Process for preparing liquid fertilizer by utilizing proline fermentation liquor

Abstract

The invention discloses a process for preparing a liquid fertilizer by using proline fermentation liquor, and relates to the technical field of fertilizer preparation, and the process has the advantages that an acrylic monomer is combined with an ammonium persulfate initiator and an N, N '-methylene bisacrylamide cross-linking agent to prepare a high-molecular polymer network, and in the process, the proline fermentation liquor is added into the high-molecular polymer network to prepare the liquid fertilizer. The carboxyl and amino of the acrylic monomer provide active sites for subsequent reaction, then a copper ion complexing group is introduced, copper ions are subjected to complexing reaction with the carboxyl and amino in the polymer to form a stable coordination bond which is combined with electrostatic interaction, proline molecules can be efficiently grabbed from proline fermentation waste liquid, and the proline can be efficiently separated from the proline fermentation waste liquid. Specific functional groups such as acylamino are introduced, so that the specific binding with the proline is enhanced, the binding of the specific material to the proline is firmer and more accurate, a solid foundation is laid for the subsequent preparation of high-quality fertilizers, the recycling rate of resources is increased, and a high-purity key raw material is provided for the production of liquid fertilizers.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer preparation, in particular to a process for preparing liquid fertilizer by utilizing proline fermentation liquid. Background Art

[0002] In modern agricultural production, fertilizer plays a vital role in improving crop yield and quality. As people pay more and more attention to environmental protection and sustainable use of resources, the development of efficient, environmentally friendly fertilizer preparation technology that can make full use of waste has become a research hotspot. The proline fermentation industry produces a large amount of waste liquid during the production process. These waste liquids contain unused proline and other organic and inorganic components. If they are directly discharged, they will not only cause serious environmental pollution, but also lead to a huge waste of resources. Under such circumstances, the use of proline fermentation waste liquid to prepare liquid fertilizer has important significance and broad application prospects. Through innovative process technology, high-purity proline and other beneficial components are extracted from proline fermentation waste liquid, and converted into liquid fertilizer with high fertility. This can not only solve the problem of waste liquid treatment, realize the recycling of resources, and reduce production costs, but also provide a green, environmentally friendly and efficient fertilizer product for agricultural production. The existing technology has certain technical defects. First, it is difficult to accurately extract proline from fermentation waste liquid with the existing technology, resulting in waste of resources and low purity of key raw materials, which affects the quality of fertilizer. Secondly, the fertilizer prepared by the existing technology has insufficient organic nitrogen source, limited effect on promoting plant growth, and insufficient fertilizer stability. Furthermore, in the process of separating and extracting proline, impurities cannot be effectively removed, which affects the purity of proline and causes unstable fertilizer quality. For this reason, we propose a process for preparing liquid fertilizer using proline fermentation liquid. Summary of the invention

[0003] The object of the present invention is to provide a process for preparing liquid fertilizer by utilizing proline fermentation liquid.

[0004] In order to solve the problems raised in the above background technology, the present invention provides the following technical solution: a process for preparing liquid fertilizer using proline fermentation liquid, wherein the process for preparing liquid fertilizer specifically comprises the following steps: Step 1: preparing a specific material, selecting an acrylic monomer with carboxyl and amino groups, dissolving the acrylic monomer, ammonium persulfate initiator and N,N'-methylenebisacrylamide crosslinker in deionized water, irradiating with ultraviolet light in a constant temperature water bath environment to initiate a polymerization reaction, forming a high molecular polymer network, then immersing the polymer network in a solution containing copper ions for reaction, so that the copper ions react with the carboxyl and amino groups in the polymer, wherein the carboxyl groups form stable coordination bonds with the copper ions, and the amino groups and the copper ions are combined by electrostatic action, thereby introducing copper ion complexing groups, then mixing the treated polymer with a small molecule compound solution containing methyl parahydroxybenzoate for reaction, using functional groups such as hydroxyl groups in methyl parahydroxybenzoate to further react with the polymer, introducing hydrogen-bonded amide receptor groups, so that the amide groups can specifically bind to proline, and obtaining a specific material; Step 2: mixing the prepared specific material with the proline fermentation waste liquid in a reaction container for reaction; Step 3, separation and extraction of proline, using a filter membrane to separate specific materials from fermentation waste liquid, transferring the specific materials to another reaction container, using sodium chloride and phosphate buffer solution to elute the specific materials, extracting high-purity proline, and then further purifying it, crystallizing the extracted high-purity proline solution under slow cooling conditions, then centrifuging to separate the crystallized proline, and washing it with deionized water to remove impurities to obtain pure proline crystals; Step 4: preparing peptide substances, adding proline crystals into deionized water, stirring and dissolving to obtain high-purity proline liquid, mixing the high-purity proline liquid with alanine fermentation liquid and aspartic acid fermentation liquid, then adding papain catalyst, placing the mixed liquid in a reactor for reaction to generate peptide substances with synergistic effects, and then separating the products, removing unreacted amino acids and impurities, and collecting waste liquid generated during the preparation process; Step 5: Mix the peptide substance with the waste liquid collected during the preparation of the peptide substance, filter it through a filter membrane to remove impurities, transfer it to a fermentation tank, add Bacillus, lactic acid bacteria, photosynthetic bacterial microbial flora, earthworm castings and wood vinegar for fermentation to obtain liquid fertilizer.

