Distributed autonomous energy supply polluted bottom mud electrochemical coupling repairing device and method

Abstract

The invention provides a distributed autonomous energy supply polluted bottom mud electrochemical coupling repair device and method, and aims to solve the energy limitation of the existing repair technology and realize efficient and comprehensive repair. The device comprises a distributed microbial fuel cell system (comprising a multi-anode module and a floating rotating wheel cathode), an electrokinetic remediation device (comprising a vertical insertion electrode and a power supply module) and an electric energy management system. The multi-anode module is buried in bottom mud in parallel; the cathode floats on the water surface and is in contact with air through the rotating wheel sheet; the electric energy management system charges the electric energy generated by the microbial fuel cell into the electrokinetic remediation power supply module (including solar auxiliary charging). According to the method, efficient removal of bottom mud deep and shallow layer pollutants is achieved through energy collaborative starting (solar energy and microbial fuel cell collaborative energy supply) and three-dimensional repairing operation (vertical microbial degradation and transverse electric migration enrichment are combined). According to the invention, electrochemical coupling and autonomous energy supply are combined, the repairing efficiency is improved, and the energy consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of electrochemical remediation technology for contaminated sediment, specifically a distributed, autonomously powered electrochemical coupling remediation device and method for contaminated sediment. Background Technology

[0002] Sediment remediation is crucial for the restoration of aquatic ecosystems. Pollutants such as organic matter and heavy metals accumulated in sediments not only affect water quality but also threaten biodiversity and ecological balance. Currently, traditional physicochemical treatment methods suffer from low efficiency and significant environmental impact, necessitating the development of more efficient and environmentally friendly sediment remediation technologies.

[0003] Electrokinetic Remediation (EKR) is a green technology for remediating contaminated sediments and soils. It utilizes a direct current electric field to drive the migration and accumulation of pollutants, effectively treating heavy metals, organic and inorganic contaminants, and is particularly suitable for remediation of low-permeability porous matrices. The pollutant migration mechanisms in EKR include electromigration, electroosmosis, and electrophoresis. However, in practical operation, EKR faces energy consumption challenges. Maintaining the direct current electric field for extended periods results in significant energy consumption, leading to substantial increases in operating costs. Furthermore, pollutant migration and separation are limited by the electric field and pollutant properties, and the migration direction is highly correlated with voltage gradient changes, limiting its effectiveness in comprehensively remediating contaminated sediments. To address the energy consumption issue and improve remediation efficiency, the combined application of EKR with Sediment Microbial Fuel Cells (SMFCs) represents an innovative approach. SMFCs utilize indigenous electrogenic microorganisms in soil or sediments to convert the chemical energy in organic matter into electrical energy. During the operation of SMFCs, the anode is buried in the sediment, and the cathode is located in the overlying water. Electrogenic bacteria in the sediment transfer electrons generated from the decomposition of organic matter to the anode via extracellular electrons. These electrons then travel through wires to the cathode, where they undergo a reduction reaction with oxidizing substances (such as O2 and nitrates) in the overlying water. Through electrochemical reactions and microbial metabolism, the electrons generated from the degradation of organic waste are converted into electrical energy, thus achieving the remediation of pollutants.

[0004] Patent CN105537261A discloses an electrodynamic-microbial fuel cell coupling device and its method for remediating contaminated soil. This patent integrates the anode of the electrodynamic (EK) method into the center of the cathode of the microbial fuel cell (MFC), forming a series structure of "EK anode - MFC cathode - MFC anode array - EK cathode". This design allows the dissolved oxygen and protons generated by the EK anode to directly provide reduction reaction conditions for the MFC cathode, reducing the internal resistance of the MFC. Simultaneously, the electric field of the EK accelerates the migration of pollutants to the MFC anode region, creating a synergistic effect of "electrochemical driving + biodegradation". However, this patent does not address the three-dimensional remediation problem and does not mention distributed energy supply. Patent CN104174648 discloses a method for remediating heavy metal contaminated soil and its dedicated equipment. This technology utilizes a microbial fuel cell to convert organic matter into electric current, driving the removal of heavy metal ions. It has the advantages of fast processing speed and low cost, and is particularly suitable for the removal of charged pollutants in low-permeability soils.

[0005] Electrochemical remediation technology has shown some potential in sediment remediation, but it also has certain limitations, mainly in the following aspects: (1) The repair range and power generation efficiency of a single MFC are relatively low, and it takes a long time and more resources to achieve a significant repair effect.

