A sewage anaerobic treatment method with enhanced internal circulation

Abstract

The present invention discloses a method for anaerobic treatment of sewage with enhanced internal circulation, wherein pressurized sewage enters the water inlet area through a water inlet pipe, the water is mixed with the sludge layer below the sludge stirring area and then diverted to multiple internal circulation unit groups, the mud-water mixture flows forward in the internal circulation unit group and enters multiple internal circulation units in sequence, the mud-water mixture enters the upflow area, and when it flows to the top of the upflow area, it enters the downflow area under the action of the guide plate to settle, and realizes the granular sludge backflow in the adjacent internal circulation unit, the water flow and the gas production bypass the guide plate and flow upward, the guide body divides the rising water flow into the gas collecting hoods on both sides to achieve gas-liquid separation, the gas in the gas collecting hood is discharged through the exhaust pipe, the water flow rises to the top of the overflow area and flows into the water outlet area through the overflow weir, the water flow flows into the sewage anaerobic treatment module below under the action of gravity, and repeats the process of mud-water mixing, reaction, circulation, separation and overflow. The anaerobic treatment method for sewage provided by the present invention can improve the sludge stirring efficiency and optimize the effluent water quality.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, in particular to an anaerobic sewage treatment method with enhanced internal circulation. Background Art

[0002] In the field of sewage and wastewater treatment, anaerobic reactors such as upflow anaerobic sludge blankets (UASBs), expanded granular sludge reactors (EGSBs), and anaerobic baffled reactors (ABRs) are often used to convert high-concentration organic matter into biogas, thereby reducing pollutants and improving biodegradability. Traditional anaerobic reactors are generally divided into a water distribution zone, a sludge zone, and a three-phase separation zone from bottom to top. The sludge zone is the core of the entire reactor. The pollutant-containing sewage fully contacts and reacts with the sludge. Under the shear force of the water flow and gas production, the sludge gradually forms granular sludge with excellent settling properties.

[0003] In practice, granular sludge typically takes a long time to form, during which time the sludge layer can easily form channels, causing wastewater to exit the reactor without adequate treatment, impacting effluent quality. Furthermore, when some of the produced gas adheres to the hydrophobic surface of the sludge, it can cause the sludge layer to float, severely impacting the sludge-water-gas three-phase separation and leading to sludge loss. This is common when using anaerobic reactors for high-load anaerobic ammonium oxidation denitrification treatment, and can seriously interfere with process stability.

[0004] Although the use of mechanical stirring or EGSB sewage return method can improve the sludge layer channel flow and sludge floating phenomenon to a certain extent, it has disadvantages such as the need to add external equipment, high operating energy consumption and the rotating shaft affecting the sealing, which limits its promotion and application.

[0005] The present invention is made in order to solve the above problems. Summary of the Invention

[0006] Based on the above problems, the purpose of the present invention is to provide an anaerobic sewage treatment method with enhanced internal circulation, which can improve the sludge stirring efficiency and optimize the effluent water quality.

[0007] In order to solve the problems in the prior art, the technical solution provided by the present invention is:

[0008] A method for anaerobic sewage treatment with enhanced internal circulation is based on an anaerobic sewage treatment device, the anaerobic sewage treatment device comprising a plurality of anaerobic sewage treatment modules stacked one above the other, the anaerobic sewage treatment modules comprising a reactor body, wherein the reactor body is provided with an inlet area, a sludge stirring area, a gas-liquid separation area, and an outlet area, which are sequentially connected. The outlet area of ​​the upper anaerobic sewage treatment module is connected to the inlet area of ​​the lower anaerobic sewage treatment module.

[0009] The sludge stirring zone is provided with a plurality of internal circulation unit groups arranged along a first direction of the reactor body, each internal circulation unit group includes a plurality of internal circulation units sequentially connected along a second direction of the reactor body, the heights of the plurality of internal circulation units sequentially increasing from the water inlet area to the water outlet area, and the first direction and the second direction are perpendicular to each other;

[0010] The internal circulation unit includes an upflow area and a downflow area that are interconnected;

