Culture pond substrate in-situ remediation device and method based on electrochemical coupling reinforcement

Abstract

The invention provides a culture pond substrate in-situ remediation device and method based on electrochemical coupling reinforcement. A culture pond substrate in-situ remediation device based on electrochemical coupling enhancement comprises a floating cathode module which comprises a floating body support, a power management unit arranged on the floating body support and a cathode electrode used for making contact with a water body; the sediment anode module comprises a water-permeable insulating shell, a composite adsorption electrode core and a micropore barrier layer, a plurality of through holes are formed in the side wall of the water-permeable insulating shell, the composite adsorption electrode core is filled in the water-permeable insulating shell, and the micropore barrier layer is arranged in the water-permeable insulating shell and wraps the composite adsorption electrode core; the connecting cable is electrically connected with the floating cathode module and the sediment anode module; the power management unit is configured to apply a positive bias voltage to the composite adsorption electrode core to form an electromigration driving field between the sediment anode module and the floating cathode module. According to the invention, active capture and internal locking of culture pond bottom mud pollutants are realized.

Description

Technical Field

[0001] This invention relates to an in-situ remediation device and method for the bottom sediment of aquaculture ponds, specifically to an in-situ remediation device and method for the bottom sediment of aquaculture ponds based on electrochemical coupling enhancement, belonging to the field of aquaculture environmental management technology. Background Technology

[0002] In aquaculture, the long-term accumulation of uneaten feed and feces leads to the accumulation of large amounts of ammonia nitrogen, nitrite, and Cu in the bottom mud of the aquaculture pond. 2+ Zn 2+ Heavy metal ions and other pollutants are continuously released into water bodies under anaerobic conditions, causing eutrophication and toxic stress in aquaculture organisms. Current technologies for treating sediment pollution mainly include physical adsorption and electrochemical remediation, but both have some limitations.

[0003] Traditional remediation methods often involve directly adding adsorbents such as vermiculite and zeolite to the sediment, or setting up fixed adsorption supports. These methods rely entirely on the natural diffusion and mass transfer of pollutants, resulting in extremely slow adsorption rates and treatment cycles that can last for months. Furthermore, due to the density of the sediment and the high diffusion resistance, the adsorbents can only act on the surface sediment, proving almost ineffective against deep pollution sources at depths greater than 20 cm, thus failing to achieve complete remediation.

[0004] Existing adsorption devices need to be removed from the sediment after adsorption saturation. However, sediment particles easily adhere to the device surface and pores during adsorption. During extraction and recovery, these attached, unstable sediment particles are agitated by water disturbance and resuspend in the overlying water, causing the adsorbed pollutants to be released again, resulting in secondary pollution and even instantaneous deterioration of water quality. Traditional electrochemical systems have high internal resistance and high energy consumption. Although sediment microbial fuel cells (SMFCs) can utilize microbial metabolism to generate electricity to drive pollutant migration, the anodes of traditional SMFCs are usually directly inserted into dense sediment, lacking an effective conductive network. This results in high system internal resistance, typically exceeding 1000 Ω, low power density, and difficulty in providing sufficient electric field driving force. Summary of the Invention

[0005] Based on the above background, the purpose of this invention is to provide an in-situ remediation device and method for aquaculture pond bottom sediment based on electrochemical coupling enhancement, which realizes active capture and internal locking of pollutants in aquaculture pond bottom sediment, and solves the technical problems of low passive adsorption efficiency, high risk of secondary pollution, and insufficient driving force of electrochemical system in the existing technology for treating aquaculture pond bottom sediment pollution.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] An in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement, comprising:

[0008] A floating cathode module capable of floating on the surface of a water body, the floating cathode module including a float support, a power management unit disposed on the float support, and a cathode electrode for contacting the water body;

[0009] A sediment anode module for placement in underwater sediments, the sediment anode module comprising a water-permeable insulating shell with multiple through holes in its sidewalls, a composite adsorption electrode core filled inside the water-permeable insulating shell, and a microporous barrier layer disposed inside the water-permeable insulating shell and surrounding the composite adsorption electrode core; and,

[0010] Connecting cables electrically connect the floating cathode module and the sediment anode module;

[0011] The power management unit is configured to apply a positive bias to the composite adsorption electrode core to form an electromigration driving field between the deposit anode module and the floating cathode module.

