A device and method for dynamically observing the effect of rainfall on the peristalsis of microplastics in karst soil

Abstract

The present application belongs to the technical field of soil research. A device and method for dynamically observing the effect of rainfall on the peristalsis of microplastics in karst soil are disclosed. The device comprises at least one water collection assembly arranged on the rock-soil exposed layer of a karst terrain and in a low-lying area. The water collection assembly comprises a support frame fixed to the surface of the soil layer, and a surface runoff collection unit and a driving unit connected to the support frame. The present application can arrange the water collection assembly in the low-lying area of the rock-soil exposed layer of the karst terrain, use the opening of the surface runoff collection unit to collect rainwater, and store and separate the collected rainwater in the microplastic receiving unit. Meanwhile, the driving unit is arranged to drive the surface runoff collection unit to open to collect rainwater during rainfall, dynamically observe the effect of rainfall on the peristalsis of microplastics in karst soil, and drive the surface runoff collection unit to close during non-rainfall, thereby prolonging the service life of the surface runoff collection unit and avoiding the influence of external factors on the collection of rainwater.

Description

Technical Field

[0001] This invention belongs to the field of soil research technology, and in particular relates to a device and method for dynamically observing the effect of rainfall on the microplastic peristalsis in karst soil. Background Technology

[0002] Plastic products are widely used in production and daily life due to their lightweight and durability. However, the large amount of microplastics (plastic fragments with a particle size <5mm) generated are chemically stable and persistently exist in the soil environment. They are easily absorbed by soil plants and animals, causing migration and thus producing toxic effects. Microplastics, with their small particle size, large specific surface area, and strong hydrophobicity, readily adsorb organic pollutants, increasing the bioavailability of these pollutants. The combination of these two factors exacerbates the harm to the ecological environment. Furthermore, microplastics undergo varying degrees of migration and movement in the environment due to environmental factors such as rainfall, natural weathering, and human disturbance. Therefore, the innovative development of devices and methods for detecting soil microplastic movement is a prerequisite and a key research topic for exploring the environmental behavior and biological effects of microplastics and coexisting pollutants.

[0003] Karst landforms are unique topographic features formed by the dissolution and precipitation of soluble rocks by groundwater and surface water, as well as by erosion and deposition. In China, they are also known as karst landforms and are one of the five major landform types. Karst regions are characterized by harsh environments and significant human-land conflicts. The surface of karst regions is characterized by rugged mountains, complex and diverse topography, exposed bedrock, and varying degrees of gravel content hidden in the soil. Underground, the unique "binary" structure and porous media characteristics of karst regions allow runoff to flow through shallow pores, fissures, channels, and funnels during rainfall, carrying away large amounts of soil and causing "soil microplastic creep." Soil microplastic leakage and creep are a unique mode of microplastic migration in karst desertification areas. The complex karst ecosystem presents many uncertainties in the study of soil microplastic creep.

[0004] While existing technologies include devices for simulating the migration of microplastics in karst soils, these devices can only simulate karst topography and rainfall conditions. Differences between the simulations and actual environmental conditions lead to discrepancies between the experimental and practical results. Furthermore, they cannot dynamically observe the impact of rainfall on the movement of microplastics in karst soils. Therefore, this paper proposes a device and method for dynamically observing the effect of rainfall on the movement of microplastics in karst soils to address these issues, which is of significant importance for the study of microplastics in karst regions. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a device and method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil. This method enables the placement of water collection components in low-lying areas of exposed rock and soil layers in karst terrain. Rainwater is collected by opening surface runoff collection units and then stored and separated in microplastic receiving units. A drive unit is also included. During rainfall, the surface runoff collection units are opened to collect rainwater, allowing for dynamic observation of the impact of rainfall on microplastic peristalsis in karst soil. When there is no rainfall, the surface runoff collection units are closed, extending their service life and preventing external factors from affecting rainwater collection.

