Microaerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor

Abstract

This invention relates to a continuous flow aerobic granular sludge reactor with integrated microaerobic-aerobic coupled sedimentation, comprising, from top to bottom, a three-phase separation zone, a biochemical zone, and an aeration zone. The biochemical zone includes an outer microaerobic zone and an inner aerobic zone, separated by a first cylindrical body. An inlet pipe is provided on the outer wall of the microaerobic zone for inputting wastewater into it. The bottom of the first cylindrical body is open, allowing water from the microaerobic zone to enter the aerobic zone. The top of the first cylindrical body is open, connecting the aerobic zone and the three-phase separation zone. The three-phase separation zone includes a second cylindrical body that is wider at the bottom and narrower at the top, capable of intercepting small-volume flocculent sludge in the water and allowing it to enter the microaerobic zone for continued growth. The top of the first cylindrical body is wider at the bottom and narrower at the top, intercepting large-volume flocculent sludge and retaining it in the aerobic zone, preventing the loss of aerobic granular sludge.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a continuous flow aerobic granular sludge reactor with integrated micro-aerobic-aerobic coupled sedimentation. Background Technology

[0002] Aerobic granular sludge (AGS) technology is a type of activated sludge formed by microbial self-aggregation, offering advantages such as good settling performance, high biomass, and simultaneous removal of carbon, nitrogen, and phosphorus. Currently, AGS technology is mainly applied to sequencing batch reactors (SBRs), but it generally suffers from problems such as small treatment capacity, low equipment utilization, and difficulty in operation and control. Compared to SBRs, continuous flow reactors can overcome these difficulties. However, applying AGS technology to continuous flow reactors makes it difficult to achieve rapid granulation and long-term stable operation. This is mainly because factors such as hydraulic selective pressure and the influence of substrate nutrients on the microbial growth cycle within the continuous flow reactor significantly affect the formation rate, structure, and stability of the aerobic granular sludge.

[0003] The hydraulic conditions affecting granulation are collectively referred to as hydraulic selective pressure, including sludge settling time and hydraulic shear force. Controlling the settling time to retain granular sludge with a faster settling rate in the reactor and discharging sludge with poor performance is the most direct way to screen granular sludge. While promoting the collision and aggregation of sludge, hydraulic shear force can also promote the formation of granular sludge by affecting the hydrophobicity of the microbial surface, the EPS components secreted, and the specific gravity of the particles. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a continuous flow aerobic granular sludge reactor with integrated microaerobic-aerobic coupled sedimentation, comprising, from top to bottom, a three-phase separation zone, a biochemical zone, and an aeration zone. The biochemical zone includes an outer microaerobic zone and an inner aerobic zone, separated by a first cylindrical body. The outer wall of the microaerobic zone is equipped with an inlet pipe for inputting wastewater into the microaerobic zone. The bottom of the first cylindrical body is open, allowing water from the microaerobic zone to enter the aerobic zone. The top of the first cylindrical body is open, connecting the aerobic zone and the three-phase separation zone.

[0005] The three-phase separation zone includes a second cylinder that is larger at the bottom and smaller at the top, which can intercept small-volume flocculent sludge in the water and allow it to enter the micro-aerobic zone to continue growing; the top of the first cylinder is shaped like a cylinder that is larger at the bottom and smaller at the top, which intercepts large-volume flocculent sludge and keeps it in the aerobic zone, preventing the loss of aerobic granular sludge.

[0006] Optionally, the continuous flow aerobic granular sludge reactor is cylindrical in shape, and the reactor is concentrically arranged with the microaerobic zone, aerobic zone, and three-phase separation zone.

[0007] The reactor is equipped with an overflow trough and an outlet pipe at the top to output the treated water; the bottom of the reactor is equipped with an aeration zone to provide air for the aerobic and microaerobic zones, and a sludge discharge pipe is located below the aeration zone.

[0008] Optionally, the first cylindrical body includes, from top to bottom, a constricted section, a straight section, and an extended section. The inner diameter of the constricted section gradually decreases from bottom to top, and the inner diameter of the extended section gradually increases from top to bottom, such that the sidewalls of both the constricted section and the extended section are inclined. The straight section is a vertical cylinder with a constant inner diameter. The constricted section, the straight section, and the extended section are integrally formed.

