Deep enzymatic hydrolysis of heparin sodium enzymolysis waste liquid to obtain chelated amino acid water-soluble fertilizer and preparation method thereof

Abstract

The application discloses a kind of heparin sodium enzymolysis waste liquid deep enzymolysis chelated amino acid water-soluble fertilizer and preparation method, belongs to fertilizer technical field.The raw material includes low-salt heparin sodium enzymolysis waste liquid, ternary complex hydrolytic enzyme, macroelement, medium element, trace element, pH regulator, stabilizer and anti-caking agent.The application uses neutral protease, flavour protease, amino peptidase compound system to waste liquid deep directional enzymolysis, and macromolecular protein polypeptide is fully degraded, so that system free amino acid content is increased to 20% or more, and amino, carboxyl natural chelation active site is fully released;Without additional EDTA, DTPA type chemical chelating agent can be chelated with mineral element, and chelation rate can reach more than 95%.The application realizes heparin sodium production waste liquid full-value resource utilization, and no secondary waste liquid is outputted;The obtained fertilizer is low-salt, and water-solubility is excellent, can be foliar spraying, drip irrigation, flushes and is applied, and crop nutrient absorption utilization rate is increased by more than 40% compared with traditional water-soluble fertilizer, and can also improve saline-alkali soil.

Description

Technical Field

[0001] This invention belongs to the technical field of fertilizer preparation and industrial waste liquid resource utilization, specifically relating to a water-soluble fertilizer for deep enzymatic hydrolysis and chelation of amino acids from heparin sodium enzymatic hydrolysis waste liquid and its preparation method. Background Technology

[0002] Heparin sodium, a core anticoagulant drug in clinical practice, is primarily extracted from the intestinal mucosa of pigs. Traditional heparin sodium extraction processes often employ salting-out, where a large amount of inorganic salt is added to precipitate the sodium from the enzymatic hydrolysate. This process generates a large amount of high-salt organic waste liquid, making resource utilization difficult and treatment costs high. In recent years, salt-free production processes have gradually become an industry trend. This process eliminates the addition of inorganic salts in the traditional salting-out method, producing only low-salt organic enzymatic hydrolysate waste liquid, which is easier to utilize than traditional high-salt waste liquid. Currently, this type of low-salt waste liquid is mostly discharged directly or discharged into municipal sewage networks after simple treatment, resulting in a serious waste of organic nutrients such as proteins and amino acids, and increasing the environmental burden on enterprises.

[0003] Existing technologies include research on preparing fertilizers from heparin sodium production wastewater. For example, Chinese patent CN107751573A discloses a compound amino acid solution containing heparin sodium enzymatic hydrolysis wastewater, using the wastewater as a solvent and adding amino acids and traditional Chinese medicine extracts to prepare a compound solution. Chinese patent CN121824201A discloses a method for preparing amino acid water-soluble fertilizer using heparin sodium enzymatic hydrolysis wastewater, through filtration pretreatment and enzymatic hydrolysis reaction with a compound enzyme preparation. Existing technologies also involve extracting proteins from heparin sodium wastewater and preparing porcine intestinal membrane protein peptide chelated iron preparations. However, existing technologies still have many shortcomings. For example, proteins and peptides in the wastewater are not fully degraded. Although existing technologies use enzymatic hydrolysis, the degree of enzymatic hydrolysis is limited, resulting in low levels of free amino acids and high levels of large-molecule peptide residues in the wastewater, leading to insufficient utilization of organic nutrients and a low content of effective amino acids in the fertilizer, thus limiting its fertilizer efficiency. Furthermore, there is a reliance on exogenous chemical chelating agents. Traditional amino acid water-soluble fertilizers often use purchased amino acid powder as the chelating matrix, or add chemical chelating agents such as EDTA and DTPA to chelate with mineral elements. This not only results in high production costs, but also because chemical chelating agents are difficult to degrade in soil, leading to soil residues and disruption of soil micro-ecological balance with long-term use. Furthermore, the chelating activity of waste liquid is not fully released. Existing technologies for preparing chelated fertilizers from industrial organic waste liquid generally suffer from insufficient degradation of the waste liquid and inadequate exposure of chelating active sites (amino and carboxyl groups). This leads to low chelation rates and poor chelation stability when using the organic components of the waste liquid itself as the chelating matrix, making it difficult to achieve efficient chelation of nutrients and crop absorption. Therefore, this invention proposes a method for deep enzymatic hydrolysis and chelation of amino acid water-soluble fertilizer from heparin sodium enzymatic hydrolysis waste liquid, and its preparation method, to overcome the aforementioned defects in existing technologies. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for preparing a water-soluble fertilizer containing deeply enzymatically hydrolyzed chelated amino acids from heparin sodium enzymatic hydrolysis waste liquid. This invention uses low-salt enzymatic hydrolysis waste liquid from the production of salt-free heparin sodium as the sole organic raw material. Through deep and targeted enzymatic hydrolysis with a complex hydrolytic enzyme, residual proteins and macromolecular peptides in the waste liquid are fully degraded into high-content free amino acids and small-molecule active peptides, maximizing the release of their rich amino and carboxyl groups and other natural chelating active sites. Using this deeply enzymatic hydrolysis liquid as a natural chelating matrix, it is used to perform multi-element chelation with macro, meso, and trace elements to prepare an amino acid chelated water-soluble fertilizer without the addition of chemical chelating agents, thus realizing the resource utilization of salt-free heparin sodium enzymatic hydrolysis waste liquid.

