Water body separation and filtration device and new pollutant detection system and method

Abstract

The invention relates to the technical field of new pollutant detection, in particular to a water separating and filtering device and a new pollutant detection system and method. The device comprises a separation tank, a first filtering assembly, a second filtering assembly, a foaming assembly and a water injection assembly, the separation tank is fixedly mounted, a discharge pipe is arranged at the bottom of the separation tank and is connected to the upper part of the first filtering assembly, and a valve is arranged at the upper part of the discharge pipe; an overflow port is formed in the upper part of the separation tank and is connected to the upper part of the second filtering assembly through a guide groove; the bubbling assembly comprises an air source and a bubbling head, the bubbling head is installed in the separation tank, and the air source is connected to the bubbling head; the water injection assembly is used for injecting water into the separation tank to raise the water level in the separation tank; the first filtering assembly is used for filtering residual liquid flowing out of the discharge pipe, and the second filtering assembly is used for filtering overflow liquid flowing out of the guide groove. The device can be used for separating the micro-plastics from the water sample to be detected, so that reliable support is provided for detecting the content of the micro-plastics in the water sample.

Description

Technical Field

[0001] The present invention relates to the technical field of new pollutant detection, and particularly relates to a water body separation and filtration device, a new pollutant detection system and method. Background Art

[0002] With the wide use of plastic products, microplastics have been widely present in natural water bodies, and microplastics have thus been listed as a major category of new pollutants (new pollutants refer to a general term for a class of chemical substances that can be detected in the environment and natural ecosystems and can pose greater risks and potential hazards to human health and environmental safety even when entering at low doses. New pollutants mainly include persistent organic pollutants, endocrine disruptors, antibiotics, microplastics, etc.).

[0003] Water quality monitoring is an important part of ecological environment monitoring work. In recent years, when conducting water quality detection work, microplastics are usually detected in water bodies. However, due to the small particle size (less than 5 mm), large variety, and large density difference of microplastics, they are often mixed with impurities such as sediment and organic suspended matter, making it difficult to effectively separate microplastics (for example, when using a filter screen for filtration, interfering particulate impurities of the same size will be mixed into the filtered "target substance"; separation based on density will also cause suspended matter to be mixed in; resulting in a large deviation in the quantitative detection results), making the quantitative detection of microplastics a major challenge in water quality detection. Summary of the Invention

[0004] The purpose of the present invention is to provide a water body separation and filtration device, a new pollutant detection system and method, which can at least partially overcome the above technical problems, can accurately separate the target new pollutant - microplastics from the water sample, and thus provide reliable support for the detection of the microplastic content in the water sample.

[0005] In the first aspect of the present invention, a water body separation and filtration device is provided. The device includes a separation tank, a first filtration component, a second filtration component, a foaming component, and a water injection component; the separation tank is fixedly installed, a discharge pipe is provided at the bottom of the separation tank, the discharge pipe is connected above the first filtration component, and a valve is provided in the upper part of the discharge pipe; an overflow port is provided in the upper part of the separation tank, and the overflow port is connected above the second filtration component through a guide groove; the foaming component includes a gas source and a foaming head, the foaming head is installed inside the separation tank, and the gas source is connected to the foaming head; the water injection component is used to inject water into the separation tank to raise the water level inside the separation tank; the first filtration component is used to filter the remaining liquid flowing out through the discharge pipe, and the second filtration component is used to filter the overflow liquid flowing out through the guide groove.

[0006] Further, the water separation and filtration device further includes a linear motor and a stirring rod. A bracket is fixedly installed on the upper part of the separation tank. The linear motor is fixedly installed on the bracket. The stirring rod includes a vertical section, an inclined section, and an offset section. The vertical section is rotatably connected to the bracket. The offset section is located above the bracket and is smoothly and transitionally connected to the vertical section. The inclined section is located inside the separation tank and is fixedly connected to the vertical section. The free end of the output shaft of the linear motor is rotatably connected to a connecting rod, and the other end of the connecting rod is rotatably connected to the offset section. The bubble head is installed on the inclined section.

[0007] Further, the stirring rod is a hollow rod. The bubble head is fixedly installed at one end of the inclined section away from the vertical section. The air source is connected to the bubble head through an air delivery pipe, and the air delivery pipe is disposed inside the stirring rod.

[0008] Further, the air source includes a cylinder block. The cylinder block is fixedly installed on the bracket. The output shaft penetrates through the cylinder block along the length direction of the cylinder block. A piston body is fixedly installed on the output shaft, and the piston body is located inside the cylinder block. A first air inlet pipe and a first air outlet pipe are provided at one end of the cylinder block, and a second air inlet pipe and a second air outlet pipe are provided at the other end. Check valves are installed on the first air inlet pipe, the first air outlet pipe, the second air inlet pipe, and the second air outlet pipe. The first air outlet pipe and the second air outlet pipe are both connected to the air inlet of a three-way valve. The first air outlet of the three-way valve is connected to the bubble head, and the second air outlet of the three-way valve is connected to the outside.

[0009] Further, the water injection assembly includes a water inlet pipe, a first tapered pipe, and a second tapered pipe. The small end of the first tapered pipe is fixedly connected to the vertical section and the large end faces the discharge pipe. The second tapered pipe is located above the first tapered pipe. The large end of the second tapered pipe faces the discharge pipe. The small end of the second tapered pipe is fixedly connected to the bracket, and the vertical section is inserted into the second tapered pipe. A water storage gap exists between the first tapered pipe and the second tapered pipe, and the width of the water storage gap gradually decreases in the vertically downward direction. The water inlet pipe is connected to the water storage gap.

[0010] Further, a plurality of drainage pipes are fixedly connected to the first tapered pipe. A third tapered pipe is fixedly sleeved on the inclined section. An outflow gap exists between the small end of the third tapered pipe and the outer peripheral wall of the inclined section. The large end of the third tapered pipe is higher than the small end. For any one of the drainage pipes, one end penetrates through the first tapered pipe and is connected to the water storage gap, and the other end is connected to the inside of the third tapered pipe. The positions where the drainage pipes penetrate through the first tapered pipe are circumferentially evenly distributed.

