A system and method for promoting aerobic composting of agricultural waste at below 30 degrees Celsius

Abstract

The present application belongs to the technical field of organic fertilizer, and particularly relates to a zero-30 DEG C below promoting agricultural waste aerobic composting system and method, the system comprises: an anode assembly for laying in the frozen soil composting site and forming a conductive anode layer; a cathode assembly comprising a columnar conductive body inserted into the interior of the pile and a planar conductive body covering the surface of the pile, the columnar conductive body and the planar conductive body are conductively connected; a direct current power supply module connected with the anode assembly and the cathode assembly through wires; the system maintains the temperature required for microbial metabolism by Joule heat generated by direct current in the pile, realizes rapid composting of the pile in the environment of 10 DEG C below zero to 30 DEG C below zero, the anode assembly is a net-like conductive structure, the columnar conductive body is graphite material, the planar conductive body is porous carbon-based material, and the output voltage of the direct current power supply module is adjustable in the range of 0-10V. The present application can make up for the technical deficiency, promote the resource utilization of waste, and help the sustainable development of agriculture in cold regions.

Description

Technical Field

[0001] This invention belongs to the field of organic fertilizer technology, and in particular relates to a system and method for promoting aerobic composting and maturation of agricultural waste at -30°C. Background Technology

[0002] Aerobic composting is a crucial technology for converting agricultural waste into stable humus through the aerobic metabolism of microorganisms. The degree of composting directly determines the agricultural safety of the compost products. Incompletely composted compost not only fails to improve soil fertility but may also lead to increased heavy metal activity, causing soil pollution and potential safety hazards for agricultural products with long-term use. In cold regions, prolonged periods of low temperatures, with extreme temperatures reaching -30°C, pose a severe challenge to aerobic composting. While low-temperature composting can avoid common summer problems such as mosquito and fly breeding, odor diffusion, and leachate pollution, and can utilize the high bearing capacity of frozen soil to reduce transportation and application costs, existing technologies have significant limitations. Most current mainstream low-temperature composting technologies are designed for mild environments between 0°C and 10°C, lacking adaptability to extreme conditions below -30°C. In ultra-low temperature environments, microbial metabolic activity is severely inhibited, causing the composting maturity period to extend more than three times compared to normal temperatures, or even completely halting. In addition, existing technologies usually require hardening of composting sites or the addition of insulation facilities, which not only increases construction costs but also makes it difficult to meet the needs of large-scale open-air composting.

[0003] Therefore, there is an urgent need for a system and method to promote aerobic composting and maturation of agricultural waste at -30°C to solve the above-mentioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide a system and method for promoting aerobic composting and maturation of agricultural waste at -30℃, to make up for technical deficiencies, promote the resource utilization of waste, and help the sustainable development of agriculture in cold regions.

[0005] To achieve the above objectives, the present invention provides the following solution: a system for promoting aerobic composting and maturation of agricultural waste at -30°C, comprising: Anode assembly, used to be laid in frozen soil composting sites and form a conductive anode layer; The cathode assembly includes a columnar conductor inserted inside the reactor body and a planar conductor covering the surface of the reactor body, wherein the columnar conductor and the planar conductor are electrically connected. The DC power supply module connects the anode assembly and the cathode assembly respectively through wires to form a closed conductive circuit; The system maintains the temperature required for microbial metabolism by generating Joule heat in the compost body through direct current, and at the same time uses electric field stimulation to enhance microbial activity, so as to achieve rapid composting in an environment of -10℃ to -30℃. The anode component has a mesh conductive structure, the columnar conductor is made of graphite, the planar conductor is made of porous carbon-based material, and the DC power supply module has an adjustable output voltage range of 0-10V.

[0006] According to the present invention, an aerobic composting system for promoting the decomposition of agricultural waste at -30℃ is provided, wherein the anode component is a stainless steel screen with a wire diameter of 0.8-1.2 mm and a pore size of 5-7 mm.

[0007] According to the present invention, a system for promoting aerobic composting and maturation of agricultural waste at -30℃ is provided, wherein the columnar conductor is a graphite rod with a height of 1.8-2.2m and a diameter of 60-80mm.

