Sewage treatment system

Abstract

The utility model discloses a sewage treatment system. The sewage treatment system comprises a filtering device, an iron removal device, a reaction device, a separation device and a mud refining device, the iron removal device is located at the downstream of the filtering device and comprises a controller and at least two iron removers, the controller is in communication connection with the iron removers, the controller is used for enabling the at least two iron removers to work alternately, the reaction device is located at the downstream of the iron removal device and communicated with the iron removers, and the separation device is located at the downstream of the reaction device and communicated with the iron removers. The separation device is communicated with the reaction cavity, the mud refining device is located at the downstream of the separation device, and in the sewage treatment process, after one iron remover works for a certain time, the machine is stopped to remove iron slag, and meanwhile, sewage is controlled to enter the other iron remover for iron removal. Therefore, in the embodiment, the two iron removers work alternately, so that the iron removal capability of the iron removers is ensured, the whole iron removal device does not need to be stopped, and the sewage treatment efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of sewage treatment, in particular to a sewage treatment system. Background Art

[0002] Sanitary ceramics and daily-use porcelain are mainly produced from clay and other inorganic non-metallic raw materials through processes such as ball milling, granulation, molding, glazing, firing, edge grinding, and polishing. In this process, the sewage discharged from the production line contains sponge residue, green sand debris, crushed gypsum residue, wood chips or iron slag, etc. In some technologies, in order to extract reusable ceramic raw material mud from sewage, the sewage is filtered, iron removed, flocculants are added, separated, and finally squeezed to obtain mud cakes. However, in the iron removal process, when the iron slag adsorbed by the iron remover reaches a certain amount, the iron remover's adsorption capacity for the iron slag is reduced, which makes it difficult to remove the iron slag in the sewage. In order to solve this problem, it is necessary to shut down the iron remover regularly to clean the iron slag adsorbed on the iron remover, resulting in low sewage treatment efficiency. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a sewage treatment system that can improve sewage treatment efficiency.

[0004] The sewage treatment system according to the embodiment of the utility model comprises: a filtering device, an iron removal device, a reaction device, a separation device and a mud refining device.

[0005] The filtering device is used to filter sewage, the iron removal device is located downstream of the filtering device, the iron removal device includes a controller and at least two iron removers, the controller is communicatively connected to each of the iron removers, and the controller is used to enable at least two iron removers to work alternately, the reaction device is located downstream of the iron removal device, the reaction device has a reaction chamber, the reactor is connected to the iron remover, the separation device is located downstream of the reaction device, the separation device has a separation chamber, and a first mud discharge port and a first liquid discharge port connected to the separation chamber, the separation chamber is connected to the reaction chamber, the first mud discharge port is used for discharging separated sludge, and the first liquid discharge port is used for discharging separated liquid, the mud refining device is located downstream of the separation device, includes a mud refining chamber, and the mud refining chamber is connected to the first mud discharge port.

[0006] The sewage treatment system according to the embodiment of the utility model has at least the following beneficial effects:

[0007] The iron removal device includes a controller and at least two iron removers, and the controller can control at least two iron removers to work alternately. Therefore, in the sewage treatment process, after one of the iron removers has worked for a certain period of time, the controller controls the iron remover to stop to remove iron slag, and at the same time controls the water flow to enter the other iron remover for iron removal. Therefore, in this embodiment, the two iron removers work alternately, while ensuring the iron removal capacity of the iron remover, there is no need to shut down the entire iron removal device, thereby improving the sewage treatment efficiency.

[0008] According to some embodiments of the utility model, the iron removal device also includes a guide groove and a magnetic bar, one end of the guide groove is connected to each of the iron removers, and the other end is connected to the reaction chamber, and the magnetic bar is arranged in the guide groove.

[0009] According to some embodiments of the present invention, the filtering device includes a first filtering component and a second filtering component, the second filtering component is located downstream of the first filtering component, the first filtering component includes a first screen, the second filtering component includes a second screen, and the mesh number of the first screen is smaller than the mesh number of the second screen.

[0010] According to some embodiments of the present invention, the second filter assembly further includes a vibration mechanism, and the vibration mechanism is connected to the second screen.

