Method for preparing high-organic-matter water flush fertilizer from kitchen garbage

Abstract

The invention relates to the technical field of kitchen garbage treatment and resource utilization, and particularly discloses a method for preparing a high-organic-matter water flush fertilizer from kitchen garbage. The method for preparing the high-organic-matter water flush fertilizer from the kitchen garbage comprises the following steps: by taking the kitchen garbage as a raw material, sequentially carrying out pretreatment impurity removal, heating sterilization, deoiling and dehydration, curing, enzymolysis and drying, pre-screening and fine powder grading, thereby obtaining the high-organic-matter water flush fertilizer. The step of curing, enzymolysis and drying comprises the following steps: uniformly mixing deoiled and dehydrated solid residues, auxiliary material liquid and a compound enzyme preparation, and pre-fermenting; adding a suspension containing trichoderma harzianum and bacillus licheniformis for fermentation, and then drying; the auxiliary material liquid is prepared by mixing polysorbate-80, choline chloride, sodium citrate and water; the compound enzyme preparation is formed by mixing cellulase, alkaline protease and lipase. The fertilizer prepared by the invention is relatively high in content of organic matters, nutrients and effective viable count, and relatively low in content of infectious microbes and water-insoluble substances.

Description

Technical Field

[0001] This application relates to the technical field of kitchen waste treatment and resource utilization, specifically to a method for preparing high-organic-matter fertigation fertilizer from kitchen waste. Background Technology

[0002] Food waste is complex in composition, including not only leftover food from hotels and restaurants but also a large amount of discarded tableware, broken utensils, and kitchen scraps. It is a mixture of oil, water, fruit peels, vegetables, rice and flour, fish, meat, bones, as well as discarded tableware, plastics, paper towels, and other substances. Food waste is mainly composed of protein, starch, sugars, and animal fats, and has a high content of oil and salt.

[0003] Food waste, particularly kitchen waste, is more difficult to dispose of due to its high moisture content, high organic matter content, and easy perishability. Improper disposal can easily cause serious pollution to the natural environment. Food waste treatment is a key and challenging aspect of waste management in major cities across the country. It accounts for a significant proportion of urban residents' waste sorting, and is a major source of urban pollution, a long-standing problem. Because its sources are scattered and difficult to monitor, the effective disposal rate of food waste is less than 10% (mainly through organic fertilizer and anaerobic fermentation technologies), with approximately 20% of food waste mixed with household waste.

[0004] Some kitchen waste is collected by farmers on the outskirts of cities and used directly as pig feed. The problem with this method is that kitchen waste contains a large number of pathogens that can cause zoonotic diseases. This not only easily leads to viral infections in animals but also to foot-and-mouth disease, hepatitis, and other diseases in humans. Pigs that consume this waste are highly susceptible to various diseases, forcing farmers to increase the dosage of medication for sick pigs. This increases antibiotic residues, which can then enter the human body through pork, potentially harming human health. Furthermore, using kitchen waste as feed may lead to contamination from the same source.

[0005] Conventional harmless treatment of kitchen waste also has certain problems. Most kitchen waste is treated using anaerobic fermentation to produce biogas. The separated biogas slurry is used for wastewater treatment, while the separated solid residue is composted, incinerated, or landfilled. Anaerobic fermentation for biogas production suffers from low and unstable biogas production, high biogas purification costs, high power generation costs, inability to connect to the grid, and low power output. Some projects also waste energy by burning biogas in flares, resulting in insufficient resource utilization of the biogas produced. The moisture content of the biogas residue produced by anaerobic fermentation is generally above 80%, and most are disposed of by incineration or landfill, incurring high solid residue disposal costs. A few are treated using aerobic composting, but the resulting organic fertilizer is characterized by low yield, low nutrient content, and high moisture content. The composting process for biogas residue can take up to a month, and the resulting organic fertilizer generally has low fertilizer efficiency, contains permanent organic pollutants, pathogens, viruses, and toxins, posing ecological risks of soil and agricultural product contamination. Furthermore, the product has a low price and is very difficult to sell. Biogas slurry, treated using biological methods for high-concentration organic wastewater, requires a large amount of electricity and chemicals. After further biological treatment, the ammonia nitrogen content remains high, making it difficult to achieve completely stable discharge standards.

