A circulation well group and circulation mode control method thereof

Abstract

The present invention relates to a circulation well group and a circulation mode control method thereof, comprising at least two multi-filter layer circulation wells, a plurality of pumping and injection components and a control module, wherein at least two multi-filter layer circulation wells are arranged in order according to the direction of groundwater flow, wherein the wellbore of the multi-filter layer circulation well is divided by at least two first barriers to form three pumping and injection sections, each pumping and injection section is provided with at least one group of pumping and injection components for pumping and injecting water, the pumping and injection components are controlled by the control module to pump water and / or inject water, the pipe wall of each pumping and injection section is provided with a pumping and injection screen section with holes, and in response to the control instruction of the control module, the pumping and injection components change the pumping and injection state, flow rate and pressure of the three pumping and injection sections of each multi-filter layer circulation well to form different water circulation modes or water circulation combination modes. The present invention can regulate the pumping and injection mode, pumping and injection flow rate and opening and closing state of the multi-filter layer circulation well according to the restoration target of each aquifer in the heterogeneous formation, so as to achieve the restoration of the target aquifer and improve the restoration efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of in-situ remediation of groundwater pollution, and in particular to a circulation well group and a circulation mode control method thereof. Background Art

[0002] Groundwater Circulation Well (GCW) is an in-situ groundwater remediation technology with significant advantages such as small footprint, wide applicability, high efficiency and low cost. It can be used in combination with chemical oxidation, biodegradation, in-situ heating and other remediation technologies, and comprehensively utilizes physical, chemical and biological processes to achieve groundwater remediation and management, solving the problem of simultaneous remediation of multi-component and difficult-to-degrade organic pollution in groundwater. It has huge development potential and broad application prospects. GCW has been widely used in countries such as the United States and Germany, and has many successful engineering remediation cases. This technology has been monopolized by patents in the United States and Germany. Related research in my country started late and is still in the research stage. There is a lack of complete equipment, and there is no case of site engineering remediation using circulation well technology.

[0003] As an advanced in-situ remediation technology, GCW has the following main factors that restrict its large-scale application in my country: (1) underground aquifers are mainly composed of multi-layer heterogeneous media with different properties. Their structures and distributions are diverse. Most heterogeneous aquifers are distributed in layers. Traditional double-screen circulation wells have high requirements for site hydrogeological conditions. The remediation effect of aquifers with strong anisotropy is poor. Large permeability gradients affect the remediation efficiency and may even cause the circulation wells to be unable to operate. (2) Traditional double-screen circulation wells fail to fully consider the hydrogeological characteristics and pollution characteristics of the contaminated site when remediating groundwater pollution. During the remediation process, the remediation method is not adjusted in time according to the degree and condition of remediation, which easily leads to low remediation efficiency and poor remediation effect. (3) There is a lack of design of circulation well groups based on the characteristics of the contaminated site and regulation of circulation patterns. The control method of coupling and interaction between multiple wells is still unclear.

[0004] The existing circulation wells used for in-situ remediation of groundwater are generally two-stage circulation wells, which form only two water circulation modes, namely, upper pumping and lower injection and upper injection and lower pumping. The circulation contours of these two circulation modes are similar, so even by adjusting the flow rate, only the remediation ranges with different but similar circulation contour shapes are formed. For aquifers with different pollution levels, it is impossible to carry out short-term remediation of severely polluted aquifers in a targeted manner. Long-term remediation can only rely on the current water circulation mode until the groundwater remediation standards are met. When multiple two-stage circulation wells are arranged along the direction of water flow, the water circulation patterns between the two two-stage circulation wells are similar, and pollutants within the range of the circulation well water flow capture are repaired and removed simultaneously, and it is impossible to carry out targeted enhanced remediation of heavily polluted areas.

[0005] For example, the Chinese patent with publication number CN113184930 A discloses a multi-effect reaction type groundwater circulation well group and repair method, including a repair well group and an observation well group; the repair well group includes a plurality of repair wells evenly arranged on the repair center line; the observation well group includes a plurality of observation wells arranged around the repair well farthest from the pollution source; the multi-effect reaction type groundwater circulation well group of the invention, through the setting of the repair well and the observation well, in the process of continuous detection, uses the medicine box to chemically treat the polluted water, uses the circulation pump to continuously pump the polluted water to the medicine box, and discharges the groundwater carrying the agent and having a low degree of pollution after the reaction into the groundwater aquifer through the flower hole of the upper well pipe through the upper well pipe. The invention adopts a two-stage circulation well, so the water circulation mode formed by it is limited. No matter how the pumping mode of two adjacent circulation wells is changed, it is impossible to focus on repairing and circulating a certain aquifer, and it is impossible to repair one aquifer without affecting another aquifer.

[0006] During the investigation of the contaminated site, it was found that even in the pollution plume of the same contaminated site, the distribution of pollutants in different areas was different. For example, in case 1, the pollution range is large and the concentration is high near the pollution source, and the pollutants are mainly distributed in the upper aquifer with a large permeability coefficient. This situation is of little significance to the restoration of the second aquifer; in case 2, the pollution range is small and the concentration is low at the edge of the pollution plume downstream of the pollution source, and the pollutants are mainly distributed in the lower aquifer with a small permeability coefficient. The above two situations are of little significance to the restoration of the first aquifer; the circulation of the two-stage circulation well, on the contrary, allows the pollutants in the upper or lower layers to enter the uncontaminated aquifer. In case 3, the pollutants are distributed more evenly in the first aquifer and the second aquifer; in case 4, the pollution plume between the two circulation wells is distributed more widely vertically, and the edge position is basically flush with the screen section; in case 5, the pollution plume between the two circulation wells has a smaller vertical distribution range, and the pollutants are mainly concentrated between the upper and lower screen sections; in cases 3 to 5, the two-stage circulation well cannot effectively repair the pollutants near the edge of the pollution plume between the circulation wells, forming a repair blind spot. Therefore, the current two-stage circulation well has limited circulation patterns and cannot be fully applied to complex groundwater pollution situations.

[0007] Based on the defects of the two-stage circulation well in the prior art, the present invention provides a three-stage multi-filter layer circulation well, and provides a variety of control modes that can be used for complex groundwater pollution situations, and can even carry out targeted repair of contaminated groundwater by isolating the contaminated groundwater.

[0008] In addition, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making the present invention, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present invention does not have the characteristics of these prior arts. On the contrary, the present invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Summary of the invention

[0009] The defects of the two-stage circulation well in the prior art include at least the following: few circulation modes and few interaction modes between adjacent circulation wells. Only the first aquifer and the second aquifer can be repaired in a large circulation manner, and the water flow circulation cannot be enhanced for a certain aquifer with more serious pollution. Therefore, the repair time is long, resulting in low repair efficiency.

[0010] In view of the deficiencies in the prior art, the present invention provides a circulation well group, comprising at least two multi-filter layer circulation wells, a plurality of pumping and injection components and a control module, wherein at least two of the multi-filter layer circulation wells are arranged in order according to the direction of groundwater flow, wherein the wellbore of the multi-filter layer circulation well is divided by at least two first barriers to form three pumping and injection sections, each pumping and injection section is provided with at least one group of pumping and injection components for pumping and injecting water, the pumping and injection components are controlled by the control module for pumping and / or injecting water, the pipe wall of each pumping and injection section is provided with a pumping and injection screen section with holes, and in response to the control instructions of the control module, the pumping and injection components change the pumping and injection states, flow rates and pressures of the three pumping and injection sections of each of the multi-filter layer circulation wells to combine and form different water circulation modes or water circulation combination modes.

