A method and device for collecting microplastics in the atmosphere

Abstract

The present invention discloses a method and device for collecting microplastics in the atmosphere. The abundance of microplastics collected by applying this method has a corresponding relationship with the sampling volume of the collected atmosphere, which can more intuitively reflect the true level of the collection area. Microplastics, dust and other particles in the atmosphere are adhered to the front end of the spiral tube of the sampling device. The method is simple, and the collection process will not cause secondary damage to the microplastics, nor will it cause the result deviation due to blocking the plug plate. The collection device adopts bionic technology to simulate the nasal cavity structure of humans, with a simple structure and convenient application.

Description

Technical Field

[0001] The present invention discloses a method and device for collecting microplastics in the atmosphere, which relates to the technical field of ecological environment monitoring, and particularly to a method and device for collecting microplastics in the atmosphere. Background Art

[0002] Microplastics refer to plastic fragments or particles with a diameter less than 5 mm, and the particle size can range from a few micrometers to a few millimeters, with a wide distribution range. Microplastics have various shapes, such as spherical, strip-shaped, fibrous or irregular fragment-shaped, etc., and are not easily distinguishable by the naked eye. The pollution of microplastics themselves to the environment has attracted widespread attention globally. More particularly, due to the large specific surface area and strong hydrophobicity of microplastics, they are prone to enrich hydrophobic pollutants in the environment, and most high-risk pollutants are hydrophobic, such as polychlorinated biphenyls, bisphenol A, etc. Microplastics become carriers carrying pollutants and migrate in nature, continuously enriching hydrophobic pollutants, which pose a hazard to the ecosystem, the healthy growth of animals and plants, and even the human food chain. At present, global scientific researchers have carried out extensive investigations on microplastics in the environment, and have done more work on microplastics in water bodies and soils, while there is less research on microplastics floating in the atmosphere. Currently, the passive collection method is mainly used to collect microplastics in the atmosphere. Since the passive collection method is a passive and indirect collection, it is impossible to avoid the possibility that non-atmospheric microplastics break away from the collector for other reasons. Due to method limitations, the passive collection method is relatively accurate for collecting atmospheric particulate matter with a particle size greater than 2 μm, but has limited ability to collect tiny microplastic particles, so the results obtained by the passive collection method may be far lower than the actual situation, and the abundance of microplastics may be underestimated. Corresponding to the passive collection method is the active collection method. Currently, there are research reports in foreign literature on collecting microplastics in the atmosphere using the active collection method, which uses a particulate matter sampler to actively suck the suspended matter in the atmosphere and filter and enrich the microplastics in the filter. However, during the collection process, microplastics continuously accumulate in the filter, and the filter membrane is prone to clogging, and the data obtained may deviate from the actual situation. To ensure the reliability of the data, this method has requirements for both the filter membrane pore size and the sampling volume.

[0003] There are already several Chinese patents related to the collection of microplastics in the atmosphere, such as CN201910622534.0, a collection method and device for the deposition of atmospheric microplastics at different heights, CN201621411213.4, an automatic collector for collecting microplastics in the atmospheric source, and CN201611186180.2, an automatic collector for collecting microplastics in the atmospheric source. These patents all use the passive collection method to collect microplastics in the atmosphere. Another example is that CN201610498760.9 discloses a device and method for detecting the concentration of microplastics in the air, which belongs to the active collection method. However, in this patent, the sampling tube is inserted into ultrapure water, and the air is pumped by a suction pump to enrich the particulate matter in the atmosphere in the ultrapure water, and then the microplastics are separated, extracted and calculated for their concentration, without considering the impact of bubble impact on microplastics. Most of the microplastics in the atmosphere are in the form of fibers, foams, films, etc. In this method, the atmosphere is dispersed in ultrapure water in the form of a series of bubbles to achieve the purpose of enriching the particulate matter in the atmosphere. During the pumping process for several hours, the impact force released by the bubbles will continuously impact the microplastics enriched in the ultrapure water, which may cause further damage to the collected microplastics. The particle size, shape and abundance of the collected microplastics may deviate from the actual situation in the atmosphere of this region. Summary of the Invention

[0004] In view of this, the present invention discloses a method and device for collecting microplastics in the atmosphere, so as to achieve the collection of microplastics in the atmosphere by pumping air through a power source, and there is a direct corresponding relationship between the collected microplastics and the volume of the collected air.