[0009] Further optionally, the angle between the sidewall of the contraction portion and the vertical plane is 20°-60°, and the angle between the sidewall of the extension portion one and the vertical plane is 45°-75°;

[0010] The height of the contraction section in the vertical plane accounts for 10%-25% of the total height of the first cylinder.

[0011] Optionally, the aeration zone is provided with a first aeration pipe and a second aeration pipe. The first aeration pipe is evenly laid directly below the extension section one, and the second aeration pipe is evenly laid directly below the micro-oxygen zone. The laying density and aeration volume of the first aeration pipe are both greater than those of the second aeration pipe.

[0012] Optionally, the second cylindrical body includes a straight cylindrical section and an extended section. The top of the straight cylindrical section extends through the top surface of the reactor, and the bottom of the straight cylindrical section is connected to the top of the extended section. The straight cylindrical section is a vertical cylinder with a constant inner diameter.

[0013] The inner diameter of the second expansion section gradually increases from top to bottom, making the sidewall of the second expansion section inclined. There is a space between the second expansion section and the contraction section, which forms a flow channel, enabling the three-phase separation zone to connect the aerobic zone and the microaerobic zone.

[0014] Further optionally, the diameter of the second straight section is 1 / 4 to 1 / 3 of the diameter of the first straight section, and the diameter of the bottom end of the second extension section is 1 to 1.2 times the diameter of the first straight section.

[0015] Optionally, several levels of flow guiding components are uniformly arranged from top to bottom in the micro-oxygen zone, and the height of each level of flow guiding component is different; each level of flow guiding component includes several flow guiding plates, and the several flow guiding plates of the same level of flow guiding component are uniformly distributed along the circumference of the straight cylinder section at their own height.

[0016] In one specific implementation, a primary flow guiding component, a secondary flow guiding component, and a tertiary flow guiding component are arranged sequentially from top to bottom in the micro-oxygen zone. The height of the primary flow guiding component corresponds to the height of the top of the straight cylinder, the height of the secondary flow guiding component corresponds to the height of the middle of the straight cylinder, and the height of the tertiary flow guiding component corresponds to the height of the bottom of the straight cylinder.

[0017] The primary flow guide assembly includes several primary flow guide plates, the secondary flow guide assembly includes several secondary flow guide plates, and the tertiary flow guide assembly includes several tertiary flow guide plates. The primary flow guide plates are evenly distributed along the circumference of the straight cylindrical section at their own height, the secondary flow guide plates are evenly distributed along the circumference of the straight cylindrical section at their own height, and the tertiary flow guide plates are evenly distributed along the circumference of the straight cylindrical section at their own height.

[0018] Optionally, the first-stage guide plate, the second-stage guide plate, and the third-stage guide plate are all downward-convex arc-shaped plates. The side of the first-stage guide plate near the inner wall of the reactor is higher than the side near the first cylinder. The side of the second-stage guide plate near the inner wall of the reactor is lower than the side near the first cylinder. The side of the third-stage guide plate near the inner wall of the reactor is higher than the side near the first cylinder.

[0019] Further optional, gaps are left between all guide plates and the inner wall of the reactor and the outer wall of the first cylinder, and there are gaps between adjacent guide plates of the same level;

[0020] In the cross-section of the micro-oxygen zone where the same level of guide vane is located, the area of ​​the guide vane accounts for 50%-80% of the total cross-sectional area of ​​the micro-oxygen zone.

[0021] Further optional, the guide vanes of different levels that are adjacent to each other are staggered in the same vertical position;

[0022] The angle between the deflector and the horizontal plane is 45°-55°.

[0023] Optionally, the height of the inlet pipe corresponds to the area between the primary flow guide component and the secondary flow guide component, preferably at the upper 1 / 3 height of the micro-oxygen zone, to avoid causing significant disturbance to the second aeration pipe, while fully realizing the effective mixing of raw water and return water from the three-phase separation zone.

[0024] Optionally, the outlet pipe is equipped with a filter screen to filter out small flocs in the product water; a return pipe is connected between the outlet pipe and the inlet pipe, with one end of the return pipe connected to the outlet pipe located between the filter screen and the reactor. The discharged product water can carry the filtered and trapped small flocs back to the micro-aerobic zone, and the amount of return water is controlled by a valve on the return pipe.

