Method for preparing organic fertilizer from garden waste

Abstract

The invention provides a method for preparing an organic fertilizer from garden wastes, which comprises the following steps: S1, crushing the garden wastes to obtain a compost main material; s2, mixing the compost main material, the compost auxiliary material, the microbial inoculum and water to obtain a mixed material; s3, carrying out primary aerobic composting on the mixed material, controlling the fermentation starting time to be 8-120 hours, controlling the temperature to be 60-100 DEG C, and carrying out secondary composting after the primary aerobic composting is finished, so as to obtain an organic fertilizer; and S4, screening the organic fertilizer obtained in the step S3, and performing compound mixing granulation to obtain an organic fertilizer finished product. According to the invention, submerged plants, emergent aquatic plants and land garden wastes are matched with a small amount of kitchen wastes, high-temperature aerobic compost is matched with a secondary rotten fertilizer, the characteristics of high water content and abundant nutrient elements such as nitrogen and potassium of aquatic plants are utilized, and the characteristics of balanced nutrition of kitchen wastes are matched to produce the organic fertilizer.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental engineering, and in particular relates to a method for preparing organic fertilizer by utilizing garden waste. Background Art

[0002] Since garden waste contains a large amount of lignin and cellulose, such as algae, water plants, small branches and leaves, flower and grass clippings, etc., it also has the characteristics of high porosity, low water content and high C / N ratio. However, the above-mentioned garden waste is not conducive to decomposition and utilization by microorganisms, which affects the fermentation rate of composting. Therefore, traditional waste treatment technology cannot be directly adopted. Aerobic composting treatment technology that can reuse garden waste as a resource needs further research and development. Summary of the invention

[0003] In view of this, the present invention aims to overcome the defects in the prior art and proposes a method for preparing organic fertilizer using water garden waste. The present invention aims to solve the problem of space occupation and secondary environmental pollution caused by the organisms (algae and plants) and small branches and leaves, flower and grass clippings and other wastes in the process of urban water ecological management, and develops a technology for producing matrix by co-composting garden waste and kitchen waste, providing ideas and references for the disposal of eutrophic rivers and lakes and harmless resource utilization.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A method for preparing organic fertilizer using garden waste comprises the following steps:

[0006] S1: crushing garden waste to obtain compost main material;

[0007] S2: mixing the compost main material, the compost auxiliary material, the bacterial agent and water to obtain a mixed material;

[0008] S3: performing primary aerobic composting on the mixed material, wherein the fermentation start time is controlled within 8 to 120 hours and the temperature is controlled within 60 to 100° C., and after the primary aerobic composting is completed, secondary composting is performed to obtain organic fertilizer;

[0009] Step S4: screening the organic fertilizer obtained in step S3, and compounding and granulating to obtain a finished organic fertilizer product.

[0010] Preferably, the main materials of the compost include but are not limited to submerged plants, emergent plants, and terrestrial garden waste.

[0011] Preferably, the composting auxiliary materials include but are not limited to food waste and substrate.

[0012] Preferably, the matrix includes but is not limited to vermiculite, medical stone, animal feces, straw, rice husk, tail vegetables, and biochar.

[0013] Preferably, the carbon-nitrogen ratio of the mixed material is 20:1 to 30:1.

[0014] Preferably, the moisture content of the mixed material is 55% to 60%, and the particle size is less than 45 mm.

[0015] Preferably, the bacterial agent is a strain capable of degrading cellulose or hemicellulose. Specifically, the bacterial agent is a thermophilic microbial agent, including but not limited to one or more of Brevibacillus Potssteine, Bacillus, Geobacillus, extreme thermophilic bacteria, and Saccharomyces cerevisiae.

[0016] The bacterial agent includes brewer's yeast, and the content of brewer's yeast is not less than 50%. The brewer's yeast is a recombinant yeast strain that can efficiently degrade cellulose substrates and hemicellulose substrates, and the thermophilic microorganism refers to a microorganism with an optimal growth temperature of more than 45°C.

[0017] Preferably, the amount of the bacterial agent added is 1 kg for every 25-35 tons of mixed materials.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) The process of the present invention uses submerged plants such as water chestnuts, Vallisneria, foxtail algae, hornwort, and Potamogeton edulis, emergent plants such as lotus, and terrestrial garden waste such as small branches, lawns, fallen leaves, etc., with a small amount of food waste, and adopts high-temperature aerobic composting combined with secondary humus fertilizer to fully utilize the characteristics of aquatic plants with high water content and abundant nutrients such as nitrogen and potassium, and the nutritional balance of food waste to produce organic fertilizer.