[0011] Pressurized sewage enters the water inlet area through the water inlet pipe. The inlet water is mixed with the sludge layer below the sludge stirring area and then diverted to multiple internal circulation unit groups. The mud-water mixture flows forward in the internal circulation unit group and enters multiple internal circulation units in turn. The mud-water mixture enters the upflow area. When it flows to the top of the upflow area, it enters the downflow area for sedimentation under the action of the guide plate, and the granular sludge is returned in the adjacent internal circulation units. The water flow and gas production bypass the guide plate and flow upward. The guide body descends the rising water flow and divides it into the gas collecting hoods on both sides to realize gas-liquid separation. The gas in the gas collecting hood is discharged through the exhaust pipe. The water flow rises to the top of the overflow area and flows into the water outlet area through the overflow weir. The water flow flows into the sewage anaerobic treatment module below under the action of gravity, repeating the process of mud-water mixing, reaction, circulation, separation and overflow.

[0012] Furthermore, the lengths of the water inlet area and the water outlet area in the second direction are 1 / 10 to 1 / 12 of the length of the reactor body in the second direction.

[0013] Furthermore, the height of the internal circulation unit is 40% to 50% of the height of the sewage anaerobic treatment module.

[0014] Furthermore, the height of the bottom of the internal circulation unit is raised by 10 to 50 cm from the water inlet area to the water outlet area.

[0015] Furthermore, the length ratio of the upflow area to the downflow area in the second direction is 1:1-2.

[0016] Furthermore, when used for the treatment of high-concentration organic wastewater, the relative abundance of methanogens to archaea in the sludge is 70-90%.

[0017] Furthermore, when used for anaerobic ammonium oxidation denitrification treatment, the relative abundance of anaerobic ammonification bacteria in the sludge is 10-60%.

[0018] Furthermore, a guide assembly is provided below the internal circulation unit, and the guide assembly includes a first plate extending in a horizontal direction and located below the downflow area, and a second plate extending obliquely upward from the water inlet area toward the water outlet area, and the second plate extends to below the upflow area to realize the diversion of the incoming water.

[0019] Furthermore, the muddy water flow rate in the upflow area is controlled to be 0.5 to 3.0 m / h by controlling the water inlet pressure and the angle between the second plate and the first plate.

[0020] Furthermore, the guide plate is arranged above the upflow area and partially extends to the downflow area.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] Pressurized water enters the water inlet area and mixes with the sludge layer before being diverted to the internal circulation unit group. The heights of the multiple internal circulation units in each internal circulation unit group gradually increase from the water inlet area to the water outlet area. The mud-water mixture can be pushed forward in the internal circulation unit. After reacting in the upflow area, the mud-water mixture enters the downflow area for sedimentation, achieving uniform water distribution and sludge return, improving sludge mixing efficiency, eliminating the need for additional mechanical mixing equipment, saving energy consumption, and optimizing effluent water quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a structural schematic diagram of an embodiment of an enhanced internal circulation sewage anaerobic treatment module of the present invention;

[0025] Figure 2 This is a second structural diagram of a sewage anaerobic treatment module with enhanced internal circulation according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic structural diagram of an anaerobic sewage treatment device with enhanced internal circulation according to an embodiment of the present invention;

[0027] in:

[0028] 1. Reactor body; 1-1. Water inlet zone; 1-2. Sludge stirring zone; 1-2a. Upflow zone; 1-2b. Downflow zone; 1-3. Gas-liquid separation zone; 1-4. Water outlet zone;

[0029] 2. First baffle; 2-1. Sludge return hole;

[0030] 3. Second partition;

[0031] 4. Internal circulation partition;

[0032] 5. First plate;

[0033] 6. Second plate;

[0034] 7. Guide plate;

[0035] 8. Diverter;

[0036] 9. Inclined board;

[0037] 10. Overflow weir;

[0038] 11. Water inlet pipe;

[0039] 12. Water outlet pipe;

[0040] 13. Mud discharge pipe;

[0041] 14. Exhaust pipe;

[0042] 15. The third partition. DETAILED DESCRIPTION

[0043] The above scheme is further described below in conjunction with specific examples. It should be understood that these examples are used to illustrate the present invention and are not intended to limit the scope of the present invention. The implementation conditions adopted in the examples can be further adjusted according to the conditions of the specific manufacturer. The implementation conditions not specified are generally those in routine experiments.