[0025] Optionally, the top of the contraction section and the top of the straight section are not integrally formed. The lower surface of the contraction section is provided with a ring of upwardly recessed mating grooves corresponding to the position of the top of the straight section, so that the top edge of the straight section can be inserted into the mating grooves, thereby limiting the relative position of the contraction section and the straight section.

[0026] The top edge of the contraction section is connected to a rotating shaft via several support rods. The rotating shaft is located at the central axis of the reactor. The rotating shaft passes vertically upward through the straight cylinder section and is connected to a motor above the reactor to drive the contraction section to rotate.

[0027] Optionally, a rotatable hollow frustum is provided at the connection between the straight section 2 and the extension section 2. The hollow frustum is concentrically arranged with the second cylinder. The top edge of the hollow frustum is connected to a rotating shaft through several support rods 2. The rotating shaft can drive the hollow frustum and the contraction section to rotate together at the same time. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the integrated micro-aerobic-aerobic sedimentation continuous flow aerobic granular sludge reactor of Example 1.

[0029] Figure 2 for Figure 1 A three-dimensional image;

[0030] Figure 3 This is a schematic diagram of the fit between the contraction section and the straight section in Example 12;

[0031] Figure 4 This is a schematic diagram of the hollow frustum of a cone in Example 13.

[0032] In the attached diagram, 1-three-phase separation zone, 2-micro-aerobic zone, 3-aerobic zone, 4-first cylinder, 5-second cylinder, 6-inlet pipe, 7-outlet pipe, 8-return pipe, 9-overflow trough, 10-sludge discharge pipe, 11-contraction section, 12-straight cylinder section one, 13-extension section one, 14-first aeration pipe, 15-second aeration pipe, 16-straight cylinder section two, 17-extension section two, 18-first-stage guide plate, 19-second-stage guide plate, 20-third-stage guide plate, 21-hollow frustum, 22-rotating shaft. Detailed Implementation

[0033] Example 1

[0034] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, such as... Figures 1-2 As shown, from top to bottom, it includes a three-phase separation zone 1, a biochemical zone, and an aeration zone. The biochemical zone includes an outer micro-aerobic zone 2 and an inner aerobic zone 3. The micro-aerobic zone 2 and the aerobic zone 3 are separated by a first cylinder 4. The outer wall of the micro-aerobic zone 2 is provided with an inlet pipe 6 for inputting sewage into the micro-aerobic zone 2. The bottom of the first cylinder 4 is open, so that the water from the micro-aerobic zone 2 can be input into the aerobic zone 3. The top of the first cylinder 4 is open, for connecting the aerobic zone 3 and the three-phase separation zone 1.

[0035] The three-phase separation zone 1 includes a second cylinder 5 that is larger at the bottom and smaller at the top, which can intercept small-volume flocculent sludge in the water and allow the small-volume flocculent sludge to enter the micro-aerobic zone 2 to continue growing; the top of the first cylinder 4 is shaped like a cylinder that is larger at the bottom and smaller at the top, which intercepts large-volume flocculent sludge and keeps it in the aerobic zone 3, preventing the loss of aerobic granular sludge.

[0036] The continuous flow aerobic granular sludge reactor is cylindrical in shape, and the reactor is concentrically arranged with the microaerobic zone 2, the aerobic zone 3, and the three-phase separation zone 1.

[0037] The reactor is equipped with an overflow trough 9 and an outlet pipe 7 at the top to output the treated water; the reactor is equipped with an aeration zone at the bottom to provide air for the aerobic zone 3 and the microaerobic zone 2; and a sludge discharge pipe 10 is provided below the aeration zone to discharge excess sludge or sludge with low activity from the reactor.

[0038] The first cylindrical body 4 includes, from top to bottom, a constricting section 11, a straight cylindrical section 12, and an expanding section 13. The inner diameter of the constricting section 11 gradually decreases from bottom to top, while the inner diameter of the expanding section 13 gradually increases from top to bottom, resulting in inclined sidewalls for both the constricting section 11 and the expanding section 13. The straight cylindrical section 12 is a vertical cylinder with a constant inner diameter. The constricting section 11, the straight cylindrical section 12, and the expanding section 13 are integrally formed.

[0039] The angle between the sidewall of the contraction section 11 and the vertical plane is 20°, and the angle between the sidewall of the extension section 13 and the vertical plane is 45°.

