Cross-medium transmission simulation device and method for pollutants between soil and underground water

Abstract

The invention discloses a cross-medium transmission simulation device and method for pollutants between soil and underground water, and relates to the technical field of environmental governance, and the cross-medium transmission simulation device for pollutants between soil and underground water comprises a soil layer system and an underground water system. The soil layer system comprises a base and a soil box arranged on the base in the vertical direction, the soil box is used for containing test soil, and the base is provided with a first water permeable hole used for being communicated with the soil box. The underground water system comprises a water tank, a mounting opening is formed in the upper side of the water tank and used for allowing the base and the soil box to sequentially penetrate through, and the height of the inner side of the water tank is larger than that of the base so that water in the water tank can penetrate through the first water permeable holes and make contact with a soil layer in the soil box. By comparing the content of the pollutants at the same position, the blocking effect of the blocking agent on the pollutants can be evaluated, and the blocking effect of the blocking agent during cross-medium transmission of the pollutants between the soil and the underground water can be evaluated on the whole.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental governance, and in particular to a device and method for simulating the cross-media transmission of pollutants between soil and groundwater. Background Art

[0002] In the field of environmental remediation, soil pollutants are often solidified and pollutants in groundwater are oxidized and reduced to achieve the treatment of pollutants in soil and groundwater media. Some pollutants are highly mobile, such as VOCs and SVOCs. Under the influence of site environmental disturbances, they will migrate, transmit and transform across media, polluting other media. For example, pollutants in solidified and stabilized soil will be released during long-term rainwater leaching and pollute the underlying groundwater source; groundwater pollutants will migrate to the overlying soil by infiltration or volatilization under the influence of periodic fluctuations in groundwater or changes in temperature and pressure, polluting the soil environment. When treating single-element pollution of soil and groundwater, it is also necessary to block the cross-media transmission of soil and groundwater pollutants, that is, to mix the lower side of the soil with blocking agents to prevent cross-contamination. However, at this stage, it is difficult for the industry to evaluate the blocking effect of blocking agents on the cross-media transmission of pollutants between soil and groundwater. Summary of the Invention

[0003] The main purpose of the present invention is to propose a device and method for simulating the cross-media transmission of pollutants between soil and groundwater, aiming to evaluate the blocking effect of blocking agents during the cross-media transmission of pollutants between soil and groundwater.

[0004] To achieve the above objectives, the present invention proposes a device for simulating cross-media transmission of pollutants between soil and groundwater, comprising:

[0005] A soil layer system includes a base and a soil box arranged on the base in an up-down direction, the soil box is used to accommodate test soil, and the base is provided with a first water permeable hole for communicating with the soil box; and

[0006] The groundwater system includes a water tank, wherein an installation opening is provided on the upper side of the water tank, and the installation opening is used for the base and the soil box to pass through in sequence. The height of the inner side of the water tank is greater than the height of the base, so that the water in the water tank passes through the first water permeable hole and contacts the soil layer in the soil box.

[0007] In one embodiment, the soil box includes a box body and multiple soil boxes, the soil boxes are used to accommodate soil layers, multiple pull-out openings are arranged in sequence along the up and down directions on the box body wall, and the multiple soil boxes correspond one to one and are installed on the pull-out openings. The soil box is used to accommodate the soil layer of the test soil, and the bottom walls of the multiple soil boxes are all provided with a second water permeable hole.

[0008] In one embodiment, the water tank is provided with a heater and a temperature sensor; and / or,

[0009] A stirrer is provided in the water tank; and / or,

[0010] The cross-media transmission simulation device for pollutants between soil and groundwater also includes a spraying system, which is arranged on the upper side of the soil box and is used to spray the uppermost soil layer in the soil box. A sampling port is provided on the upper side of the water tank.

[0011] In one embodiment, the water tank is connected to a pressure pump, the pressure pump is used to pressurize the water tank, and the water tank is provided with a pressure sensor.

[0012] In one embodiment, a sealing sleeve is provided on the outer side of the box body, and the sealing sleeve fills the installation opening.

[0013] The present invention also provides a method for simulating cross-media transmission of pollutants between soil and groundwater, and a device for simulating cross-media transmission of pollutants between soil and groundwater, comprising:

[0014] The first detection process is used to detect the reduction rate of the migration of pollutants in water into the soil layer driven by the water level;

[0015] The second testing process is used to detect the reduction rate of the migration of pollutants in water into the soil layer driven by water pressure;

[0016] The third detection process is used to detect the reduction rate of the migration of pollutants in water into the soil layer driven by water temperature; and

[0017] The fourth detection process is used to detect the reduction rate of migration of pollutants in the soil into water under a rainfall environment.

[0018] The cross-media transmission simulation device for pollutants between soil and groundwater includes:

[0019] A soil layer system includes a base and a soil box arranged on the base in an up-down direction, the soil box is used to accommodate test soil, and the base is provided with a first water permeable hole for communicating with the soil box; and

[0020] The groundwater system includes a water tank, wherein an installation opening is provided on the upper side of the water tank, and the installation opening is used for the base and the soil box to pass through in sequence. The height of the inner side of the water tank is greater than the height of the base, so that the water in the water tank passes through the first water permeable hole and contacts the soil layer in the soil box.

[0021] In one embodiment, the first detection process includes the following steps:

[0022] S101: selecting a first test duration, and selecting the number of soil layers and the thickness of each soil layer according to the soil to be simulated;

[0023] S102: placing the selected soil layers in the soil box in sequence along the up and down directions to form a first test soil;

[0024] S103: Installing the soil box in the water tank;

[0025] S104: injecting water containing pollutants into the water tank, and stopping the water injection when the water in the water tank overflows the lower side of the first test soil;

[0026] S105: After waiting for the first test time, a first sampling point is selected in the first test soil, and a first pollutant concentration at the first sampling point is measured;

[0027] S106: measuring, in the first test soil, a maximum transmission distance of the pollutants when the first blocking soil layer is not present;

[0028] S107: draining the water in the water tank, taking the soil box out of the water tank, and taking the first test soil out of the soil box;

[0029] S108: selecting a blocking object, and then mixing the bottommost soil layer with the blocking object to form a first blocking soil layer;

[0030] S109: placing the first blocking soil layer and the remaining soil layers in the soil box in sequence along the vertical direction to form a second test soil;

[0031] S110: Installing the soil box in the water tank;

[0032] S111: injecting water containing pollutants into the water tank, and stopping the water injection when the water in the water tank overflows the lower side of the second test soil;

[0033] S112: After waiting for the first test time, select a second sampling point in the second test soil according to the position of the first sampling point, and measure the second pollutant concentration at the second sampling point;

[0034] S113: In the second test soil, measuring a maximum transmission distance of the pollutants when the first blocking soil layer exists;

[0035] S114: Calculating a reduction rate of pollutant migration based on the first pollutant concentration and the second pollutant concentration.

