CN115724498B

CN115724498B - Underground pollution restoration device and method

Info

Publication number: CN115724498B
Application number: CN202211495937.1A
Authority: CN
Inventors: 周睿; 陈韶音; 任何军; 蒲生彦; 梁恒瑜; 赵星霖
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2022-11-25
Filing date: 2022-11-25
Publication date: 2024-03-19
Anticipated expiration: 2042-11-25
Also published as: CN115724498A

Abstract

The invention relates to an underground pollution restoration device and method. The remediation device comprises at least a circulation well unit, a jet well unit and a control unit. The circulating well unit enables the underground water to form circulating water flow which circulates in and out of the circulating well around the circulating well under the action of hydraulic circulation. The jet well unit generates a jet of water flowing toward the circulating water inflow well location. Preferably, the circulating water flow and the water jet flow are provided with at least two flow patterns, respectively. The control unit adjusts working parameters of the circulating well unit and the injection well unit based on the identification and judgment of the groundwater pollutants so as to change the flowing mode of circulating water flow and injection water flow, thereby enabling the circulating water flow and the injection water flow to construct a three-dimensional flow field in the underground aquifer and promoting the migration of the pollutants in the underground aquifer.

Description

Underground pollution restoration device and method

Technical Field

The invention relates to the technical field of underground water field pollution remediation, in particular to an underground pollution remediation device and method.

Background

In recent years, circulating well technology (Groundwater Circulation Well, GCW) has been used in many polluted site repair engineering projects abroad as an in-situ groundwater pollution repair technology. The technology relies on a specially designed screen structure, water flow is pumped and injected into the underground environment through the action of a mechanical pump, a water level difference is formed inside and outside the well, and pollutants in an underground aquifer are captured into the well to realize removal. The well circulation technology has the recognized advantages that the well circulation technology has small influence on the fluctuation of the whole underground water level of the area, can be coupled with various technologies such as multiphase extraction, well aeration, chemical oxidation reduction, microorganism restoration and the like while realizing hydrodynamic circulation, and has good application prospect.

For example, CN111646577a discloses a circulation well system for treating VOCs and DNAPLs in contaminated groundwater. The technical scheme of the patent is as follows: an upper section of water permeable sieve pore and a lower section of water permeable sieve pore are arranged on the circulating well pipe, the upper section of water permeable sieve pore is a water outlet, the water outlet corresponds to the groundwater level, the lower section of water permeable sieve pore is a water inlet, and the water inlet corresponds to the lower boundary of the groundwater pollution area; an air injection pipe is arranged in the circulating well pipe, and the lower end of the air injection pipe extends to the position of a water permeable sieve pore at the lower section; a gas phase extraction pipe is arranged in the circulating well pipe and is used for extracting VOCs-containing gas which escapes from rising bubbles in the underground water; and a medicine injection pipe is arranged in the filter material outside the screen pipe at the upper part of the circulating well pipe, and the bottom of the medicine injection pipe is close to the bottom of the upper section of permeable screen hole. The microbial agent in the drug injection pipe is uniformly dispersed in the groundwater environment under the effect of the circulating water at the water outlet, so that the situation that the screen pipe of the circulating well is blocked and then scrapped as a multifunctional circulating well unit is avoided. And a wedge-shaped collector is arranged at the bottom of the water inlet screen pipe of the circulating well to collect DNAPLs in the underground water.

Patent publication number CN110482737a discloses a circulation well remediation system for groundwater organic pollutants, comprising: a circulation well unit comprising a circulation well pipe, a water pumping pipe and an injection pipe, wherein the circulation well pipe is provided with an upper screen pipe section and a lower screen pipe section, so that the inside of the circulation well pipe is communicated with the outside of the pipe in a filtering manner, and water separation and separation are carried out between the upper screen pipe section and the lower screen pipe section by a sealer; one of the water suction pipe and the injection pipe extends to a position above the sealer in the circulating well pipe; another one passes through the sealer downwards and extends to a position below the sealer in the circulating well pipe; a submersible pump is arranged in the pumping pipe; the stripping unit comprises a stripping tower, the stripping tower is connected with the water pumping pipe and can carry out stripping treatment on the groundwater pumped out from the water pumping pipe; the gas distribution injection unit comprises a gas distribution water collecting tank and an injection pump, and is used for injecting the oxidant and/or the bio-enhancement agent into the circulating well pipe through the injection pipe after the oxidant and/or the bio-enhancement agent are added.

The patent with publication number CN115180714A discloses a circulating well repairing system for treating organic matters in polluted underground water, which comprises a circulating well arranged in a circulating well drill hole, wherein an aeration unit, a gas stripping unit, a water pumping unit and an oxidation module are arranged in the circulating well, and the oxidation module is an oxidation column or an oxidant fixed at the bottom of the circulating well; the aeration unit comprises an aeration pipe penetrating into the bottom of the circulating well and an air pump connected with the aeration pipe and is used for increasing the DO content of underground water and the air flow intensity in the circulating well; the pumping unit comprises a submersible pump penetrating into the bottom of the circulating well and a pumping main pipe connected with the submersible pump, wherein the other end of the pumping main pipe is connected with the sewage treatment tank and used for realizing underground water circulation and well pipe internal circulation.

The existing circulating well technology for repairing the polluted site at least has the following defects: the existing circulating well has a single working mode, cannot judge the types and the positions of pollutants, and particularly has the problems that when underground water polluted by organic pollutants is restored in situ, the existing circulating well technology is difficult to act on the top or the bottom of an underground aquifer, so that the pollutants concentrated on the top or the bottom of the underground aquifer are easy to permeate into micro pores of soil to form a long-term pollution source, a tailing effect is generated, the concentration of the pollutants is rebound after a period of restoration, and the restoration period is prolonged.

Furthermore, there are differences in one aspect due to understanding to those skilled in the art; on the other hand, since the applicant has studied a lot of documents and patents while making the present invention, the text is not limited to details and contents of all but it is by no means the present invention does not have these prior art features, but the present invention has all the prior art features, and the applicant remains in the background art to which the right of the related prior art is added.