[0020] (2) The process of the present invention can effectively degrade cellulose, polysaccharides, lignin and other substances in garden waste. The final compost product produced by fermentation can not only effectively improve the fertility of the soil and improve the physical structure of the soil, but also reduce or alleviate the problems of soil compaction, decreased water retention and air permeability to a certain extent. The advantages of the composting process are relatively obvious, with a short fermentation cycle and a relatively good development trend. The compost product has a high potassium content and sufficient nutritional value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the C / N variation diagram during composting of different raw materials;

[0022] Figure 2 is the NH3 emission during composting;

[0023] Figure 3 H2S emissions during composting;

[0024] Figure 4 This is a graph of temperature changes during composting;

[0025] Figure 5 This is the pH change diagram during composting;

[0026] Figure 6 This is a graph showing the changes in seed germination rate during composting;

[0027] Figure 7 It is a process flow chart. DETAILED DESCRIPTION

[0028] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.

[0029] The present invention will be described in detail below with reference to the embodiments.

[0030] The present invention provides a method for preparing organic fertilizer using garden waste. Figure 7 , the method comprises the following steps:

[0031] S1: crushing garden waste to obtain compost main material, sorting, desalting, deoiling and aging kitchen waste to obtain compost auxiliary material;

[0032] S2: mixing the compost main material, the compost auxiliary material, the bacterial agent and water to obtain a mixed material;

[0033] The main materials of composting include but are not limited to submerged plants, emergent plants, and land garden waste, such as submerged plants such as water hyacinth, Vallisneria, foxtail algae, hornwort, and Potamogeton, emergent plants such as lotus, and land garden waste such as small branches, lawns, and fallen leaves. Composting auxiliary materials include but are not limited to food waste and substrates, and the substrates include but are not limited to vermiculite, medical stone, animal feces, straw, rice husks, tail vegetables, and biochar.

[0034] S3: Carry out primary aerobic composting on the mixed materials, using an efficient combination of automated high-temperature closed organic fertilizer fermentation equipment and bacterial agents. After mixing, adjust the moisture content and C / N ratio of the mixed materials. The carbon-nitrogen ratio of the mixed materials is 20:1-30:1, the moisture content is 55%-60%, and the particle size is less than 45mm. The mixed materials are placed in a high-temperature fermentation equipment, and the temperature of the equipment is raised to 60-100°C by electric heating to inactivate harmful microorganisms and pathogens in the mixed materials. At the same time, the activity of thermophilic composite microbial agents is activated, and thermophilic bacteria are used to accelerate the degradation of organic matter and the formation of humus in the mixed materials, and produce stabilized, mature, and harmless organic fertilizer products. The entire high-temperature fermentation start-up time is controlled within 8 hours. After the first-level aerobic composting is completed, secondary composting is carried out to obtain organic fertilizer;

[0035] Step S4: The organic fertilizer obtained in step S3 is mixed and granulated to obtain a pure organic fertilizer product to obtain a special fertilizer product.

[0036] The bacterial agent used in the present invention is an engineered bacterial agent that has undergone metabolic engineering modification (including signal peptide optimization, promoter / terminator optimization, secretion pathway modification, etc.). The modified bacterial agent has high cellulose degradation ability or high hemicellulose degradation ability, and the problem of high cellulose content can be solved even if garden waste is composted alone.

[0037] The specific transformation process of the bacterial agent is as follows:

[0038] Screening was performed based on the enzyme activity of each strain. For strains producing CBHI enzyme, its secretion activity was detected by using soluble 4-methylumbelliferyl-β-D-lactoside. For yeast transformants secreting EGII, their CMC degradation ability was screened by the patch method on YPD medium containing 0.5% (w / v) carboxymethyl cellulose (CMC) and 20g L-1 glucose as carbon sources. After 48 hours of growth, the colonies were eluted from the plates, and the remaining CMC was stained with 0.1% Congo red and decolorized with 1M sodium chloride. The activity of the secreted EGII enzyme was determined by measuring the formation of a clearing zone in the culture medium. BGLI activity was detected by using p-nitrophenyl-β-D-pyranoglucoside (pNPG) as a substrate, and the recombinant yeast strains containing three cellulases were screened as cellulase yeast strains.

