Efficient in-situ remediation device and method suitable for DNAPLs polluted underground aquifer

Abstract

The invention discloses an efficient in-situ remediation device and method suitable for an underground aquifer polluted by DNAPLs, and relates to the technical field of underground water in-situ remediation. The efficient in-situ remediation device comprises a workbench, an air supply device is fixedly installed at the top of the workbench, and a controller is fixedly installed at the top of the workbench; and a steam generating device is fixedly mounted at the top of the workbench. Through the arrangement of the air supply device, negative pressure vacuum can be formed in the extraction assembly, through the arrangement of the limiting assembly, external underground water, DNAPLs and other liquid can enter the extraction assembly, and through the cooperative use of the limiting assembly and the extraction assembly, the interior of the extraction assembly is in a positive pressure environment; the limiting assembly can close a liquid inlet in the bottom of the extraction assembly, it is ensured that liquid extracted into the extraction assembly is smoothly discharged into a water collecting pool of a ground sewage treatment device, and the problems that when a traditional electric drive pump treats DNAPLs, due to high viscosity and large specific gravity, suction force is insufficient, and a pump body and a pipeline are prone to being blocked are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ soil and groundwater remediation, and in particular to a highly efficient 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 because of 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 fluidity, 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 work effectively.

[0003] At present, the pumps used for groundwater extraction and treatment on the market, such as ground vacuum self-priming pumps and submersible pumps, are mostly electrically driven and have large flow rates. They are mainly suitable for groundwater extraction. However, for contaminated sites with high viscosity and mixed with sediment, these pumps are prone to downtime or damage due to insufficient suction. When repairing contaminated sites with a depth greater than 10m, ordinary submersible pumps and other pumps cannot pump the liquid in the extraction well to the ground collection pool due to the deep depth and insufficient pressure. Moreover, their own specific gravity and viscosity are large, and the difficulty of suction increases sharply after being deposited at the bottom of the well and mixed with sediment. Its high viscosity will adhere to the pump body blades or the inner wall of the extraction pipeline. Long-term use can easily cause equipment damage and pipeline blockage. Therefore, when using the pumping device, a certain safe distance must be maintained from the bottom of the well. 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 for extraction, due to the characteristics, the larger pumping rate does not significantly improve its removal efficiency, but increases the cost of electricity and sewage treatment.

[0004] Existing patents such as CN117600212A disclose a stratified multiphase extraction method, which is based on phased extraction of polluted layers and dynamically adjusts the target layer to concentrate the vacuum degree, but does not solve the problem of high viscosity and difficulty in extraction. To this end, we provide an efficient in-situ remediation device and method suitable for DNAPLs-contaminated underground aquifers to solve the above problems. Summary of the invention

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

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an efficient in-situ remediation device suitable for underground aquifers contaminated by DNAPLs, 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 generating device is fixedly installed on the top of the workbench, a reagent 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 inside of the liquid storage tank, a sewage treatment device is fixedly installed on the top of the workbench, and the inside 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, a heating pipe is fixedly connected to the inside of the heater, and the end of the heating pipe away from the heater is fixedly connected to the inside of the steam generating device.

[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 with a chemical dosing pipe, and one end of the chemical dosing pipe away from the groundwater pump body is fixedly connected with 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 an 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 gas supply device, controller, steam generator, reagent 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 it to the lifting ring through the bottom of the hanging line to fix the groundwater pump body, and 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, reagent dosing pipe, etc. are connected correctly with the corresponding components;

[0015] S2: Preparation of reagents and hot water: During the operation, hot water or hot steam can be injected through the heater outside the pump body for conditioning, and surfactants, emulsifiers or hot water can be injected into the pump body through the reagent dosing device to reduce its viscosity, enhance fluidity, and strengthen the extraction effect. The specific operation is to prepare an appropriate amount of surfactants, emulsifiers and other conditioning agents in the reagent dosing device according to the degree and characteristics of pollution, ensure that the agents can be smoothly added to the groundwater pump body through the reagent dosing pipe, start the steam generating device, heat the water to a suitable temperature, and the generated hot steam can be transported to the extraction well through the heating pipe and the 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 to allow compressed air to enter the groundwater pump body through the air inlet pipe, push the piston to overcome the spring force and move downward to squeeze out the air in the pump body, 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 the second check valve 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 and mixed with the extracted liquid to prevent DNAPLs from remaining and clogging. This cycle is repeated to continuously extract the groundwater and DNAPLs mixed liquid, and then the exhaust valve is closed again and the air intake valve is opened. The air supply device is re-intaken to make the piston move downward again, forming a positive pressure environment in the pump body. The ball closes the bottom feed port under 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 are used to monitor extraction pressure, flow, temperature and other parameters in real time, and the data is transmitted 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 air supply pressure of the air supply device, the opening and closing time of the air inlet valve and the exhaust valve, the dosage of the reagent and other parameters 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 on the extracted liquid is observed, and 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 the inside and the pipes and components of the entire device, remove residual mud and other impurities, properly handle the sludge in the sewage treatment device, prevent secondary pollution, and finally, maintain the equipment, check the wear of each component, replace wearing parts, and prepare for the next repair operation.

