Preparation method of solid slow-release carbon source

Abstract

The invention discloses a preparation method of a solid slow-release carbon source, belongs to the technical field of sewage treatment, and solves the problem that the whole solid carbon source is easy to disperse under the condition that the dosage of a cross-linking agent is too small. Comprising the following steps: preparing materials: preparing polyethylene glycol terephthalate, polylactic acid, polycaprolactone, carbon nanotubes, graphene, diatomite, bentonite, kaolin, dioctyl phthalate, a graft copolymer, titanium dioxide and a fluoride compound; mixing the prepared materials by using dichloromethane as a solvent through a solvent method, and dispersing through a high-speed shearing emulsifying machine to obtain a mixture; the solid carbon source which is stable in structure and slowly releases carbon elements is prepared, the solid carbon source has high strength and toughness, material compatibility is enhanced through the grafted copolymer, water resistance is ensured, the solid carbon source is not prone to scattering, wounds are formed through friction in the preparation process, the reaction with microorganisms is accelerated, the reaction time is shortened, the reaction rate is ensured through a reinspection system, and the preparation process is simple. The method is effectively applied to sewage treatment.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a method for preparing a solid slow-release carbon source. Background Art

[0002] Composite carbon source is an efficient carbon source supplement in sewage treatment. It is a mixture of multiple carbon source substances and can provide rich organic matter to promote the degradation and treatment of organic matter in sewage. This carbon source has many advantages: first, it can be quickly absorbed and utilized by microorganisms, and has a high reaction speed and adaptability; second, the sludge yield of composite carbon source is lower than other carbon sources, which can reduce the amount of sludge by 15%-20%; third, it has a higher COD content, saves freight, and is easier to operate at low temperatures, does not require coagulation and sedimentation, and has an adaptability of up to -30 degrees; in addition, the carbon chain of composite carbon source is shorter, which is easier to be decomposed and absorbed by microorganisms, and is non-toxic and harmless. Composite carbon source in liquid form is easy to control, saves labor costs, is easy to store and transport, and does not belong to hazardous chemicals and hazardous wastes. Therefore, composite carbon source plays an important role in improving sewage treatment efficiency, reducing costs and reducing environmental pollution, and is suitable for a variety of scenarios such as municipal and industrial sewage treatment plants.

[0003] In order to ensure that the composite carbon source can maintain a stable and long-term release of carbon elements during sewage treatment, the composite carbon source is currently prepared as a solid slow-release carbon source, such as a solid slow-release carbon source and a preparation method thereof with publication number CN115594305A. The technical points are that it includes 30%-40% corn cobs, 20%-30% peanut shells, 10%-20% wheat straws, 20%-30% rice husks and 1%-3% cross-linking agent. The corn cobs, peanut shells, wheat straws and rice husks are crushed and preheated, and then freeze-formed under the action of a cross-linking agent. The formed filler is cut and placed in a carrier composed of variable chains to obtain the required carbon source.

[0004] The carrier of the above scheme increases or decreases the filling space of the filler by changing the shape of the deformable chain. The solid slow-release carbon source can be added in an orderly manner according to the requirements of the water quality for the carbon source, which can be recycled, is economical and efficient, and eliminates the problem of late cellulose degradation caused by directly adding plant solid carbon sources.

[0005] However, the solid slow-release carbon source in the above-mentioned formula is mainly formed by crushing a large amount of biomass containing starch and then freezing it with a cross-linking agent. Most of its components are debris and particles. If the amount of cross-linking agent is too much, it will cause the composition of the solid carbon source to be difficult to react with the microorganisms in the sewage environment. If the amount of cross-linking agent is too little, it is easy for the entire solid carbon source to disperse, making it unable to achieve a slow-release effect, but instead being completely decomposed by microorganisms after a certain period of time. Therefore, the current solid slow-release carbon source needs to be improved to alleviate the problem of the entire solid carbon source being easily dispersed when the amount of cross-linking agent is too little.

