A method for producing composite carbon source using wastewater biochemical excess sludge

Abstract

The present invention discloses a method for producing a composite carbon source by using wastewater biochemical excess sludge, which belongs to the technical field of sewage treatment, and solves the problem that the manufacturer does not adjust the water content in the sludge cake to a suitable range, but removes the water as much as possible, and the obtained sludge cake is demoulded after dehydration or is easily broken during the transportation to the pyrolysis link, which affects the integrity. The method includes the following steps: taking the concentrated sludge that has passed through the primary sedimentation tank, the biological tank, the secondary sedimentation tank, and the sludge concentration tank in sequence for recovery; starting the high-pressure diaphragm filter press, pressurizing and merging a plurality of filter plates and a pressing plate, forming a mud cavity between the filter plate and the pressing plate, and guiding the sludge into the high-pressure diaphragm filter press and filling each mud cavity. The present invention increases the viscosity of the sludge by a thickener, dehydrates by a high-pressure diaphragm filter press, optimizes the dehydration effect by controlling the air pressure and ultrasonic detection, and finally obtains a mud cake with low water content and high structural strength for pyrolysis to prepare a composite carbon source.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a method for producing a composite carbon source by utilizing wastewater biochemical excess sludge. Background Art

[0002] The preparation of carbon source from sludge is to use the residual sludge generated in the sewage treatment process, and convert it into a carbon source that can be used for biological denitrification and sewage treatment through a series of physical and chemical treatment methods. This process usually includes steps such as sludge concentration, dehydration and pyrolysis. First, the sludge passes through the concentration tank to remove excess water and increase the solid content; then, the dehydration equipment further reduces the water content so that the sludge reaches a state suitable for subsequent treatment. On this basis, the sludge can be converted into a solid carbon source through methods such as pyrolysis or carbonization. These methods can not only effectively remove water from the sludge, but also convert organic matter into high-value-added carbon materials. The prepared carbon source has good physical and chemical properties, can slowly release carbon elements, provide continuous nutritional support for microorganisms, and promote the degradation of organic matter in sewage. In addition, the carbon source prepared from sludge is also environmentally friendly, which can realize the resource utilization of sludge, reduce environmental pollution, and improve the overall efficiency of sewage treatment. Through this innovative treatment method, not only the economic benefits of sewage treatment are improved, but also a new solution for sustainable development is provided.

[0003] In the sewage treatment system, extracting the cleaner sludge for concentration, dehydration, and pyrolysis to prepare carbon sources is a very cheap and affordable way to provide carbon sources for many sewage treatment manufacturers. Selling the sludge extracted from the sewage treatment system after preparing the carbon source can also provide additional income for sewage treatment manufacturers. However, when the sludge is prepared as a carbon source for sale, the carbon source as a product has integrity requirements. However, when dehydrating, most manufacturers do not adjust the water content in the sludge cake to an appropriate range, but remove as much water as possible. The obtained cake is easily broken during demolding after dehydration or during transportation to the pyrolysis stage, affecting its integrity, which ultimately leads to poor integrity of the final carbon source.

[0004] Therefore, a method for producing a composite carbon source by utilizing wastewater biochemical excess sludge is proposed to solve or alleviate the above problems. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for producing a composite carbon source by utilizing wastewater biochemical excess sludge.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for producing a composite carbon source using wastewater biochemical excess sludge comprises the following steps:

[0008] Recycling concentrated sludge that has passed through the primary sedimentation tank, biological tank, secondary sedimentation tank, and sludge thickening tank in sequence;

[0009] Start the high-pressure diaphragm filter press, pressurize and merge several filter plates and compression plates, form mud cavities between the filter plates and compression plates, guide the sludge into the high-pressure diaphragm filter press and fill each mud cavity;

[0010] The sludge in the mud chamber is continuously filled with water through the compression plate, and the lower limit of the first air pressure interval and the upper limit of the first air pressure interval are set as the air pressure peak values ​​in the first filter plate and the last filter plate in the high-pressure diaphragm filter press respectively, and the air pressure peak values ​​of the remaining filter plates are set equally between the lower limit of the first air pressure interval and the upper limit of the first air pressure interval in the order of the filter plates, and a plurality of filter plates are pressurized and dehydrated in sequence;