[0005] The technical solution provided by the present invention is specifically a method for collecting microplastics in the atmosphere, including the following steps:

[0006] 1) Prepare a microplastic adhesion liquid;

[0007] 2) Uniformly coat the microplastic adhesion liquid on the inner wall of the microplastic enrichment unit of the collection device to form an adhesion film on the inner wall;

[0008] 3) Place the collection device with the adhesion film in the area to be detected, start the ultrasonic vibration device connected to the water tank in the collection device to continuously or intermittently humidify the metal spiral pipeline, and at the same time start the power source in the collection device. The particulate matter in the atmosphere adheres to the inner wall of the microplastic enrichment unit, and the air entering the collection device is discharged from the device through the power source to complete the collection and sampling;

[0009] 4) After sampling, rinse and soak the internal structural surface of the collection device adhered with microplastics with ultrapure water, and collect the ultrapure water containing microplastics into a clean container;

[0010] 5) Pass the obtained ultrapure water containing microplastics through a 0.22 μm filter membrane to enrich the microplastic particles on the filter membrane, and finally determine the types and quantities of the microplastics.

[0011] Further, the microplastic adhesion liquid is a polysaccharide viscous substance or one or a mixture of several of methyl cellulose, carboxymethyl cellulose, sodium polyacrylate, polyethylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylamide substances and their derivatives;

[0012] The polysaccharide viscous substances include starch, sodium alginate, pectin, carrageenan, agar, dextrin, gelatin.

[0013] Further, the specific coating method of the microplastic adhesion liquid in step 2) is: inject the microplastic adhesion liquid into the microplastic enrichment unit, and after the adhesion liquid is evenly coated on the inner wall of the microplastic enrichment unit, discharge the excess microplastic adhesion liquid until there are no obvious liquid drops at the outlet of the microplastic enrichment unit, and set aside for use.

[0014] Further, in step 3), the ultrasonic oscillation device is turned on at intervals, and the pumping speed of the air extraction pump is 1 - 10000 L / min.

[0015] Further, step 4) specifically includes the following steps: open the collection device in at least a ten-thousand-class clean area, and remove the microplastic enrichment unit and the local air outlet unit with adhered microplastics in the collection device for rinsing;

[0016] Then connect the microplastic enrichment unit to a clean pipeline, introduce ultrapure water, remove air bubbles, soak overnight, and rinse the collected microplastics into a clean beaker with at least 10 times the volume of the metal pipeline of ultrapure water.

[0017] An apparatus for collecting microplastics in the atmosphere, comprising an air inlet unit, a microplastic enrichment unit, and an air outlet unit that are detachably connected in sequence. The air inlet unit includes an air inlet channel, an ultrasonic generator, a water storage tank, and a anti-misentry sieve. One end of the air inlet channel is connected to the microplastic enrichment unit, and the other end is provided with an air inlet. The anti-misentry sieve and the ultrasonic generator are sequentially arranged on the air inlet pipeline after the air inlet. The ultrasonic generator is connected to the water storage tank; the air outlet unit includes an air outlet pipeline, a sieve plate, an air extraction pump, a gas flowmeter, and an air outlet. One end of the air outlet pipeline is connected to the microplastic enrichment unit, and the other end is provided with an air outlet. The gas flowmeter, the air extraction pump, and the sieve plate are sequentially arranged on the air outlet pipeline after the air outlet.