[0005] A water-soluble fertilizer containing deeply enzymatically hydrolyzed and chelated amino acids from heparin sodium enzymatic hydrolysis waste liquid, wherein the raw materials for the water-soluble fertilizer, by weight, include: The ingredients are: 60-80 parts of heparin sodium enzymatic hydrolysis waste liquid, 0.5-2.0 parts of compound hydrolytic enzyme, 5-15 parts of macro-element raw materials, 3-8 parts of medium-element raw materials, 1-5 parts of trace element raw materials, 0.3-1.5 parts of pH adjuster, 0.5-3.0 parts of stabilizer, and 0.1-0.8 parts of anti-caking agent; The heparin sodium enzymatic hydrolysis waste liquid is a low-salt organic waste liquid obtained by extracting heparin sodium using a salt-free method, followed by complex enzyme hydrolysis and membrane separation. The low-salt organic waste liquid has an initial free amino acid content ≥8%, a small molecule peptide content with a molecular weight of 200~2000Da ≥12%, and an organic matter content ≥15%; the electrical conductivity of the low-salt organic waste liquid is ≤800μS / cm. The water-soluble fertilizer is made into a liquid product or a solid powder product.

[0006] Preferably, the complex hydrolase is a compound of neutral protease, flavor protease, and aminopeptidase, with a mass ratio of 3:2:1 to 5:3:1.

[0007] Preferably, the macro-element raw materials are one or more of urea, potassium dihydrogen phosphate, and potassium nitrate, with a total nitrogen, phosphorus, and potassium content ≥10%; The medium-quantity element raw material is one or more of calcium nitrate, magnesium sulfate, and potassium magnesium sulfate, with a total calcium and magnesium content ≥5%; The trace element raw materials are water-soluble salts of EDTA iron sodium, zinc sulfate, manganese sulfate, boric acid, and ammonium molybdate, with a total content of ≥1% for iron, zinc, manganese, boron, and molybdenum.

[0008] Preferably, the pH adjuster is one or more of potassium bicarbonate, citric acid, and potassium dihydrogen phosphate, used to adjust the pH of the enzymatic hydrolysis and chelation system to 5.5-7.5; The stabilizer is one or more of sodium alginate, xanthan gum, and polyaspartic acid; The anti-caking agent is one or both of silicon dioxide and maltodextrin, and the amount added is 0.1 to 0.8% of the total weight of the raw materials.