[0039] Plasmid pBS18 (pBS19 / pBS20) containing cellulase genes and ALG9 was used as a template for EGII (BGLI / CBHI) / ALG9 real-time fluorescence quantitative PCR (qPCR) standard curve analysis. The target gene was amplified using primer pairs QEG2-F / QEG2-R (QBGL1-F / QBGL1-R, QCBH1-F / QCBH1-R), and the reference gene ALG9 was amplified using primer pairs QALG9-F / QALG9-R. The cycling conditions were set to an initial 95°C for 30 seconds, followed by 40 cycles, each cycle consisting of 95°C for 5 seconds, 57°C for 30 seconds, and 72°C for 30 seconds.

[0040] Using a POT1-mediated delta integration strategy, yeast strains expressing cellulases that can efficiently degrade different cellulosic substrates were created. The system also includes metabolic engineering strategies, including optimization of codon usage, promoters, and signal peptides. Expression of heterologous cellulases in cellulosic yeast triggers the unfolded protein response. To improve protein folding ability, the endoplasmic reticulum chaperone BiP and the disulfide isomerase Pdi1p were overexpressed, and the Golgi membrane protein Ca2 + / Mn2 +ATPase Pmr1p was used to reduce the glycosylation of cellulase. Results: Strain SK18-3 could utilize carboxymethyl cellulose. Strain SK12-50 used phosphoric acid to swell cellulose for hydrolysis.

[0041] The strain was grown in a 200 ml shake flask containing 100 ml YPD medium at 30 degrees Celsius and shaken at 220 rpm. The cells were harvested by centrifugation when the OD600 value reached 0.6. Total RNA was extracted using the RNApure Yeast Kit. cDNA was synthesized using the HiFiScript cDNA Synthesis Kit. The relative transcript levels of the genes were determined by real-time quantitative polymerase chain reaction. The splicing of HAC1 mRNA was detected by polymerase chain reaction using cDNA as a template and amplified with the HAC1-F and HAC1-R primer pairs.

[0042] To measure the degradation activity in different cellulosic materials, cellulolytic bacteria were cultured. 100 mL of YPD medium was added to a 100 mL flask at 4°C and cultured with shaking at 30°C and 220 rpm for 72 hours. After centrifugation at 4°C for 10 minutes, the cellulose degradation activity in the supernatant was determined by measuring the concentration of glucose produced.

[0043] First, the recombinant yeast strain was pre-cultured in YPD medium and grown aerobically under shaking conditions for 72 hours. The cells were collected by centrifugation for 10 minutes and then washed twice with sterile distilled water. The wet cell pellet was weighed and used for fermentation.

[0044] The wet cell pellet was resuspended in YP medium with an initial cell concentration of about 120 g of wet cells per liter. These solutions were placed in glass serum bottles, each equipped with a siliconized tube and a check valve as a CO2 outlet, and fermented under oxygen-limited conditions. The fermentation process was started by adding yeast cells to the bottles and then stirred at 37°C for 96 hours. The purpose of the study was to understand and optimize the conversion process of yeast cells to complex carbohydrate utilization and cellulose degradation.

[0045] The expression levels of four genes KAR2, ERO1, PDI1, and DER1 in the modified strains increased due to UPR induction and were selected to measure the amount of UPR during cellulase expression. The transcript levels of the four genes were slightly increased compared to the control strain. This provides additional evidence for UPR induction in the cellulolytic strain. This infers that the expression of cellulolytic enzymes may lead to the accumulation of unfolded or misfolded proteins and increase endoplasmic reticulum stress.

[0046] Example 1

[0047] PCL controlled the stirring frequency in four consecutive runs of 100 kg reactors, each lasting 20 days. In the compost, an oxygen concentration of 16% was set and the maximum temperature was controlled at 55°C. During the startup, the compost temperature was kept below 40°C until the pH of the condensed water reached and exceeded 6, which is a necessary condition for an efficient start-up of the composting process. All parameters were controlled in the same way in all runs, with the raw material ratio being the only parameter that changed. During the runs, the moisture content was controlled by adjusting the amount of distilled water added during turning, taking into account the loss of water and dry matter. The water loss was estimated based on the amount of condensed water collected in the condenser in the reactor cooling circuit. The dry matter loss was estimated by measuring the amount of oxygen consumed by an air inlet flow meter.

[0048] This embodiment designs 4 treatment methods, and the same proportion of engineered bacteria agent is added in all four schemes (the addition amount of the engineered bacteria agent is 1 kg of the engineered bacteria agent per 30 tons of mixed materials). The waste sample tests involved in this embodiment are repeated three times.