[0011] According to some embodiments of the utility model, the sewage treatment system also includes a dosing device, which includes at least two liquid storage chambers, each of which has a second liquid discharge port. The dosing device also includes a valve, and each of the second liquid discharge ports is provided with the valve.

[0012] According to some embodiments of the utility model, the sewage treatment also includes a cache device, which has a cache cavity, and a first mud inlet and a second mud discharge port connected to the cache cavity, the first mud inlet is connected to the first mud discharge port, and the second mud discharge port is connected to the mud refining cavity.

[0013] According to some embodiments of the utility model, the mud refining device has a second mud inlet connected to the mud refining chamber, the sewage treatment system includes a mud discharge pipe, the mud discharge pipe includes a main pipeline, and a first auxiliary pipeline and a second auxiliary pipeline connected to the main pipeline, the two ends of the main pipeline are respectively connected to the first mud discharge port and the second mud inlet, the end of the first auxiliary pipeline facing away from the main pipeline is connected to the first mud inlet, and the end of the second auxiliary pipeline facing away from the main pipeline is connected to the second mud discharge port.

[0014] According to some embodiments of the utility model, the first filter assembly also includes a conveying mechanism, the first screen has a water-facing surface, the angle between the water-facing surface and the horizontal direction is α, α>0, and the conveying mechanism has a conveying surface, which is located at the lower edge of the water-facing surface to receive and convey the filter residue filtered out by the first screen.

[0015] According to some embodiments of the utility model, the water facing surface is inclined relative to the horizontal direction, the first filter component has a first sewage inlet and a first sewage outlet, the first sewage inlet is located above the lower edge of the water facing surface, so that the sewage flowing out of the first sewage inlet can fall onto the water facing surface, and the conveying surface is higher than the first sewage outlet.

[0016] According to some embodiments of the present invention, the angle α between the water-facing surface and the horizontal plane has a value ranging from 30° to 40°.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0019] Figure 1 A schematic diagram of a sewage treatment system according to an embodiment of the utility model;

[0020] Figure 2 for Figure 1 Schematic diagram of the first filter component.

[0021] Reference numerals:

[0022] Filter device 100, first filter assembly 110, first screen 111, water-facing surface 1112, first sewage inlet 112, first sewage outlet 113, second filter assembly 120, second screen 121, vibration mechanism 122, conveying mechanism 130, conveying surface 131;

[0023] Iron removal device 200, iron remover 210, guide groove 220, magnetic bar 230;

[0024] Reaction device 300, reaction chamber 310;

[0025] Dosing device 400, liquid storage chamber 410, second liquid discharge port 411, valve 420;

[0026] Separation device 500, separation chamber 510, first liquid discharge port 520, first mud discharge port 530;

[0027] A mud refining device 600, a mud refining chamber 610, and a second mud inlet 620;

[0028] Buffer device 700, buffer chamber 710, first mud inlet 720, second mud outlet 730;

[0029] Mud discharge pipe 800, main pipe 810, first auxiliary pipe 820, second auxiliary pipe 830;

[0030] Sedimentation tank 900. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and 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 cannot be understood as a limitation on the present invention.

[0033] In the description of the present utility model, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0035] Sanitary ceramics and daily-use porcelain are mainly produced from clay and other inorganic non-metallic raw materials through processes such as ball milling, granulation, molding, glazing, firing, edge grinding, and polishing. In this process, the sewage discharged from the production line contains sponge residue, green sand debris, crushed gypsum residue, wood chips or iron slag, etc. In some technologies, in order to extract reusable ceramic raw material mud from sewage, the sewage is filtered, iron removed, flocculants are added, separated, and finally squeezed to obtain mud cakes. However, in the iron removal process, when the iron slag adsorbed by the iron remover reaches a certain amount, the iron remover's adsorption capacity for the iron slag is reduced, which makes it difficult to remove the iron slag in the sewage. In order to solve this problem, it is necessary to shut down the iron remover regularly to clean the iron slag adsorbed on the iron remover, resulting in low sewage treatment efficiency.

[0036] Based on this problem, this embodiment proposes a sewage treatment system, referring to Figure 1 , Figure 1 Schematic diagram of a sewage treatment system according to an embodiment of the utility model. The sewage treatment system according to the embodiment includes: a filtering device 100, an iron removal device 200, a reaction device 300, a separation device 500 and a mud refining device 600.

