Bioactive bacterium fermentation method based on biogas residue and biogas slurry

Abstract

The invention discloses a biogas residue and biogas slurry-based bioactive bacterium fermentation method in the technical field of agriculture, which comprises the following steps: step 1, pretreatment: firstly, pretreating biogas residue and biogas slurry, and adjusting the carbon nitrogen ratio to 25: 1; a compound microbial agent is added into the biogas slurry, the moisture proportion is adjusted according to the original moisture content of the biogas residues and the biogas slurry, the moisture content of fermentation materials is kept at 60%-70%, the pH value of the fermentation materials is adjusted to 6.5-7.5, and ventilation and stirring are conducted regularly during fermentation; 3, composting fermentation: carrying out solid-liquid separation on the fermentation material, and composting the separated biogas residue by using a special composting device; and 4, drying and crushing: taking out the biogas residue after composting fermentation from the special composting device, drying and crushing. The method is scientific and reasonable, the special composting device is used for composting fermentation of biogas residues, fermentation parameters in the fermentation process are accurately controlled, and moisture control of biogas residue composting fermentation is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and specifically is a method for fermenting biogas residue and liquid with biologically active bacteria. Background Art

[0002] Bioactive fermentation of digestate and liquid is a technology that uses microorganisms to convert organic matter in digestate and liquid into high value-added products. This method can improve the yield and quality of biogas while reducing environmental pollution. Bioactive fermentation of digestate and liquid involves a wide variety of microorganisms that work synergistically in the biogas fermentation process to convert organic matter into biogas and other by-products.

[0003] However, there are still some problems with the current biogas residue and liquid biogas fermentation technology. Too high or too low moisture content during biogas residue composting will cause problems for biogas residue composting. Too much moisture will lower the temperature of the pile and affect the activity of microorganisms, causing moisture to fill the material particles, increase compactness, reduce air permeability, and may produce a local anaerobic environment, thereby producing odor, reducing the composting speed and affecting the quality of the compost. If the moisture content is too low, it cannot meet the normal life activities and metabolic needs of microorganisms, restricts the movement and metabolism of microorganisms, and prevents the center of the pile from reaching a suitable high temperature, making it difficult for organic matter to decompose.

[0004] In summary, the difficulty in controlling the moisture content in the biogas residue composting process has become an urgent problem that technicians in this field need to solve. Therefore, it is necessary to propose a biogas residue and biogas liquid biogas fermentation method. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a method for fermenting biogas residue and liquid with biologically active bacteria, by using a special composting device to compost the biogas residue and ferment it, accurately controlling the fermentation parameters during the fermentation process, thereby achieving moisture control in the biogas residue composting fermentation.

[0006] In order to achieve the above object, the technical scheme of the present invention is as follows: A method for fermenting biogas residue and biogas slurry with biologically active bacteria comprises the following steps:

[0007] Step 1: Pretreatment: First, pretreat the sludge and liquid biogas to adjust the carbon-nitrogen ratio to 25:1.

[0008] Step 2, adding fermentation agent: Add composite microbial agent to the biogas slurry, adjust the moisture ratio according to the original moisture content of biogas residue and biogas slurry, keep the moisture content of the fermentation material at 60%-70%, adjust the pH value of the fermentation material to 6.5-7.5, and perform regular ventilation and stirring during fermentation.

[0009] Step three, composting fermentation: the fermented materials are separated into solid and liquid, and the separated sludge is composted using a special composting device.

[0010] Step 4: Drying and crushing: The sludge after compost fermentation is taken out from the special composting device for drying and crushing.

[0011] Furthermore, in step one, the carbon-nitrogen ratio of the raw material is adjusted by adding a nitrogen source and reducing a carbon source, and the nitrogen source includes urea, livestock and poultry manure and organic waste.

[0012] Furthermore, in step 2, the composite microbial agent is prepared by mixing lactic acid bacteria, yeast and actinomycetes in a ratio of 1:2:1, and the amount of the composite microbial agent added is 5% of the total mass of the biogas residue and the biogas liquid.

[0013] Furthermore, in step three, the solid-liquid separation is carried out by centrifugal separation, and the separated biogas slurry is used as liquid fertilizer.

[0014] Furthermore, the composted sludge in step three is regularly turned over, ventilated and watered.

[0015] Furthermore, in step 4, the drying process adopts hot air drying at a temperature of 60-80° C. and a moisture content of 10%-15%, and then the mixture is placed in a blender for crushing.