Disclosure of Invention

Groundwater has become a major component of water resources in China, but due to the aggravation of industrial production activities, a large amount of organic products, such as petroleum and products thereof, enter the underground environment during use, so that the groundwater is more and more severely polluted, and typical organic environmental pollutants which are insoluble in water are often called Non-aqueous phase fluids (Non-Aqueous Phases Liquids, NAPLs) which can be classified into Light Non-aqueous phase fluids (Light Non-Aqueous Phases Liquids, LNAPLs) and heavy Non-aqueous phase fluids (density Non-Aqueous Phases Liquids, DNAPLs) according to the relative density with water. In the existing polluted site groundwater remediation technology, the extraction-treatment technology is most widely applied, but the required remediation period is longer, some sites with serious pollution can be required to replace pore water for hundreds of times to achieve the remediation goal, and the process can be required for decades; the technology can preferentially remove pollutants in the stratum with better permeability, and the tailing phenomenon easily occurs in the low-permeability stratum repairing process, so that the repairing period is obviously prolonged, the repairing effect on the thicker pollutants of NAPLs is poorer, and the repairing period is longer. At the same time, the high volume of water extraction may also cause a series of environmental problems such as subsidence of the ground, subsidence, damage to the formation structure, etc. Therefore, aiming at the hydrogeological conditions of different underground aquifers, the restoration capability of NAPLs pollutants in the underground water is improved, the restoration period is shortened, and the method is an important problem to be solved in the field of in-situ restoration of the underground water pollution.

Aiming at the defects of the prior art, the invention provides a downhole pollution repair device. The remediation device at least comprises a circulation well unit, an injection well unit and a control unit. The circulating well unit enables underground water to form circulating water flow which circulates in and out of the circulating well around the circulating well under the action of hydraulic circulation. The injection well unit produces an injection water stream flowing toward the circulating water inflow well location. Preferably, the circulating water flow and the water jet flow are provided with at least two flow patterns, respectively. The control unit adjusts working parameters of the circulating well unit and the injection well unit based on the identification and judgment of the groundwater pollutants so as to change the flowing modes of the circulating water flow and the injection water flow, thereby enabling the circulating water flow and the injection water flow to construct a three-dimensional flow field in the underground aquifer and promoting the migration of the pollutants in the underground aquifer.

Preferably, the control unit provided by the invention switches the flow modes of the circulating water flow and the jet water flow according to the pollution condition of the underground aquifer, so as to realize directional removal and synchronous removal of pollutants enriched at the top and the bottom of the underground aquifer in a pollution site.

The invention enhances the hydrodynamic action of the ground water of the NAPLs polluted site by utilizing the combination of the circulating water flow and the jet water flow, forms a flow field in the horizontal direction at the top and the bottom of the underground aquifer, accelerates the migration of the free phase NAPLs along with the water flow, is beneficial to the analysis and diffusion of the residual phase NALs adhered at the top and the bottom of the underground aquifer into the ground water, improves the migration capacity of NAPLs pollutants to the pumping end of the circulating well, shortens the time of pumping NAPLs from the underground aquifer, and improves the removal rate of NAPLs; the control unit monitors the pollutant concentration value and the type of NAPLs in real time, and the control unit automatically switches the working mode according to the monitored pollutant information, changes the flowing mode of the circulating water flow and the jet water flow, and realizes the directional removal and the synchronous removal of NAPLs in the polluted site.

The invention combines the circulating well unit and the injection well unit to form a circulating well restoration system with wider application range, larger restoration range and higher restoration efficiency, thereby achieving the aim of restoring the groundwater which is suitable for treating different NAPLs polluted sites.

According to a preferred embodiment, the bottom of the circulation well unit and the bottom of the injection well unit are plugged and the internal space of the circulation well unit and the injection well unit is divided into two well sections which are not communicated with each other by water flow through a packer. The circulating well unit is provided with two screen sections, and two screen sections are respectively arranged on the two well sections. The injection well unit is provided with screen sections at a level with both screen sections. Preferably, two of said screen sections provided on said circulation well unit are configured to form a reversible flow of circulating water. Preferably, two of said screen sections provided on said injection well unit are used to form an injection water flow to said circulation well unit.

Preferably, the bottoms of the circulating well unit and the injection well unit are plugged, and the internal space of the circulating well unit and the injection well unit is divided into two well sections with water flows which are not communicated with each other through a packer, so that the phenomenon that the flushing effect on an underground aquifer is reduced due to the fact that circulating water flows or injection water flows in the well is avoided.

Preferably, the circulating water flow repeatedly flushes the underground aquifer, so that the vertical flushing capability of the low-permeability stratum is enhanced, NAPLs in the low-permeability stratum are facilitated to diffuse out, and the tailing problem in the in-situ remediation process of the NAPLs polluted low-permeability underground aquifer can be effectively solved; the jet of water promotes the resolution and flow of NAPLs at the top and bottom of the subsurface aquifer, accelerating NAPLs migration, shortening the time for extracting NAPLs from the subsurface aquifer, and increasing the removal rate of NAPLs.

According to a preferred embodiment, the screen section is formed by a plurality of through holes provided in the wall of the well. The circulating well unit and the injection well unit are provided with water pipes at positions corresponding to the screen sections in the well. One end of the water pipe is arranged near the screen section, and the other end of the water pipe is connected to the ground surface. The water pipe is provided with a water pump which changes the working mode in response to the regulation and control of the control unit, and the control unit changes the flow modes of the circulating water flow and the jet water flow through the water pump.

Preferably, the control unit changes the flowing modes of the circulating water flow and the jet water flow through the water pump, so that the directional removal and synchronous removal of pollutants enriched at the top and the bottom of an underground aquifer in a polluted site are realized, and the pollutant trapping dead zone is eliminated.

According to a preferred embodiment, a detection device for detecting groundwater contaminants is provided in the circulation well unit. Preferably, the detection apparatus comprises at least a first detector for detecting a contaminant at the top of the subterranean aquifer and a second detector for detecting a contaminant at the bottom of the subterranean aquifer. The control unit is provided with at least a first mode of operation for the circulation well unit and the injection well unit to treat top contaminants of the underground aquifer and a second mode of operation for the circulation well unit and the injection well unit to treat bottom contaminants of the underground aquifer. The control unit adjusts the working mode of the control unit according to the data of the first detector and the second detector.

Preferably, the control unit may set corresponding modes of operation for different pollution conditions of the underground aquifer. After the control unit acquires the pollution condition of the underground aquifer through the detection equipment, the control unit operates in a corresponding working mode, so that the directional removal of different pollutants in a polluted site is realized.

