A microbial electrolysis cell magnifying device integrating sewage treatment and carbon dioxide reduction to acetic acid

Abstract

The present application belongs to the cross field of bioelectrochemistry, environment and energy, and particularly relates to a microbial electrolysis cell amplification device integrating sewage treatment and carbon dioxide reduction to acetic acid; the amplification device is composed of a series connection of microbial electrolysis cell small test devices, and electrically active acetic acid-producing bacteria and electric bacteria loaded with high-conductivity nanomaterials and magnetic nanomaterials are respectively modified on the surface of cathode and anode electrodes; the anode electric microorganism decomposes and metabolizes organic matters in sewage to realize sewage treatment; the cathode acetic acid-producing bacteria capture CO2, catalyze CO2, H + and electron into acetic acid to realize carbon dioxide reduction to acetic acid; the microbial electrolysis cell amplification device has simple preparation method, high structural stability, low cost and low energy consumption, can simultaneously realize large-scale sewage treatment and CO2 reduction, provides a new way for domestic sewage and carbon dioxide resource utilization, and has important significance for energy saving and emission reduction and environmental governance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the cross field of bio-electrochemistry, environment and energy, and particularly relates to a microbial electrolysis cell amplification device integrating sewage treatment and carbon dioxide reduction to acetic acid. BACKGROUND

[0002] Energy, environment and water resource are the basis for human survival. In recent years, with the rapid growth of the use of fossil fuels, especially oil and natural gas, a global energy crisis has been triggered. In addition, a large amount of CO2 emitted during the use of fossil fuels will cause the greenhouse effect and lead to climate warming. At the same time, a large amount of domestic sewage is generated in people's daily life. At present, the widely used sewage treatment technology is mainly aerobic biological treatment, among which activated sludge method is mainly used. However, the activated sludge method consumes high energy when treating sewage, and at the same time, a large amount of sludge is produced, and the treatment of sludge also requires high cost. The organic matter in sewage is not only a pollutant, but also contains energy, which can be removed by resource utilization. The potential energy in sewage is about 10 times the electric energy consumed during sewage treatment.

[0003] Microbial electrolysis cell (MEC) is a new technology developed rapidly in recent years, which combines sewage treatment and energy production. It can obtain different forms of energy while biologically treating sewage. As a new process for sewage treatment, MEC has attracted widespread attention at home and abroad. MEC technology not only overcomes the shortcomings of traditional biological wastewater treatment process, but also recovers energy to reduce the cost of sewage treatment. At a time when energy, environment and water resource problems are becoming increasingly serious, MEC can achieve the three goals of reducing pollutant emissions, reducing dependence on fossil fuels and sewage recycling, achieving economic and environmental win-win.

[0004] The use of microbial electrolysis cell with biological cathode to reduce carbon dioxide to produce acetic acid has been reported (WO2009 / 155587A2). This method uses a biological cathode as a catalyst to achieve the regulation of microbial synthesis of methane and acetic acid by setting different cathode polarization potentials. However, the generation of methane in this device reduces the selectivity of CO2 reduction to acetic acid, and there are problems such as small treatment scale and low treatment efficiency. In addition, a microbial electrolysis cell device integrating CO2 conversion and sewage treatment has also been reported (CN 201110209150.X). This device uses an ion exchange membrane to separate the anode chamber and the cathode chamber of the microbial electrolysis cell. The CO2 generated in the anode chamber enters the cathode chamber through the gas pipeline, and the CO2 capture and conversion to CH4 in the cathode chamber realizes the concept of CO2 emission reduction and effective utilization. However, this device has complex structure, high construction cost and is not easy to scale up.

[0005] Therefore, it is necessary to study and develop a high-performance microbial electrolysis cell device which integrates CO2 conversion and sewage treatment, has simple structure, low construction cost and is easy to scale up. The application discloses a microbial electrolysis cell amplification device which simultaneously realizes sewage treatment and CO2 reduction to produce acetic acid, and can simultaneously realize large-scale sewage treatment and CO2 reduction. The amplification device has simple preparation method, high structural stability, can effectively improve COD degradation rate and acetic acid yield, and provides effective reference and technical support for sewage treatment and CO2 reduction. SUMMARY

[0006] The application solves the problems of high energy consumption of traditional domestic sewage biological treatment and traditional electrocatalytic reduction of carbon dioxide to produce acetic acid, slow starting speed and small treatment scale of traditional MEC, and provides a microbial electrolysis cell amplification device which integrates sewage treatment and carbon dioxide reduction to produce acetic acid.