[0011] The sludge in the mud chamber is continuously filled with water through the compression plate, and several filter plates maintain the original peak pressure and are pressurized and dehydrated in sequence. The water output of the mud chambers on both sides of each filter plate is collected until the water output of the mud chamber is zero, and the subsequent filter plates are stopped from pressurizing. The peak pressure of the previous filter plate in the sequence is taken as the upper limit of the second pressure interval, and the peak pressure in the first filter plate is taken as the lower limit of the second pressure interval;

[0012] Ultrasonic wave propagation velocity is detected in the mud cavity on both sides of the filter plate from the first filter plate to the last filter plate with non-zero water output, and a propagation velocity threshold is set for comparison. If the ultrasonic wave propagation velocity is less than the propagation velocity threshold, its air pressure peak is excluded, otherwise, its air pressure peak is retained;

[0013] Ultrasonic imaging is performed on the mud cavity where the ultrasonic propagation velocity is greater than the propagation velocity threshold, and the structural strength thereof is identified, and the mud cavity with the highest structural strength level and the corresponding air pressure peak value at the filter plate are output as the optimal air pressure peak value;

[0014] The sludge in the mud chamber is continuously filled with water through the compression plate, and all filter plates are pressurized at the optimal peak pressure to dehydrate the sludge in the mud chamber, and then demoulded to obtain a solidified mud cake;

[0015] The solidified mud cake is transferred to a high-temperature pyrolysis furnace for pyrolysis to obtain a composite carbon source.

[0016] Preferably, the method further comprises the step of adding a thickener to the concentrated sludge to increase the viscosity of the concentrated sludge to obtain thickened sludge.

[0017] Preferably, the high-pressure diaphragm filter press includes a plurality of compression plates and filter plates located between adjacent compression plates, a mud cavity for accommodating sludge is formed between the filter plates and the compression plates, the air pressure in the filter plates is adjustable, and a water inlet channel and a water outlet channel connected to the mud cavity are provided on the compression plates.

[0018] Preferably, the high-pressure diaphragm filter press also includes an air pressure acquisition module, a water output acquisition module, a data processing module, an ultrasonic acquisition module, and a control module. The air pressure acquisition module is used to collect the air pressure peak value in each filter plate and feed it back to the data processing module. The water output acquisition module is used to collect the water output in the water outlet channel connected to the mud chambers on both sides of each filter plate and feed it back to the data processing module. The ultrasonic acquisition module is used to collect the ultrasonic propagation velocity of the sludge in the mud chamber, ultrasonic imaging of the internal structure of the mud cake in the mud chamber and feed it back to the data processing module. The data processing module selects the optimal air pressure peak value according to the air pressure peak value in each filter plate, the water output in the water outlet channel connected to the mud chambers on both sides of each filter plate, the ultrasonic propagation velocity, and the ultrasonic imaging of the internal structure of the mud cake, and feeds it back to the control module. The control module is used to control the air pressure in each filter plate and control the water filling of the water inlet channel.

[0019] Preferably, the filter plate includes a filter frame, a fastening plate fixedly connected to the filter frame, and a diaphragm fixedly connected to the filter frame and located on both sides of the fastening plate, the thickness of the fastening plate is less than the thickness of the filter frame, an air cavity is formed between the diaphragm and the fastening plate, an air hole connected to the air cavity is opened on the filter frame, an air pipe connected to the air hole is fixedly connected to the filter frame, the air pipe is connected to an air pump, and the air pump is coupled to a control module.

[0020] Preferably, the clamping plate includes a clamping frame, and a support plate fixedly connected to the inner circle of the clamping frame, the thickness of the support plate is smaller than the thickness of the clamping frame, the water inlet channel is opened on the clamping frame and penetrates the clamping frame, the water outlet channel is also opened on the clamping frame and penetrates the clamping frame, the water inlet channel is located above the water outlet channel, the clamping frame is fixedly connected with a water pipe connected to the water inlet channel, the water pipe is connected to a water pump, and the water pump is coupled to the control module.

[0021] Preferably, a plurality of dynamic protrusions are integrally formed on the diaphragm, and a plurality of static protrusions corresponding to the positions of the dynamic protrusions are fixedly connected to the support plate.

