Soil groundwater remediation agent injection apparatus and method

Abstract

The application discloses a soil and groundwater remediation agent injection device and method. The device is arranged in an excavated soil layer hole and comprises a flexible air bag, which further comprises: an air bag body, the upper and lower ends of which are made of hard material and the wall surface of which is made of flexible material; a pipeline sealedly penetrating between the upper and lower ends, which is used for accommodating an agent injection pipeline, an inflation pipeline and an air pressure monitoring line; an injector arranged outside the flexible wall surface of the air bag body and communicated with the agent injection pipeline; the injector is in an arc shape or a ring shape, the inner side of the injector is attached to the flexible wall surface, and the outer side of the injector is uniformly provided with agent injection holes; after the air bag body is inflated and expanded, during the agent injection process, the injector is abutted against the soil layer to be repaired at a height and the flexible wall surface is tightly attached to the hole wall surface. The application can quickly realize the injection repair work of the agent at different depths only by drilling a suitable simple hole underground, and the recycling and reuse of the agent injection device can be realized.

Description

Technical Field

[0001] This invention relates to the field of soil and groundwater remediation technology, and in particular to a soil and groundwater remediation agent injection device and method. Background Technology

[0002] With the development of industrialization, urbanization, and agricultural modernization, the chemical industry, mining, metal smelting, use of pesticides and fertilizers, and discharge of domestic wastewater are constantly causing environmental safety problems related to soil and groundwater. The discharge of these three types of waste, as well as accidental leaks in storage devices and transportation pipelines, pose serious threats to soil and groundwater. For example, mine wastewater and industrial wastewater from chemical plants can cause pollutants to accumulate in soil and groundwater. In agriculture, the extensive use of fertilizers and pesticides is increasingly causing soil and groundwater pollution problems. Urban residential areas discharge large amounts of domestic sewage and solid waste daily, including organic matter containing nutrients for microorganisms such as carbohydrates, nitrogen, phosphorus, and sulfur, as well as various pathogenic microorganisms. When these pollutants enter water bodies, they cause a large consumption of dissolved oxygen, easily producing foul-smelling substances under the action of anaerobic bacteria, and simultaneously causing the proliferation and spread of pathogens and viruses. Therefore, soil and groundwater remediation requires long-term implementation.

[0003] Soil and groundwater remediation can be achieved using chemical agents, which requires injecting chemicals into the soil layer. Existing injection systems generally require complex injection wells and are difficult to reuse. For example, Chinese patent application CN115159600A discloses a barrier device and a multi-depth chemical injection method for soil and groundwater remediation. The barrier device in this design includes a pipe body with a first flange connected to its upper end. The first flange has an vent port, and a sealing assembly is connected to its lower surface. The pipe body passes through the sealing assembly, and a plate is connected to the lower side of the sealing assembly. The plate is bent into a tubular shape and surrounds the outside of the pipe body. The multi-depth chemical injection method for soil and groundwater remediation involves connecting the barrier device to a first pipe, with the first pipe passing through the barrier device, and extending the first pipe, along with the barrier device, into the interior of a well pipe, whereby the barrier device acts as a barrier to the well pipe. While this solution allows for chemical injection repair at different depths using a single repair well, it requires the construction of complex injection wells with high specifications and construction techniques, resulting in a large workload. Furthermore, once completed, the wells can only be abandoned on-site or require excavation and cleaning. The barrier design is complex, and the rubber sealing gasket is prone to wear during vertical movement, leading to poor sealing. Additionally, the connection of a rubber hose at the vent to the surface wellhead allows air from the lower screen section to escape through this vent, potentially causing chemical backflow.

[0004] Therefore, there is an urgent need for a soil and groundwater remediation agent injection device and method that can avoid the construction of complex agent injection wells and make the injection device easy to reuse.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a soil and groundwater remediation agent injection device and method, which can quickly achieve agent injection and remediation work at different depths by simply drilling suitable simple holes underground, and can realize the recycling and reuse of agent injection device.