According to a preferred embodiment, the circulation well unit divides its interior space into a first well section and a second well section by a first packer. The two screen sections disposed on the circulation well unit include a first screen section disposed on the first well section and a second screen section disposed on the second well section. The water pipes of the circulation well unit arranged in the well comprise a first water pipe with the tail end arranged near the first screen section and a second water pipe with the tail end arranged near the second screen section. Preferably, the second water pipe passes through the first packer, and the first water pipe and the second water pipe are connected to a separation device located at the surface while being connected to the water tank. The first water pipe or the second water pipe is provided with a valve on a pipe fitting connected with the water tank and the separating device.

Preferably, the highest position of the first screen section is below the steady water level of the underground aquifer and the lowest position of the second screen section is flush with the bottom of the underground aquifer. When the circulating water flow flushes the underground aquifer, the circulating flow field generated by the circulating well unit can be positioned in the aquifer, so that the trapping range of NAPLs in the aquifer is enlarged, and the removal rate of NAPLs is improved.

According to a preferred embodiment, the injection well unit divides its interior space into a third well section and a fourth well section by means of a second packer. The two screen sections disposed on the injection well unit include a third screen section disposed on the third well section and the fourth screen section disposed on the fourth well section. The water pipe arranged in the well of the injection well unit comprises a third water pipe with the tail end arranged near the third screen section and a fourth water pipe with the tail end arranged near the fourth screen section. Preferably, the fourth water pipe passes through the second packer, and the third water pipe and the fourth water pipe are connected with the water tank and the medicine tank at the surface. Preferably, two water pumps are arranged between the water tank and the injection well unit, and the medicine tank is connected between the two water pumps through a pipeline with a valve. Preferably, the water in the water tank flows to the third water pipe and the fourth water pipe provided with valves via the two water pumps.

Preferably, the third screen section and the fourth screen section respectively correspond to the first screen section and the second screen section, when circulating water flow enters the circulating well unit from the first screen section or the second screen section, the third screen section and the fourth screen section generate water jet flow along the well entering direction of the circulating water flow, so that the hydrodynamic effect of groundwater in the area near the first screen section or the second screen section is enhanced, the top or the bottom of an underground water layer is flushed, and NAPs enriched at the top or the bottom of the underground water layer are promoted to be resolved and diffused into the underground water, and NAPs migration is accelerated.

Preferably, the surfactant and/or the repairing agent stored in the medicine tank is/are conveyed to the position of the pollution plume in the underground aquifer through the third water pipe and the fourth water pipe, so that the removing efficiency of the repairing device on the NAPLs is improved.

According to a preferred embodiment, the valve is electrically connected with the control unit, and the control unit controls the opening and closing of the valve to regulate the flow passage of each water pipe.

Preferably, the control unit controls the opening and closing of the valve to regulate the flow passage of each water pipe, and the control unit controls the water pump connected with each water pipe, so that the repairing device generates circulating water flow and water jet flow for directionally removing pollutants enriched at the top or bottom of the underground aquifer.

According to a preferred embodiment, the separation device treats the groundwater extracted by the injection well unit and containing contaminants, separating the contaminants from the groundwater. Preferably, the separating device conveys the separated pollutants to a pollutant collecting tank for storage, and conveys the separated groundwater to a water treatment system for treatment.

Preferably, water which is treated by the water treatment system and reaches relevant standards can be injected into the underground water-bearing layer again through the circulating well, so that the problems of ground collapse, stratum structure damage and the like are avoided.

The invention also provides a system for repairing the underground pollution. The downhole contamination remediation system includes at least a circulation well unit, a jet well unit, and a control unit. The circulating well unit enables underground water to form circulating water flow which circulates in and out of the circulating well around the circulating well under the action of hydraulic circulation. The injection well unit produces an injection water stream flowing toward the circulating water inflow well location. Preferably, the circulating water flow and the water jet flow are provided with at least two flow patterns, respectively. The control unit adjusts working parameters of the circulating well unit and the injection well unit based on the identification and judgment of the groundwater pollutants so as to change the flowing modes of the circulating water flow and the injection water flow, thereby enabling the circulating water flow and the injection water flow to construct a three-dimensional flow field in the underground aquifer and promoting the migration of the pollutants in the underground aquifer.

The invention also provides a method for repairing the underground pollution. The downhole pollution remediation method at least comprises the following steps:

arranging a circulating well unit and a jet well unit in an underground aquifer;

forming a circulating water flow circulating in and out of the circulating well around the circulating well by using the circulating well unit;

A jet water stream flowing toward the circulating water inflow well location is generated with the jet well unit.

Preferably, the circulating water flow and the injection water flow are provided with at least two flow patterns, respectively, the circulating well unit and the injection well unit being regulated by the control unit.

Preferably, the control unit adjusts working parameters of the circulating well unit and the injection well unit based on identification and judgment of groundwater pollutants so as to change flow modes of the circulating water flow and the injection water flow, so that the circulating water flow and the injection water flow construct a three-dimensional flow field in an underground aquifer, and migration of pollutants in the underground aquifer is promoted.

Drawings

Fig. 1 is a simplified schematic diagram of a module connection relationship of a repair device according to a preferred embodiment of the present invention.

List of reference numerals

100: a prosthetic device; 101: a first detector; 102: a second detector; 110: a circulation well unit; 111: a first wellbore section; 112: a second well section; 113: a first screen section; 114: a second screen section; 115: a first water pipe; 116: a second water pipe; 117: a first packer; 118: a fifth water pipe; 119: a precipitation tank; 120: a jet well unit; 121: a third wellbore section; 122: a fourth wellbore section; 123: a third screen section; 124: a fourth screen section; 125: a third water pipe; 126: a fourth water pipe; 127: a second packer; 130: a control unit; 131: a water tank; 132: a medicine box; 133: a separation device; 134: a contaminant collection tank; 135: a water treatment system; 141: a first water pump; 142: a second water pump; 143: a third water pump; 144: a fourth water pump; 145: a fifth water pump; 151: a first valve; 152: a second valve; 153: a third valve; 154: a fourth valve; 155: a fifth valve; 156: a sixth valve; 157: a seventh valve;

Detailed Description

The following is a detailed description with reference to fig. 1.

Example 1

The present embodiment provides a downhole contamination remediation device 100. Referring to fig. 1, the prosthetic device 100 preferably includes at least a circulation well unit 110, a jet well unit 120, and a control unit 130. The circulation well unit 110 forms groundwater into circulation water flow circulating in and out of the circulation well around the circulation well under the action of hydraulic circulation. The jet well unit 120 generates a jet of water flowing toward the circulating water inflow well location. Preferably, the circulating water flow and the water jet flow are provided with at least two flow patterns, respectively. The control unit 130 adjusts the operation parameters of the circulation well unit 110 and the injection well unit 120 based on the recognition and judgment of the groundwater pollutants to change the flow modes of the circulation water flow and the injection water flow, thereby constructing a stereoscopic flow field in the underground aquifer by the circulation water flow and the injection water flow, and promoting the migration of the pollutants in the underground aquifer.

