Multi-group and multi-stage anaerobic fermentation treatment method for organic solid waste

Abstract

The invention discloses a multi-group and multi-stage anaerobic fermentation treatment method for organic solid waste, and relates to the technical field of waste treatment, the method comprises the following specific steps: waste pretreatment; the organic solid wastes are classified, crushed, screened and subjected to moisture regulation, so that the organic solid wastes reach a state suitable for anaerobic fermentation; screening and cultivating strains; screening and cultivating efficient microbial strains suitable for organic solid waste treatment; performing multi-group and multi-stage anaerobic fermentation; dynamically monitoring, regulating and controlling microbial communities; and post-processing. By introducing an advanced microbiological detection technology, dynamic monitoring and regulation of the microflora in each stage of fermentation unit are realized, the structure and change trend of the microflora in the fermentation process are accurately reflected, and a scientific basis is provided for timely adjustment of fermentation parameters; conditions such as nutrient substance addition, temperature and pH value are adjusted according to monitoring results, so that the stability and activity of microbial communities are maintained, and the fermentation process is always in an optimal state.

Description

Technical Field

[0001] The invention relates to the technical field of waste treatment, in particular to a multi-group and multi-stage anaerobic fermentation treatment method for organic solid waste. Background Art

[0002] Organic solid waste mainly includes agricultural waste (such as straw and livestock and poultry manure), kitchen waste in urban domestic waste, garden waste, and organic residues generated by food processing and light industry. If these wastes are not properly handled, they will not only occupy a large amount of land resources, but may also cause harm to the environment and human health through leachate, malodorous gases and pathogens.

[0003] Traditional methods for treating organic solid waste mainly include landfill, incineration and composting. However, these methods have obvious limitations in practical applications. Although landfill treatment is simple and easy, it will occupy a large amount of precious land resources and easily lead to soil, groundwater and air pollution. Although incineration treatment can significantly reduce the volume and weight of waste, it will produce harmful gases such as dioxins, causing secondary pollution to the atmospheric environment. Although composting treatment can realize the resource utilization of waste, traditional composting methods have problems such as long cycle, low efficiency, large footprint, and susceptibility to climatic conditions, which limit their large-scale application. These traditional methods are difficult to meet the current demand for efficient and environmentally friendly organic solid waste treatment technologies.

[0004] In order to improve the treatment efficiency and product quality of organic solid waste, researchers have begun to explore new fermentation methods and technologies. Among them, multi-group and multi-stage fermentation technology has become a hot topic of current research because it can flexibly adjust the combination of microbial strains and fermentation conditions according to the needs of different fermentation stages. However, to achieve the effective application of multi-group and multi-stage fermentation technology, a series of key technical issues such as strain screening and cultivation, fermentation process control, and post-processing step optimization need to be solved. In addition, during the fermentation process, the dynamic changes of the microbial community have an important influence on the fermentation efficiency and product quality. Traditional monitoring methods are often difficult to reflect the structure and change trend of the microbial community in real time and accurately, resulting in difficulty in accurately controlling the fermentation process. Therefore, the development of advanced microbial detection technology and the realization of dynamic monitoring and regulation of microbial communities are of great significance to improving fermentation efficiency and product quality. Summary of the invention

[0005] The purpose of the present invention is to make up for the shortcomings of the prior art and provide a multi-group and multi-stage anaerobic fermentation treatment method for organic solid waste. It can screen and cultivate high-efficiency microbial strains suitable for organic solid waste treatment, and carry out multi-group and multi-stage fermentation to improve fermentation efficiency and shorten fermentation cycle. At the same time, microbial detection technology is introduced to monitor the microbial community structure and change trend in each level of fermentation unit in real time, and adjust the fermentation parameters in time according to the monitoring results to maintain the stability and activity of the microbial community. This dynamic regulation ensures that the fermentation process is always in the best state, further improves the waste treatment effect and gas production quality. In addition, the present invention also post-processes the fermented organic solid waste to make it an organic fertilizer or soil conditioner that can be sold and used, thereby realizing the recycling of resources.