[0006] Therefore, a method for preparing a solid slow-release carbon source is proposed to solve or alleviate the above problems. Summary of the invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for preparing a solid slow-release carbon source.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A method for preparing a solid slow-release carbon source comprises the following steps: Preparation of materials, including polyethylene terephthalate, polylactic acid, polycaprolactone, carbon nanotubes, graphene, diatomaceous earth, bentonite, kaolin, dioctyl ester, graft copolymer, titanium dioxide, and fluoride complex; The prepared materials are mixed by a solvent method using dichloromethane as a solvent, and dispersed by a high-speed shear emulsifier to obtain a mixed material; The dispersed mixed material is put into a screw extruder for extrusion molding to obtain a plurality of granular solid slow-release carbon sources; The solid slow-release carbon source leaving the screw extruder falls into the opening component and forms a wound due to friction before leaving.

[0009] Preferably, the preparation includes 20-30% polyethylene terephthalate, 20-30% polylactic acid, 10-15% polycaprolactone, 5-10% carbon nanotubes, 3-5% graphene, 3-5% diatomaceous earth, 2-3% bentonite, 3-4% kaolin, 2-3% dioctyl ester, 3-5% graft copolymer, 1-2% titanium dioxide, and 0.5-1% fluoride complex.

[0010] Preferably, the graft copolymer includes materials such as PET grafted polyacrylate.

[0011] Preferably, the fluoride compound includes materials such as sodium fluoride or aluminum fluoride.

[0012] Preferably, when the dispersed mixed material is fed into a screw extruder for extrusion molding, the temperature in the screw extruder is between 140-180°C.

[0013] Preferably, the opening component includes a guide tube connected to the outlet end of the screw extruder, a garlic hood connected to the guide tube and vertically arranged, a support frame fixedly connected to the bottom opening of the garlic hood, a servo motor vertically fixedly connected to the support frame, and a friction disk coaxially fixedly connected to the output shaft of the servo motor and located above the support frame, the top edge of the friction disk is provided with a guide slope, the friction disk is located in the garlic hood, the lower end opening area of ​​the garlic hood is larger than the upper end opening area of ​​the garlic hood, the inner wall of the garlic hood is coated with a resin layer, the guide tube is L-shaped, one end of the guide tube is fixedly connected to the upper end of the garlic hood, the other end of the guide tube is fixedly connected to a connecting flange on the outer ring, and the guide tube is detachably connected to the outlet end of the screw extruder through the connecting flange.

[0014] Preferably, the method further comprises the following steps: The solid slow-release carbon source leaving the opening component is collected by an image collection module in the re-inspection system with a tiled image, and the background of the tiled image is a solid color; The image acquisition module in the re-inspection system transmits the tiled image to the data processing module in the re-inspection system. The data processing module in the re-inspection system determines the wound condition of the solid slow-release carbon source based on the tiled image and outputs the result to the control module in the re-inspection system. The control module controls the speed of the servo motor based on the output result.

[0015] Preferably, the step of collecting a tiled image of the solid slow-release carbon source leaving the opening component through an image collection module in a re-inspection system comprises the following steps: Take the same batch of solid slow-release carbon source leaving the opening component and spread it on the pure color material tray; The solid slow-release carbon source spread in the pure color material tray is imaged by an image acquisition module in the re-inspection system to obtain a flat image; The image acquisition module in the re-inspection system transmits the tiled image to the data processing module in the re-inspection system.

[0016] Preferably, the data processing module in the re-inspection system determines the wound condition of the solid slow-release carbon source according to the tiled image and outputs the result to the control module in the re-inspection system, including the following steps: Perform filtering and color space conversion preprocessing on the planar image; Set the color threshold to distinguish the solid slow-release carbon source from the background; The processed planar image is converted into a binary image, in which the solid slow-release carbon source is the foreground and the background is the background; The solid slow-release carbon sources in the binary images were marked by connected region analysis; The total number of solid slow-release carbon sources is counted according to the number of connected areas; Using edge detection algorithm to detect scratches on the surface of solid slow-release carbon source on the processed plane image; Extract texture features from the processed plane image through a local binary module; Combining the edge detection and texture analysis results, determine which solid slow-release carbon sources have wear scratches on their surfaces, and output the number of solid slow-release carbon sources with wear scratches; Determine whether the number of solid slow-release carbon sources with wear and scratches is greater than 85% of the total number of solid slow-release carbon sources. If so, the output result is that there is no need to control the servo motor speed. If so, the output result is to control the servo motor speed to increase the speed.

