CN215559686U

CN215559686U - Novel circular integrated biogas slurry treatment system

Info

Publication number: CN215559686U
Application number: CN202120332817.4U
Authority: CN
Inventors: 梁峰; 丁然; 陈孟园; 陈为政; 汪文丽
Original assignee: Water And Environmental Technology R & D Center Of Jiangsu Yancheng Environmental Protection Science And Technology City
Current assignee: Water And Environmental Technology R & D Center Of Jiangsu Yancheng Environmental Protection Science And Technology City; Zhongke Ecological Environment Engineering Design (Jiangsu) Co.,Ltd.
Priority date: 2021-02-05
Filing date: 2021-02-05
Publication date: 2022-01-18
Anticipated expiration: 2031-02-05

Abstract

The utility model provides a novel circular integrated biogas slurry treatment system, which comprises the following components in sequence from inside to outside: shallow air flotation, two-stage AO biological reaction tank, MBR, composite oxidation coagulation tank, sedimentation tank. COD, ammonia nitrogen and total nitrogen in the biogas slurry are efficiently removed through a technical group. Colloid and suspended particles in the biogas slurry are removed by shallow air flotation, so that the influence of suspended matters in the biogas slurry on a subsequent biochemical system is reduced; the two-stage AO system adopts a circular ring structure, an internal reflux pump is not needed, the energy consumption is reduced, and the removal rate of organic matters and total nitrogen is improved; the biochemical tank is internally provided with the filler, MBR (membrane bioreactor) is adopted for yielding water, so that the quality of the yielding water can be improved, and the mud yield can be reduced; the advanced treatment adopts a composite oxidation coagulation device, polymeric ferric sulfate and potassium permanganate are added into the first section, sodium hypochlorite is added into the second section, and PAM (polyacrylamide) is added into the third section for coagulating sedimentation, so that the dosage of the chemical agent can be reduced, and the removal effect of the refractory organic matters is improved. The whole process system adopts a circular structure to fully utilize the space and reduce the occupied area.

Description

Novel circular integrated biogas slurry treatment system

Technical Field

The utility model relates to the field of wastewater treatment, in particular to a novel circular integrated biogas slurry treatment system.

Background

Compared with the traditional mode, namely farmer decentralized feeding, the large-scale feeding can improve the production efficiency and the feed conversion rate, reduce the production cost and increase the social and economic benefits. However, the large-scale feeding of livestock and poultry also causes excessive concentration of excrement and urine and a large amount of increase of washing water, and brings great pressure to the ecological environment. Therefore, the comprehensive utilization of the poultry manure becomes the green development direction of the current livestock and poultry breeding industry. The intensive farm biogas engineering is a biomass energy engineering with great potential for providing clean energy, and is also an important link for reducing the problem of environmental pollution and developing ecological agriculture, so the ecological mode of 'raise-marsh-tank' is widely applied, but the problem of secondary pollution caused by lack of sufficient land for digestion of biogas slurry discharged by the biogas engineering is more serious.

The livestock and poultry biogas slurry is a residual liquid of livestock and poultry manure after anaerobic fermentation, contains a large amount of colloid suspended matters, organic matters and nitrogen and phosphorus, belongs to high-concentration organic matter wastewater, and has low BOD5/COD ratio, poor biodegradability, seriously imbalance of C/N/P ratio and failure of good biochemical treatment effect, so the main method at present is the combination of physicochemical treatment and biochemical treatment. The biochemical treatment process of the biogas slurry mainly comprises an AO method and an SBR technology, wherein the AO method for removing the total nitrogen needs to be provided with an internal reflux pump to form 200-300% of internal reflux, so that the energy consumption is increased, and meanwhile, the maximum removal rate of the total nitrogen is only 75% due to the limitation of an internal reflux ratio; although the SBR method does not use a reflux pump in a facility, the requirement on automation control is high, water cannot be continuously fed, and the total nitrogen removal is limited by the water feeding proportion; the conventional biochemical method for treating the sludge generally has the problem of large sludge production. The physical and chemical method mainly adopts a coagulation method and a Fenton oxidation method; the cost is overhigh and the mud yield is large due to large dosage of the coagulation medicament; the Fenton method has high requirements on pH, needs to react under an acidic condition, and needs to add a large amount of hydrogen peroxide to cause overhigh medicament cost, thereby restricting the application of the Fenton method.