[0019] Compared with the prior art, 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 coordination to form a positive pressure environment inside the extraction component. The limit component will close the bottom liquid inlet of the extraction component to ensure that the liquid extracted into the extraction component is smoothly discharged into the sump of the ground sewage treatment device, effectively solving the problems of insufficient suction and easy blockage of the pump body and pipeline due to strong viscosity and high specific gravity of traditional electric drive pumps when treating DNAPLs, improving the extraction efficiency, and overcoming the disadvantage that traditional centrifugal water pumps cannot significantly improve the removal efficiency of DNAPLs by simply relying on increasing the rotation speed to increase the amount of groundwater extracted.

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

[0022] Figure 1 It is a three-dimensional front view structural schematic diagram 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 It is a schematic diagram of the 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 cross-sectional schematic diagram 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. reagent dosing device; 6. liquid storage tank; 7. liquid outlet pipe; 8. sewage treatment device; 9. extraction assembly; 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 outlet pipe; 911. check valve 1; 912. reagent dosing pipe; 913. check valve 2; 10. limit assembly; 1001. limit 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 in conjunction with 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 further described in detail below in conjunction with the accompanying drawings and embodiments.

[0032] Embodiment 1

[0033] like Figure 1 , Figure 2 and Figure 4As shown, a high-efficiency in-situ repair device and method for underground aquifers contaminated by DNAPLs include a workbench 1, a gas 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, a liquid outlet pipe 7 is fixedly connected to the inside of the liquid storage tank 6, a sewage treatment device 8 is fixedly installed on the top of the workbench 1, and the inside 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 inside of the heater 12, and the end of the heating pipe 11 away from the heater 12 is fixedly connected to the inside of the steam generating device 4.

[0034] In this embodiment, the gas supply device 2 is responsible for providing gas, which 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 repair process. The steam generating device 4 provides 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 pipeline 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, as well as treated clean water. The liquid storage tank 6 is connected to the sewage treatment device 8 through a liquid outlet pipe 7 to form a complete liquid treatment circuit. The sewage treatment device 8 treats the liquid from the liquid storage tank. 6 is further treated to meet the discharge standards, and 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 whole 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 a groundwater pump body 903. A limit assembly 10 is provided inside the groundwater pump body 903. This assembly 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 sump 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 extract and treat.

[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 restoration 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, the controller 3, the steam generating device 4, the reagent dosing device 5, the liquid storage tank 6, the sewage treatment device 8 and other components are installed in sequence, and connected and debugged to ensure that each component operates normally, the connection is tight and there is no leakage. At the same time, the top of the extraction component 9 is connected to the winch installed at the wellhead by the hanging wire 901, and then fixed by the bottom end of the hanging wire 901. The groundwater pump body 903 is fixed on the lifting ring 902, 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 smooth, such as the air inlet pipe 904, the air outlet pipe 906, the groundwater discharge pipe 910, the reagent dosing pipe 912, etc. are correctly connected with the corresponding components, and then the air supply device 2 and the extraction component 9 are started by the controller 3 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 limit assembly 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 agent dosing device 5 and the agent 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, thereby 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] Embodiment 2

[0038] like Figure 1 , Figure 3 , Figure 4 , Figure 5 and Figure 7As shown, the extraction assembly 9 includes a suspension line 901 driven and reeled up by a winch at the wellhead, the end of the suspension line 901 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 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 with a piston 908, and the bottom surface of the piston 908 is fixedly connected with a spring 909. The interior of the groundwater pump body 903 is fixedly connected with a groundwater discharge pipe 910, and the end of the groundwater discharge pipe 910 away from the groundwater pump body 903 is fixedly connected with 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 with a chemical dosing pipe 912, and the end of the chemical dosing pipe 912 away from the groundwater pump body 903 is fixedly connected with 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 exquisite and the various 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 on 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, and 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, and 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, and 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 block the conical opening 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 procedure. 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 disk 1002 and the limit ring 1001 enter the inside of the groundwater pump body 903, then close the exhaust valve 907 again and open the intake valve 905, the air supply device 2 re-intakes air 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 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 opening screen position of the extraction component 9 is designed to be divided into two sections, with a barrier section in the middle. When used for groundwater remediation, in addition to being used as the extraction component 9 to carry out groundwater extraction treatment, 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 the groundwater extraction well is changed in use 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, the in-situ cleaning effect is increased by adding chemical and biological agents, such as hot water, redox agents, microbial agents, etc., and the in-situ addition and diffusion of repair agents are achieved to enhance the repair effect.

