassium hydroxide solution, homogenized by colloid mill for 1 hour, fully mixed and ground, transferred to a stainless steel reactor, and deacetylated at 100° C. for 4 hours to obtain a chitosan-containing liquid for later use.

[0142] (3) Preparation of graft-block copolymers: 1000 kg of waste containing lignin and water-insoluble polysaccharides (wherein the mass ratio of corn straw: wheat straw: rice straw: wheat husk: cow dung = 4:1:2:2:1) was crushed by a grinder, and then 10 times the amount of 1% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 1 hour, fully mixed and ground, and transferred to a 10-cubic-meter stainless steel reactor and dissolved at 160° C. for 2 hours to dissolve the lignin in the potassium hydroxide solution. The mixture was cooled and filtered through a plate and frame to obtain a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharides.

[0143] The clear liquid containing lignin is transferred to a 12 cubic meter stainless steel reactor, 400 kg of a 37% formaldehyde solution is added, and the hydroxymethylation reaction of lignin is carried out at pH 12 and 90° C. for 4 hours; phosphoric acid is added to adjust the pH to 9, 500 kg of urea and 350 kg of a 37% formaldehyde solution are added, and the temperature is raised to 100° C. for 4 hours. Phosphoric acid is added to adjust the pH to 5.5, and the polypeptide solution obtained in step (1) is added, and the reaction is carried out at 100° C. for 3 hours; a mixed solution containing a graft-block copolymer is obtained.

[0144] (4) Carboxymethylation of water-insoluble polysaccharides: The solid residue containing water-insoluble polysaccharides was diluted 5 times with water, 50 kg of potassium hydroxide was added, and the slurry was homogenized by a colloidal mill for 2 hours. The mixture was fully mixed and ground, and then transferred to a stainless steel reactor. The mixture was alkalized at 70°C for 2 hours, 600 kg of chloroacetic acid was added, and the carboxymethylation reaction was carried out at 80°C for 2 hours. The temperature was raised to 100°C and the reaction was continued for 1 hour to obtain a carboxymethylated polysaccharide liquid for use.

[0145] (5) The mixed liquid containing the graft-block copolymer is transferred to a stainless steel reactor, and the carboxymethylated polysaccharide liquid, the chitosan-containing liquid, and the calcium nitrate-containing liquid are added in sequence under stirring, and the mixture is uniformly mixed. The pH value is adjusted to 7.5 by adding phosphogypsum, and the mixture is stirred and uniformly mixed. The mixture is homogenized by a colloid mill, evaporated and concentrated to 45° Brix to obtain a concentrated liquid, and the concentrated liquid is spray-dried to obtain 3554.8 kg of a powdered solid; or the concentrated liquid is wet-granulated to obtain a granular solid; the concentrated liquid, the powdered solid, and the granular solid are all multifunctional organic-inorganic composite materials containing polypeptides. The powdered solid re-forms a gel after absorbing water, and this process is reversible and repeatable.

[0146] Example 7

[0147] This embodiment provides a method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, and the specific steps are as follows:

[0148] (1) Preparation of polypeptides: 280 kg of protein-containing waste (wherein the mass ratio of rice bran meal: peanut meal: fish viscera = 5:3:2) was crushed by a pulverizer, and then 10 times the amount of a 3% potassium hydroxide solution was added. The mixture was homogenized with a colloid mill for 1 hour, fully mixed and ground, and transferred to a reactor. 1600 g of alkaline protease (the activity of alkaline protease was 150,000 U / g) was added and enzymolyzed at 55° C. for 2 hours. The temperature was raised to 90° C. and maintained for 0.5 hour to inactivate the protease, thereby obtaining a polypeptide-containing liquid, which was the polypeptide feed liquid and was set aside.

[0149] (2) Preparation of graft-block copolymers: 1000 kg of waste containing lignin and water-insoluble polysaccharides (wherein the mass ratio of corn stalks: walnut shells: walnut green peels: mushroom sticks: enteromorpha = 6:1:1:1:1) was crushed by a grinder, and then 5 times the amount of 5% potassium hydroxide solution was added. The mixture was homogenized by a colloid mill for 3 hours, fully mixed and ground, and transferred to a 10 cubic meter stainless steel reactor and dissolved at 160° C. for 2 hours to dissolve the lignin in the potassium hydroxide solution. The mixture was cooled and filtered through a plate and frame to obtain a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharides.

