CN116282718A - Device and method for automatically extracting micro-plastic fibers in large amount of water body - Google Patents

Abstract

The invention discloses a device and a method for automatically extracting micro plastic fibers in a large amount of water, and belongs to the technical field of micro plastic extraction. The device comprises a filter cartridge and an automatic induction cleaning mechanism arranged on the outer side of the filter cartridge, wherein a water inlet, a plurality of microporous nets and a water outlet are sequentially arranged in the filter cartridge from top to bottom, and the pore diameters of the microporous nets are sequentially reduced from top to bottom; the automatic induction cleaning mechanism comprises a rotating main rod, a connecting rope and a scraping layer, the rotating main rod is connected with a steel wire roller through the connecting rope, the rotating main rod rotates and drives the steel wire roller to move through the connecting rope, and a bidirectional opening and closing door is arranged between the filter cartridge and the automatic induction cleaning mechanism. The invention can sense in real time, automatically clear up blockage, separate a large number of micro plastic fibers in water, partition the large number of micro plastic fibers according to the size to obtain the size distribution rule, and each layer of screening can be adjusted according to the actual situation, thereby being more suitable for separating the micro plastic fibers in a large number of water.

Description

Device and method for automatically extracting micro-plastic fibers in large amount of water body

Technical Field

The invention relates to a device and a method for automatically extracting micro plastic fibers in a large amount of water, and belongs to the technical field of micro plastic extraction.

Background

After the plastic product is worn and degraded in the environment, the plastic product can be further decomposed into microplastic with the particle size smaller than 5mm. Microplastic may pose a risk to the ecological environment and human health, and is a new contaminant of great concern. The fibrous microplastic is called microplastic fiber, and is an important component of microplastic pollution in water. In recent years, research on microplastic fibers has been directed mainly to the relative lack of research on their separation in terms of occurrence.

At present, the separation of the micro plastic fibers of the water body is mainly based on the technologies of screening filtration, density separation, digestion and the like, and the screening filtration is mainly based on the laboratory water body. The common screening filtration is only suitable for experimental water bodies with simple components and less total amount, if a large amount of experimental water bodies are to be separated, the blocking is required to be manually treated and repeated filtration is carried out for many times, time and labor are wasted, and the micro plastic fibers with different sizes in a large amount of water bodies cannot be collected in a partitioning manner, so that the size distribution rule of the micro plastic fibers in various water bodies cannot be obtained.

Disclosure of Invention

In order to solve the problems, the invention provides the device and the method for automatically extracting the micro plastic fibers in a large amount of water, which can sense in real time, automatically clean and block the micro plastic fibers in a large amount of water, partition the large amount of micro plastic fibers according to the size, and adjust each layer of screening according to the actual situation, so that the device and the method are more suitable for separating the micro plastic fibers in a large amount of water.

The first object of the invention is to provide a device for automatically extracting a large amount of micro plastic fibers in a water body, which comprises a filter cartridge and an automatic induction cleaning mechanism arranged outside the filter cartridge, wherein a water inlet, a plurality of microporous meshes and a water outlet are sequentially arranged in the filter cartridge from top to bottom, and the pore diameters of the microporous meshes are sequentially reduced from top to bottom; the automatic induction cleaning mechanism comprises a rotary main rod, a connecting rope and a scraping layer, wherein the rotary main rod is connected with a steel wire roller through the connecting rope, the rotary main rod rotates and drives the steel wire roller to move through the connecting rope, and a bidirectional opening and closing door is arranged between the filter cartridge and the automatic induction cleaning mechanism; the steel wire roller passes through the bidirectional opening and closing door, enters the filter cartridge and moves on the microporous net so as to clean micro plastic fibers on the microporous net; the steel wire roller penetrates through the two-way opening and closing door, enters the automatic induction cleaning mechanism and moves on the scraping layer so as to scrape micro-plastic fibers attached to the steel wire roller.

