Variable hydraulic circulation mud film composite sequencing batch bioreactor and operation method thereof

Abstract

The invention discloses a variable hydraulic circulation mud film composite sequencing batch bioreactor and an operation method thereof, and relates to the technical field of sewage treatment.The variable hydraulic circulation mud film composite sequencing batch bioreactor comprises a variable hydraulic circulation reaction area and a variable reaction clarification area, and the bottoms of the variable hydraulic circulation reaction area and the variable reaction clarification area are communicated through a first vertical partition plate; the first vertical partition plate, the second vertical partition plate and the third vertical partition plate divide the variable hydraulic circulation reaction area into three reaction areas, the three reaction areas are communicated through the tops and the bottoms, and each reaction area is internally provided with fixed bed biological filler and an aerator; the water inlet pipe is arranged at the upper part of the first reaction zone, and the water inlet pipe is also connected with the dephosphorization and dosing mixing reactor; the moving bed biological carrier is arranged in the variable reaction clarification area, the bottom and the top of the moving bed biological carrier are respectively provided with an aerator and a siphon effluent weir, and the bottom of the variable reaction clarification area is connected with a sludge discharge pipe and a sludge discharge pump; the effective volume ratio of the first reaction zone to the second reaction zone to the third reaction zone to the variable reaction clarification zone is 1: (1-2): 1: 1.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and more specifically, relates to a variable hydraulic circulation mud membrane composite sequencing batch bioreactor and an operation method thereof. Background Art

[0002] Rural sewage treatment is an important part of my country's beautiful countryside construction. The state proposes that local people's governments at or above the county level should coordinate the planning and construction of sewage resource utilization infrastructure, promote sewage resource utilization, and give priority to the use of recycled water for greening. The water quality and water volume of rural sewage vary greatly, the site scale is small, the location is scattered, the operation is difficult to stabilize, and the management is difficult. In recent years, industry technicians have developed small and medium-sized applicable sewage resource utilization treatment technologies in a targeted manner. The traditional sequencing batch bioreactor (SBR) technology has the characteristics of an ideal plug flow reactor in time. By changing the timing, the removal effect of various pollutants can be achieved. The sedimentation timing is an ideal static sedimentation state. There is no need for sludge return and mixed liquor return systems. The treatment effect of difficult-to-degrade organic matter is good, and it has certain advantages. It has become one of the important applicable technologies for small and medium-sized sewage resource utilization. Since its birth, traditional SBR technology has developed into a variety of improved technologies. In order to adapt to the characteristics of urban sewage, improved technologies such as ICEAS, CASS, UNITANK, DAT-IAT, and MSBR have emerged one after another. Some of them have changed the ideal plug flow, some have destroyed the ideal sedimentation, and some have increased sludge return, all of which have weakened the technical advantages of traditional SBR to varying degrees. In order to adapt to the characteristics of rural sewage, the existing improvement methods mainly include changing the form of inlet and outlet water, increasing biological fillers to form activated sludge and biofilm composite technology to improve stability, enriching special bacteria by changing the operation method, and achieving energy saving and consumption reduction. However, these improvements still have practical problems that are difficult to solve to varying degrees.

[0003] The decanter is an important water outlet device of the traditional SBR technology, with a complex structure and poor reliability. It is difficult to maintain the application of small and medium-sized reactors. The existing patent discloses a decanter-free SBR technology, which adopts a structure in which water is inletted from the bottom of the central water distributor and the water is discharged from the fixed overflow weir on the upper periphery of the top support. The operation method is simplified to three time sequences: water inlet and outlet, aeration, and sedimentation and sludge discharge. It not only retains the completely mixed flow state, ideal plug flow and ideal sedimentation, but also has a simple structure, a relatively constant operating water level, fewer equipment, and higher reliability, which has played a certain role in promoting the application of SBR technology in small and medium-sized sewage treatment. However, the actual application of this patented technology has a high suspended solids (SS) in the effluent, which is difficult to stabilize below 20 mg / L, affecting the effluent compliance. The main reasons are the following two defects that are difficult to resolve: First, after the reactor's inlet and outlet sequence, if no precipitation measures are set, the aeration reaction sequence will disturb the water level and cause the mud-water mixture to overflow the effluent weir, resulting in a high effluent SS; Second, although the inlet and outlet method adopts the design method of a vertical flow sedimentation tank, the SBR inlet flow rate is difficult to control and difficult to stabilize, inevitably disturbing the sludge settled at the bottom of the tank. Even if the reactor is manufactured and installed to high standards, it is still difficult to ensure uniform water distribution, and it is easy to form local hydraulic short-flow, resulting in high effluent SS. In response to defect 1, there are two methods of precipitation in the prior art: one is to form a passage through the central water distributor, the SBR water inlet pipe slightly lower than the outlet weir, and the water inlet pump, so that part of the mixed liquid at the bottom of the pool flows back to the regulating tank to achieve precipitation, which will cause the loss of SBR sludge and is rarely used; the second method is to lead a precipitation pipe slightly lower than the top outlet weir at the upper end of the SBR, and the supernatant flows back to the regulating tank through the precipitation electric valve, avoiding the reflux of SBR sludge. Due to the limited installation conditions of the electric valve, the failure rate is high, and it is rarely used. In response to defect 2, in order to reduce the impact of hydraulic short-circuiting on the quality of the effluent, the prior art can only change the water distribution and outlet form, maintain a low SBR drainage ratio, and subsequently add a process link for removing SS, etc., which will increase equipment, reduce treatment efficiency, increase cost investment, and increase maintenance difficulty.