[0017] Preferably, the re-inspection system includes an image acquisition module, a data processing module, and a control module. The output end of the image acquisition module is communicatively connected to the input end of the data processing module, the output end of the data processing module is communicatively connected to the input end of the control module, and the control module is coupled to the servo motor through a motor driver chip.

[0018] The present invention has the following beneficial effects: The present invention can prepare a solid carbon source with a stable structure, slow release of carbon elements and a long maintenance time, and the solid slow release carbon source itself has good strength and good toughness. The compatibility between the various materials in the solid slow release carbon source is enhanced by the graft copolymer, and it is not easy to disperse. At the same time, the water resistance of the solid slow release carbon source is also ensured by the ingredients, and it is not easy to be released prematurely when immersed in sewage. In addition, after the solid slow release carbon source is prepared, the present invention also rubs it to open a wound, so that when the solid slow release carbon source is put into the sewage, it can immediately contact and react with the microorganisms at the position of the wound, shortening its reaction time. At the same time, the solid slow release carbon source that has not been actually used after the friction treatment is tested again through the re-inspection system to ensure that wounds can be formed on most of the prepared solid slow release carbon sources to ensure its reaction rate at the first time, so that the solid slow release carbon source can effectively play a role in the sewage treatment link. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a flowchart of the present invention; Figure 2 It is a structural schematic diagram of the screw extruder and the opening assembly in the present invention; Figure 3 A partial cross-sectional view of the screw extruder and the opening assembly of the present invention; Figure 4 for Figure 3 The enlarged view of point A in the middle; Figure 5 It is a structural block diagram of the re-inspection system in the present invention.

[0021] 1. Screw extruder; 2. Opening assembly; 3. Connecting flange; 4. Guide tube; 5. Garlic cover; 6. Support frame; 7. Servo motor; 8. Friction disc; 9. Image acquisition module; 10. Data processing module; 11. Control module. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the invention is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] A method for preparing a solid slow-release carbon source, such as Figure 1 As shown, the following steps are included: Preparation of materials, including polyethylene terephthalate, polylactic acid, polycaprolactone, carbon nanotubes, graphene, diatomaceous earth, bentonite, kaolin, dioctyl ester, graft copolymer, titanium dioxide, and fluoride complex; The prepared materials are mixed by a solvent method using dichloromethane as a solvent, and dispersed by a high-speed shear emulsifier to obtain a mixed material; The dispersed mixed material is put into the screw extruder 1 for extrusion molding. When the dispersed mixed material is put into the screw extruder 1 for extrusion molding, the temperature in the screw extruder 1 is between 140-180° C., and a plurality of granular solid slow-release carbon sources are obtained; The solid slow-release carbon source leaving the screw extruder 1 falls into the opening component 2 and forms a wound after friction, and then leaves.

[0029] The present invention can provide a solid carbon source with a stable structure and the ability to slowly release carbon elements for a long time. The solid carbon source not only has good strength but also has good toughness. By using a graft copolymer, the compatibility between materials is enhanced, making the solid carbon source difficult to disperse. In addition, the formula ensures the water resistance of the carbon source, and it is not easy to release prematurely even if it is immersed in sewage for a long time. In order to improve the reaction efficiency of the carbon source when it is put into sewage for the first time, after the solid carbon source is prepared, a special friction treatment is performed to open a wound. In this way, once the carbon source is put into sewage, it can quickly contact and react with microorganisms through the wound, which greatly shortens the reaction time, thereby playing a more efficient role in the sewage treatment process.

