Continuous flow sewage treatment system and method based on aerobic granular sludge

Abstract

The invention relates to a continuous flow sewage treatment system based on aerobic granular sludge, which comprises a sewage treatment tank, a pumping pipe network and an air blower, the sewage treatment tank is sequentially divided into a denitrification laminar flow area, an aerobic area, a settling area and a clarification area from bottom to top, and the bottom of the denitrification laminar flow area is provided with a water distribution pipe network; n disc type water distribution heads are mounted at the top end of the water distribution pipe network; an air distribution pipe network is mounted at the bottom of the aerobic zone, an air inlet of the air distribution pipe network is communicated with an air outlet of an air blower, and N square annular aeration heads are mounted at the top end of the air distribution pipe network; a sludge pumping pipe is mounted in the middle of the aerobic zone, the sludge pumping pipe is communicated with an aerobic sludge pumping pipe of a pumping pipe network, and a liquid outlet pipe of the pumping pipe network is communicated with an inlet of a water distribution pipe network; a group of up-flow bioreactors are mounted in the settling zone, a plurality of effluent weir tanks are mounted at the upper part of the clarifying zone, and a lower sludge discharge port and an upper sludge discharge port are mounted on the side wall of the sewage treatment tank. Raw water is continuously subjected to sewage treatment based on aerobic granular sludge in the sewage treatment tank.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and particularly relates to a continuous flow sewage treatment system and method based on aerobic granular sludge. Background Art

[0002] The existing integrated sewage treatment system based on aerobic granular sludge uses a motor-driven stirrer to stir and mix the aerobic granular sludge and raw water. Although the uniformity of the mixture of the aerobic granular sludge and the raw water after stirring and mixing is good, due to the large driving force of the stirring and mixing, the sludge after anaerobic and aerobic reactions cannot settle naturally. It is necessary to turn off the motor to stop the stirrer to make the sludge settle, and then the sludge and clear water are discharged. Therefore, the existing integrated sewage treatment system based on aerobic granular sludge has the problem of inability to operate continuously. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above problems existing in the prior art, and provide a continuous flow sewage treatment system based on aerobic granular sludge, and at the same time provide a continuous flow sewage treatment method based on aerobic granular sludge.

[0004] To achieve the above technical purposes and reach the above technical effects, the present invention is realized through the following technical solutions:

[0005] A continuous flow sewage treatment system based on aerobic granular sludge includes a sewage treatment tank, a pumping pipe network for mixing and pumping raw water and aerobic granular sludge, and a blower for increasing the oxygen in the water. The sewage treatment tank is divided into a denitrification laminar flow area, an aerobic area, a sedimentation area, and a clarification area from bottom to top according to functions.

[0006] A water distribution pipe network is installed at the bottom of the denitrification laminar flow area, and the top of the water distribution pipe network is installed with N disk-shaped water distributors for making the mixed liquid flow in a laminar flow state from bottom to top in the denitrification laminar flow area.

[0007] A grid-shaped air distribution pipe network is installed at the bottom of the aerobic area. The air inlet of the air distribution pipe network is connected to the air outlet of the blower. The top of the air distribution pipe network is installed with N square-ring-shaped aeration heads for promoting the vertical upward flow of water and increasing oxygen. A disk-shaped water distributor corresponds to the lower part of each square-ring-shaped aeration head, and the square-ring-shaped aeration head and the disk-shaped water distributor are coaxial.

[0008] A sludge extraction pipe is installed in the middle of the aerobic area. The sludge extraction pipe is connected to the aerobic sludge extraction pipe of the pumping pipe network. The liquid outlet pipe of the pumping pipe network is connected to the inlet of the water distribution pipe network. The raw water extraction pipe of the pumping pipe network is connected to a raw water tank for storing raw water.