[0006] (2) Electrokinetic remediation (EK) technology promotes the migration and degradation of pollutants by applying an electric field. However, differences in the physical structure and conductivity of sediment can lead to uneven distribution of the electric field within the sediment, thus affecting the remediation effect. Furthermore, while EK technology has achieved good remediation results for sediments contaminated with inorganic pollutants such as heavy metals, its ability to remove organic pollutants from sediments is relatively poor, especially for some persistent organic pollutants (POPs). Moreover, EK technology consumes a large amount of electrical energy during operation due to the application of electric pumps and electric fields, resulting in high operating costs. These factors limit the current development of EK technology.

[0007] (3) MFC technology relies on microorganisms to transfer electrons between the anode and cathode to generate current. High concentrations of organic matter or other pollutants in the sediment may affect the activity of microorganisms and electron transfer efficiency, thereby reducing the energy output and remediation effect of MFC. Summary of the Invention

[0008] To address the limitations of existing microbial fuel cell and electro-remediation technologies in the remediation of contaminated sediments and achieve efficient and comprehensive remediation, a distributed, autonomously powered electrochemical coupling remediation technology and method for contaminated sediments is proposed. This technology combines the advantages of vertical remediation using sediment microbial fuel cell systems and lateral remediation using electro-remediation devices, aiming to enhance the remediation efficiency of contaminated sediments while achieving autonomous power supply through electrochemical coupling.

[0009] A distributed, autonomously powered electrochemically coupled remediation device for contaminated sediment includes a distributed microbial fuel cell system, an electric remediation device, and a power management system. The distributed microbial fuel cell system comprises several SMFCs units, each SMFCs unit including a multi-anode module and an MFCs cathode; The multi-anode module consists of three or more MFCs anodes connected in parallel to the same bus via wires and horizontally buried in the contaminated sediment. The MFCs cathode includes a rotor shaft, a rotor disk sleeved in the middle of the rotor shaft, rotor plates evenly distributed and vertically fixed to the outer periphery of the rotor disk, and a buoyancy support supporting both ends of the rotor shaft. The buoyancy support allows the MFCs cathode to float on the water surface as a whole and keeps the rotor plates in contact with the air. The electro-remediation device includes an electro-remediation anode, an electro-remediation cathode, and a power module. The electro-remediation anode and the electro-remediation cathode are vertically inserted into the contaminated sediment and connected to the power module via wires. The power management system connects the power module of the distributed microbial fuel cell system and the electric repair device, and is used to charge the power module of the electric repair device with the electrical energy generated by the distributed microbial fuel cell system.

[0010] Furthermore, the power module includes a rechargeable power supply and a solar panel connected to the rechargeable power supply, the solar panel being used to charge the rechargeable power supply.

[0011] Furthermore, it also includes a power supply wire and a variable resistor, the variable resistor being connected in series between the MFCs cathode and the bus; the node between the MFCs cathode and the bus is connected to the power module through the power management system and the power supply wire.

[0012] Furthermore, in the multi-anode module, the MFCs anode uses a titanium mesh as the electrode material, with a rectangular shape, 8-10cm in length, 5-8cm in width, and a mesh size of 30-100μm; the spacing between adjacent MFCs anodes is 30-50cm.

[0013] Furthermore, in the cathode of the MFCs, the diameter of the rotating disk is 30~50cm, the number of rotating plates is 4~8, the height of each plate is 10~15cm, and the thickness is 2~3mm; the two ends of the rotating shaft are rotatably connected to the buoyancy support through bearings.

[0014] Furthermore, in the electric repair device, the distance between the electric repair anode and the electric repair cathode is 20~30cm, and the voltage gradient is controlled at 1~2V / cm; the electric repair anode and the electric repair cathode are plate-shaped or columnar, with the plate-shaped electrodes arranged symmetrically and the columnar electrodes arranged in a hexagonal shape.

[0015] Furthermore, the resistance value of the variable resistor is adjustable from 10 to 1000Ω; the output voltage of a single SMFCs unit is 60 to 100mV, and each electric repair device unit corresponds to 30 to 50 SMFCs units.

