A groundwater pollution source control system based on interception and adsorption

Abstract

This invention discloses a groundwater pollution source control system based on interception and adsorption. By setting up an extraction unit and an adsorption degradation unit at the boundary of the control area near the pollution source, groundwater carrying pollutants flowing from upstream through the pollution source can, as it flows into the control area, first have its organic pollutants adsorbed by the adsorption material of the adsorption degradation unit, and then have the organic pollutants biodegraded by microorganisms in the adsorption material. The remaining pollutants are then extracted along with the groundwater to the extraction well for secondary wastewater treatment. Thus, this invention can achieve both preliminary groundwater pollution remediation and physical removal of remaining pollutants to the extraction well, preventing the spread of pollution sources into the control area. Moreover, the implementation of this invention is not limited by the site conditions of the control area and causes minimal groundwater disturbance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of remediation treatment of groundwater and soil, in particular to a groundwater pollution source control system based on interception and adsorption. BACKGROUND

[0002] In recent years, with the development of industry and agriculture, groundwater pollution has gradually increased and become a research hotspot at home and abroad. Due to the concealment, hysteresis, complexity and difficulty of recovery of groundwater pollution, most of the groundwater pollution source control measures in China use barrier wall technology.

[0003] In actual engineering, barrier walls are widely used to control heavy metals and organic pollutants in contaminated land and leachate in landfills. Changes in groundwater level have a significant impact on the stress characteristics of underground structures. With the passage of time, the compressive strength of concrete decreases. Water load can cause damage to vertical barrier walls, and pore water pressure accelerates the damage and expansion of micro-cracks in barrier walls, thereby affecting the impermeability and service life of barrier walls. PRB technology has excellent repair and control effect, and also has good safety, stability and economy; but it is prone to blockage, difficult to maintain, affects the actual effect, and is difficult to implement in service petrochemical sites. The traditional groundwater pollution barrier wall technology often only considers the blocking effect of the barrier wall itself, ignores the damage of groundwater pressure to the wall and blockage, and the removal and treatment of pollution sources; resulting in failure to achieve the blocking effect and service life, and the pollution source is difficult to remove. And the high-risk in-service site, the complexity of underground structures and pipelines do not have the conditions for continuous barrier wall construction, and the construction difficulty is great. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a groundwater pollution source control system based on interception and adsorption to solve the problems of existing groundwater pollution barrier technology, such as site limitation, construction difficulty, and inconvenience for repairing pollution sources.

[0005] To solve the above technical problems, the technical solution adopted by the present application is as follows:

[0006] A groundwater pollution source control system based on interception and adsorption is suitable for the case where the blocking area is located downstream of the pollution source of groundwater, characterized in that it comprises an extraction unit and an adsorption and degradation unit, both of which are arranged at the boundary position of the blocking area close to the pollution source.

[0007] The extraction unit is equipped with extraction equipment and multiple extraction wells. The extraction equipment can extract groundwater from each extraction well. The extraction wells are arranged at intervals along a straight line segment, which is perpendicular to the groundwater flow direction. The diameter of the extraction wells is selected according to the needs and conditions, and is generally 110mm. The extraction wells are set at the opening position for external groundwater to flow into them, corresponding to the thickness of the underground aquifer.

[0008] The adsorption and degradation unit is not located downstream of the extraction well in the groundwater. This unit is equipped with adsorbent material capable of adsorbing organic pollutants from the groundwater, and this adsorbent material is infused with microorganisms capable of biodegrading the organic pollutants. The selection of the adsorbent material should adhere to principles such as long lifespan, optimal adsorption effect on common organic pollutants in groundwater (alkanes, petroleum hydrocarbons, benzene compounds, halogenated hydrocarbons, chlorinated hydrocarbons, etc.), reusability and ease of treatment, and harmlessness to humans and no impact on groundwater quality. Activated carbon and zeolite molecular sieves are generally preferred. The microorganisms should be indigenous microorganisms from the controlled area, and should adhere to principles such as non-selectivity towards the organic pollutants, easy survival underground, harmlessness to humans, minimal impact on the underground environment, and long lifespan.

[0009] Therefore, the working principle of the groundwater pollution source control system of the present invention is as follows:

[0010] Groundwater carrying pollutants flowing from upstream through a pollution source can, as it flows toward the control area, first have its organic pollutants adsorbed by the adsorption material of the adsorption and degradation unit, and then have the organic pollutants biodegraded by the microorganisms in the adsorption material. The remaining pollutants are then extracted with the groundwater to the extraction well for secondary wastewater treatment. Thus, this invention can achieve both preliminary remediation of groundwater pollution and physical removal of the remaining pollutants to the extraction well to prevent the spread of pollution sources to the control area.

[0011] Moreover, the implementation of this invention is not limited by the site conditions of the controlled area, has minimal underground disturbance, and can be used as a pollution source risk management measure as well as for soil and groundwater remediation.

[0012] As a preferred embodiment of the present invention: such as Figures 1 to 3 As shown, the adsorption and degradation unit is equipped with multiple interception wells, all of which are arranged at uniform intervals perpendicular to the groundwater flow direction and located upstream of the extraction well.

[0013] See Figure 2The interception well is equipped with interception well screen holes for external groundwater to flow into its interior. The opening position of the interception well screen holes is designed according to the required vertical interception position of organic pollutants. The diameter of the interception well can be selected according to the needs and conditions. The interior of the interception well is fixed with a large-diameter interception well screen pipe and a small-diameter interception well screen pipe arranged coaxially with the lower pipe opening sealed. The space between the large-diameter interception well screen pipe and the small-diameter interception well screen pipe is filled with the adsorbent material to form an interception well adsorption column. The microorganisms are injected into the interception well adsorption column.