Preferably, the bottoms of the circulation well unit 110 and the injection well unit 120 are plugged and the internal space thereof is divided into two well sections which are not communicated with each other by a packer. The circulation well unit 110 is provided with two screen sections, which are provided on the two well sections, respectively. The injection well unit 120 is provided with screen sections at a level with both screen sections. Preferably, two screen sections are provided on the circulation well unit 110 to form a reversible flow of circulating water. Preferably, two screen sections provided on the injection well unit 120 are used to form an injection water stream to the circulation well unit 110.

Preferably, the screen sections of circulation well unit 110 are circumferentially disposed and the screen sections of injection well unit 120 are disposed on a side adjacent to circulation well unit 110.

Preferably, the screen section is formed by a plurality of through holes provided in the wall of the well. Circulation well unit 110 and injection well unit 120 are provided with water pipes at locations within the well corresponding to the screen sections. One end of the water pipe is arranged near the screen section, and the other end of the water pipe is connected to the ground surface. The water pipe is provided with a water pump that changes an operation mode in response to the regulation of the control unit 130, and the control unit 130 changes a flow mode of the circulating water flow and the injected water flow by the water pump.

Preferably, a detection device for detecting groundwater contaminants is provided in the circulation well unit 110. Preferably, the detection apparatus comprises at least a first detector 101 for detecting a contaminant at the top of the underground aquifer and a second detector 102 for detecting a contaminant at the bottom of the underground aquifer. The control unit 130 is provided with at least a first mode of operation for the circulation well unit 110 and the injection well unit 120 to treat the top contamination of the underground aquifer and a second mode of operation for the circulation well unit 110 and the injection well unit 120 to treat the bottom contamination of the underground aquifer. The control unit 130 adjusts the operation mode of the control unit 130 according to the data of the first detector 101 and the second detector 102.

Preferably, the circulation well unit 110 divides its interior space into a first well section 111 and a second well section 112 by a first packer 117. The two screen sections provided on circulation well unit 110 include a first screen section 113 provided on first well section 111 and a second screen section 114 provided on second well section 112. The water pipes disposed in the well of the circulation well unit 110 include a first water pipe 115 disposed end-on near the first screen section 113 and a second water pipe 116 disposed end-on near the second screen section 114. Preferably, the second water pipe 116 passes through a first packer 117. Preferably, the second water pipe 116 passes through the first packer 117, and the first and second water pipes 115 and 116 are connected to a separation device 133 located at the surface while being connected to a water tank 131. The first water pipe 115 or the second water pipe 116 is provided with a valve on a pipe member connected to the water tank 131 and the separating apparatus 133.

Preferably, injection well unit 120 has its interior space divided into a third well section 121 and a fourth well section 122 by a second packer 127. The two screen sections provided on injection well unit 120 include a third screen section 123 provided on third well section 121 and a fourth screen section 124 provided on fourth well section 122. The water pipes provided in the well by injection well unit 120 include a third water pipe 125 ending near third screen section 123 and a fourth water pipe 126 ending near fourth screen section 124. Preferably, the fourth water pipe 126 passes through the second packer 127, and the third and fourth water pipes 125 and 126 are connected to a tank 131 and a medicine tank 132 at the surface. Preferably, two water pumps are provided between the water tank 131 and the injection well unit 120, and the medicine tank 132 is connected between the two water pumps through a valved pipe. Preferably, the water in the water tank 131 flows to the third water pipe 125 and the fourth water pipe 126 provided with valves via two water pumps.

Preferably, the valve is electrically connected with the control unit 130, and the control unit 130 controls the opening and closing of the valve to regulate the flow passage of each water pipe.

Preferably, the separation device 133 processes the groundwater containing contaminants extracted by the injection well unit 120 to separate the contaminants from the groundwater. Preferably, the separation device 133 delivers the separated contaminants to the contaminant collection tank 134 for storage and delivers the separated groundwater to the water treatment system 135 for treatment.

Preferably, the first water pipe 115 is connected to the water tank 131 through the first valve 151, and the first water pipe 115 is connected to the separating apparatus 133 through the second valve 152. The second water pipe 116 is connected to the water tank 131 through the third valve 153, and the second water pipe 116 is connected to the separating apparatus 133 through the fourth valve 154.

Preferably, the water tank 131 is connected to the first water pump 141 and then connected to the second water pump 142. The second water pump 142 is connected to the third water pipe 125 through a fifth valve 155, and the second water pump 142 is connected to the fourth water pipe 126 through a sixth valve 156.

Preferably, the medicine tank 132 is connected between the first water pump 141 and the second water pump 142 through a seventh valve 157.

Preferably, the third water pump 143 is disposed on the first water pipe 115, and the fourth water pump 144 is disposed on the second water pipe 116.

Preferably, the separating apparatus 133 is connected to the fifth water pipe 118 by a fifth water pump 145. The end of the fifth water pipe 118 extends through the first packer 117 to the centre of a settling tank 119 arranged below the second well section 112.

Preferably, the highest position of the first screen section 113 is below the steady water level of the subterranean aquifer and the lowest position of the second screen section 114 is flush with the bottom of the subterranean aquifer.

Preferably, the precipitation tank 119 is disposed below the bottom of the subterranean aquifer. Preferably, the interior of the precipitation tank 119 is conical. Preferably, the injection well unit 120 is disposed around the circulation well unit 110. Preferably, at least two sets of injection well units 120 are equally spaced around circulation well unit 110. Preferably, the first detector 101 is positioned at a level at the top of the subsurface aquifer. Preferably, the second detector 102 is disposed at a central position inside the settling tank 119.

Preferably, when the control unit 130 is in the first operation mode for the circulation well unit 110 and the injection well unit 120 to treat the top pollutant of the underground aquifer, the control unit 130 closes the first valve 151, the fourth valve 154, the sixth valve 156, opens the second valve 152, the third valve 153, the fifth valve 155, opens the first water pump 141 and the second water pump 142, closes the fifth water pump 145, adjusts the third water pump 143 to a pumping state, and adjusts the fourth water pump 144 to a water filling state.

