Underground water circulating well primary battery repairing device and method based on biochar electrode

Abstract

The invention relates to the field of underground water in-situ remediation, and discloses an underground water circulation well primary battery remediation device and method based on a biochar electrode, and the device comprises a circulation well body which comprises a first screen section and a second screen section; the water pumping and injecting part is used for pumping the polluted underground water into the second screen section from the first screen section and recharging the polluted underground water into the aquifer from the second screen section after treatment to form an underground water circulating flow field; the primary battery assembly comprises a liquid storage part, a cathode assembly, an anode assembly and a proton exchange membrane, is arranged on the second screen section and is used for degrading pollutants in underground water. An oxidizing agent is injected into the liquid storage part and reacts with underground water pollutants collected in the second screen section, electrons are transmitted through the cathode assembly and the anode assembly, the oxidizing agent is prevented from making direct contact with the pollutants, and pollutant degradation and removal are achieved; in the whole process, the generation of high-toxicity intermediate products and the toxic action on primary microorganisms can be reduced, so that the secondary pollution risk of the underground water environment is reduced, and the purpose of green low-carbon remediation is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ groundwater remediation, and particularly to a galvanic cell remediation device and method for a groundwater circulation well based on a biochar electrode. Background Art

[0002] With the acceleration of industrialization and urbanization processes and the expansion of agricultural activities, the problem of groundwater environmental pollution has become increasingly severe, posing a serious threat to the ecosystem and human health. Among in-situ groundwater remediation technologies, the circulation well technology causes little disturbance to the aquifer, occupies less land for facilities, and has low energy consumption, and thus is widely used.

[0003] The circulation well technology pumps and injects water into the well body through a vacuum pump, and uses hydraulic power to drive the surrounding polluted groundwater to flow into the well. In recent years, the coupling of various oxidation technologies with circulation wells can effectively remove volatile / semi-volatile organic compounds in groundwater. However, when oxidants and catalysts are directly injected into the formation, there are problems such as a high risk of secondary pollution, aquifer clogging, and high remediation costs.

[0004] The prior art discloses a circulation well system for in-situ remediation of organically polluted groundwater, as Figure 1 shown. The well pipe unit includes a circulation inlet screen pipe 01 and a circulation outlet screen pipe. The circulation treatment chamber 02 is sleeved inside the circulation outlet screen pipe. A circulation water pump 03 is provided between the circulation inlet screen pipe 01 and the circulation treatment chamber 02. The circulation water pump 03 injects groundwater in the polluted area into the circulation treatment chamber 02 through the circulation inlet screen pipe 01. The chemical agent unit 04 injects an oxidation chemical agent into the circulation treatment chamber 02 to treat the polluted groundwater. After the treatment is completed, it enters the circulation outlet screen pipe and flows out of the well pipe unit after filtration.

[0005] However, in this technology, the oxidant directly contacts the polluted groundwater, which will cause a change in the underground reducing environment, and toxic and harmful by-products are generated in the reaction, posing a risk of secondary pollution. Summary of the Invention

[0006] In view of this, the present invention designs a galvanic cell oxidation device based on a biochar electrode coupled with a circulation well remediation technology, which can achieve the degradation and removal of pollutants under the condition of avoiding direct contact between the oxidant and the pollutants. The whole process can reduce the generation of highly toxic intermediate products and the poisoning effect on native microorganisms, thereby reducing the risk of secondary pollution of the groundwater environment and achieving the purpose of green and low-carbon remediation.

[0007] In a first aspect, the present invention provides a galvanic cell remediation device for a groundwater circulation well based on a biochar electrode, including:

[0008] A circular well body is arranged below the ground surface. The circular well body includes a first sieve section and a second sieve section. The first sieve section is arranged on one side of the second sieve section. The first sieve section is provided with a water inlet communicating with an aquifer, and the second sieve section is provided with a water outlet communicating with the underground.

[0009] A pumping and injection member is arranged between the first sieve section and the second sieve section, and is used for pumping the groundwater from the first sieve section into the second sieve section to realize the circulating flow of the groundwater in the aquifer.

[0010] A primary battery assembly is arranged on the side of the second sieve section away from the first sieve section and is used for degrading pollutants in the groundwater.

[0011] Wherein, the primary battery assembly includes:

[0012] A liquid storage member is arranged on the side of the second sieve section away from the first sieve section. The liquid storage member includes a first cavity, and the first cavity is used for storing a solution containing an oxidant. The liquid storage member is provided with a first through hole and a second through hole communicating the first cavity with the second sieve section.

[0013] A cathode assembly is arranged in the first cavity and is used for contacting the oxidant.

[0014] An anode assembly is arranged in the second sieve section, passes through the first through hole and is connected to the cathode assembly, and is used for contacting pollutants in the groundwater.

[0015] A proton exchange membrane is fixed at the second through hole and is used for transporting protons in the first cavity into the second sieve section without other solute exchanges.