[0012] By forming an electromigration driving field between the sediment anode module and the floating cathode module, positively charged pollutant ions in the pore water of the sediment can be actively driven to migrate into the interior of the sediment anode module, thereby breaking through the rate limitation of traditional passive diffusion and realizing the active extraction of pollutants from deep sediment.

[0013] Preferably, the composite adsorption electrode core includes a central current collector and a conductive adsorption filler. The central current collector extends along the axial direction of the water-permeable insulating shell, and the conductive adsorption filler fills the area around the central current collector. The conductive adsorption filler is a mixture of expanded vermiculite particles and conductive carbon material particles, with a volume ratio of 1:1 to 3 between the expanded vermiculite particles and the conductive carbon material particles.

[0014] The central current collector is made of graphite rod, titanium mesh, or stainless steel mesh, used to construct a low-resistance axial conductive path. By setting a specific ratio of expanded vermiculite and conductive carbon material as conductive adsorption fillers, the unique layered silicate lattice structure of vermiculite is utilized to achieve efficient ion exchange adsorption and interlayer fixation of ammonia nitrogen and heavy metal ions. The conductive carbon material is used to construct a three-dimensional conductive network, significantly reducing the anodic internal resistance and improving electromigration efficiency. Simultaneously, this ratio range ensures that the filler layer has both good conductivity and maintains suitable porosity to facilitate ion transport.

[0015] Preferably, the conductive carbon material particles are selected from at least one of granular activated carbon, biochar, graphite particles or carbon fiber chips, and the expanded vermiculite particles are expanded vermiculite particles that have undergone acid activation treatment or thermal modification treatment.

[0016] Acid-activated or thermally modified expanded vermiculite has a larger interlayer spacing and specific surface area, which can enhance its cation exchange capacity and thus improve its ability to lock in pollutants.

[0017] Preferably, the microporous barrier layer is a nylon mesh, polyester screen, or non-woven geotextile with a pore size of 0.03mm to 0.08mm.

[0018] This microporous barrier layer is configured to allow water molecules and ions to pass through while blocking sediment particles from entering the composite adsorption electrode core. By setting a microporous barrier layer with a specific pore size range, a selective physical barrier is formed during electromigration. Dissolved contaminant ions can pass freely under the influence of an electric field, while sediment particles are effectively trapped on the outside. During the recycling, cleaning, or replacement of the device, the loose sediment attached to the outside automatically detaches under gravity, while the internal filler material adsorbing contaminants is encapsulated by the microporous barrier layer, thus preventing secondary pollution.

[0019] Preferably, the floating cathode module further includes a photovoltaic panel, which is electrically connected to the connecting cable via the power management unit. The power management unit includes a switching circuit configured to switch between a microbial fuel cell mode and a microbial electrolysis cell mode. In the microbial fuel cell mode, the cathode electrode and the composite adsorption electrode core are directly electrically connected. In the microbial electrolysis cell mode, the photovoltaic panel is connected to provide an auxiliary voltage to the composite adsorption electrode core.

[0020] By setting up a dual-mode switching circuit, an intermittent enhancement strategy can be implemented to strengthen photovoltaic power during the day and maintain bio-electricity generation at night. This ensures sufficient electric field driving force during the day, avoids the reverse diffusion of pollutants when there is no sunlight at night, and reduces external energy consumption.

[0021] Preferably, the cathode electrode is a carbon brush, carbon felt, or carbon cloth loaded with a catalyst, and the cathode electrode is suspended below the floating body support.

