A water separation and filtration device and a new pollutant detection system and method

Abstract

The present invention relates to the field of new pollutant detection technology, and specifically to a water separation and filtration device and a new pollutant detection system and method. The device includes a separation tank, a first filter component, a second filter component, a bubble component and a water injection component; the separation tank is fixedly installed, and a discharge pipe is provided at the bottom of the separation tank, the discharge pipe is connected to the top of the first filter component, and a valve is provided on the upper part of the discharge pipe; an overflow port is provided on the upper part of the separation tank, and the overflow port is connected to the top of the second filter component through a guide groove; the bubble component includes an air source and a bubble head, the bubble head is installed in the separation tank, and the air source is connected to the bubble head; the water injection component is used to inject water into the separation tank, thereby raising the water level in the separation tank; the first filter component is used to filter the residual liquid flowing out through the discharge pipe, and the second filter component is used to filter the overflow liquid flowing out through the guide groove. The device can separate microplastics from the water sample to be detected, thereby providing reliable support for the detection of microplastic content in the water sample.

Description

Technical Field

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

[0002] With the widespread use of plastic products, microplastics have become widely present in natural water bodies, and microplastics have been listed as a major category of new pollutants (new pollutants are 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 hidden dangers to human health and environmental safety even if they enter in low doses. New pollutants mainly include persistent organic pollutants, endocrine disruptors, antibiotics, microplastics, etc.).

[0003] Water quality monitoring is a key component of ecological and environmental monitoring. In recent years, microplastics have been frequently detected in water bodies during water quality testing. However, due to their small particle size (less than 5mm), diverse types, and widely varying densities, microplastics are often mixed with impurities such as sediment and suspended organic matter, making them difficult to effectively separate (for example, when filtering with a filter, interfering particulate matter of the same size can be mixed into the filtered "target"; density-based separation can also lead to the incorporation of suspended matter, resulting in significant deviations in quantitative test results). This makes the quantitative detection of microplastics a major challenge in water quality testing. Summary of the Invention

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

[0005] The first aspect of the present invention provides a water separation and filtration device, which includes a separation tank, a first filter component, a second filter component, a bubble component and a water injection component; the separation tank is fixedly installed, and a discharge pipe is provided at the bottom of the separation tank, the discharge pipe is connected to the top of the first filter component, and a valve is provided on the upper part of the discharge pipe; an overflow port is provided on the upper part of the separation tank, and the overflow port is connected to the top of the second filter component through a guide groove; the bubble component includes an air source and a bubble head, the bubble head is installed inside the separation tank, and the air source is connected to the bubble head; the water injection component is used to inject water into the separation tank, thereby raising the water level inside the separation tank; the first filter component is used to filter the residual liquid flowing out through the discharge pipe, and the second filter component is used to filter the overflow liquid flowing out through the guide groove.

[0006] Furthermore, the water separation and filtration device also includes a linear motor and a stirring rod, and a bracket is fixedly installed on the upper part of the separation tank; the linear motor is fixedly installed on the bracket, and 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 transitioned to the vertical section, and the inclined section is located inside the separation tank and fixedly connected to the vertical section; the free end of the linear motor output shaft is rotatably connected to a connecting rod, and the other end of the connecting rod is rotatably connected to the offset section; the bubbling head is installed on the inclined section.

[0007] Furthermore, the stirring rod is a hollow rod, and the bubbling head is fixedly mounted on one end of the inclined section away from the vertical section; the gas source is connected to the bubbling head via an air pipe, and the air pipe is passed through the interior of the stirring rod.

[0008] Furthermore, the air source includes a cylinder body, which is fixedly mounted on the bracket, and the output shaft penetrates the cylinder body along the length direction of the cylinder body, and a piston body is fixedly mounted on the output shaft, and the piston body is located inside the cylinder body; a first air inlet pipe and a first air outlet pipe are provided at one end of the cylinder body, and a second air inlet pipe and a second air outlet pipe are provided at the other end; a one-way valve is 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 bubbler head, and the second air outlet of the three-way valve is connected to the outside world.

[0009] Furthermore, the water injection assembly includes a water inlet pipe, a first conical tube and a second conical tube; the small end of the first conical tube is fixedly connected to the vertical section and the large end faces the discharge pipe; the second conical tube is located above the first conical tube, the large end of the second conical tube faces the discharge pipe, the small end of the second conical tube is fixedly connected to the bracket, and the vertical section is inserted into the second conical tube; there is a water storage gap between the first conical tube and the second conical tube, the width of the water storage gap gradually decreases in the vertical downward direction, and the water inlet pipe is connected to the water storage gap.

[0010] Furthermore, a plurality of drainage tubes are fixedly connected to the first conical tube; a third conical tube is fixedly sleeved on the inclined section, and an outflow gap exists between the small end of the third conical tube and the outer peripheral wall of the inclined section, and the large end of the third conical tube is higher than the small end; for any drainage tube, one end thereof passes through the first conical tube and is connected to the water storage gap, and the other end is connected to the inner side of the third conical tube; the positions at which the drainage tubes pass through the first conical tube are evenly distributed around the circumference.

