A method and system for in-situ parameter measurement and extraction treatment of a groundwater pollution plume

Abstract

The application discloses a kind of in-situ parameter determination and extraction treatment method and system of groundwater pollution plume, it is related to hydrographic survey field, method includes: obtaining the boundary identification data of target pollution plume;Obtain the pitch angle of field pitch test drill hole arranged in the downstream interception section of target pollution plume, obtain the test drawdown and test stable drainage capacity of fixed drawdown stable pumping test;Based on boundary identification data, pitch angle, test drawdown and test stable drainage capacity, using seepage correction model to inverse in-situ permeability coefficient;Obtain design well spacing, design drawdown and design drill hole pitch angle, combine in-situ permeability coefficient and same seepage correction model to calculate single well design stable flow, and according to the number of pumping well and safety factor to calculate extraction treatment scale.In-situ parameter determination and extraction treatment design are placed in same boundary correction model, reduce the engineering deviation caused by parameter determination and flow design inconsistency under special boundary condition.

Description

Technical Field

[0001] This invention belongs to the field of groundwater pollution remediation and hydrogeological exploration technology, specifically relating to a method and system for in-situ parameter determination and extraction of groundwater pollution plumes. Background Technology

[0002] Groundwater contamination extraction and treatment technology typically involves pumping contaminated groundwater to the surface through wells, followed by purification through physical, chemical, or biological treatment units before disposal, reinjection, or discharge. The engineering design of this technology relies on hydrogeological parameters such as permeability coefficient, hydraulic gradient, aquifer thickness, contamination plume boundary, pumping capture range, and treatment scale.

[0003] In existing engineering projects, the permeability coefficient is typically obtained through vertical well pumping tests, pressure tests, laboratory permeability tests, or parameter inversion based on numerical models; the extraction treatment design is usually adjusted based on conventional steady flow theory, empirical well spacing, single-well pumping capacity, and field monitoring results. These methods are more common in homogeneous, near-infinite boundary, horizontal groundwater level, or vertical well conditions.

[0004] In sites such as chemical industrial parks, gas stations, and landfills, pollution plumes may extend in a strip-like pattern along the main flow direction of groundwater. These plumes are constrained on both sides by low-permeability media such as clay layers, bedrock, or artificial impermeable structures, while the upstream and downstream sections remain connected to the surrounding aquifers. These boundary conditions differ from the traditional assumptions of an infinite aquifer or a homogeneous horizontal aquifer. To intercept the strip-like pollution plume at the downstream section, inclined pumping wells may be used in engineering projects, placing the screen section or collection section within the target contaminated aquifer.

[0005] Traditional vertical well pumping tests and conventional steady-flow calculations typically do not simultaneously consider the coupling effects between lateral low-permeability constraint boundaries, flow-direction connectivity boundaries, groundwater level inclination, subducting borehole catchment sections, and drawdown control. The permeability coefficient obtained during the exploration phase and the pumping design flow rate during the remediation phase are often calculated under different boundary models, resulting in model inconsistencies between parameter determination and treatment scale design. Summary of the Invention

[0006] This invention addresses at least one deficiency of existing technologies by proposing a method to obtain in-situ permeability coefficients in strip-shaped pollution plumes with lateral low permeability constraints, upstream and downstream connectivity along the main groundwater flow direction, and sloping groundwater levels through on-site dip test borehole pumping tests. These in-situ permeability coefficients are then converted into the single-well design stable flow rate and pumping capacity required for extraction or hydraulic interception design under the same boundary correction function. Finally, based on the single-well design stable flow rate and pumping capacity, the pumping pump assembly and extraction device are controlled to achieve a closed-loop engineering process.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for in-situ parameter determination and extraction treatment of groundwater pollution plumes includes the following steps: Obtain boundary identification data of the target contamination plume, wherein the target contamination plume is a strip-shaped contamination plume that is laterally constrained by a low-permeability boundary and extends along the main seepage direction; Obtain the inclination angle of at least one field inclination test borehole deployed at the downstream interception section of the target pollution plume, wherein the field inclination test borehole is a downward inclination borehole, so that the screen section or water collection section is located within the target pollution aquifer. Obtain the test drawdown and the test stable discharge volume after reaching the stability criterion in the constant drawdown stable pumping test; Based on boundary identification data, the dip angle, test drawdown, and test stable drainage volume of the borehole, the in-situ permeability coefficient was calculated by inversion using a seepage correction model. Obtain the design well spacing, design drawdown, and design borehole inclination angle. Combine the in-situ permeability coefficient with the same seepage correction model to calculate the design stable flow rate of a single well in the design stage. Calculate the pumping treatment scale in the pumping treatment based on the design stable flow rate of a single well, the number of pumping wells, and the safety factor. The output single-well design provides a stable flow rate and extraction capacity for setting or adjusting the pump assembly and extraction device.