[0007] Another objective of this invention is to provide a soil and groundwater remediation agent injection device and method, which can not only prevent borehole wall collapse or soil from entering the well, but also effectively prevent the agent at the injector from flowing upward or downward to other soil layers at different depths.

[0008] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides a soil groundwater remediation agent injection device, which is disposed in an excavated soil cavity, including a flexible airbag, the flexible airbag further comprising: an airbag body, the upper and lower ends of which are made of rigid material and the wall surface of which is made of flexible material; a pipe that is sealed and penetrates between the upper and lower ends, the pipe being used to accommodate an injection pipeline, an inflation pipeline, and a pressure monitoring line; an injector disposed on the outside of the flexible wall surface of the airbag body and connected to the injection pipeline; the injector is generally arc-shaped or annular, the inner side of the injector is in contact with the flexible wall surface, and the outer side is uniformly provided with agent injection holes; after the airbag body is inflated, during the agent injection process, the injector abuts against the height of the soil layer to be remediated and the flexible wall surface is tightly attached to the cavity wall.

[0009] Furthermore, in the above technical solution, the airbag body can be a single-unit structure, and the injector can be set at different height positions for the fixed-depth, layered injection of the repair agent.

[0010] Furthermore, in the above technical solution, the airbag body can also be composed of multiple single structures connected in series by pipes, and the injector can be set in the middle of each single structure to repair situations where the different application depths of the medicine are far apart.

[0011] Furthermore, in the above technical solution, the airbag body can also be a single structure containing multiple sub-airbags, with adjacent sub-airbags sharing the end face of a rigid material. The injector can be set in the middle of each sub-airbag or at the end face of an adjacent sub-airbag, for situations where the different application depths of the repair agent are far apart and the agent injection needs to be independently controlled at different depths.

[0012] Furthermore, in the above technical solution, the upstream of the injection pipeline can be sequentially connected to the drug tank, the injection pump, and the first pressure gauge.

[0013] Furthermore, in the above technical solution, an air pump and a valve can be sequentially installed upstream of the air inflator.

[0014] Furthermore, in the above technical solution, the air pressure monitoring line may be equipped with a pressure sensor located inside the airbag body and a second pressure gauge for measuring air pressure.

[0015] Furthermore, in the above technical solution, the injector can be connected to the drug injection pipeline through a branch pipe; the injection hole on the injector is a one-way hole.

[0016] Furthermore, in the above technical solution, the device of the present invention can be applied to the chemical remediation of soil vadose zone and saturated zone.

[0017] To achieve the above objectives, according to a second aspect of the present invention, the present invention provides a method for injecting soil and groundwater remediation agents, using the aforementioned apparatus, comprising the following steps: A. Inserting an uninflated airbag body into the depth to be remediated within an excavated soil cavity; B. Inflating the airbag body through an inflation pipeline, causing the airbag to expand and reach a preset pressure, at which point the injector rests against the soil layer to be remediated and the flexible wall of the airbag body is tightly against the cavity wall; C. Stopping inflation, initiating the injection process, and maintaining the set injection pressure; D. The agent passes through the injection pipeline, through the airbag body, into the injector, and then into the contaminated soil layer through the injection hole; During the injection process, if the pressure near the injector increases, causing the airbag to be squeezed, re-inflating is performed to ensure that the airbag remains tightly against the cavity wall, preventing the agent from flowing to other soil depths.

[0018] Furthermore, in the above technical solution, when the airbag body adopts a single-unit structure, the repair agent can be injected at a fixed depth and in layers by injectors of different heights.

[0019] Furthermore, in the above technical solution, when the airbag body adopts multiple unit structures connected in series, the remediation agent can be injected into the contaminated soil layer at different depths by injectors set on different unit structures.

[0020] Furthermore, in the above technical solution, each airbag unit is inflated sequentially from bottom to top during the inflation process. After each airbag unit is inflated, the water level in the hole rises briefly and then slowly falls back to stabilize, and the preset pressure is reached in the airbag unit before the next airbag unit is inflated.

[0021] Furthermore, in the above technical solution, when the airbag body adopts a single structure containing multiple sub-airbags, the remediation agent can be injected into the contaminated soil layer at different depths by injectors set on different sub-airbag structures, and the agent injection on each sub-airbag can be controlled independently.

