A device for collecting microplastics in dust in the surface environment

Abstract

This utility model belongs to the technical field of collection devices, specifically relating to a gas collection device for microplastics in dust from surface environments. The device includes a gas collection hood, two sets of air inlets, and an air outlet. The gas collection hood includes a support part and a functional part. The support part is cylindrical, and the functional part is conical. The top surface of the support part and the bottom surface of the functional part are tightly fitted together. Both the support part and the functional part have cavities, forming a through structure with the cavities in the support part and the functional part. The air outlet is located at the apex of the functional part and forms a through structure with the cavity in the functional part. The two sets of air inlets are symmetrically located on both sides of the surface of the functional part and form a through structure with the cavity in the functional part. The angle between the opening direction of the two sets of air inlets and the horizontal direction is 30°, and they are rotated 45° around the longitudinal axis. The gas collection device provided by this utility model has stable collection performance for microplastic particles, with a collection efficiency of 98.2%.

Description

Technical Field

[0001] This utility model belongs to the field of collection device technology, specifically, it relates to a microplastic gas collection device for dust in the ground environment. Background Technology

[0002] With the rapid development of modern industry and life, plastic products have been widely used in various fields due to their advantages such as low cost, diverse performance, and convenient processing. From everyday packaging materials and disposable tableware to parts and fiber products in industrial production, plastics are ubiquitous. However, a large number of plastic products are difficult to degrade in the environment, and after physical, chemical, and biological processes, they gradually break down into microplastic particles smaller than 5 millimeters in size.

[0003] Environmental dust, a significant component of the urban environment, has been found to contain a certain amount of microplastics. Microplastics, characterized by their large surface area and strong adsorption capacity, can adsorb harmful substances such as heavy metals and organic pollutants from the environment, forming complex pollutants. When this dust containing microplastics enters the human body through respiration, skin contact, or other routes, it may pose potential health hazards, such as triggering inflammatory responses and disrupting the endocrine system. Simultaneously, microplastics in environmental dust can also negatively impact soil and aquatic ecosystems, for example, affecting the activity of soil microorganisms and interfering with the feeding and growth of aquatic organisms.

[0004] Currently, existing collection devices for microplastics in environmental dust have low collection efficiency and cannot effectively enrich a sufficient number of microplastic samples within a limited time. This leads to insufficient sample size, making it difficult to accurately assess the pollution status in subsequent analyses. Therefore, it is urgent to develop a highly efficient, stable, and accurate device for collecting microplastics from environmental dust. Utility Model Content

[0005] To address the aforementioned problems, this utility model provides a microplastic collection device for dust in the ground environment. This device has stable collection performance for microplastic particles, with a collection efficiency of 98.2%, and good airtightness. It can be tightly bonded to different ground environments through a polymer liquid sealing material, and can completely collect microplastics of different particle sizes from asphalt pavement in one go.

[0006] In one aspect, the present invention provides a microplastic gas collection device in dust in the ground environment in an optional embodiment, including a gas collection hood, two sets of air inlets and air outlets;

[0007] The gas collection hood includes a support part and a functional part. The support part is cylindrical in shape, and the functional part is conical in shape. The top surface of the support part and the bottom surface of the functional part are closely fitted together, and the diameter of the support part and the bottom surface diameter of the functional part are the same.

[0008] Both the support part and the functional part have cavities, and the shape is the same as that of the support part and the functional part, respectively. The cavity in the support part and the cavity in the functional part form a through structure, and the diameter of the cavity in the support part and the bottom diameter of the cavity in the functional part are the same.

[0009] The air outlet is located at the apex of the functional part and forms a through structure with the cavity inside the functional part;

[0010] The two sets of air inlets are symmetrically opened on both sides of the surface of the functional part and form a through structure with the cavity inside the functional part. The vertical distance between the two sets of air inlets and the bottom surface of the functional part is half the cone height of the functional part.

[0011] The ratio of the bottom diameter of the functional part to its cone height is 10:1, the ratio of the bottom diameter of the support part to its column height is 10:1, the angle between the opening direction of the two sets of air inlets and the horizontal direction is 30°, and they rotate 45° around the longitudinal axis.

