Variable-density self-circulation aerobic granular sludge treatment device

Abstract

The present application relates to sewage treatment technical field, provide a kind of variable density self-circulation aerobic granular sludge treatment device, comprising: anoxic tank, micro-oxygen tank, aerobic tank and sedimentation tank are arranged along the flow path of water body, water body acceleration device is arranged in anoxic tank;Return main, the inlet end of return main is provided with sludge return branch pipe that extends into sedimentation tank and / or nitrification liquid return branch pipe that extends into aerobic tank, the outlet end of return main is provided with the first pipe section that extends into anoxic tank and is located in throat pipe;The outlet end of return main is also provided with the second pipe section that extends into anoxic tank and is located outside throat pipe;Air pipe, one end extends into second pipe section, the other end is suitable for being connected with gas source, air pipe is inhaled gas into second pipe section.The device, using the negative pressure effect generated by water inlet jet, the air-lift effect generated by air pipe aeration carries out double drainage, and nitrification liquid and / or sludge return to anoxic tank, it is beneficial to energy saving and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a variable-density self-circulating aerobic granular sludge treatment device. Background Technology

[0002] Existing aerobic reactors mainly consist of an anoxic zone, an aerobic zone, and a sedimentation zone arranged sequentially along the wastewater flow path. Raw wastewater enters the anoxic zone, where it is diluted and mixed with internal microorganisms for anoxic reaction. The wastewater then enters the aerobic zone for further aerobic reaction to remove pollutants. Finally, the wastewater enters the sedimentation zone for sedimentation and separation. The downstream aerobic zone contains a large amount of nitrifying liquid, while the sedimentation zone contains a large amount of sludge. Current technologies typically use pumps and pipelines to recirculate the nitrifying liquid or sludge to improve water treatment efficiency. However, this design is not energy-efficient or environmentally friendly and increases the burden of system maintenance. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is that traditional aerobic reaction devices use pumps and pipelines to return nitrified liquid or sludge. However, such a design is not conducive to energy conservation and environmental protection and will increase the burden of system maintenance. Therefore, a variable density self-circulating aerobic granular sludge treatment device is provided.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] This invention provides a variable-density self-circulating aerobic granular sludge treatment device, comprising: an anoxic tank, a microaerobic tank, an aerobic tank, and a sedimentation tank arranged along a water flow path; both the microaerobic tank and the aerobic tank are equipped with aeration devices, and the aeration rate in the microaerobic tank is less than that in the aerobic tank; a water acceleration device, arranged in the anoxic tank, including a throat and at least one stage of spray pipe, the throat covering the top of the spray pipe, external water being accelerated by the spray pipe before entering the throat, and the water being released from the top of the throat into the anoxic tank; and a return main pipe, the inlet end of which is provided with a sludge return branch pipe extending into the sedimentation tank and / or an extension... A branch pipe for nitrifying liquid return to the aerobic tank is provided. The outlet end of the return main pipe is provided with a first pipe section extending into the anoxic tank and located inside the throat. The first pipe section uses the negative pressure in the throat to introduce sludge and / or nitrifying liquid into the throat. The outlet end of the return main pipe is also provided with a second pipe section extending into the anoxic tank and located outside the throat. An aeration pipe is provided, with one end extending into the second pipe section and the other end adapted to be connected to an air source. The aeration pipe introduces gas into the second pipe section and uses air lifting to introduce sludge and / or nitrifying liquid into the anoxic tank. A sludge discharge pipe is provided, with one end extending inward into the bottom of the sedimentation tank and the other end extending outward to the outside of the sedimentation tank.

[0006] Furthermore, a sludge hopper is provided inside the sedimentation tank, and the sludge return branch pipe extends into the bottom of the sludge hopper with its opening facing downwards.

[0007] Furthermore, the variable density self-circulating aerobic granular sludge treatment device also includes an aerobic inlet water guide channel, which is set between the anoxic tank and the microaerobic tank. The water in the anoxic tank and part of the water in the microaerobic tank enter the aerobic inlet water guide channel, mix, and then enter the microaerobic tank.

[0008] Furthermore, the variable-density self-circulating aerobic granular sludge treatment device also includes an aerobic sludge recovery channel, which is located between the microaerobic tank and the aerobic tank; a portion of the water in the microaerobic tank enters the aerobic sludge recovery channel, and a portion of the water in the aerobic tank also enters the aerobic sludge recovery channel; after the water from the microaerobic tank and the aerobic tank is mixed in the aerobic sludge recovery channel, a portion of the water flows back to the microaerobic tank, and the other portion enters the aerobic tank.

[0009] Furthermore, the variable density self-circulating aerobic granular sludge treatment device also includes a degassing channel; the degassing channel is located between the aerobic tank and the sedimentation tank; after the water in the aerobic tank is degassed in the degassing channel, part of the water flows back to the aerobic tank, and the other part of the water enters the sedimentation tank; the nitrification liquid return branch pipe is located in the degassing channel.

[0010] Furthermore, the inlet of the nitrated liquid return branch pipe faces downward and is located in the lower half of the degassing channel.

[0011] Furthermore, the variable density self-circulating aerobic granular sludge treatment device also includes a water distribution pipe, one end of which is connected to the degassing channel and the other end of which is connected to the sedimentation tank; the water distribution pipe section located in the sedimentation tank consists of multiple pipe bodies arranged parallel to the bottom of the sedimentation tank, and each pipe body has several water distribution holes on its wall.

