Floating object loaded electrooxidation electrokinetic remediation device and paddy field soil heavy metal removal method

Abstract

The invention belongs to the technical field of soil heavy metal treatment, and relates to a floater-loaded electrooxidation electrokinetic remediation device and a paddy field soil heavy metal removal method, the electrokinetic remediation device comprises a floating module, a power supply arranged in the floating module, and an anode electrode and a cathode electrode which are respectively connected with the anode and the cathode of the power supply; the anode electrode comprises an electrode core rod and an iron layer arranged outside the electrode core rod; the removing method comprises the steps that the floater-loaded electrooxidation electrokinetic remediation device is unloaded into overlying water of a paddy field to be remedied, the anode electrode and the cathode electrode are immersed, and heavy metal ions are adsorbed through electrode reaction. Compared with the prior art, heavy metal can be collected while heavy metal desorption of the paddy field soil is achieved, the follow-up treatment cost of the heavy metal is reduced, and the purpose of in-situ, low-energy-consumption and low-cost remediation of the paddy field soil polluted by the heavy metal is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of soil heavy metal treatment, and relates to a floating object load electric oxidation electric repair device and a method for removing heavy metals from paddy field soil. Background Art

[0002] At present, most of the heavy metal treatment in farmland, rivers and waterways adopts industrial site pollution control technology, which is costly and requires large investment, and is prone to secondary pollution. The biological treatment technology for heavy metals is not mature enough and has problems such as long treatment cycle. Since farmland, especially paddy fields, need a lot of irrigation during their growth process, heavy metals in the soil can be transferred to the overlying water for removal. Therefore, the contaminated soil remediation technology implemented in combination with irrigation may become a fast, efficient and low-cost heavy metal contaminated farmland soil remediation technology.

[0003] At present, there are few records of traditional remediation agent carriers. The carriers used in engineering are mainly chemical filler carriers, which generally have problems such as poor pollution resistance and low reusability. At the same time, the records in the literature are mostly based on filter mesh wrapped adsorption agents, which also have problems such as poor pollution resistance. In addition, when a large amount of water is irrigated into the paddy field, with the continuous consumption of oxygen and oxidizing substances in the soil, the soil redox potential (Eh) is significantly reduced, and heavy metals such as Cd, Pb, Cu, and Zn tend to exist in the form of sulfides with lower solubility, which is not conducive to the subsequent removal of heavy metals. The oxidation effect provided by the electrochemical oxidation method can increase the redox potential of the overlying water and soil, reduce the formation of heavy metal sulfides, promote the separation of heavy metals from the soil, enhance the mobility of heavy metals, and facilitate subsequent extraction and removal. This method has the characteristics of fast effect and wide adaptability; while the electric remediation technology can generate an electric field to enhance the effectiveness of heavy metals in the soil and make Cd in the overlying water phase 2+ Cr 3+ Cr 6+ Heavy metal cations such as AsO4 move toward the cathode under the action of the external electric field and are finally adsorbed on the cathode. 3- The metal anions and acid radicals are adsorbed on the anode, thus achieving the purpose of heavy metal removal. However, both the electrochemical oxidation method and the electric remediation method have problems such as high operating energy consumption and possible secondary pollution when used, which limits the promotion and use of this technology. How to use these two technologies stably, efficiently, quickly and at low cost has become a technical bottleneck in the industry.

[0004] CN201410745574.1 A method for electric repair of heavy metal contaminated soil, the invention belongs to the field of soil remediation, the method steps include the following: configure simulated heavy metal contaminated soil for standby; homemade electric test device: mainly includes 5 reaction tanks, in the order of: anode chamber, soil chamber, cathode chamber, soil chamber and anode chamber, there is a permeable reaction wall PRB containing molecular sieve between the reaction tanks, in addition to the cathode / anode chamber containing cathode / anode electrodes and cathode / anode working fluid, and DC stabilized power supply; then fill the contaminated soil in the homemade electric test device; run the electric test, and take the soil for heavy metal analysis after one week. The device is directly applied to the soil, not used in conjunction with the electrochemical oxidation method, with high energy consumption and high remediation cost.

