Soil groundwater layered multiphase extraction well structure

Abstract

The utility model discloses a layered multiphase extraction well structure for soil and underground water. The layered multiphase extraction well structure comprises a main shaft, branch shafts, a gas phase extraction structure, an LNAPL phase extraction structure, a water phase extraction structure, a DNAPL phase extraction structure and a layered waterproof structure. And optimizing the layout of the extraction well group through a numerical simulation method and an optimization coupling method. According to the layered multi-pump extraction well structure, the construction and layout of the layered multi-pump extraction well structure can be optimized, the MPE operation efficiency is improved, the energy consumption is reduced, and the treatment of a polluted site is more effective and economical.

Description

Technical Field

[0001] This utility model belongs to the field of multiphase extraction and remediation of soil and groundwater, specifically relating to a multiphase extraction well structure for soil and groundwater. Background Technology

[0002] Multiphase extraction (MPE) technology is one of the most commonly used technologies in the field of soil and groundwater pollution remediation. It is an in-situ remediation technology that can simultaneously treat soil gaseous pollutants, groundwater pollutants, and non-aqueous phase liquid (NAPL) pollutants.

[0003] Multiphase extraction (MPE) technology consists of three main processes: multiphase extraction, multiphase separation, and contaminant treatment. The extraction system is the core of the MPE system, including the extraction well structure, extraction equipment, and piping. MPE systems can be divided into single-pump systems and dual-pump systems. A single-pump system uses only a vacuum pump for extraction, while a dual-pump system uses both a vacuum pump and a water pump for extraction.

[0004] Multiphase extraction (MPE) technology targets soil gaseous pollutants, light non-aqueous liquid (LNAPL) pollutants, heavy non-aqueous liquid (DNAPL) pollutants, and dissolved phase pollutants. Traditional multiphase extraction typically employs a mixed extraction method, extracting water, gas, and NAPL together for post-treatment, significantly increasing the volume of wastewater and waste gas that can be treated downstream. Current technology, based on pollutant stratification, uses a stratified extraction approach for staged extraction, achieving concentrated energy efficiency in multiphase extraction, improving remediation efficiency, and saving energy. Utility Model Content

[0005] In order to optimize and upgrade the existing technology, this utility model provides a multiphase extraction well structure for soil groundwater stratification.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a multiphase extraction well structure for soil groundwater stratification, including a main well channel, branch well channels, a gas phase extraction structure, an LNAPL phase extraction structure, an aqueous phase extraction structure, a DNAPL phase extraction structure, and a stratified water-proof structure.

[0007] Furthermore, the main shaft is equipped with evenly spaced screen tubes in the LNAPL pollutant enrichment zone, the soil water phase pollution zone, and the DNAPL pollutant enrichment zone.

[0008] Furthermore, the gas phase extraction structure includes a vacuum pump and a gas pipe; the vacuum pump is connected to the main wellbore through the gas pipe, the gas pipe head is located at the intersection of the main wellbore and the branch wellbore, the branch wellbore is located in the vadose zone of the soil, and the well walls of the branch wellbore and the same section of the main wellbore are filled with bentonite.

[0009] Furthermore, the LNAPL phase extraction structure includes a water pump and a water pipe; the water pump is connected to the main wellbore through the water pipe, the water pipe passes through a three-hole water-blocking device, the water pipe head is located above a two-hole water-blocking device, the area between the three-hole water-blocking device and the two-hole water-blocking device is an LNAPL contaminant enrichment zone, and the surrounding well wall is filled with quartz sand.

[0010] Furthermore, the aqueous extraction structure includes a water pump and a water pipe; the water pump is connected to the main well via the water pipe, the water pipe passes through a three-hole water-blocking device and a two-hole water-blocking device, the water pipe head is located above a single-hole water-blocking device, the area between the two-hole water-blocking device and the single-hole water-blocking device is a soil aqueous phase contamination zone, and the surrounding well wall is filled with quartz sand.

[0011] Furthermore, the DNAPL phase extraction structure includes a water pump and a water pipe; the water pump is connected to the main wellbore through the water pipe, and the water pipe passes through a three-hole water-blocking device, a double-hole water-blocking device and a single-hole water-blocking device. The water pipe head is located above the bottom of the main wellbore. The area between the single-hole water-blocking device and the bottom of the well is a DNAPL contaminant enrichment zone, and the surrounding well wall is filled with quartz sand.

[0012] Furthermore, the water-blocking device has a perforated stainless steel plate in the middle, rubber rings around the stainless steel plate and the hole walls, and a stainless steel frame inserted into the well wall below the stainless steel plate.

[0013] Furthermore, the three-hole water-blocking device is located at the junction of bentonite and quartz sand in the main well channel, higher than the LNAPL pollutant enrichment zone, separating the soil gaseous contamination layer from the LNAPL contamination layer, realizing the direct separation of polluting gas and LNAPL pollutants, and improving remediation efficiency.