[0016] Beneficial effects: By storing the oxidant in the first cavity, storing the pollutants in the groundwater in the second sieve section, connecting the cathode assembly to the oxidant solution to form a cathode electrode, and connecting the anode assembly to the contaminated groundwater to form an anode electrode, a potential difference can be formed between the cathode assembly and the anode assembly. When the potential of the cathode assembly rises above the potential required for the oxidation of the pollutants, the pollutants can lose electrons and be oxidized and degraded, and are transported to the cathode assembly through the anode assembly. The oxidant gains electrons and is reduced and decomposed, and protons are transported through the proton exchange membrane to form a current loop with the electron transfer, thereby completing the continuous degradation of the pollutants. The whole process can avoid the direct contact between the oxidant and the pollutants, which can not only prevent the excessive interference of the oxidant on the reducing environment of the groundwater, reduce the generation of highly toxic intermediate products and the poisoning effect on the native microorganisms, thereby reducing the risk of secondary pollution of the groundwater environment and achieving the purpose of green and low-carbon remediation, but also improve the utilization rate of the oxidant and the degradation ability of the pollutants; Using the pumping and injection component to pump the groundwater in the first sieve section into the second sieve section, a pressure difference is formed between the first sieve section and the second sieve section, which can drive the groundwater around the circulation well body to continuously enter the first sieve section, thereby improving the treatment efficiency of the pollutants and being able to control the moving direction of the pollution range to prevent pollution diffusion; The proton exchange membrane only allows positively charged hydrogen ions to pass through, which can maintain the charge balance of the system and ensure the continuous flow of current.

[0017] In an alternative embodiment, the cathode assembly includes:

[0018] A cathode part for transmitting electrons;

[0019] A first catalytic part, loaded on the surface of the cathode part, for connecting with the solution containing the oxidant;

[0020] And / or, the anode assembly includes:

[0021] An anode part for transmitting electrons;

[0022] A second catalytic part, loaded on the surface of the anode part, for connecting with the groundwater containing the pollutants.

[0023] Beneficial effects: By providing the first catalytic part and the second catalytic part, a potential difference can be formed on the cathode part and the anode part, thereby realizing electron transfer; Fixing the first catalytic part on the cathode part and the second catalytic part on the anode part can improve the electron transfer efficiency and can also prevent the second catalytic part from entering the aquifer with the degraded groundwater and blocking the aquifer.

[0024] In an alternative embodiment, the cathode part and / or the anode part are columnar structures and sheet structures;

[0025] And / or, the cathode part and / or the anode part are made of graphite material;

[0026] And / or, the first catalyst and / or the second catalyst are made of biochar material.

[0027] Advantageous effects: By providing a large number of first catalysts and second catalysts, the contact area of the oxidant can be increased, thereby increasing the potential difference between the cathode and the anode, so as to improve the electron transfer rate and further improve the pollutant degradation efficiency; By using the method of fixing biochar on graphite for conduction, it is not easy to corrode, will not cause secondary pollution to groundwater, and has low production cost.

[0028] In an optional embodiment, the biochar electrode-based groundwater circulation well primary battery repair device includes:

[0029] A detection component, disposed in the first cavity and / or the second sieve section, the detection component is electrically connected to the water extraction and injection component, and is used to adjust the output power of the water extraction and injection component according to the detection value.

[0030] Advantageous effects: By providing a detection component, it can be used to analyze the redox situation of the liquid in the first cavity and the second sieve section, thereby adjusting the speed of the groundwater flowing into the second sieve section and the amount of oxidant introduced into the first cavity, and determining whether the cathode component and the anode component should be replaced.

[0031] In an optional embodiment, the detection component includes:

[0032] A first detection piece, disposed in the first cavity, and used to detect the liquid concentration in the first cavity;

[0033] And / or, a second detection piece, disposed in the second sieve section, and used to detect the liquid concentration in the second sieve section.

[0034] In an optional embodiment, the biochar electrode-based groundwater circulation well primary battery repair device includes:

[0035] A first storage piece, storing the oxidant and / or electrolyte, the first storage piece is communicated with the first cavity, and is used to provide the oxidant and / or the electrolyte to the first cavity;

[0036] And / or, a second storage piece, communicated with the first cavity, and is used to recover the electrolyte in the first cavity;

[0037] And / or, a sealing piece, fixed in the circulation well body, and is used to separate the first sieve section and the second sieve section.

[0038] Advantageous effects: By recovering the electrolyte, the anion concentration in the first cavity can be reduced, and the waste liquid discharge amount can be reduced.

[0039] In an alternative embodiment, a stirring member is provided in the first cavity for accelerating the dissolution of the oxidant and / or the electrolyte;

[0040] and / or, an anti-deposition layer is provided on the surface of the proton exchange membrane close to the second sieve section.

