An apparatus for treating heavy metal contaminants in soil using electroosmosis

Abstract

The utility model discloses a kind of devices for treating heavy metal pollutants in soil using electroosmosis technology, it is related to the technical field of soil pollution control and repair, and it includes: electroosmosis system, the electroosmosis system includes electrode plate and electrode tube inserted into the soil layer of the region to be treated, multiple electrode plates, multiple electrode tube are respectively arranged into row with interval, multiple rows of electrode plates, multiple rows of electrode tube are alternately arranged with interval between them;Liquid injection system and pumping system, the surface of the region to be treated is sequentially laid with woven geotextile and sealing membrane above infusion pipeline and drainage pipeline.This device of the utility model is cooperated by liquid injection system, electroosmosis system, pumping system, and heavy metal pollutants in soil can be quickly and effectively removed, so that soil purification is realized in a short time.

Description

Technical Field

[0001] This utility model relates to the field of soil pollution control and remediation technology, specifically to a device for treating heavy metal pollutants in soil using electroosmosis technology. Background Technology

[0002] Early electroosmosis applications used metal electrodes, which were very expensive; moreover, metal electrodes were prone to corrosion, making it difficult to meet the electroosmosis duration requirements of engineering applications. Therefore, early electroosmosis technology was difficult to widely promote and apply.

[0003] To address the issue of electrode corrosion, existing technologies have developed "electro-osmotic drainage boards" and "electro-osmotic electrode tubes" using EKG (electro-geosynthetic material), and established an electro-osmotic drainage consolidation method. The EKG electrode tube core has axially grooved outer walls, drainage holes are drilled in the tube wall, and copper wires are embedded axially within the tube wall. The EKG electro-osmotic drainage board has copper wires running through it, and the core is wrapped with a conductive geotextile filter membrane. This EKG electro-osmotic technology has been widely applied in the treatment of industrial sludge, riverbed sediment, dredged fill, and mine tailings.

[0004] Engineering practice shows that while the above-mentioned electroosmosis technology can achieve drainage consolidation, its effect on removing heavy metals is not ideal, especially when the heavy metal content in the soil is high. In such cases, this method struggles to meet relevant regulatory requirements. The main reason for these difficulties is that some heavy metals in the soil are adsorbed on the surface of soil particles, and their adsorption force is relatively strong. Electroosmosis alone is insufficient to release them, and thus, electroosmosis alone cannot effectively remove heavy metal pollutants from the soil to compliant levels.

[0005] Therefore, there is a need to develop a device with a simple structure and easy operation that uses electroosmosis technology to treat heavy metal pollutants in soil, which can quickly and effectively remove heavy metal pollutants from contaminated soil, thereby achieving soil purification in a short period of time. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the aforementioned background technology and provide a simple and easy-to-operate device for treating heavy metal pollutants in soil using electroosmosis technology. This device can quickly and effectively remove heavy metal pollutants from contaminated soil, thereby achieving soil purification in a relatively short time.

[0007] The technical solution of this utility model is: a device for treating heavy metal pollutants in soil using electroosmosis technology, characterized in that it comprises: An electroosmosis system, comprising electrode plates and electrode tubes inserted into the soil layer of the area to be treated, wherein multiple electrode plates and multiple electrode tubes are arranged in rows at intervals, and multiple rows of electrode plates and multiple rows of electrode tubes are arranged alternately at intervals. The liquid injection system includes an electroosmotic enhancement liquid tank located on one side of the area to be treated and a liquid delivery pipe with its inlet connected to the electroosmotic enhancement liquid tank. The liquid delivery pipe is connected to the top of the electrode tube on the surface of the area to be treated for injecting liquid into the soil layer. The system includes a hazardous waste liquid tank located on the other side of the area to be treated and a drainage pipe with an outlet connected to the hazardous waste liquid tank. The drainage pipe is connected to the top of the electrode plate on the surface of the area to be treated. A woven geotextile and a sealing membrane are laid sequentially on the surface of the area to be treated above the infusion pipe and the drainage pipe.

