Primary sludge fermentation treatment system
By introducing microaerobic fermentation and adsorption reaction devices into the sludge fermentation treatment system, the problems of difficult decomposition of macromolecular organic matter and removal of nitrogen and phosphorus in sludge have been solved, achieving efficient fatty acid generation and high-purity carbon source preparation, and promoting the regeneration and utilization of sludge resources.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHONGQING JIAOTONG UNIV
- Filing Date
- 2025-06-19
- Publication Date
- 2026-06-19
AI Technical Summary
In existing technologies, anaerobic fermentation of sludge is difficult to effectively decompose large molecular organic matter, resulting in low fatty acid cultivation efficiency and failure to effectively remove nitrogen and phosphorus components from sludge, which affects the wastewater treatment effect and the reuse of carbon sources.
In the sludge fermentation treatment system, a micro-aerobic fermentation container is introduced, and oxygen is supplied by an oxygen tank for micro-aerobic fermentation treatment, which degrades macromolecular organic matter into small molecule organic acids. Then, nitrogen and phosphorus are removed through anaerobic fermentation and adsorption reaction devices, and finally a high-concentration liquid carbon source is obtained through a solution dehydration device.
It improves the efficiency of fatty acid production, removes nitrogen and phosphorus components, and obtains a high-purity liquid carbon source, which is suitable as a carbon source in wastewater treatment processes, realizing the efficient reuse of sludge resources.
Smart Images
Figure CN224377878U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of sewage treatment technology, specifically a primary sedimentation sludge fermentation treatment system. Background Technology
[0002] Primary sludge is the sludge obtained from sedimentation in the primary sedimentation tank of wastewater treatment plants. It contains a large amount of organic matter, often accounting for about half of the solid matter content. Conventional methods for treating wastewater sludge include landfilling or incineration. However, these methods fail to recover the organic matter, resulting in resource waste.
[0003] Organic components in sludge can be recycled to prepare carbon sources and used in subsequent wastewater treatment processes. For example, Chinese invention patent CN201810090767.6 discloses a method for promoting anaerobic fermentation of sludge to produce volatile fatty acids. The method specifically includes the following steps: (1) placing the sludge in a container for static sedimentation to remove the supernatant and obtain a sludge sample; (2) adding S2O82- / Fe to the sludge sample, then filling with nitrogen to remove oxygen, sealing the reactor, controlling the fermentation temperature, and using mechanical stirring to mix the reaction system materials evenly for anaerobic fermentation to produce acid. This invention can both reduce the volume of sludge and reduce environmental pollution, and also realize the resource utilization of sludge to produce volatile fatty acids with high utilization value.
[0004] However, in the aforementioned patented method, the sludge is directly subjected to anaerobic fermentation, which makes it difficult to effectively decompose some larger organic substances, resulting in low fatty acid cultivation efficiency. Furthermore, the removal of nitrogen and phosphorus from the sludge is not achieved, thus introducing and increasing the nitrogen and phosphorus content in subsequent wastewater treatment, which is detrimental to achieving the final wastewater effluent standards. Additionally, this method does not consider removing the generated fatty acids from the sludge, hindering the reuse of the carbon source. Utility Model Content
[0005] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to provide a primary sedimentation sludge fermentation treatment system that can utilize sludge fermentation to prepare fatty acid carbon sources, improve the fatty acid fermentation yield, reduce the nitrogen and phosphorus content in the obtained carbon source, and make the fermentation product more suitable for use as a carbon source in subsequent wastewater treatment processes.
[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:
[0007] A primary sludge fermentation treatment system includes a sludge dewatering device, a mixing container, and an anaerobic fermentation container arranged in series. The sludge outlet of the sludge dewatering device is connected to the mixing container via a sludge feeding pipe, and a second sludge pump is installed on the sludge feeding pipe. The upper end of the mixing container is connected to a sludge feeding pipe and a soluble sugar feeding port with a switch valve, and a first stirring device is installed inside the mixing container. The system is characterized by further including a micro-aerobic fermentation container connected in series between the mixing container and the anaerobic fermentation container.
