A simulation device for microplastic aging and degradation behavior in landfill environment

Abstract

The application discloses a microplastic degradation experiment device field and relates to a simulation device for microplastic aging and degradation behavior in a landfill environment, which comprises a reaction cylinder, a pressure covering assembly, a temperature control assembly, a percolation assembly and a sampling and monitoring assembly.

Description

Technical Field

[0001] This invention relates to the field of experimental devices for microplastic degradation, and more specifically to a device for simulating the aging and degradation behavior of microplastics in a landfill environment. Background Technology

[0002] Microplastics, as a novel persistent pollutant, are abundant in landfills. Landfills are complex environments, closed systems characterized by anaerobic conditions, rich in microorganisms, and subject to dynamic changes in mechanical stress, temperature, and chemical conditions. Under these conditions, microplastics undergo multiple physical, chemical, and biological processes, resulting in aging (such as changes in surface properties and polymer chain breakage) and degradation (ultimately producing CO2 and CH4). These processes not only affect the environmental behavior of microplastics themselves but may also alter their adsorption-desorption capacity for coexisting pollutants, influencing the stabilization process of landfills and greenhouse gas emissions.

[0003] Existing laboratory studies on the aging and degradation of microplastics mostly employ single-factor simulation methods, such as: 1. UV / Ozone Aging Simulation: Primarily used to simulate photoaging in natural environments, but cannot reflect the aging mechanisms under anaerobic and light-free conditions in landfills.

[0004] 2. Chemical reagent immersion degradation: This involves treatment with strong acids, strong alkalis, or oxidants. The process is violent and differs greatly from the actual chemical and biological conditions in landfills.

[0005] 3. Simple anaerobic bottle culture: It can only conduct small-batch, static microbial degradation experiments and cannot simulate key physical and mechanical processes such as compaction pressure and leachate circulation of landfills.

[0006] These traditional methods have significant drawbacks: they cannot simulate the real environment of landfills with the coupling effects of multiple factors (physical, chemical, and biological), resulting in low reliability of experimental results extrapolated to real-world scenarios; they have long experimental cycles and low efficiency; and they cannot achieve online monitoring and active control of process parameters. Therefore, there is an urgent need in this field for an experimental simulation system that can highly reproduce the core environmental characteristics of real landfills and achieve controllable, repeatable, and real-time monitoring, in order to accurately reveal the long-term evolution and fate of microplastics in landfills.

[0007] Subsequently, a patent document with publication number CN120891181A disclosed an experimental system for simulating the formation of microplastics in a landfill environment. This system effectively solved the aforementioned problems by simulating the landfill environment to conduct microplastic degradation experiments. However, it also presents some new challenges: 1. It uses a suspension rope, guide wheel and weights to press down on the pressure plate. The simulated overpressure of the pressure plate is increased by increasing the number of weights. The upper limit of the overpressure of this method is limited by the size of the chassis and the length of the connecting column, and the suspension rope, chassis and connecting column as a whole cannot be easily replaced. 2. The leachate is directly transported into the reactor via a hydraulic circulation pump. The optimal temperature for leachate from conventional landfills is 55°C. At this temperature, microorganisms in the leachate exhibit the highest metabolic activity and degradation efficiency. However, directly transporting the leachate at room temperature into the reactor increases the heating time in the reactor and reduces the efficiency of the experiment.

[0008] To this end, we propose a simulation device for the aging and degradation behavior of microplastics in a landfill environment. Summary of the Invention

[0009] To address the aforementioned shortcomings of existing technologies, this invention provides a device for simulating the aging and degradation behavior of microplastics in a landfill environment.

[0010] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A device for simulating the aging and degradation behavior of microplastics in a landfill environment includes: a reaction cylinder, comprising a cylinder body and a cap for sealing the cylinder body, the cylinder body being vertically mounted on a base, the cylinder body providing a simulated space for microplastic aging and degradation, and a plurality of sampling ports vertically spaced apart at the lower part of the cylinder body; a pressure covering assembly, slidably mounted inside the reaction cylinder, which applies pressure to the microplastics through a tension spring structure, and the pressure is adjusted by increasing or decreasing the number and type of tension spring structures; a temperature control assembly, mounted on the cylinder body, for regulating the temperature inside the cylinder body; a leachate assembly, mounted inside the base and on the temperature control assembly, which preheats the leachate before delivering it into the reaction cylinder; a spraying assembly, also mounted inside the base, which sprays water into the cylinder body to simulate rainy weather; and a sampling and monitoring assembly, mounted on the cap, cylinder body, and leachate assembly, which monitors and analyzes the gas composition, temperature, and chemical properties of the leachate inside the cylinder body.

