A device and method for collecting microplastics in water

Abstract

This invention provides a device and method for collecting microplastics in water. The device includes: a housing with upper and lower coaxial frames at both ends; a main shaft with its lower end fixedly connected to the lower coaxial frame and its upper end passing through and fixedly connected to the upper coaxial frame, and a main rope connected to the main shaft; a movable seal including upper and lower horizontal partitions and multiple secondary shafts, each secondary shaft passing through the upper coaxial frame in the middle and connected to and passing through the lower horizontal partition at its lower end; multiple tension springs, each tension spring with its upper end fixedly connected to the upper horizontal partition and its lower end connected to the inner wall of the housing; and a pin assembly including a pin, a torsion spring, a movable ring, and a secondary rope. A clearance groove is provided on the main shaft below the upper horizontal partition, and the pin and torsion spring are disposed within the clearance groove. The torsion spring is connected to the pin, the movable ring is sleeved on the main shaft, and the secondary rope is connected to the movable ring. The advantages of this invention are: it can collect microplastics from water at different depths, and the sampling results are stable and reliable.

Description

Technical Field

[0001] This invention relates to the field of microplastic collection equipment technology, and in particular to a device and method for collecting microplastics in water. Background Technology

[0002] Due to the low abundance and small size of microplastics in water, two methods are commonly used for collecting microplastics in water: concentrated sampling and large-volume sampling. Concentrated sampling refers to methods that reduce the sample volume during sampling, primarily using trawls. This method has the following problems: 1. It requires the use of boats, resulting in high sampling costs, and the samples may be contaminated by the boat and towline; 2. Trawl nets have large pore sizes, typically ranging from 112 to 333 μm, allowing smaller microplastics to pass through; 3. Trawls are usually used for surface water samples, while the distribution of microplastics in water depends on their density, shape, size, and other properties, as well as environmental conditions such as water density, wind, current, and waves. The quantity and type of microplastics collected largely depend on the sampling location and depth. To obtain the spatial distribution characteristics of microplastics in water, it is necessary to collect water samples at different depths for analysis and testing.

[0003] Large-volume sampling refers to methods that do not reduce the volume of water, typically using water samplers or pumps to collect samples. The main problems with this method are: 1. Large water volumes are difficult to transport, requiring manual transfer of the water buckets to the laboratory; 2. Small water volumes result in a limited sampling area, and since the spatial distribution of microplastics is highly variable, a small number of samples may not be representative; 3. Traditional water samplers are simple in principle and cost-effective, but their sealing performance is poor, leading to slight leakage after the sample is lifted; 4. Acrylic glass water samplers or pumps may introduce microplastics, contaminating the sample. Summary of the Invention

[0004] In view of this, in order to solve the problems existing in current methods for collecting microplastics in water, embodiments of the present invention provide a device and method for collecting microplastics in water.

[0005] An embodiment of the present invention provides a device for collecting microplastics in water, comprising:

[0006] The cylindrical shell is open at both ends, with an upper coaxial frame at the top and a lower coaxial frame at the bottom.

[0007] The main shaft has its lower end fixedly connected to the lower coaxial frame and its upper end passing through and fixedly connected to the upper coaxial frame. The upper end of the main shaft is also connected to a main rope.

[0008] The movable seal includes an upper horizontal partition, a lower horizontal partition, and multiple auxiliary shafts. The lower horizontal partition is located at the lower end of the housing, and the upper horizontal partition is located at the upper end of the housing. Each auxiliary shaft is connected to the upper horizontal partition at its upper end, passes through the upper coaxial frame at its upper middle part, is connected to the lower horizontal partition at its lower middle part, and passes through the lower coaxial frame at its lower end, so that the upper and lower horizontal partitions can move up and down to seal the upper and lower coaxial frames. The middle part of the main shaft passes through the upper and lower horizontal partitions.