[0022] Preferably, the data processing module selects the optimal peak value of air pressure according to the peak value of air pressure in each filter plate, the water output in the water outlet channel connected to the mud chambers on both sides of each filter plate, the ultrasonic propagation speed, and the ultrasonic imaging of the internal structure of the mud cake and feeds it back to the control module, including the following steps:

[0023] Perform filtering and histogram equalization on ultrasonic imaging;

[0024] Extracting texture features through gray level co-occurrence matrix, wherein the texture features include energy, contrast, and entropy;

[0025] Extracting shape features inside the mud cake by morphological operation, wherein the shape features include area and porosity;

[0026] The mud cake images with known structural strength are used as training sets, and the structural strength of each sample is annotated, and the structural strength includes high strength, medium strength, and low strength;

[0027] Based on the extracted texture features and morphological features, the model is trained using machine learning methods;

[0028] Import the ultrasound imaging into the trained model and output the corresponding structural strength;

[0029] The mud chamber with the highest output structural strength grade and its corresponding peak air pressure at the filter plate are taken as the optimal peak air pressure.

[0030] Preferably, the ultrasonic acquisition module includes an ultrasonic detector and an ultrasonic imager, the water output acquisition module includes a water flow sensor, the air pressure acquisition module includes an air pressure sensor, the data processing module includes a processor, and the control module includes a controller.

[0031] The present invention has the following beneficial effects:

[0032] The present invention increases the viscosity of sludge by using a thickener, dehydrates the sludge by using a high-pressure diaphragm filter press, optimizes the dehydration effect by controlling air pressure and ultrasonic detection, and finally obtains a mud cake with low water content and high structural strength for pyrolysis to prepare a composite carbon source. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 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.

[0034] Figure 1 It is a flowchart of the present invention;

[0035] Figure 2 It is a flow diagram of sludge in the present invention;

[0036] Figure 3 It is a schematic diagram of the structure of the filter plate and the pressing plate in the present invention;

[0037] Figure 4 It is a structural block diagram of the water output acquisition module, air pressure acquisition module, ultrasonic acquisition module, data processing module, and control module in the present invention.

[0038] 1. Primary sedimentation tank; 2. Biological tank; 3. Secondary sedimentation tank; 4. Sludge thickening tank; 5. High-pressure diaphragm filter press; 6. High-temperature pyrolysis furnace; 7. Compression plate; 8. Support plate; 9. Static convex point; 10. Filter plate; 11. Fastening plate; 12. Diaphragm; 13. Dynamic convex point; 14. Water output collection module; 15. Air pressure collection module; 16. Ultrasonic collection module; 17. Data processing module; 18. Control module. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] A method for producing a composite carbon source using wastewater biochemical excess sludge, such as Figure 1 As shown, the following steps are included:

[0046] like Figure 2 As shown, concentrated sludge is recovered after passing through the primary sedimentation tank 1, the biological tank 2, the secondary sedimentation tank 3, and the sludge thickening tank 4 in sequence;

[0047] Adding a thickener to the concentrated sludge to increase the viscosity of the concentrated sludge to obtain thickened sludge;

[0048] The high-pressure membrane filter press 5 is started, and a plurality of filter plates 10 and compression plates 7 are pressurized to merge, so that a mud cavity is formed between the filter plates 10 and the compression plates 7, and the sludge is guided into the high-pressure membrane filter press 5 and fills each mud cavity;

[0049] The sludge in the mud chamber is continuously filled with water through the pressing plate 7, and the lower limit of the first air pressure interval and the upper limit of the first air pressure interval are set as the air pressure peak values ​​in the first filter plate 10 and the last filter plate 10 in the high-pressure diaphragm filter press 5, respectively. The air pressure peak values ​​of the remaining filter plates 10 are set in equal intervals between the lower limit of the first air pressure interval and the upper limit of the first air pressure interval in the order of the filter plates 10, and a plurality of filter plates 10 are pressurized and dehydrated in sequence;

[0050] The sludge in the mud chamber is continuously filled with water through the pressing plate 7, and several filter plates 10 maintain the original peak pressure and are pressurized and dehydrated in sequence, and the water output of the mud chambers on both sides of each filter plate 10 is collected until the water output of a mud chamber is zero, and the subsequent filter plates 10 are stopped from pressurizing, and the peak pressure of the previous filter plate 10 in the sequence is taken as the upper limit of the second pressure interval, and the peak pressure in the first filter plate 10 is taken as the lower limit of the second pressure interval;