[0022] The cathode electrode is immersed in an oxygen-rich water layer to provide sufficient oxygen as an electron acceptor, thereby improving the efficiency of the cathode reaction.

[0023] A method for in-situ remediation of aquaculture pond bottom sediment based on electrochemical coupling enhancement using the electrochemical coupling enhancement in-situ remediation device as described in any of the preceding claims, the method comprising:

[0024] The sediment anode module is inserted into the bottom sediment, so that the microporous barrier layer is in close contact with the bottom sediment, and the floating cathode module is placed on the water surface;

[0025] The power management unit connects the circuit, and an electric field is established by microbial electricity generation or external photovoltaic voltage. This drives positively charged pollutant ions in the bottom sediment to migrate through the microporous barrier layer to the composite adsorption electrode core and be adsorbed and fixed by the conductive adsorption filler.

[0026] Preferably, the method further includes:

[0027] During the daytime, the system switches to microbial electrolysis cell mode, utilizing photovoltaic panels to provide an external voltage of 0.8~1.2V.

[0028] At night, the system switches to microbial fuel cell mode, using the metabolic electricity generated by the microorganisms in the underwater sediment to maintain a weak electric field.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The present invention provides an in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement. By constructing a directional electric field, the traditional passive diffusion is transformed into active electromigration, which can increase the pollutant migration rate by more than an order of magnitude. Moreover, the electric field can penetrate into the bottom sediment layer of more than 30 cm, thereby achieving deep remediation of aquaculture pond bottom sediment.

[0031] This invention uses the physical sieving effect of the microporous barrier layer to adsorb and lock pollutants inside the filter element, while the bottom sludge particles are blocked outside. When the device is recycled, the external bottom sludge automatically falls off, and the internal pollutants are tightly wrapped, avoiding resuspension pollution in traditional methods.

[0032] This invention can enhance electromigration using photovoltaic energy during the day and switch to a self-generating mode of microbial fuel cells at night to maintain the electric field, thus ensuring both processing efficiency and energy self-sufficiency. It is suitable for unattended operation in remote breeding areas.

[0033] This invention uses expanded vermiculite and conductive carbon materials mixed in a specific ratio as a conductive adsorption filler, which provides both a high capacity of adsorption sites and constructs a three-dimensional conductive network with low internal resistance. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of an in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic cross-sectional view of the sediment anode module provided in an embodiment of the present invention;

[0037] Figure 3 This is a schematic flowchart of an in-situ remediation method for aquaculture pond bottom sediment based on electrochemical coupling enhancement provided in an embodiment of the present invention;

[0038] In the diagram: 100, floating cathode module; 110, power management unit; 120, cathode electrode; 130, photovoltaic panel; 140, floating support; 200, sediment anode module; 210, water-permeable insulating shell; 211, through hole; 220, composite adsorption electrode core; 221, central current collector; 222, conductive adsorption filler; 230, microporous barrier layer; 300, connecting cable; 400, water body; 500, bottom sediment. Detailed Implementation

[0039] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.

[0040] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art. Unless otherwise specified, the components or equipment in the following embodiments are general standard parts or components known to those skilled in the art, and their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0041] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In this detailed description, numerous specific details are set forth to facilitate explanation and provide a thorough understanding of the embodiments of the present invention. However, one or more embodiments may be practiced by those skilled in the art without these specific details.

[0042] like Figure 1 As shown, an embodiment of the present invention discloses an in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement, including a floating cathode module 100, a sediment anode module 200, and a connecting cable 300.

[0043] The floating cathode module 100 is configured to float on the surface of the water body 400, and includes a float support 140, a power management unit 110 fixedly installed on the float support 140, and a cathode electrode 120 that is in full contact with the water body 400.

[0044] The floating support 140 adopts a ring-shaped float structure injection molded from high-density polyethylene, which has good corrosion resistance and buoyancy stability, ensuring that the device can maintain a horizontal floating attitude under wind and wave conditions.

