Combined system of anaerobic reactor and granular sludge decalcification and regeneration

Abstract

This invention relates to a combined system of an anaerobic reactor and granular sludge decalcification and regeneration, comprising an anaerobic reactor, a separator, and a decalcification regenerator connected in sequence. The bottom of the anaerobic reactor is connected to the sludge inlet at the top of the separator via a sludge feed pipe. A first sludge outlet at the top of the separator is connected to the anaerobic reactor via a sludge return pipe, returning the separated activated sludge to the anaerobic reactor. A second sludge outlet at the bottom of the separator is connected to the feed inlet of the decalcification regenerator, feeding the separated calcified granular sludge into the decalcification regenerator. The decalcification regenerator includes, from top to bottom, a decalcification zone, a degassing zone, and a cultivation zone. The decalcification zone has a chemical inlet and a feed inlet on its side for feeding decalcifying agent. A first stirrer is located at the bottom of the decalcification zone. The decalcification zone is connected to the degassing zone via an openable gate. A second stirrer is located within the degassing zone. The bottom of the cultivation zone is connected to the anaerobic reactor via a pipe, returning the regenerated sludge to the anaerobic reactor.

Description

Technical Field

[0001] This invention belongs to the field of anaerobic granular sludge decalcification technology, specifically involving a combined system of anaerobic reactor and granular sludge decalcification and regeneration. Background Technology

[0002] Anaerobic biological treatment is one of the important methods in wastewater treatment. Under the action of anaerobic and facultative anaerobic microorganisms, organic matter is degraded. The effectiveness of anaerobic treatment mainly relies on the full contact and reaction between activated sludge, which is attached to anaerobic and facultative anaerobic microorganisms, and the wastewater. The microorganisms adhere to the surface and micropores of the granular sludge, making the sludge a carrier for the microorganisms. However, wastewater generally contains calcium ions. After the anaerobic reactor has been running for a period of time, calcium ions will form precipitated calcium salts, mostly calcium carbonate, which deposit on the surface of the granular sludge or in the microporous channels, forming scale and nuclei. This makes the sludge surface or interior relatively solid, at which point the anaerobic granular sludge becomes calcified. Calcified granular sludge isolates pollutants from contact with microorganisms, reducing the effectiveness of anaerobic treatment and causing sludge deactivation.

[0003] Currently, for calcified granular sludge, the usual practice is to shut down the anaerobic reactor, remove all the granular sludge, regenerate it, and then return it to the original anaerobic reactor for continued anaerobic biological treatment. This results in a long downtime for regeneration, and non-calcified sludge is also forcibly discharged, affecting wastewater treatment capacity and efficiency. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a combined system for anaerobic reactor and granular sludge decalcification and regeneration, comprising an anaerobic reactor, a separator, and a decalcification regenerator connected in sequence. The bottom of the anaerobic reactor is connected to the sludge inlet at the top of the separator via a sludge feed pipe, allowing granular sludge and wastewater from the bottom of the anaerobic reactor to be fed into the separator. The first sludge outlet at the top of the separator is connected to the anaerobic reactor via a sludge return pipe, returning the separated activated sludge to the anaerobic reactor. The second sludge outlet at the bottom of the separator is connected to the feed inlet of the decalcification regenerator, feeding the separated calcified granular sludge into the decalcification regenerator.

[0005] The decalcification regenerator consists of a decalcification zone, a degassing zone, and a cultivation zone from top to bottom. The decalcification zone has a chemical inlet and a feed inlet on its side for introducing the decalcifying agent. The bottom of the decalcification zone has a first agitator to promote contact and reaction between the decalcifying agent and the calcified anaerobic granular sludge. The decalcification zone is connected to the degassing zone through an openable gate. The degassing zone has a second agitator to promote the removal of air bubbles from the surface and micropores of the granular sludge. The bottom of the cultivation zone is connected to the anaerobic reactor through a pipe to return the regenerated sludge to the anaerobic reactor.