In one embodiment of the invention, the automatic induction cleaning mechanism comprises an inner wall and an outer wall, wherein the inner wall is attached to the filter cartridge, the rotary main rod is positioned between the inner wall and the outer wall, a plurality of collecting spaces are formed between the inner wall and the outer wall, the upper ends of the collecting spaces are of an opening structure, the lower ends of the collecting spaces are provided with filter membranes, the scraping layer is arranged on the outer wall on one side of the collecting spaces, and the bidirectional opening and closing door is arranged on the inner wall on the other side of the collecting spaces.

In one embodiment of the invention, a plurality of accommodating cavities are arranged between the inner wall and the outer wall, the accommodating cavities are positioned below the collecting space, the filter membrane is positioned on the upper end face of the accommodating cavities, an access opening is formed in one side of each accommodating cavity, a pipeline is arranged in each access opening, one end of each pipeline stretches into the lower part of the corresponding filter membrane, the other end of each pipeline is connected with an air pump, the air pumps are used for exhausting air, and in the process that air flows from the upper end opening of the collecting space to the filter membrane, micro plastic fibers scraped on the scraping layer are driven to fall and are collected on the filter membrane.

In one embodiment of the invention, a water outlet pipe is arranged in the accommodating cavity, one end of the water outlet pipe is positioned below the filter membrane, the other end of the water outlet pipe penetrates through the outer wall and extends out of the outer wall, the micro-plastic fiber is trapped above the filter membrane by the filter membrane, and the wastewater is discharged through the water outlet pipe below the filter membrane.

In one embodiment of the invention, a knob is further arranged on one side of the accommodating cavity, the accommodating cavity is detachably connected between the inner wall and the outer wall, and the accommodating cavity is pulled out through the knob.

In one embodiment of the invention, a hollow interlayer is arranged between the accommodating cavity and the collecting space below the accommodating cavity, the hollow interlayer is positioned between the inner wall and the outer wall, and one side of the hollow interlayer is of an opening structure.

In one embodiment of the invention, the bidirectional opening and closing door is in a disc shape, and the sectional area of the bidirectional opening and closing door is larger than that of the steel wire roller, so that the steel wire roller can pass through the bidirectional opening and closing door; the automatic induction cleaning mechanism further comprises a circuit main switch, the rotating main rod is connected with a driving mechanism, the driving mechanism is used for driving the rotating main rod to rotate, the circuit main switch is connected with the driving mechanism, and the circuit main switch is used for controlling the switch of the driving mechanism.

In one embodiment of the invention, the microporous net is detachably fixed on the inner wall of the filter cartridge through a spring clamping groove, the microporous nets comprise a first microporous net, a second microporous net, a third microporous net and a fourth microporous net, the first microporous net, the second microporous net, the third microporous net and the fourth microporous net are sequentially arranged from top to bottom, and the pore diameters of the meshes are sequentially reduced from top to bottom; a water pressure detector is arranged below each microporous net.

In one embodiment of the invention, a biochar adsorption layer is further arranged in the filter cartridge, the biochar adsorption layer is positioned between the fourth microporous net and the water outlet, the biochar adsorption layer is fixed on the inner wall of the filter cartridge through a fixing knob, and the fixing knob is arranged on the outer wall of the filter cartridge.

The second object of the present invention is to provide a method for automatically extracting micro plastic fibers in a large amount of water, which uses the device for automatically extracting micro plastic fibers in a large amount of water, comprising the following steps:

1. adding collected household washing wastewater into a water inlet, sequentially filtering the wastewater through a plurality of microporous meshes and a biochar adsorption layer after the wastewater enters the water inlet, and discharging the household washing wastewater with less component impurities through a water outlet after the treatment;

2. automatic induction cleaning of micro plastic fibers; under normal filtration conditions: when the water pressure detector detects continuous water pressure, the steel wire roller is in a static state in the automatic induction cleaning mechanism; filter clogging or filter end state: the water pressure detector continuously senses no water pressure for 1min, at the moment, the microporous net is blocked by micro plastic fibers in a large amount of washing wastewater or filtration is finished, the steel wire roller passes through the bidirectional opening and closing door and enters the filter cylinder, the rotating total rod rotates and drives the steel wire roller to move on the microporous net through the connecting rope so as to automatically clean and collect the micro plastic fibers on the microporous net, until the water pressure detector can detect continuous water pressure again, the steel wire roller passes through the bidirectional opening and closing door and enters a collecting space of the automatic induction cleaning mechanism, and the rotating total rod rotates and drives the steel wire roller to move on the scraping layer through the connecting rope so as to scrape the micro plastic fibers attached on the steel wire roller until filtration of household washing wastewater is finished;