[0016] A distributed, autonomously powered electrochemical coupling remediation method for contaminated sediment, using the aforementioned device, comprises the following steps: 1) SMFCs unit assembly: The MFCs anodes of the multi-anode module are horizontally inserted into the polluted sediment, and the MFCs cathodes are floated on the water surface through a buoyancy support. The bus of the multi-anode module is connected to the rotor shaft of the MFCs cathode through wires. A variable resistor is connected in series between the bus and the MFCs cathode. The bus is connected to the power management system. 2) Deployment of the electro-remediation device: Insert the electro-remediation anode and electro-remediation cathode vertically into the contaminated sediment, adjust the spacing to 20~30cm, and connect them to the power module through wires; 3) Energy Synergistic Start-up: Start-up phase: The rechargeable power source is charged by solar panels, and the power management system controls the solar panels to supply power to the electric repair device separately; Stable Phase: When the output voltage of the SMFCs unit stabilizes at 60~100mV, multiple MFC modules are combined in parallel or series to form a distributed power network, switching to a distributed microbial fuel cell system and a coordinated power supply system. When the instantaneous power of the SMFCs is less than 0.5W / m 2 In case of emergency, the energy storage device replenishes the current to maintain the continuous operation of the electric repair device. The variable resistor is dynamically adjusted to match the voltage requirements of the electric repair device. 4) 3D Repair Operation: Vertical remediation: Distributed microbial fuel cell systems degrade deep organic pollutants in sediment through microbial metabolism. Electrons are transferred from the MFCs anode to the bus, and then through the wires to the MFCs cathode to complete the redox reaction. Lateral remediation: The electric remediation device drives the lateral migration of pollutants under the action of a DC electric field, which accumulates in the electrode plate area and is removed through oxidation reaction.

[0017] Furthermore, in step 1), the insertion depth of the MFCs anode is 1 / 2 to 2 / 3 of the thickness of the sediment contamination layer, and the spacing between adjacent MFCs anodes is adjusted to 30 to 50 cm according to the organic matter content of the sediment.

[0018] Furthermore, in step 4), the electrode plate material of the electric repair device is selected as follows: when the pollutants are mainly organic pollutants, PbO2 electrode is selected; when the pollutants are mainly heavy metals, graphite electrode is selected.

[0019] Due to the adoption of the above-mentioned solution, the outstanding technical innovation and significant progress of this invention are as follows: (1) By using a distributed microbial fuel cell system and solar energy assistance, the energy supply problem in electric remediation technology was solved, and autonomous energy supply for the remediation of contaminated sediment was achieved; (2) The vertical arrangement of the microbial fuel cell makes full use of the redox potential difference between the air and the deep part of the sediment, effectively removing organic pollutants from the deep part of the polluted sediment; (3) By combining the horizontal arrangement of electroremediation and the vertical arrangement of microbial fuel cells, pollutant migration and enrichment in the horizontal direction of the contaminated sediment and removal of organic pollutants in the vertical direction can be achieved. Attached Figure Description

[0020] Figure 1 This is a flowchart of the distributed autonomous energy-powered electrochemical coupling remediation method for contaminated sediment according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the distributed autonomous power supply electrochemical coupling remediation device for contaminated sediment according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a single MFCs unit and an MFCs cathode in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the buoyancy support according to an embodiment of the present invention.

[0021] The reference numerals in the figure are described below: 1—Rechargeable power source; 2-1—MFCs cathode, 2-2—Variable resistor, 2-3—MFCs anode, 2-1-1—Rotating disk, 2-1-2—Rotating plate, 2-1-3—Rotating shaft, 2-1-4—Floating support; 3-1—Electrically repaired anode, 3-2—Electrically repaired cathode; 4—Power management system, 5—Power supply wire, 6—Solar panel, 7—Overlying water, 8—Contaminated bottom sediment. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please participate as follows Figure 1-3This invention provides a distributed autonomously powered electrochemically coupled remediation device for contaminated sediment, comprising a distributed microbial fuel cell (SMFCs) system, an electric remediation device, and an energy management system.

[0024] The distributed microbial fuel cell (SMFCs) system comprises several SMFCs units, each including a multi-anode module and an MFCs cathode 2-1. This design aims to overcome the shortcomings of single-anode SMFCs, such as low energy conversion efficiency, poor stability, and limited ability to cope with complex environments, thereby improving energy conversion efficiency and stability. The multi-anode module adopts a distributed multi-anode design, consisting of three or more MFCs anodes 2-3 connected in parallel to the same bus via wires, and horizontally buried in the contaminated sediment. The electrode materials for the MFCs cathode 2-1 and MFCs anode 2-3 are selected from titanium, which possesses high conductivity, good biocompatibility, chemical stability, excellent mechanical strength, and ductility.