[0011] Furthermore, a water baffle is slidably installed on the separation tank, and the water baffle is located above the overflow port and is slidably connected to the separation tank. By sliding the water baffle, the water baffle can be switched between a first position and a second position; when the water baffle is in the first position, the water baffle is located below the water storage gap at the overflow port position, and can block the water flow out of the water storage gap and rushing toward the inner wall of the separation tank below the overflow port; when the water baffle is in the second position, the water baffle leaves the water storage gap at the overflow port position, and at this time, the water baffle will not affect the water flow out of the water storage gap.

[0012] Furthermore, the bubbler head is a microporous aeration head, and the pore size of the microporous aeration head is less than 20μm; the first filter component includes a first filter screen, a second filter screen, a first filter membrane and a second filter membrane, the pore size of the first filter screen is 5mm, the pore size of the second filter screen is 50μm, the pore size of the first filter membrane is 5μm, and the pore size of the second filter membrane is 0.45μm; the second filter component includes a third filter screen and a third filter membrane, the pore size of the third filter screen is 50μm, and the pore size of the third filter membrane is 5μm.

[0013] The second aspect of the present invention provides a new pollutant detection system, which includes the aforementioned water separation and filtration device, and the water separation and filtration device is used to separate microplastics in the water sample to be detected; the new pollutant detection system also includes: a water sample collection module, used to collect the water sample to be detected; and a content determination module, used to determine the content of microplastics in the water sample to be detected.

[0014] The third aspect of the present invention provides a new pollutant detection method, which is based on the aforementioned water separation and filtration device, and includes: S1, collecting a water sample to be detected; S2, injecting the water sample to be detected into the separation tank to separate the microplastics in the water sample to be detected; S3, obtaining the quality and / or quantity of the microplastics, and then obtaining the microplastic content of the water sample to be detected.

[0015] Further, the S2 includes: S21, after injecting the water sample to be tested into the separation tank, injecting an oxidant into the water sample to be tested and stirring for a first preset time to obtain an oxidized water sample; S22, injecting a surfactant into the oxidized water sample and stirring for a second preset time to obtain a modified water sample; S23, using the foaming component to continuously generate bubbles for a third preset time at the bottom of the modified water sample to obtain a stratified water sample; S24, continuously adding deionized water to the stratified water sample so that the upper foam of the stratified water sample flows out through the guide groove; S25, graded filtering the residual liquid in the separation tank, washing out the filter residue less than 5 mm with deionized water to obtain an eluate, adding a density regulator to the eluate and stirring, and adjusting the density of the eluate to 1.5 g / cm3 Centrifuge the developed solution after adjusting its density, collect the supernatant after centrifugation, wash it with deionized water, and filter to obtain the first filter residue; wash the overflow solution flowing out through the guide groove with deionized water, and filter to obtain the second filter residue.

[0016] Further, the oxidant is H2O2. The oxidant is added dropwise to the water sample to be detected and stirred while adding. The concentration of H2O2 in the oxidized water sample is 3% - 5%; the first preset time period is 2h - 4h.

[0017] Further, the surfactant is cetyltrimethylammonium bromide. The surfactant is added dropwise to the oxidized water sample and stirred while adding. The concentration of cetyltrimethylammonium bromide in the modified water sample is 0.007% - 0.015%; the second preset time period is 20min - 30min.

[0018] Further, the bubble size generated by the foaming component is 20μm - 50μm, and the third preset time period is 20min - 30min; while the foaming component generates bubbles, stir the modified water sample.

[0019] Further, the density regulator is ZnCl2 or NaI, the rotation speed of the centrifugation is 3000r / min - 4000r / min, and the treatment duration is 10min - 15min.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. A water body separation and filtration device, a new pollutant detection system and method provided by the embodiments of the present disclosure can completely separate microplastics from a water sample in which impurities such as microplastics, sediment, and organic suspended matter are mixed as much as possible, and avoid the mixing of other impurities; thus, it can provide important support for quantitatively detecting the content of microplastics in the water sample; 2. A water separation and filtration device, a new pollutant detection system and method provided by an embodiment of the present disclosure. On the one hand, the rotation of the stirring rod can drive the bubble head to rotate around the axis of the vertical section in the separation tank, so that the bubbles output by the bubble head can be evenly distributed in the separation tank, and the water sample can also be made to flow, thereby increasing the collision probability between the bubbles and the microplastics, promoting the adsorption of the bubbles on the surface of the microplastics, and carrying the microplastics to float. On the other hand, while the bubble head generates bubbles, the shearing action between the rotating bubble head and the water sample makes the generated bubbles break away from the bubble head faster, thereby further refining the bubble size; and the water sample presents a "vortex" flow form. Therefore, the floating microplastics will gather towards the middle of the water surface, and the shearing action between the water sample and the inner wall of the separation tank greatly reduces the microplastics adsorbed on the inner wall of the separation tank, which is beneficial to the subsequent overflow separation of the floating microplastics. 3. A water separation and filtration device, a new pollutant detection system and method provided by an embodiment of the present disclosure. By setting the first cone tube and the second cone tube with appropriate sizes, deionized water can flow along the inner wall of the separation tank into the separation tank. On the one hand, it can raise the water level in the separation tank to achieve the overflow collection of floating microplastics. On the other hand, during the process of injecting deionized water along the inner wall of the separation tank, a small amount of microplastics originally adhered to the inner wall of the separation tank are also washed down, ensuring the separation rate of microplastics. And injecting deionized water along the inner wall of the separation tank avoids the deionized water from washing away the foam layer formed by the floating microplastics with the bubbles; in addition, the first cone tube can also act as a "flywheel", so that during the process of driving the stirring rod to rotate by the reciprocating linear motion, the stirring rod can smoothly pass through the dead point and rotate smoothly. Description of the Drawings