[0022] Furthermore, in the above technical solution, each sub-airbag is inflated sequentially from bottom to top during the inflation process. After each sub-airbag is inflated, the water level in the hole rises briefly and then slowly falls back to stabilize, and the sub-airbag reaches the preset pressure before the next sub-airbag is inflated.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) Using the drug injection device of the present invention, there is no need to construct a complex drug injection well. Only a suitable simple hole needs to be drilled underground to quickly realize the injection and repair work of drugs at different depths. The drug injection device can also be recycled and reused.

[0025] 2) The airbag in this invention has a flexible sidewall and a rigid top and bottom end. A cylindrical pipe runs through the middle of the airbag, which can be used for drug injection lines, inflation lines, and / or pressure monitoring lines. The flexible airbag is cylindrical when inflated and gradually expands as the internal pressure increases, tightly adhering to and holding the borehole wall to prevent borehole collapse or soil from entering the well. It also prevents the drug from flowing upwards or downwards from the drug injector to other soil layers at different depths.

[0026] 3) When the airbag body used in this invention is a single-unit structure, the injector can be set at different height positions to achieve fixed-depth layered injection of the remediation agent; when the longitudinal range of the pollution is relatively large, multiple airbag units can be set in series, which not only avoids the use of excessively long airbags and reduces customization difficulty, but also reduces usage costs; when the longitudinal range of the pollution is relatively large, a single-unit structure with multiple sub-airbags can also be used, which can not only cover a large range of pollution depth, but also allow the injection of the agent to be controlled separately, and is more adaptable to the pollution situation on site.

[0027] 4) When the present invention uses multiple airbag units connected in series or one airbag unit contains multiple sub-airbags, the inflation sequence is that the lower airbag (or lower sub-airbag) is inflated first, and then inflated upwards. This inflation sequence can effectively avoid the water not being able to be drained in time during the inflation process, and the need for higher inflation pressure to make the airbag fit tightly against the inner wall of the hole, thus avoiding the risk of airbag rupture.

[0028] 5) The present invention monitors the air pressure inside the airbag in real time during the injection process. When the pressure near the injector increases and causes the airbag to be squeezed, the inflation pump can be restarted to inflate it further, so as to ensure that the airbag is always in close contact with the hole wall and prevent the drug from flowing to other soil layers.

[0029] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a connection diagram of the soil and groundwater remediation agent injection device of the present invention (the airbag body adopts a single airbag, and two sets of agent injectors are set at different heights).

[0031] Figure 2 This is a schematic diagram of the structure of the airbag body of the present invention, which uses multiple individual airbags connected in series (each individual airbag is equipped with a set of drug injectors).

[0032] Figure 3 This is a schematic diagram of the structure of the airbag body of the present invention, which adopts a single airbag with multiple sub-airbags (each sub-airbag is equipped with a set of drug injectors).

[0033] Figure 4 This is a schematic diagram illustrating the application of the soil and groundwater remediation agent injection device of the present invention in the soil saturation zone.

[0034] Figure 5 This is a schematic diagram illustrating the application of the soil and groundwater remediation agent injection device of the present invention in soil contamination at different depths in the vadose zone and saturation zone.

[0035] Figure 6 This is a schematic diagram of the structure of the drug injector of the present invention (wherein) Figure 6 -A is a top-down view; Figure 6 -B is a schematic diagram of the outer surface of the arc-shaped injector.

