Simulation experiment device and evaluation method for migration and transformation of pollutants in water and soil medium

Abstract

The invention discloses a simulation experiment device for migration and transformation of pollutants in water and soil media and an evaluation method, and relates to the field of pollutant migration and pollution remediation in environmental media such as natural resources and ecological environments, and the simulation experiment device can independently simulate one scene for simulation and can also perform combined simulation on multiple scenes. The simulation scene is closer to the real condition, the water and soil environment medium condition is simulated more truly, especially, design is carried out for a large number of dominant channels and lenticules existing in the stratum, the simulation effect is more scientific and accurate, trace indexes are introduced according to the pollutant property, a pollutant migration evaluation model is established, and the method has the advantages of being high in practicability and easy to popularize. Therefore, the aim of scientifically and comprehensively evaluating the influence of the pollutants on the environmental medium is achieved, the pollutant migration evaluation method can effectively evaluate the pollutant migration path and the potential pollution area, the pollution range can be more scientifically described, and the evaluation method can provide effective theoretical support for pollution investigation and restoration.

Description

Technical Field

[0001] The present invention relates to the field of pollutant migration and pollution remediation in environmental media such as natural resources and ecological environment, and in particular to a pollutant migration and transformation simulation experimental device in water and soil media and an evaluation method. Background Art

[0002] Soil and groundwater resources are important components of human production and life. In recent years, with the rapid development of my country's social economy, the level of industrialization has also achieved rapid improvement, and the resulting soil and water pollution problems have become increasingly serious. Therefore, studying the migration and transformation laws of pollutants in soil and water media, understanding the pollution status of soil and water environment, and predicting its development trend have very important theoretical significance and extensive practical value.

[0003] The structure of water and soil environmental media is very complex and shows strong heterogeneity. For example, plant roots, animal burrows, and artificial mining burrows will form dominant channels in the aeration zone, increasing the migration speed of pollutants; clay bodies and ginger bodies in the aquifer will form lenses, hindering the migration of pollutants, etc. Therefore, affected by the heterogeneous structure of water and soil media, pollutants continue to undergo complex physical and chemical changes along the migration process. At present, most of the pollutant migration and transformation simulation experimental devices are designed for a single soil layer or aquifer homogeneous structure, which cannot reflect the actual state of the underground environmental medium, resulting in pollutant migration and transformation simulation results that are different from the actual situation, and cannot fully understand the environmental behavior of pollutants in the aeration zone and aquifer, affecting the scientific formulation of pollution remediation plans.

[0004] During the migration of pollutants in the strata, physical and chemical reactions such as adsorption and degradation often occur. When investigators cannot detect pollutants, they usually believe that the pollution boundary has been reached. However, due to the influence of rainfall infiltration and groundwater level fluctuations, pollutants reappear repeatedly in the later period, and the pollution area also changes accordingly, resulting in unscientific and inaccurate assessment of the degree and scope of pollution.

[0005] During the migration process, pollutants are prone to chemical reactions and become secondary pollutants. Usually, pollution assessment is only carried out on the original pollutants, which ultimately makes it difficult to fully and accurately assess the impact of pollutants on environmental media. Summary of the invention