[0049] Option 1 (T1): Use food waste and filler (wood chips with C / N of about 200) as compost raw materials C / N 23.21;

[0050] Option 2 (T2): using traditional garden waste (small branches and fallen leaves) and a small amount of cotton hull seeds and peanut shells as materials for composting raw materials C / N44.82;

[0051] Option 3 (T3): Use biowaste (50% food waste and 50% garden waste) as compost raw material C / N30.63;

[0052] Option 4 (T4): Use biowaste (20% of kitchen waste, 30% of algae and 20% of emergent plants, 10% of lawn, 20% of garden waste of fallen flowers, leaves and twigs) as compost raw materials C / N24.32.

[0053] Routine temperature measurements were performed at multiple points in the compost material to obtain an average value. Two points of interstitial air inside the compost were measured. The temperature of the reactor was read by a temperature sensor inserted into the reactor. The samples were immediately frozen and then stored in polyethylene bags at a storage temperature of -20°C. Total carbon and nitrogen were analyzed using the dry combustion method and CNS2000 (LECOEquipment Corporation, USA) analyzer. At the same time, gas sampling during the composting process included two methods: sampling from sampling bags and sampling points in the cooling cycle. These sampling points represent samples of continuous average and instantaneous gas measurements, respectively. These gas samples were collected manually in gas collection bags and extracted from the gas cooling cycle for analysis. The resulting gas samples were stored in sealed glass bottles with a volume of 40 ml each. Before sampling, the sample bottles must be pre-evacuated and the sample gas must be purged three times with nitrogen (N2) to remove impurities that interfere with the analysis process. The gas samples were then divided into two parts for paired analysis for determination. NH3 is absorbed by 2% boric acid and then titrated with dilute sulfuric acid of standard concentration. H2S is determined using a portable biogas analyzer.

[0054] The C / N ratio reveals the progress of mineralization during the composting process and is closely related to the maturity of the compost product. Figure 1 As shown in the figure, under the action of microorganisms, the decomposition rate of organic carbon in the pile is much faster than the consumption of nitrogen, resulting in a downward trend in the C / N ratio. At the end of the composting cycle, the carbon-nitrogen ratio of T4 was significantly lower than that of T2 and T3, decreasing by 24.99% and 37.21%, respectively. This phenomenon shows that a low initial carbon-nitrogen ratio is beneficial to accelerating the mineralization process of composting. This may be because the low carbon-nitrogen ratio treatment provides a more suitable carbon-nitrogen microenvironment for microorganisms, thereby effectively promoting nitrification and mineralization, and ultimately improving the maturity of the compost product. On the other hand, the initial carbon-nitrogen ratio of the T2 test material in the high carbon-nitrogen ratio group was greater than 40, indicating that the carbon content in the material was relatively high. After multiple life cycles of microorganisms, the excess carbon was oxidized, resulting in a decrease in the carbon-nitrogen ratio. When the carbon-nitrogen ratio drops to an appropriate level, microorganisms begin a new metabolism, and the utilization rate of nitrogen increases, which is manifested as an increase in the carbon-nitrogen ratio. As the composting process proceeds, the carbon-nitrogen ratio gradually shows a normal downward trend. A high initial carbon-nitrogen ratio is not conducive to the smooth progress of composting. At the end of composting, T2 reduced the carbon-nitrogen ratio to 31.82. It is generally believed that compost reaches a mature state when the carbon-nitrogen ratio is less than 20, so it did not meet the standard.

[0055] NH3 emissions are mainly concentrated in the high temperature period, especially in the composting process (such as Figure 2 This phenomenon is mainly attributed to the intensive mineralization of organic nitrogen, which is converted into NH4+ , which is further converted into NH3 under high temperature and alkaline conditions. Therefore, around the 7th day of composting, the NH3 emission of each treatment reached a peak. As the temperature decreases, the NH3 emission decreases to a lower concentration. As mentioned above, the turning operation can reactivate the relevant microorganisms, restore the biodegradation of organic matter, and regulate the porosity of the matrix, thereby promoting the re-release of NH3.

