Experimental system and experimental method for simulating microplastic generation rule in landfill environment

Abstract

The invention discloses an experimental system and an experimental method for simulating a microplastic generation rule in a landfill environment, and relates to the field of plastic degradation test equipment. When a plastic degradation test is carried out through the reactor, pressure can be applied to a sample through the pressure plate to simulate an overlying load of the landfill, and the temperature of the landfill is simulated by regulating and controlling the temperature of the reactor and the sample in the reactor through the temperature regulating and controlling mechanism; the percolate supply mechanism sprays percolate into the reactor to simulate the flowing of the percolate in the landfill, and meanwhile, the airflow regulation and control system aerates the sample to simulate the airflow load in the landfill, so that the plastic waste can be detected by simulating the coupling effect of various environmental factors on the plastic waste in the landfill. The complete degradation process of the plastic waste in the refuse landfill is accurately simulated, so that the test precision is improved, and accurate data support is provided for researching a micro-plastic generation mechanism in the landfill.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of plastic degradation test equipment, and particularly relates to an experimental system and an experimental method for simulating microplastic generation law in a landfill environment. BACKGROUND

[0002] Plastic waste in the landfill will be degraded to produce microplastics under the action of various environmental factors. Microplastics can greatly increase the concentration of environmental pollution, adsorb heavy metals and organic pollutants, and once they enter the food chain, they will pose a threat to biological health and ecosystem safety. Therefore, studying the generation process of microplastics is of great importance to environmental protection and public safety.

[0003] Plastic waste in the landfill environment will not only be affected by temperature and pressure from surrounding garbage, but also be affected by corrosion of liquid such as sulfuric acid salt, and fluctuating load caused by gas flow generated by garbage decomposition. However, the existing same type of device does not fully consider the high temperature, load (creep effect), leachate corrosion, and fluctuating load caused by gas flow in the landfill. Most of them focus on a single physical and chemical process, but this separation state cannot reflect the real environment of multi-field coupling in the landfill, resulting in deviation in the study of microplastic generation law.

[0004] The main purpose of the present application is to fill the gap in the existing device for studying the generation mechanism of microplastics in multi-field coupling. The present application provides a device that accurately simulates the complete degradation process of plastic waste in the landfill through the synergistic effect of multi-field coupling, and studies the generation law of microplastics through sampling and detection. SUMMARY

[0005] In view of the problems in the related art, the present application provides an experimental system and an experimental method for simulating microplastic generation law in a landfill environment to overcome the above technical problems existing in the prior art.

[0006] To solve the above technical problems, the present application is realized by the following technical scheme: The present application is an experimental system for simulating microplastic generation law in a landfill environment, which comprises a support and a reactor installed on the support. The reactor is filled with soil samples and plastic garbage. A temperature control mechanism is installed outside the reactor, which can control the temperature inside the reactor. A pressure control mechanism is provided at the top of the support. The pressure control mechanism comprises a pressure adjusting assembly, a pressure rod and a pressure plate. The pressure plate is arranged on the top surface of the soil sample in the reactor, and the pressure plate is connected with the pressure adjusting assembly through the pressure rod, so that the pressure adjusting assembly can exert pressure on the soil sample through the pressure rod and the pressure plate. The support is also provided with a leachate supply mechanism and an airflow regulating system, the leachate supply mechanism can spray and deliver leachate in the reactor, and the airflow regulating system can aerate the bottom end of the reactor; The outer wall of the reactor is also provided with an open-close type sampling port.

[0007] Further, the sampling port is provided with a plurality of sampling ports arranged vertically on the outer wall of the reactor, and the outer end of the sampling port is provided with a sealing cover.

[0008] Further, the temperature regulating mechanism comprises an outer thermal insulation cover, which is installed on the outer ring of the reactor and forms a temperature regulating chamber on the outer surface of the reactor, the outer thermal insulation cover is provided with an inlet and an outlet which are in communication with the temperature regulating chamber, and the inlet and the outlet are in communication with the external temperature control equipment.