[0012] Furthermore, the ratio of the bottom diameter of the functional part to its cone height is 10:1, and the ratio of the bottom diameter of the support part to its column height is 10:1.

[0013] Furthermore, both sets of air inlets and outlets are cylindrical in shape.

[0014] Furthermore, the diameters of both sets of air inlets and outlets are the same as the diameter of the support portion.

[0015] Furthermore, the diameter of the support portion and the bottom diameter of the functional portion are both 200mm; the column height of the support portion is 20mm, and the cone height of the functional portion is 20mm.

[0016] Furthermore, the diameter of both sets of air inlets and outlets is 20mm.

[0017] Furthermore, the vertical distance between the two sets of air inlets and the bottom surface of the functional unit is 10mm.

[0018] Furthermore, the distance between the cavity in the support portion and the outer surface of the support portion and the functional portion is 2mm.

[0019] Furthermore, the microplastics have a particle size of 250-5000 μm.

[0020] Compared with the prior art, this utility model has one of the following beneficial effects:

[0021] 1. The collection device provided by this utility model has stable performance in collecting microplastic particles, with a collection efficiency of 98.2%.

[0022] 2. The collection device provided by this utility model has good airtightness. It can be closely fitted with different ground environments through the high-polymer liquid sealing material, and can completely collect microplastics of different particle sizes in asphalt pavement in one go. Attached Figure Description

[0023] Figure 1 This is a perspective view of the microplastic gas collection device in surface dust according to Example 1;

[0024] Figure 2 This is a side view of the microplastic gas collection device in surface dust according to Example 1;

[0025] Figure 3 This is a top view of the microplastic gas collection device in surface dust according to Example 1;

[0026] Figure 4 This is a side view of the microplastic gas collection device in surface dust according to Example 1;

[0027] Figure 5 This is a side view of the streamline and velocity of the collection device in the horizontal direction during the calculation of the outlet air velocity in the application embodiment.

[0028] Figure 6 This is a side view of the vertically upward airflow velocity of the gas collected in the application embodiment when calculating the outlet airflow velocity;

[0029] Figure 7 This is a side view of the vertical upward airflow velocity of the gas collected by the application embodiment when the outlet air velocity is 10m / s.

[0030] Figure 8 This is a side view of the vertical upward airflow velocity of the gas collected by the application embodiment when the outlet air velocity is 14m / s.

[0031] Figure 9 This is a side view of the vertical upward airflow velocity of the gas collected by the application embodiment when the outlet air velocity is 18m / s.

[0032] Figure 10 This is a side view of the vertical upward airflow velocity of the gas collected by the application embodiment when the outlet air velocity is 28m / s.

[0033] Figure 11 This is a schematic diagram of the process for collecting experiments in an application embodiment;

[0034] Among them, 1-air collection hood; 2-air inlet; 3-air outlet. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions of this application, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0036] The directional terms such as above, below, left, right, front, and back used in this application are based on the positional relationships shown in the attached drawings. Different attached drawings may result in different positional relationships, therefore they should not be interpreted as limitations on the scope of protection.

[0037] In this application, the terms "installation," "connection," "interlocking," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, or a connection that allows communication between components. They can also refer to a direct connection or an indirect connection through an intermediate medium. They can refer to the internal connection of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0038] Example 1

[0039] See Figure 1-4 This embodiment provides a microplastic gas collection device for dust in the ground environment, including a gas collection hood 1, two sets of air inlets 2 and air outlets 3;

[0040] The gas collection hood 1 includes a support part and a functional part. The support part is cylindrical and the functional part is conical. The top surface of the support part and the bottom surface of the functional part are closely fitted, and the diameter of the support part and the bottom surface diameter of the functional part are the same. In this embodiment, the diameter of the support part and the bottom surface diameter of the functional part are both 200mm. The column height of the support part is 20mm and the cone height of the functional part is 20mm.