[0011] By setting up a tension spring structure to provide the covering pressure of the microplastic to the covering component, the covering pressure of the covering component on the microplastic can be adjusted by changing the type and number of tension spring structures. There are various spring coefficients, making replacement and adjustment more convenient, with less limitation on the covering pressure and a larger upper and lower limit. Furthermore, by setting the percolation component on the temperature control component, the percolation liquid is preheated by the temperature control component before being transported into the cylinder for reaction, which can improve experimental efficiency and help maintain the temperature stability inside the cylinder.

[0012] Further defined, the base includes an upper plate, a lower plate, and uprights; the bottom end of the cylinder is fixedly connected to the upper plate, both the upper and lower plates are rectangular plates, and the uprights are located at the four corners of the upper and lower plates, with both ends connected to the upper and lower plates respectively; this base setting allows for space between the upper and lower plates, providing installation positions for the spray assembly and the percolation assembly.

[0013] Further defining the pressure assembly, it includes a pressure plate, a pressure rod, a top plate, a fastening ring, and a pressure spring. The pressure plate is slidably disposed inside the cylinder. The bottom end of the pressure rod is fixedly connected to the pressure plate, and the top end passes through the cylinder cover and is connected to the top plate. The pressure rod and the cylinder cover are connected in a sealed sliding manner. The top plate is also a circular plate. The fastening rings are correspondingly disposed on the edge of the cylinder cover and the circumference of the top plate. Multiple fastening rings are provided on both the cylinder cover and the top plate along their respective circumferential directions. The two ends of the pressure spring are hooked onto the fastening rings on the cylinder cover and the top plate, respectively.

[0014] This design of the pressure assembly, by hooking the two ends of the pressure spring to the fastening rings on the top plate and the cylinder cover, pulls down the top plate, thereby pressing down the pressure plate. By properly selecting a pressure spring with an appropriate stiffness coefficient, sufficient pressure can be effectively provided. Furthermore, the connection between the pressure spring and the fastening ring makes replacement convenient.

[0015] Further defined, the temperature control component includes an outer cylinder, an inlet pipe, and an outlet pipe; the outer cylinder covers the body of the outer cylinder and leaves a gap between the outer cylinder and the body to form a partition layer; the top and bottom ends of the outer cylinder are sealed to the body; the inlet pipe is located on the bottom circumference of the outer cylinder; the outlet pipe is located on the top circumference of the outer cylinder; the end of the inlet pipe is connected to the outlet end of an external hot water source supply device; the end of the outlet pipe is connected to the inlet end of an external hot water source supply device; and the body is made of a heat-conducting material.

[0016] By setting up the temperature control components in this way, hot water is introduced into the partition through the inlet pipe and into the bottom of the cylinder. After the hot water fills the partition, it is discharged from the outlet pipe at the top, thereby heating the cylinder to reach the temperature of the landfill. Since the temperature requirements in the landfill environment are not high, mostly in the tens of degrees, this heating method can easily achieve the required temperature. The structure is simple and easy to manufacture.

[0017] Further specifying, the percolation assembly includes a percolate tank, a percolate pump, a percolate pipe, a preheating pipe, a percolate hose, and a return pipe; Both the leachate tank and the leachate pump are fixedly mounted on the lower plate. The inlet end of the leachate pump is connected to the inside of the leachate pipe. The leachate pipe is a two-section design. The preheating pipe is connected between the two sections of the leachate pipe and is sleeved outside the outlet pipe. The outlet pipe is made of heat-conducting material. The bottom end of the leachate pipe at the bottom of the preheating pipe is fixedly connected to the outlet end of the leachate pump. The top end of the leachate pipe at the top of the preheating pipe is connected to the inlet end of the leachate hose through a pipe joint. A liquid passage hole is opened on the top plate, which extends into the inside of the pressure rod. Several outlet holes communicating with the liquid passage hole are opened circumferentially on the lower part of the pressure rod. Multiple through leachate holes are opened vertically on the pressure plate. The bottom end of the return pipe is fixedly connected to the top of the leachate pipe, and the top end passes through the lower plate and communicates with the inside of the cylinder.