[0150] The clear liquid containing lignin is transferred to a 12 cubic meter stainless steel reactor, and 180 kg of a 37% formaldehyde solution is added, and the lignin is subjected to a hydroxymethylation reaction at pH 12 and 80° C. for 2 hours; phosphoric acid is added to adjust the pH to 9.0, 350 kg of urea and 130 kg of a 37% formaldehyde solution are added, and the temperature is raised to 95° C. for reaction for 2 hours. Phosphoric acid is added to adjust the pH to 4.5, and the polypeptide solution obtained in step (1) is added, and the reaction is carried out at 95° C. for 2 hours; a mixed solution containing a graft-block copolymer is obtained.

[0151] (3) Carboxymethylation of water-insoluble polysaccharides: The solid residue containing water-insoluble polysaccharides was diluted 5 times with water, and 60 kg of potassium hydroxide was added. The mixture was homogenized by a colloidal mill for 2 hours. The mixture was fully mixed and ground, and then transferred to a stainless steel reactor. The mixture was subjected to alkalization reaction at 70°C for 2 hours. 150 kg of chloroacetic acid was added, and the mixture was subjected to carboxymethylation reaction at 80°C for 2 hours. The mixture was heated to 100°C and the reaction was continued for 1 hour to obtain a carboxymethylated polysaccharide liquid for later use.

[0152] (4) The mixed liquid containing the graft-block copolymer is transferred to a stainless steel reactor, and the carboxymethylated polysaccharide liquid is added under stirring, mixed evenly, and phosphogypsum is added to adjust the pH to 7.5, stirred, mixed evenly, colloid milled and homogenized, evaporated and concentrated to 45° Brix to obtain a concentrated liquid, and the concentrated liquid is spray dried to obtain 2358.6 kg of a powdered solid. Alternatively, the concentrated liquid is wet granulated to obtain a granular solid; the concentrated liquid, the powdered solid and the granular solid are all multifunctional organic-inorganic composite materials containing polypeptides. The powdered solid re-forms a gel after absorbing water, and this process is reversible and repeatable.

[0153] Example 8

[0154] Nitrogen, phosphorus and potassium controlled release experiment

[0155] A soil column elution experiment was conducted on the multifunctional organic-inorganic composite material containing polypeptides obtained in Example 1 (hereinafter referred to as composite material 1), and the experimental method was as follows:

[0156] (1) The test soil was crushed, air-dried, and sieved through a 3 mm sieve to obtain the treated soil. The PVC leached soil column was 8 cm in diameter and 25 cm in height, with a 200 mesh filter cloth at the bottom. Each leached soil column was filled with 1 kg of treated soil (filling height 20 cm).

[0157] (2) Adding composite material 1 at a dosage of 1 g of nitrogen, phosphorus and potassium per kg of air-dried soil, urea and potassium dihydrogen phosphate as the control group (fertilizer group) were fully mixed. After the preparation, the soil column was soaked and washed with pure water to reach a saturated state and maintained for one day.

[0158] (3) Add 100 mL of pure water for elution every 7 days, collect the elution solution, determine the total nitrogen, phosphorus, and potassium contents of the elution solution according to standard GB / T17767, and calculate the cumulative amount of total nitrogen, phosphorus, and potassium leached and the cumulative release rate.

[0159] Cumulative release rate (%) = cumulative release amount / original total amount × 100%

[0160] Draw the cumulative release rate curves of total nitrogen, phosphorus and potassium respectively. The results are as follows Figure 4 , 5 , as shown in Figure 6.

[0161] Conclusion: From Figures 4 to 6 It can be seen that the cumulative release rate of total nitrogen, phosphorus and potassium in composite material 1 is significantly lower than that in the control group (chemical fertilizer group), indicating that the multifunctional organic-inorganic composite material containing polypeptides of the present invention can prolong the fertilizer effect and has a controlled release effect.

[0162] Example 9

[0163] Potted experiment on improving saline-alkali soil

[0164] The multifunctional organic-inorganic composite material containing polypeptides obtained in Example 2 (hereinafter referred to as composite material 2) was subjected to a potted plant experiment for improving saline-alkali soil. The experimental method is as follows:

[0165] (1) The test soil was taken from the arable layer (0-20 cm) of saline-alkali land in Dongying, Shandong Province, crushed, air-dried, and passed through a 3 mm sieve. The basic physical and chemical properties of the soil were as follows: pH 8.9, salt content 1.2%.

