An organic material composting agent, its preparation method and application

Abstract

The application belongs to the technical fields of biomass utilization and organic fertilizer, and discloses an organic material composting agent, a preparation method and application thereof. The preparation method comprises the following steps: (1) sequentially subjecting agricultural and forestry waste raw materials to first-step hydrothermal treatment of acid oxidation and second-step hydrothermal treatment after neutralization by ammonia, and performing solid-liquid separation to obtain hydrothermal solid product and liquid product respectively; (2) subjecting the solid product to high-temperature pyrolysis treatment to obtain porous biochar material; inoculating Bacillus subtilis and Bacillus megaterium in the liquid product to perform fermentation culture to obtain fermentation liquor; and (3) mixing and adsorbing the porous biochar material and the fermentation liquor, and drying to obtain the organic material composting agent. The application prepares fermentation liquor and carrier respectively by using agricultural and forestry waste as raw materials, and obtains the organic material composting agent with the function of promoting fermentation and composting of poultry manure through adsorption and loading, so that high-value utilization of biomass is realized.

Description

Technical Field

[0001] This invention belongs to the field of biomass utilization and organic fertilizer technology, specifically relating to an organic material composting agent, its preparation method, and its application. Background Technology

[0002] Organic material composting agents refer to live microbial preparations that can accelerate the decomposition and composting of various organic materials (including crop straw, livestock and poultry manure, domestic waste, and urban sludge). Currently, the conventional preparation method for organic material composting agents involves mixing solid microbial agents with active enzymes and carriers. For example, invention patent CN 122233831 A describes a rapid decomposition and nutrient release promoter for organic materials, whose components include 15%-25% functional composite microbial community modules, 20%-35% bio-induced catalytic modules, 30%-50% nutrient synchronous controlled release and passivation modules, and 5%-20% carrier filler. This composting agent has multiple functions such as low-temperature rapid start-up, efficient decomposition, nutrient retention, and pollution control. However, the production of solid microbial agents currently generally requires the use of specially formulated culture media for separate cultivation and proliferation.

[0003] To improve the quality and shorten the composting time of biomass, existing technologies generally involve adding composting conditioners to promote the process. For example, invention patent CN 121735702 A describes a method for composting a mixture of sheep manure and corn stalks. This method improves composting efficiency by adding zeolite and attapulgite soil loaded with nutrients to different layers of the fermenting material, thereby enhancing the composting effect. Invention patent CN 122464755 A uses a composting conditioner composed of hydrothermal charcoal and iron salts to improve composting efficiency and reduce emissions of ammonia, methane, and nitrous oxide during the composting process. Invention patent CN 122749194 A uses urea hydrothermal treatment of lignin-rich agricultural and forestry waste for aerobic composting, significantly shortening the fermentation cycle and improving the quality of the bio-organic fertilizer. Although the aforementioned existing technologies involve using biochar to improve composting efficiency, they all require separate inoculation with microbial fermentation agents and do not effectively couple the energy and active substances in the biochar preparation and fermentation agent production processes. Summary of the Invention

[0004] In view of the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide a method for preparing an organic material composting agent.

[0005] Another object of the present invention is to provide an organic material composting agent prepared by the above method.

[0006] Another object of the present invention is to provide the application of the above-mentioned organic material composting agent in the fermentation and composting of poultry and livestock manure.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for preparing an organic material composting agent includes the following steps:

[0009] (1) After chopping the agricultural and forestry waste raw materials, add them to the hydrothermal reactor with water, then add acid and oxidant, heat to 120-200℃ under sealed conditions for the first step of hydrothermal treatment, then add ammonia water to adjust the pH value to 7-8, continue to keep warm for the second step of hydrothermal treatment, cool to room temperature after the hydrothermal treatment is completed, filter, and obtain hydrothermal solid products and liquid products.

[0010] (2) The obtained solid product was pyrolyzed under a nitrogen atmosphere and a temperature of 400-600℃, and then pulverized to obtain porous biochar material; Bacillus subtilis and Bacillus megaterium were inoculated into the liquid product for fermentation culture until the total number of effective viable bacteria was ≥200 million / mL to obtain fermentation broth;

[0011] (3) The porous biochar material is mixed with the fermentation liquid for adsorption treatment and then dried to obtain an organic material composting agent.