Preferably, the first water pump 141 and the second water pump 142 are water injection pumps for injecting water into the well, the fifth water pump 145 is a water pump for pumping water from the well, and the third water pump 143 and the fourth water pump 144 are water injection pumps.

Preferably, in the first mode, the control unit 130 causes the circulating water stream to flow from bottom to top, the jet water stream to flow at the top of the subterranean aquifer, and the contaminants are withdrawn from the top of the subterranean aquifer by the first water tube 115.

Preferably, when the control unit 130 is in the second operation mode for the circulation well unit 110 and the injection well unit 120 to treat the bottom pollutant of the underground aquifer, the control unit 130 opens the first valve 151, the fourth valve 154, the sixth valve 156, closes the second valve 152, the third valve 153, the fifth valve 155, opens the first water pump 141, the second water pump 142, the fifth water pump 145, adjusts the third water pump 143 to the water filling state, and adjusts the fourth water pump 144 to the water pumping state.

Preferably, in the first mode, the control unit 130 causes the circulating water flow to flow from top to bottom, the jet water flow to flow at the bottom of the subterranean aquifer, and contaminants are drawn from the bottom of the subterranean aquifer by the second water tube 116 and the fifth water tube 118.

Preferably, the control unit 130 provided by the invention switches the flow modes of the circulating water flow and the jet water flow according to the pollution condition of the underground aquifer, so as to realize directional removal and synchronous removal of pollutants enriched at the top and the bottom of the underground aquifer in the polluted site.

The invention enhances the hydrodynamic action of the ground water of the NAPLs polluted site by utilizing the combination of the circulating water flow and the jet water flow, forms a flow field in the horizontal direction at the top and the bottom of the underground aquifer, accelerates the migration of the free phase NAPLs along with the water flow, is beneficial to the analysis and diffusion of the residual phase NALs adhered at the top and the bottom of the underground aquifer into the ground water, improves the migration capacity of NAPLs pollutants to the pumping end of the circulating well, shortens the time of pumping NAPLs from the underground aquifer, and improves the removal rate of NAPLs; the control unit 130 monitors the concentration value of the pollutant and the type of the NAPLs in real time, and the control unit 130 automatically switches the working mode according to the monitored pollutant information, and changes the flow modes of the circulating water flow and the jet water flow, so that the NAPLs in the polluted site are removed in a directional manner and synchronously removed.

The invention combines the circulating well unit 110 and the injection well unit 120 to form a circulating well repairing system with wider application range, larger repairing range and higher repairing efficiency, thereby achieving the aim of repairing the groundwater suitable for treating different NAPLs polluted sites.

Preferably, the bottoms of the circulation well unit 110 and the injection well unit 120 are plugged and the inner space of the circulation well unit and the injection well unit is divided into two well sections which are not communicated with each other by a packer, so that the flushing effect of the circulating water flow or the injection water flow on the underground aquifer is prevented from being reduced due to the flowing in the well.

Preferably, the circulating water flow repeatedly washes the underground aquifer, so that the vertical scouring capability of the low-permeability stratum is enhanced, NAPLs in the low-permeability stratum are facilitated to diffuse out, and the tailing problem in the in-situ remediation process of the NAPLs-polluted low-permeability underground aquifer can be effectively solved; the jet of water promotes the resolution and flow of NAPLs at the top and bottom of the subsurface aquifer, accelerating NAPLs migration, shortening the time to withdraw NAPLs from the subsurface aquifer, and increasing the NAPLs removal rate.

Preferably, the control unit 130 changes the flow modes of the circulating water flow and the jet water flow through the water pump, thereby realizing the directional removal and synchronous removal of the pollutants enriched at the top and the bottom of the underground aquifer in the polluted site, and eliminating the pollutant capturing blind zone.

Preferably, the control unit 130 may set the respective modes of operation for different pollution situations of the underground aquifer. After the control unit 130 obtains the pollution condition of the underground aquifer through the detection equipment, the control unit 130 operates in a corresponding working mode, so that the directional removal of different pollutants in the polluted site is realized.

When the circulating water flow flushes the underground aquifer, the top or the bottom of the underground aquifer can be flushed, so that NAPLs enriched at the top or the bottom of the underground aquifer are promoted to be resolved and diffused into the underground water, and the removal rate of the NAPLs is improved.

Preferably, the third screen section 123 and the fourth screen section 124 correspond to the first screen section 113 and the second screen section 114, respectively, and when the circulating water flow enters the circulating well unit 110 from the first screen section 113 or the second screen section 114, the third screen section 123 and the fourth screen section 124 generate a jet water flow along the circulating water inflow direction, so that the hydrodynamic action of groundwater in the area near the first screen section 113 or the second screen section 114 is enhanced, the analysis and the flow of NAPLs are promoted, and the NAPLs migration is accelerated.

Preferably, the surfactant and/or remediation agent stored in the drug-in-tank is delivered to the location of the contaminated plume in the subterranean aquifer through the third water line 125 and the fourth water line 126, thereby improving the removal efficiency of the NAPLs by the remediation device 100.

Preferably, the control unit 130 controls the opening and closing of the valves to regulate the flow paths of the water pipes, and the control unit 130 controls the water pumps connected with the water pipes, so that the repairing device 100 generates circulating water flow and water jet flow for directionally removing pollutants enriched at the top or bottom of the underground aquifer.

Preferably, water treated by the water treatment system 135 to meet the relevant criteria may be re-injected into the subterranean aquifer through the circulation well to avoid problems such as surface subsidence, damage to the formation structure, etc.

Preferably, the control unit 130 detects the contaminant through the first detector 101 and the second detector 102. Preferably, both the first detector 101 and the second detector 102 may be oil film detectors.

Preferably, the pollution conditions detected by the control unit 130 through the first and second detectors 101 and 102 may include: groundwater contains only LNAPLs pollution, groundwater contains only DNAPLs pollution, and groundwater contains both LNAPLs pollution and DNAPLs pollution.

