Strengthening A 2 Apparatus and method for treating low carbon to nitrogen ratio wastewater in an o-mbr system

Abstract

This invention relates to a reinforced A 2 O-MBR system for treating low C / N ratio wastewater: The system includes a composting system, a leachate tank, and an A... 2 In the O-MBR system, the leachate tank is connected to the composting system via a leachate pipe, and the system is connected to A via a leachate inlet pipe. 2 The O-MBR system is connected. Biomass undergoes composting within the system to produce leachate. The leachate enters a leachate tank through a leachate pipe, and the leachate in the tank is then supplied to A through a leachate inlet pipe. 2 The O-MBR system's anoxic tank houses a microbial fuel cell anode chamber. Anaerobic treatment of the anode improves the biodegradability of the leachate, serving as an A... 2 Carbon source in O-MBR wastewater treatment process. This invention targets low carbon-to-nitrogen ratio domestic wastewater and utilizes leachate obtained from agricultural waste composting as A. 2 External carbon source for O-MBR systems. To A 2 Adding biomass compost leachate to the O-MBR system as a supplementary carbon source enhances the nitrogen and phosphorus removal effect of wastewater while achieving the harmlessness and resource utilization of biomass compost leachate.

Description

TECHNICAL FIELD

[0001] The present application relates to a sewage treatment technology, in particular to a kind of enhanced A 2 O-MBR system processing low carbon nitrogen ratio sewage device and method. BACKGROUND

[0002] With the development of industry and the improvement of living standards, the proportion of nitrogen and phosphorus contained in municipal sewage is increasing, which leads to the relatively low proportion of chemical oxygen demand (COD) contained in sewage itself. The low carbon-nitrogen ratio makes it difficult for traditional sewage treatment processes to meet the discharge standards, and often requires advanced treatment of secondary treated effluent from sewage treatment plants, which will significantly increase the cost of sewage treatment. In addition, the lack of carbon source in sewage makes it difficult to meet the growth needs of denitrifying microorganisms, limiting denitrification, which often requires external carbon source, further increasing the cost of sewage treatment. Therefore, how to solve the lack of carbon source in the treatment of low carbon-nitrogen ratio domestic sewage has become a problem that needs to be solved by sewage treatment plants nationwide.

[0003] Biological denitrification requires heterotrophic denitrifying bacteria to remove NO3 - under anoxic conditions by converting it to nitrogen gas, but this process depends on the availability of carbon sources as organic electron donors. Currently, most sewage treatment plants add external carbon sources such as sodium acetate, glucose, and methanol to improve denitrification efficiency. However, the high cost and difficult dosage management of liquid carbon sources not only increase the cost of the treatment process, but also may cause secondary pollution.

[0004] In addition, an emerging solid-phase denitrification process has received increasing attention. It uses natural plant materials and synthetic biodegradable polymers as solid materials for denitrification and microbial carriers. Currently, a large number of studies mainly use PCL, PBS, PLA / PHBV, and other synthetic biodegradable solid carbon sources, but the high cost of synthetic solid carbon sources limits their further application. SUMMARY

[0005] The purpose of the present application is to provide a kind of enhanced A 2 O-MBR system processing low carbon nitrogen ratio sewage device and method to solve the problem of high cost of existing sewage treatment technology.

[0006] The present application is implemented as follows: a kind of enhanced A 2 O-MBR system processing low carbon nitrogen ratio sewage device, the device includes the following parts.

[0007] Composting system, connected by leachate pipe and leachate pool, for composting of biomass.

[0008] Leachate pool, connected with A2 The O-MBR system is connected, and a leachate inlet pump is arranged on the leachate inlet pipe to collect the leachate generated by the composting system and supply the leachate to the A 2 The O-MBR system supplies leachate as a carbon source.

[0009] The A 2 The O-MBR system is used for treating low-carbon-nitrogen-ratio sewage.