[0005] CN202120117141.7 A highly efficient adsorption carrier for sewage treatment, the patent discloses a highly efficient adsorption carrier for sewage treatment, including a first external fixed frame, eight first fixed brackets are fixedly installed on the inner side of the first external fixed frame. The highly efficient adsorption carrier for sewage treatment, using the evenly distributed first sewage treatment component, the second sewage treatment component and the third sewage treatment component, can increase the contact area between the device and the sewage, the activated carbon and the polyurethane porous hydrophilic gel loaded with nanoparticles have the characteristics of filtration, adsorption and physical and chemical effects of nanoparticles, and increase the sewage treatment capacity of the device, remove the bolts on the outside of the first mounting block and the second mounting block, and extract the first sewage treatment carrier from between the first external fixed frame and the second fixed bracket, remove the bolts on the outside of the third mounting block and the fourth mounting block, and extract the third sewage treatment carrier from between the second external fixed frame and the third fixed bracket, the operation is simple, the overall structure is compact, the design is reasonable, and it is easy to use. The device cannot remove the pollutant particles on the outer surface during use, and the adsorption capacity is greatly affected by particles such as sludge during use. However, the invention does not enhance the desorption of heavy metals in sludge, and the agents that adsorb heavy metals will be disposed of as hazardous waste, resulting in high treatment costs. Summary of the invention

[0006] The purpose of the present invention is to provide a floating object loaded electro-oxidation electric repair device and a method for removing heavy metals from paddy field soil, which can be used to desorb heavy metals from paddy field soil and collect heavy metals at the same time, reduce the subsequent disposal cost of heavy metals, and achieve the purpose of in-situ, low-energy consumption, and low-cost repair of heavy metal-contaminated paddy field soil.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A first aspect of the present invention provides a floating object load electro-oxidation electric repair device, comprising a floating module, a power supply arranged in the floating module, and an anode electrode and a cathode electrode respectively connected to the positive and negative poles of the power supply; the anode electrode comprises an electrode core rod and an iron layer arranged outside the electrode core rod.

[0009] Furthermore, the iron layer is obtained by wrapping the electrode core rod with an iron material. Specifically, the iron material can be iron sheet, and the iron sheet is ensured to be in contact with the electrode core rod, but the electrode core rod is not exposed.

[0010] Furthermore, the power source is a charge-discharge battery.

[0011] Furthermore, a photovoltaic panel is provided on the floating module, and the photovoltaic panel is electrically connected to a power source.

[0012] Furthermore, an energy conversion module is provided between the photovoltaic panel and the power source for charging the power source, and an MPPT solar charging controller may be selected.

[0013] Furthermore, a protection resistor is electrically connected between the power supply and the anode electrode.

[0014] Furthermore, a capacitor module is electrically connected between the anode electrode and the cathode electrode.

[0015] Furthermore, magnets for connecting adjacent floating modules are provided on the outer edges of the floating modules.

[0016] Furthermore, the magnets are provided in plurality and distributed on the outer edge of the floating module.

[0017] Furthermore, there are four magnets which are evenly spaced and distributed on the outer edge of the floating module.

[0018] Further, relative to the floating module, the magnetic fields of adjacent magnets are in opposite directions.

[0019] Furthermore, the electrode core rod is a carbon rod, and the cathode electrode is a carbon rod electrode.

[0020] The second aspect of the present invention provides a method for removing heavy metals from paddy field soil, comprising: unloading a floating object-loaded electro-oxidation electric repair device into the acidic overlying water of the paddy field to be repaired, immersing the anode electrode and the cathode electrode, and adsorbing heavy metal ions through electrode reactions.

[0021] Furthermore, a plurality of floating object loaded electro-oxidation electric repair devices are attracted to each other through magnets on the floating module to form an array of floating object loaded electro-oxidation electric repair devices.

[0022] Furthermore, the reaction voltage of the electrode reaction is below 12V, preferably 3-5V.

[0023] The present invention uses a floating module to place an anode electrode and a cathode electrode in the acidic overlying water of a heavy metal-contaminated paddy field, provides electric energy through a power supply, and then uses the electric energy and the anode metal to generate iron salts. The iron salts move to the cathode where hydrogen peroxide is generated under the action of an external electric field, prompting a Fenton reaction to occur near the cathode, generating hydroxyl free radicals with stronger oxidizing properties, oxidizing organic matter and low-valent heavy metals in the overlying water, destroying complexes / chelates of organic matter and heavy metals, and increasing the soil redox potential through the exchange of water and soil substances, thereby increasing the mobility and effectiveness of heavy metals in the soil and the concentration of heavy metals in the overlying water; subsequently, the electric remediation and removal of heavy metals in the overlying water is achieved through the action of the electric field.