[0008] A preferred device for treating heavy metal pollutants in soil using electroosmosis technology, wherein the electroosmosis system further includes a dedicated electroosmosis power supply device, all electrode plates are electrically connected to one of the positive and negative poles of the dedicated electroosmosis power supply device via a first wire, and all electrode tubes are electrically connected to the other of the positive and negative poles of the dedicated electroosmosis power supply device via a second wire.

[0009] A preferred device for treating heavy metal pollutants in soil using electroosmosis technology has multiple electrode plates arranged in rows along the longitudinal direction at intervals d, and multiple electrode tubes arranged in rows along the longitudinal direction at intervals d, with the width of each electrode plate arranged along the longitudinal direction of the area to be treated. Multiple rows of electrode plates and multiple rows of electrode tubes are arranged laterally at intervals d, with adjacent rows of electrode plates and electrode tubes arranged horizontally aligned or staggered.

[0010] A preferred device for treating heavy metal pollutants in soil using electroosmosis technology, wherein the electrode tube has a water outlet hole, the electrode tube is surrounded by a first filter cloth, and the bottom is fitted with a foot sleeve with an open top, the foot sleeve wrapping the lower end of the filter cloth inside, and the upper end of each electrode tube is connected to a first vertical pipe by a clamp, the upper end of the first vertical pipe is provided with a T-connector and connected to an infusion pipeline.

[0011] A more preferred device for treating heavy metal pollutants in soil using electroosmosis technology, wherein the three-way connector has a T-shaped structure, with the lower port connected to the first vertical pipe and the upper two ports connected to the infusion pipeline.

[0012] A preferred device for treating heavy metal pollutants in soil using electroosmosis technology, wherein an injection pump is provided on one side of the area to be treated, and the infusion pipeline includes a pre-pump infusion pipe connected to the inlet of the injection pump and a post-pump infusion pipe connected to the outlet of the injection pump. The post-pump infusion pipe is connected to the top of the electrode tube on the surface of the area to be treated, and the post-pump infusion pipe is a waterproof PVC steel wire hose.

[0013] A preferred device for treating heavy metal pollutants in soil using electroosmosis technology, wherein a pump is provided on the other side of the area to be treated, and the drainage pipe includes a pre-pump drainage pipe connected to the inlet of the pump and a post-pump drainage pipe connected to the outlet of the pump. The top of the electrode plate is wrapped and tied to the pre-pump drainage pipe on the surface of the area to be treated.

[0014] A preferred device for treating heavy metal pollutants in soil using electroosmosis technology, wherein the drain pipe before the pump is a water-permeable PVC steel wire hose and the surface is wrapped with a second filter cloth.

[0015] A preferred device for treating heavy metal pollutants in soil using electroosmosis technology, wherein the sealing membrane is provided with an outlet, and the infusion pipe and drainage pipe pass through the sealing membrane via the outlet.

[0016] A preferred device for treating heavy metal pollutants in soil using electroosmosis technology, wherein a pressure trench is formed around the area to be treated, and the sealing membrane is filled and compacted with soil around the pressure trench.

[0017] The beneficial effects of this utility model are as follows: 1. By injecting the electroosmotic enhancement liquid into the soil layer at a certain depth through the injection system, the adsorption force of heavy metal ions between soil particles is greatly reduced, thereby enhancing the effect of electroosmotic adsorption and removal of heavy metal pollutants under the action of an electric field.

[0018] 2. The electroosmotic enhancement solution tank of the injection system can be excavated on-site as needed and sealed with a polyethylene film at the bottom to facilitate the storage and use of sufficient electroosmotic enhancement solution. The injection pump can be a reciprocating pump to provide sufficient injection pressure, and the delivery pipe can be a PVC steel wire hose, which has high strength and is easy to adapt to deformation according to ground settlement.

[0019] 3. In the electroosmosis system, the electrode tube is a hollow tube made of EKG material with water outlet holes around the perimeter. It is wrapped with filter cloth. The length of the electrode tube is determined according to the thickness of the soil layer to be treated, and can reach 30m or longer, so that it can be used in areas to be treated at various depths. The upper end of the electrode tube is equipped with a first vertical pipe (PVC pipe) to quickly connect to the infusion pipeline.