[0009] A group of upflow bioreactors for promoting sludge sedimentation are installed in the sedimentation area. A plurality of effluent weir tanks connected in series by drain pipes are installed in the upper part of the clarification area. A lower sludge discharge port communicated with the denitrification laminar flow area and an upper sludge discharge port communicated with the aerobic area are installed on the side wall of the sewage treatment tank.

[0010] Among them, the pumping pipe network includes a denitrification power pump, a raw water pump, a spiral water mixer, an aerobic sludge extraction pipe, an aerobic sludge pumping pipe, a raw water extraction pipe, a raw water pumping pipe, and a liquid outlet pipe. The inlet of the denitrification power pump is communicated with the aerobic sludge extraction pipe, and the outlet of the denitrification power pump is communicated with the sludge inlet of the spiral water mixer through the aerobic sludge pumping pipe; the inlet of the raw water pump is communicated with the raw water extraction pipe, and the outlet of the raw water pump is communicated with the raw water inlet of the spiral water mixer through the raw water pumping pipe; the liquid outlet of the spiral water mixer is communicated with the liquid outlet pipe.

[0011] Among them, a first check valve for preventing the mixed liquid from flowing back to the denitrification power pump is installed on the aerobic sludge pumping pipe, and a second check valve for preventing the mixed liquid from flowing back to the raw water pump is installed on the raw water pumping pipe.

[0012] Among them, the spiral water mixer includes a water mixing cylinder, a movable support ring, an end cover, and a rotating shaft. The center of the head of the water mixing cylinder is the liquid outlet. A sludge inlet is arranged on one side of the tail of the water mixing cylinder. The center of the end cover is the raw water inlet. A fixed support ring is arranged in the head of the water mixing cylinder. The movable support ring and the end cover are installed at the tail end of the water mixing cylinder. The rotating shaft is rotatably installed between the movable support ring and the fixed support ring. Spiral blades are fixedly connected to the outside of the rotating shaft.

[0013] Among them, the disc-shaped water distribution head includes a disc-shaped tray, a circular rubber block, and a hoop. The rubber block covers the orifice at the top of the tray. The edge of the rubber block is fixed on the outer side wall of the tray through the hoop. An externally threaded pipe extending downward is arranged at the center of the bottom of the tray. The externally threaded pipe is screwed with the screw hole on the water distribution pipe network. A plurality of uniformly distributed "*"-shaped water distribution orifices are opened on the rubber block.

[0014] Among them, the square-ring-shaped aeration head includes a square-ring-shaped mounting seat, a square-ring-shaped pressing ring, and four microporous aeration membrane sheets. The pressing ring is stuck on the top of the mounting seat. The four microporous aeration membrane sheets are respectively sandwiched between the pressing ring and the mounting seat. A square-ring-shaped air flow channel is formed between the mounting seat, the pressing ring, and the microporous aeration membrane sheets. A hook plate and an insertion pipe extending downward are arranged at the bottom of the mounting seat. The hook plate is stuck on the air distribution pipe network. The insertion pipe is in plug-in fit with the socket opened on the air distribution pipe network. A one-way valve for preventing water from flowing back to the air distribution pipe network is installed in the insertion pipe.

[0015] Among them, the microporous aeration membrane sheets are all inclined at an angle of 45° towards the center of the square-ring-shaped aeration head.

[0016] Among them, the upflow bioreactor includes a gas collection ring arranged along the inner wall of the sewage treatment tank, M first separation covers with a cross-section in the shape of "∧", and M second separation covers with a cross-section in the shape of "∧". The first separation covers and the second separation covers are respectively installed in the middle of the gas collection ring. The first separation covers and the second separation covers are arranged alternately. A gap for water supply and sludge passage is provided between each first separation cover and the corresponding second separation cover. The first separation covers and the second separation covers are respectively communicated with the gas collection ring. An exhaust pipe is provided at the top of the gas collection ring. The tops of the first separation covers, the tops of the second separation covers, and the top of the gas collection ring are located on the same horizontal plane. The bottom end of the first side wall of the first separation cover is flush with the bottom end of the gas collection ring. The height of the second side wall of the first separation cover is half of the height of the gas collection ring. The height of the second separation cover is one-fourth of the height of the gas collection ring.