[0018] The air inlet pipeline and the air outlet pipeline are respectively connected to the inlet and outlet of the microplastic enrichment unit through a threaded structure;

[0019] Further, the microplastic enrichment unit is a metal pipe with a spiral-shaped pipeline;

[0020] The pipe diameter range of the metal pipe with a spiral pipe can be 5-100 mm, the spiral diameter range of the pipe can be 5-1000 mm, and the number of spiral turns of the pipe can be 1-10000 turns.

[0021] Furthermore, the size range of the air intake unit is 0.0001-10 m 2 , the anti-misentry screen is a metal structure with a pore diameter range of 5-100 mm; the ultrasonic oscillation frequency range is 20-5000 KHz, and the diameter range of the ultrasonic atomization sheet is 1-1000 mm; the volume of the water storage tank is 0.1-100 L, and the pore diameter range of the sieve plate is 0.01 to 5.00 mm.

[0022] A method for collecting microplastics in the atmosphere proposed by the present invention belongs to the active collection method, which can actively complete the collection of microplastics in the atmosphere. The collected microplastics have a direct corresponding relationship with the volume of the collected air, and can more intuitively reflect the true level of the collection area. During the collection process, the vast majority of microplastics in the atmosphere are enriched on the spiral tube of the enrichment unit, without blocking the sieve plate, and no secondary damage will be caused to the microplastics during the collection process. A device for collecting microplastics in the atmosphere proposed by the present invention is based on the human respiratory tract structure, with reasonable structural design and convenient application.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the disclosure of the present invention. Brief Description of the Drawings

[0024] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 It is a schematic structural diagram of a device for collecting microplastics in the atmosphere provided by an embodiment of the present invention.

[0027] Figure 2 It is an enlarged view of microplastics obtained by applying a method for collecting microplastics in the atmosphere provided by an embodiment of the present invention. Detailed Embodiments

[0028] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present invention. Instead, they are merely examples of systems consistent with some aspects of the present invention as detailed in the appended claims.

[0029] In view of the problems existing in the current methods for collecting microplastics in the atmosphere, the present invention proposes an active method for collecting atmospheric microplastics based on bionic technology. The design of the collection device is based on the structure of the human respiratory tract. The human respiratory tract can adhere the particles in the air to the mucous membrane surface of the nasal cavity, trachea and bronchus, and finally form sputum to be discharged from the body, so as to achieve the purpose of removing dust and protecting the lungs. The respiratory tract is moist, and the mucous membrane on the surface has an adhesion function, which is conducive to the enrichment of particles. In view of this, the present invention discloses a method and device for sampling microplastics.

[0030] A method for collecting microplastics in the atmosphere comprises the following steps:

[0031] 1) preparing microplastic adhesion liquid;

[0032] The microplastic adhesion liquid is a polysaccharide viscous substance or a mixture of one or more of methyl cellulose, carboxymethyl cellulose, sodium polyacrylate, polyethylene oxide, polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylamide and their derivatives; that is, the microplastic adhesion liquid can be a combination of the above substances and their different proportions, and the mass concentration can be 0.01 to 100%.

[0033] Among them, polysaccharide viscous substances include starch, sodium alginate, pectin, carrageenan, agar, dextrin, and gelatin;

[0034] 2) evenly coating the microplastic adhesion liquid on the inner wall of the microplastic enrichment unit of the collection device;

[0035] Among them, the specific coating method is: inject the microplastic adhesion liquid into the microplastic enrichment unit, so that the adhesion liquid is evenly coated on the inner wall of the microplastic enrichment unit, release the excess microplastic adhesion liquid until there are no obvious droplets at the outlet of the microplastic enrichment unit, and set it aside.

[0036] 3) Place the collection device with the adhesion liquid in the area to be tested, start the ultrasonic vibration device connected to the water tank in the collection device, continuously or intermittently humidify the metal spiral pipe, and start the vacuum pump to collect samples;

[0037] In step 3), the ultrasonic oscillation device is turned on at intervals, and the suction speed of the vacuum pump is 1 to 10000 L / min. Preferably, sampling can be performed at a suction speed of 50 L / min.