[0008] Preferably, the boundary identification data includes: the angle between the groundwater level and the horizontal plane, the length of the target pollution plume along the main seepage direction, the lateral width of the target pollution plume, the equivalent control width during the test phase, and the initial saturation thickness or equivalent hydraulic head height of the target pollution aquifer relative to the bottom plate of the aquifer.

[0009] Preferably, the method for calculating the in-situ permeability coefficient using a seepage correction model includes: The in-situ permeability coefficient is calculated after performing unit normalization on the boundary identification data, the dip angle of the field dip test borehole, the test stable drainage volume and test drawdown, and the seepage correction model. This preferred option uses unit normalized variables to express the empirical correction model, avoiding the problem of unclear formulas caused by directly taking the logarithm or exponent for dimensional variables, thus improving the feasibility of the scheme.

[0010] Preferably, the method for constructing the seepage correction model includes: constructing a numerical simulation sample based on the steady-state saturated seepage control equation and Darcy's law, which includes lateral low-permeability constraint boundaries, upstream and downstream connectivity boundaries in the main seepage direction, fixed drawdown boundaries of inclined boreholes, and inclined groundwater level boundaries; extracting boundary identification data, dip angle, experimental drawdown, and experimental stable drainage volume from the sample and performing data fitting to construct the seepage correction function in the seepage correction model.

[0011] Preferably, the method further includes the steps of: acquiring the water level data of at least one monitoring well deployed upstream and downstream of the inclination test borehole at the site, and correcting the equivalent control width of the test stage based on the changes in the water level data of the monitoring wells; or determining whether the pumping capture range covers the downstream interception section based on the changes in the water level data of the monitoring wells.

[0012] This invention also discloses a system comprising a tilting test borehole assembly, a tilting pumping well assembly, a constant drawdown pumping pump assembly, a water level monitoring assembly, a flow meter, a data acquisition unit, a processor, a memory, and an extraction processing device. The memory is used to store one or more computer instructions, which are executed by the processor to implement the above-described method for in-situ parameter determination and extraction of groundwater pollution plumes. The tilt test borehole assembly is used to deploy at least one field tilt test borehole at the downstream interception section of the target pollution plume; wherein the field tilt test borehole is a downward tilting borehole, so that the screen section or water collection section is located within the target pollution aquifer; The tilting pumping well assembly is equipped with a water level monitoring assembly, a constant drawdown pump assembly, and a flow meter, which are used to obtain the test drawdown and the test stable drainage volume. A wastewater extraction and treatment device is used to receive wastewater that has been extracted and treated.

[0013] Preferably, the tilt test borehole assembly includes a borehole, a screen or water collection section, and a sealing structure. The screen or water collection section is located within the target contaminated aquifer, and the sealing structure is used to isolate non-target aquifers.

[0014] Preferably, the system further includes a monitoring well assembly, which provides an observation channel and is equipped with a water level monitoring assembly; the water level monitoring assembly is connected to a data acquisition unit and a processor, and is used to collect groundwater level change data and adjust the water pump assembly.

[0015] The present invention also discloses a computer-readable storage medium storing a computer program or instructions thereon, characterized in that the computer program or instructions, when executed by a processor, implement the above-described method for in-situ parameter determination and extraction treatment of groundwater pollution plumes.

[0016] The present invention also discloses a computer program product, including a computer program or instructions, which, when executed by a processor, implement the method for in-situ parameter determination and extraction of groundwater pollution plumes described above.