[0006] In order to solve the above technical problems, the present invention provides a technical solution of a multi-group multi-stage anaerobic fermentation treatment method for organic solid waste, which comprises the following specific steps: Waste pretreatment: Classify, crush and screen the organic solid waste, mix the crushed organic solid waste through stirring equipment, and adjust the material humidity to make it suitable for fermentation. At the same time, regularly take samples to test the mixing uniformity to ensure the uniformity of the material components; Screening and cultivation of bacterial strains: Screening and cultivation of efficient microbial strains suitable for organic solid waste treatment. For the first-level anaerobic fermentation, the strains are selected to be able to quickly decompose organic matter and release a large amount of heat. For the second-level anaerobic fermentation, the strains are selected to be able to produce organic acid substances and inhibit the growth of harmful microorganisms. For the third-level anaerobic fermentation, the strains are selected to be able to promote the decomposition and stabilization of organic solid waste and make the fermented materials reach a decomposition and stabilization state. Multi-group multi-stage anaerobic fermentation: the pretreated organic solid waste is sent to the first-stage anaerobic fermentation tank, and high-efficiency microbial strains are added. The oxygen supply of the fermented materials is ensured by ventilation equipment, and the ventilation volume is controlled to enable rapid fermentation. When the first-stage anaerobic fermentation reaches the reaction time requirement, the fermented materials are transferred to the second-stage anaerobic fermentation tank, and different high-efficiency microbial strains are added. The ventilation and stirring operations are continued for fermentation. After the second-stage anaerobic fermentation, the fermented materials are transferred to the third-stage anaerobic fermentation tank, the fermented materials are tested, and the fermentation parameters are adjusted according to the test results and fermentation is carried out; Dynamic monitoring and regulation of microbial communities: Use microbial detection technology to regularly collect fermentation material samples and analyze the structure and stability of the microbial communities in the samples, including the total number of bacterial species, the number of stable bacterial species, and the diversity index of the microbial community. The stability of the microbial community can be calculated by the formula Assessment, where Indicates the stability of the microbial community. Indicates stable bacterial count, Indicates the total number of bacteria. represents the diversity index of microbial communities, To adjust the coefficient, according to the monitoring results, timely adjust the fermentation parameters. For unreasonable microbial community structure or decreased activity, add nutrients, adjust the temperature and pH value to adapt to the growth needs of microorganisms, and adjust the ventilation and stirring parameters to ensure the oxygen supply and uniformity of the fermentation materials; Post-treatment: Post-treatment of organic solid waste after anaerobic fermentation, collection, purification and storage of biogas produced by anaerobic fermentation to make it a usable energy source.

[0007] Furthermore, in the waste pretreatment step, the crushing requirements for organic solid waste are: organic solid waste in urban domestic waste is crushed to a particle size of 5-10 cm, organic solid waste in agricultural waste is crushed to a particle size of 3-5 cm, and the water content of organic solid waste is controlled at 45%-60%.

[0008] Furthermore, in the waste pretreatment step, samples are taken regularly to detect the mixing uniformity to ensure that the composition of each part of the material is uniform. The uniformity calculation formula is: ,in Indicates the mixing uniformity, Indicates the number of sampling points, Indicates The content of a certain key component at each sampling point, It represents the average value of the key component content of all sampling points.

[0009] Furthermore, in the multiple groups of multi-stage anaerobic fermentation steps, the pretreated organic solid waste is sent to a primary anaerobic fermentation tank, Bacillus species are added, the ventilation volume is controlled and the oxygen supply of the fermentation material is guaranteed to enable rapid fermentation, the reaction temperature is 50-60°C, the reaction time is 2-3 days, and after the reaction is completed, the fermentation material is transferred to a secondary anaerobic fermentation tank.

[0010] Furthermore, in the multiple groups of multi-stage anaerobic fermentation steps, the fermentation material is transferred to a secondary anaerobic fermentation tank, lactic acid bacteria are added, ventilation and stirring operations are performed, the fermentation temperature is controlled at 40-50°C, the reaction time is 4-5 days, and after the reaction is completed, the fermentation material is transferred to a tertiary anaerobic fermentation tank.

[0011] Furthermore, in the multiple groups of multi-stage anaerobic fermentation steps, after the secondary anaerobic fermentation, the fermented material is transferred to a tertiary anaerobic fermentation tank, actinomycetes are added, the fermentation temperature is controlled at 30-40°C, and the reaction time is 2-3 days.

