Self-elevating ultra-high-temperature composting method for agricultural and pastoral organic wastes

Abstract

The invention relates to an organic waste composting method, in particular to a self-elevating ultra-high-temperature composting method for agricultural and pastoral organic waste. The method comprises the following steps: 1, stirring and mixing the cow dung, the chicken manure, the straw and the fungicide; and 2, performing primary fermentation and secondary fermentation on the mixture in the step 1, and thoroughly decomposing for 35-45 days. According to the invention, cow dung, chicken manure and straw are matched with Geobacillus sp. For combined fermentation. Tests prove that the self-elevating ultrahigh-temperature composting fermentation technology can obviously improve the composting efficiency and greatly shorten the composting period. Meanwhile, a high-nutrient organic fertilizer is formed.

Description

Technical Field

[0001] The invention relates to an organic waste composting method. Background Art

[0002] With the rapid development of agriculture and animal husbandry in recent years, the output of livestock and poultry manure and crop straw has increased dramatically. It is reported that the global livestock industry produces about 3.8 billion tons of manure, such as cow dung and chicken manure, each year, while the annual output of crop straw reaches 900 million tons, which is a huge number. Although these solid wastes contain a large amount of biomass, only 3% of them can be effectively utilized. If the rest is not handled properly, it will not only lead to resource waste, but also pose a serious threat to the ecosystem. Therefore, it is necessary to efficiently utilize livestock and poultry solid organic waste to solve environmental pollution problems, accelerate resource recovery, and ultimately promote the healthy development of the ecosystem.

[0003] Composting technology is currently an environmentally friendly and effective method for treating solid organic waste from agriculture and animal husbandry. Composting can not only remove toxic and harmful substances, odors and pathogenic microorganisms in the waste, but the fertilizer formed can also improve and enhance the soil structure, maintain soil balance, and thus promote the recycling of resources. There are certain problems with traditional composting and conventional microbial composting. Although waste (such as plant residues, feces, etc.) can be converted into stable, humus-rich organic matter through the decomposition of microorganisms under specific conditions. However, the fermentation cycle is long, the biomass conversion efficiency is low, the fertilizer quality is poor, and there is certain environmental pollution. This makes the development of new composting and fermentation technology for agricultural and animal husbandry organic waste imminent.

[0004] Ultra-high temperature composting is a technical method that uses hyperthermophilic composting to degrade organic solid waste. Studies have shown that the ultra-high temperature composting process is similar to the traditional composting process, but the temperature control is very different. The process can reach an ultra-high temperature environment (>80°C), thereby efficiently degrading organic solid waste, with a fast processing speed and good results. This technology can not only shorten the composting cycle and improve composting efficiency. It also has good performance in reducing greenhouse gas emissions, repairing heavy metal-contaminated soil, and removing antibiotic residues. However, it is currently difficult for ultra-high temperature composting to reach and maintain an ultra-high temperature state (usually exceeding 80°C). It usually requires human intervention to heat or provide heat preservation and energy-consuming equipment (such as in fixed large equipment or factories), and the high temperature time is relatively short. This study used hyperthermophilic agents and combined them with waste such as cow dung and chicken manure to achieve its self-rising ultra-high temperature composting technology, which not only shortened the composting cycle but also improved the efficiency of composting. Summary of the invention

[0005] The invention provides a self-elevating ultra-high temperature composting method for agricultural and animal husbandry organic waste.

[0006] The method for self-raising ultra-high temperature composting of agricultural and animal husbandry organic waste of the present invention is carried out according to the following steps:

[0007] 1. Mix 7-8 parts of cow dung, 1-2 parts of chicken dung, 1-2 parts of straw and 1-2% of bacterial agent according to the weight ratio, wherein the bacterial agent is a hyperthermophilic bacteria (Geobacillus sp.) bacterial agent;

[0008] 2. The mixture of step 1 is composted for 12 to 16 days, aerated and turned to complete the first fermentation; it is composted for another 28 to 32 days, aerated and turned to complete the second fermentation, and then matured for 35 to 45 days to complete the self-rising ultra-high temperature composting of agricultural and animal husbandry organic waste.

[0009] Furthermore, the strain used for self-raising ultra-high temperature composting of agricultural and animal husbandry organic waste is a hyperthermophilic bacterium (Geobacillus sp.), which is preserved in the Guangdong Provincial Microbiological Culture Collection Center with the preservation number GDMCC 65469 and the preservation date of November 12, 2024.