[0024] In order to ensure the stability of battery voltage and current, the present invention adds modules such as protection resistors and parallel capacitors in the circuit to ensure the stability of the repair process.

[0025] The present invention converts solar energy into the electrical energy required to promote the Fenton reaction through structures such as photovoltaic panels, which is highly efficient and energy-saving, can achieve self-power supply, and is green and economical. It can effectively reduce energy consumption and environmental pollution and promote the development of the green economy.

[0026] The present invention can realize multiple groups of parallel connection by connecting multiple devices through magnets, further ensuring the stability of the treatment effect of each repair device, and realizing the process of removing heavy metals from paddy field soil with high efficiency, low energy consumption and reusable materials. Compared with the prior art, the present invention has the following characteristics:

[0027] 1) Electrochemical oxidation technology is combined with solar energy. The only consumable material is the iron sheet on the surface of the anode electrode, which can increase the redox potential of heavy metals in the soil, enhance the desorption of heavy metals, reduce the energy consumption of electrochemical oxidation, and save treatment costs.

[0028] 2) Electrochemical oxidation is combined with electric remediation, and the equipment is designed to be unitized and miniaturized. The number of equipment required can be reasonably determined according to the remediation area, the desorption effect of heavy metals in the soil can be enhanced, and the heavy metals can be enriched on the electrodes in the overlying water and recovered. The remediation of heavy metal-contaminated soil is more thorough, while further reducing energy consumption and ensuring the stability of soil remediation.

[0029] 3) The internal circuit structure of the equipment can ensure the stability of voltage and current during the repair process. The devices are connected to each other to achieve equal sharing of electrical energy among the devices, further stabilizing the working voltage and current. At the same time, it also solves the problem of poor removal of heavy metals in the overlying water caused by uneven illumination. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a front cross-sectional view of a floating object load electric oxidation electric repair device of the present invention;

[0031] Figure 2It is a top cross-sectional view of a floating object load electro-oxidation electric repair device of the present invention;

[0032] Figure 3 , Figure 4 A schematic diagram of the structure for connecting and using multiple floating object load electro-oxidation electric repair devices;

[0033] Description of the markings in the figure:

[0034] 1- Photovoltaic panel for solar energy conversion, 2- Energy conversion module, 3- Charging and discharging battery, 4- Capacitor module, 5- Cathode electrode, 6- Anode electrode, 7- Floating module, 8- Magnet, 9- Protective resistor. DETAILED DESCRIPTION

[0035] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0036] The following are more detailed implementation cases, which further illustrate the technical solutions of the present invention and the technical effects that can be obtained.

[0037] The directions (up, down, left, right, front, back) in the description of the present invention are for the convenience of intuitive description of the technical solution of the present invention, rather than that the present invention has a specific orientation structure and operation, and should not be understood as a limitation of the present invention.

[0038] In the description of the present invention, “one section”, “two sections”, “first level” and “second level” are only used to distinguish technical features and cannot be understood as the number of technical features indicated by the present invention or the order of the indicated technical features.

[0039] In the present invention, the terms "set", "install", "connect" and the like should be understood in a broad sense, and may refer to direct connection, indirect connection, fixed connection, detachable connection, or integral molding.

[0040] In the following examples, unless otherwise specified, raw materials, reagents or processing techniques are all conventional commercial products or conventional processing techniques in the art.

[0041] In order to achieve the restoration of heavy metal-contaminated paddy field soil, the present invention provides a floating object load electro-oxidation electro-remediation device and a paddy field soil heavy metal removal method. The structure of the device can be found in Figure 1 As shown in the following, including:

[0042] A floating object load electro-oxidation electric repair device, comprising: a photovoltaic panel 1 placed on the uppermost layer and used for solar energy conversion, the photovoltaic panel 1 is installed on the top of a floating module 7, the lower part of the photovoltaic panel 1 is connected to one end of an energy conversion module 2, a charge-discharge battery 3 is connected to the other end of the energy conversion module 2, the positive electrode of the charge-discharge battery 3 is connected in series with a protection resistor 9 and an anode electrode 6 in sequence, the negative electrode of the charge-discharge battery 3 is connected to a cathode electrode 5 (a carbon rod electrode may be selected), two ends of a capacitor module 4 are respectively connected to the cathode electrode 5 and the anode electrode 6, and the capacitor module 4 is in parallel with the charge-discharge battery 3, and magnets 8 are evenly distributed around the floating module 7, and a wire is provided inside to connect to an internal circuit;

[0043] In some specific embodiments, the inner ends of the plurality of magnets 8 are electrically connected to the energy conversion modules 2 respectively.