[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, which is used to separate microplastics in the water sample to be tested; the new pollutant detection system also includes: a water sample collection module, which is used to collect the water sample to be tested; and a content determination module, which is used to determine the content of microplastics in the water sample to be tested.

[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 tested; S2, injecting the water sample to be tested into the separation tank to separate the microplastics in the water sample to be tested; S3, obtaining the quality and / or quantity of the microplastics, and then obtaining the microplastic content of the water sample to be tested.

[0015] Furthermore, 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 it for a first preset time to obtain an oxidized water sample; S22, injecting a surfactant into the oxidized water sample and stirring it for a second preset time to obtain a modified water sample; S23, using the foaming component 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 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, collecting the eluate, adding a density regulator to the eluate and stirring, and adjusting the density of the eluate to 1.5 g / cm3 ; Centrifuge the eluate after density adjustment, collect the upper layer of liquid after centrifugation and wash it with deionized water, and filter to obtain the first filter residue; wash the overflow liquid flowing out of the guide groove with deionized water, and filter to obtain the second filter residue.

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

[0017] Furthermore, the surfactant is hexadecyltrimethylammonium bromide, which is added dropwise into the oxidized water sample and stirred while adding, and the concentration of hexadecyltrimethylammonium bromide in the modified water sample is 0.007%-0.015%; the second preset time is 20min-30min.

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

[0019] Furthermore, the density regulator is ZnCl2 or NaI, the rotation speed of the centrifugal separation is 3000r / min-4000r / min, and the processing time is 10min-15min.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] 1. The presently disclosed embodiments provide a water separation and filtration device and a novel pollutant detection system and method that can completely separate microplastics from water samples mixed with microplastics, sediment, suspended organic matter, and other impurities, while preventing the influx of other impurities. This provides important support for the quantitative detection of microplastic content in water samples.

[0022] 2. A water separation and filtration device and a new pollutant detection system and method provided by the embodiments of the present disclosure, in which the rotation of the stirring rod can, on the one hand, cause the bubbling head to rotate around the axis of the vertical section in the separation tank, thereby evenly distributing the bubbles output by the bubbling head in the separation tank, and also causing the water sample to flow, thereby increasing the probability of collision between bubbles and microplastics, thereby promoting the adsorption of bubbles on the surface of microplastics and carrying the microplastics to float. On the other hand, while the bubbling head generates bubbles, the shearing effect between the bubbling head rotating around the axis of the vertical section and the water sample causes the generated bubbles to detach from the bubbling head more quickly, thereby further refining the bubble size. In addition, the water sample presents a "vortex" flow form, thereby causing the floating microplastics to gather toward the middle of the water surface. The shearing effect 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.

[0023] 3. The embodiments of the present disclosure provide a water separation and filtration device and a new pollutant detection system and method. By setting a first conical tube and a second conical tube of appropriate size, deionized water can flow into the separation tank along the inner wall of the separation tank. On the one hand, the water level in the separation tank can be raised to achieve overflow collection of floating microplastics. On the other hand, the injected deionized water is injected along the inner wall of the separation tank, and a small amount of microplastics originally adhering to the inner wall of the separation tank are washed away, thereby ensuring the separation rate of the microplastics. In addition, the injection of deionized water along the inner wall of the separation tank prevents the deionized water from dispersing the foam layer formed by the microplastics floating up with the bubbles. In addition, the first conical tube can also act as a "flywheel", so that the stirring rod can smoothly pass through the dead point and rotate smoothly during the process of being driven to rotate by the reciprocating linear motion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0025] Figure 1 A schematic diagram of the three-dimensional structure of the water separation and filtration device drawn according to an embodiment of the present invention;

[0026] Figure 2 Based on Figure 1 A partial magnified view of the drawn area A;

[0027] Figure 3 Based on Figure 1 A cross-sectional view of the water separation and filtration device drawn;

[0028] Figure 4 Based on Figure 3 A partial magnified view of the drawn area B;

[0029] Figure 5 Based on Figure 4 A partial magnified view of the drawn C region;

[0030] Figure 6 This is a diagram of the air supply pipeline of the water separation and filtration device drawn according to an embodiment of the present invention;

[0031] Figure 7 A flowchart of the new pollutant detection method drawn according to an embodiment of the present invention;

[0032] Figure 8 This is a flow chart for separating microplastics from a water sample to be tested according to an embodiment of the present invention.