[0008] According to the present invention, a system for promoting aerobic composting and maturation of agricultural waste at -30℃ is provided, wherein the planar conductive body is a carbon felt with a length of 600-800cm, a width of 80-120cm, a thickness of 8-12mm, and is provided with mounting holes that match the graphite rod.

[0009] According to the present invention, a system for promoting aerobic composting and maturation of agricultural waste at -30℃ is provided, wherein the DC power supply module is a DC power supply with a maximum output power of 50-100W.

[0010] According to the present invention, a system for promoting aerobic composting and maturation of agricultural waste at -30℃ is provided, wherein the conductor is an oxygen-free copper wire with a cross-sectional area ≥2.5mm².

[0011] A method for promoting aerobic composting and maturation of agricultural waste at -30℃, utilizing an aerobic composting and maturation system for agricultural waste at -30℃, includes the following steps: Site pretreatment: Lay anode components on frozen farmland at temperatures ranging from -10°C to -30°C; Stacking construction: Agricultural waste that has undergone preliminary harmless treatment is stacked into trapezoidal windrows with a base width of 4.5-5.5m and a height of 2.2-3.2m; Material adjustment: Adjust the material C / N ratio to 25 and the moisture content to 70%-80%; Electrode arrangement: Vertically insert the columnar conductors into the stack, with the bottom end 25-45cm vertically from the anode assembly, and the spacing between adjacent columnar conductors 2.0-3.5m; cover the surface of the stack with planar conductors and make conductive connections with the columnar conductors; Power-on operation: Connect the anode assembly, cathode assembly and DC power supply module through wires, and adjust the output voltage to 8-10V to form a closed loop; Process control: If the pile temperature rises above 50℃ within 5 days and is maintained at 55-60℃, turn the pile once every 8-12 days; if the pile temperature drops below 50℃, turn the pile once and then stop turning the pile.

[0012] According to the present invention, a method for promoting aerobic composting and maturation of agricultural waste at -30℃ is provided. In the construction of the compost pile, the initial harmless treatment is carried out by maintaining a compost pile temperature of ≥50℃ for 8-12 days.

[0013] According to the present invention, in a method for promoting aerobic composting and maturation of agricultural waste at -30℃, the electrode arrangement has a coverage spacing of 1.2-2.5m for the planar conductors.

[0014] According to the present invention, a method for promoting aerobic composting and maturation of agricultural waste at -30℃ is provided, in which the current density of the closed circuit is 0.5-1.5A / m² during power-on operation.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: The present invention has a simple structure and can increase the number of electrodes proportionally according to the volume of the compost pile, thereby extending the length of the windrows and breaking the limitation that electric field composting requires containers of fixed size.

[0016] This invention directly utilizes frozen soil without requiring hardening treatment; at the same time, the method is simple to operate, low in cost, and significantly shortens the composting time of the compost pile in low-temperature environments by 30%-50%. This allows the rapidly composted compost product to be returned to the field on the frozen soil nearby, while also reducing the mechanical compaction of the soil caused by agricultural machinery used for fertilizer application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall invention.

[0019] The components include: 1. stainless steel screen; 2. graphite rod; 3. carbon felt; 4. DC power supply; and 5. wires. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Reference Figure 1 As shown, the present invention provides a system for promoting aerobic composting and maturation of agricultural waste at -30°C, comprising: Anode assembly, used to be laid in frozen soil composting sites and form a conductive anode layer; The cathode assembly includes a columnar conductor inserted into the reactor body and a planar conductor covering the surface of the reactor body, wherein the columnar conductor and the planar conductor are electrically connected. The DC power supply module is connected to the anode assembly and the cathode assembly respectively via wire 5 to form a closed conductive circuit; The system maintains the temperature required for microbial metabolism by generating Joule heat in the compost pile through direct current, and at the same time uses electric field stimulation to enhance microbial activity, so as to achieve rapid composting in an environment of -10℃ to -30℃. The anode component has a mesh conductive structure, the columnar conductor is made of graphite, and the planar conductor is made of porous carbon-based material. The DC power supply module has an adjustable output voltage range of 0-10V.