[0012] Furthermore, in the step of dynamically monitoring and regulating the microbial community, the fermentation parameters are adjusted according to the monitoring results to maintain the stability and activity of the microbial community. If it is found that the activity of the microbial community is affected by temperature, the fermentation temperature is adjusted by a heating or cooling device. If it is detected that the pH value of the fermentation material is not conducive to microbial growth, it is adjusted by adding an acid-base regulator. At the same time, the ventilation volume is adjusted according to the microbial community's demand for oxygen, and the type and amount of nutrients to be added are determined according to the monitoring results.

[0013] Furthermore, in the step of dynamically monitoring and regulating the microbial community, the ventilation volume is adjusted according to the demand of the microbial community for oxygen, and the ventilation volume control formula is: ,in Indicates the ventilation volume, represents the volume of fermentation material, Indicates the fermentation temperature, Indicates the material humidity. represents the intensity parameter of microbial activity, To adjust the coefficient control.

[0014] Furthermore, in the step of dynamic monitoring and regulation of microbial communities, the type and amount of nutrients to be added are determined according to the monitoring results, and the nutrient addition formula is: ,in Indicates the amount of nutrients added. Indicates the total number of bacteria. Indicates stable bacterial count, Indicates the fermentation temperature, Indicates the stability of the microbial community. , , is the adjustment factor.

[0015] Furthermore, in the post-processing step, the fermented organic solid waste is post-processed, and the biogas produced by the fermentation is collected, purified and stored, and the methane content in the biogas does not exceed 40%.

[0016] Compared with the prior art, this method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation has the following beneficial effects: 1. The present invention realizes dynamic monitoring and regulation of microbial communities in fermentation units at all levels by introducing advanced microbial detection technology, accurately reflects the structure and change trend of microbial communities during the fermentation process, provides a scientific basis for timely adjustment of fermentation parameters, and adjusts conditions such as nutrient addition, temperature and pH value according to the monitoring results, thereby maintaining the stability and activity of the microbial community and ensuring that the fermentation process is always in the best state.

[0017] 2. The present invention optimizes the anaerobic fermentation process by screening and cultivating efficient microbial strains suitable for the treatment of organic solid waste and cleverly designing multiple groups of multi-stage anaerobic fermentation methods. Different strains of bacteria are used in anaerobic fermentation tanks at each level, and fermentation is carried out at their respective suitable temperatures and conditions, so that organic solid waste can be decomposed quickly and efficiently, which not only significantly improves the fermentation efficiency, but also greatly shortens the fermentation cycle, thereby accelerating the treatment speed of organic solid waste and meeting the needs of modern society for efficient treatment technology.

[0018] Other advantages, objectives and features of the present invention will be set forth in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a flow chart of a multi-group and multi-stage anaerobic fermentation treatment method for organic solid waste; Figure 2 A flowchart of a multi-group and multi-stage anaerobic fermentation method for treating organic solid waste; Figure 3 The present invention is a flow chart of dynamic monitoring and regulation of microbial communities in a multi-group and multi-stage anaerobic fermentation treatment method for organic solid waste. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0022] Embodiment 1 This embodiment describes in detail the process of a multi-group and multi-stage anaerobic fermentation treatment method for organic solid waste under standard conditions.