[0017] Beneficial effects: This invention incorporates lateral low-permeability boundary, flow-direction connectivity boundary, groundwater level inclination, constant drawdown, and inclined borehole factors into the same seepage correction model, ensuring consistent boundary conditions between in-situ permeability coefficient inversion and extraction treatment design flow rate calculation; This invention, through on-site inclined test boreholes and downstream interception section layout, enables the catchment section to be located within the target contaminated aquifer, which is beneficial to improving the targeting of downstream interception design for strip-shaped pollution plumes. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of the method for in-situ hydrological parameter measurement and remediation of groundwater pollution plumes; Figure 2 This is a schematic diagram of the planar boundary of the ribbon-shaped pollution plume and the arrangement of the downstream interception section; Figure 3 These are borehole and aquifer profile diagrams from the on-site tilt test. Figure 4 It is a method for in-situ parameter determination of strip-shaped pollution plumes and an extraction and treatment system; Figure 5 This is a diagram showing the comparison between model predictions and numerical simulations. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0021] A method for in-situ parameter determination and extraction treatment of groundwater pollution plumes, such as... Figure 1 It includes the following steps: S1, acquire boundary identification data of the target contamination plume, wherein the target contamination plume is a strip-shaped contamination plume extending along the main seepage direction; S2, Obtain the dip angle ε of at least one field dip test borehole deployed at the downstream interception section of the target pollution plume. t The on-site tilt test borehole is a downward tilting borehole, so that the screen section or water collection section is located within the target polluted aquifer. S3, Obtain the test drawdown m for the constant drawdown steady-state pumping test. t And the experimentally stable displacement Q after reaching the stability criterion t ; S4, based on boundary identification data and the dip angle e of the borehole in the field dip test. t Test stable discharge Q t Based on the test depth, the in-situ permeability coefficient of the target contaminated aquifer was calculated using a seepage correction model. S5, obtain the number of pumping wells n and the design well spacing b during the design phase. d Design depth m d and design borehole tilt angle e d The design steady flow rate Q of a single well during the design phase is calculated by combining the same in-situ permeability coefficient and the seepage correction model. d Based on the single-well design stable flow rate Q d Calculate the pumping capacity Q in the water treatment process using the number of pumping wells n and the safety factor η. total ; Output single-well design stable flow rate Q d and extraction processing scale Q total Used to set or adjust water pump components and extraction processing devices.

[0022] The methods for obtaining boundary identification data of the target pollution plume are typically acquired using hydrogeological exploration techniques, all of which are common hydrogeological exploration methods and will not be disclosed in detail in this publication. The technical terms directly used in this article are all common technical terms used in hydrogeological exploration.

[0023] This invention is designed for strip-shaped contamination plumes that are connected upstream and downstream along the main groundwater flow direction, with low-permeability confined boundaries on both sides and an inclined groundwater level. It is particularly distinct from ordinary infinite aquifer, homogeneous horizontal aquifer, or general contamination plume identification methods.

[0024] Figure 2 This diagram shows the main seepage direction, the low-permeability confinement boundaries on both sides, the upstream and downstream connected permeable boundaries, the plume length L, the lateral width W, and the design well spacing b. d The upper and lower diagonal lines represent the lateral low-permeability constraint boundaries on both sides, which can be clay layers, bedrock boundaries, or artificial seepage prevention structures.

[0025] refer to Figure 3 The diagram shows the surface, upper and lower low-permeability layers, target contaminated aquifer, initial water level, drawdown level, and test drawdown depth (m). t Initial saturation thickness H, experimental stable drainage volume Q t Monitoring wells and field tilt test boreholes, screen pipe sections or water collection sections.

[0026] Preferably, the dip angle e of the in-situ dip test borehole is... t The angle is 10°-40°, and the radius of the borehole for the field tilt test is 55mm-85mm.

[0027] Among them, the test stable displacement Q t Data is obtained through on-site recordings, such as flow meter data, in units of meters (m³). 3 / d.

[0028] Specifically, the boundary identification data includes: the angle α between the groundwater level and the horizontal plane, the length L of the target pollution plume along the main seepage direction, the lateral width W of the target pollution plume, and the equivalent control width b during the test phase. t And the initial saturation thickness or equivalent head height H of the target contaminated aquifer relative to the bottom plate of the aquifer.