[0009] The second objective of this invention is to provide a method for preparing water-soluble fertilizer containing deeply enzymatically chelated amino acids from the above-mentioned heparin sodium enzymatic hydrolysis waste liquid, comprising the following steps: Waste liquid pretreatment: Take the heparin sodium enzymatic hydrolysis waste liquid, remove suspended impurities by precision filtration, adjust the temperature of the liquid to obtain pretreated waste liquid; Deep-directed enzymatic hydrolysis: Add compound hydrolytic enzyme to the pretreated waste liquid, adjust the pH of the system with a pH adjuster, perform enzymatic hydrolysis at a constant temperature, then heat up to sterilize, and cool to room temperature to obtain deep enzymatic hydrolysate; Among them, the total amount of free amino acids is ≥20%, and the content of small molecule peptides is ≥15%; Multiple chelation reaction: Add the deep enzymatic hydrolysate to the reaction vessel and stir. Add the corresponding raw materials in the order of trace elements, medium elements and macro elements in sequence. Stir continuously until completely dissolved after each addition of raw material. Adjust the pH of the system and keep it warm for chelation until the chelation rate is ≥95% to obtain the chelated solution. Stabilization and purification: Add stabilizer and anti-caking agent to the chelation solution, continue stirring, filter through ultrafiltration membrane to remove unreacted macromolecular impurities, and obtain refined fertilizer solution; Preparation of finished product: The refined fertilizer solution is concentrated to a solid content of 40-50%, sterilized by ultraviolet light, and metered and packaged to obtain a liquid finished product; or it is spray-dried to obtain a solid powder finished product. Preferably, the amount of compound hydrolytic enzyme added in step (2) is 0.5%-2.0% of the dry weight of the pretreated waste liquid; the content of chelated active sites in the deep enzymatic hydrolysate is ≥3.0 mmol / g.

[0010] Preferably, the liquid product obtained in step (5) has a water solubility of ≥99%, the solid product has a water solubility of ≥98%, and the product has no chemical chelating agent residue and a salinity of ≤2.0%.

[0011] Preferably, the inlet air pressure of the spray drying in step (5) is 0.2~0.4MPa and the atomization speed is 20000~30000r / min.

[0012] The third objective of this invention is to provide an application of the above-mentioned heparin sodium enzymatic hydrolysis waste liquid deeply enzymatically hydrolyzed chelated amino acid water-soluble fertilizer. The liquid product is diluted 800-1500 times, and the solid product is diluted 1000-2000 times, and then used for drip irrigation, fertigation, or foliar spraying of grain crops, vegetables, fruit trees, and cash crops. For drip irrigation / fertigation, the application rate is 3-8 kg per acre per application, every 10-15 days; for foliar spraying, the application rate is 1-3 kg per acre per application, every 7-10 days. The application frequency can be appropriately increased during the seedling, flowering, and fruit expansion stages of the crop.

[0013] Preferably, the water-soluble fertilizer is suitable for saline-alkali land improvement and precision fertilization in facility agriculture.

[0014] Compared with the prior art, the present invention, which adopts the above technical solution, has the following beneficial effects: This application utilizes a complex hydrolytic enzyme to deeply and specifically degrade residual proteins and peptides in waste liquid into usable free amino acids and small molecule active peptides. The total amount of free amino acids in the waste liquid is increased to over 20%, and the content of small molecule peptides is increased to over 15%. This solves the problems of insufficient resource utilization and low product added value in traditional waste liquid treatment, and there is no secondary waste liquid discharge throughout the process, realizing the full value utilization of waste liquid and reducing environmental treatment costs.

[0015] This invention utilizes the amino acids and small molecule peptides generated by the deep enzymatic hydrolysis of waste liquid as a natural chelating matrix, which can directly form stable five- or six-membered ring chelates with mineral elements. This replaces the addition of chemical chelating agents such as EDTA and DTPA and purchased amino acid powder in traditional technologies, avoiding the soil residue problem of chemical chelating agents. Long-term use can improve the physical and chemical properties of soil and increase the organic matter content of soil.

[0016] The abundant natural chelating active sites in the deep enzymatic hydrolysate of this invention form stable chelates with mineral elements, making nutrients less likely to be fixed or oxidized and deactivated in the soil. The absorption and utilization rate of nitrogen, phosphorus, potassium and micronutrients by crops is increased by more than 40% compared with traditional ordinary water-soluble fertilizers, which can effectively prevent crop nutrient deficiencies.

[0017] The product of this invention combines organic nutrients such as amino acids and small molecule peptides with mineral nutrients such as macro-, meso-, and micro-elements. The synergistic effect of organic and inorganic nutrients not only supplements the mineral nutrients required for crop growth but also promotes crop root development, enhances stress resistance, and improves the quality of agricultural products. This invention involves no high-temperature or high-pressure operations throughout the entire process, with mild enzymatic hydrolysis and chelation reaction conditions and simple process steps. The product can be prepared in both liquid and solid forms to meet the needs of different agricultural fertilization scenarios.