[0021] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings: Figure 1 It is a three-dimensional structural schematic diagram of the water separation and filtration device drawn according to an embodiment of the present invention; Figure 2 For Figure 1 A partial enlarged view of area A drawn; Figure 3 For Figure 1 A cross-sectional view of the water separation and filtration device drawn; Figure 4 For Figure 3 A partial enlarged view of area B drawn; Figure 5 For Figure 4 A partial enlarged view of area C drawn; Figure 6It is the air supply pipeline diagram of the water separation and filtration device drawn according to the embodiments of the present invention; Figure 7 It is the flow chart of the new pollutant detection method drawn according to the embodiments of the present invention; Figure 8 It is the flow chart of separating microplastics from the water sample to be detected drawn according to the embodiments of the present invention.

[0022] Marks in the attached drawings and corresponding component names: 1 - separation tank; 11 - discharge pipe; 12 - valve; 13 - overflow port; 14 - guide groove; 15 - bracket; 16 - water baffle; 41 - bubble head; 42 - gas transmission pipe; 43 - cylinder block; 431 - first air inlet pipe; 432 - first air outlet pipe; 433 - second air inlet pipe; 434 - second air outlet pipe; 435 - check valve; 44 - piston body; 45 - three - way valve; 51 - water inlet pipe; 52 - first tapered pipe; 53 - second tapered pipe; 54 - water storage gap; 55 - drainage pipe; 56 - third tapered pipe; 57 - connecting rod; 61 - linear motor; 62 - stirring rod; 621 - vertical section; 622 - inclined section; 623 - offset section; 63 - output shaft; 64 - connecting rod. Detailed implementation manners

[0023] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments and the attached drawings. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and do not limit the present invention. It should be noted that the present invention has been in the actual R & D and use stage.

[0024] With the wide use of plastic products, microplastics have been widely present in natural water bodies, and microplastics have thus been listed as a major category of new pollutants (new pollutants refer to a general term for a class of chemical substances that can be detected in the environment and natural ecosystems and can pose greater risks and potential hazards to human health and environmental safety even when entering at low doses. New pollutants mainly include persistent organic pollutants, endocrine disruptors, antibiotics, microplastics, etc.).

[0025] Water quality monitoring is an important part of ecological environment monitoring work. In recent years, when conducting water quality detection work, microplastics are usually detected in water bodies. However, due to the small particle size (less than 5 mm), large variety, and large density difference of microplastics, they are often mixed with impurities such as sediment and organic suspended solids in water samples, making it difficult to effectively separate microplastics (for example, when using a filter screen for filtration, interfering particulate impurities of the same size will be mixed into the "target substance" obtained by filtration; separation based on density will also cause suspended solids to be mixed in; resulting in a large deviation in the quantitative detection results), making the quantitative detection of microplastics a major challenge in water quality detection.

[0026] In order to accurately separate the target novel pollutant, microplastics, from water samples, and further provide reliable support for the detection of the content of microplastics in water samples. The present invention provides a water separation and filtration device, a novel pollutant detection system and method, which are used to at least partially overcome the above technical problems and achieve the above beneficial effects.

[0027] Example 1: As Figure 1 , Figure 3 shown, the water separation and filtration device includes a separation tank 1, a first filtration component, a second filtration component, a foaming component and a water injection component; The separation tank 1 is fixedly installed. A discharge pipe 11 is provided at the bottom of the separation tank 1, and the discharge pipe 11 is connected above the first filtration component. A valve 12 is provided in the upper part of the discharge pipe 11; An overflow port 13 is provided in the upper part of the separation tank 1, and the overflow port 13 is connected above the second filtration component through a guide groove 14; The foaming component includes a gas source and a foaming head 41. The foaming head 41 is installed inside the separation tank 1, and the gas source is connected to the foaming head 41; The water injection component is used to inject water into the separation tank 1, thereby raising the water level inside the separation tank 1; The first filtration component is used to filter the remaining liquid flowing out through the discharge pipe 11, and the second filtration component is used to filter the overflow liquid flowing out through the guide groove 14.

[0028] During use, the collected water sample is injected into the separation tank 1, and then a hydrogen peroxide solution is injected into the water sample and stirred so that the organic suspended matter in the water sample is oxidized and decomposed (for excessive hydrogen peroxide, it can be decomposed by adding catalase to the water sample); Then cetyltrimethylammonium bromide is added and stirred to make the originally hydrophilic microplastics become hydrophobic; Thereafter, a large number of tiny bubbles (the bubble size is 20μm - 50μm) are generated in the separation tank 1 by using the foaming component, and the microplastics are made to float by the bubbles adsorbed on the surface of the microplastics; After the microplastics float, deionized water is added to the separation tank 1 to raise the water level above the overflow port 13, and then the floating microplastics flow through the guide groove 14 to the second filtration component (not shown in the figure); Then, for the remaining liquid in the separation tank 1, the valve 12 is opened to make the remaining liquid flow through the discharge pipe 11 to the first filtration component (not shown in the figure). The filter residue less than 5 mm is retained after filtration and washed out from the corresponding filter screen and / or filter membrane with deionized water to obtain a wash solution, and ZnCl2 or NaI is added to the wash solution to adjust the density of the wash solution to 1.5 g / cm 3, and then the upper layer liquid containing microplastics can be separated from the density-adjusted eluate by centrifugal separation, the upper layer liquid is taken out and rinsed with deionized water and then filtered to obtain the first filter residue (it should be understood that before rinsing and filtering the upper layer liquid with deionized water, ethanol solution is added to the upper layer liquid and soaked for 1min-2min, so that the hexadecyltrimethylammonium bromide adsorbed on the surface of the microplastics is decomposed and removed), and for the overflow liquid, the overflow liquid is rinsed with deionized water and filtered to obtain the second filter residue (similarly, before rinsing and filtering the overflow liquid with deionized water, ethanol solution is added to the overflow liquid and soaked), and the first filter residue and the second filter residue obtained are the target new pollutants - microplastics separated from the water sample.