[0008] The lower end of the mixing container is connected to the micro-aerobic fermentation container via a sludge pipe equipped with a third sludge pump. The micro-aerobic fermentation container has a closed upper design and a second stirring device installed inside. An air supply port is also provided at the bottom of the micro-aerobic fermentation container, which is connected to an oxygen tank via an air supply pipe with a switch control valve. The lower side of the micro-aerobic fermentation container is connected to the anaerobic fermentation container via a sludge pipe equipped with a fourth sludge pump. The upper end of the anaerobic fermentation container has a closed upper design and an acid-producing bacteria agent dosing port with a switch valve. A third stirring device is installed inside the anaerobic fermentation container. A drain pipe with a switch valve is also installed at the lower end of the anaerobic fermentation container, and an outlet pipe equipped with a first liquid pump is connected to the upper end of the anaerobic fermentation container.
[0009] In this system, the initial sludge (generally dewatered to a moisture content of 90-92%) after dewatering by the sludge dewatering device is added to the mixing container through the sludge inlet pipe. Then, some soluble sugar (which can generally be industrial waste molasses or fruit and vegetable processing waste liquid, achieving waste utilization and turning waste into treasure) can be added (optional; omitting it may result in a relatively poorer overall fermentation effect) through the soluble sugar inlet into the mixing container. The carbon-to-nitrogen ratio in the sludge is adjusted to a suitable range (generally a C / N ratio of 15-25:1, which better provides suitable nutrient ratios for microorganisms, promoting their growth and reproduction) and mixed thoroughly. The mixed sludge is then pumped into the microaerobic fermentation container via a third sludge pump. The microaerobic fermentation container relies on an oxygen tank to supply oxygen and, after thorough mixing, performs microaerobic fermentation to degrade macromolecular organic matter. After microaerobic fermentation is complete, the sludge is pumped to an anaerobic fermentation vessel via a fourth sludge pump. Acid-producing bacteria, such as Klebsiella pneumoniae and Lactobacillus brunelli, are added to the anaerobic fermentation vessel through the top acid-producing bacteria inlet. Anaerobic fermentation assists in acid production. Through anaerobic fermentation, the complex organic matter in the sludge is gradually decomposed into small-molecule organic acids such as VFAs (vitamin fatty acids). Because the organic acids are liquid, they gradually rise to the surface and clarify at the top of the sludge, forming a clear liquid rich in organic acids. This clear liquid is then discharged through an outlet pipe.
[0010] Therefore, compared to existing technology patents, the system in this application sets up a micro-aerobic fermentation container before the anaerobic fermentation container. The micro-aerobic fermentation container relies on an oxygen tank to supply oxygen for micro-aerobic fermentation treatment, which can degrade large organic molecules into small organic molecules. Then, anaerobic fermentation treatment is carried out, which can better improve the treatment effect and efficiency of anaerobic fermentation and increase the efficiency of organic acid generation.
[0011] Furthermore, it also includes an adsorption reaction device and a solution dehydration device. The outlet pipe equipped with the first liquid pump is connected to the upper end of the adsorption reaction device. The adsorption reaction device is equipped with a nitrogen and phosphorus adsorption module. The bottom of the adsorption reaction device is connected to the solution dehydration device through an outlet pipe equipped with a second liquid pump.
[0012] In this way, the clarified liquid rich in organic acids can be guided to the adsorption reactor through the effluent pipe. The remaining sludge in the anaerobic fermentation vessel is discharged through the drain pipe, achieving batch processing. In the adsorption reactor, the clarified liquid rich in organic acids undergoes nitrogen and phosphorus adsorption treatment via the nitrogen and phosphorus adsorption module. It then undergoes dehydration via a solution dehydration device to obtain a high-concentration liquid carbon source. This scheme enables the preparation of a liquid carbon source from primary sludge, and the obtained high-concentration liquid carbon source is free of nitrogen and phosphorus components, making it convenient for wastewater carbon source replenishment. In implementation, the nitrogen and phosphorus adsorption module can be prepared using any material available in the prior art capable of adsorbing and removing nitrogen and phosphorus.