[0041] Advantageous effects: By providing the stirring member, the oxidant and the electrolyte can be quickly dissolved and diffused to ensure sufficient contact between the oxidant and the surface of the first catalytic member; by providing the anti-deposition layer, the scaling of Ca 2+ or Mg 2+ can be inhibited, so that the proton exchange membrane can operate in groundwater with a hardness greater than 500 mg / L for a long time without cleaning.

[0042] In an alternative embodiment, the first storage member is connected to the inside of the first cavity through a pipeline, and the stirring member is provided at the end of the pipeline away from the first storage member.

[0043] Advantageous effects: By providing the stirring member at the end of the pipeline, the structure can be simplified.

[0044] In an alternative embodiment, along the length extension direction of the circulation well body, the size of the liquid storage member is smaller than the size of the second sieve section;

[0045] and / or, the liquid storage member is detachably fixed to the circulation well body;

[0046] and / or, a loading and unloading guiding structure is provided above the liquid storage member.

[0047] Advantageous effects: By detachably connecting the liquid storage member to the circulation well body, it is convenient to replace the cathode assembly, the anode assembly and the proton exchange membrane; by providing the loading and unloading guiding structure, it is convenient to replace the liquid storage member.

[0048] In a second aspect, the present invention also provides a method for repairing a groundwater circulation well primary battery based on a biochar electrode, which is applied to the above-mentioned groundwater circulation well primary battery repair device based on a biochar electrode, and includes:

[0049] The groundwater enters the first sieve section through the water inlet;

[0050] The groundwater is pumped into the second sieve section through the pumping and injecting member;

[0051] The cathode assembly is connected to the solution containing the oxidant, and the anode assembly is connected to the groundwater containing the pollutant;

[0052] Electrons in the pollutants are transferred to the oxidant, and protons in the first cavity are transported through the proton exchange membrane into the second sieve section, forming a current loop with the electron transfer to achieve the degradation of the pollutants.

[0053] The degraded groundwater is discharged from the water outlet.

[0054] Beneficial effects: Since the primary battery repair method for groundwater circulation wells based on biochar electrodes is applied to the primary battery repair device for groundwater circulation wells based on biochar electrodes, it has the same effects as the primary battery repair device for groundwater circulation wells based on biochar electrodes, which will not be elaborated here. Description of the Drawings

[0055] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0056] Figure 1 It is a schematic structural diagram of a circulation well system for in-situ remediation of organically contaminated groundwater in the prior art;

[0057] Figure 2 It is a schematic structural diagram of a primary battery repair device for groundwater circulation wells based on biochar electrodes according to an embodiment of the present invention;

[0058] Figure 3 It is an experimental schematic diagram of a primary battery repair device for groundwater circulation wells based on biochar electrodes according to an embodiment of the present invention;

[0059] Figure 4 For Figure 3 The experimental result diagram shown.

[0060] Description of the Reference Numerals:

[0061] 01, circulating water inlet sieve tube; 02, circulating treatment chamber; 03, circulating water pump; 04, chemical agent unit

[0062] 1. Circulating well body; 101. First sieve section; 1011. Water inlet; 102. Second sieve section; 1021. Water outlet; 2. Water pumping and injection component; 3. Liquid storage component; 301. Loading and unloading guiding structure; 4. Cathode assembly; 401. Cathode part; 402. First catalytic part; 5. Anode assembly; 501. Anode part; 502. Second catalytic part; 6. Proton exchange membrane; 7. Detection assembly; 701. Sulfate ion concentration monitor; 702. Oxygen concentration monitor; 703. pH value monitor; 704. Total organic carbon concentration monitor; 8. First storage part; 9. Second storage part; 10. Sealing part; 11. Stirring part; 12. Pipeline; 13. Controller; 14. Gas collection part; 15. Sodium persulfate; 16. 2,4,6-Trichlorophenol. Detailed implementation manners

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0064] The following combines Figures 2 to 4 , to describe the embodiments of the present invention.

[0065] According to an embodiment of the present invention, on the one hand, a groundwater circulation well primary battery repair device based on a biochar electrode is provided, including: a circulating well body 1, located below the ground surface, the circulating well body 1 includes a first sieve section 101 and a second sieve section 102, the first sieve section 101 is located on one side of the second sieve section 102, the first sieve section 101 is provided with a water inlet 1011 communicating with the aquifer, and the second sieve section 102 is provided with a water outlet 1021 communicating with the ground; a water pumping and injection component 2, located between the first sieve section 101 and the second sieve section 102, for pumping groundwater from the first sieve section 101 into the second sieve section 102 to realize the circulating flow of groundwater in the aquifer; a primary battery assembly, located on the side of the second sieve section 102 away from the first sieve section 101, for degrading pollutants in the groundwater; wherein, the primary battery assembly includes: a liquid storage component 3, located on the side of the second sieve section 102 away from the first sieve section 101, the liquid storage component 3 includes a first cavity, and the first cavity is used for storing a solution containing an oxidant, and the liquid storage component 3 is provided with a first through hole and a second through hole communicating the first cavity with the second sieve section 102; a cathode assembly 4, located in the first cavity, for contacting the oxidant; an anode assembly 5, located in the second sieve section 102, passing through the first through hole and connecting with the cathode assembly 4, for contacting pollutants in the groundwater; a proton exchange membrane 6, fixed at the second through hole, for transporting protons in the first cavity into the second sieve section 102 without other solute exchange.