[0045] The power management unit 110 is sealed and installed in the waterproof cavity in the center of the float support 140. It includes a battery pack, a charge and discharge controller and a DC voltage regulator output module, which is used to provide a stable DC bias voltage to the system.

[0046] The cathode electrode 120 uses a carbon fiber brush, and its handle is vertically suspended below the float support 140 by a stainless steel rod, ensuring that the cathode electrode 120 is completely submerged in the oxygen-rich surface layer 10-20cm above the water surface in the water body 400, so as to make full use of the dissolved oxygen in the surface water as an electron acceptor.

[0047] The sediment anode module 200 is configured to be submerged in the bottom sediment 500, which is the bottom sediment, and includes a water-permeable insulating shell 210, a composite adsorption electrode core 220, and a microporous barrier layer 230.

[0048] The permeable insulating shell 210 is made of porous insulating PVC pipe and has a cylindrical structure. Multiple through holes 211 are evenly opened on its side wall, with a diameter of 5~10mm, so that pore water in the bottom mud 500 can freely enter and exit.

[0049] The bottom of the permeable insulating shell 210 is tapered, which makes it easy to insert into the bottom mud 500 with the help of external force. The insertion depth is usually set to 30-50cm to contact the deep contamination layer.

[0050] The composite adsorption electrode core 220 is tightly filled in the internal cavity of the water-permeable insulating shell 210, forming a columnar reaction zone.

[0051] A microporous barrier layer 230 is disposed between the permeable insulating shell 210 and the composite adsorption electrode core 220, specifically by tightly wrapping the composite adsorption electrode core 220 against the inner wall of the permeable insulating shell 210. The microporous barrier layer 230 is made of nylon mesh material with a pore size of 0.05 mm. Its mesh size is much smaller than the minimum particle size of common sediment particles (usually >0.1 mm), but much larger than the radius of hydrated ions (usually <0.001 mm), thereby achieving physical blocking of sediment particles and selective permeation of ions / water molecules.

[0052] The connecting cable 300 is a multi-strand copper core cable covered with a waterproof insulation layer. One end is electrically connected to the anode output terminal of the power management unit 110 through a waterproof connector, and the other end passes through the top center of the float support 140 and the water-permeable insulating shell 210, forming an electrical connection with the composite adsorption electrode core 220. The connecting cable 300 can also bear mechanical traction function and has a certain tensile strength to ensure that it will not break when recovering the sediment anode module 200.

[0053] In this embodiment, the power management unit 110 is configured to apply a positive bias voltage relative to the cathode electrode 120 to the composite adsorption electrode core 220, thereby forming an electromigration driving field between the sediment anode module 200 and the floating cathode module 100. The electric field is directed from the sediment 500 to the water body 400, driving the positively charged pollutant ions in the pore water of the sediment 500 to migrate directionally into the interior of the sediment anode module 200.

[0054] like Figure 2 As shown, the composite adsorption electrode core 220 includes a central current collector 221 and a conductive adsorption filler 222. The central current collector 221 extends axially along the water-permeable insulating shell 210, penetrating the central axis of the entire composite adsorption electrode core 220, and is made of a 10mm diameter graphite rod. The surface of the graphite rod is roughened to increase the contact area with the surrounding filler, and its top end is connected to the connecting cable 300 through a corrosion-resistant metal clip to form a low-resistance connection, ensuring a contact resistance of less than 0.1Ω. This is used to construct an axial current collection channel, thereby reducing the edge effect and high internal resistance problems commonly found in anodes in traditional methods.