[0006] Optionally, the anaerobic reactor is provided with a sludge outlet at the bottom, which is connected to a sludge feed pipe; the anaerobic reactor is provided with a sludge return port at the bottom, which is connected to a sludge return pipe.

[0007] Optionally, the separator includes a first separation zone in the upper middle part and a discharge zone in the lower part. The first separation zone is cylindrical and has several continuous spiral downward flow channels evenly arranged on its inner wall.

[0008] The discharge zone is cone-shaped, wider at the top and narrower at the bottom, to facilitate the discharge of the separated calcified granular sludge from the separator.

[0009] Optionally, the sludge return pipe passes through the first sludge outlet and extends into the interior of the first separation zone without affecting the rotation of the agitator, thereby discharging the uncalcified granular sludge flowing to the top of the first separation zone from the first separation zone.

[0010] Optionally, an aeration pipe is provided below the first agitator in the decalcification zone, and an openable gate is provided below the aeration pipe for discharging the decalcified granular sludge into the deaeration zone.

[0011] The second agitator in the degassing zone includes a guide rail and an agitator. The guide rail is located at the top of the degassing zone, and the agitator moves along the guide rail to agitate the granular sludge in the degassing zone. The bottom of the degassing zone is provided with a first discharge port for discharging the degassed granular sludge into the cultivation zone.

[0012] The cultivation area is equipped with a wastewater inlet for inputting wastewater and activated sludge to cultivate deaerated granular sludge.

[0013] Optionally, the decalcification zone includes a lower reaction zone and an upper second separation zone. A horizontal first partition is provided between the reaction zone and the second separation zone. A second discharge port is provided on the side wall at the bottom of the second separation zone. The second discharge port is connected to a nutrient pre-storage tank through a pipeline. A drug inlet and a feed inlet are provided on the side of the top of the reaction zone. The lower part of the reaction zone is a cone shape that is larger at the top and smaller at the bottom. A first stirrer and an aeration pipe are provided at the bottom of the cone.

[0014] Optionally, a second mesh is provided outside the first agitator and aeration pipe. The second mesh includes a circular horizontal mesh surface and a vertical mesh surface around the horizontal mesh surface. The bottom of the vertical mesh surface is connected to a fixed frame, and the horizontal mesh surface is above the first agitator, covering the first agitator and aeration pipe inside the second mesh.

[0015] The mesh size of the vertical mesh is smaller than the average particle size of the calcified anaerobic granular sludge.

[0016] Further optionally, the fixing frame is provided with a rotating rod that passes through the center of the fixing frame. The fixing frame is not fixedly connected to the bottom of the reaction zone. One end of the rotating rod passes through the side wall of the decalcification regenerator and is connected to an external control motor.

[0017] After the water and sediment in the second separation zone are discharged into the nutrient pre-storage tank, the gate is opened, and the rotating rod drives the fixed frame, the second partition, the first agitator and the aeration pipe to rotate vertically. The sludge in the lower part of the reaction zone is intercepted around the second partition. The rotation of the second partition causes most of the granular sludge to fall into the deaeration zone through the gaps around the opened second partition, avoiding the impact of a large amount of granular sludge falling on the first agitator and the aeration pipe.

[0018] Optionally, the degassing zone includes an exhaust zone, a guide rail, and a mixing zone from top to bottom. The exhaust zone corresponds to the lower part of the reaction zone and surrounds the outer side of the lower part of the reaction zone. The side wall of the exhaust zone is provided with an exhaust port for discharging the gas after the granular sludge is removed. The guide rail is circular and is concentrically arranged with the degassing zone. The top of the stirring rod is connected to the guide rail through a slider, so that the stirring rod can move along the guide rail and thus stir the material in the mixing zone.

[0019] The bottom of the mixing zone is conical, and the bottom of the cone is equipped with a first discharge port. The first discharge port is connected to a circulation pipe in parallel. The other end of the circulation pipe is connected to the top of the mixing zone, which can discharge the liquid in the mixing zone and then circulate it back into the mixing zone. This allows the granular sludge in the mixing zone to be intermittently exposed to the air, causing the air bubbles on the sludge to burst.