[0005] As a further scheme of the present invention: in the step 1, the acrylic monomer with carboxyl and amino groups is a mixture of 2-aminoethyl acrylate and 2-carboxyethyl acrylate in a mass ratio of 5:5, the acrylic monomer, ammonium persulfate initiator and N,N'-methylenebisacrylamide cross-linking agent are dissolved in deionized water in a mass ratio of 10-12:1-2:0.5-1.0, the water bath environment temperature is 40°C-50°C, and the polymerization reaction time is 4h-6h.

[0006] As a further scheme of the present invention: in the step 1, the solution containing copper ions is a mixed solution of copper sulfate and sodium hydroxide, the reaction temperature is 50°C-60°C, the reaction temperature of the polymer and small molecule compound solution is 45°C-55°C, and the reaction is carried out for 3h-4h under stirring conditions with a rotation speed of 120r / min-150r / min.

[0007] As a further scheme of the present invention: in the step 2, the mass ratio of the added specific material to the proline fermentation waste liquid is 1-2:5-8, the reaction temperature is 30°C-35°C, the pH value is 6.5-7.5, the stirring speed is 100r / min-150r / min, and the reaction time is 8h-10h.

[0008] As a further scheme of the present invention: in the step three, the pore size of the filter membrane is 0.2μm-0.5μm, the filtration pressure is 0.2MPa-0.5MPa, the sodium chloride concentration is 0.1mol / L-0.3mol / L, the pH value of the phosphate buffer solution is 7.0-7.5, the elution temperature is 25℃-30℃, the rotation speed is 80r / min-120r / min, the elution time is 6h-8h, and the cooling rate of the purified crystallization is controlled at 2℃ / h-3℃ / h. When the temperature drops to 5℃-10℃, the holding time is 4h-6h.

[0009] As a further solution of the present invention: in the step 4, the temperature of the deionized water added to the proline crystals is controlled at 30° C.-40° C., the high-purity proline solution is mixed with the alanine fermentation solution and the aspartic acid fermentation solution in a volume ratio of 10:2:3, the purity of the alanine fermentation solution is 85%-90%, the purity of the aspartic acid fermentation solution is 80%-85%, and the amount of papain catalyst added is 0.5%-1% of the total volume of the high-purity proline solution, the alanine fermentation solution and the aspartic acid fermentation solution.

[0010] As a further solution of the present invention: in the step 4, the reaction temperature of the mixed high-purity proline solution, alanine fermentation solution, aspartic acid fermentation solution and papain catalyst is 45-55° C., and the reaction time is 10 h-12 h.

[0011] As a further solution of the present invention: in step 5, the pore size of the filter membrane is 0.1 μm-0.3 μm, and the total concentration of the microbial flora is 1×10 6 CFU / mL-1×10 7 CFU / mL, the mass proportion of earthworm castings is 10%-15%, and the volume proportion of wood vinegar is 5%-8%.

[0012] As a further solution of the present invention: in the step five, the fermentation reaction temperature is 35-40°C, the humidity is 60%-70%, the ventilation volume is 0.5m³ / h-1.0m³ / h, and the fermentation time is 15h-20h.

