Continuous flow aerobic granular sludge culture device and method

Abstract

The invention belongs to the technical field of biological sewage treatment, and discloses a continuous flow aerobic granular sludge culture device and method. The device comprises a water inlet pump, a water inlet pipe, an anaerobic tank, an anoxic tank, an aerobic tank and a multi-hopper sedimentation tank which are connected in sequence. The device has the advantages of fast particle formation, stable operation and high nitrogen and phosphorus removal efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of biological sewage treatment, and more specifically, relates to a continuous flow aerobic granular sludge cultivation device and method. Background Art

[0002] Aerobic granular sludge is a kind of biological aggregate with a special morphological structure, and it is also different from other biofilms. The aerobic sludge granulation process does not require a carrier. It is a microbial aggregate with good sedimentation performance, high microbial mass, strong resistance to shock load and regular appearance formed by the joint action of biological, physical and chemical factors between cells under the external environmental conditions. Compared with traditional floc activated sludge, granular sludge has the advantages of more compact structure, larger biomass, faster sedimentation rate, and easy simultaneous nitrification and denitrification. Because aerobic granular sludge has the dual advantages of two aerobic biological treatment technologies, activated sludge method and biofilm method, and also has the functions of partial anoxic and anaerobic biological treatment, it shows unique superiority in terms of biomass, oxygen utilization rate and treatment effect.

[0003] At present, aerobic granular sludge is more widely used in sequencing batch processes. This is because, due to the different process operation modes, mechanisms that can promote particle growth, such as hunger-feast, selection pressure, and particle screening, are difficult to achieve in continuous flow. In addition, sludge return and digestate return are prone to particle breakage due to water pumps. The aerobic granulation efficiency in continuous flow is relatively low, and granular sludge does not have an advantage.

[0004] Therefore, the present invention urgently needs to propose a continuous flow aerobic granular sludge cultivation device and method. Summary of the invention

[0005] The purpose of the present invention is to provide a continuous flow aerobic granular sludge cultivation device and method in view of the deficiencies of the prior art. The present invention has the advantages of fast granule formation, stable operation and high nitrogen and phosphorus removal efficiency.

[0006] In order to achieve the above object, the present invention provides a continuous flow aerobic granular sludge cultivation device on one hand, the device comprises a water inlet pump, a water inlet pipe, an anaerobic tank, an anoxic tank, an aerobic tank and a multi-bucket sedimentation tank connected in sequence;

[0007] The water inlet pipe is provided with an anaerobic tank water inlet valve and an anaerobic tank water inlet flowmeter;

[0008] A sludge concentration meter is provided in the anaerobic tank and at the water outlet of the anaerobic tank respectively; an agitator is provided in the anaerobic tank and the anoxic tank;

[0009] A plurality of mud collecting buckets are arranged at the bottom of the multi-bucket sedimentation tank, and a mud return branch pipe and a mud discharge branch pipe are connected to the bottom of each mud collecting bucket, and a mud return valve is arranged on each mud return branch pipe. All mud return branch pipes are connected to the mud inlet end of the mud return main pipe through a mud return pump, and the mud outlet end of the mud return main pipe is connected to the mud inlet of the anaerobic tank; a mud return flow meter and an anaerobic tank mud inlet valve are arranged on the mud return main pipe.

[0010] In the present invention, each valve is used to control the entry or discharge of sewage or sludge; each flow meter is used to measure the amount of the sewage or sludge that is entered or discharged.

[0011] According to the present invention, preferably, a water distributor is provided at the bottom of the anaerobic tank, and a water outlet weir is provided at the upper part of the anaerobic tank; the water inlet pump is connected to the water distributor through an inlet pipe.

[0012] According to the present invention, preferably, the device is provided with a plurality of the anaerobic tanks.

[0013] According to the present invention, preferably, the water distributor is a perforated pipe evenly distributed in the bottom of the anaerobic tank in a horizontal direction, and the opening direction of the perforated pipe is 0-90 degrees obliquely downward.

[0014] According to the present invention, preferably, the device is further provided with a carbon source supplement device and a phosphorus removal agent supplement device, and the carbon source supplement device and the phosphorus removal agent supplement device are connected to the anaerobic tank. In the present invention, when the carbon-nitrogen ratio of the inlet water of the water inlet pipe is low, a carbon source can be added to enhance nitrogen removal and phosphorus removal; when the phosphorus content of the inlet water of the water inlet pipe is high, a phosphorus removal agent can be added to enhance phosphorus removal.