[0020] Optionally, the top of the cultivation zone is provided with a wastewater inlet for inputting wastewater and activated sludge into the cultivation zone, so as to promote the re-attachment of anaerobic microorganisms to the micropores and surface of the granular sludge discharged into the cultivation zone; the bottom of the cultivation zone is provided with a third discharge port, which is connected to the anaerobic reactor through a pipeline for returning the cultured anaerobic granular sludge to the anaerobic reactor. Attached Figure Description

[0021] Figure 1 A schematic diagram of the combined system of anaerobic reactor and granular sludge decalcification and regeneration;

[0022] Figure 2 This is a schematic diagram of the decalcification regenerator;

[0023] Figure 3 for Figure 2 A 3D diagram (omitting the temporary storage tank and circulation pipe).

[0024] In the attached diagram, 1-anaerobic reactor, 2-separator, 3-decalcification regenerator, 4-sludge feed pipe, 5-sludge return pipe, 6-second sludge outlet, 7-first separation zone, 8-discharge zone, 9-drainage channel, 10-decalcification zone, 11-deaeration zone, 12-cultivation zone, 13-aeration pipe, 14-first agitator, 15-gate, 16-guide rail, 17-stirring rod, 18-first discharge port, 19-reaction zone, 20-second separation zone, 21-first partition, 22-second partition, 23-second discharge port, 24-nutrient pre-storage tank, 25-fixed frame, 26-temporary storage tank, 27-venting zone, 28-mixing zone, 29-circulation pipe. Detailed Implementation

[0025] This embodiment provides a combined system of anaerobic reactor and granular sludge decalcification and regeneration, such as... Figures 1-3 As shown, the system includes an anaerobic reactor 1, a separator 2, and a decalcification regenerator 3 connected in sequence. The bottom of the anaerobic reactor 1 is connected to the sludge inlet at the top of the separator 2 via a sludge feed pipe 4, allowing the granular sludge and wastewater from the bottom of the anaerobic reactor 1 to be fed into the separator 2. The first sludge outlet at the top of the separator 2 is connected to the anaerobic reactor 1 via a sludge return pipe 5, returning the separated activated sludge to the anaerobic reactor 1. The second sludge outlet 6 at the bottom of the separator 2 is connected to the feed inlet of the decalcification regenerator 3, allowing the separated calcified granular sludge to be fed into the decalcification regenerator 3.

[0026] The decalcification regenerator 3 comprises, from top to bottom, a decalcification zone 10, a degassing zone 11, and a cultivation zone 12. The decalcification zone 10 has a chemical inlet and a feed inlet on its side for introducing the decalcifying agent. The bottom of the decalcification zone 10 is equipped with a first stirrer 14 to promote the contact and reaction between the decalcifying agent and the calcified anaerobic granular sludge. The decalcification zone 10 is connected to the degassing zone 11 through an openable gate 15. The degassing zone 11 is equipped with a second stirrer to promote the removal of air bubbles from the surface and micropores of the granular sludge. The bottom of the cultivation zone 12 is connected to the anaerobic reactor 1 through a pipe to return the regenerated sludge to the anaerobic reactor 1.

[0027] Optionally, the anaerobic reactor 1 is provided with a sludge outlet at the bottom, which is connected to a sludge feed pipe 4; the anaerobic reactor 1 is provided with a sludge return port at the bottom, which is connected to a sludge return pipe 5.