Preferably, for a ground water field only containing LNAPLs, the repairing device 100 enters a first mode through the control unit 130, the water pumping and injecting direction of the water pumping and injecting pump is adjusted, the first screen section 113 of the circulating well unit 110 is a water pumping section, the second screen section 114 is a water injecting section, and water flow circulation is started; the underground water in the first well section 111 is pumped out through the extraction action of the third water pump 143, so that the water level in the first well section 111 is reduced, the polluted underground water containing LNAPLs in the underground aquifer around the circulating well continuously flows into the circulating well through the first screen section 113 under the action of pressure difference, clear water in the water tank 131 can be transported to the second well section 112 through the first water pump 141, the water level at the second well section 112 is increased, and then flows out through the second screen section 114, and the underground aquifer is continuously supplemented, so that a hydraulic circulation mode of pumping up and pouring down is formed; simultaneously injecting well unit 120, injecting clean water into the subterranean aquifer through third screen section 123; controlling the water level in the circulating well to be in the range from the center of the first screen section 113 to the highest position, monitoring the concentration and the thickness of the LNAPLs in real time through the first detector 101, adjusting an automatic control system when the thickness of the LNAPLs cannot be detected, stopping the operation of the first water pump 141, the second water pump 142, the third water pump 143 and the fourth water pump 144, automatically adjusting the probe height of the first detector 101 to the position of the liquid level according to water level monitoring data in the first well section 111 after the peripheral groundwater level returns to be stable, and automatically starting the circulating well unit 110 and the injection well unit 120 to operate when the thickness of an oil film or the water quality of groundwater is monitored to be higher than the set standard again, and obtaining a better removing effect on the free phase LNAPLs and the residual phase LNAPLs in the groundwater layer after repeated operation for a plurality of times; the surfactant and/or the repairing agent to be added is/are placed in the medicine box 132, the seventh valve 157 is opened, clean water is injected through the first water pump 141 according to the agent proportion, the prepared agent is injected into the injection well through the second water pump 142, and the underground aquifer is continuously flushed under the action of horizontal impact force, so that the residual phase LNAPLs are facilitated to be analyzed and enter the underground aquifer, the removing capability of the LNAPLs in polluted underground water is further improved, and finally, the good effect of removing the LNAPLs in the field is realized.

For sites containing only DNAPLs contaminated groundwater, the remediation apparatus 100 enters a second mode via the control unit 130,

the water pumping and injecting direction of the water pumping and injecting pump is adjusted through the automatic control system unit 113, so that the first screen section 113 of the circulating well unit 111 is a water injection section, the second screen section 114 is a water pumping section, and water flow circulation is started; pumping out the underground water in the second well section 112 through the extraction action of the fourth water pump 144, so that the water level in the second well section 112 is reduced, the polluted underground water containing DNAPLs in the underground aquifer around the circulating well continuously flows into the circulating well through the second screen section 114 under the action of pressure difference, the clean water in the water tank 131 is conveyed to the first well section 111 through the third water pump 143, the water level at the first well section 111 is increased, and then the water flows out through the first screen section 113, continuously supplements the underground aquifer, and forms a hydraulic circulation mode of pumping up and down; simultaneously activating the injection well unit 120 to inject clean water into the underground aquifer through the fourth screen 124, and depositing DNAPLs flowing into the second well 112 in the settling tank 119 under the action of gravity; turning on the fifth water pump 145 to pump out DNAPLs, and stopping the operations of the fourth water pump 144, the third water pump 143, the first water pump 141, the second water pump 142 and the fifth water pump 145 when DNAPLs cannot be detected in the pumped liquid; after the underground water level is restored to be stable, monitoring the DNAPLs concentration in the underground water-bearing layer through the second detector 102, if the water quality exceeds the set standard, automatically starting the circulating well unit 110 and the injection well unit 120, and obtaining a good removal effect on free phase DNAPLs and residual phase DNAPLs in the underground water-bearing layer after repeated operation for a plurality of times; the surfactant and/or the repairing agent to be added are placed in the medicine box 132, the seventh valve 157 is opened, clean water is injected through the first water pump 141 according to the agent configuration ratio, the prepared agent is injected into the injection well through the second water pump 142, and the underground aquifer is continuously flushed under the action of horizontal impact force, so that the residual phase DNAPLs are facilitated to be analyzed and enter the underground aquifer, the removing capability of the DNAPLs in polluted underground water is further improved, and finally, good effect of removing the DNAPLs in the field is achieved.

The prosthetic device 100 is cycled between a first mode and a second mode for sites containing both LNAPLs and DNAPLs contaminated groundwater.

Preferably, the control unit 130 firstly enters a first mode, adjusts the water pumping and injecting direction of the water pumping and injecting pump, sets a circulation well Shan Choushui mode, enables the first screen section 113 of the circulation well unit 111 to be a water pumping screen section, and starts the hydraulic circulation system; pumping out the underground water in the first well section 1 through the extraction action of the third water pump 143, so that the water level in the first well section 111 is lowered; meanwhile, the jet well unit 120 is started to run, clean water is injected into the underground water-bearing layer through the third screen section 123, so that the water level at the third well section 121 is increased, and the polluted underground water containing LNAPLs in the underground water-bearing layer around the circulating well continuously flows into the circulating well through the first screen section 113 under the action of pressure difference; controlling the water level in the circulating well to be in the range from the center of the first screen section 113 to the highest position, monitoring the concentration and the thickness of the LNAPLs in real time through the first detector 101, and setting an automatic control system to stop the operation of the third water pump 143 and the first water pump 141 when the thickness of the LNAPLs cannot be detected; after the surrounding groundwater is restored to be stable, the probe height of the first detector 101 can be automatically adjusted to the position of the liquid level according to the water level monitoring data in the first well section 111, and when the thickness of an oil film or the quality of the pumped water exceeds the set standard, the circulation well unit 111 and the injection well unit 120 are automatically started to operate; after the free phase LNAPLs and the residual phase LNAPLs in the field are removed after repeated operation for a plurality of times, the control unit 130 enters a second mode to adjust the water pumping and injecting direction of the water pumping and injecting pump, so that the first screen section 113 of the circulating well unit 111 is a water injection screen section, the second screen section 114 is a water pumping screen section, and a hydraulic circulating mode with upper injection and lower pumping is formed; the clean water in the water tank 131 is injected into the underground aquifer through the fourth screen section 124, DNAPLs in the underground aquifer flow into the second well section 112 under the action of pressure difference, and are deposited in the precipitation tank 119 under the action of gravity; turning on the fifth water pump 145 to pump out DNAPLs, and stopping the operations of the first water pump 141, the second water pump 142, the third water pump 143, the fourth water pump 144 and the fifth water pump 145 when DNAPLs cannot be detected in the pumped liquid; after the underground water level is restored to be stable, the concentration of DNAPLs in the underground water-bearing layer is monitored by using the second detector 102, if the water quality exceeds the set standard, the circulation well unit 110 and the injection well unit 120 are automatically started to operate, and after repeated operation for multiple times, a good removal effect is achieved on free phase DNAPLs and residual phase DNAPLs in the underground water-bearing layer; the surfactant and/or the repairing agent to be added is/are placed in the medicine box 132, the seventh valve 157 is opened, clean water is injected through the first water pump 141 according to the agent configuration ratio, the prepared agent is injected into the injection well through the second water pump 142, and the prepared agent can be simultaneously injected into the underground aquifer through the third screen section 123 and the fourth screen section 124, so that the underground aquifer is continuously flushed under the action of horizontal impact force, the analysis of residual phase NAPLs into the underground aquifer is facilitated, the removal capability of NAPLs in polluted underground water is further improved, and finally a good removal effect on NAPLs in a field is achieved.