[0009] Further, the pressure regulating assembly comprises a top seat, which is fixedly installed on the top end of the support, the top surface of the top seat is provided with a sliding groove, a sliding seat is slidably installed in the sliding groove, a plurality of connecting rings are fixedly installed on the sliding seat, and a plurality of guide wheels corresponding to the connecting rings are installed on the bottom end of the top seat. The connecting ring is connected with a lifting rope, the lifting rope extends downward after being guided and limited by the corresponding guide wheel, and the bottom end of the lifting rope is fixedly connected with a connecting column, the bottom end of the connecting column is fixedly installed with a bottom disc, and the top end of the bottom disc is placed with a counterweight disc.

[0010] Further, the leachate supply mechanism comprises a leachate barrel, which is arranged below the reactor, a hydraulic circulating pump is connected and installed at the outlet end of the leachate barrel, a liquid supply conduit is connected and installed at the outlet end of the hydraulic circulating pump, the top end of the liquid supply conduit extends to the upper end of the reactor, and a liquid distribution ring pipe is also installed at the upper end of the reactor and in communication with the liquid supply conduit, a plurality of spray heads are installed at the bottom end of the liquid distribution ring pipe, and a liquid discharge conduit is installed at the bottom end of the reactor and in communication with the leachate barrel.

[0011] Further, the liquid discharge conduit is connected and installed with a flow regulating valve and a sampling pipe, and the sampling pipe is provided with a shut-off valve.

[0012] Further, the air flow regulation system comprises an air pressure balance tank, an air return pipe and an air supply pipe are connected to the air inlet and outlet of the air pressure balance tank respectively, one end of the air supply pipe is communicated with the lower end of the reactor, and an air pressure circulation pump is connected to the air supply pipe, a gravel layer is laid in the lower end of the reactor, one end of the air return pipe is communicated with the upper end of the reactor, an air pressure balance assembly is installed in the air pressure balance tank, and the air pressure balance assembly can adjust the size of the gas chamber in the air pressure balance tank according to the air pressure in the air pressure balance tank, so that the air pressure balance tank is in a constant pressure state.

[0013] Further, the air pressure balance assembly comprises a piston and a threaded sleeve, the piston is sealingly and slidingly installed in the air pressure balance tank to isolate the end of the air pressure balance tank communicated with the air return pipe to form a sealed chamber, and a pressure balance spring is installed at the end of the piston opposite to the sealed chamber; The threaded sleeve is fixedly installed at the end of the air pressure balance tank opposite to the sealed chamber, an adjusting bolt is threadedly installed in the threaded sleeve, and a pressure adjusting plate is rotatably installed at one end of the adjusting bolt.

[0014] Further, an air pressure gauge and a pressure relief valve are connected to the air return pipe.

[0015] The application further discloses an experimental method for simulating the generation rule of microplastics in a landfill environment, and the specific steps are as follows: First, the waste soil and plastic waste are sampled in the landfill, and then the samples are filled into the reactor, and then the pressure adjusting assembly applies pressure to the pressure plate through the pressure rod to apply pressure to the samples by the pressure plate, so as to simulate the overburden load in the landfill; at the same time, the temperature of the reactor and the samples in the reactor is adjusted by the temperature adjusting mechanism to simulate the temperature of the landfill; then the leachate supply mechanism sprays leachate into the reactor, so that the leachate seeps downward along the samples to simulate the flow of leachate in the landfill, and at the same time, the air flow regulation system aerates the samples to simulate the air flow load in the landfill; finally, the sampling port is opened regularly to sample and detect the samples in the reactor to detect the content of microplastics in the samples.

[0016] The application has the following beneficial effects: 1. The present application can simulate the overburden load on the landfill by applying pressure to the sample through the pressure plate, simulate the temperature of the landfill by adjusting the temperature of the reactor and the sample inside the reactor through the temperature adjustment mechanism, simulate the flow of leachate in the landfill by spraying leachate into the reactor through the leachate supply mechanism, and simulate the gas flow load in the landfill by aeration into the sample through the gas flow control system, so as to simulate the complete degradation process of plastic waste in the landfill by simulating the coupling of various environmental factors on plastic waste in the landfill, thereby improving the test accuracy and providing accurate data support for studying the mechanism of microplastic generation in the landfill.

[0017] 2. The pressure adjusting assembly in the present application adjusts the pressure of the pressure plate and the sample in the reactor by cooperating with the lifting rope and the counterweight disc, and when the sample in the reactor settles due to degradation, the lifting rope, the counterweight disc, the pressure rod and the pressure plate can be lowered synchronously, so that the sample in the reactor can always be subjected to constant overburden load without the need for manual adjustment of the pressure adjusting assembly when the sample degrades and settles, thereby making the overburden load simulation process more convenient and simple.