[0012] Preferably, the agricultural and forestry waste raw materials in step (1) include at least one of plant straw, corn cob, waste fruit, fruit peel, and bagasse.

[0013] Preferably, the mass ratio of the agricultural and forestry waste raw material to the water added in step (1) is 1:2-6.

[0014] Preferably, the acid in step (1) includes at least one of acetic acid, phosphoric acid, nitric acid, hydrochloric acid, and sulfuric acid, and the amount of acid added controls the pH value of the system to be 3-5.

[0015] Preferably, the oxidant in step (1) includes at least one of hydrogen peroxide and ammonium persulfate, and the amount of oxidant added is 0.5-5% of the mass of the agricultural and forestry waste raw material.

[0016] Preferably, the first hydrothermal treatment in step (1) takes 2-6 hours, and the second hydrothermal treatment takes 1-5 hours.

[0017] Preferably, the pyrolysis treatment in step (2) takes 2-5 hours, and the average particle size of the pulverized material is 40-100 mesh.

[0018] Preferably, the Bacillus subtilis mentioned in step (2) is a commercial strain from the China Industrial Microbial Culture Collection Center, strain number CICC 10089; the Bacillus megaterium is the applicant's self-produced strain Bacillus megaterium Z101, deposited at the Guangdong Provincial Microbial Culture Collection Center, accession number GDMCC NO: 60928. This has been published in patent application CN 111592997 A.

[0019] Preferably, the inoculation amount of Bacillus subtilis and Bacillus megaterium in step (2) is 1-5 vt.

[0020] Preferably, the fermentation conditions in step (2) are: temperature 35-37℃, and fermentation culture with sterile air introduced for 48-96 hours.

[0021] Preferably, the mixing and adsorption treatment in step (3) is carried out under normal temperature stirring conditions, with a stirring speed of 100-200 rpm and an adsorption treatment time of 0.5-2 hours.

[0022] Preferably, the drying in step (3) is spray drying, with the inlet air temperature controlled at 110-140℃ and the outlet air temperature controlled at 50-70℃.

[0023] Preferably, the total number of viable bacteria in the organic material composting agent in step (3) is ≥200 million / g.

[0024] An organic material composting agent prepared by the above method.

[0025] The application of the above-mentioned organic material composting agents in the fermentation and composting of poultry and livestock manure.

[0026] The principle of this invention is as follows: Using agricultural and forestry waste as the main raw material, a first-step high-temperature hydrothermal treatment is performed under acidic and oxidizing conditions. The crude fiber, crude protein, and crude fat components in the waste are oxidized and hydrolyzed into small-molecule organic components such as sugars, amino acids, and fatty acids. Then, ammonia water is added for a second-step hydrothermal treatment. This serves several purposes: firstly, the pH is adjusted to the suitable range for fermentation; secondly, the nitrogen source for fermentation is supplemented; and thirdly, the ammonia water forms salts with the oxidized and hydrolyzed small-molecule organic products, promoting dissolution and the release of bound cationic trace elements. The liquid product after these two hydrothermal treatments can be directly used as the culture medium for fermentation. Then, *Bacillus subtilis* and *Bacillus megaterium* are inoculated for fermentation. During the proliferation and metabolism process, a large number of bioactive enzymes beneficial to fermentation and decomposition, as well as extracellular polysaccharides that can act as desiccant for the cells, are produced. The hydrothermal solid product is then subjected to high-temperature pyrolysis to form a porous biochar material, which is then mixed with the fermentation broth for adsorption treatment. This allows for better loading of live bacteria, bioactive enzymes, extracellular polysaccharides, and other fermentation-active components, as well as the remaining oxidized and hydrolyzed small-molecule organic energy components. The resulting organic material composting agent can maintain high bacterial and enzyme activity, enabling more efficient fermentation and composting of poultry and livestock manure, thereby significantly improving composting quality and shortening composting time.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] (1) This invention starts with agricultural and forestry waste as raw material, uses the liquid product after stepwise hydrothermal treatment as fermentation culture medium, and produces highly active bacteria and bioactive enzymes through fermentation culture. The porous biochar after pyrolysis of the solid product is used as a carrier to maintain high activity. The resulting organic material composting agent has a significantly improved composting effect.