[0010] The present invention uses cow dung, chicken dung, straw and hyperthermophilic bacteria (Geobacillus sp.) inoculant for joint fermentation. The present invention finds an optimal ratio or formula, uses cow dung, chicken dung and straw, explores a condition and mode, and uses our own screened hyperthermophilic bacteria (Geobacillus sp.) inoculant to achieve ultra-high temperature fermentation, with a core temperature exceeding 80°C, which is unattainable by many high-temperature composts. The present invention does not require cumbersome external equipment or factory buildings, can be carried out under open air conditions, and has a fast heating speed and a long high-temperature period, which greatly shortens the entire composting cycle, and the resulting compost product has a high nutrient content.

[0011] The present invention verifies through experiments that the self-elevating ultra-high temperature composting fermentation technology can significantly improve composting efficiency, greatly shorten the composting cycle, and simultaneously form high-nutrient organic fertilizer.

[0012] The hyperthermophilic bacteria (Geobacillus sp.) described in the present invention are deposited in Guangdong Microbiological Culture Collection Center with the deposit number GDMCC 65469. The deposit address is: 5th Floor, Building 59, Institute of Microbiology, Guangdong Academy of Sciences, No. 100, Xianlie Middle Road, Guangzhou, and the deposit date is November 12, 2024. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a flow chart of composting fermentation in Example 1;

[0014] Figure 2 This is a schematic diagram of composting fermentation in Example 1;

[0015] Figure 3is the temperature change during the composting (maturity) process in Example 1;

[0016] Figure 4 The moisture content changes during the composting (maturity) process in Example 1;

[0017] Figure 5 is the change of total nitrogen content during the composting (maturity) process in Example 1;

[0018] Figure 6 is the change of total phosphorus content during the composting (maturity) process in Example 1;

[0019] Figure 7 is the change of total potassium content during the composting (maturity) process in Example 1;

[0020] Figure 8 is the change of organic matter content during the composting (maturity) process in Example 1;

[0021] Fig. 9 is the change of humic acid (HS) content during the composting (maturity) process in Example 1;

[0022] Fig.10 Colony morphology of hyperthermophilic bacteria (Geobacillus sp.). DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0025] Specific implementation method 1: The method for self-raising ultra-high temperature composting of agricultural and animal husbandry organic waste in this implementation method is carried out according to the following steps:

[0026] 1. Mix 7-8 parts of cow dung, 1-2 parts of chicken dung, 1-2 parts of straw and 1-2% of bacterial agent according to the weight ratio, wherein the bacterial agent is a hyperthermophilic bacteria (Geobacillus sp.) bacterial agent;

[0027] 2. The mixture of step 1 is composted for 12 to 16 days, aerated and turned to complete the first fermentation; it is composted for another 28 to 32 days, aerated and turned to complete the second fermentation, and then matured for 35 to 45 days to complete the self-rising ultra-high temperature composting of agricultural and animal husbandry organic waste.

[0028] The preparation method of the Geobacillus sp. inoculant in step 1 of the present embodiment is as follows: selecting high-quality, pollution-free rice bran to ensure that it is free of mildew or impurities; crushing the rice bran to a suitable particle size, generally about 0.5-1 mm, so as to increase the adsorption surface area; sterilizing the crushed rice bran; 121°C, 30 minutes; cooling to room temperature; diluting or concentrating the bacterial solution of the Geobacillus sp. to 1.8-2.0 OD to ensure that its bacterial concentration is suitable for adsorption; in a sterile environment, mixing the rice bran and the bacterial solution in a ratio of 1:2 (weight ratio) to ensure uniform adsorption, spreading the rice bran adsorbed with the bacterial solution in an incubator for dry culture, and the temperature is set according to the bacterial culture temperature; generally 4-8 hours are required until the water content of the rice bran is ≤10; the dried rice bran inoculant needs to be quickly sealed and packaged to prevent moisture absorption or contamination; the effective number of live bacteria in the inoculant is >20 billion / g (mL).

[0029] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that: in step 2, the first fermentation and the second fermentation are aerated regularly, with an interval ranging from 2 to 24 hours. Other steps and parameters are the same as those in specific implementation method 1.

[0030] In this embodiment, the timed aeration is adjusted according to temperature changes and the composting period.

[0031] Specific implementation method three: The strain used for self-raising ultra-high temperature composting of agricultural and animal husbandry organic waste in this implementation method is hyperthermophilic bacteria (Geobacillus sp.), which is preserved in Guangdong Provincial Microbiological Culture Collection Center with the preservation number GDMCC 65469 and the preservation date is November 12, 2024.