[0018] This setup involves a preheating tube. The leachate is drawn from the leachate tank by a leachate pump and enters the preheating tube. Meanwhile, the outlet pipe discharges hot water that has been heated by the cylinder. As the hot water flows through the preheating tube, it transfers heat to the tube, thus preheating the leachate. The preheated leachate then enters the pressure rod through a percolation hose. The leachate exits from the circumference of the pressure rod and enters the microplastics below the pressure plate through percolation holes on the pressure plate for reaction. Preheating the leachate improves the stability of the cylinder's internal temperature. Using the pressure rod as a spray nozzle eliminates the need for a separate spray nozzle. The outlet holes on the circumference of the pressure rod ensure more uniform percolation of the leachate, resulting in better experimental results.

[0019] Further defining the spray assembly, it includes a spray liquid tank, a spray liquid pump, a spray pipe, and a nozzle. The spray liquid tank and the spray liquid pump are also fixedly mounted on the lower plate. The water inlet of the spray liquid pump is connected to the inside of the spray liquid tank. The bottom end of the spray pipe is fixedly connected to the water outlet of the spray liquid pump, and the top end is fixedly connected to the nozzle through a pipe joint. The nozzle is fixedly embedded in the cylinder cover to spray water into the inside of the cylinder. The spray water inside the cylinder simulates rainy weather by spraying water through the nozzle. The spray water also enters the microplastic below the pressure plate through the permeation holes on the pressure plate. The structure is simple and easy to manufacture.

[0020] Further defining the sampling and monitoring components, the components include a controller, a gas sampling head, a multi-parameter sensor, and a gas analysis unit. The gas sampling head is embedded in the cylinder cover, and the gas sampling head and the gas analysis unit are connected by signal. The multi-parameter sensor is located on the return pipe and integrates temperature, pH, conductivity, and ORP functions. Both the multi-parameter sensor and the gas analysis unit are electrically connected to the controller.

[0021] This sampling and monitoring component setup facilitates the sampling and analysis of the gas inside the cylinder. It also enables the monitoring of the leachate's temperature, pH value, conductivity, and ORP through multi-parameter sensors, thereby achieving the monitoring of the leachate's chemical properties. Furthermore, the controller makes it easier to view various parameters.

[0022] Furthermore, the cylinder body and the cylinder cover are fixedly connected by a flange; fixing the cylinder body and the cylinder cover by a flange makes the connection more secure.

[0023] Further, the bottom surface of the cylinder is a concave arc surface, and an intercepting net is provided at the connection between the return pipe and the cylinder. This design of the bottom surface of the cylinder facilitates the recovery of leachate, and the intercepting net is used to intercept microplastics and prevent them from entering and clogging the return pipe.

[0024] The beneficial effects of this invention are as follows: by setting the covering pressure component with a tension spring structure, the adjustment range of the covering pressure is larger, and by setting the temperature control component to preheat the leachate, it is more conducive to maintaining the optimal temperature environment inside the cylinder, reducing temperature fluctuations when the leachate enters, and improving experimental efficiency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the internal structure of the present invention from a frontal view. Figure 2 This is a top view of the pressure plate; Figure 3 This is a top view of the top plate; Figure 4 This is a connection diagram of the sampling and monitoring components.