[0030] Preferably, the composition includes 20-30% polyethylene terephthalate, 20-30% polylactic acid, 10-15% polycaprolactone, 5-10% carbon nanotubes, 3-5% graphene, 3-5% diatomaceous earth, 2-3% bentonite, 3-4% kaolin, 2-3% dioctyl ester, 3-5% graft copolymer, 1-2% titanium dioxide, and 0.5-1% fluoride complex.

[0031] Preferably, the graft copolymer includes materials such as PET grafted polyacrylate.

[0032] Preferably, the fluoride compound includes materials such as sodium fluoride or aluminum fluoride.

[0033] Among them, the combination of polyethylene terephthalate PET, polylactic acid PLA and polycaprolactone PCL enables this solid slow-release carbon source to provide a stable carbon source while having excellent strength and toughness, ensuring that the material is not easily broken or damaged during use; The high strength and water resistance of PET provide a solid carrier for the carbon source, enhancing the stability of the carbon source in different environments. PLA, through its biodegradable properties, ensures that the material can be decomposed within an appropriate time and slowly release the carbon source, while also improving the environmental friendliness of the formula. The low melting point and good flexibility of PCL help regulate the degradation rate of the overall material, making the release of the carbon source more durable and controllable. In addition, the combination of PET and PLA interacts through the differences in their degradation rates and hydrolysis characteristics, playing a role in controlling the degradation rate and delaying the release of the carbon source. The slow degradation characteristics of PET can effectively delay the degradation process of PLA, while PLA provides the function of quickly releasing the carbon source. The addition of carbon nanotubes and graphene not only improves the mechanical properties and conductivity of the solid slow-release carbon source, but also further promotes the uniform release of the carbon source through its extremely high surface area and reaction activity. Carbon nanotubes enhance the structural strength of the solid slow-release carbon source and provide more reaction sites to increase the release rate of the carbon source; graphene, with its ultra-high conductivity and stability, enables the carbon source to be released uniformly and stably in environmental changes. Diatomaceous earth, bentonite and kaolin enhance the stability and hydrolysis resistance of the solid slow-release carbon source and improve the slow-release characteristics of the carbon source. Diatomaceous earth improves the water absorption and hydrolysis resistance of the composite material through its porous structure, so that the carbon source can be continuously released in the water environment; bentonite uses its layered structure to adjust the release rate of the carbon source to avoid its excessive decomposition, and kaolin further enhances the hydrolysis resistance and physical stability of the solid slow-release carbon source; Dioctyl ester and graft copolymer play an important role in improving the flexibility and processability of the material. Dioctyl ester can increase the flexibility of the solid slow-release carbon source, improve its water resistance, and extend the release period of the carbon source; while the graft copolymer helps to improve the compatibility between different components to ensure that the carbon source can be slowly released as expected during use. Finally, the titanium dioxide and fluoride complex can effectively adjust the reaction rate of the carbon source to avoid its too fast or too slow release, thereby further controlling the release curve of the carbon source.

[0034] Preferably, if Figures 2 to 4As shown, the opening component 2 includes a guide tube 4 connected to the outlet end of the screw extruder 1, a garlic cover 5 connected to the guide tube 4 and vertically arranged, a support frame 6 fixedly connected to the bottom opening of the garlic cover 5, a servo motor 7 vertically fixedly connected to the support frame 6, and a friction disk 8 coaxially fixedly connected to the output shaft of the servo motor 7 and located above the support frame 6. The friction disk 8 is made of tungsten carbide, and a guide inclined surface is provided on the top edge of the friction disk 8. The friction disk 8 is located in the garlic cover 5. The lower end opening area of ​​the garlic cover 5 is larger than the upper end opening area of ​​the garlic cover 5. The inner wall of the garlic cover 5 is coated with a resin layer. The guide tube 4 is L-shaped, one end of the guide tube 4 is fixedly connected to the upper end of the garlic cover 5, and the other end of the guide tube 4 is fixedly connected to the outer ring with a connecting flange 3. The guide tube 4 is detachably connected to the outlet end of the screw extruder 1 through the connecting flange 3.