[0004] In summary, it is necessary to continue to innovate the existing decanter-free sequencing batch reactor and its operation method while retaining the existing advantages, to solve the problem of high SS in the effluent, and to form a new SBR technology that is more stable, has lower cost investment, can meet different resource utilization needs, and is easier to maintain. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies in the prior art and provide a variable hydraulic circulation mud membrane composite sequencing batch bioreactor and an operation method thereof to solve the problem of high suspended solids (SS) in the effluent, thereby forming a new SBR technology that is more stable, has a lower cost investment, can meet different resource utilization needs, and is easier to maintain.

[0006] In order to achieve the above object, the present invention provides a variable hydraulic circulation mud membrane composite sequencing batch bioreactor, comprising:

[0007] A variable hydraulic circulation reaction zone and a variable reaction clarification zone, a first vertical baffle is arranged between the two, and the variable hydraulic circulation reaction zone and the variable reaction clarification zone are connected through the bottom of the first vertical baffle;

[0008] The second vertical baffle and the third vertical baffle are arranged in the variable hydraulic circulation reaction zone, the second vertical baffle and the third vertical baffle divide the variable hydraulic circulation reaction zone into a first reaction zone, a second reaction zone and a third reaction zone, the first reaction zone, the second reaction zone and the third reaction zone are connected through the top and the bottom, the first reaction zone, the second reaction zone and the third reaction zone are respectively provided with fixed bed biological fillers, and the bottoms of the first reaction zone, the second reaction zone and the third reaction zone are respectively provided with a first microporous aerator, a second macroporous aerator and a third microporous aerator;

[0009] A water inlet pipe, one end of which is arranged at the upper part of the first reaction zone, and the other end of which is connected to the phosphorus removal and dosing mixing reactor;

[0010] A moving bed bio-carrier is arranged in the variable reaction and clarification zone, a fourth large-pore aerator and a siphon water outlet weir are respectively arranged at the bottom and the top of the moving bed bio-carrier, the siphon water outlet weir is connected to the water outlet pipe, and a mud discharge pipe and a mud discharge pump are connected to the bottom of the variable reaction and clarification zone;

[0011] The ratio of the effective volumes of the first reaction zone, the second reaction zone, the third reaction zone and the variable reaction clarification zone is 1:(1-2):1:1.

[0012] Optionally, the siphon water outlet weir includes a water outlet weir trough, a siphon pipe and a scum baffle, the siphon pipe includes a left vertical pipe and a right vertical pipe, the length ratio of the left vertical pipe to the right vertical pipe is (0.5-0.8):1, the distance between the lower end of the right vertical pipe and the bottom of the water outlet weir trough is 50-100 mm, and the water outlet pipe is 100-200 mm higher than the bottom of the water outlet weir trough.

[0013] Optionally, the first microporous aerator, the second macroporous aerator, the third microporous aerator and the fourth macroporous aerator are respectively connected to the first air source, the second air source, the third air source and the fourth air source, the first microporous aerator, the second macroporous aerator and the third microporous aerator are all higher than the lower ends of the second vertical baffle and the third vertical baffle, and the fourth macroporous aerator is higher than the lower end of the first vertical baffle.

[0014] Optionally, a first perforated filter plate and a second perforated filter plate are disposed in the middle of the variable reaction clarification zone, and the first perforated filter plate and the second perforated filter plate are disposed at the lower part and the upper part of the moving bed bio-carrier, respectively.

