A microbial electrocatalytic carbon capture membrane and its preparation method and application

Abstract

This application discloses a microbial electrocatalytic carbon capture membrane and its preparation method and application, which belongs to the field of carbon capture and storage and industrial wastewater treatment. The microbial electrocatalytic carbon capture membrane includes a microbial anode, an anion exchange membrane and a gas diffusion cathode that are composited in sequence, wherein the microorganisms in the microbial anode include electrogenic microorganisms. It is used for the synergistic reduction of wastewater pollution and flue gas decarbonization. The electrogenic microorganisms degrade organic matter in the wastewater and release electrons, H + and CO2; the electrons reach the cathode and reduce the coexisting O2 in the flue gas under the action of the catalyst to produce OH ‑ , OH ‑ Absorbs CO2 and converts it into CO3 2‑ ; Under the action of electric field force, CO3 2‑ Crossing the anion exchange membrane, the H released by the electrogenic microorganisms + Combined with conversion into CO2, synergistic enhancement of wastewater pollution reduction and flue gas decarbonization can be achieved, and coordinated emission reduction of organic pollutants and CO2 in water / air media can be achieved.

Description

Technical Field

[0001] The present application belongs to the technical field of carbon capture and storage and industrial wastewater treatment, and specifically relates to a microbial electrocatalytic carbon capture membrane and its preparation method and application. Background Art

[0002] Currently, the most mature thermally driven carbon capture process uses alkaline absorbents to capture CO2 at room temperature, and then desorbs it at elevated temperatures for recycling. However, the energy efficiency of the thermally driven carbon capture process is limited by the Carnot cycle. Typical alkanolamine absorbents cycle between 37°C and 117°C, with a theoretical energy efficiency limit of only 21%. In contrast, electrochemical carbon capture (ECC) circumvents the energy efficiency limitations of thermally driven carbon capture. ECC captures and releases CO2 through electrochemical reactions, achieving near-minimum CO2 separation work, i.e., 100% energy efficiency. Therefore, ECC is expected to minimize the energy consumption of the carbon capture process, thereby significantly reducing the cost of carbon capture and promoting the widespread deployment of CCS.

[0003] ECC has become a research hotspot in the field of carbon capture and storage (CCS) in recent years due to its advantages such as no energy efficiency limit, mild operating conditions and easy modularization. The Weber team at the University of California, Berkeley reported the most advanced ECC, which can generate 100 mA·cm -2 The current density and 80 kJ·mol -1 Energy consumption of CO2 is to capture CO2 directly from air containing 400 ppm CO2. According to the first law of thermodynamics, the minimum separation work of CO2 ( ) is equal to the difference in Gibbs free energy before and after the separation of CO2 in the gas mixture ( ), and its calculation formula is shown in formula (1).

[0004] …………Formula (1)

[0005] Where R is the ideal gas constant (8.314 J·mol -1 ·K -1 ), T is the system temperature (298.15 K), is the partial pressure of CO2 in the gas mixture (bar), is the ambient pressure (1 bar). From Equation (1), we can see that the minimum separation work for capturing CO2 from 400 ppm CO2 air is 19.4 kJ·mol -1 As a result, Weber's team achieved an energy efficiency of 24%, exceeding the energy efficiency limit of thermally driven carbon capture processes. However, the current low energy efficiency of ECC is still far from the requirements of practical applications. Summary of the Invention

[0006] 1. Problem to be solved

[0007] The present invention addresses the technical bottleneck of high energy consumption in traditional electrocatalytic carbon capture processes and provides a microbial electrocatalytic carbon capture membrane, a preparation method, and an application thereof. The membrane uses microbial electric self-driven carbon capture to simultaneously complete wastewater pollution reduction and flue gas decarbonization in the petrochemical industry, and realize a high-energy-efficiency carbon capture process.

[0008] 2. Technical Solution

[0009] In order to solve the above problems, the technical solutions adopted in this application are as follows:

[0010] In a first aspect, the present application provides a microbial electrocatalytic carbon capture membrane, which comprises a microbial anode, an anion exchange membrane and a gas diffusion cathode that are composited in sequence, wherein the microorganisms in the microbial anode include electrogenic microorganisms. Electrogenic microorganisms are a type of microorganism that can transfer electrons generated during their own metabolism to extracellular electron acceptors. In the presence of organic matter, the electrogenic microorganisms catalytically degrade the organic matter and release electrons, H + The anion exchange membrane is used to exchange anions between the anode and cathode. When a potential difference is generated between the anode and cathode, the anions cross the anion exchange membrane from the low potential side to the high potential side. The gas diffusion cathode includes an oxygen reduction catalyst, which is the site of the gas electrocatalytic reaction. The coexisting O2 in the flue gas is reduced to OH under the action of the oxygen reduction catalyst. - , these OH - Absorbs CO2 and converts it into CO3 2- .

