Device and method for ex situ separation and repair of light non-aqueous phase liquid in groundwater

Abstract

The present invention provides an ex situ separation and remediation device and method for light non-aqueous phase liquids in groundwater. The device comprises a mobile vehicle, a separation and remediation tank, and a storage tank mounted on the mobile vehicle. The separation and remediation tank comprises a connected flotation tank and an activated sludge tank, both of which are equipped with aeration components. The top of the flotation tank is connected to the storage tank via an oil pipeline. The device also includes an extraction pipe for extracting and lifting groundwater from beneath a contaminated site into the flotation tank, and a reinjection pipe for reinjecting water from the activated sludge tank back into the contaminated site. The present invention provides an ex situ separation and remediation device and method for light non-aqueous phase liquids in groundwater, achieving efficient ex situ separation and remediation of light non-aqueous phase liquids from water.

Description

Technical Field

[0001] The present invention belongs to the technical field of groundwater pollution treatment, and in particular relates to a device and method for ex situ separation and repair of light non-aqueous phase liquid in groundwater. Background Art

[0002] Soil contamination at industrial sites is characterized by diversity and complexity. A wide variety of pollutants exist, and different pollutants enter the soil and groundwater in different forms. For example, poorly water-soluble organic pollutants may form non-aqueous phase liquids (NAPLs) when their concentrations exceed their solubility in the groundwater environment. Light non-aqueous phase liquids (LNAPLs) float on the surface of the groundwater. LNAPL migration is influenced by the direction of groundwater flow, forming a contamination plume downstream of the flow. Currently, liquid phase extraction is a commonly used treatment method for LNAPLs in groundwater. This method simultaneously removes free-phase contaminants, contaminated groundwater, and contaminated soil gas from the site through vacuum action, making it effective for remediating LNAPLs at medium- to high-permeability sites. Direct recovery of free-phase materials is the primary method for removing contaminants at sites using multiphase extraction processes. However, this method often fails to achieve efficient separation of NAPLs and rapid reinjection of treated water, generating large amounts of wastewater and requiring extensive on-site temporary water storage. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a device and method for ex situ separation and repair of light non-aqueous phase liquid in groundwater, so as to achieve efficient ex situ separation and repair of light non-aqueous phase liquid and water.

[0004] To solve the above technical problems, the embodiments of the present invention adopt the following technical solutions:

[0005] In the first aspect, an embodiment of the present invention provides an ex situ separation and remediation device for light non-aqueous phase liquid in groundwater, comprising a mobile body and a separation and remediation tank and a storage tank installed on the mobile body; the separation and remediation tank comprises a connected flotation tank and an activated sludge tank, both of which are provided with aeration components; the top of the flotation tank is connected to the storage tank via an oil pipeline; and further comprises an extraction pipe and a reinjection pipe, the extraction pipe being used to extract and lift groundwater under the contaminated site into the flotation tank, and the reinjection pipe being used to reinject groundwater in the activated sludge tank back into the contaminated site.

[0006] As a further improvement of the embodiment of the present invention, the activated sludge tank is arranged along the circumference of the flotation tank, and the water outlet of the flotation tank is connected to the water inlet of the activated sludge tank; at least one circle of active channel is formed between the water inlet and the water outlet of the activated sludge tank.

[0007] As a further improvement of the embodiment of the present invention, two circles of active channels are formed between the water inlet and the water outlet of the activated sludge tank.

[0008] As a further improvement of the embodiment of the present invention, the flotation tank and the activated sludge tank are connected via a connecting assembly.

[0009] As a further improvement of an embodiment of the present invention, the connecting assembly includes an inner plate and an outer plate, which are vertically and spaced apart at the water outlet of the flotation tank; the inner plate faces the flotation tank, and the outer plate faces the activated sludge tank; the bottom end of the outer plate is connected to the bottom of the flotation tank, and there is a gap between the bottom end of the inner plate and the bottom of the flotation tank to form a connecting water inlet; the inner plate is connected to the top end of the outer plate, and a connecting water outlet is opened on the upper part of the outer plate; a connecting channel connecting the connecting water inlet and the connecting water outlet is formed between the inner plate and the outer plate.