[0010] The composting system comprises a composting tank, an insulation layer is arranged on the inner wall of the composting tank, a leachate collection pipe is arranged in the leachate layer, the leachate collection pipe is connected with the leachate tank through a leachate pipe, an anaerobic composting area is arranged above the leachate layer, a composting agitator is arranged in the anaerobic composting area, a spraying device is arranged above the anaerobic composting area, the spraying device is connected with the leachate tank through a leachate backflow pipe, and a leachate backflow pump is arranged on the leachate backflow pipe.

[0011] The leachate collection pipe comprises a main pipe and branch pipes arranged on both sides of the main pipe, and permeation holes are uniformly arranged on the pipe wall of the leachate collection pipe.

[0012] The A 2 The O-MBR system comprises an anaerobic tank, an anoxic tank and an aerobic tank connected in sequence, agitators are arranged in the anaerobic tank and the anoxic tank, the anaerobic tank is connected with a sewage inlet pipe, a sewage inlet pump is arranged on the sewage inlet pipe, a microbial fuel cell is arranged in the anoxic tank, the microbial fuel cell comprises an anode chamber and a cathode material, an anode material is arranged in the anode chamber, a proton exchange membrane is arranged on the side of the anode chamber, an anode chamber inlet connected with the leachate inlet pipe is arranged at the bottom of the anode chamber, an anode chamber outlet connected with the anoxic tank is arranged at the upper part of the anode chamber, the cathode material and the anode material are connected via an external circuit, a variable resistor with adjustable resistance value is arranged on the external circuit, a membrane assembly is arranged in the aerobic tank, a drain pipe is connected with the outlet of the membrane assembly, and a drain pump is arranged on the drain pipe.

[0013] An aeration device is arranged in the aerobic tank, a nitrification liquid backflow pipe is connected between the aerobic tank and the anoxic tank, a nitrification liquid backflow pump is arranged on the nitrification liquid backflow pipe, a sludge backflow pipe is connected between the anoxic tank and the anaerobic tank, and a sludge backflow pump is arranged on the sludge backflow pipe.

[0014] Electrogenic bacteria are attached to the anode material, autotrophic denitrifying bacteria are attached to the surface of the cathode material, and heterotrophic denitrifying bacteria are attached to the outer layer of the cathode material.

[0015] The application also discloses a reinforced A 2 The method comprises the following steps.

[0016] a. setting the reinforced A 2 The application also discloses a device for treating low-carbon-nitrogen-ratio sewage by using an O-MBR system.

[0017] b. adding biomass into the composting tank for composting treatment, and collecting the leachate generated in the leachate tank.

[0018] c. obtaining activated sludge, distributing the activated sludge into the anaerobic tank, the anoxic tank and the aerobic tank, and starting the reinforced A 2 The application also discloses a device for treating low-carbon-nitrogen-ratio sewage by using an O-MBR system.

[0019] d. inputting the low-carbon-nitrogen-ratio sewage into the anaerobic tank through a sewage inlet pipe, and fully mixing the low-carbon-nitrogen-ratio sewage with the backflow sludge from the anoxic tank in the anaerobic tank to perform anaerobic decomposition and release phosphorus.

[0020] e. flowing the sewage after anaerobic decomposition into the anoxic tank, supplying the leachate in the leachate tank into the microbial fuel cell anode chamber in the anoxic tank through a leachate inlet pipe, degrading part of the refractory organic matter in the leachate to improve the biodegradability of the leachate, adding the leachate as a carbon source supplement into the anoxic tank, and fully mixing the leachate with the sewage and the nitrification liquid backflowed from the aerobic tank to perform denitrification treatment.