[0015] According to the present invention, preferably, the water outlet of the aerobic tank is divided into two routes, one route is connected to the water inlet of the multi-bucket sedimentation tank, and the other route is connected to the water inlet of the anoxic tank through a nitrification liquid reflux pump and a nitrification liquid reflux pipe in sequence.

[0016] According to the present invention, preferably, a nitrifying liquid reflux flowmeter is provided on the nitrifying liquid reflux pipe.

[0017] According to the present invention, preferably, a DO measuring instrument is provided in the aerobic tank.

[0018] According to the present invention, preferably, a plurality of aeration plates are arranged at the bottom of the aerobic pool, and the aeration plates are connected to a blower through an aeration pipeline.

[0019] According to the present invention, preferably, the nitrification liquid reflux pump and the sludge reflux pump are both volumetric pumps, and preferably, the nitrification liquid reflux pump and the sludge reflux pump are each independently a diaphragm pump or a screw pump. In the present invention, the volumetric pump has a smaller destructive effect on the sludge particles, is not easy to break up the sludge particles, and is conducive to the cultivation of aerobic granular sludge.

[0020] According to the present invention, preferably, each mud discharge branch pipe is provided with a mud discharge valve, all mud discharge branch pipes are connected to a mud discharge main pipe, and a mud discharge flow meter is provided on the mud discharge main pipe.

[0021] According to the present invention, preferably, the water outlet of the multi-bucket sedimentation tank is connected to a drain pipe; a drainage rectifying plate is provided at the water outlet of the multi-bucket sedimentation tank, and a water inlet rectifying plate is provided at the water inlet of the multi-bucket sedimentation tank.

[0022] According to the present invention, preferably, 2-10 mud collecting buckets are arranged at the bottom of the multi-bucket sedimentation tank.

[0023] Another aspect of the present invention provides a continuous flow aerobic granular sludge cultivation method, the method using the system, comprising the following steps:

[0024] S1: The anaerobic tank is operated in sequence with a separate water inlet process and a return water inlet process;

[0025] When the separate water inlet process is run, the anaerobic tank mud inlet valve and the agitator in the anaerobic tank are closed, and water is introduced through the water inlet pipe to make the original mud and water mixture of the anaerobic tank flow into the anoxic tank and the aerobic tank in sequence, and the sludge concentration in the anaerobic tank is controlled to be 10-50% of the sludge concentration in the anaerobic tank at the beginning of water inlet; after the water inlet amount of the anaerobic tank of the separate water inlet process reaches a preset value, the return water inlet process is run;

[0026] When the return water inflow process is running, the anaerobic tank inlet valve and the agitator in the anaerobic tank are opened, so that the precipitated sludge in the sludge collecting bucket near the water inlet of the multi-bucket sedimentation tank is returned to the anaerobic tank, thereby making the sludge concentration in the anaerobic tank reach the sludge concentration in the anaerobic tank when the water inflow of the anaerobic tank begins;

[0027] S2: The mud-water mixture discharged from the aerobic tank enters the multi-bucket sedimentation tank to obtain the precipitated sludge in the sludge collecting bucket near the water inlet of the multi-bucket sedimentation tank, the precipitated sludge in the sludge collecting bucket far from the water inlet of the multi-bucket sedimentation tank, and the supernatant.

[0028] According to the present invention, preferably, the sludge concentration in the anaerobic tank at the beginning of water inflow is 2500-8000 mg / L.

[0029] According to the present invention, preferably, the preset value is 30%-60% of the volume of the anaerobic tank.