[0051] Ultrasonic wave propagation velocity is detected in the mud cavity on both sides of the first filter plate 10 to the last filter plate 10 with non-zero water output, and a propagation velocity threshold is set for comparison. If the ultrasonic wave propagation velocity is less than the propagation velocity threshold, its air pressure peak is excluded, otherwise, its air pressure peak is retained;

[0052] Perform ultrasonic imaging on the mud cavity where the ultrasonic propagation velocity is greater than the propagation velocity threshold and identify the structural strength thereof, output the mud cavity with the highest structural strength level and the corresponding air pressure peak value at the filter plate 10 as the optimal air pressure peak value;

[0053] The sludge in the mud chamber is continuously filled with water through the pressing plate 7, and all the filter plates 10 are pressurized at the optimal peak pressure to dehydrate the sludge in the mud chamber, and then demoulded to obtain a solidified mud cake;

[0054] The solidified mud cake is transported to a high-temperature pyrolysis furnace 6 for pyrolysis to obtain a composite carbon source.

[0055] Preferably, if Figure 3 As shown, the high-pressure diaphragm filter press 5 includes a plurality of compression plates 7 and filter plates 10 located between adjacent compression plates 7. A mud cavity for accommodating sludge is formed between the filter plates 10 and the compression plates 7. The air pressure in the filter plates 10 is adjustable. The compression plates 7 are provided with a water inlet channel and a water outlet channel connected to the mud cavity.

[0056] like Figure 4 As shown, the high-pressure diaphragm filter press 5 also includes an air pressure acquisition module 15, a water output acquisition module 14, a data processing module 17, an ultrasonic acquisition module 16, and a control module 18. The air pressure acquisition module 15 is used to collect the peak air pressure in each filter plate 10 and feed it back to the data processing module 17. The water output acquisition module 14 is used to collect the water output in the water outlet channel connected to the mud chambers on both sides of each filter plate 10 and feed it back to the data processing module 17. The ultrasonic acquisition module 16 is used to collect the ultrasonic propagation velocity of the sludge in the mud chamber, ultrasonic imaging of the internal structure of the mud cake in the mud chamber, and feed it back to the data processing module 17. The data processing module 17 selects the optimal air pressure peak value according to the air pressure peak value in each filter plate 10, the water output in the water outlet channel connected to the mud cavity on both sides of each filter plate 10, the ultrasonic propagation speed, and the ultrasonic imaging of the internal structure of the mud cake, and feeds back to the control module 18. The control module 18 is used to control the air pressure in each filter plate 10 and control the water filling of the water inlet channel. The ultrasonic acquisition module 16 includes an ultrasonic detector and an ultrasonic imager. The water output acquisition module 14 includes a water flow sensor, the air pressure acquisition module 15 includes an air pressure sensor, the data processing module 17 includes a processor, and the control module 18 includes a controller.

[0057] like Figure 3 As shown, the filter plate 10 includes a filter frame, a fastening plate 11 fixedly connected in the filter frame, and a diaphragm 12 fixedly connected in the filter frame and located on both sides of the fastening plate 11, the thickness of the fastening plate 11 is less than the thickness of the filter frame, an air cavity is formed between the diaphragm 12 and the fastening plate 11, an air hole connected to the air cavity is opened on the filter frame, an air pipe connected to the air hole is fixedly connected to the filter frame, the air pipe is connected to an air pump, and the air pump is coupled to the control module 18.

[0058] like Figure 3As shown, the clamping plate 7 includes a clamping frame and a support plate 8 fixedly connected to the inner circle of the clamping frame. The thickness of the support plate 8 is smaller than the thickness of the clamping frame. The water inlet channel is opened on the clamping frame and penetrates the clamping frame. The water outlet channel is also opened on the clamping frame and penetrates the clamping frame. The water inlet channel is located above the water outlet channel. A water pipe connected to the water inlet channel is fixedly connected to the clamping frame. The water pipe is connected to a water pump, and the water pump is coupled to the control module 18.

[0059] like Figure 3 As shown, a plurality of dynamic protrusions 13 are integrally formed on the diaphragm 12 , and a plurality of static protrusions 9 corresponding to the positions of the dynamic protrusions 13 are fixedly connected to the support plate 8 .