Therefore, a novel circular integrated biogas slurry treatment system is imperative to design.

Disclosure of Invention

In order to solve the problems in the prior art, the utility model provides a novel circular biogas slurry treatment system, which combines air flotation, a two-stage AO reactor, MBR and composite oxidation coagulation technology to form an integrated device process, thereby not only reducing the occupied area and saving the energy consumption, but also improving the removal of organic matters and total nitrogen and reducing the dosage of medicaments.

According to the utility model, a novel circular integrated biogas slurry treatment system comprises a shallow air flotation device, wherein the shallow air flotation device is provided with an equipment main body, a scum collecting hopper is arranged at the upper part of the equipment main body, a sludge discharge outlet is arranged at one side of the lower part of the equipment main body, a dissolved air system is arranged at one side of the shallow air flotation device, and the dissolved air system is connected with a bottom interface at one side of the shallow air flotation device through a pipeline and is connected with an air flotation tank at one side in the shallow air flotation device through a dissolved air water pipeline; a water outlet is arranged on one side of the sludge discharge outlet, the water outlet is connected with a first AO reactor through a water outlet pipeline, a first anoxic pond and a first aerobic pond are respectively arranged in the first AO reactor, a plurality of first stirrers are additionally arranged in the first anoxic pond, a first aeration pipe is arranged at the bottom of the first aerobic pond, a first rotary gate is arranged at the top of the first AO reactor, a first side valve port of the first rotary gate is connected with the first anoxic pond through a pipeline, a second side valve port is connected with an external pipeline of the first aerobic pond through a pipeline, the other end of the external pipeline is connected with an inlet of the second AO reactor, the second AO reactor comprises a device shell, a second anoxic pond and a second aerobic pond are respectively arranged in the device shell, a plurality of second stirrers are additionally arranged in the second anoxic pond, a second aeration pipe is arranged at the bottom of the second aerobic pond, a second rotary gate is arranged at the top of the second AO reactor, a second side valve port of the rotary gate is connected with a second anoxic pond through a pipeline, the other side valve port is connected with an external pipeline of the second aerobic pond, the import department at MBR sewage treatment pond is connected to the external pipeline other end, be equipped with the MBR membrane module in the MBR sewage treatment pond, there is compound oxidation coagulation pond in the export in MBR sewage treatment pond through the pipe connection, compound oxidation coagulation pond includes the three cell body that establishes ties through the pipeline, first cell body is equipped with charge-in system measuring pump and installs the air mixing device one in the cell body bottom, second cell body is equipped with sodium hypochlorite charge-in system and installs the air mixing device two in the cell body bottom, third cell body is equipped with PAM charge-in system and installs the air mixing device three in the cell body bottom, the water inlet of pipe connection sedimentation tank is passed through to the delivery port of third cell body, sedimentation tank upper portion is equipped with the mud scraper, the lower part is equipped with the mud backwash pump.

In one embodiment of the utility model, a biogas slurry inlet pipeline is arranged at the lower part of the dissolved gas water pipeline, and biogas slurry in the biogas slurry inlet pipeline is mixed with the dissolved gas water in the dissolved gas water pipeline and then enters the flotation tank at one side through a central pipeline.

In one embodiment of the utility model, a floatation tank is arranged in the equipment main body of the shallow floatation device 1, and a scum outlet is arranged at the lower part of the floatation tank.

In one embodiment of the utility model, the MBR sewage treatment tank is connected with the first anoxic tank through a sludge pump connected by a pipeline.

In one embodiment of the utility model, the first anoxic tank and the first aerobic tank are filled with the first combined filler.