[0066] By storing the oxidant in the first cavity, storing the pollutants in the groundwater in the second sieve section 102, connecting the cathode assembly 4 with the oxidant solution to form a cathode electrode, and connecting the anode assembly 5 with the contaminated groundwater to form an anode electrode, a potential difference can be formed between the cathode assembly 4 and the anode assembly 5. When the potential of the cathode assembly 4 rises to be higher than the potential required for the oxidation of the pollutants, the pollutants can lose electrons and be oxidized and degraded, and are transmitted to the cathode assembly 4 through the anode assembly 5. The oxidant gains electrons and is reduced and decomposed. Protons are transmitted through the proton exchange membrane 6 and constitute a current loop with the electron transfer, thereby completing the continuous degradation of the pollutants. The whole process can avoid the direct contact between the oxidant and the pollutants, not only prevent the excessive interference of the oxidant on the reducing environment of the groundwater, reduce the generation of highly toxic intermediate products and the poisoning effect on the native microorganisms, thereby reducing the risk of secondary pollution of the groundwater environment and achieving the purpose of green and low-carbon remediation, but also improve the utilization rate of the oxidant and the degradation ability of the pollutants; The groundwater in the first sieve section 101 is pumped into the second sieve section 102 by the pumping and injection member 2, so that a pressure difference is formed between the first sieve section 101 and the second sieve section 102, which can drive the groundwater around the circulation well body 1 to continuously enter the first sieve section 101, thereby improving the treatment efficiency of the pollutants and simultaneously regulating the moving direction of the pollution range to prevent pollution diffusion; The proton exchange membrane 6 only allows positively charged hydrogen ions to pass through, which can maintain the charge balance of the system and ensure the continuous flow of current.

[0067] As Figure 2 shown, in one embodiment, the circulation well body 1 is vertically arranged below the ground surface, the second sieve section 102 is arranged above the first sieve section 101 and is adjacent to the first sieve section 101. As an alternative implementation, the second sieve section 102 can also be obliquely arranged with the first sieve section 101, or the second sieve section 102 is arranged on one side of the first sieve section 101 in the horizontal direction. As an alternative implementation, the second sieve section 102 can also be arranged at intervals with the first sieve section 101.

[0068] As Figure 2 shown, in one embodiment, the pumping and injection member 2 includes a water pump and a water pipe communicated with the water pump. The water inlet end of the water pipe is located in the first sieve section 101, and the water outlet end is located in the second sieve section 102. The water pump passes the groundwater in the first sieve section 101 into the second sieve section 102 through the water pipe; Multiple openings are formed in the part of the water pipe located in the second sieve section 102 to form a water outlet end. As an alternative implementation, other pumping structures such as an air pump can also be used, and no more restrictions are made here.

[0069] As Figure 2As shown, in one embodiment, along the length extension direction of the circulation well body 1, the size of the liquid storage member 3 is smaller than that of the second sieve section 102. Specifically, along the length extension direction of the circulation well body 1, the size of the liquid storage member 3 is half of the size of the second sieve section 102. As a variable implementation, the size of the liquid storage member 3 is determined according to the shape and size of the second sieve section 102, and no further limitation is imposed here.

[0070] In one embodiment, the liquid storage member 3 is detachably fixed to the circulation well body 1. Specifically, a plurality of grooves are provided at intervals on the inner side wall of the circulation well body 1, and a plurality of telescopic protrusions are provided on the outer side wall of the liquid storage member 3, and the protrusions are clamped in the grooves for fixation. By detachably connecting the liquid storage member 3 to the circulation well body 1, it is convenient to replace the cathode assembly 4, the anode assembly 5, and the proton exchange membrane 6. As a variable implementation, it may also be that the liquid storage member 3 is detachably connected to the circulation well body 1 by other means, and no further limitation is imposed here.

[0071] As Figure 2 shown, in one embodiment, the first through hole and the second through hole are provided on the side of the liquid storage member 3 close to the first sieve section 101, and the first through hole and the second through hole are arranged at intervals.

[0072] As Figure 2 shown, in one embodiment, a loading and unloading guiding structure 301 is provided above the liquid storage member 3. By providing the loading and unloading guiding structure 301, it is convenient to replace the liquid storage member 3. As a variable implementation, it may also be that a part of the liquid storage member 3 extends out of the circulation well body 1, and an opening is provided on the extended part for the loading and unloading guiding structure.