[0030] In the present invention:

[0031] When the device is first started and the separate water inlet process is run: a small water inlet volume is required to start the device to ensure that no sludge will flow out of the multi-bucket sedimentation tank from the drain pipe; after the sludge enters the multi-bucket sedimentation tank, larger particles will settle in the front mud collecting bucket, and smaller particles will settle in the rear mud collecting bucket. The sludge return valve corresponding to the front mud collecting bucket is opened to return the larger particles to the anaerobic tank, and the sludge discharge valve corresponding to the rear mud collecting bucket is opened to discharge the smaller particles out of the device;

[0032] As the sludge particles grow larger, more sludge will settle in the front sludge collecting bucket, and there will be almost no sludge in the rear sludge collecting bucket. At this time, the water intake can be increased and gradually increased to full load;

[0033] As the sludge particle size continues to increase, more sludge will still settle in the front mud hopper at the maximum load. At this time, the sludge return valve and mud discharge valve are properly adjusted to make the largest particles at the front return to the anaerobic tank, while maintaining the mud discharge volume of the device and the sludge concentration in the device within the set value of 2500-8000mg / L. In addition, when the mud volume in the rear mud hopper is small, the mud discharge valve can be opened intermittently or not opened.

[0034] According to the present invention, preferably, the water inlet rising speed of the anaerobic tank in the separate water inlet process is greater than the sludge settling speed of the anaerobic tank, and preferably, the water inlet rising speed of the anaerobic tank in the separate water inlet process is 1m / h-7m / h. In the present invention, as the cultivation proceeds, the sludge settling speed in the anaerobic tank increases, therefore, the present invention increases the water inlet rising speed of the anaerobic tank in the separate water inlet process from 1m / h to 7m / h.

[0035] According to the present invention, preferably, the method further comprises adding a carbon source and a dephosphorization agent into the anaerobic tank when the separate water inlet process is running. Preferably, the carbon source is at least one of sodium acetate, sodium propionate, glucose and methanol, and the dephosphorization agent is at least one of polyaluminum chloride, aluminum sulfate, ferric sulfate and polyaluminum ferric chloride.

[0036] According to the present invention, preferably, the amount of the precipitated sludge in the sludge collecting bucket of the multi-bucket sedimentation tank returned to the anaerobic tank is 50%-200% of the water inflow of the anaerobic tank in the separate water inflow process.

[0037] According to the present invention, preferably, the single-cycle operation time of the reflux water inlet process is 0.5-2 times the single-cycle operation time of the separate water inlet process.

[0038] According to the present invention, preferably, the retention time of the anaerobic tank is 1-3 hours, the retention time of the anoxic tank is 1-5 hours, the retention time of the aerobic tank is 3-15 hours, and the retention time of the multi-bucket sedimentation tank is 1-3 hours.

[0039] According to the present invention, preferably, a portion of the muddy-water mixture discharged from the aerobic tank is allowed to enter the multi-bucket sedimentation tank, and the remaining portion is refluxed to the anoxic tank through the nitrification liquid reflux pump and the nitrification liquid reflux pipe in sequence.

[0040] According to the present invention, preferably, the DO value of the aerobic pool is controlled at 0.5-4 mg / L.

[0041] According to the present invention, preferably, the amount of the muddy-water mixture returned from the aerobic tank to the anoxic tank is 100%-600% of the water inflow amount of the anaerobic tank in the separate water inflow process.

[0042] According to the present invention, preferably, the method also includes discharging the settled sludge in the sludge collecting bucket in the multi-bucket sedimentation tank away from the water inlet of the multi-bucket sedimentation tank from the device through the sludge discharge branch pipe and the sludge discharge main pipe in sequence, and discharging the supernatant from the device through the drain pipe.

[0043] The beneficial effects of the technical solution of the present invention are as follows: The present invention solves the problem that mechanisms that can promote particle growth, such as hunger-feast, selection pressure, and particle screening, are difficult to achieve in continuous flow, the aerobic granulation efficiency in continuous flow is relatively low, and granular sludge is not dominant. The present invention can fully realize the effects of hunger-feast and selection pressure in a continuous flow reactor to promote particle formation; the larger sludge in the multi-bucket sedimentation tank is returned to the anaerobic tank, and the smaller sludge is discharged to achieve particle screening; the present invention has the advantages of fast particle formation, stable operation, and high nitrogen and phosphorus removal efficiency. Specifically:

[0044] 1. In the present invention, the anaerobic tank separate water inlet process and the return water inlet process are operated in sequence, which can fully realize the effects of hunger-feast and selection pressure in the continuous flow reaction device and promote particle formation. When the separate water inlet process is operated, fresh sewage enters the lower end of the anaerobic tank evenly through the water distributor, pushing the original muddy water in the anaerobic tank out of the anaerobic tank, controlling the rising speed of the fresh sewage to make it slightly faster than the sedimentation speed of the sludge, and the lighter sludge in the sludge is taken out of the anaerobic tank, while the larger and heavier sludge remains in the anaerobic tank. The larger and heavier sludge remaining in the anaerobic tank quickly absorbs the carbon source in the fresh sewage, so that the larger and heavier sludge can grow faster, while the lighter sludge taken out cannot contact the fresh sewage and grows slower, thereby realizing biological selection pressure and promoting the sludge in the biological pool to gradually transform into larger and heavier aerobic granular sludge; in addition, the larger and heavier sludge directly contacts the fresh sewage, absorbs a large amount of organic matter in the fresh sewage, and is fully aerated in the aerobic section to fully consume the adsorbed organic matter, realizing the satiety-starvation process and promoting the rapid formation of aerobic granular sludge;

[0045] 2. In the present invention, when the sludge enters the multi-bucket sedimentation tank, the larger and heavier sludge enters the sludge collecting bucket near the entrance of the multi-bucket sedimentation tank, and the lighter sludge enters the sludge collecting bucket far away from the entrance of the multi-bucket sedimentation tank. Moreover, the farther from the entrance, the smaller the sludge particle size in the sludge collecting bucket. By discharging the sludge in the sludge collecting bucket far away from the entrance of the multi-bucket sedimentation tank from the reactor, the larger and heavier sludge is left to flow back into the front anaerobic tank, thereby achieving the screening of granular sludge;

[0046] 3. In the present invention, both during and after the formation of aerobic granular sludge, it has excellent denitrification and phosphorus removal effects; in the separate water intake process, fresh sewage directly contacts with sludge after entering the anaerobic tank, without oxygen and oxides, and can fully utilize the organic matter in the fresh sewage to release phosphorus; sewage and return sludge enter the anoxic tank for denitrification and denitrification, denitrification and denitrification phosphorus absorption, a large amount of total nitrogen in the water is removed, and part of the phosphorus is removed; in the aerobic tank, ammonia nitrogen is converted into nitrate nitrogen or nitrite nitrogen through nitrification reaction, and at the same time, due to the layered structure of aerobic granular sludge, the inner layer is more phosphorus removal bacteria and denitrifying bacteria, and the outer layer is more nitrifying bacteria. The aerobic granular sludge has a strong simultaneous nitrification and denitrification effect in the aerobic tank, removes part of the total nitrogen, and the polyphosphate bacteria can absorb excessive phosphorus in the aerobic tank, thereby achieving phosphorus removal.

[0047] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0049] Figure 1 A schematic diagram of a continuous flow aerobic granular sludge cultivation device provided by the present invention is shown.

[0050] Figure 2 A graph showing changes in sludge characteristics of the continuous flow aerobic granular sludge cultivation method provided in Example 1 of the present invention is shown (wherein "SVI refers to the sludge volume index, which refers to the volume (in mL) occupied by 1 g of dry sludge after the aerated mixed liquor is settled, in units of mL / g").

[0051] Description of reference numerals:

[0052] 1. Anaerobic tank; 2. Anoxic tank; 3. Aerobic tank; 4. Multi-bucket sedimentation tank; 5. Inlet pump; 6. Agitator; 7. Blower; 8. Nitrate return pump; 9. Sludge return pump; 10. Water distributor; 11. Outlet weir; 12. Aeration plate; 13. Anaerobic tank inlet valve; 14. Anaerobic tank sludge inlet valve; 15. Sludge return valve; 16. Sludge discharge valve; 17. Anaerobic tank inlet flow meter; 18. 1. Reflux flowmeter for nitrification liquid; 2. Reflux flowmeter for sludge; 3. Flowmeter for sludge discharge; 4. Mud collecting bucket; 5. Water inlet rectifier; 6. Water outlet rectifier; 7. Water inlet pipe; 8. Reflux pipe for nitrification liquid; 9. Main pipe for sludge return; 10. Main pipe for sludge discharge; 11. Sludge concentration meter in the anaerobic tank; 12. Sludge concentration meter at the outlet of the anaerobic tank; 13. DO measuring instrument. DETAILED DESCRIPTION

[0053] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0054] Example 1

[0055] This embodiment provides a continuous flow aerobic granular sludge culture device, such as Figure 1 As shown, the device includes a water inlet pump 5, a water inlet pipe 24, an anaerobic tank 1, an anoxic tank 2, an aerobic tank 3 and a multi-bucket sedimentation tank 4 connected in sequence;