[0021] f. generating electrons by the anode electricity-producing bacteria using the leachate as a substrate, transmitting the electrons to the cathode through an external circuit, and performing autotrophic denitrification by the autotrophic denitrifying bacteria attached to the inner layer of the cathode surface using the electrons transmitted to the cathode from the anode to strengthen the removal of total nitrogen;

[0022] g. flowing the sewage after denitrification treatment into the aerobic tank to perform nitrification and aerobic phosphorus absorption treatment, filtering the sewage after denitrification treatment through a membrane assembly, and discharging the sewage through a drainage pipe.

[0023] The nitrification liquid backflow ratio from the aerobic tank to the anoxic tank is 300 %, and the sludge backflow ratio from the anoxic tank to the anaerobic tank is 100 %.

[0024] The activated sludge is obtained from the secondary sedimentation tank sludge of a sewage plant, the obtained activated sludge is placed for 24 h, then the supernatant, floating matter and lower bulk sediment are removed, and then the low-carbon-nitrogen-ratio wastewater is added and continuously exposed for 24 h to remove the residual organic matter in the microorganisms.

[0025] The application takes low-carbon-nitrogen-ratio domestic sewage as a treatment object, can utilize agricultural waste for composting treatment to obtain leachate, and solves the problems of A 2 The application also discloses an additional carbon source for treating sewage by using an O-MBR system.2 The present application adds the leachate of biomass compost as a supplementary carbon source in the O-MBR system, which can strengthen the effect of wastewater denitrification and phosphorus removal, and realize the harmless and resource utilization of the leachate of biomass compost, and provides a new idea for the actual wastewater treatment process. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the structural diagram of the present application.

[0027] Figure 2 is the structural diagram of the compost system of the present application.

[0028] Figure 3 is the schematic diagram of the leachate collecting pipe of the compost system of the present application.

[0029] In the figure: 1, compost system; 2, leachate pool; 3, A 2 O-MBR system; 4, leachate pipe; 5, leachate inlet pipe; 6, leachate inlet pump; 1-1, compost pool; 1-2, heat preservation layer; 1-3, impermeable membrane layer; 1-4, permeable layer; 1-5, leachate collecting pipe; 1-6, anaerobic compost area; 1-7, compost agitator; 1-8, spraying device; 1-9, leachate backflow pipe; 1-10, leachate backflow pump; 1-11, gas collecting port; 1-12, multi-parameter probe; 1-13, permeable hole; 1-14, multifunctional data acquisition device; 3-1, anaerobic pool; 3-2, anoxic pool; 3-3, aerobic pool; 3-4, wastewater inlet pipe; 3-5, wastewater inlet pump; 3-6, liquid level transmitter; 3-7, agitating device; 3-8, anode chamber; 3-9, anode chamber water inlet; 3-10, anode chamber water outlet; 3-11, anode material; 3-12, proton exchange membrane; 3-13, variable resistor; 3-14, external circuit; 3-15, cathode material; 3-16, membrane assembly; 3-17, drain pipe; 3-18, drain pump; 3-19, pressure sensor; 3-20, paperless recorder; 3-21, aeration device; 3-22, nitrification liquid backflow pipe; 3-23, nitrification liquid backflow pump; 3-24, sludge backflow pipe; 3-25, sludge backflow pump. DETAILED DESCRIPTION

[0030] As Figure 1 , Figure 2 and Figure 3 shown, the present application strengthens the A 2 O-MBR system 3 to process low carbon-nitrogen ratio wastewater device includes compost system 1, leachate pool 2 and A 2 O-MBR system 3, the leachate pool 2 is communicated through the leachate pipe 4 and the compost system 1, and is communicated with A 2The O-MBR system 3 is connected. The leachate produced by the biomass in the composting system 1 is collected by the leachate pipe 4 into the leachate tank 2, and the leachate in the leachate tank 2 is supplied to the A 2 O-MBR, and a leachate inlet pump 6 is arranged on the leachate inlet pipe 5 as the A 2 Carbon source in the O-MBR sewage treatment process.