[0009] Multiple tension springs, each of which is fixedly connected to the upper horizontal partition at its upper end and to the inner wall of the outer shell at its lower end;

[0010] The assembly includes a pin, a torsion spring, a movable ring, and a secondary rope. A clearance groove is provided on the main shaft below the upper horizontal partition. The pin and the torsion spring are disposed in the clearance groove. The torsion spring connects to the pin, causing the pin to extend and press against the upper horizontal partition. The movable ring is sleeved on the main shaft. The secondary rope connects to the movable ring, pulling the movable ring to squeeze the pin, causing the pin to retract and thus releasing the upper horizontal partition.

[0011] Furthermore, the pin is a conical block or a triangular plate.

[0012] Furthermore, the top of the pin is provided with a ball bearing, and the lower surface of the upper horizontal partition is provided with a groove, the ball bearing can slide along the groove to retract the pin into the clearance groove.

[0013] Furthermore, a limiting ring is provided on the main shaft above the upper horizontal partition.

[0014] Furthermore, the number of auxiliary ropes is set to two, and the two auxiliary ropes are respectively connected to the opposite sides of the movable ring.

[0015] Furthermore, the upper coaxial frame and the lower coaxial frame have the same structure, both including an inner ring, an outer ring disposed around the inner ring, and multiple connecting rods connecting the inner ring and the outer ring, and both the upper surface of the inner ring and the upper surface of the outer ring are provided with sealing rings.

[0016] Furthermore, a transparent glass plate is embedded in the side wall of the outer casing, and the glass plate is provided with scale markings.

[0017] Furthermore, it includes multiple telescopic rods disposed at the bottom of the lower coaxial frame.

[0018] Furthermore, it also includes a concentration component. The outer casing is equipped with a stop valve and a water outlet pipe connected to the stop valve. The concentration component includes a funnel cup, a filter cylinder, a conical flask, and a vacuum pump. The upper part of the funnel cup is used to collect the water outlet from the water outlet pipe, and the lower part is connected to the filter cylinder. The filter cylinder is equipped with a support mesh, and a filter membrane is placed on the support mesh. The lower end of the filter cylinder is connected to a filter head, and the lower end of the filter head is connected to the mouth of the conical flask. The vacuum pump is connected to the filter head through a pipe.

[0019] In addition, based on the above-mentioned device for collecting microplastics in water, embodiments of the present invention also provide a method for collecting microplastics in water, comprising the following steps:

[0020] S1. Place the collection device in water and release the main rope to lower the outer shell to a predetermined height;

[0021] S2. After the outer shell is filled with water, pull up the auxiliary rope to retract the pin into the clearance groove, release the upper horizontal partition, and under the action of the tension spring, the upper horizontal partition moves down until the upper horizontal partition blocks the upper coaxial frame and the lower horizontal partition blocks the lower coaxial frame.

[0022] S3. Raise the main rope to remove the collection device from the water, filter the water inside the shell, and collect microplastics.

[0023] The beneficial effects of the technical solutions provided by the embodiments of the present invention are as follows:

[0024] 1. The present invention provides a device and method for collecting microplastics in water, wherein the outer shell and the movable sealing element form a tightly sealed space that can collect water samples at a specific depth, and the sealing of the outer shell after water is taken is achieved by a pin assembly, which can collect microplastics in water at different depths, and the sampling results are stable and reliable.

[0025] 2. The present invention provides a device and method for collecting microplastics in water, which is suitable for use in field work and can ensure that the collecting device descends vertically with small water layer errors, thereby greatly improving the accuracy of the experiment.

[0026] 3. The microplastic collection device in water according to the present invention can avoid the use of plastic materials to prevent the introduction of microplastics during the sampling process and contamination of the sample. At the same time, stainless steel materials can be used, which are not easily broken and have a greater weight than the plexiglass materials used in current water samplers.