[0166] (2) Take 9 kg of air-dried soil and divide it into three parts. Put 3 kg of soil into a potted plant with a size of 20 cm (diameter) × 15 cm (height) as a blank group, add 2% of the composite material 2 to the second part as a test group, and add urea, potassium sulfate, and potassium dihydrogen phosphate (the added content is the same as that in Example 5) to the third part as a control group. Mix them thoroughly. All the above materials are applied at one time and normal water management is performed.

[0167] (3) Ten water-selected rice seeds were sown in each of the three pots, and the germination rate of the rice seeds was measured. The results are shown in Table 1.

[0168] Table 1 Germination rate of rice seeds

[0169] Number of buds Blank group Control group Experimental Group Experiment 1 1 2 6 Experiment 2 0 1 8 Experiment 3 1 3 9 Average germination rate (%) 6.67 20 76.7

[0170] Conclusion: As can be seen from Table 1, the unimproved saline-alkali land (blank group) inhibits rice germination and is not suitable for growing rice. The germination rate of the experimental group of the present invention is significantly improved compared with the blank group and the control group, while the control group is not significantly improved compared with the blank group, and the average germination rate is low, indicating that the multifunctional organic-inorganic composite material containing polypeptides of the present invention has a significant improvement effect on saline-alkali land, and the traditional inorganic fertilizer (control group) has no obvious improvement effect on saline-alkali land.

[0171] Example 10

[0172] Water absorption and water retention performance test

[0173] 1. The multifunctional organic-inorganic composite material containing polypeptide obtained in Example 3 (hereinafter referred to as composite material 3) was subjected to a water absorption performance experiment. The experimental method is as follows:

[0174] (1) Accurately weigh about 10 g of composite material 3 into a beaker, with a mass of m 1 , add excess deionized water, and after 24 hours, remove excess water on the surface with filter paper, and weigh the mass of the residue m 2 , calculate the maximum water absorption rate.

[0175] Maximum water absorption rate (g / g) = (m 2 -m 1 ) / m 1 .

[0176] Three parallel experiments were conducted, and the maximum water absorption rates were 742.4, 731.5, and 745.8, respectively. The average value was 739.9 g / g. It can be seen that the composite material 3 of the present invention can absorb about 740 times its own weight of water, has excellent water absorption performance, and is a super absorbent material.

[0177] 2. The water retention performance test of composite material 3 is carried out as follows:

[0178] (1) Accurately weigh about 10 g of composite material 3 into a beaker, with a mass of m 1 , add excess deionized water, and after 24 hours, use filter paper to absorb excess water on the surface, and weigh the mass of the residue m 2 , and the remaining material was placed in a 100 mL beaker.

[0179] (2) Add (m 2 -m 1 ) grams of deionized water as the control group, and placed in a 60℃ oven at the same time. Take out and weigh at regular intervals, m t , calculate the water retention rate respectively. Set up three parallel experiments and take the average value.

[0180] Water retention rate (%) = (m t -m 1 ) / (m 2 -m 1 )×100%

[0181] Draw a curve of water retention rate changing with time, such as Figure 7 As shown, the water retention rate of the experimental group is higher than that of the control group, indicating that the composite material 3 of the present invention has good water retention performance.

[0182] 3. The water absorption performance of composite material 3 for improving soil was tested. The experimental method is as follows:

[0183] (1) The test soil was crushed, air-dried, and passed through a 3 mm sieve. 1 g of the composite material 3 was mixed with 5 g of the air-dried soil at a mass ratio of 1:5. The resulting mixture was ground while 1 g of deionized water was added dropwise. 6 g of the air-dried soil was taken as a control sample.

[0184] (2) Then dry in a vacuum oven at 80°C for 12 hours and weigh the initial mass of the sample after cooling. 1 , and placed in a constant temperature and humidity test box (temperature 25°C, relative humidity RH60%), and the sample mass m was weighed every 10 hours t , calculate the water absorption rate respectively. Set up three parallel experiments and take the average value.

[0185] Water absorption rate t (g / g)=(m t -m1 ) / m 1 .

[0186] Draw a curve of water absorption rate changing with time.