[0044] The magnet 8 has two functions. First, it absorbs nearby repair floating objects together for easy management and recovery. Second, due to changes in pollutant concentrations in the repair waters, some areas have higher power consumption and some areas have lower power consumption. Using the magnet 8 to connect the floating objects together is equivalent to connecting multiple power supplies in parallel, so that floating objects that consume more electricity can obtain power supply from other floating objects.

[0045] Photovoltaic panel 1, preferably with a specification of 5.5V or above, can provide a voltage of 3V or above for the device, and has a small mass and volume, which is convenient for installation and use. Function: used to absorb solar energy and provide energy to the device.

[0046] The charging and discharging battery 3 has the functions of charging and discharging, and the maximum charging voltage of the battery is not less than 5.5V, which corresponds to the specifications of the photovoltaic panel and can provide a DC voltage of not less than 3V for the electrode. Function: to store and release the converted electrical energy.

[0047] Capacitor module 4, with a capacitor voltage of not less than 5.5V, corresponding to the voltage of the charge-discharge battery 3, is directly connected to the two electrodes. Function: It stabilizes the voltage in the circuit and prolongs the battery life.

[0048] The anode electrode 6 is a composite electrode, with a carbon rod inside and an iron sheet with a thickness of 1 to 3 mm wrapped outside. The iron sheet is connected to the positive electrode of the charge-discharge battery 3 through the carbon rod. Function: When the iron rod is dissolved, the carbon rod can continue to work and form an electric field loop with the cathode.

[0049] The floating module 7 is a hollow structure made of plastic with a density lower than that of water, which can make the device float on the water surface, especially when the photovoltaic panel is exposed on the water surface. Function: Provide a carrier for the device to float on the water surface, and realize the device's online treatment function for heavy metals in the overlying water.

[0050] Magnets 8 are evenly distributed around the floating module 7, with S poles and N poles arranged alternately clockwise to the outside, and wires are connected to the internal circuit inside the magnets 8. Function: It can be connected with surrounding repair equipment to form a larger repair system, and can evenly distribute electricity to provide support for stable operation.

[0051] The protection resistor 9 is a circuit protection module, and the resistance is generally 1-3Ω. Function: protect the circuit.

[0052] A method for removing heavy metals from paddy field soil, based on the device described above, comprises the following steps:

[0053] (1) Pollutant detection

[0054] The concentration and type of pollutants in the overlying water of paddy field irrigation are tested, and the number of equipment to be deployed is calculated based on the volume and area of ​​the overlying water.

[0055] (2) Device deployment

[0056] After the installed equipment is transported to the vicinity of the paddy field to be repaired, it is unloaded into the overlying water. The anode electrode 6 and the cathode electrode 5 with larger mass are partially immersed in the overlying water, leaving only the photovoltaic panel 1 exposed. In addition, since magnets 8 are distributed around the floating module 7, the equipment will be tightly connected together to form a large overlying water heavy metal treatment system.

[0057] (3) Treatment of heavy metal pollutants in overlying water

[0058] During operation, solar energy is converted into electrical energy after passing through the photovoltaic panel 1 and the energy conversion module 2, and is utilized by the charge-discharge battery 3. Under the joint action of the charge-discharge battery 3 and the capacitor module 4, the anode electrode 6 is continuously dissolved to release iron salts, and the iron ions converge toward the cathode under the action of the electric field, and a large amount of hydrogen peroxide is generated around the cathode electrode 5. The generated hydrogen peroxide produces more oxidizing hydroxyl free radicals under the catalytic action of the iron salts, increasing the redox potential of heavy metals in the overlying water and soil, so that the heavy metals are desorbed from the soil and enter the overlying water. When the iron sheet is dissolved, the carbon rod electrode is exposed inside, and the carbon rod electrodes of the cathode and the anode form an electric repair electric field. In this process, Cd 2+ Cr 3+ Cr 6+ Heavy metal cations such as AsO4 move toward the cathode and are finally adsorbed on the cathode. 3- The metal anion acid radicals are adsorbed on the anode, and then the device is recovered to clean the electrode. After the electrode is separated from the water, the electric field has no circuit, forming a short circuit, and the heavy metal salts fall off. The electrode can then be regenerated by washing with clean water. The heavy metals can be recycled and disposed of, thereby achieving the purpose of heavy metal removal.