[0029] (2) This invention makes full use of the organic components of agricultural and forestry waste raw materials, and has the advantages of high energy utilization and green environmental protection. Attached Figure Description

[0030] Figure 1 This is a sample image of the test method of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0032] Example 1

[0033] A method for preparing an organic material composting agent includes the following steps:

[0034] (1) Agricultural and forestry waste materials (rice straw, corn cob and tangerine pulp in a mass ratio of 2:1:1) were mechanically crushed and then added to a hydrothermal reactor with water in a material-liquid mass ratio of 1:4. Acetic acid and phosphoric acid (in a mass ratio of 3:1) solution were added to adjust the pH of the system to 3.5. Then, hydrogen peroxide was added at 4% relative to the mass of agricultural and forestry waste materials. After sealing, the reactor was heated to 150°C for the first step of hydrothermal treatment for 4 hours. Then, ammonia water was added to adjust the pH to 7.5. The reactor was kept warm for the second step of hydrothermal treatment for 2 hours. After the hydrothermal treatment was completed, the reactor was cooled to room temperature and filtered to obtain hydrothermal solid products and liquid products respectively.

[0035] (2) The obtained solid product was pyrolyzed for 3 hours under a nitrogen atmosphere and at 500℃, then pulverized and passed through an 80-mesh sieve to obtain porous biochar material. 2 vt% of Bacillus subtilis CICC 10089 and 2 vt% of Bacillus megaterium Z101 were inoculated into the liquid product, and sterile air was introduced for fermentation for 60 hours, maintaining the fermentation temperature at 35-37℃. After fermentation, the total number of viable bacteria (Bacillus subtilis and Bacillus megaterium) in the fermentation broth was determined to be 720 million / mL, with a contamination rate of 4.3%.

[0036] (3) The obtained porous biochar material was mixed with the fermentation broth and subjected to adsorption treatment at room temperature with stirring for 1 hour. The stirring speed was controlled at 150 rpm during the adsorption process. Then, the mixture was added to a spray dryer with the inlet air temperature controlled at 120℃ and the outlet air temperature controlled at 60℃. After drying, an organic material composting agent was obtained. The total number of effective viable bacteria in the obtained organic material composting agent was determined to be 1.52 billion / g, and the miscellaneous bacteria rate was 4.6%.

[0037] Example 2

[0038] A method for preparing an organic material composting agent includes the following steps:

[0039] (1) Agricultural and forestry waste materials (rice straw, corn cob and tangerine pulp in a mass ratio of 2:1:1) were mechanically crushed and then added to a hydrothermal reactor with water in a material-to-liquid mass ratio of 1:3. Acetic acid and nitric acid (mass ratio of 3:1) solution were added to adjust the pH of the system to 4.0. Then, hydrogen peroxide was added at a mass ratio of 3% relative to the agricultural and forestry waste materials. After sealing, the reactor was heated to 120°C for the first step of hydrothermal treatment for 6 hours. Then, ammonia water was added to adjust the pH to 7.8. The reactor was kept warm for the second step of hydrothermal treatment for 1 hour. After the hydrothermal treatment was completed, the reactor was cooled to room temperature and filtered to obtain hydrothermal solid products and liquid products respectively.

[0040] (2) The obtained solid product was pyrolyzed for 5 hours under a nitrogen atmosphere and at 400℃, then pulverized and passed through an 80-mesh sieve to obtain porous biochar material. 1.5 vt% Bacillus subtilis CICC 10089 and 1.5 vt% Bacillus megaterium Z101 were inoculated into the liquid product, and sterile air was introduced for fermentation culture for 72 hours, maintaining the temperature at 35-37℃ during the fermentation process. After fermentation, the total number of viable bacteria in the fermentation broth was determined to be 650 million / mL, and the contamination rate was 3.9%.