[0013] Furthermore, the sludge inlet of the sludge dewatering device is connected to a primary sludge storage tank via an inlet pipe equipped with a first sludge pump. This makes sludge feeding more convenient.
[0014] Furthermore, a floating liquid outlet device and a liquid outlet pipe are installed at the upper end of the anaerobic fermentation container. The liquid outlet device includes a float with a downward-facing inverted cone-shaped liquid intake port at the lower end. The upper end of the float has a liquid outlet that communicates with the liquid intake port. The liquid outlet is connected upward to a flexible hose with a certain amount of mobility and is connected to the liquid outlet pipe at the upper end of the anaerobic fermentation container. A suspension rope is also installed upward at the middle of the upper end of the float. The upper end of the suspension rope is wound and connected to the spool of a winch installed on the upper end panel of the anaerobic fermentation container.
[0015] During the anaerobic fermentation process in the anaerobic fermentation vessel, the winch is used to suspend the float, ensuring it does not interfere with the sludge mixing and fermentation process. Once the anaerobic fermentation is complete and a clear liquid is formed at the top of the sludge, the winch is then used to lower the float to the surface of the clear liquid. At this point, the clear liquid produced at the top of the anaerobic fermentation vessel can be pumped away through the outlet pipe, minimizing disturbance to the sludge below.
[0016] Furthermore, each of the four sides of the lower surface of the float is provided with a telescopic adjustment rod pointing downwards, and a horizontal baffle is provided at the lower end of each telescopic adjustment rod.
[0017] In this way, as the clarified liquid is gradually absorbed, the liquid level drops, and the float follows the drop until the baffle falls onto the upper surface of the settled sludge below and is blocked. At this point, the float stops sinking, preventing the sludge from being drawn away. A small amount of residual clarified liquid is discharged with the sludge. The distance between the baffle and the float can be adjusted by a telescopic adjustment rod to avoid excessive residual clarified liquid. Therefore, this device can achieve the effect of maximizing the removal of clarified liquid while minimizing disturbance to the sludge.
[0018] Furthermore, observation windows made of glass are vertically installed on the side wall of the anaerobic fermentation vessel. This allows for real-time observation of the height of the clarified liquid produced to determine the progress of anaerobic fermentation and to promptly process the discharged liquid.
[0019] Furthermore, the nitrogen and phosphorus adsorption module includes a zeolite material layer, a magnesium-modified zeolite material layer, and a physical adsorption material layer arranged sequentially from top to bottom. The magnesium-modified zeolite material layer is filled with modified zeolite loaded with magnesium ions, and the physical adsorption material layer is activated carbon or phosphorus removal resin.
[0020] In this process, the clarified liquid first passes through an upper layer of unmodified zeolite material, which adsorbs and removes some ammonia nitrogen. Then it passes through a layer of magnesium-modified zeolite material. This magnesium-modified zeolite material is an existing modified zeolite material, obtained by chemical impregnation, mixing natural zeolite with a magnesium salt solution, and then drying to load magnesium ions. The resulting magnesium-modified zeolite contains a large amount of magnesium ions. Zeolite itself has a strong ammonia nitrogen removal capacity, and the added magnesium ions after modification can dissolve and react with phosphate and ammonium ions to form struvite precipitate. Therefore, the modified zeolite greatly improves its adsorption capacity for ammonia nitrogen and phosphate in the clarified liquid, and the struvite precipitate can be used as a slow-release fertilizer in agriculture. This achieves the recovery and utilization of nitrogen and phosphorus components. Finally, the water passes through a lower layer of activated carbon or phosphorus removal resin to capture any remaining trace pollutants, better ensuring the quality of the effluent.