[0040] The height of the contraction section 11 in the vertical plane accounts for 10% of the total height of the first cylinder 4.

[0041] The aeration zone is provided with a first aeration pipe 14 and a second aeration pipe 15. The first aeration pipe 14 is evenly laid directly below the extension section 13, and the second aeration pipe 15 is evenly laid directly below the micro-aerobic zone 2. The laying density and aeration volume of the first aeration pipe 14 are greater than those of the second aeration pipe 15. The first aeration pipe 14 and the second aeration pipe 15 are each connected to an air supply device, and the aeration volume of the first aeration pipe 14 and the second aeration pipe 15 are controlled separately, so as to meet the different oxygen requirements of the aerobic zone 3 and the micro-aerobic zone 2 respectively.

[0042] By adjusting the aeration rate of the first aeration pipe 14, the dissolved oxygen in the aerobic zone 3 is controlled at 1.0-3.0 mg / L; by adjusting the aeration rate of the second aeration pipe 15, the dissolved oxygen in the micro-aerobic zone 2 is controlled at 0.2-0.5 mg / L.

[0043] Water from the microaerobic zone 2 flows into the aerobic zone 3 through the extension section 13. The funnel shape of the extension section 13 prevents the aeration from the first aeration pipe 14 from affecting the microaerobic zone 2. The first aeration pipe 14 performs a stripping function, causing the water to flow from bottom to top in the aerobic zone 3. The water mixes and reacts with the aerobic granular sludge under strong aeration, preventing sludge deposition. The contraction section 11 screens the sludge-water mixture flowing to the top of the aerobic zone 3, allowing large aerobic granular sludge particles with good settling properties to settle rapidly, achieving preliminary sludge-water separation. At the same time, the settling of large aerobic granular sludge particles also increases the effective collision between microorganisms in the aerobic zone 3, forming a vigorous internal circulation movement, continuously inducing the secretion of microbial EPS, increasing the hydrophobicity of the microbial surface, and promoting the aggregation of aerobic granular sludge into granules.

[0044] The second cylindrical body 5 includes a straight cylindrical section 16 and an extended section 17. The top of the straight cylindrical section 16 extends through the top surface of the reactor, and the bottom of the straight cylindrical section 16 is connected to the top of the extended section 17. The straight cylindrical section 16 is a vertical cylinder with a constant inner diameter.

[0045] The inner diameter of the second extension section 17 gradually increases from top to bottom, making the sidewall of the second extension section 17 inclined. There is a space between the second extension section 17 and the contraction section 11, which forms a flow channel, enabling the three-phase separation zone 1 to connect the aerobic zone 3 and the microaerobic zone 2.

[0046] The diameter of the second straight section 16 is 1 / 3 of the diameter of the first straight section 12, and the diameter of the bottom end of the second extension section 17 is 1 times the diameter of the first straight section 12.

[0047] After initial sludge-water separation, the water enters the three-phase separation zone 1 and encounters the lower surface of the downwardly sloping extension section 2 17, where three-phase separation occurs. Gas is discharged from the reactor through the straight section 2 16. Small aerobic sludge particles with good settling performance settle back into the aerobic zone 3. A small amount of small-diameter sludge with poor settling performance and most of the flocculent sludge enter the micro-aerobic zone 2 through the flow channel with the water flow, forming a circulation between the aerobic zone 3 and the micro-aerobic zone 2.

[0048] The overflow trough 9 is located on the side wall at the top of the reactor. After the biochemical treatment, the produced water flows into the micro-oxygen zone 2 through the three-phase separation zone 1. The water accumulates upward in the space between the second cylinder 5 and the inner wall of the reactor until it overflows out of the overflow trough 9 and is discharged from the reactor.

[0049] The micro-oxygen zone 2 is provided with a first-level flow guide component, a second-level flow guide component and a third-level flow guide component from top to bottom. The height of the first-level flow guide component corresponds to the height of the top of the straight cylinder section 12, the height of the second-level flow guide component corresponds to the height of the middle of the straight cylinder section 12, and the height of the third-level flow guide component corresponds to the height of the bottom of the straight cylinder section 12.