[0036] In one embodiment, the water tank is connected to a pressure pump, the pressure pump is used to pressurize the water tank, the water tank is provided with a pressure sensor, the outer side of the tank body is provided with a sealing sleeve, and the sealing sleeve fills the installation port;

[0037] The second detection process includes the following steps:

[0038] S201: selecting a second test duration and a water pressure to be measured, and selecting the number of soil layers and the thickness of each soil layer according to the soil to be simulated;

[0039] S202: placing the selected soil layers in the soil box in sequence along the up and down directions to form a third test soil;

[0040] S203: Installing the soil box in the water tank, and then installing the sealing sleeve;

[0041] S204: injecting water containing pollutants into the water tank, and stopping water injection when the water level in the water tank is flush with the lower side of the third test soil;

[0042] S205: controlling the pressure pump to pressurize the water in the water tank so that the water pressure in the water tank reaches the water pressure to be measured;

[0043] S206: After waiting for the second test time, a third sampling point is selected in the third test soil, and a third pollutant concentration at the third sampling point is measured;

[0044] S207: measuring, in the third test soil, a maximum transmission distance of the pollutants when the second blocking soil layer is not present;

[0045] S208: draining the water in the water tank, removing the soil box from the water tank, and removing the third test soil from the soil box;

[0046] S209: selecting a blocking object, and then mixing the lowermost soil layer with the blocking object to form a second blocking soil layer;

[0047] S210: placing the second blocking soil layer and the remaining soil layers in the soil box in sequence along the vertical direction to form a fourth test soil;

[0048] S211: Install the soil box in the water tank, and then install the sealing sleeve;

[0049] S212: injecting water containing pollutants into the water tank, and stopping the water injection when the water level in the water tank is flush with the lower side of the fourth test soil;

[0050] S213: controlling the pressure pump to pressurize the water in the water tank so that the water pressure in the water tank reaches the water pressure to be measured;

[0051] S214: After waiting for the second test time, select the fourth sampling point in the fourth test soil according to the position of the third sampling point, and measure the fourth pollutant concentration at the fourth sampling point;

[0052] S215: measuring, in the fourth test soil, a maximum transmission distance of the pollutants when a second blocking soil layer is present;

[0053] S216: Calculating a reduction rate of pollutant migration based on the third pollutant concentration and the fourth pollutant concentration.

[0054] In one embodiment, the water tank is provided with a heater and a temperature sensor; the third detection process comprises the following steps:

[0055] S301: selecting a third test duration and a test temperature, and selecting the number of soil layers and the thickness of each soil layer according to the soil to be simulated;

[0056] S302: placing the corresponding soil layers in the soil box in sequence along the up and down directions to form a fifth test soil;

[0057] S303: installing the soil box in the water tank, and then injecting water containing pollutants into the water tank. When the water level in the water tank is flush with the lower side of the fifth test soil, stopping water injection;

[0058] S304: controlling the heater so that the water temperature in the water tank maintains a test temperature;

[0059] S305: After waiting for a third test time, a fifth sampling point is selected in the fifth test soil, and a fifth pollutant concentration at the fifth sampling point is measured;

[0060] S306: In the fifth test soil, a maximum transmission distance of pollutants is measured when a third blocking soil layer is not present.

[0061] S307: draining the water in the water tank, removing the soil box from the water tank, and removing the fifth test soil from the soil box;

[0062] S308: selecting a blocking object, and then mixing the bottommost soil layer with the blocking object to form a third blocking soil layer;

[0063] S309: placing the third blocking soil layer and the remaining soil layers in the soil box in sequence along the vertical direction to form a sixth test soil;

[0064] S310: installing the soil box in the water tank, then injecting water containing pollutants into the water tank, and stopping water injection when the water level in the water tank is flush with the lower side of the sixth test soil;

[0065] S311: controlling the heater so that the water temperature in the water tank maintains a test temperature;

[0066] S312: After waiting for the third test time, select the sixth sampling point in the sixth test soil according to the position of the fifth sampling point, and measure the sixth pollutant concentration at the sixth sampling point;

[0067] S313: measuring, in the sixth test soil, a maximum transmission distance of the pollutants when a third blocking soil layer is present;

[0068] S314: Calculating a reduction rate of pollutant migration based on the fifth pollutant concentration and the sixth pollutant concentration.

[0069] In one embodiment, the apparatus for simulating cross-media transmission of pollutants between soil and groundwater further includes a spray system, the spray system being disposed on the upper side of the soil box for spraying the uppermost soil layer within the soil box, and a sampling port being disposed on the upper side of the water tank. The fourth detection process includes the following steps:

[0070] S401: selecting a fourth test duration and a predetermined spraying speed, selecting the number of soil layers and the thickness of each soil layer according to the soil to be simulated, and determining the location of the contaminated soil layer in the soil to be simulated;

[0071] S402: mixing the soil layer at the corresponding position with the pollutants to form a first contaminated soil layer, and then placing the first contaminated soil layer and the other soil layers in the soil box in sequence along the vertical direction to form a seventh test soil;

[0072] S403: installing the soil box in the water tank, then injecting clean water into the water tank, and stopping water injection when the water level in the water tank is flush with the lower side of the seventh test soil;

[0073] S404: Controlling the spraying system to spray clean water at a predetermined spraying speed;

[0074] S405: After waiting for the fourth test time, a seventh sampling point is selected in the water in the water tank, and a seventh pollutant concentration at the seventh sampling point is measured;

[0075] S406: measuring, in the water tank, a maximum transmission distance of the pollutants in the water tank when the fourth blocking soil layer is not present;

[0076] S407: draining the water in the water tank, removing the soil box from the water tank, and removing the seventh test soil from the soil box;

[0077] S408: selecting a blocking object, and then mixing the bottommost soil layer with the blocking object to form a fourth blocking soil layer;

[0078] S409: Mixing the soil layer at the corresponding position with the pollutants to form a second contaminated soil layer, so that the concentration and amount of the second contaminated soil layer are the same as those of the first contaminated soil layer;

[0079] S410: placing the fourth blocking soil layer, the second contaminated soil layer, and the remaining soil layers in the soil box in sequence along the vertical direction to form an eighth test soil;

[0080] S411: installing the soil box in the water tank, then injecting clean water into the water tank, and stopping water injection when the water level in the water tank is flush with the lower side of the eighth test soil;

[0081] S412: Control the spraying system to spray clean water at a predetermined spraying speed;

[0082] S413: After waiting for the fourth test time, an eighth sampling point is selected in the water in the water tank according to the position of the seventh sampling point, and an eighth pollutant concentration at the eighth sampling point is measured;

[0083] S414: measuring, in the water tank, a maximum transmission distance of pollutants in the water tank when a fourth blocking soil layer is present;

[0084] S415: Calculating a reduction rate of pollutant migration based on the seventh pollutant concentration and the eighth pollutant concentration.