[0033] Markings and corresponding parts names in the accompanying drawings:

[0034] 1-separation tank; 11-discharge pipe; 12-valve; 13-overflow port; 14-guide groove; 15-bracket; 16-water baffle; 41-bubble head; 42-air supply pipe; 43-cylinder body; 431-first air inlet pipe; 432-first air outlet pipe; 433-second air inlet pipe; 434-second air outlet pipe; 435-one-way valve; 44-piston body; 45-three-way valve; 51-water inlet pipe; 52-first cone pipe; 53-second cone pipe; 54-water storage gap; 55-drainage pipe; 56-third cone pipe; 57-connecting rod; 61-linear motor; 62-agitation rod; 621-vertical section; 622-inclined section; 623-offset section; 63-output shaft; 64-connecting rod. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the examples and accompanying drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention. It should be noted that the present invention is already in the actual development and use stage.

[0036] With the widespread use of plastic products, microplastics have become widely present in natural water bodies, and microplastics have been listed as a major category of new pollutants (new pollutants are 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 hidden dangers to human health and environmental safety even if they enter in low doses. New pollutants mainly include persistent organic pollutants, endocrine disruptors, antibiotics, microplastics, etc.).

[0037] Water quality monitoring is a key component of ecological and environmental monitoring. In recent years, microplastics have been frequently detected in water bodies during water quality testing. However, due to their small particle size (less than 5mm), diverse types, and widely varying densities, microplastics are often present in water samples mixed with impurities such as sediment and suspended organic matter. This makes it difficult to effectively separate microplastics (for example, when filtering with a filter, interfering particulate matter of the same size can be mixed into the filtered "target"; density-based separation can also lead to the incorporation of suspended matter, resulting in significant deviations in quantitative test results). This makes the quantitative detection of microplastics a major challenge in water quality testing.

[0038] In order to accurately separate the target emerging pollutant—microplastics—from water samples and provide reliable support for detecting microplastic content in water samples, the present invention provides a water separation and filtration device and an emerging pollutant detection system and method, which are designed to at least partially overcome the above-mentioned technical problems and achieve the above-mentioned beneficial effects.

[0039] Example 1:

[0040] like Figure 1 、 Figure 3 As shown, the water separation and filtration device includes a separation tank 1, a first filtration component, a second filtration component, a bubbler component and a water injection component;

[0041] The separation tank 1 is fixedly installed, and a discharge pipe 11 is provided at the bottom of the separation tank 1. The discharge pipe 11 is connected to the top of the first filter assembly, and a valve 12 is provided on the upper part of the discharge pipe 11; an overflow port 13 is provided on the upper part of the separation tank 1, and the overflow port 13 is connected to the top of the second filter assembly through a guide groove 14;

[0042] The foaming assembly includes an air source and a foaming head 41, the foaming head 41 is installed inside the separation tank 1, and the air source is connected to the foaming head 41;

[0043] The water injection assembly is used to inject water into the separation tank 1, thereby raising the water level inside the separation tank 1;

[0044] The first filter assembly is used to filter the residual liquid flowing out through the discharge pipe 11 , and the second filter assembly is used to filter the overflow liquid flowing out through the guide groove 14 .

[0045] During use, the collected water sample is injected into the separation tank 1, and then 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 (excess hydrogen peroxide can be decomposed by adding catalase to the water sample); then cetyltrimethylammonium bromide is added and stirred, so that the originally hydrophilic microplastics become hydrophobic; thereafter, a large number of tiny bubbles (bubble size is 20μm-50μm) are generated in the separation tank 1 by using a bubbling component, and the bubbles are adsorbed on the surface of the microplastics to make the microplastics float; on the microplastics After floating, deionized water is added to the separation tank 1 to raise the water level to above the overflow port 13, and the floating microplastics flow to the second filter assembly (not shown in the figure) through the guide groove 14; then, for the residual liquid in the separation tank 1, the valve 12 is opened to allow the residual liquid to flow to the first filter assembly (not shown in the figure) through the discharge pipe 11. After filtration, the filter residue less than 5 mm is retained and washed out from the corresponding filter screen and / or filter membrane with deionized water to obtain an eluate, and ZnCl2 or NaI is added to the eluate to adjust the density of the eluate 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). 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). The obtained first filter residue and second filter residue are the target new pollutants - microplastics separated from the water sample.

[0046] 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.

[0047] It should be understood that in order to avoid the introduction of exogenous microplastics, the water separation and filtration device should not be made of plastic materials as much as possible.

[0048] Example 2:

[0049] like Figures 1 to 5 As shown, this embodiment is based on embodiment 1, except 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;

[0050] 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 smoothly transitions to the vertical section 621, and the inclined section 622 is located inside the separation tank 1 and fixedly connected to the vertical section 621;

[0051] 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;

[0052] The foaming head 41 is mounted on the inclined section 622 .