[0029] Therefore, the water separation and filtration device provided in this embodiment can completely separate microplastics from water samples mixed with impurities such as microplastics, mud, and organic suspended matter as much as possible, and avoid the mixing of other impurities; thereby, it can provide important support for the quantitative detection of the microplastic content in water samples.

[0030] It should be understood that in order to avoid the introduction of exogenous microplastics, the water separation and filtration device should avoid using plastic materials as much as possible.

[0031] Embodiment 2: like Figures 1 to 5 As shown, this embodiment is based on the embodiment 1, and the difference is that, in this embodiment, the water separation and filtration device further includes a linear motor 61 and a stirring rod 62, and a bracket 15 is fixedly installed on the upper part of the separation tank 1; The linear motor 61 is fixedly mounted on the bracket 15, and the stirring rod 62 includes a vertical section 621, an inclined section 622 and an offset section 623; the vertical section 621 is rotatably connected to the bracket 15, the offset section 623 is located above the bracket 15 and is smoothly transitionally connected to the vertical section 621, and the inclined section 622 is located inside the separation tank 1 and is fixedly connected to the vertical section 621; The free end of the output shaft 63 of the linear motor 61 is rotatably connected to a connecting rod 64, and the other end of the connecting rod 64 is rotatably connected to the offset section 623; The foaming head 41 is installed on the inclined section 622 .

[0032] Thus, as the output shaft 63 of the linear motor 61 reciprocates linearly, the stirring rod 62 rotates around the axis of the vertical section 621. Consequently, the inclined section 622 located in the separation tank 1 can stir the water sample in the separation tank 1, thereby realizing the stirring operation in the above-mentioned usage process. In addition, the rotation of the stirring rod 62 can, on the one hand, drive the bubble head 41 to rotate around the axis of the vertical section 621 in the separation tank 1, and thus can evenly distribute the bubbles output by the bubble head 41 in the separation tank 1, and also make the water sample flow, thereby increasing the collision probability between the bubbles and the microplastics, and then promoting the adsorption of the bubbles on the surface of the microplastics and carrying the microplastics to float. On the other hand, while the bubble head 41 generates bubbles, the shearing action between the rotating bubble head 41 around the axis of the vertical section 621 and the water sample causes the generated bubbles to break away from the bubble head 41 faster, thereby being able to further refine the bubble size (the bubbles break away from the bubble head 41 before having enough time to grow). And the water sample presents a "vortex" flow form. Thus, the floating microplastics (foam aggregates) will gather towards the middle of the water surface, and the shearing action between the water sample and the inner wall of the separation tank 1 greatly reduces the microplastics (foam aggregates) adsorbed on the inner wall of the separation tank 1, which is beneficial to the subsequent overflow separation of the floating microplastics.

[0033] It can be understood that the linear motor 61 is used to drive the stirring rod 62 to avoid lubricating oil at the meshing parts of gear transmission, chain transmission, etc. from falling into the lower separation tank 1 and polluting the water sample.

[0034] Embodiment 3: As Figures 1 to 6 shown, this embodiment is based on Embodiment 2. The difference is that in this embodiment, the stirring rod 62 is a hollow rod, and the bubble head 41 is fixedly installed at one end of the inclined section 622 away from the vertical section 621; The gas source is connected to the bubble head 41 through an air delivery pipe 42, and the air delivery pipe 42 is disposed inside the stirring rod 62.

[0035] Thus, by hiding the gas pipeline 42 inside the stirring rod 62, it is possible to prevent the gas pipeline 42 from winding around the stirring rod 62 during the rotation of the stirring rod 62. In addition, compared with the case where the gas pipeline 42 is located outside the stirring rod 62 and tied to the stirring rod 62, it is possible to prevent the gap between the stirring rod 62 and the gas pipeline 42 from jamming the microplastics, thereby ensuring that the floating process of the microplastics is unobstructed. Installing the bubble head 41 at one end of the inclined section 622 away from the vertical section 621 can make the bubble head 41 as close as possible to the bottom of the separation tank 1, so that the generated bubbles can collide with the microplastics in the lower layer of water. In addition, the stirring action of the stirring rod 62 can also roll up the microplastics at the bottom of the separation tank 1, giving them the opportunity to collide with the bubbles and then be attached by the bubbles and float. It should be understood that the gas pipeline 42 is a flexible pipe (such as a corrugated pipe), which can automatically change its bending degree during the rotation of the stirring rod 62 to adapt to the position change of the offset section 623.

[0036] Further, the gas source includes a cylinder block 43, the cylinder block 43 is fixedly installed on the bracket 15, the output shaft 63 penetrates through the cylinder block 43 along the length direction of the cylinder block 43, and a piston body 44 is fixedly installed on the output shaft 63, and the piston body 44 is located inside the cylinder block 43; A first intake pipe 431 and a first outlet pipe 432 are provided at one end of the cylinder block 43, and a second intake pipe 433 and a second outlet pipe 434 are provided at the other end; check valves 435 are installed on the first intake pipe 431, the first outlet pipe 432, the second intake pipe 433, and the second outlet pipe 434; Both the first outlet pipe 432 and the second outlet pipe 434 are connected to the intake port of a three-way valve 45, the first outlet port of the three-way valve 45 is connected to the bubble head 41, and the second outlet port of the three-way valve 45 is connected to the outside. Specifically, the first outlet port can be connected to the bubble head 41 through the gas pipeline 42.