[0015] Optionally, the first perforated filter plate and the second perforated filter plate are in the form of circular hole plates or grid-shaped hole plates, the diameter of the circular holes of the circular hole plates is less than 15 mm, the grid spacing of the grid-shaped hole plates is less than 10 mm, the opening rate of the first perforated filter plate and the second perforated filter plate is greater than 60%, and the material of the first perforated filter plate and the second perforated filter plate is 304 stainless steel.

[0016] Optionally, the fixed bed biological filler is a vertically suspended combined fiber biological filler, the material of the fixed bed biological filler is one or more of polyethylene, polypropylene, and formaldehyde-chemical fiber, and the filling rate of the fixed bed biological filler is 60% to 80%.

[0017] Optionally, the moving bed bio-carrier is one or more of a columnar honeycomb suspended bio-carrier and a porous sponge suspended bio-carrier, the material of the moving bed bio-carrier is one or more of polyethylene, polypropylene, polyurethane, and calcium alginate, and the filling rate of the moving bed bio-carrier is greater than 40% to 70%.

[0018] The present invention also provides an operation method of a variable hydraulic circulation mud membrane composite sequencing batch bioreactor, using the variable hydraulic circulation mud membrane composite sequencing batch bioreactor, the operation method comprises:

[0019] After the variable hydraulic circulation mud film composite sequencing batch bioreactor completes the microbial startup culture and domestication and forms a system of activated sludge and filler biofilm symbiosis, it enters normal operation. The normal operation cycle includes A inlet and outlet water sequence, B precipitation sequence, C anoxic reaction sequence, D aerobic reaction sequence, E sedimentation sequence and F sludge discharge sequence. After the above six sequences are completed, it enters the next cycle and operates in a continuous cycle batch.

[0020] Optionally, A water inlet and outlet sequence: the water inlet pipe starts to inlet water, the second large-pore aerator aerates the second reaction zone to form an upward flow, the first reactor and the third reaction zone form a downward flow, and a large-scale hydraulic circulation on both sides is maintained; under the action of the inlet water, the variable reaction clarification zone forms an upward flow, and the moving bed biological carrier intercepts the activated sludge; at the same time, the water level increases from W1 to W2, the siphon pipe in the siphon outlet weir is gradually submerged, and the outlet weir groove and the siphon pipe in the siphon outlet weir both have water outlet, until the end of the water inlet and outlet sequence, the water inlet pipe stops inletting water; the water inlet and outlet sequence is maintained for 40 to 60 minutes;

[0021] B. Precipitation sequence: After the water inlet and outlet sequence ends, the second large-pore aerator maintains the operating state, the water level starts to decrease from W2, the water outlet weir stops discharging water, and the siphon continues to discharge water under the action of the right water seal and siphon of the siphon. When the water level drops to W1, the left water seal of the siphon is broken, and the water discharge stops completely until the precipitation sequence ends; the precipitation sequence is maintained for 2 to 8 minutes;

[0022] C. Anoxic reaction sequence: After the precipitation sequence ends, the second macroporous aerator maintains the running state, maintaining the dissolved oxygen in the variable hydraulic circulation reaction zone at 0.1-0.6 mg / L until the anoxic reaction sequence ends; the maintenance time of the anoxic reaction sequence is 10-60 minutes;

[0023] D Aerobic reaction sequence: After the anoxic reaction sequence ends, the first microporous aerator, the third microporous aerator and the fourth macroporous aerator aerate the first reaction zone, the third reaction zone and the variable reaction clarification zone, the second macroporous aerator stops running, the first reaction zone and the third reaction zone form an upward flow, the second reaction zone forms a downward flow, and a small-scale hydraulic cycle opposite to the previous one is maintained, and the dissolved oxygen in the variable hydraulic cycle reaction zone is maintained at 2-4 mg / L; the moving bed biological carrier and the trapped activated sludge begin to suspend and participate in the biological reaction; until the end of the aerobic reaction sequence; the maintenance time of the aerobic reaction sequence is 60-180 min;

[0024] E Sedimentation Sequence: After the aerobic reaction sequence ends, the first microporous aerator, the third microporous aerator and the fourth macroporous aerator stop running, the second macroporous aerator resumes running, the dissolved oxygen in the variable hydraulic circulation reaction zone is reduced to anoxic, the moving bed biological carrier in the variable reaction clarification zone stops suspending, and the activated sludge starts static sedimentation until the end of the sedimentation sequence; the sedimentation sequence is maintained for 30 to 60 minutes;

[0025] F Sludge discharge sequence: After the sedimentation sequence ends, the second large-pore aerator maintains the operating state, the dissolved oxygen in the variable hydraulic circulation reaction zone continues to decrease, the variable reaction clarification zone is completely clarified, the activated sludge is deposited at the bottom of the pool, the sludge discharge pump runs, and the activated sludge at the bottom of the pool is discharged through the sludge discharge pipe until the sludge discharge sequence ends, and the sludge discharge pump stops; the maintenance time of the sludge discharge sequence is 0 to 10 minutes.

