In-situ capturing device and method for settled micro-plastics in marine atmosphere

Abstract

The device comprises a guide cylinder, a support and a filter screen, the guide cylinder is a cylinder with an upper opening and a lower opening, the bottom opening of the guide cylinder is covered with the filter screen, a plurality of notches are formed in the cylinder wall of the top of the guide cylinder, and the filter screen is arranged on the support. The filter screen is in the shape of a net bag which is sunken downwards, the support supports the guide cylinder, and the filter screen is clamped and fixed by the support and the guide cylinder. According to the device, airflow turbulence caused by rapid steering or space sudden change can be reduced, the possibility that airflow forms vortexes in the device is reduced, and the device is simple in structure, convenient to replace, disassemble and clean and suitable for large-scale application and in-situ capture.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine atmospheric environment monitoring, and specifically relates to an in-situ capture device and method for sedimentation microplastics in the marine atmosphere. Background Art

[0002] With the widespread use of plastic products, microplastic pollution has become a global environmental problem. In recent years, with the further expansion of production, irrational use and inefficient management of plastic products, existing monitoring data show that microplastic pollution has been widely present in various environments, creating huge environmental and ecological risks. As a result, the issue of microplastic pollution is gradually attracting the attention of academic circles in various countries.

[0003] Microplastics refer to plastic fragments or particles with a diameter of less than 5 mm, ranging from a few microns to a few millimeters, with a wide distribution range. These microplastics have different shapes, such as spheres, strips, fibers or irregular fragments, and are difficult to distinguish with the naked eye. These small-sized microplastics are easily migrated and widely distributed under the influence of wind, water and ocean currents. Among them, marine atmospheric migration is considered an important way for microplastics to be transmitted over long distances and spread globally.

[0004] At present, there are two main methods for collecting microplastics in the atmosphere - atmospheric dry and wet deposition samplers and pump-type high-flow samplers. There have also been some studies on the sample collection of microplastics in the atmosphere, such as the device and method for detecting the concentration of microplastics in the air (application number: CN201610498760.9), which collects microplastic samples in the atmosphere through an air pump.

[0005] The above-mentioned device and method mainly rely on the pressure difference generated by the air pump to collect samples. The samples collected by this method can be used to reflect the distribution of microplastics in the atmosphere, but the concentration of microplastics in the collected samples may be higher than the actual value, and it is also impossible to explain the sedimentation process of microplastics during transmission. In addition, for field in-situ monitoring areas without power supply, pump-type high-flow samplers are difficult to use. In addition, the high cost and complex sampling procedures of high-flow sampling pumps have greatly hindered the establishment of a wide-area monitoring network for atmospheric microplastics. Therefore, it is urgent to develop a simple, convenient, widely applicable, and long-term atmospheric microplastic sampling device. Summary of the invention

[0006] In response to the above problems, the present invention provides an in situ capture device and method for sedimentation microplastics in the marine atmosphere. On the one hand, it can solve the technical problems of traditional pump-type large-flow samplers with high dependence on electricity, high sampling costs, and inability to collect samples for a long time. On the other hand, it can meet the needs of in situ monitoring, is easy to carry and transport, and can be set up in the field. It can collect in situ samples quickly and accurately, and has the advantage of easy operation.

[0007] To achieve one of the above purposes, the present invention provides the following technical solutions: An in-situ capture device for sedimentation microplastics in the marine atmosphere comprises a guide tube 1, a bracket 2 and a filter screen 3. The guide tube 1 is a tube with upper and lower openings, the bottom opening of the guide tube 1 is covered by the filter screen 3, and the top wall of the guide tube 1 is provided with a plurality of notches 7. The filter screen 3 is in the shape of a net bag that is concave downwards. The bracket 2 supports the guide tube 1 , and the filter screen 3 is clamped and fixed by the bracket 2 and the guide tube 1 .

[0008] Furthermore, the notches 7 are arranged opposite to each other in pairs. The notches arranged opposite to each other become channels for gas flow, which is beneficial to reducing air flow turbulence caused by abrupt turns or sudden changes in space.

[0009] Furthermore, a plurality of fixing holes 8 are provided on the top wall of the guide tube 1. The fixing holes can be used to fix the entire device in the microcosm experimental device, so as to cooperate with the in-situ experiment for monitoring.

[0010] Furthermore, a flange is fixedly connected to the bottom of the guide tube 1, a corresponding flange is arranged on the top of the bracket 2, and the outer edge of the filter 3 is a horizontally arranged ring. The flanges arranged relatively to the bracket and the guide tube can clamp and fix the filter through the ring on the outer edge of the filter.

[0011] Furthermore, the bracket 2 has the same shape as the guide tube 1 and is arranged in opposite directions. The bracket 2 and guide tube 1 of the same structure can reduce the cost of injection molding, and when the guide tube is damaged, the parts can be replaced at low cost by reversing the positions of the bracket and the guide tube.

[0012] Furthermore, the pore size of the filter screen 3 is 1 μm.

[0013] Furthermore, the guide tube 1 is a cylinder.

[0014] Furthermore, the diameter and height of the guide tube 1 are both 150 mm, and the thickness of the tube wall of the guide tube 1 is 3 mm.