[0023] Furthermore, the anode assembly is a stainless steel screen 1 with a wire diameter of 0.8-1.2 mm and an aperture of 5-7 mm.

[0024] Furthermore, the columnar conductor is a graphite rod 2, with a height of 1.8-2.2m and a diameter of 60-80mm.

[0025] Furthermore, the planar conductor is a carbon felt 3, with a length of 600-800cm, a width of 80-120cm, a thickness of 8-12mm, and is provided with mounting holes that match the graphite rod 2.

[0026] Furthermore, the DC power supply module is a DC power supply 4 with a maximum output power of 50-100W.

[0027] Furthermore, conductor 5 is an oxygen-free copper wire with a cross-sectional area ≥ 2.5 mm².

[0028] A method for promoting aerobic composting and maturation of agricultural waste at -30℃, utilizing an aerobic composting and maturation system for agricultural waste at -30℃, includes the following steps: Site pretreatment: Lay anode components on frozen farmland at temperatures ranging from -10°C to -30°C; Stacking construction: Agricultural waste that has undergone preliminary harmless treatment is stacked into trapezoidal windrows with a base width of 4.5-5.5m and a height of 2.2-3.2m; Material adjustment: Adjust the material C / N ratio to 25, spray water on each layer of material, and adjust the material moisture content to 70%-80%; Electrode arrangement: Vertically insert the columnar conductors into the stack, with the bottom end 25-45cm vertically from the anode assembly, and the spacing between adjacent columnar conductors 2.0-3.5m; cover the surface of the stack with planar conductors and make conductive connections with the columnar conductors; Power-on operation: Connect the anode assembly, cathode assembly and DC power supply module through wire 5, and adjust the output voltage to 8-10V to form a closed loop; Process control: If the pile temperature rises above 50℃ within 5 days and is maintained at 55-60℃, turn the pile once every 8-12 days; if the pile temperature drops below 50℃, turn the pile once and then stop turning the pile.

[0029] Furthermore, during the construction of the reactor, the initial harmless treatment involves maintaining a reactor temperature of ≥50℃ for 8-12 days.

[0030] Furthermore, in the electrode arrangement, the spacing between the planar conductors is 1.2-2.5m.

[0031] Furthermore, during energized operation, the current density of the closed circuit is 0.5-1.5 A / m².

[0032] First, in an environment where the temperature drops to -30°C, frozen farmland soil is directly selected as the composting site. A stainless steel screen (1.0mm wire diameter, 6mm aperture) is laid flat on the frozen soil as the compost base and circuit anode. Then, pre-treated agricultural waste (such as a mixture of livestock manure and corn stalks) is piled on the screen to form a trapezoidal windrow pile that is wider at the bottom and narrower at the top. The bottom width of the pile is controlled at 4.8-5.2m, and the height is 2.5-3m.

[0033] Next, the electrodes are arranged as follows: Graphite rods 2 (2m high, 70mm in diameter) are vertically inserted into the pile body, ensuring that the vertical distance between their bottom ends and the stainless steel screen 1 is maintained at 30-40cm, and the spacing between adjacent graphite rods 2 is 2.5-3.0m. At the same time, carbon felt 3 (700cm long, 100cm wide, 10mm thick, with a center hole diameter of 70mm) is inserted into the graphite rods 2 through the reserved holes, tightly covering the surface of the pile body, with the spacing between adjacent carbon felt 3 controlled at 1.5-2.0m.

[0034] After completing the physical setup, connect the stainless steel screen 1, graphite rod 2, and DC power supply 4 using wire 5 (oxygen-free copper wire) to form a closed circuit. Turn on the power and set the voltage to 10V. During operation, monitor the pile temperature in real time: when the temperature is maintained between 55-60℃, turn the pile every 10 days; when the pile temperature drops below 50℃, only one more turn is needed to stop subsequent turning operations.

[0035] This system utilizes the Joule heating and electric field effect generated by direct current passing through the compost pile to effectively overcome the inhibitory effect of extreme low temperatures on microorganisms. Compared with traditional low-temperature composting, this invention significantly shortens the composting cycle by 30%-50% and eliminates the need for hardening of frozen soil sites, significantly reducing construction and operating costs. The compost product is fully decomposed, and the activity of heavy metals is effectively controlled, allowing for direct application to the field on frozen soil, avoiding soil compaction caused by agricultural machinery operations. This achieves efficient and harmless treatment and resource utilization of agricultural waste in cold winter regions.