[0011] Furthermore, the above-mentioned electrogenic microorganisms include Shewanella Genus and / or Geobacter Belongs to microorganisms.

[0012] Furthermore, the microbial anode is a carbon-based current collector loaded with activated sludge, and the activated sludge comes from a microbial fuel cell reactor.

[0013] Furthermore, the thickness of the carbon-based current collector in the above-mentioned microbial anode is 0.1~0.5 mm.

[0014] Furthermore, the volume density of the carbon-based current collector in the microbial anode is 0.3-0.5 g / cm 3 .

[0015] Furthermore, the porosity of the carbon-based current collector in the above-mentioned microbial anode is 70-80%.

[0016] Furthermore, the resistivity of the carbon-based current collector in the above-mentioned microbial anode is less than 100 mΩ·cm.

[0017] Furthermore, the anion exchange membrane is Fumasep FAA-3-PK-75 or Fumasep FAA-3-PK-130 or Fumasep FAB-PK-130, and the anion exchange membranes are all anion exchange membranes sold by Fumasep of Germany.

[0018] Furthermore, the gas diffusion cathode includes a carbon-based current collector and an oxygen reduction catalyst, and the oxygen reduction catalyst is loaded on the carbon-based current collector.

[0019] Furthermore, the oxygen reduction catalyst includes iron phthalocyanine and / or manganese phthalocyanine.

[0020] Furthermore, the thickness of the carbon-based current collector in the gas diffusion cathode is 0.1-0.5 mm.

[0021] Furthermore, the volume density of the carbon-based current collector in the gas diffusion cathode is 0.3-0.5 g / cm 3 .

[0022] Furthermore, the porosity of the carbon-based current collector in the gas diffusion cathode is 70-80%.

[0023] Furthermore, the resistivity of the carbon-based current collector in the gas diffusion cathode is less than 100 mΩ·cm.

[0024] Furthermore, the microbial electrocatalytic carbon capture membrane is composited with a wastewater flow channel network at the microbial anode, which is used as a wastewater flow channel.

[0025] Furthermore, the wastewater flow network is made of polypropylene or polyester.

[0026] Furthermore, the thickness of the wastewater flow channel network is 0.2~2.0 mm.

[0027] Furthermore, the mesh size of the above-mentioned wastewater flow channel network is 20~100 meshes.

[0028] Furthermore, the microbial electrocatalytic carbon capture membrane is composited with a gas flow channel network on the gas diffusion cathode, which is used as a gas flow channel.

[0029] Furthermore, the gas flow network is made of polypropylene or polyester.

[0030] Furthermore, the thickness of the gas flow channel network is 0.2-2.0 mm.

[0031] Furthermore, the mesh size of the gas flow channel network is 20-100 meshes.

[0032] In a second aspect, the present application provides a method for preparing the above-mentioned microbial electrocatalytic carbon capture membrane, the method comprising the following steps:

[0033] S1, preparation of microbial anode

[0034] The activated sludge from the microbial fuel cell reactor is shaken and broken up using glass microbeads to form a uniform activated sludge dispersion.

[0035] The activated sludge dispersion is loaded onto a carbon-based current collector by suction filtration to form a microbial anode. Suction filtration helps the activated sludge to quickly form a biofilm on the carbon-based current collector, shortening the acclimatization time of the microbial anode.

[0036] S2, preparation of gas diffusion cathode

[0037] The multi-walled carbon nanotube and Nafion solution are added to an anhydrous ethanol solution, and ultrasonic treatment is performed to form a uniform multi-walled carbon nanotube dispersion; the oxygen reduction catalyst is added to the anhydrous ethanol solution, and ultrasonic treatment is performed to form a uniform oxygen reduction catalyst dispersion;

[0038] Adding the oxygen reduction catalyst dispersion dropwise to the multi-walled carbon nanotube dispersion, stirring and mixing to form a gas diffusion cathode precursor solution;

[0039] The gas diffusion cathode precursor liquid is loaded onto the carbon-based current collector by spraying to form a gas diffusion cathode;

[0040] S3, Preparation of Microbial Electrocatalytic Carbon Capture Membrane

[0041] A microbial electrocatalytic carbon capture membrane is compositely formed in the order of microbial anode, anion exchange membrane and gas diffusion cathode, or wastewater flow channel network, microbial anode, anion exchange membrane, gas diffusion cathode and gas flow channel network.