[0012] Furthermore, the aeration device includes an aerator and an accelerator; the aerator is disposed at the bottom of the microaerobic tank and the aerobic tank, and is used to provide the gas required for the aerobic reaction; the accelerator includes a premixing hood and a speed-maintaining component; the premixing hood is disposed at the air outlet of the aerator, and the space between the premixing hood and the aerator forms a first premixing zone; a gap is left between the premixing hood and the aerator to form a first return water inlet, which connects the interior and exterior spaces of the first premixing zone; wherein, the flow area of ​​the release port of the premixing hood is smaller than the flow area of ​​the inlet of the premixing hood, so as to increase the pressure in the first premixing zone under aeration conditions; one end of the speed-maintaining component is connected to the release port of the premixing hood, and the other end extends away from the premixing hood.

[0013] Furthermore, the variable-density self-circulating aerobic granular sludge treatment device also includes a partition plate; the partition plate is provided in the lower half of both the microaerobic tank and the aerobic tank, and the partition plate divides the lower half of the aerobic tank and the microaerobic tank into multiple aeration zones, and the aeration device is installed in the aeration zone; the space between two adjacent aeration zones forms an internal return channel, and the bottom of the partition plate has a gap connecting the aeration zone and the internal return channel, and the water in the internal return channel flows in the opposite direction to the water in the aeration zone; a guide cone is provided at the bottom of the internal return channel to guide the water in the internal return channel back to the aeration zone.

[0014] Furthermore, a sludge filter layer is formed in the sedimentation tank, with a nitrification filter layer at the bottom and a denitrification filter layer at the top. While the sludge filter layer filters the water, the nitrification filter layer removes ammonia nitrogen from the water, and the denitrification filter layer removes total nitrogen and COD from the water.

[0015] Furthermore, the anoxic pool contains, in sequence, a mixing zone, an anoxic guide channel, and an upflow anoxic zone along the water flow path; both the nozzle and the throat are located within the mixing zone, with a second return inlet between them, through which a portion of the water in the mixing zone flows back into the throat; another portion of the water in the mixing zone flows out from the top into the anoxic guide channel, flows downward to the bottom within the channel, and then enters the upflow anoxic zone; the water in the upflow anoxic zone flows upward to the top and then enters the aerobic inlet guide channel; the second pipe section is located within the anoxic guide channel.

[0016] Furthermore, the variable density self-circulating aerobic granular sludge treatment device also includes an anoxic return pipe, one end of which extends into the throat pipe and the other end is located in the upflow anoxic zone; the opening of the anoxic return pipe faces upward and extends into the upper half of the upflow anoxic zone, so that the anaerobic wastewater in the upflow anoxic zone is returned to the mixing zone.

[0017] Furthermore, the anoxic pool, microaerobic pool, aerobic pool, and sedimentation pool are integrated into one pool body, and the different areas divided within the pool body form the anoxic pool, microaerobic pool, aerobic pool, and sedimentation pool; or one or more of the anoxic pool, microaerobic pool, aerobic pool, and sedimentation pool are each composed of a separate pool body.

[0018] Furthermore, the variable density self-circulating aerobic granular sludge treatment device also includes a lifting agitator, which is installed in the mixing zone to accelerate the rise of water in the throat.

[0019] The technical solution of this invention has the following advantages:

[0020] The variable-density self-circulating aerobic granular sludge treatment device provided by this invention utilizes the negative pressure generated by the influent jet and the air lift generated by the aeration pipe for dual diversion, allowing nitrified liquid and / or sludge to return to the anoxic tank. Compared to using a pump and pipeline for nitrified liquid and / or sludge return, this method is energy-saving and environmentally friendly, and does not increase the burden of system maintenance. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a top view of the variable density self-circulating aerobic granular sludge treatment device in an embodiment of the present invention;

[0023] Figure 2 For along Figure 1 A cross-sectional view along the AA direction;

[0024] Figure 3 This is a partial enlarged schematic diagram of the aerobic tank in the variable density self-circulating aerobic granular sludge treatment device according to an embodiment of the present invention.

[0025] Figure 4 For along Figure 1 A cross-sectional view along the BB direction;

[0026] Figure 5This is an enlarged schematic diagram of the water distribution pipe in the variable density self-circulating aerobic granular sludge treatment device in an embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of an aeration device according to one embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of an aeration device in another embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of an aeration device in another embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram of an aeration device in another embodiment of the present invention;

[0031] Figure 10 This is a schematic diagram of the aerator layout in one embodiment of the present invention; Figure 11 This is a schematic diagram of the lifting agitator in a variable density self-circulating sludge granulation device according to one embodiment of the present invention;

[0032] Figure 12 This is a schematic diagram of the lifting agitator in a variable density self-circulating sludge granulation device according to another embodiment of the present invention.

[0033] Figure 13 This is a schematic diagram of the lifting agitator in a variable density self-circulating sludge granulation device according to another embodiment of the present invention.

[0034] Figure 14 This is a schematic diagram of the lifting agitator in a variable density self-circulating sludge granulation device according to another embodiment of the present invention.

[0035] Figure 15 This is a schematic diagram of the lifting agitator in a variable density self-circulating sludge granulation device according to another embodiment of the present invention.

[0036] Figure 16 This is a schematic diagram of the lifting agitator in a variable density self-circulating sludge granulation device according to another embodiment of the present invention.