[0035] When the opening component 2 frictionally opens the solid slow-release carbon source leaving the screw extruder 1 to form an incision, the solid slow-release carbon source will enter the garlic cover 5 through the guide tube 4, and because the shape of the guide tube 4 is set to be L-shaped, the solid slow-release carbon source will fall vertically when entering the garlic cover 5 from the guide tube 4, which makes the solid slow-release carbon source hit the fast-rotating friction disk 8, so that the friction disk 8 can bring greater friction to the solid slow-release carbon source in the horizontal direction, and the solid slow-release carbon source When the inertial displacement is maintained, the top surface of the friction disk 8 can rub against the solid slow-release carbon source, and then the surface of the solid slow-release carbon source will be worn and scratched as a wound. After that, the solid slow-release carbon source will be affected by the friction force of the friction disk 8 and the reaction force generated by its impact, so it will sputter outward. The solid slow-release carbon source sputters onto the inner wall of the garlic cover 5, which contacts the resin layer, and then the resin layer absorbs part of its mechanical potential energy, so that the solid slow-release carbon source can fall out from the lower end opening of the garlic cover 5 and be recovered by people; The solid slow-release carbon source after such wear and tear can expose its internal materials. When it is put into sewage, the solid slow-release carbon source can react at the first time, thereby improving its reaction efficiency.

[0036] Preferably, the method further comprises the following steps: The solid slow-release carbon source leaving the opening component 2 is collected by the image acquisition module 9 in the re-inspection system with a tiled image, and the background of the tiled image is a solid color; The image acquisition module 9 in the re-inspection system transmits the tiled image to the data processing module 10 in the re-inspection system. The data processing module 10 in the re-inspection system determines the wound condition of the solid sustained-release carbon source according to the tiled image and outputs the result to the control module 11 in the re-inspection system. The control module 11 controls the speed of the servo motor 7 according to the output result.

[0037] Preferably, the solid slow-release carbon source leaving the opening component 2 is collected by the image collection module 9 in the re-inspection system, and the steps include: Take the same batch of solid slow-release carbon source leaving from opening component 2 and spread it on the pure color material tray; The image acquisition module 9 in the re-inspection system acquires an image of the solid slow-release carbon source spread in the pure color material tray to obtain a spread image; The image acquisition module 9 in the re-inspection system transmits the tiled image to the data processing module 10 in the re-inspection system.

[0038] Preferably, the data processing module 10 in the re-inspection system determines the wound condition of the solid slow-release carbon source according to the tiled image and outputs the result to the control module 11 in the re-inspection system, including the following steps: Filtering of planar images And color space conversion preprocessing, convert RGB to HSV, where, is the original pixel value of the plane image, is the pixel value after filtering; Set color threshold to distinguish solid slow-release carbon source from background ,in, is the indicator function; The processed planar image is converted into a binary image, in which the solid slow-release carbon source is the foreground and the background is the background. ,in, is the pixel value of the processed plane image, is the pixel value of the binary image; Labeling of solid slow-release carbon sources in binary images by connected region analysis ,in, are all connected regions in the binary image, is the i-th connected region; Count the total number of solid slow-release carbon sources based on the number of connected areas ; The Canny edge detection algorithm is used to detect scratches on the surface of the solid slow-release carbon source on the processed plane image. The Canny edge detection calculates the gradient of the image. , using the double threshold method for edge detection, ,in, and are high and low thresholds; The texture features of the processed plane image are extracted through the local binary module ,in, is the pixel value of the processed plane image, is the sign function, n is the number of neighborhood pixels, is the position of the neighborhood pixel; Combine edge detection and texture analysis results to determine which solid slow-release carbon sources have wear scratches on their surfaces ,in, Solid slow-release carbon source The edge strength, is the texture feature, is the threshold for the presence of wear and scratches, and outputs the number of solid slow-release carbon sources with wear and scratches ,in, is the indicator function; Determine whether the number of solid slow-release carbon sources with wear and scratches is greater than 85% of the total number of solid slow-release carbon sources. If so, the output result is that there is no need to control the speed of servo motor 7. If so, the output result is to control the speed of servo motor 7 to increase.