[0026] The present invention provides a variable hydraulic circulation mud membrane composite sequencing batch bioreactor and an operation method thereof, which has the following beneficial effects:

[0027] 1. The sequencing batch bioreactor is provided with two vertical partitions in the variable hydraulic circulation reaction zone, which is divided into three reaction zones, and fixed bed biological fillers are respectively filled to form a composite activated sludge fixed bed biofilm reactor. By setting different independently controllable aerators and air sources, it can not only form a circulating flow, realize a completely mixed flow state, overcome the hydraulic short flow of the inlet and outlet sequence, reduce the hydraulic dead zone with low flow rate of the biochemical reactor, and stabilize the effluent water quality, but also control the operation of the air source, change the hydraulic circulation direction, realize the anoxic stirring and aeration oxygenation functions at different time sequences, and can be flexibly adjusted to realize various functions of removing carbon, nitrogen and phosphorus pollutants, improve the operation efficiency and reduce the operation cost;

[0028] 2. The sequencing batch bioreactor is provided with a moving bed biological filler between the upper and lower filter plates in the variable reaction clarification zone. By setting up independently controllable macroporous aerators and air sources, it can not only increase the sedimentation area of ​​the sedimentation sequence and ensure the SS removal effect of the effluent, but also form a composite activated sludge moving bed biofilm reactor by running the air source in the anoxic and aerobic reaction sequences, thereby further removing pollutants. At the same time, the sludge deposited inside the biological filler is cleaned, eliminating the filler backwashing system and increasing the volume utilization efficiency. The bottom sludge formed in the sedimentation sequence automatically flows back to the variable hydraulic circulation reaction zone, eliminating the reflux pump and reducing equipment investment and repair and maintenance.

[0029] 3. The sequencing batch bioreactor combines the composite activated sludge fixed bed biofilm reactor with the composite activated sludge moving bed biofilm reactor, so that the reactor as a whole has better biodiversity, higher stability of the biological system, and more obvious advantages in dealing with adverse conditions such as water quality shock, water volume shock, low temperature, toxic substances, etc.

[0030] 4. The sequencing batch bioreactor is provided with a siphon weir with a scum baffle above the variable reaction clarification zone. The precipitation is achieved through the siphon effect of the siphon tube, which can not only improve the water production efficiency and effectively avoid the problem of the sludge mixed liquid overflowing the effluent weir during the anoxic and aerobic reaction sequence, but also can prevent the influence of scum on the effluent SS together with the scum baffle;

[0031] 5. This sequencing batch bioreactor is suitable for small and medium-sized sewage treatment equipment. It has a simpler and more reliable overall structure, effectively avoids hydraulic short-circuiting, has lower investment cost, is easy to maintain, has flexible operation methods, has strong shock load tolerance, can adapt to seasonal changes, and cope with water inlet fluctuations. The effluent SS is stable below 15 mg / L, has higher operation efficiency, and meets a variety of effluent resource needs;

[0032] 6. In addition, operational assurance is a severe challenge currently faced by small and medium-sized sewage treatment systems. Gas source is a key equipment affecting operational assurance. The sequencing batch bioreactor is equipped with 4 independent gas sources, which is not only easy to flexibly adjust the gas supply to achieve energy saving, but also the failure of 1 to 2 of the gas sources can maintain the basic functions of the process system, and the operational assurance is higher; in addition, the sequencing batch bioreactor omits the reflux system and backwash system, further reducing the equipment failure rate and further improving the operational assurance.

[0033] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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.

[0035] Figure 1 A schematic structural diagram of a variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to an embodiment of the present invention is shown.

[0036] Figure 2 A flow chart showing an operation method of a variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to an embodiment of the present invention is shown.

[0037] Figure 3 A schematic structural diagram of a siphon weir according to an embodiment of the present invention is shown.