[0029] In the above boundary identification data, the angle α between the groundwater level and the horizontal plane is calculated by the hydraulic gradient I from at least two water level monitoring wells installed along the main seepage direction. h The result was obtained later, and the preferred option was selected. If the slope of the site varies along the course, the local hydraulic gradient near the downstream interception section should be used. The preferred included angle α is 5°-25°.

[0030] The preferred parameter for the length L of the target plume along the main seepage direction is 10m-30m. The lateral width W of the target plume is used to determine the strip proportion and the number of pumping wells, and is determined based on the site conditions, in meters. and L and W are determined by pollutant concentration contour lines, areas exceeding standards, or pollution plume boundary surveys. The methods for determining L and W are all commonly used methods in hydrological surveys and will not be disclosed in detail.

[0031] Preferably, in this scheme, the ratio of the length to the lateral width of the target contaminant plume is greater than or equal to 3; the permeability coefficient K of the lateral low-permeability confinement boundary of the target contaminant plume... side The ratio K to the permeability coefficient of the target contaminated aquifer a The ratio of K side / K a Less than or equal to 0.1. When L / W is less than or K side / K a When the value is greater than 0.1, inaccurate seepage correction models may occur, requiring recalibration of the seepage correction model or the use of other hydrogeological models. This scheme is a preferred solution; although inconsistencies may arise in accuracy if this preferred solution is not met, the technical effect can still be achieved.

[0032] The absolute water level elevation under an arbitrary elevation datum is not used relative to the initial saturation thickness or equivalent head height H of the aquifer floor. Preferably, the initial saturation thickness or equivalent head height H is 20m-40m.

[0033] equivalent control width b during the experimental phase tThe determination method is as follows: During the experimental phase, when a single hole represents the entire cross-section during implementation, the equivalent control width b during the experimental phase is... t The effective plume width W can be taken. eff Among them, in order to achieve effective coverage, W eff >W.

[0034] When conducting multi-hole segmented testing, the equivalent control width b of the testing phase is... t The width between the centerlines of the control boundaries of adjacent test wells can be taken; when monitoring well data is available, the equivalent control width b during the test phase is... t The lateral range within which the water level response reaches a preset threshold can be considered; if necessary, the equivalent control width b for specific test phases can be determined. t It can be verified by a numerical model. The preferred embodiment disclosed in this implementation is 3m-9m.

[0035] m t The drawdown for a fixed-depth pumping test is determined by the target layer saturation thickness, pump capacity, and allowable drawdown, with a preferred range of 3.0m-5.0m, and must meet the stability criterion.

[0036] It is the inclination angle of the borehole for the field inclination test. The requirement for setting the inclination angle of the borehole for the field inclination test is that the screen section or water collection section should be located within the target contaminated aquifer and avoid non-target aquifers or underground obstacles. It is preferably 10°-40°, and the unit is °.

[0037] The method for determining the number of pumping wells includes: during the design phase, first determining the effective width W of the pollution plume to be covered. eff The well spacing b of the pumping wells in the preliminary design stage d , and according to Determine the number of pumping wells. This embodiment discloses an implementable well spacing b. d The preferred option is 3m-9m.

[0038] The design depth m d Determined based on the initial saturation thickness or equivalent head height H, allowable drawdown, and pump capacity; The design tilt angle e d The location is determined based on the depth of the target layer, surface construction conditions, and the location of the water catchment section.

[0039] The permissible drawdown disclosed in this article refers to the strict limits imposed by relevant standards on water level drawdown. For example, during pumping tests, the regulations explicitly require that "the water level drop must not exceed the permissible drawdown."

[0040] In hydrogeology, the water-bearing strata that need to be surveyed, drilled, or mined are called the "target strata." The depth of the target strata is a relevant determining factor for well structure, casing depth, and filter pipe installation location. Other technical terms are standard terms in hydrogeological engineering, and those skilled in the art know how to implement them, so they will not be disclosed in detail in this embodiment.

[0041] For site conditions with multiple wells or varying local parameters, calculate the single-well design steady flow rate Q for each well. d,i And calculate the total extraction processing scale. When the parameters of each well are the same, the total extraction processing capacity is... η is preferably 1.1-1.3, Q total The unit is m 3 / d.