[0085] In the technical solution of the present invention, a blank control group is first selected, that is, blank test soil is first placed in a soil box, and the soil box is placed in the water tank. The water in the water tank can contact the blank test soil through the first permeable hole, and the pollutants in the water in the water tank can migrate from the bottom of the blank test soil to the top of the blank test soil. After waiting for a certain period of time, the pollutant content at any point in the blank test soil can be measured. After selecting the corresponding blocking agent according to the pollutant, new test soil is selected, the agent is mixed with the lower soil layer of the test soil, and then the test soil mixed with the blocking agent is placed in the soil box, and then the soil box is placed in the water tank. After waiting for the same period of time, the pollutant content at any point in the test soil mixed with the blocking agent can be measured. By comparing the pollutant content at the same position, the blocking effect of the blocking agent on the pollutant can be evaluated, and the overall blocking effect of the blocking agent on the cross-media transmission of pollutants between soil and groundwater can be evaluated. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0087] Figure 1 This is a schematic structural diagram of an embodiment of a device for simulating cross-media transmission of pollutants between soil and groundwater provided by the present invention;

[0088] Figure 2 A partial schematic diagram of the first detection process in the cross-media transmission simulation method of pollutants between soil and groundwater provided by the present invention;

[0089] Figure 3 Another partial schematic diagram of the first detection process in the cross-media transmission simulation method of pollutants between soil and groundwater provided by the present invention;

[0090] Figure 4 A partial schematic diagram of the second detection process in the cross-media transmission simulation method of pollutants between soil and groundwater provided by the present invention;

[0091] Figure 5 Another partial schematic diagram of the second detection process in the cross-media transmission simulation method of pollutants between soil and groundwater provided by the present invention;

[0092] Figure 6A partial schematic diagram of the third detection process in the cross-media transmission simulation method of pollutants between soil and groundwater provided by the present invention;

[0093] Figure 7 Another partial schematic diagram of the third detection process in the cross-media transmission simulation method of pollutants between soil and groundwater provided by the present invention;

[0094] Figure 8 A partial schematic diagram of the fourth detection process in the cross-media transmission simulation method of pollutants between soil and groundwater provided by the present invention;

[0095] Figure 9 This is another partial schematic diagram of the fourth detection process in the cross-media transmission simulation method of pollutants between soil and groundwater provided by the present invention.

[0096] Description of Figure Numbers:

[0097] 1. Base; 2. Soil box; 21. Soil box; 211. Pull-out handle; 22. Second scale line; 3. Water tank; 31. Installation port; 32. Heater; 33. Temperature sensor; 34. Sampling port; 35. Pressure pump; 36. Pressure sensor; 37. Water inlet pipe; 371. Pressure reducing valve; 38. Drain pipe; 39. First scale line; 4. Soil layer; 41. Humus layer; 42. Clay layer; 43. Fine sand layer; 44. Gravel layer; 5. Sprinkler system; 51. Nozzle; 6. Agitator; 7. Sealing sleeve.

[0098] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0099] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0100] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0101] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0102] In the field of environmental remediation, soil pollutants are often solidified and pollutants in groundwater are oxidized and reduced to achieve the treatment of pollutants in soil and groundwater media. Some pollutants are highly mobile, such as VOCs and SVOCs. Under the influence of site environmental disturbances, they will migrate, transmit and transform across media, polluting other media. For example, pollutants in solidified and stabilized soil will be released during long-term rainwater leaching and pollute the underlying groundwater source; groundwater pollutants will migrate to the overlying soil by infiltration or volatilization under the influence of periodic fluctuations in groundwater or changes in temperature and pressure, polluting the soil environment. When treating single-element pollution of soil and groundwater, it is also necessary to block the cross-media transmission of soil and groundwater pollutants, that is, to mix the lower side of the soil with blocking agents to prevent cross-contamination. However, at this stage, it is difficult for the industry to evaluate the blocking effect of blocking agents on the cross-media transmission of pollutants between soil and groundwater.

[0103] The present invention provides a device for simulating cross-media transmission of pollutants between soil and groundwater.

[0104] See also Figure 1 In one embodiment of the present invention, the apparatus for simulating the cross-media transmission of pollutants between soil and groundwater includes a soil layer 4 system and a groundwater system. The soil layer 4 system comprises a base 1 and a soil box 2 vertically disposed on the base 1. The soil box 2 is used to accommodate test soil, and the base 1 is provided with a first water-permeable hole for communication with the soil box 2. The groundwater system includes a water tank 3, with an installation opening 31 provided on its upper side. The installation opening 31 is configured to allow the base 1 and the soil box 2 to pass through in sequence. The inner side of the water tank 3 is higher than the height of the base 1, allowing water in the water tank 3 to pass through the first water-permeable hole and contact the soil layer 4 within the soil box 2.

[0105] In the technical solution of the present invention, a blank control group is first selected, that is, blank test soil is first placed in a soil box 2, and the soil box 2 is placed in the water tank 3. The water in the water tank 3 can contact the blank test soil through the first permeable hole, and the pollutants in the water in the water tank 3 can migrate from the bottom of the blank test soil to the blank test soil from bottom to top. After waiting for a certain period of time, the pollutant content at any point in the blank test soil can be measured. After selecting the corresponding blocking agent according to the pollutant, a new test soil is selected, the agent is mixed with the lower soil layer 4 of the test soil, and then the test soil mixed with the blocking agent is placed in the soil box 2. Then, the soil box 2 is placed in the water tank 3. After waiting for the same period of time, the pollutant content at any point in the test soil mixed with the blocking agent can be measured. By comparing the pollutant content at the same position, the blocking effect of the blocking agent on the pollutant can be evaluated, and overall, the blocking effect of the blocking agent on the cross-media transmission of pollutants between soil and groundwater can be evaluated.

[0106] The soil box 2 extends in the vertical direction, and the upper and lower ends of the soil box 2 are both open. The first water-permeable hole of the base 1 is connected to the soil box 2. The opening direction of the first water-permeable hole can be vertical or in any direction, which is not limited here. Specifically, the base 1 is hollowed out, and the first water-permeable hole is located in the hollow hole of the base 1. The upper side of the water tank 3 is connected to a water inlet pipe 37, and a pressure reducing valve 371 is provided on the metal pipe. After the pressure reducing valve 371 is opened, water with or without pollutants can be fed into the water tank 3 through the water inlet pipe 37. When the pressure inside the water tank 3 is high, the pressure reducing valve 371 can automatically open to reduce the pressure inside the water tank 3.

[0107] See also Figure 1 A drain pipe 38 is also provided on the lower side of the water tank 3. The drain pipe 38 is provided with an on-off valve. When the on-off valve is opened, the water in the water tank 3 can be discharged from the drain pipe 38. The water tank 3 can also be made of a transparent material, such as glass or acrylic, to facilitate observation of the water level and conditions in the water tank 3. The water tank 3 is a rectangular box. Three first scale lines 39 are provided on the outer wall of the water tank 3. The three first scale lines 39 extend along the length, width, and height of the water tank 3 respectively. According to the first scale lines 39 on the water tank 3, it is convenient to accurately detect the position in the water tank 3, so as to achieve fixed-point sampling of the water in the water tank 3.

[0108] The height of the inner side of the water tank 3 is greater than the height of the base 1. When the soil box 2 is installed in the water tank 3, it can ensure that at least a portion of the soil box 2 is located in the water tank 3, ensuring that the water in the water tank 3 is in contact with the soil in the soil box 2. A water level detector is provided in the water tank 3. With the help of the water level detector, the water level in the water tank 3 can be detected, so as to control the water inlet pipe 37 to automatically infuse water into the water tank 3, thereby ensuring the water level in the water tank 3 and thus ensuring the contact between the water in the water tank 3 and the soil in the soil box 2.