In one embodiment of the utility model, the second anoxic tank and the second aerobic tank are filled with a second combined filler.

In one embodiment of the utility model, the first AO reactor and the second AO reactor are respectively positioned at the second circular ring and the third circular ring of the integral circular device system, the first aerobic pool water outlet is arranged in the middle of the circular rings and corresponds to the first anoxic pool inlet, and the second aerobic pool water outlet is arranged in the middle of the circular rings and corresponds to the second anoxic pool inlet.

In one embodiment of the utility model, the first stirrer and the first aerator pipe play a role of pushing part of the sludge-water mixed liquid in the first AO reactor, so that the sludge-water mixed liquid circulates in the circular ring and flows back to the first anoxic tank, a return port of the first anoxic tank is arranged at a position close to the first stirrer, and a rotary gate I arranged at the return port is used for controlling the return ratio.

In one embodiment of the utility model, the second stirrer and the second aerator pipe play a role in pushing part of the sludge-water mixed liquid in the second AO reactor, so that the sludge-water mixed liquid circulates in the circular ring and flows back to the second anoxic tank, a return port of the second anoxic tank is arranged close to the second stirrer, and a second rotary gate arranged at the return port is used for controlling the return ratio.

Compared with the prior art, the technical scheme of the utility model has the following advantages: 1. compared with the prior art, the circular integrated treatment system fully utilizes the space e and occupies small area.

2. Effectively get rid of the suspended particles in the natural pond liquid through the air supporting device, avoid high suspended solid to influence biochemical system treatment effect.

3. Compared with the traditional AO process, the two-stage AO can improve the removal of total nitrogen and organic matters, adopts a circular ring structure, and reduces energy consumption because an internal circulation does not need to be additionally provided with a power internal reflux pump.

4. The composite oxidation coagulation device realizes the standard reaching of the effluent COD through the combination and the practicability of the coagulant and the oxidant, and compared with the conventional independent coagulation or independent Fenton oxidation, the composite oxidation coagulation device does not need to adjust the pH value, has small adding amount, has obvious organic matter removing effect and reduces the operation cost.

5. The biochemical system adopts the combined packing and MBR process to effectively reduce the occupied area and reduce the sludge production of the biochemical system.

Drawings

In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the present disclosure taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a process schematic diagram of the novel circular integrated biogas slurry treatment system.

FIG. 2 is a schematic flow chart of the plane design of the novel circular integrated biogas slurry treatment system.

As shown in the figure: 1. a shallow air flotation device 101, a biogas slurry water inlet pipeline 102, a dissolved air system 103, a dissolved air water pipeline 104, a scum collecting hopper 105, a sludge discharge outlet 106, a scum discharge outlet 107, a water outlet pipeline 2, an AO reactor I201, a stirrer I202, an aeration pipe I203, a rotary gate I204, an anoxic tank I205, an aerobic tank I206I, a combined filler I3, an AO reactor II 301, a stirrer II 302, an aeration pipe II 303, a rotary gate II 304, an anoxic tank II 305, an aerobic tank II 306, a combined filler II 4, an MBR sewage treatment tank 401, an MBR membrane module 402, a sludge pump 5, a composite oxidation coagulation tank 501, an air stirring device I502, a sodium hypochlorite dosing system 503, an air stirring device II 504, a dosing system 506, an air stirring device III 507, a PAM system, 6. a sedimentation tank 601, a mud scraper 602 and a sludge reflux pump.