[0055] The conductive adsorption filler 222 is tightly packed around the central current collector 221, with a packing density of 0.8~1.0 g / cm³. 3 The conductive adsorption filler 222 is composed of expanded vermiculite particles and granular activated carbon particles, with the volume ratio of expanded vermiculite particles to granular activated carbon particles controlled at 1:2. The expanded vermiculite particles undergo acid activation modification treatment, specifically by soaking in a 1 mol / L hydrochloric acid solution for 24 hours and then drying, to enable the exchange of Na+ cations between its layers. + K + H + Replacement increases interlayer spacing and specific surface area, thereby improving its ability to resist NH4+. + The ion exchange capacity can be increased from the original 40 mg / g to 65 mg / g. The granular activated carbon particles are made of coconut shell-based activated carbon with a particle size of about 2-4 mm and an iodine value greater than 800 mg / g. It not only provides physical adsorption sites for pollutants, but also forms a continuous electron transport network between the expanded vermiculite particles, ensuring that the entire packing layer has good conductivity.

[0056] The microporous barrier layer 230 is made of polyester screen with a pore size of 0.08mm. It is fixed to the inner wall of the water-permeable insulating shell 210 by hot-melt welding or stainless steel clamps to prevent the bottom mud 500 particles from accumulating and clogging at the interface.

[0057] In addition, the floating cathode module 100 also includes a photovoltaic panel 130. The photovoltaic panel 130 is a monocrystalline silicon solar panel with a peak power of 20W. It is fixed above the floating body support 140 by a bracket, and its tilt angle is adjusted according to the local latitude to obtain optimal sunlight. The photovoltaic panel 130 is electrically connected to the battery pack in the power management unit 110 through a charging controller.

[0058] The power management unit 110 also includes a switching circuit (not shown), which can be implemented using a relay or a MOSFET switch array. The switching circuit is configured to switch between a microbial fuel cell mode and a microbial electrolyzer mode.

[0059] In the microbial fuel cell mode, the switching circuit directly connects the cathode electrode 120 and the composite adsorption electrode core 220 to form a closed loop, and uses the bioelectricity generated by the metabolism of organic matter by naturally occurring electrogenic microorganisms in the sediment 500 to drive the migration of pollutants.

[0060] In the microbial electrolysis cell mode, the switching circuit connects the photovoltaic panel 130 or the battery pack in series to the circuit, providing an auxiliary voltage to the composite adsorption electrode core 220. The applied voltage range is 0.8~1.2V to enhance the electric field driving force. The applied positive bias voltage of 0.8~1.2V is lower than the theoretical electrolysis voltage of water (1.23V), avoiding the generation of harmful gases and drastic fluctuations in water pH. Simultaneously, the 10~20V / m micro-electric field formed inside the sediment anode module 200 is physically confined within the pores of the permeable insulating shell 210 and the surrounding bottom sediment. The macroscopic electric field strength in the overlying water is extremely low, less than 1 V / m, far below the stun threshold of 50 V / m for aquaculture organisms. Furthermore, the weak electric field on the surface of the permeable insulating shell 210 has a mild repellent effect on benthic organisms such as shrimp, crabs, and loaches, preventing them from burrowing into or damaging the adsorption filter.

[0061] The cathode electrode 120 is made of carbon cloth supported on a platinum-carbon catalyst to improve the oxygen reduction reaction rate and reduce the cathode overpotential.

[0062] Embodiments of the present invention also disclose a method for in-situ remediation of aquaculture pond bottom sediment based on electrochemical coupling enhancement using the aforementioned electrochemical coupling-enhanced in-situ remediation device. Figure 3 As shown, the method includes the following steps:

[0063] The sediment anode module 200 is inserted into the contaminated sediment 500 to be remediated, ensuring that the outer surface of the microporous barrier layer 230 is in close contact with the sediment 500 without any obvious gaps or collapse. At this time, the microporous barrier layer 230 acts as a physical barrier, allowing only pore water and dissolved ions in the sediment 500 to come into contact with it, while solid particles in the sediment 500 are blocked from the outside.

[0064] Place the floating cathode module 100 on the water surface, and adjust the length of the connecting cable 300 so that the cathode electrode 120 is in an oxygen-rich water layer approximately 15 cm below the water surface. Check the circuit connections to ensure that the power management unit 110 is in standby mode.