[0037] Figure 17 This is a schematic diagram of the lifting agitator in a variable density self-circulating sludge granulation device according to another embodiment of the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Anoxic tank; 2. Microaerobic tank; 3. Aerobic tank; 4. Sedimentation tank; 5. Return main pipe; 6. Aerobic inlet guide channel; 7. Aerobic sludge recovery channel; 8. Deaeration channel; 9. Mixing zone; 10. Anoxic guide channel; 11. Upflow anoxic zone; 12. Sludge hopper; 13. Sludge return branch pipe; 14. Water distribution pipe; 15. Anoxic return pipe; 16. Throat pipe; 17. Spray pipe; 18. Nitrified liquor return branch pipe; 19. First pipe section; 20. Second pipe section; 21. Aeration pipe; 22. Aerator; 23. 24. Aeration zone; 25. Internal return channel; 26. Inlet chamber; 27. Sludge filter layer; 28. Inclined tube separator; 29. ​​Outlet trough; 30. Sludge discharge pipe; 31. First return water inlet; 32. Guide cone; 33. Divider plate; 34. First premixing zone; 35. Speed-maintaining component; 36. Premixing hood; 37. Second return water inlet; 38. Denitrification filter layer; 39. Nitrification filter layer; 40. Water distribution hole; 41. Rectifier hood; 42. Baffle; 43. Second premixing zone; 44. Diversion port; 45. Toothed inlet; 46. Lifting agitator. Detailed Implementation

[0040] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] like Figure 1 , Figure 2 As shown, the present invention provides a variable-density self-circulating aerobic granular sludge treatment device, comprising: an anoxic tank 1, a microaerobic tank 2, an aerobic tank 3, and a sedimentation tank 4 arranged along a water flow path; for example, the anoxic tank 1, microaerobic tank 2, aerobic tank 3, and sedimentation tank 4 can be integrated into one tank body, with different areas divided within the tank body forming the anoxic tank 1, microaerobic tank 2, aerobic tank 3, and sedimentation tank 4. Alternatively, one or more of the anoxic tank 1, microaerobic tank 2, aerobic tank 3, and sedimentation tank 4 can be composed of separate tank bodies; for example, the anoxic tank 1 can be composed of a separate tank body, while the microaerobic tank 2, aerobic tank 3, and sedimentation tank 4 can be integrated into another tank body; or, for yet another example, the anoxic tank 1, microaerobic tank 2, aerobic tank 3, and sedimentation tank 4 can all be composed of separate tank bodies.

[0045] In some scenarios, there may be more than one anoxic tank 1, microaerobic tank 2, aerobic tank 3, and sedimentation tank 4; they can be multiple paired with multiple tanks, or one paired with multiple tanks. For example, in some scenarios, one anoxic tank 1 can correspond to multiple microaerobic tanks 2, aerobic tanks 3, and sedimentation tanks 4. Moreover, as long as the upstream and downstream relationships of anoxic tank 1, microaerobic tank 2, aerobic tank 3, and sedimentation tank 4 remain unchanged, their positional relationships can be designed as needed. For example, from left to right, they can be anoxic tank 1, microaerobic tank 2, aerobic tank 3, and sedimentation tank 4.

[0046] Among them, the bodies of the anoxic tank 1, microaerobic tank 2, aerobic tank 3 and sedimentation tank 4 can be made of steel or concrete, and the cross-sectional shape of each tank can be circular, rectangular or other polygonal, etc.

[0047] To more clearly illustrate the inventive concept of this application, the following embodiments take the anoxic tank 1, microaerobic tank 2, aerobic tank 3 and sedimentation tank 4 as an example, and the anoxic tank 1, microaerobic tank 2, aerobic tank 3 and sedimentation tank 4 are arranged in the same tank body along the first direction (left and right direction) in sequence.

[0048] A water acceleration device is installed in the anoxic pool 1, including a throat 16 and at least one stage of nozzle 17. That is, the nozzle 17 can be set with one or more stages according to the acceleration needs of the water. The throat 16 is covered on the top of the nozzle 17. The water outside enters the throat 16 after being accelerated by the nozzle 17, and the water is then released from the top of the throat 16 into the anoxic pool 1.

[0049] When the volume of water to be treated is large, multiple water acceleration devices can be installed in the anoxic tank 1 at the same time, and water can be introduced into the multiple water acceleration devices at the same time to increase the water intake.

[0050] The return main pipe 5 has a sludge return branch pipe 13 extending into the sedimentation tank 4 and / or a nitrified liquor return branch pipe 18 extending into the aerobic tank 3 at its inlet end. The return main pipe 5 has a first pipe section 19 extending into the anoxic tank 1 and located within the throat 16. The first pipe section 19 utilizes the negative pressure within the throat 16 to introduce sludge and / or nitrified liquor into the throat 16. For example, the first pipe section 19 may include two sections, one extending near the bottom of the throat 16 and the other extending near the middle of the throat 16. The return main pipe 5 also has a second pipe section 20 extending into the anoxic tank 1 and located outside the throat 16 at its outlet end.

[0051] A vent pipe 21 extends into the second pipe section 20 at one end and is adapted to connect to a gas source at the other end. Gas is introduced into the second pipe section 20 through the vent pipe 21, and sludge and / or nitrified liquid are introduced into the anoxic tank 1 using airlift. For example, the air inlet of the vent pipe 21 is located at its top end, extending outside the anoxic tank 1 and connected to an air pump or other gas source device. The air outlet of the vent pipe 21 is located at its bottom end, where the gas is released. A concentration difference is created between the outlet and inlet ends of the return main pipe 5, and the fluid at the inlet end of the return main pipe 5 is then diverted to the outlet end for release. For example, the nitrified liquid return branch pipe 18 and the sludge return branch pipe 13 can be arranged simultaneously, or only one of them can be arranged.

[0052] The variable-density self-circulating aerobic granular sludge treatment device provided by this invention utilizes the negative pressure generated by the influent jet and the air lift generated by the aeration pipe 21 for dual diversion, allowing nitrified liquid and / or sludge to return to the anoxic tank 1. Compared to using a pump and pipeline for nitrified liquid and / or sludge return, this method is energy-saving and environmentally friendly, and does not increase the burden of system maintenance.