3. characterization of micro plastic fibers; after the partition extraction and collection are finished, controlling an air pump to start suction filtration, driving micro-plastic fibers scraped on the scraping layer to fall down and collect on the filter membrane in the process that air flows from the upper end opening of the collection space to the filter membrane, collecting the micro-plastic fibers in each region on the surface of the filter membrane after the end, taking out the filter membrane by a knob, and discharging redundant wastewater through a water outlet pipe; placing the taken-out filter membrane under a stereoscopic microscope for 80 times of observation; the filter membrane is placed under a scanning electron microscope to observe the morphology, the accelerating voltage is 4kV, and the magnification is 500;

4. qualitative property of the micro plastic fiber; analyzing microplastic fiber on filter membrane by using Fourier transform microscopic infrared spectrometer, and scanning with 4000-700cm ^-1 The number of scans was 16, the spectral resolution was 4cm ^-1 Collecting infrared spectrum of a sample, and searching and analyzing characteristic spectrum to determine the type of the micro plastic;

5. counting the size of the micro plastic fiber; the areas with different sizes are numbered a, b, c, d, and the sizes of the corresponding micro plastic fibers under the initial conditions are 5-1.5 mm, 1.5-0.5 mm, 0.5-0.1 mm and 0.1-0.05 mm respectively; and carrying out statistical analysis on the micro plastic fibers on the filter membrane in different areas by using software Image J to obtain the size distribution rule of the micro plastic fibers in the washing wastewater.

Advantageous effects

(1) The invention can sense and automatically clear the blockage and separate a large number of micro plastic fibers in the water body in real time, simultaneously can partition the large number of micro plastic fibers according to the size, can adjust each layer of screening according to the actual situation, is more suitable for separating the micro plastic fibers in the large number of water bodies, can automatically clear and collect the micro plastic fibers blocked on the microporous net during the filtration, and can automatically scrape and collect the micro plastic fibers.

(2) The invention separates and extracts a large amount of water, effectively solves the blocking condition caused by excessive micro plastic fibers in the water, can automatically select size distribution according to actual conditions, and has the advantages of high extraction rate, strong timeliness, convenient operation, reusability and the like.

(3) The invention is convenient for the experimenter to separate a large amount of water bodies and obtain experimental data of the micro plastic fibers with different sizes, has high extraction rate, is convenient to operate and can be reused.

(4) According to the invention, the micro plastic fibers with different sizes in a large amount of water samples can be collected in a partitioned manner, and then the corresponding micro plastic fibers are obtained through suction filtration in the corresponding area, so that the distribution rule of the micro plastic fibers in a large amount of washing wastewater is further obtained, the operation is convenient, and the efficiency is high.

Drawings

FIG. 1 is a schematic structural view of an apparatus for automatically extracting microplastic fibers from a large volume of water according to the present invention;

FIG. 2 is a schematic diagram of an auto-induction cleaning mechanism according to the present invention;

FIG. 3 is a perspective view of an extracted microplastic fiber of the present invention;

FIG. 4 is a drawing of an extracted microplastic fiber of the present invention under a scanning electron microscope;

FIG. 5 is a distribution of microplastic sizes in a large amount of household washing wastewater extracted by the present invention.