[0065] The power management unit 110 connects the circuit to establish an electric field. During periods of sufficient daylight, the switching circuit switches to the microbial electrolysis cell mode. The photovoltaic panel 130 generates electricity, which, after being regulated by the power management unit 110, is applied to the composite adsorption electrode core 220 with a positive bias of 1.0V. At this time, a DC electric field with an intensity of approximately 10-20V / m is formed between the sediment anode module 200 and the floating cathode module 100. Under the action of this electric field, positively charged pollutant ions in the pore water of the sediment 500 are driven by the electric field force to undergo directional electromigration, migrating towards the sediment anode module 200. Simultaneously, the pore water also migrates towards the anode under the action of electroosmosis, driving ion convection. The ion flow passes through the microporous barrier layer 230 and enters the interior of the composite adsorption electrode core 220. This process overcomes the mass transfer limitations of traditional passive diffusion, significantly increasing the migration rate.

[0066] During nighttime periods without sunlight, the switching circuit switches to microbial fuel cell mode, disconnecting the photovoltaic power supply and utilizing the bioelectricity generated by microbial metabolism in the sediment 500 to maintain a weak electric field. Although this weak electric field is insufficient to rapidly drive pollutant migration, it effectively prevents pollutant ions that have migrated to the vicinity of the composite adsorption electrode core 220 from diffusing back into the sediment 500 due to the concentration gradient, thus playing a role in locking and maintaining the field.

[0067] Pollutant ions that migrate into the composite adsorption electrode core 220 come into contact with the conductive adsorption filler 222. For NH4... + It is mainly captured by the layered silicate lattice of expanded vermiculite particles through ion exchange and fixed in the interlayer domains. For Cu 2+ Heavy metal ions are fixed through hydroxyl complexation between vermiculite layers and chemisorption by oxygen-containing functional groups on the surface of granular activated carbon. The central current collector 221 collects electrons and conducts them to the cathode electrode 120, completing the electrochemical circuit and maintaining a continuous electromigration driving force. Because the pollutants are locked within the packing material inside the microporous barrier layer 230, they are completely isolated from the external sediment 500.

[0068] At the end of a repair cycle, or when the conductive adsorption filler 222 reaches adsorption saturation, the operator slowly pulls the sediment anode module 200 out of the water by lifting the connecting cable 300. During the lifting process, the loose bottom sediment 500 attached to the outer surface of the permeable insulating shell 210 falls off under gravity and sinks to the bottom; while the conductive adsorption filler 222, which has adsorbed a large amount of pollutants, is tightly wrapped by the microporous barrier layer 230, preventing leakage. Because the pore size of the microporous barrier layer 230 is much smaller than the particle size of the bottom sediment, and the internal filler is compacted, a stable physical interception structure is formed, avoiding the resuspension pollution problem during recovery in traditional adsorption devices.

[0069] It can be seen that the electric field driving, microporous barrier, and internal adsorption of this invention have a synergistic effect. Without the microporous barrier layer, the electric field driving would cause sediment particles to migrate towards the anolyte via electrophoresis or electroosmosis, resulting in anolyte blockage and a sharp increase in resistance. The microporous barrier layer, while allowing ions to pass through, blocks the particles, maintaining a low-resistance environment in the anolyte region and ensuring the long-term stability of the electric field. The microporous barrier layer confines the adsorption space within the internal filter element, ensuring that adsorbent materials such as vermiculite only contact the high-concentration ions enriched by the electric field, rather than balancing with the low-concentration ions of the entire sediment system. This significantly improves adsorption efficiency. Acid-activated vermiculite exhibits a faster ion exchange rate under the high electric field of the microbial electrolysis cell mode, while exhibiting stronger adsorption stability under the weak electric field of the microbial fuel cell mode, demonstrating a certain fast-charge, slow-discharge characteristic. This characteristic matches the day and night dual modes well, achieving a good balance between energy efficiency and remediation effect.