[0013] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention prepares a high molecular polymer network by mixing 2-aminoethyl acrylate and 2-carboxyethyl acrylate as acrylic monomers, combining ammonium persulfate initiator and N,N'-methylenebisacrylamide crosslinker. In this process, the carboxyl group and amino group of the acrylic monomer provide active sites for subsequent reactions. The ammonium persulfate initiator initiates a polymerization reaction at a specific temperature, so that the monomer quickly forms a high molecular polymer network. The network has certain stability and pore structure, and provides a good carrier for the subsequent introduction of functional groups. Subsequently, the polymer network is immersed in a mixed solution containing copper sulfate and sodium hydroxide to introduce copper ion complexing groups. The copper ions bind to the carboxyl groups in the polymer. The copper ion complexing group reacts with the amino group to form a stable coordination bond and electrostatic binding. This copper ion complexing group has a highly selective binding ability to proline and can efficiently capture proline molecules from the proline fermentation waste liquid. Then, it reacts with a small molecule compound solution containing methyl parahydroxybenzoate to introduce specific functional groups such as amide groups. The amide groups further enhance the specific binding with proline, making the specific material more firmly and accurately bound to proline, thus achieving accurate extraction of proline from waste liquid, laying a solid foundation for the subsequent preparation of high-quality fertilizers, not only improving the recycling rate of resources and reducing pollution to the environment, but also providing high-purity key raw materials for the production of liquid fertilizers; 2. The present invention generates peptide substances by mixing high-purity proline liquid with diluted alanine fermentation liquid and aspartic acid fermentation liquid, and adding papain catalyst for reaction. The high-purity proline liquid can enhance plant stress resistance after extraction and purification. The purity of alanine fermentation liquid and aspartic acid fermentation liquid is within a specific range, providing stable and reliable raw materials for the reaction and helping plants to metabolize better. The papain catalyst can efficiently catalyze the reaction between amino acids to generate peptide substances with synergistic effects. These peptide substances provide rich organic nitrogen sources for fertilizers, are easily absorbed and utilized by plants, and promote plant growth and development. At the same time, the peptide structure can enhance the absorption and utilization efficiency of nutrients by plants, and improve the ability to absorb other nutrient elements in the soil. In addition, the peptide substances improve the stability of fertilizers, extend the effective period, and greatly improve the practicality of fertilizers. 3. The present invention effectively separates specific materials from fermentation waste liquid by filtering under a specific pressure, laying a foundation for the subsequent extraction of high-purity proline. Then, elution is performed by using a phosphate buffer solution containing sodium chloride and a specific pH value, wherein the sodium chloride provides a specific ionic strength to promote the separation of proline. Subsequently, crystallization purification is performed by precisely controlling the cooling rate and holding time to obtain purer proline crystals, which not only improves the utilization rate of resources and provides high-purity raw materials for the preparation of high-quality liquid fertilizers, but also reduces the adverse effects of impurities on the fertilizer effect, so that the final liquid fertilizer can more effectively promote plant growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the process steps in an embodiment of the present invention; Figure 2 Schematic diagram of performance comparison of embodiments in the present invention. DETAILED DESCRIPTION

[0015] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0016] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] Please refer to the attached Figure 1 -Attached Figure 2 The present invention provides a process for preparing liquid fertilizer using proline fermentation liquid, and the process for preparing liquid fertilizer specifically comprises the following steps: Step 1: preparing a specific material, selecting an acrylic monomer with carboxyl and amino groups, dissolving the acrylic monomer, ammonium persulfate initiator and N,N'-methylenebisacrylamide crosslinker in deionized water, irradiating with ultraviolet light in a constant temperature water bath environment to initiate a polymerization reaction, forming a high molecular polymer network, then immersing the polymer network in a solution containing copper ions for reaction, so that the copper ions react with the carboxyl and amino groups in the polymer, wherein the carboxyl groups form stable coordination bonds with the copper ions, and the amino groups and the copper ions are combined by electrostatic action, thereby introducing copper ion complexing groups, then mixing the treated polymer with a small molecule compound solution containing methyl parahydroxybenzoate for reaction, using functional groups such as hydroxyl groups in methyl parahydroxybenzoate to further react with the polymer, introducing hydrogen-bonded amide receptor groups, so that the amide groups can specifically bind to proline, and obtaining a specific material; Step 2: mixing the prepared specific material with the proline fermentation waste liquid in a reaction container for reaction; Step 3, separation and extraction of proline, using a filter membrane to separate specific materials from fermentation waste liquid, transferring the specific materials to another reaction container, using sodium chloride and phosphate buffer solution to elute the specific materials, extracting high-purity proline, and then further purifying it, crystallizing the extracted high-purity proline solution under slow cooling conditions, then centrifuging to separate the crystallized proline, and washing it with deionized water to remove impurities to obtain pure proline crystals; Step 4: preparing peptide substances, adding proline crystals into deionized water, stirring and dissolving to obtain high-purity proline liquid, mixing the high-purity proline liquid with alanine fermentation liquid and aspartic acid fermentation liquid, then adding papain catalyst, placing the mixed liquid in a reactor for reaction to generate peptide substances with synergistic effects, and then separating the products, removing unreacted amino acids and impurities, and collecting waste liquid generated during the preparation process; Step 5: Mix the peptide substance with the waste liquid collected during the preparation of the peptide substance, filter it through a filter membrane to remove impurities, transfer it to a fermentation tank, add Bacillus, lactic acid bacteria, photosynthetic bacterial microbial flora, earthworm castings and wood vinegar for fermentation to obtain liquid fertilizer.