[0056] The water inlet pipe 24 is provided with an anaerobic tank water inlet valve 13 and an anaerobic tank water inlet flowmeter 17;

[0057] The device is provided with two anaerobic tanks 1;

[0058] A sludge concentration meter is provided in the anaerobic tank 1 and at the outlet of the anaerobic tank 1 respectively; an agitator 6 is provided in the anaerobic tank 1 and the anoxic tank 2; a water distributor 10 is provided at the bottom of the anaerobic tank 1, and a water outlet weir 11 is provided at the upper part of the anaerobic tank 1; the water inlet pump 5 is connected to the water distributor 10 through an inlet pipe 24; the water distributor 10 is a perforated pipe evenly distributed at the bottom of the anaerobic tank 1 in a horizontal direction, and the opening direction of the perforated pipe is 0-90° downwardly inclined;

[0059] The water outlet of the aerobic pool 3 is divided into two paths, one of which is connected to the water inlet of the multi-bucket sedimentation tank 4, and the other is connected to the water inlet of the anoxic pool 2 through the nitrification liquid reflux pump 8 and the nitrification liquid reflux pipe 25 in sequence; the nitrification liquid reflux flowmeter 18 is arranged on the nitrification liquid reflux pipe 25; the aerobic pool 3 is provided with a DO measuring instrument 31; the bottom of the aerobic pool 3 is provided with a plurality of aeration plates 12, and the aeration plates 12 are connected to the blower 7 through an aeration pipeline;

[0060] Four mud collecting buckets 21 are arranged at the bottom of the multi-bucket sedimentation tank 4, and a mud return branch pipe and a mud discharge branch pipe are connected to the bottom of each mud collecting bucket 21, and a mud return valve 15 is arranged on each mud return branch pipe. All mud return branches are connected to the mud inlet end of the mud return main pipe 26 through a mud return pump 9, and the mud outlet end of the mud return main pipe 26 is connected to the mud inlet of the anaerobic tank 1; the mud return main pipe 26 is provided with a mud return flowmeter 19 and an anaerobic tank mud inlet valve 14. A mud discharge valve 16 is provided on each mud discharge branch pipe, and all mud discharge branch pipes are connected to the mud discharge main pipe 28, on which a mud discharge flow meter 20 is provided; the water outlet of the multi-bucket sedimentation tank 4 is connected to a drain pipe 27, a drainage rectifier plate 23 is provided at the water outlet of the multi-bucket sedimentation tank 4, and an inlet rectifier plate 22 is provided at the water inlet of the multi-bucket sedimentation tank 4.

[0061] The nitrification liquid reflux pump 8 and the sludge reflux pump 9 are screw pumps;

[0062] The device is also provided with a carbon source supplement device and a dephosphorus agent supplement device (not shown), and the carbon source supplement device and the dephosphorus agent supplement device are connected to the anaerobic tank 1 .

[0063] This embodiment uses the above device to carry out continuous flow aerobic granular sludge cultivation, including the following steps:

[0064] S1: The anaerobic tank 1 is operated in sequence for a separate water inlet process and a return water inlet process;

[0065] The influent is fresh domestic sewage, with an influent COD of 187-378 mg / L, an influent ammonia nitrogen of 26-39 mg / L, an influent total nitrogen of 33-47 mg / L, and an influent total phosphorus of 1.9-4.5 mg / L;

[0066] The retention time of the two anaerobic tanks 1 is 1.5 h, the retention time of the anoxic tank 2 is 4 h, and the retention time of the aerobic tank 3 is 10 h;