[0017] Among them, the height ratio of the denitrification laminar flow zone, the aerobic zone, the sedimentation zone, and the clarification zone is 7:6:2:5.

[0018] A continuous-flow sewage treatment method based on aerobic granular sludge, using the above continuous-flow sewage treatment system, includes the following steps:

[0019] S1. Start the pumping pipeline network to evenly mix the aerobic granular sludge in the aerobic zone with the raw water after pretreatment to form a mixed liquid, and pump the mixed liquid into the water distribution pipeline network. Then, the mixed liquid is continuously distributed into the denitrification laminar flow zone through the disc-shaped water distribution head. The mixed liquid flowing out from the water distribution ports of the disc-shaped water distribution head forms ascending columnar regions, and in each columnar region, the mixed liquid flows upward in a laminar state from bottom to top, and denitrification reactions are carried out layer by layer to produce biochemical sludge, and the biochemical sludge is screened by the shear force between adjacent laminar raw waters.

[0020] S2. The mixed liquid after the denitrification reaction continues to flow upward into the aerobic zone in a laminar state under the air-lifting force of the gas released by the square-ring-shaped aeration head. And the gas released by the square-ring-shaped aeration head is mixed with the mixed liquid to increase the oxygen content in the mixed liquid, so that the nitrifying bacteria in the mixed liquid carry out nitrification reactions under aerobic conditions to form supernatant and biochemical sludge. The blower is periodically turned off and the upper sludge discharge port is opened to discharge the biochemical sludge accumulated in the aerobic zone.

[0021] S3. The supernatant continues to flow upward into the sedimentation zone under the push of hydraulic force and aeration air flow. Under the separation action of the upflow bioreactor, the gas in the supernatant is collected and discharged, the biochemical sludge precipitates and falls into the aerobic zone and the denitrification laminar flow zone, and the clear water continues to flow upward into the clarification zone.

[0022] S4. The biochemical sludge carried in the clear water falls into the upflow bioreactor under the action of gravity, and the clarified clear water overflows into the effluent weir trough and flows out.

[0023] The beneficial effects of the present invention are as follows: By cooperating with the denitrification dynamic pump, the raw water pump, the first pipeline, the second pipeline, and the third pipeline, the aerobic granular sludge in the aerobic zone is sent into the water distribution system for primary mixing with the raw water. The raw water carrying the aerobic granular sludge is evenly distributed into the denitrification laminar flow zone through the water distribution system for secondary mixing, so that the aerobic granular sludge is continuously mixed with the raw water; An upflow bioreactor is installed in the sedimentation zone to promote the reaction of the raw water and the sedimentation of the sludge, and the upflow bioreactor is used to separate the clarification zone from the aerobic zone, reducing the disturbance of aeration on the sludge sedimentation in the clarification zone; The above two points cooperate to enable continuous-flow sewage treatment based on aerobic granular sludge in the sewage treatment tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 is a schematic structural diagram of the sewage treatment system in the present invention;

[0026] Figure 2 is a schematic top-view structural diagram of the combined state of the disk water distributor, the air distribution pipe network, and the square-ring-shaped aeration head in the present invention;

[0027] Figure 3 is a schematic structural diagram of the pumping pipe network in the present invention;

[0028] Figure 4 is a schematic structural diagram of the spiral water mixer in the present invention;

[0029] Figure 5 is a schematic side-view structural diagram of the combined state of the water distribution pipe network and the disk water distributor in the present invention;

[0030] Figure 6 is a schematic structural diagram of the disk water distributor in the present invention;

[0031] Figure 7 is a schematic side-view structural diagram of the combined state of the air distribution pipe network and the square-ring-shaped aeration head in the present invention;

[0032] Figure 8 is a schematic structural diagram of the square-ring-shaped aeration head in the present invention;