[0109] See also Figure 1 The soil box 2 includes a box body and multiple soil boxes 21. The soil boxes 21 are used to accommodate the soil layer 4. The box body wall is provided with multiple drawer openings in a vertical direction. The multiple soil boxes 21 are mounted one-to-one in correspondence with the drawer openings. The soil boxes 21 are used to accommodate the test soil layer 4. The bottom walls of the multiple soil boxes 21 are each provided with a second water-permeable hole. The provision of the soil boxes 21 facilitates the replacement of the soil within the box body, reducing the difficulty of soil replacement within the box body. The second water-permeable hole provided on the bottom wall of the soil box 21 ensures communication between adjacent boxes, providing a channel for the migration of water and pollutants.

[0110] The diameter of the second water-permeable hole is not less than 1 cm, and the diameter of the second water-permeable hole is not greater than 2 cm. The number of the soil boxes 21 is not less than 3, and the number of the soil boxes 21 is not more than 6. Specifically, there are four soil boxes 21. The height of each soil box 21 is not more than 10 cm, and the height of each soil box 21 is not less than 5 cm. Specifically, the height of each soil box 21 is 10 cm.

[0111] The soil box 21 is provided with a pull-out handle 211, which is located on the outside of the box body and can be easily pulled out and inserted into the box body. The sizes of the multiple soil boxes 21 are consistent and can accommodate soil of the same thickness. For example, the thickness of the soil layer 4 that each soil box 21 can contain can be 10 cm. By providing the soil box 21, when testing the pollutant content of a sampling point, the soil box 21 at the corresponding position can be pulled out and the pollutants at the corresponding sampling point can be tested, which can avoid other soil layers 4 and improve the accuracy of sampling. The surrounding side of the soil box 21 and the inner side of the box body are sealed and anti-seepage treated.

[0112] See also Figure 1 The outer side of the box body is provided with second scale lines 22 along the up and down direction. Through the second scale lines 22, the position of the soil layer 4 in each soil box 21 can be judged more conveniently.

[0113] The water tank 3 is provided with a heater 32 and a temperature sensor 33. By providing the heater 32, the water in the water tank 3 can be heated. In conjunction with the temperature sensor 33, the water in the water tank 3 can be heated and maintained at a preset temperature. The migration of pollutants from water to soil driven by water temperature can be detected, and the blocking effect of blocking agents on cross-media transmission of pollutants between soil and groundwater can be evaluated.

[0114] See also Figure 1 The heater 32 may be a heating wire or any other suitable heater 32, and is not limited here. The temperature sensor 33 may be any existing temperature sensor 33. Both the heater 32 and the temperature sensor 33 are electrically connected to a controller, which enables braking control of the heater 32. The temperature sensor 33 is disposed adjacent to the bottom wall of the water tank 3, enabling the temperature sensor 33 to directly detect the water temperature within the water tank 3.

[0115] The water tank 3 is provided with an agitator 6; the agitator 6 may be a stirring blade provided on the output shaft of a stirring motor. By providing the agitator 6, the water in the water tank 3 can be stirred so that the pollutants in the water in the water tank 3 are evenly mixed. In addition, the agitator 6 can also make the water temperature in the water tank 3 more uniform.

[0116] The water tank 3 is connected to a pressure pump 35 for pressurizing the water tank 3. The water tank 3 is provided with a pressure sensor 36. The pressure pump 35 can increase the pressure in the water tank 3, thereby increasing the water pressure in the water tank 3. The pressure sensor 36 can detect the pressure in the water tank 3, thereby facilitating accurate control of the pressure in the water tank 3.

[0117] See also Figure 1 The booster pump 35 and the pressure sensor 36 can be electrically connected to the same controller, and the controller can control the booster pump 35 based on the pressure value detected by the pressure sensor 36. The booster pump 35 can be a circulating booster pump 35, with both its water inlet and outlet connected to the water tank 3. After the water in the water tank 3 is fed into the circulating booster pump 35, it is pressurized by the circulating booster pump 35 and then fed into the water tank 3, thereby increasing the pressure within the water tank 3. The booster pump 35 can also be a water pump or an air pump, with its water outlet connected to the water tank 3 and its air outlet connected to the water tank 3. By supplying air or water into the water tank 3, the pressure within the water tank 3 can be increased, thereby increasing the pressure of the water within the water tank 3. The pressure sensor 36 is disposed adjacent to the bottom side of the water tank 3, enabling the pressure sensor 36 to detect the water pressure within the water tank 3.

[0118] The outer side of the box body is provided with a sealing sleeve 7, and the sealing sleeve 7 fills the installation opening 31. When the box body is installed in the water tank 3, the sealing sleeve 7 can seal the installation opening 31, thereby ensuring the sealing of the water tank 3 and thus ensuring the pressure in the water tank 3.

[0119] The sealing sleeve 7 can be a silicone sleeve, and the sealing sleeve 7 is detachable and can be installed as needed.

[0120] See also Figure 1 A sampling port 34 is provided on the upper side of the tank body. Water samples can be taken from the water tank 3 through the sampling port 34 to analyze the pollutant content of the water in the water tank 3. The opening of the sampling port 34 can be rectangular or circular, with a diameter or side length of 3 cm. After inserting a sampling needle into the sampling port 34, the sampling needle can be tilted to sample water from different areas.

[0121] A sampling cover is installed at the sampling port 34 . When the sampling cover is closed on the sampling port 34 , the sampling port 34 can be sealed to ensure the sealing of the water tank 3 .

[0122] The apparatus for simulating the cross-media transmission of pollutants between soil and groundwater also includes a spray system 5, which is located above the soil box 2 and is used to spray the uppermost soil layer 4 within the soil box 2. A sampling port 34 is provided on the upper side of the water tank 3. After the pollutants are mixed in the soil layer 4, the spray system 5 is activated. After a period of spraying, the pollutant content in the water within the water tank 3 can be detected, thereby enabling the assessment of the migration of pollutants from the soil to the water.

[0123] The spraying system 5 includes a spray head 51 , and a spray hole is opened on the spray head 51 . By setting the size and number of the spray head 51 , it is possible to ensure that the spray head 51 sprays the soil in the soil box 2 evenly.

[0124] See also Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6The present invention also provides a method for simulating the cross-media transmission of pollutants between soil and groundwater. The method is used in a device for simulating the cross-media transmission of pollutants between soil and groundwater. The specific structure of the device is similar to the above-mentioned embodiment. Since the method adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described in detail here. The device for simulating the cross-media transmission of pollutants between soil and groundwater includes a first detection process, a second detection process, a third detection process, and a fourth detection process. The first detection process is used to detect the reduction rate of the migration of pollutants from water into the soil layer 4 driven by water level; the second detection process is used to detect the reduction rate of the migration of pollutants from water into the soil layer 4 driven by water pressure; the third detection process is used to detect the reduction rate of the migration of pollutants from water into the soil layer 4 driven by water temperature; and the fourth detection process is used to detect the reduction rate of the migration of pollutants from soil into water under rainfall.

[0125] When selecting the number and thickness of the soil layers 4 within the soil box 2, the soil layers 4 can be divided, from top to bottom, into a humus layer 41, a clay layer 424, a fine sand layer 43, and a gravel layer 44, depending on the composition of the soil to be simulated. The simulated soil can include one or more of the humus layer, the clay layer 424, the fine sand layer 43, and the gravel layer 44, depending on the composition. The order, type, and number of the soil layers 4 within the soil box 2 are consistent with those of the soil to be simulated, and the height of the soil layers 4 within the soil box 2 is a proportional reduction value of the soil layers 4 in the simulated soil.