[0038] Description of reference numerals:

[0039] 1. Phosphorus removal and dosing mixing reactor; 2. Water inlet pipe; 3. Variable hydraulic circulation reaction zone; 301. First reaction zone; 302. Second reaction zone; 303. Third reaction zone; 304. Fixed bed biological filler; 4. Variable reaction clarification zone; 401. First perforated filter plate; 402. Moving bed biological carrier; 403. Second perforated filter plate; 5. Water outlet pipe; 6. First vertical partition plate; 7. Second vertical partition plate; 8. Third vertical partition plate; 9. Siphon outlet weir; 901. Outlet weir trough; 902. Siphon pipe; 903. Scum baffle; 10. First microporous aerator; 11. Second macroporous aerator; 12. Third microporous aerator; 13. Fourth macroporous aerator; 14. First air source; 15. Second air source; 16. Third air source; 17. Fourth air source; 18. Mud discharge pipe; 19. Mud discharge pump. DETAILED DESCRIPTION

[0040] 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.

[0041] like Figures 1 to 3 As shown, the variable hydraulic circulation mud film composite sequencing batch bioreactor specifically includes a phosphorus removal and dosing mixed reactor 1, a water inlet pipe 2, a variable hydraulic circulation reaction zone 3, a variable reaction clarification zone 4, and a water outlet pipe 5 connected in sequence, wherein a first vertical baffle 6 connected at the bottom is arranged between the variable hydraulic circulation reaction zone 3 and the variable reaction clarification zone 4, the variable hydraulic circulation reaction zone 3 includes a second vertical baffle 7 and a third vertical baffle 8, and the reaction zone is divided into a first reaction zone 301, a second reaction zone 302 and a third reaction zone 303 which are connected at the top and the bottom, the water inlet pipe 2 is connected to the upper part of the first reaction zone 301, and fixed bed biological fillers 304 are arranged in the three reaction zones, and a first microporous aerator 10, a second macroporous aerator 11, and a third microporous aerator 12 which are higher than the lower end of the baffle are respectively arranged at the bottom of the three reaction zones, and the three aerators are respectively connected to an independent first air source 14, a second air source 15 and a third air source 16; a first perforated aerator is arranged in the variable reaction clarification zone 4 The filter plate 401 and the second perforated filter plate 403 are provided with a moving bed biological carrier 402 between the two perforated filter plates, and a fourth large-pore aerator 13 higher than the lower end of the first vertical partition plate 6 is provided at the bottom, and the aerator is connected to an independent fourth gas source 17. A siphon water outlet weir 9 is provided at the upper part of the variable reaction clarification zone 4, connected to the water outlet pipe 5, and the bottom of the variable reaction clarification zone 4 is connected to the mud pump 19 through the mud discharge pipe 18; the siphon water outlet weir 9 is provided with a water outlet weir groove 901, a siphon pipe 902 and a scum retaining Plate 903, the number of siphon tubes is set according to the length of the outlet weir, all siphon tubes are spaced apart with a spacing of 50 to 100 mm, the length of the outlet weir is determined according to the water inlet flow rate, and the outlet weir load should be lower than 1.0 L / m / s, the ratio of the left vertical pipe to the right vertical pipe length is (0.5 to 0.8): 1, the lower end of the right vertical pipe is 5 to 10 mm away from the bottom of the outlet weir, and the bottom of the outlet pipe 5 is 100 to 200 mm higher than the bottom of the outlet weir 901.

[0042] In addition, the ratio of the effective volumes of the first reaction zone 301, the second reaction zone 302, the third reaction zone 303, and the variable reaction clarification zone 4 is 1:(1-2):1:1.

[0043] The fixed bed biofiller is in the form of vertically suspended combined fiber biofiller, made of one or more of polyethylene, polypropylene, and formaldehyde-based fiber, with a filling rate of 60% to 80%.

[0044] The moving bed bio-carrier is in the form of one or more of a columnar honeycomb suspended bio-carrier and a porous sponge suspended bio-carrier, and is made of one or more of polyethylene, polypropylene, polyurethane, and calcium alginate, with a specific gravity of 0.95-1.05, a particle size of 25-50 mm, and a filling rate of 40%-70%.

[0045] The first perforated filter plate 401 and the second perforated filter plate 403 are in the form of a circular perforated plate or a grid-shaped perforated plate. The opening rate of the perforated filter plate is greater than 60%, and the filter plate material can be selected from 304 stainless steel.

[0046] The second large-pore aerator 11 and the fourth large-pore aerator 13 can be in the form of an aeration perforated tube or a diffuser aerator, the aperture of the aeration perforated tube is 4-8 mm, and the wind speed at the orifice is 10-15 m / s; the first microporous aerator 10 and the third microporous aerator 12 can be in the form of a disc type, a tube type, or a tower type, and the material can be rubber, polyurethane, ceramic, or plastic; all air sources connected to the aerator need to meet the aeration intensity of 4-8 m 3 / m 2 / h.