[0042] Furthermore, the sludge concentration in the activated sludge dispersion is 1.0-10 g / L.

[0043] Furthermore, the loading amount of activated sludge on the carbon-based current collector is 10-1000 mg / cm 2 .

[0044] Furthermore, the shaking and breaking up includes: adding glass beads to the activated sludge from the microbial fuel cell reactor and shaking and breaking up the sludge.

[0045] Furthermore, the average diameter of the glass microbeads is 10-1000 μm.

[0046] Furthermore, in the above S1, the thickness of the carbon-based current collector is 0.1-0.5 mm.

[0047] Furthermore, in the above S1, the volume density of the carbon-based current collector is 0.3-0.5 g / cm 3 .

[0048] Furthermore, in the above S1, the porosity of the carbon-based current collector is 70-80%.

[0049] Furthermore, in the above S1, the resistivity of the carbon-based current collector is less than 100 mΩ·cm.

[0050] Furthermore, the concentration of the multi-walled carbon nanotube dispersion is 0.1-1.0 g / L.

[0051] Furthermore, the concentration of the Nafion solution is 5-20 wt%.

[0052] Furthermore, the volume ratio of the Nafion solution to anhydrous ethanol is 1:1000 to 1:10000.

[0053] Furthermore, the oxygen reduction catalyst is iron phthalocyanine and / or manganese phthalocyanine.

[0054] Furthermore, the concentration of the oxygen reduction catalyst dispersion is 1.0-100 mg / L.

[0055] Furthermore, the ultrasonic treatment time is 2.0~6.0 h.

[0056] Furthermore, the dropwise addition rate of the oxygen reduction catalyst dispersion is 0.1-100 mL / min.

[0057] Furthermore, in the above S2, the thickness of the carbon-based current collector is 0.1-0.5 mm.

[0058] Furthermore, in the above S2, the volume density of the carbon-based current collector is 0.3-0.5 g / cm 3 .

[0059] Furthermore, in the above S2, the porosity of the carbon-based current collector is 70-80%.

[0060] Furthermore, in the above S2, the resistivity of the carbon-based current collector is less than 100 mΩ·cm.

[0061] Furthermore, the anion exchange membrane is Fumasep FAA-3-PK-75, Fumasep FAA-3-PK-130 or FAB-PK-130.

[0062] Furthermore, the wastewater flow network is made of polypropylene or polyester.

[0063] Furthermore, the thickness of the wastewater flow channel network is 0.2~2.0 mm.

[0064] Furthermore, the mesh size of the above-mentioned wastewater flow channel network is 20~100 meshes.

[0065] Furthermore, the gas flow network is made of polypropylene or polyester.

[0066] Furthermore, the thickness of the gas flow channel network is 0.2-2.0 mm.

[0067] Furthermore, the mesh size of the gas flow channel network is 20-100 meshes.

[0068] In a third aspect, the present application provides an application of the above-mentioned microbial electrocatalytic carbon capture membrane or its preparation method in the synergistic reduction of wastewater pollution and flue gas decarbonization, the application comprising the following steps:

[0069] M1, pumps the wastewater into the wastewater flow network of the microbial electrocatalytic carbon capture membrane, and the electrogenic microorganisms on the microbial anode catalyze the degradation of organic matter in the wastewater, releasing electrons and H + and CO2, with electrons transferred to the external circuit through the microbial anode interface;

[0070] M2, the flue gas after desulfurization and denitrification is pumped into the gas flow network of the microbial electrocatalytic carbon capture membrane. The electrons reach the cathode and reduce the O2 in the flue gas to produce OH under the action of the catalyst. - , these OH - Absorbs CO2 and converts it into CO3 2- Under the action of the electric field force generated by the potential difference between the microbial anode and the gas diffusion cathode, CO3 2- Crossing the anion exchange membrane, the H released by the electrogenic microorganisms + Combined with conversion into CO2, synergistic treatment of wastewater pollution reduction and flue gas decarbonization can be achieved.