[0006] To achieve the above objectives, the present invention provides a device for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil, comprising:

[0007] At least one water collection component is arranged on the exposed soil and rock layer of karst topography and in a low-lying area. The water collection component includes a support frame fixed to the soil surface. A surface runoff collection unit and a drive unit are connected to the support frame. The drive unit is configured to drive the movable end of the surface runoff collection unit to move so that the surface runoff collection unit switches between an open state and a closed state.

[0008] The microplastic receiving unit is buried in the soil, and its inlet end is connected to the surface runoff collection unit through the support frame.

[0009] In the open state, the movable end of the surface runoff collection unit is close to the soil layer, and the surface runoff collection unit is open and attached to the soil surface. In the closed state, the movable end of the surface runoff collection unit is away from the soil layer, and the surface runoff collection unit is contracted.

[0010] Furthermore, the surface runoff collection unit includes: a collar, which is fitted and slidably fitted onto the support frame and serves as the movable end of the surface runoff collection unit;

[0011] The umbrella support frame is hinged to the outer wall of the collar. The telescopic end of the drive unit drives the collar to move along the support frame so that the umbrella support frame switches between the open state and the closed state.

[0012] The canopy, connected to the umbrella support frame, is configured to collect water.

[0013] Furthermore, the drive unit includes a storage cylinder fixed to one end of the support frame away from the soil layer;

[0014] A telescopic cylinder is fixed inside the storage cylinder, and the movable end of the telescopic cylinder passes through the support frame. A sliding groove is provided on the side wall of the support frame.

[0015] A connecting plate is fixed to the telescopic end of the telescopic cylinder and extends out of the support frame through the slide groove. The connecting plate is fixed to the movable end of the surface runoff collection unit.

[0016] Furthermore, the storage cylinder is equipped with a power supply and a controller, the controller being configured to control the opening and closing of the telescopic cylinder.

[0017] Furthermore, the support frame includes: a buried cylinder, which is buried in the soil layer;

[0018] A connecting column is fixed and connected to the top of the buried cylinder. The fixed end of the surface runoff collection unit is sleeved and fixed on the connecting column. A water passage hole communicating with the surface runoff collection unit is opened on the side wall of the connecting column.

[0019] A support rod is fixed to the end of the connecting column away from the buried cylinder, and the movable ends of the drive unit and the surface runoff collection unit are connected to the support rod.

[0020] Furthermore, the microplastic receiving unit includes: a microplastic separating cylinder, with a supporting circular plate fixed inside;

[0021] A sludge settling cylinder is disposed on the top surface of the supporting circular plate, and the liquid inlet end of the sludge settling cylinder is connected to the support frame through a connecting pipe.

[0022] Furthermore, it also includes a support ring plate, which is fixed on the inner wall of the microplastic separation cylinder and located below the support circular plate;

[0023] A microplastic filter cartridge is disposed between the support ring plate and the support circular plate and is supported by the support ring plate. The microplastic filter cartridge is configured to separate water and microplastics.

[0024] The liquid guide pipe has an inlet end connected to the side wall of the sludge sedimentation cylinder and an outlet end connected to the microplastic filter cylinder. A valve is installed on the liquid guide pipe.

[0025] Furthermore, the microplastic separation cylinder includes a pair of half-cylinders, a pair of ear plates are fixed on the side wall of the half-cylinders, and connecting bolts are passed through the ear plates. The pair of half-cylinders are fixed by the ear plates and the connecting bolts to form the microplastic separation cylinder.

[0026] Furthermore, multiple water collection components are arranged on each height gradient of the soil layer, and the multiple water collection components on each height gradient are connected to a microplastic receiving unit.

[0027] A method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil, employing the aforementioned device for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil, includes the following operating steps:

[0028] Select a low-lying area with exposed rock and soil layers in a karst topography and deploy water collection components in the low-lying area;

[0029] The microplastic receiving unit is buried in the soil and connected to the support frame.

[0030] The system monitors weather conditions in real time. When rainfall occurs, the drive unit is activated to move the movable end of the surface runoff collection unit, thus switching the surface runoff collection unit to the open state. When there is no rainfall, the drive unit is activated to move the movable end of the surface runoff collection unit, thus switching the surface runoff collection unit to the closed state.