[0018] The product of this invention has a salinity of ≤2.0% and a water solubility of ≥98%. It is suitable for grain crops such as wheat and rice, vegetable crops such as tomatoes and cucumbers, fruit crops such as apples and citrus, and cash crops such as cotton and rapeseed. It can be used for various fertilization methods such as drip irrigation, fertigation, and foliar spraying, and is especially suitable for precision fertilization scenarios such as saline-alkali land and facility agriculture. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments. Example

[0021] The raw materials are proportioned by weight as follows: 70 parts of salt-free process heparin sodium enzymatic hydrolysis waste liquid, 1.2 parts of compound hydrolytic enzyme, 8 parts of potassium dihydrogen phosphate, 4 parts of calcium nitrate, 2 parts of magnesium sulfate, 2 parts of trace element raw materials, 0.8 parts of potassium bicarbonate, 1.5 parts of sodium alginate, and 0.3 parts of silicon dioxide.

[0022] The complex hydrolase is prepared by combining neutral protease, flavor protease and aminopeptidase in a mass ratio of 4:2:1.

[0023] The trace element raw materials are a water-soluble salt compound of EDTA iron sodium, zinc sulfate, manganese sulfate, boric acid and ammonium molybdate, in a mass ratio of 3:2:2:2:0.5.

[0024] Preparation method of liquid water-soluble fertilizer: (1) Waste liquid pretreatment: Take the salt-free process heparin sodium enzymatic hydrolysis waste liquid, remove suspended impurities by 0.3μm precision filtration, and adjust the temperature of the liquid to 35℃ to obtain pretreated waste liquid.

[0025] (2) Deep-directed enzymatic hydrolysis: 1.2 parts of compound hydrolytic enzyme were added to the pretreated waste liquid, the pH of the system was adjusted to 6.5 with potassium bicarbonate, and the enzymatic hydrolysis was carried out at a constant temperature of 40℃ for 6 hours. Then, the temperature was raised to 80℃ for sterilization for 15 minutes, and cooled to room temperature to obtain the deep-enzymatic hydrolysate. The results showed that the total free amino acid content in the deep-enzymatic hydrolysate was 22.5%, the content of small molecule peptides (200~1000Da) was 16.8%, and the content of chelated active sites (amino + carboxyl groups) was 3.5 mmol / g.

[0026] (3) Multicomponent chelation reaction: The deep enzymatic hydrolysate was added to a stainless steel reactor and stirred at 250 r / min. The trace element compound, calcium nitrate, magnesium sulfate, and potassium dihydrogen phosphate were added sequentially. After each addition, the mixture was stirred for 25 min until completely dissolved. The pH of the system was adjusted to 6.8 with potassium bicarbonate, and the temperature was raised to 45℃ and maintained for chelation for 4.5 h. The chelation rate was determined to be 96.2% by atomic absorption spectrophotometry, and the chelated solution was obtained.

[0027] (4) Stabilization and purification: Add sodium alginate and silicon dioxide to the chelate solution, continue stirring for 1.5 h, filter through a 6 kDa ultrafiltration membrane to remove unreacted macromolecular impurities, and obtain refined fertilizer solution.

[0028] (5) Preparation of finished product: The refined fertilizer liquid is vacuum-concentrated to a solid content of 45% under vacuum conditions of -0.09MPa and 50℃. It is then sterilized for 30 seconds by 254nm ultraviolet light (100W power) and metered and packaged to obtain the finished liquid water-soluble fertilizer.

[0029] Product testing indicators: water solubility 99.5%, salinity 1.8%, total nitrogen, phosphorus and potassium content 12.5%, total calcium and magnesium content 6.2%, total iron, zinc, manganese, boron and molybdenum content 1.8%, no chemical chelating agent residue (EDTA, DTPA and other chemical chelating agents were not detected by high performance liquid chromatography), chelation stability ≥90% (no precipitation or ion dissociation after 6 months of storage at room temperature). Example

[0030] The raw materials are proportioned as follows by weight: 65 parts of salt-free process heparin sodium enzymatic hydrolysis waste liquid, 1.5 parts of compound hydrolase, 10 parts of potassium nitrate, 5 parts of calcium nitrate, 3 parts of magnesium sulfate, 3 parts of trace element compound, 0.6 parts of citric acid, 2.0 parts of xanthan gum, and 0.7 parts of maltodextrin.