[0036] Explanation of key figure labels:

[0037] 1-Inflatable unit, 11-Upper end face, 12-Lower end face, 13-Pipeline, 131-Injection line, 1310-Branch pipe, 132-Inflation line, 133-Pressure monitoring line, 14-Injector, 140-Outer side of injector, 141-Injection hole, 142-Connecting thread, 15-Pressure sensor;

[0038] 1-1-First airbag, 1-2-Second airbag, 1-3-Third airbag; 1A-First sub-airbag, 1B-Second sub-airbag, 1C-Third sub-airbag;

[0039] 2-Air pump, 3-Valve, 4-Medicine tank, 5-Injection pump, 6-First pressure gauge, 7-Second pressure gauge; 100-Excavated soil hole. Detailed Implementation

[0040] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0041] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0042] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0043] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0044] like Figure 1 As shown, the present invention provides a soil groundwater remediation agent injection device, which is installed in an excavated soil cavity 100 and includes a flexible airbag, the flexible airbag further comprising: an airbag body ( Figure 1 The airbag body consists of an airbag unit 1) and an injector 14. The upper and lower ends (i.e., upper end face 11 and lower end face 12) of the airbag body are made of rigid material, while the walls are made of flexible material. A pipe 13 is sealed and passes through the upper end face 11 and lower end face 12, and the pipe 13 accommodates the drug injection line 131, the inflation line 132, and the pressure monitoring line 133. Further, the upstream of the drug injection line 131 is connected in sequence to the drug tank 4, the drug injection pump 5, and the first pressure gauge 6. The upstream of the inflation line 132 is connected in sequence to the inflation pump 2 and the valve 3. The pressure monitoring line 133 is equipped with a pressure sensor 15 located within the airbag body and a second pressure gauge 7 for measuring air pressure. The injector 14 is located on the outside of the flexible wall of the airbag body and communicates with the drug injection line 131; further reference... Figure 6 (include Figure 6-A and 6-B), the injector 14 is arc-shaped or ring-shaped, with the inner side of the injector fitting against the flexible wall and the outer side 140 having uniformly arranged injection holes 141. After the airbag body is inflated and during the injection process, the injector 14 rests against the height of the soil layer to be repaired and the flexible wall is in close contact with the wall of the hole 100.

[0045] The flexible airbag used in this invention possesses both high strength and flexibility. Its upper and lower ends are made of rigid materials, with a cylindrical pipe running through the middle. The pipe is preferably made of aluminum, but other high-strength rigid materials can also be used, connecting the upper and lower ends of the airbag. Both ends of the pipe can be open for the passage of injection lines, inflation lines, and / or pressure monitoring lines, but are sealed relative to the gas space inside the airbag. When using a single airbag unit, the lower end of the unit only has the cylindrical pipe opening, while the upper end is equipped with a pressure sensor (the sensing part is located inside the airbag) and an inflation pipe interface. The flexible airbag is cylindrical when inflated and gradually expands as the internal pressure increases, tightly conforming to and holding the borehole wall to prevent collapse or soil ingress. It also prevents the agent from flowing upwards or downwards from the injector to other soil layers. In application, extraction wells can be deployed around the excavated borehole to increase the agent diffusion radius.

[0046] Further as Figure 1 As shown, when the airbag body is a single-unit structure, the injector 14 can be set at different height positions. Figure 1 Two sets of injectors 14 (located at different heights) are shown for the fixed-depth, layered injection of repair agents. Specifically, the airbag unit 1 is inflated through a sequentially connected air pump 2, valve 3, and air inlet pipe 132. After the internal pressure of the airbag unit reaches a preset value as measured by pressure sensor 15 and second pressure gauge 7, the air pump 2 stops working and the air valve 3 closes. This invention achieves agent injection through a sequentially connected agent tank 4, injection pump 5, first pressure gauge 6, injection pipe 131, branch pipe 1310, and injector 14. The arc-shaped or annular injector 14 ensures that its inner surface can tightly adhere to the outer surface of the flexible airbag. The inner surface has a connection port (not shown in the figure), which connects to the agent injection branch pipe 1310 through the connection port (not shown in the figure) on the side wall of the flexible airbag. That is, the injector 14 is connected to the injection pipe 131 through the branch pipe 1310. To prevent agent backflow, the injection hole 141 on the injector 14 is a one-way hole (see reference). Figure 6 ).