[0007] The technical scheme of the application is as follows:

[0008] A microbial electrolysis cell amplification device which integrates sewage treatment and carbon dioxide reduction to produce acetic acid, comprising a microbial electrolysis cell small test device connected in series through wires; the series connection mode is that the small test devices are connected in series at the head and tail, that is, the anode of the first small test device is connected to the cathode of the second small test device, the anode of the second small test device is connected to the cathode of the third small test device, and the like; under the premise of not affecting the treatment effect of a single small test device, a plurality of small test devices are connected in series to improve the sewage treatment scale;

[0009] The microbial electrolysis cell small test device comprises an anode chamber and a cathode chamber, and the anode chamber and the cathode chamber are separated by a proton exchange membrane; the anode chamber and the cathode chamber are respectively provided with a biological anode and a biological cathode, and the biological anode and the biological cathode are respectively connected to the counter electrode and the working electrode of an electrochemical workstation through wires;

[0010] The biological cathode comprises a cathode electrode and an electrochemically active acetogenic bacterium S.ovata attached to the surface of the cathode electrode, and the surface of the acetogenic bacterium is modified with Au and Fe3O4 nanoparticles; the biological anode comprises an anode electrode and an electrochemically active electrogenic bacterium G.sulfurreducens attached to the surface of the anode electrode, and the electrogenic bacterium G.sulfurreducens is modified with a PDA polymer and Fe3O4 nanoparticles; G.sulfurreducens PCA is purchased from the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, DSMZ), with strain number DSM 12127; S.ovata is purchased from the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, DSMZ), with strain number DSM 2662. Fe3O4 nanoparticles are loaded on the surface of the bacteria, so that the modified electroactive bacteria can quickly gather to the magnetic electrode;

[0011] The anode chamber and the cathode chamber are both provided with an inlet and an outlet, and the height of the outlet is higher than that of the inlet;

[0012] The inlet of the anode chamber is connected to sewage without oxygen, and the inlet of the cathode chamber is connected to an acetogenic bacterium culture medium solution;

[0013] The cathode chamber is provided with an aeration pipe near the bottom, and the aeration pipe is parallel to the biological cathode.

[0014] Preferably, the microbial electrolysis cell amplification device further comprises a gas monitoring device, which is arranged at the gas inlet pipe connected to the aeration pipe of the microbial electrolysis cell small test device, and is used for detecting the gas flow.

[0015] Preferably, the microbial electrolysis cell amplification device further comprises a drain pipe connected to the outlet pipes of the anode chamber and the cathode chamber.

[0016] Preferably, the microbial electrolysis cell amplification device further comprises a support. The support is used for mounting the microbial electrolysis cell small test devices connected in series.

[0017] Preferably, the inlet pipe, the outlet pipe, the anode chamber, the cathode chamber, the inlet pipe, the outlet pipe, and the aeration pipe of the microbial electrolysis cell small test device are all made of PVC.

[0018] Preferably, the output current of the electrochemical workstation is -10 mA.

[0019] Preferably, the microbial electrolysis cell amplification device comprises 9 small test devices of 40L

[0020] Preferably, the microbial electrolysis cell amplification device is placed in a board room or other suitable temperature environment that can maintain the survival of bacteria.

[0021] Preferably, the anode electrode and the cathode electrode are both graphite electrode plates, and the preparation method of the graphite electrode plate is as follows: a permanent magnet is packaged in a hollow graphite rod and a detachable carbon cloth is loaded on the surface of the graphite rod to form a magnetic graphite electrode, the magnetic graphite electrode is vertically embedded in a double-layer plastic support with the same size, and the upper surface is packaged with epoxy resin to form an electrode plate. More preferably, the number of magnetic graphite electrodes on the electrode plate is 8.

[0022] Preferably, sampling ports are arranged on the side surfaces of the anode chamber and the cathode chamber to facilitate monitoring of the operation status of the device.

[0023] Preferably, an air valve is arranged on the aeration pipe, and the air valve is arranged at a position corresponding to the magnetic graphite electrode on the biological cathode; more preferably, the number of air valves is equal to the number of magnetic graphite electrodes, so that each magnetic graphite electrode is fully exposed to a carbon dioxide environment.