[0041] (3) The obtained porous biochar material was mixed with the fermentation broth and subjected to adsorption treatment at room temperature with stirring for 1 hour. The stirring speed was controlled at 200 rpm during the adsorption process. Then, the mixture was added to a spray dryer with the inlet air temperature controlled at 130℃ and the outlet air temperature controlled at 65℃. After drying, an organic material composting agent was obtained. The total number of effective viable bacteria in the obtained organic material composting agent was determined to be 1.14 billion / g, and the miscellaneous bacteria rate was 4.5%.

[0042] Example 3

[0043] A method for preparing an organic material composting agent includes the following steps:

[0044] (1) Agricultural and forestry waste materials (rice straw, corn cob and tangerine pulp in a mass ratio of 2:1:1) were mechanically crushed and then added to a hydrothermal reactor with water in a material-liquid mass ratio of 1:5. Acetic acid and hydrochloric acid (mass ratio of 3:1) solution were added to adjust the pH of the system to 4.5. Then, ammonium persulfate at 2% relative to the mass of agricultural and forestry waste materials was added. After sealing, the reactor was heated to 180°C for the first step of hydrothermal treatment for 3 hours. Then, ammonia water was added to adjust the pH to 7.2. The reactor was kept warm for the second step of hydrothermal treatment for 3 hours. After the hydrothermal treatment was completed, the reactor was cooled to room temperature and filtered to obtain hydrothermal solid products and liquid products respectively.

[0045] (2) The obtained solid product was pyrolyzed for 2 hours under a nitrogen atmosphere and at 600℃, then pulverized and passed through an 80-mesh sieve to obtain porous biochar material. 2.5 vt% Bacillus subtilis CICC 10089 and 2.5 vt% Bacillus megaterium Z101 were inoculated into the liquid product, and sterile air was introduced for fermentation culture for 48 hours, maintaining the temperature at 35-37℃ during the fermentation process. After fermentation, the total number of viable bacteria in the fermentation broth was determined to be 500 million / mL, and the contamination rate was 4.7%.

[0046] (3) The obtained porous biochar material was mixed with the fermentation broth and subjected to adsorption treatment at room temperature with stirring for 1.5 hours. The stirring speed was controlled at 100 rpm during the adsorption process. Then, the mixture was added to a spray dryer with the inlet air temperature controlled at 140℃ and the outlet air temperature controlled at 70℃. After drying, an organic material composting agent was obtained. The total number of effective viable bacteria in the obtained organic material composting agent was determined to be 780 million / g, and the miscellaneous bacteria rate was 5.2%.

[0047] Example 4

[0048] A method for preparing an organic material composting agent includes the following steps:

[0049] (1) Agricultural and forestry waste materials (rice straw, corn cob and tangerine pulp in a mass ratio of 2:1:1) were mechanically crushed and added to a hydrothermal reactor with water in a material-liquid mass ratio of 1:6. Then, acetic acid and sulfuric acid (mass ratio of 3:1) solution were added to adjust the pH of the system to 5.0. Then, ammonium persulfate of 1.5% relative to the mass of agricultural and forestry waste materials was added. After sealing, the reactor was heated to 200°C for the first step of hydrothermal treatment for 2 hours. Then, ammonia water was added to adjust the pH to 7.5. The reactor was kept warm for the second step of hydrothermal treatment for 5 hours. After the hydrothermal treatment was completed, the reactor was cooled to room temperature and filtered to obtain hydrothermal solid products and liquid products respectively.

[0050] (2) The obtained solid product was pyrolyzed for 2.5 hours under a nitrogen atmosphere and at 550℃, then pulverized and passed through an 80-mesh sieve to obtain porous biochar material. 1 vt% of Bacillus subtilis CICC 10089 and 1 vt% of Bacillus megaterium Z101 were inoculated into the liquid product, and sterile air was introduced for fermentation culture for 96 hours, maintaining the fermentation temperature at 35-37℃. After fermentation, the total number of viable bacteria in the fermentation broth was determined to be 750 million / mL, and the contamination rate was 5.9%.