[0014] Furthermore, the effective range of the interception well adsorption column in the interception well adsorbing organic pollutants in the groundwater is defined as the adsorption influence range. This adsorption influence range is a cylindrical range coaxial with the adsorption column of the interception well, and the adsorption influence ranges of two adjacent interception wells partially overlap.

[0015] During the operation of the groundwater pollution source control system, the extraction equipment controls whether to extract groundwater from the corresponding extraction well based on the groundwater level in each extraction well. Specifically, when the groundwater level in any extraction well rises to a preset upper limit level, the extraction equipment extracts the groundwater from that extraction well; when the groundwater level in any extraction well drops to a preset lower limit level, the extraction equipment stops pumping water from that extraction well.

[0016] Therefore, the working principle of the groundwater pollution source control system in Embodiment 2 of the present invention is as follows:

[0017] See Figure 1 and Figure 2 This invention employs multiple interception wells, evenly spaced perpendicular to the groundwater flow direction, as adsorption and degradation units. Each interception well contains an adsorption column, and the interception wells are positioned upstream of the extraction wells. This ensures that groundwater from upstream reaches the interception wells first, entering the adsorption influence range of each well. Organic pollutants in the groundwater are adsorbed into the adsorption columns of the corresponding interception wells, where microorganisms biodegrade the organic pollutants. Thus, each interception well forms a non-continuous physical barrier adsorption wall capable of intercepting, adsorbing, and degrading organic pollutants in groundwater.

[0018] Furthermore, by comparing groundwater levels, this invention controls the extraction equipment to intermittently extract groundwater from the extraction wells. This allows organic pollutants not intercepted by the intercepting wells to flow with the groundwater from the gaps between the intercepting wells to the extraction wells, where the extraction equipment then extracts the groundwater, thus removing pollutants from the groundwater and preventing the pollution source from spreading into the controlled area. The intermittent extraction of groundwater from the extraction wells also controls the direction of groundwater flow, ensuring that the groundwater flows through the intercepting wells rather than bypassing them. This helps improve the interception efficiency of the intercepting wells for organic pollutants and intermittently accelerates the groundwater flow rate, thereby speeding up the groundwater renewal process in the controlled area.

[0019] The adsorbent material is used to form an adsorption column in the interception well by filling the space between the large-diameter screen tube and the small-diameter screen tube of the interception well, thus constructing a biofilm. This can improve the adsorption capacity of the adsorbent material for organic pollutants and extend the service life of the adsorbent material.

[0020] Preferred: See Figure 1 The number of extraction wells is one less than the number of interception wells, and each extraction well is located 0.5m to 1m directly behind the midpoint of two adjacent interception wells. This ensures that each extraction well is positioned at the weakest point in the barrier adsorption wall formed by the interception wells, where the interception of organic pollutants is least effective, thus achieving optimal removal of pollutants from groundwater.

[0021] Preferred: See Figure 2 The groundwater pollution source control system also includes an oxygen supply system. The oxygen supply pipe of this system is inserted into the cavity of the small-diameter screen pipe of the interception well and extends to the bottom. Thus, by continuously aerating at appropriate pressure through the oxygen supply system, an aerobic environment is provided for the adsorption column of the interception well, thereby accelerating the biodegradation rate of organic pollutants by microorganisms.

[0022] Preferably, the section of the oxygen supply pipe located within the interception well is equipped with an oxygen supply pipe union for easy maintenance and replacement. The large-diameter and small-diameter screen pipes of the interception well are preferably secured by steel wire ropes suspended from the wellhead. A pressure gauge is preferably installed at the wellhead. The outer diameter of the large-diameter screen pipe is preferably 1-2 cm smaller than the inner diameter of the interception well, and the inner diameter of the small-diameter screen pipe is preferably 1-2 cm larger than the outer diameter of the oxygen supply pipe.

[0023] Preferred: See Figure 3 The extraction equipment includes liquid phase extraction equipment and gas phase extraction equipment;

[0024] The liquid phase extraction equipment is equipped with a submersible pump and a level gauge for monitoring the groundwater level in the extraction well. The submersible pump is placed at the bottom of the extraction well, with its outlet connected to one end of the submersible pump's pumping pipe. The other end of the pumping pipe extends outside the extraction well, allowing the submersible pump to extract groundwater from the well. The level gauge is suspended from the wellhead of the extraction well by a steel wire rope. Preferably, the section of the submersible pump's pumping pipe inside the extraction well is equipped with a submersible pump's pumping pipe union and a check valve. The section of the submersible pump's pumping pipe outside the extraction well is preferably equipped with a submersible pump's pumping pipe ball valve and an electronic flow meter. Preferably, the submersible pump's pumping pipe branches off to a sampling branch equipped with a sampling branch ball valve for sampling and analysis. A negative pressure gauge is preferably installed at the wellhead of the extraction well.

[0025] The extraction well is equipped with a gas phase extraction port on its side wall. The gas phase extraction equipment uses a vacuum pump, and the vacuum pump's extraction port is connected to the gas phase extraction port of the extraction well via a vacuum pump extraction pipe. This allows for the intermittent operation of the vacuum pump to remove free gas phase, gases produced by microbial degradation, and VOCs from the soil within the extraction well. Preferably, the vacuum pump extraction pipe is equipped with a vacuum pump extraction pipe ball valve and a vacuum pump extraction pipe flow sensor.

