An efficient in-situ remediation device and method for DNAPLs-contaminated underground aquifers

Abstract

The present invention discloses an efficient in-situ remediation device and method for underground aquifers contaminated by DNAPLs, which relates to the field of groundwater in-situ remediation technology. The device comprises a workbench, a gas supply device fixedly mounted on the top of the workbench, a controller fixedly mounted on the top of the workbench, and a steam generator fixedly mounted on the top of the workbench. By providing the gas supply device, a negative pressure vacuum can be formed inside the extraction component. By providing a limit component, external groundwater and liquids such as DNAPLs can be allowed to enter the extraction component. The limit component and the extraction component are used in conjunction to form a positive pressure environment inside the extraction component. The limit component will close the bottom liquid inlet of the extraction component, ensuring that the liquid extracted into the extraction component is smoothly discharged into the sump of the ground sewage treatment device, effectively solving the problem of insufficient suction and easy blockage of the pump body and pipeline caused by the high viscosity and high specific gravity of traditional electric drive pumps when treating DNAPLs.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ soil and groundwater remediation, and in particular to a high-efficiency in-situ remediation device and method suitable for DNAPLs-contaminated underground aquifers. Background Art

[0002] For underground aquifers contaminated by organic matter, especially those contaminated by heavy non-aqueous liquids such as petroleum hydrocarbons and chlorinated hydrocarbons, groundwater extraction and treatment technology is widely used in in-situ treatment technologies due to its good treatment effect and excellent economy. The effect of groundwater extraction and remediation is mainly affected by factors such as pumping rate, well construction density, formation permeability, pollutant mobility, and pollutant viscosity. It has the characteristics of high density, low water solubility and high interfacial tension. These characteristics are more difficult to repair than LNAPLs, and commonly used extraction and treatment equipment is difficult to be effective.

[0003] Currently, most groundwater pumps used in the market for groundwater extraction and treatment, such as above-ground vacuum self-priming pumps and submersible pumps, are electrically driven and have high flow rates. They are primarily suitable for groundwater extraction. However, for contaminated sites with high viscosity and mixed sediment, these pumps are prone to downtime or damage due to insufficient suction. When remediating contaminated sites deeper than 10 meters, ordinary submersible pumps and other pumps are unable to lift the liquid from the extraction well to the surface collection pool due to the deep depth and insufficient pressure. Moreover, due to their high specific gravity and viscosity, the liquid deposited at the bottom of the well and mixed with sediment becomes increasingly difficult to extract. The high viscosity can adhere to the pump blades or the inner wall of the extraction pipe, which can easily cause equipment damage and pipe blockage during long-term use. Therefore, the pumping equipment must be maintained at a safe distance from the well bottom when in use. In addition, the water volume and pumping depth of centrifugal pumps such as vacuum self-priming pumps and submersible pumps are proportional to the motor speed. Although increasing the speed can increase the pumping volume and vacuum degree, which is beneficial for extraction, due to its characteristics, a higher pumping rate does not significantly improve its removal efficiency, but instead increases electricity and sewage treatment costs.

[0004] Existing patents, such as CN117600212A, disclose a stratified multiphase extraction method based on phased extraction of polluted layers and dynamically adjust the target layer to concentrate the vacuum level. However, this method does not address the problem of high viscosity and difficulty in extraction. To address this issue, we provide a highly efficient in-situ remediation device and method for DNAPLs-contaminated underground aquifers to address the above issues. Summary of the Invention

[0005] The purpose of the present invention is to remedy the deficiencies of the prior art and to provide an efficient in-situ remediation device and method suitable for DNAPLs-contaminated underground aquifers.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: A high-efficiency in-situ remediation device suitable for DNAPLs-contaminated underground aquifers, comprising a workbench, characterized in that: an air supply device is fixedly installed on the top of the workbench, a controller is fixedly installed on the top of the workbench, a steam generator is fixedly installed on the top of the workbench, a chemical dosing device is fixedly installed on the top of the workbench, a liquid storage tank is fixedly installed on the top of the workbench, a liquid outlet pipe is fixedly connected to the interior of the liquid storage tank, a sewage treatment device is fixedly installed on the top of the workbench, and the interior of the sewage treatment device is fixedly connected to an end of the liquid outlet pipe away from the liquid storage tank, an extraction component is provided below the workbench, the extraction component includes a suspension line for workbench transmission and winding, the end of the suspension line away from the workbench is fixedly connected to a suspension ring, the outer surface of the suspension ring is fixedly connected to a groundwater pump body, a limit assembly is provided inside the groundwater pump body, a heater is fixedly installed on the outer surface of the groundwater pump body, the interior of the heater is fixedly connected to a heating pipe, and the end of the heating pipe away from the heater is fixedly connected to the interior of the steam generator.