[0018] In one embodiment of the present invention: in step 1, the acrylic monomer with carboxyl and amino groups is a mixture of 2-aminoethyl acrylate and 2-carboxyethyl acrylate in a mass ratio of 5:5, the acrylic monomer, ammonium persulfate initiator and N,N'-methylenebisacrylamide cross-linking agent are dissolved in deionized water in a mass ratio of 10-12:1-2:0.5-1.0, the water bath environment temperature is 40°C-50°C, and the polymerization reaction time is 4h-6h.

[0019] In one embodiment of the present invention: in step one, the solution containing copper ions is a mixed solution of copper sulfate and sodium hydroxide, the reaction temperature is 50°C-60°C, the reaction temperature of the polymer and small molecule compound solution is 45°C-55°C, and the reaction is carried out for 3h-4h under stirring conditions with a rotation speed of 120r / min-150r / min.

[0020] In one embodiment of the present invention: in step 2, the mass ratio of the added specific material to the proline fermentation waste liquid is 1-2:5-8, the reaction temperature is 30°C-35°C, the pH value is 6.5-7.5, the stirring speed is 100r / min-150r / min, and the reaction time is 8h-10h.

[0021] In one embodiment of the present invention: in step three, the pore size of the filter membrane is 0.2μm-0.5μm, the filtration pressure is 0.2MPa-0.5MPa, the sodium chloride concentration is 0.1mol / L-0.3mol / L, the pH value of the phosphate buffer solution is 7.0-7.5, the elution temperature is 25℃-30℃, the rotation speed is 80r / min-120r / min, the elution time is 6h-8h, and the cooling rate of the purified crystallization is controlled at 2℃ / h-3℃ / h. When the temperature drops to 5℃-10℃, the holding time is 4h-6h.

[0022] In one embodiment of the present invention: in step 4, the temperature of the deionized water added to the proline crystals is controlled at 30° C.-40° C., the high-purity proline solution is mixed with the alanine fermentation broth and the aspartic acid fermentation broth in a volume ratio of 10:2:3, the purity of the alanine fermentation broth is 85%-90%, the purity of the aspartic acid fermentation broth is 80%-85%, and the amount of papain catalyst added is 0.5%-1% of the total volume of the high-purity proline solution, the alanine fermentation broth and the aspartic acid fermentation broth.

[0023] In one embodiment of the present invention: in step 4, the reaction temperature of the mixed high-purity proline solution, alanine fermentation solution, aspartic acid fermentation solution and papain catalyst is 45-55° C., and the reaction time is 10 h-12 h.

[0024] In one embodiment of the present invention: in step 5, the pore size of the filter membrane is 0.1 μm-0.3 μm, and the total concentration of the microbial flora is 1×10 6 CFU / mL-1×10 7 CFU / mL, the mass proportion of earthworm castings is 10%-15%, and the volume proportion of wood vinegar is 5%-8%.

[0025] In one embodiment of the present invention: in step five, the fermentation reaction temperature is 35-40°C, the humidity is 60%-70%, the ventilation volume is 0.5m³ / h-1.0m³ / h, and the fermentation time is 15h-20h.

[0026] In one embodiment of the present invention: before preparing the specific material, the acrylic monomer is pretreated by placing it in a vacuum environment and treating it at a temperature of 20-30°C and a pressure of 0.05-0.1MPa for 1h-2h to remove trace oxygen and moisture in the monomer, so as to improve the efficiency of the polymerization reaction and the quality of the specific material, thereby enhancing the adsorption and binding capacity of proline.

[0027] In one embodiment of the present invention: before mixing the specific material with the proline fermentation waste liquid, the proline fermentation waste liquid is pretreated, the fermentation waste liquid is firstly separated by an ultrafiltration membrane (molecular weight cutoff of 1000-5000Da) to remove macromolecular impurities, and then the pH value is adjusted to 5.0-6.0, and then activated carbon with a mass fraction of 0.1%-0.5% is added, and stirred for 2h-4h at a temperature of 25-35°C and a stirring speed of 80-120r / min for adsorption decolorization and further impurity removal. The pretreated fermentation waste liquid can better react with the specific material.

[0028] In one embodiment of the present invention: N,N'-methylenebisacrylamide crosslinking agent can be partially or completely replaced by polyvinyl butyral (PVB), the mass ratio of PVB to acrylic monomer is 0.3-0.8:10, PVB molecules contain multiple hydroxyl (-OH) groups, these hydroxyl groups have high reactivity, when mixed with acrylic monomers and in the presence of initiator (ammonium persulfate), the hydroxyl groups can chemically react with the unsaturated bonds (carbon-carbon double bonds) in the acrylic monomers to form chemical bonds to connect different monomer molecules, thereby constructing a three-dimensional network polymer structure, that is, playing the role of a crosslinking agent.

