A preparation method for converting garden waste into fertilizer

Abstract

This application relates to the technical field of landscaping, specifically disclosing a method for preparing fertilizer from landscaping waste. The method includes the following steps: sorting and crushing landscaping waste to obtain broken waste; naturally drying the broken waste, followed by carbonization and crushing to obtain carbonized material; adding an initiator and an expanding agent to the carbonized material, mixing thoroughly, and then composting in windrows. For the first two weeks of composting, the compost pile is turned every three days, and then every five days thereafter, controlling the moisture content and continuing fermentation to obtain initial fertilizer material; adding bamboo vinegar and a compound enzyme to the initial fertilizer material, mixing thoroughly, and then fermenting again to obtain fertilizer. This method for preparing fertilizer from landscaping waste, through the synergistic effect between raw materials, has the advantages of reducing environmental pollution, realizing waste utilization, and improving the efficient conversion of landscaping waste.

Description

Technical Field

[0001] This application relates to the field of horticulture technology, and in particular to a method for preparing fertilizer by converting horticultural waste. Background Technology

[0002] Garden waste refers to waste generated during the natural or maintenance process of greening plants in urban green spaces or suburban woodlands, including shrub and tree trimmings, lawn trimmings, weeds, fallen leaves, branches, and discarded flowers and plants in gardens and flower beds. The main component of garden plant waste is organic matter, rich in cellulose and lignin.

[0003] With the development of society and economy, the urbanization process is accelerating, and people's needs for a better life are increasing day by day. This has led to the rapid development of the landscaping industry and a rapid increase in the output of landscaping waste, most of which is organic matter.

[0004] Currently, the main methods for disposing of garden waste in my country are incineration and landfill, which cause environmental pollution and affect the aesthetics of cities. Therefore, it is necessary to develop a method for converting garden waste into fertilizer. Summary of the Invention

[0005] In order to reduce environmental pollution, realize waste utilization, and improve the efficient conversion of garden waste, this application provides a preparation method for converting garden waste into fertilizer.

[0006] In a first aspect, this application provides a method for preparing fertilizer by converting garden waste into fertilizer, which adopts the following technical solution:

[0007] A method for preparing fertilizer by converting garden waste includes the following steps:

[0008] S1: Sorting and crushing garden waste to obtain broken waste;

[0009] S2: The crushed waste is naturally dried, then carbonized and crushed to obtain carbonized material;

[0010] S3: Add an initiator and an expanding agent to the carbonized material, mix them evenly, and use windrow composting. Turn the pile every 3 days for the first 2 weeks before composting begins, and then turn it every 5 days thereafter to control the moisture content and continue fermentation to obtain the initial fertilizer material.

[0011] S4: Add bamboo vinegar and compound enzymes to the initial fertilizer material, mix well, and carry out secondary fermentation to obtain fertilizer.

[0012] Furthermore, a method for preparing fertilizer by converting garden waste includes the following steps:

[0013] S1: Sorting and crushing garden waste to obtain broken waste;

[0014] S2: The crushed waste is naturally dried, then carbonized and crushed to obtain carbonized material;

[0015] S3: Add an initiator and an expanding agent to the carbonized material, mix them evenly, and use windrow composting. Turn the pile every 3 days for the first 2 weeks before composting begins, and then turn it every 5 days thereafter. Control the moisture content to 60-80% and continue fermenting for 25-35 days to obtain the initial fertilizer material.

[0016] S4: Add bamboo vinegar and compound enzymes to the initial fertilizer material, mix well, and ferment again for 6-8 days to obtain fertilizer;

[0017] In step S4, the amount of bamboo vinegar added is 10-15 wt% of garden waste, and the amount of compound enzyme added is 20-30 wt% of garden waste.