[0011] Compared with the two-stage circulation well, the present invention creatively designs a three-stage circulation well. In addition to the traditional large-circulation repair mode, the multi-filter layer circulation well of the present invention can implement small circulation for the first aquifer or the second aquifer to increase the repair cycle frequency of groundwater while performing large-circulation repair. As the circulation mode of a single multi-filter layer circulation well increases, the circulation combination modes formed by the combination of adjacent circulation wells also increase accordingly, thereby increasing and improving the repair efficiency of the overall circulation well group, and realizing the circulation combination mode and repair effect that cannot be achieved by the two-stage circulation well group.

[0012] Preferably, the wellbore is divided by two of the first barrier devices to form a first pumping section, a second pumping section and a third pumping section, the levels of the first pumping section, the second pumping section and the third pumping section are successively reduced, and the level of the second pumping section approaches or is equal to the level of the medium stratification interface, and the water circulation mode formed by the control module based on changing the pumping state of each pumping section includes at least: a first small circulation located in the first aquifer formed by the combination of the first pumping section and the second pumping section, water flows out of the first pumping section through the first aquifer and flows into the second pumping section, or flows out of the second pumping section through the first aquifer and flows into the first pumping section; a second small circulation located in the second aquifer formed by the combination of the second pumping section and the third pumping section, water flows out of the second pumping section through the second aquifer and flows into the third pumping section, or flows out of the third pumping section through the second aquifer layer flows into the second pumping section; a double circulation formed by the first pumping section, the second pumping section and the third pumping section, water flows out from the first pumping section and the third pumping section respectively through the first aquifer and the second aquifer into the second pumping section, or flows out from the second pumping section respectively through the first aquifer and the second aquifer into the first pumping section and the third pumping section respectively; a large circulation formed by the combination of the first pumping section and the third pumping section, water flows out from the first pumping section successively through the first aquifer and the second aquifer into the third pumping section, or flows out from the third pumping section successively through the second aquifer and the first aquifer into the first pumping section. When the control module adjusts the pumping state, flow rate, pressure and circulation direction, the first small circulation, the second small circulation, the double circulation and the large circulation can be controlled by the control module to form at least one water circulation combination mode.

[0013] Obviously, the multi-filter circulation well of the present invention has as many as four water circulation modes, and the water circulation modes can be circulated simultaneously to form a combination for use. Adjacent circulation wells can also form more water circulation combination modes by coordinating the pumping directions to achieve multi-frequency remediation of groundwater, and even form a hydraulic barrier to prevent the spread of pollution plumes downstream.

[0014] Preferably, the control module selects an adaptive water circulation mode or a water circulation combination mode based on the distribution characteristics of pollutants in the aquifer.

[0015] Since the present invention has more water circulation modes, special repairs can be carried out on the first aquifer, the second aquifer and the middle area respectively within the repair range of the circulation well and between the circulation wells. Therefore, there is no blind spot in the repair of the circulation well group of the present invention, and the repair effect is better.

[0016] Preferably, the multi-filter layer circulation well also includes a plurality of auxiliary wells, and the auxiliary wells are arranged in a manner centered on the multi-filter layer circulation well, and the wellbore of the auxiliary well is divided into two space parts by a second barrier, and at least one space part of the auxiliary well is provided with at least one injection pump connected by an injection pipe, and the horizontal height of the second barrier approaches or is equal to the horizontal height of the medium stratification interface.

[0017] The auxiliary well of the present invention can observe the restoration of groundwater, and can inject drugs into different aquifers to enhance the restoration effect of groundwater. The present invention can also change the water circulation combination mode according to the restoration of groundwater, reduce meaningless restoration of non-polluted areas, and reduce energy loss.

[0018] Preferably, based on the change in the degree of groundwater remediation, the control module changes the water circulation combination mode in a manner of orderly closing at least one of the multi-filter layer circulation wells.

[0019] In the working mode of the traditional circulation well group, all the circulation wells are started and repaired. As the groundwater repair progresses, the pollutants in the downstream are getting less and less, but the water circulation mode of each circulation well has not changed, which leads to some aquifers without pollution still being repaired by circulation wells, resulting in waste of materials and energy, and increasing the risk of secondary environmental pollution. Based on this, the present invention orderly closes the circulation wells that are not meaningful for repair in response to changes in the groundwater repair situation, reduces the operation of the circulation wells without affecting the efficiency of groundwater repair, and reduces energy consumption.

[0020] Preferably, based on the groundwater contamination situation, the control module adjusts the water circulation pattern, flow rate and / or pressure of each of the multi-layer circulation wells in a manner that enables the contaminated groundwater to circulate in the circulation well group, thereby forming a truncation effect on the contaminated groundwater.

[0021] The traditional circulation well group, due to the single water circulation mode, cannot form a complete circulation of the polluted groundwater in the groundwater pollution area by pumping and injecting, and combining pressure, nor can it prevent the polluted groundwater from continuing to flow downstream. The present invention has multiple water circulation modes, and the polluted groundwater circulates in the circulation well group through the pressure difference, thus realizing the fact of cutting off the polluted groundwater, and being able to discharge the repaired groundwater into the downstream, so the groundwater repair effect is better.

[0022] Preferably, when the pollutants are mainly distributed in the first aquifer or the second aquifer, the control module performs groundwater remediation based on a water circulation combination mode of the first small circulation or the second small circulation combined with the large circulation; when the pollutants are evenly distributed in the first aquifer and the second aquifer, the control module performs groundwater remediation based on a double circulation mode; when the pollution plume between the multi-filter layer circulation wells is widely distributed vertically and the edge position is basically flush with the screen section, the control module forms a water circulation combination mode in which the adjacent multi-filter layer circulation wells circulate water in a double circulation mode with opposite circulation directions; when the pollution plume between the multi-filter layer circulation wells is distributed vertically in a small range and the pollutants are mainly concentrated between the upper and lower screen sections, the control module forms a water circulation combination mode in which the adjacent multi-filter layer circulation wells circulate water in a double circulation mode with the same circulation direction. Obviously, the multi-filter layer circulation well group of the present invention can realize targeted water circulation combination modes for different groundwater pollution characteristics and improve the remediation efficiency of groundwater.

[0023] The present invention also provides a circulation mode control method for a circulation well group, the control method at least comprising: adjusting the pumping state, flow rate and pressure of the three pumping sections of each multi-filter layer circulation well to combine and form different water circulation modes or water circulation combination modes, wherein the wellbore of the multi-filter layer circulation well is divided into three pumping sections by at least two first barrier devices, each pumping section is provided with at least one group of pumping and injection components for pumping and injecting water, the pumping and injection components are controlled by the control module to pump water and / or inject water, and the pipe wall of each pumping section is provided with a pumping and injection screen section with holes.

[0024] Preferably, the method further comprises: forming at least one water circulation mode based on changing the pumping state of each pumping section; the water circulation mode at least comprises: a first small circulation located in the first aquifer formed by the combination of the first pumping section and the second pumping section, water flows out from the first pumping section through the first aquifer and flows into the second pumping section, or flows out from the second pumping section through the first aquifer and flows into the first pumping section; a second small circulation located in the second aquifer formed by the combination of the second pumping section and the third pumping section, water flows out from the second pumping section through the second aquifer and flows into the third pumping section, or flows out from the third pumping section through the second aquifer and flows into the second pumping section; a water circulation mode formed by the first pumping section, the second pumping section and the third pumping section Double circulation, water flows out from the first pumping section and the third pumping section through the first aquifer and the second aquifer respectively into the second pumping section, or flows out from the second pumping section through the first aquifer and the second aquifer respectively into the first pumping section and the third pumping section respectively; the large circulation formed by the combination of the first pumping section and the third pumping section, water flows out from the first pumping section through the first aquifer and the second aquifer successively into the third pumping section, or flows out from the third pumping section through the second aquifer and the first aquifer successively into the first pumping section. Under the condition of adjusting the pumping state, flow rate, pressure and circulation direction, the first small circulation, the second small circulation, the double circulation and the large circulation can be controlled and combined to form at least one water circulation combination mode.