[0018] 3. The leachate supply mechanism and the gas flow control system in the present application can realize the circulation of leachate and gas flow, which not only reduces the loss of leachate and the cost of the test, but also prevents the leakage of toxic waste gas generated during the test process by sealing circulation, thereby improving the safety of the test.

[0019] 4. The gas pressure balancing assembly is installed in the inner part of the gas pressure balancing tank in the present application, and the gas pressure balancing assembly can adjust the size of the gas chamber in the gas pressure balancing tank according to the gas pressure in the gas pressure balancing tank, so that the gas pressure balancing tank is in a constant pressure state, thereby improving the stability of the gas flow in the gas flow control system and the sample, which is beneficial to improve the accuracy of the plastic degradation test; and as the test proceeds, the sample in the reactor will gradually degrade to generate gas, so that the overall gas pressure in the reactor and the gas flow control system gradually increases, at which time the gas chamber in the gas pressure balancing tank synchronously increases, thereby adjusting and reducing the overall gas pressure in the reactor and the gas flow control system, so that the gas pressure is kept in a nearly constant pressure state, thereby improving the stability of the gas pressure in the reactor and the gas flow control system, and further improving the accuracy of the plastic degradation test.

[0020] Of course, any product implementing the present application does not necessarily need to achieve all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0022] Figure 1 It is a schematic diagram of the stereoscopic structure of the experimental system for simulating the generation rule of microplastics in landfill environment according to the present application; Figure 2 It is a schematic diagram of the stereoscopic structure of the experimental system for simulating the generation rule of microplastics in landfill environment according to the present application; Figure 1 It is a schematic diagram of the local enlarged structure at A of the present application; Figure 3 It is a schematic diagram of the stereoscopic structure of the experimental system for simulating the generation rule of microplastics in landfill environment according to the present application; Figure 4 It is a schematic diagram of the local enlarged structure at B of the present application; Figure 3 Figure 5 It is a schematic diagram of the front structure of the experimental system for simulating the generation rule of microplastics in landfill environment according to the present application; Figure 6 It is a schematic diagram of the local enlarged structure at C of the present application; Figure 5 Figure 7 It is a schematic diagram of the stereoscopic structure of the experimental system for simulating the generation rule of microplastics in landfill environment according to the present application; Figure 8 It is a schematic diagram of the stereoscopic structure of the experimental system for simulating the generation rule of microplastics in landfill environment according to the present application; Figure 9 It is a schematic diagram of the local enlarged structure at D of the present application. Figure 8

[0023] ​​​In the figure: 1, support; 2, reactor; 21, sampling port; 22, sealing cover; 3, temperature regulating mechanism; 31, liquid inlet; 32, liquid outlet; 33, external insulation cover; 34, temperature regulating chamber; 4, pressure regulating mechanism; 41, hanging rope; 42, base plate; 43, connecting column; 44, counterweight plate; 45, pressure rod; 46, top seat; 47, sliding groove; 48, sliding seat; 49, connecting ring; 410, guide wheel; 411, pressure plate; 5, leachate supply mechanism; 51, leachate barrel; 52, hydraulic circulating pump; 53, liquid supply conduit; 54, liquid discharge conduit; 55, flow regulating valve; 56, sampling tube; 57, shut-off valve; 58, liquid distribution ring pipe; 6, airflow regulating system; 61, air pressure balance tank; 62, air return conduit; 63, air supply conduit; 64, air pressure circulating pump; 65, air pressure gauge; 66, pressure relief valve; 67, gravel layer; 68, piston; 69, pressure balance spring; 610, pressure regulating plate; 611, threaded sleeve; 612, adjusting bolt. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0025] In the description of the application, it should be understood that the terms "opening", "upper", "lower", "top", "middle", "inner" and the like indicate the orientation or positional relationship, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply that the referred component or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application.