[0038] 4) After sampling, rinse and soak the inner structural surface of the collection device adhered with microplastics with ultrapure water, and collect the ultrapure water containing microplastics into a clean container;

[0039] Step 4) specifically includes the following steps: Open the collection device in a clean area of at least ten thousand class, remove the microplastic enrichment unit and the local air outlet unit adhered with microplastics in the collection device for rinsing;

[0040] Then connect the microplastic enrichment unit to a clean pipeline, introduce ultrapure water, remove air bubbles, soak overnight, and rinse the collected microplastics into a clean beaker with at least 10 times the volume of the metal pipeline of ultrapure water.

[0041] 5) Pass the obtained ultrapure water containing microplastics through a 0.22μm filter membrane to enrich the microplastic particles on the filter membrane, and finally determine the types and quantities of microplastics.

[0042] This implementation scheme also provides a collection device for microplastics in the atmosphere for the above method, including an air inlet unit, a microplastic enrichment unit, and an air outlet unit that are detachably connected in sequence;

[0043] The air inlet unit includes an air inlet channel, an ultrasonic generator 2, a water storage tank 3, and an anti-misentry screen. One end of the air inlet channel is connected to the microplastic enrichment unit, and the other end is provided with an air inlet 1. An anti-misentry screen and an ultrasonic generator 2 are sequentially arranged on the air inlet pipeline after the air inlet. The ultrasonic generator is connected to the water storage tank;

[0044] Among them, the ultrasonic generator 2 can uniformly atomize water to humidify the adhesion liquid coated in the spiral metal tube and improve the adhesion ability;

[0045] Further improvement, the ultrasonic oscillation frequency range of the ultrasonic generator 2 can be 20 - 5000KHz, preferably 1700KHz or 2400KHz can be used. The diameter range of the ultrasonic atomization sheet can be 1 - 1000mm, preferably 16 or 25mm can be used to uniformly atomize water.

[0046] An anti-misentry screen is installed before the ultrasonic generator 2. The anti-misentry screen is made of metal, and its aperture range is 5 - 100mm, preferably 10mm is used.

[0047] The water storage tank 3 can hold ultrapure water to continuously humidify the microplastic collection device, and can meet the usage amount of continuous enrichment and humidification for multiple days.

[0048] The water tank volume of the water storage tank 3 can be 0.1 - 100L, preferably 10L is used. It is used to hold ultrapure water to continuously or intermittently humidify the microplastic collection device through the ultrasonic generator. More usage amounts can be obtained by replenishing ultrapure water into the water tank.

[0049] The size range of the intake unit port is 0.0001 - 10 m 2 , preferably 0.01 m is adopted 2 .

[0050] The air outlet unit 9 includes an air outlet pipeline, a sieve plate 5, an air extraction pump 7, a gas flow meter 6 and an air outlet. One end of the air outlet pipeline is connected to the microplastic enrichment unit, and the other end is provided with an air outlet. After the air outlet, a gas flow meter 6, an air extraction pump 7, and a sieve plate 5 are sequentially arranged on the air outlet pipeline.

[0051] Specifically, the two ends of the microplastic enrichment unit are provided with inlets and outlets. The intake pipeline and the outlet pipeline can be respectively connected to the inlets and outlets of the microplastic enrichment unit through a threaded structure; the spiral extension direction inside the metal pipe with a spiral pipeline is perpendicular to the intake or outlet direction of the intake channel or the outlet channel, which will be more conducive to the centrifugal action of the spiral pipe.

[0052] Further improvement, the range of the sieve plate 5 is 0.01 to 5.00 mm. Preferably, 0.80 μm can be used. Most of the research on microplastics focuses on the particle size range of 0.038 to 4.75 mm to verify that the sieve plate 5 can effectively intercept the collected microplastics.