[0033] Figure 9 is a schematic structural diagram of the upflow bioreactor in the present invention;

[0034] Description of reference numerals in the figure: sewage treatment tank 1, denitrification laminar flow area 11, aerobic zone 12, sedimentation zone 13, clarification zone 14, lower sludge discharge port 15, upper sludge discharge port 16, pumping pipe network 2, denitrification power pump 21, raw water pump 22, spiral water mixer 23, water mixing cylinder 231, movable support ring 232, end cover 233, rotating shaft 234, liquid outlet 235, sludge inlet 236, raw water inlet 237, fixed support ring 238, spiral blade 239, aerobic sludge extraction pipe 24, aerobic sludge pumping pipe 25, first check valve 251, raw water extraction pipe 26, raw water pumping pipe 27, second check valve 271, liquid outlet pipe 28, water distribution pipe network 3, disc-shaped water distribution head 4, tray 41, rubber block 42, water distribution port 421, hoop 43, external threaded pipe 44, air distribution pipe network 5, square ring-shaped aeration head 6, mounting seat 61, pressure ring 62, microporous aeration membrane 63, hook plate 64, insertion pipe 65, sludge extraction pipe 7, upflow bioreactor 8, gas collection ring 81, first separation cover 82, second separation cover 83, exhaust pipe 84, drain pipe 91, water outlet weir trough 92. Detailed implementation mode

[0035] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0036] As Figures 1 to 9 shown, a continuous flow sewage treatment system based on aerobic granular sludge includes a sewage treatment tank 1, a pumping pipe network 2 for mixing and pumping raw water and aerobic granular sludge, and a blower for increasing the oxygen in the water.

[0037] In the sewage treatment tank 1, it is divided into a denitrification laminar flow area 11, an aerobic zone 12, a sedimentation zone 13, and a clarification zone 14 in sequence from bottom to top according to functions. The height ratio of the denitrification laminar flow area 11, the aerobic zone 12, the sedimentation zone 13, and the clarification zone 14 is 7:6:2:5.

[0038] As Figure 3 shown, the pumping pipe network 2 includes a denitrification power pump 21, a raw water pump 22, a spiral water mixer 23, an aerobic sludge extraction pipe 24, an aerobic sludge pumping pipe 25, a raw water extraction pipe 26, a raw water pumping pipe 27, and a liquid outlet pipe 28. The inlet of the denitrification power pump 21 is communicated with the aerobic sludge extraction pipe 24, and the outlet of the denitrification power pump 21 is communicated with the sludge inlet of the spiral water mixer 23 through the aerobic sludge pumping pipe 25. A first check valve 251 for preventing the mixed liquid from flowing back to the denitrification power pump 21 is installed on the aerobic sludge pumping pipe 25; the inlet of the raw water pump 22 is communicated with the raw water extraction pipe 26, and the outlet of the raw water pump 22 is communicated with the raw water inlet of the spiral water mixer 23 through the raw water pumping pipe 27. A second check valve 271 for preventing the mixed liquid from flowing back to the raw water pump 22 is installed on the raw water pumping pipe 27; the liquid outlet of the spiral water mixer 23 is communicated with the liquid outlet pipe 28.

[0039] AsFigure 4 As shown in the figure, the spiral water mixer 23 includes a water mixing cylinder 231, a movable support ring 232, an end cover 233, and a rotating shaft 234. The center of the head of the water mixing cylinder 231 is a liquid outlet 235. A sludge inlet 236 is provided on one side of the tail of the water mixing cylinder 231. A raw water inlet 237 is provided at the center of the end cover 233. A fixed support ring 238 is provided in the head of the water mixing cylinder 231. The movable support ring 232 and the end cover 233 are installed at the tail end of the water mixing cylinder 231. The rotating shaft 234 is rotatably installed between the movable support ring 232 and the fixed support ring 238. A spiral blade 239 is fixedly connected to the outside of the rotating shaft 234.