[0047] Further as Figure 2 As shown, when the longitudinal range of pollution is relatively large, multiple airbag units can be connected in series. Figure 2The diagram shows three individual airbag units (airbag 1-1, airbag 1-2, and airbag 1-3) to ensure coverage of the entire contaminated cross-section. Specifically, the airbag body consists of multiple individual structures connected in series via pipe 13. An injector 14 is positioned in the middle of each individual structure to address situations where the depth of the repair agent application varies significantly. When the contamination depth spans a large range, using a single airbag unit for repair would require increasing the airbag length. In this scenario, multiple airbag units can be placed at different contamination depths within the hole, avoiding the use of excessively long airbags, reducing customization complexity, and lowering operating costs. The inflation sequence is as follows: the lower airbag is inflated first, followed by airbags at higher depths.

[0048] Further as Figure 3 As shown, when the longitudinal range of pollution is relatively large, a single-unit structure with multiple sub-airbags can also be used. Figure 3 The diagram shows a single airbag unit with three sub-airbags (i.e., sub-airbag 1A, sub-airbag 1B, and sub-airbag 1C). Adjacent sub-airbags share a rigid material end face. The injector 14 can be located in the middle of each sub-airbag or at the end face of an adjacent sub-airbag (not shown in the diagram). This airbag structure not only covers a large range of contamination depths but also allows for individual control of agent injection. Furthermore, it offers greater adaptability to different contamination conditions. Regardless of the size of the contamination depth range, a single airbag unit with multiple sub-airbags can adapt to the site conditions. For smaller ranges, inflating one sub-airbag and injecting the agent is sufficient. For larger ranges, two or more sub-airbags can be inflated and injected into soil layers at different depths, depending on the site conditions. The inflation sequence remains the same: the lower sub-airbags are inflated first, followed by the upper sub-airbags.

[0049] It should be noted that the aforementioned different methods of agent injection devices of the present invention can be applied to the agent remediation of soil vadose zone and saturated zone.

[0050] The present invention also provides a method for injecting soil and groundwater remediation agents, using any of the aforementioned agent injection devices, comprising the following steps:

[0051] Step S101: Place the uninflated airbag body into the excavated soil cavity at the desired repair depth. The airbag body can be a single airbag unit, multiple airbag units connected in series, or a single airbag unit containing multiple sub-airbags.

[0052] In step S102, air is injected into the airbag body through the inflation pipe, causing the airbag to expand and reach the preset pressure. At this time, the injector is pressed against the soil layer to be repaired, and the flexible wall of the airbag body is in close contact with the hole wall. Specifically, when multiple airbag units are used in series, each airbag unit is inflated sequentially from bottom to top during the inflation process. After each airbag unit is inflated, the water level in the hole rises briefly and then slowly falls back to stabilize, and the preset pressure is reached in the airbag unit before inflating the next airbag unit. When a structure in which one airbag unit contains multiple sub-airbags is used, each sub-airbag is also inflated sequentially from bottom to top during the inflation process. After each sub-airbag is inflated, the water level in the hole rises briefly and then slowly falls back to stabilize, and the preset pressure is reached in the sub-airbag before inflating the next sub-airbag.

[0053] Step S103: Stop inflation, start the injection process, and maintain the set injection pressure. Specifically, when the airbag body adopts a single-unit structure, the remediation agent is injected at a fixed depth in layers by injectors at different heights; when the airbag body adopts multiple single-unit structures connected in series, the remediation agent is injected at different depths of contaminated soil by injectors set on different single-unit structures; when the airbag body adopts a single-unit structure containing multiple sub-airbags, the remediation agent is injected at different depths of contaminated soil by injectors set on different sub-airbag structures, and the agent injection on each sub-airbag can be controlled independently.

[0054] In step S104, the agent enters the injector through the injection pipeline, passes through the airbag body, and then enters the contaminated soil layer through the injection hole. During the injection process, when the pressure near the injector increases and causes the airbag to be squeezed, it is re-inflated to ensure that the airbag always adheres tightly to the hole wall and prevents the agent from flowing to other soil layers.