[0067] When the separate water inlet process is running, the anaerobic tank mud inlet valve 14 and the agitator in the anaerobic tank are closed, and water is introduced through the water inlet pipe 24 so that the original mud and water mixture of the anaerobic tank 1 flows into the anoxic tank 2 and the aerobic tank 3 in sequence, and the sludge concentration in the anaerobic tank 1 is controlled to be 10-50% of the sludge concentration in the anaerobic tank (3000-4500 mg / L) at the beginning of the water inlet of the anaerobic tank; when the water inlet amount of the anaerobic tank of the separate water inlet process reaches the preset value (the preset value is the volume of the anaerobic tank), the anaerobic tank 1 is closed, and the anaerobic tank 1 is closed. 30%-60%), the reflux water inlet process is run; wherein, in this embodiment, sodium acetate is added to the anaerobic tank 1 when the separate water inlet process is run as a carbon source to strengthen nitrogen and phosphorus removal; and the water inlet rising speed of the anaerobic tank 1 of the separate water inlet process needs to be greater than the sludge sedimentation speed of the anaerobic tank. As the cultivation proceeds, the sludge sedimentation speed in the anaerobic tank 1 increases. Therefore, in this embodiment, the water inlet rising speed of the anaerobic tank 1 of the separate water inlet process is gradually increased from 1m / h to 7m / h;

[0068] When the return water inflow process is running, the anaerobic tank mud inlet valve 14 and the agitator in the anaerobic tank are opened, so that the precipitated sludge in the mud collecting hopper 21 near the water inlet of the multi-bucket sedimentation tank 4 in the multi-bucket sedimentation tank 4 is returned to the anaerobic tank 1, thereby making the sludge concentration in the anaerobic tank reach the sludge concentration in the anaerobic tank when the water inflow starts; wherein the amount of precipitated sludge in the mud collecting hopper of the multi-bucket sedimentation tank returned to the anaerobic tank is 50%-200% of the water inflow of the anaerobic tank in the separate water inflow process; the single cycle operation time of the return water inflow process is 0.5-2 times the single cycle operation time of the separate water inflow process;

[0069] S2: a part of the muddy and water mixture discharged from the aerobic tank 3 enters the multi-bucket sedimentation tank 4, and the remaining part is refluxed to the anoxic tank 2 through the nitrification liquid reflux pump 8 and the nitrification liquid reflux pipe 25 in turn;

[0070] From the mud-water mixture entering the multi-bucket sedimentation tank 4, the settled sludge in the mud collecting bucket near the water inlet of the multi-bucket sedimentation tank, the settled sludge in the mud collecting bucket far from the water inlet of the multi-bucket sedimentation tank and the supernatant are obtained.

[0071] The DO value of the aerobic tank 3 is controlled at 0.5-4 mg / L; the amount of the mud-water mixture returned from the aerobic tank 3 to the anoxic tank 2 is 100%-600% of the water inlet amount of the anaerobic tank in the separate water inlet process; in this embodiment, the precipitated sludge in the sludge collecting bucket away from the water inlet of the multi-bucket sedimentation tank is discharged from the device through the sludge discharge branch pipe and the sludge discharge main pipe 28 in sequence, and the supernatant is discharged from the device through the drain pipe 27.

[0072] After 45 days of operation, the particle size (median diameter) of the sludge particles obtained in this embodiment increased to 407 μm, and the SVI of the sludge decreased to 45 g / mL. Figure 2 , it can be seen that this embodiment cultivates aerobic granular sludge.

[0073] Example 2

[0074] This embodiment provides a continuous flow aerobic granular sludge culture device. The difference between this embodiment and embodiment 1 is that:

[0075] The nitrification liquid reflux pump 8 and the sludge reflux pump 9 are diaphragm pumps;

[0076] Five mud collecting buckets 21 are arranged at the bottom of the multi-bucket sedimentation tank 4 .

[0077] The device of this embodiment is used to carry out continuous flow aerobic granular sludge cultivation. The method of this embodiment is different from that of embodiment 1 only in that:

[0078] The influent is fresh industrial park sewage, which is a mixture of industrial water and domestic sewage. The influent COD is 455-738mg / L, the influent ammonia nitrogen is 49-68mg / L, the influent total nitrogen is 60-81mg / L, and the influent total phosphorus is 4.8-10.1mg / L.

[0079] The retention time of the two anaerobic tanks 1 is 2 hours, the retention time of the anoxic tank 2 is 5 hours, and the retention time of the aerobic tank 3 is 14 hours;

[0080] The sludge concentration in the anaerobic tank at the beginning of water inflow is 4000-6500 mg / L;

[0081] In this embodiment, PAC is also added into the anaerobic tank 1 when the single water inlet process is running as a phosphorus removal agent to assist in phosphorus removal;

[0082] After 60 days of operation, the particle size (median diameter) of the sludge particles obtained in the device of this embodiment increased to 278 μm, and the SVI of the sludge decreased to 48 g / mL. It can be seen that aerobic granular sludge was also cultivated in this embodiment.