[0007] Furthermore, an air intake pipe is fixedly connected to the interior of the groundwater pump body, and one end of the air intake pipe away from the groundwater pump body is fixedly connected to the interior of the air supply device, and an air intake valve is fixedly installed inside the air intake pipe.

[0008] Furthermore, an air outlet pipe is fixedly connected to the interior of the groundwater pump body, and one end of the air outlet pipe away from the groundwater pump body is connected to the atmosphere, and an exhaust valve is fixedly installed inside the air outlet pipe.

[0009] Furthermore, a piston is slidably connected to the inner wall of the groundwater pump body, and a spring is fixedly connected to the bottom surface of the piston.

[0010] Furthermore, the interior of the groundwater pump body is fixedly connected to a groundwater discharge pipe, and one end of the groundwater discharge pipe away from the groundwater pump body is fixedly connected to the interior of the liquid storage tank, and a check valve is fixedly installed inside the groundwater discharge pipe.

[0011] Furthermore, the interior of the groundwater pump body is fixedly connected to a chemical dosing pipe, and one end of the chemical dosing pipe away from the groundwater pump body is fixedly connected to the interior of the chemical dosing device, and a second check valve is fixedly installed inside the chemical dosing pipe.

[0012] Furthermore, the limiting assembly includes a limiting ring fixedly connected to the inner wall of the groundwater pump body, the upper surface of the limiting ring is fixedly connected to a hollow disc, and the upper surface of the hollow disc is fixedly connected to the end of the spring away from the piston, and the inner wall of the limiting ring is slidably connected to a ball.

[0013] Furthermore, the repair method comprises the following steps:

[0014] S1: Installation and commissioning of equipment: transport the entire device to the contaminated underground aquifer remediation site, place the workbench in a suitable position according to the actual situation on site, ensure its stability, then install the air supply device, controller, steam generator, chemical dosing device, liquid storage tank, sewage treatment device and other components in turn, and connect and debug them to ensure that each component operates normally, the connection is tight and there is no leakage. At the same time, connect the top of the extraction component to the winch installed at the wellhead with a hanging line, and then fix the bottom end of the hanging line to the lifting ring to fix the groundwater pump body. Then lower the groundwater pump body into the extraction well, so that the lower end feed port of the groundwater pump body is located near the enrichment layer, and ensure that each pipeline is connected smoothly, such as the air inlet pipe, air outlet pipe, groundwater discharge pipe, chemical dosing pipe, etc., and are correctly connected to the corresponding components;

[0015] S2: Preparation of chemicals and hot water: During the operation, hot water or hot steam can be injected through the heater outside the pump body for conditioning, or surfactants, emulsifiers or hot water can be injected into the pump body through the chemical dosing device to reduce its viscosity, enhance fluidity and strengthen the extraction effect. The specific operation is to prepare an appropriate amount of conditioning chemicals such as surfactants and emulsifiers in the chemical dosing device according to the degree and characteristics of pollution, ensure that the chemicals can be smoothly added into the groundwater pump body through the chemical dosing pipe, start the steam generating device to heat the water to an appropriate temperature, and the generated hot steam can be transported to the extraction well through the heating pipe and heater to heat and condition the liquid, improve its fluidity and reduce the difficulty of extraction;

[0016] S3: Start extraction and reagent addition: Start the air supply device, so that the compressed air enters the groundwater pump body through the air inlet pipe, pushing the piston to move downward to overcome the spring force, squeezing out the air in the pump body, and then close the air inlet valve on the air inlet pipe and open the exhaust valve on the air outlet pipe to exhaust according to the preset program. At this time, the piston moves upward under the action of the spring rebound force, and a negative pressure vacuum environment is formed in the groundwater pump body. Under the action of negative pressure, the ball in the limit assembly at the bottom is pushed open by the external liquid, and the external groundwater and DNAPLs liquid enter the pump body through the hollow disc and the limit ring. At the same time, during the exhaust process, the solenoid valve and check valve 2 on the reagent dosing pipe are opened according to the controller signal, and the conditioning reagent in the reagent dosing device is added to the pump body through the reagent dosing pipe according to the preset ratio to mix with the extracted liquid to prevent DNAPLs residue and blockage. This cycle is repeated to continuously extract the groundwater and DNAPLs mixture. After that, the exhaust valve is closed again and the air inlet valve is opened. The air supply device is re-introduced to make the piston move downward again, forming a positive pressure environment in the pump body. The ball closes the bottom feed port under the action of pressure, and the extracted liquid is discharged along the groundwater discharge pipe;