[0041] Both the support section and the functional section have cavities, and the shapes of the support section and the functional section are the same. The cavities in the support section and the cavities in the functional section form a through structure, and the diameter of the cavity in the support section and the bottom diameter of the cavity in the functional section are the same.

[0042] The air outlet 3 is located at the apex of the functional part and forms a through structure with the cavity inside the functional part. In this embodiment, the air outlet 3 is cylindrical in shape and has a diameter of 20mm.

[0043] Two sets of air inlets 2 are symmetrically opened on both sides of the surface of the functional part and form a through structure with the cavity inside the functional part. The vertical distance between the two sets of air inlets 2 and the bottom surface of the functional part is half the diameter of the bottom surface of the functional part. In this embodiment, the vertical distance between the two sets of air inlets 2 and the bottom surface of the functional part is 10mm. The shape of the two sets of air inlets 2 is cylindrical and the diameter is 20mm. The angle between the opening direction of the two sets of air inlets 2 and the horizontal direction is 30°, and they are rotated 45° around the longitudinal axis.

[0044] Application Examples

[0045] 1. Experimental Materials

[0046] Example 1: Microplastics collection device for surface dust, including: air pump: model 2755, range 100-500L / min; diaphragm vacuum pump: SCJ-10; electric thermostatic drying oven: DH101; electronic balance: AE160, accuracy: Class I, 0.001g; anemometer: VT115, range 0.15-30m / s; water-soluble microfiltration membrane: pore size 10μm, diameter 47mm; glass fiber filter membrane: pore size 10μm, diameter 47mm; high-density water-based sealant: liquid, initial curing time 7min.

[0047] Based on the type, particle size, and abundance of microplastics in road sediments, several widely distributed microplastics in the ground environment were purchased, including polystyrene (PS), polyester (PET), polypropylene (PP), polyvinyl chloride (PVC), and butadiene rubber (BR). These microplastics were pulverized using a pulverizer and sieved to obtain plastic particles of different sizes. Each microplastic sample consisted of microplastic particles of different types and sizes, mixed in a specific mass fraction ratio, with a total mass of 1.20 g. This mixture was used to calibrate and verify the performance of the gas collection device, as detailed in Table 1.

[0048] Table 1. Density, particle size distribution, and mass percentage of different types of microplastics

[0049]

[0050] To ensure that the gas collection device can completely collect microplastics of different particle sizes in the ground environment, the experiment selected the minimum wind speed required to collect large, high-density microplastic particles in the ground environment. Specifically, the wind speed (14 m / s) required to collect spherical butadiene rubber microplastic particles with a diameter of 5 mm and a density of 1.93 g / cm³ was used as the initial test condition for gas flow within the gas collection device.

[0051] 2. Calculation of outlet air velocity

[0052] When air is drawn from the outlet at a wind speed of 28 m / s using an air pump, the gas inside the device forms a vortex-like gas flow field resembling a vertical hollow tube or funnel. The horizontal gas flow velocity is high at the periphery and low in the central region. Analyzing the gas flow direction, in the horizontal direction, the airflow velocity around the periphery is between 28-36 m / s, slightly lower at the device edge at 28 m / s, and between 14-28 m / s in the central region. This wind speed allows large microplastic particles from the ground environment inside the device to be carried by the airflow. In the vertical upward direction, the airflow velocity around the periphery is between 2-5 m / s, and between 5-20 m / s at the bottom of the central region. Furthermore, there is a vertically upward airflow from the bottom of the device to the outlet. This wind speed can quickly transport microplastic particles from the central region to the outlet. Therefore, a gas flow field is formed within the device, which not only gathers the microplastic particles moving with the airflow into the central region of the flow field, but also quickly transports all the microplastic particles in the central region to the air outlet, thereby achieving effective collection of microplastic particles. See details... Figures 5-6 .