[0053] Therefore, as the output shaft 63 of the linear motor 61 moves back and forth, the stirring rod 62 will rotate around the axis of the vertical section 621, and then 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 during the above-mentioned use; in addition, the rotation of the stirring rod 62 can, on the one hand, drive the bubbling head 41 to rotate around the axis of the vertical section 621 in the separation tank 1, and then the bubbles output by the bubbling head 41 can be evenly distributed in the separation tank 1, and the water sample can flow, thereby increasing the collision probability of bubbles and microplastics, and then promoting the adsorption of bubbles on the surface of microplastics, carrying microplastics The material floats up. On the other hand, while the bubbling head 41 generates bubbles, the shearing effect between the bubbling head 41 rotating around the axis of the vertical section 621 and the water sample causes the generated bubbles to detach from the bubbling head 41 more quickly, thereby further refining the bubble size (the bubbles do not have enough time to grow and then detach from the bubbling head 41); and the water sample presents a "vortex" flow form, thereby, the floating microplastics (foam combination) will gather toward the middle of the water surface, and the shearing effect between the water sample and the inner wall of the separation tank 1 greatly reduces the microplastics (foam combination) adsorbed on the inner wall of the separation tank 1, which is beneficial to the subsequent overflow separation of the floating microplastics.

[0054] It is understandable that the linear motor 61 is used to drive the stirring rod 62 in order to prevent lubricating oil from the meshing parts of the gear transmission, chain transmission, etc. from falling into the separation tank 1 below and contaminating the water sample.

[0055] Example 3:

[0056] like Figures 1 to 6 As shown, this embodiment is based on embodiment 2, except that, in this embodiment, the stirring rod 62 is a hollow rod, and the foaming head 41 is fixedly mounted on the end of the inclined section 622 away from the vertical section 621;

[0057] The gas source is connected to the foaming head 41 via an air supply pipe 42 , and the air supply pipe 42 is disposed inside the stirring rod 62 .

[0058] Thus, by hiding the air supply pipe 42 inside the stirring rod 62, it is possible to prevent the air supply pipe 42 from being entangled on the stirring rod 62 during the rotation of the stirring rod 62. In addition, compared to the case where the air supply pipe 42 is located outside the stirring rod 62 and tied to the stirring rod 62, the gap between the stirring rod 62 and the air supply pipe 42 is prevented from getting stuck in the microplastics, thereby ensuring that the microplastics float up unimpeded. Installing the bubbler head 41 on the end of the inclined section 622 away from the vertical section 621 can make the bubbler head 41 as close to the bottom of the separation tank 1 as possible, thereby allowing the generated bubbles to collide with the microplastics in the lower water body. 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 to the bubbles and float up. It should be understood that the air supply pipe 42 is a flexible tube (such as a corrugated tube) that can automatically change its bending degree as the stirring rod 62 rotates to adapt to the position change of the offset section 623.

[0059] Furthermore, the gas source includes a cylinder body 43, which is fixedly mounted on the bracket 15. The output shaft 63 passes through the cylinder body 43 along the length direction of the cylinder body 43. A piston body 44 is fixedly mounted on the output shaft 63, and the piston body 44 is located inside the cylinder body 43.

[0060] A first air inlet pipe 431 and a first air outlet pipe 432 are provided at one end of the cylinder body 43, and a second air inlet pipe 433 and a second air outlet pipe 434 are provided at the other end; a one-way valve 435 is installed on each of the first air inlet pipe 431, the first air outlet pipe 432, the second air inlet pipe 433 and the second air outlet pipe 434;

[0061] The first and second air outlet pipes 432 and 434 are both connected to the air inlet of a three-way valve 45. The first air outlet of the three-way valve 45 is connected to the bubbler head 41, and the second air outlet of the three-way valve 45 is connected to the outside world. Specifically, the first air outlet can be connected to the bubbler head 41 via the air supply pipe 42.

[0062] It should be understood that the one-way valves 435 installed on the first and second air inlet pipes 431, 433 allow external gas to enter the cylinder body 43 only through the first and second air inlet pipes 431, 433. Similarly, the one-way valves 435 installed on the first and second air outlet pipes 432, 434 allow gas inside the cylinder body 43 to be discharged to the outside only through the first and second air outlet pipes 432, 434. By operating the three-way valves 45, the airflow output from the first and second air outlet pipes 432, 434 can flow into the air supply pipe 42, or the airflow output from the first and second air outlet pipes 432, 434 can flow into the outside.

[0063] Therefore, during the reciprocating linear motion of the output shaft 63 of the linear motor 61, the piston body 44 moves back and forth linearly inside the cylinder body 43, so that the second air outlet pipe 434 discharges air when the first air inlet pipe 431 takes in air, or the first air outlet pipe 432 discharges air when the second air inlet pipe 433 takes in air, that is, there is always one of the first air inlet pipe 431 and the second air inlet pipe 433 that supplies air to the three-way valve 45. When it is necessary to ventilate the bubble head 41 so that bubbles are generated in the bubble head 41, the air flow output from the first air outlet pipe 432 and the second air outlet pipe 434 can be made to flow into the air supply pipe 42 by operating the three-way valve 45; 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 so that the air flow output from the first air outlet pipe 432 and the second air outlet pipe 434 can flow into the outside.