[0028] The other structures and configurations of anaerobic reactor 1 are the same as those of a conventional anaerobic reactor 1. For example, a water distribution system is used to ensure uniform wastewater distribution, and an inlet pipe is used to input the wastewater to be treated. The anaerobic reactor controls the upward flow rate of the water to keep the granular sludge in a suspended state, thereby promoting thorough mixing of wastewater and granular sludge and improving wastewater treatment efficiency. This invention incorporates a separator 2, which discharges the sludge and some wastewater from the bottom of anaerobic reactor 1 into the separator 2. Utilizing the greater weight of the calcified granular sludge, the calcified and uncalcified sludge are separated. The uncalcified granular sludge, being lighter, returns to anaerobic reactor 1 from the first sludge outlet, while the calcified granular sludge, being heavier, is discharged into the decalcification regenerator 3 from the second sludge outlet 6. Therefore, by separating and recovering the granular sludge through separator 2, anaerobic reactor 1 does not need to be shut down. Initially, due to the removal of calcified granular sludge, new activated sludge can be added to anaerobic reactor 1 at any time to meet wastewater treatment requirements. The separated calcified granular sludge, after regeneration in the decalcification regenerator 3, can be returned to anaerobic reactor 1. Because of the continuous or intermittent discharge of calcified sludge and the intermittent input of regenerated sludge, anaerobic reactor 1 can enter a new equilibrium, and the replenishment of new activated sludge can be reduced or eliminated.

[0029] Optionally, the separator 2 includes a first separation zone 7 in the upper middle part and a discharge zone 8 in the lower part. The first separation zone 7 is cylindrical and has several continuous spiral downward flow channels 9 evenly arranged on its inner wall.

[0030] The discharge zone 8 is a cone shape with a larger top and a smaller bottom, which is used to facilitate the discharge of the separated calcified granular sludge from the separator 2.

[0031] Optionally, the sludge return pipe 5 passes through the first sludge outlet and extends into the interior of the first separation zone 7 without affecting the rotation of the agitator, thereby discharging the uncalcified granular sludge flowing to the top of the first separation zone 7 from the first separation zone 7.

[0032] The calcified granular sludge has a greater weight than the uncalcified granular sludge. The calcified granular sludge has a greater centrifugal force and is thrown into the guide channel 9 of the first separation zone 7. It can slide down the guide channel 9 to the discharge zone 8. The uncalcified granular sludge has a smaller centrifugal force and most of it does not move to the inner wall of the first separation zone 7. Instead, it rotates and flows inside the first separation zone 7 with the water flow. As sludge and sewage continue to enter the first separation zone 7, the lighter sludge enters the top of the first separation zone 7 and is returned to the anaerobic reactor 1 through the sludge return pipe 5.

[0033] Optionally, an aeration pipe 13 is provided below the first agitator 14 in the decalcification zone 10, and an openable gate 15 is provided below the aeration pipe 13 for discharging the decalcified granular sludge into the deaeration zone 11.

[0034] The second agitator in the degassing zone 11 includes a guide rail 16 and an agitator 17. The guide rail 16 is located at the top of the degassing zone 11, and the agitator 17 moves along the guide rail 16 to agitate the granular sludge in the degassing zone 11. The bottom of the degassing zone 11 is provided with a first discharge port 18 for discharging the degassed granular sludge into the cultivation zone 12.

[0035] The cultivation zone 12 is equipped with a wastewater inlet for inputting wastewater and activated sludge to cultivate deaerated granular sludge. The first discharge port is equipped with a control valve to control its opening and closing.

[0036] Optionally, the decalcification zone 10 includes a lower reaction zone 19 and an upper second separation zone 20. A horizontal first partition 21 is provided between the reaction zone 19 and the second separation zone 20. A second discharge port 23 is provided on the side wall at the bottom of the second separation zone 20. The second discharge port 23 is connected to the nutrient pre-storage tank 24 through a pipeline. A drug inlet and a feed inlet are provided on the side of the top of the reaction zone 19. The lower part of the reaction zone 19 is a cone shape with a larger top and a smaller bottom. A first agitator 14 and an aeration pipe 13 are provided at the bottom of the cone. The aeration pipe 13 is located below the first agitator 14. An openable and closable gate 15 is provided below the aeration pipe 13.

[0037] Optionally, the mesh size of the first mesh 21 is smaller than the average particle size of the calcified anaerobic granular sludge, thus intercepting the calcified anaerobic granular sludge in the reaction zone 19 and continuing to react with the decalcifying agent. The decalcified granular sludge and the precipitate obtained from the reaction can enter the second separation zone 20 under the action of stirring and aeration.