[0024] Preferably, the microbial electrolysis cell amplification device further comprises a sewage treatment automatic control device and a human-computer operation panel for inputting control instructions; the sewage treatment automatic control device can be an existing computer or a single-chip microcomputer.

[0025] A method for realizing sewage treatment and carbon dioxide reduction to acetic acid by using the microbial electrolysis cell amplification device, comprising the following steps: injecting oxygen-excluded sewage containing organic matter into the anode chamber through the anode water inlet pipe, injecting acetic acid bacteria culture solution into the cathode chamber through the cathode water inlet pipe, inputting CO2 gas into the cathode chamber through the aeration pipe, and opening the electrochemical workstation for electrolysis.

[0026] Sewage treatment: oxygen-excluded sewage is injected into the microbial electrolysis cell through the sewage water inlet pipe as a nutrient source for the growth of anode electricity-producing microorganisms, and the anode electricity-producing microorganisms decompose and metabolize the organic matter in the sewage to achieve sewage treatment.

[0027] CO2 capture and conversion: CO2 in biogas combustion exhaust gas is input into the cathode chamber through the gas inlet pipe at the bottom of the cathode chamber, and CO2, H + , and electrons migrate to the cathode, and the electroactive acetic acid-producing bacteria attached to the surface of the cathode electrode capture CO2, H + and electrons to convert them into acetic acid under the assistance of electricity.

[0028] Preferably, the method comprises the following steps:

[0029] Step 1, first keep the water inlet valve of the water inlet pipe in the anode chamber and cathode chamber open and the water outlet valve of the water outlet pipe closed, inject the wastewater containing organic matter into the anode chamber after oxygen removal, inject the acetic acid bacteria culture medium solution into the cathode chamber through the cathode water inlet pipe, input the contained CO2 gas into the cathode chamber through the aeration pipe, and open the electrochemical workstation for electrolysis; when the wastewater flow approaches the volume of the electrolytic cell, the water inlet valve is closed, wherein the time when the water inlet valve is opened is the starting point calculated by the gas monitoring device;

[0030] Step 2, then enter the processing waiting stage, when the detected CO2 concentration is lower than the threshold, the water inlet valve is in a high flow state and the water outlet valve is in a low flow state;

[0031] Step 3, after a predetermined time interval, the water inlet valve and the water outlet valve are closed.

[0032] The above method is first performed from step 1, and then steps 2 and 3 are cycled to achieve an optimized wastewater treatment effect.

[0033] Preferably, the predetermined time interval is determined according to the capacity of the electrolytic cell and the rate of water inlet and outlet, and can be 10 seconds to 1 hour, preferably 10 seconds, 20 seconds, 30 seconds, 1 minute, 2 minutes, 5 minutes, 10 minutes, 15 minutes, 45 minutes.

[0034] Compared with the prior art, the advantages of the present application are as follows,

[0035] The present application is based on a single bacterial modification strategy, which modifies nanomaterials with high conductivity on the surface of electroactive bacteria, significantly improving the extracellular electron transfer efficiency; on the other hand, Fe3O4 nanoparticles are loaded on the surface of the bacteria, so that the modified electroactive bacteria can quickly gather to the magnetic electrode, thereby significantly increasing the bacterial loading capacity on the electrode surface and greatly shortening the startup time (from the original 24h-48h to 30min); In this method, the treatment of domestic sewage and the reduction of carbon dioxide to generate acetic acid are faster, solving the problems of high energy consumption of traditional domestic sewage biological treatment and traditional electrocatalytic reduction of carbon dioxide to acetic acid, slow startup speed of traditional MEC, and low interface electron transfer rate between bacteria and electrode; The microbial electrolysis cell magnification device of the present application has the advantages of simple preparation method, high structural stability, low cost and low energy consumption, and can simultaneously realize large-scale sewage treatment and CO2 reduction, providing a new way for domestic sewage and carbon dioxide resource utilization, which has important significance for energy saving and emission reduction and environmental governance. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1Figure 1 is a schematic diagram of a microbial electrolysis cell small test device; 1 is an anode chamber water inlet pipe, 2 is an anode chamber, 3 is an anode chamber water outlet pipe, 4 is a biological anode, 5 is a proton exchange membrane, 6 is a cathode chamber, 7 is a biological cathode, 8 is a cathode chamber water inlet pipe, 9 is a wire, 10 is an electrochemical workstation, 11 is a wire, 12 is an aeration pipe; 13 is a cathode water outlet pipe.