[0044] See also Figure 1 and Figure 2 , a schematic diagram of the structure of the present invention, provides an enhanced internal circulation anaerobic sewage treatment module, comprising a reactor body 1, within which are sequentially interconnected an inlet zone 1-1, a sludge agitation zone 1-2, a gas-liquid separator 1-3, and an outlet zone 1-4. The inlet zone 1-1 and the outlet zone 1-4 are disposed on opposite sides of the reactor body 1 and extend along the height of the reactor body 1. The sludge agitation zone 1-2 is disposed at the bottom of the reactor body 1, and the gas-liquid separation zone 1-3 is disposed above the sludge agitation zone 1-2.

[0045] In this example, the reactor body 1 is a rectangular parallelepiped closed at the top and bottom, with a square transverse cross-section and a ratio of height to square side length of 1 to 3:1. A first baffle 2 and a second baffle 3 extending vertically are arranged in the reactor body 1. The first baffle 1 extends from the top to the bottom of the reactor body 1 and forms an inlet area 1-1 between the first baffle 1 and the inner wall of the reactor body 1. There is a gap between the upper end of the second baffle 3 and the top of the reactor body 1 and the lower end extends to the bottom. A water outlet area 1-4 is formed between the second baffle 3 and the reactor body 1.

[0046] The sludge agitation zone 1-2 is disposed between the first baffle 2 and the second baffle 3 and comprises two internal circulation unit groups arranged in parallel along the first direction of the reactor body 1, separated by a third baffle 15. Each internal circulation unit group comprises four internal circulation units arranged in series along the second direction of the reactor body 1. The height of the four internal circulation units increases from the inlet zone 1-1 to the outlet zone 1-4, with the first and second directions being perpendicular to each other. In this example, the sides of the reactor body 1 in the first and second directions are equal. The length of the inlet zone 1-1 and the outlet zone 1-4 in the second direction is 1 / 10 to 1 / 12 of the length of the reactor body 1 in the second direction. The height of the internal circulation units is 40% to 50% of the height of the reactor body 1, and the bottom height of each internal circulation unit is raised by 10 to 50 cm. It should be understood that the number of internal circulation unit groups and the number of internal circulation units can be adjusted as needed and is not specified in the present invention.

[0047] Specifically, the internal circulation unit includes a downflow zone 1-2b close to the water inlet zone 1-1 and an upflow zone 1-2a away from the water inlet zone 1-1. The downflow zone 1-2b and the upflow zone 1-2a extend in the vertical direction and are interconnected. The length ratio of the upflow zone 1-2a to the downflow zone 1-2b in the second direction of the reactor body 1 is 1:1 to 2. Specifically, a plurality of internal circulation baffles 4 arranged in the vertical direction are provided in the reactor body 1. Downflow zones 1-2b or upflow zones 1-2a are formed between the internal circulation baffles 4 and the first baffle 2, between adjacent internal circulation baffles 4, and between the internal circulation baffles 4 and the second baffle 3. The bottom heights of the plurality of internal circulation baffles 4 are sequentially raised.

[0048] A flow guide assembly is provided below the internal circulation unit, and a flow guide plate 7 partially extending to above the downflow zone 1-2b is provided above the upflow zone 1-2a. In this example, most of the flow guide plates 7 are fixed to the upper end of the internal circulation plate 4, and the flow guide plates 7 near the outlet zone 1-4 are fixed to the second partition plate 3 and are in a convex arc shape, so as to guide the sludge in the upflow zone 1-2a to the downflow zone 1-2b for sedimentation. The flow guide assembly includes a first plate 5 extending in the horizontal direction and located below the downflow zone 1-2b, and a second plate 6 extending obliquely upward from the water inlet zone 1-1 toward the water outlet zone 1-4. The second plate 6 extends to the bottom of the upflow zone 1-2a to realize the diversion of the incoming water. A sludge return hole 2-1 connected to the downflow zone 1-2b is provided on the first partition plate 2.

[0049] The angle between the first plate 5 and the second plate 6 is 135-150°. The second plate 6 acts as a gate. A velocity meter measures the flow rate in different upflow zones 1-2a to control the water inlet pressure. The angle between the second plate 6 and the first plate 5 is then adjusted to maintain the muddy water upflow rate at 0.5-3.0 m / h. The second plate 6 is hinged to the first plate 5 and driven by a cylinder to rotate along the first plate 5 to adjust the angle between the second plate 6 and the first plate 5. This structure is prior art and is not specifically illustrated in the present invention.