[0026] The symbols for each component are as follows: 1. Reaction cylinder, 11. Cylinder body, 12. Cylinder cover, 13. Sampling port, 14. Flange, 2. Base, 21. Upper plate, 22. Lower plate, 23. Upright rod, 3. Overlapping assembly, 3. Pressure plate, 31. Percolation hole, 311. Pressure rod, 32. Liquid passage hole, 321. Liquid outlet hole, 322. Top plate, 33. Fastening ring, 34. Overlapping tension spring, 35. Temperature control assembly, 4. Outer cylinder, 41. Water inlet pipe, 42. Water outlet pipe, 43. Percolation assembly, 5. Percolate tank, 51. Percolate pump, 52. Percolate pipe, 53. Preheating pipe, 54. Percolate hose, 55. Return pipe, 56. Spray assembly, 6. Spray tank, 61. Spray pump, 62. Spray pipe, 63. Nozzle, 64. Sampling and monitoring assembly, 7. Controller, 71. Gas sampling head, 72. Multi-parameter sensor, 73. Gas analysis unit, 74. Detailed Implementation

[0027] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0028] Example: like Figures 1-4As shown, a simulation device for the aging and degradation behavior of microplastics in a landfill environment includes a reaction cylinder 1, a base 2, a pressure covering component 3, a temperature control component 4, a percolation component 5, a spraying component 6, and a sampling and monitoring component 7. The reaction cylinder 1 includes a cylinder body 11 and a cylinder cover 12 that encloses the cylinder body 11. The cylinder body 11 and the cylinder cover 12 are fixedly connected by a flange 14. The cylinder body 11 is vertically mounted on the base 2. The cylinder body 11 is used to provide a simulated space for the aging and degradation of microplastics. Several sampling ports 13 are vertically spaced at the bottom of the cylinder body 11. The base 2 includes an upper plate 21, a lower plate 22 and a vertical rod 23. The bottom end of the cylinder body 11 is fixedly connected to the upper plate 21. Both the upper plate 21 and the lower plate 22 are rectangular plates. The vertical rod 23 is located at the four corners of the upper plate 21 and the lower plate 22, and its two ends are respectively connected to the upper plate 21 and the lower plate 22. The covering pressure assembly 3 achieves the covering pressure on the microplastic through the tension spring structure, and the covering pressure is adjusted by increasing or decreasing the number and type of tension spring structure; the covering pressure assembly 3 includes a pressure plate 31, a pressure rod 32, a top plate 33, a fastening ring 34, and a covering pressure tension spring 35; the pressure plate 31 is slidably disposed inside the cylinder 11, the bottom end of the pressure rod 32 is fixedly connected to the pressure plate 31, and the top end passes through the cylinder cover 12 and is connected to the top plate 33. The pressure rod 32 and the cylinder cover 12 are sealed and slidably connected. The top plate 33 is also a circular plate. The fastening ring 34 is correspondingly disposed on the edge of the cylinder cover 12 and the circumference of the top plate 33. Multiple fastening rings 34 are provided on the cylinder cover 12 and the top plate 33 along their respective circumferential directions. The two ends of the covering pressure tension spring 35 are hooked onto the fastening rings 34 on the cylinder cover 12 and the top plate 33, respectively. The temperature control component 4 is used to regulate the temperature inside the cylinder 11. The temperature control component 4 includes an outer cylinder 41, an inlet pipe 42, and an outlet pipe 43. The outer cylinder 41 is wrapped around the cylinder 11 and a gap is left between it and the cylinder 11 to form a partition. The top and bottom ends of the outer cylinder 41 are sealed to the cylinder 11. The inlet pipe 42 is located on the bottom circumference of the outer cylinder 41, and the outlet pipe 43 is located on the top circumference of the outer cylinder 41. The end of the inlet pipe 42 is connected to the outlet end of the external hot water source supply device, and the end of the outlet pipe 43 is connected to the inlet end of the external hot water source supply device. The cylinder 11 is made of a heat-conducting material. The percolation assembly 5, after being preheated by the temperature control assembly 4, delivers the percolate to the reaction cylinder 1. The percolation assembly 5 includes a percolate tank 51, a percolate pump 52, a percolate pipe 53, a preheating pipe 54, a percolate hose 55, and a return pipe 56. The percolate tank 51 and the percolate pump 52 are both fixedly mounted on the lower plate 22. The inlet end of the percolate pump 52 is connected to the inside of the percolate pipe 53. The percolate pipe 53 is a two-section design. The preheating pipe 54 is connected between the two sections of the percolate pipe 53 and is sleeved outside the outlet pipe 43. The outlet pipe 43 is made of a heat-conducting material. The bottom end of the percolate pipe 53 at the bottom of the preheating pipe 54 is fixedly connected to the percolate. The outlet end of pump 52 and the top end of percolate pipe 53 at the top of preheating pipe 54 are connected to the inlet end of percolate hose 55 through pipe joints. A liquid passage hole 321 is opened on the top plate 33, which extends into the inside of pressure rod 32. Several outlet holes 322 communicating with liquid passage hole 321 are opened circumferentially on the lower part of pressure rod 32. Several through percolate holes 311 are opened vertically on pressure plate 31. The bottom end of return pipe 56 is fixedly connected to the top of percolate pipe 53, and the top end passes through lower plate 22 and communicates with the inside of cylinder 11. The bottom surface of cylinder 11 is a concave arc surface in the middle. An interception net is provided at the connection between return pipe 56 and cylinder 11. The spray assembly 6 is used to spray water inside the cylinder 11 to simulate rainy weather. The spray assembly 6 includes a spray liquid tank 61, a spray liquid pump 62, a spray pipe 63, and a nozzle 64. The spray liquid tank 61 and the spray liquid pump 62 are also fixedly mounted on the lower plate 22. The water inlet end of the spray liquid pump 62 is connected to the inside of the spray liquid tank 61. The bottom end of the spray pipe 63 is fixedly connected to the water outlet end of the spray liquid pump 62, and the top end is fixedly connected to the nozzle 64 through a pipe joint. The nozzle 64 is fixedly embedded in the cylinder cover 12 to spray water inside the cylinder 11. The sampling and monitoring component 7 is used to monitor and analyze the gas composition, temperature, and chemical properties of the leachate inside the cylinder 11. The sampling and monitoring component 7 includes a controller 71, a gas sampling head 72, a multi-parameter sensor 73, and a gas analysis unit 74. The gas sampling head 72 is embedded in the cylinder cover 12 and is signal-connected to the gas analysis unit 74. The multi-parameter sensor 73 is located on the return pipe 56 and integrates temperature, pH, conductivity, and ORP functions. Both the multi-parameter sensor 73 and the gas analysis unit 74 are electrically connected to the controller 71.