[0017] S4: Real-time monitoring and parameter adjustment: During the extraction process, sensors installed at key locations monitor extraction pressure, flow rate, temperature and other parameters in real time, and transmit the data to the controller. The controller analyzes the data based on preset thresholds and algorithms to determine whether the extraction process is normal. If the extraction efficiency decreases or the pressure is abnormal, the controller promptly adjusts the air supply pressure of the air supply device, the opening and closing time of the air inlet and exhaust valves, the dosage of the reagent and other parameters to ensure the stability and efficiency of the extraction process. At the same time, the treatment effect of the sewage treatment device on the extracted liquid is observed. According to the water quality after treatment, the reagent formula is adjusted or other treatment reagents are added if necessary;

[0018] S5: Complete repair and equipment cleaning: Continue extraction until the monitoring data shows that the groundwater content reaches the predetermined repair standard, or the extraction volume reaches a certain limit, stop the extraction operation, lift the groundwater pump body to the ground, clean its interior and the pipes and components of the entire device, remove residual mud and other impurities, and properly handle the sludge in the sewage treatment device to prevent secondary pollution. Finally, maintain the equipment, check the wear of each component, replace wearing parts, and prepare for the next repair operation.

[0019] Compared with the existing technology, the efficient in-situ remediation device and method for DNAPLs-contaminated underground aquifers have the following beneficial effects:

[0020] 1. The present invention can form a negative pressure vacuum inside the extraction component by providing an air supply device, and can allow external groundwater and other liquids to enter the extraction component by providing a limit component. The limit component and the extraction component are used in conjunction to create a positive pressure environment inside the extraction component. The limit component will close the bottom liquid inlet of the extraction component, ensuring that the liquid extracted into the extraction component is smoothly discharged into the sump of the ground sewage treatment device. This effectively solves the problems of insufficient suction and easy blockage of the pump body and pipeline caused by the strong viscosity and specific gravity of traditional electric-driven pumps when treating DNAPLs, thereby improving the extraction efficiency and overcoming the disadvantage that traditional centrifugal water pumps cannot significantly improve the efficiency of DNAPL removal by simply relying on increasing the speed to increase the amount of groundwater extracted.

[0021] 2. The present invention provides a chemical addition system consisting of a chemical dosing device, a chemical dosing pipe and a check valve, which can accurately add surfactants, emulsifiers and other conditioning materials into the groundwater pump body at a specific time, preventing contaminated liquid from remaining on the inner wall of the groundwater pump body, further optimizing the extraction effect, and at the same time reducing the pressure on subsequent sewage treatment and reducing treatment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional front view structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the top view of the structure of the present invention;

[0024] Figure 3 is a schematic diagram of an extraction component of the present invention;

[0025] Figure 4 It is a schematic diagram of the cross-sectional structure of the present invention;

[0026] Figure 5 is a schematic cross-sectional view of an extraction component of the present invention;

[0027] Figure 6 It is a schematic diagram of the limiting component of the present invention;

[0028] Figure 7 It is a schematic diagram of the downhole liquid level of the present invention.

[0029] In the figure: 1. Workbench; 2. Air supply device; 3. Controller; 4. Steam generating device; 5. Chemical dosing device; 6. Liquid storage tank; 7. Liquid outlet pipe; 8. Sewage treatment device; 9. Extraction component; 901. Hanging line; 902. Lifting ring; 903. Groundwater pump body; 904. Air inlet pipe; 905. Air inlet valve; 906. Air outlet pipe; 907. Exhaust valve; 908. Piston; 909. Spring; 910. Groundwater discharge pipe; 911. Check valve 1; 912. Chemical dosing pipe; 913. Check valve 2; 10. Limiting component; 1001. Limiting ring; 1002. Hollow disc; 1003. Ball; 11. Heating pipe; 12. Heater. DETAILED DESCRIPTION

[0030] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0031] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0032] Example 1