[0006] Therefore, reducing the generation of biogas residue and comprehensively utilizing the separated solid residue have become critical issues in the food waste treatment industry. Summary of the Invention

[0007] To address the aforementioned technical problems, this application provides a method for preparing high-organic-matter fertigation fertilizer from kitchen waste.

[0008] This application provides a method for preparing high organic matter fertigation fertilizer from kitchen waste, which uses kitchen waste as raw material and sequentially undergoes pretreatment to remove impurities, heating and sterilization, degreasing and dehydration, ripening and enzymatic hydrolysis and drying, and fine powder grading to obtain the fertilizer. The specific steps of the ripening enzymatic hydrolysis and drying are as follows: The de-oiled and dehydrated solid residue with a moisture content of 60%-72%, the auxiliary liquid, and the compound enzyme preparation are mixed evenly at a weight ratio of 300-400:80-100:0.002-0.005. Pre-fermentation is then carried out for 2-4 hours at a pH of 4-6 and a temperature of 42-48℃. After cooling to room temperature, a spore concentration of 1-3 × 10⁻⁶ spores is added. 8 The concentration of Trichoderma harzianum spores per mL is 1-3 × 10⁻⁶. 7 The suspension of Bacillus licheniformis at a concentration of 1 / mL was prepared to a final concentration of 0.003-0.007 wt%, and the pH was adjusted to 7-9 and the temperature to 32-38℃. Fermentation was carried out for 8-10 hours, followed by drying. The auxiliary material solution is composed of polysorbate-80, choline chloride, sodium citrate, and water in a weight ratio of 10-16:1-5:0.3-0.9:100. The compound enzyme preparation is composed of a mixture of cellulase, alkaline protease and lipase in a weight ratio of 3-5:1-2:0.2-0.8.

[0009] The auxiliary liquid used in this application, polysorbate-80, emulsifies residual oils and disrupts the lignocellulose structure, while simultaneously increasing the enzyme contact area and promoting enzyme fermentation. Choline chloride enhances cell membrane permeability, promoting enzyme-substrate binding. Sodium citrate buffers pH fluctuations during fermentation and chelates heavy metal ions to prevent enzyme inactivation. During fermentation, this application employs a two-stage enzymatic hydrolysis reaction. The pre-fermentation stage utilizes an acidic environment of pH 4-6 and a temperature of 42-48℃, which strongly activates cellulase. Cellulase decomposes the plant fiber skeleton, and lipase degrades residual oils. The acidic environment inhibits the growth of unwanted microorganisms while facilitating enzyme activity. During the rear fermentation stage, the addition of *Trichoderma harzianum* and *Bacillus licheniformis* can secrete complex extracellular enzymes, enhancing the degradation of cellulose, hemicellulose, and stubborn polysaccharides. The enzyme-bacterial synergy transforms large organic molecules (cellulose / protein / fat) into smaller humic acid molecules, increasing organic matter content and stability. It also facilitates the synthesis of organic acids and chelates, secreting citric acid and oxalic acid to dissolve mineral phosphorus and potassium, improving nutrient availability. The proliferation of *Trichoderma harzianum* and *Bacillus licheniformis* forms a dominant bacterial community, with their spores and metabolically active cells contributing the majority of effective viable bacteria. This process also plays a biological antagonistic role, reducing the number of miscellaneous bacteria by seizing ecological niches and secreting antibacterial substances.

[0010] Therefore, this application employs a two-stage enzymatic hydrolysis process during the ripening and enzymatic hydrolysis, and selects specific auxiliary liquids and compound enzymes to efficiently convert the recalcitrant organic matter in kitchen waste into forms that can be utilized by plants. At the same time, it uses environmental parameters to precisely regulate the microbial community, ultimately obtaining a high-quality organic fertilizer with high organic matter content, good nutrient solubility, high live bacteria density, and meeting safety standards.