[0010] As a further improvement to the embodiment of the present invention, an inclined mudguard is provided at the connection water inlet.

[0011] As a further improvement of the embodiment of the present invention, the top of the activated sludge tank is connected to the storage tank through an oil pipeline.

[0012] In a second aspect, an embodiment of the present invention further provides a method for ex situ separation and remediation of light non-aqueous phase liquid in groundwater, using the ex situ separation and remediation device for light non-aqueous phase liquid in groundwater provided in the first aspect; the ex situ separation and remediation method for light non-aqueous phase liquid in groundwater comprises:

[0013] Step 10: The light non-aqueous phase liquid ex situ separation and remediation device in groundwater is driven to the contaminated site.

[0014] Step 20: extracting groundwater containing light non-aqueous phase liquid from the contaminated site and lifting it to a flotation tank; aeration is performed in the flotation tank, and the bubbles generated by the aeration act as carriers to adhere to the light non-aqueous phase liquid in the groundwater and carry the light non-aqueous phase liquid to the top of the flotation tank, thereby separating the light non-aqueous phase liquid from water and reducing the concentration of the light non-aqueous phase liquid in the groundwater; the separated light non-aqueous phase liquid flows into the storage tank through the oil pipeline, and the groundwater flows into the activated sludge tank;

[0015] Step 30: aeration is performed in the activated sludge tank to promote the growth of aerobic microorganisms in the activated sludge tank to form activated sludge. The activated sludge adsorbs and decomposes the light non-aqueous phase liquid in the groundwater, further removing the light non-aqueous phase liquid in the groundwater. The groundwater is then repaired ex situ in the activated sludge tank.

[0016] In step 40, the groundwater containing microorganisms in the activated sludge tank is reinjected into the contaminated site, and the groundwater continues to be repaired in situ under the contaminated site.

[0017] As a further improvement to the embodiment of the present invention, in step 20, groundwater is extracted from the heavily polluted plume area under the contaminated site and lifted into the flotation tank; in step 40, the groundwater containing microorganisms in the activated sludge tank is reinjected into the lightly polluted plume area under the contaminated site.

[0018] As a further improvement of the embodiment of the present invention, the groundwater flows into the activated sludge tank, specifically including:

[0019] When the groundwater in the flotation tank enters the connecting water inlet from the bottom of the connecting component, the mud guard blocks the precipitated impurities in the groundwater, preventing the impurities from entering the connecting water inlet; the groundwater entering the connecting channel flows upward, and finally flows into the activated sludge tank from the upper part through the connecting water outlet; the groundwater flowing out of the connecting water outlet impacts the groundwater in the activated sludge tank downward, forming fine water droplets, which is conducive to the separation of light non-aqueous phase liquid.

[0020] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0021] (1) The device and method for ex situ separation and remediation of light non-aqueous phase liquid in groundwater provided by the present invention can quickly reach the pollution site, extract groundwater, perform ex situ separation of light non-aqueous phase liquid and activated sludge remediation on site, and reinject groundwater containing microorganisms. The entire process does not require the transportation of groundwater, and it can be treated on site and then reinjected. The treatment efficiency is high, the structure is simple, no wastewater is generated, and no water storage device is required.

[0022] (2) The present invention provides an ex situ separation and repair device and method for light non-aqueous phase liquid in groundwater, which couples the flotation method with the activated sludge method. After extraction, the flotation method is first used to quickly capture the light non-aqueous phase liquid in the groundwater, greatly reducing the concentration of the light non-aqueous phase liquid in the groundwater, thereby realizing the ex situ separation of the light non-aqueous phase liquid; then the activated sludge method is used to further remove the light non-aqueous phase liquid remaining in the groundwater, thereby realizing the ex situ repair of the groundwater; finally, the groundwater containing microorganisms in the activated sludge pool is reinjected to input microorganisms into the underground of the contaminated site, thereby realizing the in situ repair of the groundwater under the contaminated site.