[0029] Example 1, please refer to the attached Figure 1 -Attached Figure 2First, a mixture of 2-aminoethyl acrylate and 2-carboxyethyl acrylate in a mass ratio of 5:5 was selected as an acrylic monomer with carboxyl and amino groups, and was dissolved in deionized water with an ammonium persulfate initiator and an N,N'-methylenebisacrylamide crosslinker in a mass ratio of 10:1:0.5. Then, a polymerization reaction was initiated by ultraviolet light in a constant temperature water bath environment of 50°C for 6 hours to form a high molecular polymer network. Then, it was immersed in a mixed solution of copper sulfate and sodium hydroxide at 60°C to react and introduce copper ion complexing groups. Then, it was reacted with a solution containing parahydroxyl radicals to form a high molecular polymer network. The small molecule compound solution of methyl benzoate was reacted at 55°C and a stirring speed of 150 r / min for 4 hours to introduce a hydrogen-bonded amide acceptor group to obtain a specific material. Subsequently, the specific material and proline fermentation waste liquid were mixed in a reaction vessel with a stirring device and a temperature control system at a mass ratio of 1:5, and stirred at 35°C and a pH value of 6.5 at a speed of 150 r / min for 10 hours. Subsequently, a filter membrane with a pore size of 0.5 μm was used to separate the specific material from the fermentation waste liquid at a filtration pressure of 0.2 MPa, and then the specific The material was transferred to another reaction container, and eluted with a phosphate buffer solution having a sodium chloride concentration of 0.3 mol / L and a pH value of 7.0 at 30°C and a rotation speed of 120 r / min for 8 hours. After that, high-purity proline was extracted and the solution was slowly cooled at a cooling rate of 2°C / h. When the temperature dropped to 8°C, it was kept for 6 hours for crystallization, centrifuged and washed with deionized water to obtain pure proline crystals. Then, the proline crystals were added to deionized water controlled at a temperature of 40°C and stirred to dissolve to obtain a high-purity proline solution. The high-purity proline solution was then mixed with alanine fermentation broth (pure The mixture was mixed with aspartic acid fermentation broth (purity of 90%) and aspartic acid fermentation broth (purity of 85%) in a volume ratio of 10:2:3, and papain catalyst (added in an amount of 1% of the total volume) was added. The mixture was reacted at 55°C for 12 h to generate peptide substances with synergistic effects. The products were separated to remove unreacted amino acids and impurities, and the waste liquid was collected. Finally, the peptide substances were mixed with the collected waste liquid, filtered through a filter membrane with a pore size of 0.3 μm to remove impurities, and then transferred to a fermentation tank, and Bacillus, lactic acid bacteria, and photosynthetic bacterial microbial flora (total concentration of 1×10 7 CFU / mL), vermicompost (12% by mass) and wood vinegar (6% by volume) were fermented at 40°C, 70% humidity and 1.0 m³ / h ventilation for 20 h to obtain liquid fertilizer.

[0030] Example 2, please refer to the attached Figure 1 -Attached Figure 2First, a mixture of 2-hydroxyethyl methacrylate and 2-methoxyethyl methacrylate in a mass ratio of 5:5 was selected as a methacrylic acid monomer with a hydroxyl group and a methoxy group, and dissolved in deionized water with a potassium persulfate initiator and a divinylbenzene crosslinker in a mass ratio of 10:1:0.5. Then, a polymerization reaction was initiated by ultraviolet light in a constant temperature water bath environment of 50°C for 6 hours to form a high molecular polymer network. Then, it was immersed in a mixed solution of zinc chloride and potassium hydroxide at 60°C to react and introduce zinc ion complexing groups. Then, it was mixed with a solution containing o-phenylene glycol to form a high molecular polymer network. The small molecule compound solution of dimethyl dicarboxylate was reacted at 55°C and a stirring speed of 150 r / min for 4 hours to introduce a hydrogen-bonded ester acceptor group to obtain a specific material. Subsequently, the specific material and proline fermentation waste liquid were mixed in a reaction vessel with a stirring device and a temperature control system at a mass ratio of 1:5, and stirred at 35°C and a pH value of 6.5 at a speed of 150 r / min for 10 hours. Subsequently, a filter membrane with a pore size of 0.5 μm was used to separate the specific material from the fermentation waste liquid at a filtration pressure of 0.2 MPa, and then the specific material was filtered. The material was transferred to another reaction container, and eluted with a potassium dihydrogen phosphate buffer solution with a potassium chloride concentration of 0.3 mol / L and a pH value of 7.0 at 30°C and a rotation speed of 120r / min for 8 hours. After that, the high-purity proline was extracted and the solution was slowly cooled at a cooling rate of 2°C / h. When the temperature dropped to 8°C, it was kept for 6 hours for crystallization, centrifuged and washed with deionized water to obtain pure proline crystals. Then, the proline crystals were added to deionized water controlled at a temperature of 40°C and stirred to dissolve to obtain a high-purity proline solution. Then, the high-purity proline solution was mixed with alanine fermentation broth (pure The mixture was mixed with aspartic acid fermentation broth (purity of 90%) and aspartic acid fermentation broth (purity of 85%) in a volume ratio of 10:2:3, and bromelain catalyst (added in an amount of 1% of the total volume) was added. The mixture was reacted at 55°C for 12 h to generate peptide substances with synergistic effects. The products were separated to remove unreacted amino acids and impurities, and the waste liquid was collected. Finally, the peptide substances were mixed with the collected waste liquid, filtered through a filter membrane with a pore size of 0.3 μm to remove impurities, and then transferred to a fermentation tank, and Bacillus, lactic acid bacteria, and photosynthetic bacterial microbial flora (total concentration of 1×10 7 CFU / mL), vermicompost (12% by mass) and wood vinegar (6% by volume) were fermented at 40°C, 70% humidity and 1.0 m³ / h ventilation for 20 h to obtain liquid fertilizer.