[0025] The MFCs cathode 2-1 is a titanium electrode with rotating plates. Specifically, the MFCs cathode 2-1 includes a rotating shaft 2-1-3, a rotating disk 2-1-1 sleeved in the middle of the rotating shaft 2-1-3, rotating plates 2-1-2 evenly distributed and vertically fixed to the outer periphery of the rotating disk 2-1-1, and buoyancy supports 2-1-4 (such as...) supporting both ends of the rotating shaft 2-1-3. Figure 4 As shown in the diagram, the buoyancy support 2-1-4 allows the MFC cathode 2-1 to float entirely on the water surface and keeps the rotating disc 2-1-2 in contact with the air. The diameter of the rotating disc 2-1-1 is 30~50cm. Under the action of wind, water flow, or electricity, the rotating disc 2-1-2 drives the rotating disc 2-1-1 to rotate, allowing the cathode to fully contact oxidizing substances such as oxygen.

[0026] The MFCs anode 2-3 is a rectangular titanium mesh, 8-10 cm long and 5-8 cm wide. The mesh size is 30-100 μm. While providing the reaction site, the titanium mesh also filters and intercepts electroactive microorganisms in the sediment, enhancing electrode reaction efficiency. Based on the physicochemical properties of the contaminated sediment, it is divided into multiple zones, each containing an SMFCs unit. Each unit consists of a multi-anode module and a single cathode 2-1 connected by wires. The multi-anode module consists of three or more titanium plates connected in parallel, with a distance of 30-50 cm between the plates, adjusted according to the sediment depth and organic matter content; the design is not fixed. The single cathode 2-1 floats on the water surface using buoyancy material, maintaining contact with air. The single cathode 2-1 and the MFCs anode 2-3 are connected by wires, with a variable resistor 2-2 connected in the middle for circuit protection, thus forming an SMFCs unit. See details... Figure 3 .

[0027] This invention designs multiple high-efficiency microbial fuel cell (SMFC) units, connecting the multi-anode modules of these units and the MFC cathodes 2-1 in series, and then connecting them to a rechargeable power supply 1 via wires. A single SMFC unit has a stable output voltage of approximately 60~100 mV, and the generated electrical energy is stored and distributed by an energy management system 4.

[0028] In this embodiment of the invention, each SMFC unit is connected in parallel. The multi-anode structure ensures greater stability and reliability of the MFC during long-term operation. A single-anode MFC may be affected by uneven microbial growth or electrode corrosion, while the multi-anode system can disperse these effects, improving the overall stability of the battery. Multi-anode MFCs are particularly suitable for use in complex sediment environments, flexibly responding to changes in environmental parameters such as sediment concentration and pH value, maintaining battery performance. By increasing the number of anodes, the multi-anode system effectively increases the electrode surface area and electron transport paths, thereby improving the battery's energy conversion efficiency. It can more effectively utilize sediment microorganisms to oxidize organic pollutants, generating electrons and converting them into electrical energy.

[0029] The electric repair device includes an anode 3-1, a cathode 3-2, and a power module. The power module includes a rechargeable power supply 1 and a solar panel 6 connected to the rechargeable power supply 1. The solar panel 6 is used to charge the rechargeable power supply 1.

[0030] The power management system 4 is connected to the power module of the distributed microbial fuel cell (SMFCs) system and the electric repair device, and is used to charge the power module of the electric repair device with the electrical energy generated by the distributed microbial fuel cell system (SMFCs).

[0031] like Figure 2 As shown, this embodiment of the invention also provides a distributed, autonomously powered electrochemical coupling remediation method for contaminated sediment, using the aforementioned device. The method includes the following steps (taking two contaminated areas as an example): First, assemble a single SMFC unit by horizontally inserting multiple MFC anodes 2-3 into the contaminated sediment and securing them firmly. The MFC cathode 2-1 floats on the water surface. Then, connect the MFC cathode 2-1 and MFC anodes 2-3 to the power management system 4 and the rechargeable power supply 1 via wires to complete the assembly of a single SMFC unit. Determine the required number of SMFC units based on the number of contaminated sediment zones, and connect all SMFC units to the rechargeable power supply 1 in the same manner to form the entire SMFC system.