[0020] 4. In an electroosmosis system, a potential difference is applied to the electrode tube and electrode plate. Through electroosmosis, the heavy metal cations to be removed (such as Cd) are removed. 2+ Pb 2+ Zn 2+ Cu 2+ Ni 2+ (etc.) or anionic groups containing heavy metals (such as chromate CrO4) 2- The pollutants gather around the electrode plate, facilitating the discharge of hazardous waste liquid containing heavy metal pollutants into the hazardous waste liquid pool through the electrode plate and drainage pipe.

[0021] 5. In the electroosmotic system, the electrode plates and electrode tubes are connected to the two poles of the power supply respectively, that is, the electrode plates are connected to the positive / negative poles of the power supply, and the electrode tubes are connected to the negative / positive poles of the power supply. The alternating arrangement of each row of electrode plates and each row of electrode tubes can ensure that the positive and negative poles correspond one-to-one and maintain the electric field effect. The electrode plates and electrode tubes in adjacent rows are arranged horizontally aligned or staggered. When staggered, the adjacent electrode plates have less obstruction to the liquid injection of the electrode tubes, and the liquid injection efficiency of the electrode tubes in the soil layer is higher.

[0022] 6. In the pumping system, the drainage pipe is a water-permeable PVC steel wire hose with a second filter cloth wrapped around its surface. This allows the water drawn from the soil layer to the ground by the electrode plate to be filtered and discharged. The hose is also designed to adapt to ground subsidence.

[0023] 7. In the extraction system, a woven geotextile and a sealing membrane are installed above the ground surface. The purpose of the woven geotextile is to protect the sealing membrane from being punctured by debris such as sheet ends and wire ends. The sealing membrane covers the entire treatment area and is pressed into the membrane trench around the perimeter to ensure that the vacuum pressure under the membrane reaches the required level during the extraction process. For cases where only heavy metal pollutants need to be removed, the vacuum pressure under the membrane ranges from 20 to 50 kPa. For cases where the removal of heavy metal pollutants is combined with the improvement of soil mechanical properties, the vacuum pressure under the membrane ranges from 60 to 80 kPa.

[0024] 8. This invention can purify soil contaminated by various pollution sources. Based on the pollutants in the soil, an electroosmotic enhancement solution is selected to effectively separate these pollutants, and then this invention is used to remove them. It can treat contaminated soil layers of varying thicknesses, effectively treating thicknesses up to 30m or even thicker.

[0025] 9. The electrode tube of this utility model serves as both an electrode and a fitting for injecting electroosmotic enhancement liquid, thus having the advantage of multiple uses in one tube.

[0026] The device of this invention, through the coordinated operation of an injection system, an electroosmosis system, and a pumping system, can quickly and effectively remove heavy metal pollutants from contaminated soil, thereby achieving soil purification in a relatively short time. Attached Figure Description

[0027] Figure 1 This is a schematic diagram (vertical) of the overall device of this application. Figure 2 This is a schematic diagram showing the liquid flow direction during operation of the device in this application. Figure 3 Electrode tube structure diagram Figure 4 A schematic diagram of the planar arrangement of the electrode plates and electrode tubes (aligned arrangement). Figure 5 A schematic diagram of the planar arrangement of electrode plates and electrode tubes (staggered arrangement). Wherein: 1-Area to be treated; 2-Electrode plate; 3-Electrode tube (31-Water outlet; 32-First filter cloth; 33-Foot cover); 4-Hazardous waste liquid pool; 5-Injection pump; 6-Pre-pump infusion pipe; 7-Post-pump infusion pipe; 8-Film pressing trench; 9-Pre-pump drainage pipe; 10-Post-pump drainage pipe; 11-Woven geotextile; 12-Sealing membrane; 13-First conductor; 14-Second conductor; 15-Drainage pump; 16-Electroosmosis dedicated power supply equipment; 17-Electroosmosis enhanced liquid pool; 18-Clamping hoop; 19-First vertical pipe; 20-T-connector. Detailed Implementation

[0028] The embodiments of this utility model are described in detail below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0029] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] Example 1 like Figure 1-5 As shown, this utility model provides a device for treating heavy metal pollutants in soil using electroosmosis technology, including an electroosmosis system, a liquid injection system, and a pumping system. Through the coordinated operation of the liquid injection system, the electroosmosis system, and the pumping system, heavy metal pollutants in contaminated soil can be removed quickly and effectively, thereby achieving soil purification in a relatively short time.

