Microbial electro-catalysis carbon capture membrane as well as preparation method and application thereof

Abstract

The invention discloses a microbial electro-catalysis carbon capture membrane as well as a preparation method and application thereof, and belongs to the field of carbon capture and storage and industrial wastewater treatment. The microbial electrocatalytic carbon capture membrane comprises a microbial anode, an anion exchange membrane and a gas diffusion cathode which are sequentially compounded, wherein microorganisms in the microbial anode comprise electrogenic microorganisms. The method is used for cooperative emission reduction of wastewater pollution reduction and flue gas decarburization, and electrogenesis type microorganisms degrade organic matters in wastewater and release electrons, H < + > and CO2; the electrons reach the cathode and reduce coexisting O2 in the flue gas under the action of the catalyst to generate OH <->, and the OH <-> absorbs CO2 and converts the CO2 into CO3 < 2->; under the action of electric field force, CO3 < 2-> crosses the anion exchange membrane and is combined with H < + > released by the electrogenic microorganisms to be converted into CO2, so that the synergistic interaction of wastewater pollution reduction and flue gas decarburization is realized, and the synergistic emission reduction of organic pollutants and CO2 in a water / gas medium is realized.

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 a preparation method and application thereof. Background Art

[0002] The most mature thermally driven carbon capture process currently uses alkaline absorbents to capture CO at room temperature. 2 , and then the temperature is raised to desorb 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, and their theoretical energy efficiency limit is only 21%. In contrast, electrochemical carbon capture (ECC) circumvents the energy efficiency limitations of thermally driven carbon capture. ECC is a process that uses electrochemical reactions to achieve CO 2 The capture and release of CO 2 Minimum separation work operation, that is, 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 restrictions, 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 CO 2 Energy consumption from 400 ppm CO 2 Direct capture of CO from the air 2 According to the first law of thermodynamics, CO 2 The minimum separation work ( ) is equal to CO in the gas mixture 2 The difference in Gibbs free energy before and after separation ( ), and its calculation formula is shown in formula (1).

[0004] …………Formula (1) Where R is the ideal gas constant (8.314 J·mol -1 ·K -1 ), T is the system temperature (298.15 K), CO in the gas mixture 2 Partial pressure (bar), is the ambient pressure (1 bar). From equation (1), we can see that from 400 ppm CO 2 Capture CO from the air 2The minimum separation work is 19.4 kJ·mol -1 CO 2 As a result, Weber's team achieved an energy efficiency of 24%, which exceeds the energy efficiency limit of the thermally driven carbon capture process. However, the current low energy efficiency of ECC is still far from the actual application requirements. Summary of the invention

[0005] 1. Problem to be solved In view of the technical bottleneck of high energy consumption in the traditional electrocatalytic carbon capture process, the present invention provides a microbial electrocatalytic carbon capture membrane and its preparation method and application. The membrane can simultaneously complete wastewater pollution reduction and flue gas decarbonization in the petrochemical industry through microbial electrical self-driven carbon capture, and realize a carbon capture process with high energy efficiency.

[0006] 2. Technical solution In order to solve the above problems, the technical solutions adopted in this application are as follows: 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 which are composited in sequence, wherein the microorganisms in the microbial anode include electrogenic microorganisms, which are microorganisms that can transfer electrons generated in 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 the cathode. When a potential difference is generated between the anode and the 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. O 2 Oxygen reduction catalyst is used to reduce the - , these OH - Absorbing CO 2 and convert it into CO 3 2- .

[0007] Furthermore, the above-mentioned electrogenic microorganisms include Shewanella Genus and / or Geobacter Belongs to microorganisms.

[0008] 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.

[0009] Furthermore, the thickness of the carbon-based current collector in the above-mentioned microbial anode is 0.1~0.5 mm.

[0010] Furthermore, the volume density of the carbon-based current collector in the microbial anode is 0.3-0.5 g / cm3 .

[0011] Furthermore, the porosity of the carbon-based current collector in the above-mentioned microbial anode is 70-80%.