[0050] The primary flow guiding assembly includes four primary flow guiding plates 18, the secondary flow guiding assembly includes four secondary flow guiding plates 19, and the tertiary flow guiding assembly includes four tertiary flow guiding plates 20. The four primary flow guiding plates 18 are evenly distributed along the circumference of the straight cylindrical section 12 at their own height, the four secondary flow guiding plates 19 are evenly distributed along the circumference of the straight cylindrical section 12 at their own height, and the four tertiary flow guiding plates 20 are evenly distributed along the circumference of the straight cylindrical section 12 at their own height.

[0051] The primary guide plate 18, the secondary guide plate 19, and the tertiary guide plate 20 are all downward-convex arc-shaped plates. The side of the primary guide plate 18 closest to the inner wall of the reactor is higher than the side closest to the first cylinder 4. The side of the secondary guide plate 19 closest to the inner wall of the reactor is lower than the side closest to the first cylinder 4. The side of the tertiary guide plate 20 closest to the inner wall of the reactor is higher than the side closest to the first cylinder 4.

[0052] All guide plates are connected to the outer wall of the first cylinder 4 or the inner wall of the reactor via connecting rods, so that the guide plates are suspended and fixed in the micro-oxygen zone 2.

[0053] All guide vanes have gaps between themselves and the inner wall of the reactor and the outer wall of the first cylinder 4, and there are gaps between adjacent guide vanes of the same level.

[0054] On the cross-section of the micro-oxygen zone 2 where the same level guide plate 18 is located, the area of ​​the guide plate accounts for 50% of the total cross-sectional area of ​​the micro-oxygen zone 2.

[0055] The guide vanes of different stages that are adjacent to each other are staggered in the same vertical position; the angle between the guide vanes and the horizontal plane is 45°.

[0056] This invention, by setting up multi-stage flow guiding components, can continuously change the flow direction of the mud-water mixture in the micro-oxygen zone 2, forming hydraulic shear forces in various directions, thereby creating hydraulic selective pressure.

[0057] This invention combines the three-phase separation technology of upflow reactor with traditional activated sludge technology to construct the reactor, which can eliminate the need for a secondary settling tank; through the extension section 2 17 and the contraction section 11, gas, solid and liquid separation can be carried out in two stages, while a vigorous internal circulation is formed in the aerobic zone 3, thereby screening aerobic granular sludge with good settling performance and realizing continuous flow denitrification of aerobic granular sludge.

[0058] No power lifting is required in aerobic zone 3. The mixed liquor is made to move in a circle between aerobic zone 3 and microaerobic zone 2 by air lifting power (first aeration pipe 14), creating a better hydraulic selective pressure. Second aeration pipe 15 provides a microaerobic environment for microaerobic zone 2. Stable alternating feast-famine conditions are formed in microaerobic zone 2 and aerobic zone 3. The stage in which microorganisms adsorb and utilize the high concentration of external substrate for growth is called the feast stage, and the stage in which they grow with the internal substrate is called the famine stage. The alternation of feast and famine stages can promote the generation of EPS, thereby inducing the rapid formation of aerobic granular sludge and contributing to its long-term stability. It also makes full use of the carbon source in the raw water to achieve simultaneous nitrification and denitrification.

[0059] An arc-shaped guide plate is installed in micro-aerobic zone 2 to further create hydraulic conditions, generate hydraulic shear force in the mud-water mixture, promote the rapid granulation of flocculent sludge, and at the same time prolong the residence time of the mud-water mixture in micro-aerobic zone 2, thereby enhancing the denitrification effect.

[0060] Within the micro-oxygen zone 2, under low dissolved oxygen conditions, a mixed denitrification system is constructed. Through simultaneous nitrification-denitrification and simultaneous short-cut nitrification-denitrification, organic matter degradation and the removal of ammonia nitrogen and total nitrogen are achieved in the same reactor.

[0061] The height of the inlet pipe 6 corresponds to the distance between the primary flow guide component and the secondary flow guide component. The inlet pipe 6 is located at the upper 1 / 3 height of the micro-oxygen zone 2, which avoids causing significant disturbance to the second aeration pipe 15, while fully realizing the effective mixing of raw water and return water from the three-phase separation zone 1.

[0062] The outlet pipe 7 is equipped with a filter screen to filter out small flocs in the product water. A return pipe 8 is connected between the outlet pipe 7 and the inlet pipe 6, with one end of the return pipe 8 connected to the outlet pipe 7 located between the filter screen and the reactor. The discharged product water can carry the filtered and trapped small flocs back to the micro-aerobic zone 2, and the amount of return water is controlled by a valve on the return pipe 8.