[0031] Example 3, please refer to the attached Figure 1 -Attached Figure 2First, a mixture of 2-aminoethyl acrylate and 2-carboxyethyl acrylate in a mass ratio of 5:5 was selected as an acrylic monomer with carboxyl and amino groups, and dissolved in deionized water with an ammonium persulfate initiator and an N,N'-methylenebisacrylamide cross-linker in a mass ratio of 10:2:1. Then, a polymerization reaction was initiated by ultraviolet light in a constant temperature water bath at 40°C for 4 hours to form a high molecular polymer network. Then, it was immersed in a mixed solution of copper sulfate and sodium hydroxide at 60°C to react and introduce copper ion complexing groups. Then, it was reacted with a solution containing p-hydroxyphenyl. The small molecule compound solution of methyl formate was reacted at 55°C and a stirring speed of 120r / minn for 4h to introduce a hydrogen-bonded amide acceptor group to obtain a specific material. Subsequently, the specific material and proline fermentation waste liquid were mixed in a reaction vessel with a stirring device and a temperature control system at a mass ratio of 2:5, and stirred at 35°C and a pH value of 7.5 at a speed of 150r / min for 8h. Then, a filter membrane with a pore size of 0.2μm was used to separate the specific material from the fermentation waste liquid at a filtration pressure of 0.2MPa, and then the specific The material was transferred to another reaction container, and eluted with a phosphate buffer solution having a sodium chloride concentration of 0.1 mol / L and a pH value of 7.5 at 30°C and a rotation speed of 120 r / min for 8 hours. After that, the high-purity proline was extracted and the solution was slowly cooled at a cooling rate of 2°C / h. When the temperature dropped to 8°C, it was kept for 6 hours for crystallization, centrifuged and washed with deionized water to obtain pure proline crystals. Then, the proline crystals were added to deionized water controlled at a temperature of 40°C and stirred to dissolve to obtain a high-purity proline solution. The high-purity proline solution was then mixed with alanine fermentation broth (pure The mixture was mixed with aspartic acid fermentation broth (purity of 90%) and aspartic acid fermentation broth (purity of 85%) in a volume ratio of 10:2:3, and papain catalyst (added in an amount of 1% of the total volume) was added. The mixture was reacted at 55°C for 12 h to generate peptide substances with synergistic effects. The products were separated to remove unreacted amino acids and impurities, and the waste liquid was collected. Finally, the peptide substances were mixed with the collected waste liquid, filtered through a filter membrane with a pore size of 0.3 μm to remove impurities, and then transferred to a fermentation tank, and Bacillus, lactic acid bacteria, and photosynthetic bacterial microbial flora (total concentration of 1×10 7 CFU / mL), vermicompost (12% by mass) and wood vinegar (6% by volume) were fermented at 40°C, 70% humidity and 1.0 m³ / h ventilation for 20 h to obtain liquid fertilizer.