[0037] Among them, the filter device 100 includes, for example, a filter screen, which is used to filter out particles such as sponge residue, green sand debris, crushed gypsum residue, and wood chips in the sewage, and it is difficult to remove iron residue with smaller particles through the filter screen, so an iron removal device 200 is arranged downstream of the filter device 100, and the iron removal device 200 includes a controller and at least two iron removers 210, and the controller is connected to each iron remover 210 for communication, and the controller is used to enable at least two iron removers 210 to work alternately. The reaction device 300 is located downstream of the iron removal device 200, and the reaction device 300 has a reaction chamber 310, and the reaction chamber 310 is connected to the iron remover 210. After the sewage flows into the reaction chamber 310, pH regulators and flocculants are added to the reaction chamber 310 to adjust the sewage composition and make the fine particles in the sewage condense into large flocs.

[0038] The separation device 500 is located downstream of the reaction device 300. The separation device 500 has a separation chamber 510, and a first mud discharge port 530 and a first liquid discharge port 520 connected to the separation chamber 510. The separation chamber 510 is connected to the reaction chamber 310. The sewage after adding the reagent flows from the reaction chamber 310 into the separation chamber 510 for solid-liquid separation. The first mud discharge port 530 is used for discharging the separated sludge, and the first liquid discharge port 520 is used for discharging the separated liquid.

[0039] The mud refining device 600 is located downstream of the separation device 500. The mud refining device 600 has a mud refining chamber 610, which is connected to the first mud discharge port 530. The mud refining device can be, for example, a filter press or a centrifuge, thereby obtaining mud with a water content of less than 30% as a ceramic raw material.

[0040] Specifically, in this embodiment, the iron removal device 200 includes a controller and at least two iron removers 210. The controller can control at least two iron removers 210 to work alternately. During the sewage treatment process, after one of the iron removers 210 has worked for a certain period of time, the iron remover 210 is turned off to remove the iron slag adsorbed on the iron remover 210. While cleaning the iron remover 210, the controller controls the sewage to enter the other iron remover 210. In this way, the two iron removers 210 work alternately, thereby ensuring the adsorption capacity of the working iron remover 210 for the iron slag in the sewage, thereby improving the sewage treatment system of this embodiment The ability to remove iron slag in sewage is improved without shutting down the equipment to clean the iron slag on the iron remover 210, thereby improving the sewage treatment efficiency. Specifically, the iron remover 210 has a second sewage inlet, and a movable or rotatable shielding door is provided at the second sewage inlet for switching the opening and closing of the second sewage inlet. Both shielding doors are communicatively connected to the controller. For the convenience of description, the two iron removers 210 are respectively referred to as the first iron remover 210 and the second iron remover 210 below. When sewage is treated, the first iron remover 210 is first used to remove iron from the sewage, that is, the shielding door of the first iron remover 210 is controlled by the controller to move to a position avoiding the second sewage inlet so that the second sewage inlet is opened, and the second sewage inlet of the second iron remover 210 is controlled to be closed. The first iron remover 210 is closed to allow the sewage to pass through the first iron remover 210. After the first iron remover 210 works for a set period of time (set according to demand, for example, when the sewage contains more iron, the set period of time can be set shorter, and when the sewage contains less iron, the set period of time can be set longer), the second sewage inlet of the first iron remover 210 is controlled by the controller to be closed, and the second sewage inlet of the second iron remover 210 is controlled to be opened to allow the sewage to flow into the second iron remover 210. At this time, the iron slag adsorbed in the first iron remover 210 can be removed. In addition, the magnet in the first iron remover 210 can also be controlled to be powered off, so as to facilitate the removal of the iron slag.

[0041] In addition, in some embodiments, there is also a sedimentation tank 900, which is connected to the first drain port 520. The separated clean water flows out through the first drain port 520 and flows to the sedimentation tank 900 for sedimentation. The clean water after sedimentation can be recycled and reused.