[0037] Figure 2 Figure 2 is a schematic diagram of a microbial electrolysis cell large device; wherein 14 is a gas flow meter, 15 is a drain pipe, 16 is a support. DETAILED DESCRIPTION

[0038] Example 1

[0039] The present embodiment uses a microbial electrolysis cell large device to realize a method for wastewater treatment and reduction of carbon dioxide to acetic acid, which is specifically operated in the following order and steps:

[0040] (1) Construction of a microbial electrolysis cell large device:

[0041] The microbial electrolysis cell large device is composed of 9 microbial electrolysis cell small test devices connected in series by wires. The series connection mode is that the anode of the first small test device is connected to the cathode of the second small test device, the anode of the second small test device is connected to the cathode of the third small test device, and so on (on the premise that it does not affect the treatment effect of a single small test device, several small test devices are connected in series to improve the scale of wastewater treatment, and in the present embodiment, 9 small test devices of 40L are connected in series). Figure 1 The small test device comprises: an anode chamber water inlet pipe 1, an anode chamber 2, an anode chamber water outlet pipe 3, a biological anode 4, a proton exchange membrane 5, a cathode chamber 6, a biological cathode 7, a cathode chamber water inlet pipe 8, a wire 9, an electrochemical workstation 10, a wire 11, an aeration pipe 12, and a cathode water outlet pipe 13. The anode chamber 2 and the cathode chamber 6 are respectively provided with a biological anode 4 and a biological cathode 7, and the anode chamber 2 and the cathode chamber 3 are separated by a proton exchange membrane 5; the biological anode 4 and the biological cathode 7 are respectively connected to the counter electrode and the working electrode of the electrochemical workstation 10 through the wires 9 and 11. The anode chamber 2 and the cathode chamber 3 are both provided with water inlets and water outlets, and the height of the water outlet is higher than that of the water inlet; the water inlet of the anode chamber is connected to the deoxygenated wastewater through the anode water inlet pipe 1, and the water inlet of the cathode chamber is connected to the acetic acid bacteria culture medium solution through the cathode water inlet pipe 8; the aeration pipe 12 is arranged near the bottom of the cathode chamber 3, and is parallel to the biological cathode 7.

[0042] The anode chamber inlet pipe 1, anode chamber outlet pipe 3, anode chamber 2, cathode chamber 6, cathode chamber inlet pipe 8, cathode chamber outlet pipe 13, and aeration pipe 12 are all made of PVC material. The bioanode 4 and biocathode 7 are graphite electrode plates (with built-in magnets). Permanent magnets are encapsulated in hollow graphite rods, and removable carbon cloth is mounted on the surface of the graphite rods to form magnetic graphite electrodes. These electrodes are arranged in groups of eight, vertically embedded in a double-layered plastic support of matching dimensions, and then encapsulated with epoxy resin to form the graphite electrode plate.

[0043] See the scale-up apparatus for microbial electrolysis cells. Figure 2 In addition to the pilot-scale device, the scale-up device also includes: a gas flow meter 14, a drain pipe 15, and a support 16. The gas flow meter 14 is installed at the air inlet pipe and is used to detect the gas flow rate. The air inlet pipe is connected to the aeration pipe 12 of the pilot-scale microbial electrolysis cell device. The drain pipe 15 is connected to the anode chamber outlet pipe 3 and the cathode outlet pipe 13. The support 16 is used to install the pilot-scale microbial electrolysis cell device connected in series.

[0044] (2) Start-up of the microbial electrolysis cell system

[0045] The start-up process of the wastewater treatment and carbon dioxide reduction acetic acid production system proposed in this invention is as follows:

[0046] ① Fabrication of biological cathodes

[0047] The electroactive acetogenic bacterium *S. ovata* was first anaerobically cultured in DSMZ-311 growth medium in a 250 mL anaerobic flask with a thick rubber stopper. Before inoculation into the microbial electrolysis cell, the culture medium was centrifuged, and the concentrate was then suspended and dispersed in anoxic, sterile DSMZ-311 growth medium free of organic carbon sources, modified with Au and Fe3O4 nanoparticles. This cell suspension was then inoculated into the anaerobic microbial electrolysis cell, and immediately purged with biogas combustion waste gas containing CO2. The constant current of the electrochemical workstation was set to -10 mA. Under electrical assistance, the electroactive acetogenic bacterium *S. ovata* attached to the cathode surface of the microbial electrolysis cell catalyzed the reduction of CO2 gas to acetic acid. The voltage data of the microbial electrolysis cell was sampled periodically. Once the voltage of the microbial electrolysis cell reached its maximum and stabilized, it was considered that the electroactive acetogenic bacterium *S. ovata* had fully adhered to the cathode electrode, and the biocathode was considered to be successfully fabricated.