[0033] like Figure 1 、 Figure 2 and Figure 4As shown, a high-efficiency in-situ remediation device and method for DNAPLs-contaminated underground aquifers include a workbench 1, an air supply device 2 is fixedly installed on the top of the workbench 1, a controller 3 is fixedly installed on the top of the workbench 1, a steam generator 4 is fixedly installed on the top of the workbench 1, a reagent dosing device 5 is fixedly installed on the top of the workbench 1, a liquid storage tank 6 is fixedly installed on the top of the workbench 1, a liquid outlet pipe 7 is fixedly connected to the interior of the liquid storage tank 6, a sewage treatment device 8 is fixedly installed on the top of the workbench 1, and the interior of the sewage treatment device 8 is fixedly connected to the end of the liquid outlet pipe 7 away from the liquid storage tank 6, an extraction component 9 is provided below the workbench 1, a limit component 10 is provided inside the groundwater pump body 903, a heater 12 is fixedly installed on the outer surface of the groundwater pump body 903, a heating pipe 11 is fixedly connected to the interior of the heater 12, and the end of the heating pipe 11 away from the heater 12 is fixedly connected to the interior of the steam generator 4.

[0034] In this embodiment, the gas supply device 2 is responsible for providing gas and is connected to the groundwater pump body 903 in the extraction component 9 through a specific pipeline to form a negative pressure vacuum inside the extraction component 9, which is conducive to the extraction of groundwater and pollutants. The controller 3 serves as the "brain" of the entire system. The controller 3 is responsible for receiving various sensor signals and accurately controlling each component according to a preset program to ensure the efficiency and safety of the entire remediation process. The steam generating device 4 provides the necessary thermal energy, which can be used to heat water or hot steam to improve the treatment effect. The agent dosing device 5 is used to store and add various treatment agents, which may help decompose, dilute or emulsify pollutants, prevent pump mentions and pipeline blockages, and ensure smooth discharge of liquid. The steam generating device 4 is connected to the heater 12 through a heating pipe 11, allowing the liquid in the contaminated layer to be preheated before extraction to improve its fluidity. The liquid storage tank 6 is used to temporarily store water containing pollutants extracted from the ground and clean water after treatment. The liquid storage tank 6 is connected to the sewage treatment device 8 through the liquid outlet pipe 7 to form a complete liquid treatment circuit. The sewage treatment device 8 processes the liquid from the liquid storage tank 6 is further treated to meet the discharge standards. The treated clean water can be recycled or discharged into the natural environment. Below the workbench 1, there is an extraction component 9, which is the core part of the entire device. The extraction component 9 includes a suspension line 901 that can be driven and wound by a winch installed at the wellhead. The end of the suspension line 901 is fixedly connected to a suspension ring 902 for hanging and fixing the groundwater pump body 903. The interior of the groundwater pump body 903 is provided with a limit component 10, which plays a key role in the extraction process. When negative pressure is formed inside the extraction component 9, the limit component 10 opens to allow external groundwater and other liquids to enter; when positive pressure is formed inside the extraction component 9, the limit component 10 closes to prevent liquid backflow and ensure that the extracted liquid can be smoothly discharged into the collection tank of the ground sewage treatment device 8. The heater 12 can heat and dilute the liquid near the pollutant-enriched layer, thereby improving its fluidity. In particular, for pollutants such as DNAPLs with high density, low water solubility and high interfacial tension, heating can significantly reduce their viscosity, making them easier to be extracted and treated.

[0035] The working steps of this embodiment are as follows:

[0036] like Figure 1 、 Figure 2 and Figure 4As shown, the entire device is transported to the contaminated underground aquifer remediation site. According to the actual situation on site, the workbench 1 is placed in a suitable position to ensure its stability. Then, the gas supply device 2, controller 3, steam generator 4, reagent dosing device 5, liquid storage tank 6, sewage treatment device 8 and other components are installed in sequence, and connected and debugged to ensure that each component operates normally and the connection is tight without leakage. At the same time, the top of the extraction component 9 is connected to the winch installed at the wellhead by using the hanging line 901, and then fixed by the bottom end of the hanging line 901. On the lifting ring 902, the groundwater pump body 903 is fixed, and then the groundwater pump body 903 is lowered into the extraction well so that the lower end feed port of the groundwater pump body 903 is located near the pollutant enrichment layer, and the connection of each pipeline is ensured to be smooth, such as the air inlet pipe 904, the air outlet pipe 906, the groundwater discharge pipe 910, the reagent injection pipe 912, etc. are correctly connected to the corresponding components, and then the controller 3 is used to start the air supply device 2 and the extraction component 9 to cooperate, so that the external groundwater and other liquids can smoothly enter the interior of the extraction component 9. The contaminated liquid enters the groundwater pump body 903 through the limiting component 10 and is then transported to the liquid storage tank 6. During the extraction process, the heater 12 can heat the liquid outside the groundwater pump body 903 to improve the fluidity of the liquid and ensure that it can easily flow into the groundwater pump body 903 to improve the treatment efficiency. As needed, appropriate surfactants, emulsifiers and other conditioning materials are added to the groundwater pump body 903 through the chemical dosing device 5 and the chemical dosing pipe 912 to prevent the extracted contaminated liquid from remaining in the groundwater pump body 903 or causing blockage of the groundwater discharge pipe 910, further optimizing the extraction effect and reducing the pressure on subsequent sewage treatment and the treatment cost. The extracted contaminated liquid enters the sewage treatment device 8 for further treatment. After the treated clean water meets the discharge standard, it can be reused or discharged into the natural environment. During the entire repair process, the controller 3 continuously monitors the operating status and parameters of each component, and adjusts and optimizes them as needed. At the same time, the equipment is regularly maintained and serviced to ensure its long-term stable operation.