[0063] In this embodiment, the reactor has a total height of 10 meters, an inner diameter of 5 meters, an inner diameter of 2.5 meters for the straight section 12, a total height of 7.5 meters for the first cylinder 4, and the height of the extension section 17 on the vertical plane is equal to the height of the straight section 16.

[0064] Comparative Example 1

[0065] This comparative example provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as Example 1, except that the first cylinder 4 is a vertical cylinder and does not have a contraction section 11 and an expansion section 13.

[0066] Example 2

[0067] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1, except that the angle between the sidewall of the contraction section 11 and the vertical plane is 60°.

[0068] Example 3

[0069] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1, except that the angle between the sidewall of the contraction section 11 and the vertical plane is 19°.

[0070] Example 4

[0071] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1, except that the height of the contraction section 11 in the vertical plane accounts for 25% of the total height of the first cylinder 4.

[0072] Example 5

[0073] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1, except that the height of the contraction section 11 on the vertical plane accounts for 9% of the total height of the first cylinder 4.

[0074] Example 6

[0075] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1, except that the diameter of the bottom end of the extension section 2 17 is 1.2 times the diameter of the straight section 12.

[0076] Example 7

[0077] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1, except that the diameter of the bottom end of the extension section 2 17 is 0.9 times the diameter of the straight section 12.

[0078] Example 8

[0079] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1. The difference is that, on the cross-section of the micro-aerobic zone 2 where the same level guide plate 18 is located, the area of ​​the guide plate accounts for 80% of the total cross-sectional area of ​​the micro-aerobic zone 2.

[0080] Example 9

[0081] This embodiment provides a continuous flow aerobic granular sludge reactor with integrated micro-aerobic-aerobic coupling sedimentation, which is the same as that in embodiment 1. The difference is that, on the cross-section of the micro-aerobic zone 2 where the same level guide plate 18 is located, the area of ​​the guide plate accounts for 49% of the total cross-sectional area of ​​the micro-aerobic zone 2.

[0082] Example 10

[0083] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1, except that the angle between the guide plate and the horizontal plane is 55°.

[0084] Example 11

[0085] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in embodiment 1, except that the angle between the guide plate and the horizontal plane is 56°.

[0086] Example 12

[0087] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in Embodiment 1, except that, as Figure 3 As shown, the top of the contraction part 11 and the top of the straight cylindrical part 12 are not integrally formed. The lower surface of the contraction part 11 is provided with a ring of upwardly recessed docking grooves corresponding to the position of the top of the straight cylindrical part 12, so that the top edge of the straight cylindrical part 12 can be inserted into the docking grooves, thereby limiting the relative position of the contraction part 11 and the straight cylindrical part 12.

[0088] The top edge of the contraction section 11 is connected to the rotating shaft 22 by three support rods. The rotating shaft 22 is located at the central axis of the reactor. The rotating shaft 22 passes vertically upward through the straight cylinder section 16 and is connected to the motor above the reactor to drive the contraction section 11 to rotate.

[0089] When the water in aerobic zone 3 carrying aerobic granular sludge rises to the contraction section 11, it encounters the horizontally rotating lower surface of the contraction section 11. The rotation of the contraction section 11 provides centrifugal force to the mixed liquid, causing it to continuously rotate as it rises along the contraction section 11. This spiral rotation facilitates solid-liquid separation, allowing medium-sized granular sludge that would otherwise be unable to separate and enter the microaerobic zone 2 to remain in the aerobic zone 3 for further cultivation. It also prevents medium-sized granular sludge from impacting the guide plate when flowing in the microaerobic zone 2. Such impact would not only be detrimental to maintaining the tilt of the guide plate but could also break up the medium-sized granular sludge. The three support rods are radially distributed on the top surface of the contraction section 11, without affecting the water outlet at the top of the contraction section 11.