[0021] Furthermore, the solution dehydration device includes a container, inside which is a container-shaped frame. The outer surface of the frame is entirely covered with an ultrafiltration membrane. The pore size of the ultrafiltration membrane is larger than that of water molecules and smaller than that of organic acid molecules (around 50 nm). The frame is provided with a liquid extraction pipe and connected to the outside of the container. A third liquid pump is installed on the liquid extraction pipe.
[0022] This allows for the use of a third liquid pump to generate pressure, drawing water away through an ultrafiltration membrane, leaving a high-concentration organic acid solution, thus efficiently achieving solution dehydration. Ultimately, a high-purity liquid carbon source with VFA ≥ 8000 mg / L and COD:N:P ≥ 200:5:1 can be obtained.
[0023] Therefore, the equipment of this utility model can realize the recycling of primary sedimentation sludge, and has the advantages of high fatty acid yield and high efficiency of biomass resource reuse in sludge. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the sludge treatment system used in this utility model.
[0025] Figure 2 for Figure 1 A schematic diagram of the structure of a standalone floating liquid outlet device. Detailed Implementation
[0026] The present invention will be further described below with reference to specific embodiments and accompanying drawings.
[0027] Preferred Implementation: A primary sludge fermentation treatment system, see [link to previous document]. Figure 1-2 As shown, the system includes a sludge dewatering device 17, a mixing container 1, a microaerobic fermentation container 2, and an anaerobic fermentation container 3 arranged in series. The sludge outlet of the sludge dewatering device 17 is connected to the mixing container via a sludge feeding pipe, and a second sludge pump 18 is installed on the sludge feeding pipe. The upper end of the mixing container 1 is provided with a sludge feeding pipe and a soluble sugar feeding port 6 with a switch valve. A first stirring device 7 is installed inside the mixing container 1. The lower end of the mixing container 1 is connected to the microaerobic fermentation container 2 via a sludge pipe equipped with a third sludge pump 8. The upper end of the microaerobic fermentation container 2 is closed. Furthermore, a second stirring device 9 is installed inside, and an air supply port is also provided at the bottom of the micro-aerobic fermentation container 2. The air supply port is connected to the oxygen tank 10 through an air supply pipe with a switch control valve. The lower end of the micro-aerobic fermentation container 2 is connected to the anaerobic fermentation container 3 through a sludge pipe with a fourth sludge pump 11 installed. The upper end of the anaerobic fermentation container 3 is closed and equipped with an acid-producing bacteria agent addition port 12 with a switch valve. A third stirring device 13 is installed inside the anaerobic fermentation container 3. A sewage pipe 14 with a switch valve is also installed at the lower end of the anaerobic fermentation container. The upper end of the anaerobic fermentation container 3 is also connected to an outlet pipe with a first liquid pump 15 installed.
[0028] In this system, the initial sludge (generally dewatered to a moisture content of 90-92%) after dewatering by the sludge dewatering device is added to the mixing container through the sludge inlet pipe. Then, some soluble sugar (typically industrial waste molasses or fruit and vegetable processing waste liquid, achieving waste utilization and turning waste into treasure) is added to the mixing container through the soluble sugar inlet. The carbon-to-nitrogen ratio in the sludge is adjusted to a suitable range (generally a C / N ratio of 15-25:1, which better provides suitable nutrients for microorganisms and promotes their growth and reproduction) and mixed thoroughly. The mixed sludge is then pumped into the microaerobic fermentation container via a third sludge pump. The microaerobic fermentation container relies on an oxygen tank to supply oxygen and, after thorough mixing, performs microaerobic fermentation treatment to degrade macromolecular organic matter. After microaerobic fermentation is complete, the sludge is pumped to an anaerobic fermentation vessel via a fourth sludge pump. Acid-producing bacteria, such as Klebsiella pneumoniae and Lactobacillus brunelli, are added to the anaerobic fermentation vessel through the top acid-producing bacteria inlet. Anaerobic fermentation assists in acid production. Through anaerobic fermentation, the complex organic matter in the sludge is gradually decomposed into small-molecule organic acids such as VFAs (vitamin fatty acids). Because the organic acids are liquid, they gradually rise to the surface and clarify at the top of the sludge, forming a clear liquid rich in organic acids. This clear liquid is then discharged through an outlet pipe.