[0038] Optionally, a horizontal fixing frame 25 is provided below the aeration pipe 13. The aeration pipe 13 is installed on the fixing frame 25 and is evenly distributed below the first agitator 14. The first agitator 14 is horizontally arranged. The motor of the first agitator 14 can be located at the center of the fixing frame 25 or above the outside of the decalcification regenerator. The motor shaft is vertically arranged and connected to the center of the first agitator 14. Several agitators are evenly distributed radially around the center of the first agitator 14. The cross-section of the first agitator 14 is circular, and the fixing frame 25 is also circular.

[0039] Optionally, a second mesh 22 is provided outside the first agitator 14 and the aeration pipe 13. The second mesh 22 includes a circular horizontal mesh surface and a vertical mesh surface around the horizontal mesh surface. The bottom of the vertical mesh surface is connected to the fixing frame 25, and the horizontal mesh surface is above the first agitator 14, covering the first agitator 14 and the aeration pipe 13 inside the second mesh 22.

[0040] The mesh size of the vertical mesh is smaller than the average particle size of the calcified anaerobic granular sludge.

[0041] Further optionally, the top of the second separation zone 20 is provided with an air outlet and a cleaning spray pipe. The air outlet is used to discharge excess gas in the decalcification zone 10, and the cleaning spray pipe is used to clean the decalcification zone 10 after the decalcified granular sludge is discharged from the reaction zone 19. The cleaning water is discharged from the gate 15 into the degassing zone 11.

[0042] The stirring paddle is plate-shaped and forms an angle of 30-60° with the horizontal plane to avoid the accumulation of particulate sludge on the surface of the stirring paddle.

[0043] The decalcification regenerator is cylindrical in shape, which facilitates the flow and contact of materials in different internal zones and avoids the dead corners caused by a square shape. Decalcifying agent (phosphate) and calcified anaerobic granular sludge are fed into reaction zone 19. The liquid level of the decalcifying agent can reach the upper part or top of the second separation zone 20. The decalcifying agent and calcified anaerobic granular sludge mainly undergo chemical reaction in reaction zone 19. Under the dual agitation of stirring and aeration, the reactants are fully contacted and reacted, removing the calcium on the surface and in the micropores of the granular sludge, reducing the particle size of the granular sludge. At the same time, new chemical precipitates and gas (CO2) are generated. The gas is discharged from the gas outlet. The granular sludge rises through the first mesh 21 and enters the second separation zone 20 under the action of stirring and aeration. The gas generated by the decalcification reaction and the aeration bubbles are beneficial to occupying the micropores of the granular sludge, preventing newly generated precipitates from occupying the micropores of the granular sludge and causing re-clogging, thus promoting the separation of the decalcified granular sludge from the calcified granular sludge. At the same time, the bubbles are also beneficial to the adhesion of newly generated precipitates, promoting the precipitates to continue to float and further separate from the decalcified granular sludge.

[0044] In reaction zone 19, materials flow upwards under the action of stirring and aeration. Unreacted calcified anaerobic granular sludge is intercepted by the first partition 21. Under the influence of subsequent upward material flow, the intercepted material flows downwards around the reaction zone 19, falling along the conical inclined wall at the bottom of the reaction zone 19 to the bottom, where it is intercepted by the vertical mesh of the second partition 22. This prevents the material from entering and affecting the operation of the first agitator 14, allowing it to continue flowing towards the horizontal mesh. A gap is left between the outer end of the agitator paddle of the first agitator 14 and the vertical mesh to ensure that the rotation of the first agitator 14 is not affected. Once the material enters the horizontal mesh area, it will flow upwards under the action of stirring and aeration, preventing it from falling through the horizontal mesh and affecting the first agitator 14. The mesh size of the horizontal mesh should not affect the output of stirring and aeration.