[0053] The flow velocity within the gas collection device was investigated using fluid dynamics simulation (CFD) technology at outlet air velocities of 10 m / s, 14 m / s, 18 m / s, and 28 m / s. Figures 7-10 It can be seen that when the outlet air velocity is 10 m / s and 14 m / s, the wind speed at the edge of the gas collection device is 5 m / s and 9 m / s, respectively, both lower than the required wind speed of 14 m / s for large, high-density microplastic particles. When the outlet air velocity is increased to 18 m / s or 28 m / s, the minimum wind speed inside the gas collection device can reach 14 m / s, which meets the wind speed required to move large, high-density spherical silicone rubber particles with the airflow. Therefore, in this experiment, the minimum outlet air velocity selected for the gas collection device to collect environmental microplastics is 9 m / s. For details on the airflow within the device at different inlet air velocities, please refer to [link to relevant documentation]. Figure 5-8 .

[0054] 3. Data collection time calculation

[0055] Using fluid dynamics simulation (CFD) technology, the time required for the gas inside the device to form a stable flow field was calculated to be 4 seconds. When the outlet air velocity reaches 18 m / s, the gas inside the device can be replaced in only 0.074 seconds. Based on this, the sampling time was set to 1 minute each time, at which point the gas inside the device can be replaced more than 700 times, ensuring that the microplastic samples can be completely collected.

[0056] Conclusion: When the outlet air velocity reaches the minimum air velocity of 18 m / s, the time required for the gas inside the device to form a stable flow field is 4 seconds. This flow field is similar to a vertical hollow tube or funnel-shaped vortex. This flow field can quickly gather the microplastic particles inside the device to the central area of ​​the flow field and transport these particles to the air outlet with the airflow for collection.

[0057] Based on wind speed and device mechanism calculations, the gas inside the device can be replaced in just 0.074 seconds. Therefore, the sampling time for each collection session is set to 1 minute.

[0058] 4. Collect experiments

[0059] The efficiency of the gas collection device in collecting microplastics was calculated using the gravimetric method.

[0060] Laboratory experiments: See Figure 11 A 1.20g sample of microplastics was evenly spread on a clean, smooth laboratory surface with a diameter of less than 200mm. A gas collection device was then used to collect the microplastic sample from the laboratory surface. After collection, the gas extracted from the outlet was sent into the collection device (with a water-soluble filter membrane at the outlet). After collection, the water-soluble filter membrane at the outlet was immersed in the solution in the gas collection bottle. Once the filter membrane dissolved, the microplastic particles in the collection bottle were filtered onto a glass filter membrane fiber. After drying to a constant weight, the collected microplastic sample volume was weighed using a balance. This process was repeated in triplicate, and the average value was calculated to determine the collection efficiency of the gas collection device for microplastic samples.

[0061] Record experimental data and analyze the sampling efficiency of the microplastic gas collection device in the ground environment. The results are shown in Table 2. Evaluate the device performance.

[0062] Efficiency test of gas collection device for collecting microplastic samples in laboratory setting

[0063] Table 2. Collection efficiency of microplastics from the gas collection device in the laboratory setting.

[0064]

[0065] The results of the three microplastic collections show that the gas collection device achieved collection efficiencies of 98.9%, 98.6%, and 97.2% for the microplastic spiked samples, respectively, all above 96.0%, with an average collection efficiency of 98.2%.

[0066] Road surface experiment: A microplastic sample was evenly spread on an asphalt road surface with a diameter of less than 200 mm. A gas collection device was used to collect the microplastic sample from the road surface. Then, the microplastics on the water-soluble filter membrane were transferred to the collection liquid, subjected to flotation, separation, and drying to constant weight. The mass of the collected microplastic sample was weighed using a balance. Four consecutive collections were performed, and the collection efficiency of the gas collection device for microplastic samples was calculated.

[0067] Record experimental data and analyze the sampling efficiency of the microplastic gas collection device in the ground environment. The results are shown in Table 3. Evaluate the device performance.

[0068] Table 3. Collection efficiency of microplastic samples from paved ground

[0069] Microplastic sample spiking amount (g) 1.200 / / / Sample size of microplastics collected (g) 1.42 0.022 0.005 Not detected Data collection efficiency (%) 119％ / / /

[0070] The initial sample volume was higher than the spiked microplastic sample volume, likely because the asphalt road itself contains microplastic particles. This collection included both spiked microplastic samples and naturally occurring microplastic samples from the road surface. During the second, third, and fourth collections, the detected levels of microplastics gradually decreased or even disappeared, indicating that the first sample collection effectively gathered most of the microplastics from the road.