[0027] 4. The present invention provides a device for collecting microplastics in water. The concentration component can concentrate microplastics in a large volume of water sample onto a filter membrane at the sampling site. It is convenient to transport and can screen microplastics by setting filter membranes of different diameters on the filter cylinder. Attached Figure Description

[0028] Figure 1 This is a three-dimensional schematic diagram of a device for collecting microplastics in water according to the present invention;

[0029] Figure 2 This is a side view of a device for collecting microplastics in water according to the present invention;

[0030] Figure 3 This is a partial schematic diagram of the latch assembly.

[0031] 1. Main rope; 2. Secondary rope; 3. Main shaft; 4. Upper horizontal partition; 5. Secondary shaft; 6. Sealing ring; 7. Upper coaxial frame; 8. Connecting rod; 9. Tension spring; 10. Outer shell; 11. Glass plate; 12. Lower horizontal partition; 13. Lower coaxial frame; 14. Water stop valve; 15. Detachable connector; 16. Water outlet pipe; 17. Telescopic rod; 18. Dust cover; 19. Funnel cup; 20. Aluminum alloy clamp; 21. Filter cylinder; 22. Filter head; 23. Air outlet; 24. Conical flask; 25. Hose; 26. Vacuum pump; 27. Limiting ring; 28. Ball bearing; 29. ​​Pin; 30. Torsion spring; 31. Movable ring. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described below in conjunction with the accompanying drawings. The following description presents a preferred embodiment of the various possible embodiments of the present invention, intended to provide a basic understanding of the invention, but not intended to identify key or decisive elements of the invention or to limit the scope of protection sought.

[0033] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0034] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0035] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures. Also, it should be understood that, for ease of description, the dimensions of the various parts shown in the figures are not drawn to actual scale.

[0036] In the description of this invention, it should be noted that the circuits, electronic components, and modules involved in this invention are all prior art, which can be fully implemented by those skilled in the art, and need not be elaborated upon. The content protected by this invention does not involve improvements to the internal structure and methods.

[0037] It should be further noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Please refer to Figure 1 and 2 The present invention provides a device for collecting microplastics in water, which includes a housing 10, a main shaft 3, a movable seal, multiple pull rope springs, a pin assembly, and a concentration assembly.

[0039] Specifically, the outer shell 10 is cylindrical, hollow inside, and open at both ends. A transparent glass plate 11 is embedded in the side wall of the outer shell 10, and the glass plate 11 has scale markings. The scale markings are vertically arranged, and the water depth inside the outer shell 10 can be observed through the scale markings.

[0040] Furthermore, the outer casing 10 has an upper coaxial frame 7 at its upper end and a lower coaxial frame 13 at its lower end. Specifically, the upper coaxial frame 7 and the lower coaxial frame 13 have the same structure, each including an inner ring, an outer ring disposed around the inner ring, and a plurality of connecting rods 8 connecting the inner ring and the outer ring. The inner ring and the outer ring are coaxially arranged, and each connecting rod 8 is evenly distributed between the inner ring and the outer ring. One end of each connecting rod 8 is connected to the inner ring, and the other end is connected to the outer ring.

[0041] The main shaft 3 is disposed on the axis of the outer shell 10. The lower end of the main shaft 3 is fixedly connected to the inner ring of the lower coaxial frame 13, and the upper end passes through and is fixedly connected to the inner ring of the upper coaxial frame 7. The upper end of the main shaft 3 is also connected to a main rope 1, through which the main shaft 3 can be lowered or raised, thereby lowering or raising the lower coaxial frame 13, that is, lowering or raising the outer shell 10.

[0042] The movable seal mainly includes an upper horizontal partition 4, a lower horizontal partition 12, and multiple countershafts 5. For example... Figure 1 As shown, both the upper horizontal partition 4 and the lower horizontal partition 12 are circular plates with a through hole in the middle, and their diameter is smaller than the inner diameter of the outer shell 10. The lower horizontal partition 12 is disposed at the lower end of the outer shell 10, and the upper horizontal partition 4 is disposed at the upper end of the outer shell 10. Each of the sub-shafts 5 is connected to the upper horizontal partition 4 at its upper end, passes through the upper coaxial frame 7 at its upper middle part, is connected to the lower horizontal partition 12 at its lower middle part, and passes through the lower coaxial frame 13 at its lower end.