[0018] By adopting the above technical solution, the preparation method of garden waste into fertilizer proposed in this application, through the synergistic effect between each step, improves the organic matter content, total humic acid content, available phosphorus content, available potassium content, total nitrogen content, and E4 / E6 value, resulting in a high degree of decomposition and achieving efficient conversion of garden waste. Specifically, the organic matter content is 36.5-50.7 wt%, the total humic acid content is 21.9-32.5 wt%, the available phosphorus content is 75.3-87.9 g / kg, the available potassium content is 17.5-25.2 g / kg, the total nitrogen content is 6.0-7.7 g / kg, and the E4 / E6 value is 4.56-5.34.

[0019] First, garden waste is sorted and crushed, then dried and carbonized to obtain carbonized material, which converts waste into biochar through pyrolysis. Next, an initiator and an expanding agent are added to the carbonized material, followed by windrow composting to obtain initial fertilizer. The initiator provides microbial agents and oxygen to facilitate fermentation, as well as trace nutrients such as magnesium and copper ions, facilitating the efficient conversion of garden waste. The expanding agent provides abundant carbon, nitrogen, and other nutrients, regulating... The process of adjusting the carbon-nitrogen ratio during composting reduces nutrient loss and improves compost quality. Finally, bamboo vinegar and compound enzymes are added to the initial compost material, and after secondary fermentation, the fertilizer is obtained. Bamboo vinegar is the condensate recovery liquid of bamboo pyrolysis components during bamboo charcoal production, mainly containing organic acids, phenols, alcohols, and esters. It can also promote the activity of microbial agents in the detonator. Adding it to the composting process improves the maturation effect and facilitates efficient conversion. The compound enzymes can degrade lignin, cellulose, and hemicellulose, accelerating the conversion of waste into fertilizer and speeding up the maturation process.

[0020] Preferably, the amount of initiator added in step S3 is 4-6 wt% of garden waste.

[0021] Preferably, the initiator is prepared using the following method:

[0022] To prepare a compound microbial agent, the modified maifanite was mixed evenly with the compound microbial agent to obtain an initiator.

[0023] By adopting the above technical solution, the amount of initiator added and the preparation method are limited. It is made by mixing modified maifan stone and compound microbial agent. Modified maifan stone itself is loose and porous. When applied to the raw materials of garden waste, it can provide enough oxygen to facilitate better fermentation of compound microbial agent, thereby accelerating the degradation rate of garden waste, improving the degree of composting, and facilitating the efficient conversion of garden waste.

[0024] Preferably, the weight ratio of the modified maifanite and the compound microbial agent is 1:(3-5).

[0025] Insufficient addition of the compound microbial agent results in poor fermentation of garden waste, prolonging the fermentation process and hindering composting. Conversely, excessive addition leaves residues after the garden waste has been degraded, potentially causing environmental impact. By employing the aforementioned technical solution, when the amounts of modified maifanite and the compound microbial agent are within the specified range, efficient conversion of garden waste can be facilitated.

[0026] Preferably, the compound microbial agent is a mixture of Trichoderma reesei, Escherichia coli, Bacillus mycoides, Corynebacterium glutamicum, and Aspergillus glaucus, and the weight ratio of Trichoderma reesei, Escherichia coli, Bacillus mycoides, Corynebacterium glutamicum, and Aspergillus glaucus is 1:1:1:1:1:1.

[0027] By adopting the above technical solution, the synergistic effect between the raw materials of the compound microbial agent can better degrade garden waste, facilitate fermentation, improve the degree of composting corrosion, and help improve the efficient conversion of garden waste.

[0028] Preferably, the modified maifanite is prepared using the following method:

[0029] A1: Crush, wash, dry, pulverize, and sieve the maifan stone, add it to hydrochloric acid solution, mix evenly, let stand, filter, wash, and dry to obtain pretreated maifan stone.

[0030] A2: The pretreated maifanite was placed in an ethanol solution of lanthanum oxide, the pH was adjusted, the mixture was allowed to stand, filtered, washed, dried, calcined, and cooled to obtain modified maifanite.