[0023] Firstly, a combination of manual and mechanical sorting is used to treat urban domestic waste. Through preliminary manual selection, obvious non-fermentable substances such as metals, glass, and plastics are separated. Mechanical sorting equipment, such as magnetic separators, is used to remove metals, and air separators are used to separate lightweight plastics. This ensures that the waste entering the fermentation system is mainly biodegradable organic solid waste. Specific separation processes and standards are formulated for different types of non-fermentable substances. For example, metals are classified and recycled according to their magnetism and conductivity. Glass and plastics are separated according to their material and shape. Professional crushers are used to crush organic solid waste into particles of about 6 cm in size. This particle size is conducive to full contact between microorganisms and waste, and can ensure ventilation and stirring in the subsequent fermentation process. During the crushing process, the crushing equipment is monitored in real time. According to the operating status, adjust the crushing force and speed to avoid excessive crushing that causes the material to be too finely broken, affecting the air permeability during the fermentation process, or insufficient crushing that makes the material particle size uneven, affecting the fermentation effect. In addition, the crushed organic solid waste is mixed through a stirring equipment. During the mixing process, add an appropriate amount of water to make the material humidity reach about 50%. This humidity can provide a suitable environment for the growth of microorganisms. It will not inhibit the activity of microorganisms due to being too dry, nor will it cause poor ventilation due to being too humid. The crushed organic solid waste is mixed through a stirring equipment. During the mixing process, add an appropriate amount of water to make the material humidity reach about 50%. This humidity can provide a suitable environment for the growth of microorganisms. It will not inhibit the activity of microorganisms due to being too dry, nor will it cause poor ventilation due to being too humid. Use the mixing uniformity evaluation formula The mixed materials are tested to ensure that the mixing uniformity reaches more than 90%. Through multiple sampling and analysis, the distribution uniformity of key components in the materials (such as organic matter content, etc.) at different locations is determined to ensure that the fermentation conditions of each part of the material are consistent during the fermentation process.

[0024] Secondly, from the strains preserved in nature, strain banks or laboratories, efficient microbial strains that can quickly decompose organic matter, release heat and produce beneficial substances such as organic acids are screened out. These strains should have good adaptability and stability, and be able to survive and function in complex waste environments. According to multiple groups of multi-stage anaerobic fermentation conditions, the first-level anaerobic fermentation strains are used to quickly decompose organic matter, release a large amount of heat, and promote the increase of fermentation temperature. Bacillus strains are selected, the second-level anaerobic fermentation strains are used to produce organic acid substances and inhibit the growth of harmful microorganisms. Lactobacillus strains are selected, and the third-level anaerobic fermentation strains are used to promote composting and stabilization, so that the fermented materials reach a state of composting and stabilization. Actinomycetes strains are selected, and the screened strains are cultivated and optimized under laboratory conditions. By providing suitable nutrients, temperature, humidity, pH value and other conditions, the growth and reproduction of the strains are promoted, and their activity and decomposition ability are improved. At the same time, the strains are purified and identified to ensure their stability and safety in the subsequent fermentation process.

[0025] Then, the pretreated organic solid waste is sent to the primary fermentation stage, and the bacillus species is added to promote the increase of fermentation temperature. The amount of bacillus added is adjusted according to the amount and nature of the waste to ensure that it can quickly start the fermentation process, and the oxygen supply of the fermentation material is guaranteed by ventilation equipment. The ventilation volume is calculated according to the formula Calculate, where Indicates the volume of fermented material, which is determined by measuring the size of the fermentation device and the filling degree of the material. Indicates the fermentation temperature, which is monitored and controlled at 55°C in real time. Indicates material humidity, maintained at 50%, It represents the intensity parameter of microbial activity, which can be evaluated by measuring indicators such as oxygen consumption rate. , , , It is determined through the fermentation experiment of urban domestic waste, and the fermented materials are regularly stirred by stirring equipment. The stirring frequency is based on the formula: ,in, Indicates the density of the material, which can be calculated by measuring the mass and volume of the material. It represents the fermentation rate parameter, which can be evaluated by measuring the degradation rate of organic matter and other indicators. , , , Through experiments, it was determined that the purpose of stirring is to heat the materials evenly, improve fermentation efficiency, and avoid local overheating or overcooling. The first-level fermentation time is 2.5 days. During this process, the fermentation temperature, humidity, oxygen content and other parameters are closely monitored, and the ventilation and stirring parameters are adjusted in time to ensure the smooth progress of the fermentation process. After the fermentation is completed, the materials after the first-level fermentation are transferred to the second-level fermentation stage, lactic acid bacteria are added, the pH value of the fermentation materials is lowered, and the growth of harmful microorganisms is inhibited. The amount of lactic acid bacteria added is adjusted according to the properties of the materials after the first-level fermentation and the structure of the microbial community, and ventilation and stirring operations are continued. According to the changes in the fermentation materials, the ventilation and stirring parameters are adjusted in real time to keep the fermentation materials in good condition. The fermentation temperature is controlled at 45°C, and the temperature is monitored in real time by temperature sensors and other equipment, and the temperature is adjusted by heating or cooling devices. The second-level fermentation time is 3 .5 days, during which the fermentation materials are regularly tested, such as pH value, organic matter content, etc., to ensure that the fermentation process develops in the expected direction. After the fermentation is completed, the materials after the secondary fermentation are sent to the tertiary fermentation stage, and strain C is added to make the fermented materials reach a state of maturity and stabilization. The amount of actinomycetes added is adjusted according to the maturity of the materials after the secondary fermentation, and the fermentation materials are tested and adjusted. The test items include temperature, pH value, organic matter content, maturity and other indicators. According to the test results, the temperature, humidity, ventilation and other parameters are adjusted to ensure that the fermentation materials meet the relevant standards. The fermentation temperature is controlled at 35°C, and a stable temperature environment is maintained by temperature control equipment to promote the maturity and stabilization of the fermentation materials. The tertiary fermentation time is 2.5 days. During this process, it is ensured that the fermentation materials reach the best state of maturity and stabilization to prepare for subsequent post-processing.