[0031] The complex hydrolase is prepared by combining neutral protease, flavor protease and aminopeptidase in a mass ratio of 5:3:1.

[0032] The trace element raw materials are a water-soluble salt compound of EDTA iron sodium, zinc sulfate, manganese sulfate, boric acid and ammonium molybdate, in a mass ratio of 4:2:2:2:0.6.

[0033] Preparation method of solid powder water-soluble fertilizer: (1) Waste liquid pretreatment: Take the salt-free process heparin sodium enzymatic hydrolysis waste liquid, remove suspended impurities by 0.22μm precision filtration, and adjust the temperature of the liquid to 38℃ to obtain pretreated waste liquid.

[0034] (2) Deep-directed enzymatic hydrolysis: 1.5 parts of compound hydrolytic enzyme were added to the pretreated waste liquid, the pH of the system was adjusted to 6.0 with citric acid, and the enzymatic hydrolysis was carried out at a constant temperature of 42℃ for 5 hours. Then, the temperature was raised to 78℃ for sterilization for 18 minutes, and then cooled to room temperature to obtain the deep enzymatic hydrolysate. The total free amino acid content in the deep enzymatic hydrolysate was 23.8%, the content of small molecule peptides (200~1000Da) was 17.5%, and the content of chelated active sites was 3.8 mmol / g.

[0035] (3) Multicomponent chelation reaction: The deep enzymatic hydrolysate was added to a stainless steel reactor and stirred at 280 r / min. The trace element complex, calcium nitrate, magnesium sulfate, and potassium nitrate were added sequentially. After each addition, the mixture was stirred for 20 min until completely dissolved. The pH of the system was adjusted to 6.5 with citric acid, and the temperature was raised to 48℃ and maintained for chelation for 4 h. The chelation rate was determined to be 97.0% by atomic absorption spectrophotometry, and the chelated solution was obtained.

[0036] (4) Stabilization and purification: Xanthan gum and maltodextrin were added to the chelate solution and stirred for 2 hours. The solution was then filtered through a 5kDa ultrafiltration membrane to remove unreacted macromolecular impurities and obtain refined fertilizer solution.

[0037] (5) Preparation of finished product: The refined fertilizer solution is concentrated to a solid content of 48% under vacuum of -0.095MPa and temperature of 52℃, and then spray dried (inlet air temperature of 170℃, outlet air temperature of 75℃, inlet air pressure of 0.3MPa, atomization speed of 25000r / min) to obtain solid powder water-soluble fertilizer finished product.

[0038] Product testing indicators: water solubility 98.8%, salinity 1.6%, total nitrogen, phosphorus and potassium content 14.2%, total calcium and magnesium content 7.5%, total iron, zinc, manganese, boron and molybdenum content 2.1%, no chemical chelating agent residue, hygroscopicity ≤5%, no clumping or nutrient loss after 6 months of storage at room temperature. Example

[0039] The raw materials are proportioned by weight as follows: 80 parts of salt-free process heparin sodium enzymatic hydrolysis waste liquid, 0.8 parts of compound hydrolase, 6 parts of urea, 4 parts of magnesium sulfate, 1 part of trace element compound, 0.5 parts of potassium dihydrogen phosphate, 1.0 part of polyaspartic acid, and 0.1 parts of silicon dioxide.

[0040] The complex hydrolase is prepared by combining neutral protease, flavor protease and aminopeptidase in a mass ratio of 3:2:1.

[0041] The trace element raw materials are a water-soluble salt compound of EDTA iron sodium, zinc sulfate, manganese sulfate, boric acid and ammonium molybdate, in a mass ratio of 3:3:3:0.4.

[0042] Preparation method of low-cost water-soluble fertilizer formula: (1) Waste liquid pretreatment: Take the salt-free process heparin sodium enzymatic hydrolysis waste liquid, remove suspended impurities by 0.45μm precision filtration, and adjust the temperature of the liquid to 30℃ to obtain pretreated waste liquid.