[0023] (3) The present invention provides an ex situ separation and repair device and method for light non-aqueous phase liquid in groundwater. The activated sludge tank is arranged circumferentially around the flotation tank to form a separation and repair tank. The flotation tank in the middle uses flotation to extract light non-aqueous phase liquid in the groundwater, and the groundwater with greatly reduced light non-aqueous phase liquid concentration is input into the peripheral activated sludge tank. The activated sludge tank uses the activated sludge method to decompose the light non-aqueous phase liquid in the groundwater, further reducing the concentration of light non-aqueous phase liquid in the groundwater, thereby achieving ex situ separation and repair of groundwater in the separation and repair tank.

[0024] (4) The present invention provides an ex situ separation and repair device and method for light non-aqueous phase liquid in groundwater. The activated sludge tank is arranged circumferentially around the flotation tank, and at least one circle of active channels is formed between the water inlet and the water outlet. The flow time of groundwater in the activated sludge tank is prolonged, and the time for the activated sludge to adsorb and decompose the light non-aqueous phase liquid is increased, which can improve the repair effect; at the same time, the volume of the separation and repair tank is reduced, which is convenient for installation on a mobile vehicle.

[0025] (5) The present invention provides an ex situ separation and repair device and method for light non-aqueous phase liquid in groundwater. The flotation tank and the activated sludge tank are connected by a connecting assembly. When the groundwater after the light non-aqueous phase liquid is removed from the flotation tank enters the connecting water inlet from the bottom end of the connecting assembly, the mud guard can block the precipitated impurities in the groundwater, reducing the impurities from entering the connecting water inlet. The groundwater entering the connecting channel flows upward and finally flows into the activated sludge tank from the upper part through the connecting water outlet, impacting the groundwater in the activated sludge tank from top to bottom, forming fine water droplets, which is beneficial to the separation of the light non-aqueous phase liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a device for ex situ separation and remediation of light non-aqueous phase liquid in groundwater according to an embodiment of the present invention;

[0027] Figure 2 for Figure 1 Top view of the separation and repair pool;

[0028] Figure 3 for Figure 1 Cross-sectional view of the separation and repair pool;

[0029] Figure 4 Bit Figure 2 Schematic diagram of the structure of the connected components.

[0030] In the figure: mobile body 1, separation and remediation tank 2, storage tank 3, extraction pipe 4, contaminated site 5, sandy groundwater layer 6, heavily polluted plume area 7, reinjection pump 8, reinjection pipe 9, heavily polluted plume area 10, flotation tank 201, activated sludge tank 202, oil overflow weir 203, connecting assembly 204, first aeration assembly 205, second aeration assembly 206, air pump 207, water outlet 208 of activated sludge tank, inner plate 2041, outer plate 2042, connecting water inlet 2043, connecting water outlet 2044, and mudguard 2045. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is described in detail below.

[0032] The embodiment of the present invention provides a device for separating and repairing light non-aqueous phase liquid in groundwater in situ, such as Figure 1As shown, it includes a mobile body 1 and a separation and repair tank 2 and a storage tank 3 installed on the mobile body 1. Figure 2 and Figure 3 As shown, the separation and remediation tank 2 includes a flotation tank 201 and an activated sludge tank 202, and the flotation tank 201 and the activated sludge tank 202 are connected. A first aeration assembly 205 is provided in the flotation tank 201, and a second aeration assembly 206 is provided in the activated sludge tank 202. The first aeration assembly 205 and the second aeration assembly 206 are both connected to an air pump 207, and the air pump 207 supplies air to the first aeration assembly 205 and the second aeration assembly 206. An oil overflow weir 203 and an oil pipeline are provided at the top of the flotation tank 201. The inlet of the oil pipeline is located outside the oil overflow weir 203, and the outlet of the oil pipeline is connected to the storage tank 3. The ex situ separation and remediation device for light non-aqueous phase liquid in groundwater of this embodiment also includes an extraction pipe 4 and a re-injection pipe 9. The extraction pipe 4 is provided with an extraction pump. The extraction pipe 4 is used to extract groundwater from the contaminated site and lift it into the flotation tank 201. A reinjection pump 8 is provided on the reinjection pipe 9, and the reinjection pipe 9 is used to reinject the groundwater in the activated sludge tank 202 into the contaminated site.

