Prawn culture sewage treatment system
Through the gravity sewage separator and graded treatment device, the shrimp farming sewage system achieves efficient and economical sewage treatment, solves the problems of resource waste and high cost in the existing technology, and ensures the environmentally friendly discharge and reuse of sewage.
Patent Information
- Application Number
- CN202422106876.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2034-08-28
AI Technical Summary
The existing shrimp aquaculture wastewater treatment system is inefficient in treating all wastewater, resulting in waste of resources and increased costs, especially the improper treatment of wastewater with lower pollution levels.
A gravity sewage separator is used to separate sewage into two layers, the upper and lower layers, which enter different treatment devices respectively. The appropriate treatment device is selected according to the amount of dirt in the sewage, including the grass purification area, nitrification area and denitrification area to achieve graded treatment.
It improves sewage treatment efficiency, reduces treatment costs and pressure, ensures that sewage meets discharge or reuse standards, and protects the environment.
Smart Images
Figure CN223409474U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of shrimp farming, in particular to a shrimp farming sewage treatment system. Background Art
[0002] Prawns are rich in high-quality protein, as well as a variety of vitamins and minerals, and are very low in fat, especially saturated fat. They are a good choice for a healthy diet and are loved by people. They are the raw material for the most common delicacy on people’s tables.
[0003] With the large-scale farming of shrimp, a large amount of shrimp farming wastewater is generated. In order to prevent the farming wastewater from polluting the surrounding environment or waters, it is necessary to treat and purify the farming wastewater in a timely manner so that it can be directly discharged or recycled. Of course, the recycling mentioned here generally refers to the reuse of purified or treated purified water in farming.
[0004] In the existing technology, aquaculture wastewater treatment systems mostly perform broad-spectrum treatment on wastewater, that is, all aquaculture wastewater is treated in the same way. This will cause some wastewater with lower pollution levels to consume a lot of treatment resources and time, reduce wastewater treatment efficiency, increase wastewater treatment costs, and increase aquaculture costs. Utility Model Content
[0005] In order to overcome at least one of the defects of the above-mentioned prior art, the present invention provides a shrimp farming wastewater treatment system. By setting a first treatment device and a second treatment device, the appropriate treatment device is selected as needed according to the amount of dirt in the sewage, thereby improving the sewage treatment efficiency, reducing the sewage treatment pressure, and reducing the sewage treatment cost.
[0006] The technical solution adopted by the present invention to solve the problem is:
[0007] A shrimp farming wastewater treatment system comprises a gravity wastewater separator connected to the rear of a farming pond, and a first treatment device and a second treatment device connected to the rear of the gravity wastewater separator, wherein the first treatment device and the second treatment device are at least partially arranged side by side;
[0008] The first treatment device comprises a grass-planting purification zone, a first nitrification zone and a first denitrification zone connected in sequence;
[0009] The second treatment device includes a first precipitation zone, a second nitrification zone and a second denitrification zone connected in sequence;
[0010] The upper sewage separated by the gravity sewage separator enters the first treatment device, and the lower sewage separated by the gravity sewage separator enters the second treatment device. The lower sewage contains more pollutants than the upper sewage.
[0011] Furthermore: the upper sewage separated by the gravity sewage separator enters the first nitrification zone.
[0012] Furthermore: the water outlet of the first sedimentation zone is connected to the water inlet of the grass planting purification zone and / or the first nitrification zone.
[0013] Furthermore, the rear of the first denitrification zone and / or the second denitrification zone is connected to a water storage area, and the water outlet of the water storage area is connected to the water inlet of the breeding pond.
[0014] Furthermore: the water outlet of the grass planting purification area is connected to the water inlet of the water storage area.
[0015] Furthermore: a transfer area is provided at the front of the gravity sewage separator, and the water outlet of the transfer area is connected to the water inlet of the gravity sewage separator.
[0016] Furthermore: the drain outlet of the culture pond is connected to the water inlet of the transfer area and / or the water inlet of the gravity sewage separator.