[0012] Furthermore, the resistivity of the carbon-based current collector in the above-mentioned microbial anode is less than 100 mΩ·cm.

[0013] 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.

[0014] Furthermore, the gas diffusion cathode comprises a carbon-based current collector and an oxygen reduction catalyst, and the oxygen reduction catalyst is loaded on the carbon-based current collector.

[0015] Furthermore, the oxygen reduction catalyst includes iron phthalocyanine and / or manganese phthalocyanine.

[0016] Furthermore, the thickness of the carbon-based current collector in the above-mentioned gas diffusion cathode is 0.1~0.5 mm.

[0017] Furthermore, the volume density of the carbon-based current collector in the gas diffusion cathode is 0.3-0.5 g / cm 3 .

[0018] Furthermore, the porosity of the carbon-based current collector in the gas diffusion cathode is 70-80%.

[0019] Furthermore, the resistivity of the carbon-based current collector in the gas diffusion cathode is less than 100 mΩ·cm.

[0020] Furthermore, the above-mentioned microbial electrocatalytic carbon capture membrane is compounded with a wastewater flow channel network at the microbial anode, which is used as a wastewater flow channel.

[0021] Furthermore, the wastewater flow channel network is made of polypropylene or polyester.

[0022] Furthermore, the thickness of the above-mentioned wastewater flow channel network is 0.2~2.0 mm.

[0023] Furthermore, the mesh size of the above-mentioned wastewater flow channel network is 20~100 meshes.

[0024] 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.

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

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

[0027] Furthermore, the mesh size of the gas flow channel network is 20-100 meshes.

[0028] 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: 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 loaded onto the carbon-based current collector by suction filtration to form a microbial anode; suction filtration helps the activated sludge to form a biofilm quickly on the carbon-based current collector, thus shortening the acclimatization time of the microbial anode; S2, Preparation of Gas Diffusion Cathode The multi-walled carbon nanotubes and Nafion solution are added to an anhydrous ethanol solution, and a uniform multi-walled carbon nanotube dispersion is formed after ultrasonic treatment; the oxygen reduction catalyst is added to the anhydrous ethanol solution, and a uniform oxygen reduction catalyst dispersion is formed after ultrasonic treatment; Adding the oxygen reduction catalyst dispersion dropwise into 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 compositely formed in the order of microbial anode, anion exchange membrane and gas diffusion cathode, or wastewater flow network, microbial anode, anion exchange membrane, gas diffusion cathode and gas flow network.

[0029] Furthermore, the sludge concentration in the above-mentioned activated sludge dispersion is 1.0~10 g / L.

[0030] Furthermore, the loading amount of activated sludge on the carbon-based current collector is 10-1000 mg / cm 2 .

[0031] Furthermore, the shaking and breaking up comprises: adding glass beads to the activated sludge from the microbial fuel cell reactor and shaking and breaking up.

[0032] Furthermore, the average diameter of the glass microspheres is 10-1000 μm.

[0033] Furthermore, in the above S1, the thickness of the carbon-based current collector is 0.1-0.5 mm.

[0034] Furthermore, in the above S1, the volume density of the carbon-based current collector is 0.3-0.5 g / cm 3 .

[0035] Furthermore, in the above S1, the porosity of the carbon-based current collector is 70-80%.

[0036] Furthermore, in the above S1, the resistivity of the carbon-based current collector is less than 100 mΩ·cm.

[0037] Furthermore, the concentration of the multi-walled carbon nanotube dispersion is 0.1-1.0 g / L.

[0038] Furthermore, the concentration of the Nafion solution is 5-20 wt%.

[0039] Furthermore, the volume ratio of the Nafion solution to anhydrous ethanol is 1:1000 to 1:10000.

[0040] Furthermore, the oxygen reduction catalyst is iron phthalocyanine and / or manganese phthalocyanine.

[0041] Furthermore, the concentration of the oxygen reduction catalyst dispersion is 1.0-100 mg / L.

[0042] Furthermore, the ultrasonic treatment time is 2.0~6.0 h.