[0006] The purpose of the present invention is to provide a simulation experimental device and evaluation method for the migration and transformation of pollutants in water and soil media to solve the above-mentioned problems.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] The present invention discloses a simulated experimental device for the migration and transformation of pollutants in water and soil media, comprising an outer shell and a plurality of bottom sand plates and downstream sand plates clamped inside the outer shell, wherein the outer shell, the bottom sand plates and the downstream sand plates form the main body of the experimental device, the bottom sand plates are provided with a bottom liquid channel 1 and a bottom liquid channel 2, the bottom liquid channel 1 is connected to a liquid discharge component, the bottom liquid channel 2 is connected to a liquid supply component, an air-containing zone, an aquifer and a weakly permeable layer are arranged in a space formed by the inner wall of the outer shell, the bottom sand plates and the downstream sand plates, and the downstream sand plates are provided with a bottom liquid channel 1 and a bottom liquid channel 2 at positions corresponding to the air-containing zone, the aquifer and the weakly permeable layer. An upstream liquid channel is provided, the downstream liquid channel is connected to the drainage component, and the downstream sand plate is provided with sampling ports of different heights; a dominant channel simulation cavity, a lens body simulation cavity and a simulation experimental well are also provided in the space composed of the inner wall of the shell, the bottom sand plate and the downstream sand plate; a spray mechanism is provided above the shell, and the spray mechanism supplies liquid through the liquid supply component, and the liquid supply component and the drainage component are both controlled by a controller; an upstream liquid channel is installed upstream of the shell, and the upstream liquid channel is connected to the liquid supply component, and a waste liquid port is installed at the downstream bottom of the shell, and the waste liquid port is connected to the drainage component.

[0009] Furthermore, buckles are provided on the inner wall of the shell and on the ends of the bottom sand plate and the downstream sand plate. The bottom sand plate and the downstream sand plate are both snapped onto the inner wall of the shell through the buckles, adjacent bottom sand plates are snapped onto each other, and two adjacent downstream sand plates are snapped onto each other.

[0010] Furthermore, the bottom sand plate is connected to the outer shell through a support rod.

[0011] Furthermore, the dominant channel simulation cavity includes a sand filter layer and a capillary channel, and the dominant channel simulation cavity is placed in any one, two or three layers of the aeration zone, the aquifer and the weakly permeable layer.

[0012] Furthermore, the lens body simulation cavity includes a second sand filter layer and a weakly permeable layer filling cavity, the second sand filter layer is placed outside the weakly permeable layer filling cavity, and the lens body simulation cavity is placed in the aquifer.

[0013] Furthermore, the simulated experimental well passes through the aeration zone and the aquifer, or passes through the aeration zone, the aquifer and the weakly permeable layer.

[0014] Furthermore, the drainage component includes a drainage pipeline connected to the bottom liquid channel 1, the downstream liquid channel and the waste liquid port, the drainage pipeline is connected to the drainage pump, the drainage port of the drainage pump is connected to the waste liquid tank, and the controller is connected to the drainage pump.

[0015] Furthermore, the liquid supply component includes a water tank, a medicine tank and a liquid supply pump, the liquid supply pump is connected to the water tank and the medicine tank through a liquid supply pipeline, the liquid outlet of the liquid supply pump is connected to the spray mechanism, the upstream liquid channel and the bottom liquid channel, and the liquid supply pump is connected to the controller.

[0016] Furthermore, valve switches are provided on the bottom liquid channel 1, the downstream liquid channel, the upstream liquid channel and the waste liquid port.

[0017] An evaluation method using a simulated experimental device for the migration and transformation of pollutants in water and soil media, characterized in that it includes the following steps:

[0018] S1. Select the environment to be simulated according to the experimental requirements: According to the requirements, you can simulate individual scenarios such as precipitation, aquifer runoff, water level rise, and comprehensive environmental models with different scenarios combined;

[0019] S2. Functional module selection: dominant channel, lens, and monitoring well are optional functional modules. When designing a simulation experiment, you can choose to install any one, two, or all of the dominant channel, lens, and monitoring well to compare the pollutant migration and transformation effects under the presence of the dominant channel and lens;

[0020] S3, set up a comparative experiment group, in which no functional modules are set up, and other experimental conditions are exactly the same as those in step S2, to compare the environmental behavior of pollutants in water and soil media under the presence of advantageous channels, lenses, monitoring wells, or other combined functions, and to what extent;