[0083] Example 3

[0084] This embodiment provides a continuous flow aerobic granular sludge culture device. The difference between this embodiment and embodiment 1 is that:

[0085] The device is not provided with carbon source supplement equipment and phosphorus removal agent supplement equipment.

[0086] The device of this embodiment is used to carry out continuous flow aerobic granular sludge cultivation. The method of this embodiment is different from that of embodiment 1 only in that:

[0087] The influent is the effluent from an anaerobic reactor of a certain factory, with COD of 623-899mg / L, ammonia nitrogen of 25-31mg / L, total nitrogen of 39-51mg / L, and total phosphorus of 5.5-9.6mg / L.

[0088] The retention time of the two anaerobic tanks 1 is 2 hours, the retention time of the anoxic tank 2 is 3 hours, and the retention time of the aerobic tank 3 is 12 hours;

[0089] The sludge concentration in the anaerobic tank at the beginning of water inflow is 5000-6000 mg / L;

[0090] After 40 days of operation, the particle size (median diameter) of the sludge particles obtained in the device of this embodiment increased to 553 μm, and the SVI of the sludge decreased to 44 g / mL. It can be seen that aerobic granular sludge was also cultivated in this embodiment.

[0091] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A continuous flow aerobic granular sludge culture device, characterized in that: The device comprises a water inlet pump, a water inlet pipe, an anaerobic tank, an anoxic tank, an aerobic tank and a multi-bucket sedimentation tank connected in sequence; The water inlet pipe is provided with an anaerobic tank water inlet valve and an anaerobic tank water inlet flowmeter; A sludge concentration meter is provided in the anaerobic tank and at the water outlet of the anaerobic tank respectively; an agitator is provided in the anaerobic tank and the anoxic tank; A plurality of mud collecting buckets are arranged at the bottom of the multi-bucket sedimentation tank, and a mud return branch pipe and a mud discharge branch pipe are connected to the bottom of each mud collecting bucket, and a mud return valve is arranged on each mud return branch pipe. All mud return branch pipes are connected to the mud inlet end of the mud return main pipe through a mud return pump, and the mud outlet end of the mud return main pipe is connected to the mud inlet of the anaerobic tank; a mud return flow meter and an anaerobic tank mud inlet valve are arranged on the mud return main pipe.

2. The continuous flow aerobic granular sludge cultivation device according to claim 1, wherein: The device is provided with a plurality of anaerobic tanks; A water distributor is provided at the bottom of the anaerobic tank, and a water outlet weir is provided at the upper part of the anaerobic tank; the water inlet pump is connected to the water distributor through a water inlet pipe; The water distributor is a perforated pipe evenly distributed in the bottom of the anaerobic tank in the horizontal direction, and the opening direction of the perforated pipe is 0-90 degrees obliquely downward; Preferably, the device is also provided with a carbon source supplement device and a phosphorus removal agent supplement device, and the carbon source supplement device and the phosphorus removal agent supplement device are connected to the anaerobic tank.

3. The continuous flow aerobic granular sludge cultivation device according to claim 1 of the present application, wherein: The water outlet of the aerobic tank is divided into two paths, one of which is connected to the water inlet of the multi-bucket sedimentation tank, and the other is connected to the water inlet of the anoxic tank through a nitrification liquid reflux pump and a nitrification liquid reflux pipe in sequence; The nitrification liquid reflux pipe is provided with a nitrification liquid reflux flowmeter; A DO measuring instrument is provided in the aerobic pool; A plurality of aeration plates are arranged at the bottom of the aerobic pool, and the aeration plates are connected to the blower through an aeration pipeline; The nitrification liquid reflux pump and the sludge reflux pump are both positive displacement pumps. Preferably, the nitrification liquid reflux pump and the sludge reflux pump are each independently a diaphragm pump or a screw pump.

4. The continuous flow aerobic granular sludge cultivation device according to claim 1 of the present application, wherein: Each mud discharge branch pipe is provided with a mud discharge valve, and all mud discharge branch pipes are connected to a mud discharge main pipe, and a mud discharge flow meter is provided on the mud discharge main pipe; The water outlet of the multi-bucket sedimentation tank is connected to a drainage pipe; a drainage rectifying plate is arranged at the water outlet of the multi-bucket sedimentation tank, and a water inlet rectifying plate is arranged at the water inlet of the multi-bucket sedimentation tank; The bottom of the multi-bucket sedimentation tank is provided with 2-10 mud collecting buckets.