[0037] Example 2

[0038] like Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 7As shown, the extraction component 9 includes a hanging line 901 that is driven and reeled by a winch at the wellhead, the end of the hanging line 901 is fixedly connected to a hanging ring 902, the outer surface of the hanging ring 902 is fixedly connected to a groundwater pump body 903, the interior of the groundwater pump body 903 is fixedly connected to an air inlet pipe 904, and the end of the air inlet pipe 904 away from the groundwater pump body 903 is fixedly connected to the interior of the air supply device 2, and an air inlet valve 905 is fixedly installed inside the air inlet pipe 904; the interior of the groundwater pump body 903 is fixedly connected to an air outlet pipe 906, and the end of the air outlet pipe 906 away from the groundwater pump body 903 is connected to the atmosphere, and an exhaust valve 907 is fixedly installed inside the air outlet pipe 906. ; The inner wall of the groundwater pump body 903 is slidably connected to a piston 908, and the bottom surface of the piston 908 is fixedly connected to a spring 909. The interior of the groundwater pump body 903 is fixedly connected to a groundwater discharge pipe 910, and the end of the groundwater discharge pipe 910 away from the groundwater pump body 903 is fixedly connected to the interior of the liquid storage tank 6, and a check valve 1 911 is fixedly installed inside the groundwater discharge pipe 910. The interior of the groundwater pump body 903 is fixedly connected to a chemical dosing pipe 912, and the end of the chemical dosing pipe 912 away from the groundwater pump body 903 is fixedly connected to the interior of the chemical dosing device 5, and a check valve 2 913 is fixedly installed inside the chemical dosing pipe 912.

[0039] In this embodiment, the extraction component 9 is the core part of the device, and its structural design is sophisticated and its components work together. One end of the suspension line 901 is connected to the winch installed at the wellhead, which can realize the retraction and extension operation of the suspension line 901, thereby controlling the lifting and lowering of the groundwater pump body 903 in the extraction well. The other end of the suspension line 901 is connected to the lifting ring 902, and the lifting ring 902 is firmly fixed to the outer surface of the groundwater pump body 903 to ensure that the groundwater pump body 903 is stable and reliable in the suspended state. The interior of the groundwater pump body 903 is connected to the air inlet pipe 904 and the air outlet pipe 906. The air inlet pipe 904 is connected to the interior of the air supply device 2, and the air outlet pipe 906 is connected to the atmosphere, and the air inlet valve 905 and The exhaust valve 907 on the exhaust pipe 906 can accurately control the inflow and outflow of gas. The piston 908 slides on the inner wall of the groundwater pump body 903. The spring 909 provides elastic potential energy for the movement of the piston 908, so that it can reciprocate under the action of air pressure, thereby realizing the extraction function. The groundwater discharge pipe 910 connects the groundwater pump body 903 with the liquid storage tank 6. The check valve 1 911 is installed in the groundwater discharge pipe 910 to effectively prevent the liquid from flowing back to the groundwater pump body 903. The agent dosing pipe 912 also connects the groundwater pump body 903 with the agent dosing device 5. The check valve 2 913 ensures that the agent can only flow into the groundwater pump body 903 in one direction, thereby ensuring the accuracy and stability of the agent addition.