[0026] Additionally, in this second embodiment, the single-pump multiphase extraction unit described in the third embodiment below can also be used to replace the above-mentioned liquid phase extraction equipment and gas phase extraction equipment as the extraction equipment.

[0027] As a preferred embodiment of the present invention: such as Figures 4 to 6 As shown, the adsorption and degradation unit has a large-diameter screen pipe and a small-diameter screen pipe fixed inside each extraction well and arranged coaxially with the lower pipe opening sealed. The space between the large-diameter screen pipe and the small-diameter screen pipe is filled with the adsorbent material to form an extraction well adsorption column, and the microorganisms are injected into the extraction well adsorption column; wherein, see Figure 5 Preferably, the top surface of the adsorption column in the extraction well is flush with the original liquid level of the groundwater before it is extracted.

[0028] Furthermore, the spacing between two adjacent extraction wells increases progressively from the middle of the straight line segment towards both ends; for example: Figure 4 The seven extraction wells shown are spaced 1.0m, 0.75m, 0.5m, 0.5m, 0.75m and 1.0m apart from top to bottom.

[0029] During the operation of the groundwater pollution source control system, the extraction equipment continuously extracts groundwater from each extraction well.

[0030] Therefore, the working principle of the groundwater pollution source control system in Embodiment 3 of the present invention is as follows:

[0031] See Figures 4 to 6 This invention arranges extraction wells with increasing spacing from the middle to both ends of the straight segment, and controls the extraction equipment to continuously extract groundwater from each well. This alters the hydraulic gradient of the groundwater flowing from upstream to the extraction well, causing groundwater to form at that location. Figure 5 The drop funnel shape shown remains stable. Figure 5 The water level line in the drop funnel is used to draw groundwater to the center of all the extraction wells, thereby controlling the groundwater and its pollutants.

[0032] Furthermore, this invention employs adsorption columns installed in each extraction well as adsorption and degradation units, enabling the following: organic pollutants in the groundwater pumped into the extraction well are adsorbed by the adsorption columns and biodegraded by microorganisms, achieving preliminary remediation of the groundwater, thereby reducing the concentration of pollutants in the groundwater and reducing the cost and time of subsequent secondary wastewater treatment; then, the remaining pollutants are extracted with the groundwater to the outside of the extraction well for secondary wastewater treatment.

[0033] Moreover, by placing the adsorption and degradation unit inside the extraction well, the present invention can reduce the number of wells drilled, thereby reducing implementation costs and floor space required.

[0034] The adsorbent material is filled between the large-diameter screen tube and the small-diameter screen tube of the extraction well to form an adsorption column in the extraction well, thus constructing a biofilm. This can improve the adsorption capacity of the adsorbent material for organic pollutants and extend the service life of the adsorbent material.

[0035] Preferred: See Figure 6 The extraction equipment employs a single-pump multiphase extraction unit, including an SVE extraction device. The extraction port of the SVE device is connected to one end of a multiphase extraction pipe. The other end of the multiphase extraction pipe passes through the small-diameter screen pipe of the extraction well and extends to the bottom, allowing simultaneous extraction of both liquid and gas phases within the extraction well via the SVE device. Preferably, the other end of the multiphase extraction pipe is positioned a certain distance from the bottom of the well and is wrapped with gauze for filtering silt and impurities. The section of the multiphase extraction pipe inside the extraction well is preferably equipped with a multiphase extraction pipe union and a multiphase extraction pipe check valve. The section of the multiphase extraction pipe outside the extraction well is preferably equipped with a multiphase extraction pipe ball valve, a multiphase extraction pipe electronic flow meter, and a transparent PVC pipe for observing water flow. A negative pressure gauge is preferably installed at the head of the extraction well.

[0036] As a preferred embodiment of the present invention: such as Figure 4 andFigure 5 As shown, the groundwater pollution source control system further includes an aeration barrier unit; the aeration barrier unit is equipped with an air injection system and multiple aeration wells; the air injection system can aerate the groundwater by injecting compressed air into each aeration well; all the aeration wells are arranged at intervals along the vertical direction of the groundwater flow and are located downstream of all the extraction wells; wherein, the air injection system preferably adopts an AS air injection system.

[0037] The gas injection system operates continuously during the operation of the groundwater pollution source control system.

[0038] Therefore, the working principle of the groundwater pollution source control system in Embodiment 4 of the present invention is as follows:

[0039] This invention establishes an aeration barrier unit downstream of the extraction well, consisting of an air injection system and multiple aeration wells. This unit allows the compressed air injected into the groundwater through the aeration wells to form an airflow barrier, preventing the groundwater from continuing to flow and diffuse into the control area after passing through the extraction well. This effectively blocks residual pollutants in the groundwater, keeping them upstream of the control area so they can be removed and repaired by the extraction and adsorption degradation units.

[0040] In addition, for the above embodiment three, the aeration barrier unit can also provide an aerobic environment for the adsorption column of the extraction well to accelerate the biodegradation rate of organic pollutants by microorganisms.