[0025] Preferably, the method also includes: selecting an adaptive water circulation mode or a water circulation combination mode based on the distribution characteristics of pollutants in the aquifer; or, based on changes in the degree of groundwater remediation, changing the water circulation combination mode by orderly closing at least one of the multi-filter layer circulation wells; or, adjusting the water circulation mode, flow rate and / or pressure of each of the multi-filter layer circulation wells in a manner that enables the contaminated groundwater to circulate in the circulation well group, thereby forming a truncation effect on the contaminated groundwater.

[0026] As shown above, the control method of the circulation well group of the present invention can implement the water circulation combination mode in a targeted manner for complex groundwater pollution situations, eliminating the existing groundwater remediation blind spots. The present invention realizes more water circulation combination modes through the water circulation mode of the three-stage circulation well, and can change the water circulation combination mode according to the changes in the groundwater remediation situation, thereby realizing more efficient groundwater remediation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a simplified structural schematic diagram of a multi-filter layer circulation well of a preferred embodiment provided by the present invention;

[0028] Figure 2 It is a top view schematic diagram of the layout of a multi-filter layer circulation well and an auxiliary well in a preferred embodiment provided by the present invention;

[0029] Figure 3 It is a schematic diagram of the structure of a multi-filter layer circulation well group according to a preferred embodiment of the present invention.

[0030] Reference numerals list

[0031] 1: Main pipeline; 2: Pumping and injection water pump; 3: Valve; 4: Pumping and injection water pipe; 5: Dosing device; 6: Injection pipe; 7: Multi-filter layer circulation well; 8: Auxiliary well; 9: Pumping and injection water screen section; 10: First barrier; 11: Pump head; 12: Bottom plug; 13: Injection pump; 14: Medium stratification interface; 15: Aeration zone; 16: First aquifer; 17: Second aquifer; 18: Pollution source; 19: Pollution plume; 20: Wellbore; 21: Filter layer; 22: Second barrier. DETAILED DESCRIPTION

[0032] The following is a detailed description with reference to the accompanying drawings.

[0033] like Figure 1 and Figure 3 As shown, the site in the figure is a layered heterogeneous aquifer. The first aquifer 16 is coarse sand, and the second aquifer 17 is fine sand. The leakage of the pollution source 18 on the surface causes part of the aeration zone 15 to be polluted, and the pollutants migrate downward into the groundwater under the action of gravity. The pollution plume 19 of the groundwater gradually decreases from upstream to downstream, and the concentration of pollutants gradually decreases. Five sets of multi-filter circulation wells 7 are set at equal intervals along the groundwater flow direction in the distribution area of ​​the pollution plume 19. The drilling depth should pass through the lower edge of the pollution plume 19.

[0034] Preferably, the multi-layer circulation well group referred to in the present invention contains at least two multi-layer circulation wells, and is not limited to the five multi-layer circulation wells shown in the figure. The five multi-layer circulation wells are shown in the figure to fully demonstrate the various water circulation modes of the multi-layer circulation wells.

[0035] like Figure 1 As shown, the multi-filter layer circulation well of the present invention is a three-stage circulation well. Preferably, the multi-filter layer circulation well in the present invention is not limited to the three-stage type, but can also be a four-stage type, a five-stage type, etc., which can also realize the water circulation mode of the present invention. In the present invention, the three-stage circulation well is one of the most preferred embodiments, and does not mean that it is the only embodiment.

[0036] The present invention takes a three-stage circulation well as an example to illustrate the water circulation mode.

[0037] like Figure 1As shown, the multi-filter layer circulation well 7 is a multi-layer structure, including a wellbore 20, a filter layer 21, a water extraction and injection screen section 9, a barrier 10 and a bottom plug 12. Among them, the wellbore 20 of the multi-filter layer circulation well 7 is divided by at least two first barriers 10 to form three extraction sections. Preferably, the wellbore 20 is divided by at least two first barriers 10 to form a first extraction section, a second extraction section and a third extraction section, and the horizontal heights of the first extraction section, the second extraction section and the third extraction section decrease successively. The horizontal height of the second extraction section approaches or is equal to the horizontal height of the medium stratification interface 14, so that the first extraction section is located in the first aquifer 16, and the third extraction section is located in the second aquifer 17. The bottom plug 12 is located at the bottom of the circulation well, and its inner diameter is consistent with the inner diameter of the circulation well to prevent groundwater from entering from the bottom of the circulation well.

[0038] Preferably, the pipe wall of each pumping section is provided with a water pumping screen section 9 with holes. The water pumping screen section is preferably provided as a perforated flower pipe, that is, a pipe body provided with a plurality of holes for the circulation of groundwater.

[0039] Each pumping section is provided with at least one pumping assembly for pumping and injecting water. The pumping assembly is controlled by a control module to pump water and / or inject water. Specifically, Figure 1 As shown, the pumping assembly includes a pumping water pump 2, a pumping water pipe 4 and a pump head 11. The end of the pumping water pipe 4 is connected to the pump head 11. The pumping water pipe 4 is provided with at least one valve 3 for controlling the on-off of the pumping water pipe. The valve 3 is connected to the control module in a wired or wireless manner so as to receive the control instruction of the control module for automatic on-off control. Preferably, the valve 3 can also be set on the surface through the pumping pipe 4, and the valve 3 can be manually opened and closed to realize the on-off control of the pumping water pipe 4.

[0040] like Figure 1 As shown, in the first pumping section, the first pump head 11-1 is connected to the first pumping water pipe 4-1. The first pumping water pipe 4-1 is provided with a first valve 3-1. In the second pumping section, the second pump head 11-2 is connected to the second pumping water pipe 4-2. The second pumping water pipe 4-2 is provided with a third valve 3-3. At this time, the second pumping water pipe 4-2 passes through the first sub-blocker 10-1. In the third pumping section, the third pump head 11-3 is connected to the third pumping water pipe 4-3. The third pumping water pipe 4-3 is provided with a fifth valve 3-5. At this time, the third pumping water pipe 4-2 passes through the first sub-blocker 10-1 and the second sub-blocker 10-2.

[0041] like Figure 3 As shown, in the multi-filter layer circulation well of the present invention, the pumping and injection of each pumping and injection section can be independently controlled, thus forming a variety of water circulation modes.

[0042] The water circulation mode of the multi-filter layer circulation well at least includes: a first small circulation located in the first aquifer formed by the combination of the first pumping section and the second pumping section. Figure 3 As shown, the first pumping section pumps water, and the second pumping section injects water, forming a first small cycle that can repair the first aquifer.

[0043] like Figure 3 As shown, the second small cycle located in the second aquifer is formed by the combination of the second pumping section and the third pumping section. The third pumping section pumps water, and the second pumping section injects water, forming a second small cycle capable of repairing the second aquifer.

[0044] like Figure 3 As shown, a double cycle formed by the first pumping section, the second pumping section and the third pumping section and a large cycle formed by the combination of the first pumping section and the third pumping section. Specifically, the first pumping section and the third pumping section pump water at the same time, and the second pumping section injects water, forming a double circulation mode that can repair the first aquifer and the second aquifer at the same time, that is, the first small circulation mode and the second small circulation mode are combined to form a double circulation mode. When the pumping and injection methods of the first pumping section and the third pumping section are opposite, a large cycle is formed between the first pumping section and the third pumping section.