[0040] At the same time, the raw water pump and the denitrification power pump are started. The raw water after pretreatment is continuously pumped into the spiral water mixer by the raw water pump, and the aerobic granular sludge in the aerobic zone is continuously pumped into the spiral water mixer by the denitrification power pump. And the spiral blade rotates under the action of the water flow impact, so that the aerobic granular sludge and the raw water are evenly mixed to form a mixed liquid. Then, the mixed liquid is continuously distributed into the denitrification laminar flow zone through the water distribution pipe network and the disc-shaped water distribution head. The mixed liquid flowing out of the water distribution ports of each disc-shaped water distribution head forms an ascending columnar area, and the raw water in each columnar area flows in a laminar state from bottom to top, and the denitrification reaction is carried out layer by layer to produce biochemical sludge, and the biochemical sludge is screened by the shear force between the adjacent laminar raw water.

[0041] As Figure 1 and Figure 5 shown, a water distribution pipe network 3 is installed at the bottom of the denitrification laminar flow zone 11, and 64 disc-shaped water distribution heads 4 for making the mixed liquid flow in a laminar state from bottom to top in the denitrification laminar flow zone are installed at the top of the water distribution pipe network 3.

[0042] Among them, as Figure 6 shown, the disc-shaped water distribution head 4 includes a disc-shaped tray 41, a circular rubber block 42, and a hoop 43. The rubber block 42 covers the orifice at the top of the tray 41, and the edge of the rubber block 42 is fixed to the outer side wall of the tray 41 through the hoop 43. A downward-extending external threaded pipe 44 is provided at the center of the bottom of the tray 41, and the external threaded pipe 44 is screwed into the screw hole on the water distribution pipe network 3. A plurality of uniformly distributed "*"-shaped water distribution ports 421 are opened on the rubber block 42.

[0043] As Figure 1 , Figure 2 and Figure 7As shown in the figure, a grid-shaped air distribution pipe network 5 is installed at the bottom of the aerobic zone 12. The air inlet of the air distribution pipe network 5 is connected to the air outlet of the blower. At the top of the air distribution pipe network 5, 64 square annular aeration heads 6 for promoting the vertical upward flow of water and increasing oxygen are installed. A disc-shaped water distribution head 4 corresponds to the position directly below each square annular aeration head 6, and the square annular aeration head 6 and the disc-shaped water distribution head 4 are coaxial. The diameter of the disc-shaped water distribution head 4 is smaller than the inner side length of the square annular aeration head 6.

[0044] As Figure 8 shown in the figure, the square annular aeration head 6 includes a square annular mounting seat 61, a square annular pressing ring 62, and four microporous aeration diaphragms 63. The pressing ring 62 is stuck on the top of the mounting seat 61, and the four microporous aeration diaphragms 63 are respectively sandwiched between the pressing ring 62 and the mounting seat 61. A square annular air flow channel is formed between the mounting seat 61, the pressing ring 62, and the microporous aeration diaphragms 63. A hook plate 64 and an insertion tube 65 extending downward are provided at the bottom of the mounting seat 61. The hook plate 64 is stuck on the air distribution pipe network 5, and the insertion tube 65 is in plug-and-play fit with the socket provided on the air distribution pipe network 5. A one-way valve for preventing water from flowing back to the air distribution pipe network 5 is installed in the insertion tube 65; and the microporous aeration diaphragms 63 are all inclined at an angle of 45° towards the center of the square annular aeration head.

[0045] As Figure 1 shown in the figure, a sludge extraction pipe 7 is installed in the middle of the aerobic zone 12. The sludge extraction pipe 7 is connected to the aerobic sludge extraction pipe of the pumping pipe network 2. The liquid outlet pipe of the pumping pipe network 2 is connected to the inlet of the water distribution pipe network. The raw water extraction pipe of the pumping pipe network 2 is connected to the raw water tank for storing raw water.