[0016] Furthermore, the special composting device includes a composting box and a first box door, the first box door is rotatably connected to the top of the composting box, the second box door is rotatably connected to the bottom of one side of the outer wall of the composting box, a temperature regulating liquid pump is fixedly connected to the outer wall of the composting box away from the second box door, a capillary layer is fixedly connected to the inner wall of the composting box, the capillary layer is connected to the output end of the temperature regulating liquid pump, a first biodegradable film, a first support rod, a second biodegradable film, a second support rod, a third biodegradable film and a third support rod are fixedly connected in sequence along the direction from the first box door to the inner bottom wall of the composting box on the inner wall of the composting box, a plurality of water connecting pipes are opened on an inner wall of the composting box close to the oblique bottom end of the first support rod, the second support rod and the third support rod, and the water connecting pipes are connected to the input end of the temperature regulating liquid pump, a plurality of temperature and humidity sensors and pH sensors are embedded in the capillary layer, a controller is fixedly connected to the outer wall of the composting box, and the temperature regulating liquid pump, the temperature and humidity sensor, the pH sensor and the pressure sensor are all electrically connected to the controller.

[0017] Furthermore, the total amount of microorganisms required for degradation of the first biodegradable film is less than that of the second biodegradable film, and the total amount of microorganisms required for degradation of the second biodegradable film is less than that of the third biodegradable film, and the capillary layer distribution density gradually decreases from the first strut to the third strut.

[0018] Furthermore, pressure sensors are fixedly connected to the first support rod, the second support rod and the third support rod.

[0019] Furthermore, a filter screen is fixedly connected to the inner wall of the water receiving pipe.

[0020] The following principles and beneficial effects are achieved by adopting the above scheme:

[0021] 1. In the present invention, a first, second and third multi-layer biodegradable film are sequentially arranged in the compost bin along the height direction, and these degradation films have different requirements for the degradation ability of microorganisms. As the fermentation proceeds, the biogas residue gradually falls from the upper layer to the lower layer, and adheres and ferments on the degradation films of different levels to achieve the gradual degradation of organic matter. Since the total amount of microorganisms required for the degradation of the first biodegradable film is less than that of the second biodegradable film, and the second biodegradable film is less than that of the third biodegradable film, this design helps to form a gradient distribution of microorganisms, which is convenient for users to intuitively understand the composting process.

[0022] 2. The water receiving pipe of the special composting device of the present invention is connected to the temperature regulating liquid pump to form a circulating water system. During the fermentation process, the excess water generated in the composting material can naturally penetrate into the water receiving pipe by gravity, and after being filtered by the filter screen, it is pumped back into the capillary layer by the temperature regulating liquid pump for recycling. In this way, the moisture balance of the composting material can be maintained, and the temperature in the composting box can be controlled by adjusting the water temperature, providing a suitable growth environment for microorganisms. The fermentation efficiency of the biogas residue is improved and the fermentation cycle is shortened.

[0023] 3. The present invention provides a suitable nutritional environment for subsequent microbial fermentation by adjusting the carbon-nitrogen ratio of biogas residue and biogas liquid to 25:1. The carbon-nitrogen ratio is one of the key factors affecting microbial growth and fermentation effect. The addition of composite microbial agents such as lactic acid bacteria, yeast and actinomycetes can accelerate the decomposition and conversion of organic matter and improve the fermentation efficiency. At the same time, by adjusting the water ratio and pH value, it is ensured that the fermented material is in the best conditions for microbial growth.

[0024] 4. In the present invention, the composting fermentation utilizes a special composting device to perform composting operations. By regularly turning the pile, ventilating and replenishing water, the temperature, humidity and oxygen content in the fermentation process are controlled to promote the reproduction and metabolic activities of microorganisms, thereby achieving the stabilization and harmlessness of the biogas residue. The biogas residue after composting fermentation is dried with hot air to reduce the moisture content to an appropriate range of 10%-15%, and then is crushed to obtain a biofertilizer with uniform particle size that is easy to store and use. The biogas residue after composting fermentation and drying and crushing is converted into high-quality biofertilizer with the characteristics of high nutrient content, lasting fertilizer effect and harmlessness. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a flow chart of a method according to an embodiment of the present invention.

[0026] Figure 2 This is an axonometric view of a compost bin according to an embodiment of the present invention.

[0027] Figure 3 It is a side cross-sectional view of a composting box according to an embodiment of the present invention.

[0028] Figure 4 This is an axonometric view of a first support rod according to an embodiment of the present invention.

[0029] Figure 5 Schematic diagram of a capillary according to an embodiment of the present invention.