Detailed Description

As shown in fig. 1 and 2, the utility model provides a novel circular integrated biogas slurry treatment system, which comprises a shallow air flotation device 1, wherein the shallow air flotation device 1 is provided with an equipment main body, a scum collecting hopper 104 is arranged at the upper part of the equipment main body, a sludge discharging outlet 105 is arranged at one side of the lower part of the equipment main body, a dissolved air system 102 is arranged at one side of the shallow air flotation device 1, the dissolved air system 102 is connected with a bottom interface at one side of the shallow air flotation device 1 through a pipeline, and is connected with an air flotation tank at one side in the shallow air flotation device 1 through a dissolved air water pipeline 103; a water outlet is arranged on one side of the sludge discharge outlet 105, the water outlet is connected with a first AO reactor 2 through a water outlet pipeline 107, a first anoxic tank 204 and a first aerobic tank 205 are respectively arranged in the first AO reactor 2, a plurality of stirrers 201 are additionally arranged in the first anoxic tank 204, an aerator pipe 202 is arranged at the bottom of the first aerobic tank 205, a first rotary gate 203 is arranged at the top of the first AO reactor 2, a valve port on one side of the first rotary gate 203 is connected with the first anoxic tank 204 through a pipeline, a valve port on the other side of the first rotary gate is connected with an external pipeline of the first aerobic tank 205 through a pipeline, the other end of the external pipeline is connected with an inlet of a second AO reactor 3, the second AO reactor 3 comprises a device shell, a second anoxic tank 304 and a second aerobic tank 305 are respectively arranged in the device shell, a plurality of stirrers 301 are additionally arranged in the second anoxic tank 304, and an aerator pipe 302 is arranged at the bottom of the second aerobic tank 305, the top of the AO reactor II 3 is provided with a rotary gate II 303, a valve port at one side of the rotary gate II 303 is connected with an anoxic tank II 304 through a pipeline, a valve port at the other side is connected with an external pipeline of an aerobic tank II 305 through a pipeline, the other end of the external pipeline is connected with an inlet of an MBR sewage treatment tank 4, the MBR sewage treatment tank 4 is internally provided with an MBR membrane assembly 401, an outlet of the MBR sewage treatment tank 4 is connected with a composite oxidation coagulation tank 5 through a pipeline, the composite oxidation coagulation tank 5 comprises three tank bodies which are connected in series through a pipeline, the first tank body is provided with a dosing system metering pump 502 and an air stirring device I501 arranged at the bottom of the tank body, the second tank body is provided with a sodium hypochlorite dosing system 504 and an air stirring device II 503 arranged at the bottom of the tank body, the third tank body is provided with a PAM dosing system 507 and an air stirring device III 506 arranged at the bottom of the tank body, the water outlet of the third tank body is connected with the water inlet of the sedimentation tank 6 through a pipeline, the upper part of the sedimentation tank 6 is provided with a mud scraper 601, and the lower part is provided with a mud reflux pump 602.

The lower part of the gas-dissolved water pipeline 103 is provided with a biogas slurry inlet pipeline 101, and biogas slurry in the biogas slurry inlet pipeline 101 is mixed with the gas-dissolved water in the gas-dissolved water pipeline 103 and then enters the air floatation tank on one side through a central pipeline.

The shallow air floating device 1 is provided with an air floating tank in the main body, and a scum outlet 106 is arranged at the lower part of the air floating tank.

The MBR sewage treatment tank 4 is connected with the first anoxic tank 204 through a sludge pump 402 connected with a pipeline.

And a combined filler I206 is filled in the anoxic tank I204 and the aerobic tank I205.

And a second combined filler 306 is filled in the second anoxic tank 304 and the second aerobic tank 305.

The AO reactor I2 and the AO reactor II 3 are respectively positioned at a second circular ring and a third circular ring of the integral circular device system, a water outlet of the aerobic pool I205 is arranged in the middle of the circular ring and corresponds to an inlet of the anoxic pool I204, and a water outlet of the aerobic pool II 305 is arranged in the middle of the circular ring and corresponds to an inlet of the anoxic pool II 304.

The first stirrer 201 and the first aerator pipe 202 play a role in pushing part of the sludge-water mixed liquid in the AO reactor 2, so that the sludge-water mixed liquid circulates in the circular ring and flows back to the first anoxic tank 204, a return port of the first anoxic tank 204 is arranged at a position close to the first stirrer 201, and a rotary gate 203 arranged at the return port is used for controlling a return ratio.