[0017] Furthermore: the gravity sewage separator includes a sewage inlet, an upper sewage outlet, a lower sewage outlet, and a sleeved inner cylinder and outer cylinder; the upper sewage outlet is arranged on the outer cylinder, and the lower sewage outlet is arranged on the inner cylinder,
[0018] The sewage inlet is located in the inner cylinder, and the sewage outlet is located higher than the mouth of the inner cylinder, and the mouth of the inner cylinder is located lower than the mouth of the outer cylinder;
[0019] A water blocking plate is provided in the inner tube, the water blocking plate divides the inner tube space into an upper buffer zone and a lower sedimentation zone, a separation port is provided on the water blocking plate, the separation port is communicated with the lower sedimentation zone, and the separation port is at a distance from the inner wall of the inner tube to the water blocking plate;
[0020] The bottom of the inner cylinder is set as an inclined bottom surface, and the lower sewage outlet is set at the lower end of the inclined bottom surface;
[0021] The sewage inlet is connected with a sewage pipe, which is sleeved with the inner tube and extends from the bottom of the inner tube to the mouth of the inner tube.
[0022] In summary, the shrimp farming wastewater treatment system provided by the utility model has the following technical effects:
[0023] 1. Set up the first treatment device and the second treatment device, and select the appropriate treatment device as needed based on the amount of dirt in the sewage to improve sewage treatment efficiency, reduce sewage treatment pressure, and reduce sewage treatment costs.
[0024] 2. Set up a transfer area to serve the gravity sewage separator and ensure the separation effect of the gravity sewage separator.
[0025] 3. Install a gravity sewage separator to separate the sewage, separating the sediment from the sewage, obtaining sewage with more and less impurities, and achieving sewage classification. The gravity sewage separator has a simple structure and fast separation, avoiding the long sedimentation process to achieve separation, speeding up sewage treatment efficiency and reducing sewage treatment costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 This is a structural schematic diagram of an embodiment of a shrimp farming wastewater treatment system of the present invention.
[0027] Figure 2 This is a structural diagram of the gravity sewage separator in the technical solution of the utility model.
[0028] The meanings of the reference numerals are as follows:
[0029] 1. Breeding pond; 2. Transfer area; 3. Gravity sewage separator; 31. Sewage inlet; 32. Lower sewage outlet; 33. Upper sewage outlet; 34. Sewage pipe; 35. Inner tube; 36. Outer tube; 37. Water blocking plate; 38. Separation port; 39. Water retaining plate; 4. Grass-planted purification area; 5. First nitrification area; 6. First denitrification area; 7. Water storage area; 8. First sedimentation area; 9. Second nitrification area; 10. Second denitrification area; 151. Water inlet of transfer area; 152. Sewage outlet of transfer area; 153. Water outlet of transfer area; 16. Bare pole; 171. First end; 172. Second end. DETAILED DESCRIPTION
[0030] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.
[0031] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. 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 direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.
[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.
[0033] See Figure 1 The utility model discloses a shrimp farming wastewater treatment system, which is used to treat the wastewater or tail water generated by shrimp farming, so that the wastewater discharged after farming can meet the direct discharge standard or reuse standard after being treated and purified by this system, or at least can be used again for farming or irrigation, etc., avoiding the impact and pollution of the farming wastewater on the surrounding environment or waters, protecting the environment, and achieving sustainable farming and development.
[0034] The following is an introduction and explanation of the specific scheme of a shrimp farming wastewater treatment system in this scheme.
[0035] like Figure 1 As shown, a shrimp farming wastewater treatment system includes a gravity wastewater separator 3 connected to the rear of the farming pond 1 and a first treatment device and a second treatment device connected to the rear of the gravity wastewater separator 3, wherein the first treatment device and the second treatment device are at least partially arranged in parallel.
[0036] The first treatment device includes a grass-planting purification zone 4, a first nitrification zone 5 and a first denitrification zone 6 which are connected in sequence.
[0037] The second treatment device includes a first precipitation zone 8, a second nitrification zone 9 and a second denitrification zone 10 connected in sequence.
[0038] The upper sewage separated by the gravity sewage separator 3 enters the first treatment device, and the lower sewage separated by the gravity sewage separator 3 enters the second treatment device. The pollutants contained in the lower sewage are more than those contained in the upper sewage.