[0043] (2) Deep-directed enzymatic hydrolysis: 0.8 parts of compound hydrolytic enzyme were added to the pretreated waste liquid, the pH of the system was adjusted to 7.0 with potassium dihydrogen phosphate, and the enzymatic hydrolysis was carried out at a constant temperature of 35℃ for 8 hours. Then, the temperature was raised to 85℃ for sterilization for 10 minutes, and then cooled to room temperature to obtain the deep enzymatic hydrolysate. The total free amino acid content in the deep enzymatic hydrolysate was 20.5%, the content of small molecule peptides (200~1000Da) was 15.2%, and the content of chelated active sites was 3.2 mmol / g.

[0044] (3) Multi-component chelation reaction: The deep enzymatic hydrolysate was added to a stainless steel reactor and stirred at 200 r / min. The trace element compound, magnesium sulfate, and urea were added sequentially. After each raw material was added, the mixture was stirred for 30 min until completely dissolved. The pH of the system was adjusted to 7.0, and the temperature was raised to 40℃ and kept at that temperature for chelation for 6 h. The chelation rate was determined to be 95.5% by atomic absorption spectrophotometry, and the chelated solution was obtained.

[0045] (4) Stabilization and purification: Polyaspartic acid and silicon dioxide were added to the chelate solution, and the mixture was stirred for 1 hour. The solution was then filtered through an 8kDa ultrafiltration membrane to obtain the refined fertilizer solution.

[0046] (5) Preparation of finished product: The refined fertilizer solution is concentrated to a solid content of 40% under vacuum of -0.08MPa and temperature of 50℃, and then sterilized by ultraviolet light for 20s to obtain the liquid water-soluble fertilizer product.

[0047] Product testing indicators: water solubility 99.2%, salinity 1.5%, total nitrogen, phosphorus and potassium content 9.8%, total calcium and magnesium content 5.1%, total iron, zinc, manganese, boron and molybdenum content 1.2%, no chemical chelating agent residue, suitable for large-scale application in field crops.

[0048] Comparative Example 1: Amino acid water-soluble fertilizer was prepared using the method described in Example 1 of Chinese Patent CN121824201A. Specifically, heparin sodium enzymatic hydrolysate wastewater was used as raw material. After filtration and pretreatment, a compound enzyme preparation was added for enzymatic hydrolysis. After the reaction was completed, a flocculant was added to precipitate and remove the precipitate, thus obtaining the amino acid water-soluble fertilizer.

[0049] Comparative Example 2: The preparation of amino acid chelated water-soluble fertilizer using traditional purchased amino acid powder and EDTA chemical chelating agent involves using purchased compound amino acid powder as the chelating matrix, adding EDTA-2Na as the chemical chelating agent, and mixing and chelating it with nitrogen, phosphorus, potassium raw materials and trace element raw materials to prepare water-soluble fertilizer. Experimental example: Field comparison trial A field comparison experiment was conducted between the liquid water-soluble fertilizer prepared in Example 1 of this invention and the water-soluble fertilizers prepared in Comparative Examples 1 and 2. The test crop was Provence tomato, and the experimental field was slightly saline-alkali land with a soil salinity of 0.3%. Four treatment groups were set up, with each group covering an area of ​​10 mu (approximately 0.67 hectares). Other field management measures were the same.

[0050] Blank control group: Apply an equal amount of water.

[0051] Experimental Group 1: Water-soluble fertilizer from Example 1 was applied, diluted 1000 times, and drip-irrigated at a rate of 5 kg per acre per application, once every 12 days.

[0052] Control group 1: Apply water-soluble fertilizer of control group 1, diluted 1000 times and drip-irrigated, at a rate of 5 kg per acre per application, once every 12 days.

[0053] Control group 2: Apply water-soluble fertilizer of control group 2, diluted 1000 times and drip-irrigated, 5 kg per acre per application, once every 12 days. The results of various indicators measured at harvest time are as follows: (1) Crop growth indicators: In experimental group 1, the tomato plant height increased by 32.5% compared to the blank control group, 18.2% compared to control group 1, and 15.8% compared to control group 2; the root fresh weight increased by 45.2% compared to the blank control group, 25.6% compared to control group 1, and 22.3% compared to control group 2; the incidence of nutrient deficiency diseases such as blossom-end rot and little leaf disease was only 0.8%, which was 82.3% lower than control group 1 and 85.7% lower than control group 2.