[0064] Thus, the linear motor 61 can be used to drive the stirring rod 62 to stir the separator 1. It can also drive the piston 44 to reciprocate linearly in the cylinder 43 to generate airflow when air is supplied to the bubbler head 41 to generate bubbles in the separator 1. Preferably, the reciprocating linear motion frequency of the output shaft 63 of the linear motor 61 is adjustable.

[0065] Example 4:

[0066] Please continue to refer to Figures 1 to 5 This embodiment is based on embodiment 2, except that, in this embodiment,

[0067] The water injection assembly includes a water inlet pipe 51, a first tapered pipe 52 and a second tapered pipe 53;

[0068] The small end of the first conical tube 52 is fixedly connected to the vertical section 621, and the large end faces the discharge pipe 11. The second conical tube 53 is located above the first conical tube 52, with the large end of the second conical tube 53 facing the discharge pipe 11. The small end of the second conical tube 53 is fixedly connected to the bracket 15, and the vertical section 621 is inserted into the second conical tube 53.

[0069] There is a water storage gap 54 between the first tapered tube 52 and the second tapered tube 53 . The width of the water storage gap 54 gradually decreases in the vertical downward direction. The water inlet pipe 51 is connected to the water storage gap 54 .

[0070] Therefore, when it is necessary to inject deionized water into the separation tank 1 to increase the liquid level in the separation tank 1, deionized water is injected into the water storage gap 54 through the water inlet pipe 51, so that the deionized water in the water storage gap 54 can flow out along the gap at the bottom of the water storage gap 54. By setting the first tapered tube 52 and the second tapered tube 53 of appropriate size, the deionized water can flow into the separation tank 1 along the inner wall of the separation tank 1. On the one hand, the water level in the separation tank 1 can be increased to achieve overflow collection of floating microplastics. On the other hand, the injected deionized water is also injected along the inner wall of the separation tank 1. In the process of being injected, a small amount of microplastics (foam combination) originally adhered to the inner wall of the separation tank 1 is also washed down, thereby ensuring the separation rate of the microplastics. In addition, along the inner wall of the separation tank 1 Injecting deionized water prevents the deionized water from dispersing the foam layer formed by the microplastics floating up with the bubbles (dispersion will cause the originally floating microplastics to be unable to remain floating on the water surface); in addition, the first conical tube 52 can also act as a "flywheel" (in the process of the output shaft 63 driving the stirring rod 62 to rotate, there is a "dead point". In the process of the stirring rod 62 rotating, the inertia of the rotation of the first conical tube 52 fixed on the vertical section 621 can help the stirring rod 62 to smoothly pass through the dead point and complete the complete circular motion. In order to increase the inertia of the first conical tube 52, a counterweight block can be added to the inner wall of the large end of the first conical tube 52), so that in the process of the reciprocating linear motion driving the stirring rod 62 to rotate, the stirring rod 62 can smoothly pass through the dead point and rotate smoothly. Preferably, when injecting deionized water, the stirring rod 62 is still rotating slowly, so that the deionized water in the water storage gap 54 can be evenly injected along the peripheral wall of the separation tank 1, forcing the floating objects to converge toward 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 can flow out smoothly through the overflow port 13.

[0071] Preferably, a plurality of drainage tubes 55 are fixedly connected to the first conical tube 52;

[0072] A third conical tube 56 is fixedly mounted on the inclined section 622. There is a flow-out gap between the small end of the third conical tube 56 and the outer peripheral wall of the inclined section 622. The large end of the third conical tube 56 is higher than the small end (e.g., Figure 4 、 Figure 5 As shown, the large end of the third tapered tube 56 is fixedly connected to the first tapered tube 52 via a connecting rod 57, so that when the third tapered tube 56 is fixedly sleeved on the inclined section 622, there is an outflow gap between the small end of the third tapered tube 56 and the outer peripheral wall of the inclined section 622. Of course, the third tapered tube 56 can also be fixedly connected to the inclined section 622 via the connecting rod 57 to achieve fixed sleeve installation, and the present application is not limited to this);

[0073] For any drainage tube 55 , one end thereof passes through the first conical tube 52 and is connected to the water storage gap 54 , and the other end is connected to the inner side of the third conical tube 56 ; the positions where the drainage tubes 55 pass through the first conical tube 52 are evenly distributed around the circumference.

[0074] As a result, part of the deionized water in the water storage gap 54 is introduced into the third conical tube 56 by the drainage tube 55, and then flows into the separation tank 1 along the outer peripheral wall of the inclined section 622 through the outflow gap, thereby flushing a small amount of microplastics (foam combinations) adhering to the outer peripheral wall of the inclined section 622 into the water and keeping them floating.

[0075] Preferably, a water baffle 16 is further 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 at the location of the overflow port 13).

[0076] When the water baffle 16 is in the first position, the water baffle 16 is located below the water storage gap 54 at the overflow port 13, and can block the water flow out of the water storage gap 54 and rush toward the inner wall of the separation tank 1 below the overflow port 13, ensuring that floating objects flow out smoothly; when the water baffle 16 is in the second position, the water baffle 16 leaves the water storage gap 54 at the overflow port 13. At this time, the water baffle 16 will not affect the water flow out of the water storage gap 54.