[0045] The rotation speed and aeration intensity of the first agitator 14 are sufficient to create a circulating flow of particles within the reaction zone 19, preventing granular sludge from falling onto the horizontal mesh surface of the second mesh 22. Calcified granular sludge can be carried by the water flow, while decalcified granular sludge and settled particles are more easily carried into the separation zone by the water flow.

[0046] Optionally, the second discharge port 23 is provided with a third mesh to prevent a large amount of decalcified granular sludge from being discharged into the nutrient pre-storage tank 24 along with the water and newly generated sediment.

[0047] The outlet of the nutrient pre-storage tank 24 is connected to the culture zone 12 via a pipeline for supplying nutrients to the culture zone 12;

[0048] A particulate matter detector is installed in the second separation zone 20. When the stirring and aeration intensity remain constant, if the particulate matter concentration in the second separation zone 20 no longer changes, it indicates that the granular sludge decalcification is complete and no new precipitate is generated. At this time, the pump corresponding to the second discharge port 23 is turned on to discharge the water and precipitate in the second separation zone 20 into the nutrient pre-storage tank 24. The precipitate particles generated by the reaction are smaller than the particle size of the decalcified granular sludge.

[0049] Optionally, the fixed frame 25 is provided with a rotating rod that passes through the center of the fixed frame 25. The fixed frame 25 is not fixedly connected to the bottom of the reaction zone 19. One end of the rotating rod passes through the side wall of the decalcification regenerator and is connected to an external control motor.

[0050] After the water and sediment in the second separation zone 20 are discharged into the nutrient pre-storage tank 24, the gate 15 is opened, and the rotating rod drives the fixed frame 25, the second partition 22, the first agitator 14 and the aeration pipe 13 to rotate in the vertical direction. The sludge in the lower part of the reaction zone 19 is intercepted around the second partition 22. The rotation of the second partition 22 causes most of the granular sludge to fall into the degassing zone 11 through the gaps around the opened second partition 22, avoiding the impact of a large amount of granular sludge falling on the first agitator 14 and the aeration pipe 13.

[0051] The decalcification zone 10, as well as each partition, the first agitator 14, and the fixed frame 25, are cleaned using a cleaning spray pipe. The residual sludge is also discharged into the deaeration zone 11. Then, the rotating rod rotates in the opposite direction, causing the second partition 22 to reset and the gate 15 to close, so that the next batch of calcified granular sludge can be decalcified in the decalcification zone 10.

[0052] Optionally, the degassing zone 11 includes, from top to bottom, an exhaust zone 27, a guide rail 16, and a mixing zone 28. The exhaust zone 27 corresponds to the lower part of the reaction zone 19 and surrounds the outer side of the lower part of the reaction zone 19. The side wall of the exhaust zone 27 is provided with an exhaust port for discharging the gas after the granular sludge is removed. The guide rail 16 is circular and is concentrically arranged with the degassing zone 11. The top of the stirring rod 17 is connected to the guide rail 16 through a slider, so that the stirring rod 17 can move along the guide rail 16, thereby stirring the material in the mixing zone 28.

[0053] The bottom of the mixing zone 28 is conical, and the bottom of the cone is provided with a first discharge port 18. The first discharge port 18 is connected in parallel with a circulation pipe 29. The other end of the circulation pipe 29 is connected to the top of the mixing zone 28, which can discharge the liquid in the mixing zone 28 and then circulate it back into the mixing zone 28. This allows the granular sludge in the mixing zone 28 to be intermittently exposed to the air, causing the bubbles on the sludge to burst.

[0054] Optionally, an inclined vessel wall is provided between the lower part of the exhaust zone 27 and the reaction zone 19 to isolate the exhaust zone 27 and the reaction zone 19.

[0055] Optionally, at least one ultrasonic plate is provided on the outer surface of the stirring rod 17. The ultrasonic plate is electrically connected to an external ultrasonic control device. Under the action of ultrasound, the granular sludge in the mixing zone 28 has an improved degassing effect. When the stirring rod 17 stirs the material in the mixing zone 28, the ultrasonic plate is activated to promote the degassing of the granular sludge. The degassed gas enters the exhaust zone 27 and is then discharged from the exhaust port.