[0032] Design of the experiment: Experimental materials and equipment Materials: 2-aminoethyl acrylate, 2-carboxyethyl acrylate, ammonium persulfate, N,N'-methylenebisacrylamide, copper sulfate, sodium hydroxide, methyl paraben, proline fermentation waste liquid, alanine fermentation broth, aspartic acid fermentation broth, papain, Bacillus, lactic acid bacteria, photosynthetic bacteria, vermicompost, wood vinegar, deionized water, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, potassium persulfate, divinylbenzene, zinc chloride, dimethyl phthalate, bromelain, potassium chloride, potassium dihydrogen phosphate, etc. Equipment: constant temperature water bath, ultraviolet lamp, stirrer, reaction vessel, filter, centrifuge, fermenter, pH meter, thermometer, high performance liquid chromatograph (for detecting the content of proline and peptide substances), electronic balance, plant growth incubator, etc.; Example 1: Liquid fertilizer was prepared according to the process of Example 1, Example 2: Liquid fertilizer was prepared according to the process of Example 2, Example 3: Liquid fertilizer was prepared according to the process of Example 3; Resource recovery rate measurement Calculate the proline extraction rate: measure the proline content of the three groups before and after the separation and extraction of proline, extraction rate = (proline mass after extraction ÷ proline mass before extraction) × 100%, use high performance liquid chromatography to detect the proline content, each group of samples was measured three times in parallel, and the average value was taken; Calculate the utilization rate of effective ingredients in the final fertilizer: Determine the changes in the content of effective ingredients such as amino acids in the fermentation waste liquid before and after the fertilizer is prepared. The utilization rate = (the amount of effective ingredients reduced after the fertilizer is prepared / the total amount of effective ingredients before the fertilizer is prepared) × 100%. Similarly, each group of samples is measured three times in parallel and the average value is taken. Determination of the effect of fertilizers on plant growth promotion A number of plant seedlings (such as tomato seedlings) with similar growth conditions were selected and randomly divided into three groups. The liquid fertilizers prepared in Example 1, Example 2, and Example 3 were used for irrigation respectively, and a blank control group (irrigated with an equal amount of clean water) was set. Each group was set with one replicate; Cultivate under the same environmental conditions (light intensity of about 5000 lux, temperature of 25 ± 2 °C, humidity of 60%) for a period of 28 days; Determine the growth indicators of plants, including plant height, stem diameter, number of leaves, fresh weight and dry weight, etc. The plant height is measured with a ruler, accurate to 0.1 cm, the stem diameter is measured with a vernier caliper, accurate to 0.01 mm, the number of leaves is directly counted, and the fresh weight and dry weight are determined by drying and weighing method (first weigh the fresh weight, accurate to 0.01 g, then dry the plant sample in an oven at 80°C to constant weight and weigh the dry weight, accurate to 0.001 g); Fertilizer quality stability test Determination of changes in peptide content: At different time points (0 days, 14 days, and 28 days) after preparation, the content of peptides in the fertilizer was detected using a high performance liquid chromatograph, and the content change rate was calculated = (peptide content at different time points - initial peptide content) ÷ initial peptide content × 100%. Each group of samples was measured three times in parallel and the average value was taken. Observe the appearance and smell of fertilizers: observe the color, transparency, precipitation, smell and other changes of fertilizers every other day, and make qualitative descriptions and records; Experimental data recording and analysis The experimental data were recorded in a table and statistically analyzed. The differences among the three groups of data were compared using analysis of variance (ANOVA) and other methods. P < 0.05 indicated a significant difference. As attached Figure 2 As shown, in terms of resource recovery and utilization rate, the proline extraction rate of Example 1 and the utilization rate of the effective ingredients in the final fertilizer are higher than those of Example 2 and Example 3. In terms of the effect on plant growth promotion, the various growth indicators of the plants treated with Example 1 (plant height, stem thickness, number of leaves, fresh weight and dry weight) are better than those of Example 2 and Example 3. In terms of fertilizer quality stability, the change rate of the peptide content at different time points in Example 1 is small, and the changes in the appearance and odor of the fertilizer are relatively small, indicating that it has better stability. On the whole, the effect of Example 1 is better than that of Example 2 and Example 3 in terms of the three beneficial effects.