[0039] Preferably, if Figure 5 As shown, the re-inspection system includes an image acquisition module 9, a data processing module 10, and a control module 11. The output end of the image acquisition module 9 is communicatively connected to the input end of the data processing module 10, and the output end of the data processing module 10 is communicatively connected to the input end of the control module 11. The control module 11 is coupled to the servo motor 7 through a motor driver chip. The image acquisition module 9 includes a camera, the data processing module 10 includes a processor, and the control module 11 includes a controller.

[0040] The setting of the above-mentioned re-inspection system enables people to conduct a quality inspection in advance when they need to collect and produce the solid slow-release carbon source leaving the opening component 2, so as to ensure that there are clear scratches on the surface of the solid slow-release carbon source, and avoid the situation that the solid slow-release carbon source needs to be reworked for a second time. In addition, the above-mentioned re-inspection system has a high accuracy in inspecting the solid slow-release carbon source of the same batch, so that the re-inspection system can completely count the total number of solid slow-release carbon sources through the color difference between the background and the solid slow-release carbon source in the plane image, and can also extract multiple features to ensure that the solid slow-release carbon source with wear and scratches extracted by the re-inspection system is accurate. The accuracy of the number of carbon-released carbon sources is relatively high. In this case, judging whether the number of solid slow-release carbon sources with wear and scratches is greater than 85% of the total number of solid slow-release carbon sources can make the result more accurate. If it is not greater than 85%, it means that when the solid slow-release carbon source falls on the friction disc 8, the friction disc 8 does not bring about a large friction force when in contact with the solid slow-release carbon source, that is, the friction disc 8 does not wear the surface of the solid slow-release carbon source to form a wound. Therefore, it is necessary to adjust the speed of the servo motor 7 by the control module 11 of the controller to speed up its speed, so that relative friction can occur when the solid slow-release carbon source hits the top surface of the friction disc 8.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a solid slow-release carbon source, characterized in that: The following steps are included: Preparation of materials, including polyethylene terephthalate, polylactic acid, polycaprolactone, carbon nanotubes, graphene, diatomaceous earth, bentonite, kaolin, dioctyl ester, graft copolymer, titanium dioxide, and fluoride complex; The prepared materials are mixed by a solvent method using dichloromethane as a solvent, and dispersed by a high-speed shear emulsifier to obtain a mixed material; The dispersed mixed material is fed into a screw extruder (1) for extrusion molding to obtain a plurality of granular solid slow-release carbon sources; The solid slow-release carbon source leaving the screw extruder (1) falls into the opening component (2) and forms a wound due to friction before leaving.

2. The method for preparing a solid slow-release carbon source according to claim 1, characterized in that: The preparation includes 20-30% polyethylene terephthalate, 20-30% polylactic acid, 10-15% polycaprolactone, 5-10% carbon nanotubes, 3-5% graphene, 3-5% diatomaceous earth, 2-3% bentonite, 3-4% kaolin, 2-3% dioctyl ester, 3-5% graft copolymer, 1-2% titanium dioxide, and 0.5-1% fluoride complex.

3. The method for preparing a solid slow-release carbon source according to claim 1, characterized in that: The graft copolymer includes materials such as PET grafted polyacrylate.

4. The method for preparing a solid slow-release carbon source according to claim 1, characterized in that: The fluoride compound includes materials such as sodium fluoride or aluminum fluoride.

5. The method for preparing a solid slow-release carbon source according to claim 1, characterized in that: When the dispersed mixed material is fed into the screw extruder (1) for extrusion molding, the temperature inside the screw extruder (1) is between 140-180°C.