[0090] Example 13

[0091] This embodiment provides a micro-aerobic-aerobic coupled sedimentation integrated continuous flow aerobic granular sludge reactor, which is the same as that in Embodiment 12, except that, as Figure 4As shown, a rotatable hollow frustum 21 is provided at the connection between the straight cylindrical section 2 16 and the extended section 2 17. The hollow frustum 21 is concentrically arranged with the second cylindrical body 5. The top edge of the hollow frustum 21 is connected to a rotating shaft 22 through two support rods. The rotating shaft 22 can simultaneously drive the hollow frustum 21 and the contracting section 11 to rotate together. The top of the hollow frustum 21 is flush with the top of the extended section 2 17, and the height of the hollow frustum 21 in the vertical plane accounts for 1 / 3 of the height of the extended section 2 17 in the vertical plane.

[0092] In the three-phase separation zone 1, the mixed liquid contacts the extension section 2 17 for gas-solid-liquid separation. The separated gas is discharged through the straight section 2 16. However, when the water volume is large, some water may overflow through the straight section 2 16. A small gap is left between the outer surface of the hollow frustum 21 and the inner surface of the extension section 2 17. When the hollow frustum 21 rotates, gas is allowed to pass through. When the liquid passes through, it forms a swirling flow under the action of centrifugal force, flowing close to or tightly against the inner surface of the hollow frustum 21 and the inner wall of the straight section 2 16. This facilitates the water flowing down the inner wall and returning to the three-phase separation zone 1.

[0093] Example 14

[0094] This embodiment provides a continuous flow aerobic granular sludge reactor with integrated micro-aerobic-aerobic coupling sedimentation, which is the same as that in embodiment 1, except that no guide plate is set in the micro-aerobic zone.

[0095] In the following examples and comparative examples, the wastewater is from a brewery with a treatment capacity of 100 tons / day. The wastewater quality is as follows: COD 632-700 mg / L, ammonia nitrogen 36-50 mg / L, and total nitrogen 48-60 mg / L. The product water quality standards are: COD ≤ 100 mg / L, ammonia nitrogen ≤ 8 mg / L, and total nitrogen ≤ 15 mg / L.

[0096] The standard for stable operation of the reactor is that, within a certain range of influent fluctuations, the pollutant removal rate, sludge properties (sludge concentration, particle size, settling performance), and effluent indicators tend to stabilize.

[0097] Table 1 Comparison of startup time between the examples and comparative examples

[0098]

[0099]

[0100] Start-up time is the time from the beginning of cultivating aerobic granular sludge to the stable operation of the reactor.

[0101] As shown in the table above, the integrated micro-aerobic-aerobic coupled sedimentation continuous flow aerobic granular sludge reactor provided by this invention can effectively shorten the reactor start-up time and rapidly cultivate aerobic granular sludge. After the start-up time of Examples 1-13, the average particle size of the cultivated aerobic granular sludge is 0.5-2 mm, the average sludge concentration in the reactor is in the range of 6000-12000 mg / L, and the average COD load is 1.8-2.4 kg COD / m³. 3 ·d.

Claims

1. A continuous flow aerobic granular sludge reactor with integrated microaerobic-aerobic coupled sedimentation, characterized in that, The reactor comprises, from top to bottom, a three-phase separation zone, a biochemical zone, and an aeration zone. The biochemical zone includes an outer microaerobic zone and an inner aerobic zone, separated by a first cylindrical body. The outer wall of the microaerobic zone is equipped with an inlet pipe for feeding wastewater into the microaerobic zone. The bottom of the first cylindrical body is open, allowing water from the microaerobic zone to flow into the aerobic zone. The top of the first cylindrical body is open, connecting the aerobic zone and the three-phase separation zone. The three-phase separation zone includes a second cylinder that is larger at the bottom and smaller at the top, which can intercept small-volume flocculent sludge in the water and allow the small-volume flocculent sludge to enter the micro-aerobic zone to continue growing; the top of the first cylinder is shaped like a cylinder that is larger at the bottom and smaller at the top, which intercepts large-volume flocculent sludge and keeps it in the aerobic zone, preventing the loss of aerobic granular sludge. The first cylindrical body includes a constricted section, a straight section 1, and an extended section 1 from top to bottom. The inner diameter of the constricted section gradually decreases from bottom to top, and the inner diameter of the extended section 1 gradually increases from top to bottom, so that the side walls of the constricted section and the extended section 1 are inclined. The straight section 1 is a vertical cylinder with a constant inner diameter. The angle between the sidewall of the contraction section and the vertical plane is 20°-60°, and the height of the contraction section on the vertical plane accounts for 10%-25% of the total height of the first cylinder. The lower surface of the contraction section is provided with an upwardly recessed mating groove corresponding to the top of the straight section, so that the top edge of the straight section can be inserted into the mating groove, thereby defining the relative position of the contraction section and the straight section. The top edge of the contraction section is connected to a rotating shaft by several support rods. The rotating shaft is located at the central axis of the reactor. The rotating shaft passes vertically upward through the straight cylinder section and is connected to a motor above the reactor to drive the contraction section to rotate. The second cylindrical body includes a straight cylindrical section and an extended section. The top of the straight cylindrical section extends through the top surface of the reactor, and the bottom of the straight cylindrical section is connected to the top of the extended section. The straight cylindrical section is a vertical cylinder with a constant inner diameter. The inner diameter of the second expansion section gradually increases from top to bottom, making the sidewall of the second expansion section inclined. There is a space between the second expansion section and the contraction section, which forms a flow channel, enabling the three-phase separation zone to connect the aerobic zone and the microaerobic zone. A rotatable hollow frustum is provided at the connection between the straight section 2 and the extension section 2. The hollow frustum is concentrically arranged with the second cylinder. The top edge of the hollow frustum is connected to a rotating shaft through several support rods 2. The rotating shaft can drive the hollow frustum and the contraction section to rotate together.