[0033] The working process of the device for ex situ separation and remediation of light non-aqueous phase liquid in groundwater in the above embodiment is as follows:

[0034] Mobile vehicle 1, carrying separation and remediation tank 2 and storage tank 3, travels to contaminated site 5. Groundwater beneath the contaminated site is extracted via extraction pipe 4 by an extraction pump and transported to flotation tank 201. Air pump 207 supplies air to first aeration assembly 205 within the flotation tank, aerating the water within the tank. The bubbles generated by aeration act as carriers, adhering to the light non-aqueous phase liquid in the groundwater and carrying it to the top of the flotation tank. This achieves ex situ separation of the light non-aqueous phase liquid from water, reducing the concentration of the light non-aqueous phase liquid in the groundwater. The light non-aqueous phase liquid that rises to the top of the flotation tank overflows through oil overflow weir 203 into the oil pipeline, and then flows through the pipeline into storage tank 3. The groundwater, after the light non-aqueous phase liquid concentration is reduced in the flotation tank, flows into activated sludge tank 202. Air pump 207 supplies air to second aeration assembly 206 within activated sludge tank 202, aerating the water within the activated sludge tank. The activated sludge tank promotes the growth of aerobic microorganisms, forming activated sludge. The activated sludge absorbs and decomposes light non-aqueous phase liquids in the groundwater, further removing them and achieving ex situ groundwater remediation. The groundwater in the activated sludge tank contains microorganisms, which are then re-injected into the contaminated site via the re-injection pipe by the re-injection pump 8, achieving in situ groundwater remediation.

[0035] The above-mentioned embodiment of the ex situ separation and remediation device for light non-aqueous phase liquid in groundwater can quickly reach the contaminated site and carry out the entire process of groundwater extraction, ex situ separation and remediation of light non-aqueous phase liquid, and reinjection of groundwater containing microorganisms on site. There is no need to transport groundwater, and it can be treated on site and then reinjected. The treatment efficiency is high, the structure is simple, no wastewater is generated, and no water storage device is required. The above-mentioned embodiment couples the flotation method with the activated sludge method. After extraction, the flotation method is first used to quickly capture the light non-aqueous phase liquid in the groundwater, greatly reducing the concentration of the light non-aqueous phase liquid in the groundwater, and achieving ex situ separation of the light non-aqueous phase liquid; then, the activated sludge method is used to further remove the light non-aqueous phase liquid remaining in the groundwater, achieving ex situ remediation of the groundwater; finally, the groundwater containing microorganisms in the activated sludge tank is reinjected, and microorganisms are introduced into the underground of the contaminated site, achieving in situ remediation of the groundwater.

[0036] As a preferred example, Figure 2 and Figure 3 As shown, the activated sludge tank 202 is arranged circumferentially around the flotation tank 201, and the outlet of the flotation tank 201 is connected to the water inlet of the activated sludge tank 202. At least one circle of active channels is formed between the water inlet and the outlet of the activated sludge tank 202. Preferably, two circles of active channels are formed between the water inlet and the outlet of the activated sludge tank. Groundwater flows along the active channels from the water inlet to the water outlet of the activated sludge tank. This arrangement can extend the flow time of groundwater in the activated sludge tank, increase the time for the activated sludge to adsorb and decompose the light non-aqueous phase liquid, and improve the remediation effect; at the same time, it reduces the footprint of the separation and remediation tank, making it easier to set it on a mobile vehicle.

[0037] As a preferred example, the flotation tank 201 and the activated sludge tank 202 are connected via a connecting assembly 204 , and the groundwater in the flotation tank 201 flows into the activated sludge tank 202 through the connecting assembly 204 .