6. The method for preparing a solid slow-release carbon source according to claim 1, characterized in that: The opening assembly (2) comprises a guide tube (4) connected to the outlet end of the screw extruder (1), a garlic cover (5) connected to the guide tube (4) and arranged vertically, a support frame (6) fixedly connected to the bottom opening of the garlic cover (5), a servo motor (7) vertically fixedly connected to the support frame (6), and a friction disk (8) coaxially fixedly connected to the output shaft of the servo motor (7) and located above the support frame (6), wherein the top edge of the friction disk (8) is provided with a guide inclined surface, and the friction disk (8) is provided with a guide inclined surface. The wiping plate (8) is located inside the garlic cover (5); the lower end opening area of ​​the garlic cover (5) is larger than the upper end opening area of ​​the garlic cover (5); the inner wall of the garlic cover (5) is coated with a resin layer; the guide tube (4) is L-shaped; one end of the guide tube (4) is fixedly connected to the upper end of the garlic cover (5); the other end of the guide tube (4) is fixedly connected to a connecting flange (3) at its outer ring; the guide tube (4) is detachably connected to the outlet end of the screw extruder (1) via the connecting flange (3).

7. The method for preparing a solid slow-release carbon source according to claim 6, characterized in that: It also includes the following steps, The solid slow-release carbon source leaving the self-opening component (2) is collected by an image collection module (9) in the re-inspection system with a tiled image, wherein the background of the tiled image is a solid color; The image acquisition module (9) in the re-inspection system transmits the tiled image to the data processing module (10) in the re-inspection system. The data processing module (10) in the re-inspection system determines the wound condition of the solid slow-release carbon source in the tiled image based on the tiled image and outputs the result to the control module (11) in the re-inspection system. The control module (11) controls the rotation speed of the servo motor (7) based on the output result.

8. The method for preparing a solid slow-release carbon source according to claim 7, characterized in that: The step of collecting a tiled image of the solid slow-release carbon source leaving the opening component (2) through an image collection module (9) in a re-inspection system comprises the following steps: Take the same batch of solid slow-release carbon source leaving the opening component (2) and spread it on the pure color material tray; The solid slow-release carbon source spread on the pure color material tray is imaged by an image acquisition module (9) in the re-inspection system to obtain a flat image; The image acquisition module (9) in the re-inspection system transmits the tiled image to the data processing module (10) in the re-inspection system.

9. The method for preparing a solid slow-release carbon source according to claim 8, characterized in that: The data processing module (10) in the re-inspection system determines the wound condition of the solid slow-release carbon source according to the tiled image and outputs the result to the control module (11) in the re-inspection system, comprising the following steps: Perform filtering and color space conversion preprocessing on the planar image; Set the color threshold to distinguish the solid slow-release carbon source from the background; The processed planar image is converted into a binary image, in which the solid slow-release carbon source is the foreground and the background is the background; The solid slow-release carbon sources in the binary images were marked by connected region analysis; The total number of solid slow-release carbon sources is counted according to the number of connected areas; Using edge detection algorithm to detect scratches on the surface of solid slow-release carbon source on the processed plane image; Extract texture features from the processed plane image through a local binary module; Combining the edge detection and texture analysis results, determine which solid slow-release carbon sources have wear scratches on their surfaces, and output the number of solid slow-release carbon sources with wear scratches; It is determined whether the number of solid slow-release carbon sources with wear and scratches is greater than 85% of the total number of solid slow-release carbon sources. If so, the output result is that there is no need to control the speed of the servo motor (7). If so, the output result is that the speed of the servo motor (7) is increased.

10. The method for preparing a solid slow-release carbon source according to claim 9, characterized in that: The re-inspection system comprises an image acquisition module (9), a data processing module (10), and a control module (11); an output end of the image acquisition module (9) is communicatively connected to an input end of the data processing module (10); an output end of the data processing module (10) is communicatively connected to an input end of the control module (11); and the control module (11) is coupled to a servo motor (7) via a motor drive chip.

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