[0031] The microplastic recycling receiving unit separates soil, microplastics, and rainwater.

[0032] Compared with the prior art, the present invention has the following advantages and technical effects:

[0033] 1. Water collection components are arranged in the low-lying areas of exposed soil and rock layers in karst topography. This can take advantage of the terrain of karst areas and collect rainwater by opening the surface runoff collection unit. The collected rainwater is then sent into the microplastic receiving unit for storage and separation. At the same time, a drive unit is set up to dynamically collect the microplastic creep in the surface soil of karst areas under different rainfall intensities. This enables dynamic simulation of the microplastic creep process in the soil microplastics in the above-ground and underground bedrock fissures of karst areas. It can also dynamically detect the creep speed and achieve dynamic monitoring of the microplastic creep process in the two-dimensional and three-dimensional structure of karst areas.

[0034] 2. This technology can quantitatively reveal the underground creep process and mechanism of microplastics in karst soil, and has universal applicability in karst areas. At the same time, during rainfall, the surface runoff collection unit is activated to collect rainwater, and the impact of rainfall on the creep of microplastics in karst soil is dynamically observed. When there is no rainfall, the surface runoff collection unit is activated to close, which can extend the service life of the surface runoff collection unit and avoid the influence of external factors on rainwater collection.

[0035] 3. This device provides a transparent simulation, clearly demonstrating the dynamic changes of microplastics with precise numerical values. The simulation process of this invention achieves dynamic tracking of microplastics throughout the entire karst process, from rainwater input to microplastic collection and dynamic changes, all of which can be elucidated for scientific research. This invention has a simple structure, no complex process steps, and is easy to manufacture. Furthermore, the microplastic receiving unit, bare sludge sedimentation tank, and microplastic filter tank of this device are recyclable, durable, and not easily damaged. The equipment required for this experiment is inexpensive and readily available. Attached Figure Description

[0036] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0037] Figure 1 This is a schematic diagram showing the arrangement of the water collection components;

[0038] Figure 2 A schematic diagram showing the connection relationship between multiple surface runoff collection units and microplastic receiving units;

[0039] Figure 3 A 3D view of the water collection assembly;

[0040] Figure 4 for Figure 3 The front view;

[0041] Figure 5 A three-dimensional diagram of the umbrella support frame;

[0042] Figure 6 This is a schematic diagram of the internal structure of the microplastic separation cylinder;

[0043] Among them, 1-support frame, 101-buried cylinder, 102-connecting column, 103-water passage hole, 104-support rod, 105-slide groove, 2-surface runoff collection unit, 201-ring, 202-umbrella frame, 203-umbrella surface, 3-drive unit, 301-storage cylinder, 302-telescopic cylinder, 303-connecting plate, 4-microplastic receiving unit, 401-microplastic separation cylinder, 402-support circular plate, 403-sludge sedimentation cylinder, 404-support ring plate, 405-microplastic filter cylinder, 406-liquid guide pipe, 407-valve, 408-ear plate, 409-connecting bolt, 410-liquid storage cylinder, 5-connecting pipe. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Reference Figures 1-6The present invention provides a device for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil, comprising: at least one water collection component arranged on the exposed soil and rock layer of karst terrain and in a low-lying area, the water collection component including a support frame 1 fixed to the soil surface, a surface runoff collection unit 2 and a drive unit 3 connected to the support frame 1, the drive unit 3 being configured to drive the movable end of the surface runoff collection unit 2 to move, so that the surface runoff collection unit 2 switches between an open state and a closed state.

[0047] In the open state, the movable end of the surface runoff collection unit 2 is close to the soil layer, and the unit opens and adheres to the soil surface. In the closed state, the movable end of the unit closes away from the soil layer, and the unit retracts. With this structure, the surface runoff collection unit 2 is controlled to open or close via the drive unit 3. When rainfall is imminent, the unit opens to collect rainwater during the rainfall. After the rainfall ends, the unit closes, preventing dust and other contaminants from entering the microplastic receiving unit 4, thus improving the accuracy of the observation experiment.