[0039] Based on the above scheme, the aquaculture wastewater discharged from the aquaculture pond 1 enters the gravity sewage separator, which classifies the wastewater to obtain upper and lower sewage layers. The upper sewage layer contains fewer pollutants, while the lower sewage layer contains more pollutants than the upper sewage layer. That is, the gravity sewage separator effectively separates and classifies the wastewater discharged from the aquaculture pond, and then the wastewater containing different levels of pollutants is respectively transported to the first treatment device and the second treatment device for treatment. In this scheme, a first treatment device and a second treatment device are set up, and the appropriate treatment device is selected as needed based on the amount of pollutants in the sewage, thereby improving sewage treatment efficiency, reducing sewage treatment pressure, and reducing sewage treatment costs.
[0040] Based on the above scheme, the first treatment unit includes a grass purification zone 4, a first nitrification zone 5, and a first denitrification zone 6, all connected in sequence; the second treatment unit includes a first sedimentation zone 8, a second nitrification zone 9, and a second denitrification zone 10, all connected in sequence. As the name suggests, the second treatment unit includes a first sedimentation zone. As the name suggests, the first sedimentation zone is used to re-precipitate the lower layer of sewage separated by the gravity sewage separator 3, precipitating and separating the large amount of pollutants contained in the lower layer of sewage. Since the upper layer of sewage contains fewer pollutants, it can directly enter the grass purification zone 4 for purification. The grass absorbs the free ammonia nitrogen in the sewage, purifying the upper layer of sewage and providing nutrients for the growth of the grass. The sewage that has passed through the grass purification zone enters the first nitrification zone 5. Nitrifying bacteria within the first nitrification zone undergo a nitrification reaction under aerobic conditions, converting the free ammonia nitrogen in the sewage that has passed through the grass purification zone into nitrate or nitrite. The upper layer of sewage that has undergone nitrification enters the first denitrification zone 6. In the first denitrification zone, denitrifying bacteria denitrify nitrates or nitrites into nitrogen gas, which is then discharged directly. This essentially completes the treatment of the upper wastewater.
[0041] In the above scheme, the first treatment unit incorporates a grass-planted purification zone to perform the initial purification of the upper wastewater layer. This consumes free ammonia nitrogen in the upper wastewater layer, accelerates the subsequent nitrification reaction in the first nitrification zone, and improves the first treatment unit's wastewater treatment efficiency. Furthermore, the nitrification reaction is demanding in terms of reaction conditions, such as temperature, and is also highly susceptible to temperature and environmental influences. In this scheme, the inclusion of a grass-planted purification zone mitigates the effects of the first nitrification zone, ensuring smooth and efficient wastewater treatment by the first treatment unit.
[0042] In the above scheme, a first sedimentation zone is added to the second treatment device to precipitate the lower sewage separated by the gravity sewage separator 3 again, and precipitate and separate a large amount of pollutants contained in the lower sewage, so as to achieve physical removal of pollutants in the sewage again after the gravity sewage separator, and then carry out nitrification and denitrification reactions, thereby reducing the pressure of the nitrification reaction in the second nitrification tank, improving the nitrification reaction efficiency, improving the sewage treatment efficiency, shortening the sewage treatment time, and reducing the sewage treatment cost.
[0043] In the above scheme, the first treatment device and the second treatment device are at least partially co-located. That is, under normal circumstances, the upper layer of sewage and the lower layer of sewage after passing through the gravity sewage separator enter the first treatment device and the second treatment device respectively. Of course, in certain circumstances, such as when the water quality of the sewage changes, or when there are fewer pollutants in the sewage, or when the lower layer of sewage separated by the gravity sewage separator also contains fewer pollutants, parts of the first treatment device and the second treatment device may be shared, or the lower layer of sewage may also be processed in some treatment steps in the first treatment device, or the upper layer of sewage may enter some treatment steps in the second treatment device. Based on this, the following describes several embodiments.
[0044] Example 1
[0045] The upper sewage separated by the gravity sewage separator 3 enters the first treatment device, and the lower sewage separated by the gravity sewage separator 3 enters the second treatment device. The pollutants contained in the lower sewage are relatively more than the pollutants contained in the upper sewage. The first treatment device includes a grass purification area 4, a first nitrification area 5 and a first denitrification area 6 connected in sequence. The second treatment device includes a first sedimentation area 8, a second nitrification area 9 and a second denitrification area 10 connected in sequence. At this time, the upper sewage and the lower sewage separated by the gravity sewage separator enter the first treatment device and the second treatment device respectively, and are processed in sequence in the first treatment device and the second treatment device respectively.