[0032] The electroosmosis system includes electrode plates 2 and electrode tubes 3 inserted into the soil layer of the treatment area 1. Multiple electrode plates 2 and electrode tubes 3 are arranged in rows with intervals between them. The electroosmosis system also includes a dedicated electroosmosis power supply 16 located outside the treatment area 1. All electrode plates 2 are electrically connected to one of the positive and negative electrodes of the dedicated electroosmosis power supply 16 via a first wire 13, and all electrode tubes 3 are electrically connected to the other of the positive and negative electrodes of the dedicated electroosmosis power supply 16 via a second wire 14. The connection of the electrode plates 2 and electrode tubes 3 to the positive and negative electrodes is determined by the substance to be removed: to remove heavy metal cations (such as Cd). 2+ Pb 2+ Zn 2+ Cu 2+ Ni 2+ When (etc.), electrode tube 3 is connected to the positive electrode of electroosmosis power supply 16, and electrode plate 2 is connected to the negative electrode of electroosmosis power supply 16; to remove heavy metal anionic groups (such as heavy metal anion chromate CrO4), 2- When the electrode tube 3 is connected to the negative terminal of the electroosmosis power supply device 16, the electrode plate 2 is connected to the positive terminal of the electroosmosis power supply device 16, and the voltage range of the electroosmosis power supply device 16 is 20V~60V.

[0033] In a preferred embodiment, if one of the horizontal directions of the area to be processed is taken as the longitudinal direction, then the other horizontal direction perpendicular to the longitudinal direction is taken as the transverse direction. The specific arrangement of the electrode tubes 3 and the electrode plates 2 is as follows: multiple electrode plates 2 are arranged in rows along the longitudinal direction of the area to be processed at intervals d, and multiple electrode tubes 3 are arranged in rows along the longitudinal direction of the area to be processed at intervals d. The width of all electrode plates 2 is arranged along the longitudinal direction of the area to be processed. At this time, the length direction of each electrode plate 2 is along the vertical direction, the thickness direction is along the transverse direction of the area to be processed, and the width direction is along the longitudinal direction of the area to be processed.

[0034] In a preferred embodiment, multiple rows of electrode plates 2 and multiple rows of electrode tubes 3 are arranged laterally along the area to be treated at intervals d, alternating in this manner. Adjacent rows of electrode plates 2 and electrode tubes 3 are arranged laterally aligned or staggered, with the interval d ranging from 0.8 to 1.5 m. In another preferred embodiment, the number of electrode plates 2 and electrode tubes 3 in each row are the same, the number of rows of electrode plates 2 is the same as the number of rows of electrode tubes 3, and all rows of electrode plates 2 and electrode tubes 3 are arranged laterally aligned.

[0035] In a preferred embodiment, the area to be processed is square, with the width direction as the vertical axis, such as... Figure 4-5 Up and down; with length as the horizontal direction, such as... Figure 4-5 The arrangement is oriented left-right. Six electrode plates 2 are arranged longitudinally at intervals d, and six electrode tubes 3 are also arranged longitudinally at intervals d. The three rows of electrode plates 2 and three rows of electrode tubes 3 are arranged laterally at intervals d, alternating between each other. Adjacent rows of corresponding electrode plates 2 and electrode tubes 3 can be laterally aligned, such as... Figure 4 As shown; adjacent rows of corresponding electrode plates 2 and electrode tubes 3 can also be arranged laterally staggered, such as... Figure 5 As shown, the staggered spacing is d / 2, that is, the longitudinal spacing between the electrode plate 2 and the electrode tube 3 corresponding to the adjacent rows is d / 2. At this time, there is no electrode plate 2 blocking the transverse sides of each electrode tube 3. Therefore, when the staggered arrangement is used, the adjacent electrode plate 2 has less obstruction to the liquid injection of the electrode tube 3, and the liquid injection efficiency of the electrode tube in the soil layer is higher.