In the figure: 1. a water inlet; 2. a spring clamping groove; 3. a two-way opening and closing door, 4 and a steel wire roller; 5. a water pressure detector; 6. a first microporous web; 7. a second microporous web; 8. a third microporous web; 9. a fourth microporous web; 10. a biochar adsorption layer; 11. fixing a knob; 12. a water outlet; 13. a filter cartridge; 14. an automatic induction cleaning mechanism; 15. rotating the main rod; 16. a connecting rope; 17. scraping the layer; 18. a pipe; 19. an air extracting pump; 20. a filter membrane; 21. a knob; 22. a water outlet pipe; 23. a circuit main switch; 24. an outer wall; 25. an access port; 26. a receiving chamber; 27. a collection space; 28. a hollow interlayer; 29. an inner wall.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the present invention, unless explicitly specified and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

Example 1

As shown in fig. 1 and 2, the embodiment provides a device for automatically extracting micro plastic fibers in a large amount of water, which comprises a filter cartridge 13 and an automatic induction cleaning mechanism 14 arranged on the outer side of the filter cartridge 13, wherein a water inlet 1, a plurality of microporous meshes and a water outlet 12 are sequentially arranged in the filter cartridge 13 from top to bottom, and the pore diameters of the meshes of the microporous meshes are sequentially reduced from top to bottom; the automatic induction cleaning mechanism 14 comprises a rotary total rod 15, a connecting rope 16 and a scraping layer 17, wherein the rotary total rod 15 is connected with the steel wire roller 4 through the connecting rope 16, the rotary total rod 15 rotates and drives the steel wire roller 4 to move through the connecting rope 16, and a bidirectional opening and closing door 3 is arranged between the filter cartridge 13 and the automatic induction cleaning mechanism 14; the steel wire roller 4 passes through the bidirectional opening and closing door 3, enters the filter cylinder 13 and moves on the microporous net so as to clean micro plastic fibers on the microporous net; the steel wire roller 4 passes through the bidirectional opening and closing door 3, enters the automatic induction cleaning mechanism 14 and moves on the scraping layer 17 so as to scrape the micro plastic fibers attached to the steel wire roller 4.

Optionally, the microporous net is detachably fixed on the inner wall of the filter cartridge 13 through the spring clamping groove 2, the fixing mode is convenient for the microporous net to be detached and replaced, the microporous net comprises a first microporous net 6, a second microporous net 7, a third microporous net 8 and a fourth microporous net 9, the first microporous net 6, the second microporous net 7, the third microporous net 8 and the fourth microporous net 9 are sequentially arranged from top to bottom, and the pore diameters of the meshes are sequentially reduced from top to bottom. Optionally, the first microporous mesh 6 is a 2 mesh microporous mesh; the second microporous net 7 is a 13-mesh microporous net; the third microporous net 8 is a 100-mesh microporous net; the fourth microporous net 9 is a 200-mesh microporous net; wherein, the material of the micropore net is preferably copper. The microporous net can be freely detached, can be replaced by other proper sizes according to actual conditions, and can be used for adjusting the distribution of a plurality of microporous nets in the vertical direction according to actual water sample requirements.

Optionally, a water pressure detector 5 is arranged below each of the microporous webs. The water pressure detector 5 detects the water pressure below the microporous net, if the water pressure is smaller or the water pressure is not felt, the microporous net is blocked by the micro plastic fibers in a large amount of washing wastewater, and at the moment, the automatic induction cleaning mechanism 14 controls the steel wire roller 4 to clean the microporous net, so that the microporous net is prevented from being blocked due to overlarge fiber quantity.

Optionally, a biochar adsorption layer 10 is further disposed in the filter cartridge 13, the biochar adsorption layer 10 is located between the fourth microporous net 9 and the water outlet 12, the biochar adsorption layer 10 is fixed on the inner wall of the filter cartridge 13 through a fixing knob 11, and the fixing knob 11 is disposed on the outer wall of the filter cartridge 13. The biochar adsorption layer 10 is convenient to detach and replace through the fixed knob 11, the biochar adsorption layer 10 is used for cleaning impurities, a large amount of water bodies are filtered by the microporous net and the biochar adsorption layer 10, and the water bodies with less component impurities can be discharged through the water outlet 12 so as to meet other experimental requirements.

Optionally, the filter cartridge 13 is made of organic glass, and has a length of 400-450mm and a diameter of 200-250mm; the water inlet 1 is a spiral water inlet and is convenient to connect with a waste water port; the diameter of the wire roll 4 is not more than 100-125mm.