[0021] S4. According to the type of pollutant, trace indicators with similar properties and concentrations are selected for coupling. The concentration of pollutant X in the sample is collected from each sampling port (including the simulation experiment well). This concentration is the real-time concentration of pollutant X during the simulation experiment. The concentration of trace indicator a in the sample is collected from each sampling port (including the simulation experiment well). This concentration is the real-time concentration of trace indicator a during the simulation experiment. The concentration of trace indicator a in the reagent tank is the initial concentration of trace indicator a at the pollution source, that is, at the point where the pollutant concentration is the maximum, defined as Ca0. The relationship between the pollutant index E and the concentration of each indicator is: Where: E-pollution index, Cx-pollutant (X) concentration, Ca-trace index (a) concentration, Ca0-trace index (a) initial concentration, the evaluation criteria are as follows:

[0022] E>0.2: pollution source;

[0023] E is 0-0.2: the main path of pollutant migration;

[0024] E is -0.2 to 0: potential pollution area;

[0025] E<-0.2: non-polluting area.

[0026] Compared with the prior art, the beneficial technical effects of the present invention are:

[0027] 1. It can simulate one scenario alone or multiple scenarios in combination, making the simulation scenario closer to the real situation and simulating the water and soil environment media more realistically. In particular, it is designed for the large number of advantageous channels and lenses in the strata, making the simulation effect more scientific and accurate;

[0028] 2. The conservative anions and cations existing in groundwater were introduced as trace indicators, and the migration and transformation laws of pollutants were further simulated based on the environmental behavior of trace indicators in water and soil media, so as to achieve the purpose of comprehensive and scientific evaluation of the environmental behavior of pollutants;

[0029] 3. It truly reflects the heterogeneous conditions of the strata and can provide preliminary simulation data for soil and groundwater pollution remediation, including the migration and transformation data of pollutants under different hydrological environments (rainfall, groundwater funnel, water level rise, etc.), and pollution remediation experimental data under simulation of different technologies (in-situ remediation, extraction treatment, natural attenuation, etc.).

[0030] The present invention also introduces trace indicators according to the properties of pollutants and establishes a pollutant migration assessment model, so as to achieve the purpose of scientifically and comprehensively evaluating the impact of pollutants on environmental media. The pollutant migration (pollution range) assessment method can effectively evaluate the pollutant migration path and potential pollution areas, and can more scientifically characterize the pollution range. The assessment method can provide effective theoretical support for pollution investigation and remediation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings.

[0032] Figure 1 It is a schematic diagram of a simulated experimental device for the migration and transformation of pollutants in water and soil media of the present invention;

[0033] Figure 2 Schematic diagram of the simulation cavity for the dominant channel;

[0034] Figure 3 It is a schematic diagram of the cavity filled with aquitard;

[0035] Figure 4 Model diagram for pollutant transport assessment;

[0036] Explanation of the reference numerals: 1. outer shell; 2. bottom sand plate; 3. downstream sand plate; 4. aeration zone; 5. aquifer; 6. weakly permeable layer; 7. dominant channel simulation cavity; 701. sand filter layer one; 702. capillary channel; 8. lens simulation cavity; 801. sand filter layer two; 802. weakly permeable layer filling cavity; 9. simulated experimental well; 10. bottom liquid channel one; 11. downstream liquid channel; 12. sampling port; 13. spray mechanism; 14. controller; 15. upstream liquid channel; 16. waste liquid port; 17. buckle; 18. support rod; 19. drainage pipeline; 20. drainage pump; 21. waste liquid tank; 22. water tank; 23. medicine tank; 24. liquid supply pump; 25. liquid supply pipeline; 26. bottom liquid channel two. DETAILED DESCRIPTION

[0037] like Figure 1-4 As shown, a pollutant migration and transformation simulation experimental device and evaluation method in water and soil media include an outer shell 1 and a plurality of bottom sand plates 2 and downstream sand plates 3 clamped inside the outer shell 1. The outer shell 1 is made of impermeable material. The outer shell 1, the bottom sand plates 2 and the downstream sand plates 3 form the main body of the experimental device. The bottom sand plate 2 is connected to the outer shell 1 through a support rod 18.

[0038] The bottom sand plate 2 and the downstream sand plate 3 are water-permeable and can naturally penetrate water.