[0056] Figure 2 The evolution of NH3 during composting is shown. Compared with T1 treatment, T3 treatment can effectively reduce the cumulative NH3 emission by more than 75% (e.g. Figure 2 ). The main reason is that garden waste improves the C / N ratio and substrate biodegradation efficiency during composting. In fact, T1 treatment inhibits biodegradation efficiency and prolongs the high temperature period (e.g. Figure 2 ), resulting in increased NH3 production during the activation of the substrate from day 7 to day 21 of turning the compost. This process not only involves changes in microbial activity, but is also affected by environmental factors such as temperature, humidity, and the physical and chemical properties of the substrate. Therefore, optimizing composting management strategies is crucial to reducing NH3 emissions and improving composting efficiency.

[0057] The H2S emission rates from all composting scenarios initially increased, then decreased, and eventually approached zero (see Figure 3 ). During the entire composting process, most of the H2S emissions (about 80%) occurred in the first seven days. During the KW composting process, H2S emissions were mainly concentrated in the initial stage. This may be attributed to the intense microbial activity and rapid increase in temperature in the early stages of the reactor, which consumed oxygen and created a local anaerobic environment. Other studies have also shown that insufficient ventilation is the main cause of H2S emissions during composting. To address this issue, the use of fillers increased the porosity of the composted organic material. A peak in H2S emissions was observed after the turn, which is consistent with existing studies. Compared with the T1 treatment, the T3 treatment effectively reduced the cumulative H2S emissions by more than 85%. This is mainly due to the fact that garden waste increased the permeability of the substrate during the composting process, enhanced the flow of oxygen within the material, and thus inhibited the production of H2S.

[0058] Example 2

[0059] Scheme 1 (GW): Use 1 kg of compost raw materials (20% of kitchen waste, 30% of algae and 20% of emergent plants, 10% of lawn, 20% of garden waste such as fallen flowers, leaves and twigs) and 0.035 g of conventional bacterial agent (E-NS Ehrlich fermentation agent) as compost raw materials.

[0060] Scheme 2 (GK): Use 1 kg of compost raw materials (20% of kitchen waste, 30% of algae and 20% of emergent plants, 10% of lawn, and 20% of garden waste such as fallen flowers, leaves and twigs) and 0.035 g of engineered bacterial agent as compost raw materials.

[0061] The composting experiment was continued for three weeks, during which the compost was turned on the third and seventh days and after each week. After each turning, about 200 grams of solid samples were collected to analyze the physicochemical properties of the compost material. The waste sample tests involved in this embodiment were all repeated three times.

[0062] Routine temperature measurements were performed at multiple points of the compost material to obtain an average value. Interstitial air inside the compost was measured at two points. At the same time, samples of the compost and raw materials were collected for the determination of different parameters. The final product was analyzed to determine its quality (stability, heavy metal content, carbon and nitrogen percentage, nutrients, presence of foreign matter, etc.). The moisture content was measured by drying fresh solid samples at 105°C for 12 hours to obtain a constant weight. Fresh solid samples were mixed with deionized water in a mass ratio of 1:10 and shaken for 30 minutes to obtain water extracts for the determination of the pH, electrical conductivity (EC), C / N ratio and germination index (GI) of the matrix. A pH meter (pHS-3C, Mince Instrument, China) was used, and EC was measured with a conductivity meter (DDS-307A, Juyihui, China). 5 ml of water extract of the mixed fertilizer was taken in a culture dish with filter paper, and 10 seeds were evenly placed in an incubator at (25±1)°C for 48 hours. The germination rate and root length of the seeds were measured, and the GI was calculated by the formula.

[0063] Throughout the composting process, all treated samples showed a similar pattern of temperature change, with an initial rapid increase followed by a gradual decrease (e.g. Figure 4 This pattern is attributed to the rapid degradation of organic matter in the composting material, which results in significant heat generation. This high temperature can effectively eradicate roundworm eggs, E. coli, and other harmful pathogens.

[0064] Because the thermophilic phase is achieved faster due to the high decomposition of organic matter. All treatments reached a peak temperature of about 60 °C between the third and fourth days, which then declined. The turning of the compost pile promoted the redistribution of organic matter and the migration of associated microorganisms, resulting in another increase in the temperature of all treatments on the seventh day after turning. In the following two weeks, the temperature showed a similar pattern of first rising and then falling. At the end of the composting process, the temperature of all treatments had basically returned to the ambient temperature, indicating that the compost had reached the mature stage. This result is characterized by a consistent pattern of temperature fluctuations throughout the process, with periods of rapid rise and fall.