[0048] ② Fabrication of biological anodes

[0049] The electroactive electricity-producing bacteria G. sulfurreducens is first cultured anaerobically in a 250 mL anaerobic bottle with a thick rubber stopper using PCA standard medium. Before inoculating the microbial electrolysis cell, the above-mentioned culture solution is centrifuged, and the concentrate is then suspended and dispersed in an anaerobic, sterilized PCA standard medium without organic carbon source to modify the PDA polymer and Fe3O4 nanoparticles. Then the above-mentioned cell suspension is inoculated into the anaerobic microbial electrolysis cell, and nitrogen gas is immediately filled. The constant current of the electrochemical workstation is set to -10 mA. Under the assistance of electricity, the organic matter in the wastewater is reduced to CO2 by the catalytic action of the electroactive electricity-producing bacteria G. sulfurreducens attached to the surface of the anode of the microbial electrolysis cell. The voltage data of the microbial electrolysis cell are regularly sampled, and when the voltage of the microbial electrolysis cell is maximum and stable, it is considered that the electroactive electricity-producing bacteria G. sulfurreducens is fully attached to the cathode electrode, and the biological anode is completed.

[0050] (3) Organic wastewater treatment and acetic acid production

[0051] After the biological cathode and the biological anode are completed, the solution in the cathode chamber 6 is continuously filled with biogas combustion waste gas containing CO2 through the aeration pipe 12 of the cathode chamber 6, and the current of the electrochemical workstation is fixed at -10 mA. The electricity-producing microorganisms attached to the surface of the anode 4 use the organic matter in the wastewater as a substrate to produce CO2, H + and electrons while treating the wastewater. The produced H + and electrons migrate to the cathode chamber 6 and the cathode 7, respectively. At the same time, under the assistance of electricity, the acetic acid-producing bacteria attached to the surface of the cathode 7 capture CO2, and catalyze the conversion of CO2, H + and electrons into acetic acid. The specific chemical reaction equation is as follows:

[0052] Anode electrode C x H y O z +nH2O→H + +CO2+e -

[0053] Cathode electrode 2CO2+8H + +8e - →CH3COOH+2H2O

[0054] The removal rate of organic matter in the wastewater can reach 87%, and the rate of conversion of CO2 captured by the acetic acid-producing bacteria into acetic acid can reach 1 g / L / d.

[0055] Example 2:

[0056] The microbial electrolysis cell amplification device in embodiment 1 can be provided with a gas monitoring device for detecting gas flow at the gas inlet pipe, a sewage treatment automatic control device and a human-computer operation panel for inputting control instructions, and the sewage treatment automatic control device can be an existing computer or a single-chip microcomputer.

[0057] The microbial electrolysis cell amplification device adopts a closed treatment mode. The closed treatment mode aims to achieve the highest sewage treatment effect, and the specific steps of the mode are as follows: a, first keep the water inlet valve open and the water outlet valve closed, and when the sewage flow approaches the volume of the electrolysis cell, close the water inlet valve, wherein the time when the water inlet valve is open is the starting point calculated by the gas flow meter; b, then enter the treatment waiting stage, and when the detected CO2 concentration is lower than the threshold value, make the water inlet valve in a high flow state and the water outlet valve in a low flow state; c, close the water inlet valve and the water outlet valve after a predetermined time interval.

[0058] The first execution of the closed treatment mode starts from step 1, and then steps 2 and 3 are cycled to achieve the optimal sewage treatment effect.

[0059] The predetermined time interval is determined according to the capacity of the electrolysis cell and the rates of water inlet and water outlet, and can be 10 seconds to 1 hour, preferably 10 seconds, 20 seconds, 30 seconds, 1 minute, 2 minutes, 5 minutes, 10 minutes, 15 minutes or 45 minutes.

[0060] It should be noted that the above embodiments are only preferred embodiments of the present application, and are not used to limit the protection scope of the present application, and equivalent substitutions or replacements made on the basis of the above all belong to the protection scope of the present application.