[0037] It should be understood that the check valves 435 installed on the first intake pipe 431 and the second intake pipe 433 allow external gas to enter the inside of the cylinder block 43 only through the first intake pipe 431 and the second intake pipe 433. Similarly, the check valves 435 installed on the first outlet pipe 432 and the second outlet pipe 434 allow the gas inside the cylinder block 43 to be output to the outside only through the first outlet pipe 432 and the second outlet pipe 434. By operating the three-way valve 45, the air flow output from the first outlet pipe 432 and the second outlet pipe 434 can be made to flow into the gas pipeline 42, or the air flow output from the first outlet pipe 432 and the second outlet pipe 434 can be made to flow into the outside.

[0038] Thus, during the reciprocating linear motion of the output shaft 63 of the linear motor 61, the piston body 44 reciprocates linearly inside the cylinder block 43, such that when the first air inlet pipe 431 intakes air, the second air outlet pipe 434 exhausts air, or when the second air inlet pipe 433 intakes air, the first air outlet pipe 432 exhausts air, that is, one of the first air inlet pipe 431 and the second air inlet pipe 433 always supplies air to the three-way valve 45. When it is necessary to supply air to the bubble head 41 to cause the bubble head 41 to generate bubbles, by operating the three-way valve 45, the air flows output from the first air outlet pipe 432 and the second air outlet pipe 434 can flow into the air delivery pipe 42; when it is not necessary for the bubble head 41 to generate bubbles, the linear motor 61 can be shut down and / or the three-way valve 45 can be operated such that the air flows output from the first air outlet pipe 432 and the second air outlet pipe 434 flow into the outside world as well.

[0039] Thus, the linear motor 61 can be used to drive the stirring rod 62 to perform a stirring operation in the separation tank 1, and can also drive the piston body 44 to reciprocate linearly in the cylinder block 43 to generate an air flow when it is necessary to supply air to the bubble head 41 to generate bubbles in the separation tank 1. Preferably, the reciprocating linear motion frequency of the output shaft 63 of the linear motor 61 is adjustable.

[0040] Embodiment 4: Please continue to refer to Figures 1 to 5 , this embodiment is based on Embodiment 2, the difference being that, in this embodiment, the water injection assembly includes a water inlet pipe 51, a first tapered pipe 52, and a second tapered pipe 53; the small end of the first tapered pipe 52 is fixedly connected to the vertical section 621 and the large end faces the discharge pipe 11; the second tapered pipe 53 is located above the first tapered pipe 52, the large end of the second tapered pipe 53 faces the discharge pipe 11, the small end of the second tapered pipe 53 is fixedly connected to the bracket 15, and the vertical section 621 is inserted into the second tapered pipe 53; a water storage gap 54 exists between the first tapered pipe 52 and the second tapered pipe 53, the width of the water storage gap 54 gradually decreases in the vertically downward direction, and the water inlet pipe 51 is connected to the water storage gap 54.

[0041] Therefore, in the case where it is necessary to inject deionized water into the separation tank 1 to increase the liquid level height in the separation tank 1, injecting deionized water into the water storage gap 54 through the water inlet pipe 51 can make the deionized water in the water storage gap 54 flow out through the gap at the bottom of the water storage gap 54. By setting the first tapered pipe 52 and the second tapered pipe 53 with appropriate sizes, the deionized water can flow into the separation tank 1 along the inner wall of the separation tank 1. On the one hand, it can increase the water level in the separation tank 1 and thus achieve the overflow collection of floating microplastics. On the other hand, during the process of injecting the deionized water along the inner wall of the separation tank 1, a small amount of microplastics (foam aggregates) originally adhered to the inner wall of the separation tank 1 are also washed down, ensuring the separation rate of microplastics. Moreover, injecting the deionized water along the inner wall of the separation tank 1 avoids the deionized water from flushing away the foam layer formed by the floating of microplastics with bubbles (flushing away will cause the originally floating microplastics to lose their floating state on the water surface). In addition, the first tapered pipe 52 can also act as a "flywheel" (during the process of driving the stirring rod 62 to rotate by the output shaft 63, there is a "dead point". During the rotation of the stirring rod 62, the inertia of the rotation of the first tapered pipe 52 fixedly arranged on the vertical section 621 can help the stirring rod 62 smoothly pass through the dead point and complete a full circular motion. In order to increase this inertia of the first tapered pipe 52, a counterweight can be added to the inner wall of the large end of the first tapered pipe 52), so that during the process of driving the stirring rod 62 to rotate by the reciprocating linear motion, the stirring rod 62 can smoothly pass through the dead point and then rotate smoothly. Preferably, when injecting deionized water, the stirring rod 62 is still slowly rotating, so that the deionized water in the water storage gap 54 can be evenly injected along the circumferential wall of the separation tank 1, forcing the floating objects to converge towards the middle. It should be understood that the stirring needs to be stopped when the water level rises to the overflow port 13 to ensure that the floating objects flow out smoothly through the overflow port 13.

[0042] Preferably, a plurality of drainage pipes 55 are also fixedly connected to the first tapered pipe 52; A third tapered pipe 56 is also fixedly sleeved on the inclined section 622. There is an outflow gap between the small end of the third tapered pipe 56 and the outer peripheral wall of the inclined section 622, and the large end of the third tapered pipe 56 is higher than the small end (as Figure 4 、 Figure 5 shown, the large end of the third tapered pipe 56 is fixedly connected to the first tapered pipe 52 through a connecting rod 57, so that when the third tapered pipe 56 is fixedly sleeved on the inclined section 622, there is an outflow gap between the small end of the third tapered pipe 56 and the outer peripheral wall of the inclined section 622. Of course, it can also be realized that the third tapered pipe 56 is fixedly sleeved through the form that the third tapered pipe 56 is fixedly connected to the inclined section 622 through the connecting rod 57. The present application is not limited thereto); For any drainage pipe 55, one end thereof penetrates through the first tapered pipe 52 and is connected to the water storage gap 54, and the other end is connected to the inner side of the third tapered pipe 56; the positions where the drainage pipes 55 penetrate through the first tapered pipe 52 are circumferentially distributed.