[0031] The composting system 1 includes a composting tank 1-1, an insulation layer 1-2 is arranged on the inner wall of the composting tank 1-1, a leachate collection pipe 1-5 is arranged in the leachate tank 2, and the leachate collection pipe 1-5 is connected with the leachate tank 2 through the leachate pipe 4, and the leachate tank 2 is connected with the O-MBR system 3 through the leachate inlet pipe 5.

[0032] The leachate collection pipe 1-5 includes a main pipe and branch pipes on both sides of the main pipe, and the leachate collection pipe 1-5 is arranged on the pipe wall of the leachate collection pipe 1-5. The leachate enters the leachate collection pipe 1-5 through the uniform permeable holes 1-14 on the pipe wall of the leachate collection pipe 1-5, and is discharged into the leachate tank 2 through the leachate collection pipe 1-5. In order to facilitate the collection and discharge of the leachate, the bottom of the composting tank 1-1 is of a structure with the middle lower and the two sides higher, and the bottom of the composting tank 1-1 is of an inclined state with the front end higher and the rear end lower. The leachate collection pipe 1-5 is located at the middle lower position, the branch pipes on both sides are in an inclined state, and the branch pipes on both sides are arranged in a V shape. In this way, the leachate can be collected at the leachate collection pipe 1-5 at the bottom of the composting tank 1-1 and discharged by the leachate collection pipe 1-5.

[0033] The leachate collection pipe 1-5 includes a main pipe and branch pipes on both sides of the main pipe, and the leachate collection pipe 1-5 is arranged on the pipe wall of the leachate collection pipe 1-5. The leachate enters the leachate collection pipe 1-5 through the uniform permeable holes 1-14 on the pipe wall of the leachate collection pipe 1-5, and is discharged into the leachate tank 2 through the leachate collection pipe 1-5. In order to facilitate the collection and discharge of the leachate, the bottom of the composting tank 1-1 is of a structure with the middle lower and the two sides higher, and the bottom of the composting tank 1-1 is of an inclined state with the front end higher and the rear end lower. The leachate collection pipe 1-5 is located at the middle lower position, the branch pipes on both sides are in an inclined state, and the branch pipes on both sides are arranged in a V shape. In this way, the leachate can be collected at the leachate collection pipe 1-5 at the bottom of the composting tank 1-1 and discharged by the leachate collection pipe 1-5.

[0034] The composting agitator 1-7 is driven by a motor, and the biomass in the composting tank 1-1 is turned over by the composting agitator 1-7.

[0035] A multi-parameter probe 1-12 is arranged in the anaerobic composting area 1-6, the multi-parameter probe 1-12 is electrically connected with the multifunctional data acquisition device 1-14, and the temperature and humidity of the anaerobic composting area 1-6 are controlled by the multifunctional data acquisition device 1-14.

[0036] The spraying device 1-8 above the anaerobic composting area 1-6 is communicated with the leachate return pipe 1-9 and the leachate pool 2, the leachate in the leachate pool 2 is pumped to the spraying device 1-8 by the leachate return pump 1-10 to spray the organic matter in the anaerobic composting area 1-6, and the leachate return pipe 1-9 can also be connected with tap water to control the water content of the aerobic composting area 1-6.

[0037] The top of the composting pool 1-1 is in a sealed state, and a gas collecting port 1-11 is arranged at the top of the composting pool 1-1, the gas generated in the anaerobic composting area 1-6 is discharged and collected through the gas collecting port 1-11.