[0029] In this application, the controller 71 is a PLC controller 71 or an industrial computer, and the gas analysis unit 74 is a portable gas chromatograph.

[0030] By setting up a tension spring structure to provide the covering pressure of the microplastic to the covering assembly 3, the covering pressure of the covering assembly 3 on the microplastic can be adjusted by changing the type and number of tension spring structures. Various spring stiffness coefficients are available, making replacement and adjustment more convenient, with less limitation on the covering pressure and a wider upper and lower limit. Furthermore, by placing the percolation assembly 5 on the temperature control assembly 4, the percolation liquid is preheated by the temperature control assembly 4 before being transported into the cylinder 11 for reaction, which improves experimental efficiency and helps maintain a stable temperature inside the cylinder 11. This arrangement of the base 2 allows for space between the upper plate 21 and the lower plate 22, providing an installation position for the spray assembly 6 and the percolation assembly 5. This arrangement of the covering assembly 3, by hooking the two ends of the covering spring to the top plate 33 and the cylinder... The snap ring 34 on the cover 12 pulls down the top plate 33, thereby pressing down the pressure plate 31. By appropriately selecting a pressure spring 35 with a suitable stiffness coefficient, sufficient pressure can be effectively provided. The pressure spring and snap ring 34 are hooked together, making replacement convenient. The temperature control component 4 is configured such that hot water is introduced into the partition through the inlet pipe 42 and from the bottom of the cylinder 11. After the partition is filled with hot water, it is discharged from the outlet pipe 43 at the top, thus heating the cylinder 11 to reach the landfill temperature. Since the temperature requirements in the landfill environment are not high, mostly in the tens of degrees Celsius, this heating method can easily achieve the required temperature. The structure is simple and easy to manufacture. A preheating pipe 54 is also installed, and leachate flows from the leachate tank 51... The leachate is drawn out by the percolate pump 52 and enters the preheating tube 54, while the outlet pipe 43 discharges the hot water that has been heated by the cylinder 11. As the hot water flows through the preheating tube 54, it transfers heat to the tube, thus preheating the percolate. The preheated percolate then enters the pressure rod 32 through the percolation hose 55. The percolate is discharged from the circumference of the pressure rod 32 and enters the microplastic below the pressure plate 31 through the percolation holes 311 on the pressure plate 31 for reaction. Preheating the percolate improves the stability of the internal temperature of the cylinder 11. Using the pressure rod 32 as a spray nozzle eliminates the need for a separate spray nozzle. The outlet holes 322 on the circumference of the pressure rod 32 ensure more uniform percolation of the percolate, resulting in better experimental results. The head 64 sprays water inside the cylinder 11 to simulate rainy weather. The sprayed water also enters the microplastic below the pressure plate 31 through the percolation holes 311 on the pressure plate 31. The structure is simple and easy to manufacture. This setting of the sampling and monitoring component 7 facilitates the sampling and analysis of the gas inside the cylinder 11. It can also monitor the temperature, pH value, conductivity and ORP of the leachate through the multi-parameter sensor 73, thereby realizing the monitoring of the chemical properties of the leachate. The setting of the controller 71 makes it easier to view various parameters. The flange 14 fixes the cylinder 11 and the cylinder cover 12 for a more stable connection. This setting of the bottom surface of the cylinder 11 facilitates the recovery of leachate. The interception net is set to intercept microplastics and prevent microplastics from entering and clogging the return pipe 56.