[0045] As mentioned above, a single multi-filter layer circulation well can realize at least four water circulation modes. Preferably, the water circulation modes can be combined to realize a water circulation combination mode.

[0046] For example, when the pollutants are mainly distributed in the first aquifer or the second aquifer, the control module performs groundwater remediation based on the water cycle combination mode of the first small cycle or the second small cycle combined with the large cycle. Specifically, the first pumping section pumps water, and the second and third pumping sections inject water, which can form a first small cycle in the first aquifer and a large cycle in the entire aquifer. The third pumping section pumps water, and the first and second pumping sections inject water, forming a second small cycle in the second aquifer and a large cycle in the entire aquifer.

[0047] When the pollutants are evenly distributed in the first aquifer and the second aquifer, the control module performs groundwater remediation based on a dual circulation mode. Figure 3 As shown, in adjacent multi-filter layer circulation wells 7, the water circulation mode of one multi-filter layer circulation well is middle pumping and two-end injection, while the water circulation mode of the other multi-filter layer circulation well is middle injection and two-end pumping, thereby forming a first small circulation and a second small circulation in the first aquifer and the second aquifer respectively, constituting a double circulation.

[0048] Preferably, the multi-filter circulation well 7 further comprises a plurality of auxiliary wells 8. The auxiliary wells 8 are used to monitor the concentration changes of pollutants in the aquifer. The auxiliary wells are also used as reagent injection wells to inject reagents into the first aquifer 16 and the second aquifer 17.

[0049] like Figure 2 As shown, the auxiliary well 8 is arranged in a manner centered on the multi-layer circulation well 7. Preferably, four auxiliary wells 8 surround one multi-layer circulation well 7.

[0050] The wellbore of the auxiliary well 8 is divided into two space parts by the second barrier 22. At least one space part of the auxiliary well 8 is provided with at least one injection pump 13 connected by an injection pipe 6. The level of the second barrier 22 approaches or is equal to the level of the medium stratification interface 14. Preferably, the injection pipe 6 is also connected to the dosing device 5, so that the drug enters the injection pump 13 through the injection pipe 6 and is further injected into the first or second aquifer. Preferably, the dosing device is arranged on the surface.

[0051] Preferably, if Figure 3 As shown, several multi-filter layer circulation wells are arranged according to the direction of groundwater flow to form a circulation well group.

[0052] like Figure 3 As shown, the pumping and injection pipes 4 of each multi-filter layer circulation well are connected to the main pipeline 1. Preferably, a main valve 3-30 is provided in the main pipeline 1. A circulation well group consisting of five multi-filter layer circulation wells is taken as an example for description.

[0053] like Figure 3 As shown, the first multi-layer circulation well 7-1, the second multi-layer circulation well 7-2, the third multi-layer circulation well 7-3, the fourth multi-layer circulation well 7-4 and the fifth multi-layer circulation well 7-5 are arranged in sequence according to the flow direction of groundwater. In the case where five multi-layer circulation wells are arranged, fourteen valves are arranged in the main pipeline 1. A valve is connected between every two pumping components 2. For example, the second valve 3-2, the fourth valve 3-4, the sixth valve 3-6, the eighth valve 3-8, the tenth valve 3-10, the twelfth valve 3-12, the fourteenth valve 3-14, the sixteenth valve 3-16, the eighteenth valve 3-18 and the twentieth valve 3-20 are arranged in sequence on the main pipeline 1.

[0054] Each valve in the present invention may be a manual valve, which is opened and closed by manual control, or an electronic valve, which is opened and closed automatically by a control module.

[0055] The water circulation combination pattern formed by the circulation well group is at least as shown below.

[0056] When the pollution plume between the multi-layer circulation wells 7 is widely distributed vertically and is basically flush with the screen section at the edge, the adjacent multi-layer circulation wells 7 circulate water in a double circulation mode with opposite circulation directions to form a water circulation combination mode. Specifically, among the water circulation modes of the two multi-layer circulation wells, one water circulation mode is middle injection and two-end pumping; the other water circulation mode is middle pumping and two-end injection, so that the water injected into the screen section of one multi-layer circulation well is captured by the pumping and injection screen section on the same horizontal line of the other multi-layer circulation well, accelerating the repair of pollution at the edge of the pollution plume.

[0057] When the vertical distribution range of the pollution plume between the multi-filter layer circulation wells 7 is small and the pollutants are mainly concentrated between the upper and lower screen sections, the control module forms a water circulation combination mode in which the adjacent multi-filter layer circulation wells 7 circulate water in a double circulation mode with the same circulation direction. Specifically, the water circulation modes of the two multi-filter layer circulation wells are both middle pumping and double-end injection, so that the water injection of the first pumping and injection section and the third pumping and injection section of one multi-filter layer circulation well can be captured by the second pumping and injection section of another multi-filter layer circulation well, accelerating the repair of the pollution between the upper and lower screen sections.

[0058] When each valve of the multi-layer circulation well is automatically controlled by the control module, the water circulation mode of each multi-layer circulation well can be changed to form a dynamic update of the water circulation combination mode. In response to the control instruction of the control module, the pumping assembly changes the pumping state, flow rate, and pressure of the three pumping sections of each multi-layer circulation well 7 to form different water circulation modes or water circulation combination modes.

[0059] Preferably, the control module selects an adaptive water circulation mode or a water circulation combination mode based on the distribution characteristics of the pollutants in the aquifer.

[0060] Preferably, based on the change in the degree of groundwater remediation, the control module changes the water circulation combination mode in a manner of orderly closing at least one of the multi-filter layer circulation wells 7 .

[0061] Preferably, the control module of the present invention is used to receive the groundwater pollution data provided by each auxiliary well, and match the corresponding water circulation combination mode according to the groundwater pollution data of each multi-filter layer circulation well. The control module of the present invention is a processor, a dedicated integrated chip or a server that can match the water circulation mode data based on the pollution data. That is, the processor, the dedicated integrated chip or the server can run the control program of the control method of the present invention.

[0062] Preferably, the control module is configured to match or change the water circulation combination mode or the water circulation mode of a single multi-filter layer circulation well in the following manner.

[0063] Preferably, the plurality of multi-filter circulation wells and their auxiliary wells are divided into upstream equipment, midstream equipment and downstream equipment according to the geographical location. The pollution data monitored from one of the auxiliary wells in the upstream section is the upstream pollution data. The pollution data monitored from one of the auxiliary wells in the midstream section is the midstream pollution data. The pollution data monitored from one of the auxiliary wells in the downstream section is the downstream pollution data.

[0064] Preferably, the control module determines and implements the water circulation combination mode based on changes in upstream pollution data, midstream pollution data and downstream pollution data.

[0065] Preferably, based on the groundwater contamination situation, the control module adjusts the water circulation mode, flow rate and / or pressure of each multi-layer circulation well 7 in a manner that enables the contaminated groundwater to circulate in the circulation well group, thereby forming a cutoff effect on the contaminated groundwater.

[0066] For example, the first pumping section of the fifth multi-layer circulation well 7-5 is shut down, the second pumping section is switched to the water injection state, and the third pumping section remains in the water injection state, so that the water circulation of the fifth multi-layer circulation well 7-5 is stopped, and the water flow circulation between the fifth multi-layer circulation well 7-5 and the fourth multi-layer circulation well 7-4 is started. During the water circulation, part of the groundwater flows from the fifth multi-layer circulation well 7-5 to the fourth multi-layer circulation well 7-4 in the direction opposite to the natural flow of the groundwater, which cuts off the downstream advancement trend of the pollution plume along the natural flow direction, and instead brings it back to the fourth multi-layer circulation well 7-4 in the reverse direction, realizing the purification cycle. This causes a significant change in the flow direction of the groundwater.