[0047] The operation method of the variable hydraulic circulation mud film composite sequencing batch bioreactor is to enter normal operation only after the sequencing batch bioreactor completes the microbial startup culture and domestication, and forms a system of activated sludge and filler biofilm symbiosis. This normal operation cycle can be divided into six time sequences, namely A water inlet and outlet sequence, B precipitation sequence, C anoxic reaction sequence, D aerobic reaction sequence, E precipitation sequence, and F sludge discharge sequence. After the completion of these six time sequences, the next cycle is entered to achieve continuous cycle batch operation; when encountering strict water quality standards, high influent load or low temperature and other unfavorable conditions, the cycle can be extended, the operation sequence can be adjusted, and according to the needs of phosphorus removal, the phosphorus removal agent is injected before the phosphorus removal and dosing mixed reactor. The specific steps of the operation method are:

[0048] A. Inlet and outlet sequence: water starts to flow into the water inlet pipe, the first, third and fourth air sources stop running, the second air source starts running, the second large-pore aerator aerates the second reaction zone, forming an upward flow in the second reaction zone, thereby forming a downward flow in the first and third reaction zones, maintaining a large-scale hydraulic circulation on both sides; under the action of water inflow, an upward flow is also formed in the variable reaction clarification zone, and the moving bed biological carrier accumulates to form a fixed sedimentation filter bed for intercepting activated sludge, which can play a clarifying role; at the same time, the water level in the reactor increases from W1 to W2, the siphon is gradually submerged, and the outlet weir and siphon both have water outflow until the end of the inlet and outlet sequence, when the water inlet pipe stops flowing. This sequence generally lasts 40 to 60 minutes.

[0049] B Precipitation sequence: After the water inlet and outlet sequence ends, the air source and aerator operating status remain unchanged in the previous sequence, the water level starts to decrease from W2, and the water outflow from the water weir stops. Since the right vertical pipe outlet of the siphon is still under the water surface at this time, a water seal is formed, thereby forming a siphon effect, and the siphon continues to discharge water. When the water level drops to W1, the water seal on the left side of the siphon is destroyed, and the water outflow of the siphon stops completely until the precipitation sequence ends. This sequence generally lasts 2 to 8 minutes.

[0050] C Anoxic reaction sequence: After the precipitation sequence ends, all air sources and aerators maintain the same operating status as the previous sequence, and the dissolved oxygen in the variable hydraulic circulation reaction zone is maintained at 0.1-0.6 mg / L until the anoxic reaction sequence ends. This sequence generally lasts for 10-60 minutes.

[0051] D Aerobic reaction sequence: After the anoxic reaction sequence ends, the first, third, and fourth air sources start to operate, the second air source stops operating, the first and third microporous aerators aerate the first and third reaction zones, forming an upward flow in these two reaction zones, and a downward flow in the second reaction zone, maintaining a small-proportion hydraulic cycle opposite to the previous one (a large-proportion hydraulic cycle means that under the same air supply, when the second large-pore aerator aerates, the stirring effect is strong, while the oxygenation effect is weak, and the circulation driving force is large, resulting in a larger circulating water flow. When the first and third microporous aerators aerate, it is just the opposite, and the circulating water flow is relatively small.), maintaining the dissolved oxygen in the variable hydraulic circulation reaction zone at 2-4 mg / L; the fourth large-pore aerator aerates the variable reaction clarification zone, providing suspension power for the moving bed carrier, and the carrier and the trapped activated sludge begin to suspend and participate in the biological reaction; until the end of the aerobic reaction sequence. This sequence generally lasts for 60-180 minutes.

[0052] E Sedimentation Sequence: After the aerobic reaction sequence ends, the first, third, and fourth gas sources stop, the second gas source starts, the second reaction zone forms an upward flow, the first and third reaction zones form a downward flow, the dissolved oxygen in the variable hydraulic circulation reaction zone decreases to anoxic, the moving bed biological carrier in the variable reaction clarification zone stops suspending, and the activated sludge begins to statically precipitate until the end of the sedimentation sequence. This sequence generally lasts 30 to 60 minutes.

[0053] F Sludge discharge sequence: After the sedimentation sequence ends, the operation status of all air sources and aerators remains unchanged from the previous sequence, the dissolved oxygen in the variable hydraulic circulation reaction zone continues to decrease, the variable reaction clarification zone is completely clarified, the activated sludge is deposited at the bottom of the pool, the sludge discharge pump is running, and the activated sludge at the bottom of the pool is discharged through the sludge discharge pipe until the end of the sludge discharge sequence, when the sludge discharge pump stops. This sequence generally lasts 0 to 10 minutes.

