Soil-rock interface comprehensive leaching device and method for simulating different rainfall intensities and natural attenuation of pollutants

Abstract

The invention relates to the technical field of simulation experiment devices, in particular to a soil-rock interface comprehensive leaching device and method for simulating different rainfall intensities and natural attenuation of pollutants. The device comprises a simulated soil-rock interface system (1), and a simulated rainfall system (2), a filtrate collection system (3) and a double-layer medium vertical permeation experiment system (4) which are respectively connected with the simulated soil-rock interface system (1). According to the soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants, a vertical permeation experiment of a double-layer medium, migration, adsorption and biodegradation effects of the pollutants on a soil-rock interface and batch leaching experiments under different rainfall intensities and different pollutant concentrations can be realized. Meanwhile, the device is convenient to operate, short in experimental period and suitable for carrying out rapid and effective physical simulation experiments indoors.

Description

Technical Field

[0001] The invention belongs to the technical field of simulation test devices, and relates to a soil-rock interface comprehensive leaching device and method for simulating different rainfall intensities and natural attenuation of pollutants. Background Art

[0002] In the study of environmental protection, the migration, adsorption and degradation of pollutants at the soil-rock interface is an important and creative research topic. At present, most experimental devices are used to conduct simulation tests on this topic. However, the existing experimental devices are difficult to accurately simulate the actual environment in terms of simulating the comprehensive leaching experiment of the soil-rock interface under different rainfall intensities and rainfall times, and there are certain defects.

[0003] On the one hand, the existing leaching devices are usually designed as closed structures, which are difficult to disassemble, clean, maintain and reassemble, and the sampling port is fixed, which makes it difficult to meet the needs of taking solid samples at multiple locations and multiple points. In addition, due to the large differences in the physical and chemical properties of soil and rock, uneven flow is prone to occur during the infiltration process. Therefore, it is difficult to complete the vertical infiltration experiment of double-layer media using existing test devices. They often focus on a single environment or a single process, and lack low-cost batch leaching test devices at the soil-rock interface that can simulate different rainfall intensities and different pollutant concentrations. Summary of the invention

[0004] The object of the present invention is to solve the above-mentioned problem and to provide a soil-rock interface comprehensive leaching device and method for simulating different rainfall intensities and natural attenuation of pollutants.

[0005] To achieve the above-mentioned object, the present invention provides a soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants, comprising a simulated soil-rock interface system, a simulated rainfall system respectively connected to the simulated soil-rock interface system, a filtrate collection system and a double-layer medium vertical permeability experimental system;

[0006] The simulated soil-rock interface system comprises a bottom device and a column installed on the bottom device, wherein a filling layer is provided in the column;

[0007] The simulated rainfall system comprises a multi-channel peristaltic pump, a liquid inlet bottle and a liquid inlet pipe respectively connected to the multi-channel peristaltic pump, the front end of the liquid inlet pipe is connected to an atomizing device, and the atomizing device is located above the column;

[0008] The filtrate collection system comprises a liquid collecting funnel arranged at the lower side of the bottom device and connected to the bottom device, and a liquid collecting bottle detachably connected to the liquid collecting funnel, wherein the liquid collecting funnel is in communication with the column;

[0009] The double-layer medium vertical permeability experimental system comprises an overflow device and a pressure measuring device respectively connected to the column;

[0010] An overflow interface is provided on the column, the overflow interface is located above the filling layer, and the overflow device is connected to the overflow interface;

[0011] The column is also provided with a pressure measuring interface, which is located at the filling layer. The pressure measuring device includes a pressure measuring tube connected to the pressure measuring interface, a seepage tube detachably connected to the liquid collecting funnel, and a seepage bottle connected to the seepage tube.

[0012] Further, the bottom device comprises a support frame and a bottom plate fixedly connected to the support frame, and a porous glass plate is installed on the bottom plate;

[0013] The lower end of the column is provided with a connecting flange which is sealed and fixedly connected to the porous glass plate. The middle part of the bottom plate is provided with a through hole, and the liquid collecting funnel is connected to the column through the porous glass plate.