[0038] A 2 The O-MBR system 3 comprises an anaerobic pool 3-1, an anoxic pool 3-2 and an aerobic pool 3-3 which are sequentially communicated, stirring devices 3-7 are arranged in the anaerobic pool 3-1 and the anoxic pool 3-2 respectively, the anaerobic pool 3-1 is communicated with a sewage inlet pipe 3-4, a sewage inlet pump 3-5 is arranged on the sewage inlet pipe 3-4, a leachate inlet pipe 5 and an anode chamber 3-8 of a microbial fuel cell in the anoxic pool 3-2 are communicated, a microbial fuel cell is arranged in the anoxic pool 3-2, the microbial fuel cell comprises an anode chamber 3-8 and a cathode material 3-15, an anode material 3-11 is arranged in the anode chamber 3-8 and a proton exchange membrane 3-12 is arranged on the side surface of the anode chamber 3-8, a water inlet 3-9 is arranged at the bottom of the anode chamber 3-8 and a water outlet 3-10 is arranged at the upper portion of the anode chamber 3-8, the water inlet 3-9 is communicated with the leachate inlet pipe 5, the leachate from the leachate pool 2 enters the anode chamber 3-8 and then enters the anoxic pool 3-2, the cathode material 3-12 and the anode material 3-11 are connected via an external circuit 3-14, a variable resistor 3-13 with adjustable resistance is arranged on the external circuit 3-14, a membrane assembly 3-16 is arranged in the aerobic pool 3-3, a drainage pump 3-18 is connected to a drainage pipe 3-17 of the membrane assembly 3-16, a pressure sensor 3-19 is connected to the drainage pipe 3-17 between the membrane assembly 3-16 and the drainage pump 3-18, and a paperless recorder 3-20 is connected to the pressure sensor 3-19.

[0039] The anode material 3-11 is attached with electrogenic bacteria, the surface of the cathode material 3-15 is attached with autotrophic denitrifying bacteria, and the outer layer of the cathode material 3-15 is attached with heterotrophic denitrifying bacteria.

[0040] An aeration device 3-21 is arranged in the aerobic tank 3-3, a nitrification liquid reflux pipe 3-22 is communicated between the aerobic tank 3-3 and the anoxic tank 3-2, a nitrification liquid reflux pump 3-23 is arranged on the nitrification liquid reflux pipe 3-22, a sludge reflux pipe 3-24 is communicated between the anoxic tank 3-2 and the anaerobic tank 3-1, and a sludge reflux pump 3-25 is arranged on the sludge reflux pipe 3-24.

[0041] The anaerobic tank 3-1 mainly performs anaerobic decomposition on the sewage and the reflux sludge, a sewage inlet pipe 3-4 is arranged on the upper left side wall of the anaerobic tank 3-1, a sewage inlet pump 3-5 is arranged on the sewage inlet pipe 3-4, a liquid level transmitter 3-6 is arranged in the anaerobic tank 3-1, and the start and stop of the sewage inlet pump 3-5 is controlled by the liquid level transmitter 3-6, so that the liquid level of the whole device is controlled at the same height. A stirring device 3-7 is arranged in the anaerobic tank 3-1, and the anaerobic tank 3-1 is kept in a low-oxygen environment below 0.2 mg / L by the stirring device 3-7. A water pipe communicated with the anoxic tank 3-2 is arranged on the lower right side wall of the anaerobic tank 3-1.

[0042] The anoxic tank 3-2 mainly performs denitrification reaction, and a stirring device 3-7 and a microbial fuel cell are arranged in the anoxic tank 3-2, so that the anoxic tank 3-2 is kept in an anoxic environment of 0.2-0.5 mg / L.

[0043] The aerobic tank 3-3 mainly performs nitrification reaction, and a membrane module 3-16 and an aeration device 3-21 are arranged in the aerobic tank 3-3. The aeration device 3-21 is connected with a gas pump, and the aeration amount is controlled by a gas flow meter, so that the aerobic tank 3-3 is kept in an aerobic environment with a dissolved oxygen concentration of 2-4 mg / L. Preferably, the aeration device 3-21 is slightly away from the bottom of the tank body, so as to better realize aeration.