[0039] Buckles 17 are provided on the inner wall of the outer shell 1 and on the ends of the bottom sand plate 2 and the downstream sand plate 3. The bottom sand plate 2 and the downstream sand plate 3 are both snapped onto the inner wall of the outer shell 1 through the buckles 17. Adjacent bottom sand plates 2 are snapped onto each other, and two adjacent downstream sand plates 3 are snapped onto each other.

[0040] The wall of the shell 1 is used as the upstream baffle at the upstream of the main body of the experimental device, and the side walls of the shell 1 can be used as the side baffles on both sides of the main body of the experimental device. A separate waterproof material can also be used as the side baffles, and a sand plate can also be used as the side baffles. When the liquid can only flow downstream, waterproof materials or the side walls of the shell should be used as the side baffles. When the liquid flow direction is lateral and downstream flow, sand plates should be used as the side baffles. The buckles 17 are installed on the upstream baffle and the side baffles. The upstream baffle buckle, the buckles on the side baffles, the bottom sand plate buckle and the downstream sand plate 3 buckle can be clamped with each other.

[0041] An upstream liquid channel 15 is installed upstream of the shell, and the upstream liquid channel 15 is connected to the liquid supply component. The upstream liquid channel 15 is connected to the aquifer part of the middle layer of the experimental device body to transport experimental liquid to the aquifer.

[0042] The bottom sand plate 2 is provided with a bottom liquid channel 10 and a bottom liquid channel 2 26. The bottom liquid channel 10 is connected to the drainage component, the bottom liquid channel 2 26 is connected to the liquid supply component, and the bottom liquid channel 2 26 is connected to the weakly permeable layer of the lower layer of the main body of the experimental device to transport the experimental liquid to the weakly permeable layer.

[0043] The space formed by the inner wall of the outer shell 1, the bottom sand plate 2 and the downstream sand plate 3 is provided with an air-containing zone 4, an aquifer 5 and a weakly permeable layer 6. The downstream sand plate 3 is provided with a downstream liquid channel 11 at the position corresponding to the air-containing zone 4, the aquifer 5 and the weakly permeable layer 6. The downstream liquid channel 11 is connected to the drainage component.

[0044] The downstream sand plate 3 is provided with sampling ports 12 at different heights, which can respectively sample the soil, sand and liquid in the aeration zone 4, the aquifer 5 and the weak permeable layer 6;

[0045] The space formed by the inner wall of the shell 1, the bottom sand plate 2 and the downstream sand plate 3 is also provided with a dominant channel simulation cavity 7, a lens body simulation cavity 8 and a simulation experimental well 9.

[0046] The dominant channel simulation cavity 7 is a comprehensive simulation of the dominant channel type. The dominant channel simulation cavity 7 includes a sand filter layer 701 and a capillary channel 702. The sand filter layer 701 simulates a permeable zone formed under natural conditions, and the capillary channel 702 simulates plant roots, animal tunnels, artificial mining tunnels, etc. The dominant channel simulation cavity 7 is placed in any one, two or three layers of the aeration zone 4, aquifer 5 and weakly permeable layer 6.

[0047] The lens simulation cavity 8 includes a sand filter layer 801 and a weakly permeable layer filling cavity 802. The sand filter layer 801 is placed on the outside of the weakly permeable layer filling cavity 802. The sand filter layer 801 is on the outside and has a permeable support function. The weakly permeable layer filling cavity 802 is on the inside and is filled with a weakly permeable medium for simulating the influence of the lens on the migration and transformation of pollutants. The lens is a weakly permeable layer, so the lens simulation cavity 8 is located in the aquifer 5.

[0048] The simulated experimental well 9 runs through the aeration zone 4 and the aquifer 5, or runs through the aeration zone 4, the aquifer 5 and the weak permeable layer 6. The simulated experimental well 9 can inject water into the formation to simulate groundwater uplift or underground water replenishment, and can also pump water through the simulated experimental well to simulate groundwater decline or groundwater drop funnel.