[0026] Next, high-throughput sequencing and real-time fluorescence quantitative PCR technology are used to dynamically monitor the microbial communities in the fermentation units at all levels. Fermentation material samples are collected regularly, such as once a day or every two days, and the collected samples are subjected to microbial detection and analysis. High-throughput sequencing can fully reveal the diversity of microbial communities and determine the types and relative abundance of various bacteria and fungi. Real-time fluorescence quantitative PCR can quantitatively analyze specific key strains to understand their dynamic changes during the fermentation process. According to the monitoring results, a microbial community structure and change trend diagram is drawn, including the total number of strains, changes in the relative abundance of various strains, and the dynamics of dominant strains. By analyzing these data, changes in the microbial community can be discovered in a timely manner to provide a basis for regulation. If the stability of the microbial community is found to have decreased, the formula Add appropriate nutrients, including: Indicates the total number of bacterial species, determined by microbiological testing, It indicates the number of stable bacterial species, that is, the number of bacterial species that always exist and have high activity during the fermentation process. Indicates the fermentation temperature, which can be obtained through real-time monitoring. The stability of the microbial community is expressed by the formula Calculated, where Represents the diversity index of the microbial community, which can be calculated from high-throughput sequencing data. , , It is determined through experiments that the temperature is adjusted within the range of ±2°C. If the fermentation temperature is monitored to be too high or too low, fine-tuning is performed through heating or cooling devices to keep the temperature within the range suitable for microbial growth. The ventilation volume and stirring frequency are fine-tuned according to actual conditions. If it is found that the microbial community requires more oxygen or better mixing effect, the ventilation volume or stirring frequency can be appropriately increased. Conversely, if sufficient oxygen supply or excessive stirring may cause material breakage, the ventilation volume or stirring frequency can be appropriately reduced.

[0027] Finally, the fermented materials are dried to remove excess moisture. The drying temperature and time should be adjusted according to the properties of the materials and the performance of the drying equipment to ensure that the moisture content of the final product meets the standard (generally controlled below 25%). The organic solid waste after fermentation is post-processed, and the biogas produced by fermentation is collected, purified and stored to make it a usable energy source. At the same time, instructions for use and other information should be marked so that users can use it correctly.

[0028] Embodiment 2 Based on the first embodiment, the present embodiment optimizes the reaction rate and saves the processing time of organic solid waste by adjusting the reaction parameters of multiple groups of multi-stage anaerobic fermentation.

[0029] In this embodiment, the pretreatment step of the waste is the same as that of the first embodiment. The municipal domestic waste is treated by combining manual and mechanical sorting. Through preliminary manual selection, obvious non-fermentable substances such as metal, glass, and plastic are separated, and mechanical sorting equipment is used to ensure that the main biodegradable organic solid waste entering the fermentation system is biodegradable. Specific separation processes and standards are formulated for different types of non-fermentable substances. Professional crushers are used to crush the organic solid waste to a particle size of 6 cm. This particle size is conducive to the full contact between microorganisms and waste, and can ensure that in the subsequent fermentation process The effect of ventilation and stirring. During the crushing process, the operating status of the crushing equipment is monitored in real time, and the crushing force and speed are adjusted to avoid excessive crushing that causes the material to be too finely crushed, affecting the air permeability during the fermentation process, or insufficient crushing that causes uneven particle size of the material, affecting the fermentation effect. In addition, the crushed organic solid waste is mixed by stirring equipment. During the mixing process, the humidity is accurately controlled at 52% through a precise water addition system, and advanced mixing equipment and detection technology are used to ensure that the mixing uniformity reaches more than 95%. Through multiple sampling and analysis, the distribution uniformity of key components in the material (such as organic matter content, etc.) at different locations is determined.