[0014] Furthermore, the column includes a first half body and a second half body that are symmetrically arranged, and the first half body and the second half body are both provided with a leakproof sealing connection part, and the leakproof sealing connection part of the first half body and the second half body is fixedly connected by screws.

[0015] Furthermore, the filling layer includes a first filter paper layer, a first quartz sand layer, a rock powder layer, a soil layer, a second filter paper layer and a second quartz sand layer which are sequentially arranged from bottom to top along the vertical direction of the column.

[0016] Furthermore, the pressure measuring interfaces are provided on the column at 2 cm from the top and bottom of the soil layer, and at 3 cm from the top and bottom of the rock powder layer, and the pressure measuring interfaces are provided with pressure measuring control valves;

[0017] The pressure measuring device also includes a pressure measuring bracket, a scale is provided on the pressure measuring bracket, and the pressure measuring tube is fixed on the pressure measuring bracket.

[0018] Further, the overflow device includes an overflow pipe connected to the overflow interface and an overflow bottle connected to the overflow pipe;

[0019] An overflow control valve is provided at the overflow interface.

[0020] Furthermore, the liquid collecting funnel is provided with a spouting interface, and a spouting control valve is provided at the spouting interface;

[0021] The liquid collecting bottle or the seepage pipe is connected to the elution interface.

[0022] Furthermore, a cross mesh is provided at the upper end of the column, and the atomizing device is fixed on the cross mesh;

[0023] The atomizing device comprises a multi-channel conversion joint, an atomizing nozzle and a nozzle.

[0024] The present invention also provides a simulation method using the soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants, comprising:

[0025] S1. Collect soil and rock samples;

[0026] S2. Pretreatment of filling layer: quartz sand is sieved through 2-2.5mm sieve, soil is air-dried and ground through 2.5mm sieve, rock is crushed by crusher, ground by ball mill, and sieved through 2.5mm sieve for standby use;

[0027] S3, installing the simulated soil-rock interface system, applying vaseline to the inner wall of the column, then laying the first filter paper layer on the porous glass plate, covering the first quartz sand layer on the first filter paper layer and laying it evenly, then filling rock powder and soil in sequence, and after filling in amount by amount, gently tapping and compacting with a hammer to form the rock powder layer and the soil layer, then laying the second filter paper layer, covering the second quartz sand layer on the second filter paper layer, and scraping it flat with a scraper;

[0028] S4. Double-layer medium vertical permeability experiment: first install the simulated rainfall system and the double-layer medium vertical permeability experimental system, measure the liquid level height of the pressure gauge tube, calculate the seepage path length and water-passing section of the soil layer and the rock powder layer, then use a multi-channel peristaltic pump to inject deionized water at a constant speed so that water always overflows from the overflow port, record the water level difference of the pressure gauge tube, the water volume of the seepage bottle, and the water temperature at the water inlet and outlet, lower the height of the seepage tube to the interface of the soil layer and the rock powder layer, repeat the above experimental steps, and calculate the vertical permeability coefficient of the soil and rock powder;

[0029] S5, closing the pressure control valve at the pressure measuring interface, removing and disconnecting the pressure measuring device from the pressure measuring interface, and removing and disconnecting the seepage tube from the elution interface, and connecting the liquid collecting bottle to the elution interface;

[0030] S6. Prepare leaching solution: prepare pollutant leaching solution within 24 hours before the start of leaching, draw the pollutant standard curve, determine the actual concentration, and store the prepared solution in a sealed container at 4°C away from light;

[0031] S7, balance the experimental column: use a multi-channel peristaltic pump to pour NaCl solution as the background electrolyte solution to balance the chemical environment of the experimental column, and let it stand for 2 days;