[0049] A spray mechanism 13 is provided above the housing 1, and the spray mechanism supplies liquid through a liquid supply component. The liquid supply component and the liquid discharge component are both controlled by a controller 14. The spray mechanism 13 and the controller 14 are both prior arts, and the specific structures are not described in detail here.

[0050] A waste liquid port 16 is installed at the downstream bottom of the shell, and the waste liquid port 16 is connected to the drainage component.

[0051] The drainage component includes a drainage pipeline 19 connected to the bottom liquid channel 10, the downstream liquid channel 11 and the waste liquid port 16, the drainage pipeline 19 is connected to the drainage pump 20, the drainage port of the drainage pump 20 is connected to the waste liquid tank 21, and the controller 14 is connected to the drainage pump 20.

[0052] The liquid discharge pump 20 discharges the liquid through the downstream liquid channel 11, the bottom liquid channel 10, and the waste liquid port 16 into the waste liquid tank 21. At the same time, the liquid discharge pump 20 can provide power to extract the liquid in the aeration zone 4, the aquifer 5, and the weak permeable layer 6 through the downstream liquid channel 11 to accelerate the migration speed of the liquid in the aeration zone 4, the aquifer 5, and the weak permeable layer 6. When the liquid discharge pump 20 extracts the liquid in the weak permeable layer 6 through the bottom liquid channel 10, the migration and transformation of pollutants in the aeration zone 4 and the aquifer 5 in the presence of a groundwater drop funnel can be simulated.

[0053] The liquid pump provides liquid extraction power in the following situations:

[0054] a. When the liquid runoff velocity in the aeration zone 4 is changed, the liquid in the aeration zone 4 is extracted through the downstream liquid channel 11 of the aeration zone layer;

[0055] b. When the runoff velocity of the liquid in the aquifer 5 is changed, the liquid in the aquifer 5 is extracted through the downstream liquid channel 11 of the aquifer 5;

[0056] c. When the liquid runoff velocity in the weakly permeable layer 6 below the aquifer 5 is changed, the liquid in the weakly permeable layer 6 is extracted through the downstream liquid channel 11 of the weakly permeable layer 6;

[0057] d. When the liquid runoff velocity in the aeration zone 4 and the aquifer 5 is changed at the same time, the liquid in the aeration zone 4 and the aquifer 5 is simultaneously extracted through the downstream liquid channel 11 of the aeration zone 4 and the aquifer 5;

[0058] e. When the liquid runoff velocity in the aeration zone 4, the aquifer 5, and the weakly permeable layer 6 is changed at the same time, the liquid in the aeration zone 4, the aquifer 5, and the weakly permeable layer 6 is simultaneously extracted through the downstream liquid channel 11 of the aeration zone 4, the aquifer 5, and the weakly permeable layer 6;

[0059] f. When simulating the groundwater drop funnel, the liquid in the weak permeable layer 6 and the aquifer 5 is pumped downward through the bottom liquid channel 10.

[0060] The liquid supply assembly includes a water tank 22, a medicine tank 23 and a liquid supply pump 24. The liquid supply pump 24 is connected to the water tank 22 and the medicine tank 23 through a liquid supply pipeline 25. The liquid outlet of the liquid supply pump 24 is connected to the spray mechanism 13, the upstream liquid channel 15 and the bottom liquid channel 26. The liquid supply pump 24 is connected to the controller 14.

[0061] The water tank 22 stores aqueous solution, and the reagent tank 23 stores pollutant solution or remediation reagent solution. When the pollutant solution is supplied, the experimental device body is used to simulate the migration and transformation behavior of pollutants; when the remediation reagent is supplied, the experimental device body can be used to simulate the remediation effect of contaminated soil, groundwater, and aquifer.