[0011] Preferably, the specific steps of the pretreatment and impurity removal are as follows: after the kitchen waste is collected, it enters the pretreatment system and passes through coarse crushing and sorting, fine crushing and sorting, primary sand removal, slurry liquefaction and sorting, and secondary sand removal to remove heavy impurities, so as to obtain kitchen waste slurry with high organic matter and low impurities.

[0012] Preferably, the specific steps of the heat sterilization are: heating temperature 90-100℃, 20-40min.

[0013] Preferably, the specific steps of the ripening enzymatic hydrolysis and drying are as follows: The solid residue, auxiliary liquid, and compound enzyme preparation are mixed evenly at a weight ratio of 330-370:85-95:0.003-0.004, and pre-fermented for 2-4 hours at a pH of 4.5-5.5 and a temperature of 43-47℃; after cooling to room temperature, a spore concentration of 1.5-2.5 × 10⁻⁶ is added. 8The concentration of Trichoderma harzianum spores per mL is 1-3 × 10⁻⁶. 7 The suspension of Bacillus licheniformis at a concentration of 0.004-0.006 wt% was prepared, and the pH was adjusted to 7.5-8.5 and the temperature to 53-57℃. Fermentation was carried out for 8-10 hours, followed by dehydration and drying.

[0014] Preferably, the auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate, and water in a weight ratio of 11-15:2-4:0.4-0.8:100.

[0015] Preferably, the auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate, and water in a weight ratio of 12-14:2.5-3.5:0.5-0.7:100.

[0016] In one specific embodiment, the auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate, and water in a weight ratio of 13:3:0.6:100.

[0017] Experimental analysis shows that the auxiliary material solution composed of polysorbate-80, choline chloride, sodium citrate, and water in the above weight ratio can further improve the overall performance of the fertilizer.

[0018] Preferably, the compound enzyme preparation is composed of a mixture of cellulase, alkaline protease and lipase in a weight ratio of 3.5-4.5:1.2-1.8:0.4-0.6.

[0019] In one specific embodiment, the compound enzyme preparation is composed of a mixture of cellulase, alkaline protease and lipase in a weight ratio of 4:4.5:0.5.

[0020] Experimental analysis shows that the compound enzyme preparation composed of cellulase, alkaline protease and lipase in the above weight ratio can further improve the overall performance of fertilizer.

[0021] Preferably, the particle size of the high organic matter fertilizer obtained by the fine powder grading is ≤60μm.

[0022] This application also provides a high-organic-matter fertigation fertilizer, which is prepared using the above method.

[0023] Preferably, the performance parameters of the high organic matter fertigation fertilizer are: organic matter content ≥90%, organic matter content ≥77%, easily oxidizable organic matter ≥38%, total nutrients (N+P2O5+K2O) ≥4.3%, effective viable bacteria count ≥200 million / g, miscellaneous bacteria rate ≤13%, and solid insoluble matter ≤4.2%.

[0024] In summary, the technical solution of this application has the following effects: This application takes reducing the generation of biogas residue as its starting point and proposes a new solution by converting kitchen waste into fertilizer for agricultural applications. It adds a new utilization method for the resource-based treatment of kitchen waste and expands new ideas and models for the industry's development. The solid residue after pretreatment of kitchen waste can be matured and enzymatically hydrolyzed to produce high-organic-matter organic fertilizer. As a new type of green fertilizer raw material, high-organic-matter organic fertilizer is rich in organic matter and nutrients, and has significant application value in agricultural production.

[0025] This application proposes a method for preparing high-organic-matter fertigation fertilizer from kitchen waste. The method involves pre-screening the matured enzymatic hydrolysis products and then refining them to maximize the protection of viable bacteria. The pre-screening and refining process improves the dissolution efficiency of the matured enzymatic hydrolysis products, meeting the production standards for fertigation fertilizer. This increases the rate at which the effective substances in the product are absorbed, thereby enhancing the product's application effect.