[0187] 4. The composite material 3 was used to perform an experiment on the water retention performance of the improved soil. The experimental method is as follows:

[0188] (1) The test soil was crushed, air-dried, and passed through a 3 mm sieve. 1 g of the composite material 3 was mixed with 5 g of the air-dried soil at a mass ratio of 1:5. Another 6 g of the air-dried soil was taken as a control sample.

[0189] (2) Then dry in a vacuum oven at 80°C for 12 hours and weigh the initial mass of the sample after cooling. 1 , add deionized water to saturate, filter out excess water, weigh, m 2 , and placed in a constant temperature and humidity test box (temperature 60°C, relative humidity RH30%), and the mass m was measured once a day t , calculate the water retention rate respectively. Set up three parallel experiments and take the average value.

[0190] Water retention rate (%) = (m t -m 1 ) / (m 2 -m 1 )×100%.

[0191] Draw a curve of water retention rate changing with time.

[0192] Conclusion: The improved soil water absorption rate curve and improved soil water retention rate curve of composite material 3 are shown in Figure 8 and Fig. 9 As shown. The soil added with composite material 3 has the function of absorbing water vapor in the air, thereby maintaining soil moisture. Therefore, the multifunctional organic-inorganic composite material containing polypeptides of the present invention has excellent water absorption and water retention effects. When added to the soil in a dry environment (temperature 60°C, relative humidity RH30%), it can still allow the soil to maintain a certain amount of moisture.

[0193] Embodiment 11

[0194] The composite material 3 was subjected to a potted plant simulation experiment on drought resistance, growth promotion performance and desert control. The experimental method is as follows:

[0195] (1) The sand used for the test was taken from the Kubuqi Desert and air-dried.

[0196] (2) Take 9 kg of sand and divide it into three parts. Put 3 kg of sand into a plastic basin of 20 cm (diameter) × 15 cm (height) as a blank group, add 5% of the composite material 3 by weight of the sand into the second part as a test group, and add urea, potassium sulfate, potassium dihydrogen phosphate (the added content is the same as that in Example 5) and 5% of sodium polyacrylate water-retaining agent into the third part as a control group. Mix them thoroughly.

[0197] (3) 15-day-old spring wheat seedlings were transplanted into pots, with 10 plants planted in each pot. Each pot was moistened with 1500 mL of water and placed in a plant growth incubator at a temperature of 15°C, a relative humidity of 30%, and a light intensity of 5000 LUX. No more watering was performed during the period. Three parallel experiments were set up for each group, and the average value was taken.

[0198] (4) After 100 days of wheat maturity, the wheat was harvested and the survival rate and the weight of wheat grains in each pot were calculated. The results are shown in Table 2.

[0199] Table 2 Wheat survival rate and wheat grain quality per pot

[0200]

[0201]

[0202] Conclusion: From Table 2, it can be seen that when wheat is directly planted in the sand and watered only once, the survival rate of wheat is zero (blank group). After the sand is mixed with water retaining agent and fertilizer (control group), the survival rate of wheat is increased to more than 50%, indicating that the use of water retaining agent can improve the survival rate of plants in the desert. The use of the multifunctional organic-inorganic composite material containing polypeptides of the present invention can further improve the survival rate. Under drought stress, the single plant grain yield, the grain yield per unit area and the biomass produced per unit area are significantly higher than the combination of polyacrylic acid water retaining agent and fertilizer, and there is a significant difference. Therefore, the multifunctional organic-inorganic composite material containing polypeptides of the present invention has the effect of resisting drought and promoting crop growth, saving water for agricultural production, achieving increased production and income, conducting desert ecological management, and transforming deserts into fertile fields.

[0203] Example 12

[0204] A potting experiment of heavy metal contaminated soil remediation was carried out on the multifunctional organic-inorganic composite material containing polypeptide obtained in Example 4 (hereinafter referred to as composite material 4), and the experimental method was as follows:

[0205] (1) The test soil was taken from the tillage layer of a heavy metal-contaminated rice field in Hunan (depth 0-20 cm), crushed, air-dried, and sieved through a 3 mm sieve. The heavy metal content of the soil was: total Cu 368 mg / Kg, total Zn 384 mg / Kg, total Cd 0.526 mg / Kg, effective Cu 2.21 mg / Kg, effective Zn 3.84 mg / Kg, and effective Cd 0.323 mg / Kg.