[0032] S8. Simulate the soil-rock interface leaching experiment under different rainfall intensities and pollutant concentrations: set different leaching conditions, including rainfall intensity, rainfall time, leaching solution, and pollutant concentration, use a multi-channel peristaltic pump to pump the solution from the liquid inlet bottle into the atomization device, and leach once every other day;

[0033] S9. Collection and testing of water and solid samples: During the experiment, the leaching liquid from the liquid collection bottle and the pressure measuring interface was collected regularly. After the experiment, the multi-channel peristaltic pump was turned off, the column was opened, and samples were taken from the soil layer and the rock powder layer (at three points in the upper, middle and lower parts). After treatment, the pollutant concentrations in the water and solid samples were tested, and the microbial community structure, functional genes and ion concentrations in the solid samples were tested to evaluate the migration, adsorption and biodegradation of pollutants at the soil-rock interface.

[0034] The beneficial effects of the present invention are as follows:

[0035] The comprehensive soil-rock interface leaching device of the present invention, which simulates different rainfall intensities and natural attenuation of pollutants, can realize vertical permeability experiments of double-layer media, migration, adsorption and biodegradation of pollutants at the soil-rock interface, and batch leaching experiments under different rainfall intensities and different pollutant concentrations.

[0036] At the same time, the device of the present invention is easy to operate and has a short experimental cycle, and is suitable for conducting fast and effective physical simulation experiments indoors. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram showing the structure of a soil-rock interface integrated leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to an embodiment of the present invention;

[0038] Figure 2 A schematic diagram showing the structure of a column according to an embodiment of the present invention;

[0039] Figure 3 A schematic diagram showing the structure of a column, a bottom device and a filtrate collection system according to one embodiment of the present invention;

[0040] Figure 4 A schematic top view of a bottom device according to one embodiment of the present invention is shown;

[0041] Figure 5 A diagram schematically showing a pressure measurement interface according to an embodiment of the present invention;

[0042] Figure 6 The figure schematically shows the structure of an atomization device according to one embodiment of the present invention.

[0043] The meanings of the symbols in the accompanying drawings are as follows:

[0044] 1. Simulated soil-rock interface system; 2. Simulated rainfall system; 3. Filtrate collection system; 4. Double-layer medium vertical infiltration experimental system; 11. Bottom device; 12. Column; 13. Filling layer; 21. Multi-channel peristaltic pump; 22. Liquid inlet bottle; 23. Liquid inlet pipe; 24. Atomization device; 31. Liquid collecting funnel; 32. Liquid collecting bottle; 5. Overflow device; 6. Pressure measuring device; 51. Overflow interface; 61. Pressure measuring interface; 62. Pressure measuring tube; 63. Seepage tube; 64. Seepage bottle; 111. Support frame; 112. Bottom plate; 113. Porous glass plate; 121. Connection method Lan; 12A, first half body; 12B, second half body; 12C, leak-proof sealing connection; 12D, screw; 131, first filter paper layer; 132, first quartz sand layer; 133, rock powder layer; 134, soil layer; 135, second filter paper layer; 136, second quartz sand layer; 65, pressure measuring bracket; 66, scale; 611, pressure measuring control valve; 52, overflow pipe; 53, overflow bottle; 511, overflow control valve; 311, elution interface; 312, elution control valve; 241, multi-channel conversion joint; 242, atomizing nozzle; 243, nozzle. DETAILED DESCRIPTION

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not therefore limited to the following embodiments.

[0047] Combination Figure 1-Figure 6 As shown, the present invention provides a soil-rock interface comprehensive leaching device that simulates different rainfall intensities and natural attenuation of pollutants, including a simulated soil-rock interface system 1, a simulated rainfall system 2 respectively connected to the simulated soil-rock interface system 1, a filtrate collection system 3 and a double-layer medium vertical permeability experimental system 4.