[0053] like Figure 4As shown, under normal circumstances, due to the sludge return, gravity, and influent flow, a sludge filter layer 26 is formed in the sedimentation tank 4. The lower layer of the sludge filter layer 26 is a nitrification filter layer 38, and the upper layer of the sludge filter layer 26 is a denitrification filter layer 37. While the sludge filter layer 26 filters the suspended solids in the water, the nitrification filter layer 38 removes ammonia nitrogen from the water, and the denitrification filter layer 37 removes total nitrogen and COD (Chemical Oxygen Demand) from the water. The variable density self-circulating aerobic granular sludge treatment device also includes a sludge hopper 12. For example, the sludge hopper 12 can be set in the center of the sedimentation tank 4, with micro sludge filter layers 26 on both sides or around the sludge hopper 12. The opening of the sludge hopper 12 is set upward, and the opening position of the sludge hopper 12 can be flush with the upper denitrification filter layer 37. The sludge of the denitrification filter layer 37 is returned, and the pipe opening of the sludge return branch pipe 13 extends to the bottom of the sludge hopper 12. The returned sludge is used to carry out denitrification reaction in the anoxic tank 1, thereby removing COD and total nitrogen from the water.

[0054] The variable-density self-circulating aerobic granular sludge treatment device also includes an aerobic inlet channel 6, located between the anoxic tank 1 and the microaerobic tank 2. An inlet is located on the channel wall near the top of the aerobic inlet channel 6, with one portion connecting the aerobic inlet channel 6 to the anoxic tank 1 and another portion connecting the microaerobic tank 2 to the aerobic inlet channel 6. An outlet is located on the channel wall near the bottom of the aerobic inlet channel 6, connecting the aerobic inlet channel 6 to the microaerobic tank 2. During operation, water from the anoxic tank 1 and a portion of the water from the microaerobic tank 2 enter the aerobic inlet channel 6, mix, and then enter the microaerobic tank 2.

[0055] The variable-density self-circulating aerobic granular sludge treatment device also includes an aerobic sludge recovery channel 7, located between the microaerobic tank 2 and the aerobic tank 3. An inlet is located on the top wall of the aerobic sludge recovery channel 7, with one portion connecting the microaerobic tank 2 and the channel itself, and the other portion connecting the channel itself to the aerobic tank 3. This allows a portion of the water from the microaerobic tank 2 to enter the aerobic sludge recovery channel 7, and simultaneously, a portion of the water from the aerobic tank 3 to enter the channel itself. An outlet is located on the bottom wall of the aerobic sludge recovery channel 7, connecting the channel itself to the aerobic tank 3. After mixing in the aerobic sludge recovery channel 7, a portion of the water flows back to the microaerobic tank 2, while the remaining portion enters the aerobic tank 3.

[0056] The variable-density self-circulating aerobic granular sludge treatment device also includes a degassing channel 8. The degassing channel 8 is located between the aerobic tank 3 and the sedimentation tank 4. An inlet is located on the channel wall near the top of the degassing channel 8, through which water from the aerobic tank 3 enters the degassing channel 8. Furthermore, because the inlet level of the degassing channel 8 is at the top of the aerobic tank 3, the sludge can be allowed to settle within the aerobic tank 3 due to its height. After degassing in the degassing channel 8, a portion of the water in the aerobic tank 3 flows back to the aerobic tank 3, while the other portion enters the sedimentation tank 4. A nitrification liquid return branch pipe 18 is located within the degassing channel 8. For example, the opening of the nitrification liquid return branch pipe 18 can face downwards and be located in the lower half of the degassing channel 8. For example, an opening is provided at the bottom of the degassing channel 8 near the channel wall of the aerobic tank 3 for returning water from the degassing channel 8 to the aerobic tank 3. At the bottom of the degassing channel 8, a guide plate inclined toward the opening can be installed to guide the water to flow back into the aerobic tank 3 preferentially.

[0057] like Figure 2 , Figure 5 As shown, the space on the side of the guide plate opposite to the opening serves as the inlet chamber 25 of the sedimentation tank 4. One end of the water distribution pipe 14 is connected to the inlet chamber 25, and the other end extends into the sedimentation tank 4. The pipe section of the water distribution pipe 14 located in the sedimentation tank 4 consists of multiple pipes arranged parallel to the bottom of the sedimentation tank 4. The pipes are located outside the sludge hopper 12, and each pipe has several water distribution holes 39 on its wall. For example, when water is sprayed from the water distribution holes 39, it can distribute water at a 45° downward angle.

[0058] like Figure 3 As shown, the aeration device includes an aerator 22 and an accelerator; the aerator 22 is located at the bottom of the microaerobic tank 2 and the aerobic tank 3, and is used to provide the gas required for the aerobic reaction; the accelerator includes a premixing hood 35 and a speed-maintaining component 34; the premixing hood 35 covers the air outlet of the aerator 22, and the space between the premixing hood 35 and the aerator 22 forms a first premixing zone 33; a gap is left between the premixing hood 35 and the aerator 22 to form a first return water inlet 30, which connects the interior and exterior spaces of the first premixing zone 33; wherein, the flow area of ​​the release port of the premixing hood 35 is smaller than the flow area of ​​the inlet of the premixing hood 35, so as to increase the pressure in the first premixing zone 33 under aeration conditions; one end of the speed-maintaining component 34 is connected to the release port of the premixing hood 35, and the other end extends away from the premixing hood 35. The number or power of aerators 22 in the microaerobic tank 2 can be controlled to ensure that the aeration rate in the microaerobic tank 2 is less than that in the aerobic tank 3. With this configuration, the microaerobic tank 2 acts as a pre-aerobic section. Since the system is a plug-flow treatment, anoxic and aerobic reactions occur in the microaerobic tank 2, pre-treating the pollutants and reducing the load on the subsequent aerobic tank 3, thus improving the treatment efficiency of the latter.