5. A continuous flow aerobic granular sludge culture method, characterized in that: The method adopts the system according to any one of claims 1 to 4, comprising the following steps: S1: The anaerobic tank is operated in sequence with a separate water inlet process and a return water inlet process; When the separate water inlet process is running, the anaerobic tank mud inlet valve and the agitator in the anaerobic tank are closed, and the original mud and water mixture of the anaerobic tank is allowed to flow into the anoxic tank and the aerobic tank in sequence through the water inlet pipe, and the sludge concentration in the anaerobic tank is controlled to be 10-50% of the sludge concentration in the anaerobic tank at the beginning of the water inlet; After the water inflow of the anaerobic tank of the separate water inflow process reaches a preset value, the return water inflow process is operated; When the return water inflow process is running, the anaerobic tank inlet valve and the agitator in the anaerobic tank are opened, so that the precipitated sludge in the sludge collecting bucket near the water inlet of the multi-bucket sedimentation tank is returned to the anaerobic tank, thereby making the sludge concentration in the anaerobic tank reach the sludge concentration in the anaerobic tank when the water inflow of the anaerobic tank begins; S2: The mud-water mixture discharged from the aerobic tank enters the multi-bucket sedimentation tank to obtain the precipitated sludge in the sludge collecting bucket near the water inlet of the multi-bucket sedimentation tank, the precipitated sludge in the sludge collecting bucket far from the water inlet of the multi-bucket sedimentation tank, and the supernatant.

6. The continuous flow aerobic granular sludge culture method according to claim 5 of the present application, wherein: The sludge concentration in the anaerobic tank at the beginning of water inflow is 2500-8000 mg / L; The preset value is 30%-60% of the volume of the anaerobic tank; The water inlet rising speed of the anaerobic tank in the separate water inlet process is greater than the sludge settling speed of the anaerobic tank. Preferably, the water inlet rising speed of the anaerobic tank in the separate water inlet process is 1m / h-7m / h; The method also includes adding a carbon source and a dephosphorization agent into the anaerobic tank when the separate water intake process is running. Preferably, the carbon source is at least one of sodium acetate, sodium propionate, glucose and methanol, and the dephosphorization agent is at least one of polyaluminum chloride, aluminum sulfate, ferric sulfate and polyaluminum ferric chloride.

7. The continuous flow aerobic granular sludge culture method according to claim 5 of the present application, wherein: The amount of the precipitated sludge in the sludge collecting bucket of the multi-bucket sedimentation tank that flows back to the anaerobic tank is 50%-200% of the water inflow of the anaerobic tank in the single water inflow process; The single-cycle operation time of the reflux water inlet process is 0.5-2 times the single-cycle operation time of the separate water inlet process.

8. The continuous flow aerobic granular sludge culture method according to claim 5 of the present application, wherein: The retention time of the anaerobic tank is 1-3 hours, the retention time of the anoxic tank is 1-5 hours, the retention time of the aerobic tank is 3-15 hours, and the retention time of the multi-bucket sedimentation tank is 1-3 hours.

9. The continuous flow aerobic granular sludge culture method according to claim 5 of the present application, wherein: A portion of the muddy-water mixture discharged from the aerobic tank is allowed to enter the multi-bucket sedimentation tank, and the remaining portion is sequentially refluxed to the anoxic tank through the nitrification liquid reflux pump and the nitrification liquid reflux pipe; The DO value of the aerobic pool is controlled at 0.5-4 mg / L; The amount of the muddy-water mixture returned from the aerobic tank to the anoxic tank is 100%-600% of the water inflow amount of the anaerobic tank in the separate water inflow process.

10. The continuous flow aerobic granular sludge culture method according to claim 5 of the present application, wherein: The method also includes discharging the precipitated sludge in the sludge collecting bucket in the multi-bucket sedimentation tank away from the water inlet of the multi-bucket sedimentation tank from the device through the sludge discharge branch pipe and the sludge discharge main pipe in sequence, and discharging the supernatant from the device through the drain pipe.

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