[0071] 5. Air tightness test

[0072] Experimental Method: The gas collection device was installed on different surfaces in both the laboratory and real-world environments. A polymer liquid sealant was used to seal the bottom edge of the device where it contacted the ground. An air pump was connected to the outlet, and an anemometer was connected to the inlet. After the sealant had completely cured, the air pump was started, and the outlet speed was gradually increased while observing the changes in wind speed at both inlets.

[0073] The device was installed on a smooth laboratory floor for airtightness testing. During the test, the air velocity at the outlet was gradually increased from 1 m / s to 28 m / s, and the air velocity at both inlets was measured using an anemometer. As the outlet air velocity gradually increased, the inlet air velocity also increased accordingly, consistently remaining at 0.499 times the outlet air velocity, indicating that the device has good airtightness.

[0074] The device was installed on a common asphalt pavement in an urban environment for air tightness testing. During the test, the air velocity at the outlet was gradually increased from 1 m / s to 28 m / s, and the air velocity at both inlets was measured using an anemometer. As the outlet air velocity gradually increased, the inlet air velocity also increased accordingly, consistently remaining between 0.498 and 0.499 times the outlet air velocity, which is essentially consistent with the outlet air velocity on a smooth laboratory surface. This indicates that the device can fit tightly against the asphalt pavement, exhibiting good air tightness and meeting the experimental requirements.

[0075] The above description is merely an embodiment of this utility model, and common knowledge regarding specific structures and characteristics is not described in detail here. It will be apparent to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A device for collecting microplastics from dust in a surface environment, characterized in that, Includes a gas collection hood, two sets of air inlets and outlets; The gas collection hood includes a support part and a functional part. The support part is cylindrical in shape, and the functional part is conical in shape. The top surface of the support part and the bottom surface of the functional part are closely fitted together, and the diameter of the support part and the bottom surface diameter of the functional part are the same. Both the support part and the functional part have cavities, and the shape is the same as that of the support part and the functional part, respectively. The cavity in the support part and the cavity in the functional part form a through structure, and the diameter of the cavity in the support part and the bottom diameter of the cavity in the functional part are the same. The air outlet is located at the apex of the functional part and forms a through structure with the cavity inside the functional part; The two sets of air inlets are symmetrically opened on both sides of the surface of the functional part and form a through structure with the cavity inside the functional part. The vertical distance between the two sets of air inlets and the bottom surface of the functional part is half the cone height of the functional part. The ratio of the bottom diameter of the functional part to its cone height is 10:1, the ratio of the bottom diameter of the support part to its column height is 10:1, the angle between the opening direction of the two sets of air inlets and the horizontal direction is 30°, and they rotate 45° around the longitudinal axis.

2. The microplastic gas collection device for surface environmental dust according to claim 1, characterized in that, Both sets of air inlets and outlets are cylindrical in shape.

3. The microplastic gas collection device for surface environmental dust according to claim 2, characterized in that, The diameters of both sets of air inlets and outlets are the same as the diameter of the support portion.

4. The microplastic gas collection device for surface environmental dust according to claim 1, characterized in that, The diameter of the support part and the bottom diameter of the functional part are both 200 mm. The column height of the support part is 20mm, and the cone height of the functional part is 20mm.

5. The microplastic gas collection device for surface environmental dust according to claim 3, characterized in that, The diameter of both the air inlet and outlet is 20mm.

6. The microplastic gas collection device for surface environmental dust according to claim 1, characterized in that, The vertical distance between the two sets of air inlets and the bottom surface of the functional unit is 10mm.

7. The microplastic gas collection device for surface environmental dust according to claim 1, characterized in that, The distance between the cavity in the support part and the outer surface of the support part and the functional part is 2mm.

8. The microplastic gas collection device for surface environmental dust according to claim 1, characterized in that, The microplastics have a particle size of 250-5000 μm.

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