[0015] Furthermore, the height of the notch is 30 mm.

[0016] Furthermore, there are 6 fixing holes.

[0017] Furthermore, the outer diameter of the flange is 180 mm.

[0018] Furthermore, screw holes are provided on the flange.

[0019] The second object of the present invention is to provide a method for in-situ capturing of microplastics settled in the marine atmosphere using the above-mentioned device, comprising the following steps: (1) Cleaning the device to remove any contaminants that may be present on the surface; (2) placing the device at a predetermined capture position so that the guide tube 1 is vertically arranged for a period of time to capture microplastics; (3) After the capture is completed, the inner wall of the guide tube 1 is rinsed with distilled water, so that the microplastics attached to the inner wall of the guide tube 1 flow into the filter 3 and are intercepted by the filter 3; (4) disassembling the device, rinsing the inverted filter 3 with distilled water, and collecting the distilled water after rinsing as the sample liquid; (5) Filtering the sample liquid through a filter membrane, and collecting the microplastics on the filter membrane.

[0020] Preferably, the pore size of the filter membrane is 0.22 μm.

[0021] The beneficial effects of the present invention are: (1) The edge of the filter screen of the present invention is sandwiched between the guide tube 1 and the bracket 2 and is not easily damaged.

[0022] (2) The net bag structure of the filter of the present invention helps to concentrate the captured microplastics and reduce the escape of microplastics caused by factors such as wind.

[0023] (3) The present invention has a notch at the top of the guide tube, which can provide a relatively open space, so that the airflow entering the device can enter more smoothly, reducing the airflow turbulence caused by abrupt turns or sudden changes in space. At the notch, the air flow rate will be relatively reduced, which helps to reduce the impact and disturbance of high-speed airflow on the collected samples, making it easier for microplastic particles to settle on the filter.

[0024] (4) The notches designed in the present invention can reduce the possibility of airflow forming vortices inside the device, which may disrupt the sedimentation process and affect the collection efficiency and accuracy. By reducing air turbulence, the notches help improve the collection efficiency of microplastic particles, making the collection process more stable and reliable. While reducing air turbulence, the notches also help protect the collected samples from external environmental factors, such as wind speed changes or secondary suspension of pollutants.

[0025] (5) The capture device of the present invention is not affected by weather when sampling. When a bracket with the same structure as the guide tube is used, it can not only reduce costs, but also drain rainwater in time to avoid the problem of microplastic sample loss caused by rainwater overflow. The device can perform stable sampling in the field for a long time, providing strong support for the study of marine atmospheric microplastics.

[0026] (6) The capture device of the present invention has a simple structure and is easy to replace, disassemble and clean, and is suitable for large-scale application and in-situ capture. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the device of the present invention.

[0028] Figure 2 It is a schematic diagram of the structure of the filter screen 3 from a top view.

[0029] Among them, 1 is the guide tube, 2 is the bracket, 3 is the filter, 4 is the flange, 5 is the screw, 6 is the nut, 7 is the notch, and 8 is the fixing hole. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described below in conjunction with specific embodiments, and the present invention is further described in detail. The examples are shown in the accompanying drawings.

[0031] It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. The numerical values ​​used here are only for describing specific embodiments, and the same numbers in the accompanying drawings represent the same or similar elements. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application. Example

[0032] like Figure 1-2 An in-situ capture device for settling microplastics in the marine atmosphere is shown, comprising a guide tube 1, a bracket 2 and a filter screen 3. The guide tube 1 is a tube open at the top and bottom, the bottom opening of the guide tube 1 is covered by the filter screen 3, the top wall of the guide tube 1 is provided with a plurality of notches 7, the filter screen 3 is in the shape of a downwardly concave net bag, the bracket 2 supports the guide tube 1, and the filter screen 3 is clamped and fixed by the bracket 2 and the guide tube 1.

[0033] The notches 7 are arranged opposite to each other in pairs. The notches arranged opposite to each other become channels for gas flow, which is beneficial to reducing air flow turbulence caused by rapid turning or sudden change of space.

[0034] A plurality of fixing holes 8 are arranged on the wall of the top of the guide tube 1. The fixing holes can be used to fix the whole device in the microcosm experimental device, so as to cooperate with the in-situ experiment for monitoring.

[0035] The bottom of the guide tube 1 is fixedly connected with a flange, the top of the bracket 2 is provided with a corresponding flange, and the outer edge of the filter 3 is a horizontally arranged ring. The flanges arranged opposite to each other on the bracket and the guide tube can clamp and fix the filter through the ring on the outer edge of the filter.

[0036] The bracket 2 has the same shape as the guide tube 1 and is arranged in the opposite direction. The bracket 2 and guide tube 1 of the same structure can reduce the cost of injection molding, and when the guide tube is damaged, the position of the bracket and the guide tube can be reversed to achieve low-cost replacement of accessories.

[0037] The pore size of the filter 3 is 1 μm.

[0038] The guide tube 1 is a cylinder.

[0039] The diameter and height of the guide tube 1 are both 150 mm, and the thickness of the tube wall of the guide tube 1 is 3 mm.