[0040] The working steps of this embodiment are as follows:

[0041] like Figure 1 、 Figure 3、 Figure 4 、 Figure 5 and Figure 7 As shown, the air supply device 2 is started, and the compressed air enters the groundwater pump body 903 through the air inlet pipe 904, pushing the piston 908 to overcome the elastic force of the spring 909 and move downward. The ball 1003 moves downward to seal the conical port at the bottom of the groundwater pump body 903, squeezing out the air in the pump body, and then the air inlet valve 905 on the air inlet pipe 904 is closed and the exhaust valve 907 on the air outlet pipe 906 is opened to exhaust according to the preset program. At this time, the piston 908 moves upward under the rebound force of the spring 909, and a negative pressure vacuum environment is formed in the groundwater pump body 903. Under the action of the negative pressure, the ball 1003 in the limit assembly 10 at the bottom is pushed open by the external liquid, and the ball 1003 moves upward. External groundwater and other liquids pass through the hollow disc 1002 and the limiting ring 1001 enter the inside of the groundwater pump body 903, and then the exhaust valve 907 is closed again and the air inlet valve 905 is opened. The air supply device 2 is re-intaken to make the piston 908 move downward again, and a positive pressure environment is formed in the pump body. The ball 1003 moves downward under the action of pressure to close the bottom feed port, ensuring that the extracted liquid is discharged along the groundwater discharge pipe 910. At the same time, during the air intake process, the solenoid valve and the check valve 2 913 on the agent dosing pipe 912 are opened according to the signal of the controller 3, and the tempering agent in the agent dosing device 5 is added to the pump body through the agent dosing pipe 912 according to the preset proportion and mixed with the extracted liquid to prevent the residue and blockage of the contaminated liquid. The cycle is repeated to continuously extract groundwater and the mixed liquid.

[0042] Cross extraction of groundwater and contaminated liquid can be achieved by installing a winch at the wellhead and adjusting the position of the extraction component 9. Due to the low amount of contaminated liquid in the formation and its poor fluidity, extraction is generally carried out at intervals. During the intervals, the contaminated groundwater can be extracted and repaired, achieving dual use of one pump.

[0043] In order to further improve the adaptability of the extraction component 9, the extraction well screening position of the extraction component 9 is designed to be divided into two sections, with an upper and lower section in the middle. When used for groundwater remediation, in addition to being able to carry out groundwater extraction treatment as the extraction component 9, the groundwater discharge pipe 910 of the extraction component 9 can also be passed through the middle barrier section of the groundwater extraction well without being connected to the ground groundwater extraction and treatment device. Instead, the groundwater pump is modified and its use together with the groundwater extraction well is changed as a groundwater in-situ circulation well. The groundwater in the lower half of the groundwater aquifer is extracted and transferred to the upper half of the groundwater extraction well, thereby realizing hydraulic exchange of water between the upper and lower layers of the groundwater aquifer, and achieving in-situ cleaning.

[0044] While the groundwater is hydraulically circulated, chemical and biological agents such as hot water, redox agents, and microbial agents are added to increase the in-situ cleaning effect and achieve in-situ addition and diffusion of repair agents to enhance the repair effect.

[0045] Example 3

[0046] like Figure 1 、 Figure 4 and Figure 6 As shown, the limiting assembly 10 includes a limiting ring 1001 fixedly connected to the inner wall of the groundwater pump body 903, the upper surface of the limiting ring 1001 is fixedly connected to a hollow disc 1002, and the upper surface of the hollow disc 1002 is fixedly connected to the end of the spring 909 away from the piston 908, and the inner wall of the limiting ring 1001 is slidably connected to a ball 1003.

[0047] In this embodiment, the limiting assembly 10 is a key component inside the groundwater pump body 903. It ensures that the liquid can effectively enter the groundwater pump body 903 and closes the bottom feed port when a positive pressure environment is formed inside the groundwater pump body 903. Specifically, the limiting assembly 10 includes the following parts: a limiting ring 1001 is fixedly connected to the inner wall of the groundwater pump body 903, which can limit the up and down movement of the ball 1003 within a certain range, and can timely open the liquid inlet of the groundwater pump body 903 to allow liquid to enter, and can timely block the inlet. The opening prevents the liquid from flowing out. The hollow disc 1002 is fixedly connected to the upper surface of the limiting ring 1001, and its hollow design allows the liquid to pass through. At the same time, the upper surface of the hollow disc 1002 is fixedly connected to the end of the spring 909 away from the piston 908. The limiting ring 1001 and the top hollow disc 1002 together form a platform that can support the top spring 909. The diameter of the ball 1003 is slightly larger than the feed port at the bottom of the pump body. Therefore, when a positive pressure environment is formed in the pump body, the ball 1003 can close the bottom feed port under the action of pressure to prevent liquid backflow.