[0059] For example, the premixing hood 35 can be a frustum-shaped structure with open ends at both the top and bottom, the larger opening at the bottom and the smaller opening at the top, with the smaller opening serving as the release port. Alternatively, the premixing hood 35 can also be a frustum-shaped structure with open ends at both the top and bottom, the larger opening at the bottom and the smaller opening at the top, with the smaller opening serving as the release port. The premixing hood 35 can be welded to the side wall of the aerobic tank 3 by means of connecting rods welded to its side wall; or it can be installed as an integral structure with the air pipe support of the aerator 22, fixed to the air pipe support of the aerator 22. The velocity retainer 34 can be a round tube or a square tube, depending on the requirements. Because the velocity retainer 34 increases the height of the release port of the premixing hood 35, the flow velocity of the air-water mixture outside the premixing hood 35 is lower, resulting in a larger velocity difference between the air-water mixture outside the first premixing zone 33 and the premixing hood 35. Therefore, the pressure difference is greater, resulting in a better flow diversion effect compared to when the velocity retainer 34 is not present.

[0060] In operation, aerator 22 releases air into the first premixing zone 33. The rapid rise of the bubbles draws water from outside the zone into the first premixing zone 33 via the first return water inlet 30. Additionally, the narrowing of the release port directly above the premixing hood 35 increases the pressure in the first premixing zone 33, further mixing the bubbles with the water returning through the first return water inlet 30. The increased pressure also improves the dissolution of the gas into the water. The resulting air-water mixture is then sprayed out through the release port and rises to the aerobic area outside the first premixing zone 33. The speed-maintaining component 34 prolongs the high-speed water movement time, delaying the release. This design allows the aeration device to increase dissolved oxygen concentration through reflux, mixing, and pressurized gas dissolution, resulting in higher efficiency and greater energy savings under the same aeration conditions.

[0061] The variable-density self-circulating aerobic granular sludge treatment device also includes a partition plate 32. The lower half of both the microaerobic tank 2 and the aerobic tank 3 are equipped with partition plates 32, which divide the lower half of the aerobic tank 3 and the microaerobic tank 2 into multiple aeration zones 23. Aeration devices are installed in the aeration zones 23. The space between two adjacent aeration zones 23 forms an internal return channel 24. The bottom of the partition plate 32 has a gap connecting the aeration zone 23 and the internal return channel 24. The water in the internal return channel 24 flows in the opposite direction to the water in the aeration zone 23. In use, the gas action of the aerator 22 can be used to accelerate water intake, resulting in a larger volume of return water, thereby accelerating the circulation and return between the internal return channel 24 and the aeration zone 23, allowing the water to mix rapidly. Moreover, under the action of aeration, the water flow in the aeration zone 23 rises rapidly, and the heavy sludge will descend from the inner return channel 24 and then participate in the aeration upward process again, which makes the sludge particle formation efficiency faster. In addition, through this high-speed rise and fall, air and water scrubbing makes the granular sludge more stable and the granular sludge ball diameter ratio better.

[0062] The bottom of the internal return channel 24 is equipped with a guide cone 31 to guide the water in the internal return channel 24 back to the aeration zone 23. This design can prevent sludge accumulation in the internal return channel 24 and facilitate the guidance of airlift flow.

[0063] like Figure 6 As shown, in one embodiment, the release port of the premixed hood 35 may not be equipped with a speed-keeping component 34.

[0064] like Figure 7 As shown, the aeration device also includes a rectifier 40, which covers the release port of the premixing hood 35. The end of the rectifier 40 away from the premixing hood 35 is sealed, and the inner diameter of the rectifier 40 gradually decreases in the direction away from the premixing hood 35. The space between the rectifier 40 and the premixing hood 35 forms a second premixing zone 42. A gap is left between the rectifier 40 and the premixing hood 35 to form a diversion port 43, which connects the second premixing zone 42 to the space outside the second premixing zone 42. The rectifier 40 can be welded to the side wall of the aeration zone 23 by means of connecting rods provided on the side wall. For example, the rectifier 40 can be a conical structure with the cone apex at the top. As another example, the premixing hood 35 can also be a prismatic structure with the smaller top surface at the top. The shape of the rectifier 40 is adapted to the shape of the premixing hood 35. For example, when the premixing hood 35 is a frustum-shaped structure, the rectifier 40 can be a conical structure. For example, when the premixing hood 35 has a frustum-shaped structure, the rectifier hood 40 can have a prism-shaped structure. In use, the air-water mixture in the first premixing zone 33 enters the second premixing zone 42 through the release port of the premixing hood 35. The air-water mixture in the second premixing zone 42 flows out through the branch port 43 and splits into a first branch and a second branch. The air-water mixture in the first branch moves towards the first return port 30, thus forming a circulation. The air-water mixture in the second branch flows downstream over the rectifier hood 40. Furthermore, because the sidewall of the rectifier hood 40 is inclined, it forms a slope. A portion of the air-water mixture slides down the slope (due to the velocity difference created by the acceleration of the edge fluid), mixing with the rapidly rising air-water mixture in the second branch, thereby improving the mixing effect. With this configuration, the aeration zone 23 has recirculation, mixing, and pressurized dissolved gas, increasing the dissolved oxygen concentration. Under the same aeration conditions, efficiency is improved, resulting in greater energy savings.