[0032] The screening method of the hyperthermophilic bacteria (Geobacillus sp.) described in this embodiment:

[0033] In 2021, soil was collected from the forest area near hot springs in Antu County, Yanbian Korean Autonomous Prefecture, Jilin Province. Weigh 10g of soil sample, add it to a 250mL conical flask containing 100mL of sterile NaCl solution, let it stand at room temperature for 1h, and shake it at 180rpm at 60℃ for 30min. Absorb 100μL of the supernatant, add it to 5mL of fresh LB medium, enrich it under dark conditions at 60℃ and 180 rpm, and culture it on a 60℃ plate after 24h. After 24h, select a single colony and culture it in 5mL of fresh LB medium. The whole process includes 10 subcultures; the purified single bacterial colony liquid is subjected to molecular biological identification and sent to Kumei Technology Co., Ltd. for 16SrRNA sequencing. The sequencing results are submitted to the NCBI GenBank database for BLAST verification. The 6S rRNA sequencing results are shown in SEQID NO.1. Finally, the hyperthermophile (Geobacillus sp.) was determined. The colony morphology of the hyperthermophile (Geobacillus sp.) is shown in the figure Fig.10 shown.

[0034] Example 1 The method of the present invention is used to carry out ultra-high temperature composting fermentation. The composting fermentation flow chart is as follows: Figure 1 The schematic diagram of composting fermentation is shown in Figure 2 As shown in the figure, the composting was completed in a 60-ton "straw + cow dung + chicken dung" composting test carried out in the cooperative enterprise, Nong'an County Wanshun Agricultural and Animal Husbandry Demonstration Professional Cooperative.

[0035] Specific method: 1. Mix 8 parts of cow dung, 2 parts of chicken manure, 2 parts of straw and 2% of microbial agent according to the weight ratio. The microbial agent is a hyperthermophilic bacteria (Geobacillus sp.) microbial agent. The preparation method of the microbial agent is as follows: select high-quality, pollution-free rice bran to ensure that it is free of mold or impurities; crush the rice bran to a suitable particle size, generally about 0.5-1 mm, so as to increase the adsorption surface area; sterilize the crushed rice bran; 121°C, 30 minutes. Cool to room temperature; dilute or concentrate the bacterial solution to be prepared to 1.8-2.0OD to ensure that its bacterial concentration is suitable for adsorption; in a sterile environment, mix the rice bran and the bacterial solution in a ratio of 1:2 (weight ratio) to ensure uniform adsorption, spread the rice bran adsorbed with the bacterial solution in an incubator for dry culture, and the temperature is set according to the bacterial culture temperature; generally 4-8 hours are required until the water content of the rice bran is ≤10; the dried rice bran bacterial agent needs to be quickly sealed and packaged to prevent moisture absorption or contamination; the number of effective live bacteria in the bacterial agent is>20 billion / g (mL).

[0036] 2. The mixture in step 1 is composted for 14 days, oxygenated and turned to complete the first fermentation (sampling); it is composted for another 28 days, oxygenated and turned to complete the second fermentation (sampling), and then matured for 40 days (sampling), thus completing the self-raising ultra-high temperature composting of agricultural and animal husbandry organic waste. In step 2, the first and second fermentations are aerated regularly, and the aeration is adjusted according to the temperature changes and the composting period, with an interval range of 2 to 24 hours.

[0037] Combination Figure 1 and 2 , showing the specific implementation process of composting. The initial moisture content and C / N ratio of the compost in this implementation are shown in Table 1. The sampling device (sampler) is used regularly to take core samples, and the samples are taken 14 days after the first fermentation, 28 days after the second fermentation, and 40 days after maturity. After 14 and 28 days of composting, the pile is turned and oxygenated, and the compost temperature is monitored every day with an automatic thermometer placed in the center of the pile. The core temperature of the compost in this embodiment is >80°C, the highest temperature reaches 106°C, and the full composting (maturity) cycle is shortened to 40 days. The mature compost samples of this embodiment are dried and ground for the determination of the physical and chemical properties of the compost and the determination of humic acid (stored at 4°C).

[0038] Table 1. Experimental plan for ultra-high temperature composting fermentation

[0039]

[0040]

[0041] 1. Determination of temperature and moisture content during composting (maturity)

[0042] Method: Use CS-T10R-PT temperature recorder to measure temperature. Divide the pile into three equal parts, and regularly (0, 3, 7, 14, 21, 28, 40 days) use samplers to insert into the upper, middle and lower parts of the pile to take samples. The moisture content is determined according to GB / 8576.

[0043] result: Figure 3 It is the temperature change during the composting (maturity) process; Figure 4 is the change of moisture content during composting (maturity); Figure 3 and Figure 4 It can be seen that the compost body is in a high temperature period (>80℃) for 15 days, the highest temperature in the process reaches 106℃, the whole composting period is shortened to 40 days, the water content gradually decreases, and the final water content at the end of fermentation is 19.1%. The composting efficiency of the method of the present invention is significantly improved and the composting period is significantly shortened.

[0044] 2. Determination of changes in total nitrogen, total phosphorus and total potassium content during composting (maturity)

[0045] Methods: TN was determined by Kjeldahl method, TP was determined by ammonium vanadate molybdate colorimetry, and TK was determined by flame spectrophotometry.