[0062] The liquid delivery pipeline 25 delivers the liquid in the water tank 22 and the medicine tank 23 to the liquid supply pump 24, and the liquid is mixed in proportion by the liquid supply pump 24 and selectively input to the spray mechanism 13, the upstream liquid channel 15, and the bottom liquid channel 2 26, so that the following environmental simulation can be performed:

[0063] a. When simulating rainfall, it is only delivered to the sprinkler mechanism;

[0064] b. When simulating the impact of aquifer runoff, it is only transported to the upstream liquid channel 15;

[0065] c. When simulating water level recovery (groundwater recharge), it is only transported to the bottom liquid channel 26;

[0066] d. When simulating the impact of rainfall and runoff at the same time, it is delivered to the spray mechanism 13 and the upstream liquid channel 15;

[0067] e. Simultaneously simulate rainfall and water level rise (groundwater recharge), the liquid is delivered to the spray mechanism 13 and the bottom liquid channel 26;

[0068] f. Simultaneously simulating runoff and water level recovery (groundwater recharge), the liquid is transported to the upstream liquid channel 15 and the bottom liquid channel 26;

[0069] g. When simulating rainfall, runoff and water level rise (groundwater recharge) at the same time, it is transported to the spray mechanism 13, the upstream liquid channel 15 and the bottom liquid channel 26.

[0070] The bottom liquid channel 10, the downstream liquid channel 11, the upstream liquid channel 15 and the waste liquid port 16 are all provided with valve switches.

[0071] The controller 14 automatically controls the operation of the liquid supply pump 24 and the liquid discharge pump 20 , can adjust the ratio of the liquid in the water tank 22 and the liquid in the medicine tank 23 by the liquid supply pump 24 online, and can adjust the liquid supply and liquid discharge speed / flow rate of the liquid supply pump 24 and the liquid discharge pump 20 .

[0072] An evaluation method using a simulated experimental device for pollutant migration and transformation in water and soil media includes the following steps:

[0073] S1. Select the environment to be simulated according to the experimental requirements: According to the requirements, you can simulate individual scenarios such as precipitation, aquifer runoff, water level rise, and comprehensive environmental models with different scenarios combined;

[0074] S2. Functional module selection: dominant channel, lens, and monitoring well are optional functional modules. When designing a simulation experiment, you can choose to install any one, two, or all of the dominant channel, lens, and monitoring well to compare the pollutant migration and transformation effects under the presence of the dominant channel and lens;

[0075] S3, set up a comparative experiment group, in which no functional modules are set up, and other experimental conditions are exactly the same as those in step S2, to compare the environmental behavior of pollutants in water and soil media under the presence of advantageous channels, lenses, monitoring wells, or other combined functions, and to what extent;

[0076] S4. According to the type of pollutant, trace indicators with similar properties and concentrations are selected for coupling. The concentration of pollutant X in the sample is collected from each sampling port (including the simulation experiment well). This concentration is the real-time concentration of pollutant X during the simulation experiment. The concentration of trace indicator a in the sample is collected from each sampling port (including the simulation experiment well). This concentration is the real-time concentration of trace indicator a during the simulation experiment. The concentration of trace indicator a in the reagent tank is the initial concentration of trace indicator a at the pollution source, that is, at the point where the pollutant concentration is the maximum, defined as Ca0. The relationship between the pollutant index E and the concentration of each indicator is: Where: E-pollution index, Cx-pollutant (X) concentration, Ca-trace index (a) concentration, Ca0-trace index (a) initial concentration, the evaluation criteria are as follows:

[0077] E>0.2: pollution source;

[0078] E is 0-0.2: the main path of pollutant migration;

[0079] E is -0.2 to 0: potential pollution area;

[0080] E<-0.2: non-polluting area.

[0081] Experimental process of the dominant channel simulation cavity: Under situations such as precipitation, aquifer runoff, and water level rise, groundwater flows rapidly through the capillary channels in the dominant channel simulation cavity (the sand filter layer mainly plays a supporting and permeable role). The migration speed of pollutants in the dominant channel simulation cavity is greater than the migration speed of pollutants in the vadose zone and aquifer, reflecting the uneven and inconsistency of pollutant migration in the environmental medium.