[0014] Furthermore, the dual-hole water-blocking device is located above the water-phase contaminated soil layer and below the LNAPL pollutant enrichment zone. The surrounding well walls are filled with clay to separate the LNAPL contaminated layer from the water-phase contaminated layer, thereby achieving direct separation of LNAPL pollutants and water-soluble pollutants and improving remediation efficiency.

[0015] Furthermore, the single-hole water-blocking device is located in the lower layer of the soil water phase pollution zone, higher than the DNAPL pollutant enrichment zone. The surrounding well wall is filled with clay to separate the water phase pollution layer from the DNAPL pollution layer, thereby achieving direct separation of water-soluble pollutants and DNAPL pollutants and improving remediation efficiency.

[0016] The beneficial effects of this utility model are:

[0017] 1. This utility model optimizes the existing single-well structure of multi-layered extraction wells by studying the effects of layered isolation materials and sealing processes, vacuum pump (water pump) type, quantity, installation position, and screen tube position on extraction efficiency, thereby improving MPE operating efficiency, reducing energy consumption, and ultimately reducing the cost of contaminated site remediation.

[0018] 2. This utility model utilizes an optimized coupling method, taking the number of extraction wells, the number of extraction pumps, extraction time, and extraction rate as decision variables, and extraction efficiency and cost as objective functions, to optimize the layout of extraction well groups, making the remediation of contaminated sites more effective and economical. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the single-well structure of the multi-layered pump extraction well in this utility model;

[0020] Figure 2 Here is a schematic diagram of the porous water-stopping device in this utility model:

[0021] a-Three-hole water-stop device, b-Double-hole water-stop device, c-Single-hole water-stop device.

[0022] Figure label:

[0023] 1 Main shaft, 2 Branch shaft, 3 LNAPL contaminant enrichment zone, 4 Soil water phase contamination zone, 5 DNAPL contaminant enrichment zone, 6 Screen tube, 7 Vacuum pump, 8 Gas pipe, 9 Soil vadose zone, 10 Bentonite, 11 Water pump, 12 Water pipe, 13 Three-hole water-stop device, 14 Two-hole water-stop device, 15 Quartz sand, 16 Single-hole water-stop device, 17 Clay, 18 Stainless steel plate, 19 Rubber ring, 20 Stainless steel frame. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1 and Figure 2 As shown, this utility model provides a multiphase extraction well structure for soil groundwater stratification, including a main well channel (1), branch well channels (2), a gas phase extraction structure, an LNAPL phase extraction structure, an aqueous phase extraction structure, a DNAPL phase extraction structure, and a stratified water-proof structure.

[0026] The main shaft has evenly spaced sieve tubes (6) inserted in the LNAPL pollutant enrichment zone (3), soil water phase pollution zone (4), and DNAPL pollutant enrichment zone (5).

[0027] The gas extraction structure includes a vacuum pump (7) and a gas pipe (8); the vacuum pump (7) is connected to the main well (1) through the gas pipe (8), the head of the gas pipe (8) is located at the intersection of the main well (1) and the branch well (2), the branch well (2) is located in the soil vadose zone (9), and the well walls of the branch well (2) and the same section of the main well (1) are filled with bentonite (10).

[0028] The LNAPL phase extraction structure includes a water pump (11) and a water pipe (12); the water pump (11) is connected to the main wellbore (1) through the water pipe (12), the water pipe passes through a three-hole water-blocking device (13), the head of the water pipe (12) is located above the double-hole water-blocking device (14), the middle of the three-hole water-blocking device (13) and the double-hole water-blocking device (14) is the LNAPL contaminant enrichment zone (3), and the surrounding well wall is filled with quartz sand (15).

[0029] The aqueous extraction structure includes a water pump (11) and a water pipe (12); the water pump (11) is connected to the main well (1) through the water pipe (12), the water pipe (12) passes through the three-hole water-blocking device (13) and the double-hole water-blocking device (14), the head of the water pipe (12) is located above the single-hole water-blocking device (16), the middle of the double-hole water-blocking device (14) and the single-hole water-blocking device (16) is the soil aqueous phase pollution zone (4), and the surrounding well wall is filled with quartz sand (15).

[0030] The DNAPL phase extraction structure includes a water pump (11) and a water pipe (12); the water pump (11) is connected to the main well (1) through the water pipe (12), the water pipe (12) passes through a three-hole water-blocking device (13), a double-hole water-blocking device (14) and a single-hole water-blocking device (16), the head of the water pipe (12) is located above the bottom of the main well (1), the single-hole water-blocking device (16) and the bottom of the well are in the DNAPL contaminant enrichment zone (5), and the surrounding well wall is filled with quartz sand (15).

[0031] The water-blocking device has a perforated stainless steel plate (18) in the middle, and rubber rings (19) around the stainless steel plate (18) and the hole wall. Pressure-bearing pipes are installed between the stainless steel plates, and a stainless steel frame (20) inserted into the well wall is located under the stainless steel plate (18).

[0032] The three-hole water-blocking device (13) is located at the junction of bentonite (10) and quartz sand (15) in the main well (1), higher than the LNAPL pollutant enrichment zone (3). It can separate the soil gaseous pollution layer from the LNAPL pollution layer, realize the direct separation of pollutant gas and LNAPL pollutants, and improve the remediation efficiency.