[0067] Preferably, the present invention describes the specific implementation scenario of the control module for the water circulation combination mode as follows.

[0068] 1. Scenario 1

[0069]

[0070] Near the pollution source, the pollution range is large and the concentration is high. Pollutants are mainly distributed in the first aquifer with a large permeability coefficient in the upper layer. The first multi-layer circulation well 7-1 is controlled to be a water circulation mode of upper pumping, middle injection and lower injection, that is, the first pumping section and the second pumping section of the first multi-layer circulation well 7-1 in the first aquifer form a first small cycle. The first pumping section and the third pumping section of the first multi-layer circulation well 7-1 in the entire aquifer form a large cycle, which can enhance the vertical scouring of the first aquifer and accelerate the repair of pollution in the upper heavily polluted aquifer.

[0071] When the pollutants are evenly distributed in the first aquifer and the second aquifer, the second multi-layer circulation well 7-2, the third multi-layer circulation well 7-3 and the fourth multi-layer circulation well 7-4 are configured to adopt a water circulation mode of intermediate pumping and injection or intermediate injection and pumping. That is, the first pumping section and the second pumping section in the first aquifer form a first small cycle, and the second pumping section and the third pumping section in the second aquifer form a second small cycle. With this arrangement, the pollution in the two aquifers can be repaired simultaneously. Which of the above two water circulation modes is selected depends on the distribution of the pollution plume between the two circulation wells.

[0072] In general, the pollutants between the second multi-layer circulation well 7-2 and the third multi-layer circulation well 7-3 are evenly distributed in the upper and lower aquifers and the vertical distribution range of the pollution plume is wide. When the upper and lower edges of the pollution plume are basically at the same horizontal height as the upper and lower boundaries of the screen section, there may be a circulation repair blind area in some areas between the circulation wells. The second multi-layer circulation well 7-2 adopts the water circulation mode of middle injection and upper and lower pumping to form the first double circulation, and the third multi-layer circulation well 7-3 adopts the water circulation mode of middle pumping and upper and lower injection to form the second double circulation, that is, different double circulation modes are adopted. In this way, part of the water injection of the first pumping section of the third multi-layer circulation well 7-3 flows to the first pumping section of the second multi-layer circulation well 7-2, and part of the water injection of the third pumping section of the third multi-layer circulation well 7-3 flows to the third pumping section of the second multi-layer circulation well 7-2. The pollutants located in the circulation blind area are driven by the hydraulic force of this part of the water injection into the circulation repair area, thereby solving the problem of repair blind areas in single well repair. Part of the injected water from the second pumping section of the second multi-filter layer circulation well 7-2 flows to the second pumping section of the third multi-filter layer circulation well 7-3. The pollutants between the circulation wells are removed along with this part of water into the pumping screen section, thereby accelerating the removal of pollutants between the circulation wells.

[0073] The pollutants between the third multi-layer circulation well 7-3 and the fourth multi-layer circulation well 7-4 are distributed relatively evenly in the upper and lower aquifers, but the vertical distribution range of the general pollution plume is significantly smaller than that of the upstream, and the pollutants are mainly concentrated between the first pumping section and the third pumping section. Therefore, the fourth multi-layer circulation well 7-4 adopts a water circulation mode of intermediate pumping and upper and lower injection, that is, the same pumping method is adopted, and part of the water injected from the first pumping section and the third pumping section of the third multi-layer circulation well 7-3 flows to the second pumping section of the fourth multi-layer circulation well 7-4, and part of the water injected from the first pumping section and the third pumping section of the fourth multi-layer circulation well 7-4 flows to the second pumping section of the third multi-layer circulation well 7-3. The interaction formed therebetween accelerates the remediation of pollution between the circulation wells.

[0074] At the edge of the pollution plume downstream of the pollution source, the pollution range is small and the concentration is low. The pollutants are mainly distributed in the second aquifer with a smaller permeability coefficient in the lower layer. The fifth multi-layer circulation well 7-5 adopts a water circulation mode of pumping down and injecting in the middle. That is, the second pumping section and the third pumping section of the fifth multi-layer circulation well 7-5 in the second aquifer form a second small circulation, and the first pumping section and the third pumping section of the fifth multi-layer circulation well 7-5 in the entire aquifer form a large circulation, which can enhance the vertical flushing of the second aquifer and accelerate the removal of pollutants in the second aquifer.

[0075] In addition, interaction can also be formed between the first multi-filter layer circulation well 7-1 and the second multi-filter layer circulation well 7-2, and between the fourth multi-filter layer circulation well 7-4 and the fifth multi-filter layer circulation well 7-5, that is, part of the injected water in a multi-filter layer circulation well can flow to the pumping screen section of the adjacent multi-filter layer circulation well, and the pollutants between the circulation wells enter the pumping screen section with the part of water and are removed, thereby realizing multi-well collaboration, eliminating the blind spots of single-well multi-filter layer circulation well repair, and accelerating the overall repair of the aquifer.

[0076] 2. Scenario 2

[0077]

[0078] As the repair process continues to develop, the concentration of pollutants in the monitoring wells is monitored in real time, and the control module can draw a curve chart based on the pollution data. Through the monitoring of the ninth monitoring well 8-9 and the tenth monitoring well 8-10 on the outermost side of the pollution plume, it was found that the concentration of pollutants in the first aquifer tended to be stable, and the stable concentration was lower than the groundwater quality standard. At the same time, the concentration of pollutants in the second aquifer remained higher than the groundwater quality standard for three consecutive days, indicating that the repair of the first aquifer was completed, but the repair of the second aquifer was not completed. The hydrodynamic control system can be adjusted to stop the repair of the first aquifer, that is, stop the injection of water in the first pumping section of the fifth multi-filter layer circulation well 7-5, so that the large circulation between the first pumping section and the third pumping section of the fifth multi-filter layer circulation well 7-5 is stopped, and only the second pumping section and the third pumping section of the fifth multi-filter layer circulation well 7-5 are used to form a second small circulation in the second aquifer. The first aquifer reaches the repair target and no longer participates in the circulation. The injection flow rate of the second pumping section of the fifth multi-filter layer circulation well 7-5 is further increased to 200m 3 / d, maintaining the balance of pumping and injection flow in the fifth multi-filter circulation well 7-5, thereby accelerating the remediation of pollution in the second aquifer.

[0079] The seventh monitoring well 8-7 and the eighth monitoring well 8-8 monitored that the pollutant concentration in the first aquifer was close to but slightly higher than the groundwater quality standard for three consecutive days, and the pollutant concentration in the second aquifer was still higher than the groundwater quality standard for three consecutive days, indicating that the pollution remediation of the first aquifer is about to be completed, while the remediation of the second aquifer is not completed. The remediation of the first aquifer can be weakened and the remediation of the second aquifer can be enhanced. The second pumping section of the fourth multi-layer circulation well 7-4 will be switched to water injection, and the flow rate will be reduced to 100m 3 / d, the third pumping section of the fourth multi-layer circulation well 7-4 is switched to pumping, and the flow rate increases to 200m 3 / d, the fourth multi-filter layer circulation well 7-4 is converted from a pumping mode to a water circulation mode of lower pumping and upper middle injection. The second pumping section and the third pumping section of the fourth multi-filter layer circulation well 7-4 in the second aquifer form a second small circulation, and the first pumping section and the third pumping section of the fourth multi-filter layer circulation well 7-4 in the entire aquifer form a large circulation, thereby enhancing the vertical flushing of the second aquifer, thereby accelerating the removal of pollutants in the second aquifer.

[0080] When the concentration curves monitored in other monitoring wells are all higher than the limit values ​​of groundwater quality standards, it indicates that the repair is not completed, and the original pumping and injection modes of the first multi-filter layer circulation well 7-1, the second multi-filter layer circulation well 7-2, and the third multi-filter layer circulation well 7-3 remain unchanged.