[0082] Sampling positions can be set before and after the dominant channel simulation cavity as needed. Similarly, the same sampling position is set at the same position of the control experimental device without the dominant channel simulation cavity implanted, so as to achieve the purpose of studying the fine migration and transformation of local pollutants.

[0083] Experimental process of lens simulation cavity: Under situations such as precipitation, aquifer runoff, and water level rise, groundwater is blocked by the weakly permeable medium in the weakly permeable layer filling cavity in the lens simulation cavity, affecting the migration / flow of groundwater around the lens simulation cavity. The sand filter layer plays a supporting and permeable role. The migration speed of pollutants around the lens simulation cavity is lower than the migration speed of pollutants in the aquifer, which also reflects the uneven and inconsistency of pollutant migration in the environmental medium.

[0084] Experimental process of simulated experimental well: Under the conditions of precipitation, aquifer runoff, water level rise, etc., the water level in the simulated experimental well will change according to different situations. By monitoring the water level changes in the simulated experimental well, the groundwater flow field and water volume changes can be monitored. At the same time, the simulated experimental well can be used to sample and monitor groundwater in real time to understand the changes in groundwater quality at different locations of the experimental device.

[0085] By extracting a large amount of groundwater from the simulated experimental well, the groundwater funnel scenario can be simulated; by injecting a large amount of water into the simulated experimental well, the groundwater level rise scenario can be locally simulated.

[0086] By conducting aeration tests in simulated experimental wells, aeration remediation experiments for groundwater pollutants can be carried out; by injecting agents into simulated experimental wells, chemical remediation experiments for groundwater pollutants can be carried out.

[0087] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A simulated experimental device for the migration and transformation of pollutants in water and soil media, characterized by: The experimental device comprises a shell (1) and a plurality of bottom sand plates (2) and downstream sand plates (3) clamped inside the shell (1); the shell (1), the bottom sand plates (2) and the downstream sand plates (3) form a main body of the experimental device; the bottom sand plates (2) are provided with a bottom liquid channel 1 (10) and a bottom liquid channel 2 (26); the bottom liquid channel 1 (10) is connected to a liquid discharge component; the bottom liquid channel 2 (26) is connected to a liquid supply component; an air-containing zone (4), an aquifer (5) and a weakly permeable layer (6) are provided in a space formed by the inner wall of the shell (1), the bottom sand plates (2) and the downstream sand plates (3); the downstream liquid channel (10) is provided at a position corresponding to the air-containing zone (4), the aquifer (5) and the weakly permeable layer (6) on the downstream sand plates (3). 1), the downstream liquid channel (11) is connected to the drainage component, and the downstream sand plate (3) is provided with sampling ports (12) of different heights; the space formed by the inner wall of the shell (1), the bottom sand plate (2) and the downstream sand plate (3) is also provided with a dominant channel simulation chamber (7), a lens body simulation chamber (8) and a simulation experimental well (9); a spray mechanism (13) is provided above the shell (1), and the spray mechanism supplies liquid through the liquid supply component, and the liquid supply component and the drainage component are both controlled by a controller (14); an upstream liquid channel (15) is installed upstream of the shell, and the upstream liquid channel (15) is connected to the liquid supply component, and a waste liquid port (16) is installed at the downstream bottom of the shell, and the waste liquid port (16) is connected to the drainage component.

2. The simulated experimental device for the migration and transformation of pollutants in water and soil media according to claim 1 is characterized by: Buckles (17) are provided on the inner wall of the outer shell (1) and on the ends of the bottom sand plate (2) and the downstream sand plate (3); the bottom sand plate (2) and the downstream sand plate (3) are both snap-fitted to the inner wall of the outer shell (1) via the buckles (17); adjacent bottom sand plates (2) are snap-fitted to each other; and adjacent two downstream sand plates (3) are snap-fitted to each other.

3. The simulated experimental device for the migration and transformation of pollutants in water and soil media according to claim 1 is characterized by: The bottom sand plate (2) is connected to the outer shell (1) via a support rod (18).