[0041] Preferably, the number of aeration wells is one less than the number of extraction wells, and each aeration well is located 0.5m to 1m directly behind the midpoint of two adjacent extraction wells, with the aeration position of the aeration well 0.5m to 1m below the bottom surface of the extraction well. This optimizes the pollutant blocking effect of the aeration barrier unit.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] First, see Figures 1 to 6 This invention sets up an extraction unit and an adsorption degradation unit at the boundary A1 of the control zone A near the pollution source, so that: when groundwater W carrying pollutants flows from upstream through the pollution source into the control zone A, the organic pollutants in the groundwater W can be adsorbed by the adsorption material 2 of the adsorption degradation unit, and the organic pollutants can be biodegraded by the microorganisms in the adsorption material 2. Then, the remaining pollutants are extracted with the groundwater W to the extraction well 1 for secondary sewage treatment. Thus, this invention can achieve both preliminary pollution remediation of groundwater W and physical removal of the remaining pollutants to the extraction well 1 to prevent the spread of pollution source into the control zone A.

[0044] Moreover, the implementation of this invention is not limited by the site conditions of the controlled area A, and causes little underground disturbance.

[0045] Second, see Figure 1 and Figure 2 This invention employs multiple interception wells 3, evenly spaced perpendicular to the groundwater flow direction V, as adsorption and degradation units. Each interception well 3 contains an adsorption column 2A. The interception wells 3 are positioned upstream of the extraction well 1, so that groundwater from upstream first reaches the interception wells 3 and enters the adsorption influence range of each interception well 3. The organic pollutants in the groundwater are adsorbed into the corresponding adsorption column 2A, where microorganisms biodegrade the organic pollutants. Thus, each interception well 3 forms a non-continuous physical barrier adsorption wall capable of intercepting, adsorbing, and degrading organic pollutants in groundwater.

[0046] Furthermore, by comparing groundwater levels, this invention controls the extraction equipment to intermittently extract groundwater from extraction well 1. This ensures that when organic pollutants not intercepted by interception well 3 flow with groundwater from the gaps between interception wells 3 to extraction well 1, the extraction equipment extracts the groundwater through extraction well 1, thereby removing pollutants from the groundwater and preventing the pollution source from spreading into the control area A. Moreover, the intermittent extraction of groundwater by extraction well 1 controls the direction of groundwater flow, ensuring that groundwater flows through interception wells 3 rather than bypassing them. This helps improve the interception efficiency of interception wells 3 for organic pollutants and can intermittently accelerate the flow rate of groundwater, thereby speeding up the groundwater renewal process in control area A.

[0047] The adsorbent material 2 is formed by filling the space between the large-diameter screen tube 4A and the small-diameter screen tube 5A of the interception well to form an adsorption column 2A in the interception well, thus constructing a biofilm. This can improve the adsorption capacity of the adsorbent material 2 for organic pollutants and extend the service life of the adsorbent material 2.

[0048] Third, see Figures 4 to 6 In this invention, extraction wells 1 are arranged with increasing spacing from the middle to both ends of the straight line segment. The extraction equipment is controlled to continuously extract groundwater W from each extraction well 1, thereby altering the hydraulic gradient of the groundwater W flowing from upstream to the extraction well 1, and causing groundwater W to form at that location. Figure 5 The drop funnel shape shown is kept stable so that the groundwater W converges at the middle position of all extraction wells 1, thereby achieving the effect of blocking and controlling the groundwater W and the pollutants in it.

[0049] Furthermore, this invention employs an adsorption column 2B, which is installed in each extraction well 1, as an adsorption and degradation unit. This allows the organic pollutants in the groundwater W pumped into the extraction well 1 to be adsorbed by the adsorption column 2B and biodegraded by microorganisms, thus achieving preliminary remediation of the groundwater W. This reduces the concentration of pollutants in the groundwater W and decreases the cost and time of subsequent secondary wastewater treatment. Then, the remaining pollutants are extracted with the groundwater W to the outside of the extraction well 1 for secondary wastewater treatment.

[0050] Moreover, by placing the adsorption and degradation unit inside the extraction well 1, the present invention can reduce the number of wells drilled, thereby reducing implementation costs and floor space required.

[0051] The adsorbent material 2 is formed by filling the large-diameter screen tube 4B and the small-diameter screen tube 5B of the extraction well to form an adsorption column 2B, which constitutes a biofilm. This can improve the adsorption capacity of the adsorbent material 2 for organic pollutants and extend the service life of the adsorbent material 2.

[0052] Fourth, see Figure 4 and Figure 5 This invention sets up an aeration barrier unit consisting of an air injection system and multiple aeration wells 12 downstream of the extraction well 1. The compressed air injected into the groundwater W by the air injection system through each aeration well 12 forms an airflow barrier to prevent the groundwater W after passing through the extraction well 1 from continuing to flow into the control area A. This achieves the effect of blocking the pollutants remaining in the groundwater W, keeping them upstream of the control area A so that they can continue to be extracted and repaired by the extraction unit and the adsorption degradation unit. Attached Figure Description

[0053] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0054] Figure 1 This is a plan view of the groundwater pollution source control system according to Embodiment 2 of the present invention;

[0055] Figure 2 This is a cross-sectional view of the interception well 3 in Embodiment 2 of the present invention;

[0056] Figure 3 This is a schematic cross-sectional view of extraction well 1 in Embodiment 2 of the present invention;

[0057] Figure 4 This is a plan view of the groundwater pollution source control system according to Embodiment 3 of the present invention;

[0058] Figure 5 This is a schematic elevation view of the groundwater pollution source control system according to Embodiment 3 of the present invention;

[0059] Figure 6 This is a cross-sectional view of extraction well 1 in Embodiment 3 of the present invention. Detailed Implementation

[0060] The present invention will now be described in detail with reference to the embodiments and accompanying drawings to help those skilled in the art better understand the inventive concept of the present invention. However, the scope of protection of the claims of the present invention is not limited to the following embodiments. For those skilled in the art, all other embodiments obtained without creative effort without departing from the inventive concept of the present invention are within the scope of protection of the present invention.