[0126] See also Figure 2 and Figure 3 The first detection process includes the following steps:

[0127] S101: Selecting a first test duration, and selecting the number of soil layers 4 and the thickness of each soil layer 4 according to the soil to be simulated.

[0128] The first test duration is the migration time of the pollutants in the water into the soil in the soil box 2, which can be selected as needed. Specifically, the first test duration is selected to be 8 hours.

[0129] S102: placing the selected soil layers 4 in the soil box 2 in sequence along the up and down directions to form a first test soil.

[0130] S103: Install the soil box 2 in the water tank 3.

[0131] S104: injecting water containing pollutants into the water tank 3. When the water in the water tank 3 overflows the lower side of the first test soil, the water injection is stopped.

[0132] By setting the water in the water tank 3 to overflow the lower side of the first test soil, and the water level is recorded as h1, driven by the water level, the water and the pollutants in the water can migrate toward the first test soil and continue to migrate toward the upper side of the first test soil along the up and down direction.

[0133] S105: After waiting for the first test time, a first sampling point is selected in the first test soil, and a first pollutant concentration at the first sampling point is measured.

[0134] The first sampling point can be any point in the first test soil, without limitation. Specifically, the first sampling point is the bottommost soil layer 4. There can be multiple first sampling points, all at the same height to reduce error. The first pollutant concentration can be the average of the pollutant concentrations at the multiple first sampling points. Furthermore, by repeating steps S102-S105, the first pollutant concentration can be averaged to reduce error.

[0135] S106: In the first test soil, measuring the maximum transmission distance of the pollutants when the first blocking soil layer does not exist.

[0136] Specifically, by detecting the pollutant content at different locations in the first test soil, the farthest location to which the pollutants are transmitted can be detected, so as to facilitate the detection of the transmission distance of the pollutants in the first test soil when there is no first blocking soil layer to block the pollutants.

[0137] S107 : draining the water in the water tank 3 , taking the soil box 2 out of the water tank 3 , and taking the first test soil out of the soil box 2 .

[0138] By draining the water in the water tank 3 and taking out the first test soil, it is possible to facilitate the next test.

[0139] S108: A blocking object is selected, and then the lowermost soil layer 4 is mixed with the blocking object to form a first blocking soil layer 4 .

[0140] S109: placing the first blocking soil layer 4 and the remaining soil layers 4 in the soil box 2 in sequence along the up and down directions to form a second test soil.

[0141] The first blocking soil layer 4 is located directly below the second test soil, and the first blocking soil layer 4 can block the migration of pollutants.

[0142] S110: Install the soil box 2 in the water tank 3.

[0143] S111: injecting water containing pollutants into the water tank 3. When the water in the water tank 3 overflows the lower side of the second test soil, the water injection is stopped.

[0144] After the water in the water tank 3 overflows the lower side of the second test soil, that is, the water level in the water tank 3 is below the lowest side of the first blocking soil layer 4, and the water level in the water tank 3 cannot be higher than the highest side of the first blocking soil layer 4. The water level in the water tank 3 is denoted as h2, then h2=h1, and the water in the water tank 3 can migrate toward the first blocking soil layer 4.

[0145] S112: After waiting for the first test time, a second sampling point is selected in the second test soil according to the position of the first sampling point, and a second pollutant concentration at the second sampling point is measured.

[0146] The second sampling point is located at the same position as the first sampling point, that is, the second sampling point is located in the first blocking soil layer 4. By repeating steps S108-S112, the second pollutant concentration can be averaged to reduce errors.

[0147] S113: In the second test soil, measuring the maximum transmission distance of the pollutants when the first blocking soil layer exists.

[0148] Specifically, by detecting the concentration of pollutants at different positions in the second test soil, the farthest position where the pollutants are transmitted in the second soil can be detected, so as to measure the transmission distance of the pollutants in the second test soil when the first blocking soil layer is present to block the pollutants.

[0149] S114: Calculating a reduction rate of pollutant migration based on the first pollutant concentration and the second pollutant concentration.

[0150] The difference between the first pollutant concentration and the second pollutant concentration is divided by the first pollutant concentration to obtain the reduction rate of pollutant migration, thereby evaluating the reduction effect of pollutant migration from water to soil driven by water level.

[0151] In a specific embodiment of the present scheme, in the first detection process, the soil layer 4 is selected as four layers, namely, a humus layer 41, a clay layer 424, a fine sand layer 43 and a gravel layer 44 from top to bottom. Contaminated water with a nitrate concentration of 150 mg / L is poured into the water tank 3 at a depth of 25 cm so that the water level overflows the gravel layer 44, and the first sampling point is set in the gravel layer 44. A 2.5% sodium sulfide zero-valent iron-calcium peroxide composite agent is selected as the blocking agent, and the blocking agent is mixed with the gravel layer 44. The testing time is 8 hours. The first pollutant concentration is 58.6 mg / kg, and the second pollutant concentration is 4.9 mg / kg. The reduction rate of pollutant migration can be obtained by calculation to be 91.6%.

[0152] See also Figure 4 and Figure 5 The second detection process includes the following steps:

[0153] S201: Select a second test duration and a water pressure to be measured, and select the number of soil layers 4 and the thickness of each soil layer 4 according to the soil to be simulated.

[0154] The water pressure to be measured can be any value between 0.1 MPa and 2 MPa, which is not limited here. The second test duration can be any duration. Specifically, the second test duration is 8 hours.

[0155] S202: placing the selected soil layers 4 in the soil box 2 in sequence along the up and down directions to form a third test soil.

[0156] S203: Install the soil box 2 in the water box 3, and then install the sealing sleeve 7.

[0157] By providing the sealing sleeve 7 , the sealing of the water tank 3 can be strengthened, the pressure in the water tank 3 can be guaranteed, and thus the water pressure in the water tank 3 can be guaranteed.

[0158] S204: injecting water containing pollutants into the water tank 3. When the water level in the water tank 3 is flush with the lower side of the third test soil, the water injection is stopped.

[0159] During the entire experiment, water can be continuously added to the water tank 3 so that the water level in the water tank 3 remains unchanged.

[0160] S205: Control the pressure pump 35 to pressurize the water in the water tank 3 so that the water pressure in the water tank 3 reaches the water pressure to be measured.

[0161] S206: After waiting for the second test time, a third sampling point is selected in the third test soil, and a third pollutant concentration at the third sampling point is measured.

[0162] The third sampling point can be any point in the third test soil, without limitation. Specifically, the third sampling point is located within the lowest soil layer 4. Multiple third sampling points can be provided, each at the same height. The third pollutant concentration is the average of the pollutant concentrations at these multiple third sampling points. Furthermore, by repeating steps S202-S206, the third pollutant concentration can be averaged to reduce errors.

[0163] S207: In the third test soil, a maximum transmission distance of pollutants is measured when a second blocking soil layer is not present.

[0164] Specifically, by detecting the pollutant content at different positions in the third test soil, the farthest position to which the pollutants are transmitted can be detected, so as to facilitate the detection of the transmission distance of the pollutants in the third test soil when there is no second blocking soil layer to block the pollutants.

[0165] S208 : draining the water in the water tank 3 , taking the soil box 2 out of the water tank 3 , and taking the third test soil out of the soil box 2 .