[0206] (2) Take 9 kg of air-dried heavy metal contaminated soil and divide it into three parts. Put 3 kg of heavy metal contaminated soil into a pot of 20 cm (diameter) × 15 cm (height) as a blank group, add 1.5% of the composite material 4 of the heavy metal contamination mass to the second part as a test group, and add urea, potassium sulfate and potassium dihydrogen superphosphate (the added content is the same as that in Example 5) to the third part as a control group. Mix them thoroughly and water them until the soil on the pot surface is just moist.

[0207] (3) After 3-4 days of equilibration, 15-day-old rice seedlings were transplanted into pots, with 6 plants planted in each pot. During the experimental period, a 3-cm water layer was maintained on the soil surface of the plastic pots, and normal water management was performed. Three parallel experiments were set up for each group, and the average value was taken.

[0208] (4) After 100 days of maturity, rice plant samples were collected, and the roots, stalks and grains of the plants were separated, washed with deionized water, placed in an oven at 105°C for 1 hour, and then dried at 60°C to constant weight. After cooling, the plant samples were ground with a grinder and passed through a 100-mesh sieve for the determination of Cd, Cu and Zn contents in various parts. The heavy metal content was determined by ICP-MS according to standard HJ1315-2023, and the results are shown in Table 3.

[0209] Table 3 Heavy metal content in each part

[0210]

[0211] Conclusion: As can be seen from Table 3, compared with the blank group and the control group, after the heavy metal contaminated soil was improved with the composite material 4, the metal content in the roots, straw and grains of the planted rice was greatly reduced, and the Cd content in the grains was far below the standard limit of 0.2 mg / kg in the national food safety standard GB2762-2012. Therefore, the multifunctional organic-inorganic composite material containing polypeptides of the present invention can be used for the restoration of heavy metal contaminated farmland to ensure food safety.

[0212] Although the above embodiments have been described in detail, they are only a part of the embodiments of the present invention, not all of them. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all belong to the protection scope of the present invention.

Claims

1. A method for preparing a multifunctional organic-inorganic composite material containing a polypeptide, characterized in that: The following steps are involved: (1) Preparation of polypeptides: After the protein-containing waste is crushed, a potassium hydroxide solution is added, and then a protease is added for enzymolysis to obtain a polypeptide liquid; (2) Preparation of graft-block copolymer: After the waste containing lignin and water-insoluble polysaccharide is crushed, a potassium hydroxide solution is added, and the lignin is dissolved in the potassium hydroxide solution. After filtering, a clear liquid containing lignin and a solid residue containing water-insoluble polysaccharide are obtained; The clear liquid containing lignin is added with formaldehyde solution to carry out lignin hydroxymethylation reaction, and after the reaction is completed, the pH is adjusted to 8.0-9.0, and urea and formaldehyde solution are added to carry out reaction; the pH is adjusted to 3.5-5.5, and the polypeptide liquid obtained in step (1) is added to carry out reaction, and after the reaction is completed, a mixed liquid containing graft-block copolymer is obtained; (3) Carboxymethylation of water-insoluble polysaccharides: diluting the solid residue containing water-insoluble polysaccharides obtained in step (2) with water, adding potassium hydroxide to carry out an alkalization reaction, and adding chloroacetic acid to carry out a carboxymethylation reaction to obtain a carboxymethylated polysaccharide liquid; (4) The mixed liquid containing the graft-block copolymer is added with stirring to the carboxymethylated polysaccharide liquid obtained in step (3), mixed, the pH value is adjusted to 4.5-7.5, and evaporated to obtain a concentrated liquid, which is a multifunctional organic-inorganic composite material containing polypeptides.

2. The preparation method according to claim 1, characterized in that: The preparation method further comprises the following steps: Preparation of chitosan and calcium nitrate: Chitosan-containing waste is crushed and diluted with water, nitric acid is added for decalcification, and a calcium nitrate-containing liquid and a chitosan-containing solid residue are obtained after filtration; a potassium hydroxide solution is added to the chitosan-containing solid residue for deacetylation to obtain a chitosan-containing liquid; The mixed liquid containing the graft-block copolymer is added to the carboxymethylated polysaccharide liquid obtained in step (3), the liquid containing chitosan and the liquid containing calcium nitrate in sequence under stirring, mixed, the pH value is adjusted to 4.5-7.5, and evaporated and concentrated to obtain a concentrated liquid, which is a multifunctional organic-inorganic composite material containing polypeptides.