[0043] Furthermore, the dropping speed of the oxygen reduction catalyst dispersion is 0.1-100 mL / min.

[0044] Furthermore, in the above S2, the thickness of the carbon-based current collector is 0.1~0.5 mm.

[0045] Furthermore, in the above S2, the volume density of the carbon-based current collector is 0.3-0.5 g / cm 3 .

[0046] Furthermore, in the above S2, the porosity of the carbon-based current collector is 70-80%.

[0047] Furthermore, in the above S2, the resistivity of the carbon-based current collector is less than 100 mΩ·cm.

[0048] Furthermore, the anion exchange membrane is Fumasep FAA-3-PK-75 or Fumasep FAA-3-PK-130 or FAB-PK-130.

[0049] Furthermore, the wastewater flow channel network is made of polypropylene or polyester.

[0050] Furthermore, the thickness of the above-mentioned wastewater flow channel network is 0.2~2.0 mm.

[0051] Furthermore, the mesh size of the above-mentioned wastewater flow channel network is 20~100 meshes.

[0052] Furthermore, the gas flow channel network is made of polypropylene or polyester.

[0053] Furthermore, the thickness of the gas flow channel network is 0.2-2.0 mm.

[0054] Furthermore, the mesh size of the gas flow channel network is 20-100 meshes.

[0055] 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 reduction and flue gas decarbonization, and the application comprises the following steps: M1, pumps wastewater into the wastewater flow network of the microbial electrocatalytic carbon capture membrane, and the electrogenic microorganisms on the microbial anode catalytically degrade the organic matter in the wastewater and release electrons, H + and CO 2 , electrons are transferred to the external circuit through the microbial anode interface; M2, the flue gas after desulfurization and denitrification is pumped into the gas flow network of the microbial electrocatalytic carbon capture membrane, and the electrons reach the cathode and reduce the O in the flue gas under the action of the catalyst. 2 Produces OH - , these OH - Absorbing CO 2 and convert it into CO 3 2- Under the action of the electric field force generated by the potential difference between the microbial anode and the gas diffusion cathode, CO 3 2- Crossing the anion exchange membrane, the H released by the electrogenic microorganisms + Combined with CO 2 , achieving coordinated management of wastewater pollution reduction and flue gas decarbonization.

[0056] Furthermore, the above application also includes: M3, pumps the effluent from the wastewater flow network into the air stripping membrane to achieve CO 2 of escape.

[0057] 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 CO 2 Capture rate.

[0058] Furthermore, the hydraulic retention time of the above wastewater in the wastewater flow network is 1.0~6.0 h.

[0059] Furthermore, the flow rate of the flue gas after desulfurization and denitrification in the gas flow network is 1.0~100 mL / min.

[0060] 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.

[0061] Furthermore, the above applications include: being used for synergistic emission reduction of wastewater pollution and flue gas decarbonization in the petrochemical industry.

[0062] 3. Beneficial effects Compared with the prior art, the present application has the following beneficial effects: (1) The present application provides a microbial electrocatalytic carbon capture membrane and a preparation method and application thereof. The microorganisms in the microbial anode include electrogenic microorganisms. The electrogenic microorganisms can catalytically degrade organic matter in wastewater and release H + , CO 2 The electrons are transferred through the microbial anode interface and reach the gas diffusion cathode interface through the external loop, which not only degrades the organic matter in the wastewater into H for further reaction, but also + and recyclable CO 2 , 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.

[0063] (2) The present 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 O in the flue gas is reduced under the action of the oxygen reduction catalyst. 2 Produces OH - , these OH - Absorbing CO 2 and convert it into CO 3 2- ; Under the action of electric field, CO 3 2- Crossing the anion exchange membrane, the H released by the electrogenic microorganisms + Combined with CO 2 , achieving the coordinated management of wastewater pollution reduction and flue gas decarbonization.

[0064] (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 coordinated 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 CO 2 Energy consumption from 8.5% CO 2 Direct capture of CO from flue gas2 From formula (1), we can see that from 8.5% CO 2 Capture CO from flue gas 2 The minimum separation work is 6.1 kJ·mol -1 CO 2 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

[0065] Figure 1 This is a diagram of the structure and working principle of the microbial electrocatalytic carbon capture membrane.