[0065] The different treatments had little effect on the pH of the composting process. In the early stages of composting, the pH of all treatments increased significantly within the first week and eventually stabilized in the range of 7 to 8 (e.g. Figure 5 shown). Figure 5 The changes in temperature during the composting process are shown. In general, in the early stages, during the co-composting of food waste and garden waste, the pH value of the material was approximately 4 due to the acidification phenomenon during the early storage of garden waste. With the rapid degradation of degradable organic matter, small molecular organic acids are produced. As the temperature rises, the volatilization of organic acids and the mineralization of organic nitrogen will gradually increase the pH value. In this study, due to the high temperature in the high temperature stage and continuous ventilation that accelerated the process of ammonia to produce NH3, the volatilization and neutralization of organic acids were more thorough, resulting in an initial increase in the pH of the substrate. In the later stages of composting, due to the increase in the activity of nitrifying bacteria, the pH values ​​of all treatments no longer increased significantly, which promoted a small amount of NH4 + Converted to NO3 - This drives the conversion of organic nitrogen to inorganic nitrogen. Overall, the temperature increase and microbial activity together affect the pH changes during the composting process. Temperature also plays an important role in the composting process.

[0066] Toxicity testing of plant seeds with extracts from compost water is one of the important methods to evaluate the maturity of compost. Throughout the composting process, the germination index (GI) of all treatments showed an upward trend (e.g. Figure 6 The higher GI may be related to the removal of toxic substances (such as small molecular organic acids and NH4 + ) and the formation of humus. After 21 days of composting, the GI of GK was higher than 80%, which means that the compost product was non-phytotoxic and mature. Compared with the traditional leaf composting GW, GK using engineered bacteria has a higher GI value, and its product is less toxic to plants, and the degradation of cellulose and lignin is more thorough.

[0067] When evaluating the impact of compost on plant seeds, the germination index is a key biological indicator that reflects the effectiveness of material transformation during the composting process. By comparing different treatments, we can find that combined composting is more effective in promoting seed germination, suggesting less toxicity and more mature compost quality. This became particularly evident after a three-week fermentation cycle. Scientifically validated data shows that GK's GI reaches a high level, ensuring the safety of the compost product and its beneficial effects on plant growth.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing organic fertilizer using garden waste, characterized in that: The steps include: S1: crushing garden waste to obtain compost main material; S2: mixing the compost main material, the compost auxiliary material, the bacterial agent and water to obtain a mixed material; S3: performing primary aerobic composting on the mixed material, wherein the fermentation start time is controlled within 8 to 120 hours and the temperature is controlled within 60 to 100° C., and after the primary aerobic composting is completed, secondary composting is performed to obtain organic fertilizer; Step S4: screening the organic fertilizer obtained in step S3, and compounding and granulating to obtain a finished organic fertilizer product.

2. The method for preparing organic fertilizer using garden waste according to claim 1, wherein: The main materials of the compost include but are not limited to submerged plants, emergent plants, and terrestrial garden waste.

3. The method for preparing organic fertilizer using garden waste according to claim 1, wherein: The composting auxiliary materials include but are not limited to restaurant waste, mushroom husks, and substrates. The restaurant waste is processed through sorting, desalting, deoiling, and aging processes.

4. The method for preparing organic fertilizer using garden waste according to claim 3, wherein: The matrix includes, but is not limited to, vermiculite, medical stone, animal feces, straw, rice husk, tail vegetables, and biochar.

5. The method for preparing organic fertilizer using garden waste according to claim 1, wherein: The carbon-nitrogen ratio of the mixed material is 20:1 to 30:

1.

6. The method for preparing organic fertilizer using garden waste according to claim 1, wherein: The water content of the mixed material is 55% to 60%, and the particle size is less than 45 mm.

7. The method for preparing organic fertilizer using garden waste according to claim 1, wherein: The bacterial agent is a thermophilic microbial agent, and the bacterial agent includes but is not limited to one or more of Brevibacillus Potssteine, Bacillus, Geobacillus, extreme thermophiles, and Saccharomyces cerevisiae.

8. The method for preparing organic fertilizer from garden waste according to claim 7, wherein: The bacterial agent includes brewer's yeast, which is a recombinant yeast strain capable of efficiently degrading cellulose substrates and hemicellulose substrates. The content of brewer's yeast in the bacterial agent is not less than 50%.

9. The method for preparing organic fertilizer using garden waste according to claim 1, wherein: The amount of the bacterial agent added is 1 kg for every 25-35 tons of mixed materials.

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