[0054] The above operation steps can meet the needs of summer sewage recycling and miscellaneous water greening, while winter does not require greening. The operation method is adjusted to ornamental landscape water use, which requires nitrogen and phosphorus removal, and the cycle is extended to 6 hours. The operation sequence is adjusted to A→B→C→D→C→D→E→F, and the phosphorus removal agent is injected before the phosphorus removal and dosing mixed reactor. In addition, when entering the anoxic reaction sequence, this sequence lasts for 14 minutes in summer and 50 minutes in winter; when entering the aerobic reaction sequence, this sequence lasts for 140 minutes in summer and 87 minutes in winter.

[0055] The implementation effects of the present invention include: the drainage ratio is increased from 25% to 33%, the operation efficiency is high, the return pump is omitted, the investment cost is lower, and it is easier to maintain. In summer, the miscellaneous water greening standards for sewage recycling are stably met, and in winter, the water standards for ornamental landscape waterscapes for sewage recycling are stably met. The effluent SS is stably less than 10 mg / L, the operation method is flexible, and the impact load resistance is strong, which is suitable for small and medium-sized sewage resource treatment devices.

[0056] 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 variable hydraulic circulation mud membrane composite sequencing batch bioreactor, characterized in that: include: A variable hydraulic circulation reaction zone and a variable reaction clarification zone, a first vertical baffle is arranged between the two, and the variable hydraulic circulation reaction zone and the variable reaction clarification zone are connected through the bottom of the first vertical baffle; The second vertical baffle and the third vertical baffle are arranged in the variable hydraulic circulation reaction zone, the second vertical baffle and the third vertical baffle divide the variable hydraulic circulation reaction zone into a first reaction zone, a second reaction zone and a third reaction zone, the first reaction zone, the second reaction zone and the third reaction zone are connected through the top and the bottom, the first reaction zone, the second reaction zone and the third reaction zone are respectively provided with fixed bed biological fillers, and the bottoms of the first reaction zone, the second reaction zone and the third reaction zone are respectively provided with a first microporous aerator, a second macroporous aerator and a third microporous aerator; A water inlet pipe, one end of which is arranged at the upper part of the first reaction zone, and the other end of which is connected to the phosphorus removal and dosing mixing reactor; A moving bed bio-carrier is arranged in the variable reaction and clarification zone, a fourth large-pore aerator and a siphon water outlet weir are respectively arranged at the bottom and the top of the moving bed bio-carrier, the siphon water outlet weir is connected to the water outlet pipe, and a mud discharge pipe and a mud discharge pump are connected to the bottom of the variable reaction and clarification zone; The ratio of the effective volumes of the first reaction zone, the second reaction zone, the third reaction zone and the variable reaction clarification zone is 1:(1-2):1:

1.

2. The variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to claim 1 is characterized in that: The siphon water outlet weir includes a water outlet weir trough, a siphon pipe and a scum baffle, the siphon pipe includes a left vertical pipe and a right vertical pipe, the length ratio of the left vertical pipe to the right vertical pipe is (0.5-0.8):1, the distance between the lower end of the right vertical pipe and the bottom of the water outlet weir trough is 50-100 mm, and the water outlet pipe is 100-200 mm higher than the bottom of the water outlet weir trough.

3. The variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to claim 1, characterized in that: The first microporous aerator, the second macroporous aerator, the third microporous aerator and the fourth macroporous aerator are connected to the first air source, the second air source, the third air source and the fourth air source respectively. The first microporous aerator, the second macroporous aerator and the third microporous aerator are all higher than the lower ends of the second vertical baffle and the third vertical baffle, and the fourth macroporous aerator is higher than the lower end of the first vertical baffle.

4. The variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to claim 1, characterized in that: A first perforated filter plate and a second perforated filter plate are arranged in the middle of the variable reaction clarification zone. The first perforated filter plate and the second perforated filter plate are arranged at the lower part and the upper part of the moving bed bio-carrier respectively.

5. The variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to claim 4 is characterized in that: The first perforated filter plate and the second perforated filter plate are in the form of circular perforated plates or grid-shaped perforated plates, the diameter of the circular holes of the circular perforated plates is less than 15 mm, the grid spacing of the grid-shaped perforated plates is less than 10 mm, the opening rate of the first perforated filter plate and the second perforated filter plate is greater than 60%, and the material of the first perforated filter plate and the second perforated filter plate is 304 stainless steel.