[0061] Example 1

[0062] like Figures 1 to 6 As shown, the present invention discloses a groundwater pollution source control system based on interception and adsorption, which is applicable to the situation where the control area A is located downstream of the pollution source in the groundwater. It includes an extraction unit and an adsorption and degradation unit, both of which are set at the boundary A1 of the control area A near the pollution source.

[0063] The extraction unit is equipped with extraction equipment and multiple extraction wells 1. The extraction equipment can extract groundwater W from each extraction well 1. The extraction wells 1 are arranged at intervals along a straight line segment, which is perpendicular to the groundwater flow direction V of the groundwater W. The diameter of the extraction well 1 is selected according to the requirements and conditions, and is generally 110mm. The extraction well 1 is set at the opening position for external groundwater to flow into its interior, corresponding to the thickness of the underground aquifer.

[0064] The adsorption and degradation unit is not located downstream of the extraction well 1 in the groundwater W. The unit is equipped with an adsorption material 2 capable of adsorbing organic pollutants in the groundwater W, and this adsorption material 2 is infused with microorganisms capable of biodegrading the organic pollutants. The selection of the adsorption material 2 should adhere to principles such as long lifespan, optimal adsorption effect on common organic pollutants in groundwater (alkanes, petroleum hydrocarbons, benzene compounds, halogenated hydrocarbons, chlorinated hydrocarbons, etc.), reusability and ease of treatment, and harmlessness to humans and no impact on groundwater quality. Activated carbon and zeolite molecular sieves are generally preferred. The microorganisms should be indigenous microorganisms from the controlled area A, and should adhere to principles such as non-selectivity towards the organic pollutants, easy survival underground, harmlessness to humans, minimal impact on the underground environment, and long lifespan.

[0065] Therefore, the working principle of the groundwater pollution source control system of the present invention is as follows:

[0066] Groundwater W, carrying pollutants from an upstream pollution source, can first have its organic pollutants adsorbed by the adsorption material 2 of the adsorption degradation unit as it flows into the control zone A. The microorganisms in the adsorption material 2 then biodegrade the organic pollutants. The remaining pollutants are then extracted with the groundwater W to the extraction well 1 for secondary wastewater treatment. Thus, this invention can achieve both preliminary remediation of groundwater W and physical removal of the remaining pollutants to the extraction well 1, preventing the spread of pollution from the pollution source to the control zone A.

[0067] Moreover, the implementation of this invention is not limited by the site conditions of the controlled area A, and has minimal underground disturbance. It can be used as a pollution source risk control measure, as well as for soil and groundwater remediation.

[0068] Example 2

[0069] Based on the above embodiment one, this embodiment two also adopts the following preferred implementation method:

[0070] like Figures 1 to 3 As shown, the adsorption and degradation unit is equipped with multiple interception wells 3. All the interception wells 3 are arranged at uniform intervals perpendicular to the groundwater flow direction V and are located upstream of the extraction well 1.

[0071] See Figure 2 The interception well 3 is equipped with interception well screen holes for external groundwater to flow into its interior. The opening position of the interception well screen holes is designed according to the required vertical interception position of organic pollutants. The well diameter of the interception well 3 can be selected according to the needs and conditions. The interception well 3 is fixed with a large-diameter screen pipe 4A and a small-diameter screen pipe 5A arranged coaxially with the lower pipe opening sealed. The space between the large-diameter screen pipe 4A and the small-diameter screen pipe 5A is filled with the adsorbent material 2 to form an interception well adsorption column 2A. The microorganisms are injected into the interception well adsorption column 2A.

[0072] Furthermore, the effective range of the interception well adsorption column 2A in the interception well 3 for adsorbing organic pollutants in groundwater is defined as the adsorption influence range. This adsorption influence range is a cylindrical range coaxial with the adsorption column 2A of the interception well, and the adsorption influence ranges of two adjacent interception wells 3 partially overlap.

[0073] During the operation of the groundwater pollution source control system, the extraction equipment controls whether to extract groundwater from the corresponding extraction well 1 based on the groundwater level in each extraction well 1. That is, when the groundwater level in any extraction well 1 rises to the preset upper limit level, the extraction equipment extracts the groundwater from that extraction well 1; when the groundwater level in any extraction well 1 drops to the preset lower limit level, the extraction equipment stops pumping water from that extraction well 1.

[0074] Therefore, the working principle of the groundwater pollution source control system in Embodiment 2 of the present invention is as follows:

[0075] See Figure 1 and Figure 2 This invention employs multiple interception wells 3, evenly spaced perpendicular to the groundwater flow direction V, as adsorption and degradation units. Each interception well 3 contains an adsorption column 2A. The interception wells 3 are positioned upstream of the extraction well 1, so that groundwater from upstream first reaches the interception wells 3 and enters the adsorption influence range of each interception well 3. The organic pollutants in the groundwater are adsorbed into the corresponding adsorption column 2A, where microorganisms biodegrade the organic pollutants. Thus, each interception well 3 forms a non-continuous physical barrier adsorption wall capable of intercepting, adsorbing, and degrading organic pollutants in groundwater.