[0055] The following is combined with Figure 2 The implementation of the device is described below through two application examples:

[0056] Example 1

[0057] Applications of pollution treatment at different depths within the saturation zone: such as Figure 4As shown, the saturation zone, also known as the water-saturated zone, is the portion located below the groundwater level. The first airbag 1-1, the second airbag 1-2, and the third airbag 1-3 are placed at different contamination depths within the saturation zone. With the valve open, the inflation pump first inflates the third airbag 1-3 through the inflation pipeline. The third airbag 1-3 gradually expands, displacing the surrounding groundwater. The water level in the borehole briefly rises and then slowly falls back to a stable level. Once the third airbag 1-3 reaches the preset pressure, the inflation pipeline for the third airbag 1-3 is closed. The inflation pipeline for the second airbag 1-2 is then opened, and the inflation pump inflates it through the inflation pipeline. The second airbag 1-2 gradually expands, displacing the surrounding groundwater. The water level in the borehole briefly rises and then slowly falls back to a stable level, reaching the preset pressure. After pressurization, the inflation lines of the second airbag 1-2 are closed; the inflation line of the first airbag 1-1 is opened, and the inflation pump inflates the first airbag 1-1 through the inflation line. The first airbag 1-1 gradually expands, displacing the surrounding groundwater. The water level in the borehole rises briefly and then slowly falls back to a stable level. Once the preset pressure is reached, the inflation line of the first airbag 1-1 is closed, and the inflation pump stops working. The injection pump starts, maintaining the set injection pressure. The agent passes through the injection tubes through the first airbag 1-1, the second airbag 1-2, and the third airbag 1-3, entering the injectors on each airbag, and then enters the saturated zone contaminated aquifer through the injection holes. The agent diffuses with the groundwater, achieving the remediation purpose. In this saturated zone embodiment, the inflation sequence of the airbags is third airbag - second airbag - first airbag. Otherwise, water may not be able to be displaced in time during the inflation process, requiring a higher inflation pressure to make the airbags fit tightly against the borehole wall. In this case, the airbags also risk rupture.

[0058] Example 2

[0059] Simultaneous repair of contamination at different depths in the vadose zone and saturation zone: such as... Figure 5As shown, the vadose zone refers to the unsaturated zone between the surface and the groundwater level, that is, the part above the groundwater level. The second airbag 1-2 and the third airbag 1-3 are placed at different contamination depths in the saturated zone, while the first airbag 1-1 is placed in the vadose zone above the groundwater level. The valve is opened, and the inflation pump first inflates the third airbag 1-3 through the inflation pipeline. The third airbag 1-3 gradually expands, displacing the surrounding groundwater. The water level in the borehole briefly rises and then slowly falls back to stabilize. After the third airbag 1-3 reaches the preset pressure, the inflation pipeline for the third airbag 1-3 is closed. The inflation pipeline for the second airbag 1-2 is opened, and the inflation pump inflates the second airbag 1-2 through the inflation pipeline. The second airbag 1-2 gradually expands, displacing the surrounding groundwater. The water level in the borehole briefly rises and then slowly falls back to stabilize. After reaching the preset pressure, the inflation pipeline for the second airbag 1-2 is closed. The inflation line of airbag 1-1 is opened, and the inflation pump inflates air into airbag 1-1 through the inflation line. Airbag 1-1 gradually expands, displacing the surrounding groundwater. The water level in the borehole rises briefly and then slowly falls back to stabilize. Once the preset pressure is reached, the inflation line of airbag 1-1 is closed, and the inflation pump stops working. The injection pump starts, maintaining the set injection pressure. The agent passes through the injection line through airbag 1-1, airbag 1-2, and airbag 1-3 respectively, entering the injector on each airbag. Then, it enters the contaminated formation in the vadose zone and saturation zone through the injection holes, achieving the remediation purpose. In this embodiment with both vadose zone and saturation zone, the preferred inflation sequence of the airbags is "third airbag - second airbag - first airbag", but it can also be "first airbag - third airbag - second airbag", as long as the second airbag is inflated after the third airbag.