[0032] Next, the electrically operated repair device, consisting of the electrically operated repair anode 3-1 and the electrically operated repair cathode 3-2, is inserted into the sediment. After insertion, it is connected to the rechargeable power supply 1 via a wire. Then, press... Figure 2The variable resistor 2-2, the power management system 4, and the solar panel 6 are connected to the entire device in a specific manner. The variable resistor 2-2 has a resistance range of 10-1000Ω. The solar panel 6 stores electrical energy for the rechargeable power source 1 before the device operates, and provides energy to the entire repair system when the SMFCs system begins normal operation, ensuring the normal operation of the device.

[0033] Electroremediation mainly consists of a power source and electrodes. The power source utilizes electricity generated by a distributed microbial fuel cell system coupled with solar energy, and is distributed by a power management system. Typically, each electroremediation unit corresponds to 30-50 distributed microbial fuel cell systems. The electrodes of the electroremediation device can be made of specific materials selected based on the type and content characteristics of pollutants in the sediment. For example, when the pollutants are mainly organic, materials with high oxygen evolution potential, such as PbO2 electrodes, are selected, which can generate strong oxidizing groups (such as ·OH) on the electrode surface, effectively mineralizing recalcitrant organic matter. The electrode spacing of the electroremediation device is 20-30 cm to ensure a voltage gradient of 1-2 V / cm. The electrode shape can be plate-shaped or columnar. When using plate-shaped electrodes, they are arranged in a stacked configuration; when using columnar electrodes, they are arranged in a hexagonal pattern. A DC electric field is applied to the sediment through the power source. Under the influence of the electric field, the pollutants in the sediment migrate and accumulate, achieving effective removal of pollutants.

[0034] The power management system 4 is responsible for storing the electrical energy generated by the solar energy and the distributed microbial fuel cell system. It has functions such as monitoring system voltage and current, storing electrical energy, and dynamically adjusting energy distribution. During the startup phase of the distributed microbial fuel cell system, the electric repair device is mainly powered by the solar panels 6. Once the distributed microbial fuel cell system is found to be operating stably, the system is powered by a combination of the distributed microbial fuel cell system and solar energy. The power supply is adjusted according to changes in the output power of the distributed microbial fuel cell system by regulating the number of distributed microbial fuel cells and the size of the solar panels.

[0035] In this embodiment of the invention, vertical remediation of contaminated sediment is handled by a distributed microbial fuel cell, and during the vertical remediation process, the electrical energy generated by the distributed microbial fuel cell supplies the power to an electric remediation device for horizontal remediation of the contaminated sediment. The mechanism by which the distributed microbial fuel cell removes pollutants includes microbial metabolism, electron transfer, proton migration, and cathodic reactions; the mechanism of electric remediation includes electrodialysis, electromigration, electrophoresis, and redox reactions, achieving the migration and enrichment of pollutants, thereby removing them.

[0036] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A distributed, autonomously powered electrochemical coupling remediation device for contaminated sediment, characterized in that, This includes distributed microbial fuel cell (SMFC) systems, electric repair devices, and power management systems (4): The distributed microbial fuel cell (SMFCs) system comprises several SMFCs units, each of which includes a multi-anode module and an MFCs cathode (2-1). The multi-anode module consists of three or more MFC anodes (2-3) connected in parallel to the same bus via wires and horizontally buried in the contaminated sediment. The MFCs cathode (2-1) includes a rotating shaft (2-1-3), a rotating disk (2-1-1) sleeved in the middle of the rotating shaft (2-1-3), rotating plates (2-1-2) evenly distributed and vertically fixed on the outer periphery of the rotating disk (2-1-1), and a buoyancy support (2-1-4) supporting both ends of the rotating shaft (2-1-3). The buoyancy support (2-1-4) makes the MFCs cathode (2-1) float on the water surface and keeps the rotating plates (2-1-2) in contact with the air. The electric remediation device includes an electric remediation anode (3-1), an electric remediation cathode (3-2), and a power module. The electric remediation anode (3-1) and the electric remediation cathode (3-2) are vertically inserted into the contaminated sediment and connected to the power module via wires. The power management system (4) is connected to the power module of the distributed microbial fuel cell system and the electric repair device. During the startup phase of the distributed microbial fuel cell system, the power module controls the power supply module to provide power to the electric repair device. When the distributed microbial fuel cell system is detected to be operating stably, the power generated by the distributed microbial fuel cell system and the power module are coupled to provide power to the electric repair device.