Optionally, the automatic induction cleaning mechanism 14 is a double-layer structure, and comprises an inner wall 29 and an outer wall 24, the inner wall 29 is attached to the filter cartridge 13, the rotary total rod 15 is located between the inner wall 29 and the outer wall 24, a plurality of collecting spaces 27 are formed between the inner wall 29 and the outer wall 24, the upper ends of the collecting spaces 27 are of an opening structure, the lower ends of the collecting spaces are provided with filter membranes 20, the scraping layer 17 is arranged on the outer wall 24 on one side of the collecting spaces 27, and the bidirectional opening and closing door 3 is arranged on the inner wall 29 on the other side of the collecting spaces 27. Optionally, both the inner wall 29 and the outer wall 24 are arcuate.

Optionally, a plurality of accommodating chambers 26 are disposed between the inner wall 29 and the outer wall 24, the accommodating chambers 26 are located below the collecting space 27, the filter membrane 20 is located on an upper end surface of the accommodating chambers 26, an access port 25 is formed in one side of the accommodating chambers 26, a pipeline 18 is disposed in the access port 25, one end of the pipeline 18 extends into the lower portion of the filter membrane 20, and an air pump 19 is connected to the other end of the pipeline 18. The suction is performed by the suction pump 19, and in the process that the air flow flows to the filter membrane 20 from the upper end opening of the collecting space 27, the micro plastic fibers scraped on the scraping layer 17 are driven to fall and collected on the filter membrane 20. Alternatively, one of the suction pumps 19 may be connected to a plurality of pipes 18, and the micro plastic fibers in the plurality of collecting spaces 27 are simultaneously sucked by one suction pump 19.

Optionally, a water outlet pipe 22 is disposed in the accommodating cavity 26, one end of the water outlet pipe 22 is located below the filter membrane 20, and the other end passes through the outer wall 24 and extends out of the outer wall 24. Since the waste water is adhered to the scraping layer 17 and the micro plastic fibers on the steel wire roller 4, the micro plastic fibers are trapped above the filter membrane 20 by the filter membrane 20, and the waste water is discharged through the water outlet pipe 22 below the filter membrane 20.

Optionally, a knob 21 is further disposed at one side of the accommodating cavity 26, the accommodating cavity 26 is detachably connected between the inner wall 29 and the outer wall 24, and the accommodating cavity 26 is drawn out through the knob 21, so that the micro plastic fibers on the filter membrane 20 in the accommodating cavity 26 are collected, and meanwhile, the filter membrane 20 is convenient to replace.

Optionally, a hollow partition 28 is disposed between the accommodating cavity 26 and the collecting space 27 below the accommodating cavity, the hollow partition 28 is located between the inner wall 29 and the outer wall 24, and one side of the hollow partition 28 is in an open structure. For the collecting space 27 located below, an auxiliary tool can be used to extend into the collecting space 27 from the opening on the side of the hollow partition 28 and the opening on the top end of the collecting space 27 below, and the wire roller 4 in the collecting space 27 can be inserted into the filter cartridge 13 from the two-way opening and closing door 3, or the wire roller 4 can be taken out from the filter cartridge 13 into the collecting space 27. For the collecting space 27 located above, an auxiliary tool can be used to directly extend into the collecting space 27 from the opening of the top end of the collecting space 27 above, so that the wire roller 4 passes through the two-way opening and closing door 3.

Optionally, the bidirectional opening and closing door 3 is in a shape of a circular plate, and a sectional area of the bidirectional opening and closing door 3 is larger than a sectional area of the wire roller 4, so that the wire roller 4 can pass through the bidirectional opening and closing door 3. The bidirectional opening and closing door 3 can be controlled to open and close by a toggle button. The two-way opening and closing door 3 can be completely closed under the suction filtration state so as to ensure the space to be closed.

Optionally, the automatic induction cleaning mechanism 13 further includes a circuit main switch 23, the rotating main rod 15 is connected with a driving mechanism, the driving mechanism is used for driving the rotating main rod 15 to rotate, the circuit main switch 23 is connected with the driving mechanism, and the circuit main switch 23 is used for controlling the switch of the driving mechanism. Preferably, the driving mechanism is a motor.