[0071] Furthermore, the above application also includes:

[0072] M3, pumps the effluent from the wastewater flow network into the air stripping membrane to remove CO2 from the wastewater.

[0073] Furthermore, an external power supply can be connected between the microbial anode and the gas diffusion cathode to generate a larger current through the voltage of the external power supply, thereby increasing the CO2 capture rate in the flue gas.

[0074] Furthermore, the hydraulic retention time of the above-mentioned wastewater in the wastewater flow network is 1.0~6.0 h.

[0075] Furthermore, the flow rate of the flue gas after desulfurization and denitrification in the gas flow network is 1.0~100 mL / min.

[0076] Furthermore, the pressure difference between the liquid phase and the gas phase in the above-mentioned air stripping membrane is controlled at 1~100 kPa.

[0077] Furthermore, the above applications include: synergistic emission reduction for wastewater pollution reduction and flue gas decarbonization in the petrochemical industry.

[0078] 3. Beneficial effects

[0079] Compared with the prior art, the present application has the following advantages:

[0080] (1) This application provides a microbial electrocatalytic carbon capture membrane and its preparation method and application. The microorganisms in the microbial anode include electrogenic microorganisms. Electrogenic microorganisms can catalytically degrade organic matter in wastewater and release H + , CO2 and electrons, which are transferred through the microbial anode interface and reach the gas diffusion cathode interface through the external loop, not only degrading the organic matter in the wastewater into H for further reaction, but also + and recyclable CO2, achieving wastewater pollution reduction treatment; at the same time, the electrons generated also realize microbial electric self-driven carbon capture, without the need for external power supply, which can minimize the energy consumption of carbon capture.

[0081] (2) This application provides a microbial electrocatalytic carbon capture membrane and its preparation method and application. The electrons released by the electrogenic microorganisms are transferred through the microbial anode interface and the external circuit to the gas diffusion cathode interface, and the oxygen reduction catalyst reduces the O2 in the flue gas to produce OH. - , these OH - Absorbs CO2 and converts it into CO3 2- ;CO3 under the action of electric field 2- Crossing the anion exchange membrane, the H released by the electrogenic microorganisms + Combined with conversion into CO2, the coordinated management of wastewater pollution reduction and flue gas decarbonization is achieved.

[0082] (3) This application provides a microbial electrocatalytic carbon capture membrane and its preparation method and application, which can be used in parallel according to the treatment volume of wastewater and flue gas, and applied to different scenarios, which is convenient for promotion and use. It is used for the synergistic reduction of wastewater pollution and flue gas decarbonization in the petrochemical industry, which can significantly reduce the energy consumption of carbon capture and achieve 9.7 kJ·mol -1 The energy consumption of CO2 is to capture CO2 directly from flue gas with 8.5% CO2. According to formula (1), the minimum separation work for capturing CO2 from flue gas with 8.5% CO2 is 6.1 kJ·mol -1 Therefore, the carbon capture process of the present application achieves an energy efficiency of 63%, which exceeds the current most advanced ECC carbon capture process. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 This is a diagram of the structure and working principle of the microbial electrocatalytic carbon capture membrane.

[0084] Figure 2 It is the performance evaluation of microbial electrocatalytic carbon capture membrane, where: (A) is the current density and Faraday efficiency at different cell pressures, the circle represents the current density, and the diamond represents the Faraday efficiency; (B) is the carbon capture rate and energy efficiency at different cell pressures, the light color represents the carbon capture rate, and the dark color represents the energy efficiency. DETAILED DESCRIPTION

[0085] The present application is further described below with reference to specific embodiments.

[0086] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0087] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or those recommended by the manufacturer. All reagents or instruments used, if the manufacturer is not specified, are commercially available conventional products.

[0088] Concentration, amount and other numerical data can be presented in range format herein.It should be understood that such range format is used only for convenience and brevity, and should be flexibly interpreted as not only including the numerical value clearly stated as the range limit, but also including all individual numerical values ​​or sub-ranges encompassed within the range, just as each numerical value and sub-range is clearly stated.For example, a numerical range of about 1 to about 4.5 should be interpreted as including not only the clearly stated limit value of 1 to about 4.5, but also including individual numbers (such as 2, 3, 4) and sub-ranges (such as 1 to 3, 2 to 4, etc.).The same principle applies to the range of only narrating a numerical value, such as "less than about 4.5", which should be interpreted as including all the above-mentioned values ​​and ranges.In addition, no matter how the breadth of the described range or feature is, this interpretation should be applied.