[0056] Optionally, the circulation pipe 29 is provided with a temporary storage tank 26 for temporarily storing the liquid input into the circulation pipe 29. After all the liquid in the mixing zone 28 is discharged, the liquid in the temporary storage tank 26 is returned to the mixing zone 28.

[0057] The liquid in the mixing zone 28 is drained intermittently, so that the granular sludge is intermittently exposed to the air. The atmospheric pressure difference causes the bubbles on the granular sludge to burst, thus preparing the conditions for subsequent sludge cultivation.

[0058] The degassing time depends on the air pressure change in the exhaust zone 27. When the air pressure is close to atmospheric pressure, it means that degassing is complete. Then, the granular sludge is discharged into the cultivation zone 12 from the first discharge port 18. The conical bottom of the mixing zone 28 ensures that the granular sludge and water are completely discharged. The degassing zone 11 can carry out the degassing treatment of the next batch of decalcified granular sludge.

[0059] The precipitate and chelate formed by decalcification, as well as the remaining decalcifying agent solution, contain phosphorus, calcium and other elements, which are nutrients required for the cultivation of anaerobic microorganisms. In this invention, the nutrient pre-storage tank 24 is used to collect this material and then use it in the cultivation zone 12.

[0060] Optionally, the top of the cultivation zone 12 is equipped with a wastewater inlet for introducing wastewater and activated sludge (active granular sludge) into the cultivation zone 12, promoting the reattachment of anaerobic microorganisms to the micropores and surface of the granular sludge discharged into the cultivation zone 12; the bottom of the cultivation zone 12 is equipped with a third discharge port, which is connected to the anaerobic reactor via a pipeline for returning the cultivated anaerobic granular sludge to the anaerobic reactor. Throughout the cultivation process, the material in the nutrient pre-storage tank 24 is continuously and constantly fed into the cultivation zone 12.

Claims

1. A combined system of anaerobic reactor and granular sludge decalcification and regeneration, characterized in that, The system includes an anaerobic reactor, a separator, and a decalcification regenerator connected in sequence. The bottom of the anaerobic reactor is connected to the sludge inlet at the top of the separator via a sludge feed pipe, allowing the granular sludge and wastewater from the bottom of the anaerobic reactor to be fed into the separator. The first sludge outlet at the top of the separator is connected to the anaerobic reactor via a sludge return pipe, returning the separated activated sludge to the anaerobic reactor. The second sludge outlet at the bottom of the separator is connected to the feed inlet of the decalcification regenerator, feeding the separated calcified granular sludge into the decalcification regenerator. The decalcification regenerator consists of a decalcification zone, a degassing zone, and a cultivation zone from top to bottom. The decalcification zone has a chemical inlet and a feed inlet on its side for introducing the decalcifying agent. A first agitator is located at the bottom of the decalcification zone to promote contact and reaction between the decalcifying agent and the calcified anaerobic granular sludge. The decalcification zone is connected to the degassing zone via an openable gate. A second agitator is located in the degassing zone to promote the removal of air bubbles from the surface and micropores of the granular sludge. The bottom of the cultivation zone is connected to the anaerobic reactor via a pipe, returning the regenerated sludge to the anaerobic reactor. An aeration pipe is provided below the first agitator. A second partition is provided outside the first agitator and the aeration pipe. The second partition includes a circular horizontal mesh surface and a vertical mesh surface around the horizontal mesh surface. The bottom of the vertical mesh surface is connected to a fixed frame. The horizontal mesh surface is located above the first agitator, covering the first agitator and the aeration pipe inside the second partition. The mesh size of the vertical mesh surface is smaller than the average particle size of the calcified anaerobic granular sludge.

2. The combined system of anaerobic reactor and granular sludge decalcification and regeneration according to claim 1, characterized in that, The anaerobic reactor is provided with a sludge outlet at the bottom, which is connected to a sludge feed pipe; the anaerobic reactor is provided with a sludge return port at the bottom, which is connected to a sludge return pipe.