[0026] The method for preparing high-organic-matter fertigation fertilizer from kitchen waste proposed in this application has the basis for large-scale industrial production. Each process step in the fertigation fertilizer production is controlled by equipment, and the various indicators of the produced fertigation fertilizer product are stable and controllable, the product quality is stable, and it has broad prospects for market promotion. Attached Figure Description

[0027] Figure 1 This is a process flow diagram of the method for preparing high organic matter fertigation fertilizer from kitchen waste in Example 1. Detailed Implementation

[0028] The present application will be further described in detail below with reference to embodiments, comparative examples and performance test results. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0029] Cellulase (product number FFG-0672, enzyme activity 3500u / g), alkaline protease (product number GDY-3333), lipase (product number GDG-2006), and neutral protease (product number GDG-2007) were purchased from Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd.; the remaining raw materials were all available through commercial purchase. Example

[0030] Example 1 Example 1 provides a method for preparing high-organic-matter fertigation fertilizer from kitchen waste.

[0031] The specific method for preparing high-organic-matter fertigation fertilizer from kitchen waste in Example 1 is shown below.

[0032] (1) Pre-treatment and impurity removal: After the kitchen waste is collected, it enters the pre-treatment system and passes through coarse crushing and sorting, fine crushing and sorting, primary sand removal, slurry liquefaction and sorting, and secondary sand removal to remove heavy impurities, so as to obtain kitchen waste slurry with high organic matter and low impurities. The specific steps are as follows.

[0033] Coarse crushing and sorting: After the kitchen waste is collected, it enters the coarse crushing and sorting equipment. The equipment uses flexible crushing technology to break the organic matter in the waste into smaller particles. The sorting part uses a 45mm aperture, and most plastic products, textile products, and some difficult-to-crush metal products are also sorted out.

[0034] Fine crushing and sorting: Kitchen waste that has undergone coarse crushing and sorting enters the fine crushing and sorting equipment, where the organic matter in the waste is further crushed. Most of the organic matter is broken down into slurry, and the intracellular water is converted into free water. The sorting component uses a 10mm aperture to separate out difficult-to-crush plastic products, textile products, rubber products, metal products, bones, bamboo and wood, etc. A certain amount of wastewater generated in the subsequent process is recycled during the fine crushing and sorting process to reduce the solids content of the slurry, increase the fluidity of the slurry, and create favorable conditions for subsequent treatment processes.

[0035] Primary sand removal: The kitchen waste that has been finely crushed and sorted has been processed into slurry and enters the primary sand removal system. Under the combined action of centrifugal force and gravity, heavy impurities such as bone particles, fish bones, metals, ceramics, glass, and shells with a larger specific gravity in the kitchen waste slurry are settled and separated.

[0036] Slurry liquefaction sorting: The kitchen waste slurry after primary sand removal enters the slurry liquefaction sorting equipment. The screen of the slurry liquefaction sorting equipment has a mesh size of 1.5mm, and chili seeds, long plant fibers, plastic flakes, water-containing plant tubers, etc. in the slurry are separated out.

[0037] Secondary sand removal: Large solid particles in the kitchen waste slurry after liquefaction are separated out, the solid content is reduced, the slurry fluidity is improved, and it enters the secondary sand removal equipment. Small particles such as eggshells, fish bones, glass shards, ceramsite, and seashells in the slurry are further removed under the action of centrifugal force and gravity sedimentation, resulting in kitchen waste slurry with low impurity content.

[0038] (2) Heat sterilization: The kitchen waste slurry after impurity removal is subjected to heat sterilization treatment at a temperature of 100℃ for 30 minutes. Pathogenic bacteria such as E. coli, Salmonella, and Listeria in the kitchen waste are killed, as are weed seeds carried in the waste. Due to the increased temperature, the viscosity of the kitchen waste slurry decreases, its fluidity increases, and the demulsification effect is enhanced, accelerating the rate of oil precipitation.

[0039] (3) Degreasing and dehydration: The slurry after heating and sterilization enters the degreasing and dehydration equipment. The oil and water in the slurry are separated separately under the action of high-speed centrifugal force to obtain kitchen waste solid residue. This process yields kitchen waste solid residue with a water content of 68%.