[0031] Furthermore, the modified maifanite is prepared using the following method:

[0032] A1: Crush the maifan stone, wash it with water, dry it, pulverize it, pass it through a 150-250 mesh sieve, add it to hydrochloric acid solution, mix it evenly, let it stand for 1-3 hours, filter it, wash it with water until it is neutral, dry it, and obtain the pretreated maifan stone.

[0033] A2: The pretreated maifanite is placed in an ethanol solution of lanthanum oxide, the pH is adjusted to 9-11 with ammonia, and it is allowed to stand for 15-18 hours. It is then filtered, washed with water until neutral, dried, calcined at 400-500℃, and cooled to obtain modified maifanite.

[0034] In step A1, the concentration of the hydrochloric acid solution is 1 mol / L, and the amount of hydrochloric acid solution added per 1g of maifanite is 8-12 mL; in step A2, the amount of lanthanum oxide ethanol solution added per 1g of maifanite is 30-50 mL, the mass fraction of lanthanum oxide in the lanthanum oxide ethanol solution is 5%, the mass fraction of ethanol is 40%, and the concentration of ammonia is 1 mol / L.

[0035] By adopting the above technical solution, the pores of natural maifan stone are filled with various impurities, which reduces the adsorption capacity of maifan stone and makes it unable to optimally load the compound microbial agent. Therefore, the above method is used to prepare modified maifan stone. First, the maifan stone is activated by acid to remove some acid-soluble impurities. Then, the pretreated maifan stone is modified by rare earth lanthanum to open up the pores of the maifan stone, further improve the adsorption capacity of maifan stone, facilitate better mixing with the compound microbial agent, facilitate the preparation of the detonator, improve the air permeability of the pile, facilitate composting fermentation, and facilitate the efficient conversion of garden waste.

[0036] Preferably, the amount of the expanding agent added is 15-27 wt% of garden waste.

[0037] Preferably, the expanding agent in step S3 is a mixture of beet pulp, sugarcane bagasse, and grape pomace, and the weight ratio of beet pulp, sugarcane bagasse, and grape pomace is 1:1:1.

[0038] By adopting the above technical solution, limiting the amount and composition of the expansion agent, and using beet pulp, sugarcane bagasse, and grape pomace as expansion agents, not only is waste utilization achieved, resources are saved, and the environment is protected, but the porosity of the compost pile is also increased, ventilation is improved, and water is effectively controlled, which can promote composting and contribute to the efficient conversion of garden waste.

[0039] As a preferred option, the bamboo vinegar in step S4 is pretreated by the following method before use: ozone is introduced into the bamboo vinegar, the mixture is allowed to stand, filtered, and distilled to obtain pretreated bamboo vinegar.

[0040] Furthermore, the bamboo vinegar in step S4 is pretreated by the following method before use: ozone is introduced into the bamboo vinegar at a flow rate of 0.17 mg / min for 10-20 min, allowed to stand for 5-8 h, filtered, and distilled to obtain the pretreated bamboo vinegar.

[0041] By adopting the above technical solution, it can be found that bamboo vinegar contains harmful substances such as methanol, formaldehyde, and 3,4-benzopyrene. Therefore, by using the above method to refine the bamboo vinegar, harmful substances can be removed, making the bamboo vinegar more effective and facilitating composting.

[0042] Preferably, the complex enzyme in step S4 is a mixture of cellulase, lignin peroxidase, manganese peroxidase, and laccase, and the weight ratio of cellulase, lignin peroxidase, manganese peroxidase, and laccase is 1:1:1:1.

[0043] By adopting the above technical solutions, cellulase can degrade cellulose, lignin peroxidase can degrade lignin, and manganese peroxidase and laccase are extracellular phenol oxidases that can play a catalytic role on the surface of garden waste or inside the cell wall that has decayed and has enough pores for enzyme molecules to penetrate, all of which can degrade lignin. Through the synergistic effect between several enzymes, cellulose and lignin can be degraded better, which facilitates the composting and maturation of garden waste and helps to efficiently transform garden waste.