[0076] Furthermore, by comparing groundwater levels, this invention controls the extraction equipment to intermittently extract groundwater from extraction well 1. This ensures that when organic pollutants not intercepted by interception well 3 flow with groundwater from the gaps between interception wells 3 to extraction well 1, the extraction equipment extracts the groundwater through extraction well 1, thereby removing pollutants from the groundwater and preventing the pollution source from spreading into the control area A. Moreover, the intermittent extraction of groundwater by extraction well 1 controls the direction of groundwater flow, ensuring that groundwater flows through interception wells 3 rather than bypassing them. This helps improve the interception efficiency of interception wells 3 for organic pollutants and can intermittently accelerate the flow rate of groundwater, thereby speeding up the groundwater renewal process in control area A.

[0077] The adsorbent material 2 is formed by filling the space between the large-diameter screen tube 4A and the small-diameter screen tube 5A of the interception well to form an adsorption column 2A in the interception well, thus constructing a biofilm. This can improve the adsorption capacity of the adsorbent material 2 for organic pollutants and extend the service life of the adsorbent material 2.

[0078] The above is the basic implementation method of this embodiment two, and further optimizations, improvements and limitations can be made based on this basic implementation method:

[0079] Preferred: See Figure 1 The number of extraction wells 1 is one less than the number of interception wells 3, and each extraction well 1 is located 0.5m to 1m directly behind the midpoint of two adjacent interception wells 3. This ensures that each extraction well 1 is positioned at the weakest point in the barrier adsorption wall formed by the interception wells 3, where the interception of organic pollutants is least effective, thus achieving optimal removal of pollutants from groundwater by the extraction wells 1.

[0080] Preferred: See Figure 2The groundwater pollution source control system also includes an oxygen supply system. The oxygen supply pipe 6 of this system is inserted into the cavity of the small-diameter screen pipe 5A of the interception well and extends to the bottom. Thus, by continuously aerating at appropriate pressure through the oxygen supply system, an aerobic environment is provided for the adsorption column 2A of the interception well, thereby accelerating the biodegradation rate of organic pollutants by microorganisms.

[0081] Preferably, the section of the oxygen supply pipe 6 located within the interception well 3 is equipped with an oxygen supply pipe union 6-1 for easy maintenance and replacement. The large-diameter screen pipe 4A and the small-diameter screen pipe 5A of the interception well are preferably secured by steel wire ropes attached to the wellhead 3-1 of the interception well 3. A pressure gauge is preferably installed on the wellhead 3-1. Preferably, the outer diameter of the large-diameter screen pipe 4A is 1-2 cm smaller than the inner diameter of the interception well 3, and the inner diameter of the small-diameter screen pipe 5A is 1-2 cm larger than the outer diameter of the oxygen supply pipe 6.

[0082] Preferred: See Figure 3 The extraction equipment includes liquid phase extraction equipment and gas phase extraction equipment;

[0083] The liquid extraction equipment is equipped with a submersible pump 7 and a level gauge 8 for monitoring the groundwater level in the extraction well 1. The submersible pump 7 is placed at the bottom of the extraction well 1, and its outlet is connected to one end of a submersible pump suction pipe 9. The other end of the submersible pump suction pipe 9 extends outside the extraction well 1, so that the groundwater in the extraction well 1 can be extracted by the submersible pump 7. The level gauge 8 is attached to the extraction well head 1-1 of the extraction well 1 by a steel wire rope. The submersible pump suction pipe 9... The pipe section located inside the extraction well 1 is preferably equipped with a submersible pump water pipe union 9-1 and a submersible pump water pipe check valve 9-2. The pipe section of the submersible pump water pipe 9 located outside the extraction well 1 is preferably equipped with a submersible pump water pipe ball valve 9-3 and a submersible pump water pipe electronic flow meter 9-4. The submersible pump water pipe 9 is preferably branched off with a sampling branch equipped with a sampling branch ball valve 9-5 to facilitate sampling and analysis through the sampling branch. The extraction well head 1-1 is preferably equipped with a negative pressure gauge.

[0084] The extraction well 1 has a gas phase extraction port 1-2 on its side wall. The gas phase extraction equipment uses a vacuum pump. The vacuum pump's extraction port is connected to the gas phase extraction port 1-2 of the extraction well 1 through a vacuum pump extraction pipe 10. By intermittently operating the vacuum pump, the free gas phase, gases produced by microbial degradation, and VOCs in the soil within the extraction well 1 can be removed. Preferably, the vacuum pump extraction pipe 10 is equipped with a vacuum pump extraction pipe ball valve 10-1 and a vacuum pump extraction pipe flow sensor 10-2.

[0085] Additionally, in this second embodiment, the single-pump multiphase extraction unit described in the third embodiment below can also be used to replace the above-mentioned liquid phase extraction equipment and gas phase extraction equipment as the extraction equipment.

[0086] Example 3

[0087] Based on the above embodiment one, this embodiment three also adopts the following preferred implementation method:

[0088] like Figures 4 to 6 As shown, the adsorption and degradation unit has a large-diameter screen pipe 4B and a small-diameter screen pipe 5B fixed inside each extraction well 1, with the lower pipe opening sealed and arranged coaxially. The space between the large-diameter screen pipe 4B and the small-diameter screen pipe 5B is filled with the adsorbent material 2 to form an extraction well adsorption column 2B. The microorganisms are injected into the extraction well adsorption column 2B. See also... Figure 5 The top surface of the adsorption column 2B in the extraction well is preferably flush with the original liquid level of the groundwater W before it is extracted.

[0089] Furthermore, the spacing between two adjacent extraction wells 1 increases progressively from the middle position of the straight line segment towards both ends; for example: Figure 4 The seven extraction wells shown are spaced 1.0m, 0.75m, 0.5m, 0.5m, 0.75m and 1.0m apart from top to bottom.