6. The variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to claim 1, characterized in that: The fixed bed biological filler is a vertically suspended combined fiber biological filler, the material of the fixed bed biological filler is one or more of polyethylene, polypropylene, and aldehyde chemical fiber, and the filling rate of the fixed bed biological filler is 60% to 80%.

7. The variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to claim 1, characterized in that: The moving bed bio-carrier is one or more of a columnar honeycomb suspended bio-carrier and a porous sponge suspended bio-carrier. The material of the moving bed bio-carrier is one or more of polyethylene, polypropylene, polyurethane, and calcium alginate. The filling rate of the moving bed bio-carrier is greater than 40% to 70%.

8. A method for operating a variable hydraulic circulation mud membrane composite sequencing batch bioreactor, using the variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to any one of claims 1 to 7, characterized in that: The operation method includes: After the variable hydraulic circulation mud film composite sequencing batch bioreactor completes the microbial startup culture and domestication and forms a system of activated sludge and filler biofilm symbiosis, it enters normal operation. The normal operation cycle includes A inlet and outlet water sequence, B precipitation sequence, C anoxic reaction sequence, D aerobic reaction sequence, E sedimentation sequence and F sludge discharge sequence. After the above six sequences are completed, it enters the next cycle and operates in a continuous cycle batch.

9. The method for operating the variable hydraulic circulation mud membrane composite sequencing batch bioreactor according to claim 8, characterized in that: A. Inlet and outlet water sequence: water starts to flow into the water inlet pipe, the second large-pore aerator aerates the second reaction zone to form an upward flow, the first reactor and the third reaction zone form a downward flow, and a large-scale hydraulic circulation on both sides is maintained; under the action of the inlet water, the variable reaction clarification zone forms an upward flow, and the moving bed biological carrier intercepts the activated sludge; at the same time, the water level increases from W1 to W2, the siphon pipe in the siphon outlet weir is gradually submerged, and the outlet weir groove and the siphon pipe in the siphon outlet weir both have water outlet, until the end of the inlet and outlet water sequence, the water inlet pipe stops inletting; the maintenance time of the inlet and outlet water sequence is 40 to 60 minutes; B. Precipitation sequence: After the water inlet and outlet sequence ends, the second large-pore aerator maintains the operating state, the water level starts to decrease from W2, the water outlet weir stops discharging water, and the siphon continues to discharge water under the action of the right water seal and siphon of the siphon. When the water level drops to W1, the left water seal of the siphon is broken, and the water discharge stops completely until the precipitation sequence ends; the precipitation sequence is maintained for 2 to 8 minutes; C. Anoxic reaction sequence: After the precipitation sequence ends, the second macroporous aerator maintains the running state, maintaining the dissolved oxygen in the variable hydraulic circulation reaction zone at 0.1-0.6 mg / L until the anoxic reaction sequence ends; the maintenance time of the anoxic reaction sequence is 10-60 minutes; D Aerobic reaction sequence: After the anoxic reaction sequence ends, the first microporous aerator, the third microporous aerator and the fourth macroporous aerator aerate the first reaction zone, the third reaction zone and the variable reaction clarification zone, the second macroporous aerator stops running, the first reaction zone and the third reaction zone form an upward flow, the second reaction zone forms a downward flow, and a small-scale hydraulic cycle opposite to the previous one is maintained, and the dissolved oxygen in the variable hydraulic cycle reaction zone is maintained at 2-4 mg / L; the moving bed biological carrier and the trapped activated sludge begin to suspend and participate in the biological reaction; until the end of the aerobic reaction sequence; the maintenance time of the aerobic reaction sequence is 60-180 min; E Sedimentation Sequence: After the aerobic reaction sequence ends, the first microporous aerator, the third microporous aerator and the fourth macroporous aerator stop running, the second macroporous aerator resumes running, the dissolved oxygen in the variable hydraulic circulation reaction zone is reduced to anoxic, the moving bed biological carrier in the variable reaction clarification zone stops suspending, and the activated sludge starts static sedimentation until the end of the sedimentation sequence; the sedimentation sequence is maintained for 30 to 60 minutes; F Sludge discharge sequence: After the sedimentation sequence ends, the second large-pore aerator maintains the operating state, the dissolved oxygen in the variable hydraulic circulation reaction zone continues to decrease, the variable reaction clarification zone is completely clarified, the activated sludge is deposited at the bottom of the pool, the sludge discharge pump runs, and the activated sludge at the bottom of the pool is discharged through the sludge discharge pipe until the sludge discharge sequence ends, and the sludge discharge pump stops; the maintenance time of the sludge discharge sequence is 0 to 10 minutes.

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