[0081] As the pumping mode of the fourth multi-layer circulation well 7-4 and the fifth multi-layer circulation well 7-5 is changed, the water flow direction and cooperation mode between the two wells are also changed. Part of the injected water from the second pumping section of the fifth multi-layer circulation well 7-5 flows to the third pumping section of the fourth multi-layer circulation well 7-4, and part of the injected water from the first and second pumping sections of the fourth multi-layer circulation well 7-4 flows to the third pumping section of the fifth multi-layer circulation well 7-5. The interaction formed between them accelerates the remediation of pollution between the circulation wells.

[0082] Other multi-well collaboration methods remain unchanged.

[0083] 3. Scenario 3

[0084]

[0085]

[0086] The ninth monitoring well 8-9 and the tenth monitoring well 8-10 detected that the pollutant concentrations in the first aquifer and the second aquifer tended to be stable, and the stable concentrations were lower than the groundwater quality standards. The seventh monitoring well 8-7 and the eighth monitoring well 8-8 detected that the pollutant concentrations in the first aquifer tended to be stable, and the stable concentrations were lower than the groundwater quality standards. The pollutant concentrations in the second aquifer remained higher than the groundwater quality standards for three consecutive days, indicating that the repair of the aquifer near the fifth multi-layer circulation well 7-5 has been completed, and the circulation repair in the fifth multi-layer circulation well 7-5 can be stopped. The repair of the first aquifer near the fourth multi-layer circulation well 7-4 has been completed, and the repair of the second aquifer has not been completed, so the repair of the first aquifer can be stopped. That is, the third pumping section of the fifth multi-layer circulation well 7-5 is switched to water injection, and the flow rates of the second and third pumping sections of the fifth multi-layer circulation well 7-5 are reduced to 50m 3 / d, stop water injection in the first pumping section of the fourth multi-filter layer circulation well 7-4. Increase the flow rate of the second pumping section of the fourth multi-filter layer circulation well 7-4 to 200m 3 / d, the flow rate of the third pumping section of the fourth multi-layer circulation well 7-4 increased to 300m 3 / d, so that the water circulation in the fifth multi-filter layer circulation well 7-5 stops, the large circulation between the first pumping section and the third pumping section of the fourth multi-filter layer circulation well 7-4 stops, and only the second pumping section and the third pumping section of the fourth multi-filter layer circulation well 7-4 are used to form a second small circulation in the second aquifer. The first aquifer has achieved the repair goal and no longer participates in the circulation. At the same time, water circulation starts between the fourth multi-filter layer circulation well 7-4 and the fifth multi-filter layer circulation well 7-5. That is, the circulation from the fifth multi-layer circulation well 7-5 to the fourth multi-layer circulation well 7-4 is against the natural flow direction of groundwater, which causes a huge change in the groundwater flow direction. The water flow direction and cooperation mode between the two wells are also changed. The second pumping section and part of the third pumping section of the fifth multi-layer circulation well 7-5 flow to the third pumping section of the fourth multi-layer circulation well 7-4. The pollutants between the circulation wells enter the pumping screen section with this part of water and are removed, thereby accelerating the restoration of pollution in the second aquifer. At the same time, the hydraulic barrier formed at the fifth multi-layer circulation well 7-5 prevents the spread of the pollution plume downstream.

[0087] The fifth monitoring well 8-5 and the sixth monitoring well 8-6 ​​detected that the pollutant concentration in the first aquifer was close to but slightly higher than the groundwater quality standard for three consecutive days, and the pollutant concentration in the second aquifer was still higher than the groundwater quality standard for three consecutive days, indicating that the pollution remediation of the first aquifer is about to be completed, while the remediation of the second aquifer is not yet completed. The remediation of the first aquifer can be weakened and the remediation of the second aquifer can be enhanced, that is, the second pumping section of the third multi-layer circulation well 7-3 is switched to water injection, and the flow rate is reduced to 100m 3 / d, the third pumping section of the third multi-layer circulation well 7-3 is switched to pumping, and the flow rate increases to 200m 3 / d, the pumping mode of the third multi-filter layer circulation well 7-3 is converted to downward pumping and upward injection, the second pumping section and the third pumping section of the third multi-filter layer circulation well 7-3 in the second aquifer form a second small circulation, and the first pumping section and the third pumping section of the third multi-filter layer circulation well 7-3 in the entire aquifer form a large circulation, which enhances the vertical flushing of the second aquifer, thereby accelerating the pollution remediation of the second aquifer.

[0088] The pollutant concentrations detected in other monitoring wells were higher than the groundwater quality standards for three consecutive days, indicating that the repair was not completed. The original pumping and injection methods of the first multi-layer circulation well 7-1 and the second multi-layer circulation well 7-2 remained unchanged.

[0089] Due to the change in the pumping method of the third multi-layer circulation well 7-3 and the fourth multi-layer circulation well 7-4, the water flow direction and cooperation method between the two wells are also changed. Part of the injection water from the second pumping section of the fourth multi-layer circulation well 7-4 flows to the third pumping section of the third multi-layer circulation well 7-3, and part of the injection water from the first pumping section and the second pumping section of the third multi-layer circulation well 7-3 flows to the third pumping section of the fourth multi-layer circulation well 7-4. The interaction formed between them accelerates the remediation of pollution between the circulation wells.

[0090] Other multi-well collaboration methods remain unchanged.

[0091] 4. Scenario 4

[0092]

[0093] The seventh monitoring well 8-7 and the eighth monitoring well 8-8 detected that the pollutant concentrations in the first aquifer and the second aquifer tended to be stable, and the stable concentrations were lower than the groundwater quality standards. The fifth monitoring well 8-5 and the sixth monitoring well 8-6 ​​detected that the pollutant concentrations in the first aquifer tended to be stable, and the stable concentrations were lower than the groundwater quality standards. The pollutant concentrations in the second aquifer remained higher than the groundwater quality standards for three consecutive days, indicating that the pollution remediation in the vicinity of the fourth multi-layer circulation well 7-4 and in the downstream aquifer has been completed, while the pollution remediation in the upstream aquifer has not been completed. The circulation within the fourth multi-layer circulation well 7-4 and the water circulation between the fourth multi-layer circulation well 7-4 and the fifth multi-layer circulation well 7-5 can be stopped. The repair of the first aquifer near the third multi-layer circulation well 7-3 has been completed, while the repair of the second aquifer has not been completed. The repair of the first aquifer can be stopped. That is, the second and third pumping sections of the fifth multi-layer circulation well 7-5 are stopped, and the third pumping section of the fourth multi-layer circulation well 7-4 is switched to water injection, and the flow rate of the second and third pumping sections of the fourth multi-layer circulation well 7-4 is reduced to 50m 3 / d, stop water injection in the first pumping section of the third multi-filter layer circulation well 7-3, and increase the flow rate of the second pumping section of the third multi-filter layer circulation well 7-3 to 200m3 / d, the flow rate of the third pumping section of the third multi-layer circulation well 7-3 increased to 300m 3 / d, so that the water flow in the fourth multi-layer circulation well 7-4 stops circulating, the large circulation between the first pumping section and the third pumping section of the third multi-layer circulation well 7-3 stops, and only the second pumping section and the third pumping section of the third multi-layer circulation well 7-3 are used to form a second small circulation in the second aquifer. The first aquifer reaches the restoration target and no longer participates in the circulation. At the same time, water circulation starts between the third multi-layer circulation well 7-3 and the fourth multi-layer circulation well 7-4, that is, water flows from the fourth multi-layer circulation well 7-4 to the third multi-layer circulation well 7-3 against the natural flow of groundwater The circulation in the second direction causes a huge change in the groundwater flow direction, and the water flow direction and cooperation mode between the two wells are also changed. Part of the injected water from the second pumping section of the fourth multi-layer circulation well 7-4 and the third pumping section of the fourth multi-layer circulation well 7-4 flows to the third pumping section of the third multi-layer circulation well 7-3. The pollutants between the circulation wells enter the pumping screen section with this part of water and are removed, thereby accelerating the removal of pollutants in the second aquifer. At the same time, the hydraulic barrier formed at the fourth multi-layer circulation well 7-4 prevents the pollution plume from further spreading downstream.