[0048] According to the concept of the present invention, the simulated soil-rock interface system 1 is used to simulate the soil and rock powder environment, the simulated rainfall system 2 is used to simulate the rainfall environment, the simulated rainfall system 2 can be connected to multiple simulated soil-rock interface systems 1, and batch experimental operation can be realized. The filtrate collection system 3 is used to collect leachate, and the double-layer medium vertical permeability experimental system 4 is used to measure the vertical permeability coefficient of soil and rock powder. A simulated soil-rock interface system 1 is equipped with a filtrate collection system 3 and a double-layer medium vertical permeability experimental system 4. For example, Figure 1In the illustrated embodiment, two simulated soil-rock interface systems 1 are provided, and each simulated soil-rock interface system 1 is connected to a filtrate collection system 3 and a double-layer medium vertical permeability experimental system 4 .

[0049] According to one embodiment of the present invention, the simulated soil-rock interface system 1 includes a bottom device 11 and a column 12 installed on the bottom device 11, and a filling layer 13 is provided in the column 12. The bottom device 11 includes a support frame 111 and a bottom plate 112 fixedly connected to the support frame 111, and a porous glass plate 113 is installed on the bottom plate 112. In this embodiment, the column 12 includes a first half body 12A and a second half body 12B that are symmetrically arranged, and the first half body 12A and the second half body 12B are both provided with a leakproof sealing connection part 12C, and the leakproof sealing connection part 12C of the first half body 12A and the second half body 12B is fixedly connected by a screw 12D. A connecting flange 121 is provided at the lower end of the column 12 to be sealed and fixedly connected to the porous glass plate 113.

[0050] According to one embodiment of the present invention, the filling layer 13 includes a first filter paper layer 131, a first quartz sand layer 132, a rock powder layer 133, a soil layer 134, a second filter paper layer 135 and a second quartz sand layer 136 which are arranged in sequence from bottom to top along the vertical direction of the column 1.

[0051] The comprehensive leaching device for soil-rock interface simulating different rainfall intensities and natural attenuation of pollutants of the present invention installs the simulated soil-rock interface system 1 with the above-mentioned structural arrangement, which can be easily disassembled, cleaned, maintained and sampled.

[0052] The present invention provides a comprehensive leaching device for soil-rock interface that simulates different rainfall intensities and natural attenuation of pollutants, wherein the simulated rainfall system 2 includes a multi-channel peristaltic pump 21, a liquid inlet bottle 22 and a liquid inlet pipe 23 respectively connected to the multi-channel peristaltic pump 21, and the front end of the liquid inlet pipe 23 is connected to an atomizing device 24, and the atomizing device 24 is located above the column 12. The liquid inlet bottle 22 is used to hold pollutants, deionized water, and pollutant removers. A cross mesh is provided at the upper end of the column 12, and the atomizing device 24 is fixed on the cross mesh. The atomizing device 24 includes a multi-channel conversion joint 241, an atomizing nozzle 242 and a nozzle 243. In this embodiment, the multi-channel peristaltic pump 21 can be connected to multiple liquid inlet pipes 23 at the same time, and the leaching time of the leaching solution and the flow rate of each liquid inlet bottle 22 are set by the setter, so as to achieve the purpose of simulating different rainfall intensities and rainfall times.

[0053] The soil-rock interface comprehensive leaching device of the present invention that simulates different rainfall intensities and natural attenuation of pollutants, the filtrate collection system 3 includes a liquid collecting funnel 31 arranged at the lower side of the bottom device 11 and connected to the bottom device 11, and a liquid collecting bottle 32 detachably connected to the liquid collecting funnel 31, and the liquid collecting funnel 31 is connected to the column 1. Specifically, a through hole is provided in the middle of the bottom plate 112, and the liquid collecting funnel 11 is connected to the column 12 through a porous glass plate 113. The liquid collecting funnel 31 is provided with a leaching interface 311, and a leaching control valve 312 is provided at the leaching interface 311, and the liquid collecting bottle 32 or the seepage pipe 63 is connected to the leaching interface 311. In the present invention, the liquid collecting bottle 32 is used to collect the leachate flowing out through the liquid collecting funnel 31 and the elution interface 311. The seepage tube 63 in the permeation experiment stage connects the elution interface 311 and the seepage bottle 64, and cooperates with the double-layer medium vertical permeation experiment system 4 to achieve the purpose of measuring the vertical permeability coefficient of the double-layer medium. During the leaching experiment stage, the pollutant concentration of the leachate in the liquid collecting bottle 32 is regularly detected, and cooperates with the double-layer medium vertical permeation experiment system to achieve the purpose of simulating the migration law of pollutants.