The second stirrer 301 and the second aerator pipe 302 play a role in pushing part of the sludge-water mixed liquid in the second AO reactor 3, so that the sludge-water mixed liquid circulates in the circular ring and flows back to the second anoxic tank 304, the return port of the second anoxic tank 304 is arranged at a position close to the second stirrer 301, and the second rotary gate 303 arranged on the return port is used for controlling the return ratio.

The working principle of the utility model is as follows: as shown in fig. 1 and fig. 2, the system provides a device integrating shallow air flotation, a two-stage AO device, an MBR, a composite oxidation coagulation device and a sedimentation tank, and the specific process steps are as follows: feeding biogas slurry separated from biogas residues into a circular integrated central shallow air flotation device 1 which is positioned at the circular center of an integrated circular device system; sewage is mixed with dissolved water in a dissolved air water pipeline 103 through a biogas slurry water inlet pipeline 101 and enters the air floatation tank through a central pipeline, and the dissolved air water is generated by treated water in the device through a dissolved air system 102. The dissolved gas water saturated with micro bubbles and the raw water are fully collided and adhered in the air flotation device, so that the particles in the raw water form scum with the specific gravity of less than 1, the scum layer formed on the surface is collected by a scum collecting hopper 104 and is discharged through a scum discharge port 106, and the treated water is sent to the next reactor by a water outlet pipeline 107.

The wastewater after air floatation pretreatment sequentially flows into a first AO reactor 2 and a second AO reactor 3 under neutral traction, and the first AO reactor 2 and the second AO reactor 3 are respectively arranged into a second circular ring and a third circular ring; firstly, biogas slurry enters an anoxic tank I204, a combined filler I206 is arranged in the anoxic tank, and a stirrer I201 is arranged in an aligned mode; the anoxic tank nitrification liquid return port is positioned close to the first anoxic stirrer 201 at the upper end, a first rotary gate 203 is arranged to control the nitrification liquid return amount, the sludge return port is arranged at the upper part of the first stirrer 201, and biogas slurry, returned sludge and returned nitrification liquid are fully mixed under the stirring action; the anoxic tank has the function of converting nitrate nitrogen and nitrite nitrogen (NO 3-N, NO 2-N) in the aerobic nitrification reflux water into nitrogen (N2) by denitrifying bacteria by utilizing the organic matters in the water, so that the organic matters and the total nitrogen are removed simultaneously; the effluent of the first-stage anoxic tank flows into a first-stage aerobic tank (205), biogas slurry is aerated through an aeration pipe (202) at the bottom of the aerobic tank to create an aerobic environment, organic matters and ammonia nitrogen are removed by using aerobic microorganisms suspended and filled in the tank, the ammonia nitrogen is oxidized into nitrate nitrogen and nitrite nitrogen (NO 3-N, NO 2-N), the required nitrate nitrogen and nitrite nitrogen are provided for denitrification, a submersible impeller is arranged at the water inlet of the aerobic tank and at the bottom of the tank section relative to the circle center of the aerobic tank to push water flow to circularly flow around the ring, part of sludge-water mixed liquid flows back into the anoxic tank under the push of the impeller to realize the reflux of nitrified liquid, the other part of sludge-water mixed liquid flows into a second-stage AO system through a water outlet arranged at the middle part of the ring, and the aerobic water outlet is arranged opposite to the inlet of the anoxic tank to ensure less short flow and effective hydraulic retention time.

The second AO reactor 3 operates in the same way as the first stage, and the removal of organic matters, ammonia nitrogen and total nitrogen is greatly improved through two-stage AO treatment.

The biogas slurry is treated by two stages of AO and then enters an MBR membrane tank 4, the MBR membrane tank is arranged on an external fourth ring, and the sludge and water are separated by a membrane module 401 in the tank, the solid-liquid separation capability of the system is greatly improved due to the existence of the MBR, so that the water quality and the volume load of the effluent are greatly improved, and the water quality after membrane treatment is high; the sludge is trapped in the MBR membrane biological reaction zone and pumped back to the anoxic tank of the first stage AO system by an internal sludge return pump 402. The MBR tank eliminates the sludge bulking problem in the traditional activated sludge process, and the sludge yield is less.