[0029] In practice, the system also includes an adsorption reaction device 4 and a solution dehydration device 5; the outlet pipe equipped with the first liquid pump 15 is connected to the upper end of the adsorption reaction device 4, the adsorption reaction device 4 is equipped with a nitrogen and phosphorus adsorption module, and the bottom of the adsorption reaction device is connected to the solution dehydration device 5 through an outlet pipe equipped with the second liquid pump 16.
[0030] In this way, the clarified liquid rich in organic acids can be guided to the adsorption reactor through the effluent pipe. The remaining sludge in the anaerobic fermentation vessel is discharged through the drain pipe, achieving batch processing. In the adsorption reactor, the clarified liquid rich in organic acids undergoes nitrogen and phosphorus adsorption treatment via the nitrogen and phosphorus adsorption module. It then passes through a solution dehydration device to obtain a high-concentration liquid carbon source. This scheme can prepare a liquid carbon source from primary sludge, and the obtained high-concentration liquid carbon source is free of nitrogen and phosphorus components, making it convenient for wastewater carbon source replenishment. During implementation, each vessel is also equipped with a safety vent valve and vent pipe to ensure safe gas pressure by venting the generated fermentation gases.
[0031] During implementation, the oxygen content (DO) of the sludge can be controlled at 0.2-0.5 mg / L during microaerobic fermentation. This better promotes the rapid degradation of macromolecular organic matter by facultative bacteria (such as Bacillus). The microaerobic environment, with an oxygen content of DO of 0.2-0.5 mg / L, simultaneously promotes the synergistic effect of aerobic, facultative, and some anaerobic microorganisms. This environment allows aerobic and facultative bacteria to utilize trace amounts of oxygen to degrade small-molecule organic matter, while simultaneously alleviating the toxic effects of organic acids and oxygen on methanogens, thus achieving highly efficient organic matter degradation. The microaerobic fermentation time is generally controlled at around 24 hours, ideally adjusted to ensure the complete degradation of macromolecular organic matter.
[0032] During implementation, an acid-producing compound microbial agent is added to assist anaerobic fermentation. This compound microbial agent can include *Klebsiella acidogenetica* and *Lactobacillus bruneri*, specifically the compound microbial agent with preservation number CCTCC NO:447558. The synergistic effect of *Klebsiella acidogenetica* and *Lactobacillus bruneri* can better disrupt the colloidal structure of the sludge, making the organic matter in the sludge more readily available for microbial utilization, thereby shortening the fermentation cycle. During implementation, the anaerobic fermentation temperature should be appropriately controlled at 30-35℃, and the pH at 5.5-6.5 to better ensure fermentation efficiency.
[0033] The sludge dewatering device 17 has its inlet connected to a primary sedimentation sludge storage tank 20 via an inlet pipe equipped with a first sludge pump 19. The sludge dewatering device 17 itself is a conventional, existing device and will not be described in detail here. This design facilitates sludge feeding.
[0034] The anaerobic fermentation container 3 is also equipped with a floating liquid outlet device and a liquid outlet pipe. The liquid outlet device includes a float 21. The lower end of the float 21 is provided with a downward-facing inverted cone-shaped liquid inlet 22. The upper end of the float 21 is provided with a liquid outlet and a liquid inlet that communicate with each other. The liquid outlet is connected upward to a flexible hose 23 with a movable margin and connected to the liquid outlet pipe at the upper end of the anaerobic fermentation container 3. The middle part of the upper end of the float 21 is also provided with a hanging rope 24. The upper end of the hanging rope 24 is wound and connected to the coil of a winch 26 installed on the upper end panel 25 of the anaerobic fermentation container.