Claims

1. A device for simulating the aging and degradation behavior of microplastics in a landfill environment, characterized in that, include: The reaction cylinder (1) includes a cylinder body (11) and a cylinder cover (12) that closes the cylinder body (11). The cylinder body (11) is vertically mounted on the base (2). The cylinder body (11) is used to provide a simulated space for microplastic aging and degradation. Several sampling ports (13) are vertically spaced at the bottom of the cylinder body (11). The covering component (3) is slidably disposed inside the reaction cylinder (1) and achieves the covering pressure on the microplastics through the tension spring structure. The covering pressure can be adjusted by increasing or decreasing the number and type of tension spring structures. Temperature control component (4) is provided on the cylinder (11) to regulate the temperature inside the cylinder (11); The percolation assembly (5) is located inside the base (2) and on the temperature control assembly (4). After being preheated by the temperature control assembly (4), the percolation liquid is transported to the reaction cylinder (1). The spray assembly (6) is also located inside the base (2) and sprays water into the cylinder (11) to simulate rainy weather. The sampling and monitoring component (7) is provided on the cylinder cover (12), the cylinder body (11) and the percolation component (5). The sampling and monitoring component (7) is used to monitor and analyze the gas composition inside the cylinder body (11), the temperature inside the cylinder body (11) and the chemical properties of the percolate.

2. The simulation device for microplastic aging and degradation behavior in a landfill environment according to claim 1, characterized in that, The base (2) includes an upper plate (21), a lower plate (22) and a vertical rod (23); the bottom end of the cylinder (11) is fixedly connected to the upper plate (21). The upper plate (21) and the lower plate (22) are both rectangular plates. The vertical rod (23) is located at the four corners of the upper plate (21) and the lower plate (22) and its two ends are respectively connected to the upper plate (21) and the lower plate (22).

3. The device for simulating the aging and degradation behavior of microplastics in a landfill environment according to claim 2, characterized in that, The pressure assembly (3) includes a pressure plate (31), a pressure rod (32), a top plate (33), a fastening ring (34), and a pressure spring (35). The pressure plate (31) is slidably disposed inside the cylinder (11). The bottom end of the pressure rod (32) is fixedly connected to the pressure plate (31), and the top end passes through the cylinder cover (12) and is connected to the top plate (33). The pressure rod (32) and the cylinder cover (12) are sealed and slidably connected. The top plate (33) is also a circular plate. The fastening ring (34) is correspondingly disposed on the edge of the cylinder cover (12) and the circumferential surface of the top plate (33). The fastening rings (34) on the cylinder cover (12) and the top plate (33) are provided in multiple directions along their respective circumferential directions. The two ends of the pressure spring (35) are hooked onto the fastening rings (34) on the cylinder cover (12) and the top plate (33), respectively.