[0040] The height of the notch is 30 mm.

[0041] There are 6 fixing holes.

[0042] The outer diameter of the flange is 180 mm.

[0043] The flange is provided with screw holes, through which screws 5 and nuts 6 are passed to fix the guide tube 1 and the bracket 2.

[0044] When in use, microplastics in the marine atmosphere settle from the upper stainless steel round tube 1 in the vertical direction, and microplastics flowing in the non-vertical direction enter the guide tube 1 through the notch and collide with the inner wall to settle and gather on the filter 3; in rainy weather, the filter 3 can filter rainwater and intercept microplastics. Therefore, the capture device can filter and collect microplastics that settle under rainwater and wind driving without manual operation, improve the analysis and detection efficiency, and meet the needs of long-term sampling.

[0045] The specific operations are as follows: (1) Cleaning the device to remove any contaminants that may be present on the surface; (2) placing the device at a predetermined capture position so that the guide tube 1 is vertically arranged for a period of time to capture microplastics; (3) After the capture is completed, the inner wall of the guide tube 1 is rinsed with distilled water, so that the microplastics attached to the inner wall of the guide tube 1 flow into the filter 3 and are intercepted by the filter 3; (4) disassembling the device, rinsing the inverted filter 3 with distilled water, and collecting the distilled water after rinsing as the sample liquid; (5) Filter the sample liquid through a filter membrane with a pore size of 0.22 μm, and collect the microplastics on the filter membrane.

[0046] (6) The collected microplastics were initially observed using a microscope and further analyzed using a Fourier transform infrared spectrometer to determine the types and quantities of microplastics.

[0047] The capture device was used to collect and test three types of microplastic particles, polypropylene (PP), polyethylene (PE), and polystyrene (PS), and three parallel experiments were performed on each sample. As shown in Table 1, the recovery rates of the three types of microplastic particles were all higher than 90%, indicating that the marine atmospheric microplastic capture device and the method of use of the present invention can effectively collect microplastics settled in the atmosphere.

[0048] Table 1 Recovery rates of three types of microplastic particles by the device described in the present invention

[0049] Those skilled in the art will conjure up other embodiments after considering the specification and practicing the disclosed invention. This application is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art that are not disclosed in the present invention.

Claims

1. An in-situ capture device for sedimentation of microplastics in the marine atmosphere, characterized in that: The invention comprises a guide tube (1), a bracket (2) and a filter screen (3), wherein the guide tube (1) is a tube with upper and lower openings, the bottom opening of the guide tube (1) is covered by the filter screen (3), and the top wall of the guide tube (1) is provided with a plurality of notches (7). The filter screen (3) is in the shape of a net bag that is concave downwards. The bracket (2) supports the guide tube (1), and the filter screen (3) is clamped and fixed by the bracket (2) and the guide tube (1).

2. The in-situ capture device for sedimentation of microplastics in the marine atmosphere according to claim 1, characterized in that: The notches (7) are arranged opposite to each other in pairs.

3. The in-situ capture device for sedimentation of microplastics in the marine atmosphere according to claim 1, characterized in that: A plurality of fixing holes (8) are provided on the cylinder wall at the top of the guide cylinder (1).

4. The in-situ capture device for sedimentation of microplastics in the marine atmosphere according to claim 1, characterized in that: The bottom of the guide tube (1) is fixedly connected with a flange, the top of the bracket (2) is provided with a corresponding flange, and the outer edge of the filter screen (3) is a horizontally arranged ring.

5. The in-situ capture device for sedimentation of microplastics in the marine atmosphere according to claim 1, characterized in that: The bracket (2) and the guide tube (1) have the same shape and are arranged in opposite directions.

6. The in-situ capture device for sedimentation of microplastics in the marine atmosphere according to claim 1, characterized in that: The pore size of the filter (3) is 1 μm.

7. The in-situ capture device for sedimentation of microplastics in the marine atmosphere according to claim 1, characterized in that: The guide tube (1) is a cylinder.

8. The in-situ capture device for sedimentation of microplastics in the marine atmosphere according to claim 7, characterized in that: The diameter and height of the guide tube (1) are both 150 mm, and the thickness of the tube wall of the guide tube (1) is 3 mm.

9. The in-situ capture device for settling microplastics in the marine atmosphere according to claim 1, characterized in that: The height of the notch (7) is 30 mm.

10. A method for in-situ capturing of microplastics deposited in the marine atmosphere using the in-situ capture device according to any one of claims 1 to 9, characterized in that: The steps include: (1) Cleaning the device to remove any contaminants that may be present on the surface; (2) placing the device at a predetermined capture position so that the guide tube (1) is placed vertically for a period of time to capture microplastics; (3) After the capture is completed, the inner wall of the guide tube (1) is rinsed with distilled water, so that the microplastics attached to the inner wall of the guide tube (1) flow into the filter (3) and are intercepted by the filter (3); (4) disassembling the device, rinsing the inverted filter (3) with distilled water, and collecting the distilled water after rinsing as the sample liquid; (5) Filtering the sample liquid through a filter membrane, and collecting the microplastics on the filter membrane.

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