[0060] Preferably, the data processing module 17 selects the optimal peak value of air pressure according to the peak value of air pressure in each filter plate 10, the water output in the water outlet channel connected to the mud chambers on both sides of each filter plate 10, the ultrasonic propagation speed, and the ultrasonic imaging of the internal structure of the mud cake and feeds it back to the control module 18, including the following steps:

[0061] Filtering Ultrasound Imaging ,in, For the image The pixel value of the point, is the standard deviation, For the filtered image, and histogram equalization ,in, is the pixel value of the original image, is the pixel value after enhancement;

[0062] The texture features are extracted through the gray level co-occurrence matrix. The texture features include energy Describes the uniformity of the image. The greater the energy, the tighter the structure and the higher the contrast. Describes the intensity of grayscale changes in the image. The greater the contrast, the more structural inhomogeneity and entropy in the mud cake. Reflects the amount of information in the image. The larger the entropy, the more complex the structure.

[0063] The shape features inside the mud cake are extracted through morphological operations. The morphological operations include corrosion, expansion, opening operation, closing operation, etc. The shape features include area and porosity. Area includes the size of the area in the mud cake. A larger area usually indicates a stronger structure. Porosity includes calculating the proportion of pores in the image. Mud cakes with fewer pores are usually stronger.

[0064] The mud cake images with known structural strength are used as training sets, and the structural strength of each sample is annotated. The structural strength includes high strength, medium strength, and low strength.

[0065] Based on the extracted texture features and morphological features, the model is trained using machine learning methods;

[0066] Import the ultrasound imaging into the trained model and output the corresponding structural strength;

[0067] The mud cavity with the highest output structural strength grade and its corresponding peak air pressure at the filter plate 10 are taken as the optimal peak air pressure.

[0068] The present invention can recycle the sludge after being treated by the primary sedimentation tank 1, the biological tank 2, the secondary sedimentation tank 3 and the sludge thickening tank 4, and add a thickener to the concentrated sludge to increase its viscosity, so that the concentrated sludge can discard the vast majority of water therein, and can make the solid materials therein agglomerate as much as possible. When the concentrated sludge is actually sent to the high-pressure diaphragm filter press 5, the high-pressure diaphragm filter press 5 will preferentially make the filter plate 10 and the pressing plate 7 fit each other, and the hydraulic cylinder in the high-pressure diaphragm filter press 5 applies a force of 3000 pounds per square inch to both, ensuring that the filter plate 10 and the pressing plate 7 fit closely, so as to form a mud cavity for accommodating the sludge, and after the thickened sludge enters the mud cavity, it can ensure that most of the mud cavity is composed of sludge, thereby alleviating the uneven distribution of solid materials in each mud cavity due to the excessive dilution of the sludge;

[0069] Then, the water pump is controlled by the control module 18 to make the water pump pump water into the water inlet channel, so that the sludge in the mud chamber can be cleaned, and while taking away the sewage, it can also ensure that the mud chamber is in a state of sufficient water. After that, the water pump is controlled to stop working and each air pump is controlled to work instead. Each air pump adjusts the air pressure in the filter plate 10, and sets the lower limit of the first air pressure interval and the upper limit of the first air pressure interval as the air pressure peak values ​​in the first filter plate 10 and the last filter plate 10 in the high-pressure diaphragm filter press 5, respectively. The air pressure peak values ​​of the remaining filter plates 10 are set in equal difference between the lower limit of the first air pressure interval and the upper limit of the first air pressure interval in the order of the filter plates 10. In this way, when each filter is pressurized and dehydrated in sequence, the air pressure peak values ​​corresponding to each filter plate 10 are also different, thereby ensuring that in this method, when the high-pressure diaphragm filter press 5 is performing the action of pressing filtration, it can complete the preparation for the subsequent air pressure peak judgment in the first round;

[0070] Then, the sludge in the mud chamber is continuously flushed with water to ensure that the mud cake that has not been pressed to a compact state can fully absorb water to increase its water content. Then, when a number of filter plates 10 maintain the original peak pressure and pressurize and dehydrate in sequence, according to the water output of the mud chambers on both sides of each filter plate 10, it can be judged which filter plates 10 have pressed the sludge into a compact mud cake in the first round of pressurization. By making such a judgment, the upper limit of the subsequent peak pressure can be determined;

[0071] After that, ultrasonic testing is performed in the mud chamber that has completed pressurized dehydration. Generally speaking, a slow ultrasonic propagation speed indicates a high water content, while a fast ultrasonic propagation speed indicates a low water content. In addition, the lower limit of the peak pressure can be limited by combining the propagation speed threshold.