[0026] Embodiment one

[0027] Please refer to Figure 1 , Figure 2 , Figure 7As shown, the application is an experimental system for simulating the generation rule of microplastics in landfill environment, which comprises a support 1 and a reactor 2 installed on the support 1, the reactor 2 is filled with soil samples and plastic garbage, a temperature control mechanism 3 is installed outside the reactor 2, the temperature control mechanism 3 can control the temperature inside the reactor 2; a pressure control mechanism 4 is arranged at the top of the support 1, the pressure control mechanism 4 comprises a pressure adjusting assembly, a pressure rod 45 and a pressure plate 411, the pressure plate 411 is arranged on the top surface of the soil sample inside the reactor 2, and the pressure plate 411 is connected with the pressure adjusting assembly through the pressure rod 45, so that the pressure adjusting assembly can exert pressure on the soil sample through the pressure rod 45 and the pressure plate 411; a leachate supply mechanism 5 and an airflow control system 6 are also installed on the support 1, the leachate supply mechanism 5 can spray and deliver leachate in the reactor 2, and the airflow control system 6 can aerate the bottom end inside the reactor 2; an open-close sampling port 21 is also arranged on the outer wall of the reactor 2.

[0028] During the test, first, the garbage soil and plastic garbage are sampled in the landfill, then the samples are filled into the reactor 2, then the pressure adjusting assembly exerts pressure on the pressure plate 411 through the pressure rod 45, so that the pressure plate 411 exerts pressure on the top end of the sample, simulating the overburden load on the landfill; at the same time, the temperature of the reactor 2 and the sample inside the reactor 2 is controlled by the temperature control mechanism 3, to simulate the temperature of the landfill; then the leachate supply mechanism 5 sprays leachate into the reactor 2, so that the leachate seeps downward along the sample, simulating the flow of leachate in the landfill, at the same time, the sample is aerated by the airflow control system 6, to simulate the airflow load in the landfill; finally, the sampling port 21 is opened regularly to sample and detect the sample in the reactor 2, to detect the content of microplastics in the sample; Wherein, the pressure exerted on the sample by the pressure plate 411 simulates the overburden load on the landfill, the temperature control mechanism 3 controls the temperature of the sample to simulate the temperature of the landfill, the leachate supply mechanism 5 sprays leachate into the reactor 2 to simulate the flow of leachate in the landfill, at the same time, the airflow control system 6 aerates the sample to simulate the airflow load in the landfill, so that the complete degradation process of plastic waste in the landfill can be accurately simulated by simulating the coupling effect of multiple environmental factors on plastic waste in the landfill, thereby improving the test precision and providing accurate data support for studying the generation mechanism of microplastics in the landfill.

[0029] Further, the inside of the reactor 2 is provided with a pressure sensor, a temperature sensor, an air pressure sensor and a liquid level sensor, to monitor the pressure, temperature, interstitial air pressure and leachate level of the sample inside the reactor 2, and the temperature control mechanism 3, the pressure control mechanism 4, the leachate supply mechanism 5 and the airflow control system 6 simulate and control the parameters in the reactor 2.

[0030] Example two

[0031] Please refer to Figure 1 As shown in the figure, the difference between this embodiment and the above-mentioned embodiments is that a plurality of sampling ports 21 are arranged on the outer wall of the reactor 2 in up-down arrangement, and a sealing cover 22 is installed on the outer end of each sampling port 21. By arranging a plurality of sampling ports 21 in up-down arrangement, when sampling, the sampler can be inserted into the sample at different depths in the reactor 2 for layered sampling detection, thereby improving the sampling detection accuracy. By installing the sealing cover 22 on the sampling port 21, the sampling port 21 can be sealed during the test to prevent the leachate and gas from leaking from the sampling port 21.

[0032] Embodiment three

[0033] Please refer to Figure 1 , Figure 7 As shown in the figure, the difference between this embodiment and the above-mentioned embodiments is that the temperature control mechanism 3 includes an outer thermal insulation cover 33, which is installed around the reactor 2 and forms a temperature control chamber 34 on the outer surface of the reactor 2. The outer thermal insulation cover 33 is installed with a liquid inlet 31 and a liquid outlet 32 which are in communication with the temperature control chamber 34, and the liquid inlet 31 and the liquid outlet 32 are in communication with the external temperature control equipment.

[0034] The external temperature control equipment is a water heater, which heats the water, and then drives the hot water to circulate in the temperature control chamber 34 through the liquid inlet 31 and the liquid outlet 32, thereby performing water bath heating on the reactor 2, and further performing temperature control on the sample in the reactor 2 to simulate the temperature of the landfill.