MBR effluent further enters a composite oxidation coagulation tank for advanced treatment, the composite oxidation coagulation tank 5 is connected with the MBR tank and arranged on a fourth ring of an integrated circular device system, the composite oxidation coagulation device is divided into three tanks, the bottom of the first tank is provided with an air stirring device I501, the upper part of the first tank is provided with a dosing system metering pump 502, and the reaction time is not less than 30 minutes; the bottom of the second pool is provided with an air stirring device 503, the upper part is provided with a sodium hypochlorite dosing system 504, and the reaction time is not less than 30 minutes; the third pond bottom is equipped with air stirring device 506, upper portion PAM medicine system 507. The reaction tank ensures that the medicament and the biogas slurry are fully mixed and react through stirring the air at the bottom.

The biogas slurry treated by the composite oxidation coagulation tank 5 further enters a sedimentation tank 6 for sludge-water separation, the sedimentation tank is arranged on a fourth ring of the integral circular device system, a mud scraper 601 is arranged at the upper part of the sedimentation tank, the mud scraper runs along an arc-shaped track, and a sludge tank is arranged at the tail end of the sedimentation tank; the mud scraper collects the precipitated mud into a mud tank and then the mud is pumped out by a mud return pump 602 for recycling. Finally, returning the supernatant to the field for fertilization after the final treatment.

Example (b):

biogas slurry wastewater generated by anaerobic fermentation of excrement of a certain dairy farm is treated by adopting the system, the water quality COD of the biogas slurry is 12000-; the retention time of the second-stage AO reactor is 4.5 days, the COD of the effluent is reduced to 1200mg/L, the total nitrogen is 120mg/L, and the total phosphorus is 8 mg/L; and finally, carrying out composite oxidation coagulation treatment on biochemical effluent, adding 300mg/L of polyferric sulfate and 30mg/L of potassium permanganate into the first section, adding 300mg/L of sodium hypochlorite (effective chlorine) into the second section, adding 5mg/LPAM into the third section, wherein COD (chemical oxygen demand) of reaction precipitation effluent is less than or equal to 180mg/L, NH3-N is less than 15mg/L, TN is less than 100mg/L, and total phosphorus is less than 1 mg/L. The whole biochemical treatment stays for about 12.5 days.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the utility model may be made without departing from the spirit or scope of the utility model.

Claims

1. The utility model provides a novel circular integration natural pond liquid processing system, includes shallow layer air supporting device (1), its characterized in that: the shallow air floating device (1) is provided with an equipment main body, a scum collecting hopper (104) is arranged at the upper part of the equipment main body, a sludge discharge outlet (105) is arranged at one side of the lower part of the equipment main body, an air dissolving system (102) is arranged at one side of the shallow air floating device (1), the air dissolving system (102) is connected with a bottom interface at one side of the shallow air floating device (1) through a pipeline, and is connected with an air floating tank at one side in the shallow air floating device (1) through an air dissolving water pipeline (103); a water outlet is arranged on one side of the sludge discharge outlet (105), the water outlet is connected with a first AO reactor (2) through a water outlet pipeline (107), a first anoxic tank (204) and a first aerobic tank (205) are respectively arranged in the first AO reactor (2), a plurality of first stirrers (201) are additionally arranged in the first anoxic tank (204), a first aerator pipe (202) is arranged at the bottom of the first aerobic tank (205), a first rotary gate (203) is arranged at the top of the first AO reactor (2), a valve port on one side of the first rotary gate (203) is connected with the first anoxic tank (204) through a pipeline, a valve port on the other side of the first rotary gate is connected with an external pipeline of the first aerobic tank (205) through a pipeline, the other end of the external pipeline is connected with an inlet of a second AO reactor (3), the second AO reactor (3) comprises a device shell, a second anoxic tank (304) and a second aerobic tank (305) are respectively arranged in the device shell, a plurality of second stirrers (301) are additionally arranged in the second anoxic pond (304), a second aerator pipe (302) is arranged at the bottom of the second aerobic pond (305), a second rotary gate (303) is arranged at the top of the second AO reactor (3), a valve port on one side of the second rotary gate (303) is connected with the second anoxic pond (304) through a pipeline, a valve port on the other side of the second rotary gate is connected with an external pipeline of the second aerobic pond (305) through a pipeline, the other end of the external pipeline is connected with an inlet of the MBR sewage treatment pond (4), an MBR (membrane bioreactor) component (401) is arranged in the MBR sewage treatment pond (4), an outlet of the MBR sewage treatment pond (4) is connected with a composite oxidation coagulation pond (5) through a pipeline, the composite oxidation coagulation pond (5) comprises three pond bodies which are connected in series through a pipeline, the first pond body is provided with a system dosing metering pump (502) and an air stirring device (501) arranged at the bottom of the pond body, the second cell body is equipped with sodium hypochlorite medicine system (504) and installs air mixing device two (503) in the cell body bottom, and the third cell body is equipped with PAM medicine system (507) and installs air mixing device three (506) in the cell body bottom, the water inlet of pipe connection sedimentation tank (6) is passed through to the delivery port of third cell body, sedimentation tank (6) upper portion is equipped with mud scraper (601), and the lower part is equipped with sludge reflux pump (602).