[0036] The electrode tube 3 has an outlet hole 31. A first filter cloth 32 surrounds the electrode tube 3, and a foot sleeve 33 with an open top is fitted at the bottom, enclosing the lower end of the first filter cloth 32. Each electrode tube 3 is connected to a first vertical tube 19 via a clamp 18. A T-connector 20 is installed at the upper end of the first vertical tube 19, connecting it to the infusion pipeline. The T-connector 20 has a T-shaped structure, with its lower end connected to the first vertical tube 19 and its two upper ends connected to the infusion pipeline. The electrode tube 3 is a hollow tube made of EKG material. The outlet holes 31 are circumferentially spaced on the tube wall and spaced along the tube's length. In a preferred embodiment, the electrode tube 3 generally has an outer diameter of 30mm, and the outer wall has grooves along the tube's length, with multiple grooves spaced circumferentially. The outlet holes 31 are located within these grooves. The length of the electrode tube 3 is determined by the thickness of the soil layer to be treated. The first vertical tube 19 is preferably a DN40 PVC pipe with an outer diameter of 40mm.

[0037] The injection system includes an electroosmotic enhancement solution tank 17 located on one side of the treatment area 1 outside the site, and a delivery pipeline with its inlet connected to the electroosmotic enhancement solution tank 17. The electroosmotic enhancement solution tank 17 is excavated on-site as needed and sealed with a polyethylene film at the bottom. The delivery pipeline connects to the top of the electrode tube 3 on the surface of the treatment area 1 for injecting solution into the soil layer. An injection pump 5 is also provided on one side of the treatment area 1 outside the site. In a preferred embodiment, the injection pump 5 can be a reciprocating pump with a rated pressure of 2.0~3.0 MPa. The delivery pipeline includes a pre-pump delivery pipe 6 connected to the inlet of the injection pump 5 and a post-pump delivery pipe 7 connected to the outlet of the injection pump 5. The post-pump delivery pipe 7 connects to the top of the electrode tube 3 on the surface of the treatment area 1 via a tee connector 20 and a first vertical pipe 19. The post-pump delivery pipe 7 is a waterproof PVC steel wire hose, preferably a DN25 PVC steel wire hose with an outer diameter of 25 mm.

[0038] The drainage system includes a hazardous waste liquid tank 4 located on the other side of the treatment area 1, and a drainage pipe connected to the outlet of the hazardous waste liquid tank 4. The hazardous waste liquid tank 4 is excavated on-site as needed and sealed with a polyethylene membrane at the bottom. The drainage pipe is connected to the top of the electrode plate 2 on the surface of the treatment area 1. Woven geotextile 11 and a sealing membrane 12 are laid sequentially above the infusion and drainage pipes on the surface of the treatment area 1. A drainage pump 15 is also provided on the other side of the treatment area 1. In a preferred embodiment, the drainage pump 15 is preferably a water-air separator pump. The number of drainage pumps can be set according to their own power and the area of ​​the treatment area. The drainage pipe includes a pre-pump drainage pipe 9 connected to the inlet of the drainage pump 15 and a post-pump drainage pipe 10 connected to the outlet of the drainage pump 15. The top of the electrode plate 2 is wrapped and tied to the pre-pump drainage pipe 9 on the surface of the treatment area 1. The pre-pump drainage pipe 9 is a water-permeable PVC steel wire hose and its surface is wrapped with a second filter cloth.