[0051] (3) The obtained porous biochar material was mixed with the fermentation broth and subjected to adsorption treatment at room temperature with stirring for 2 hours. The stirring speed was controlled at 150 rpm during the adsorption process. Then, the mixture was added to a spray dryer with the inlet air temperature controlled at 110℃ and the outlet air temperature controlled at 50℃. After drying, an organic material composting agent was obtained. The total number of effective viable bacteria in the obtained organic material composting agent was determined to be 2.06 billion / g, and the miscellaneous bacteria rate was 6.3%.

[0052] Comparative Example 1

[0053] A method for preparing an organic material composting agent, which, compared to Example 1, does not involve the addition of acid and oxidant during the hydrothermal treatment process, includes the following steps:

[0054] (1) Agricultural and forestry waste materials (rice straw, corn cob and tangerine pulp in a mass ratio of 2:1:1) were mechanically crushed and then added to a hydrothermal reactor with water in a material-liquid mass ratio of 1:4. After sealing, the reactor was heated to 150°C for the first step of hydrothermal treatment for 4 hours. Then, ammonia was added to adjust the pH value to 7.5, and the reactor was kept warm for the second step of hydrothermal treatment for 2 hours. After the hydrothermal treatment was completed, the reactor was cooled to room temperature and filtered to obtain hydrothermal solid products and liquid products respectively.

[0055] (2) The obtained solid product was pyrolyzed for 3 hours under a nitrogen atmosphere and at 500℃, then pulverized and passed through an 80-mesh sieve to obtain porous biochar material. 2 vt% of Bacillus subtilis CICC 10089 and 2 vt% of Bacillus megaterium Z101 were inoculated into the liquid product, and sterile air was introduced for fermentation for 60 hours, maintaining the fermentation temperature at 35-37℃. After fermentation, the total number of viable bacteria in the fermentation broth was determined to be 0.96 billion / mL, and the contamination rate was 11.5%.

[0056] (3) The obtained porous biochar material was mixed with the fermentation broth and subjected to adsorption treatment at room temperature with stirring for 1 hour. The stirring speed was controlled at 150 rpm during the adsorption process. Then, the mixture was added to a spray dryer with the inlet air temperature controlled at 120℃ and the outlet air temperature controlled at 60℃. After drying, an organic material composting agent was obtained. The total number of effective viable bacteria in the obtained organic material composting agent was determined to be 140 million / g, and the miscellaneous bacteria rate was 18.4%.

[0057] A comparison with the results of Example 1 shows that, under hydrothermal conditions without the addition of acid and oxidants, the total number of viable bacteria in the resulting fermentation broth and organic material composting agent was significantly reduced, while the rate of contaminating bacteria was significantly increased. This is because the liquid product contains a low content of soluble small-molecule organic components, which inhibits the proliferation of viable bacteria.

[0058] Comparative Example 2

[0059] A method for preparing an organic material composting agent includes the following steps:

[0060] (1) Agricultural and forestry waste materials (rice straw, corn cobs, and tangerine peel pulp in a mass ratio of 2:1:1) were mechanically crushed and then added to a hydrothermal reactor with water at a material-to-liquid mass ratio of 1:4. Acetic acid and phosphoric acid (mass ratio of 3:1) solutions were then added to adjust the pH of the system to 3.5. Hydrogen peroxide at 4% of the mass of the agricultural and forestry waste materials was then added. The reactor was sealed and heated to 150℃ for the first hydrothermal treatment for 4 hours. Ammonia was then added to adjust the pH to 7.5, and the reactor was kept at this temperature for the second hydrothermal treatment for 2 hours. After the hydrothermal treatment was completed, the reactor was cooled to room temperature. Then, 2 vt% Bacillus subtilis CICC10089 and 2 vt% Bacillus megaterium Z101 were inoculated into the mixture. Sterile air was introduced for fermentation culture for 60 hours, maintaining the temperature at 35-37℃. After fermentation, the total number of viable bacteria in the fermentation mixture was determined to be 660 million / mL, and the contamination rate was 4.4%.