[0046] As Figure 1 and Figure 9As shown in the figure, a group of upflow bioreactors 8 for promoting sludge sedimentation are installed in the sedimentation zone 13. The upflow bioreactor 8 includes a gas collection ring 81 arranged along the inner wall of the sewage treatment tank, 11 first separation covers 82 with a cross-section in the shape of "∧", and 11 second separation covers 83 with a cross-section in the shape of "∧". The first separation covers 82 and the second separation covers 83 are respectively installed in the middle of the gas collection ring 81. The first separation covers 82 and the second separation covers 83 are arranged alternately. There are gaps for water and sludge to pass between the first separation covers 82 and the second separation covers 83. The first separation covers 82 and the second separation covers 83 are respectively communicated with the gas collection ring 81. An exhaust pipe 84 is arranged at the top of the gas collection ring 81; the top ends of the first separation covers 82, the top ends of the second separation covers 83, and the top end of the gas collection ring 81 are on the same horizontal plane. The bottom end of the first side wall of the first separation cover 82 is flush with the bottom end of the gas collection ring 81. The height of the second side wall of the first separation cover 82 is half of the height of the gas collection ring 81. The height of the second separation cover 83 is one-fourth of the height of the gas collection ring. Installing an upflow bioreactor in the sedimentation zone promotes the reaction of raw water and sludge sedimentation, and uses the upflow bioreactor to separate the clarification zone from the aerobic zone, reducing the disturbance of aeration on the sludge sedimentation in the clarification zone.

[0047] As Figure 1 shown, a plurality of effluent weir troughs 92 connected in series by drain pipes 91 are installed in the upper part of the clarification zone 14.

[0048] As Figure 1 shown, a lower sludge discharge port 15 communicated with the denitrification laminar flow zone 11 and an upper sludge discharge port 16 communicated with the aerobic zone 12 are installed on the side wall of the sewage treatment tank 1. The excess sludge is discharged through the lower sludge discharge port 15 or the upper sludge discharge port 16 according to the sludge volume in the sewage treatment tank.

[0049] A continuous flow sewage treatment method based on aerobic granular sludge, using the above continuous flow sewage treatment system, includes the following steps:

[0050] S1. Start the pumping pipe network to evenly mix the aerobic granular sludge in the aerobic zone with the pretreated raw water to form a mixed liquid and pump it into the distribution pipe network. Then, the mixed liquid is continuously distributed into the denitrification laminar flow zone through the disk-shaped water distribution head. The mixed liquid flowing out of the water distribution ports of the disk-shaped water distribution head forms rising columnar regions, and in each columnar region, the mixed liquid flows upward in a laminar state from bottom to top, and denitrification reactions are carried out layer by layer to generate biochemical sludge, and the biochemical sludge is screened by the shear force between adjacent laminar raw waters;

[0051] S2. The mixed liquid after the denitrification reaction continues to flow upward into the aerobic zone in a laminar flow state under the air-lifting force of the gas released by the square annular aeration head. Moreover, the gas released by the square annular aeration head mixes with the mixed liquid to increase the oxygen content in the mixed liquid, enabling the nitrifying bacteria in the mixed liquid to carry out nitrification reactions under aerobic conditions to form supernatant and biochemical sludge. The blower is periodically turned off and the upper sludge discharge port is opened to discharge the biochemical sludge accumulated in the aerobic zone.

[0052] S3. The supernatant continues to flow upward into the sedimentation zone under the push of hydraulic force and aeration air flow. Under the separation action of the upflow bioreactor, the gas in the supernatant is collected and discharged, the biochemical sludge precipitates and falls into the aerobic zone and the denitrification laminar flow zone, and the clear water continues to flow upward into the clarification zone.

[0053] S4. The biochemical sludge carried in the clear water falls into the upflow bioreactor under the action of gravity, and the clarified clear water overflows into the effluent weir trough and flows out.