[0048] The working steps of this embodiment are as follows:

[0049] like Figure 1 、 Figure 4 and Figure 6As shown, when the device starts working, air is first supplied to the groundwater pump body 903 through the air supply device 2, so that the piston 908 moves downward under the push of the gas, and the compressed air enters the groundwater pump body 903 along the air inlet pipe 904, squeezing the piston 908 and the spring 909 to move downward and compress, squeezing out the air in the groundwater pump body 903, and the ball 1003 will move downward to block the conical liquid inlet at the bottom end of the groundwater pump body 903; close the air inlet valve 905, open the exhaust valve 907, and the piston 908 moves upward under the rebound action of the spring 909 to form a negative pressure vacuum in the groundwater pump body 903, and the ball 1003 under the groundwater pump body 903 is pushed open by the external liquid, and external groundwater and other polluted liquids enter the groundwater pump The air inlet 905 is opened and the piston 908 is compressed again by the compressed air, and the liquid in the groundwater pump body 903 is discharged along the groundwater discharge pipe 910. During the downward movement of the piston 908, the groundwater pump body 903 is in a positive pressure environment. The ball 1003 is pressed downward to close the conical liquid inlet at the bottom of the groundwater pump body 903, ensuring that the liquid extracted into the groundwater pump body 903 is smoothly discharged along the groundwater discharge pipe 910 to the liquid storage tank 6 of the surface sewage treatment equipment and the sewage treatment device 8. The cycle is repeated, groundwater and mixed liquid are continuously extracted, and are treated through the sewage treatment device 8, thereby finally achieving the purpose of repairing the contaminated underground aquifer.

[0050] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, and a specific direction structure and operation, and therefore, cannot be understood as limiting the present invention. In addition, "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0051] It should be noted that the standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt conventional models in the existing technology, and the inventor will not elaborate here.

[0052] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0053] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. An efficient in-situ remediation device for underground aquifers contaminated by DNAPLs, comprising a workbench (1), characterized in that: An air supply device (2) is fixedly installed on the top of the workbench (1), a controller (3) is fixedly installed on the top of the workbench (1), a steam generating device (4) is fixedly installed on the top of the workbench (1), a reagent dosing device (5) is fixedly installed on the top of the workbench (1), a liquid storage tank (6) is fixedly installed on the top of the workbench (1), the interior of the liquid storage tank (6) is fixedly connected to a liquid outlet pipe (7), a sewage treatment device (8) is fixedly installed on the top of the workbench (1), and the interior of the sewage treatment device (8) and the end of the liquid outlet pipe (7) away from the liquid storage tank (6) are connected. The working platform (1) is fixedly connected, and an extraction component (9) is provided below the working platform (1). The extraction component (9) includes a suspension line (901) for transmission and winding at the wellhead. The end of the suspension line (901) away from the working platform (1) is fixedly connected to a suspension ring (902). The outer surface of the suspension ring (902) is fixedly connected to a groundwater pump body (903). The interior of the groundwater pump body (903) is fixedly connected to an air intake pipe (904), and the end of the air intake pipe (904) away from the groundwater pump body (903) is fixedly connected to the interior of the air supply device (2). The interior of the air intake pipe (904) is fixedly installed with an air intake pipe. The air valve (905) is fixedly connected to the interior of the groundwater pump body (903) with an air outlet pipe (906), and one end of the air outlet pipe (906) away from the groundwater pump body (903) is connected to the atmosphere. An exhaust valve (907) is fixedly installed inside the air outlet pipe (906). The inner wall of the groundwater pump body (903) is slidably connected to a piston (908), and the bottom surface of the piston (908) is fixedly connected to a spring (909). A limit assembly (10) is provided inside the groundwater pump body (903), and the limit assembly (10) includes a fixed inner wall of the groundwater pump body (903) and a spring (909). A limiting ring (1001) is provided, wherein the upper surface of the limiting ring (1001) is fixedly connected to a hollow disc (1002), and the upper surface of the hollow disc (1002) is fixedly connected to the end of the spring (909) away from the piston (908), the inner wall of the limiting ring (1001) is slidably connected to a ball (1003), a heater (12) is fixedly mounted on the outer surface of the groundwater pump body (903), the interior of the heater (12) is fixedly connected to a heating pipe (11), and the end of the heating pipe (11) away from the heater (12) is fixedly connected to the interior of the steam generating device (4).

2. The high-efficiency in-situ remediation device for DNAPLs-contaminated underground aquifers according to claim 1, characterized in that: The interior of the groundwater pump body (903) is fixedly connected to a groundwater discharge pipe (910), and one end of the groundwater discharge pipe (910) away from the groundwater pump body (903) is fixedly connected to the interior of the liquid storage tank (6), and a check valve (911) is fixedly installed inside the groundwater discharge pipe (910).