[0036] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0037] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A system for promoting aerobic composting and maturation of agricultural waste at -30℃, characterized in that, include: Anode assembly, used to be laid in frozen soil composting sites and form a conductive anode layer; The cathode assembly includes a columnar conductor inserted inside the reactor body and a planar conductor covering the surface of the reactor body, wherein the columnar conductor and the planar conductor are electrically connected. The DC power supply module is connected to the anode assembly and the cathode assembly respectively through wires (5) to form a closed conductive circuit; The system maintains the temperature required for microbial metabolism by generating Joule heat in the compost body through direct current, and at the same time uses electric field stimulation to enhance microbial activity, so as to achieve rapid composting in an environment of -10℃ to -30℃. The anode component has a mesh conductive structure, the columnar conductor is made of graphite, the planar conductor is made of porous carbon-based material, and the DC power supply module has an adjustable output voltage range of 0-10V.

2. The system for promoting aerobic composting and maturation of agricultural waste at -30℃ according to claim 1, characterized in that, The anode assembly is a stainless steel screen (1) with a wire diameter of 0.8-1.2 mm and a aperture of 5-7 mm.

3. The system for promoting aerobic composting and maturation of agricultural waste at -30℃ according to claim 1, characterized in that, The columnar conductor is a graphite rod (2) with a height of 1.8-2.2m and a diameter of 60-80mm.

4. The -30℃ aerobic composting system for agricultural waste according to claim 3, characterized in that, The planar conductor is a carbon felt (3), with a length of 600-800cm, a width of 80-120cm, a thickness of 8-12mm, and is provided with mounting holes that match the graphite rod (2).

5. The system for promoting aerobic composting and maturation of agricultural waste at -30℃ according to claim 1, characterized in that, The DC power supply module is a DC power supply (4) with a maximum output power of 50-100W.

6. The system for promoting aerobic composting and maturation of agricultural waste at -30℃ according to claim 1, characterized in that, The conductor (5) is an oxygen-free copper wire with a cross-sectional area ≥2.5mm².

7. A method for promoting aerobic composting and maturation of agricultural waste at -30℃, utilizing the -30℃ aerobic composting and maturation system for agricultural waste as described in any one of claims 1-6, characterized in that, Includes the following steps: Site pretreatment: Lay anode components on frozen farmland at temperatures ranging from -10°C to -30°C; Stacking construction: Agricultural waste that has undergone preliminary harmless treatment is stacked into trapezoidal windrows with a base width of 4.5-5.5m and a height of 2.2-3.2m; Material adjustment: Adjust the material C / N ratio to 25 and the moisture content to 70%-80%; Electrode arrangement: Vertically insert the columnar conductors into the stack, with the bottom end 25-45cm vertically from the anode assembly, and the spacing between adjacent columnar conductors 2.0-3.5m; cover the surface of the stack with planar conductors and make conductive connections with the columnar conductors; Power-on operation: Connect the anode assembly, cathode assembly and DC power supply module through wire (5), adjust the output voltage to 8-10V to form a closed loop; Process control: If the pile temperature rises above 50℃ within 5 days and is maintained at 55-60℃, turn the pile once every 8-12 days; if the pile temperature drops below 50℃, turn the pile once and then stop turning the pile.

8. The method for promoting aerobic composting and maturation of agricultural waste at -30℃ according to claim 7, characterized in that, During the construction of the reactor, the initial harmless treatment involves maintaining a reactor temperature of ≥50℃ for 8-12 days.

9. A method for promoting aerobic composting and maturation of agricultural waste at -30℃ according to claim 7, characterized in that, In the electrode arrangement, the spacing between the planar conductors is 1.2-2.5m.

10. A method for promoting aerobic composting and maturation of agricultural waste at -30℃ according to claim 7, characterized in that, During operation, the current density of the closed circuit is 0.5-1.5A / m².

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