Example 2

This embodiment is a further improvement of embodiment 1, and the repeated contents are not repeated.

The present embodiment provides a downhole contamination remediation system. The downhole contamination remediation system includes at least a circulation well unit 110, a injection well unit 120, and a control unit 130. The circulation well unit 110 forms groundwater into circulation water flow circulating in and out of the circulation well around the circulation well under the action of hydraulic circulation. The jet well unit 120 generates a jet of water flowing toward the circulating water inflow well location. Preferably, the circulating water flow and the water jet flow are provided with at least two flow patterns, respectively. The control unit 130 adjusts the operation parameters of the circulation well unit 110 and the injection well unit 120 based on the recognition and judgment of the groundwater pollutants to change the flow modes of the circulation water flow and the injection water flow, thereby constructing a stereoscopic flow field in the underground aquifer by the circulation water flow and the injection water flow, and promoting the migration of the pollutants in the underground aquifer.

Example 3

This embodiment is a further improvement of embodiment 1 and embodiment 2, and the repeated description is omitted.

The embodiment provides a method for repairing underground pollution. The method for repairing the underground pollution at least comprises the following steps:

providing a circulation well unit 110 and a injection well unit 120 in an underground aquifer;

forming a circulating water flow circulating in and out of the circulating well around the circulating well by using the circulating well unit 110;

a jet of water flowing toward the circulating water inflow well site is generated by the jet well unit 120.

Preferably, the circulating water flow and the injection water flow are provided with at least two flow patterns, respectively, and the circulating well unit 110 and the injection well unit 120 are regulated by the control unit 130.

Preferably, the control unit 130 adjusts the operation parameters of the circulation well unit 110 and the injection well unit 120 based on the recognition and judgment of the groundwater pollutants to change the flow mode of the circulation water flow and the injection water flow, so that the circulation water flow and the injection water flow construct a three-dimensional flow field in the underground aquifer to promote the migration of the pollutants in the underground aquifer.

Preferably, the circulation well unit 110 divides its interior space into a first well section 111 and a second well section 112 by a first packer 117. The two screen sections provided on injection well unit 120 include a first screen section 113 provided on first well section 111 and a second screen section 114 provided on second well section 112. The water pipes disposed in the well of the circulation well unit 110 include a first water pipe 115 disposed end-on near the first screen section 113 and a second water pipe 116 disposed end-on near the second screen section 114. Preferably, the second water pipe 116 passes through a first packer 117. Preferably, the second water pipe 116 passes through the first packer 117, and the first and second water pipes 115 and 116 are connected to a separation device 133 located at the surface while being connected to a water tank 131. The first water pipe 115 or the second water pipe 116 is provided with a valve on a pipe member connected to the water tank 131 and the separating apparatus 133.

The invention combines the circulating flow field generated by the circulating well technology and the horizontal flow field generated by the auxiliary well, enhances the hydrodynamic action of the ground water of the NAPLs polluted site, forms the flow field in the horizontal direction at the top and the bottom of the underground aquifer, accelerates the migration of the free phase NAPLs along with water flow, simultaneously is beneficial to the analysis and diffusion of the residual phase NALs adhered to the top and the bottom of the underground aquifer into the ground water, improves the migration capacity of NAPLs pollutants to the pumping end of the circulating well, shortens the time for pumping the NAPLs from the underground aquifer, and improves the removal rate of the NAPLs. The invention forms a hydraulic circulation flow field around the circulation well by utilizing the action of the water pumping and injecting pump in the main well of the circulation well, continuously and repeatedly flushes the underground aquifer, particularly enhances the vertical flushing capability for the low-permeability stratum, is beneficial to the NAPLs in the low-permeability stratum to diffuse out, and can effectively solve the tailing problem in the in-situ restoration process of the NAPLs polluted low-permeability underground aquifer. According to the invention, the water pumping and injecting modes at different screen sections of the circulating well can realize automatic switching according to the concentration value of the pollutant and the type of NAPLs monitored in real time in the automatic control system, and the directional removal and synchronous removal of NAPLs in a polluted site are realized. The auxiliary well is used as an injection well of a surfactant or a repairing agent, so that the residual phase NAPLs can be resolved into an underground water-bearing layer, and the purpose of reinforcing the circulating well to repair the underground water of the NAPLs polluted site in situ is achieved. The invention utilizes the cone sedimentation tank 119 arranged under the circulating well to collect DNAPLs entering the circulating well, so as to prevent DNAPLs pollutants from entering the underground water-bearing layer again to participate in underground water circulation, the circulating well and the auxiliary well are used for controlling the underground water flow field together to form a hydraulic barrier, the polluted area of the underground water-bearing layer is isolated from the surrounding uncontaminated area, further expansion of the polluted area can be prevented, and water reaching relevant standards after being treated by a surface water treatment system can be injected into the underground water-bearing layer again through the circulating well, so that the problems of ground subsidence, stratum structure damage and the like are avoided.

It should be noted that the above-described embodiments are exemplary, and that a person skilled in the art, in light of the present disclosure, may devise various solutions that fall within the scope of the present disclosure and fall within the scope of the present disclosure. It should be understood by those skilled in the art that the present description and drawings are illustrative and not limiting to the claims. The scope of the invention is defined by the claims and their equivalents. Throughout this document, the word "preferably" is used in a generic sense to mean only one alternative, and not to be construed as necessarily required, so that the applicant reserves the right to forego or delete the relevant preferred feature at any time. The description of the invention encompasses multiple inventive concepts, such as "preferably," "according to a preferred embodiment," or "optionally," all means that the corresponding paragraph discloses a separate concept, and that the applicant reserves the right to filed a divisional application according to each inventive concept.