Example 2

The present embodiment provides a method for automatically extracting micro plastic fibers in a large amount of water, the method using the device provided in embodiment 1, comprising the steps of:

1. adding a large amount of collected household washing wastewater into the water inlet 1, filtering the wastewater through a plurality of microporous meshes and a biochar adsorption layer 10 in sequence after the wastewater enters the water inlet 1, and discharging the household washing wastewater with fewer component impurities through a water outlet 12 after the treatment;

2. automatic induction cleaning of micro plastic fibers; under normal filtration conditions: when the water pressure detector 5 detects continuous water pressure, the steel wire roller 4 is in a static state in the automatic induction cleaning mechanism 14; filter clogging or filter end state: the water pressure detector 5 senses no water pressure for 1min, at this time, the microporous net is blocked by micro plastic fibers in a large amount of washing wastewater or filtration is finished, the steel wire roller 4 passes through the bidirectional opening and closing door 3 and enters the filter cylinder 13, the rotating total rod 20 rotates and drives the steel wire roller 4 to move on the microporous net through the connecting rope 16 to automatically clean and collect the micro plastic fibers on the microporous net until the water pressure detector 5 can detect continuous water pressure again, the steel wire roller 4 passes through the bidirectional opening and closing door 3 and enters the collecting space 27 of the automatic sensing cleaning mechanism 14, and the rotating total rod 20 rotates and drives the steel wire roller 4 to move on the scraping layer 17 through the connecting rope 16 to scrape the micro plastic fibers attached on the steel wire roller 4 until filtration of a large amount of household washing wastewater is finished;

3. characterization of micro plastic fibers; after the partition extraction and collection are finished, controlling an air pump 19 to start suction filtration, driving micro-plastic fibers scraped on the scraping layer 17 to fall and collect on the filter membrane 20 in the process that air flows from the upper end opening of the collection space 27 to the filter membrane 20, collecting the micro-plastic fibers in each region on the surface of the filter membrane 20 after the end, taking out the filter membrane 20 by a knob 21, and discharging redundant wastewater through a water outlet pipe 22; the removed filter 20 was placed under a stereoscopic microscope and observed at 80-fold magnification, the results are shown in FIG. 3; the filter membrane 20 is placed under a scanning electron microscope to observe the morphology, the accelerating voltage is 4kV, the magnification is 500, and the result is shown in figure 4;

4. qualitative property of the micro plastic fiber; the microplastic fibers on the filter membrane 20 were analyzed using a Fourier transform micro-infrared spectrometer, scanning range of 4000-700cm ^-1 The number of scans was 16, the spectral resolution was 4cm ^-1 Collecting infrared spectrum of a sample, and searching and analyzing characteristic spectrum to determine the type of the micro plastic;

5. counting the size of the micro plastic fiber; the areas with different sizes are numbered a, b, c, d, and the sizes of the corresponding micro plastic fibers under the initial conditions are 5-1.5 mm, 1.5-0.5 mm, 0.5-0.1 mm and 0.1-0.05 mm respectively; the statistical analysis of the micro plastic fibers on the filter membrane 20 in different areas is performed by using the software Image J to obtain the size distribution rule of the micro plastic fibers in a large amount of washing wastewater, and the result is shown in fig. 5.

According to the embodiment, the workload of extracting a large amount of micro plastic fibers in experimental water can be obviously reduced, experimental data of micro plastic fibers with different sizes can be obtained, and the method has the advantages of high separation rate, convenience in operation, reusability and the like.

While the invention has been described with reference to the preferred embodiments, it is not limited thereto, and various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (10)