[0073] In one embodiment, the oxidant is sodium persulfate. Sodium persulfate can improve the electron transfer efficiency and can be efficiently activated on the surface of the biochar electrode. As a variable implementation, the oxidant can also be one or a combination of other oxidants such as sodium monopersulfate, potassium monopersulfate, and potassium persulfate.

[0074] As Figure 2 shown, in one embodiment, the cathode assembly 4 includes: a cathode member 401 for transmitting electrons; a first catalytic member 402 loaded on the surface of the cathode member 401 for connecting with a solution containing an oxidant. The anode assembly 5 includes: an anode member 501 for transmitting electrons; a second catalytic member 502 loaded on the surface of the anode member 501 for connecting with the groundwater containing pollutants. Among them, the cathode member 401 and the anode member 501 are in a columnar structure and a sheet structure, and the sheet structures are respectively connected to both sides of the columnar structure; there are a plurality of sheet structures, and a plurality of sheet structures are provided at intervals on the columnar structure on each side. Further, the loading amount of the first catalytic member 402 on the cathode member 401 and the loading amount of the second catalytic member 502 on the anode member 501 are both 0 g / m 2 -10 g / m2 By setting the first catalyst 402 and the second catalyst 502, a potential difference can be formed between the cathode 401 and the anode 501, thereby realizing electron transfer. Fixing the first catalyst 402 on the cathode 401 and the second catalyst 502 on the anode 501 can improve the electron transfer efficiency and prevent the second catalyst 502 from entering the aquifer with the degraded groundwater and blocking the aquifer. By setting a large number of the first catalyst 402 and the second catalyst 502, the contact area of the oxidant can be increased, thereby increasing the potential difference between the cathode 401 and the anode 501 to improve the electron transfer speed and then improve the pollutant degradation efficiency. As an alternative embodiment, the cathode 401 and the anode 501 can also be other special-shaped structures such as a cross, which is not limited here. As an alternative embodiment, the first catalyst 402 and the second catalyst 502 can also be spherical structures or polygonal structures, which is not limited here. As an alternative embodiment, the number of the first catalyst 402 and the second catalyst 502 is determined according to the actual situation, which is not limited here. As an alternative embodiment, the loading amount of the first catalyst 402 on the cathode 401 and the loading amount of the second catalyst 502 on the anode 501 can also be greater than 10 g / m 2 , such as 11 g / m 2 , which can be specifically adjusted according to actual requirements.

[0075] In one embodiment, the cathode 401 and the anode 501 are made of graphite materials, and the first catalyst 402 and the second catalyst 502 are made of biochar materials. By using the method of fixing biochar on graphite for conduction, it is not easy to corrode, will not cause secondary pollution to groundwater, and has low production costs. As an alternative embodiment, the cathode 401 and the anode 501 can also be made of insulating materials such as mica. As an alternative embodiment, the first catalyst 402 and the second catalyst 502 can also be made of glassy carbon or other non-metallic materials.

[0076] In one embodiment, the preparation methods of the cathode assembly 4 and the anode assembly 5 are as follows:

[0077] Step 1: Wash the shrimp shells with tap water, dry them, and crush them to a particle size less than 2 mm;

[0078] Step 2: Weigh 10 g of shrimp shells and 40 g of melamine, put them into a crucible and mix them, then transfer them to a muffle furnace, evacuate, introduce nitrogen, and then heat up. Among them, the heating rate is 5 °C·min -1 , heat up to 900 °C and keep it for 2 h, take out the crucible and let it cool naturally to room temperature. The black substance in the crucible is biochar;

[0079] Step 3: Take out the biochar and grind it with an agate mortar ball for 30 min. Wash 25 g of biochar with 1 L of 1 mol / L hydrochloric acid solution for 4 h, then centrifuge at a speed of 2900 g for 20 min and put it back into the hydrochloric acid solution for washing again. Repeat the washing three times and then wash it with deionized water until neutral.

[0080] Step 4: Dry the treated biochar in a vacuum drying oven at 60 °C, grind it again to a particle size of 50 - 200 nm, filter it through a 100-mesh sieve, and store it in a desiccator for later use.

[0081] Step 5: Mix the biochar in the desiccator with Nafion solution, isopropanol, and ultrapure water, mix them evenly by ultrasonic treatment, then drop it onto the surface of the graphite rod and let it dry naturally.