[0077] Thus, after 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, thereby using the water baffle 16 to receive the deionized water flowing out of the water storage gap 54, thereby preventing this deionized water from impacting floating objects flowing out of the overflow port, thereby ensuring the smooth flow of floating objects. The deionized water received by the water baffle 16 flows down along both sides of the water baffle 16 due to the inclined surfaces on both sides of the water baffle 16 (both sides of the sliding direction).

[0078] Preferably, the foaming head 41 is a microporous aeration head, and the pore size of the microporous aeration head is less than 20 μm;

[0079] The first filter assembly 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 5 mm, the pore size of the second filter screen is 50 μm, the pore size of the first filter membrane is 5 μm, and the pore size of the second filter membrane is 0.45 μm.

[0080] The second filter assembly includes a third filter screen and a third filter membrane. The pore size of the third filter screen is 50 μm, and the pore size of the third filter membrane is 5 μm.

[0081] It should be understood that by adjusting the reciprocating frequency of the output shaft 63 of the linear motor 61, the microporous aeration head can continuously produce bubbles of 20μm-50μm. The first filter screen can filter out impurities larger than 5mm in the residual liquid. The second filter screen, the first filter membrane, and the second filter membrane achieve graded filtration of the residual liquid, thereby filtering out as much microplastics as possible from the residual liquid. The second filter assembly can retain larger microplastics in the overflow liquid on the third filter screen, while the third filter membrane retains the remaining smaller microplastics. Because the bubble size ranges from 20μm to 50μm, microplastics smaller than 5μm are less likely to collide with and attach to the bubbles due to their small size, and thus will not float up with the bubbles to form floating objects.

[0082] Example 5:

[0083] This embodiment provides a new pollutant detection system, based on the aforementioned water separation and filtration device, and the new pollutant detection system includes:

[0084] The aforementioned water separation and filtration device is used to separate microplastics from the water sample to be tested;

[0085] Water sample collection module, used to collect water samples to be tested;

[0086] The content determination module is used to determine the content of microplastics in the water sample to be tested.

[0087] It should be understood that the water sample collection module can be carried out using relevant sampling equipment and methods in the prior art, but it is necessary to avoid the use of plastic collection and storage instruments. The content determination module includes at least a mass measurement 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 number of microplastics, thereby obtaining the number density and particle size distribution of microplastics in the water sample. Based on this, the new pollutant detection system provided by this embodiment can separate the microplastics in the collected water sample to be tested as completely as possible, thereby achieving quantitative detection of microplastics in the water sample to be tested.

[0088] Example 6:

[0089] like Figure 7 、 Figure 8 As shown, this embodiment provides a new pollutant detection method based on the aforementioned water separation and filtration device, the method comprising:

[0090] S1, collect water samples to be tested;

[0091] S2, injecting the water sample to be tested into the separation tank 1 to separate the microplastics in the water sample to be tested;

[0092] S3, obtaining the mass and / or quantity of the microplastics, and then obtaining the microplastic content of the water sample to be tested.

[0093] It should be understood that the water samples to be tested can be collected according to the conventional sampling methods for water quality testing. It should be noted that in order to avoid exogenous microplastic contamination during sampling and sample transportation, the instruments used for sampling (collection, holding, etc.) should not be made of plastic.

[0094] More specifically, the S2 includes:

[0095] S21, after injecting the water sample to be tested into the separation tank 1, injecting an oxidant into the water sample to be tested and stirring it for a first preset time to obtain an oxidized water sample;

[0096] S22, injecting a surfactant into the oxidized water sample and stirring for a second preset time to obtain a modified water sample;

[0097] S23, continuously generating bubbles at the bottom of the modified water sample for a third preset time using the bubbling component to obtain a stratified water sample;

[0098] 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 14;

[0099] S25, grade-filter the residual liquid in the separation tank 1, wash out the filter residue less than 5 mm with deionized water to collect the eluate, add a density regulator to the eluate and stir, and adjust the density of the eluate to 1.5 g / cm 3 The density-adjusted eluate was centrifuged, the upper layer of the centrifuged liquid was collected and washed with deionized water, and filtered to obtain a first filter residue;

[0100] The overflow liquid flowing out of the guide groove 14 is washed with deionized water and filtered to obtain a second filter residue.

[0101] Specifically, the oxidant is H2O2, which is added dropwise to the water sample to be tested while stirring. The concentration of H2O2 in the oxidized water sample is 3%-5%, and the first preset time is 2 hours to 4 hours. Preferably, after the oxidant is injected into the water sample to be tested and stirred for the first preset time, catalase is injected into the water sample and stirred to decompose the remaining H2O2 in the water sample.