4. The device for simulating the aging and degradation behavior of microplastics in a landfill environment according to claim 3, characterized in that, The temperature control component (4) includes an outer cylinder (41), an inlet pipe (42), and an outlet pipe (43). The outer cylinder (41) covers the outside of the cylinder body (11) and leaves a gap between it and the cylinder body (11) to form a partition. The top and bottom ends of the outer cylinder (41) are closed to the cylinder body (11). The inlet pipe (42) is located on the bottom circumference of the outer cylinder (41), and the outlet pipe (43) is located on the top circumference of the outer cylinder (41). The end of the inlet pipe (42) is connected to the outlet end of an external hot water source supply device, and the end of the outlet pipe (43) is connected to the inlet end of an external hot water source supply device. The cylinder body (11) is made of a heat-conducting material.

5. The device for simulating the aging and degradation behavior of microplastics in a landfill environment according to claim 4, characterized in that, The percolation assembly (5) includes a percolate tank (51), a percolate pump (52), a percolate pipe (53), a preheating pipe (54), a percolation hose (55), and a return pipe (56). The leachate tank (51) and the leachate pump (52) are both fixedly mounted on the lower plate (22). The inlet end of the leachate pump (52) is connected to the inside of the leachate pipe (53). The leachate pipe (53) is a two-section structure. The preheating pipe (54) is connected between the two sections of the leachate pipe (53) and is sleeved outside the outlet pipe (43). The outlet pipe (43) is made of a heat-conducting material. The bottom end of the leachate pipe (53) at the bottom of the preheating pipe (54) is fixedly connected to the outlet end of the leachate pump (52). The top end of the preheating pipe (54) is fixedly connected to the outlet end of the leachate pump (52). The top end of the leachate pipe (53) is connected to the inlet end of the leachate hose (55) through a pipe joint. The top plate (33) has a liquid passage hole (321) that extends into the inside of the pressure rod (32). The lower part of the pressure rod (32) has several outlet holes (322) that communicate with the liquid passage hole (321) in a circumferential manner. The pressure plate (31) has several vertically extending leachate holes (311). The bottom end of the return pipe (56) is fixedly connected to the top of the leachate pipe (53), and the top end passes through the lower plate (22) and communicates with the inside of the cylinder (11).

6. The simulation device for microplastic aging and degradation behavior in a landfill environment according to claim 5, characterized in that, The spray assembly (6) includes a spray liquid tank (61), a spray liquid pump (62), a spray pipe (63), and a nozzle (64). The spray liquid tank (61) and the spray liquid pump (62) are also fixedly mounted on the lower plate (22). The water inlet of the spray liquid pump (62) is connected to the inside of the spray liquid tank (61). The bottom end of the spray pipe (63) is fixedly connected to the water outlet of the spray liquid pump (62), and the top end is fixedly connected to the nozzle (64) through a pipe joint. The nozzle (64) is fixedly embedded in the cylinder cover (12) to spray the inside of the cylinder (11).

7. The device for simulating the aging and degradation behavior of microplastics in a landfill environment according to claim 6, characterized in that, The sampling and monitoring component (7) includes a controller (71), a gas sampling head (72), a multi-parameter sensor (73), and a gas analysis unit (74). The gas sampling head (72) is embedded in the cylinder cover (12), and the gas sampling head (72) and the gas analysis unit (74) are connected by a signal. The multi-parameter sensor (73) is located on the return pipe (56). The multi-parameter sensor (73) integrates temperature, pH value, conductivity, and ORP functions. The multi-parameter sensor (73) and the gas analysis unit (74) are both electrically connected to the controller (71).

8. The simulation device for microplastic aging and degradation behavior in a landfill environment according to claim 1, characterized in that, The cylinder (11) and the cylinder cover (12) are fixedly connected by a flange (14).

9. The device for simulating the aging and degradation behavior of microplastics in a landfill environment according to claim 5, characterized in that, The bottom surface of the cylinder (11) is a concave arc surface, and an interception net is provided at the connection between the return pipe (56) and the cylinder (11).

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