[0054] This continuous-flow sewage treatment system based on aerobic granular sludge enables the raw water to continuously undergo continuous-flow sewage treatment based on aerobic granular sludge in the sewage treatment tank.

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A continuous flow sewage treatment system based on aerobic granular sludge, characterized by: It includes a sewage treatment pool, a pumping network for mixing raw water and aerobic granular sludge, and a blower for increasing oxygen in the water. The sewage treatment pool is divided into a denitrification laminar flow zone, an aerobic zone, a sedimentation zone, and a clarification zone from bottom to top according to function. A water distribution network is installed at the bottom of the denitrification laminar flow zone, and N disc-type water distribution heads are installed at the top of the water distribution network for making the mixed liquid flow in a laminar flow state from bottom to top in the denitrification laminar flow zone; A grid-type air distribution network is installed at the bottom of the aerobic zone, the air inlet of the air distribution network is connected to the air outlet of the blower, and N square ring-shaped aeration heads for promoting vertical upward flow of water and increasing oxygen are installed at the top of the air distribution network. There is a disc-type water distribution head directly below each of the square ring-shaped aeration heads, and the square ring-shaped aeration heads are coaxial with the disc-type water distribution heads; A sludge extraction pipe is installed in the middle of the aerobic zone, the sludge extraction pipe is connected to the aerobic sludge extraction pipe of the pumping network, the liquid outlet pipe of the pumping network is connected to the inlet of the water distribution network, and the raw water extraction pipe of the pumping network is connected to the raw water tank for storing raw water; A group of upflow bioreactors for promoting sludge sedimentation are installed in the sedimentation zone, a plurality of water outlet weirs connected in series through drainage pipes are installed on the upper part of the clarification zone, and a lower sludge outlet connected to the denitrification laminar flow zone and an upper sludge outlet connected to the aerobic zone are installed on the side wall of the sewage treatment tank.

2. The continuous flow sewage treatment system according to claim 1, characterized in that: The pumping pipe network includes a denitrification power pump, a raw water pump, a spiral water mixer, an aerobic sludge extraction pipe, an aerobic sludge pumping pipe, a raw water extraction pipe, a raw water pumping pipe, and a liquid outlet pipe. The inlet of the denitrification power pump is connected to the aerobic sludge extraction pipe, and the outlet of the denitrification power pump is connected to the sludge inlet of the spiral water mixer through the aerobic sludge pumping pipe; the inlet of the raw water pump is connected to the raw water extraction pipe, and the outlet of the raw water pump is connected to the raw water inlet of the spiral water mixer through the raw water pumping pipe; the liquid outlet of the spiral water mixer is connected to the liquid outlet pipe.

3. The continuous flow sewage treatment system according to claim 2, characterized in that: The aerobic sludge pumping pipe is provided with a first check valve to prevent the mixed liquid from flowing back to the denitrification power pump, and the raw water pumping pipe is provided with a second check valve to prevent the mixed liquid from flowing back to the raw water pump.

4. The continuous flow sewage treatment system according to claim 2, characterized in that: The spiral water mixer includes a water mixing cylinder, a movable support ring, an end cover, and a rotating shaft. The center of the head of the water mixing cylinder is a liquid outlet, a sludge inlet is arranged on one side of the tail of the water mixing cylinder, a raw water inlet is arranged at the center of the end cover, a fixed support ring is arranged in the head of the water mixing cylinder, the movable support ring and the end cover are installed at the tail end of the water mixing cylinder, the rotating shaft is rotatably installed between the movable support ring and the fixed support ring, and a spiral blade is fixedly connected to the outside of the rotating shaft.

5. The continuous flow sewage treatment system according to claim 1, characterized in that: The disc-type water distribution head includes a disc-shaped tray, a round rubber block, and a clamp. The rubber block covers the tray opening at the top of the tray. The edge of the rubber block is fixed to the outer wall of the tray through the clamp. A downwardly extending external threaded pipe is provided at the bottom center of the tray. The external threaded pipe is screwed to the screw hole on the water distribution pipe net. The rubber block is provided with a plurality of evenly distributed "*"-shaped water distribution ports.