[0040] (4) Maturation and Enzymatic Hydrolysis Drying: The kitchen waste solid residue with a moisture content of 68% obtained after degreasing and dehydration is mixed evenly with auxiliary liquid and compound enzyme preparation and then put into the maturation and enzymatic hydrolysis drying equipment for enzymatic hydrolysis treatment. The kitchen waste undergoes degradation, condensation and polymerization reactions, and completes a rapid maturation and enzymatic hydrolysis process in the maturation and enzymatic hydrolysis equipment, transforming into an organic product with a high content of bio-humic acid. Then, it is dried to obtain a mature enzymatic hydrolysis product with a high organic matter content. The specific steps are as follows.

[0041] Preparation of Trichoderma harzianum and Bacillus licheniformis spore suspensions: 0.5 g of a single colony of Trichoderma harzianum (Trichoderma harzianum BGB-171R, details can be found in the patent application filed by the applicant on October 25, 2024, application number CN202411500415.5) and Bacillus licheniformis (Bacillus licheniformis BGB-85F, details can be found in the patent application filed by the applicant on May 5, 2022, application number CN202210483248.2) were inoculated onto PDA slant culture medium and cultured at 30℃ for 90 h until the spores matured. Then, the mature spores were washed off with physiological saline and placed in Erlenmeyer flasks containing glass beads, and shaken on a shaker for 2 h to disperse the spores. The spore suspension was filtered through three layers of gauze, diluted with physiological saline, and the spore concentration was counted using a hemocytometer. The final spore concentration was adjusted to obtain a concentration of 2 × 10⁻⁶ spores. 8 A suspension of Trichoderma harzianum at a spore concentration of 2 × 10⁶ / mL, and a suspension containing spores at a concentration of 2 × 10⁶ / mL. 7 A suspension of Bacillus licheniformis at a concentration of 2 × 10⁶ spores / mL was prepared. The two bacterial suspensions were mixed at a 1:1 volume ratio to obtain a spore concentration of 2 × 10⁶ spores / mL. 8 Trichoderma harzianum spores concentration was 2 × 10⁻⁶ / mL. 7 A suspension of Bacillus licheniformis per mL.

[0042] The auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate and water in a weight ratio of 13:3:0.6:100.

[0043] The compound enzyme preparation is composed of cellulase, alkaline protease and lipase in a weight ratio of 4:1.5:0.5.

[0044] Kitchen waste solids with a moisture content of 68%, auxiliary liquid, and compound enzyme preparation were mixed evenly in a weight ratio of 350g:90g:0.0035g. The mixture was pre-fermented for 3 hours at pH 5 and 45℃. After cooling to room temperature, a spore concentration of 2×10⁻⁶ was added. 8 Trichoderma harzianum spores concentration was 2 × 10⁻⁶ / mL. 7A suspension of Bacillus licheniformis at a concentration of 1 / mL was prepared to a final content of 0.005 wt%. The pH was adjusted to 8, the temperature was set at 35°C, and fermentation was carried out for 9 hours. The product was then dried to obtain a mature enzymatic hydrolysate with high organic matter content.

[0045] (5) Pre-screening: The ripened enzymatic hydrolysis product is transported to the screening equipment of the pre-screening unit through the material conveying unit to pre-screen the ripened enzymatic hydrolysis product. The particle size of the undersize material is ≤60μm.

[0046] (6) Fine Powder Grading: The material oversize from the pre-screening unit is conveyed to the grinding chamber of the fine powder processing unit via the material conveying unit. The motor is started, driving the pulverizer rotor to rotate at high speed, causing the blades and fixed blades to engage with each other, applying high-intensity impact, compression, cutting, and friction forces to the material entering the grinding chamber, achieving initial pulverization. During the blade cutting and pulverizing process, the high-speed airflow generated by the pulverizer rotor accelerates the material within the grinding chamber, repeatedly impacting, cutting, and rubbing it for further pulverization. The pulverized material enters the material collection unit with the airflow. At the connection between the material collection unit and the fine powder processing unit, the material is screened using the interaction of the centrifugal force of the rotating blades and the centripetal force of the airflow. Material meeting the particle size requirements is collected in the material collection unit, while coarse material is returned to the fine powder processing unit for further pulverization until all material meets the particle size requirement of ≤60μm for fertigation.