[0065] like Figure 8 As shown, in one embodiment, the fairing 40 may also be disposed over the end of the speed-maintaining member 34 away from the premixing cover 35.

[0066] like Figure 10As shown, the edge of the shroud 40 can be provided with several toothed orifices 44, which are distributed circumferentially along the shroud 40. This arrangement has two advantages: first, the toothed orifices 44 enhance the mixing effect because the flow velocities in the concave and convex areas of the orifices differ, increasing the turbulent mixing effect; second, it has the function of cutting bubbles, breaking large bubbles into smaller ones, increasing the contact area with water, and thus increasing dissolved oxygen. Furthermore, the horizontal and downward backflow of the air-water mixture further enhances the mixing effect, and the downward flow of the mixture increases the mixing distance, extending the effective contact time and preventing it from rising directly to the liquid surface. This arrangement increases the mixing distance, prolongs the reaction time, and improves the dissolved oxygen concentration; under the same aeration conditions, it increases efficiency and is more energy-efficient.

[0067] like Figure 9 As shown, the aeration device also includes a baffle 41, which is disposed inside the shroud 40, with the baffle 41 facing the outlet of the retaining element 34. During use, the gas-water mixture released from the outlet at the top of the retaining element 34 impacts the baffle 41 and then diffuses outwards. This arrangement prevents air from accumulating at the top of the shroud 40, thus preventing bubble aggregation and ensuring smooth gas release into the water, thereby improving the gas-water mixing effect.

[0068] Within the anoxic pool 1, along the water flow path are, in order, a mixing zone 9, an anoxic guide channel 10, and an upflow anoxic zone 11; both the nozzle 17 and the throat 16 are located within the mixing zone 9, and a second return water inlet 36 is left between the nozzle 17 and the throat 16, through which a portion of the water in the mixing zone 9 flows back to the throat 16.

[0069] Both nozzle 17 and throat 16 are located within mixing zone 9. A second return inlet 36 is provided between nozzle 17 and throat 16, allowing a portion of the water in mixing zone 9 to flow back into throat 16 via the second return inlet 36. An inlet is located on the top wall of the anoxic guide channel, through which water from mixing zone 9 enters the anoxic guide channel. An inverted V-shaped channel is located near the bottom of the anoxic guide channel, allowing water flowing back into the anoxic zone to enter the upflow anoxic zone. This design ensures that the water in the upflow anoxic zone 11 flows upwards, allowing microorganisms to rise hydraulically and remain suspended, facilitating nutrient acquisition and more thorough reactions.

[0070] The second pipe section 20 is located inside the hypoxia guide channel. The top of the second pipe section 20 is bent and extends into the upper half of the mixing zone 9. One end of the ventilation pipe 21 extends into the hypoxia guide channel and is inserted into the second pipe section 20. The other end extends to the outside of the hypoxia guide channel and can be connected to the gas source.

[0071] The variable-density self-circulating aerobic granular sludge treatment device also includes an anoxic return pipe 15, one end of which extends into the throat pipe 16, and the other end is located in the upflow anoxic zone 11. The opening of the anoxic return pipe 15 faces upward and extends into the upper half of the upflow anoxic zone 11, so that the anaerobic wastewater in the upflow anoxic zone 11 is returned to the mixing zone 9. For example, the opening of the anoxic return pipe 15 can also be a funnel-shaped structure to increase the inflow rate during return. This configuration increases the water volume in the mixing zone 9, increases the upward flow velocity, suspends the sludge, and replenishes and inoculates the sludge in the mixing zone 9 by returning a portion of the anoxic sludge.

[0072] During use, before the raw water enters the mixing zone 9, it is accelerated by spraying from the nozzles and the water returning from the mixing zone. In the mixing zone 9, a circulating mixing reaction occurs with the water flowing upward in the center and downward around the edges. This section has the return of anoxic wastewater from the upflow anoxic zone 11, the return of sludge from the sedimentation tank 4, and the return of nitrified liquid from the degassing channel 8. After these returned waters are mixed with the raw water, a denitrification reaction is carried out to remove COD and total nitrogen.

[0073] The sedimentation tank 4 can also be equipped with an inclined tube separator 27 to further settle and separate small suspended solids that have escaped. A effluent trough 28 is located downstream of the inclined tube separator 27, and an effluent pipe is connected to the outside of the effluent trough 28. Clean water enters the effluent trough 28 and is discharged from the effluent pipe. A sludge discharge pipe 29 can also be installed at the bottom of the sedimentation tank 4. One end of the sludge discharge pipe 29 extends inward into the bottom of the sedimentation tank 4, and the other end extends outward to the outside of the sedimentation tank 4, for discharging sludge from the sedimentation tank 4.

[0074] like Figure 11 As shown, in one embodiment, the variable-density self-circulating aerobic granular sludge treatment device further includes a lifting agitator 45. The base of the lifting agitator 45 can be installed on top of the mixing zone 9, and the connecting rod and the spiral fan blades of the lifting agitator 45 extend into the throat 16. In use, the lifting agitator 45 can promote the rise of water in the throat 16. For example, the lifting agitator 45 can be frequency-controlled so that the speed of the spiral fan blades can be adjusted, and the flow rate of the rising water can also be adjusted, thus the amount of water returning will also change with the speed. The lifting agitator 45 can be used alone or in conjunction with jetting and airlift.

[0075] like Figure 12 As shown, in one embodiment, the bottom of the mixing zone 9 uses pressurized water intake, which is accelerated by jets after intake. Multiple acceleration devices are used in the rising section for flow diversion. In addition to the jet acceleration, an upper-level agitator 45 provides upward flow assistance. The rotation speed of the spiral fan blades can change the force and flow rate of the diversion. The throat 16 has two or more layers of diversion, which can recirculate and mix the water that needs to be returned from the anoxic zone, aerobic zone, and sedimentation zone.