[0043] It should be noted that the vertical distance between the upper horizontal partition 4 and the lower horizontal partition 12 is the same as the vertical distance between the upper coaxial frame 7 and the lower coaxial frame 13, so that the upper horizontal partition 4 and the lower horizontal partition 12 can move up and down to simultaneously seal the upper coaxial frame 7 and the lower coaxial frame 13. Preferably, both the upper surface of the inner ring and the upper surface of the outer ring are provided with sealing rings 6 to achieve better sealing.

[0044] The main shaft 3 passes through the through hole in the middle of the upper horizontal partition 4 and the through hole in the middle of the lower horizontal partition 12, so that the main shaft 3, the upper horizontal partition 4 and the lower horizontal partition 12 move separately.

[0045] The number of tension springs 9 is set to multiple, and the specific number can be flexibly selected according to the diameter of the outer shell 10. In this embodiment, the number of tension springs 9 is set to four, and the four tension springs are evenly distributed around the main shaft 3.

[0046] Each tension spring 9 has its upper end extending beyond the upper coaxial frame 7 and fixedly connected to the upper horizontal partition 4, and its lower end connected to the inner wall of the outer casing 10. The tension spring 9 is inclined, with its upper end close to the middle of the upper horizontal partition 4.

[0047] The function of the pin assembly is to release the upper horizontal partition 4, thereby sealing the upper coaxial frame 7 and the lower coaxial frame 13 at both ends of the outer casing 10. The pin assembly mainly includes a pin 29, a torsion spring 30, a movable ring 31, and a secondary rope 2.

[0048] Specifically, such as Figure 2 and 3 As shown, the pin 29 is a conical block or a triangular plate. A clearance groove is provided on the main shaft 3 below the upper horizontal partition 4. The shape of the clearance groove is adapted to the shape of the pin 29 so that the pin 29 can enter and exit the clearance groove. The pin 29 and the torsion spring 30 are disposed within the clearance groove. The torsion spring 30 connects to the pin 29, causing the pin 29 to extend and press against the upper horizontal partition 4.

[0049] The movable ring 31 is sleeved on the main shaft 3, and the auxiliary rope 2 is connected to the movable ring 31. The auxiliary rope 2 can pull the movable ring 31 to move along the main shaft 3. When it moves to the pin 29, it squeezes the pin 29 to retract the pin 29, thereby releasing the upper horizontal partition 4.

[0050] The number of auxiliary ropes 2 can be set to one or more. In order to ensure that the movable ring 31 is as balanced as possible when it is pulled, in this embodiment, the number of auxiliary ropes 2 is set to two, and the two auxiliary ropes 2 are respectively connected to the opposite sides of the movable ring 31 and located at both ends of a diameter of the movable ring 31.

[0051] Preferably, the top of the pin 29 is provided with a ball bearing 28, and the lower surface of the upper horizontal partition 4 is provided with a groove. The ball bearing 28 can slide along the groove to allow the pin 29 to retract into the clearance groove, thus ensuring that the pin 29 can accurately retract into the clearance groove.

[0052] Furthermore, a limiting ring 27 can be provided on the main shaft 3 above the upper horizontal partition 4. The outer diameter of the limiting ring 27 is larger than the inner diameter of the movable ring 31. After the auxiliary rope 2 pulls the movable ring 31 to release the upper horizontal partition 4, it continues to move along the main shaft 3. The limiting ring 27 blocks the movement of the movable ring 31, preventing the movable ring 31 from falling off.

[0053] In addition, the bottom of the lower coaxial frame 13 is provided with multiple telescopic rods 17. The telescopic rods 17 are retracted to their shortest length before the outer shell 10 is lowered into the water, and extended when the water is taken out of the outer shell 10 and placed on the ground, so that the bottom of the outer shell 10 is a certain distance from the bottom surface, which facilitates the concentration operation of the water collected inside the outer shell 10 from the bottom of the outer shell 10.