[0047] Examples 2-5 Examples 2-5 provide a method for preparing high-organic-matter fertigation fertilizer from kitchen waste.

[0048] The difference between the above embodiments and Embodiment 1 is that the types of auxiliary liquids in the ripening enzymatic hydrolysis and drying process are different, as shown below.

[0049] In Example 2: The auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate and water in a weight ratio of 11:4:0.4:100.

[0050] In Example 3: the auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate and water in a weight ratio of 15:2:0.8:100.

[0051] In Example 4: The auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate and water in a weight ratio of 10:5:0.3:100.

[0052] In Example 5: The auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate and water in a weight ratio of 16:1:0.9:100.

[0053] All other process parameters in the above embodiments are the same as those in Embodiment 1.

[0054] Examples 6-9 Examples 6-9 provide a method for preparing high-organic-matter fertigation fertilizer from kitchen waste.

[0055] The difference between the above embodiments and Embodiment 1 is that the types of auxiliary liquids in the ripening enzymatic hydrolysis and drying process are different, as shown below.

[0056] In Example 6: The compound enzyme preparation is composed of cellulase, alkaline protease and lipase in a weight ratio of 3.5:1.8:0.4.

[0057] In Example 7: The compound enzyme preparation is composed of cellulase, alkaline protease and lipase in a weight ratio of 4.5:1.2:0.6.

[0058] In Example 8: The compound enzyme preparation is composed of cellulase, alkaline protease and lipase in a weight ratio of 3:2:0.2.

[0059] In Example 9: The compound enzyme preparation is composed of cellulase, alkaline protease and lipase in a weight ratio of 5:1:0.8.

[0060] All other process parameters in the above embodiments are the same as those in Embodiment 1.

[0061] Comparative Example Comparative Examples 1-6 Comparative Examples 1-6 each provide a method for preparing organic fertilizer from kitchen waste.

[0062] The difference between the above comparative example and Example 1 is that the methods of ripening, enzymatic hydrolysis, and drying are different, as detailed below.

[0063] Comparative Example 1: No auxiliary liquid was added.

[0064] In Comparative Example 2: the excipient solution was composed of polysorbate-80, choline chloride, sodium citrate and water in a weight ratio of 20:0.6:3:100.

[0065] In Comparative Example 3: the compound enzyme preparation was composed of cellulase, neutral protease and lipase in a weight ratio of 4:1.5:0.5.

[0066] In Comparative Example 4: the compound enzyme preparation was composed of cellulase, alkaline protease and lipase in a weight ratio of 4:0.5:1.5.

[0067] In Comparative Example 5, the specific steps for ripening, enzymatic hydrolysis, and drying were as follows: Kitchen waste solids with a moisture content of 68%, auxiliary liquid, and compound enzyme preparation were mixed evenly at a weight ratio of 350g:90g:0.0035g. Pre-fermentation was carried out for 3 hours at pH 8 and a temperature of 45℃. After cooling to room temperature, a spore concentration of 2×10⁻⁶ was added. 8 Trichoderma harzianum spores concentration was 2 × 10⁻⁶ / mL. 7 A suspension of Bacillus licheniformis at a concentration of 0.005 wt% was prepared, and the pH was adjusted to 5 and the temperature to 35°C. Fermentation was carried out for 9 hours, followed by drying to obtain the mature enzymatic hydrolysate.

[0068] In Comparative Example 6: an equal amount of Bacillus berleis (Bacillus berleis BGB-89R, for details please refer to the patent filed by the applicant on December 29, 2023, application number CN202311856789.6) was used to replace Bacillus licheniformis, and the preparation method of Bacillus berleis spore suspension was the same as that of Bacillus licheniformis spore suspension.

[0069] All other process parameters in the above comparative examples are the same as those in Example 1.

[0070] Performance testing The fertilizers prepared in the examples and comparative examples were subjected to performance testing, specifically including the following performance tests.