3. The high-efficiency in-situ remediation device for DNAPLs-contaminated underground aquifers according to claim 1, characterized in that: The interior of the groundwater pump body (903) is fixedly connected to a drug dosing pipe (912), and one end of the drug dosing pipe (912) away from the groundwater pump body (903) is fixedly connected to the interior of the drug dosing device (5), and a second check valve (913) is fixedly installed inside the drug dosing pipe (912).

4. A repair method for a high-efficiency in-situ repair device for a DNAPLs-contaminated underground aquifer according to any one of claims 1 to 3, characterized in that: The repair method comprises the following steps: S1: Installation and commissioning of equipment: transport the entire device to the DNAPLs contaminated underground aquifer remediation site, place the workbench (1) in a suitable position according to the actual situation on site, ensure its stability, install the air supply device (2), controller (3), steam generator (4), reagent dosing device (5), liquid storage tank (6) and sewage treatment device (8) components in sequence, and connect and commission them, connect the top of the extraction component (9) to the winch installed at the wellhead using the hanging line (901), and then fix the bottom end of the hanging line (901) to the hanging ring (902) to achieve the fixation of the groundwater pump body (903), and then lower the groundwater pump body (903) into the extraction well, so that the lower end feed port of the groundwater pump body (903) is located near the enrichment layer, and ensure that all pipelines are connected smoothly; S2: Preparation of reagents and hot water: According to the degree and characteristics of the pollution, an appropriate amount of surfactant and emulsifier conditioning reagent is prepared in the reagent dosing device (5), and the reagent is added to the groundwater pump body (903) through the reagent dosing pipe (912). The steam generating device (4) is started to heat the water to a suitable temperature. The generated hot steam is transported to the extraction well through the heating pipe (11) and the heater (12) to heat and condition the DNAPLs liquid; S3: Start extraction and reagent addition: Start the air supply device (2), so that the compressed air enters the groundwater pump body (903) through the air inlet pipe (904), pushes the piston (908) to overcome the elastic force of the spring (909) and move downward, squeezes out the air in the pump body, and then closes the air inlet valve (905) on the air inlet pipe (904) and opens the exhaust valve (907) on the air outlet pipe (906) to exhaust according to the preset program. At this time, the piston (908) moves upward under the rebound force of the spring (909), and a negative pressure vacuum environment is formed in the groundwater pump body (903). Under the action of the negative pressure, the ball (1003) in the limit assembly (10) at the bottom is pushed open by the external liquid, and the external groundwater and DNAPLs liquid are discharged through the hollow disc (1002) and the limit assembly (1003). The position ring (1001) enters the interior of the pump body. At the same time, during the exhaust process, the solenoid valve and the second check valve (913) on the reagent dosing pipe (912) are opened according to the signal of the controller (3). The tempering reagent in the reagent dosing device (5) is added into the pump body through the reagent dosing pipe (912) according to the preset ratio and mixed with the extracted liquid to prevent DNAPLs from remaining and clogging. The groundwater and DNAPLs mixed liquid is continuously extracted in this cycle. After that, the exhaust valve (907) is closed again and the air inlet valve (905) is opened. The air supply device (2) is re-introduced to make the piston (908) move downward again, forming a positive pressure environment in the pump body. The ball (1003) closes the bottom feed port under the action of pressure, and the extracted liquid is discharged along the groundwater discharge pipe (910); S4: Parameter adjustment: If the extraction efficiency is reduced or the pressure is abnormal, the air supply pressure of the air supply device (2), the opening and closing time of the air inlet valve (905) and the exhaust valve (907), and the dosage parameters of the reagent are adjusted in time to ensure the stability and efficiency of the extraction process. At the same time, the treatment effect of the sewage treatment device (8) on the extracted liquid is observed. According to the water quality after treatment, the reagent formula is adjusted or other treatment reagents are added; S5: Complete the repair and equipment cleaning: Continue extraction until the monitoring data shows that the content in the groundwater reaches the predetermined repair standard, or the extraction volume reaches a certain limit, stop the extraction operation, lift the groundwater pump body (903) to the ground, clean the pipes and components inside it and the entire device, remove residual mud and other impurities, and properly handle the sludge in the sewage treatment device (8) to prevent secondary pollution. Finally, perform maintenance on the equipment, check the wear of each component, replace wearing parts, and prepare for the next repair operation.

Images