[0042] This embodiment discloses a seepage correction model, the method for constructing the seepage correction model includes: Based on the steady-state saturated seepage control equation and Darcy's law, a numerical simulation sample was constructed, including lateral low-permeability constraint boundaries, upstream and downstream connectivity boundaries in the main seepage direction, fixed drawdown boundaries of inclined boreholes, and inclined groundwater level boundaries. Boundary identification data, dip angle, experimental drawdown, and experimental stable drainage volume were extracted from the sample and used for data fitting to construct the seepage correction function in the seepage correction model.

[0043] That is, the seepage correction model of the present invention is based on the steady-state saturated seepage control equation. Darcy's Law Numerical simulation samples were constructed. The boundaries of the seepage correction model include lateral low-permeability constraint boundaries, upstream and downstream connectivity boundaries along the main seepage direction, inclined groundwater level boundaries, and fixed drawdown boundaries for the subducted borehole.

[0044] As a preferred embodiment, the method for calculating the in-situ permeability coefficient using a seepage correction model includes: performing unit normalization on the boundary identification data, the dip angle of the field dip test borehole, the test stable drainage volume and test drawdown, and the seepage correction model before calculating the in-situ permeability coefficient. This method avoids directly taking the logarithm or exponent for dimensional variables, reducing the risk of unclear formulas and impracticality. The subscript N represents the dimensionless value after dividing by the reference unit and does not indicate northward direction, node, or sample number.

[0045] , , The normalized seepage correction function F is: , In the above formula Indicates HN as the base is the exponential term; ln is the natural logarithm; 0.21384, 0.27042 and 2.6217 are empirical correction coefficients obtained based on numerical simulation sample fitting.

[0046] The formula for calculating the forward seepage flow rate Q is: ; The formula for permeability coefficient inversion is: ; The design stable flow rate for a single well during the repair design phase is: ; ; When the parameters of each well are the same, .

[0047] Where i is the number of each pumping well, i = 1, 2, 3, ..., Q d,i For the design stable flow rate of the i-th pumping well, Q total The pumping capacity is defined as n, which represents the number of pumping wells.

[0048] Among them, C m It is the correction factor for the descent range, C m The selection rule is: when 3.0m ≤ m < 4.0m, C m =3; when 4.0m ≤ m < 5.0m, C m =4.

[0049] In the experimental inversion stage, the parameter is taken as m. t e t and b t Calculate F t And inverse k; during the design phase, the parameters are taken as m respectively. d e d and b d Calculate F d And output Q d By defining them separately, we avoid directly substituting the test flow rate back into the design flow rate, thus enhancing the technical significance of the engineering design closed loop.

[0050] The use of the same correction function, as referred to in this disclosure, means that within the applicable boundaries of the seepage correction model, the experimental inversion and design calculations use the same set of variables, the same functional form, and the same fitting coefficients. If m, e, and b differ locally at different well locations, F should be calculated separately. i and Q d,i If the target site boundary conditions or parameter ranges exceed the limits specified in this manual, the seepage correction function should be recalibrated.

[0051] Furthermore, the seepage correction function was constructed by using a numerical simulation sample containing the drawdown boundary of the inclined borehole and the inclined groundwater level boundary, based on the steady-state saturated seepage control equation and Darcy's law. The boundary identification data, dip angle, test drawdown, and test steady-state drainage volume in the sample were extracted and fitted to obtain the correct function.

[0052] In one implementation, the model construction sample includes 8748 parameter combinations, i.e., 3×4×3×3×3×3×3×3 sets of parameter levels, as shown in Table 1 below. The borehole radius r in the field tilt test... w The construction structure conditions used in model building are preferably limited to 55mm-85mm; after variable screening, the borehole radius r of the field tilt test is... w Since it is not an explicit variable in the seepage correction function, when the borehole radius r in the field tilt test is... w If the error exceeds 55mm-85mm, the model should be recalibrated.

[0053] Table 1:

[0054] Model training and testing results can be evaluated using mean absolute error, mean square error, root mean square error, and coefficient of determination. In a single sample partition, the test set metrics for seepage flow Q are MAE=0.3055, MSE=0.2330, RMSE=0.4827, and R²=0.2330. 2 =0.9822; training set metrics are MAE=0.3083, MSE=0.2315, RMSE=0.4811, R 2 =0.9837.