[0038] Preferably, Figure 4 As shown, the connection assembly 204 includes an inner plate 2041 and an outer plate 2042. The inner plate 2041 and the outer plate 2042 are vertically spaced apart at the water outlet of the flotation tank 201. The inner plate 2041 faces the flotation tank 201, while the outer plate 2042 faces the activated sludge tank 202. The bottom end of the outer plate 2042 is connected to the bottom of the flotation tank 201. A gap is formed between the bottom end of the inner plate 2041 and the bottom of the flotation tank 201, forming a connecting water inlet 2043. The inner plate 2041 is connected to the top end of the outer plate 2042. The upper portion of the outer plate 2042 is provided with a connecting water outlet 2044. A connecting channel is formed between the inner plate 2041 and the outer plate 2042, connecting the connecting water inlet 2043 and the connecting water outlet 2044.

[0039] Groundwater in flotation tank 201, after its light non-aqueous phase liquid concentration has been significantly reduced, enters connecting water inlet 2043 from the bottom of the connecting assembly, then flows upward through the connecting channel, finally flowing into the activated sludge tank 202 from the top through connecting water outlet 2044. The connecting assembly is configured so that groundwater in the flotation tank enters the connecting assembly from the bottom, reducing the influx of oil and sludge into the activated sludge tank. Groundwater flows out from the top of the connecting assembly, impacting the groundwater in the activated sludge tank from top to bottom, forming fine water droplets. This facilitates the separation of the light non-aqueous phase liquid and water, facilitating adsorption and decomposition by the activated sludge, and improving the remediation effect.

[0040] Preferably, an inclined mud guard 2045 is provided at the water inlet 2043. When groundwater enters the water inlet 2043 from the bottom of the connecting assembly, the mud guard 2045 can block the precipitated impurities in the groundwater, reducing the impurities from entering the water inlet and entering the activated sludge tank.

[0041] The present invention also provides a method for ex situ separation and repair of light non-aqueous phase liquid in groundwater, which uses the ex situ separation and repair device for light non-aqueous phase liquid in groundwater of the above embodiment. The method comprises:

[0042] Step 10: The light non-aqueous phase liquid ex situ separation and remediation device in groundwater is driven to the contaminated site 5.

[0043] In step 20, groundwater from the contaminated site is extracted and lifted to flotation tank 201. Aeration occurs in the flotation tank, and the bubbles generated by the aeration act as carriers, adhering to the light non-aqueous phase liquid in the groundwater and carrying the light non-aqueous phase liquid to the top of the flotation tank. This separates the light non-aqueous phase liquid from the water, reducing the concentration of the light non-aqueous phase liquid in the groundwater. The separated light non-aqueous phase liquid flows through the oil pipeline into storage tank 3, and the groundwater flows into activated sludge tank 202.

[0044] In step 30, aeration is performed in the activated sludge tank to promote the reproduction of aerobic microorganisms in the activated sludge tank to form activated sludge. The activated sludge adsorbs and decomposes the light non-aqueous phase liquid in the groundwater, further removing the light non-aqueous phase liquid in the groundwater. The groundwater is repaired ex situ in the activated sludge tank.

[0045] In step 40, the groundwater containing microorganisms in the activated sludge tank is reinjected into the contaminated site, and the groundwater continues to be repaired in situ under the contaminated site.

[0046] As a preferred example, in step 20, groundwater is extracted from the heavily polluted plume area under the contaminated site and lifted into the flotation tank 201. In step 40, the groundwater containing microorganisms in the activated sludge tank is reinjected into the lightly polluted plume area under the contaminated site.