Claims

1. A downhole contamination remediation device, the remediation device comprising at least a circulation well unit (110), a jet well unit (120) and a control unit (130);

the circulating well unit (110) enables underground water to form circulating water flow which circulates in and out of the circulating well around the circulating well under the action of hydraulic circulation;

-the injection well unit (120) generating an injection water flow flowing towards the circulation water inflow well location;

wherein the circulating water flow and the water jet flow are respectively provided with at least two flow modes,

the control unit (130) adjusts working parameters of the circulating well unit (110) and the injection well unit (120) based on the identification and judgment of the groundwater pollutants so as to change the flow modes of the circulating water flow and the injection water flow, thereby enabling the circulating water flow and the injection water flow to construct a three-dimensional flow field in an underground aquifer and promoting the migration of the pollutants in the underground aquifer;

the bottoms of the circulating well unit (110) and the injection well unit (120) are plugged, and the internal space of the circulating well unit is divided into two well sections with water flow which are not communicated with each other through a packer;

the circulating well unit (110) is provided with two screen sections, and the two screen sections are respectively arranged on the two well sections;

the screen sections of the injection well unit (120) are arranged at a level with the two screen sections of the circulation well unit (110);

wherein two screen sections provided on the circulation well unit (110) are used to form the circulating water flow with reversible flow direction;

Two screen sections provided on the injection well unit (120) for forming the injection water flow to the circulation well unit (110); a detection device for detecting the pollutants of the underground water is arranged in the circulating well unit (110), wherein the detection device at least comprises a first detector (101) for detecting the pollutants at the top of the underground aquifer and a second detector (102) for detecting the pollutants at the bottom of the underground aquifer;

the control unit (130) is provided with at least a first mode of operation for the circulation well unit (110) and the injection well unit (120) to treat the top contamination of the underground aquifer and a second mode of operation for the circulation well unit (110) and the injection well unit (120) to treat the bottom contamination of the underground aquifer;

the control unit (130) adjusts the operation mode of the control unit (130) according to the data of the first detector (101) and the second detector (102).

2. The downhole contamination repair device according to claim 1 wherein the screen section is comprised of a plurality of through holes provided in the borehole wall;

the circulating well unit (110) and the injection well unit (120) are provided with water pipes at positions corresponding to the screen sections in the well;

One end of the water pipe is arranged near the screen section, and the other end of the water pipe is connected to the ground surface;

the water pipe is provided with a water pump which changes an operation mode in response to the regulation and control of the control unit (130), and the control unit (130) changes the flow modes of the circulating water flow and the jet water flow through the water pump.

3. A downhole contamination repair device according to claim 2, wherein the circulation well unit (110) divides its inner space into a first well section (111) and a second well section (112) by a first packer (117);

two screen sections arranged on the circulation well unit (110) comprise a first screen section (113) arranged on the first well section (111) and a second screen section (114) arranged on the second well section (112);

the water pipe arranged in the circulation well unit (110) comprises a first water pipe (115) with the tail end arranged near the first screen section (113) and a second water pipe (116) with the tail end arranged near the second screen section (114),

wherein the second water pipe (116) passes through the first packer (117), and the first water pipe (115) and the second water pipe (116) are connected with a water tank (131) and a separation device (133) positioned on the ground;

The first water pipe (115) or the second water pipe (116) is provided with a valve on a pipe fitting connected with the water tank (131) and the separating device (133).

4. A downhole contamination repair device according to claim 3, wherein the injection well unit (120) divides its inner space into a third well section (121) and a fourth well section (122) by a second packer (127);

two screen sections provided on the injection well unit (120) include a third screen section (123) provided on the third well section (121) and a fourth screen section (124) provided on the fourth well section (122);

the water pipe of the injection well unit (120) arranged in the well comprises a third water pipe (125) with the tail end arranged near the third screen section (123) and a fourth water pipe (126) with the tail end arranged near the fourth screen section (124),

wherein the fourth water pipe (126) passes through the second packer (127), and the third water pipe (125) and the fourth water pipe (126) are connected with the water tank (131) and are also connected with a medicine tank (132) positioned on the ground surface;

wherein two water pumps are arranged between the water tank (131) and the injection well unit (120), and the medicine box (132) is connected between the two water pumps through a pipeline with a valve;

The water in the water tank (131) flows to the third water pipe (125) and the fourth water pipe (126) provided with valves through the two water pumps.

5. The downhole contamination repair device according to claim 4, wherein the valve is electrically connected to the control unit (130), and the control unit (130) regulates the flow passage of each water pipe by controlling the opening and closing of the valve.

6. A downhole contamination repair apparatus according to claim 3 wherein the separation device (133) treats groundwater extracted from the injection well unit (120) containing contaminants, separates the contaminants from groundwater,

wherein the separation device (133) conveys the separated pollutants to a pollutant collection tank (134) for storage, and conveys the separated groundwater to a water treatment system (135) for treatment.

7. A method of downhole contamination remediation, the method comprising:

arranging a circulation well unit (110) and a jet well unit (120) in an underground aquifer; the bottoms of the circulating well unit (110) and the injection well unit (120) are plugged, and the internal space of the circulating well unit is divided into two well sections with water flow which are not communicated with each other through a packer; the circulating well unit (110) is provided with two screen sections, and the two screen sections are respectively arranged on the two well sections;

The screen sections of the injection well unit (120) are arranged at a level with the two screen sections of the circulation well unit (110); forming a circulating water flow circulating in and out of the circulating well around the circulating well by using the circulating well unit (110); wherein two screen sections provided on the circulation well unit (110) are used to form the circulating water flow with reversible flow direction;

generating, with the injection well unit (120), an injection water stream flowing to the circulating water inflow well location; wherein two screen sections provided on the injection well unit (120) are used to form the injection water flow to the circulation well unit (110);

wherein the circulating water flow and the injection water flow are respectively provided with at least two flow modes, and the circulating well unit (110) and the injection well unit (120) are regulated by a control unit (130);

the control unit (130) adjusts working parameters of the circulating well unit (110) and the injection well unit (120) based on identification and judgment of groundwater pollutants so as to change flow modes of the circulating water flow and the injection water flow, so that a three-dimensional flow field is constructed by the circulating water flow and the injection water flow in an underground aquifer, and migration of pollutants in the underground aquifer is promoted;

A detection device for detecting the pollutants of the underground water is arranged in the circulating well unit (110), wherein the detection device at least comprises a first detector (101) for detecting the pollutants at the top of the underground aquifer and a second detector (102) for detecting the pollutants at the bottom of the underground aquifer;