[0033] The double-hole water-blocking device (14) is located above the soil water phase pollution zone (4) and below the LNAPL pollutant enrichment zone (3). The surrounding well walls are filled with clay (17), and the clay balls have a diameter of 20-40 mm. This is used to separate the LNAPL pollution layer from the water phase pollution layer, so as to achieve direct separation of LNAPL pollutants and water-soluble pollutants and improve remediation efficiency.

[0034] The single-hole water-blocking device (16) is located below the soil water phase pollution zone (4) and above the DNAPL pollutant enrichment zone (5). The surrounding well wall is filled with clay (17), and the clay ball has a diameter of 20-40 mm. This can separate the water phase pollution layer from the DNAPL pollution layer, realize the direct separation of water-soluble pollutants and DNAPL pollutants, and improve the remediation efficiency.

[0035] In soil and groundwater remediation projects, situations often arise where gaseous pollutants, water-soluble pollutants, and DNAPL pollutants coexist. Traditional multiphase extraction typically employs a mixed extraction method, extracting water, gas, and DNAPL together for subsequent treatment, significantly increasing the volume of wastewater and exhaust gases to be processed. This new technology is based on pollutant stratification, utilizing a porous water-tight device and a stratified extraction method to simultaneously extract and separate multiphase pollutants, concentrating extraction energy efficiency, improving remediation efficiency, and saving energy consumption.

[0036] Finally, it should be noted that the above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. For those skilled in the art, various variations can be made based on the above description. Any modifications, substitutions, or improvements made within the spirit and principles of this utility model are within the protection scope of this utility model.

Claims

1. A multiphase extraction well structure for stratified groundwater in soil, characterized in that, It includes a main wellbore (1), a branch wellbore (2), a gas phase extraction structure, an LNAPL phase extraction structure, an aqueous phase extraction structure, a DNAPL phase extraction structure, and a layered water-blocking structure. The main shaft (1) has uniformly spaced sieve tubes (6) inserted in the LNAPL pollutant enrichment zone (3), soil water phase pollution zone (4) and DNAPL pollutant enrichment zone (5). The gas extraction structure includes a vacuum pump (7) and a gas pipe (8); the vacuum pump (7) is connected to the main well (1) through the gas pipe (8), the head of the gas pipe (8) is located at the intersection of the main well (1) and the branch well (2), the branch well (2) is located in the soil vadose zone (9), and the well walls of the branch well (2) and the same section of the main well (1) are filled with bentonite (10); The LNAPL phase extraction structure includes a water pump (11) and a water pipe (12); the water pump (11) is connected to the main wellbore (1) through the water pipe (12), the water pipe (12) passes through a three-hole water-proof device (13), the head of the water pipe (12) is located above the double-hole water-proof device (14), the middle of the three-hole water-proof device (13) and the double-hole water-proof device (14) is the LNAPL pollutant enrichment zone (3), and the surrounding well wall is filled with quartz sand (15); The aqueous extraction structure includes a water pump (11) and a water pipe (12); the water pipe (12) passes through a three-hole water-blocking device (13) and a two-hole water-blocking device (14), the head of the water pipe (12) is located above a single-hole water-blocking device (16), the middle of the two-hole water-blocking device (14) and the single-hole water-blocking device (16) is a soil aqueous pollution zone (4), and the surrounding well wall is filled with quartz sand (15); The DNAPL phase extraction structure includes a water pump (11) and a water pipe (12); the water pipe (12) passes through a three-hole water-blocking device (13), a double-hole water-blocking device (14) and a single-hole water-blocking device (16), the head of the water pipe (12) is located above the bottom of the main well (1), the single-hole water-blocking device (16) and the bottom of the well are in the DNAPL contaminant enrichment zone (5), and the surrounding well wall is filled with quartz sand (15).

2. The soil groundwater stratified multiphase extraction well structure according to claim 1, characterized in that, The water-blocking device has a perforated stainless steel plate (18) in the middle, and rubber rings (19) around the stainless steel plate (18) and the hole wall. The stainless steel plate (18) is equipped with a stainless steel frame (20) that is inserted into the well wall.

3. The soil groundwater stratified multiphase extraction well structure according to claim 1, characterized in that, The three-hole water-blocking device (13) is located at the junction of bentonite (10) and quartz sand (15) in the main well (1), above the LNAPL pollutant enrichment zone (3).

4. The soil groundwater stratified multiphase extraction well structure according to claim 1, characterized in that, The double-hole water-proof device (14) is located above the soil water phase pollution zone (4) and below the LNAPL pollutant enrichment zone (3), with the surrounding well walls filled with clay (17).

5. The soil groundwater stratified multiphase extraction well structure according to claim 1, characterized in that, The single-hole water-proof device (16) is located in the lower layer of the soil water phase pollution zone (4), above the DNAPL pollutant enrichment zone (5), and the surrounding well wall is filled with clay (17).

Images