[0076] like Figure 13 As shown, in one embodiment, gravity inlet is used at the bottom of mixing zone 9. Due to the increased upward flow velocity of the lifting agitator 45, the required backflow during the ascent can be accelerated by a variable diameter flow. All upward flow is through channel spiral fan blades, and the number of spiral fan blade layers can be calculated to be two or more layers. The rotation speed of the spiral fan blades can change the inflow force and flow rate. The throat 16 has two or more layers of flow channels, which can recirculate and mix the water that needs to be returned from the anoxic zone, aerobic zone, and sedimentation zone.

[0077] like Figure 14 As shown, in one embodiment, the bottom of the mixing zone 9 uses gravity-fed water intake. The water first enters an annular water distribution chamber with annular gaps at the bottom for uniform water distribution. After distribution, the water enters the central rising zone, where it is lifted upwards by the lifting agitator 45. The speed of the spiral fan blades can change the force and flow rate of the flow. During the lifting process, points requiring recirculation are accelerated by narrowing the diameter, and then connected to a return pipe. The throat 16, which requires the flow to two or more layers, is narrowed to allow for the recirculation and mixing of water from the anoxic zone, aerobic zone, and sedimentation zone.

[0078] like Figure 15 As shown, in one embodiment, the bottom of the mixing zone 9 uses gravity-fed water intake. The water first enters an annular water distribution chamber with annular gaps at the bottom for even water distribution. After distribution, the water enters the central rising zone, where it is lifted upwards by the lifting agitator 45. The rotation speed of the spiral fan blades can change the force and flow rate of the flow. Points requiring recirculation during the lifting process are accelerated by narrowing the diameter before connecting to a return pipe. The impeller is mainly arranged in the upper region.

[0079] like Figure 16 As shown, in one embodiment, the bottom of the mixing zone 9 uses gravity-fed water intake, and the spiral fan blades are configured with unequal diameters.

[0080] like Figure 17 As shown, in one embodiment, the bottom of the mixing zone 9 uses gravity-fed water intake. After rebounding from the bottom plate, the water rises due to the lifting action of the lifting agitator 45. After water distribution, it enters the central rising zone, where it is further lifted upwards by the lifting agitator 45. The rotation speed of the spiral fan blades can change the force and flow rate of the flow. Then, a return pipe is connected. The spiral fan blades are arranged in an independent hopper, and the return pipe is connected inside the hopper, so that the water that needs to be returned from the anoxic zone, aerobic zone, sedimentation zone, etc., returns to the central mixing zone.

[0081] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A variable density self-circulating aerobic granular sludge treatment device, characterized by, It comprises: an anoxic tank (1), a micro-aerobic tank (2), an aerobic tank (3) and a sedimentation tank (4) arranged along the flow path of the water body, the micro-aerobic tank (2) and the aerobic tank (3) are provided with aeration devices, and the aeration amount in the micro-aerobic tank (2) is less than that in the aerobic tank (3); a water body accelerating device arranged in the anoxic tank (1), comprising a throat pipe (16) and at least one level of nozzle (17), the throat pipe (16) is covered on the top of the nozzle (17), the external water body enters the throat pipe (16) after being accelerated by the nozzle (17), and the water body is released from the top of the throat pipe (16) into the anoxic tank (1); a return main pipe (5), the inlet end of the return main pipe (5) is provided with a sludge return branch pipe (13) extending into the sedimentation tank (4) and / or a nitrification liquid return branch pipe (18) extending into the aerobic tank (3), and the outlet end of the return main pipe (5) is provided with a first pipe section (19) extending into the anoxic tank (1) and located in the throat pipe (16), the first pipe section (19) introduces sludge and / or nitrification liquid into the throat pipe (16) by the negative pressure in the throat pipe (16); the outlet end of the return main pipe (5) is also provided with a second pipe section (20) extending into the anoxic tank (1) and located outside the throat pipe (16); an air pipe (21) extending into the second pipe section (20) at one end and adapted to be connected with a gas source at the other end, the air pipe (21) introduces gas into the second pipe section (20) to introduce sludge and / or nitrification liquid into the anoxic tank (1) by air stripping; a sludge discharge pipe (29) extending into the bottom of the sedimentation tank (4) at one end and extending out of the sedimentation tank (4) at the other end.

2. The variable density self-recycling aerobic granular sludge treatment device according to claim 1, characterized in that, The sedimentation tank (4) is provided with a sludge hopper (12), the sludge return branch pipe (13) extends into the bottom of the sludge hopper (12), and the pipe opening of the sludge return branch pipe (13) is arranged downward.

3. The variable-density self-circulating aerobic granular sludge treatment device according to claim 1, further comprising an aerobic water inlet guide channel (6) arranged between the anoxic tank (1) and the micro-aerobic tank (2), wherein the water body in the anoxic tank (1) and part of the water body in the micro-aerobic tank (2) enter the aerobic water inlet guide channel (6) to mix and then enter the micro-aerobic tank (2).