[0043] Thus, a part of the deionized water in the water storage gap 54 is introduced into the third tapered pipe 56 by the drainage pipe 55, and then flows into the separation tank 1 along the outer peripheral wall of the inclined section 622 through the outflow gap, so that a small amount of microplastics (foam aggregates) adhered to the outer peripheral wall of the inclined section 622 can be washed into the water and kept floating.

[0044] Preferably, a water baffle 16 is slidably mounted on the separation tank 1. The water baffle 16 is located above the overflow port 13 and is slidably connected to the separation tank 1. By sliding the water baffle 16, the water baffle 16 can be switched between a first position and a second position (i.e., the water baffle 16 slides radially along the separation tank 1 where the overflow port 13 is located); When the water baffle 16 is in the first position, the water baffle 16 is located below the water storage gap 54 at the position of the overflow port 13, and can block the water flow flowing out of the water storage gap 54 and rushing towards the inner wall of the separation tank 1 below the overflow port 13, ensuring the smooth outflow of floating objects; when the water baffle 16 is in the second position, the water baffle 16 leaves the lower part of the water storage gap 54 at the position of the overflow port 13. At this time, the water baffle 16 does not affect the water flow flowing out of the water storage gap 54.

[0045] Thus, when the water level in the separation tank 1 rises to the overflow port 13, the water baffle 16 can be operated to slide to the first position, and then the water baffle 16 is used to receive the deionized water flowing out of the water storage gap 54, avoiding the impact of this deionized water on the floating objects flowing out through the overflow port, and thus ensuring the smooth outflow of the floating objects. The deionized water received by the water baffle 16 flows down along both sides of the water baffle 16 under the action of the inclined surfaces on both sides (both sides in the sliding direction) of the water baffle 16.

[0046] Preferably, the bubble head 41 is a microporous aeration head, and the pore diameter of the microporous aeration head is less than 20 μm; The first filtration assembly includes a first filter screen, a second filter screen, a first filter membrane and a second filter membrane. The pore diameter of the first filter screen is 5 mm, the pore diameter of the second filter screen is 50 μm, the pore diameter of the first filter membrane is 5 μm, and the pore diameter of the second filter membrane is 0.45 μm; The second filtration assembly includes a third filter screen and a third filter membrane. The pore diameter of the third filter screen is 50 μm, and the pore diameter of the third filter membrane is 5 μm.

[0047] It should be understood that by adjusting the reciprocating frequency of the output shaft 63 of the linear motor 61, it is possible to continuously generate bubbles with a size of 20 μm - 50 μm in the microporous aeration head. The first filter screen can filter out impurities with a size greater than 5 mm in the remaining liquid, and the second filter screen, the first filter membrane, and the second filter membrane achieve hierarchical filtration of the remaining liquid, thereby filtering out microplastics in the remaining liquid as much as possible. The setting of the second filtration component can intercept larger microplastics in the overflow liquid on the third filter screen, while the third filter membrane intercepts the remaining smaller microplastics. Since the bubble size is 20 μm - 50 μm, microplastics with a size less than 5 μm are difficult to collide with the bubbles and be attached by the bubbles due to their small size, and thus will not float up with the bubbles to form floating objects.

[0048] Example 5: This embodiment provides a new pollutant detection system. Based on the aforementioned water separation and filtration device, the new pollutant detection system includes: The aforementioned water separation and filtration device, which is used to separate microplastics in the water sample to be detected; A water sample collection module, which is used to collect the water sample to be detected; A content determination module, which is used to determine the content of microplastics in the water sample to be detected.

[0049] It should be understood that the water sample collection module can use relevant sampling equipment and methods in the prior art, but it is necessary to avoid using plastic material collection and storage utensils. The content determination module at least includes a mass determination unit (such as a balance) for weighing the mass of microplastics, thereby measuring the mass concentration of microplastics in the water sample, and an optical microscope (or fluorescence microscope) and image analysis software (such as ImageJ) for identifying the particle size and quantity of microplastics, thereby obtaining the number density and particle size distribution of microplastics in the water sample. Based on this, through the new pollutant detection system provided in this embodiment, the microplastics in the water sample to be detected can be separated as completely as possible, and thus the quantitative detection of microplastics in the water sample to be detected can be achieved.

[0050] Example 6: As Figure 7 、 Figure 8 shown, this embodiment provides a new pollutant detection method. Based on the aforementioned water separation and filtration device, the method includes: S1, collect the water sample to be detected; S2, inject the water sample to be detected into the separation tank 1 to separate microplastics in the water sample to be detected; S3, obtain the mass and / or quantity of the microplastics, and thus obtain the microplastic content of the water sample to be detected.

[0051] It should be understood that the water sample to be detected can be sampled according to the conventional sampling means of water quality detection. It should be noted that in order to avoid external microplastic pollution during sampling and sample transportation, the instruments used for sampling (such as collection and storage instruments) should avoid plastic materials.

[0052] More specifically, S2 includes: S21, after injecting the water sample to be detected into the separation tank 1, injecting an oxidant into the water sample to be detected and stirring for a first preset time to obtain an oxidized water sample; S22, injecting a surfactant into the oxidized water sample and stirring for a second preset time to obtain a modified water sample; S23, using the foaming assembly to continuously generate bubbles at the bottom of the modified water sample for a third preset time to obtain a stratified water sample; S24, continuously adding deionized water to the stratified water sample so that the upper floating foam of the stratified water sample flows out through the guide groove 14; S25, filtering the remaining liquid in the separation tank 1 in stages, washing out and collecting the filter residue less than 5 mm with deionized water to obtain a washed-out liquid, adding a density regulator to the washed-out liquid and stirring to adjust the density of the washed-out liquid to 1.5 g / cm 3 ; subjecting the washed-out liquid with adjusted density to centrifugal separation, collecting the upper layer liquid after centrifugal separation and washing it with deionized water, and filtering to obtain a first filter residue; Washing the overflow liquid flowing out through the guide groove 14 with deionized water and filtering to obtain a second filter residue.