[0033] Although the present invention is disclosed as above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A process for preparing liquid fertilizer using proline fermentation liquid, characterized in that: The process for preparing liquid fertilizer specifically comprises the following steps: Step 1: preparing a specific material, selecting an acrylic monomer with a carboxyl group and an amino group, dissolving the acrylic monomer, an ammonium persulfate initiator and an N,N'-methylenebisacrylamide crosslinker in deionized water, irradiating with ultraviolet light in a constant temperature water bath to initiate a polymerization reaction, forming a high molecular polymer network, then immersing the polymer network in a solution containing copper ions to react, so that the copper ions react with the carboxyl group and the amino group in the polymer, and then mixing the treated polymer with a small molecule compound solution containing methyl parahydroxybenzoate to obtain a specific material; Step 2: mixing the prepared specific material with the proline fermentation waste liquid in a reaction container for reaction; Step 3, separation and extraction of proline, using a filter membrane to separate specific materials from fermentation waste liquid, transferring the specific materials to another reaction container, using sodium chloride and phosphate buffer solution to elute the specific materials, extracting high-purity proline, and then further purifying it, crystallizing the extracted high-purity proline solution under slow cooling conditions, then centrifuging to separate the crystallized proline, and washing it with deionized water to remove impurities to obtain pure proline crystals; Step 4: preparing peptide substances, adding proline crystals into deionized water, stirring and dissolving to obtain high-purity proline liquid, mixing the high-purity proline liquid with alanine fermentation liquid and aspartic acid fermentation liquid, then adding papain catalyst, placing the mixed liquid in a reactor for reaction to generate peptide substances with synergistic effects, and then separating the products, removing unreacted amino acids and impurities, and collecting waste liquid generated during the preparation process; Step 5: Mix the peptide substance with the waste liquid collected during the preparation of the peptide substance, filter it through a filter membrane to remove impurities, transfer it to a fermentation tank, add Bacillus, lactic acid bacteria, photosynthetic bacterial microbial flora, earthworm castings and wood vinegar for fermentation to obtain liquid fertilizer.

2. A process for preparing liquid fertilizer using proline fermentation liquid according to claim 1, characterized in that: In the step 1, the acrylic monomer with carboxyl and amino groups is a mixture of 2-aminoethyl acrylate and 2-carboxyethyl acrylate in a mass ratio of 5:5, the acrylic monomer, ammonium persulfate initiator and N,N'-methylenebisacrylamide cross-linking agent are dissolved in deionized water in a mass ratio of 10-12:1-2:0.5-1.0, the water bath environment temperature is 40°C-50°C, and the polymerization reaction time is 4h-6h.

3. A process for preparing liquid fertilizer using proline fermentation liquid according to claim 1, characterized in that: In the step 1, the solution containing copper ions is a mixed solution of copper sulfate and sodium hydroxide, the reaction temperature is 50°C-60°C, the reaction temperature of the polymer and small molecule compound solution is 45°C-55°C, and the reaction is carried out for 3h-4h under stirring conditions with a rotation speed of 120r / min-150r / min.

4. A process for preparing liquid fertilizer using proline fermentation liquid according to claim 1, characterized in that: In the step 2, the mass ratio of the added specific material to the proline fermentation waste liquid is 1-2:5-8, the reaction temperature is 30°C-35°C, the pH value is 6.5-7.5, the stirring speed is 100r / min-150r / min, and the reaction time is 8h-10h.

5. The process for preparing liquid fertilizer using proline fermentation liquid according to claim 1, characterized in that: In the step three, the pore size of the filter membrane is 0.2μm-0.5μm, the filtration pressure is 0.2MPa-0.5MPa, the sodium chloride concentration is 0.1mol / L-0.3mol / L, the pH value of the phosphate buffer solution is 7.0-7.5, the elution temperature is 25℃-30℃, the rotation speed is 80r / min-120r / min, the elution time is 6h-8h, and the cooling rate of the purified crystallization is controlled at 2℃ / h-3℃ / h. When the temperature drops to 5℃-10℃, the holding time is 4h-6h.

6. A process for preparing liquid fertilizer using proline fermentation liquid according to claim 1, characterized in that: In the step 4, the temperature of the deionized water added to the proline crystals is controlled at 30° C.-40° C., the high-purity proline solution is mixed with the alanine fermentation solution and the aspartic acid fermentation solution in a volume ratio of 10:2:3, the purity of the alanine fermentation solution is 85%-90%, the purity of the aspartic acid fermentation solution is 80%-85%, and the amount of papain catalyst added is 0.5%-1% of the total volume of the high-purity proline solution, the alanine fermentation solution and the aspartic acid fermentation solution.

7. The process for preparing liquid fertilizer using proline fermentation liquid according to claim 1, characterized in that: In the step 4, the reaction temperature of the mixed high-purity proline solution, alanine fermentation solution, aspartic acid fermentation solution and papain catalyst is 45-55° C., and the reaction time is 10 h-12 h.

8. The process for preparing liquid fertilizer using proline fermentation liquid according to claim 1, characterized in that: In step 5, the pore size of the filter membrane is 0.1 μm-0.3 μm, and the total concentration of the microbial flora is 1×10 6 CFU / mL-1×10 7 CFU / mL, the mass proportion of earthworm castings is 10%-15%, and the volume proportion of wood vinegar is 5%-8%.

9. The process for preparing liquid fertilizer using proline fermentation liquid according to claim 1, characterized in that: In the step 5, the fermentation reaction temperature is 35-40°C, the humidity is 60%-70%, the ventilation volume is 0.5m³ / h-1.0m³ / h, and the fermentation time is 15h-20h.

Images