[0044] In summary, this application includes at least one of the following beneficial technical effects:

[0045] 1. Because this application uses an initiator and an expanding agent to perform preliminary composting and fermentation on garden waste to obtain initial fertilizer material, and then uses bamboo vinegar and compound enzymes to perform secondary fermentation on the initial fertilizer material to obtain fertilizer, it can enhance the degree of decomposition of garden waste, facilitate the efficient conversion of garden waste, and make the organic matter content reach 50.7wt%, the total humic acid content reach 32.5wt%, the available phosphorus content reach 87.9g / kg, the available potassium content reach 25.2g / kg, the total nitrogen content reach 7.7g / kg, and the E4 / E6 value reach 5.34.

[0046] 2. In this application, ozone is preferably used for pretreatment of bamboo vinegar before use. This can remove harmful impurities from the bamboo vinegar, reduce pollution to the environment and soil, and also facilitate better degradation of garden waste, which helps to improve the efficient conversion of garden waste and improve the degree of decomposition. Detailed Implementation

[0047] The following provides a more detailed description of this application in conjunction with specific details.

[0048] raw material

[0049] All raw materials used in this application are commercially available.

[0050] The viable count of Trichoderma reesei was 2 × 10⁻⁶. 9 / g; the viable count of Escherichia coli Fergusonii was 1.8 × 10⁻⁶. 9 / g; the viable count of Bacillus mycosis fungoides was 1.9 × 10⁻⁶. 9 / g; the viable count of Corynebacterium glutamicum was 2×10⁻⁶. 9 / g; the viable count of Aspergillus glaucus was 1.8 × 10⁻⁶. 9 / g; the average particle size of beet pulp, sugarcane bagasse, and grape pomace is 15mm; cellulase activity is 10000u / g; lignin peroxidase activity is 6000u / g; manganese peroxidase activity is 6000u / g; laccase activity is 8000u / g.

[0051] Preparation Example

[0052] Preparation Example 1

[0053] A modified maifanite is prepared by the following method:

[0054] A1: Crush 2 kg of maifan stone, wash with water, dry, pulverize, pass through a 200-mesh sieve, add to 20 L of 1 mol / L hydrochloric acid solution, mix evenly, let stand for 2 h, filter, wash with water until neutral, dry, and obtain pretreated maifan stone; A2: Place the pretreated maifan stone in 80 L of lanthanum oxide ethanol solution, adjust the pH to 10 with 1 mol / L ammonia water, let stand for 16 h, filter, wash with water until neutral, dry, calcine at 450℃, cool, and obtain modified maifan stone;

[0055] In the lanthanum oxide ethanol solution, the mass fraction of lanthanum oxide is 5%, and the mass fraction of ethanol is 40%.

[0056] Preparation Example 2

[0057] An initiator is prepared by the following method:

[0058] 1.2 kg of Trichoderma reesei, 1.2 kg of Escherichia coli, 1.2 kg of Bacillus mycoides, 1.2 kg of Corynebacterium glutamicum, and 1.2 kg of Aspergillus glaucus were mixed evenly. 2 kg of modified maifanite prepared in Preparation Example 1 was then mixed evenly with the composite microbial agent to obtain the detonator.

[0059] Preparation Example 3

[0060] An initiator, which differs from Preparation Example 2 in that the amount of compound microbial agent added is different. The amount of compound microbial agent added in Preparation Example 3 is 8 kg, namely 1.6 kg of Trichoderma reesei, 1.6 kg of Escherichia coli, 1.6 kg of Bacillus mycoides, 1.6 kg of Corynebacterium glutamicum, and 1.6 kg of Aspergillus glaucus.

[0061] Preparation Example 4

[0062] An initiator, which differs from Preparation Example 2 in that the amount of compound microbial agent added is different. The amount of compound microbial agent added in Preparation Example 3 is 10 kg, namely 2 kg of Trichoderma reesei, 2 kg of Escherichia coli, 2 kg of Bacillus mycoides, 2 kg of Corynebacterium glutamicum, and 2 kg of Aspergillus glaucus.