[0053] The installation of the gas flow meter 6 and the air extraction pump 7 can achieve an air extraction speed of 1 - 10000 L / min. Preferably, an air extraction speed of 50 L / min can be used for sampling. The large gas volume collected is counted by the gas flow meter and used for subsequent calculation of the abundance of microplastics. The air filtered by the sieve plate 5 is discharged from the collection device through the air extraction pump 7.

[0054] The microplastic enrichment unit is a metal pipe with a spiral pipeline; the microplastic adsorption liquid is evenly coated inside the pipeline. The fine particles in the atmosphere adhere to the surface of the metal pipeline due to the centrifugal force brought by the air extraction pump. During the collection process, external forces will not be repeatedly applied to the microplastics to cause damage. The particulate matter adheres to the metal pipeline and will not block the finally filtered sieve plate 5.

[0055] The microplastic enrichment unit 8 is a metal pipe 4 with a spiral pipeline. The pipeline pore diameter range can be 5 - 100 mm, and preferably 10 mm can be used. The spiral diameter range of the pipeline can be 5 - 1000 mm, and preferably 100 mm can be used. The number of spiral turns of the pipeline can be 1 - 10000 turns, and preferably 30 turns can be used.

[0056] In this implementation, an ultrasonic generator 2 is used at the inlet end of the collector to atomize and generate water vapor for humidifying the collector. The collection pipeline is designed as a spiral tubular structure. The spiral tube in the collector is first coated with an adhesive adsorption liquid, so that the adsorption liquid forms a thin film on the spiral tube. Through the humidification of water vapor, the adsorption film can have strong adhesion performance after absorbing water. Then, with the centrifugal action of the spiral tube, particulate matters such as microplastics in the atmosphere are adhered to the surface of the spiral tube. A sieve plate 5 is installed at the outlet end of the collector. The sieve plate can adopt an appropriate pore size according to the particle size of the pre-collected microplastics. A gas flow meter and an air pump are arranged outside the sieve plate, which can control and record the volume of the collected atmosphere.

[0057] The following will further explain and illustrate the present invention in conjunction with specific embodiments, but it is not used to limit the protection scope of the present invention.

[0058] To avoid the influence of particles that may exist in the operating environment, test conditions and equipment on the test results. Solutions should be prepared, devices should be cleaned, and research should be carried out in a laboratory with at least a cleanliness class of 10,000. Before conducting the experiment, all vessels, equipment and transfer utensils involved in the experiment are cleaned with ultrapure water, dried in a clean, cool and dry place. The same environmental conditions are adopted in other embodiments and will not be elaborated here.

[0059] Example 1

[0060] Take an appropriate amount of ultrapure water and heat it to 30°C. Slowly add polyacrylamide (molecular weight 1800) dry powder to the ultrapure water under stirring conditions until it is completely dissolved to prepare a 0.3% polyacrylamide solution. Filter it through a 0.22 μm filter membrane to obtain the microplastic adhesion liquid.

[0061] Remove the metal tube with a spiral pipeline, fill the metal tube with a spiral pipeline with a 0.3% polyacrylamide solution, pay attention to removing air bubbles, so that the 0.3% polyacrylamide solution is evenly coated on the inner wall of the metal spiral pipeline, and release the excess 0.3% polyacrylamide solution so that there are no obvious liquid drops at the outlet of the metal spiral pipeline, and set it aside for use.

[0062] In this example, the water tank volume of the water storage tank 3 used is 10 L, the oscillation frequency of the ultrasonic generator 2 is 2400 KHz, the diameter of the ultrasonic atomization sheet is 25 mm, the pipeline pore diameter of the metal tube of the spiral pipeline is 10 mm. The spiral diameter of the pipeline is 100 mm. The number of spiral turns of the pipeline is 30 turns. The sieve plate 5 is a metal sintered titanium filter plate with a pore size of 400 meshes.