[0042] Reference Figure 1On the basis of the above embodiment, the iron remover 210 further includes a guide groove 220 and a magnetic rod 230, one end of the guide groove 220 is connected to each iron remover 210, and the other end is connected to the reaction chamber 310, and the magnetic rod 230 is arranged in the guide groove 220. Thus, after the sewage flows to the guide groove 220 after iron removal by the iron remover 210, the magnetic rod 230 arranged in the guide groove 220 can remove iron from the sludge again, thereby improving the iron removal capacity of the sewage treatment system of this embodiment. In addition, it can be understood that the magnetic rod 230 has a certain magnetic attraction capacity, and the guide groove 220 is used as part of the pipeline for the sewage to flow from the iron remover 210 to the reaction chamber 310. The magnetic rod 230 is arranged in the guide groove 220 without occupying other space. Thus, while improving the iron removal capacity, no additional space is required.

[0043] Reference Figure 1 In some embodiments, the filter device 100 includes a first filter assembly 110 and a second filter assembly 120, the first filter assembly 110 includes a first screen 111, the second filter assembly 120 is located downstream of the first filter assembly 110, and the second filter assembly 120 includes a second screen 121, and the mesh number of the first screen 111 is smaller than the mesh number of the second screen 121. For example, in some embodiments, the first screen 111 is 170-180 meshes, and the second screen 121 is 200-210 meshes, so that the sewage can be preliminarily screened by the first filter assembly 110 first, and then finely screened by the second filter assembly 120. Specifically, if the sewage is directly filtered through the second screen 121 of 200-210 meshes, the filter residue in the sewage will be filtered out at one time during the filtration, so the second screen 121 is easily blocked due to the accumulation of filter residues, affecting the flow rate of the sewage, thereby affecting the sewage treatment efficiency. The present embodiment can effectively improve this problem. The present embodiment filters the sewage twice through the first sieve 111 and the second sieve 121, that is, the first sieve 111 is used for initial screening to filter out filter residues with larger particles, and then the second sieve 121 is used to filter out filter residues with smaller particles to disperse the particles in the sewage, thereby effectively reducing the risk of clogging of the first sieve 111 and the second sieve 121.

[0044] Reference Figure 1 On the basis of the above embodiment, the second filter assembly 120 further includes a vibration mechanism 122, and the vibration mechanism 122 is connected to the second screen 121. Specifically, since the second screen 121 has more meshes, that is, the mesh holes of the second screen 121 are smaller, its filtering ability is stronger, but the obstruction to the water flow is also greater. In order to increase the speed of sewage passing through the second screen 121, the present embodiment is further provided with a vibration mechanism 122, which drives the second screen 121 to vibrate, so that the sewage can quickly pass through the second screen 121, thereby improving the sewage treatment efficiency.

[0045] Reference Figure 1 In some embodiments, the sewage treatment system further includes a dosing device 400, which includes at least two liquid storage chambers 410, each of which has a second liquid discharge port 411. The dosing device 400 also includes a valve 420, and each second liquid discharge port 411 is provided with a valve 420. When treating sewage, the agent is first adjusted in the liquid storage chamber 410, and then the adjusted agent is discharged into the reaction chamber 310. Among them, the reason why at least two liquid storage chambers 410 are required is to enable the two liquid storage chambers 410 to be used alternately, thereby ensuring that when one of the liquid storage chambers 410 is used to adjust the agent, the other liquid storage chamber 410 can add the prepared agent to the reaction chamber 310, so that the dosing device 400 can continuously add the agent to the reaction chamber 310. In addition, by using the two liquid storage chambers 410 alternately, there is sufficient time to stir the reagents when adjusting the reagents so that the reagents are fully mixed. Therefore, when the reagents are discharged into the reaction chamber 310, the liquid medicine is more fully mixed with the sewage in the reaction chamber 310.

[0046] Reference Figure 1 In some embodiments, the sewage treatment system further includes a buffer device 700, which has a buffer chamber 710, and a first mud inlet 720 and a second mud outlet 730 connected to the buffer chamber 710, wherein the first mud inlet 720 is connected to the first mud outlet 530, and the second mud outlet 730 is connected to the mud refining chamber 610. Therefore, when the amount of sludge discharged from the separation chamber 510 exceeds the processing capacity of the mud refining device 600, the sludge can be temporarily stored in the buffer chamber 710. Specifically, for example, when the amount of mud in the sewage is high, or, in some embodiments, when part of the mud refining device 600 (under the premise of having multiple mud refining devices 600) fails, part of the sludge will automatically stay in the buffer chamber 710 without shutting down the entire system for maintenance, thereby ensuring the sewage treatment efficiency. It can also avoid the risk of blockage or pipe burst due to excessive sludge in the system, thereby improving the safety of sewage treatment in this embodiment.