[0063] Example

[0064] Example 1

[0065] A method for preparing fertilizer by converting garden waste includes the following steps:

[0066] S1: Sorting and crushing 10kg of garden waste to obtain crushed waste;

[0067] S2: The crushed waste is naturally dried, then carbonized and crushed to obtain carbonized material;

[0068] S3: Add 0.4 kg of the initiator prepared in Preparation Example 2 and 1.5 kg of the expanding agent to the carbonized material, namely 0.5 kg of beet pulp, 0.5 kg of sugarcane bagasse, and 0.5 kg of grape pomace. Mix them evenly and use windrow composting. Turn the pile every 3 days for the first 2 weeks of composting, and then turn it every 5 days thereafter. Control the moisture content to 70% and continue fermentation for 30 days to obtain the initial fertilizer material.

[0069] S4: Add 1.2kg of bamboo vinegar and 2.8kg of compound enzymes (0.7kg of cellulase, 0.7kg of lignin peroxidase, 0.7kg of manganese peroxidase, and 0.7kg of laccase) to the initial fertilizer material, mix well, and ferment again for 7 days to obtain the fertilizer.

[0070] Example 2

[0071] A method for preparing fertilizer by converting garden waste is different from Example 1 in that the amount of detonator added is different. In Example 2, the amount of detonator added is 0.5 kg.

[0072] Example 3

[0073] A method for preparing fertilizer by converting garden waste is different from Example 1 in that the amount of detonator added is different. In Example 3, the amount of detonator added is 0.6 kg.

[0074] Example 4

[0075] A method for preparing fertilizer by converting garden waste is different from Example 2 in that the amount of expanding agent added is different. In Example 4, the amount of expanding agent added is 2.1 kg, that is, 0.7 kg of beet pulp, 0.7 kg of sugarcane bagasse, and 0.7 kg of grape pomace.

[0076] Example 5

[0077] A method for preparing fertilizer by converting garden waste is different from Example 2 in that the amount of expanding agent added is different. In Example 4, the amount of expanding agent added is 2.7 kg, that is, 0.9 kg of beet pulp, 0.9 kg of sugarcane bagasse, and 0.9 kg of grape pomace.

[0078] Example 6

[0079] A method for preparing fertilizer for converting garden waste differs from Example 4 in that the source of the detonator is different; the detonator in Example 6 is prepared using the method described in Example 3.

[0080] Example 7

[0081] A method for preparing fertilizer by converting garden waste is different from Example 4 in that the source of the detonator is different. The detonator in Example 7 is prepared using the method described in Example 4.

[0082] Example 8

[0083] A method for preparing fertilizer by converting garden waste into fertilizer differs from Example 6 in that the bamboo vinegar is pretreated by the following method before use: ozone is introduced into the bamboo vinegar at a flow rate of 0.17 mg / min for 15 min, allowed to stand for 6.5 h, filtered, and distilled to obtain the pretreated bamboo vinegar.

[0084] Comparative Example

[0085] Comparative Example 1

[0086] A method for preparing fertilizer by converting garden waste is different from Example 1 in that the modified maifanite in the detonator is replaced with an equal amount of maifanite.

[0087] Comparative Example 2

[0088] A method for preparing fertilizer by converting garden waste into fertilizer, which differs from Example 1 in that modified maifanite is not added to the initiator.

[0089] Comparative Example 3

[0090] A method for preparing fertilizer for converting garden waste differs from Example 1 in that the compound microbial agent in the initiator is replaced in equal amounts with any one of Trichoderma reesei, Escherichia coli, Bacillus mycoides, Corynebacterium glutamicum, and Aspergillus glaucus.

[0091] Comparative Example 4

[0092] A method for preparing fertilizer by converting garden waste into fertilizer, which differs from Example 1 in that no initiator is added in step S3.