[0063] Connect the metal pipe with a spiral pipe coated with the adhesion liquid to the intake unit and the outlet unit respectively. Place the connected collection device at a location 1.8 m above the ground in the suburbs, and a power supply is equipped nearby. Fill the water storage tank 3 with ultrapure water, start the ultrasonic oscillator 2, turn it on for 10 minutes every 30 minutes to generate water vapor. Turn on the air extraction pump and adjust the air extraction speed to 50 L / min. After 6 hours of collection, turn off the air extraction pump, retrieve the device to the laboratory, open it in a clean area of at least 10,000 class, remove the metal pipe with a spiral pipe and the sieve plate 5. Wash the side of the sieve plate 5 connected to the pipeline with ultrapure water and transfer it to a beaker. Connect the metal spiral pipeline 4 to a clean pipeline, introduce ultrapure water, pay attention to removing air bubbles, soak overnight, and rinse the collected microplastics into a clean beaker with at least 10 times the volume of the metal pipeline of ultrapure water. Pass the obtained ultrapure water containing microplastics through a 0.22 μm filter membrane to enrich microplastics and other particles on the filter membrane. Make a preliminary judgment through a microscope and use a microscopic infrared spectrometer to determine the types and quantities of microplastics. As Figure 2 shown, it is an enlarged view of the microplastics collected by the above method.

[0064] Example 2

[0065] Take an appropriate amount of ultrapure water and heat it to 25 °C. Slowly add polyvinyl alcohol (1750) dry powder to the ultrapure water under stirring conditions until it is completely dissolved to prepare a 1.0% polyvinyl alcohol solution. Filter it through a 0.22 μm filter membrane to prepare the adhesion liquid. Remove the metal pipe 4 with a spiral pipe, fill the metal pipe 4 with a spiral pipe with a 1.0% polyvinyl alcohol solution, pay attention to removing air bubbles to make the adhesion liquid evenly coated on the inner wall of the metal spiral pipeline. Drain the excess liquid so that there are no obvious droplets at the two ends of the inlet and outlet of the metal pipe 4 with a spiral pipe, and set it aside.

[0066] In this test, the volume of the water storage tank 3 of the water storage tank is 10 L, the oscillation frequency of the ultrasonic generator 2 is 1700 KHz, the diameter of the ultrasonic atomization sheet is 16 mm, the pipe diameter of the metal pipe of the spiral pipe is 10 mm. The spiral diameter of the pipeline is 100 mm. The number of spiral turns of the pipeline is 30 turns. The sieve plate 5 is a metal sintered titanium filter plate with a pore size of 400 meshes.

[0067] Install the metal spiral pipeline 4 on the intake unit and the outlet unit of the collection device. Place the collection device 2.0 m above the ground at a certain location in the suburbs, and a power supply is equipped nearby. Fill the water storage tank 3 with ultrapure water, start the ultrasonic oscillation device, turn it on for 5 minutes every 30 minutes to generate water vapor. Turn on the air pump and adjust the air extraction speed to 50 L / min. After 6 hours of collection, turn off the air pump, retrieve the device to the laboratory, open it in a clean area of at least 10,000 class, remove the metal spiral pipeline 4 to the sieve plate 5, and transfer the side of the sieve plate 5 connected to the pipeline to a beaker after cleaning with ultrapure water. Connect the metal spiral pipeline 4 to a clean pipeline, introduce ultrapure water, pay attention to removing air bubbles, soak it overnight with ultrapure water filled, and rinse the collected microplastics into a clean beaker with at least 10 times the volume of the metal pipeline of ultrapure water. Pass the obtained ultrapure water containing microplastics through a 0.22 μm filter membrane to enrich microplastics and other particles on the filter membrane, and preliminarily judge through a microscope and use a microscopic infrared spectrometer to determine the types and quantities of microplastics.

[0068] Those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include known common knowledge or conventional technical means in the technical field not disclosed in the present invention. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present invention are pointed out by the claims.