[0045] Embodiment 3

[0046] like Figure 1 , Figure 4 and Figure 6 As shown, the limit assembly 10 includes a limit ring 1001 fixedly connected to the inner wall of the groundwater pump body 903, a hollow disc 1002 is fixedly connected to the upper surface of the limit ring 1001, 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 a ball 1003 is slidably connected to the inner wall of the limit ring 1001.

[0047] In this embodiment, the limit 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 limit assembly 10 includes the following parts: a limit 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 hollow disc 1002 is fixedly connected to the upper surface of the limiting ring 1001, and its hollow design allows 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 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 inside of 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 to squeeze 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 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 inside of the groundwater pump body 903 is then closed, and the exhaust valve 907 is closed, and the intake valve 905 is opened. The piston 908 and the spring 909 are compressed by the compressed air again, 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, and 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 ground sewage treatment equipment and the sewage treatment device 8. The cycle is repeated, groundwater and mixed liquid are continuously extracted, and treated through the sewage treatment device 8, ultimately achieving the purpose of repairing the polluted underground aquifer.

[0050] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", etc. 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 a limitation on 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, special-shaped parts can be customized according to the instructions and drawings, and the specific connection methods of each part adopt mature conventional means such as bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art, and the inventor will not elaborate here.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation 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) is fixedly connected to an end of the liquid outlet pipe (7) away from the liquid storage tank (6), and the bottom of the workbench (1) is fixedly connected to a liquid outlet pipe (7). An extraction component (9) is provided, the extraction component (9) comprising a suspension line (901) for transmission and winding at the wellhead, the end of the suspension line (901) away from the workbench (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), 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), 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 underground aquifers contaminated by DNAPLs according to claim 1, characterized in that: The interior of the groundwater pump body (903) is fixedly connected to an air intake pipe (904), and one 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), and an air intake valve (905) is fixedly installed inside the air intake pipe (904).

3. The high-efficiency in-situ remediation device for underground aquifers contaminated by DNAPLs according to claim 1, characterized in that: The interior of the groundwater pump body (903) is fixedly connected to 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).

4. The high-efficiency in-situ remediation device for underground aquifers contaminated by DNAPLs according to claim 1, characterized in that: 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).

5. The high-efficiency in-situ remediation device for underground aquifers contaminated by DNAPLs 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).

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

7. The high-efficiency in-situ remediation device for underground aquifers contaminated by DNAPLs according to claim 1, characterized in that: The limiting assembly (10) comprises a limiting ring (1001) fixedly connected to the inner wall of the groundwater pump body (903); a hollow disc (1002) is fixedly connected to the upper surface of the limiting ring (1001); and the upper surface of the hollow disc (1002) is fixedly connected to an end of the spring (909) away from the piston (908); and a ball (1003) is slidably connected to the inner wall of the limiting ring (1001).

8. A highly efficient in-situ remediation device for underground aquifers contaminated by DNAPLs according to any one of claims 1 to 7, 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 gas supply device (2), controller (3), steam generator (4), reagent dosing device (5), liquid storage tank (6) and sewage treatment device (8) components in sequence, connect and commission them, connect the top of the extraction component (9) to the winch installed at the wellhead by using the hanging wire (901), and then fix the bottom end of the hanging wire (901) to the hanging ring (902) to fix 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 pollution, a proper 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 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 air 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 disk (1002) and the limit assembly (1003). The position ring (1001) enters 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 conditioning reagent in the reagent dosing device (5) is added to 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 are continuously extracted in this cycle. After that, the exhaust valve (907) is closed again and the air intake valve (905) is opened. The air supply device (2) is re-intaken 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 reagent dosage parameters 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 if necessary; S5: Complete the repair and equipment cleaning: Continue to extract 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 inside and the pipes and components of the entire device, remove residual mud and other impurities, properly handle the sludge in the sewage treatment device (8), and 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.

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