[0082] The porous structure, surface functional groups, and highly aromatic structure of the above biochar can improve the electron transfer efficiency; by using melamine as an external nitrogen source for the biochar and doping N elements into the biochar structure, the π-π conjugated system can be broadened to form an electron-rich structure with a surface rich in C-N bonds, enhancing the conductivity of the biochar, thereby enhancing the catalytic activity and further increasing the electron transfer rate to 2 - 3 times that of traditional biochar; by calcining the biochar at a high temperature (≥900 °C), the electron transfer ability can be improved; by vacuum pumping and high-temperature calcination, the order degree of the carbon structure, surface functional groups, and specific surface area in the biochar can be regulated, making it have both conductivity, redox activity, and adsorption ability. As a variable implementation method, other animal and plant wastes such as fish bones and corn straw can also be used as raw materials for preparing biochar. As a variable implementation method, urea can also be used for nitrogen doping or directly using biomass with a high nitrogen element content as a raw material for preparing biochar.

[0083] As Figure 3 shown, immerse the cathode assembly 4 and the anode assembly 5 into the cathode chamber and the anode chamber containing 100 mL of 0.05 mmol / L sodium sulfate solution respectively. Connect the cathode chamber and the anode chamber with a proton exchange membrane 6. Add 1 mmol / L of sodium persulfate 15 to the cathode chamber and add 20 mg / L of 2,4,6-trichlorophenol 16 to the anode chamber. Set magnetic stirring structures in both the cathode chamber and the anode chamber for stirring. Take samples from the anode chamber every 1 h, take samples four times in total, measure the concentration of 2,4,6-trichlorophenol 16, and detect it by high-performance liquid chromatography to calculate the concentration of the remaining 2,4,6-trichlorophenol 16 in the anode chamber. As Figure 4 shown, after 4 h, the concentration of the remaining 2,4,6-trichlorophenol 16 in the anode chamber is 0.33 mg / L, that is, the removal rate of 2,4,6-trichlorophenol 16 in the anode chamber is 98.35%.

[0084] In one embodiment, an anti-deposition layer is provided on the surface of the proton exchange membrane 6 close to the second sieve section 102. Specifically, the anti-deposition layer is a mixture of polyacrylate, organophosphonate, and acrylamide copolymer; the thickness of the anti-deposition layer is 50 nm - 100 nm. By providing the anti-deposition layer, the scaling of Ca 2+ or Mg 2+ can be inhibited, enabling the proton exchange membrane 6 to operate in groundwater with a hardness greater than 500 mg / L for a long time without cleaning. As an alternative embodiment, the anti-deposition layer can also be other zwitterionic polymers such as sulfobetaine, or an ultrasonic transducer with a frequency of 20 kHz - 40 kHz can be fixed near the proton exchange membrane 6 to inhibit the deposition of organic substances, inorganic ions, and solid particles on the surface of the proton exchange membrane 6 through ultrasonic action. As an alternative embodiment, the thickness of the anti-deposition layer can also be 40 nm or 110 nm, and no further limitations are imposed here.

[0085] In one embodiment, the groundwater circulation well primary battery repair device based on a biochar electrode includes: a detection component 7, disposed in the first cavity and the second sieve section 102. The detection component 7 is electrically connected to the water pumping and injection component 2 and is used to adjust the output power of the water pumping and injection component 2 according to the detection value. Further, the detection component 7 includes: a first detection piece, disposed in the first cavity, for detecting the liquid concentration in the first cavity; a second detection piece, disposed in the second sieve section 102, for detecting the liquid concentration in the second sieve section 102. By providing the detection component 7, it can be used to analyze the redox situation of the liquid in the first cavity and the second sieve section 102, and then adjust the velocity of the groundwater introduced into the second sieve section 102 and the quantity of the oxidant introduced into the first cavity, and determine whether the cathode component 4 and the anode component 5 should be replaced. As an alternative embodiment, it can also be that the detection component 7 is not provided, but the oxidant is regularly put into the first cavity, and the output power of the water pump is adjusted to be smaller.

[0086] In one embodiment, the groundwater circulation well primary battery repair device based on a biochar electrode includes: an air tank, communicating with the first cavity, for aerating the first cavity to increase the oxygen concentration in the first cavity. By aerating the first cavity, oxygen can be adsorbed on the surface of the first catalytic piece 402 to rapidly increase the potential of the cathode piece 401, thereby improving the degradation ability of pollutants. As an alternative embodiment, the air tank can also not be provided.

[0087] As Figure 2As shown, in one embodiment, the first detection component includes a sulfate ion concentration monitor 701 and an oxygen concentration monitor 702, which are used to obtain the reduction situation of persulfate ions and the change situation of oxygen concentration. The second detection component includes a pH value monitor 703 and a total organic carbon concentration monitor 704, which are used to obtain the acidity and alkalinity of groundwater and the degradation situation of pollutants. Specifically, when the total organic carbon concentration > 200 mg / L, adjust the flow rate of the water pump ≤ 0.8 m 3 / h; when the total organic carbon concentration < 50 mg / L, adjust the flow rate of the water pump ≥ 2 m 3 / h.

[0088] As Figure 2 shown, in one embodiment, the detection component 7 and the water pump are both electrically connected to the controller 13. The detection component 7 transmits the detection data to the controller 13, and after processing, controls the output power of the water pump.