[0050] Gas-liquid separation zones 1-3 are provided with a guide body 8 and a gas collection hood arranged from bottom to top. A gas collection zone is formed between the gas collection hood and the reactor body 1. An overflow zone is formed above the gas collection hood. The gas collection zone is connected to an exhaust pipe 14 and is provided with an overflow weir 10. The guide body 8 diverts the rising water flow to the gas collection zone to achieve gas-liquid separation.

[0051] The gas collecting hood includes two symmetrically arranged inclined plates 9 , one end of the inclined plates 9 is fixed on the reactor body 1 and the other end extends toward the middle of the reactor body 1 , and the flow guide 8 is arranged below the two inclined plates 9 .

[0052] In this example, the longitudinal cross-section of the guide body 8 is an axisymmetric quadrilateral, the vertex angle at the lower part of the quadrilateral is 136°, and the vertex angle at the upper part of the quadrilateral is 94°.

[0053] The reactor body 1 is located below the sludge stirring zone 1 - 2 and is connected to a sludge discharge pipe 13 to discharge the sludge in the sewage anaerobic module.

[0054] The average particle size of sludge in each module is preferably 0.5-3.0 mm, the sludge age is preferably controlled at 30-60 days, and the sludge concentration (MLVSS) in the internal circulation unit is 5-30 g / L; when used for high-concentration organic wastewater treatment, the effective volume load of a single module is 5-30 kg COD / m 3 / d, COD removal rate is 70% to 85%, and the relative abundance of methanogens such as Methanobacterium, Methanothrix and Methanospirillum in the sludge is preferably 70% to 90% of the archaea. When used for anaerobic ammonium oxidation denitrification treatment, the influent nitrogen load of a single module is 0.5 to 10 kg N / m 3 / d, the total nitrogen removal rate is 75% to 90%, and the relative abundance of anaerobic ammonia-oxidizing bacteria such as Candidatus Brocadia, Candidatus Kuenenia and Candidatus Jettenia in the sludge is preferably 10 to 60%.

[0055] like Figure 3As shown, the present invention also discloses an enhanced internal circulation anaerobic sewage treatment device, comprising two anaerobic sewage treatment modules stacked one above the other. The outlet area 1-4 of the upper anaerobic sewage module is connected to the inlet area 1-1 of the lower anaerobic sewage module. The inlet area 1-1 of the top anaerobic sewage module is connected to an inlet pipe 11, and the outlet area 1-4 of the bottom anaerobic sewage module is connected to an outlet pipe 12. It should be understood that other numbers of anaerobic sewage modules can be provided according to different wastewater treatment requirements, and adjacent anaerobic sewage modules are connected via flanges.

[0056] The treatment method of the above-mentioned sewage anaerobic treatment device is as follows: pressurized sewage enters the water inlet area 1-1 through the water inlet pipe 11, and the inlet water is mixed with the sludge layer below the sludge stirring area 1-2 and then evenly divided into multiple internal circulation unit groups; the mud-water mixture flows forward under the internal circulation unit group and enters multiple internal circulation units in turn. The mud-water mixer enters the upflow area 1-2a through the second plate 6, and when it flows to the top of the upflow area 1-2a, it enters the downflow area 1-2b for sedimentation under the action of the guide plate 7, and realizes the granular sludge backflow in the adjacent internal circulation unit, and the water flow and gas production bypass the guide plate 7 and flow upward; the guide body 8 divides the rising water flow into the gas collecting hoods on both sides to realize gas-liquid separation, and the gas in the gas collecting area is discharged by the exhaust pipe 14. The water flow rises to the top of the gas-liquid separation area 1-3 and flows into the water outlet area 1-4 through the overflow weir 10, and flows into the sewage anaerobic module below under the action of gravity, repeating the process of mud-water mixing, reaction, circulation, separation and overflow.

[0057] The following is a specific example of an anaerobic sewage treatment device treating anaerobic wastewater:

[0058] Example 1: The water to be treated is a chemical wastewater with an average pollutant concentration of COD 4000mg / L, total nitrogen 150mg / L, pH 8.0-8.2, alkalinity 1000mg / L (calculated as CaCO3), and a treatment scale of about 300m 3 / d.