[0054] According to an embodiment of the present invention, a double-layer medium vertical permeation experimental system 4 includes an overflow device 5 and a pressure measuring device 6 respectively connected to the column 1. In this embodiment, an overflow interface 51 is provided on the column 12, and the overflow interface 51 is located above the filling layer 13. The overflow device 5 is connected to the overflow interface 51. The overflow device 5 includes an overflow pipe 52 connected to the overflow interface 51 and an overflow bottle 53 connected to the overflow pipe 52. The overflow interface 51 is provided with an overflow control valve 511.

[0055] The column 12 is also provided with a pressure measuring interface 61, which is located at the filling layer 13. The pressure measuring device 6 includes a pressure measuring tube 62 connected to the pressure measuring interface 61, a seepage tube 63 detachably connected to the liquid collecting funnel 31, and a seepage bottle 64 connected to the seepage tube 63. In this embodiment, the pressure measuring interface 61 is provided on the column 12 at 2 cm from the top and bottom of the soil layer 134 and 3 cm from the top and bottom of the rock powder layer 133, and a pressure measuring control valve 611 is provided at the pressure measuring interface 61. The pressure measuring device 6 also includes a pressure measuring bracket 65, on which a scale 66 is provided, and the pressure measuring tube 62 is fixed to the pressure measuring bracket 65. After completing the double-layer medium permeation experiment, the pressure measuring interface 61 can be used as a water intake to take water samples of the double-layer medium for analysis of pollutant migration rules.

[0056] The soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants of the present invention, the column 12, the porous glass plate 113, the support frame 111, the bottom plate 112, the liquid collecting funnel 31, the leakproof sealing connection part 12C and the connecting flange 121 are made of acrylic material, and the overflow pipe 52, the pressure measuring tube 62 and the liquid inlet pipe 23 are made of soft silicone material. The atomizing nozzle 242, the nozzle 243, the multi-channel adapter 241 and the valve are made of ABS resin material, and the inner wall of each port of the multi-channel adapter 241 is provided with an internal thread structure, and when one end is not in use, the port can be closed with an external thread screw.

[0057] The present invention provides a soil-rock interface comprehensive leaching device that simulates different rainfall intensities and natural attenuation of pollutants. The simulated rainfall system 2 controls the flow rate and time of the solution in the liquid inlet bottle 22 through a multi-channel peristaltic pump 21 to achieve the simulation of different rainfall intensities and rainfall times. By setting the number of multi-channel adapters 241, the batch leaching experiment simulation of different pollutant concentrations is achieved; the simulated soil-rock interface system 1 adopts a separate design, which is convenient for cleaning and sampling after the experiment, and realizes the adsorption and biodegradation simulation of pollutants at the soil-rock interface; the filtrate collection system 3 is bidirectionally linked with the double-layer medium vertical permeability experimental system 4, and the vertical permeability coefficient of the double-layer medium and the permeation and migration simulation of pollutants at the soil-rock interface are achieved through the multifunctionality of the pressure measuring interface 61 and the leaching interface 311. In general, the device can realize the vertical permeability experiment of the double-layer medium, the migration, adsorption and biodegradation of pollutants at the soil-rock interface, and the batch leaching experiment under different rainfall intensities and different pollutant concentrations. The device of the present invention is easy to operate and has a short experimental cycle, and is suitable for indoor rapid and effective physical simulation experiments.