[0046] result: Figure 5 It is the change of total nitrogen content during composting (maturity); Figure 6 It is the change of total phosphorus content during composting (maturity); Figure 7 The change of total potassium content during composting (maturity); combined Figure 5 , 6 From Figure 7, we can see that during the composting process, the TN content has the largest variation. Microorganisms use nitrogen as a nutrient source, and part of the N will be absorbed by the microorganisms and used for their growth and reproduction, resulting in a decrease in the N content. In addition, as the temperature rises, microbial activity intensifies, and the decomposition of organic matter accelerates, causing part of the N to be converted into ammonia, thereby reducing the N content. At the end of the final reaction, the N content still meets the standard of returning to the soil as a fertilizer.

[0047] At the same time, phosphorus and potassium will also change their forms under the action of microorganisms. The TP and TK contents gradually increase in the high temperature stage as the degradation of organic matter by microorganisms intensifies, and tend to stabilize in the compost cooling stage. Due to the decomposition of organic matter in this process, the total amount decreases, which increases the relative content of TP and TK. In the early stage of composting, the growth and reproduction of microorganisms usually also require the participation of P and K, which causes a decrease in TP and TK in the early stage of composting. At the end of composting, the TP and TK contents are high, which can provide sufficient nutrients for the soil.

[0048] 3. Changes in organic matter content during composting (maturity)

[0049] Method: National Standard NY / T525-2021

[0050] result: Figure 8 is the change of organic matter content during composting (maturity); Figure 8 It can be seen that as the temperature rises during the composting process, the activity of ultra-high temperature thermophiles increases, which can accelerate the decomposition of organic matter, resulting in a rapid decrease in the organic matter content in the pile. The organic matter is consumed fastest during the high temperature period. As the temperature drops, the activity of ultra-high temperature thermophiles decreases, the decomposition rate slows, and the remaining organic matter tends to stabilize after a long period of degradation and transformation. At the end of composting, the remaining organic matter content is 62%, which meets the requirements of the national standard NY / T525-2021 for organic matter content (≥30%).

[0051] 4. Changes in humic acid (HS) content during composting (maturity)

[0052] Methods: Humic acid (HS) was extracted by alkaline extraction-acid precipitation method.

[0053] The specific steps are as follows: weigh 2.5g of the air-dried and ground sample, add it to a conical flask, add 0.1M NaOH solution, and extract it with a solid-liquid ratio of 1:10 (1 gram of sample uses 10 ml of solution). The extracted solution is filtered through filter paper to remove solid impurities, retain the filtrate, and adjust the pH of the filtrate to 1-2 with hydrochloric acid (HCl). At this time, humic acid (HA) will form a precipitate. The precipitate is filtered, dried and weighed to obtain the content of humic acid. Fulvic acid can be determined by further treatment (such as spectrophotometry). The total amount of humic acid (HA) and fulvic acid (FA) constitutes humic acid (HS).

[0054] result: Fig. 9 is the change of humic acid (HS) content during composting (maturity), from Fig. 9 It can be seen that the maturity of compost is closely related to the change of HS. The HS content decreased significantly in the first 15 days. During this period, the high temperature stage caused the decomposition of unstable organic compounds in HS. At the end of composting, the HS content increased sharply to 75.2g / kg, which is consistent with the research that the formation of HS mainly occurs in the cooling and maturity stages of compost.

Claims

1. A method for self-raising ultra-high temperature composting of agricultural and animal husbandry organic waste, characterized in that The self-elevation ultra-high temperature composting method of agricultural and animal husbandry organic waste is carried out according to the following steps:

1. Mix 7-8 parts of cow dung, 1-2 parts of chicken dung, 1-2 parts of straw and 1-2% of bacterial agent according to the weight ratio, wherein the bacterial agent is a hyperthermophilic bacteria (Geobacillus sp.) bacterial agent; 2. The mixture of step 1 is composted for 12 to 16 days, aerated and turned to complete the first fermentation; it is composted for another 28 to 32 days, aerated and turned to complete the second fermentation, and then matured for 35 to 45 days to complete the self-rising ultra-high temperature composting of agricultural and animal husbandry organic waste.

2. The method for self-raising ultra-high temperature composting of agricultural and animal husbandry organic waste according to claim 1, characterized in that In step 2, the first fermentation and the second fermentation are aerated regularly, with the interval ranging from 2 to 24 hours.

3. A strain for self-raising ultra-high temperature composting of agricultural and animal husbandry organic waste, characterized in that The strain is a hyperthermophilic bacterium (Geobacillus sp.), which is deposited in Guangdong Provincial Microbiological Culture Collection Center with the deposit number GDMCC 65469 and the deposit date is November 12, 2024.

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