[0047] Based on preliminary site investigations, the heavily contaminated plume and lightly contaminated plume areas of the contaminated site were identified. Groundwater was extracted from the heavily contaminated plume area, treated in flotation tanks and dosing tanks, and then reinjected into the lightly contaminated plume area. This groundwater flowed from the lightly contaminated plume area to the heavily contaminated plume area, achieving groundwater circulation. After groundwater was extracted from the heavily contaminated plume area, the water pressure in the heavily contaminated plume area decreased, allowing groundwater from the lightly contaminated plume area to flow toward the heavily contaminated plume area. As groundwater flowed from the lightly contaminated plume area to the heavily contaminated plume area, it carried away contaminants, achieving remediation of the heavily contaminated plume area. Injecting treated groundwater into the lightly contaminated plume area not only remediates the lightly contaminated plume area in situ, but also increases the water pressure there, facilitating the flow of groundwater from the lightly contaminated plume area to the heavily contaminated plume area. Microbial agents also traveled along with the water flow to the heavily contaminated plume area, achieving both physical remediation of the heavily contaminated plume area and in-situ microbial remediation, mitigating potential contamination risks.

[0048] Preferably, the extraction and treatment of groundwater and its reinjection are carried out simultaneously. The groundwater in the heavily polluted plume area is treated, and the treated groundwater containing microorganisms is reinjected into the lightly polluted plume area. There is no need to transport the separated water for special treatment, which reduces the transportation cost and realizes in-situ remediation of the contaminated site. The overall process is efficient and low-carbon.

[0049] As a preferred example, when the groundwater after the concentration of the light non-aqueous phase liquid in the flotation tank is reduced enters the connecting water inlet from the bottom of the connecting component, the mud baffle blocks the precipitated impurities in the groundwater, reducing the impurities entering the connecting water inlet; the groundwater entering the connecting channel flows upward, and finally flows into the activated sludge tank from the upper part of the activated sludge tank through the connecting water outlet; the groundwater flowing out of the connecting water outlet impacts the groundwater in the activated sludge tank downward, forming fine water droplets, which is conducive to the separation of the light non-aqueous phase liquid.

[0050] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are only intended to further illustrate the principles of the present invention. Various changes and improvements are possible without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the invention as claimed.

Claims

1. A device for separating and repairing light non-aqueous phase liquid in groundwater in situ, characterized in that: The invention comprises a mobile vehicle (1) and a separation and remediation tank (2) and a storage tank (3) installed on the mobile vehicle (1); the separation and remediation tank (2) comprises a connected flotation tank (201) and an activated sludge tank (202), and both the flotation tank (201) and the activated sludge tank (202) are provided with an aeration assembly; the top of the flotation tank (201) is connected to the storage tank (3) through an oil pipeline; the activated sludge tank (202) further removes the residual light non-aqueous phase liquid in the groundwater through an activated sludge method to obtain groundwater containing microorganisms; and further comprises an extraction pipe (4) and a reinjection pipe (9), the extraction pipe (4) being used to extract and lift groundwater from a heavily contaminated plume area under a contaminated site into the flotation tank (201), and the reinjection pipe (9) being used to reinject the groundwater containing microorganisms in the activated sludge tank (202) into a lightly contaminated plume area under the contaminated site, thereby inputting microorganisms into the contaminated site and realizing in-situ remediation of groundwater; The extraction and treatment of groundwater are carried out simultaneously with its reinjection. The groundwater in the heavily contaminated plume area is treated, and the treated groundwater containing microorganisms is reinjected into the lightly contaminated plume area. The groundwater in the lightly contaminated plume area flows towards the heavily contaminated plume area, thus achieving groundwater circulation. When the treated groundwater is injected into the lightly contaminated plume area, on the one hand, the lightly contaminated plume area is repaired in situ, and on the other hand, the water pressure in the lightly contaminated plume area is increased, making it easier for the groundwater in the lightly contaminated plume area to flow towards the heavily contaminated plume area. Microbial agents also reach the heavily contaminated plume area along with the water flow, thus achieving both physical remediation of the heavily contaminated plume area by extraction and in situ remediation of microorganisms, thereby reducing the risk of potential pollution. The device does not generate wastewater and does not require a water storage device. The activated sludge tank (202) is arranged along the circumference of the flotation tank (201), and the water outlet of the flotation tank (201) is connected to the water inlet of the activated sludge tank (202); at least one circle of active channels is formed between the water inlet and the water outlet of the activated sludge tank (202); The flotation tank (201) and the activated sludge tank (202) are connected via a connecting assembly (204); the connecting assembly (204) comprises an inner plate (2041) and an outer plate (2042); the inner plate (2041) and the outer plate (2042) are arranged vertically and spaced apart at the water outlet of the flotation tank (201); the inner plate (2041) faces the flotation tank (201), and the outer plate (2042) faces the activated sludge tank (202); the bottom end of the outer plate (2042) is connected to the bottom of the flotation tank, and the inner plate (2041) and the outer plate (2042) are connected to the bottom of the flotation tank. There is a gap between the bottom end of the side plate (2041) and the bottom of the flotation tank, forming a connecting water inlet (2043); the inner side plate (2041) is connected to the top end of the outer side plate (2042), and a connecting water outlet (2044) is provided on the upper portion of the outer side plate (2042); a connecting channel connecting the connecting water inlet (2043) and the connecting water outlet (2044) is formed between the inner side plate (2041) and the outer side plate (2042); and a mudguard (2045) arranged obliquely is provided at the connecting water inlet (2043).