[0055] When this method is used as a single extraction treatment remediation scheme, it is preferably applied to sites where the equivalent permeability coefficient of the target aquifer is not less than 0.0432 m / d. For low-permeability sites, this method can be used as part of parameter determination, hydraulic interception evaluation, or combined remediation design. This limitation helps to avoid over-claiming the applicability of extraction treatment.

[0056] Furthermore, two specific embodiments based on this method are disclosed below: Example 1: Calculation of Strip-shaped Pollution Plume in Chemical Industrial Park A strip-shaped pollution plume exists at a groundwater contaminated site in a chemical industrial park. The plume is 20m long along the main seepage direction and 5m wide laterally, with an L / W ratio of 4. The two sides are low-permeability clay layers, and the ratio of the lateral boundary permeability coefficient to the permeability coefficient of the target contaminated aquifer is less than 0.1. The strip-shaped pollution plume connects with the surrounding aquifer upstream and downstream along the flow path.

[0057] A field dip test borehole was drilled downstream of the groundwater pollution plume, with the following test parameters: α=15°, H=30m, L=20m, b t =6 m, e t =25°, m t =4 m. Based on the drawdown range, C m =4. The pumping time shall not be less than 24 hours, and after the stability criterion is reached, the stable discharge volume shall be recorded as Q. t =1.2256 m 3 / d.

[0058] F t =324.497; .

[0059] Repair design phase take b d =6 m、e d =25°, m d =4.5 m, C m =4, and F is calculated. d =345.959.

[0060]

[0061]

[0062] The above embodiments are used to illustrate the model substitution method and the design flow conversion process, and do not limit the present invention to be applicable only to this set of parameters.

[0063] Example 2: Calculation of Strip-shaped Pollution Plumes from Gas Stations The pollution plume of a groundwater contaminated site at a gas station has a length L=18 m along the main seepage direction, a transverse width W=5 m, and an L / W=3.6 ratio; the two sides are low-permeability bedrock boundaries, and it is connected to the upstream and downstream along the flow direction.

[0064] The experimental parameters were: α = 12°, H = 25 m, L = 18 m, b t =5 m, e t =20°, m t =3.5 m. Based on the drawdown range, C m =3. Record Q after reaching the stability criterion. t =0.9862 m 3 / d .

[0065] ; ; .

[0066] Take b during the design phased =5 m、e d =20°, m d =4.0 m, C m =4, calculate Q d =1.0482 m 3 / d. If n=3 inclined pumping wells are arranged and η=1.2, then: ; This example is also used to illustrate the calculation process and should not be written as "all standards have been met" or "acceptance has been passed" without evidence in the formal application documents; if there is real engineering data, monitoring records, operating time, pollutant type, concentration change and acceptance basis should be added.

[0067] In other embodiments, multiple downstream interception sections can be set according to the target plume width and the location of downstream receptors, and the Q of each section can be calculated separately. d Then sum them up to determine the total processing size.

[0068] In other implementations, the percolation correction function can be constructed using one of regression fitting, response surface methodology, lookup table interpolation, or machine learning regression.

[0069] A further disclosed system includes: a tilting test borehole assembly, a tilting pumping well assembly, a drawdown pumping pump assembly, a water level monitoring assembly, a flow meter, a data acquisition unit, a processor, a memory, and an extraction processing device, such as... Figure 4 The diagram shows the connection relationships between the tilting pumping well group, flow meter, pump (constant drawdown pump assembly), water level monitoring assembly, data acquisition unit, processor / memory, output parameters, and extraction processing device; monitoring feedback enters the processor and pump control, directly forming the design output without bypassing the seepage correction function.

[0070] The memory is used to store one or more computer instructions, which are executed by the processor to implement the above-disclosed method for in-situ determination of hydrological parameters of groundwater pollution plumes. The tilt test borehole assembly is used to deploy at least one field tilt test borehole at the downstream interception section of the target pollution plume; wherein the field tilt test borehole is a downward tilting borehole, so that the screen section or water collection section is located within the target pollution aquifer; The tilting pumping well assembly is equipped with a water level monitoring assembly, a constant drawdown pump assembly, and a flow meter, which are used to obtain the test drawdown and the test stable drainage volume. The extraction and treatment unit is used to receive and treat wastewater. It is used for treatment (purification), reinjection, and discharge.