[0102] The surfactant is cetyltrimethylammonium bromide, which is added dropwise to the oxidized water sample while stirring. The concentration of cetyltrimethylammonium bromide in the modified water sample is 0.007%-0.015%;

[0103] The second preset time length is 20 minutes to 30 minutes.

[0104] The bubble size generated by the foaming component is 20 μm-50 μm, and the third preset time is 20 min-30 min;

[0105] While the bubble generating assembly is generating bubbles, the modified water sample is stirred.

[0106] The density regulator is ZnCl2 or NaI, the rotation speed of the centrifugal separation is 3000r / min-4000r / min, and the processing time is 10min-15min.

[0107] Before rinsing and filtering the upper layer of liquid with deionized water, add ethanol solution to the upper layer of liquid and soak it for 1-2 minutes to allow the hexadecyltrimethylammonium bromide adsorbed on the surface of the microplastics to decompose and fall off. Similarly, before rinsing and filtering the overflow liquid with deionized water, add ethanol solution to the overflow liquid and soak it for 1-2 minutes.

[0108] Thus, in this embodiment, the organic suspended matter in the water sample is decomposed by adding hydrogen peroxide to the water sample to be tested, thereby decomposing the larger organic suspended matter into small molecular substances or even CO2 and H2O, and then using cetyltrimethylammonium bromide 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 be attached to the surface of the bubbles after contact with the bubbles, and then float to the water surface under the action of the bubbles. For these floating microplastics, by injecting deionized water into the water sample, the floating microplastics can be discharged through the overflow port 13. Preferably, the operation of "introducing bubbles-overflowing and collecting the upper layer of foam" is repeated 2-3 times to make the microplastics float as much as possible. In the process of injecting deionized water, the deionized water is preferably injected along the inner wall of the separation tank 1, thereby avoiding the dispersion of the floating upper layer of foam on the one hand, and on the other hand, a small amount of microplastics originally adhering to the inner wall of the separation tank 1 can be washed into the water sample. Obviously, the first filter residue and the second filter residue obtained are the target pollutants - microplastics. After low-temperature drying, the mass concentration, number concentration, etc. of the microplastics in the water sample to be tested can be obtained by existing weighing and counting methods.

[0109] It should be understood that, in this application, the term "rotational connection" means that the two can only rotate relative to each other, such as the rotation setting of the hole and the shaft rod, which can achieve the limitation of axial relative movement by setting a shoulder on the shaft and a limit groove in the hole; the term "sliding connection" and "sliding installation" mean that the two can only slide relative to each other, such as dovetail grooves, T-slots and other structures.

[0110] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A water separation and filtration device, characterized in that: It comprises a separation tank (1), a first filtering component, a second filtering component, a foaming component and a water injection component; The separation tank (1) is fixedly installed, and a discharge pipe (11) is provided at the bottom of the separation tank (1), and the discharge pipe (11) is connected to the top of the first filter assembly; an overflow port (13) is provided at the top of the separation tank (1), and the overflow port (13) is connected to the top of the second filter assembly through a guide groove (14); The foaming assembly comprises an air source and a foaming head (41), the foaming head (41) is installed inside the separation tank (1), and the air source is connected to the foaming head (41); The water injection assembly is used to inject water into the separation tank (1); The first filter assembly is used to filter the residual liquid flowing out through the discharge pipe (11), and the second filter assembly is used to filter the overflow liquid flowing out through the guide groove (14); The water separation and filtration device further comprises a linear motor (61) and a stirring rod (62), and a bracket (15) is fixedly mounted on the upper part of the separation tank (1); The stirring rod (62) comprises a vertical section (621), an inclined section (622) and an offset section (623); The foaming head (41) is mounted on the inclined section (622); The water injection assembly comprises a water inlet pipe (51), a first tapered tube (52) and a second tapered tube (53); The small end of the first conical tube (52) is fixedly connected to the vertical section (621) and the large end faces the discharge pipe (11); the second conical tube (53) is located above the first conical tube (52), the large end of the second conical tube (53) faces the discharge pipe (11), the small end of the second conical tube (53) is fixedly connected to the bracket (15), and the vertical section (621) is inserted into the second conical tube (53); A water storage gap (54) exists between the first conical tube (52) and the second conical tube (53), the width of the water storage gap (54) gradually decreases in a vertical downward direction, and the water inlet pipe (51) is connected to the water storage gap (54).

2. The water separation and filtration device according to claim 1, characterized in that: 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).

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 mounted on an end of the inclined section (622) away from the vertical section (621); The gas source is connected to the foaming head (41) via an air supply pipe (42), and the air supply pipe (42) is arranged inside the stirring rod (62).