2. The device for ex situ separation and repair of light non-aqueous phase liquid in groundwater according to claim 1, characterized in that: Two circles of active channels are formed between the water inlet and outlet of the activated sludge tank.

3. The device for ex situ separation and repair of light non-aqueous phase liquid in groundwater according to claim 1, characterized in that: The top of the activated sludge tank (202) is connected to the storage tank (3) through an oil pipeline.

4. A method for ex situ separation and remediation of light non-aqueous phase liquid in groundwater, characterized in that: The device for ex situ separation and remediation of light non-aqueous phase liquid in groundwater according to any one of claims 1 to 3 is used; The method for ex situ separation and remediation of light non-aqueous phase liquid in groundwater comprises: Step 10: The ex situ separation and remediation device for light non-aqueous phase liquid in groundwater is driven to the contaminated site; Step 20, extracting groundwater containing light non-aqueous phase liquid from the contaminated site and lifting it to the flotation tank (201); aeration is performed in the flotation tank, and the bubbles generated by aeration act as carriers to adhere to the light non-aqueous phase liquid in the groundwater and carry the light non-aqueous phase liquid to the top of the flotation tank, thereby separating the light non-aqueous phase liquid from water and reducing the concentration of the light non-aqueous phase liquid in the groundwater; the separated light non-aqueous phase liquid flows into the storage tank (3) through the oil pipeline, and the groundwater flows into the activated sludge tank (202); Step 30, aeration is performed in the activated sludge tank (202) to promote the growth of aerobic microorganisms in the activated sludge tank to form activated sludge, the activated sludge adsorbs and decomposes the light non-aqueous phase liquid in the groundwater, further removes the light non-aqueous phase liquid in the groundwater, and the groundwater is ex situ repaired in the activated sludge tank to obtain groundwater containing microorganisms; Step 40: injecting the groundwater containing microorganisms in the activated sludge tank back into the contaminated site to introduce microorganisms into the contaminated site, and the groundwater continues to be remediated in situ. The groundwater flows into the activated sludge tank (202), which specifically includes: When the groundwater in the flotation tank (201) enters the connecting water inlet (2043) from the bottom end of the connecting assembly (204), the fender (2045) blocks the precipitated impurities in the groundwater, preventing the impurities from entering the connecting water inlet (2043); the groundwater entering the connecting channel flows upward, and finally flows into the activated sludge tank (202) from the upper part of the activated sludge tank (202) through the connecting water outlet (2044); the groundwater flowing out of the connecting water outlet (2044) impacts the groundwater in the activated sludge tank downward, forming fine water droplets, which is conducive to the separation of the light non-aqueous phase liquid; In step 20, groundwater is extracted from the heavily polluted plume area under the contaminated site and lifted into the flotation tank (201); in step 40, the groundwater containing microorganisms in the activated sludge tank is reinjected into the lightly polluted plume area under the contaminated site.

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