[0035] Embodiment four

[0036] Please refer to Figure 1 , Figure 2 , Figure 7 As shown in the figure, the difference between this embodiment and the above-mentioned embodiments is that the pressure regulating assembly includes a top seat 46 fixedly installed at the top end of the support 1, the top surface of the top seat 46 is provided with a sliding groove 47, a sliding seat 48 is slidingly installed in the sliding groove 47, a plurality of connecting rings 49 are fixedly installed on the sliding seat 48, and a plurality of guide wheels 410 corresponding to the connecting rings 49 are installed on the bottom end of the top seat 46; the connecting rings 49 are tied with a lifting rope 41, the lifting rope 41 extends downward after being guided and limited by the corresponding guide wheels 410, and the bottom end of the lifting rope 41 is fixedly connected with a connecting column 43, the bottom end of the connecting column 43 is fixedly installed with a bottom disc 42, and the top end of the bottom disc 42 is placed with a counterweight disc 44. When the pressure is regulated, the same weight of the weight plate 44 is placed on each base plate 42, and then the weight plate 44 exerts a downward pulling force on the sliding seat 48 through the lifting rope 41, so that the sliding seat 48 exerts a downward pressure on the pressure plate 411 through the pressure rod 45, and then the pressure plate 411 is pressed against the top end of the sample inside the reactor 2, the top end of the sample is pressed down, the overburden is simulated, and by adjusting the weight of the weight plate 44, the downward pressure of the pressure plate 411 can be adjusted, so that different sizes of overburden can be simulated. When the sample degrades and sinks, the sliding seat 48 can move downward along the sliding groove 47 under the action of the gravity of the weight plate 44, so that the pressure plate 411 is always pressed on the top surface of the sample, so that the sample in the reactor 2 can always be subjected to a constant overburden, and the overburden simulation process is more convenient and simple without manual adjustment of the pressure regulating assembly when the sample degrades and settles.

[0037] Further, the pressure plate 411 is provided with uniformly distributed through holes for the percolate and airflow to pass through, so that the flow and transportation of the percolate and airflow in the reactor 2 are facilitated.

[0038] Example Five

[0039] Please refer to Figure 1 , Figures 3-7 , the difference between the present embodiment and the above-mentioned embodiments is that the percolate supply mechanism 5 comprises a percolate barrel 51, the percolate barrel 51 is arranged below the reactor 2, a hydraulic circulating pump 52 is connected and installed at the outlet end of the percolate barrel 51, a liquid supply conduit 53 is connected and installed at the outlet end of the hydraulic circulating pump 52, the top end of the liquid supply conduit 53 extends to the upper end inside the reactor 2, and a liquid distribution ring pipe 58 which communicates with the liquid supply conduit 53 is further installed at the upper end inside the reactor 2, a plurality of spray heads are installed at the bottom end of the liquid distribution ring pipe 58, and a liquid discharge conduit 54 which communicates with the percolate barrel 51 is installed at the bottom end of the reactor 2; a flow regulating valve 55 and a sampling pipe 56 are connected and installed on the liquid discharge conduit 54, and a shut-off valve 57 is installed on the sampling pipe 56; The percolate barrel 51 contains percolate, which can be directly obtained from the landfill or artificially prepared according to the composition of the percolate in the landfill. During the test, the hydraulic circulating pump 52 extracts the percolate in the percolate barrel 51 and delivers it to the liquid distribution ring pipe 58 inside the reactor 2 through the liquid supply conduit 53, and finally the percolate is uniformly sprayed to the top end of the sample inside the reactor 2 by the spray heads at the bottom end of the liquid distribution ring pipe 58, and then the percolate flows downward along the sample gap, thereby simulating the flow of percolate in the landfill. When the percolate flows to the bottom end of the reactor 2, it is returned to the percolate barrel 51 through the liquid discharge conduit 54, so as to realize the recycling use of the percolate. The flow regulating valve 55 can be used to open and close the liquid discharge conduit 54 and adjust the flow, so as to adjust the return speed of the percolate and the liquid level depth of the percolate in the reactor 2, thereby simulating different percolate environments and making the test data more comprehensive and accurate. And when sampling, the intercept valve 57 can be opened to sample the leachate through the sampling pipe 56 to detect the microplastic content in the leachate, which, in combination with the solid sample detection in the reactor 2, can help improve the detection accuracy.