[0044] A drain pipe 3-17 is arranged on the top of the membrane module 3-16, so as to drain the water treated by the membrane module 3-16, wherein the drain pipe 3-17 is connected with a pressure sensor 3-19, the pressure sensor 3-19 is signal connected with a drain pump 3-18, the transmembrane pressure (TMP) of the membrane module 3-16 is detected by the pressure sensor 3-19 and transmitted to a paperless recorder 3-20, and when the transmembrane pressure (TMP) reaches 30 kpa, the membrane module 3-16 is taken out from the aerobic tank 3-3 for flushing.

[0045] The volume ratio of the anaerobic tank 3-1, the anoxic tank 3-2 and the aerobic tank 3-3 is 1:2:4, and the corresponding hydraulic retention times are 1.8 h, 3.6 h and 7.2 h respectively.

[0046] The application further discloses a method for treating low carbon-nitrogen ratio sewage by using the O-MBR system 3. 2 The application further discloses a method for treating low carbon-nitrogen ratio sewage by using the O-MBR system 3.

[0047] a. Set up the same as the previous reinforcement A 2 O-MBR system 3 handles low carbon-nitrogen ratio sewage device.

[0048] b. Add biomass in the composting tank 1-1 for composting treatment, and the leachate generated is collected in the leachate tank 2.

[0049] c. Obtain activated sludge, distribute the activated sludge to the anaerobic tank 3-1, the anoxic tank 3-2 and the aerobic tank 3-3, and after acclimation of the activated sludge, start the reinforcement A 2 O-MBR system 3 handles low carbon-nitrogen ratio sewage device.

[0050] d. The low carbon-nitrogen ratio sewage is input into the anaerobic tank 3-1 through the sewage inlet pipe 3-4, and after being fully mixed with the return sludge from the anoxic tank 3-2, the low carbon-nitrogen ratio sewage is subjected to anaerobic decomposition and releases phosphorus.

[0051] e. The sewage after anaerobic decomposition flows into the anoxic tank 3-2, and the leachate in the leachate tank 2 is supplied into the microbial fuel cell anode chamber 3-8 built-in the anoxic tank 3-2 through the leachate inlet pipe 5, where part of the refractory organic matter in the leachate is degraded to improve the biodegradability of the leachate, which is then added as a carbon source to the anoxic tank 3-2, and is fully mixed with the sewage and the nitrification liquid returned from the aerobic tank 3-3 for denitrification treatment.

[0052] f. The surface of the microbial fuel cell cathode 3-15 built-in the anoxic tank 3-2 is attached with autotrophic denitrifying bacteria in the inner layer and heterotrophic denitrifying bacteria in the outer layer, and the electron-producing bacteria in the anode 3-11 generates electrons using the leachate as substrate and transfers the electrons to the cathode 3-15 through the external circuit 3-14, and the autotrophic denitrifying bacteria attached to the surface of the cathode 3-15 can utilize the electrons transferred from the anode 3-11 to the cathode 3-15 for autotrophic denitrification, thereby strengthening the removal of total nitrogen.

[0053] g. The sewage after denitrification treatment flows into the aerobic tank 3-3 for nitrification and aerobic phosphorus uptake treatment, and after filtration by the membrane assembly 3-16, it is discharged through the drain pipe 3-17.

[0054] The nitrification liquid return ratio from the aerobic tank 3-3 to the anoxic tank 3-2 is 300%, and the sludge return ratio from the anoxic tank 3-2 to the anaerobic tank 3-1 is 100%.

[0055] The activated sludge is taken from the secondary sedimentation tank sludge of the sewage plant, and after the retrieved activated sludge is left standing for 24h, the supernatant, floating matter and lower layer large sediment are removed, and then low carbon-nitrogen ratio wastewater is added for continuous mellowing for 24h to remove residual organic matter in the microorganisms.

[0056] The biomass added into the composting tank 1-1 can be agricultural waste.