[0048] Specifically, due to the influence of karst topography, rainwater has a flow path during actual rainfall. Therefore, based on the karst topography, surface runoff collection units 2 are arranged along the rainwater flow path and placed in low-lying areas to collect rainwater and the soil and microplastics contained in the rainwater.

[0049] In some cases, low-lying areas can be created by manual excavation, so that when the surface runoff collection unit 2 is in the open state, the top of its umbrella 203 is in contact with or below the soil surface, so as to achieve effective rainwater collection.

[0050] Among them, the surface runoff collection unit 2 is an inverted umbrella-shaped structure that uses the umbrella surface 203 to collect rainwater, and the umbrella surface 203 is easy to open or close.

[0051] The microplastic receiving unit 4 is buried in the soil, and its inlet end is connected to the surface runoff collection unit 2 through the support frame 1.

[0052] Specifically, the microplastic receiving unit 4 is used to store rainwater, and it also has the function of separating soil, microplastics and rainwater.

[0053] Further optimize the plan, referring to Figure 3 , Figure 4 , Figure 5The surface runoff collection unit 2 includes: a collar 201, which is slidably fitted onto the support frame 1 and serves as the movable end of the surface runoff collection unit 2; an umbrella support frame 202, which is hinged to the outer wall of the collar 201, and the telescopic end of the drive unit 3 drives the collar 201 to move along the support frame 1 so that the umbrella support frame 202 switches between an open state and a closed state; and an umbrella surface 203, which is connected to the umbrella support frame 202 and is configured to collect water.

[0054] Specifically, the support frame 1 is fixed on the soil layer, and the collar 201 is fitted on the support frame 1. As the collar 201 moves along the support frame 1, the umbrella support frame 202 moves with the collar 201 to open or close the umbrella support frame 202. At the same time, the opening or closing of the umbrella support frame 202 drives the umbrella surface 203 to open or close.

[0055] When the umbrella surface 203 is in the open state, it forms an upward-facing cover structure. Rainwater enters the cover structure and is then sent into the microplastic receiving unit 4 through the support frame 1.

[0056] Among them, the umbrella support frame 202 is the existing umbrella rib structure.

[0057] Further optimize the plan, referring to Figure 3 , Figure 4 , Figure 5 The drive unit 3 includes: a storage cylinder 301, fixed to the end of the support frame 1 away from the soil layer; a telescopic cylinder 302, fixed inside the storage cylinder 301, with the movable end of the telescopic cylinder 302 passing through the support frame 1, and a sliding groove 105 provided on the side wall of the support frame 1; and a connecting plate 303, fixed to the telescopic end of the telescopic cylinder 302, and extending out of the support frame 1 through the sliding groove 105, with the connecting plate 303 fixed to the movable end of the surface runoff collection unit 2.

[0058] Specifically, the storage cylinder 301 is fixed on the support frame 1, and a cavity is provided inside for housing the telescopic cylinder 302. When the telescopic end of the telescopic cylinder 302 moves, it drives the connecting plate 303 to move along the support frame 1, which in turn drives the collar 201 to move, thereby driving the umbrella support frame 202 to open or close. The slide groove 105 is used to allow the connecting plate 303 to move and to limit the movement of the connecting plate 303.

[0059] In a further optimized design, a power supply and a controller are installed inside the storage cylinder 301. The controller is configured to control the opening and closing of the telescopic cylinder 302.

[0060] Specifically, the controller is used to control the switch connecting the power supply to the telescopic cylinder 302. By controlling the opening and closing of the switch, the controller can control the telescopic cylinder 302 to extend or remain stationary.

[0061] In one specific embodiment of the present invention, the storage cylinder 301 has a wireless connection device, which is connected to the controller. The test personnel can remotely operate the controller by cooperating with the wireless connection device through peripheral devices.

[0062] In another specific embodiment of the present invention, the storage cylinder 301 has a wireless connection device, which is connected to the controller and a weather forecasting device. The weather forecasting device can determine whether there is rainfall through real-time weather forecast and feed the signal back to the controller, so that the controller controls the telescopic cylinder 302 to work.