[0040] Example six

[0041] Please refer to Figure 1 、 Figure 3 、 Figure 4 、 Figure 8 、 Figure 9 The difference between this embodiment and the above-mentioned embodiments is that the air flow control system 6 includes an air pressure balance tank 61, the inlet and outlet ends of the air pressure balance tank 61 are respectively connected to the air return pipe 62 and the air supply pipe 63, one end of the air supply pipe 63 is in communication with the lower end inside the reactor 2, and the air supply pipe 63 is connected to the air pressure circulating pump 64, the lower end inside the reactor 2 is also paved with a gravel layer 67, one end of the air return pipe 62 is in communication with the upper end inside the reactor 2, and the air pressure balance assembly is installed inside the air pressure balance tank 61, which can adjust the size of the gas chamber inside the air pressure balance tank 61 according to the air pressure inside the air pressure balance tank 61, so that the air pressure balance tank 61 is in a constant pressure state.

[0042] During the test, the air pressure circulating pump 64 aerates the bottom end of the reactor 2 through the air supply pipe 63, and a waterproof air-permeable membrane is installed at the aeration end of the air supply pipe 63 to prevent the leachate from flowing back through the air supply pipe 63, then the gas flows upward through the gravel layer 67, enters the sample, and continuously flows upward through the sample gap to simulate the gas flow load in the landfill, at the same time, the gas at the upper end inside the reactor 2 is sucked into the air pressure circulating pump 64 through the air return pipe 62 and the air pressure balance tank 61, thereby realizing the circulating flow of the gas, preventing the toxic waste gas generated by degradation in the reactor 2 from being discharged, and at the same time, making the aeration gas flow contain landfill degradation waste gas, which can further improve the environmental simulation effect and improve the test accuracy; And in the process of the test, with the degradation of the sample, the air permeability of the sample will fluctuate, causing the air pressure in the air flow circulation pipeline to fluctuate, affecting the normal work of the air flow regulation and the air pressure circulating pump 64, at this time, the air pressure balance assembly can adjust the size of the gas chamber inside the air pressure balance tank 61 according to the air pressure in the air pressure balance tank 61, so that the air pressure balance tank 61 is in a constant pressure state, thereby improving the stability of the air flow in the air flow circulation pipeline and the sample, which is beneficial to improve the accuracy of the plastic degradation test; and with the test, the sample in the reactor 2 will gradually degrade to produce waste gas, so that the overall air pressure in the reactor 2 and the air flow circulation pipeline gradually increases, at this time the gas chamber inside the air pressure balance tank 61 is increased synchronously, thereby adjusting and reducing the overall air pressure in the reactor 2 and the air flow circulation pipeline, so that the air pressure is kept in a state of nearly constant pressure, thereby improving the air pressure stability in the reactor 2 and the air flow circulation pipeline, further improving the accuracy of the plastic degradation test.

[0043] Further, the air pressure balance assembly includes a piston 68 and a threaded sleeve 611, the piston 68 is sealingly and slidingly installed inside the air pressure balance tank 61 to isolate one end of the air pressure balance tank 61 in communication with the gas return conduit 62 to form a sealed chamber, and the end of the piston 68 opposite to the sealed chamber is abutted and installed with a pressure balance spring 69; Wherein, the piston 68 inside the air pressure balance tank 61 is balanced under the left air pressure and the elastic force of the right pressure balance spring 69, during the air flow circulation conveying process, when the air pressure inside the air pressure balance tank 61 increases, the piston 68 slides to the right under the air pressure, thereby increasing the gas storage space inside the air pressure balance tank 61 to adjust and reduce the air pressure, correspondingly, when the air pressure inside the air pressure balance tank 61 decreases, the piston 68 moves to the left under the elastic force of the pressure balance spring 69, thereby reducing the gas storage space inside the air pressure balance tank 61 to adjust and increase the air pressure.