[0089] As used herein, exoelectrogenic microorganisms, also known as electrochemically active bacteria (EAB), are a type of microorganism that can transfer electrons generated during its own metabolism to extracellular electron acceptors.

[0090] As used herein, a microbial fuel cell reactor is a reactor that utilizes a microbial fuel cell electrode enrichment method to enrich electricity-producing microorganisms, and its activated sludge is rich in electricity-producing microorganisms.

[0091] As used herein, compounding is the process of combining different materials together. Those skilled in the art will appreciate that compounding includes a variety of technical means. For example, cold rolling compounding involves forcibly pressing different materials together through a rolling mill at room temperature to achieve a layered composite effect.

[0092] Example 1

[0093] This embodiment provides a microbial electrocatalytic carbon capture membrane and a preparation method thereof.

[0094] A microbial electrocatalytic carbon capture membrane, the structure of which is as follows Figure 1 As shown, it includes a wastewater flow channel network, a microbial anode, an anion exchange membrane, a gas diffusion cathode, and a gas flow channel network that are composited in sequence, wherein:

[0095] The material of the wastewater flow channel net is polyester, with a thickness of 0.5 mm and a mesh size of 20 mesh;

[0096] The microorganisms in the microbial anode include electrochemically active bacteria (EAB), which include Shewanella Genus and / or Geobacter Genus; in this embodiment, the microbial anode is a carbon-based current collector loaded with activated sludge from a microbial fuel cell reactor; the anion exchange membrane is Fumasep FAA-3-PK-130;

[0097] The gas diffusion cathode is a carbon-based current collector loaded with an oxygen reduction catalyst; in this embodiment, the oxygen reduction catalyst is iron phthalocyanine;

[0098] The gas flow channel net is made of polyester, with a thickness of 0.5 mm and a mesh size of 20 meshes.

[0099] The method for preparing a microbial electrocatalytic carbon capture membrane comprises the following steps:

[0100] S1, preparation of microbial anode

[0101] Take Municipal Wastewater Treatment Plant A 2 The activated sludge from the anaerobic tank in the / O process was used as inoculum, and the electrogenic microorganisms in the activated sludge were enriched using the microbial fuel cell electrode enrichment method. When a stable current appeared, it was considered that the activated sludge enrichment culture had produced electrogenic microorganisms. 100 μm glass microbeads were added to the activated sludge from the microbial fuel cell reactor and the mixture was shaken to form an activated sludge dispersion with a suspended solids concentration of 1.0 g / L.

[0102] The activated sludge dispersion was evenly loaded onto a carbon-based current collector (Toray TGP-H-060, Japan, thickness 0.19 mm, volume density 0.44 g / cm) by suction filtration. 3 , porosity 78%, resistivity 80 mΩ·cm) to form a microbial anode;

[0103] S2, preparation of gas diffusion cathode

[0104] 100 mg of multi-walled carbon nanotubes (MWCNTs, Aladdin, C139872) and 20 μL of 5.0 wt% Nafion solution (Dupont, D-520) were added to 100 mL of anhydrous ethanol and sonicated to form a 1.0 g / L MWCNT dispersion.

[0105] 2.0 mg of oxygen reduction catalyst iron phthalocyanine (FePc, Aladdin, I157718) was added to 100 mL of anhydrous ethanol and ultrasonicated at 300 W for 4.0 h to form an oxygen reduction catalyst dispersion with a concentration of 20 mg / L.

[0106] The oxygen reduction catalyst dispersion was added dropwise to the multi-walled carbon nanotube dispersion at a dropping rate of 1.0 mL / min, and stirred to form a gas diffusion cathode precursor solution;

[0107] The gas diffusion cathode precursor liquid was evenly loaded onto the carbon-based current collector (Toray TTGP-H-060, Japan, thickness 0.19 mm, volume density 0.44 g / cm) by spraying. 3 , porosity 78%, resistivity 80 mΩ·cm) to form a gas diffusion cathode;

[0108] S3, Preparation of Microbial Electrocatalytic Carbon Capture Membrane

[0109] The microbial electrocatalytic carbon capture membrane was formed by cold rolling and compounding the wastewater flow channel net (made of polyester, 0.5 mm thick, and 20 mesh), microbial anode, anion exchange membrane (Fumasep, FAA-3-PK-130), gas diffusion cathode and gas flow channel net (made of polyester, 0.5 mm thick, and 20 mesh).