4. The water separation and filtration device according to claim 2, characterized in that: The gas source comprises a cylinder body (43), the cylinder body (43) being fixedly mounted on the bracket (15), the output shaft (63) penetrating the cylinder body (43) along the length direction of the cylinder body (43), a piston body (44) being fixedly mounted on the output shaft (63), and the piston body (44) being located inside the cylinder body (43); A first air inlet pipe (431) and a first air outlet pipe (432) are provided at one end of the cylinder body (43), and a second air inlet pipe (433) and a second air outlet pipe (434) are provided at the other end; a one-way valve (435) is installed on each of the first air inlet pipe (431), the first air outlet pipe (432), the second air inlet pipe (433), and the second air outlet pipe (434); The first air outlet pipe (432) and the second air outlet pipe (434) are both connected to the air inlet of a three-way valve (45), the first air outlet of the three-way valve (45) is connected to the foaming head (41), and the second air outlet of the three-way valve (45) is connected to the outside world.

5. The water separation and filtration device according to claim 1, characterized in that: A plurality of drainage tubes (55) are also fixedly connected to the first conical tube (52); A third conical tube (56) is fixedly sleeved on the inclined section (622), an outflow gap exists between the small end of the third conical tube (56) and the outer peripheral wall of the inclined section (622), and the large end of the third conical tube (56) is higher than the small end; For any drainage tube (55), one end thereof passes through the first conical tube (52) and is connected to the water storage gap (54), and the other end is connected to the inner side of the third conical tube (56); the positions where the drainage tubes (55) pass through the first conical tube (52) are evenly distributed around the circumference.

6. The water separation and filtration device according to claim 1, characterized in that: A water baffle (16) is also slidably mounted on the separation tank (1), the water baffle (16) being located above the overflow port (13) and slidably connected to the separation tank (1), and the water baffle (16) being capable of switching between a first position and a second position; When the water baffle (16) is located in the first position, the water baffle (16) is located below the water storage gap (54) at the overflow port (13), and can block the water flowing out of the water storage gap (54) and rushing toward the inner wall of the separation tank (1) below the overflow port (13), thereby ensuring that floating objects flow out smoothly; when the water baffle (16) is located in the second position, the water baffle (16) is away from below the water storage gap (54) at the overflow port (13), and at this time, the water baffle (16) will not affect the water flowing out of the water storage gap (54).

7. The water separation and filtration device according to claim 1, characterized in that: The foaming head (41) is a microporous aeration head, and the pore size of the microporous aeration head is less than 20 μm; The first filter assembly 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 5 mm, the pore size of the second filter screen is 50 μm, the pore size of the first filter membrane is 5 μm, and the pore size of the second filter membrane is 0.45 μm. The second filter assembly includes a third filter screen and a third filter membrane. The pore size of the third filter screen is 50 μm, and the pore size of the third filter membrane is 5 μm.

8. A new pollutant detection system, characterized in that: The water separation and filtration device comprises the water separation and filtration device according to any one of claims 1 to 7, wherein the water separation and filtration device is used to separate microplastics in a water sample to be detected; The new pollutant detection system also includes: Water sample collection module, used to collect water samples to be tested; The content determination module is used to determine the content of microplastics in the water sample to be tested.

9. A new pollutant detection method based on the water separation and filtration device according to any one of claims 1 to 7, characterized in that: include: S1, collect water samples to be tested; S2, injecting the water sample to be tested into the separation tank (1) to separate the microplastics in the water sample to be tested; S3, obtaining the mass and / or quantity of the microplastics, and then obtaining the microplastic content of the water sample to be tested.

10. The new pollutant detection method according to claim 9, characterized in that: The S2 includes: S21, after injecting the water sample to be tested into the separation tank (1), 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, continuously generating bubbles at the bottom of the modified water sample for a third preset time using the bubbling component 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 (14); S25, grade-filter the residual liquid in the separation tank (1), wash out the filter residue less than 5 mm with deionized water to collect the eluate, add a density regulator to the eluate and stir, and adjust the density of the eluate to 1.5 g / cm 3 The density-adjusted eluate was centrifuged, the upper layer of the centrifuged liquid was collected and washed with deionized water, and filtered to obtain a first filter residue; The overflow liquid flowing out of the guide groove (14) is washed with deionized water and filtered to obtain a second filter residue.

11. The new pollutant detection method according to claim 10, characterized in that: The oxidant is H2O2, which is added dropwise to the water sample to be tested while stirring. The concentration of H2O2 in the oxidized water sample is 3%-5%; The first preset duration is 2h-4h.

12. The new pollutant detection method according to claim 10, characterized in that: The surfactant is cetyltrimethylammonium bromide, which is added dropwise to the oxidized water sample while stirring. The concentration of cetyltrimethylammonium bromide in the modified water sample is 0.007%-0.015%; The second preset time length is 20 minutes to 30 minutes.

13. The new pollutant detection method according to claim 10, characterized in that: The bubble size generated by the foaming component is 20 μm-50 μm, and the third preset time is 20 min-30 min; While the bubble generating assembly is generating bubbles, the modified water sample is stirred.

14. The new pollutant detection method according to claim 10, characterized in that: The density regulator is ZnCl2 or NaI, the rotation speed of the centrifugal separation is 3000r / min-4000r / min, and the processing time is 10min-15min.

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