1. The device for automatically extracting the micro plastic fibers in a large amount of water is characterized by comprising a filter cartridge (13) and an automatic induction cleaning mechanism (14) arranged on the outer side of the filter cartridge (13), wherein a water inlet (1), a plurality of micro-pore nets and a water outlet (12) are sequentially arranged in the filter cartridge (13) from top to bottom, and the pore diameters of the meshes of the micro-pore nets are sequentially reduced from top to bottom; the automatic induction cleaning mechanism (14) comprises a rotary total rod (15), a connecting rope (16) and a scraping layer (17), wherein the rotary total rod (15) is connected with a steel wire roller (4) through the connecting rope (16), the rotary total rod (15) rotates and drives the steel wire roller (4) to move through the connecting rope (16), and a bidirectional opening and closing door (3) is arranged between the filter cartridge (13) and the automatic induction cleaning mechanism (14); the steel wire roller (4) passes through the bidirectional opening and closing door (3) to enter the filter cartridge (13) and moves on the microporous net so as to clean micro plastic fibers on the microporous net; the steel wire roller (4) passes through the bidirectional opening and closing door (3) to enter the automatic induction cleaning mechanism (14) and moves on the scraping layer (17) so as to scrape micro plastic fibers attached to the steel wire roller (4).

2. The device for automatically extracting a large amount of micro plastic fibers in a water body according to claim 1, wherein the automatic induction cleaning mechanism (14) comprises an inner wall (29) and an outer wall (24), the inner wall (29) is attached to the filter cartridge (13), the rotary total rod (15) is located between the inner wall (29) and the outer wall (24), a plurality of collecting spaces (27) are formed between the inner wall (29) and the outer wall (24), the upper end of the collecting spaces (27) is of an opening structure, the lower end of the collecting spaces is provided with a filter membrane (20), the scraping layer (17) is arranged on the outer wall (24) on one side of the collecting spaces (27), and the bidirectional opening and closing door (3) is arranged on the inner wall (29) on the other side of the collecting spaces (27).

3. The device for automatically extracting a large amount of micro plastic fibers in a water body according to claim 2, wherein a plurality of accommodating cavities (26) are arranged between the inner wall (29) and the outer wall (24), the accommodating cavities (26) are positioned below the collecting space (27), the filter membrane (20) is positioned on the upper end face of the accommodating cavities (26), an access opening (25) is formed in one side of the accommodating cavities (26), a pipeline (18) is arranged in the access opening (25), one end of the pipeline (18) stretches into the lower portion of the filter membrane (20), an air pump (19) is connected to the other end of the pipeline (18), the air pump (19) is used for pumping air, and in the process that air flows from the upper end opening of the collecting space (27) to the filter membrane (20), micro plastic fibers scraped on the scraping layer (17) are driven to fall down and are collected on the filter membrane (20).

4. A device for automatically extracting micro plastic fibers in a large amount of water according to claim 3, wherein a water outlet pipe (22) is arranged in the accommodating cavity (26), one end of the water outlet pipe (22) is positioned below the filter membrane (20), the other end of the water outlet pipe passes through the outer wall (24) and extends out of the outer wall (24), the micro plastic fibers are trapped above the filter membrane (20) by the filter membrane (20), and the waste water is discharged through the water outlet pipe (22) below the filter membrane (20).

5. A device for automatically extracting micro-plastic fibers in a large quantity of water according to claim 3, characterized in that a knob (21) is further arranged on one side of the accommodating cavity (26), the accommodating cavity (26) is detachably connected between the inner wall (29) and the outer wall (24), and the accommodating cavity (26) is extracted through the knob (21).

6. A device for automatically extracting micro-plastic fibers from a large amount of water according to claim 3, characterized in that a hollow partition (28) is arranged between the accommodating cavity (26) and the collecting space (27) below the accommodating cavity, the hollow partition (28) is arranged between the inner wall (29) and the outer wall (24), and one side of the hollow partition (28) is of an opening structure.

7. The device for automatically extracting micro plastic fibers in a large amount of water according to claim 1, wherein the bidirectional opening and closing door (3) is disc-shaped, and the sectional area of the bidirectional opening and closing door (3) is larger than the sectional area of the steel wire roller (4), so that the steel wire roller (4) can pass through the bidirectional opening and closing door (3); the automatic induction cleaning mechanism 13 further comprises a circuit main switch (23), the rotating main rod (15) is connected with a driving mechanism, the driving mechanism is used for driving the rotating main rod (15) to rotate, the circuit main switch (23) is connected with the driving mechanism, and the circuit main switch (23) is used for controlling the switch of the driving mechanism.