[0030] From strains preserved in nature, strain banks or laboratories, efficient microbial strains that can quickly decompose organic matter, release heat and produce beneficial substances such as organic acids are screened out. These strains should have good adaptability and stability, and be able to survive and function in complex waste environments. According to multiple groups of multi-stage fermentation conditions, primary anaerobic fermentation strains are used to quickly decompose organic matter, release a large amount of heat, and promote the increase of fermentation temperature. Bacillus strains are selected, secondary anaerobic fermentation strains are used to produce organic acid substances and inhibit the growth of harmful microorganisms. Lactobacillus strains are selected, and tertiary anaerobic fermentation strains are used to promote composting and stabilization, so that the fermented materials reach a state of composting and stabilization. Actinomycetes strains are selected, and the screened strains are cultivated and optimized under laboratory conditions. By providing suitable nutrients, temperature, humidity, pH value and other conditions, the growth and reproduction of the strains are promoted, and their activity and decomposition ability are improved. At the same time, the strains are purified and identified to ensure their stability and safety in the subsequent fermentation process.

[0031] The pretreated organic solid waste is sent to the primary fermentation stage, and Bacillus is added. The fermentation temperature is precisely controlled at 56°C. The fermentation temperature is monitored and adjusted in real time through high-precision temperature sensors and automatic temperature control systems to ensure that the temperature fluctuation is within a very small range. When the temperature is lower than 56°C, the heating device is automatically started to heat up. When the temperature is higher than 56°C, the ventilation equipment is turned on to cool down. The ventilation volume and stirring frequency are dynamically adjusted according to the volume, density, temperature and other parameters of the fermentation material to ensure sufficient oxygen supply and uniform heating of the material. When insufficient oxygen content is detected, the ventilation volume is automatically increased. When the material is locally overheated When fermenting, increase the stirring frequency to promote uniform distribution of heat, shorten the primary fermentation time to 2 days, optimize the fermentation parameters, improve the fermentation efficiency, shorten the fermentation cycle, closely monitor the fermentation temperature, humidity, oxygen content and other parameters during the fermentation process, adjust the ventilation and stirring parameters in time to ensure the smooth progress of the fermentation process, transfer the materials after primary fermentation to the secondary fermentation stage, add lactic acid bacteria, reduce the pH value of the fermented materials, inhibit the growth of harmful microorganisms, determine the amount of lactic acid bacteria added according to the properties of the materials after primary fermentation and the structure of the microbial community, control the temperature at 46°C, and keep the fermentation temperature stable through the automatic temperature control system. At the same time, according to the fermentation process and the changes in the microbial community, the ventilation volume and stirring frequency are adjusted in real time. The ventilation volume and stirring frequency are dynamically adjusted according to the real-time monitoring data to ensure that the fermented materials are always in a good state. When it is detected that the microbial community needs more oxygen, the ventilation volume is increased. When the material clumps, the stirring frequency is increased to break up the material. The secondary fermentation time is 3 days. During this process, the fermentation materials are regularly tested, such as pH value, organic matter content, microbial community structure, etc., to ensure that the fermentation process develops in the expected direction. The materials after the secondary fermentation are sent to the tertiary fermentation stage and actinomycetes are added. According to the maturity of the material after the secondary fermentation, the amount of actinomycetes to be added is determined, and the fermentation temperature is strictly controlled at 36°C. Through precise temperature control equipment, the temperature fluctuation is ensured to be within a very small range. The fermentation materials are tested and adjusted to ensure that they meet the relevant standards. The test items include temperature, pH value, organic matter content, maturity, heavy metal content and other indicators. According to the test results, if necessary, the temperature, humidity, ventilation and other parameters can be adjusted to ensure the quality and safety of the fermented materials. The tertiary fermentation time is 2 days. During this process, it is ensured that the fermented materials reach the optimal maturity and stabilization state to prepare for subsequent post-processing.