[0030] The figure marks in the drawings of the specification include: 1. first box door; 2. compost box; 3. controller; 4. second box door; 5. temperature regulating liquid pump; 6. capillary layer; 7. temperature and humidity sensor; 8. pH sensor; 9. pressure sensor; 10. water connecting pipe; 11. first biodegradable membrane; 12. first support rod; 13. second biodegradable membrane; 14. second support rod; 15. third biodegradable membrane; 16. third support rod. DETAILED DESCRIPTION

[0031] The following is further described in detail through specific implementation methods:

[0032] Example 1

[0033] Basically as attached Figure 1 As shown: A method for fermenting biogas residue and biogas slurry with biologically active bacteria, comprising the following steps:

[0034] Step 1, pretreatment: First, pretreat the sludge and liquid biogas by adding nitrogen sources and reducing carbon sources to adjust the carbon-nitrogen ratio of the raw materials. The nitrogen sources include urea, livestock and poultry manure and organic waste. The adjusted carbon-nitrogen ratio is 25:1.

[0035] Step 2, adding fermentation agent: adding compound microbial agent to the biogas slurry, the compound microbial agent is made by mixing lactic acid bacteria, yeast and actinomycetes in a ratio of 1:2:1, and the amount of compound microbial agent added is 5% of the total mass of biogas residue and biogas slurry. Then, according to the original water content of biogas residue and biogas slurry, adjust the water ratio to keep the water content of the fermentation material at 60%-70%, adjust the pH value of the fermentation material to 6.5-7.5, and perform regular ventilation and stirring during fermentation.

[0036] Step three, composting and fermentation: the fermented materials are separated into solid and liquid by centrifugal separation. The separated biogas slurry is used as liquid fertilizer, and the separated biogas residue is composted using a special composting device. The composted biogas residue is regularly turned, ventilated and hydrated.

[0037] Step 4, drying and crushing: The sludge after compost fermentation is taken out from the special composting device for drying and crushing. The drying process uses hot air drying at a temperature of 60-80°C and a moisture content of 10%-15%, and then put into a mixer for crushing.

[0038] Specific implementation steps:

[0039] First, collect the residue and liquid biogas from the digester. Determine the initial carbon-nitrogen ratio of the residue and liquid biogas by chemical analysis. Based on the measurement results, add an appropriate amount of nitrogen source such as urea, livestock and poultry manure or organic waste to the residue to increase the nitrogen content. If the carbon content is too high, it can be reduced by diluting or removing some high-carbon substances. The residue and liquid biogas after the addition of nitrogen source are thoroughly mixed to ensure that the carbon-nitrogen ratio reaches 25:1.

[0040] Prepare a composite microbial agent by mixing lactic acid bacteria, yeast and actinomycetes in a preset ratio of 1:2:1 to form a composite microbial agent. Add the composite microbial agent to the mixed fermentation material at 5% of the total mass of the sludge and liquid biogas. Use a moisture meter to measure the original moisture content of the sludge and liquid biogas. Maintain the moisture content of the fermentation material at 60%-70% by adding an appropriate amount of water or dry material. Use an acid-base regulator such as lime or phosphoric acid to adjust the pH value of the fermentation material to 6.5-7.5. During the fermentation process, use ventilation equipment and stirring devices for regular ventilation and stirring to ensure oxygen supply in the fermentation material and uniform distribution of microorganisms.

[0041] After the preset fermentation time, the centrifuge is used to separate the solid and liquid of the fermented material. The separated biogas liquid is collected and used as liquid fertilizer. The separated biogas residue is placed in a special composting device for composting fermentation. During the composting process, the compost is turned regularly to promote uniform fermentation of the material, ventilation is carried out to provide oxygen and remove excess heat and moisture, and water is added when necessary to maintain an appropriate moisture content.

[0042] The biogas residue after composting is taken out from the composting device and placed in a hot air dryer for drying. The drying temperature is controlled at 60-80°C until the moisture content of the biogas residue drops to 10%-15%. The dried biogas residue is placed in a mixer for crushing to obtain the desired particle size or powder product.

[0043] Example 2

[0044] Basically as attached Figure 2-Figure 5 As shown: Different from the above embodiment, the special composting device includes a composting box 2 and a first box door 1, the first box door 1 is rotatably matched with the top of the composting box 2, and the second box door 4 is rotatably matched with the bottom of one side of the outer wall of the composting box 2. The outer wall of the composting box 2 away from the second box door 4 is fixedly connected with a temperature regulating liquid pump 5 by bolts, and a capillary layer 6 is embedded on the inner wall of the composting box 2. The capillary layer 6 is connected to the output end of the temperature regulating liquid pump 5. The first biodegradable film 11, the first support rod 12, the second biodegradable film 13, the second support rod 14, the third biodegradable film 15 and the third support rod 16 are fixedly connected with bolts on the inner wall of the composting box 2 in an oblique manner in sequence along the direction from the first box door 1 to the inner bottom wall of the composting box 2, and the first support rod 12, the second support rod 14 and the third support rod 16 are fixedly connected with a pressure sensor 9 by bolts.