[0059] (4) Electrode replacement

[0060] The equipment floating on the water surface is recovered by tools. After the recovery, the equipment only needs to process the cathode and replace the anode before it can be put into use again.

[0061] The above embodiment is described in more detail below in conjunction with specific embodiments.

[0062] Example 1

[0063] A floating object load electro-oxidation electric repair device has a structure as described above, wherein the floating module 7 is a cylindrical body made of PP material with a diameter of 80 mm, the photovoltaic panel 1 on the top of the floating module 7 uses a 5.5V specification, and the capacitor module 4 uses a 5.5V 0.22FH type farad capacitor, which can provide a buffer voltage of 3 to 5V for the device, and 4 magnets with a diameter of 5mm and a thickness of 2mm are evenly distributed around the floating module 7, showing an alternating distribution of S poles and N poles, the outer iron sheet thickness of the anode electrode 6 is about 1.5mm, and the protection resistor in the internal circuit of the device is 1Ω.

[0064] A method for removing heavy metals from paddy field soil based on a floating object loaded electro-oxidation electro-remediation device comprises the following steps:

[0065] (1) Pollutant detection

[0066] The main pollutant in the paddy field soil to be treated is cadmium, with a cadmium content of 4.19 mg / kg and a pH of 4.88, which exceeds the corresponding risk screening value of the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (Trial)" (GB 15618-2018). Irrigate the paddy field, and use tillage equipment to plow the topsoil. Use enhanced remediation equipment (crawler self-propelled rotary tiller, manufacturer: Changfa Agricultural Equipment, model: 1GZL-230) to enhance the desorption and leaching of soil cadmium; then settle for 3 hours and measure the cadmium concentration in the overlying water.

[0067] The cadmium concentration in the overlying water is about 93μg / L. The specific amount is determined based on the overlying water area and volume of the rice field irrigation water. According to the area of ​​paddy fields to be repaired, about 260 repair devices are needed.

[0068] (2) Placement of restoration equipment and paddy field soil restoration

[0069] 260 restoration devices were arranged in an array according to the size of the paddy field and dropped into the overlying water of the paddy field to be restored. The purpose of restoring the paddy field soil was achieved by removing cadmium in the overlying water.

[0070] (3) Electrode replacement

[0071] After about 5 days of repair, the cadmium concentration in the overlying water was reduced from 93μg / L to 3μg / L. The equipment scattered in the overlying water of the irrigation water was recovered, and the recovered anode electrodes needed to be replaced and waited for the next use.

[0072] Example 2

[0073] A floating object load electro-oxidation electric repair device, the structure of which is different from that of Example 1 only in that: the anode electrode 6 has no carbon rod, and is made of iron wire with a diameter of about 1.5 mm, and the protective resistor in the internal circuit of the device is also 1Ω. The rest is the same as Example 1.

[0074] A method for removing heavy metals from paddy field soil based on a floating object loaded electro-oxidation electro-remediation device comprises the following steps:

[0075] (1) Pollutant detection

[0076] The paddy field soil to be treated is the contaminated land adjacent to Example 1, with similar pollutant types and concentrations, of which the main pollutant is cadmium, with a cadmium content of 4.12 mg / kg and a pH of 4.83, and the pollutant content also exceeds the corresponding risk screening value of the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (Trial)" (GB 15618-2018). Irrigate the paddy field, and use farming equipment to plow the plough layer soil, and use enhanced remediation equipment (same as Example 1) to enhance the desorption and leaching of soil cadmium; then precipitate for 3 hours, and measure the concentration of cadmium in the overlying water.

[0077] The cadmium concentration in the overlying water is about 91μg / L. The specific amount is determined based on the overlying water area and volume of the rice field irrigation water. According to the area of ​​paddy fields to be repaired, about 258 repair devices are needed.

[0078] (2) Placement of restoration equipment and paddy field soil restoration

[0079] 258 restoration devices were arranged in an array according to the size of the paddy field and dropped into the overlying water of the paddy field to be restored, so as to achieve the purpose of restoring the paddy field soil by removing cadmium in the overlying water.