3. The combined system of anaerobic reactor and granular sludge decalcification and regeneration according to claim 1, characterized in that, The separator includes a first separation zone in the upper middle part and a discharge zone in the lower part. The first separation zone is cylindrical and has several continuous spiral downward flow channels evenly arranged on its inner wall. The discharge zone is cone-shaped, wider at the top and narrower at the bottom, to facilitate the discharge of the separated calcified granular sludge from the separator.

4. The combined system of anaerobic reactor and granular sludge decalcification and regeneration according to claim 3, characterized in that, The sludge return pipe passes through the first sludge outlet and extends into the interior of the first separation zone without affecting the rotation of the agitator, discharging the uncalcified granular sludge flowing to the top of the first separation zone from the first separation zone.

5. The combined system of anaerobic reactor and granular sludge decalcification and regeneration according to claim 1, characterized in that, The aeration pipe in the decalcification zone is equipped with an openable and closable gate below it; The second agitator in the degassing zone includes a guide rail and an agitator. The guide rail is located at the top of the degassing zone, and the agitator moves along the guide rail to agitate the granular sludge in the degassing zone. The bottom of the degassing zone is provided with a first discharge port for discharging the degassed granular sludge into the cultivation zone. The cultivation area is equipped with a wastewater inlet for inputting wastewater and activated sludge to cultivate deaerated granular sludge.

6. The combined system of anaerobic reactor and granular sludge decalcification and regeneration according to claim 5, characterized in that, The decalcification zone includes a lower reaction zone and an upper second separation zone. A horizontal first partition is provided between the reaction zone and the second separation zone. A second discharge port is provided on the side wall at the bottom of the second separation zone. The second discharge port is connected to the nutrient pre-storage tank through a pipeline. A drug inlet and a feed inlet are provided on the side of the top of the reaction zone. The lower part of the reaction zone is a cone shape that is larger at the top and smaller at the bottom. A first stirrer and an aeration pipe are provided at the bottom of the cone.

7. The combined system of anaerobic reactor and granular sludge decalcification and regeneration according to claim 6, characterized in that, The fixed frame is equipped with a rotating rod that passes through the center of the fixed frame. The fixed frame is not fixedly connected to the bottom of the reaction zone. One end of the rotating rod passes through the side wall of the decalcification regenerator and is connected to an external control motor. After the water and sediment in the second separation zone are discharged into the nutrient pre-storage tank, the gate is opened, and the rotating rod drives the fixed frame, the second partition, the first agitator and the aeration pipe to rotate in the vertical direction. The sludge in the lower part of the reaction zone is intercepted around the second partition. The rotation of the second partition causes most of the granular sludge to fall into the deaeration zone through the gaps around the opened second partition.

8. The combined system of anaerobic reactor and granular sludge decalcification and regeneration according to claim 7, characterized in that, The degassing zone includes an exhaust zone, a guide rail, and a mixing zone from top to bottom. The exhaust zone corresponds to the lower part of the reaction zone and surrounds the outer side of the lower part of the reaction zone. The side wall of the exhaust zone is provided with an exhaust port. The guide rail is circular, and the top of the stirring rod is connected to the guide rail through a slider, so that the stirring rod can move along the guide rail. The bottom of the mixing zone is conical, and the bottom of the cone is equipped with a first discharge port. The first discharge port is connected to a circulation pipe in parallel. The other end of the circulation pipe is connected to the top of the mixing zone, which can discharge the liquid in the mixing zone and then circulate it back into the mixing zone. This allows the granular sludge in the mixing zone to be intermittently exposed to the air, causing the air bubbles on the sludge to burst.

9. The combined system of anaerobic reactor and granular sludge decalcification and regeneration according to claim 8, characterized in that, The top of the cultivation zone is equipped with a wastewater inlet for inputting wastewater and activated sludge into the cultivation zone. The bottom of the cultivation zone is equipped with a third discharge port, which is connected to the anaerobic reactor through a pipeline for returning the cultured anaerobic granular sludge to the anaerobic reactor.

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