[0072] At this time, there are not many air pressure peaks corresponding to the filters that can meet the requirements of the first two rounds of screening. By identifying the structural strength through ultrasonic imaging, the mud cavity with the highest structural strength level and its corresponding air pressure peak at the filter plate 10 are output as the optimal air pressure peak, and the most suitable air pressure peak can be directly confirmed. At this time, the mud cake after pressurized dehydration by the filter plate 10 corresponding to the air pressure peak not only has a low water content, but also can ensure that it has the best structural strength, so that when the mud cake is demolded from the high-pressure diaphragm filter press 5, it will not be broken or other problems that affect its integrity;

[0073] Afterwards, the complete mud cake is transferred to the high-temperature pyrolysis furnace 6 to complete the pyrolysis process, thereby obtaining a composite carbon source with a high integrity.

[0074] 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 producing a composite carbon source using wastewater biochemical excess sludge, characterized in that: The following steps are included: Recovering concentrated sludge that has passed through the primary sedimentation tank (1), the biological tank (2), the secondary sedimentation tank (3), and the sludge thickening tank (4) in sequence; Starting the high-pressure membrane filter press (5), pressurizing and combining a plurality of filter plates (10) and a pressing plate (7), forming a mud cavity between the filter plates (10) and the pressing plate (7), and guiding the sludge into the high-pressure membrane filter press (5) and filling each mud cavity; The sludge in the mud chamber is continuously filled with water through a compression plate (7), and a lower limit of a first air pressure interval and an upper limit of the first air pressure interval are set as the air pressure peak values ​​in the first filter plate (10) and the last filter plate (10) in the high-pressure diaphragm filter press (5), respectively, and the air pressure peak values ​​of the remaining filter plates (10) are set in equal intervals between the lower limit of the first air pressure interval and the upper limit of the first air pressure interval in the order of the filter plates (10), and a plurality of filter plates (10) are pressurized and dehydrated in sequence; The sludge in the mud chamber is continuously filled with water through the pressing plate (7), and a plurality of filter plates (10) are pressurized and dehydrated in sequence while maintaining the original peak pressure. The water output of the mud chambers on both sides of each filter plate (10) is collected, and the subsequent filter plates (10) are stopped from pressurizing until the water output of a mud chamber is zero; Ultrasonic wave propagation speed is detected in the mud cavity on both sides of the first filter plate (10) to the last filter plate (10) with non-zero water output, and a propagation speed threshold is set for comparison. If the ultrasonic wave propagation speed is less than the propagation speed threshold, its air pressure peak is excluded, otherwise, its air pressure peak is retained; Ultrasonic imaging is performed on the mud cavity where the ultrasonic propagation speed is greater than the propagation speed threshold, and the structural strength thereof is identified, and the mud cavity with the highest structural strength level and the air pressure peak value at the corresponding filter plate (10) are output as the optimal air pressure peak value; The sludge in the mud chamber is continuously filled with water through the pressing plate (7), and all the filter plates (10) are pressurized at the optimal peak pressure to dehydrate the sludge in the mud chamber, and then demoulding is performed to obtain a solidified mud cake; The solidified mud cake is transported to a high-temperature pyrolysis furnace (6) for pyrolysis to obtain a composite carbon source.

2. The method for producing a composite carbon source by utilizing wastewater biochemical excess sludge according to claim 1, characterized in that: The method also includes the following steps: adding a thickener to the concentrated sludge to increase the viscosity of the concentrated sludge to obtain thickened sludge.

3. The method for producing a composite carbon source by utilizing wastewater biochemical excess sludge according to claim 1, characterized in that: The high-pressure diaphragm filter press (5) comprises a plurality of compression plates (7) and filter plates (10) located between adjacent compression plates (7), a mud cavity for accommodating sludge is formed between the filter plates (10) and the compression plates (7), the air pressure in the filter plates (10) is adjustable, and a water inlet channel and a water outlet channel connected to the mud cavity are provided on the compression plates (7).