[0046] The first embodiment is a conventional working mode of a shrimp farming wastewater treatment system. Its function has been introduced above and will not be described in detail here.
[0047] Example 2
[0048] The upper sewage separated by the gravity sewage separator 3 enters the first nitrification zone 5.
[0049] That is, the upper sewage separated by the gravity sewage separator 3 enters the first treatment device, and the lower sewage separated by the gravity sewage separator 3 enters the second treatment device, and the pollutants contained in the lower sewage are relatively more than the pollutants contained in the upper sewage. The first treatment device includes a grass-planted purification area 4, a first nitrification area 5 and a first denitrification area 6 connected in sequence. The second treatment device includes a first sedimentation area 8, a second nitrification area 9 and a second denitrification area 10 connected in sequence. At this time, the upper sewage separated by the gravity sewage separator does not pass through the grass-planted purification area 4, but directly enters the first nitrification area for nitrification reaction. After nitrification in the first nitrification area, it enters the first denitrification area for denitrification reaction, while the lower sewage enters the second treatment device and is processed in sequence in the second treatment device.
[0050] In the second embodiment, the upper layer of sewage does not enter the grass purification zone 4, but directly enters the first nitrification zone for nitrification. At this time, nutrient control can be performed in the grass purification zone 4 to ensure the growth of grass plants therein. Other operations, such as grass harvesting, can also be performed in the grass purification zone 4, preparing for the next normal and efficient operation of the grass purification zone 4. This also facilitates operations for operators.
[0051] Example 3
[0052] The water outlet of the first sedimentation zone 8 is communicated with the water inlet of the grass planting purification zone 4 and / or the first nitrification zone 5 .
[0053] That is, the upper sewage separated by the gravity sewage separator 3 enters the first treatment device, and the lower sewage separated by the gravity sewage separator 3 enters the second treatment device, and the pollutants contained in the lower sewage are relatively more than the pollutants contained in the upper sewage. The first treatment device includes a grass purification area 4, a first nitrification area 5 and a first denitrification area 6 connected in sequence. The second treatment device includes a first sedimentation area 8, a second nitrification area 9 and a second denitrification area 10 connected in sequence. At this time, the upper sewage separated by the gravity sewage separator enters the first treatment device and is processed in sequence, while the lower sewage, after passing through the first sedimentation area 8, does not enter the second nitrification area, but enters the grass purification area 4 or the first nitrification area 5 in the first treatment device for purification treatment.
[0054] In the third embodiment, after the lower sewage passes through the first sedimentation zone 8, it does not enter the second nitrification zone, but enters the grass purification zone 4 or the first nitrification zone 5 in the first treatment device for purification treatment. The main reason is that the second nitrification zone is temporarily unavailable, or the lower sewage has less pollutants after sedimentation in the first sedimentation zone, which meets the requirements for entering the first treatment device for treatment. At this time, the second nitrification zone is also avoided. The staff can operate and process the second nitrification zone and the second denitrification zone, such as maintenance or pipeline laying, but at the same time, it does not affect the normal treatment operation of the sewage, and the sewage treatment process will not be suspended.
[0055] Example 4
[0056] The first denitrification zone 6 and / or the second denitrification zone 10 are connected to a water storage zone 7 at their rear ends. Specifically, the first and second denitrification zones are connected to the water storage zone, or the first or second denitrification zones are connected to the water storage zone at their rear ends. The water outlet of the grass purification zone 4 is connected to the water inlet of the water storage zone 7.
[0057] After the upper sewage is purified in the grass-planted purification area, the free ammonia nitrogen is removed. If the pollutants in the sewage meet the standards for discharge or reuse at this time, the sewage that has passed the grass-planted purification area will no longer enter the first nitrification area, but will directly enter the water storage area for temporary storage, waiting to be used.
[0058] Of course, as needed, disinfection equipment can also be installed in the water storage area, such as using ozone or ultraviolet rays to disinfect the water to be used in the water storage area, and further remove bacteria in the water.