[0045] The total amount of microorganisms required for the degradation of the first biodegradable film 11 is less than that of the second biodegradable film 13, and the total amount of microorganisms required for the degradation of the second biodegradable film 13 is less than that of the third biodegradable film 15. The distribution density of the capillary layer 6 gradually decreases from the first support rod 12 to the third support rod 16. The inner side wall of the composting box 2 close to the oblique bottom end of the first support rod 12, the second support rod 14 and the third support rod 16 is provided with a plurality of water receiving pipes 10, and a filter screen is fixedly connected to the inner wall of the water receiving pipe 10 with bolts. The water receiving pipes 10 are all connected to the input end of the temperature regulating liquid pump 5, and a plurality of temperature and humidity sensors 7 and pH sensors 8 are embedded in the capillary layer 6. The outer wall of the composting box 2 is fixedly connected to the controller 3 with bolts, and the temperature regulating liquid pump 5, the temperature and humidity sensor 7, the pH sensor 8 and the pressure sensor 9 are all electrically connected to the controller 3.

[0046] Specific implementation steps:

[0047] The separated biogas residue is placed into the compost bin 2 through the first door 1, so that the biogas residue is accumulated on the first biodegradable film 11. With the addition of biogas residue, the first biodegradable film 11 begins to sink due to gravity and contacts the first support rod 12. The contact of the first support rod 12 provides auxiliary support for the first biodegradable film 11. Close the first door 1 and the second door 4 to ensure that the inside of the compost bin 2 is sealed to maintain a stable fermentation environment. The controller 3 monitors the temperature, humidity and pH in the compost bin 2 in real time through the temperature and humidity sensor 7 and the pH sensor 8. According to the preset fermentation conditions, such as the optimal temperature range, humidity level and pH value, the controller 3 automatically adjusts the working state of the temperature regulating liquid pump 5, and circulates the liquid of suitable temperature into the compost bin 2 through the capillary layer 6 to maintain a constant temperature and humidity environment, and adjust the pH value to a suitable range.

[0048] The biogas residue begins to ferment in the compost bin 2, and the microorganisms are active. Since the first biodegradable film 11, the second biodegradable film 13 and the third biodegradable film 15 have different degradation abilities for microorganisms, the microorganisms gradually ferment completely in the process of degrading the films layer by layer. As the biogas residue degrades and the biodegradable films decompose, the materials fall naturally, and are automatically broken up and turned over during the falling process, realizing automatic and uniform turning of the pile without manual intervention.

[0049] The pressure sensors 9 on the first support rod 12, the second support rod 14 and the third support rod 16 monitor the pressure change of the compost material in real time and provide feedback data to the controller 3. The controller 3 determines the composting stage of the biogas residue according to the change trend of the pressure data and adjusts the control strategy accordingly to ensure that the best fermentation effect can be achieved in each stage.

[0050] The excess water generated during the composting process penetrates into the water receiving pipe 10 along the obliquely placed support rods, and after being filtered by the filter screen, is pumped back into the capillary layer 6 by the temperature regulating liquid pump 5 to reach the composting box 2 for recycling. The controller 3 monitors the humidity and temperature in the composting box 2 and adjusts the working state of the temperature regulating liquid pump 5 in time to maintain an appropriate moisture content and ensure the smooth progress of the composting process.

[0051] As the biogas residue is degraded layer by layer and the biodegradable film is decomposed, the water content in the biogas residue falling to the lower layer will gradually increase. In order to balance this uneven water distribution, the distribution density of the capillary layer 6 gradually decreases from the first support rod 12 to the third support rod 16. The upper biogas residue is supplemented with an appropriate amount of water through more capillary layers 6, while the lower material is supplemented with less water through fewer capillary layers 6, so that the overall water loss is more and the water is less, thereby adapting to the water change law of the biogas residue composting fermentation in the entire composting box 2.

[0052] When the compost reaches the preset completion standard temperature, humidity and pH value, the controller 3 sends a prompt signal, indicating that the compost is completed. The second box door 4 is opened to take out the compost product for subsequent drying, crushing and other treatments, and finally obtain high-quality organic fertilizer.