4. The method for producing a composite carbon source by utilizing wastewater biochemical excess sludge according to claim 3, characterized in that: The high-pressure diaphragm filter press (5) further comprises an air pressure acquisition module (15), a water output acquisition module (14), a data processing module (17), an ultrasonic acquisition module (16), and a control module (18), wherein the air pressure acquisition module (15) is used to acquire the peak value of the air pressure in each filter plate (10) and feed it back to the data processing module (17), the water output acquisition module (14) is used to acquire the water output in the water output channel connected to the mud cavity on both sides of each filter plate (10) and feed it back to the data processing module (17), and the ultrasonic acquisition module (16) is used to acquire the peak value of the air pressure in each filter plate (10) and feed it back to the data processing module (17), and the ultrasonic acquisition module (16) is used to acquire the peak value of the air pressure in each filter plate (10) and feed it back to the data processing module (17). The block (16) is used to collect the ultrasonic propagation velocity of the sludge in the mud cavity, ultrasonically image the internal structure of the mud cake in the mud cavity, and feed it back to the data processing module (17). The data processing module (17) selects the optimal air pressure peak value according to the air pressure peak value in each filter plate (10), the water output in the water outlet channel connected to the mud cavity on both sides of each filter plate (10), the ultrasonic propagation velocity, and the ultrasonic imaging of the internal structure of the mud cake, and feeds it back to the control module (18). The control module (18) is used to control the air pressure in each filter plate (10) and control the water filling of the water inlet channel.

5. The method for producing a composite carbon source by utilizing wastewater biochemical excess sludge according to claim 4, characterized in that: The filter plate (10) comprises a filter frame, a fastening plate (11) fixedly connected to the filter frame, and a diaphragm (12) fixedly connected to the filter frame and located on both sides of the fastening plate (11); the thickness of the fastening plate (11) is less than the thickness of the filter frame; an air cavity is formed between the diaphragm (12) and the fastening plate (11); an air hole connected to the air cavity is provided on the filter frame; an air pipe connected to the air hole is fixedly connected to the filter frame; the air pipe is connected to an air pump; and the air pump is coupled to a control module (18).

6. The method for producing a composite carbon source by utilizing wastewater biochemical excess sludge according to claim 5, characterized in that: The clamping plate (7) comprises a clamping frame, and a support plate (8) fixedly connected to the inner circle of the clamping frame, the thickness of the support plate (8) is smaller than the thickness of the clamping frame, the water inlet channel is opened on the clamping frame and penetrates the clamping frame, the water outlet channel is also opened on the clamping frame and penetrates the clamping frame, the water inlet channel is located above the water outlet channel, the clamping frame is fixedly connected to a water pipe connected to the water inlet channel, the water pipe is connected to a water pump, and the water pump is coupled to a control module (18).

7. The method for producing a composite carbon source by utilizing wastewater biochemical excess sludge according to claim 6, characterized in that: A plurality of dynamic convex points (13) are integrally formed on the diaphragm (12), and a plurality of static convex points (9) corresponding to the positions of the dynamic convex points (13) are fixedly connected to the support plate (8).

8. The method for producing a composite carbon source by utilizing wastewater biochemical excess sludge according to claim 4, characterized in that: The data processing module (17) selects the optimal peak value of air pressure according to the peak value of air pressure in each filter plate (10), the water output in the water outlet channel connected to the mud chambers on both sides of each filter plate (10), the ultrasonic propagation speed, and the ultrasonic imaging of the internal structure of the mud cake, and feeds back to the control module (18), comprising the following steps: Perform filtering and histogram equalization on ultrasonic imaging; Extracting texture features through gray level co-occurrence matrix, wherein the texture features include energy, contrast, and entropy; Extracting shape features inside the mud cake by morphological operation, wherein the shape features include area and porosity; The mud cake images with known structural strength are used as training sets, and the structural strength of each sample is annotated, and the structural strength includes high strength, medium strength, and low strength; Based on the extracted texture features and morphological features, the model is trained using machine learning methods; Import the ultrasound imaging into the trained model and output the corresponding structural strength; The peak air pressure at the mud cavity with the highest output structural strength level and its corresponding filter plate (10) is taken as the optimal peak air pressure.

9. The method for producing a composite carbon source by utilizing wastewater biochemical excess sludge according to claim 4, characterized in that: The ultrasonic acquisition module (16) comprises an ultrasonic detector and an ultrasonic imager, the water output acquisition module (14) comprises a water flow sensor, the air pressure acquisition module (15) comprises an air pressure sensor, the data processing module (17) comprises a processor, and the control module (18) comprises a controller.

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