[0061] (2) The obtained fermentation mixture was added to a spray dryer, with the inlet air temperature controlled at 120℃ and the outlet air temperature controlled at 60℃. After drying, an organic material composting agent was obtained. The total number of effective viable bacteria in the obtained organic material composting agent was determined to be 950 million / g, and the rate of miscellaneous bacteria was 6.0%.

[0062] A comparison with the results of Example 1 shows that the total number of viable bacteria in the organic material composting agent obtained without pyrolysis of the hydrothermal solid product is significantly reduced. This indicates that the porous biochar material formed by the high-temperature pyrolysis treatment of this invention can provide better adsorption and loading protection.

[0063] The organic material composting agents of Example 1 and Comparative Example 2 were used in composting and composting experiments of poultry and livestock manure (cow manure):

[0064] 1. Test material: Uncomposted raw cow manure, which contains 19.42% dry matter, 2.8% crude protein, 0.29% crude fat, 0.39% nitrogen, 0.26% phosphorus, and 0.15% potassium.

[0065] 2. Test fertilizer: Organic material composting agent of Example 1 and Comparative Example 2.

[0066] 3. Plot arrangement: This experiment included 3 treatments, using a stacked structure. The compost volumes for the 3 treatments were 1.4m × 0.8m × 0.5m (length × width × height), and each treatment was labeled.

[0067] 4. Experimental Design:

[0068] Experimental group: Uncomposted raw cow manure + organic material composting agent of Example 1 added at 0.10% of compost amount (by weight).

[0069] Control group: Uncomposted raw cow manure + organic material composting agent of Comparative Example 2 added at 0.16% (designed according to the same total number of effective live bacteria) of compost amount (by weight).

[0070] Blank group: Uncomposted raw cow manure + no added organic composting agent.

[0071] 5. Test methods:

[0072] According to the test protocol requirements of "Organic Material Composting Agent" (NY / 609-2002), the moisture content of the compost material was adjusted to approximately 60%. This test began on December 17, 2024, and ended on January 6, 2025. Temperature was measured every 5 days, and the compost pile was turned over once before sampling. Samples were taken on days 0, 5, 10, 15, and 20 of the composting test. During sampling, a cross-section was cut vertically along the top of the pile, and materials from the 20-30cm layer were taken. Five samples were taken from each pile, randomly on December 17, December 22, December 27, January 1, 2025, and January 6, 2025. One kg of sample was retained using the quartering method, sealed, and refrigerated for later use. Corresponding sampling photos are shown below. Figure 1 As shown, the following parameters were measured in the compost: temperature, dried weight (drying method), total organic carbon (phosphate bath oxidation with potassium dichromate, degradation rate and C / N ratio were calculated), and total nitrogen (Kjeldahl method, C / N ratio was calculated).

[0073] 6. Results and Analysis:

[0074] 6.1 Effects of different organic material composting agents on composting temperature changes

[0075] Temperature was measured by inserting an electronic thermometer 10 cm deep into the center of the fermentation pile and taking a reading after 15-20 minutes of equilibration. Measurements were taken daily. Table 1 shows that the fermentation temperature changes of the cow manure compost in both the experimental and control groups met the hygienic standards for harmless manure treatment, with the compost entering the high-temperature fermentation stage within 5-15 days. However, the experimental group experienced a faster temperature rise in the early stages, reaching 37.5℃ after 5 days, with a maximum temperature of 56.0℃. The pile temperature remained higher than the control for the first 15 days, but cooled down rapidly in the later stages.

[0076] Table 1. Changes in compost temperature over different time periods

[0077]

[0078] 6.2 Effects of different organic material composting agents on the degradation of organic carbon in compost materials

[0079] Table 2 shows that the organic carbon degradation rate of cow manure compost in both the experimental and control groups was significantly higher than that in the blank group. It is generally considered that compost is considered fully decomposed when the organic carbon degradation rate is above 38%. This indicates that the application of organic material composting agents promoted the decomposition of cow manure. However, the organic carbon degradation rate in the experimental group was significantly higher than that in the control group 10-20 days after application, suggesting that the promoting effect was more significant in the experimental group.