[0089] As Figure 2 shown, in one embodiment, the groundwater circulation well primary battery repair device based on a biochar electrode includes: a first storage component 8, which stores an oxidant and an electrolyte. The first storage component 8 is communicated with the first cavity and is used to provide the oxidant and the electrolyte to the first cavity. Among them, both the oxidant and the electrolyte are in powder form. The first storage component 8 is provided with two chambers, which are respectively used to store the oxidant powder and the electrolyte powder, and both chambers are communicated with the first cavity. As an alternative implementation, it can also be that an opening is provided on the liquid storage component 3 for putting the oxidant into the first cavity. As an alternative implementation, it can also be that two storage components are provided, which are respectively used to store the oxidant powder and the electrolyte powder.

[0090] As Figure 2 shown, in one embodiment, the groundwater circulation well primary battery repair device based on a biochar electrode includes: a second storage component 9, which is communicated with the first cavity and is used to recover the electrolyte in the first cavity. Among them, the electrolyte is a sodium sulfate solution, and the water level line submerges the end of the cathode component 401. By recovering the electrolyte, the anion concentration in the first cavity can be reduced and the waste liquid discharge amount can be reduced. As an alternative implementation, a separate connecting pipe can also be provided for discharging the waste liquid.

[0091] In one embodiment, a sedimentation tank with a slope > 5° is provided at the bottom of the second storage component 9. The waste liquid in the first cavity is regularly discharged into the sedimentation tank, and a CaCl2 solution with a concentration of 0.5 mol / L - 1.0 mol / L is put into the waste liquid. Ca 2+ can react with SO4 2- in the waste liquid to generate CaSO4 precipitate, and the precipitate is gypsum for recovery; the remaining clear liquid is then reinjected into the first cavity.

[0092] As Figure 2As shown, in one embodiment, the biochar electrode-based groundwater circulation well galvanic cell remediation device includes: a sealing member 10 fixed within the circulation well body 1 for separating a first screen section 101 and a second screen section 102. Among them, the sealing member 10 is a packer, and the cross-sectional shape is the same as that of the circulation well body 1. As an alternative implementation, it is also possible that the first screen section 101 and the second screen section 102 are two separate shells, in which case the sealing member 10 does not need to be provided.

[0093] In one embodiment, a stirring member 11 is provided in the first cavity for accelerating the dissolution of the oxidant and the electrolyte. Among them, the stirring member 11 is a rotating blade, and the blade is a thin right-angled shape. By providing the stirring member 11, the oxidant and the electrolyte can be quickly dissolved and diffused to ensure sufficient contact between the oxidant and the surface of the first catalytic member 402. As an alternative implementation, the stirring member 11 can also be a magnetic stirring structure. As an alternative implementation, the blade can also be a thick bent angle shape, a thin bent angle shape or other irregular shapes, which will not be overly restricted here.

[0094] In one embodiment, the first storage member 8 is connected to the first cavity through a pipeline 12, and the stirring member 11 is provided at the end of the pipeline 12 away from the first storage member 8. By providing the stirring member 11 at the end of the pipeline 12, the structure can be simplified. As an alternative implementation, a separate support platform can also be provided above the liquid storage member 3 for fixing the stirring member 11.

[0095] As Figure 2 shown, in one embodiment, the biochar electrode-based groundwater circulation well galvanic cell remediation device includes: a gas collection member 14 provided above the circulation well body 1 for collecting volatile gases in the groundwater. After the gas collection member 14 collects the volatile gases, they are transported to a gas treatment member which contains an activated carbon filter plate for adsorbing and treating the volatile gases and then discharging them into the air.

[0096] According to an embodiment of the present invention, on the other hand, a biochar electrode-based groundwater circulation well galvanic cell remediation method is also provided, which is applied to the above-mentioned biochar electrode-based groundwater circulation well galvanic cell remediation device, and includes: groundwater enters the first screen section 101 through the water inlet 1011; the groundwater is pumped into the second screen section 102 through the pumping and injection member 2; the cathode assembly 4 is connected to a solution containing an oxidant, and the anode assembly 5 is connected to the groundwater containing pollutants; electrons in the pollutants are transferred to the oxidant, and protons in the first cavity are transmitted to the second screen section 102 through the proton exchange membrane 6 to form a current loop with the electron transfer to achieve the degradation of pollutants; the degraded groundwater is discharged from the water outlet 1021.