[0063] In the above setup, the surface runoff collection unit 2 can be remotely operated to open or close, thereby reducing the burden on the test personnel.

[0064] Further optimize the plan, referring to Figure 3 , Figure 4 , Figure 5 The support frame 1 includes: a buried cylinder 101, buried in the soil layer; a connecting column 102, fixed and connected to the top of the buried cylinder 101, the fixed end of the surface runoff collection unit 2 is sleeved and fixed on the connecting column 102, and a water passage hole 103 connected to the surface runoff collection unit 2 is opened on the side wall of the connecting column 102; and a support rod 104, fixed to the end of the connecting column 102 away from the buried cylinder 101, and the driving unit 3 and the movable end of the surface runoff collection unit 2 are connected to the support rod 104.

[0065] Specifically, the buried cylinder 101 is the support base of the support frame 1, which is buried and fixed in the soil. The connecting column 102 extends out of the soil and is sleeved and fixed on the connecting column 102 at the fixed end of the umbrella support frame 202. Multiple water passage holes 103 are opened on the side wall of the connecting column 102. The water passage holes 103 are located on the side of the umbrella surface 203 away from the soil, so that the rainwater collected by the umbrella surface 203 enters the buried cylinder 101 through the water passage holes 103, and then is introduced into the microplastic receiving unit 4 through the connecting pipe 5.

[0066] The support rod 104 is fixed on the connecting column 102, which serves as a support for the collar 201. The collar 201 moves along the support rod 104 to open or close the umbrella support frame 202.

[0067] Further optimize the plan, referring to Figure 6 The microplastic receiving unit 4 includes: a microplastic separation cylinder 401, with a supporting circular plate 402 fixed inside; and a sludge settling cylinder 403, which is disposed on the top surface of the supporting circular plate 402. The liquid inlet end of the sludge settling cylinder 403 is connected to the support frame 1 through a connecting pipe 5.

[0068] Specifically, a sludge settling cylinder 403 is arranged inside the microplastic separation cylinder 401. The sludge settling cylinder 403 is used to settle the mud in the rainwater mixture, while the microplastics are suspended in the rainwater due to their own characteristics.

[0069] Further optimize the plan, referring to Figure 6 It also includes a support ring plate 404, which is fixed on the inner wall of the microplastic separation cylinder 401 and located below the support circular plate 402; a microplastic filter cylinder 405, which is disposed between the support ring plate 404 and the support circular plate 402 and is supported by the support ring plate 404, and the microplastic filter cylinder 405 is configured to separate water and microplastics; and a liquid guide pipe 406, whose inlet end is connected to the side wall of the sludge sedimentation cylinder 403 and whose outlet end is connected to the microplastic filter cylinder 405, and a valve 407 is provided on the liquid guide pipe 406.

[0070] Specifically, after the rainwater mixture settles in the sludge settling tank 403 for a certain period of time, the valve 407 is opened, and the suspension in the sludge settling tank 403 is sent into the microplastic filter tank 405 through the liquid guide pipe 406. The microplastic filter tank 405 has a filter membrane at the bottom, which is used to separate microplastics and rainwater. The separated rainwater falls into the liquid storage tank 410 for storage, thereby realizing the separation of soil, microplastics and rainwater.

[0071] Further optimize the solution, refer to the following: Figure 2 , Figure 6 The microplastic separation cylinder 401 includes a pair of half cylinders, and a pair of ear plates 408 are fixed on the side wall of the half cylinders. A connecting bolt 409 is provided on the ear plates 408. The pair of half cylinders are fixed by the ear plates 408 and the connecting bolt 409 to form the microplastic separation cylinder 401.

[0072] With the above structural configuration, the microplastic separation cylinder 401 is an openable structure, and the supporting circular plate 402 and the supporting ring plate 404 are fixed to the inner wall of one half of the cylinder. When collecting rainwater mixture, the two half cylinders are joined together. After the rainwater mixture is collected, the microplastic separation cylinder 401 is removed from the soil layer, disassembled, and the half cylinder without the supporting circular plate 402 and the supporting ring plate 404 is separated. Then, the liquid guide tube 406 can be operated to carry out the separation step. At the same time, the separated products are located in different cylinders, and the different cylinders can be easily removed and their contents measured.