[0053] Through the above steps, the special composting device realizes efficient, environmentally friendly and automated treatment of sludge and liquid biogas, which not only improves the composting efficiency and quality, but also reduces labor costs and environmental pollution risks.

[0054] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A bioactive bacteria fermentation method based on biogas residue and biogas liquid, characterized in that: The steps include: Step 1: Pretreatment: First, pretreat the biogas residue and biogas slurry to adjust the carbon-nitrogen ratio to 25:1; Step 2, adding fermentation agent: adding composite microbial agent to the biogas slurry, adjusting the water ratio according to the original water content of biogas residue and biogas slurry, so that the water content of the fermentation material is maintained at 60%-70%, adjusting the pH value of the fermentation material to 6.5-7.5, and performing regular ventilation and stirring during the fermentation; Step 3, composting and fermentation: the fermented materials are separated into solid and liquid, and the separated biogas residue is composted using a special composting device; Step 4: Drying and crushing: The sludge after compost fermentation is taken out from the special composting device for drying and crushing.

2. The biogas residue and liquid biogas fermentation method according to claim 1, characterized in that: In step 1, the carbon-nitrogen ratio of the raw material is adjusted by adding nitrogen sources and reducing carbon sources. The nitrogen sources include urea, livestock and poultry manure and organic waste.

3. The biogas residue and liquid biogas fermentation method according to claim 2, characterized in that: In step 2, the composite microbial agent is prepared by mixing lactic acid bacteria, yeast and actinomycetes in a ratio of 1:2:1, and the addition amount of the composite microbial agent is 5% of the total mass of the biogas residue and the biogas liquid.

4. The biogas residue and liquid biogas fermentation method according to claim 3, characterized in that: In step three, the solid-liquid separation is carried out by centrifugal separation, and the separated biogas slurry is used as liquid fertilizer.

5. The biogas residue and liquid biogas fermentation method according to claim 4, characterized in that: The composted sludge in step three should be turned over regularly, ventilated and watered.

6. The biogas residue and liquid biogas fermentation method according to claim 5, characterized in that: In step 4, the drying process adopts hot air drying at a temperature of 60-80° C. and a moisture content of 10%-15%, and then the mixture is put into a blender for crushing.

7. The biogas residue and liquid biogas fermentation method according to claim 6, characterized in that: The special composting device comprises a composting box (2) and a first box door (1), wherein the first box door (1) is rotatably connected to the top of the composting box (2), a second box door (4) is rotatably connected to the bottom of one side of the outer wall of the composting box (2), a temperature regulating liquid pump (5) is fixedly connected to the outer wall of the composting box (2) away from the second box door (4), a capillary layer (6) is fixedly connected to the inner wall of the composting box (2), the capillary layer (6) is connected to the output end of the temperature regulating liquid pump (5), and a first biodegradable film (11), a first support rod (12), a second biodegradable film (13), a second biodegradable film (14) are fixedly connected to the inner wall of the composting box (2) in a direction from the first box door (1) to the inner bottom wall of the composting box (2) in an oblique manner in sequence. 13), a second support rod (14), a third biodegradable film (15) and a third support rod (16); a plurality of water receiving pipes (10) are provided on an inner side wall of the compost box (2) close to the oblique bottom end of the first support rod (12), the second support rod (14) and the third support rod (16); the water receiving pipes (10) are connected to the input end of the temperature regulating liquid pump (5); a plurality of temperature and humidity sensors (7) and a pH value sensor (8) are embedded in the capillary layer (6); a controller (3) is fixedly connected to the outer wall of the compost box (2); the temperature regulating liquid pump (5), the temperature and humidity sensor (7), the pH value sensor (8) and the pressure sensor (9) are electrically connected to the controller (3).

8. The biogas residue and liquid biogas fermentation method according to claim 7, characterized in that: The total amount of microorganisms required for degradation of the first biodegradable film (11) is less than that of the second biodegradable film (13), the total amount of microorganisms required for degradation of the second biodegradable film (13) is less than that of the third biodegradable film (15), and the distribution density of the capillary layer (6) gradually decreases from the first support rod (12) to the third support rod (16).

9. The biogas residue and liquid biogas fermentation method according to claim 8, characterized in that: The first support rod (12), the second support rod (14) and the third support rod (16) are all fixedly connected with a pressure sensor (9).

10. The biogas residue and liquid biogas fermentation method according to claim 9, characterized in that: The inner wall of the water receiving pipe (10) is fixedly connected with a filter screen.

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