Claims

1. A microbial electrolysis cell amplification device, characterized by, The microorganism electrolysis cell small test device comprises an anode chamber and a cathode chamber, the anode chamber and the cathode chamber are separated by a proton exchange membrane, the anode chamber and the cathode chamber are respectively provided with a biological anode and a biological cathode, and the biological anode and the biological cathode are respectively connected with a counter electrode and a working electrode of an electrochemical workstation through wires; The biological cathode comprises a cathode electrode and an electrochemically active acetogenic bacteria attached to the surface of the cathode electrode S. ovata, The acetogenic bacteria are surface-modified with Au and Fe3O4 nanoparticles; the biological anode comprises an anode electrode and an electrochemically active electrogenic bacteria attached to the surface of the anode electrode G. sulfurreducens, The electrogenic bacteria are surface-modified with PDA polymer and Fe3O4 nanoparticles; The anode electrode and the cathode electrode are both graphite electrode plates, and the graphite electrode plate is prepared by packaging a permanent magnet in a hollow graphite rod, loading carbon cloth on the surface of the graphite rod to form a magnetic graphite electrode, and vertically embedding the magnetic graphite electrode in a support with a size that matches the graphite electrode to form an electrode plate. The anode chamber and the cathode chamber are both provided with a water inlet and a water outlet, and the height of the water outlet is higher than that of the water inlet. The water inlet of the anode chamber is connected with sewage, and the water inlet of the cathode chamber is connected with an acetic acid bacteria culture medium solution. An aeration pipe is arranged near the bottom of the cathode chamber, and the aeration pipe is parallel to the biological cathode.

2. The microbial electrolysis cell amplifying device of claim 1, wherein, The microorganism electrolysis cell magnification device further comprises a gas monitoring device, which is arranged at the air inlet pipe connected with the aeration pipe of the microorganism electrolysis cell small test device.

3. The microbial electrolysis cell amplification device of claim 1, wherein, The microorganism electrolysis cell magnification device further comprises a drain pipe and a support, the drain pipe is connected with the water outlet pipe of the anode chamber and the water outlet pipe of the cathode chamber, and the microorganism electrolysis cell small test device is installed on the support.

4. The microbial electrolysis cell amplification device of claim 1, wherein, Sampling ports are arranged on the side surfaces of the anode chamber and the cathode chamber.

5. The microbial electrolysis cell amplification device of claim 1, wherein, A gas valve is arranged on the aeration pipe, and the gas valve is arranged at a position corresponding to the magnetic graphite electrode on the biological cathode.

6. The microbial electrolysis cell amplification device of claim 1, wherein, The microorganism electrolysis cell magnification device further comprises a sewage treatment automatic control device and a human-computer operation panel for inputting control instructions, and the sewage treatment automatic control device is a computer or a single-chip microcomputer.

7. A method for wastewater treatment and carbon dioxide reduction to acetic acid by using the microbial electrolysis cell amplification device according to any one of claims 1-6, characterized in that, After the organic matter-containing sewage is deoxygenated, the sewage is injected into the anode chamber through the anode water inlet pipe, the acetic acid bacteria culture medium solution is injected into the cathode chamber through the cathode water inlet pipe, the gas containing CO2 is input into the cathode chamber through the aeration pipe, and the electrochemical workstation is turned on for electrolysis.

8. The method of claim 7, wherein, The method comprises the following steps: Step 1: first, keep the water inlet valve of the water inlet pipe in the anode chamber and the cathode chamber open and the water outlet valve closed, deoxygenate the organic matter-containing sewage, inject the sewage into the anode chamber through the anode water inlet pipe, inject the acetic acid bacteria culture medium solution into the cathode chamber through the cathode water inlet pipe, input the gas containing CO2 into the cathode chamber through the aeration pipe, and turn on the electrochemical workstation for electrolysis; when the sewage flow approaches the volume of the electrolysis cell, the water inlet valve is closed, wherein the opening time of the water inlet valve is the starting point calculated by the gas monitoring device; Step 2: then enter the treatment waiting stage, when the detected CO2 concentration is lower than the threshold value, the water inlet valve is in a high flow state and the water outlet valve is in a low flow state; Step 3: after a predetermined time interval, the water inlet valve and the water outlet valve are closed.

9. The method of claim 8, wherein, The predetermined time interval is 10 seconds to 1 hour.

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