[0073] Further optimize the plan, referring to Figure 1 Multiple water collection components are arranged on each height gradient of the soil layer, and the multiple water collection components on each height gradient are connected to a microplastic receiving unit 4.

[0074] Specifically, in actual experiments, since most karst terrain consists of slopes with varying inclination angles, an experimental area is determined before the experiment. Within this experimental area, multiple water collection components are arranged along the same elevation gradient. All rainwater within the experimental area is collected by these multiple water collection components and converged into the microplastic receiving unit 4 for separation. This setup allows for effective dynamic observation of the impact of rainfall on microplastic creep in karst soil in a specific area.

[0075] A method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil, employing the aforementioned device for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil, includes the following operating steps:

[0076] S1. Select a low-lying area with exposed rock and soil layers in a karst topography and arrange water collection components in the low-lying area.

[0077] Before the experiment, the test area was determined, and the exposed soil and rock layers were observed. A low-lying area was selected for arranging the water collection components. The low-lying area was excavated to form the low-lying area according to actual needs. Then, the buried cylinder 101 was buried and fixed in the soil layer. The telescopic cylinder 302 was activated to push the collar 201 to move, so that the umbrella frame 202 would drive the umbrella surface 203 to open. It was observed whether the opening height of the umbrella surface 203 was level with or below the soil surface. According to the placement of the umbrella surface 203, the placement position and angle of the umbrella surface 203 were adjusted accordingly. After the adjustment was completed, the telescopic cylinder 302 was activated to drive the collar 201 to move, so that the umbrella surface 203 would close.

[0078] S2. Bury the microplastic receiving unit 4 in the soil and connect the support frame 1 and the microplastic receiving unit 4.

[0079] A microplastic separation cylinder 401 is buried at a location with a height lower than the surface runoff collection unit, and is connected to the sludge sedimentation cylinder 403 and the buried cylinder 101 through a connecting pipe 5.

[0080] S3. Real-time monitoring of weather conditions. When there is rainfall, the drive unit 3 is activated to move the movable end of the surface runoff collection unit 2, so that the surface runoff collection unit 2 is switched to the open state. When there is no rainfall, the drive unit 3 is activated to move the movable end of the surface runoff collection unit 2, so that the surface runoff collection unit 2 is switched to the closed state.

[0081] The system determines whether rainwater needs to be collected based on the weather conditions. When it rains or is about to rain, the telescopic cylinder 302 opens, allowing the rainwater mixture to be collected by the umbrella surface 203 and introduced into the microplastic receiving unit 4. When it does not rain, the umbrella surface 203 closes.

[0082] S4, Microplastic Recycling Unit 4, separates soil, microplastics, and rainwater.

[0083] After a period of time, the microplastic separation cylinder 401 is removed from the soil layer, the microplastic separation cylinder 401 is disassembled, and the half cylinder without the supporting circular plate 402 and the supporting ring plate 404 is separated. Then the liquid guide tube 406 can be operated to carry out the separation step. At the same time, the separated products are located in different cylinders, and the different cylinders can be easily removed and their contents measured.