[0066] Figure 2 It is the performance evaluation of microbial electrocatalytic carbon capture membrane, where: (A) is the current density and Faraday efficiency under 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 under different cell pressures, the light color represents the carbon capture rate, and the dark color represents the energy efficiency. DETAILED DESCRIPTION

[0067] The present application is further described below in conjunction with specific embodiments.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled 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.

[0069] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0070] 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 contained in the range, just as each numerical value and sub-range are clearly stated.For example, the numerical range of about 1 to about 4.5 should be interpreted as not only including the limit value of 1 to about 4.5 clearly stated, 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 is applicable 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.

[0071] 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.

[0072] As used herein, a microbial fuel cell reactor is a reactor that uses a microbial fuel cell electrode enrichment method to enrich electricity-producing microorganisms, and its activated sludge is rich in electricity-producing microorganisms.

[0073] As used herein, compounding is the combination of different materials. Those skilled in the art will appreciate that compounding includes a variety of technical means. For example, cold rolling compounding is the process of strongly pressing different materials together at room temperature through a rolling mill to achieve a layered composite effect.

[0074] Example 1 This embodiment provides a microbial electrocatalytic carbon capture membrane and a preparation method thereof.

[0075] A microbial electrocatalytic carbon capture membrane having a structure such as 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 which are composited in sequence, wherein: The material of the wastewater flow channel net is polyester, with a thickness of 0.5 mm and a mesh size of 20 meshes; 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; 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; The material of the gas flow channel net is polyester, the thickness is 0.5 mm, and the mesh size is 20 mesh.

[0076] The method for preparing the microbial electrocatalytic carbon capture membrane comprises the following steps: S1, Preparation of microbial anode Take Municipal Wastewater Treatment Plant A 2The activated sludge from the anaerobic tank in the / O process was used as an inoculum, and the electrogenic microorganisms in the activated sludge were enriched by the microbial fuel cell electrode enrichment method. When a stable current appeared, it was considered that the activated sludge enrichment culture produced electrogenic microorganisms; 100 μm glass beads were added to the activated sludge from the microbial fuel cell reactor, and the mixed liquid was shaken and dispersed to form an activated sludge dispersion with a suspended solid concentration of 1.0 g / L; 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 3 , porosity 78%, resistivity 80 mΩ·cm) to form a microbial anode; S2, Preparation of Gas Diffusion Cathode 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 ultrasonically treated to form a 1.0 g / L multi-walled carbon nanotube dispersion; 2.0 mg of oxygen reduction catalyst iron phthalocyanine (FePc, Aladdin, I157718) was added to 100 mL of anhydrous ethanol and subjected to ultrasonic treatment at 300 W for 4.0 h to form an oxygen reduction catalyst dispersion with a concentration of 20 mg / L; The oxygen reduction catalyst dispersion liquid is added dropwise to the multi-walled carbon nanotube dispersion liquid at a dropping speed of 1.0 mL / min, and stirred to form a gas diffusion cathode precursor liquid; The gas diffusion cathode precursor liquid was uniformly 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; S3, Preparation of microbial electrocatalytic carbon capture membrane The microbial electrocatalytic carbon capture membrane was formed by cold rolling composite method in the order of wastewater flow channel net (polyester material, thickness 0.5 mm, mesh size 20 mesh), microbial anode, anion exchange membrane (Fumasep, FAA-3-PK-130), gas diffusion cathode and gas flow channel net (polyester material, thickness 0.5 mm, mesh size 20 mesh).

[0077] Example 2 This embodiment provides the application of microbial electrocatalytic carbon capture membrane in the coordinated treatment of wastewater pollution reduction and flue gas decarbonization in the petrochemical industry.

[0078] In this embodiment, The water quality characteristics of wastewater from the petrochemical industry are as follows: COD concentration ~3400 mg / L, ammonia nitrogen concentration ~120 mg / L, pH between 7 and 9; The flue gas composition of the petrochemical industry is as follows: CO 2 8.5% 2 Accounting for 10.7%, N 2 It accounts for 80%, and water vapor accounts for 0.3%.