[0058] The present invention also provides a simulation experimental method of the soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants, comprising:

[0059] S1. Collect soil and rock samples. Set up "S"-shaped sampling points in the study area and use the quartering method to collect soil and rock samples below 20 cm from the surface.

[0060] S2, pretreatment of filling layer: quartz sand is passed through a 2-2.5 mm sieve, soil is air-dried and ground to pass through a 2.5 mm sieve, rock is crushed with a crusher, ground with a ball mill, and passed through a 2.5 mm sieve, and 100 g of quartz sand, 500 g of soil and 900 g of rock powder are obtained after weighing and sieving for standby use;

[0061] S3. Install the simulated soil-rock interface system 1. The column 12 is 25 cm high and 5 cm in inner diameter. The mesh number of the porous glass plate 113 is 500-600 mesh. The inner diameter of the overflow interface 51 and the pressure measuring interface 61 is 0.5 cm. The pressure measuring interface 61 is first sealed with an artist's tape. Apply vaseline to the inner wall of the column 12, and then lay the first filter paper layer 131 on the porous glass plate 113, cover the first quartz sand layer 132 (1 cm thick) on the first filter paper layer 131 and lay it evenly, and then fill the rock powder and soil in turn. After filling in quantity, tap and compact with a hammer to form the rock powder layer 133 (10 cm thick) and the soil layer 134 (6 cm thick), and then lay the second filter paper layer 135, cover the second quartz sand layer 136 (1 cm thick) on the second filter paper layer 135, and scrape it flat with a scraper;

[0062] S4, double-layer medium vertical permeability experiment: first install the simulated rainfall system 2 and the double-layer medium vertical permeability experimental system 4, measure the liquid level of the pressure measuring tube 62, calculate the seepage path length and water-passing section of the soil layer 134 and the rock powder layer 133, and then use the multi-channel peristaltic pump 21 to inject deionized water at a flow rate of 2mL / min so that water always overflows from the overflow port 51, record the water level difference of the pressure measuring tube 62, the water volume of the seepage bottle 64, and the water temperature at the water inlet and outlet, lower the height of the seepage tube 63 to the interface of the soil layer 134 and the rock powder layer 133 (i.e., the soil-rock interface, in the initial state, the highest point of the seepage tube 63 is fixed to the upper end of the pressure measuring bracket 65), repeat the above experimental steps, and calculate the vertical permeability coefficients of the soil and rock powder;

[0063] S5, preparation before leaching: close the pressure control valve at the pressure measuring interface 61, remove and disconnect the pressure measuring device 6 from the pressure measuring interface 61, and remove and disconnect the seepage tube 63 from the leaching interface 311, and connect the liquid collecting bottle 32 to the leaching interface 311;

[0064] S6. Prepare the leaching solution: prepare the pollutant (sulfonamide antibiotics as an example) leaching solution within 24 hours before the start of leaching, draw the standard curve of sulfonamide antibiotics, determine the actual concentration, and store the prepared solution in a sealed and dark place at 4°C;

[0065] S7, balance the experimental column: use the multi-channel peristaltic pump 21 to inject 5 μM NaCl solution as the background electrolyte solution to balance the chemical environment of the experimental column, and let it stand for 2 days;

[0066] S8, simulate soil-rock interface leaching experiment under different rainfall intensities and pollutant concentrations: set different leaching conditions, including rainfall intensity, rainfall time, leaching solution, and pollutant concentration, use a multi-channel peristaltic pump to pump the solution from the liquid inlet bottle 22 into the atomization device 24, leaching once every other day, and leaching 720 mL each time;

[0067] S9, water sample and solid sample collection and testing: During the experiment, the effluent from the liquid collection bottle 32 and the pressure measuring interface 61 is collected regularly (at this time, since the double-layer medium vertical permeation experimental system 4 has been dismantled, the pressure measuring control valve 611 can be opened regularly to collect the effluent from the pressure measuring interface 61). After the experiment, the multi-channel peristaltic pump 21 is turned off, the column 12 is opened, and samples are taken from three points in the upper, middle and lower parts of the soil layer 134 and the rock powder layer 133. After treatment, the pollutant concentration in the water sample and the solid sample is tested, and the microbial community structure, the functional genes of the resistance genes and the ion concentration in the solid sample are tested to evaluate the migration, adsorption and biodegradation of pollutants at the soil-rock interface.