[0039] The sealing membrane 12 has an outlet (not shown in the figure). The infusion pipe 7 after the pump of the infusion pipeline and the drainage pipe 9 before the pump of the drainage pipeline both pass through the sealing membrane 12 through the outlet. A membrane pressure trench 8 is opened around the treatment area 1. Soil is filled and compacted around the sealing membrane 12 in the membrane pressure trench 8 to ensure that the vacuum pressure under the membrane reaches the required level during the pumping process. For cases where only heavy metal pollutants need to be removed, the vacuum pressure under the membrane ranges from 20 to 50 kPa. For cases where the mechanical properties of the soil need to be improved while removing heavy metal pollutants, the vacuum pressure under the membrane ranges from 60 to 80 kPa. The sealing membrane 12 can be made of polyethylene film with a thickness of 0.12 to 0.16 mm.

[0040] In a preferred embodiment, to prevent the spread of the chemical solution, the area to be treated 1 can be separated from the surrounding area by an isolation wall or isolation sheet piles.

[0041] Example 2 This embodiment specifically discloses the installation process of the utility model device and the working process of electroosmosis treatment of heavy metal cations.

[0042] 1) Construction of electrode plate 2: According to the design requirements, electrode plate 2 is installed using a plate inserter. The insertion depth of electrode plate 2 is 8~12m.

[0043] 2) Installation of Electrode Tube 3: Following the design plan layout, use an insertion machine to insert the electrode tube 3 to the same depth as the lower end of the electrode plate 2. Before insertion, the electrode tube 3 is wrapped with the first filter cloth 32, fitted with a foot sleeve 33 at the bottom, and connected to the upper first vertical pipe 19, with the wire extended. After insertion, the electrode tube 3 is led to the ground, and the opening is backfilled and compacted with soil to ensure the electrode tube 3 remains secure.

[0044] 3) Install pumping pump 15, injection pump 5 and electroosmosis power supply equipment 16 outside the treatment site, and excavate electroosmosis enhancement liquid pool 17 and hazardous waste liquid pool 4.

[0045] 4) Connection of the injection system: Lay the pump delivery pipe 7 on the ground of the area to be treated 1. One end is connected to the electrode pipe 3, and the other end is connected to the outlet of the injection pump 5 through the membrane outlet and the sealing membrane 12. The inlet of the injection pump 5 is connected to the outlet of the pump delivery pipe 6. The inlet of the pump delivery pipe 6 is connected to the electroosmotic enhancement liquid pool 17.

[0046] 5) Connection of the electroosmosis system: The first wire 13 connects all electrode plates 2, and the second wire 14 connects all electrode tubes 3. Both the first wire 13 and the second wire 14 are led out of the site through the bottom of the pressure trench 8 and connected to the electroosmosis power supply equipment 16. The first wire 13 is connected to the negative electrode, and the second wire 14 is connected to the positive electrode.

[0047] 6) Connection of the pumping system: Lay the pump inlet drain pipe 9 on the ground of the area to be treated 1. The top of the electrode plate 2 is connected to the pump inlet drain pipe 9 by winding. The pump inlet drain pipe 9 passes through the membrane outlet and the sealing membrane 12 to the inlet of the pumping pump 15. The outlet of the pumping pump 15 is connected to the inlet of the pump outlet drain pipe 10. The outlet of the drain pipe 10 is connected to the hazardous waste liquid tank 4.

[0048] 7) Laying the sealing membrane 12: The membrane trench 8 has been dug around the area to be treated 1. First, a layer of woven geotextile 11 is laid on the ground, then the sealing membrane 12 is laid, and the edge of the sealing membrane 12 is stepped into the membrane trench 8 and backfilled and compacted.

[0049] The above steps complete the installation of the utility model device. The electroosmosis treatment steps are as follows: 8) Injection of electroosmotic enhancement solution: Citric acid solution is used as the electroosmotic enhancement solution with a concentration of 0.1~0.3 mol / L, and it is stored in the electroosmotic enhancement solution tank 17. The injection pump 5 is started to inject the electroosmotic enhancement solution into the soil layer through the inlet pipeline and electrode tube 3.

[0050] 9) Start electroosmosis: Turn on the dedicated electroosmosis power supply device 16 and apply a voltage of 30V~40V between the electrode plate 2 (first wire 13) and the electrode tube 3 (second wire 14).

[0051] 10) Pumping out hazardous waste liquid: Start pumping pump 15 to pump out the hazardous waste liquid containing heavy metals that has accumulated around electrode plate 2 to hazardous waste liquid pool 4.