[0166] By draining the water in the water tank 3, it is easy to replace the water in the water tank 3. By taking out the third test soil from the soil box 2, it is easy to put new test soil into the soil box 2 for the next test.

[0167] S209: Select a blocking object, and then mix the lowermost soil layer 4 with the blocking object to form a second blocking soil layer 4.

[0168] S210: placing the second blocking soil layer 4 and the remaining soil layers 4 in the soil box 2 in sequence along the up and down directions to form a fourth test soil.

[0169] S211: Install the soil box 2 in the water box 3, and then install the sealing sleeve 7.

[0170] S212: injecting water containing pollutants into the water tank 3, and stopping water injection when the water level in the water tank 3 is flush with the lower side of the fourth test soil.

[0171] S213: Control the pressure pump 35 to pressurize the water in the water tank 3 so that the water pressure in the water tank 3 reaches the water pressure to be measured.

[0172] Under the action of water pressure, part of the water and pollutants migrate into the second blocking soil layer 4 and continue to migrate upward.

[0173] S214: After waiting for the second test time, select the fourth sampling point in the fourth test soil according to the position of the third sampling point, and measure the fourth pollutant concentration at the fourth sampling point.

[0174] The fourth sampling point is located in the third blocking soil layer 4. The concentration of the fourth pollutant can be the average concentration of the pollutant at multiple fourth sampling points. In addition, steps S209-S214 are repeated to average the fourth pollutant concentrations for multiple times to reduce errors.

[0175] S215: In the fourth test soil, measuring the maximum transmission distance of the pollutants when the second blocking soil layer exists.

[0176] Specifically, by detecting the content of pollutants at different positions in the fourth test soil, the farthest distance the pollutants are transmitted can be detected, so as to facilitate the detection of the transmission distance of the pollutants in the fourth test soil when there is a second blocking soil layer to block the pollutants.

[0177] S216: Calculating a reduction rate of pollutant migration based on the third pollutant concentration and the fourth pollutant concentration.

[0178] By dividing the difference between the third pollutant concentration and the fourth pollutant concentration by the third pollutant concentration, the reduction rate of the migration of pollutants driven by water pressure can be measured.

[0179] See also Figure 6 and Figure 7 The water tank 3 is provided with a heater 32 and a temperature sensor 33. The third detection process includes the following steps:

[0180] S301: Selecting a third test duration and a test temperature, and selecting the number of soil layers 4 and the thickness of each soil layer 4 according to the soil to be simulated.

[0181] The test temperature can be any value between 10°C and 40°C, and is not limited here.

[0182] S302: placing the corresponding soil layers 4 in the soil box 2 in sequence along the up and down directions to form a fifth test soil.

[0183] S303: Install the soil box 2 in the water tank 3, then inject water containing pollutants into the water tank 3, and stop injecting water when the water level in the water tank 3 is flush with the lower side of the fifth test soil.

[0184] S304: Control the heater 32 so that the water temperature in the water tank 3 is maintained at the test temperature.

[0185] S305: After waiting for the third test time, a fifth sampling point is selected in the fifth test soil, and a fifth pollutant concentration at the fifth sampling point is measured.

[0186] The fifth sampling point can be any point in the fifth test soil and is not limited here. Specifically, the fifth sampling point is the bottommost soil layer 4 of the fifth test soil. There are multiple fifth sampling points, and the heights of the multiple fifth sampling points are the same. The fifth pollutant concentration is the average value of the concentrations of the multiple fifth sampling points, and steps S302-S305 are repeated to average the fifth pollutant concentrations multiple times to reduce errors.

[0187] S306: In the fifth test soil, a maximum transmission distance of pollutants is measured when a third blocking soil layer is not present.

[0188] Specifically, by detecting the pollutant concentrations at different positions in the fifth test soil, the maximum transmission distance of the pollutants in the fifth test soil can be detected, thereby detecting the maximum transmission distance of the pollutants in the fifth test soil when there is no third blocking soil layer to block the transmission of the pollutants.

[0189] S307 : draining the water in the water tank 3 , taking the soil box 2 out of the water tank 3 , and taking the fifth test soil out of the soil box 2 .

[0190] S308 : Select a blocking object, and then mix the lowermost soil layer 4 with the blocking object to form a third blocking soil layer 4 .

[0191] S309: placing the third blocking soil layer 4 and the remaining soil layers 4 in the soil box 2 in sequence along the up and down directions to form a sixth test soil.

[0192] S310: Install the soil box 2 in the water tank 3, then inject water containing pollutants into the water tank 3, and stop injecting water when the water level in the water tank 3 is flush with the lower side of the sixth test soil.

[0193] S311: Control the heater 32 so that the water temperature in the water tank 3 is maintained at the test temperature.

[0194] S312: After waiting for the third test time, a sixth sampling point is selected in the sixth test soil according to the position of the fifth sampling point, and the concentration of the sixth pollutant at the sixth sampling point is measured.

[0195] The position of the sixth sampling point is the same as that of the fifth sampling point. When the sixth sampling point is set to multiple, the sixth pollutant concentration is the average of the pollutant concentrations of the multiple sixth sampling points, and repeating steps S308-S312 to average the multiple sixth pollutant concentrations can reduce the error of the sixth pollutant concentration.

[0196] S313: In the sixth test soil, a maximum transmission distance of pollutants is measured when a third blocking soil layer exists.

[0197] Specifically, by detecting the pollutant concentrations at different positions in the sixth test soil, the maximum transmission distance of the pollutants in the sixth test soil can be detected, thereby detecting the transmission distance of the pollutants in the sixth test soil when there is a third blocking soil layer blocking the pollutants.

[0198] S314: Calculating a reduction rate of pollutant migration based on the fifth pollutant concentration and the sixth pollutant concentration.

[0199] The value obtained by dividing the difference between the fifth pollutant concentration and the sixth pollutant concentration by the fifth pollutant concentration is the reduction rate of pollutant migration.

[0200] See also Figure 8 and Figure 9 , the fourth detection process includes the following steps:

[0201] S401: Select a fourth test duration and a predetermined spraying speed, select the number of soil layers 4 and the thickness of each soil layer 4 according to the soil to be simulated, and determine the position of the contaminated soil layer in the soil to be simulated.

[0202] The fourth test duration may be 8 hours, which is not limited here. The contaminated soil layer may be any one or more of the soil layers. Specifically, the contaminated soil layer is selected according to the soil to be simulated.

[0203] S402: The soil layer 4 at the corresponding position is mixed with the pollutants to form a first contaminated soil layer 4, and then the first contaminated soil layer 4 and the other soil layers 4 are placed in the soil box 2 in sequence along the up and down directions to form a seventh test soil.

[0204] S403: Install the soil box 2 in the water tank 3, then inject clean water into the water tank 3. When the water level in the water tank 3 is flush with the lower side of the seventh test soil, stop injecting water.

[0205] S404: Control the spraying system 5 to spray clean water at a predetermined spraying speed.

[0206] The water sprayed by the spraying system 5 can be sprayed onto the first contaminated soil layer 4 , and drive the pollutants in the first contaminated soil layer 4 to migrate downward, pass through the soil layer 4 in sequence and enter the water in the water tank 3 .