[0093] Performance testing

[0094] The following performance tests were conducted on the fertilizers derived from garden waste in Examples 1-8 and Comparative Examples 1-4:

[0095] Organic matter content: The organic matter content in the fertilizer was determined according to HJ761-2015 "Determination of Organic Matter in Solid Waste by Ignition Loss Method". The test results are shown in Table 1.

[0096] Total humic acid content: The total humic acid content in the fertilizer was determined according to HG / T5603-2019 "Determination of bio-humic acid content in fertilizer produced from kitchen waste". The test results are shown in Table 1.

[0097] Available phosphorus content: The available phosphorus content in the fertilizer was determined according to NY / T300-1995 "Determination of available phosphorus in organic fertilizers". The test results are shown in Table 1.

[0098] Available potassium content: The available potassium content in fertilizer was determined according to NY / T889-2004 "Determination of available and slow-release potassium content in soil". The test results are shown in Table 1.

[0099] Total nitrogen content: The total nitrogen content in the fertilizer was determined according to NY / T297-1995 "Determination of total nitrogen in organic fertilizers". The test results are shown in Table 1.

[0100] E4 / E6 value: Take 1g of each and put it into 10g of water. After extraction and filtration, the extract is obtained. The absorbance of the extract at 465nm and 665nm is measured by visible light spectrophotometer. The ratio of the two values ​​is used to obtain the E4 / E6 value. The test results are shown in Table 1.

[0101] Table 1 Test Results

[0102]

[0103] As can be seen from Table 1, the preparation method of garden waste into fertilizer proposed in this application, through the synergistic effect between each step, improves the organic matter content, total humic acid content, available phosphorus content, available potassium content, total nitrogen content, and E4 / E6 value, achieving a high degree of decomposition and realizing the efficient conversion of garden waste. Specifically, the organic matter content is 36.5-50.7 wt%, the total humic acid content is 21.9-32.5 wt%, the available phosphorus content is 75.3-87.9 g / kg, the available potassium content is 17.5-25.2 g / kg, the total nitrogen content is 6.0-7.7 g / kg, and the E4 / E6 value is 4.56-5.34.

[0104] Combining Example 1 and Comparative Examples 1-4, it can be seen that the fertilizer in Example 1 has an organic matter content of 36.5 wt%, a total humic acid content of 21.9 wt%, a available phosphorus content of 75.3 g / kg, a available potassium content of 17.5 g / kg, a total nitrogen content of 6.0 g / kg, and an E4 / E6 value of 4.56, which is better than that in Comparative Examples 1-4. This indicates that adding an initiator during composting is more suitable, and that modified maifanite and compound microbial agents are more suitable initiators, which can better improve the degree of composting of garden waste and facilitate the efficient conversion of garden waste.

[0105] As can be seen from Examples 1-3, the fertilizer in Example 2 has an organic matter content of 43.1 wt%, a total humic acid content of 25.1 wt%, a available phosphorus content of 79.5 g / kg, a available potassium content of 19.8 g / kg, a total nitrogen content of 6.6 g / kg, and an E4 / E6 value of 4.91, which is better than other examples. This indicates that the amount of initiator added in Example 2 is more appropriate, which can better improve the composting degree of garden waste and facilitate the efficient conversion of garden waste.

[0106] As can be seen from Examples 2 and 4-5, the fertilizer in Example 4 has an organic matter content of 46.4 wt%, a total humic acid content of 27.6 wt%, a available phosphorus content of 82.1 g / kg, a available potassium content of 21.9 g / kg, a total nitrogen content of 7.0 g / kg, and an E4 / E6 value of 4.97, which is better than other examples. This indicates that the amount of expansion agent added in Example 4 is more appropriate, which can better improve the composting degree of garden waste and facilitate the efficient conversion of garden waste.