[0035] During the anaerobic fermentation process in the anaerobic fermentation vessel, the winch is controlled to suspend the float, ensuring it does not interfere with the sludge mixing and fermentation process. Once the anaerobic fermentation is complete and a clear liquid forms at the top of the sludge, the winch is then controlled to lower the float to the surface of the clear liquid. At this point, the clear liquid produced at the top of the anaerobic fermentation vessel can be pumped away through the outlet pipe, minimizing disturbance to the sludge below. Therefore, based on the working process and its principle, the outlet device can also be implemented independently and used for the discharge of supernatant from other sediments, further avoiding interference with the sediment.
[0036] Each of the four sides of the lower surface of the float 21 is provided with a telescopic adjustment rod 27, and a horizontal baffle 28 is provided at the lower end of each telescopic adjustment rod 27.
[0037] In this way, as the clarified liquid is gradually absorbed, the liquid level drops, and the float follows the drop until the baffle falls onto the upper surface of the settled sludge below and is blocked. At this point, the float stops sinking, preventing the sludge from being drawn away. A small amount of residual clarified liquid is discharged with the sludge. The distance between the baffle and the float can be adjusted using a telescopic adjustment rod to avoid excessive residual clarified liquid. Therefore, this device can achieve the effect of maximizing the removal of clarified liquid while minimizing disturbance to the sludge. In implementation, the telescopic adjustment rod uses a screw-fitted stud and a threaded sleeve for telescopic adjustment, resulting in a simple structure and convenient and reliable adjustment.
[0038] During implementation, a layer of filter paper is further installed at the lower end of the suction port to better prevent sludge from being sucked in.
[0039] The anaerobic fermentation vessel has vertically installed glass observation windows on its side walls. This allows for real-time monitoring of the clarified liquid output height to determine the progress of anaerobic fermentation and to promptly process the discharged liquid.
[0040] The nitrogen and phosphorus adsorption module includes a zeolite material layer 41, a magnesium-modified zeolite material layer 42, and a physical adsorption material layer 43 arranged sequentially from top to bottom. The magnesium-modified zeolite material layer is filled with modified zeolite loaded with magnesium ions, and the physical adsorption material layer is activated carbon or phosphorus removal resin.
[0041] In this process, the clarified liquid first passes through an upper layer of unmodified zeolite material, which adsorbs and removes some ammonia nitrogen. Then it passes through a layer of magnesium-modified zeolite material. This magnesium-modified zeolite material is an existing modified zeolite material, obtained by chemical impregnation, mixing natural zeolite with a magnesium salt solution, and then drying to load magnesium ions. The resulting magnesium-modified zeolite contains a large amount of magnesium ions. Zeolite itself has a strong ammonia nitrogen removal capacity, and the added magnesium ions after modification can dissolve and react with phosphate and ammonium ions to form struvite precipitate. Therefore, the modified zeolite greatly improves its adsorption capacity for ammonia nitrogen and phosphate in the clarified liquid, and the struvite precipitate can be used as a slow-release fertilizer in agriculture. This achieves the recovery and utilization of nitrogen and phosphorus components. Finally, the water passes through a lower layer of activated carbon or phosphorus removal resin to capture any remaining trace pollutants, better ensuring the quality of the effluent.
[0042] The solution dehydration device 5 includes a container, inside which is a container-shaped frame 51. The outer surface of the frame 51 is covered with an ultrafiltration membrane. The pore size of the ultrafiltration membrane is larger than that of water molecules and smaller than that of organic acid molecules (around 50 nm). The frame 51 is provided with a liquid extraction pipe and connected to the outside of the container. A third liquid pump 52 is installed on the liquid extraction pipe.
[0043] This allows for the use of a third liquid pump to generate pressure, drawing water away through an ultrafiltration membrane, leaving a high-concentration organic acid solution, thus efficiently achieving solution dehydration. Ultimately, a high-purity liquid carbon source with VFA ≥ 8000 mg / L and COD:N:P ≥ 200:5:1 can be obtained.