[0060] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A soil and groundwater remediation agent injection device, characterized in that, This device is applicable to the treatment of contamination at different depths within the saturation zone or to the simultaneous remediation of contamination at different depths within both the vadose zone and the saturation zone. The device is installed in excavated soil cavities and includes a flexible airbag, which further comprises: The airbag body has a rigid material at its upper and lower ends and a flexible material on its walls; a pipe is sealed between the upper and lower ends, which is used to accommodate the drug injection line, the inflation line and the air pressure monitoring line; An injector is disposed on the outer side of the flexible wall of the airbag body and connected to the drug injection pipeline; the injector is generally arc-shaped or ring-shaped, with the inner side of the injector fitting against the flexible wall and the outer side having uniformly arranged drug injection holes; After the airbag body is inflated and during the injection of the medicine, the injector is pressed against the soil layer to be repaired and the flexible wall is in close contact with the hole wall. When the airbag body is a single-unit structure, the injector is positioned at different heights to facilitate layered injection of the repair agent at a fixed depth. When the airbag body is composed of multiple single-unit structures connected in series via the pipe, the injector is positioned in the middle of each single-unit structure to address situations where the different application depths of the repair agent differ significantly. When the airbag body is a single-unit structure containing multiple sub-airbags, adjacent sub-airbags share the end face of a rigid material, and the injector is positioned in the middle of each sub-airbag or at the end face of an adjacent sub-airbag to address situations where the different application depths of the repair agent differ significantly and require independent control of the agent injection at different depths.

2. The soil and groundwater remediation agent injection device according to claim 1, characterized in that, The upstream of the injection pipeline is connected in sequence to the medicine tank, the injection pump, and the first pressure gauge.

3. The soil and groundwater remediation agent injection device according to claim 1, characterized in that, An air pump and a valve are sequentially installed upstream of the air inflator.

4. The soil and groundwater remediation agent injection device according to claim 1, characterized in that, The air pressure monitoring line is equipped with a pressure sensor located inside the airbag and a second pressure gauge for measuring air pressure.

5. The soil and groundwater remediation agent injection device according to claim 1, characterized in that, The injector is connected to the drug injection pipeline via a branch pipe; the injection hole on the injector is a one-way hole.

6. A method for injecting soil and groundwater remediation agents, characterized in that, Using the apparatus as described in any one of claims 1 to 5, the method includes the following steps: A. Place the uninflated airbag body into the depth to be repaired in the excavated soil cavity; B. Inflate the airbag body through the inflation tube to make the airbag expand and reach the preset pressure. At this time, the injector is against the height of the soil layer to be repaired and the flexible wall of the airbag body is in close contact with the hole wall. C. Stop inflation, start the drug injection process and maintain the set injection pressure; D. The agent enters the injector through the injection pipeline, passes through the airbag body, and then enters the contaminated soil layer through the injection hole. During the injection process, if the pressure near the injector increases and causes the airbag to be squeezed, it is re-inflated to ensure that the airbag always adheres tightly to the hole wall and prevents the agent from flowing to other soil layers.

7. The method for injecting soil and groundwater remediation agents according to claim 6, characterized in that, When the airbag body adopts a single-unit structure, the repair agent is injected at a fixed depth and in layers by injectors at different heights.

8. The method for injecting soil and groundwater remediation agents according to claim 6, characterized in that, When the airbag body adopts multiple unit structures connected in series, the remediation agent is injected into the contaminated soil layer at different depths by injectors set on different unit structures.

9. The method for injecting soil and groundwater remediation agents according to claim 8, characterized in that, Each airbag unit is inflated sequentially from bottom to top during the inflation process. After each airbag unit is inflated, the water level in the hole rises briefly and then slowly falls back to stabilize. Once the preset pressure is reached in the airbag unit, the next airbag unit is then inflated.

10. The method for injecting soil and groundwater remediation agents according to claim 6, characterized in that, When the airbag body adopts a single structure containing multiple sub-airbags, the remediation agent is injected into the contaminated soil layer at different depths by injectors set on different sub-airbag structures, and the agent injection on each sub-airbag can be controlled independently.

11. The method for injecting soil and groundwater remediation agents according to claim 10, characterized in that, Each sub-airbag is inflated sequentially from bottom to top during the inflation process. After each sub-airbag is inflated, the water level in the hole rises briefly and then slowly falls back to stabilize. Once the preset pressure is reached in the sub-airbag, the next sub-airbag is inflated.

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