[0054] The concentration assembly is used to collect microplastics from the water collected inside the shell. The concentration assembly includes a funnel cup 19, a filter cartridge 21, a conical flask 24, and a vacuum pump 26.

[0055] Specifically, such as Figure 1 As shown, the outer casing 10 is provided with a water stop valve 14 and a water outlet pipe. The water stop valve 14 is specifically installed in the inner ring of the lower coaxial frame 13. The water stop valve 14 is connected to a detachable connector 15, and the water outlet pipe is connected through the detachable connector 15.

[0056] The upper part of the funnel cup 19 is used to collect the water from the outlet pipe, and the lower part is connected to the filter cylinder 21. A dust cover 18 is provided on the upper part of the funnel cup 19. Multiple filter cylinders 21 can be provided according to experimental needs, and these multiple filter cylinders 21 are connected sequentially by aluminum alloy clips 20. A support mesh is provided inside each filter cylinder 21, and a filter membrane is placed on the support mesh; different specifications of filter membranes can be placed according to experimental requirements.

[0057] The mouth of the conical flask 24 is connected to the lower end of the filter cartridge 21, and the vacuum pump 26 is connected to the mouth of the conical flask 24 via a pipe. Specifically, the lower end of the bottom filter cartridge 21 is connected to a filter head 22, which is a three-stage stepped tube with a smaller diameter in the middle and larger diameters at the top and bottom. The lower end of the filter head 22 is fitted onto the mouth of the conical flask 24 for a sealed connection. The vacuum pump 26 is an oil-free vacuum pump, and the outer wall of the lower end of the filter head 22 has an air outlet 23, which is connected to the air outlet 23 via a flexible hose 25. The vacuum pump 26 creates a negative pressure at the mouth of the conical flask 24, causing water to flow into the conical flask 24, while microplastics are filtered down by the filter membrane.

[0058] It should be noted that, apart from the glass plate 11 being made of glass, all other components of the collection device are made of metal, such as stainless steel. This avoids the use of plastic materials, so as to prevent the introduction of microplastics during the sampling process and the contamination of the sample.

[0059] In addition, such as Figure 1 and 2 As shown, based on the above-mentioned device for collecting microplastics in water, embodiments of the present invention also provide a method for collecting microplastics in water, comprising the following steps:

[0060] S1. Place the collection device in the water and release the main rope 1 to lower the outer shell 10 to a predetermined height. At this time, the tension spring 9 is in the extended state, the upper horizontal partition 4 is blocked by the pin 29, and water can enter the outer shell 10 through the space between the upper horizontal partition 4 and the upper coaxial frame 7.

[0061] S2. After the outer casing 10 is filled with water, pull up the auxiliary rope 2 to retract the pin 29 into the clearance groove.

[0062] Release the upper horizontal partition 4, and under the action of the tension spring 9, the upper horizontal partition 4 moves downward until the upper horizontal partition 4 covers the upper coaxial frame 7 to seal the upper port of the outer shell 10, and the lower horizontal partition 12 covers the lower coaxial frame 13 to seal the lower port of the outer shell 10, forming a sealed space;

[0063] S3. Lift the main rope 1 to remove the collection device from the water, filter the water inside the outer shell 10 through the concentration component, and collect the microplastics filtered off the filter membrane inside the filter cylinder 21.

[0064] In this document, the directional terms such as front, back, top, and bottom are defined based on the position of the components in the accompanying drawings and their relative positions to each other, solely for the purpose of clarity and convenience in expressing the technical solution. It should be understood that these are relative concepts and can vary depending on different methods of use and placement; the use of these directional terms should not limit the scope of protection claimed in this application.