[0052] 11) Repeat steps 8)-10) as needed until the heavy metal content in the soil drops to meet the relevant specifications.

[0053] 12) Construction completed.

[0054] Example 3 This embodiment specifically discloses the installation process of the utility model device and the working process of electroosmosis treatment of heavy metal anion groups.

[0055] 1) Construction of electrode plate 2: According to the design requirements, electrode plate 2 is installed using a plate inserter. The insertion depth of electrode plate 2 is 8~12m.

[0056] 2) Installation of Electrode Tube 3: Following the design plan layout, use an insertion machine to insert the electrode tube 3 to the same depth as the lower end of the electrode plate 2. Before insertion, the electrode tube 3 is wrapped with the first filter cloth 32, fitted with a foot sleeve 33 at the bottom, and connected to the upper first vertical pipe 19, with the wire extended. After insertion, the electrode tube 3 is led to the ground, and the opening is backfilled and compacted with soil to ensure the electrode tube 3 remains secure.

[0057] 3) Install pumping pump 15, injection pump 5 and electroosmosis power supply equipment 16 outside the treatment site, and excavate electroosmosis enhancement liquid pool 17 and hazardous waste liquid pool 4.

[0058] 4) Connection of the injection system: Lay the pump delivery pipe 7 on the ground of the area to be treated 1. One end is connected to the electrode pipe 3, and the other end is connected to the outlet of the injection pump 5 through the membrane outlet and the sealing membrane 12. The inlet of the injection pump 5 is connected to the outlet of the pump delivery pipe 6. The inlet of the pump delivery pipe 6 is connected to the electroosmotic enhancement liquid pool 17.

[0059] 5) Connection of the electroosmosis system: The first wire 13 connects all the electrode plates 2, and the second wire 14 connects all the electrode tubes 3. Both the first wire 13 and the second wire 14 are led out of the site through the bottom of the pressure trench 8 and connected to the electroosmosis power supply equipment 16. The first wire 13 is connected to the positive electrode, and the second wire 14 is connected to the negative electrode.

[0060] 6) Connection of the pumping system: Lay the pump inlet drain pipe 9 on the ground of the area to be treated 1. The top of the electrode plate 2 is connected to the pump inlet drain pipe 9 by winding. The pump inlet drain pipe 9 passes through the membrane outlet and the sealing membrane 12 to the inlet of the pumping pump 15. The outlet of the pumping pump 15 is connected to the inlet of the pump outlet drain pipe 10. The outlet of the drain pipe 10 is connected to the hazardous waste liquid tank 4.

[0061] 7) Laying the sealing membrane 12: The membrane trench 8 has been dug around the area to be treated 1. First, a layer of woven geotextile 11 is laid on the ground, then the sealing membrane 12 is laid, and the edge of the sealing membrane 12 is stepped into the membrane trench 8 and backfilled and compacted.

[0062] The above steps complete the installation of the utility model device. The processing steps are as follows: 8) Injection of electroosmotic enhancement solution: Hydrochloric acid solution is used as the electroosmotic enhancement solution, with a concentration of 0.1~0.3 mol / L, and stored in the electroosmotic enhancement solution tank 17. Start the injection pump 5 and inject the electroosmotic enhancement solution into the soil layer through the inlet pipeline and electrode tube 3.

[0063] 9) Start electroosmosis: Turn on the dedicated electroosmosis power supply device 16 and apply a voltage of 30V~40V between the electrode plate 2 (first wire 13) and the electrode tube 3 (second wire 14).

[0064] 10) Pumping out hazardous waste liquid: Start pumping pump 15 to pump out the hazardous waste liquid containing heavy metals that has accumulated around electrode plate 2 to hazardous waste liquid pool 4.

[0065] 11) Repeat steps 8)-10) as needed until the content of heavy metal anionic groups in the soil decreases to meet the relevant specifications.

[0066] 12) Construction completed.