[0068] The above is only one embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A soil-rock interface comprehensive leaching device simulating different rainfall intensities and natural attenuation of pollutants, characterized in that: It comprises a simulated soil-rock interface system (1), a simulated rainfall system (2) respectively connected to the simulated soil-rock interface system (1), a filtrate collection system (3) and a double-layer medium vertical permeability experimental system (4); The simulated soil-rock interface system (1) comprises a bottom device (11) and a column (12) installed on the bottom device (11), wherein a filling layer (13) is provided in the column (12); The simulated rainfall system (2) comprises a multi-channel peristaltic pump (21), a liquid inlet bottle (22) and a liquid inlet pipe (23) respectively connected to the multi-channel peristaltic pump (21), the front end of the liquid inlet pipe (23) is connected to an atomizing device (24), and the atomizing device (24) is located above the column (12); The filtrate collection system (3) comprises a liquid collecting funnel (31) arranged at the lower side of the bottom device (11) and connected to the bottom device (11), and a liquid collecting bottle (32) detachably connected to the liquid collecting funnel (31), wherein the liquid collecting funnel (31) is in communication with the column (1); The double-layer medium vertical permeability experimental system (4) comprises an overflow device (5) and a pressure measuring device (6) respectively connected to the column (1); The column (12) is provided with an overflow interface (51), the overflow interface (51) is located above the filling layer (13), and the overflow device (5) is connected to the overflow interface (51); The column (12) is also provided with a pressure measuring interface (61), the pressure measuring interface (6) is located at the filling layer (13), and the pressure measuring device (6) comprises a pressure measuring tube (62) connected to the pressure measuring interface (61), a seepage tube (63) detachably connected to the liquid collecting funnel (31), and a seepage bottle (64) connected to the seepage tube (63).

2. The soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to claim 1 is characterized in that: The bottom device (11) comprises a support frame (111) and a bottom plate (112) fixedly connected to the support frame (111), and a porous glass plate (113) is installed on the bottom plate (112); The lower end of the column (12) is provided with a connecting flange (121) which is sealed and fixedly connected to the porous glass plate (113); the middle of the bottom plate (112) has a through hole; the liquid collecting funnel (11) is connected to the column (12) through the porous glass plate (113).

3. The soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to claim 2 is characterized in that: The column (12) comprises a first half body (12A) and a second half body (12B) which are symmetrically arranged. The first half body (12A) and the second half body (12B) are both provided with a leakproof sealing connection part (12C). The leakproof sealing connection part (12C) between the first half body (12A) and the second half body (12B) is fixedly connected by a screw (12D).

4. The soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to claim 3 is characterized in that: The filling layer (13) comprises a first filter paper layer (131), a first quartz sand layer (132), a rock powder layer (133), a soil layer (134), a second filter paper layer (135) and a second quartz sand layer (136) which are arranged in sequence from bottom to top along the vertical direction of the column (1).

5. The soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to claim 4 is characterized in that: The column (12) is provided with the pressure measuring interface (61) at 2 cm from the top and bottom of the soil layer (134) and at 3 cm from the top and bottom of the rock powder layer (133), and the pressure measuring interface (61) is provided with a pressure measuring control valve (611); The pressure measuring device (6) further comprises a pressure measuring bracket (65), a scale (66) is provided on the pressure measuring bracket (65), and the pressure measuring tube (62) is fixed on the pressure measuring bracket (65).

6. The soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to claim 5 is characterized in that: The overflow device (5) comprises an overflow pipe (52) connected to the overflow interface (51) and an overflow bottle (53) connected to the overflow pipe (52); An overflow control valve (511) is provided at the overflow interface (51).