[0094] The third monitoring well 8-3 and the fourth monitoring well 8-4 detected that the pollutant concentration in the first aquifer was close to but slightly higher than the groundwater quality standard for three consecutive days, and the pollutant concentration in the second aquifer was still higher than the groundwater quality standard for three consecutive days, indicating that the pollution remediation of the first aquifer is about to be completed, while the remediation of the second aquifer is not yet completed. The remediation of the first aquifer can be weakened and the remediation of the second aquifer can be enhanced. The first pumping section of the second multi-filter layer circulation well 7-2 is switched to water injection, and the flow rate of the second pumping section of the second multi-filter layer circulation well 7-2 is reduced to 100m 3 / d, the flow rate of the third pumping section of the second multi-layer circulation well 7-2 increased to 200m 3 / d, the pumping mode of the second multi-filter layer circulation well 7-2 is converted to downward pumping and upward injection. The second pumping section and the third pumping section of the second multi-filter layer circulation well 7-2 in the second aquifer form a second small circulation, and the first pumping section and the third pumping section of the second multi-filter layer circulation well 7-2 in the entire aquifer form a large circulation, which can enhance the vertical flushing of the second aquifer, thereby accelerating the pollution remediation of the second aquifer.

[0095] The concentrations monitored in the first monitoring well 8-1 and the second monitoring well 8-2 were higher than the groundwater quality standard for three consecutive days, indicating that the repair was not completed and the original pumping mode of the first multi-layer circulation well 7-1 was maintained unchanged.

[0096] As the pumping mode of the second multi-layer circulation well 7-2 and the third multi-layer circulation well 7-3 is changed, the water flow direction and cooperation mode between the two wells are also changed. Part of the injected water from the second pumping section of the third multi-layer circulation well 7-3 flows to the third pumping section of the second multi-layer circulation well 7-2, and part of the injected water from the first pumping section and the second pumping section of the second multi-layer circulation well 7-2 flows to the third pumping section of the third multi-layer circulation well 7-3. The interaction formed between them accelerates the remediation of pollution between the circulation wells.

[0097] 5. Scenario 5

[0098]

[0099] The fifth monitoring well 8-5 and the sixth monitoring well 8-6 ​​detected that the pollutant concentrations in the first aquifer and the second aquifer tended to be stable, and the stable concentrations were lower than the groundwater quality standards. The third monitoring well 8-3 and the fourth monitoring well 8-4 detected that the pollutant concentrations in the first aquifer tended to be stable, and the stable concentrations were lower than the groundwater quality standards. The pollutant concentrations in the second aquifer remained higher than the groundwater quality standards for three consecutive days, indicating that the pollution remediation in the vicinity of the third multi-layer circulation well 7-3 and in the downstream aquifer has been completed, while the pollution remediation in the upstream aquifer has not been completed. The circulation in the third multi-layer circulation well 7-3 and the water circulation between the third multi-layer circulation well 7-3 and the fourth multi-layer circulation well 7-4 can be stopped. The repair of the first aquifer near the second multi-layer circulation well 7-2 has been completed, while the repair of the second aquifer has not been completed. The repair of the first aquifer can be stopped. That is, the second and third pumping sections of the fourth multi-layer circulation well 7-4 are stopped, and the third pumping section of the third multi-layer circulation well 7-3 is switched to water injection, and the flow rate of the second and third pumping sections of the third multi-layer circulation well 7-3 is reduced to 50m 3 / d, stop water injection in the first pumping section of the second multi-filter layer circulation well 7-2, and increase the flow rate of the second pumping section of the second multi-filter layer circulation well 7-2 to 200m 3 / d, the flow rate of the third pumping section of the second multi-filter circulation well 7-2 increased to 300m 3 / d, so that the water flow in the third multi-layer circulation well 7-3 stops circulating, the first pumping section and the third pumping section of the second multi-layer circulation well 7-2 are stopped for large circulation, and only the second pumping section and the third pumping section of the second multi-layer circulation well 7-2 are used to form a small circulation in the second aquifer. The first aquifer reaches the restoration target and no longer participates in the circulation. At the same time, water circulation starts between the second multi-layer circulation well 7-2 and the third multi-layer circulation well 7-3, that is, water flows from the third multi-layer circulation well 7-3 to the second multi-layer circulation well 7-2 against the ground. The circulation of the natural flow direction of the underground water has caused a huge change in the direction of the groundwater flow, and the water flow direction and cooperation mode between the two wells have also changed. The second pumping section and part of the third pumping section of the third multi-layer circulation well 7-3 flow to the third pumping section of the second multi-layer circulation well 7-2. The pollutants between the circulation wells enter the pumping screen section with this part of water and are removed, thereby accelerating the remediation of the pollution in the second aquifer. At the same time, the hydraulic barrier formed at the third multi-layer circulation well 7-3 prevents the spread of the pollution plume downstream.

[0100] Monitoring wells 8-2 and 8-1 detected that the pollutant concentration in the second aquifer tended to be stable, and the stable concentration was lower than the groundwater quality standard. The pollutant concentration in the first aquifer was still higher than the groundwater quality standard for three consecutive days, indicating that the pollution remediation of the second aquifer was completed, but the remediation of the first aquifer was not completed. The remediation of the second aquifer can be stopped, that is, the injection of water in the third pumping section of the first multi-filter layer circulation well 7-1 is stopped, and the large circulation between the first pumping section and the third pumping section of the first multi-filter layer circulation well 7-1 is stopped. Only the first small circulation is formed between the first pumping section and the second pumping section of the first multi-filter layer circulation well 7-1 in the first aquifer. The second aquifer reaches the remediation target and no longer participates in the circulation. The injection flow rate of the second pumping section of the first multi-filter layer circulation well 7-1 is increased to 200m 3 / d, to maintain the balance of pumping and injection flow in the first multi-filter circulation well 7-1, so as to accelerate the remediation of the second aquifer pollution.

[0101] As the pumping and injection methods of the first multi-layer circulation well 7-1 and the second multi-layer circulation well 7-2 are changed, the water flow direction and cooperation method between the two wells are also changed. Part of the injected water from the second pumping section of the second multi-layer circulation well 7-2 flows to the first pumping section of the first multi-layer circulation well 7-1, and part of the injected water from the second pumping section of the first multi-layer circulation well 7-1 flows to the third pumping section of the second multi-layer circulation well 7-2. The interaction formed between the two accelerates the remediation of pollution between the circulation wells.