[0032] In the step of dynamic monitoring and regulation of microbial communities, more advanced microbial detection technologies are used to achieve real-time online monitoring of changes in microbial communities. For example, microfluidic chip technology and biosensor technology are used to quickly and accurately detect the types, quantity and activity of microorganisms in fermentation materials, and the monitoring frequency is increased to grasp the dynamic changes of microbial communities in real time. Samples are collected for testing every hour or less to detect problems in a timely manner and take corresponding regulatory measures. According to the monitoring results, nutrients are added more accurately, and the nutrient addition formula is used. , combined with real-time monitoring data, the type and quantity of nutrients to be added are accurately calculated. For example, when it is detected that the microbial community lacks a certain nutrient element, nutrients containing the element are automatically added to promote the growth and metabolism of microorganisms. The temperature adjustment range is controlled within ±1°C. Through high-precision temperature sensors and automatic temperature control systems, precise control of fermentation temperature is achieved. When the temperature exceeds the set range, the heating or cooling device is immediately started for fine-tuning to ensure that the temperature is always kept within the range suitable for microbial growth. The ventilation volume and stirring frequency are automatically adjusted dynamically. According to the microbial community's demand for oxygen and the state of the material, the ventilation volume and stirring frequency are automatically adjusted. For example, when insufficient oxygen content is detected, the ventilation volume is automatically increased. When the material is locally overheated or agglomerated, the stirring frequency is increased to promote uniform distribution of heat and loosening of the material.

[0033] The post-processing steps are similar to those in Example 1. The fermented organic solid waste is post-processed, and the biogas generated by the fermentation is collected, purified and stored to make it a usable energy source. At the same time, instructions for use and other information are marked to facilitate users to use it correctly. It should be noted that more heat and gas may be generated during the rapid fermentation process, so special attention should be paid to safety issues and environmental protection requirements in the post-processing stage.

[0034] In summary, the present invention provides an efficient, environmentally friendly and sustainable solution for the treatment of organic solid waste through the careful design and optimization of waste pretreatment, strain screening and cultivation, multi-group and multi-stage fermentation, dynamic monitoring and regulation of microbial communities, and post-treatment. It can be concluded from the above embodiments that by adjusting the reaction temperature and other parameters, the time for treating garbage can be shortened and the efficiency can be greatly improved.

[0035] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A multi-group and multi-stage anaerobic fermentation method for treating organic solid waste, characterized in that: The following steps are involved: Waste pretreatment: classify, crush and screen organic solid waste, mix the crushed organic solid waste through stirring equipment, and adjust the material humidity to make it suitable for fermentation. At the same time, regularly take samples to test the mixing uniformity to ensure the uniformity of the material components in each part; Screening and cultivation of bacterial strains: Screening and cultivation of efficient microbial strains suitable for the treatment of organic solid waste. For the first-level anaerobic fermentation, the strains are selected to be able to quickly decompose organic matter and release a large amount of heat. For the second-level anaerobic fermentation, the strains are selected to be able to produce organic acid substances and inhibit the growth of harmful microorganisms. For the third-level anaerobic fermentation, the strains are selected to be able to promote the decomposition and stabilization of organic solid waste and make the fermented materials reach a decomposition and stabilization state. Multiple groups and multiple stages of anaerobic fermentation; the pretreated organic solid waste is sent to the primary anaerobic fermentation tank, high-efficiency microbial strains are added, the oxygen supply of the fermented material is ensured by ventilation equipment, and the ventilation volume is controlled to enable rapid fermentation. When the primary anaerobic fermentation reaches the reaction time requirement, the fermented material is transferred to the secondary anaerobic fermentation tank, different high-efficiency microbial strains are added, ventilation and stirring operations are continued, and fermentation is carried out. After the secondary anaerobic fermentation, the fermented material is transferred to the tertiary anaerobic fermentation tank, the fermented material is tested, and the fermentation parameters are adjusted according to the test results and fermentation is carried out; Dynamic monitoring and regulation of microbial communities: Use microbial detection technology to regularly collect fermentation material samples and analyze the structure and stability of the microbial communities in the samples, including the total number of bacterial species, the number of stable bacterial species, and the diversity index of the microbial community. The stability of the microbial community can be calculated by the formula Assessment, where Indicates the stability of the microbial community. Indicates stable bacterial count, Indicates the total number of bacteria. represents the diversity index of microbial communities, To adjust the coefficient, according to the monitoring results, timely adjust the fermentation parameters. For unreasonable microbial community structure or decreased activity, add nutrients, adjust the temperature and pH value to adapt to the growth needs of microorganisms, and adjust the ventilation and stirring parameters to ensure the oxygen supply and uniformity of the fermentation materials; Post-treatment: Post-treatment of organic solid waste after anaerobic fermentation, collection, purification and storage of biogas produced by anaerobic fermentation, making it a usable energy source.

2. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 1, characterized in that: In the waste pretreatment step, the crushing requirements of the organic solid waste are: the organic solid waste in the urban domestic waste is crushed to a particle size of 5-10 cm, the organic solid waste in the agricultural waste is crushed to a particle size of 3-5 cm, and the water content of the organic solid waste is controlled at 45%-60%.

3. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 1, characterized in that: In the waste pretreatment step, samples are taken regularly to detect the mixing uniformity to ensure that the composition of each part of the material is uniform. The uniformity calculation formula is: ,in Indicates the mixing uniformity, Indicates the number of sampling points, Indicates The content of a certain key component at each sampling point, It represents the average value of the key component content of all sampling points.

4. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 1, characterized in that: In the multi-group multi-stage anaerobic fermentation step, the pretreated organic solid waste is sent to the primary anaerobic fermentation tank, Bacillus species are added, the ventilation volume is controlled and the oxygen supply of the fermentation material is guaranteed to enable rapid fermentation, the reaction temperature is 50-60° C., the reaction time is 2-3 days, and after the reaction is completed, the fermentation material is transferred to the secondary anaerobic fermentation tank.

5. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 1, characterized in that: In the multi-group multi-stage anaerobic fermentation step, the fermentation material is transferred to a secondary anaerobic fermentation tank, lactic acid bacteria are added, ventilation and stirring operations are performed, the fermentation temperature is controlled at 40-50° C., the reaction time is 4-5 days, and after the reaction is completed, the fermentation material is transferred to a tertiary anaerobic fermentation tank.

6. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 1, characterized in that: In the multi-group multi-stage anaerobic fermentation step, after the secondary anaerobic fermentation, the fermented material is transferred to the tertiary anaerobic fermentation tank, actinomycetes are added, the fermentation temperature is controlled at 30-40° C., and the reaction time is 2-3 days.

7. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 1, characterized in that: In the step of dynamically monitoring and regulating the microbial community, the fermentation parameters are adjusted according to the monitoring results to maintain the stability and activity of the microbial community. If it is found that the activity of the microbial community is affected by temperature, the fermentation temperature is adjusted by a heating or cooling device. If it is detected that the pH value of the fermentation material is not conducive to the growth of microorganisms, it is adjusted by adding an acid-base regulator. At the same time, the ventilation volume is adjusted according to the demand for oxygen by the microbial community, and the type and amount of nutrients to be added are determined according to the monitoring results.

8. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 7, characterized in that: In the step of dynamic monitoring and regulation of the microbial community, the ventilation volume is adjusted according to the demand of the microbial community for oxygen, and the ventilation volume control formula is: ,in Indicates the ventilation volume, represents the volume of fermentation material, Indicates the fermentation temperature, Indicates the material humidity. represents the intensity parameter of microbial activity, To adjust the coefficient control.

9. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 7, characterized in that: In the step of dynamic monitoring and regulation of the microbial community, the type and amount of nutrients to be added are determined according to the monitoring results, and the nutrient addition formula is: ,in Indicates the amount of nutrients added. Indicates the total number of bacteria. Indicates stable bacterial count, Indicates the fermentation temperature, Indicates the stability of the microbial community. , , is the adjustment factor.

10. The method for treating organic solid waste by multi-group and multi-stage anaerobic fermentation according to claim 1, characterized in that: In the post-treatment step, the fermented organic solid waste is post-treated, and the biogas generated by the fermentation is collected, purified and stored, and the methane content in the biogas does not exceed 40%.

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