Claims
1. A primary sludge fermentation treatment system, comprising a sludge dewatering device, a mixing container, and an anaerobic fermentation container arranged in series; the sludge outlet of the sludge dewatering device is connected to the mixing container via a sludge feeding pipe, and a second sludge pump is installed on the sludge feeding pipe; the upper end of the mixing container is connected to a sludge feeding pipe and a soluble sugar feeding port with a switch valve, and a first stirring device is installed inside the mixing container; characterized in that, It also includes microaerobic fermentation vessels connected in series between a mixing vessel and an anaerobic fermentation vessel; The lower end of the mixing container is connected to the micro-aerobic fermentation container via a sludge pipe equipped with a third sludge pump. The micro-aerobic fermentation container has a closed upper design and a second stirring device installed inside. An air supply port is also provided at the bottom of the micro-aerobic fermentation container, which is connected to an oxygen tank via an air supply pipe with a switch control valve. The lower side of the micro-aerobic fermentation container is connected to the anaerobic fermentation container via a sludge pipe equipped with a fourth sludge pump. The upper end of the anaerobic fermentation container has a closed upper design and an acid-producing bacteria agent dosing port with a switch valve. A third stirring device is installed inside the anaerobic fermentation container. A drain pipe with a switch valve is also installed at the lower end of the anaerobic fermentation container, and an outlet pipe equipped with a first liquid pump is connected to the upper end of the anaerobic fermentation container.
2. The primary sedimentation sludge fermentation treatment system according to claim 1, characterized in that: It also includes an adsorption reaction device and a solution dehydration device. The outlet pipe equipped with the first liquid pump is connected to the upper end of the adsorption reaction device. The adsorption reaction device is equipped with a nitrogen and phosphorus adsorption module. The bottom of the adsorption reaction device is connected to the solution dehydration device through an outlet pipe equipped with a second liquid pump.
3. The primary sludge fermentation treatment system according to claim 1, characterized in that: The sludge inlet of the sludge dewatering device is connected to a primary sedimentation sludge storage tank via an inlet pipe equipped with a first sludge pump.
4. The primary sedimentation sludge fermentation treatment system according to claim 2, characterized in that: The anaerobic fermentation container is also equipped with a floating liquid outlet device and a liquid outlet pipe. The liquid outlet device includes a float with a downward-facing inverted cone-shaped liquid inlet at the lower end. The upper end of the float has a liquid outlet that communicates with the liquid inlet. The liquid outlet is connected upward to a flexible hose with a certain amount of mobility and is connected to the liquid outlet pipe at the upper end of the anaerobic fermentation container. A suspension rope is also provided upward at the middle of the upper end of the float. The upper end of the suspension rope is wound and connected to the spool of a winch installed on the upper end panel of the anaerobic fermentation container.
5. The primary sludge fermentation treatment system according to claim 4, characterized in that: Each of the four sides of the lower surface of the float has a telescopic adjustment rod pointing downwards, and a horizontal baffle is provided at the lower end of each telescopic adjustment rod.
6. The primary sedimentation sludge fermentation treatment system according to claim 4, characterized in that: The anaerobic fermentation vessel has vertically installed observation windows made of glass material on its side wall.
7. The primary sludge fermentation treatment system according to claim 2, characterized in that: The nitrogen and phosphorus adsorption module includes a zeolite material layer, a magnesium-modified zeolite material layer, and a physical adsorption material layer arranged sequentially from top to bottom. The magnesium-modified zeolite material layer is filled with modified zeolite loaded with magnesium ions, and the physical adsorption material layer is activated carbon or phosphorus removal resin.
8. The primary sludge fermentation treatment system according to claim 2, characterized in that: The solution dehydration device includes a container, inside which is a container-shaped frame. The outer surface of the frame is entirely covered with an ultrafiltration membrane. The pore size of the ultrafiltration membrane is larger than that of water molecules and smaller than that of organic acid molecules. The frame is provided with a liquid extraction pipe and connected to the outside of the container. A third liquid pump is installed on the liquid extraction pipe.