[0054] (2) Production indicators: The tomato yield in experimental group 1 was 6580 kg per mu, which was 42.3% higher than that in the blank control group, 22.6% higher than that in control group 1, and 18.5% higher than that in control group 2.

[0055] (3) Quality indicators: The vitamin C content of tomatoes in experimental group 1 was 32.5 mg / 100g, which was 20.8% higher than that in control group 1 and 18.2% higher than that in control group 2; the soluble solids content was 6.2%, which was 15.0% higher than that in control group 1 and 13.8% higher than that in control group 2; the fruit firmness was 12.3% higher than that in control group 1 and 10.5% higher than that in control group 2, and the storage and transportation resistance was significantly improved.

[0056] (4) Soil indicators: In experimental group 1, the soil organic matter content increased by 15.6% compared to before the experiment, by 10.2% compared to control group 1, and by 9.8% compared to control group 2; the soil electrical conductivity decreased by 12.5% ​​compared to before the experiment, indicating an improvement in salinity. EDTA residues were detected in the soil of control group 2 (approximately 0.8 mg / kg), while no chemical chelating agent residues were detected in either experimental group 1 or control group 1.

[0057] (5) Nutrient absorption efficiency: In experimental group 1, the absorption efficiency of nitrogen, phosphorus, and potassium in tomato plants increased by 38.5% compared with control group 1 and by 41.2% compared with control group 2; the absorption efficiency of calcium and magnesium increased by 35.2% compared with control group 1 and by 38.5% compared with control group 2; and the absorption efficiency of trace elements such as iron, zinc, and manganese increased by 42.3% compared with control group 1 and by 45.7% compared with control group 2.

[0058] In summary, the water-soluble fertilizer prepared by this invention is significantly superior to Comparative Example 1 and Comparative Example 2 in promoting crop growth, increasing yield, improving quality, and enhancing nutrient absorption efficiency. It also improves the physicochemical properties of slightly saline-alkali soils and leaves no chemical chelating agent residue. Compared to Comparative Example 1, this invention fully releases the chelating active sites of the waste liquid through deep, targeted enzymatic hydrolysis, achieving highly efficient chelation without the need for external chemical chelating agents. Compared to Comparative Example 2, this invention avoids the use of chemical chelating agents, eliminating the risk of soil residue.

[0059] This process is compatible with the production process of salt-free heparin sodium, realizing a circular industrial chain of heparin sodium production, deep enzymatic hydrolysis of waste liquid, and preparation of chelated water-soluble fertilizer. It significantly improves the comprehensive utilization rate of raw materials and the added value of products, and has significant economic and environmental benefits.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0061] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A water-soluble fertilizer containing deeply enzymatically hydrolyzed and chelated amino acids from heparin sodium enzymatic hydrolysis waste liquid, characterized in that, The raw materials for water-soluble fertilizers, by weight, include: The ingredients are: 60-80 parts of heparin sodium enzymatic hydrolysis waste liquid, 0.5-2.0 parts of compound hydrolytic enzyme, 5-15 parts of macro-element raw materials, 3-8 parts of medium-element raw materials, 1-5 parts of trace element raw materials, 0.3-1.5 parts of pH adjuster, 0.5-3.0 parts of stabilizer, and 0.1-0.8 parts of anti-caking agent; The heparin sodium enzymatic hydrolysis waste liquid is a low-salt organic waste liquid obtained by extracting heparin sodium using a salt-free method, followed by complex enzyme hydrolysis and membrane separation. The low-salt organic waste liquid has an initial free amino acid content ≥8%, a small molecule peptide content with a molecular weight of 200~2000Da ≥12%, and an organic matter content ≥15%; the electrical conductivity of the low-salt organic waste liquid is ≤800μS / cm. The water-soluble fertilizer is made into a liquid product or a solid powder product.

2. The water-soluble fertilizer containing deeply enzymatically hydrolyzed and chelated amino acids from heparin sodium enzymatic hydrolysis waste liquid according to claim 1, characterized in that, The complex hydrolase is a compound of neutral protease, flavor protease, and aminopeptidase, with a mass ratio of 3:2:1 to 5:3:

1.