[0059] The anaerobic sewage treatment device uses a single anaerobic sewage treatment module, made of stainless steel covered with enamel, which is mainly used to remove organic matter from the influent. Each module is a rectangular parallelepiped with closed upper and lower bottoms, about 8 meters in height, square in cross section, and an internal side length of 4 meters. The effective volume load is controlled at 17kgCOD / m 3 / d. The width of the inlet and outlet areas is 0.3m, and the thickness of the first, second, and internal circulation baffles is approximately 0.03m. Two internal circulation unit groups are located inside, separated by a central baffle. Each internal circulation unit group consists of four internal circulation cells, each approximately 3m tall, with upflow and downflow zones 0.3m and 0.5m wide, respectively. The bottom of the first internal circulation cell near the inlet is 0.5m above the module floor, and each subsequent cell is raised 0.3m higher. The effective volume of the sludge layer within the module is approximately 4.5m x 4.0m x 4.0m. A guide body is installed 0.5m above the internal circulation unit group. The longitudinal cross-section of the guide body is an axisymmetric tetrahedron and is approximately 0.3m high. A 1.7m-high inclined gas collection hood is installed on both sides above the guide body, with a biogas exhaust pipe at the top. A 4m-wide overflow weir is installed 0.5m above the gas collection hood, using a conventional triangular weir design. During operation, the MLVSS concentration in the internal circulation unit is about 20g / L, the remaining sludge is discharged from the sludge discharge pipe, and the sludge age is controlled to be about 50d.

[0060] The results of Example 1 showed that the particle size of the granular sludge in the device ranged from 1.2 to 3.0 mm, and the relative abundance of methanogens such as Methanobacterium, Methanothrix, and Methanospirillum in the sludge accounted for approximately 82% of the archaea. The device achieved a COD removal rate of 75% to 78% in the influent, and the effluent COD concentration remained stable below 1000 mg / L. The water quality met the influent requirements of traditional A / O processes, allowing for further biological denitrification.

[0061] Example 2: Water to be treated: Wastewater from a sludge drying plant, which is treated by anaerobic ammonium oxidation after pretreatment. The average concentration of pollutants is 180 mg / L ammonia nitrogen, 200 mg / L nitrite nitrogen, COD < 150 mg / L, pH 8.5, alkalinity 300 mg / L (calculated as CaCO3), and the treatment scale is about 900 m 3 / d.

[0062] The sewage anaerobic treatment device is composed of two anaerobic sewage treatment modules stacked together. The modules are made of stainless steel covered with enamel and connected by flanges. The outlet of the top module is connected to the inlet of the bottom module. Each module is a rectangular parallelepiped with closed top and bottom, about 7 meters high, square in cross section, and an internal side length of 4 meters. The effective volume load is controlled at 5kgCOD / m 3 / d. The width of the inlet and outlet areas is 0.3m, and the thickness of the first, second, and internal circulation baffles is approximately 0.03m. Two internal circulation unit groups are located inside, separated by a central baffle. Each internal circulation unit group consists of four internal circulation cells, each approximately 2.5m tall, with upflow and downflow zones 0.4m and 0.4m wide, respectively. The bottom of the first internal circulation cell near the inlet is 0.5m above the module floor, and each subsequent cell is raised 0.4m higher. The effective volume of the sludge layer within the module is approximately 4.5m x 4.0m x 4.0m. A guide body is installed 0.5m above the internal circulation unit group. The longitudinal cross-section of the guide body is an axisymmetric tetrahedron and is approximately 0.3m high. A 1.5m-high inclined gas collection hood is installed on both sides above the guide body, with a biogas exhaust pipe at the top. A 4m-wide overflow weir is installed 0.3m above the gas collection hood, using a conventional triangular weir design. The bottom module structure is the same as the top module, but the installation direction is opposite. The effective volume load is controlled at 1kgN / m 3 During operation, the MLVSS concentrations in the circulation units of the top and bottom modules were 27 g / L and 8 g / L, respectively. The remaining sludge was discharged from the sludge discharge pipe, and the sludge ages were 40 days and 32 days, respectively.