8. The device for automatically extracting micro plastic fibers in a large amount of water according to claim 1, wherein the micro pore net is detachably fixed on the inner wall of the filter cartridge (13) through a spring clamping groove (2), a plurality of micro pore nets comprise a first micro pore net (6), a second micro pore net (7), a third micro pore net (8) and a fourth micro pore net (9), the first micro pore net (6), the second micro pore net (7), the third micro pore net (8) and the fourth micro pore net (9) are sequentially arranged from top to bottom, and the pore diameters of meshes are sequentially reduced from top to bottom; a water pressure detector (5) is arranged below each microporous net.

9. The device for automatically extracting micro plastic fibers in a large amount of water according to claim 8, wherein a biochar adsorption layer (10) is further arranged in the filter cartridge (13), the biochar adsorption layer (10) is positioned between the fourth microporous net (9) and the water outlet (12), the biochar adsorption layer (10) is fixed on the inner wall of the filter cartridge (13) through a fixing knob (11), and the fixing knob (11) is arranged on the outer wall of the filter cartridge (13).

10. A method for automatically extracting micro plastic fibers in a large amount of water, characterized in that the device for automatically extracting micro plastic fibers in a large amount of water according to any one of claims 1 to 9 is applied, comprising the following steps:

1. adding collected household washing wastewater into a water inlet (1), sequentially filtering the wastewater through a plurality of microporous meshes and a biochar adsorption layer (10) after the wastewater enters the water inlet (1), and discharging the household washing wastewater with less component impurities through a water outlet (12);

2. automatic induction cleaning of micro plastic fibers; under normal filtration conditions: when the water pressure detector (5) detects continuous water pressure, the steel wire roller (4) is in a static state in the automatic induction cleaning mechanism (14); filter clogging or filter end state: the water pressure detector (5) senses no water pressure for 1min, at the moment, the micro-porous net is blocked by micro-plastic fibers in a large amount of washing wastewater or filtration is finished, the steel wire roller (4) passes through the bidirectional opening and closing door (3) to enter the filter cylinder (13), the rotary total rod (20) rotates and drives the steel wire roller (4) to move on the micro-porous net through the connecting rope (16) so as to automatically clean and collect the micro-plastic fibers on the micro-porous net, until the water pressure detector (5) can detect the continuous water pressure again, the steel wire roller (4) passes through the bidirectional opening and closing door (3) to enter the collecting space (27) of the automatic sensing cleaning mechanism (14), and the rotary total rod (20) rotates and drives the steel wire roller (4) to move on the scraping layer (17) through the connecting rope (16) so as to scrape the micro-plastic fibers attached on the steel wire roller (4) until filtration of household washing wastewater is finished;

3. characterization of micro plastic fibers; after the partition extraction and collection are finished, controlling an air pump (19) to start suction filtration, driving micro-plastic fibers scraped on a scraping layer (17) to fall and collect on the filter membrane (20) in the process that air flows from an upper end opening of a collection space (27) to the filter membrane (20), collecting the micro-plastic fibers in each region on the surface of the filter membrane (20), taking out the filter membrane (20) by a knob (21), and discharging redundant wastewater through a water outlet pipe (22); placing the removed filter membrane (20) under a stereoscopic microscope for 80 times of observation; the filter membrane (20) is placed under a scanning electron microscope to observe the morphology, the accelerating voltage is 4kV, and the magnification is 500;

4. qualitative property of the micro plastic fiber; analyzing microplastic fibers on a filter membrane (20) using a Fourier transform micro-infrared spectrometer, with a scanning range of 4000-700cm ^-1 The number of scans was 16, the spectral resolution was 4cm ^-1 Collecting infrared spectrum of a sample, and searching and analyzing characteristic spectrum to determine the type of the micro plastic;

5. counting the size of the micro plastic fiber; the areas with different sizes are numbered a, b, c, d, and the sizes of the corresponding micro plastic fibers under the initial conditions are 5-1.5 mm, 1.5-0.5 mm, 0.5-0.1 mm and 0.1-0.05 mm respectively; and carrying out statistical analysis on the micro plastic fibers on the filter membrane (20) in different areas by using the software Image J to obtain the size distribution rule of the micro plastic fibers in the washing wastewater.

Images