[0079] The app includes: M1, pumping petrochemical wastewater into the wastewater flow network of microbial electrocatalytic carbon capture membrane, with a hydraulic retention time of 4.0h; 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 CO in the effluent of the microbial electrocatalytic carbon capture membrane was tested by a constant potential instrument. 2 concentration, and calculate the carbon capture Faraday efficiency, carbon capture rate and carbon capture energy consumption of microbial electrocatalytic carbon capture membrane under different cell pressures; M3, pump the effluent from the wastewater flow network into the air stripping membrane, control the pressure difference between the liquid phase and the gas phase to 10 kPa, and achieve CO 2 of escaping; The principle of this application is as follows Figure 1 As shown: Electrogenic microorganisms (EAB) on the microbial anode catalyze the degradation of organic matter in wastewater and release electrons, H + and CO 2 , electrons are transferred to the external circuit through the microbial anode interface; The electrons reach the cathode and reduce the O in the flue gas under the action of iron phthalocyanine molecules. 2 Produces OH - , these OH - Absorbing CO 2 and convert it into CO 3 2- ; 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, CO 3 2- Crossing the anion exchange membrane, the H released by the electrogenic microorganisms + Combined with CO 2 , achieving coordinated management of wastewater pollution reduction and flue gas decarbonization.

[0080] Result analysis: The results are as follows Figure 2 As shown in Figure 2, at a cell voltage of 0.05 V, a peak current of 1.21 mA cm was achieved. -2The 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 peak current 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 Medium 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; and the gas diffusion cathode includes an oxygen reduction catalyst.

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 microbial anode is a carbon-based current collector loaded with activated sludge, the activated sludge comes from a microbial fuel cell reactor; and / or the gas diffusion cathode is a carbon-based current collector loaded with an oxygen reduction catalyst; And / or the anion exchange membrane is Fumasep FAA-3-PK-75 or 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 microbial electrocatalytic carbon capture membrane is composited with a wastewater flow network at the microbial anode; and / or is composited with a gas flow network at the gas diffusion cathode; the wastewater flow network is made of 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 meshes; 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 meshes.

6. The method for preparing a microbial electrocatalytic carbon capture membrane according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: S1, Preparation of microbial anode The activated sludge from the microbial fuel cell reactor is shaken and broken up by glass beads to form a uniform activated sludge dispersion; the activated sludge dispersion is loaded onto a carbon-based current collector by suction filtration to form a microbial anode; S2, Preparation of Gas Diffusion Cathode The multi-walled carbon nanotubes and Nafion solution are added to an anhydrous ethanol solution, and a uniform multi-walled carbon nanotube dispersion is formed after ultrasonic treatment; the oxygen reduction catalyst is added to the anhydrous ethanol solution, and a uniform oxygen reduction catalyst dispersion is formed after ultrasonic treatment; Adding the oxygen reduction catalyst dispersion dropwise into 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 The microbial electrocatalytic carbon capture membrane is formed by cold rolling composite in the order of microbial anode, anion exchange membrane and gas diffusion cathode, or wastewater flow network, microbial anode, anion exchange membrane, gas diffusion cathode and gas flow network.

7. The method for preparing a microbial electrocatalytic carbon capture membrane according to claim 6, characterized in that: The sludge concentration in the activated sludge dispersion is 1.0-10 g / L; and / or the loading amount of activated sludge 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 speed of the oxygen reduction catalyst dispersion is 0.1~100 mL / min.

8. Application of a microbial electrocatalytic carbon capture membrane as described in any one of claims 1 to 5 or a method for preparing a microbial electrocatalytic carbon capture membrane as described in any one of claims 6 to 7 in synergistic emission reduction of wastewater pollution reduction and flue gas decarbonization.

9. The use according to claim 8, characterized in that: The application comprises the following steps: M1, pumping 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.

10. The use according to claim 9, 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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