[0059] Example 5
[0060] The water outlet of the grass-planted purification zone 4 is connected to the water inlet of the first denitrification zone, that is, the sewage purified by the grass-planted purification zone 4 has its free ammonia nitrogen purified, and the remaining nitrate or nitrite sewage directly enters the first denitrification zone for denitrification treatment, avoiding the step of sewage entering the first nitrification zone for treatment again, speeding up the sewage treatment process, and further weakening the role of the first nitrification zone, especially in colder seasons, when the nitrification reaction is suppressed by temperature. At this time, the sewage does not need to undergo nitrification reaction, ensuring the smooth treatment of the sewage.
[0061] Example 6
[0062] A transfer zone 2 is provided in front of the gravity sewage separator 3, and the water outlet of the transfer zone 2 is connected to the water inlet of the gravity sewage separator 3. The drain outlet of the aquaculture pond 1 is connected to the water inlet 151 of the transfer zone and / or the water inlet of the gravity sewage separator 3.
[0063] By setting up the transfer area 2, the sewage can be temporarily stored before entering the gravity sewage separator 3. In this way, on the one hand, when the sewage flow is large, the speed at which the sewage enters the gravity sewage separator 3 can be controlled, so that the sewage enters the gravity sewage separator 3 at an appropriate speed, so that the gravity sewage separator 3 can play its separation role. On the other hand, when the amount of sewage is small, the sewage is temporarily stored and waits for a larger amount of sewage to be processed at the same time, thereby improving the processing efficiency and saving the processing cost.
[0064] In addition, when the sewage enters the transfer area, it can also undergo a certain sedimentation process in the transfer area, reducing the amount of pollutants in the sewage entering the gravity sewage separator 3, and further reducing the pressure of subsequent sewage treatment.
[0065] Of course, a transfer area is provided here, but in actual operation, if the sewage in the aquaculture pond does not need to pass through the transfer area, it can directly enter the gravity sewage separator 3 for separation.
[0066] In summary, the embodiments of the shrimp farming wastewater treatment system of the present technical solution in various working states are introduced. It can be seen that farmers can reasonably select appropriate treatment processes or treatment implementation methods based on time, climate, amount of aquaculture wastewater, content of pollutants in aquaculture wastewater, grade of sewage, etc., to improve sewage treatment efficiency, reduce sewage treatment pressure, and reduce sewage treatment costs.
[0067] In this technical solution, the water outlet of the water storage area 7 is connected to the water inlet of the aquaculture pond 1, so that the purified sewage can be reused for aquaculture, realizing water recycling, saving water resources, and reducing aquaculture water costs.
[0068] In this technical solution, the gravity sewage separator 3 includes a sewage inlet 31, an upper sewage outlet 33, a lower sewage outlet 32, and a sleeved inner tube 35 and outer tube 36; the upper sewage outlet 33 is arranged on the outer tube 36, and the lower sewage outlet 32 is arranged on the inner tube 35.
[0069] The sewage inlet 31 is located within the inner tube 35, and the sewage outlet is located above the opening of the inner tube 35, which is also located below the opening of the outer tube 36. Sewage enters the inner tube and diffuses radially outward. Due to their heavy weight, pollutants in the sewage quickly settle downward and are eventually discharged from the bottom of the inner tube, forming the lower layer of sewage. The portion of sewage with less pollutants passes through the opening of the inner tube and enters the outer tube, where it is discharged, forming the upper layer of sewage.
[0070] A water-blocking plate 37 is provided in the inner cylinder 35. The water-blocking plate 37 divides the space of the inner cylinder 35 into an upper buffer zone and a lower sedimentation zone. A separation port 38 is provided on the water-blocking plate 37. The separation port 38 is connected to the lower sedimentation zone. The separation port 38 is spaced from the inner wall of the inner cylinder 35 by a water-blocking plate 39. The water-blocking plate prevents the sewage entering the inner cylinder from moving directly downward and is directly discharged through the lower sewage outlet, that is, the water-blocking plate ensures the separation of the upper sewage. The separation port is provided on the outside of the water-blocking plate, so that the flow rate of the sewage passing above the water-blocking plate is reduced, and the pollutants in the sewage sink. At this time, it passes through the separation port and enters the lower sedimentation zone, realizing the separation of the upper sewage and the lower sewage. The purpose of providing the water-blocking plate is to prevent the lower sewage entering the lower sedimentation zone from floating up again, passing through the inner cylinder, and entering the outer cylinder, thereby ensuring the separation of the upper sewage and the lower sewage.