[0110] Example 2

[0111] This embodiment provides the application of microbial electrocatalytic carbon capture membranes in the coordinated treatment of wastewater pollution reduction and flue gas decarbonization in the petrochemical industry.

[0112] In this embodiment,

[0113] The water quality characteristics of wastewater from the petrochemical industry are as follows: COD concentration ~3400 mg / L, ammonia nitrogen concentration ~120 mg / L, and pH between 7 and 9;

[0114] The flue gas composition of the petrochemical industry is as follows: CO2 accounts for 8.5%, O2 accounts for 10.7%, N2 accounts for 80%, and water vapor accounts for 0.3%.

[0115] The app includes:

[0116] M1, pumping petrochemical wastewater into the wastewater flow network of microbial electrocatalytic carbon capture membrane with a hydraulic retention time of 4.0h;

[0117] M2, the flue gas after desulfurization and denitrification was pumped into the gas flow network of the microbial electrocatalytic carbon capture membrane at a flow rate of 10 mL / min; the CO2 concentration in the effluent of the microbial electrocatalytic carbon capture membrane was controlled by a constant potential instrument, and the carbon capture Faraday efficiency, carbon capture rate and carbon capture energy consumption of the microbial electrocatalytic carbon capture membrane under different cell pressures were calculated;

[0118] M3, pumps the effluent from the wastewater flow network into the air stripping membrane, controls the pressure difference between the liquid and gas phases to be 10 kPa, and realizes the removal of CO2 from the wastewater;

[0119] The principle of this application is as follows Figure 1 As shown:

[0120] Electrogenic microorganisms (EAB) on the microbial anode catalyze the degradation of organic matter in wastewater and release electrons, H + and CO2, with electrons transferred to the external circuit through the microbial anode interface;

[0121] The electrons reach the cathode and reduce O2 in the flue gas to produce OH under the action of iron phthalocyanine molecules. - , these OH - Absorbs CO2 and converts it into CO3 2- ;

[0122] Under the action of the electric field force generated by the potential difference between the microbial anode and the gas diffusion cathode or the electric field force generated by the external power supply voltage, CO3 2- Crossing the anion exchange membrane, the H released by the electrogenic microorganisms + Combined with conversion into CO2, synergistic treatment of wastewater pollution reduction and flue gas decarbonization can be achieved.

[0123] Result analysis:

[0124] The results are as follows Figure 2 As shown, at a cell voltage of 0.05 V, a charge transfer rate of 1.21 mA cm -2 The current density ( Figure 2 Middle A), 99.8% Faraday efficiency ( Figure 2 (middle A), 2.8 mg m -2 s -1 The carbon capture rate ( Figure 2 Medium B) and 63% energy efficiency ( Figure 2 (B). At an inter-cell voltage of 0.1 V, a flow rate of 1.36 mA cm was achieved. -2 The current density ( Figure 2 Middle A), 99.5% Faraday efficiency ( Figure 2 (middle A), 3.1 mg m -2 s -1 The carbon capture rate ( Figure 2 Middle B) and 31% energy efficiency ( Figure 2 Middle B).