[0071] Furthermore, the tilt test borehole assembly includes a borehole, a screen section or a water collection section, and a sealing structure. The screen section or water collection section is located within the target contaminated aquifer, and the sealing structure is used to isolate non-target aquifers.

[0072] As a preferred embodiment, the system also includes a monitoring well assembly that provides an observation channel and contains a water level monitoring component; the water level monitoring component is connected to a data acquisition unit. The water level monitoring component collects groundwater level change data and uses a processor to adjust the water pump assembly.

[0073] Figure 5 This is a diagram comparing the model predictions and numerical simulations, with the horizontal axis representing the numerical simulation value Q / (m). 3 ·d -1 The vertical axis represents the model's predicted value Q / (m). 3 ·d -1 This model has extremely high prediction accuracy and reliability, and can accurately reflect the characteristics of groundwater extraction flow.

[0074] This invention also discloses a computer-readable storage medium storing a computer program or instructions thereon, characterized in that, when the computer program or instructions are executed by a processor, they implement the in-situ permeability coefficient inversion calculation and / or the calculation of the extraction processing scale in the disclosed method.

[0075] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. A computer program product includes a computer program or instructions that, when executed by a processor, implement the in-situ permeability coefficient inversion and / or extraction processing scale calculation in the disclosed methods. The methods disclosed in the embodiments of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product stored in a storage medium, including several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0076] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for in-situ parameter determination and extraction treatment of groundwater pollution plumes, characterized in that, Includes the following steps: Obtain boundary identification data of the target contamination plume, wherein the target contamination plume is a strip-shaped contamination plume that is laterally constrained by a low-permeability boundary and extends along the main seepage direction; Obtain the dip angle of at least one field dip test borehole deployed at the downstream interception section of the target pollution plume; Obtain the test drawdown and the test stable discharge volume after reaching the stability criterion in the constant drawdown stable pumping test; Based on boundary identification data, the dip angle, test drawdown, and test stable drainage volume of the borehole, the in-situ permeability coefficient was calculated by inversion using a seepage correction model. Obtain the design well spacing, design drawdown, and design borehole inclination angle. Combine the in-situ permeability coefficient with the same seepage correction model to calculate the design stable flow rate of a single well in the design stage. Calculate the pumping treatment scale in the pumping treatment based on the design stable flow rate of a single well, the number of pumping wells, and the safety factor. The output single-well design provides a stable flow rate and extraction capacity for setting or adjusting the pump assembly and extraction device.

2. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 1, characterized in that, The boundary identification data includes: The angle between the groundwater level and the horizontal plane, the length of the target pollution plume along the main seepage direction, the lateral width of the target pollution plume, the equivalent control width during the test phase, and the initial saturation thickness or equivalent head height of the target pollution aquifer relative to the bottom plate of the aquifer.

3. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 1 or 2, characterized in that, The method for calculating the in-situ permeability coefficient using a seepage correction model includes: The in-situ permeability coefficient is calculated after performing unit normalization on the boundary identification data, the dip angle of the field dip test borehole, the test stable drainage volume and test drawdown, and the seepage correction function.

4. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 1, characterized in that, The method for constructing the seepage correction model includes: Based on the steady-state saturated seepage control equation and Darcy's law, a numerical simulation sample was constructed, including lateral low-permeability constraint boundaries, upstream and downstream connectivity boundaries in the main seepage direction, fixed drawdown boundaries of inclined boreholes, and inclined groundwater level boundaries. Boundary identification data, inclination angle, experimental drawdown, and experimental stable drainage volume were extracted from the sample and used for data fitting to construct the seepage correction function in the seepage correction model.

5. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 2, characterized in that, The method also includes the following steps: obtaining water level data from at least one monitoring well deployed upstream and downstream of the inclination test borehole at the site, and adjusting the equivalent control width of the test phase based on changes in the water level data; or determining whether the pumping capture range covers the downstream interception section based on changes in the water level data.

6. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 2, characterized in that, The ratio of the length of the target contaminant plume along the main seepage direction to the transverse width of the target contaminant plume is greater than or equal to 3. The ratio of the permeability coefficient of the lateral low-permeability confined boundary of the target contamination plume to the permeability coefficient of the target contaminated aquifer is less than or equal to 0.

1.

7. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 2, characterized in that, The angle between the groundwater level and the horizontal plane is 5°-25°; the length of the target pollution plume along the main seepage direction is 10m-30m; the initial saturation thickness or equivalent head height is 20m-40m; the equivalent control width during the test phase is 3m-9m; and the designed well spacing is 3m-9m.

8. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 2, characterized in that, The initial saturation thickness or equivalent water head height is determined by the difference between the bottom elevation of the target contaminated aquifer and the stable groundwater level before the pumping test, or by the initial saturation thickness of the target contaminated aquifer.

9. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 1, characterized in that, The inclination angle of the field inclination test borehole is 10°-40°, and the radius of the field inclination test borehole is 55mm-85mm.

10. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 5, characterized in that, The equivalent control width during the test phase is determined by one or more of the following: the lateral width of the target plume, the effective width of the plume, the water level response range of the monitoring well, the length of the downstream interception section, or the site numerical model.

11. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 1, characterized in that, The stability criteria for the constant drawdown stable pumping test are: pumping time not less than 24 hours, flow rate change rate not greater than 5% for 6 consecutive hours or more, and water level fluctuation in the borehole not greater than 0.05 meters.

12. The method for in-situ parameter determination and extraction treatment of groundwater pollution plumes as described in claim 1, characterized in that, The method for determining the number of pumping wells includes: during the design phase, first determining the effective width W of the pollution plume to be covered. eff The well spacing b of the pumping wells in the preliminary design stage d The formula for calculating the number of pumping wells is: n is the number of pumping wells, b d This refers to the distance between pumping wells; The design drawdown is determined based on the initial saturation thickness or equivalent head height, the allowable drawdown, and the pump capacity. The design dip angle is determined based on the target layer depth, surface construction conditions, and the location of the water catchment section. When multiple wells or different local parameters are used, calculate the single-well design steady flow rate for each well separately, and take... Where η is the safety factor, i is the pumping well number, and Q is the pumping well number. d,i For the design stable flow rate of the i-th pumping well, Q total To determine the processing scale; When the parameters of each well are the same , where n is the number of pumping wells.

13. A system, characterized in that, It includes tilt test borehole assembly, tilt pumping well assembly, constant drawdown pump assembly, water level monitoring assembly, flow meter, data acquisition unit, processor, memory, and extraction processing device. The memory is used to store one or more computer instructions, which are executed by the processor to implement the method for in-situ parameter determination and extraction of groundwater pollution plumes according to any one of claims 1-12. The tilt test borehole assembly is used to deploy at least one field tilt test borehole at the downstream interception section of the target pollution plume; wherein, the field tilt test borehole is a downward tilting borehole, so that the screen section or water collection section is located within the target pollution aquifer; The tilting pumping well assembly is equipped with a water level monitoring assembly, a constant drawdown pump assembly, and a flow meter, which are used to obtain the test drawdown and the test stable drainage volume. A wastewater extraction and treatment device is used to receive wastewater that has been extracted and treated.

14. The system according to claim 13, characterized in that, The tilt test borehole assembly includes a borehole, a screen or water collection section, and a sealing structure. The screen or water collection section is located within the target contaminated aquifer, and the sealing structure is used to isolate non-target aquifers.

15. The system as described in claim 13, characterized in that, It also includes monitoring well components, The monitoring well assembly is used to provide an observation channel and is equipped with a water level monitoring component inside. The water level monitoring component is connected to a data acquisition unit and a processor. The water level monitoring component is used to collect groundwater level change data and adjust the water pump assembly.

16. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by the processor, they implement the method for in-situ parameter determination and extraction of groundwater pollution plumes as described in any one of claims 1 to 12.

17. A computer program product, characterized in that, It includes a computer program or instructions that, when executed by a processor, implement the method for in-situ parameter determination and extraction of groundwater pollution plumes as described in any one of claims 1 to 12.

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