2. The apparatus according to claim 1, characterized in that: The power module includes a rechargeable power supply (1) and a solar panel (6) connected to the rechargeable power supply (1). The solar panel (6) is used to charge the rechargeable power supply (1), and the rechargeable power supply (1) is used to power the electric repair device.

3. The apparatus according to claim 1, characterized in that: It also includes a power supply wire (5) and a variable resistor (2-2), the variable resistor (2-2) being connected in series between the MFCs cathode (2-1) and the bus; the node between the MFCs cathode (2-1) and the bus is connected to the power module through the power management system and the power supply wire (5).

4. The apparatus according to claim 1, characterized in that: In the multi-anode module, the MFCs anode (2-3) uses a titanium mesh as the electrode material. The mesh is rectangular in shape, with a length of 8-10cm, a width of 5-8cm, and a mesh size of 30-100μm. The spacing between adjacent MFCs anodes (2-3) is 30-50cm.

5. The apparatus according to claim 1, characterized in that: In the MFCs cathode (2-1), the diameter of the rotating disk (2-1-1) is 30~50cm, the number of rotating plates (2-1-2) is 4~8, the height of each plate is 10~15cm, and the thickness is 2~3mm; the two ends of the rotating shaft (2-1-3) are rotatably connected to the buoyancy support (2-1-4) through bearings.

6. The apparatus according to claim 1, characterized in that: In the electric repair device, the distance between the electric repair anode (3-1) and the electric repair cathode (3-2) is 20~30cm, and the voltage gradient is controlled at 1~2V / cm; the electric repair anode (3-1) and the electric repair cathode (3-2) are plate-shaped or columnar, with the plate-shaped electrodes arranged symmetrically and the columnar electrodes arranged in a hexagonal shape.

7. The apparatus according to claim 3, characterized in that: The resistance of the variable resistor (2-2) is adjustable from 10 to 1000Ω; the output voltage of a single SMFCs unit is 60 to 100mV, and each electric repair device unit corresponds to 30 to 50 SMFCs units.

8. A distributed, autonomously powered electrochemical coupling remediation method for contaminated sediment, characterized in that, The method, performed using any one of claims 1-7, comprises the following steps: (1) SMFCs unit assembly: The MFCs anode (2-3) of the multi-anode module is horizontally inserted into the polluted bottom sediment, and the MFCs cathode (2-1) floats on the water surface through the buoyancy support (2-1-4). The bus of the multi-anode module is connected to the wheel shaft (2-1-3) of the MFCs cathode (2-1) through the wire. A variable resistor (2-2) is connected in series between the bus and the MFCs cathode (2-1), and the bus is connected to the power management system. (2) Deployment of the electric remediation device: Insert the electric remediation anode (3-1) and the electric remediation cathode (3-2) vertically into the contaminated sediment, adjust the spacing to 20~30cm, and connect them to the power module through wires; (3) Energy-coordinated start-up: Start-up phase: The rechargeable power supply (1) is charged by the solar panel (6), and the power management system (4) controls the solar panel (6) to supply power to the electric repair device separately; Stable Phase: When the output voltage of the SMFCs unit stabilizes at 60~100mV, multiple MFC modules are combined in parallel or series to form a distributed power network, switching to a distributed microbial fuel cell system and solar panels (6) for coordinated power supply. When the instantaneous power of the SMFCs is less than 0.5W / m 2 At this time, the energy storage device replenishes the current to maintain the continuous operation of the electric repair device; the variable resistor (2-2) is dynamically adjusted to match the voltage requirements of the electric repair device; (4) Three-dimensional repair operation: Vertical remediation: The distributed microbial fuel cell system degrades deep organic pollutants in the sediment through microbial metabolism. Electrons are transferred from the MFCs anode (2-3) to the bus, and then through the wire to the MFCs cathode (2-1) to complete the redox reaction. Lateral remediation: The electric remediation device drives the lateral migration of pollutants under the action of a DC electric field, which accumulates in the electrode plate area and is removed through oxidation reaction.

9. The method according to claim 8, characterized in that: In step (1), the insertion depth of the MFCs anode (2-3) is 1 / 2 to 2 / 3 of the thickness of the sediment contamination layer, and the spacing between adjacent MFCs anodes (2-3) is adjusted to 30 to 50 cm according to the organic matter content of the sediment.

10. The method according to claim 8, characterized in that: In step (4), the electrode plate material of the electric repair device is selected as follows: when the pollutants are mainly organic pollutants, PbO2 electrode is selected; when the pollutants are mainly heavy metals, graphite electrode is selected.

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