4. The simulated experimental device for the migration and transformation of pollutants in water and soil media according to claim 1 is characterized by: The dominant channel simulation chamber (7) comprises a sand filter layer (701) and a capillary channel (702), and the dominant channel simulation chamber (7) is placed in any one, two or three layers of the aeration zone (4), the aquifer (5) and the weakly permeable layer (6).

5. The simulated experimental device for the migration and transformation of pollutants in water and soil media according to claim 1 is characterized by: The lens simulation cavity (8) comprises a second sand filter layer (801) and a weakly permeable layer filling cavity (802), wherein the second sand filter layer (801) is arranged outside the weakly permeable layer filling cavity (802), and the lens simulation cavity (8) is arranged inside the aquifer (5).

6. The simulated experimental device for the migration and transformation of pollutants in water and soil media according to claim 1 is characterized by: The simulated experimental well (9) penetrates the aeration zone (4) and the aquifer (5), or penetrates the aeration zone (4), the aquifer (5) and the weakly permeable layer (6).

7. The simulated experimental device for the migration and transformation of pollutants in water and soil media according to claim 1 is characterized by: The drainage assembly comprises a drainage pipeline (19) connected to a bottom liquid channel (10), a downstream liquid channel (11) and a waste liquid port (16); the drainage pipeline (19) is connected to a drainage pump (20); the drainage port of the drainage pump (20) is connected to a waste liquid tank (21); and the controller (14) is connected to the drainage pump (20).

8. The simulated experimental device for the migration and transformation of pollutants in water and soil media according to claim 1 is characterized by: The liquid supply assembly comprises a water tank (22), a medicine tank (23) and a liquid supply pump (24); the liquid supply pump (24) is connected to the water tank (22) and the medicine tank (23) via a liquid supply pipeline (25); the liquid outlet of the liquid supply pump (24) is connected to the spray mechanism (13), the upstream liquid channel (15) and the second bottom liquid channel (26); and the liquid supply pump (24) is connected to the controller (14).

9. The simulated experimental device for the migration and transformation of pollutants in water and soil media according to claim 1 is characterized by: The bottom liquid channel 1 (10), the downstream liquid channel (11), the upstream liquid channel (15) and the waste liquid port (16) are all provided with valve switches.

10. An evaluation method using the simulated experimental device for pollutant migration and transformation in water and soil media as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Select the environment to be simulated according to the experimental requirements: According to the requirements, you can simulate individual scenarios such as precipitation, aquifer runoff, water level rise, and comprehensive environmental models with different scenarios combined; S2. Functional module selection: dominant channel, lens, and monitoring well are optional functional modules. When designing a simulation experiment, you can choose to install any one, two, or all of the dominant channel, lens, and monitoring well to compare the pollutant migration and transformation effects under the presence of the dominant channel and lens; S3, set up a comparative experiment group, in which no functional modules are set up, and other experimental conditions are exactly the same as those in step S2, to compare the environmental behavior of pollutants in water and soil media under the presence of advantageous channels, lenses, monitoring wells, or other combined functions, and to what extent; S4. According to the type of pollutant, trace indicators with similar properties and concentrations are selected for coupling. The concentration of pollutant X in the sample is collected from each sampling port (including the simulation experiment well). This concentration is the real-time concentration of pollutant X during the simulation experiment. The concentration of trace indicator a in the sample is collected from each sampling port (including the simulation experiment well). This concentration is the real-time concentration of trace indicator a during the simulation experiment. The concentration of trace indicator a in the reagent tank is the initial concentration of trace indicator a at the pollution source, that is, at the point where the pollutant concentration is the maximum, defined as Ca0. The relationship between the pollutant index E and the concentration of each indicator is: Where: E-pollution index, Cx-pollutant (X) concentration, Ca-trace index (a) concentration, Ca0-trace index (a) initial concentration, the evaluation criteria are as follows: E>0.2: pollution source; E is 0-0.2: the main path of pollutant migration; E is -0.2 to 0: potential pollution area; E<-0.2: non-polluting area.

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