[0065] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for collecting microplastics in water, characterized in that, include: The cylindrical shell is open at both ends, with an upper coaxial frame at the top and a lower coaxial frame at the bottom. The main shaft has its lower end fixedly connected to the lower coaxial frame and its upper end passing through and fixedly connected to the upper coaxial frame. The upper end of the main shaft is also connected to a main rope. A movable seal includes an upper horizontal partition, a lower horizontal partition, and multiple auxiliary shafts. The lower horizontal partition is located at the lower end of the housing, and the upper horizontal partition is located at the upper end of the housing. Each auxiliary shaft is connected to the upper horizontal partition at its upper end, passes through the upper coaxial frame at its upper middle part, is connected to the lower horizontal partition at its lower middle part, and passes through the lower coaxial frame at its lower end, so that the upper and lower horizontal partitions can move up and down to seal the upper and lower coaxial frames. The middle part of the main shaft passes through the upper and lower horizontal partitions. Multiple tension springs, each of which is fixedly connected to the upper horizontal partition at its upper end and to the inner wall of the outer shell at its lower end; The assembly includes a pin, a torsion spring, a movable ring, and a secondary rope. A clearance groove is provided on the main shaft below the upper horizontal partition. The pin and the torsion spring are disposed in the clearance groove. The torsion spring connects to the pin, causing the pin to extend and press against the upper horizontal partition. The movable ring is sleeved on the main shaft. The secondary rope connects to the movable ring, pulling the movable ring to squeeze the pin, causing the pin to retract and thus releasing the upper horizontal partition.

2. The device for collecting microplastics in water as described in claim 1, characterized in that: The pin is a conical block or a triangular plate.

3. The device for collecting microplastics in water as described in claim 1, characterized in that: The top of the pin is provided with a ball bearing, and the lower surface of the upper horizontal partition is provided with a groove. The ball bearing can slide along the groove to retract the pin into the clearance groove.

4. The device for collecting microplastics in water as described in claim 1, characterized in that: A limiting ring is provided on the main shaft above the upper horizontal partition.

5. The device for collecting microplastics in water as described in claim 1, characterized in that: The number of auxiliary ropes is set to two, and the two auxiliary ropes are respectively connected to the opposite sides of the movable ring.

6. The device for collecting microplastics in water as described in claim 1, characterized in that: The upper coaxial frame and the lower coaxial frame have the same structure, both including an inner ring, an outer ring disposed around the inner ring, and multiple connecting rods connecting the inner ring and the outer ring. Both the upper surface of the inner ring and the upper surface of the outer ring are provided with sealing rings.

7. The device for collecting microplastics in water as described in claim 1, characterized in that: The sidewall of the outer casing is fitted with a transparent glass plate, and the glass plate is marked with scale marks.

8. The device for collecting microplastics in water as described in claim 1, characterized in that: It includes multiple telescopic rods located at the bottom of the lower coaxial frame.

9. The device for collecting microplastics in water as described in claim 1, characterized in that: It also includes a concentration component. The outer shell is equipped with a stop valve and a water outlet pipe connected to the stop valve. The concentration component includes a funnel cup, a filter cylinder, a conical flask, and a vacuum pump. The upper part of the funnel cup is used to receive the water outlet from the water outlet pipe, and the lower part is connected to the filter cylinder. The filter cylinder is equipped with a support mesh, and a filter membrane is placed on the support mesh. The lower end of the filter cylinder is connected to a filter head, and the lower end of the filter head is connected to the mouth of the conical flask. The vacuum pump is connected to the filter head through a pipe.

10. A method for collecting microplastics in water, characterized in that: Using a water microplastics collection device as described in any one of claims 1 to 9, and comprising the following steps: S1. Place the collection device in water and release the main rope to lower the outer shell to a predetermined height; S2. After the outer shell is filled with water, pull up the auxiliary rope to retract the pin into the clearance groove, release the upper horizontal partition, and under the action of the tension spring, the upper horizontal partition moves down until the upper horizontal partition blocks the upper coaxial frame and the lower horizontal partition blocks the lower coaxial frame. S3. Raise the main rope to remove the collection device from the water, filter the water inside the shell, and collect microplastics.

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