[0057] When starting the device: the MLSS measured before adding the device is 30000 mg / L, the activated sludge in the device is diluted to 3000 mg / L and then evenly distributed into the anaerobic, anoxic and aerobic tanks, then the continuous flow is adopted for domestication, and the membrane assembly 3-16 is arranged in the aerobic tank 3-3; the stirring device 3-7 of the anaerobic tank 3-1 and the anoxic tank 3-2 and the aeration device 3-21 of the aerobic tank 3-3 are started, and the sludge reflux pump 3-25 is started at the same time, the sludge reflux from the anoxic tank 3-2 to the anaerobic tank 3-1 is 100%, and the nitrification liquid reflux ratio from the aerobic tank 3-3 to the anoxic tank 3-2 is 300%. After the device runs for a period of time, the effluent quality is stable, and it is found that there are rotifers, vorticella and other protozoa in the device, which indicates that the amount of microorganisms in the device is relatively rich, and the device is successfully started.

[0058] The present application takes low carbon-nitrogen ratio domestic sewage as the treatment object, and can utilize agricultural waste for composting treatment to obtain leachate to solve the problem of A 2 The O-MBR system 3 is used for treating sewage, and the external carbon source is insufficient. 2 The biomass compost leachate is added into the O-MBR system 3, part of the refractory organic matter in the leachate is degraded in the anoxic tank by using the microbial fuel cell, the biodegradability of the leachate is improved, and then the leachate is added into the anoxic tank 3-2 as a carbon source, so that the effect of denitrification and phosphorus removal of the sewage is strengthened, the harmless and resource utilization of the biomass compost leachate are realized, and a new idea for the actual sewage treatment process is provided.

[0059] The present application provides a new process design idea for newly-built sewage plants at the present stage, provides an effective improvement approach for the reconstruction of process systems in old plants, and also provides data support and theoretical basis for the actual popularization of the combined process.

[0060] The A 2 The O-MBR device has a large audience group, compared with the traditional decarbonization and phosphorus removal process, the membrane assembly 3-16 is arranged in the aerobic tank 3-3, and the traditional secondary sedimentation tank is cancelled, so that the construction cost is saved. Meanwhile, the problems such as insufficient carbon source in the influent in the traditional biological denitrification and phosphorus removal process are improved and solved, the effluent quality is ensured, and the device has broad development potential.

Claims

1. A method of strengthening A 2 O-MBR system for treating low carbon to nitrogen ratio sewage, characterized in that, Comprising A composting system for composting treatment of biomass, comprising a leachate pipe and a leachate tank; leachate pool, through the leachate inlet pipe and A 2 O-MBR system is communicated, and a leachate inlet pump is arranged on the leachate inlet pipe, for collecting the leachate generated by the composting system and supplying the leachate to A 2 O-MBR system supplies the leachate as a carbon source; and A 2 O-MBR system for treating low carbon-nitrogen ratio sewage; The composting system comprises a composting tank, an insulation layer is arranged on the inner wall of the composting tank, a leachate collection pipe is arranged in the leachate tank, and the leachate collection pipe is connected with the leachate tank through a leachate pipe, an anaerobic composting area is arranged above the leachate collection pipe, a composting agitator is arranged in the anaerobic composting area, a spraying device is arranged above the anaerobic composting area, and the spraying device is connected with the leachate tank through a leachate return pipe and a leachate return pump is arranged on the leachate return pipe; The A 2 The O-MBR system comprises an anaerobic tank, an anoxic tank and an aerobic tank connected in sequence, a stirring device is arranged in the anaerobic tank and the anoxic tank respectively, a sewage inlet pipe is communicated with the anaerobic tank, a sewage inlet pump is arranged on the sewage inlet pipe, a microbial fuel cell is arranged in the anoxic tank, the microbial fuel cell comprises an anode chamber and a cathode material, an anode material is arranged in the anode chamber, a proton exchange membrane is arranged on the side of the anode chamber, an anode chamber inlet is arranged at the bottom of the anode chamber and communicated with the leachate inlet pipe, an anode chamber outlet is arranged at the upper portion of the anode chamber and communicated with the anoxic tank, the cathode material and the anode material are connected via an external circuit, a variable resistor with adjustable resistance value is arranged on the external circuit, a membrane assembly is arranged in the aerobic tank, a drain pipe is communicated with the outlet of the membrane assembly, and a drain pump is arranged on the drain pipe. An aeration device is arranged in the aerobic tank, a nitrification liquid return pipe is connected between the aerobic tank and the anoxic tank, a nitrification liquid return pump is arranged on the nitrification liquid return pipe, a sludge return pipe is connected between the anoxic tank and the anaerobic tank, and a sludge return pump is arranged on the sludge return pipe; The anode material is attached with electrogenic bacteria, the cathode material is attached with autotrophic denitrifying bacteria on the surface, and heterotrophic denitrifying bacteria are attached on the outer layer of the cathode material.