[0097] While embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A primary battery repair device for a groundwater circulation well based on a biochar electrode, characterized in that Comprising: A circular well body (1), arranged below the ground surface. The circular well body (1) includes a first screen section (101) and a second screen section (102). The first screen section (101) is arranged on one side of the second screen section (102). The first screen section (101) is provided with a water inlet (1011) communicating with the aquifer, and the second screen section (102) is provided with a water outlet (1021) communicating with the underground. A water pumping and injection component (2), arranged between the first screen section (101) and the second screen section (102), for pumping the groundwater from the first screen section (101) into the second screen section (102) to realize the circular flow of the groundwater in the aquifer. A primary battery component, arranged on the side of the second screen section (102) away from the first screen section (101), for degrading the pollutants in the groundwater. Wherein, the primary battery component includes: A liquid storage component (3), arranged on the side of the second screen section (102) away from the first screen section (101). The liquid storage component (3) includes a first cavity, and the first cavity is used for storing a solution containing an oxidant. The liquid storage component (3) is provided with a first through hole and a second through hole communicating the first cavity with the second screen section (102). A cathode component (4), arranged in the first cavity, for contacting the oxidant. An anode component (5), arranged in the second screen section (102), passing through the first through hole and connecting with the cathode component (4), for contacting the pollutants in the groundwater. A proton exchange membrane (6), fixed at the second through hole, for transporting the protons in the first cavity into the second screen section (102) without other solute exchanges.

2. The groundwater circulation well primary battery repair device based on a biochar electrode according to claim 1, characterized in that The cathode component (4) includes: A cathode piece (401), for transporting electrons. A first catalyst piece (402), loaded on the surface of the cathode piece (401), for connecting with the solution containing the oxidant. And / or, the anode component (5) includes: An anode piece (501), for transporting electrons. A second catalyst piece (502), loaded on the surface of the anode piece (501), for connecting with the groundwater containing the pollutants.

3. The groundwater circulation well primary battery repair device based on a biochar electrode according to claim 2, characterized in that The cathode piece (401) and / or the anode piece (501) is composed of a columnar structure and a sheet structure. And / or, the cathode piece (401) and / or the anode piece (501) is made of graphite material. And / or, the first catalyst piece (402) and / or the second catalyst piece (502) is made of biochar material.

4. The groundwater circulation well primary battery repair device based on a biochar electrode according to any one of claims 1 to 3, characterized in that The groundwater circulation well primary battery repair device based on a biochar electrode includes: A detection component (7), arranged in the first cavity and / or the second screen section (102). The detection component (7) is electrically connected with the water pumping and injection component (2), for adjusting the output power of the water pumping and injection component (2) according to the detection value.

5. The groundwater circulation well primary battery repair device based on a biochar electrode according to claim 4, wherein, The detection component (7) includes: A first detection piece, arranged in the first cavity, for detecting the liquid concentration in the first cavity. And / or, a second detection piece, arranged in the second screen section (102), for detecting the liquid concentration in the second screen section (102).

6. The groundwater circulation well primary battery repair device based on a biochar electrode according to any one of claims 1 to 3, characterized in that, The groundwater circulation well galvanic cell remediation device based on a biochar electrode comprises: A first storage member (8) storing the oxidant and / or electrolyte, the first storage member (8) communicating with the first cavity for supplying the oxidant and / or the electrolyte into the first cavity; And / or, a second storage member (9) communicating with the first cavity for recovering the electrolyte solution in the first cavity; And / or, a sealing member (10) fixed in the circulation well body (1) for separating the first screen section (101) and the second screen section (102).

7. The groundwater circulation well galvanic cell remediation device based on a biochar electrode according to claim 6, characterized in that, A stirring member (11) is provided in the first cavity for accelerating the dissolution of the oxidant and / or the electrolyte; And / or, an anti-deposition layer is provided on the surface of the proton exchange membrane (6) close to the second screen section (102).

8. The device for repairing the groundwater circulation well primary battery based on the biochar electrode according to claim 7, wherein The first storage member (8) is connected to the first cavity through a pipeline (12), and the stirring member (11) is arranged at the end of the pipeline (12) away from the first storage member (8).

9. The groundwater circulation well primary battery repair device based on a biochar electrode according to any one of claims 1 to 3, characterized in that, Along the length extension direction of the circulation well body (1), the size of the liquid storage member (3) is smaller than that of the second screen section (102); And / or, the liquid storage member (3) is detachably fixed on the circulation well body (1); And / or, a loading and unloading guiding structure (301) is provided above the liquid storage member (3).

10. A method for repairing a groundwater circulation well primary battery based on a biochar electrode, which is applied to the groundwater circulation well primary battery repair device based on a biochar electrode described in any one of claims 1 to 9, and is characterized in that, Comprises: The groundwater enters the first screen section (101) through the water inlet (1011); The groundwater is pumped into the second screen section (102) through the pumping and injection member (2); The cathode assembly (4) is connected to the solution containing the oxidant, and the anode assembly (5) is connected to the groundwater containing the pollutant; Electrons in the pollutant are transferred to the oxidant, and protons in the first cavity are transmitted into the second screen section (102) through the proton exchange membrane (6), constituting a current loop with the electron transfer to achieve the degradation of the pollutant; The degraded groundwater is discharged from the water outlet (1021).

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