7. The soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to claim 1 or 6, characterized in that: The liquid collecting funnel (31) is provided with a oozing interface (311), and a oozing control valve (312) is provided at the oozing interface (311); The liquid collecting bottle (32) or the seepage pipe (63) is connected to the elution interface (311).

8. The soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to claim 1 is characterized in that: The upper end of the column (12) is provided with a cross mesh, and the atomizing device (24) is fixed on the cross mesh; The atomizing device (24) comprises a multi-channel conversion joint (241), an atomizing nozzle (242) and a nozzle (243).

9. A simulation method using the soil-rock interface comprehensive leaching device for simulating different rainfall intensities and natural attenuation of pollutants according to any one of claims 1 to 8, characterized in that: include: S1. Collect soil and rock samples; S2. Pretreatment of filling layer: quartz sand is sieved through 2-2.5mm sieve, soil is air-dried and ground through 2.5mm sieve, rock is crushed by crusher, ground by ball mill, and sieved through 2.5mm sieve for standby use; S3, installing the simulated soil-rock interface system (1), smearing the inner wall of the column (12) with vaseline, then laying the first filter paper layer (131) on the porous glass plate (113), covering the first quartz sand layer (132) on the first filter paper layer (131) and laying it evenly, then filling rock powder and soil in sequence, and after filling in quantity, lightly tapping and compacting with a hammer to form the rock powder layer (133) and the soil layer (134), then laying the second filter paper layer (135), covering the second quartz sand layer (136) on the second filter paper layer (135), and scraping it flat with a scraper; S4, double-layer medium vertical permeability experiment: first install the simulated rainfall system (2) and the double-layer medium vertical permeability experiment system (4), measure the liquid level of the pressure measuring tube (62), calculate the seepage path length and water-passing section of the soil layer (134) and the rock powder layer (133), then use a multi-channel peristaltic pump (21) to inject deionized water at a constant speed so that water always overflows from the overflow port (51), record the water level difference of the pressure measuring tube (62), the water volume of the seepage bottle (64), and the water temperature at the water inlet and outlet, lower the height of the seepage tube (63) to the interface between the soil layer (134) and the rock powder layer (133), repeat the above experimental steps, and calculate the vertical permeability coefficients of the soil and rock powder; S5, closing the pressure measuring control valve at the pressure measuring interface (61), removing and disconnecting the pressure measuring device (6) from the pressure measuring interface (61), and removing and disconnecting the seepage tube (63) from the elution interface (311), and connecting the liquid collecting bottle (32) to the elution interface (311); S6. Prepare leaching solution: prepare pollutant leaching solution within 24 hours before the start of leaching, draw the pollutant standard curve, determine the actual concentration, and store the prepared solution in a sealed container at 4°C away from light; S7, balancing the experimental column: using a multi-channel peristaltic pump (21) to pour NaCl solution as the background electrolyte solution to balance the chemical environment of the experimental column, and leaving it to stand for 2 days; S8, simulating soil-rock interface leaching experiment under different rainfall intensities and pollutant concentrations: setting different leaching conditions, including rainfall intensity, rainfall time, leaching solution, and pollutant concentration, using a multi-channel peristaltic pump to pump the solution from the liquid inlet bottle (22) into the atomization device (24), and leaching once every other day; S9. Collection and testing of water and solid samples: During the experiment, the effluent from the liquid collection bottle (32) and the pressure measuring interface (61) is collected regularly. After the experiment, the multi-channel peristaltic pump (21) is turned off, the column (12) is opened, and samples are taken from three points in the upper, middle and lower parts of the soil layer (134) and the rock powder layer (133). After treatment, the pollutant concentrations in the water and solid samples are tested, and the microbial community structure, functional genes and ion concentrations in the solid samples are tested to evaluate the migration, adsorption and biodegradation of pollutants at the soil-rock interface.

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