4. The variable-density self-circulating aerobic granular sludge treatment device according to claim 1, further comprising an aerobic sludge recovery channel (7) arranged between the micro-aerobic tank (2) and the aerobic tank (3); part of the water body in the micro-aerobic tank (2) enters the aerobic sludge recovery channel (7), and part of the water body in the aerobic tank (3) enters the aerobic sludge recovery channel (7); part of the water body from the micro-aerobic tank (2) and the aerobic tank (3) mixes in the aerobic sludge recovery channel (7) and then flows back to the micro-aerobic tank (2), and the other part enters the aerobic tank (3). further comprising a degassing channel (8). ​ 5. The variable density self-recycling aerobic granular sludge treatment device according to claim 1, characterized in that, ​ The degassing passage (8) is arranged between the aerobic tank (3) and the sedimentation tank (4); After degassing in the degassing passage (8), part of the water in the aerobic tank (3) is returned to the aerobic tank (3), and the other part of the water enters the sedimentation tank (4); The nitrification liquid return branch pipe (18) is arranged in the degassing passage (8).

6. The variable density self-recycling aerobic granular sludge treatment device according to claim 5, characterized in that, The nozzle of the nitrification liquid return branch pipe (18) faces downward and is arranged in the lower half of the degassing passage (8).

7. The variable-density self-circulation aerobic granular sludge treatment device according to claim 5, further comprising a water distribution pipe (14) having one end connected to the degassing passage (8) and the other end connected to the sedimentation tank (4). The water distribution pipe (14) is arranged in the sedimentation tank (4) and comprises a plurality of pipe bodies arranged parallel to the bottom of the sedimentation tank (4), and each pipe body is provided with a plurality of water distribution holes (39) on the pipe wall.

8. The variable-density self-circulation aerobic granular sludge treatment device according to claim 1, wherein the aeration device comprises an aerator (22) and an acceleration member. The aerator (22) is arranged at the bottom of the micro-aerobic tank (2) and the aerobic tank (3), and is used to provide the gas required for aerobic reaction. The acceleration member comprises a premixing cover (35) and a speed maintaining member (34). The premixing cover (35) is arranged at the gas outlet end of the aerator (22), and the space between the premixing cover (35) and the aerator (22) forms a first premixing area (33). A first water return port (30) is arranged between the premixing cover (35) and the aerator (22) to form a space between the inside and the outside of the first premixing area (33). The flow area of the release port of the premixing cover (35) is smaller than the flow area of the water inlet port of the premixing cover (35) to increase the pressure in the first premixing area (33) in the aeration state. One end of the speed maintaining member (34) is connected to the release port of the premixing cover (35), and the other end extends away from the premixing cover (35).

9. The variable-density self-circulation aerobic granular sludge treatment device according to claim 8, further comprising a partition plate (32). The micro-aerobic tank (2) and the lower half of the aerobic tank (3) are both provided with the partition plate (32), and the partition plate (32) divides the lower half of the aerobic tank (3) and the micro-aerobic tank (2) into a plurality of aeration areas (23), and the aeration device is arranged in the aeration areas (23). The space between two adjacent aeration areas (23) forms an internal return passage (24), and the bottom of the partition plate (32) is provided with a gap connecting the aeration area (23) and the internal return passage (24). The water in the internal return passage (24) flows in the opposite direction of the water in the aeration area (23). The bottom of the internal return passage (24) is provided with a flow guide cone (31) to guide the water in the internal return passage (24) to return to the aeration area (23). ​ ​ ​ 10. The variable-density self-circulation aerobic granular sludge treatment device according to claim 1, characterized in that, a sludge filter layer (26) is formed in the sedimentation tank (4), the lower layer of the sludge filter layer (26) is a nitrification filter layer (38), and the upper layer of the sludge filter layer (26) is a denitrification filter layer (37); the sludge filter layer (26) filters the passing water body while removing ammonia nitrogen in the water body by the nitrification filter layer (38) and removing total nitrogen and COD in the water body by the denitrification filter layer (37).

11. The variable-density self-circulation aerobic granular sludge treatment device according to claim 3, characterized in that, the anoxic tank (1) has, in sequence along the water flow path, a mixing zone (9), an anoxic flow guide channel (10), and an upflow anoxic zone (11); the spray pipe (17) and the throat pipe (16) are both located in the mixing zone (9), and a second backwater opening (36) is left between the spray pipe (17) and the throat pipe (16), a part of the water body in the mixing zone (9) flows back to the throat pipe (16) through the second backwater opening (36); another part of the water body in the mixing zone (9) flows out from the top into the anoxic flow guide channel (10), flows downward in the anoxic flow guide channel (10) to the bottom, and then enters the upflow anoxic zone (11), the water body in the upflow anoxic zone (11) flows upward to the top and then enters the aerobic water inlet flow guide channel (6); the second pipe section (20) is located in the anoxic flow guide channel (10).

12. The variable density self-recycling aerobic granular sludge treatment device according to claim 11, characterized in that, an anoxic backflow pipe (15) is further included, one end of which extends into the throat pipe (16) and the other end of which is located in the upflow anoxic zone (11); the pipe opening of the anoxic backflow pipe (15) faces upward and extends to the upper half of the upflow anoxic zone (11), so that the anaerobic sewage in the upflow anoxic zone (11) flows back to the mixing zone (9).

13. The variable-density self-circulation aerobic granular sludge treatment device according to claim 1, characterized in that, the anoxic tank (1), the micro-aerobic tank (2), the aerobic tank (3), and the sedimentation tank (4) are integrated in one tank body, and different regions divided in the tank body form the anoxic tank (1), the micro-aerobic tank (2), the aerobic tank (3), and the sedimentation tank (4); or one or more of the anoxic tank (1), the micro-aerobic tank (2), the aerobic tank (3), and the sedimentation tank (4) are each formed by a separate tank body.

14. The variable-density self-circulation aerobic granular sludge treatment device according to claim 11, characterized in that, a lifting agitator (45) is further included and is arranged in the mixing zone (9) to accelerate the upward flow of the water body in the throat pipe (16).

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