[0090] During the operation of the groundwater pollution source control system, the extraction equipment continuously extracts groundwater W from each extraction well 1.

[0091] Therefore, the working principle of the groundwater pollution source control system in Embodiment 3 of the present invention is as follows:

[0092] See Figures 4 to 6 In this invention, extraction wells 1 are arranged with increasing spacing from the middle to both ends of the straight line segment. The extraction equipment is controlled to continuously extract groundwater W from each extraction well 1, thereby altering the hydraulic gradient of the groundwater W flowing from upstream to the extraction well 1, and causing groundwater W to form at that location. Figure 5 The drop funnel shape shown remains stable. Figure 5 W1 in the diagram represents the water level of the drop funnel, so that the groundwater W converges at the middle position of all the extraction wells 1, thereby achieving the effect of blocking and controlling the groundwater W and the pollutants in it.

[0093] Furthermore, this invention employs an adsorption column 2B, which is installed in each extraction well 1, as an adsorption and degradation unit. This allows the organic pollutants in the groundwater W pumped into the extraction well 1 to be adsorbed by the adsorption column 2B and biodegraded by microorganisms, thus achieving preliminary remediation of the groundwater W. This reduces the concentration of pollutants in the groundwater W and decreases the cost and time of subsequent secondary wastewater treatment. Then, the remaining pollutants are extracted with the groundwater W to the outside of the extraction well 1 for secondary wastewater treatment.

[0094] Moreover, by placing the adsorption and degradation unit inside the extraction well 1, the present invention can reduce the number of wells drilled, thereby reducing implementation costs and floor space required.

[0095] The adsorbent material 2 is formed by filling the large-diameter screen tube 4B and the small-diameter screen tube 5B of the extraction well to form an adsorption column 2B, which constitutes a biofilm. This can improve the adsorption capacity of the adsorbent material 2 for organic pollutants and extend the service life of the adsorbent material 2.

[0096] The above is the basic implementation method of this embodiment three, and further optimizations, improvements and limitations can be made based on this basic implementation method:

[0097] Preferred: See Figure 6 The extraction equipment adopts a single-pump multiphase extraction unit, including an SVE extraction device. The extraction port of the SVE extraction device is connected to one end of the multiphase extraction pipe 11, and the other end of the multiphase extraction pipe 11 is inserted into the small-diameter screen pipe 5B of the extraction well and extends to the bottom, so as to simultaneously extract the liquid phase and gas phase in the extraction well 1 through the SVE extraction device. Preferably, the other end of the multiphase extraction pipe 11 is left at a certain distance from the bottom of the well and is wrapped with gauze for filtering silt and impurities; the section of the multiphase extraction pipe 11 located inside the extraction well 1 is preferably equipped with a multiphase extraction pipe union 11-1 and a multiphase extraction pipe check valve 11-2; the section of the multiphase extraction pipe 11 located outside the extraction well 1 is preferably equipped with a multiphase extraction pipe ball valve 11-3, a multiphase extraction pipe electronic flow meter 11-4 and a transparent PVC pipe 11-5, the transparent PVC pipe 11-5 being used to observe the water supply; a negative pressure gauge is preferably installed at the extraction well head 1-1 of the extraction well 1.

[0098] Example 4

[0099] Based on any one of the above embodiments one to three, this embodiment four further adopts the following preferred implementation method:

[0100] like Figure 4 and Figure 5As shown, the groundwater pollution source control system further includes an aeration barrier unit; the aeration barrier unit is equipped with an air injection system and multiple aeration wells 12; the air injection system can aerate the groundwater W by injecting compressed air into each aeration well 12; all the aeration wells 12 are arranged at intervals along the vertical direction of the groundwater flow direction V and are located downstream of all the extraction wells 1; wherein, the air injection system preferably adopts an AS air injection system.

[0101] The gas injection system operates continuously during the operation of the groundwater pollution source control system.

[0102] Therefore, the working principle of the groundwater pollution source control system in Embodiment 4 of the present invention is as follows:

[0103] This invention establishes an aeration barrier unit downstream of extraction well 1, consisting of an air injection system and multiple aeration wells 12. This unit allows the compressed air injected into groundwater W through each aeration well 12 to form an airflow barrier, preventing the groundwater W from continuing to flow and diffuse into the control area A after passing through extraction well 1. This achieves the barrier effect on pollutants remaining in the groundwater W, keeping them upstream of the control area A so that they can continue to be extracted and repaired by the extraction unit and adsorption degradation unit.

[0104] In addition, for the above embodiment three, the aeration barrier unit can also provide an aerobic environment for the adsorption column 2B of the extraction well to accelerate the biodegradation rate of organic pollutants by microorganisms.

[0105] The above is the basic implementation method of this embodiment four, and further optimizations, improvements and limitations can be made based on this basic implementation method:

[0106] Preferably, the number of aeration wells 12 is one less than the number of extraction wells 1, and each aeration well 12 is located 0.5m to 1m directly behind the midpoint of two adjacent extraction wells 1, with the aeration position 12a of the aeration well 12 located 0.5m to 1m below the bottom surface of the extraction well 1. This optimizes the aeration barrier unit's ability to block pollutants.

[0107] This invention is not limited to the specific embodiments described above. Based on the above content and in accordance with common technical knowledge and conventional methods in the field, without departing from the basic technical concept of this invention, this invention can also make other equivalent modifications, substitutions or alterations, all of which fall within the protection scope of this invention.