2. The novel circular integrated biogas slurry treatment system according to claim 1, characterized in that: a biogas slurry water inlet pipeline (101) is arranged at the lower part of the dissolved gas water pipeline (103), and biogas slurry in the biogas slurry water inlet pipeline (101) is mixed with dissolved gas water in the dissolved gas water pipeline (103) and then enters the air floatation tank at one side through a central pipeline.

3. The novel circular integrated biogas slurry treatment system according to claim 2, characterized in that: an air floatation tank is arranged in the equipment main body of the shallow air floatation device (1), and a scum outlet (106) is arranged at the lower part of the air floatation tank.

4. The novel circular integrated biogas slurry treatment system according to claim 1, characterized in that: the MBR sewage treatment tank (4) is connected with a first anoxic tank (204) through a sludge pump (402) connected with a pipeline.

5. The novel circular integrated biogas slurry treatment system according to claim 1, characterized in that: and a first combined filler (206) is filled in the first anoxic tank (204) and the first aerobic tank (205).

6. The novel circular integrated biogas slurry treatment system according to claim 1, characterized in that: and a second combined filler (306) is filled in the second anoxic tank (304) and the second aerobic tank (305).

7. The novel circular integrated biogas slurry treatment system according to claim 1, characterized in that: the AO reactor I (2) and the AO reactor II (3) are respectively positioned at a second circular ring and a third circular ring of the integral circular device system, a water outlet of the aerobic pool I (205) is arranged in the middle of the circular ring and corresponds to an inlet of the anoxic pool I (204), and a water outlet of the aerobic pool II (305) is arranged in the middle of the circular ring and corresponds to an inlet of the anoxic pool II (304).

8. The novel circular integrated biogas slurry treatment system according to claim 1, characterized in that: the first stirrer (201) and the first aerator pipe (202) play a role of pushing part of sludge-water mixed liquid in the first AO reactor (2), so that the sludge-water mixed liquid circulates in a circular ring and flows back to the first anoxic tank (204), a return port of the first anoxic tank (204) is arranged at a position close to the first stirrer (201), and a first rotary gate (203) arranged at the return port is used for controlling a return ratio.

9. The novel circular integrated biogas slurry treatment system according to claim 1, characterized in that: the second stirrer (301) and the second aerator pipe (302) play a role in pushing part of the muddy water mixed liquor in the second AO reactor (3), so that the muddy water mixed liquor circulates in the circular ring and flows back to the second anoxic tank (304), the return port of the second anoxic tank (304) is arranged at a position close to the second stirrer (301), and the second rotary gate (303) arranged on the return port is used for controlling the return ratio.