[0047] Reference Figure 1In some embodiments, the mud refining device 600 has a second mud inlet 620 connected to the mud refining chamber 610, and the sewage treatment system includes a mud discharge pipe 800, the mud discharge pipe 800 has a main pipeline 810, and a first auxiliary pipeline 820 and a second auxiliary pipeline 830 connected to the main pipeline 810, the two ends of the main pipeline 810 are respectively connected to the first mud discharge port 530 and the second mud inlet 620, the end of the first auxiliary pipeline 820 facing away from the main pipeline 810 is connected to the first mud inlet 720, and the end of the second auxiliary pipeline 830 facing away from the main pipeline 810 is connected to the second mud discharge port 730. Therefore, when the sludge discharged from the separation chamber 510 does not exceed the amount of sludge that can be processed by the sludge refining device 600, the sludge can directly enter the sludge refining chamber 610 through the main pipe 810 without passing through the buffer device 700, thereby improving the sludge refining efficiency. In addition, since the sludge does not need to pass through the buffer device 700, when cleaning the system, it can also reduce the cleaning matters of the sewage treatment system, that is, there is no need to clean the buffer chamber 710.

[0048] Reference Figure 1 and Figure 2 In some embodiments, the first filter assembly 110 further includes a conveyor 130, the first screen 111 has a water-facing surface 1112, the angle between the water-facing surface 1112 and the horizontal direction is α, α>0, and the conveying mechanism 130 has a conveying surface 131, and the conveying surface 131 is located at the lower edge of the water-facing surface 1112 to receive and convey the filter residue filtered out by the first screen 111. For example, the water-facing surface 1112 is inclined or vertically arranged relative to the horizontal direction, and the filter residue filtered out of the sewage can be quickly moved to the conveying mechanism 130 under the action of gravity, and then the filter residue is discharged by the conveying mechanism 130 to prevent the filter residue from clogging the first screen 111. Specifically, for example, the first filter component 110 has a first sewage inlet 112 and a residue discharge port. The lower edge of the water-facing surface 1112 is located at the residue discharge port. When sewage needs to be filtered, the first sewage inlet 112 is opened and the residue discharge port is closed at the same time to prevent sewage from leaking through the residue discharge port. When the filter residue at the residue discharge port accumulates to a certain extent, the first sewage inlet 112 is closed and the residue discharge port is opened to allow the filter residue to move to the conveying mechanism 130 through the residue discharge port.

[0049] Furthermore, in some embodiments, the first filter component 110 is provided with two filter channels, each of which has a first sewage inlet 112 and a slag discharge port, and a first screen 111 is provided in the filter channel. Thus, the two filter channels can be used alternately, and there is no need to shut down the entire first filter component 110 when discharging slag, thereby improving the efficiency of industrial sewage treatment.

[0050] Reference Figure 2On the basis of the above embodiment, the water-facing surface 1112 is tilted relative to the horizontal direction, the first filter assembly 110 has a first sewage inlet 112 and a sewage outlet, the first sewage inlet 112 is located above the lower edge of the water-facing surface 1112, so that the sewage flowing out of the first sewage inlet 112 can fall to the water-facing surface 1112, and the conveying mechanism 130 has a conveying surface 131, and the conveying surface 131 is higher than the first sewage outlet 113, so that during the sewage treatment process, the conveying surface 131 is higher than the height of the liquid level in the first filter assembly 110. As a result, the height of the residue outlet can be made higher than the height of the liquid level, so that the sewage will not leak through the residue outlet. Therefore, during the sewage treatment process, the filter residue can be directly moved to the conveying surface 131, and the filter residue can be discharged through the residue outlet by the conveying mechanism 130, without the need to close the first sewage inlet 112 first and then discharge the residue as in the above embodiment, thereby improving the efficiency of sewage treatment.