[0207] S405: After waiting for the fourth test time, a seventh sampling point is selected in the water in the water tank 3, and the seventh pollutant concentration at the seventh sampling point is measured.

[0208] Before sampling, the water in the water tank 3 may be stirred to make the pollutants in the water tank 3 uniform, so that the seventh pollutant concentration is the average concentration in the water tank 3. By repeating steps S402-S405 and averaging the seventh pollutant concentration multiple times, errors can be reduced.

[0209] S406: In the water tank, a maximum transmission distance of pollutants in the water tank is measured when the fourth blocking soil layer does not exist.

[0210] Specifically, by detecting the pollutant content in water at different positions in the water tank, the transmission distance of the pollutants in the water can be detected, thereby detecting the maximum transmission distance of the pollutants in the water tank when the fourth blocking soil layer does not exist.

[0211] S407 : draining the water in the water tank 3 , taking the soil box 2 out of the water tank 3 , and taking the seventh test soil out of the soil box 2 .

[0212] By draining the water in the water tank 3 and taking the seventh test soil out of the soil box 2 , it is possible to facilitate the next test.

[0213] S408: Select a blocking object, and then mix the lowermost soil layer 4 with the blocking object to form a fourth blocking soil layer 4.

[0214] S409 : Mixing the soil layer 4 at the corresponding position with the pollutants to form a second contaminated soil layer 4 , so that the concentration and quantity of the second contaminated soil layer 4 are the same as those of the first contaminated soil layer 4 .

[0215] S410: placing the fourth blocking soil layer 4, the second contaminated soil layer 4 and the remaining soil layers 4 in the soil box 2 in sequence along the up and down directions to form an eighth test soil.

[0216] S411: Install the soil box 2 in the water tank 3, then inject clean water into the water tank 3. When the water level in the water tank 3 is flush with the lower side of the eighth test soil, stop injecting water.

[0217] S412: Control the spraying system 5 to spray clean water at a predetermined spraying speed.

[0218] After the clean water sprayed by the spraying system 5 is sprayed onto the second contaminated soil layer 4 , the pollutants can migrate downward under the drive of the water, and the fourth blocking soil layer 4 can block the pollutants to reduce the pollutants entering the water tank 3 .

[0219] S413: After waiting for the fourth test time, an eighth sampling point is selected in the water in the water tank 3 according to the position of the seventh sampling point, and the eighth pollutant concentration at the eighth sampling point is measured.

[0220] The eighth sampling point is consistent with the seventh sampling point, which can reduce the error. Repeating steps S408-S413 to average the eighth pollutant concentration multiple times can reduce the error of the eighth pollutant concentration.

[0221] S414: In the water tank, a maximum transmission distance of pollutants in the water tank is measured when a fourth blocking soil layer exists.

[0222] Specifically, by detecting the pollutant content in water at different positions in the water tank, the transmission distance of the pollutants in the water can be detected, thereby detecting the maximum transmission distance of the pollutants in the water tank when the fourth blocking soil layer exists.

[0223] S415: Calculating a reduction rate of pollutant migration based on the seventh pollutant concentration and the eighth pollutant concentration.

[0224] In the fourth detection process, in one specific embodiment, there are four soil layers 4, namely, from top to bottom, a humus layer 41, a clay layer 424, a fine sand layer 43, and a gravel layer 44. The thickness of each of the humus layer 41, the clay layer 424, the fine sand layer 43, and the gravel layer 44 is 10 cm. The concentration of the first and second contaminated soil layers 4 is 500 mg / kg, and the pollutant is petroleum hydrocarbons. The spray flow rate of the spray system 5 is 15 mm / h. A 2.5% sodium sulfide zero-valent iron-calcium peroxide composite agent is mixed into the gravel layer 44 to form the fourth blocking soil layer 4. The concentration of the seventh pollutant is 5 mg / L, the concentration of the eighth pollutant is 0.4 mg / L, and the reduction rate of pollutant migration from the soil to groundwater is 92%.

[0225] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by utilizing the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A device for simulating cross-media transmission of pollutants between soil and groundwater, characterized in that: include: A soil layer system includes a base and a soil box arranged on the base in an up-down direction, the soil box is used to accommodate test soil, and the base is provided with a first water permeable hole for communicating with the soil box; and The groundwater system includes a water tank, wherein an installation opening is provided on the upper side of the water tank, and the installation opening is used for the base and the soil box to pass through in sequence. The height of the inner side of the water tank is greater than the height of the base, so that the water in the water tank passes through the first water permeable hole and contacts the soil layer in the soil box.

2. The cross-medium transmission simulation device for pollutants between soil and groundwater according to claim 1, characterized in that: The soil box includes a box body and multiple soil boxes, the soil boxes are used to accommodate soil layers, multiple pull-out openings are arranged in sequence along the up and down directions on the box body wall, and the multiple soil boxes correspond one to one and are installed on the pull-out openings. The soil box is used to accommodate the soil layer of the test soil, and the bottom walls of the multiple soil boxes are all provided with second water permeable holes.

3. The cross-medium transmission simulation device for pollutants between soil and groundwater according to claim 1, characterized in that: The water tank is provided with a heater and a temperature sensor; and / or, A stirrer is provided in the water tank; and / or, The cross-media transmission simulation device for pollutants between soil and groundwater also includes a spraying system, which is arranged on the upper side of the soil box and is used to spray the uppermost soil layer in the soil box. A sampling port is provided on the upper side of the water tank.

4. The device for simulating cross-media transmission of pollutants between soil and groundwater according to claim 1, wherein: The water tank is connected to a pressure pump, and the pressure pump is used to pressurize the water tank. The water tank is provided with a pressure sensor.

5. The device for simulating cross-media transmission of pollutants between soil and groundwater according to claim 4, characterized in that: A sealing sleeve is provided on the outer side of the box body, and the sealing sleeve fills the installation opening.

6. A method for simulating cross-media transmission of pollutants between soil and groundwater, used in the cross-media transmission simulation device for simulating cross-media transmission of pollutants between soil and groundwater according to any one of claims 1 to 5, characterized in that: include: The first detection process is used to detect the reduction rate of the migration of pollutants in water into the soil layer driven by the water level; The second testing process is used to detect the reduction rate of the migration of pollutants in water into the soil layer driven by water pressure; The third testing process is used to detect the reduction rate of the migration of pollutants in water into the soil layer driven by water temperature; as well as, The fourth detection process is used to detect the reduction rate of migration of pollutants in the soil into water under a rainfall environment.

7. The method for simulating cross-media transmission of pollutants between soil and groundwater according to claim 6, characterized in that: The first detection process includes the following steps: S101: selecting a first test duration, and selecting the number of soil layers and the thickness of each soil layer according to the soil to be simulated; S102: placing the selected soil layers in the soil box in sequence along the up and down directions to form a first test soil; S103: Installing the soil box in the water tank; S104: injecting water containing pollutants into the water tank, and stopping the water injection when the water in the water tank overflows the lower side of the first test soil; S105: After waiting for the first test time, a first sampling point is selected in the first test soil, and a first pollutant concentration at the first sampling point is measured; S106: measuring, in the first test soil, a maximum transmission distance of the pollutants when the first blocking soil layer is not present; S107: draining the water in the water tank, taking the soil box out of the water tank, and taking the first test soil out of the soil box; S108: selecting a blocking object, and then mixing the bottommost soil layer with the blocking object to form a first blocking soil layer; S109: placing the first blocking soil layer and the remaining soil layers in the soil box in sequence along the vertical direction to form a second test soil; S110: Installing the soil box in the water tank; S111: injecting water containing pollutants into the water tank, and stopping the water injection when the water in the water tank overflows the lower side of the second test soil; S112: After waiting for the first test time, select a second sampling point in the second test soil according to the position of the first sampling point, and measure the second pollutant concentration at the second sampling point; S113: In the second test soil, measuring a maximum transmission distance of the pollutants when the first blocking soil layer exists; S114: Calculating a reduction rate of pollutant migration based on the first pollutant concentration and the second pollutant concentration.