[0053] Specifically, the oxidant is H2O2, the oxidant is added drop by drop to the water sample to be detected and stirred while adding, and the concentration of H2O2 in the oxidized water sample is 3%-5%; the first preset time is 2h-4h. Preferably, after injecting the oxidant into the water sample to be detected and stirring for the first preset time, adding catalase to the water sample and stirring to decompose the remaining H2O2 in the water sample.

[0054] The surfactant is cetyltrimethylammonium bromide, the surfactant is added drop by drop to the oxidized water sample and stirred while adding, and the concentration of cetyltrimethylammonium bromide in the modified water sample is 0.007%-0.015%; The second preset time is 20min-30min.

[0055] The bubble size generated by the foaming assembly is 20μm-50μm, and the third preset time is 20min-30min; While the foaming assembly generates bubbles, stir the modified water sample.

[0056] The density regulator is ZnCl2 or NaI, the rotation speed of the centrifugal separation is 3000 r / min - 4000 r / min, and the treatment duration is 10 min - 15 min.

[0057] Before rinsing the filtered supernatant with deionized water, add an ethanol solution to the supernatant and soak it for 1 min - 2 min to decompose and shed the cetyltrimethylammonium bromide adsorbed on the surface of the microplastics. Similarly, before rinsing the filtered overflow liquid with deionized water, add an ethanol solution to the overflow liquid and soak it for 1 min - 2 min.

[0058] Thus, in this embodiment, the organic suspended matter in the water sample is decomposed by adding hydrogen peroxide to the water sample to be detected. Furthermore, the larger organic suspended matter is decomposed into small molecule substances or even CO2 and H2O. Then, cetyltrimethylammonium bromide is used to make the hydrophilic microplastics in the water sample have hydrophobic properties. Thus, by injecting fine bubbles into the bottom of the water sample, the microplastics can adhere to the surface of the bubbles after contacting the bubbles, and then float to the water surface under the action of the bubbles. For these floating microplastics, injecting deionized water into the water sample can make the floating microplastics drain out through the overflow port 13. Preferably, the operation of "injecting bubbles - overflowing and collecting the upper floating foam" is repeated 2 - 3 times to make the microplastics float as much as possible. During the process of injecting deionized water, the deionized water is preferably injected along the inner wall of the separation tank 1. On the one hand, this can avoid dispersing the floating upper floating foam, and on the other hand, it can also wash the small amount of microplastics originally adhering to the inner wall of the separation tank 1 into the water sample. Obviously, the obtained first filter residue and second filter residue are the target pollutants - microplastics. After drying them at low temperature, existing weighing and counting means can be used to obtain the mass concentration, number concentration, etc. of the microplastics in the water sample to be detected.

[0059] It should be understood that in this application, the term "rotational connection" means that the two can only rotate relative to each other. For example, the rotational setting of a hole and a shaft rod can be achieved by setting a shaft shoulder on the shaft and a limiting groove in the hole to limit the relative axial movement; the terms "sliding connection" and "sliding installation" mean that the two can only slide relative to each other, such as structures like dovetail grooves and T-shaped grooves.

[0060] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A water separation and filtration device, characterized in that it includes a separation tank (1), a first filtration component, a second filtration component, a foaming component, and a water injection component; The separation tank (1) is fixedly installed. A discharge pipe (11) is provided at the bottom of the separation tank (1), and the discharge pipe (11) is connected above the first filtration component; an overflow port (13) is provided at the upper part of the separation tank (1), and the overflow port (13) is connected above the second filtration component through a guide groove (14); The foaming component includes a gas source and a foaming head (41), the foaming head (41) is installed inside the separation tank (1), and the gas source is connected to the foaming head (41); The water injection component is used to inject water into the separation tank (1); The first filtration component is used to filter the remaining liquid flowing out through the discharge pipe (11), and the second filtration component is used to filter the overflow liquid flowing out through the guide groove (14).

2. The water separation and filtration device according to claim 1, characterized in that the water separation and filtration device further includes a linear motor (61) and a stirring rod (62). A bracket (15) is fixedly installed at the upper part of the separation tank (1); The stirring rod (62) includes a vertical section (621), an inclined section (622), and an offset section (623); the vertical section (621) is rotatably connected to the bracket (15), the offset section (623) is located above the bracket (15) and is smoothly connected to the vertical section (621) in a smooth transition, and the inclined section (622) is located inside the separation tank (1) and is fixedly connected to the vertical section (621); The free end of the output shaft (63) of the linear motor (61) is rotatably connected to a connecting rod (64), and the other end of the connecting rod (64) is rotatably connected to the offset section (623); The foaming head (41) is installed on the inclined section (622).

3. The water separation and filtration device according to claim 2, characterized in that the stirring rod (62) is a hollow rod, and the foaming head (41) is fixedly installed at one end of the inclined section (622) away from the vertical section (621); The gas source is connected to the foaming head (41) through an air delivery pipe (42), and the air delivery pipe (42) passes through the inside of the stirring rod (62).

4. The water separation and filtration device according to claim 2, characterized in that the gas source includes a cylinder block (43), the cylinder block (43) is fixedly installed on the bracket (15), the output shaft (63) penetrates through the cylinder block (43) along the length direction of the cylinder block (43), and a piston body (44) is fixedly installed on the output shaft (63), and the piston body (44) is located inside the cylinder block (43); At one end of the cylinder block (43), a first intake pipe (431) and a first exhaust pipe (432) are provided, and at the other end, a second intake pipe (433) and a second exhaust pipe (434) are provided; check valves (435) are installed on the first intake pipe (431), the first exhaust pipe (432), the second intake pipe (433), and the second exhaust pipe (434). Both the first exhaust pipe (432) and the second exhaust pipe (434) are connected to the intake port of a three-way valve (45). The first outlet of the three-way valve (45) is connected to the bubble head (41), and the second outlet of the three-way valve (45) is connected to the outside.