[0080] (3) Electrode replacement

[0081] After about 4 days of repair, the cadmium concentration in the overlying water was detected to have dropped from 93μg / L to 33μg / L, and the anode electrode was completely dissolved, requiring the electrode to be replaced to continue the repair.

[0082] Example 3

[0083] A floating object load electric oxidation electric repair device, the structure of which is different from that of Example 1 only in that the anode electrode is a carbon rod electrode, and the rest is the same as Example 1.

[0084] A method for removing heavy metals from paddy field soil based on a floating object loaded electro-oxidation electro-remediation device comprises the following steps:

[0085] (1) Pollutant detection

[0086] The paddy field soil to be treated is the contaminated land adjacent to Example 1, with similar pollutant types and concentrations, wherein the main pollutant is cadmium, wherein the cadmium content is 4.14 mg / kg, and the pH is 4.87. The paddy field is irrigated, and the topsoil is plowed using tillage equipment, and enhanced remediation equipment (same as Example 1) is used to enhance the desorption and leaching of soil cadmium; thereafter, the soil is precipitated for 3 hours, and the cadmium concentration in the overlying water is measured.

[0087] The cadmium concentration in the overlying water is about 87μg / L. The specific amount is determined based on the overlying water area and volume of the rice field irrigation water. According to the area of ​​paddy fields to be repaired, about 262 repair devices are needed.

[0088] (2) Placement of restoration equipment and paddy field soil restoration

[0089] 262 restoration devices were arranged in an array according to the size of the paddy field and dropped into the overlying water of the paddy field to be restored. The purpose of restoring the paddy field soil was achieved by removing cadmium in the overlying water.

[0090] (3) Repair time

[0091] After about 4 days of repair, the cadmium concentration in the overlying water dropped from 87μg / L to 72μg / L; after another 2 days of repair, the cadmium concentration in the overlying water dropped from 87μg / L to 67μg / L; after another 4 days of repair, the cadmium concentration in the overlying water dropped from 67μg / L to 66μg / L, and the repair effect remained almost unchanged. In total, it took 10 days, and the concentration of heavy metal cadmium only dropped by about 24%.

[0092] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A floating object load electro-oxidation electric repair device, characterized in that: It comprises a floating module (7), a power source arranged in the floating module (7), and an anode electrode (6) and a cathode electrode (5) respectively connected to the positive and negative electrodes of the power source; the anode electrode (6) comprises an electrode core rod and an iron layer arranged outside the electrode core rod.

2. The floating object load electro-oxidation electric repair device according to claim 1 is characterized in that: The floating module (7) is provided with a photovoltaic panel (1), and the photovoltaic panel (1) is electrically connected to a power source.

3. The floating object load electro-oxidation electric repair device according to claim 1 is characterized in that: An energy conversion module (2) is provided between the photovoltaic panel (1) and the power source.

4. The floating object load electro-oxidation electric repair device according to claim 1 is characterized in that: A protective resistor (9) is electrically connected between the power supply and the anode electrode (6).

5. The floating object load electro-oxidation electric repair device according to claim 1 is characterized in that: A capacitor module (4) is also electrically connected between the anode electrode (6) and the cathode electrode (5).

6. The floating object load electro-oxidation electric repair device according to claim 1 is characterized in that: The outer edge of the floating module (7) is provided with a magnet (8) for connecting adjacent floating modules (7).

7. The floating object load electro-oxidation electric repair device according to claim 6 is characterized in that: Relative to the floating module (7), the magnetic fields of adjacent magnets (8) are in opposite directions.

8. The floating object load electro-oxidation electric repair device according to claim 1 is characterized in that: The electrode core rod is a carbon rod, and the cathode electrode (5) is a carbon rod electrode.

9. A method for removing heavy metals from paddy field soil based on the device according to any one of claims 1 to 8, characterized in that: include: The floating object-loaded electro-oxidation electric repair device is unloaded into the acidic overlying water of the paddy field to be repaired, so that the anode electrode (6) and the cathode electrode (5) are immersed, and heavy metal ions are adsorbed through electrode reaction.

10. The method for removing heavy metals from paddy field soil according to claim 9, characterized in that: A plurality of floating object loaded electro-oxidation electric repair devices are mutually attracted via a magnet (8) on a floating module (7) to form an array of floating object loaded electro-oxidation electric repair devices; and / or a reaction voltage of the electrode reaction is below 12V.

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