Claims

1. A groundwater pollution source control system based on interception adsorption, suitable for the case where a blocking control area (A) is located at a position downstream of a pollution source with respect to groundwater, characterized in that, The groundwater pollution source control system comprises: an extraction unit and an adsorption degradation unit, both of which are arranged at a boundary position (A1) of the control area (A) close to the pollution source; the extraction unit is provided with an extraction device and a plurality of extraction wells (1), the extraction device is capable of extracting the groundwater (W) in each extraction well (1), and each extraction well (1) is arranged at intervals along a straight line segment, which is perpendicular to the groundwater flow direction (V) of the groundwater (W); the adsorption degradation unit is not located downstream of the extraction well (1) in the groundwater (W), the adsorption degradation unit is provided with an adsorption material (2) capable of adsorbing organic pollutants in the groundwater (W), and the adsorption material (2) is injected with microorganisms capable of biodegrading the organic pollutants; the adsorption degradation unit is fixed with an extraction well large-diameter screen pipe (4B) and an extraction well small-diameter screen pipe (5B) inside each extraction well (1), the extraction well large-diameter screen pipe (4B) and the extraction well small-diameter screen pipe (5B) are coaxially arranged and blocked at the lower pipe opening, the space between the extraction well large-diameter screen pipe (4B) and the extraction well small-diameter screen pipe (5B) is filled with the adsorption material (2) to form an extraction well adsorption column (2B), and the microorganisms are injected into the extraction well adsorption column (2B); and the spacing between two adjacent extraction wells (1) gradually increases from the middle position of the straight line segment to the two end positions; during the operation of the groundwater pollution source control system, the extraction device continuously extracts the groundwater (W) in each extraction well (1).

2. The system for groundwater pollution source control based on interception adsorption according to claim 1, characterized in that: The adsorption degradation unit is provided with a plurality of interception wells (3), all the interception wells (3) are uniformly arranged at intervals perpendicular to the groundwater flow direction (V) and located upstream of the extraction well (1); the interception well (3) is provided with an interception well screen hole for external groundwater to flow into its interior; the interior of the interception well (3) is fixed with an interception well large-diameter screen pipe (4A) and an interception well small-diameter screen pipe (5A) which are coaxially arranged and blocked at the lower pipe opening, the space between the interception well large-diameter screen pipe (4A) and the interception well small-diameter screen pipe (5A) is filled with the adsorption material (2) to form an interception well adsorption column (2A), and the microorganisms are injected into the interception well adsorption column (2A); and the effective range of the interception well adsorption column (2A) in the interception well (3) for adsorbing organic pollutants in the groundwater is defined as the adsorption influence range, and the adsorption influence ranges of two adjacent interception wells (3) partially overlap; the number of the extraction wells (1) is one less than the number of the interception wells (3), and each extraction well (1) is located 0.5m to 1m behind the middle position between two adjacent interception wells (3).

3. The system for in-situ groundwater pollution source control based on interception adsorption according to claim 2, characterized in that: The groundwater pollution source control system is also provided with an oxygen supply system, and the oxygen supply pipe (6) of the oxygen supply system penetrates into the lumen of the interception well small-diameter screen pipe (5A) and extends to the bottom position.

4. The system for in-situ groundwater pollution source control based on interception adsorption according to claim 1, characterized in that: The extraction device comprises a liquid-phase extraction device and a gas-phase extraction device; The liquid phase extraction device is provided with a submersible pump (7) and a liquid level meter (8) for monitoring the water level of the underground water in the extraction well (1); the submersible pump (7) is placed at the bottom of the extraction well (1), the water outlet of the submersible pump (7) is connected to one end of the submersible pump water suction pipe (9), and the other end of the submersible pump water suction pipe (9) extends out of the extraction well (1); the liquid level meter (8) is hung below the extraction well wellhead (1-1) of the extraction well (1) through a steel wire rope; The sidewall of the extraction well (1) is provided with a gas phase extraction port (1-2), the gas phase extraction device adopts a vacuum pump, and the air suction port of the vacuum pump is connected to the gas phase extraction port (1-2) of the extraction well (1) through a vacuum pump air suction pipe (10).

5. The system for groundwater pollution source control based on interception adsorption according to claim 1, characterized in that: The extraction device adopts a single-pump multi-phase extraction unit, which contains an SVE extraction device, the extraction port of the SVE extraction device is connected to one end of a multi-phase extraction pipe (11), and the other end of the multi-phase extraction pipe (11) penetrates into the extraction well small-diameter screen pipe (5B) and extends to the bottom.

6. The system for interception and adsorption based control of groundwater pollution sources according to any one of claims 1 to 5, characterized in that: The groundwater pollution source control system further comprises an aeration barrier unit; the aeration barrier unit is provided with a gas injection system and a plurality of aeration wells (12); the gas injection system can realize aeration of the underground water (W) by injecting compressed air into each aeration well (12); all the aeration wells (12) are arranged in a spaced manner along the vertical direction of the groundwater flow direction (V) and located downstream of all the extraction wells (1); During the operation of the groundwater pollution source control system, the gas injection system continuously operates.

7. The system for in-situ groundwater pollution source control based on interception adsorption according to claim 6, characterized in that: The number of the aeration wells (12) is less than that of the extraction wells (1) by one, and each aeration well (12) is located 0.5m to 1m behind the middle position between two adjacent extraction wells (1), and the aeration position (12a) of the aeration well (12) is located 0.5m to 1m below the bottom surface of the extraction well (1).

Images