Claims

1. A microbial electrocatalytic carbon capture membrane, characterized in that: The microbial electrocatalytic carbon capture membrane comprises a microbial anode, an anion exchange membrane and a gas diffusion cathode which are composited in sequence; wherein: the microorganisms in the microbial anode include electricity-producing microorganisms; the gas diffusion cathode includes an oxygen reduction catalyst; the microbial anode is a carbon-based current collector loaded with activated sludge, and the activated sludge comes from a microbial fuel cell reactor; the gas diffusion cathode is a carbon-based current collector loaded with an oxygen reduction catalyst; the microbial electrocatalytic carbon capture membrane is composited with a wastewater flow channel network on the microbial anode; and with a gas flow channel network on the gas diffusion cathode; The preparation method of the microbial electrocatalytic carbon capture membrane comprises the following steps: S1, preparation of microbial anode The activated sludge from the microbial fuel cell reactor is shaken and broken up using glass microbeads to form a uniform activated sludge dispersion. The activated sludge dispersion is then loaded onto a carbon-based current collector by filtration to form a microbial anode. S2, preparation of gas diffusion cathode The multi-walled carbon nanotube and Nafion solution are added to an anhydrous ethanol solution, and ultrasonic treatment is performed to form a uniform multi-walled carbon nanotube dispersion; the oxygen reduction catalyst is added to the anhydrous ethanol solution, and ultrasonic treatment is performed to form a uniform oxygen reduction catalyst dispersion; Adding the oxygen reduction catalyst dispersion dropwise to the multi-walled carbon nanotube dispersion, stirring and mixing to form a gas diffusion cathode precursor solution; The gas diffusion cathode precursor liquid is loaded onto the carbon-based current collector by spraying to form a gas diffusion cathode; S3, Preparation of Microbial Electrocatalytic Carbon Capture Membrane A microbial electrocatalytic carbon capture membrane is formed by cold rolling and laminating in the order of a wastewater flow channel network, a microbial anode, an anion exchange membrane, a gas diffusion cathode and a gas flow channel network.

2. The microbial electrocatalytic carbon capture membrane according to claim 1, characterized in that: The electrogenic microorganisms include Shewanella Genus and / or Geobacter and / or the oxygen reduction catalyst comprises iron phthalocyanine and / or manganese phthalocyanine.

3. A microbial electrocatalytic carbon capture membrane according to claim 1 or 2, characterized in that: The anion exchange membrane is Fumasep FAA-3-PK-75, Fumasep FAA-3-PK-130 or Fumasep FAB-PK-130.

4. The microbial electrocatalytic carbon capture membrane according to claim 3, characterized in that: The thickness of the carbon-based current collector is 0.1-0.5 mm; and / or the volume density of the carbon-based current collector is 0.3-0.5 g / cm 3 ; and / or the porosity of the carbon-based current collector is 70-80%; and / or the resistivity of the carbon-based current collector is less than 100 mΩ·cm.

5. The microbial electrocatalytic carbon capture membrane according to claim 4, characterized in that: The material of the wastewater flow network is polypropylene or polyester; and / or the thickness of the wastewater flow network is 0.2~2.0 mm; and / or the mesh size of the wastewater flow network is 20~100 mesh; and / or the material of the gas flow network is polypropylene or polyester; and / or the thickness of the gas flow network is 0.2~2.0 mm; and / or the mesh size of the gas flow network is 20~100 mesh.

6. The microbial electrocatalytic carbon capture membrane according to claim 5, characterized in that: The sludge concentration in the activated sludge dispersion is 1.0-10 g / L; and / or the activated sludge loading on the carbon-based current collector is 10-1000 mg / cm 2 ; and / or the concentration of the multi-walled carbon nanotube dispersion is 0.1~1.0 g / L; and / or the concentration of the Nafion solution is 1~20 wt%; and / or the volume ratio of the Nafion solution dosage to anhydrous ethanol is 1:1000~1:10000; and / or the oxygen reduction catalyst is an iron phthalocyanine molecule and / or a manganese phthalocyanine molecule; and / or the concentration of the oxygen reduction catalyst dispersion is 1.0~100 mg / L; and / or the ultrasonic treatment time is 2.0~6.0 h; and / or the dripping rate of the oxygen reduction catalyst dispersion is 0.1~100 mL / min.

7. Use of a microbial electrocatalytic carbon capture membrane according to any one of claims 1 to 6 in the synergistic reduction of wastewater pollution and flue gas decarbonization.

8. The use according to claim 7, characterized in that The application comprises the following steps: M1, pumps wastewater into the wastewater flow network of microbial electrocatalytic carbon capture membrane; M2, pumps the flue gas after desulfurization and denitrification into the gas flow network of the microbial electrocatalytic carbon capture membrane; M3, pumps the effluent from the wastewater flow network into the air stripping membrane to remove CO2 from the wastewater.

9. The use according to claim 8, characterized in that An external power supply is connected between the microbial anode and the gas diffusion cathode; and / or the hydraulic retention time of the wastewater in the wastewater flow network is 1.0~6.0 h; and / or the flow rate of the flue gas after desulfurization and denitrification in the gas flow network is 1.0~100mL / min; and / or the pressure difference between the liquid phase and the gas phase in the gas stripping membrane is controlled at 1~100 kPa.

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