2. The strengthened A of claim 1 2 The device is characterized in that the O-MBR system processes low carbon-nitrogen ratio sewage, The leachate collection pipe comprises a main pipe and branch pipes arranged on both sides of the main pipe, and permeation holes are uniformly arranged on the pipe wall of the leachate collection pipe.

3. A method to enhance A 2 The method for treating low C / N ratio wastewater using an O-MBR system is characterized by... The method comprises the following steps: a. providing the enhanced A as claimed in any one of claims 1-2 2 O-MBR system for treating low carbon-nitrogen ratio sewage device; b. Adding biomass in the composting tank for composting treatment, and collecting the generated leachate in the leachate tank; c. Obtain activated sludge, distribute the activated sludge into the anaerobic tank, the anoxic tank and the aerobic tank, and start the enhanced A 2 O-MBR system for treating low carbon-nitrogen ratio sewage d. Inputting low-carbon-nitrogen-ratio wastewater into the anaerobic tank through a wastewater inlet pipe, and performing anaerobic decomposition on the low-carbon-nitrogen-ratio wastewater after fully mixing the low-carbon-nitrogen-ratio wastewater with the returned sludge from the anoxic tank, and releasing phosphorus; e. After the anaerobic decomposition, the wastewater flows into the anoxic tank, and the leachate in the leachate tank is supplied into the microbial fuel cell anode chamber arranged in the anoxic tank through a leachate inlet pipe, part of the refractory organic matter in the leachate is degraded in the anode chamber, the biodegradability of the leachate is improved, the leachate is added as a supplemental carbon source into the anoxic tank, and the leachate is fully mixed with the wastewater and the nitrification liquid returned from the aerobic tank for denitrification treatment; f. The anode electrogenic bacteria generate electrons by using the leachate as a substrate, the electrons are transmitted to the cathode through an external circuit, the autotrophic denitrifying bacteria attached to the surface of the cathode utilize the electrons transmitted to the cathode from the anode to perform autotrophic denitrification, and the removal of total nitrogen is strengthened; g. After the denitrification treatment, the wastewater flows into the aerobic tank for nitrification and aerobic phosphorus absorption treatment, and is filtered by a membrane assembly after the denitrification treatment, and is discharged through a drainage pipe.

4. The enhanced A of claim 3 2 The O-MBR system treatment method of low carbon-nitrogen ratio sewage, characterized in that, The nitrification liquid return ratio of the aerobic tank to the anoxic tank is 300%, and the sludge return ratio of the anoxic tank to the anaerobic tank is 100%.

5. The compound of claim 3, wherein A is 2 The O-MBR system treatment method of low carbon-nitrogen ratio sewage is characterized in that, The activated sludge is taken from the secondary sedimentation tank of a sewage plant, the taken activated sludge is left for 24 hours, then the supernatant, floating matter and large block sediment in the lower layer are removed, then low-carbon-nitrogen-ratio wastewater is added and is continuously exposed for 24 hours, and the residual organic matter in the microorganisms is removed.

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