[0063] The results of Example 2 showed that the particle size of the granular sludge in the top module was 1.2 to 2.5 mm, the anaerobic ammonia-oxidizing bacteria were mainly Candidatus Brocadia and Candidatus Kuenenia, with a relative abundance of about 47%, and the total nitrogen removal rate of the influent was about 80%; the particle size of the granular sludge in the bottom module was 0.8 to 1.9 mm, the relative abundance of anaerobic ammonia-oxidizing bacteria was about 18%, the total nitrogen concentration of the effluent was less than 20 mg / L, and the water quality met the "Water Quality Standard for Sewage Discharge into Urban Sewers" (GB / T31962-2015).

[0064] The above examples are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A method for anaerobic treatment of sewage with enhanced internal circulation, characterized by: The treatment method is based on an anaerobic sewage treatment device, which includes a plurality of anaerobic sewage treatment modules stacked one above the other. The anaerobic sewage treatment modules include a reactor body, wherein a water inlet area, a sludge stirring area, a gas-liquid separation area, and a water outlet area are sequentially connected within the reactor body. The water outlet area of ​​the upper anaerobic sewage treatment module is connected to the water inlet area of ​​the lower anaerobic sewage treatment module. The sludge stirring zone is provided with a plurality of internal circulation unit groups arranged along a first direction of the reactor body, each internal circulation unit group includes a plurality of internal circulation units sequentially connected along a second direction of the reactor body, the heights of the plurality of internal circulation units sequentially increasing from the water inlet area to the water outlet area, and the first direction and the second direction are perpendicular to each other; The internal circulation unit includes an upflow area and a downflow area that are interconnected; A guide plate is provided above the upflow area, partially extending to the downflow area, and the guide plate is in a convex arc shape; A flow guide assembly is provided below the internal circulation unit, the flow guide assembly comprising a first plate extending horizontally and located below the downflow area, and a second plate extending obliquely upward from the water inlet area toward the water outlet area, the second plate extending to below the upflow area to guide the incoming water; Pressurized sewage enters the water inlet area through the water inlet pipe. The inlet water is mixed with the sludge layer below the sludge mixing area and then diverted to multiple internal circulation unit groups. The mud-water mixture flows forward in the internal circulation unit group and enters multiple internal circulation units in turn. The mud-water mixture enters the upflow area. When it flows to the top of the upflow area, it enters the downflow area for sedimentation under the action of the guide plate, and the granular sludge is returned in the adjacent internal circulation unit. The water flow and gas production bypass the guide plate and flow upward. The guide body divides the rising water flow into the gas collecting hoods on both sides to realize gas-liquid separation. The gas in the gas collecting hood is discharged through the exhaust pipe. The water flow rises to the top of the overflow area and flows into the water outlet area through the overflow weir. Under the action of gravity, the water flow flows into the sewage anaerobic treatment module below, repeating the process of mud-water mixing, reaction, circulation, separation and overflow.

2. The method for anaerobic treatment of sewage with enhanced internal circulation according to claim 1, characterized in that: The lengths of the water inlet area and the water outlet area in the second direction are 1 / 10 to 1 / 12 of the length of the reactor body in the second direction.

3. The method for anaerobic treatment of sewage with enhanced internal circulation according to claim 1, characterized in that: The height of the internal circulation unit is 40% to 50% of the height of the sewage anaerobic treatment module.

4. The method for anaerobic treatment of sewage with enhanced internal circulation according to claim 1, characterized in that: The height of the bottom of the internal circulation unit is raised by 10 to 50 cm from the water inlet area to the water outlet area.

5. The method for anaerobic treatment of sewage with enhanced internal circulation according to claim 1, characterized in that: The length ratio of the upflow area to the downflow area in the second direction is 1:1-2.

6. The method for anaerobic sewage treatment with enhanced internal circulation according to claim 1, characterized in that: When used for the treatment of high-concentration organic wastewater, the relative abundance of methanogens to archaea in sludge is 70-90%.

7. The method for anaerobic sewage treatment with enhanced internal circulation according to claim 1, characterized in that: When used for anaerobic ammonium oxidation denitrification treatment, the relative abundance of anaerobic ammonifying bacteria in the sludge is 10~60%.

8. The method for anaerobic sewage treatment with enhanced internal circulation according to claim 1, characterized in that: The muddy water flow rate in the upflow area is controlled to be 0.5-3.0 m / h by controlling the water inlet pressure and the angle between the second plate and the first plate.

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