8. The method for simulating cross-media transmission of pollutants between soil and groundwater according to claim 6, characterized in that: The water tank is connected to a pressure pump, which is used to pressurize the water tank. The water tank is provided with a pressure sensor. A sealing sleeve is provided on the outer side of the box body, and the sealing sleeve fills the installation port. The second detection process includes the following steps: S201: selecting a second test duration and a water pressure to be measured, and selecting the number of soil layers and the thickness of each soil layer according to the soil to be simulated; S202: placing the selected soil layers in the soil box in sequence along the up and down directions to form a third test soil; S203: Installing the soil box in the water tank, and then installing the sealing sleeve; S204: injecting water containing pollutants into the water tank, and stopping water injection when the water level in the water tank is flush with the lower side of the third test soil; S205: controlling the pressure pump to pressurize the water in the water tank so that the water pressure in the water tank reaches the water pressure to be measured; S206: After waiting for the second test time, a third sampling point is selected in the third test soil, and a third pollutant concentration at the third sampling point is measured; S207: measuring, in the third test soil, a maximum transmission distance of the pollutants when the second blocking soil layer is not present; S208: draining the water in the water tank, removing the soil box from the water tank, and removing the third test soil from the soil box; S209: selecting a blocking object, and then mixing the lowermost soil layer with the blocking object to form a second blocking soil layer; S210: placing the second blocking soil layer and the remaining soil layers in the soil box in sequence along the vertical direction to form a fourth test soil; S211: Install the soil box in the water tank, and then install the sealing sleeve; S212: injecting water containing pollutants into the water tank, and stopping the water injection when the water level in the water tank is flush with the lower side of the fourth test soil; S213: controlling the pressure pump to pressurize the water in the water tank so that the water pressure in the water tank reaches the water pressure to be measured; S214: After waiting for the second test time, select the fourth sampling point in the fourth test soil according to the position of the third sampling point, and measure the fourth pollutant concentration at the fourth sampling point; S215: measuring, in the fourth test soil, a maximum transmission distance of the pollutants when a second blocking soil layer is present; S216: Calculating a reduction rate of pollutant migration based on the third pollutant concentration and the fourth pollutant concentration.

9. The method for simulating cross-media transmission of pollutants between soil and groundwater according to claim 6, wherein: The water tank is provided with a heater and a temperature sensor; the third detection process comprises the following steps: S301: selecting a third test duration and a test temperature, and selecting the number of soil layers and the thickness of each soil layer according to the soil to be simulated; S302: placing the corresponding soil layers in the soil box in sequence along the up and down directions to form a fifth test soil; S303: installing the soil box in the water tank, and then injecting water containing pollutants into the water tank. When the water level in the water tank is flush with the lower side of the fifth test soil, stopping water injection; S304: controlling the heater so that the water temperature in the water tank maintains a test temperature; S305: After waiting for a third test time, a fifth sampling point is selected in the fifth test soil, and a fifth pollutant concentration at the fifth sampling point is measured; S306: measuring, in the fifth test soil, a maximum transmission distance of the pollutants when the third blocking soil layer is not present; S307: draining the water in the water tank, removing the soil box from the water tank, and removing the fifth test soil from the soil box; S308: selecting a blocking object, and then mixing the bottommost soil layer with the blocking object to form a third blocking soil layer; S309: placing the third blocking soil layer and the remaining soil layers in the soil box in sequence along the vertical direction to form a sixth test soil; S310: installing the soil box in the water tank, then injecting water containing pollutants into the water tank, and stopping water injection when the water level in the water tank is flush with the lower side of the sixth test soil; S311: controlling the heater so that the water temperature in the water tank maintains a test temperature; S312: After waiting for the third test time, select the sixth sampling point in the sixth test soil according to the position of the fifth sampling point, and measure the sixth pollutant concentration at the sixth sampling point; S313: measuring, in the sixth test soil, a maximum transmission distance of the pollutants when a third blocking soil layer is present; S314: Calculating a reduction rate of pollutant migration based on the fifth pollutant concentration and the sixth pollutant concentration.

10. The method for simulating cross-media transmission of pollutants between soil and groundwater according to claim 6, characterized in that: The cross-medium transmission simulation device for pollutants between soil and groundwater further includes a spray system, which is provided on the upper side of the soil box and is used to spray the uppermost soil layer in the soil box. A sampling port is provided on the upper side of the water tank. The fourth detection process includes the following steps: S401: selecting a fourth test duration and a predetermined spraying speed, selecting the number of soil layers and the thickness of each soil layer according to the soil to be simulated, and determining the location of the contaminated soil layer in the soil to be simulated; S402: mixing the soil layer at the corresponding position with the pollutants to form a first contaminated soil layer, and then placing the first contaminated soil layer and the other soil layers in the soil box in sequence along the vertical direction to form a seventh test soil; S403: installing the soil box in the water tank, then injecting clean water into the water tank, and stopping water injection when the water level in the water tank is flush with the lower side of the seventh test soil; S404: Controlling the spraying system to spray clean water at a predetermined spraying speed; S405: After waiting for the fourth test time, a seventh sampling point is selected in the water in the water tank, and a seventh pollutant concentration at the seventh sampling point is measured; S406: measuring, in the water tank, a maximum transmission distance of the pollutants in the water tank when the fourth blocking soil layer is not present; S407: draining the water in the water tank, removing the soil box from the water tank, and removing the seventh test soil from the soil box; S408: selecting a blocking object, and then mixing the bottommost soil layer with the blocking object to form a fourth blocking soil layer; S409: Mixing the soil layer at the corresponding position with the pollutants to form a second contaminated soil layer, so that the concentration and amount of the second contaminated soil layer are the same as those of the first contaminated soil layer; S410: placing the fourth blocking soil layer, the second contaminated soil layer, and the remaining soil layers in the soil box in sequence along the vertical direction to form an eighth test soil; S411: installing the soil box in the water tank, then injecting clean water into the water tank, and stopping water injection when the water level in the water tank is flush with the lower side of the eighth test soil; S412: Control the spraying system to spray clean water at a predetermined spraying speed; S413: After waiting for the fourth test time, an eighth sampling point is selected in the water in the water tank according to the position of the seventh sampling point, and an eighth pollutant concentration at the eighth sampling point is measured; S414: measuring, in the water tank, a maximum transmission distance of pollutants in the water tank when a fourth blocking soil layer is present; S415: Calculating a reduction rate of pollutant migration based on the seventh pollutant concentration and the eighth pollutant concentration.

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