[0051] Reference Figure 2 In some embodiments, the angle between the water-facing surface 1112 and the direction is α, 30°≤α≤40°. Specifically, it can be understood that the larger the angle between the water-facing surface 1112 and the horizontal direction, the smaller the projection of the water-facing surface 1112 in the vertical direction, thereby resulting in a smaller area of ​​the water-facing surface 1112 receiving sewage falling from the first sewage inlet 112, which affects the sewage treatment efficiency. The smaller the angle between the water-facing surface 1112 and the horizontal direction, the more difficult it will be for the filter residue to move quickly to the conveying mechanism 130 under the action of gravity. Based on this, the present embodiment sets the angle α within a suitable range to ensure that the filter residue can be quickly moved to the conveying mechanism while ensuring the discharge volume of sewage.

[0052] The above is a detailed description of the embodiment of the utility model in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned embodiment, and various changes can be made without departing from the purpose of the utility model within the scope of knowledge possessed by ordinary technicians in the relevant technical field. In addition, in the description of the utility model, the description of the reference terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Claims

1. A sewage treatment system, characterized in that: include: A filtering device for filtering sewage; An iron removal device, located downstream of the filtering device, the iron removal device comprises a controller and at least two iron removers, the controller is in communication connection with each of the iron removers, and the controller is used to enable at least two of the iron removers to work alternately; A reaction device, located downstream of the iron removal device, the reaction device having a reaction chamber, the reaction chamber being connected to the iron remover; A separation device, located downstream of the reaction device, comprising a separation chamber, and a first mud discharge port and a first liquid discharge port communicated with the separation chamber, the separation chamber being communicated with the reaction chamber, the first mud discharge port being used for discharging separated sludge, and the first liquid discharge port being used for discharging separated liquid; The mud refining device is located downstream of the separation device, and the mud refining device has a mud refining chamber, and the mud refining chamber is connected to the first mud discharge port.

2. The sewage treatment system according to claim 1, characterized in that: The device also includes a guide groove and a magnetic bar. One end of the guide groove is connected to each of the iron removers, and the other end is connected to the reaction chamber. The magnetic bar is arranged in the guide groove.

3. The sewage treatment system according to claim 1, characterized in that: The filtering device includes a first filtering component and a second filtering component, wherein the second filtering component is located downstream of the first filtering component, the first filtering component includes a first screen, and the second filtering component includes a second screen, wherein the mesh number of the first screen is smaller than the mesh number of the second screen.

4. The sewage treatment system according to claim 3, characterized in that: The second filter assembly further includes a vibration mechanism connected to the second screen.

5. The sewage treatment system according to claim 1, characterized in that: The sewage treatment system further comprises a dosing device, which comprises at least two liquid storage chambers, each of which has a second liquid discharge port. The dosing device further comprises a valve, and each of the second liquid discharge ports is provided with the valve.

6. The sewage treatment system according to claim 1, characterized in that: The sewage treatment system also includes a cache device, which has a cache cavity, and a first mud inlet and a second mud outlet communicated with the cache cavity, wherein the first mud inlet is communicated with the first mud outlet, and the second mud outlet is communicated with the mud refining cavity.

7. The sewage treatment system according to claim 6, characterized in that: The mud refining device has a second mud inlet connected to the mud refining chamber, and the sewage treatment system includes a mud discharge pipe, which includes a main pipeline, and a first auxiliary pipeline and a second auxiliary pipeline connected to the main pipeline. The two ends of the main pipeline are respectively connected to the first mud discharge port and the second mud inlet, the end of the first auxiliary pipeline facing away from the main pipeline is connected to the first mud inlet, and the end of the second auxiliary pipeline facing away from the main pipeline is connected to the second mud discharge port.

8. The sewage treatment system according to claim 3, characterized in that: The first filter assembly also includes a conveying mechanism, the first screen has a water-facing surface, the angle between the water-facing surface and the horizontal direction is α, α>0, and the conveying mechanism has a conveying surface, which is located at the lower edge of the water-facing surface to receive and convey the filter residue filtered out by the first screen.

9. The sewage treatment system according to claim 8, characterized in that: The water-facing surface is inclined relative to the horizontal direction. The first filter component has a first sewage inlet and a first sewage outlet. The first sewage inlet is located above the lower edge of the water-facing surface so that sewage flowing out of the first sewage inlet can fall onto the water-facing surface. The conveying surface is higher than the first sewage outlet.

10. The sewage treatment system according to claim 9, characterized in that: The angle α between the water-facing surface and the horizontal plane has a value ranging from 30° to 40°.

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