[0071] Testing methods for organic matter, organic content, easily oxidizable organic matter, and nutrients (N, P2O5, K2O): The testing methods specified in NY / T525-2021 "Organic Fertilizers" (Organic Content Grading Standard). Effective viable bacteria count detection method: GB20287-2006 Agricultural microbial inoculants.

[0072] Method for detecting contamination rate: GB20287-2006 Agricultural microbial agents.

[0073] Test method for water-insoluble matter: NY / T3831-2021 Organic water-soluble fertilizer.

[0074] Test results are shown in Table 1.

[0075] Table 1. Performance test results of fertilizers in the examples and comparative examples. Based on the test results in Table 1 above, and by comparing the test results of the examples and comparative examples, it can be seen that the organic matter content of the high organic matter fertigation fertilizer prepared in this application is as high as 90% or more, the organic matter content is as high as 77% or more, the easily oxidizable organic matter is as high as 38% or more, and the total N+P2O5+K2O content is as high as 4.3% or more. It can achieve balanced nutrient supply, which is significantly higher than that of conventional fertigation fertilizers. Moreover, the prepared fertigation fertilizer has an effective live bacteria count ≥210 million / g, a miscellaneous bacteria rate ≤13%, and a solid insoluble matter ≤4.2%, which shows excellent solubility, wide applicability, and the effect of promoting crop growth.

[0076] By comparing the test results of Examples 1-5 with those of Comparative Examples 1-2, it can be seen that Comparative Example 1 did not add any auxiliary material solution, while the auxiliary material solution in Comparative Example 2 was composed of polysorbate-80, choline chloride, sodium citrate, and water in a weight ratio of 20:0.6:3:100. The fertilizer prepared in Comparative Example 2 had poor overall performance. In contrast, the examples in this application used an auxiliary material solution composed of polysorbate-80, choline chloride, sodium citrate, and water in a weight ratio of 10-16:1-5:0.3-0.9:100. The fertilizer prepared in this application had higher organic matter, nutrient, and effective viable bacteria content, and lower levels of miscellaneous bacteria and water-insoluble matter.

[0077] By comparing the test results of Examples 1, 6-9 and Comparative Examples 3-4, it can be seen that the compound enzyme preparation in Comparative Example 3 is composed of a mixture of cellulase, neutral protease, and lipase in a weight ratio of 4:1.5:0.5, and the compound enzyme preparation in Comparative Example 4 is composed of a mixture of cellulase, alkaline protease, and lipase in a weight ratio of 4:0.5:1.5. The fertilizer prepared from these examples has poor overall performance. In contrast, the examples in this application use a compound enzyme preparation composed of a mixture of cellulase, alkaline protease, and lipase in a weight ratio of 3.5-4.5:1.2-1.8:0.4-0.6, and the fertilizer prepared from this compound enzyme preparation has excellent overall performance.

[0078] By comparing the test results of Example 1 and Comparative Example 5, it can be seen that in Comparative Example 5, the pH of the two stages of enzymatic hydrolysis in the specific steps of ripening, enzymatic hydrolysis, and drying was mismatched, resulting in poor overall performance of the prepared fertilizer. In Comparative Example 6, the fertilizer prepared by replacing Bacillus licheniformis with an equal amount of Bacillus belye was also of poor overall performance. In contrast, the embodiments of this application first carried out pre-fermentation at a pH of 4-6 and a temperature of 42-48°C, then added a suspension of Trichoderma harzianum and Bacillus licheniformis spores, and carried out fermentation at a pH of 7-9 and a temperature of 32-38°C, resulting in fertilizer with excellent overall performance.

[0079] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing high-organic-matter fertigation fertilizer from kitchen waste, characterized in that, It is made from kitchen waste, which undergoes pretreatment to remove impurities, heating and sterilization, oil and water removal, cooking and enzymatic hydrolysis and drying, pre-screening and fine powder grading in sequence. The specific steps of the ripening enzymatic hydrolysis and drying are as follows: Solid residue with a moisture content of 60%-72% after degreasing and dehydration, auxiliary liquid, and compound enzyme preparation are mixed evenly at a weight ratio of 300-400:80-100:0.002-0.