[0044] Further, the threaded sleeve 611 is fixedly installed on the end of the air pressure balance tank 61 opposite to the sealed chamber, the threaded sleeve 611 is internally threaded with an adjusting bolt 612, one end of the adjusting bolt 612 is rotationally installed with a pressure adjusting plate 610, and the pressure adjusting plate 610 abuts one end of the pressure balance spring 69; Wherein, by rotating the adjusting bolt 612, the adjusting bolt 612 can move left and right along the threaded sleeve 611, thereby adjusting the position of the pressure adjusting plate 610 and the elastic force of the pressure balance spring 69, and further adjusting the air pressure in the air flow circulation pipeline inside the air pressure balance tank 61, so that the test device can perform plastic degradation tests under different air flow loads, making the test data more comprehensive and accurate; Specifically, when the test gas pressure needs to be adjusted to increase, the adjusting screw 612 is rotated to drive the pressure adjusting plate 610 to move left in the gas pressure balance tank 61, at this time, the pressure adjusting plate 610 drives the piston 68 to move left through the pressure balance spring 69, so that the gas storage space in the gas pressure balance tank 61 is reduced and the pressure is increased; correspondingly, when the test gas pressure needs to be adjusted to decrease, the adjusting screw 612 is rotated in the opposite direction to drive the pressure adjusting plate 610 to move right in the gas pressure balance tank 61, at this time, the pressure adjusting plate 610 releases the extrusion of the pressure balance spring 69, so that the elastic force of the pressure balance spring 69 is reduced; then the piston 68 moves right under the action of the gas pressure, so that the gas storage space in the gas pressure balance tank 61 is increased and the pressure is reduced.

[0045] Further, the gas return pipe 62 is connected with the gas pressure gauge 65 and the pressure relief valve 66; with the generation of degradation waste gas, the gas pressure in the gas circulation pipeline will gradually increase, when the gas pressure in the gas return pipe 62 is detected to be too large through the gas pressure gauge 65, the pressure relief valve 66 can be opened to discharge the waste gas, preventing the excessive gas pressure from affecting the normal test, and the pressure relief valve 66 is communicated with the air purifier through a pipe, so that the waste gas can be discharged after being purified, preventing the waste gas from polluting the environment.

[0046] Example Seven

[0047] The embodiment discloses an experimental method for simulating the generation rule of microplastics in a landfill environment, and the specific steps are as follows: First, the waste soil and plastic waste are sampled in the landfill, and then the samples are filled into the reactor 2, and then the pressure adjusting assembly applies pressure to the pressure plate 411 through the pressure rod 45 to apply pressure to the sample by the pressure plate 411, so as to simulate the overburden load on the landfill; at the same time, the temperature of the reactor 2 and the sample in the reactor 2 is adjusted by the temperature adjusting mechanism 3, so as to simulate the temperature of the landfill; then the leachate supply mechanism 5 sprays leachate into the reactor 2, so that the leachate seeps downward along the sample, simulating the flow of leachate in the landfill, and at the same time, the sample is aerated by the gas flow adjusting system 6, so as to simulate the gas flow load in the landfill; finally, the sampling port 21 is opened regularly to sample and detect the sample in the reactor 2, so as to detect the content of microplastics in the sample.

[0048] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the invention. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0049] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments described. Obviously, many modifications and variations can be made in light of the teachings above. The description is chosen and described in order to provide the best illustration of the application principles and their practical application, so that those skilled in the art can well understand and utilize the application.

Claims

1. An experimental system for simulating the formation of microplastics in a landfill environment, comprising a support and a reactor mounted on the support, characterized in that: The reactor is filled with soil samples and plastic waste, and a temperature control mechanism is installed outside the reactor to regulate the internal temperature. The top of the support is provided with a pressure regulation mechanism, which includes a pressure regulating component, a pressure rod and a pressure plate. The pressure plate is located on the top surface of the soil sample inside the reactor, and the pressure plate is connected to the pressure regulating component through the pressure rod, so that the pressure regulating component can apply pressure to the soil sample through the pressure rod and the pressure plate. The support is also equipped with a leachate supply mechanism and an airflow control system. The leachate supply mechanism can spray and deliver leachate inside the reactor, and the airflow control system can aerate the bottom of the reactor. The airflow control system includes a pressure balance tank. The inlet and outlet ends of the pressure balance tank are respectively connected to a return gas pipe and a supply gas pipe. One end of the supply gas pipe is connected to the lower end of the reactor interior, and a pressure circulation pump is connected to the supply gas pipe. One end of the return gas pipe is connected to the upper end of the reactor interior. A pressure balance component is installed inside the pressure balance tank. The pressure balance component can adjust the size of the gas chamber inside the pressure balance tank according to the gas pressure inside the pressure balance tank, so that the pressure balance tank is in a constant pressure state. The pressure balancing assembly includes a piston and a threaded sleeve. The piston is slidably installed inside the pressure balancing tank to isolate the end of the pressure balancing tank that is connected to the return air pipe to form a sealed chamber. A pressure balancing spring is installed on the piston at the end opposite to the sealed chamber. The reactor is also equipped with an openable sampling port on its outer wall.