[0107] As can be seen from Examples 4 and 6-7, the fertilizer in Example 6 has an organic matter content of 48.5 wt%, a total humic acid content of 30.1 wt%, a available phosphorus content of 85.4 g / kg, a available potassium content of 24.9 g / kg, a total nitrogen content of 7.5 g / kg, and an E4 / E6 value of 5.12, which is better than other examples. This indicates that the initiator prepared in Example 3 is more suitable, resulting in a high degree of decomposition of garden waste and achieving efficient conversion of garden waste.

[0108] Combining Examples 6 and 8, it can be seen that the fertilizer in Example 8 has an organic matter content of 50.7 wt%, a total humic acid content of 32.5 wt%, a available phosphorus content of 87.9 g / kg, a available potassium content of 25.2 g / kg, a total nitrogen content of 7.7 g / kg, and an E4 / E6 value of 5.34, which is better than that in Example 6. This indicates that it is more appropriate to pretreat the bamboo vinegar with ozone before use, so that the garden waste has a high degree of composting and achieves efficient conversion of garden waste.

[0109] The embodiments described above are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for preparing fertilizer by converting garden waste, characterized in that: Includes the following steps: S1: Sorting and crushing garden waste to obtain broken waste; S2: The crushed waste is naturally dried, then carbonized and crushed to obtain carbonized material; S3: Add an initiator and an expanding agent to the carbonized material, mix them evenly, and use windrow composting. Turn the pile every 3 days for the first 2 weeks before composting begins, and then turn it every 5 days thereafter to control the moisture content and continue fermentation to obtain the initial fertilizer material. S4: Add bamboo vinegar and compound enzymes to the initial fertilizer material, mix well, and carry out secondary fermentation to obtain fertilizer; The detonator is prepared by the following method: preparing a composite microbial agent by mixing modified maifanite with the composite microbial agent evenly to obtain the detonator; the weight ratio of the modified maifanite to the composite microbial agent is 1:(3-5). The modified maifanite was prepared using the following method: A1: Crush, wash, dry, pulverize, and sieve the maifan stone, add it to hydrochloric acid solution, mix evenly, let stand, filter, wash, and dry to obtain pretreated maifan stone. A2: The pretreated maifanite was placed in an ethanol solution of lanthanum oxide, the pH was adjusted, the mixture was allowed to stand, filtered, washed, dried, calcined, and cooled to obtain modified maifanite.

2. The method for preparing fertilizer by converting garden waste into fertilizer according to claim 1, characterized in that: The amount of initiator added in step S3 is 4-6 wt% of garden waste.

3. The method for preparing fertilizer by converting garden waste into fertilizer according to claim 1, characterized in that: The compound microbial agent is a mixture of Trichoderma reesei, Escherichia coli, Bacillus mycoides, Corynebacterium glutamicum, and Aspergillus glaucus, with the weight ratio of Trichoderma reesei, Escherichia coli, Bacillus mycoides, Corynebacterium glutamicum, and Aspergillus glaucus being 1:1:1:1:1:

1.

4. The method for preparing fertilizer by converting garden waste into fertilizer according to claim 1, characterized in that: The amount of the expanding agent added is 15-27 wt% of garden waste.

5. A method for preparing fertilizer by converting garden waste into fertilizer according to claim 4, characterized in that: The expanding agent in step S3 is a mixture of beet pulp, sugarcane bagasse, and grape pomace, and the weight ratio of beet pulp, sugarcane bagasse, and grape pomace is 1:1:

1.

6. A method for preparing fertilizer by converting garden waste into fertilizer according to claim 1, characterized in that: The bamboo vinegar in step S4 is pretreated using the following method before use: Ozone was introduced into the bamboo vinegar, the mixture was allowed to stand, filtered, and distilled to obtain pretreated bamboo vinegar.

7. A method for preparing fertilizer by converting garden waste into fertilizer according to claim 1, characterized in that: The complex enzyme in step S4 is a mixture of cellulase, lignin peroxidase, manganese peroxidase, and laccase, and the weight ratio of cellulase, lignin peroxidase, manganese peroxidase, and laccase is 1:1:1:1.

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