3. The water-soluble fertilizer containing deeply enzymatically hydrolyzed and chelated amino acids from heparin sodium enzymatic hydrolysis waste liquid according to claim 1, characterized in that, The macro-elemental raw materials are one or more of urea, potassium dihydrogen phosphate, and potassium nitrate, with a total nitrogen, phosphorus, and potassium content of ≥10%; The medium-quantity element raw material is one or more of calcium nitrate, magnesium sulfate, and potassium magnesium sulfate, with a total calcium and magnesium content ≥5%; The trace element raw materials are water-soluble salts of EDTA iron sodium, zinc sulfate, manganese sulfate, boric acid, and ammonium molybdate, with a total content of ≥1% for iron, zinc, manganese, boron, and molybdenum.

4. The water-soluble fertilizer containing deeply enzymatically hydrolyzed and chelated amino acids from heparin sodium enzymatic hydrolysis waste liquid according to claim 1, characterized in that, The pH adjuster is one or more of potassium bicarbonate, citric acid, and potassium dihydrogen phosphate, used to adjust the pH of the enzymatic hydrolysis and chelation system to 5.5-7.5; The stabilizer is one or more of sodium alginate, xanthan gum, and polyaspartic acid; The anti-caking agent is one or both of silicon dioxide and maltodextrin, and the amount added is 0.1 to 0.8% of the total weight of the raw materials.

5. A method for preparing a water-soluble fertilizer containing deeply enzymatically hydrolyzed and chelated amino acids from heparin sodium enzymatic hydrolysis waste liquid as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Waste liquid pretreatment: Take the heparin sodium enzymatic hydrolysis waste liquid, remove suspended impurities by precision filtration, adjust the temperature of the liquid to obtain pretreated waste liquid; Deep-directed enzymatic hydrolysis: Add compound hydrolytic enzyme to the pretreated waste liquid, adjust the pH of the system with a pH adjuster, perform enzymatic hydrolysis at a constant temperature, then heat up to sterilize, and cool to room temperature to obtain deep enzymatic hydrolysate; Among them, the total amount of free amino acids is ≥20%, and the content of small molecule peptides is ≥15%; Multiple chelation reaction: Add the deep enzymatic hydrolysate to the reaction vessel and stir. Add the corresponding raw materials in the order of trace elements, medium elements and macro elements in sequence. Stir continuously until completely dissolved after each addition of raw material. Adjust the pH of the system and keep it warm for chelation until the chelation rate is ≥95% to obtain the chelated solution. Stabilization and purification: Add stabilizer and anti-caking agent to the chelation solution, continue stirring, filter through ultrafiltration membrane to remove unreacted macromolecular impurities, and obtain refined fertilizer solution; Preparation of finished product: The refined fertilizer solution is concentrated to a solid content of 40-50%, sterilized by ultraviolet light, and metered and packaged to obtain a liquid finished product; or it is spray-dried to obtain a solid powder finished product.

6. The preparation method according to claim 5, characterized in that, In step (2), the amount of compound hydrolytic enzyme added is 0.5% to 2.0% of the dry weight of the pretreated waste liquid; the content of chelated active sites in the deep enzymatic hydrolysate is ≥3.0 mmol / g.

7. The preparation method according to claim 5, characterized in that, The liquid product obtained in step (5) has a water solubility of ≥99%, the solid product has a water solubility of ≥98%, and the product has no chemical chelating agent residue and a salinity of ≤2.0%.

8. The preparation method according to claim 5, characterized in that, The inlet air pressure of the spray drying in step (5) is 0.2~0.4MPa, and the atomization speed is 20000~30000r / min.

9. An application of a water-soluble fertilizer containing deeply enzymatically hydrolyzed and chelated amino acids from heparin sodium enzymatic hydrolysis waste liquid as described in any one of claims 1 to 4, characterized in that, The liquid product is diluted 800-1500 times, and the solid product is diluted 1000-2000 times, and can be used for drip irrigation, fertigation, or foliar spraying of grain crops, vegetables, fruit trees, and cash crops. For drip irrigation / fertigation, the application rate is 3-8 kg per acre per application, once every 10-15 days. For foliar spraying, the application rate is 1-3 kg per acre per application, once every 7-10 days. The application frequency can be appropriately increased during the seedling, flowering, and fruit expansion stages of crops.

10. The application according to claim 9, characterized in that, The water-soluble fertilizer is suitable for saline-alkali land improvement and precision fertilization in facility agriculture.