[0071] The bottom of the inner cylinder 35 is set as an inclined bottom surface, and the lower sewage outlet 32 is set at the lower end of the inclined bottom surface. It is convenient for the lower sewage to be discharged through the inner cylinder and prevent the pollutants in the lower sewage from being deposited in the inner cylinder.
[0072] The sewage inlet 31 is connected to a sewage pipe 34, which is sleeved with the inner tube 35 and extends from the bottom of the inner tube 35 to the mouth of the inner tube 35. This allows sewage to be discharged from the middle of the inner tube into the inner tube, allowing sewage entering the inner tube to spread outward, facilitating the sedimentation of pollutants in the sewage and allowing the upper layer of sewage to enter the outer tube, thereby achieving separation of the upper and lower layers of sewage.
[0073] The technical means disclosed in the present invention are not limited to those disclosed in the above-mentioned embodiments, but also include technical solutions composed of any combination of the above-mentioned technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also considered to be within the scope of protection of the present invention.
Claims
1. A shrimp farming wastewater treatment system, characterized by: The invention comprises a gravity sewage separator connected to the rear of the culture pond, and a first treatment device and a second treatment device connected to the rear of the gravity sewage separator, wherein the first treatment device and the second treatment device are at least partially arranged side by side; The first treatment device comprises a grass-planting purification zone, a first nitrification zone and a first denitrification zone connected in sequence; The second treatment device includes a first precipitation zone, a second nitrification zone and a second denitrification zone connected in sequence; The upper sewage separated by the gravity sewage separator enters the first treatment device, and the lower sewage separated by the gravity sewage separator enters the second treatment device. The lower sewage contains more pollutants than the upper sewage.
2. The shrimp farming wastewater treatment system according to claim 1, characterized in that: The upper sewage separated by the gravity sewage separator enters the first nitrification zone.
3. The shrimp farming wastewater treatment system according to claim 1 or 2, characterized in that: The water outlet of the first sedimentation zone is communicated with the water inlet of the grass planting purification zone and / or the first nitrification zone.
4. The shrimp farming wastewater treatment system according to claim 1 or 2, characterized in that: The rear part of the first denitrification zone and / or the second denitrification zone is connected to a water storage area, and the water outlet of the water storage area is connected to the water inlet of the culture pond.
5. The shrimp farming wastewater treatment system according to claim 4, characterized in that: The water outlet of the grass-planting purification area is communicated with the water inlet of the water storage area.
6. The shrimp farming wastewater treatment system according to claim 1, characterized in that: A transfer area is provided at the front of the gravity sewage separator, and a water outlet of the transfer area is communicated with a water inlet of the gravity sewage separator.
7. The shrimp farming wastewater treatment system according to claim 6, characterized in that: The drain outlet of the culture pond is communicated with the water inlet of the transfer zone and / or the water inlet of the gravity sewage separator.
8. The shrimp farming wastewater treatment system according to claim 1, characterized in that: The gravity sewage separator includes a sewage inlet, an upper sewage outlet, a lower sewage outlet, and a sleeved inner cylinder and outer cylinder; the upper sewage outlet is arranged on the outer cylinder, and the lower sewage outlet is arranged on the inner cylinder. The sewage inlet is located in the inner cylinder, and the sewage outlet is located higher than the mouth of the inner cylinder, and the mouth of the inner cylinder is located lower than the mouth of the outer cylinder; A water blocking plate is provided in the inner tube, the water blocking plate divides the inner tube space into an upper buffer zone and a lower sedimentation zone, a separation port is provided on the water blocking plate, the separation port is communicated with the lower sedimentation zone, and the separation port is at a distance from the inner wall of the inner tube to the water blocking plate; The bottom of the inner cylinder is set as an inclined bottom surface, and the lower sewage outlet is set at the lower end of the inclined bottom surface; The sewage inlet is connected with a sewage pipe, which is sleeved with the inner tube and extends from the bottom of the inner tube to the mouth of the inner tube.