2. The experimental system for simulating the formation law of microplastics in a landfill environment according to claim 1, characterized in that: The sampling ports are provided in multiple ways, and are arranged vertically on the outer wall of the reactor. Each sampling port is equipped with a sealing cap on its outer end.

3. The experimental system for simulating the formation law of microplastics in a landfill environment according to claim 1, characterized in that: The temperature control mechanism includes an outer heat insulation cover, which is installed around the outer ring of the reactor and forms a temperature control chamber on the outer surface of the reactor. The outer heat insulation cover is equipped with an inlet and an outlet that communicate with the temperature control chamber, and the inlet and outlet are connected to an external temperature control device.

4. The experimental system for simulating the formation law of microplastics in a landfill environment according to claim 1, characterized in that: The pressure regulating assembly includes a top seat, which is fixedly installed on the top of the bracket. The top surface of the top seat is provided with a sliding groove, and a sliding seat is slidably installed in the sliding groove. Multiple connecting rings are fixedly installed on the sliding seat, and multiple guide wheels corresponding to the connecting rings are installed on the bottom edge of the top seat. A sling is attached to the connecting ring. The sling extends downward after being guided and limited by a corresponding guide wheel. A connecting column is fixedly connected to the bottom end of the sling. A base is fixedly installed at the bottom end of the connecting column. A counterweight plate is placed on the top of the base.

5. The experimental system for simulating the formation law of microplastics in a landfill environment according to claim 1, characterized in that: The leachate supply mechanism includes a leachate tank located below the reactor. A hydraulic circulation pump is connected to the outlet end of the leachate tank, and a supply conduit is connected to the outlet end of the hydraulic circulation pump. The top end of the supply conduit extends into the upper part of the reactor, and a distribution ring pipe communicating with the supply conduit is installed at the upper part of the reactor. Multiple nozzles are installed at the bottom end of the distribution ring pipe, and a discharge conduit communicating with the leachate tank is installed at the bottom end of the reactor.

6. The experimental system for simulating the formation law of microplastics in a landfill environment according to claim 5, characterized in that: The drain pipe is connected to a flow regulating valve and a sampling tube, and the sampling tube is equipped with a shut-off valve.

7. The experimental system for simulating the formation law of microplastics in a landfill environment according to claim 1, characterized in that: The lower part of the reactor interior is also lined with a gravel layer.

8. The experimental system for simulating the formation law of microplastics in a landfill environment according to claim 1, characterized in that: The threaded sleeve is fixedly installed on the end of the pressure balance tank opposite to the sealed chamber. An adjusting bolt is installed on the internal thread of the threaded sleeve. A pressure adjusting plate is rotatably installed on one end of the adjusting bolt. The pressure adjusting plate abuts against one end of the pressure balance spring.

9. The experimental system for simulating the formation law of microplastics in a landfill environment according to claim 1, characterized in that: A pressure gauge and a pressure relief valve are connected and installed on the return air duct.

10. An experimental method for simulating the formation of microplastics under a landfill environment, using the experimental system for simulating the formation of microplastics under a landfill environment as described in any one of claims 1-9, characterized in that, The specific steps are as follows: First, samples of soil and plastic waste are taken from the landfill. These samples are then filled into a reactor. A pressure regulating component applies pressure to a pressure plate via a pressure rod, simulating the overburden load in the landfill. Simultaneously, a temperature control mechanism regulates the temperature of the reactor and the samples inside, simulating landfill temperature. Next, a leachate supply mechanism sprays leachate into the reactor, allowing it to seep downwards along the sample, simulating leachate flow in a landfill. An airflow control system aerates the sample, simulating airflow load in a landfill. Finally, the sampling port is periodically opened to collect and test the samples inside the reactor to determine the microplastic content.

Images