3. The preparation method according to claim 1, characterized in that: In the step (1), the concentration of the potassium hydroxide solution is 1-5%, and the mass volume ratio of the protein-containing waste to the potassium hydroxide solution is 1:3-10; The protease is one or a combination of alkaline protease and neutral protease, the mass ratio of protease to protein-containing waste is 0.1-1:100, and the enzymolysis conditions are 40-60°C and 2-6 hours.

4. The preparation method according to claim 1, characterized in that: In the step (2), the mass ratio of the waste containing lignin and water-insoluble polysaccharides to the waste containing protein is 1:0.05-0.3; the concentration of the potassium hydroxide solution is 1-10%; the mass volume ratio of the waste containing lignin and water-insoluble polysaccharides to the potassium hydroxide solution is 1:3-10; the lignin dissolution reaction conditions are 80-160°C and 2-4 hours; The concentration of the formaldehyde solution is 37%, the mass ratio of the waste containing lignin and water-insoluble polysaccharides to the first added formaldehyde solution is 1:0.1-0.4; the mass ratio of the waste containing lignin and water-insoluble polysaccharides to the second added formaldehyde solution is 1:0.1-0.35; the mass ratio of the waste containing lignin and water-insoluble polysaccharides to urea is 1:0.1-0.5; The conditions for the hydroxymethylation of lignin are: pH 11-12, 70-90°C, 2-4 hours; the conditions for the reaction with urea and formaldehyde are: 90-100°C, 2-4 hours; the conditions for the reaction with the polypeptide liquid are: 90-100°C, 1-3 hours; Phosphoric acid was used to adjust the pH.

5. The preparation method according to claim 1, characterized in that: In the step (3), the mass ratio of the waste containing lignin and water-insoluble polysaccharides, potassium hydroxide and chloroacetic acid is 1:0.05-0.2:0.1-0.6; Alkalization reaction conditions: 50-70°C, 1-2 hours; carboxymethylation reaction conditions: 50-80°C for 2-4 hours, then heated to 90-100°C for 1-8 hours.

6. The preparation method according to claim 1, characterized in that: In the step (4), phosphogypsum is used to adjust the pH; and triple-effect evaporation is used to concentrate the solution to 35-45° Brix.

7. The preparation method according to claim 2, characterized in that: The chitosan-containing waste is one or a combination of crayfish shells and crab shells; The mass ratio of waste containing chitin to waste containing lignin and water-insoluble polysaccharide is 0.1-0.3:1; water is added to dilute to 3-10 times; nitric acid is added to a concentration of 1-5%; the decalcification reaction conditions are 50-80°C and 1-4 hours; The concentration of the potassium hydroxide solution is 40-50%, the mass ratio of the chitosan-containing waste to the potassium hydroxide solution is 1-3:1-3, and the deacetylation reaction conditions are 80-100° C. and 1-4 hours.

8. A multifunctional organic-inorganic composite material containing a polypeptide prepared by the preparation method of claim 1, characterized in that: The multifunctional organic-inorganic composite material containing polypeptides is mainly prepared from waste containing lignin and water-insoluble polysaccharides, waste containing protein, and inorganic substances containing nitrogen, phosphorus, and potassium; Polypeptides are obtained from protein-containing wastes, and lignin / urea acetal / polypeptide graft-block copolymers and carboxymethylated polysaccharides are obtained from wastes containing lignin and water-insoluble polysaccharides, respectively. The two are cross-linked to form a three-dimensional network structure that can store water and nitrogen, phosphorus, and potassium nutrients.

9. The multifunctional organic-inorganic composite material containing polypeptide according to claim 8, characterized in that: The multifunctional organic-inorganic composite material containing polypeptides has multiple functions of promoting plant growth, controlling the release of nitrogen, phosphorus and potassium, improving soil water absorption and water retention performance, reducing the damage of saline-alkali land to plants, and passivating heavy metal ions.

10. An application of a multifunctional organic-inorganic composite material containing polypeptides prepared by the preparation method according to any one of claims 1 to 7 in promoting plant growth, controlling the release of nitrogen, phosphorus and potassium, improving saline-alkali soil, improving soil water absorption and retention properties, and repairing heavy metal contaminated soil.

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