[0102] 6. Scenario 6

[0103]

[0104] Monitoring wells 8-3 and 8-4 detected that the pollutant concentrations in the first aquifer and the second aquifer tended to be stable, and the stable concentrations were both lower than the groundwater quality standards. Monitoring wells 8-1 and 8-2 detected that the pollutant concentrations in the first aquifer were still higher than the groundwater quality standards for three consecutive days, indicating that the pollution remediation in the vicinity of the second multi-layer circulation well 7-2 and the downstream aquifer has been completed, while the pollution remediation in the upstream aquifer has not been completed. The circulation in the second multi-layer circulation well 7-2 and the water circulation between the second multi-layer circulation well 7-2 and the third multi-layer circulation well 7-3 can be stopped, and the first aquifer near the first multi-layer circulation well 7-1 will continue to be repaired. That is, the second and third pumping sections of the third multi-layer circulation well 7-3 will stop injecting water, so that the third multi-layer circulation well 7-3 will stop operating, and the third pumping section of the second multi-layer circulation well 7-2 will stop pumping water, and the flow rate of the second pumping section of the second multi-layer circulation well 7-2 will be reduced to 50m 3 / d, the flow rate of the first pumping section of the second multi-filter circulation well 7-2 increased to 250m 3 / d, so that the water circulation in the second multi-layer circulation well 7-2 stops, and at the same time, the water circulation starts between the first multi-layer circulation well 7-1 and the second multi-layer circulation well 7-2, that is, the circulation from the second multi-layer circulation well 7-2 to the first multi-layer circulation well 7-1 is reversed to the natural flow direction of the groundwater, thereby causing a huge change in the groundwater flow direction, and the water flow direction and cooperation mode between the two wells are also changed. Part of the injection water from the second pumping section of the second multi-layer circulation well 7-2 flows to the first pumping section of the second multi-layer circulation well 7-2, and the pollutants between the circulation wells enter the pumping screen section with this part of the water and are removed, thereby accelerating the restoration of the pollution in the second aquifer. At the same time, the hydraulic barrier formed at the second multi-layer circulation well 7-2 prevents the spread of the pollution plume downstream.

[0105] 7. Scenario 7

[0106]

[0107] Monitoring wells 8-1 and 8-2 detected that the concentration of pollutants in the first aquifer and the second aquifer tended to be stable, and the stable concentrations were both lower than the groundwater quality standard, indicating that the pollution remediation in the vicinity of the first multi-layer circulation well 7-1 and the downstream aquifer has been completed, that is, the remediation in the entire contaminated area has been completed, and the operation of the first multi-layer circulation well 7-1 and the second multi-layer circulation well 7-2 can be stopped. Stop pumping water from the first pumping section of the first multi-layer circulation well 7-1, stop injecting water from the second pumping section of the first multi-layer circulation well 7-1 and the second multi-layer circulation well 7-2, and stop the operation of the first multi-layer circulation well 7-1 and the second multi-layer circulation well 7-2.

[0108] It should be noted that the above-mentioned specific embodiments are exemplary, and those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the present invention specification and its drawings are illustrative and do not constitute a limitation on the claims. The scope of protection of the present invention is defined by the claims and their equivalents. The present invention specification contains multiple inventive concepts, such as "preferably", "according to a preferred embodiment" or "optionally", all of which indicate that the corresponding paragraph discloses an independent concept, and the applicant reserves the right to file a divisional application based on each inventive concept.

Claims

1. A circulation well group, comprising at least two multi-filter layer circulation wells (7), a plurality of pumping and injection components and a control module, characterized in that: At least two of the multi-filter layer circulation wells (7) are arranged in order according to the groundwater flow direction. The wellbore (20) of the multi-filter layer circulation well (7) is divided into three pumping sections by at least two first barriers (10), each pumping section is provided with at least one group of pumping and injection components for pumping and injecting water, the pumping and injection components are controlled by the control module to pump water and / or inject water, and the pipe wall of each pumping section is provided with a pumping and injection screen section (9) with holes. In response to the control instruction of the control module, the pumping component changes the pumping state, flow rate and pressure of the three pumping sections of each of the multi-filter layer circulation wells (7) to form different water circulation modes or water circulation combination modes. A plurality of multi-filter layer circulation wells (7) and their auxiliary wells (8) are divided into upstream equipment, midstream equipment and downstream equipment according to the set geographical location, and the control module determines and implements the water circulation combination mode based on the changes of upstream pollution data, midstream pollution data and downstream pollution data; The wellbore (20) is divided by two of the first barriers (10) into a first pumping section, a second pumping section and a third pumping section, the levels of the first pumping section, the second pumping section and the third pumping section decrease in sequence, and the level of the second pumping section approaches or is equal to the level of the medium layer interface (14). The water circulation mode formed by the control module based on changing the pumping state of each pumping section at least includes: a first small circulation located in the first aquifer formed by the combination of the first pumping section and the second pumping section, a second small circulation located in the second aquifer formed by the combination of the second pumping section and the third pumping section, a double circulation formed by the first pumping section, the second pumping section and the third pumping section, and a large circulation formed by the combination of the first pumping section and the third pumping section. When the control module adjusts the pumping state, flow rate, pressure and circulation direction, the first small circulation, the second small circulation, the double circulation and the large circulation can be controlled and combined by the control module to form at least one water circulation combination mode.

2. A circulation well group according to claim 1, characterized in that: The control module selects an adaptive water circulation mode or a water circulation combination mode based on the distribution characteristics of pollutants in the aquifer.

3. A circulation well group according to claim 1, characterized in that: The multi-filter circulation well (7) further comprises a plurality of auxiliary wells (8). The auxiliary well (8) is arranged in a manner centered on the multi-filter layer circulation well (7). The wellbore of the auxiliary well (8) is divided into two space parts by a second barrier (22), and at least one space part of the auxiliary well (8) is provided with at least one injection pump (13) connected by an injection pipe (6). The level of the second barrier (22) approaches or is equal to the level of the medium layer interface (14).

4. A circulation well group according to claim 1, characterized in that: Based on the change in the degree of groundwater restoration, the control module changes the water circulation combination mode in a manner of orderly closing at least one of the multi-filter layer circulation wells (7).

5. A circulation well group according to claim 1, characterized in that: Based on the groundwater contamination situation, the control module adjusts the water circulation mode, flow rate and / or pressure of each of the multi-filter layer circulation wells (7) in a manner that enables the contaminated groundwater to circulate in the circulation well group, thereby forming a cutoff effect on the contaminated groundwater.

6. A circulation well group according to claim 1, characterized in that: In the case where the pollutants are mainly distributed in the first aquifer or the second aquifer, the control module performs groundwater remediation based on a water cycle combination mode of the first small cycle or the second small cycle combined with the large cycle; In the case where the pollutants are distributed relatively evenly in the first aquifer and the second aquifer, the control module performs groundwater remediation based on a dual circulation mode; When the pollution plume is widely distributed vertically between the multi-layer circulation wells (7) and the edge position is substantially flush with the screen section, the control module forms a water circulation combination mode by circulating water in the adjacent multi-layer circulation wells (7) in a double circulation manner with opposite circulation directions. When the vertical distribution range of the pollution plume between the multi-filter layer circulation wells (7) is small and the pollutants are mainly concentrated between the upper and lower screen sections, the control module forms a water circulation combination mode in which the adjacent multi-filter layer circulation wells (7) circulate water in a double circulation manner with the same circulation direction.

7. A circulation mode control method for a circulation well group according to claim 1, characterized in that: The control method at least comprises: adjusting the pumping state, flow rate and pressure of three pumping sections of each multi-filter layer circulation well (7) to form different water circulation modes or water circulation combination modes.

8. The circulation mode control method of a circulation well group according to claim 7, characterized in that: The method further includes: selecting an adaptive water circulation mode or a water circulation combination mode based on the distribution characteristics of the pollutants in the aquifer; Alternatively, based on the change in the degree of groundwater remediation, the water circulation combination mode is changed by orderly closing at least one of the multi-filter layer circulation wells (7); Alternatively, the water circulation pattern, flow rate and / or pressure of each of the multi-filter layer circulation wells (7) are adjusted in a manner that allows the contaminated groundwater to circulate in the circulation well group, thereby creating a cutoff effect on the contaminated groundwater.

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