2. The continuous flow aerobic granular sludge reactor according to claim 1, characterized in that, The continuous flow aerobic granular sludge reactor is cylindrical in shape, and the reactor is concentrically arranged with the microaerobic zone, aerobic zone, and three-phase separation zone. The reactor is equipped with an overflow trough and an outlet pipe at the top to output the treated water; the bottom of the reactor is equipped with an aeration zone to provide air for the aerobic and microaerobic zones, and a sludge discharge pipe is located below the aeration zone.

3. The continuous flow aerobic granular sludge reactor according to claim 1, characterized in that, The angle between the sidewall of the extension section one and the vertical plane is 45°-75°.

4. The continuous flow aerobic granular sludge reactor according to claim 1, characterized in that, The aeration zone is provided with a first aeration pipe and a second aeration pipe. The first aeration pipe is evenly laid directly below the extension section one, and the second aeration pipe is evenly laid directly below the micro-oxygen zone. The laying density and aeration volume of the first aeration pipe are both greater than those of the second aeration pipe.

5. The continuous flow aerobic granular sludge reactor according to claim 1, characterized in that, The diameter of the second straight section is 1 / 4 to 1 / 3 of the diameter of the first straight section, and the diameter of the bottom end of the second extension section is 1 to 1.2 times the diameter of the first straight section.

6. The continuous flow aerobic granular sludge reactor according to claim 1, characterized in that, Within the micro-oxygen zone, several levels of flow guiding components are uniformly arranged from top to bottom, with each level of flow guiding component having a different height; each level of flow guiding component includes several levels of flow guiding plates, and the several levels of flow guiding plates of the same level of flow guiding component are uniformly distributed along the circumference of the straight cylindrical part at their own height.

7. The continuous flow aerobic granular sludge reactor according to claim 6, characterized in that, The micro-oxygen zone is provided with a primary flow guiding component, a secondary flow guiding component, and a tertiary flow guiding component arranged from top to bottom. The primary flow guiding component includes several primary flow guiding plates, the secondary flow guiding component includes several secondary flow guiding plates, and the tertiary flow guiding component includes several tertiary flow guiding plates. The primary, secondary, and tertiary guide plates are all downward-convex arc-shaped plates. The side of the primary guide plate closest to the reactor inner wall is higher than the side closest to the first cylinder. The side of the secondary guide plate closest to the reactor inner wall is lower than the side closest to the first cylinder. The side of the tertiary guide plate closest to the reactor inner wall is higher than the side closest to the first cylinder.

8. The continuous flow aerobic granular sludge reactor according to claim 6, characterized in that, All guide vanes have gaps between themselves and the inner wall of the reactor and the outer wall of the first cylinder, and there are gaps between adjacent guide vanes of the same level. In the cross-section of the micro-oxygen zone where the same level of guide vane is located, the area of ​​the guide vane accounts for 50%-80% of the total cross-sectional area of ​​the micro-oxygen zone.

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