5. The water separation and filtration device according to claim 2, characterized in that The water injection assembly includes a water inlet pipe (51), a first tapered pipe (52), and a second tapered pipe (53). The small end of the first tapered pipe (52) is fixedly connected to the vertical section (621) and the large end faces the discharge pipe (11); the second tapered pipe (53) is located above the first tapered pipe (52), the large end of the second tapered pipe (53) faces the discharge pipe (11), the small end of the second tapered pipe (53) is fixedly connected to the bracket (15), and the vertical section (621) is inserted into the second tapered pipe (53). There is a water storage gap (54) between the first tapered pipe (52) and the second tapered pipe (53). The width of the water storage gap (54) gradually decreases in the vertically downward direction, and the water inlet pipe (51) is connected to the water storage gap (54).

6. The water separation and filtration device according to claim 5, characterized in that A plurality of drainage pipes (55) are also fixedly connected to the first tapered pipe (52). A third tapered pipe (56) is also fixedly sleeved on the inclined section (622). There is an outflow gap between the small end of the third tapered pipe (56) and the outer peripheral wall of the inclined section (622), and the large end of the third tapered pipe (56) is higher than the small end. For any one of the drainage pipes (55), one end penetrates through the first tapered pipe (52) and is connected to the water storage gap (54), and the other end is connected to the inside of the third tapered pipe (56); the positions where the drainage pipes (55) penetrate through the first tapered pipe (52) are circumferentially evenly distributed.

7. The water separation and filtration device according to claim 5, characterized in that A water baffle (16) is also slidably installed on the separation tank (1). The water baffle (16) is located above the overflow port (13) and is slidably connected to the separation tank (1). The water baffle (16) can be switched between a first position and a second position. When the water baffle (16) is in the first position, the water baffle (16) is located below the water storage gap (54) at the position of the overflow port (13), and can block the water flow rushing out of the water storage gap (54) and towards the inner wall of the separation tank (1) below the overflow port (13), ensuring the smooth outflow of floating objects; when the water baffle (16) is in the second position, the water baffle (16) leaves below the water storage gap (54) at the position of the overflow port (13). At this time, the water baffle (16) does not affect the water flow flowing out of the water storage gap (54).

8. The water body separation and filtration device according to claim 1, wherein the bubbling head (41) is a microporous aeration head, and the pore diameter of the microporous aeration head is less than 20 μm; the first filtration component includes a first filter screen, a second filter screen, a first filter membrane and a second filter membrane. The pore diameter of the first filter screen is 5 mm, the pore diameter of the second filter screen is 50 μm, the pore diameter of the first filter membrane is 5 μm, and the pore diameter of the second filter membrane is 0.45 μm; the second filtration component includes a third filter screen and a third filter membrane. The pore diameter of the third filter screen is 50 μm, and the pore diameter of the third filter membrane is 5 μm.

9. A new pollutant detection system, characterized in that, including the water body separation and filtration device according to any one of claims 1 to 8, and the water body separation and filtration device is used to separate microplastics in the water sample to be detected; the new pollutant detection system further includes: a water sample collection module for collecting the water sample to be detected; a content determination module for determining the content of microplastics in the water sample to be detected.

10. A method for detecting new pollutants, based on the water body separation and filtration device according to any one of claims 1 to 8, characterized in that, including: S1, collecting the water sample to be detected; S2, injecting the water sample to be detected into the separation tank (1) to separate microplastics in the water sample to be detected; S3, obtaining the mass and / or quantity of the microplastics, and further obtaining the microplastic content of the water sample to be detected.

11. The new pollutant detection method according to claim 10, wherein The S2 includes: S21, after injecting the water sample to be detected into the separation tank (1), injecting an oxidant into the water sample to be detected and stirring for a first preset time period to obtain an oxidized water sample; S22, injecting a surfactant into the oxidized water sample and stirring for a second preset time period to obtain a modified water sample; S23, using the bubbling component to continuously generate bubbles at the bottom of the modified water sample for a third preset time period to obtain a stratified water sample; S24, continuously adding deionized water to the stratified water sample so that the upper floating foam of the stratified water sample flows out through the guide groove (14); S25, fractionally filter the residual liquid in the separation tank (1), wash out the filter residue smaller than 5 mm with deionized water and collect the wash liquor, add a density regulator to the wash liquor and stir to adjust the density of the wash liquor to 1.5 g / cm 3 ; subject the wash liquor with adjusted density to centrifugal separation, collect the upper layer liquid after centrifugal separation and wash it with deionized water, and filter to obtain the first filter residue; Washing the overflow liquid flowing out through the guide groove (14) with deionized water and filtering to obtain a second filter residue.

12. The new pollutant detection method according to claim 11, wherein the oxidant is H2O2, the oxidant is added drop by drop to the water sample to be detected and stirred while dropping, and the concentration of H2O2 in the oxidized water sample is 3%-5%; the first preset time period is 2h-4h.

13. The new pollutant detection method according to claim 11, wherein The surfactant is cetyltrimethylammonium bromide. The surfactant is added drop by drop to the oxidized water sample while stirring during the addition. The concentration of cetyltrimethylammonium bromide in the modified water sample is 0.007% - 0.015%. The second preset duration is 20 min - 30 min.

14. The new pollutant detection method according to claim 11, wherein The bubble size generated by the bubble generating component is 20 μm - 50 μm, and the third preset duration is 20 min - 30 min; While the bubble generating component generates bubbles, stir the modified water sample.

15. The new pollutant detection method according to claim 11, wherein The density regulator is ZnCl2 or NaI. The rotation speed of the centrifugal separation is 3000 r / min - 4000 r / min, and the treatment duration is 10 min - 15 min.

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