Claims

1. A device for treating heavy metal pollutants in soil using electroosmosis technology, characterized in that, include: An electroosmosis system, comprising an electrode plate (2) and an electrode tube (3) inserted into the soil layer of the area to be treated (1), wherein multiple electrode plates (2) and multiple electrode tubes (3) are arranged in rows at intervals, and the multiple rows of electrode plates (2) and multiple rows of electrode tubes (3) are arranged alternately at intervals. The liquid injection system includes an electroosmotic enhancement liquid tank (17) located on one side of the area to be treated (1) and a liquid delivery pipe with an inlet connected to the electroosmotic enhancement liquid tank (17). The liquid delivery pipe is connected to the top of the electrode tube (3) on the surface of the area to be treated (1) for injecting liquid into the soil layer. The drainage system includes a hazardous waste liquid tank (4) located on the other side of the treatment area (1) and a drainage pipe with an outlet connected to the hazardous waste liquid tank (4). The drainage pipe is connected to the top of the electrode plate (2) on the surface of the treatment area (1). A woven geotextile (11) and a sealing membrane (12) are laid on the surface of the treatment area (1) above the infusion pipe and the drainage pipe.

2. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 1, characterized in that, The electroosmosis system also includes an electroosmosis power supply device (16). All electrode plates (2) are electrically connected to one of the positive and negative poles of the electroosmosis power supply device (16) via a first wire (13), and all electrode tubes (3) are electrically connected to the other of the positive and negative poles of the electroosmosis power supply device (16) via a second wire (14).

3. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 1, characterized in that, Multiple electrode plates (2) are arranged in rows along the longitudinal direction of the area to be treated at a distance d, and multiple electrode tubes (3) are arranged in rows along the longitudinal direction of the area to be treated at a distance d. The width of each electrode plate (2) is arranged along the longitudinal direction of the area to be treated. The multiple rows of electrode plates (2) and multiple rows of electrode tubes (3) are arranged horizontally along the area to be treated at intervals d and alternately. The electrode plates (2) and electrode tubes (3) of adjacent rows are arranged horizontally aligned or staggered.

4. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 1, characterized in that, The electrode tube (3) is provided with a water outlet (31). The electrode tube (3) is surrounded by a first filter cloth (32). The bottom is fitted with a foot sleeve (33) with an opening at the top. The foot sleeve (33) wraps the lower end of the filter cloth (32) inside. The upper end of each electrode tube (3) is connected to a first vertical tube (19) via a clamp (18). The upper end of the first vertical tube (19) is provided with a three-way connector (20) that connects to the infusion pipeline.

5. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 4, characterized in that, The three-way connector (20) has a T-shaped structure, with its lower port connected to the first vertical pipe (19) and its upper two ports connected to the infusion pipeline.

6. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 1, characterized in that, A liquid injection pump (5) is provided on one side of the area to be treated (1). The infusion pipeline includes a pre-pump infusion pipe (6) connected to the inlet of the liquid injection pump (5) and a post-pump infusion pipe (7) connected to the outlet of the liquid injection pump (5). The post-pump infusion pipe (7) is connected to the top of the electrode tube (3) on the surface of the area to be treated (1). The post-pump infusion pipe (7) is a waterproof PVC steel wire hose.

7. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 1, characterized in that, A pump (15) is provided on the other side of the area to be treated (1). The drainage pipe includes a front drain pipe (9) connected to the inlet of the pump (15) and a rear drain pipe (10) connected to the outlet of the pump (15). The top of the electrode plate (2) is wrapped and tied to the front drain pipe (9) on the surface of the area to be treated (1).

8. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 7, characterized in that, The pump inlet drain pipe (9) is a water-permeable PVC steel wire hose with a second filter cloth wrapped around its surface.

9. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 1, characterized in that, The sealing membrane (12) is provided with an outlet, and the infusion pipe and drainage pipe pass through the sealing membrane (12) through the outlet.

10. The apparatus for treating heavy metal pollutants in soil using electroosmosis technology as described in claim 1, characterized in that, The area to be treated (1) is surrounded by a pressure trench (8), and the sealing membrane (12) is surrounded by soil filled and compacted in the pressure trench (8).

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