005. Pre-fermentation is then carried out for 2-4 hours at a pH of 4-6 and a temperature of 42-48℃. After cooling to room temperature, a spore concentration of 1-3 × 10⁻⁶ spores is added. 8 The concentration of Trichoderma harzianum spores per mL is 1-3 × 10⁻⁶. 7 The suspension of Bacillus licheniformis at a concentration of 1 / mL was prepared to a final concentration of 0.003-0.007 wt%, and the pH was adjusted to 7-9 and the temperature to 32-38℃. Fermentation was carried out for 8-10 hours, followed by drying. The auxiliary material solution is composed of polysorbate-80, choline chloride, sodium citrate, and water in a weight ratio of 10-16:1-5:0.3-0.9:

100. The compound enzyme preparation is composed of a mixture of cellulase, alkaline protease and lipase in a weight ratio of 3-5:1-2:0.2-0.

8.

2. The method for preparing high-organic-matter fertigation fertilizer from kitchen waste according to claim 1, characterized in that, The specific steps of the pretreatment and impurity removal are as follows: after the kitchen waste is collected, it enters the pretreatment system and passes through coarse crushing and sorting, fine crushing and sorting, primary sand removal, slurry liquefaction and sorting, and secondary sand removal to remove heavy impurities, so as to obtain kitchen waste slurry with high organic matter and low impurities.

3. The method for preparing high-organic-matter fertigation fertilizer from kitchen waste according to claim 1, characterized in that, The specific steps for heat sterilization are as follows: heating temperature 90-100℃, 20-40 min.

4. The method for preparing high-organic-matter fertigation fertilizer from kitchen waste according to claim 1, characterized in that, The specific steps of the ripening enzymatic hydrolysis and drying process are as follows: The solid residue, auxiliary liquid, and compound enzyme preparation are mixed evenly at a weight ratio of 330-370:85-95:0.003-0.

004. Pre-fermentation is then carried out for 2-4 hours at a pH of 4.5-5.5 and a temperature of 43-47℃. After cooling to room temperature, a spore concentration of 1.5-2.5 × 10⁻⁶ is added. 8 The concentration of Trichoderma harzianum spores per mL is 1-3 × 10⁻⁶. 7 The spore suspension of Bacillus licheniformis was prepared with a final content of 0.004-0.006 wt%, and the pH was adjusted to 7.5-8.5 and the temperature to 53-57℃. Fermentation and enzymatic hydrolysis were carried out for 8-10 hours, followed by dehydration and drying.

5. The method for preparing high-organic-matter fertigation fertilizer from kitchen waste according to claim 1, characterized in that, The auxiliary liquid is composed of polysorbate-80, choline chloride, sodium citrate, and water in a weight ratio of 11-15:2-4:0.4-0.8:

100.

6. The method for preparing high-organic-matter fertigation fertilizer from kitchen waste according to claim 5, characterized in that, The auxiliary liquid has a weight ratio of 12-14: It is composed of polysorbate-80, choline chloride, sodium citrate, and water in a ratio of 2.5-3.5:0.5-0.7:

100.

7. The method for preparing high-organic-matter fertigation fertilizer from kitchen waste according to claim 1, characterized in that, The compound enzyme preparation is composed of a mixture of cellulase, alkaline protease and lipase in a weight ratio of 3.5-4.5:1.2-1.8:0.4-0.

6.

8. The method for preparing high-organic-matter fertigation fertilizer from kitchen waste according to claim 1, characterized in that, The high organic matter fertilizer obtained by the fine powder grading has a particle size ≤60μm.

9. A high-organic-matter fertigation fertilizer, characterized in that, It is prepared using the method described in any one of claims 1-8.

10. The high-organic-matter fertigation fertilizer according to claim 9, characterized in that, The performance parameters of the high organic matter fertigation fertilizer are as follows: organic matter content ≥90%, organic matter content ≥77%, easily oxidizable organic matter ≥38%, total nutrients (N+P2O5+K2O) ≥4.3%, effective viable bacteria count ≥200 million / g, miscellaneous bacteria rate ≤13%, and solid insoluble matter ≤4.2%.

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