6. The continuous flow sewage treatment system according to claim 1, characterized in that: The square ring-shaped aeration head comprises a square ring-shaped mounting seat, a square ring-shaped pressure ring, and four microporous aeration membranes. The pressure ring is clamped on the top of the mounting seat. The four microporous aeration membranes are respectively clamped between the pressure ring and the mounting seat. A square ring-shaped airflow channel is formed between the mounting seat, the pressure ring, and the microporous aeration membranes. A downwardly extending hook plate and a plug are provided at the bottom of the mounting seat. The hook plate is clamped on the air distribution pipe network. The plug is plug-in-plug-matched with a socket provided on the air distribution pipe network. A one-way valve is installed in the plug to prevent water from flowing back into the air distribution pipe network.

7. The continuous flow sewage treatment system according to claim 5, characterized in that: The microporous aeration membranes are all inclined at an angle of 45° toward the center of the square annular aeration head.

8. The continuous flow sewage treatment system according to claim 1, characterized in that: The upflow bioreactor includes an air collecting ring arranged along the inner wall of the sewage treatment tank, M first separation hoods with "∧"-shaped cross sections, and M second separation hoods with "∧"-shaped cross sections. The first separation hood and the second separation hood are respectively installed in the middle of the air collecting ring, and the first separation hood and the second separation hood are arranged alternately. Gaps for water supply and sludge passage are provided between the first separation hood and the second separation hood. The first separation hood and the second separation hood are respectively connected to the air collecting ring, and an exhaust pipe is provided on the top of the air collecting ring; the top of the first separation hood, the top of the second separation hood, and the top of the air collecting ring are located on the same horizontal plane, the bottom end of the first side wall of the first separation hood is flush with the bottom end of the air collecting ring, the height of the second side wall of the first separation hood is half of the height of the air collecting ring, and the height of the second separation hood is one quarter of the height of the air collecting ring.

9. The continuous flow sewage treatment system according to claim 1, characterized in that: The height ratio of the denitrification laminar flow zone, the aerobic zone, the sedimentation zone and the clarification zone is 7:6:2:

5.

10. A continuous flow sewage treatment method based on aerobic granular sludge, using the continuous flow sewage treatment system according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Start the pumping network to evenly mix the aerobic granular sludge in the aerobic zone with the pretreated raw water to form a mixed liquid, which is then pumped into the water distribution network. The mixed liquid is then continuously distributed to the denitrification laminar flow zone through the disc water distribution head. The mixed liquid flowing out of the water distribution port of the disc water distribution head forms a series of rising columnar areas. In each columnar area, the mixed liquid flows from bottom to top in a laminar flow state, and denitrification reaction is carried out in layers to produce biochemical sludge. The biochemical sludge is screened by shear force between adjacent laminar raw waters. S2. The mixed liquid after denitrification reaction continues to flow upward into the aerobic zone in a laminar flow state under the action of the gas lift force of the gas released by the square ring aeration head, and the gas released by the square ring aeration head mixes with the mixed liquid to increase the oxygen content in the mixed liquid, so that the nitrifying bacteria in the mixed liquid undergo nitrification reaction under aerobic conditions to form supernatant and biochemical sludge. The blower is turned off at a fixed time and the upper sludge discharge port is opened to discharge the biochemical sludge accumulated in the aerobic zone; S3, the supernatant continues to flow upward into the sedimentation zone under the impetus of hydraulic power and aeration airflow, and the gas in the supernatant is collected and discharged under the separation effect of the upflow bioreactor, the biochemical sludge precipitates and falls into the aerobic zone and the denitrification laminar flow zone, and the clean water continues to flow upward into the clarification zone; S4. The biochemical sludge carried in the clean water falls into the upflow bioreactor under the action of gravity, and the clarified clean water overflows into the outlet weir and flows out.

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