[0084] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil, characterized in that, A device for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil includes: At least one water collection component is arranged on the exposed soil and rock layer of karst topography and in a low-lying area. The water collection component includes a support frame (1) fixed to the soil surface. A surface runoff collection unit (2) and a drive unit (3) are connected to the support frame (1). The drive unit (3) is configured to drive the movable end of the surface runoff collection unit (2) to move so that the surface runoff collection unit (2) switches between an open state and a closed state. The microplastic receiving unit (4) is buried in the soil, and the water inlet end is connected to the surface runoff collection unit (2) through the support frame (1); In the open state, the movable end of the surface runoff collection unit (2) is close to the soil layer, and the surface runoff collection unit (2) is open and attached to the surface of the soil layer. In the closed state, the movable end of the surface runoff collection unit (2) is away from the soil layer, and the surface runoff collection unit (2) is contracted. The surface runoff collection unit (2) includes: a collar (201), which is fitted and slidably fitted on the support frame (1) and is the movable end of the surface runoff collection unit (2); The umbrella support frame (202) is hinged to the outer wall of the collar (201). The telescopic end of the drive unit (3) drives the collar (201) to move along the support frame (1) so that the umbrella support frame (202) switches between the open state and the closed state. The canopy (203), connected to the umbrella support frame (202), is configured to collect water; The microplastic receiving unit (4) includes: a microplastic separating cylinder (401) with a supporting circular plate (402) fixed inside; A sludge settling cylinder (403) is disposed on the top surface of the supporting circular plate (402), and the liquid inlet end of the sludge settling cylinder (403) is connected to the support frame (1) through a connecting pipe (5); It also includes a support ring plate (404), which is fixed on the inner wall of the microplastic separation cylinder (401) and located below the support circular plate (402); A microplastic filter cartridge (405) is disposed between the support ring plate (404) and the support circular plate (402) and is supported by the support ring plate (404). The microplastic filter cartridge (405) is configured to separate water and microplastics. The liquid guide pipe (406) has an inlet end connected to the side wall of the sludge sedimentation cylinder (403) and an outlet end connected to the microplastic filter cylinder (405). A valve (407) is provided on the liquid guide pipe (406).

2. The method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil according to claim 1, characterized in that: The drive unit (3) includes: a storage cylinder (301) fixed to one end of the support frame (1) away from the soil layer; A telescopic cylinder (302) is fixed inside the storage cylinder (301). The movable end of the telescopic cylinder (302) passes through the support frame (1). A sliding groove (105) is provided on the side wall of the support frame (1). A connecting plate (303) is fixed on the telescopic end of the telescopic cylinder (302) and extends out of the support frame (1) through the slide groove (105). The connecting plate (303) is fixed to the movable end of the surface runoff collection unit (2).

3. The method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil according to claim 2, characterized in that: The storage cylinder (301) is equipped with a power supply and a controller, which is configured to control the opening and closing of the telescopic cylinder (302).

4. The method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil according to claim 1, characterized in that: The support frame (1) includes: a buried cylinder (101) buried in the soil layer; A connecting column (102) is fixed and connected to the top of the buried cylinder (101). The fixed end of the surface runoff collection unit (2) is sleeved and fixed on the connecting column (102). A water passage hole (103) communicating with the surface runoff collection unit (2) is opened on the side wall of the connecting column (102). A support rod (104) is fixed to one end of the connecting column (102) away from the buried cylinder (101), and the movable ends of the drive unit (3) and the surface runoff collection unit (2) are connected to the support rod (104).

5. The method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil according to claim 1, characterized in that: The microplastic separation cylinder (401) includes a pair of half cylinders, and a pair of ear plates (408) are fixed on the side wall of the half cylinders. A connecting bolt (409) is provided on the ear plate (408). The pair of half cylinders are fixed by the ear plate (408) and the connecting bolt (409) to form the microplastic separation cylinder (401).

6. The method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil according to claim 1, characterized in that: Multiple water collection components are arranged on each height gradient of the soil layer, and the multiple water collection components on each height gradient are connected to a microplastic receiving unit (4).

7. The method for dynamically observing the effect of rainfall on microplastic peristalsis in karst soil according to claim 1, characterized in that: The operating steps include: Select a low-lying area with exposed rock and soil layers in a karst topography and deploy water collection components in the low-lying area; The microplastic receiving unit (4) is buried in the soil and connected to the support frame (1). Real-time weather monitoring: When there is rainfall, the drive unit (3) is activated to move the movable end of the surface runoff collection unit (2) so that the surface runoff collection unit (2) is switched to the open state. When there is no rainfall, the drive unit (3) is activated to move the movable end of the surface runoff collection unit (2) so that the surface runoff collection unit (2) is switched to the closed state. The microplastic receiving unit (4) separates soil, microplastics, and rainwater.

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