[0069] It should be understood that the present invention is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A method for collecting microplastics in the atmosphere, characterized in that, It includes the following steps: 1) Prepare the microplastic adhesion liquid; 2) Uniformly coat the microplastic adhesion liquid on the inner wall of the microplastic enrichment unit of the collection device to form an adhesion film on the inner wall; 3) Place the collection device with the adhesion film in the area to be detected, start the ultrasonic vibration device connected to the water tank in the collection device to continuously or intermittently humidify the metal spiral pipeline, and at the same time start the power source in the collection device. The particulate matter in the atmosphere adheres to the inner wall of the microplastic enrichment unit, and the atmosphere entering the collection device is discharged through the power source device to complete the collection and sampling; 4) After sampling, rinse and soak the internal structural surface of the collection device adhered with microplastics with ultrapure water, and collect the ultrapure water containing microplastics into a clean container; 5) Pass the obtained ultrapure water containing microplastics through a 0.22μm filter membrane to enrich the microplastic particles on the filter membrane, and finally analyze and determine the types and quantities of microplastics; The specific coating method of the microplastic adhesion liquid in step 2) is: inject the microplastic adhesion liquid into the microplastic enrichment unit, and after the adhesion liquid is evenly coated on the inner wall of the microplastic enrichment unit, release the excess microplastic adhesion liquid until there are no obvious droplets at the outlet of the microplastic enrichment unit, and set aside for use; The collection device includes an air inlet unit, a microplastic enrichment unit and an air outlet unit that are detachably connected in sequence. The air inlet unit includes an air inlet channel, an ultrasonic generator, a water storage tank and a anti-misentry screen. One end of the air inlet channel is connected to the microplastic enrichment unit, and the other end is provided with an air inlet. An anti-misentry screen and an ultrasonic generator are sequentially arranged on the air inlet channel after the air inlet. The ultrasonic generator is connected to the water storage tank; the air outlet unit includes an air outlet pipeline, a sieve plate, an air extraction pump, a gas flow meter and an air outlet. One end of the air outlet pipeline is connected to the microplastic enrichment unit, and the other end is provided with an air outlet. A gas flow meter, an air extraction pump and a sieve plate are sequentially arranged on the air outlet pipeline after the air outlet; the microplastic enrichment unit is a metal pipe with a spiral pipeline; The pipe diameter range of the metal pipe with a spiral pipeline is 5-100mm, the spiral diameter range of the pipeline is 5-1000mm, and the number of spiral coils of the pipeline is 1-10000 turns; The size range of the intake unit is 0.0001 to 10 m 2 , the anti-misentry screen is of metal structure, and its aperture range is 5 to 100 mm; the ultrasonic oscillation frequency range is 20 to 5000 KHz, and the diameter range of the ultrasonic atomization sheet is 1 to 1000 mm; the volume of the water storage tank is 0.1 to 100 L, and the aperture range of the sieve plate is 0.01 to 5.00 mm.

2. The method for collecting microplastics in the atmosphere according to claim 1, wherein The microplastic adhesion liquid is a polysaccharide viscous substance or one or a mixture of methyl cellulose, carboxymethyl cellulose, sodium polyacrylate, polyethylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylamide substances and their derivatives; The polysaccharide viscous substances include starch, sodium alginate, pectin, carrageenan, agar, dextrin, gelatin.

3. The method for collecting microplastics in the atmosphere according to claim 1, characterized in that, In step 3), the ultrasonic oscillation device can be continuously or intermittently turned on, and the air extraction speed of the air extraction pump is 1-10000L / min.

4. The collection method of microplastics in the atmosphere according to claim 1, wherein Step 4) specifically includes the following steps: Open the collection device in at least a Class 10,000 clean area, remove the microplastic enrichment unit and the local air outlet unit adhered with microplastics in the collection device for rinsing; Then connect the microplastic enrichment unit to a clean pipeline, introduce ultrapure water, remove air bubbles, soak overnight, and rinse the collected microplastics into a clean beaker with at least 10 times the volume of the metal pipeline of ultrapure water.

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