[0070] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A device for in-situ remediation of aquaculture pond bottom sediment based on electrochemical coupling enhancement, characterized in that: The in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement includes: A floating cathode module (100) capable of floating on the surface of a water body includes a float support (140), a power management unit (110) disposed on the float support, and a cathode electrode (120) for contacting the water body. A sediment anode module (200) for installation in underwater sediments, the sediment anode module (200) comprising a water-permeable insulating shell (210) with multiple through holes on its sidewalls, a composite adsorption electrode core (220) filled inside the water-permeable insulating shell (210), and a microporous barrier layer (230) disposed inside the water-permeable insulating shell (210) and surrounding the composite adsorption electrode core (220); and, A connecting cable (300) electrically connects the floating cathode module (100) to the sediment anode module (200). The power management unit (110) is configured to apply a positive bias to the composite adsorption electrode core (220) to form an electromigration driving field between the deposited anode module (200) and the floating cathode module (100).

2. The in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement according to claim 1, characterized in that: The composite adsorption electrode core (220) includes a central current collector (221) and a conductive adsorption filler (222). The central current collector (221) extends along the axial direction of the water-permeable insulating shell (210). The conductive adsorption filler (222) fills the area around the central current collector (221). The conductive adsorption filler (222) is a mixture of expanded vermiculite particles and conductive carbon material particles, with a volume ratio of 1:1 to 3 between the expanded vermiculite particles and the conductive carbon material particles.

3. The in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement according to claim 2, characterized in that: The conductive carbon material particles are selected from at least one of granular activated carbon, biochar, graphite particles or carbon fiber chips, and the expanded vermiculite particles are expanded vermiculite particles that have undergone acid activation treatment or thermal modification treatment.

4. The in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement according to claim 1, characterized in that: The microporous barrier layer (230) is a nylon mesh, polyester screen or non-woven geotextile with a pore size of 0.03mm~0.08mm.

5. The in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement according to claim 1, characterized in that: The floating cathode module (100) also includes a photovoltaic panel (130), which is electrically connected to the connecting cable (300) via the power management unit (110). The power management unit (110) includes a switching circuit configured to switch between a microbial fuel cell mode and a microbial electrolysis cell mode. In the microbial fuel cell mode, the cathode electrode (120) is directly electrically connected to the composite adsorption electrode core (220). In the microbial electrolysis cell mode, the photovoltaic panel (130) is connected to provide an auxiliary voltage to the composite adsorption electrode core (220).

6. The in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement according to claim 1, characterized in that: The cathode electrode (120) is a carbon brush, carbon felt, or carbon cloth loaded with a catalyst, and the cathode electrode (120) is suspended below the floating body support (140).

7. A method for in-situ remediation of aquaculture pond bottom sediment based on electrochemical coupling enhancement using the electrochemical coupling-enhanced in-situ remediation device as described in any one of claims 1-6, characterized in that: The method includes: Insert the sediment anode module (200) into the bottom sediment, so that the microporous barrier layer (230) is in close contact with the bottom sediment, and place the floating cathode module (100) on the water surface; The circuit is connected by the power management unit (110), and an electric field is established by microbial electricity generation or external photovoltaic voltage. This drives positively charged pollutant ions in the bottom sediment to migrate through the microporous barrier layer (230) to the composite adsorption electrode core (220) and be adsorbed and fixed by the conductive adsorption filler (222).

8. The in-situ remediation device for aquaculture pond bottom sediment based on electrochemical coupling enhancement according to claim 7, characterized in that: The method also includes: During the day, the system switches to microbial electrolysis cell mode, using photovoltaic panels (130) to provide an applied voltage of 0.8~1.2V; At night, the system switches to microbial fuel cell mode, using the metabolic electricity generated by the microorganisms in the underwater sediment to maintain a weak electric field.

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