[0080] Table 2. Changes in compost organic carbon degradation rate over different time periods

[0081]

[0082] 6.3 Effect of different organic material composting agents on the C / N ratio of compost materials

[0083] As time progressed, the C / N ratios of all treatment groups showed a decreasing trend. It is generally believed that compost is considered mature when the C / N ratio drops below 16. As can be seen from Table 3, the blank group was not yet mature at 20 days, the control group was mature at 20 days, and the experimental group was mature at 15 days, which is 5 days earlier than the control group.

[0084] Table 3. Changes in C / N ratio of compost materials over different time periods.

[0085]

[0086] The above experimental results show that, under the same effective live bacteria addition, the organic material composting agent of Example 1, compared with the organic material composting agent of Comparative Example 2, achieved a higher carbon degradation rate and a lower C / N ratio (5 days earlier) for composting poultry and livestock manure (cow manure) when used for composting. This indicates that the organic material composting agent obtained by using the porous biochar material formed by the high-temperature pyrolysis treatment of this invention as an adsorption carrier can further improve the composting quality of uncomposted cow manure and shorten the composting time.

[0087] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an organic material composting agent, characterized in that... Includes the following steps: (1) After chopping the agricultural and forestry waste raw materials, add them to the hydrothermal reactor with water, then add acid and oxidant, heat to 120-200℃ under sealed conditions for the first step of hydrothermal treatment, then add ammonia water to adjust the pH value to 7-8, continue to keep warm for the second step of hydrothermal treatment, cool to room temperature after the hydrothermal treatment is completed, filter, and obtain hydrothermal solid products and liquid products. (2) The obtained solid product was pyrolyzed under a nitrogen atmosphere and a temperature of 400-600℃, and then pulverized to obtain porous biochar material; Bacillus subtilis and Bacillus megaterium were inoculated into the liquid product for fermentation culture until the total number of effective viable bacteria was ≥200 million / mL to obtain fermentation broth; (3) The porous biochar material is mixed with the fermentation liquid for adsorption treatment and then dried to obtain an organic material composting agent.

2. The method for preparing an organic material composting agent according to claim 1, characterized in that: The agricultural and forestry waste raw materials mentioned in step (1) include at least one of plant straw, corn cob, waste fruit, fruit peel, and bagasse. The mass ratio of the agricultural and forestry waste raw materials to the added water is 1:2-6.

3. The method for preparing an organic material composting agent according to claim 1, characterized in that: The acid mentioned in step (1) includes at least one of acetic acid, phosphoric acid, nitric acid, hydrochloric acid, and sulfuric acid, and the amount of acid added controls the pH value of the system to be 3-5; the oxidant includes at least one of hydrogen peroxide and ammonium persulfate, and the amount of oxidant added is 0.5-5% of the mass of agricultural and forestry waste raw materials.

4. The method for preparing an organic material composting agent according to claim 1, characterized in that: The first step of hydrothermal treatment in step (1) takes 2-6 hours, and the second step of hydrothermal treatment takes 1-5 hours.

5. The method for preparing an organic material composting agent according to claim 1, characterized in that: The pyrolysis treatment in step (2) takes 2-5 hours, and the average particle size of the pulverized material is 40-100 mesh.

6. The method for preparing an organic material composting agent according to claim 1, characterized in that: In step (2), the inoculation amount of Bacillus subtilis and Bacillus megaterium is 1-5 vt%, and the fermentation culture conditions are: temperature 35-37℃, fermentation culture with sterile air for 48-96 hours.

7. The method for preparing an organic material composting agent according to claim 1, characterized in that: The mixing and adsorption treatment in step (3) is carried out under normal temperature stirring conditions, with a stirring speed of 100-200 rpm and an adsorption treatment time of 0.5-2 hours; the drying is carried out by spray drying, with the inlet air temperature controlled at 110-140℃ and the outlet air temperature controlled at 50-70℃.

8. The method for preparing an organic material composting agent according to claim 1, characterized in that: The total number of viable bacteria in the organic material composting agent described in step (3) is ≥200 million / g.

9. An organic material composting agent prepared by the method according to any one of claims 1-8.

10. The application of the organic material composting agent according to claim 9 in the fermentation and composting of poultry and livestock manure.

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