A filtration cartridge, filtration device, and filtration method for nearshore marine environmental monitoring.

Abstract

This invention relates to the field of marine environmental monitoring equipment technology, and in particular to a filtration cylinder, filtration device, and filtration method for nearshore marine environmental monitoring. It includes a cylinder body, with a filter membrane detachably mounted at the lower end of the cylinder body, and a coarse filter plate detachably mounted at the upper end of the cylinder body. A piston is located inside the cylinder body, and a liquid transfer tube is mounted on the piston. The liquid transfer tube is connected to a drive assembly. The cylinder body is divided into a liquid inlet zone, a coarse filtration zone, a liquid transfer zone, and a filtration zone by the coarse filter plate, piston, and filter membrane. The drive assembly drives the liquid transfer tube to slide within the piston, simultaneously moving the piston within the cylinder body. Liquid is transferred from the coarse filtration zone to the liquid transfer zone. Simultaneously, the piston applies pressure towards the filter membrane to the liquid. A negative pressure is created in the filtration zone via a suction mechanism, causing liquid to be drawn from the liquid transfer zone to the filtration zone. This invention solves the problems of frequent filter membrane replacement, low filtration efficiency, and inconsistent test results when filtering parallel samples for quality control.

Description

Technical Field

[0001] This invention relates to the field of marine environmental monitoring equipment technology, and in particular to a filtration cylinder, filtration device and filtration method for nearshore marine environmental monitoring. Background Technology

[0002] Monitoring seawater quality is fundamental to studying, understanding, and protecting the ocean environment. Rigorous and accurate collection of representative samples is of great significance for obtaining accurate monitoring data and scientifically supporting marine environmental protection decision-making.

[0003] Seawater filtration is a pretreatment step in sampling for detecting suspended solids, chlorophyll content, and many other physicochemical indicators in seawater, directly affecting the authenticity and accuracy of seawater quality monitoring and evaluation results. Currently, existing technologies mainly use a filtration pump connected to a single filter for filtration, which is inefficient, especially in turbid nearshore waters. Multiple filter membrane replacements are often required to meet the filtration volume requirements for suspended solids, chlorophyll, and other monitoring indicators. Furthermore, filtration is time-consuming, and the sedimentation of suspended sediment can distort the test results of water samples filtered after subsequent membrane replacements, failing to accurately reflect the actual water quality of the monitored sea area. When filtration parallel samples for quality control, each sample also requires membrane replacement, easily leading to inconsistent test results among parallel samples. Summary of the Invention

[0004] To address the aforementioned issues of frequent filter membrane replacement, low filtration efficiency, and inconsistent test results when using parallel samples for quality control during filtration, this invention provides a filtration cylinder, filtration device, and filtration method for nearshore marine environmental monitoring.

[0005] In a first aspect, the present invention provides a filtration cylinder for nearshore marine environmental monitoring, comprising a cylinder body, a filter membrane detachably disposed at the lower end of the cylinder body, a coarse filter plate detachably disposed at the upper end of the cylinder body, a piston disposed within the cylinder body, a liquid transfer tube disposed on the piston, and a drive assembly connected to the liquid transfer tube. The cylinder body is divided into a liquid inlet zone, a coarse filtration zone, a liquid transfer zone, and a filtration zone by the coarse filter plate, the piston, and the filter membrane. The drive assembly drives the liquid transfer tube to slide within the piston, and simultaneously drives the piston to move within the cylinder body, transferring liquid from the coarse filtration zone to the liquid transfer zone. At the same time, the piston applies pressure to the liquid towards the filter membrane. The filtration zone forms a negative pressure through a suction mechanism, causing the liquid to be drawn from the liquid transfer zone to the filtration zone.

[0006] Furthermore, the liquid transfer tube has an inlet section and a transfer section. The inlet section has an inlet hole on its side wall, and the transfer section has a transfer hole on its side wall. The bottom of the transfer section has a connecting hole. The coarse filter is fixedly connected to the liquid transfer tube. The liquid transfer tube penetrates the cylinder and can slide at the end of the cylinder and inside the piston, thereby driving the coarse filter to slide inside the cylinder. The transfer section has a lower pressure plate and an upper lifting plate distributed on both sides of the piston. The drive assembly drives the liquid transfer tube to slide inside the piston. The liquid is transferred from the coarse filtration zone to the transfer zone through the transfer hole and the connecting hole.

[0007] Furthermore, the cylinder body includes a coarse filter cylinder, a liquid transfer cylinder detachably connected to the coarse filter cylinder, and a fine filter cylinder detachably connected to the liquid transfer cylinder. The lower end of the fine filter cylinder is provided with a filtrate pipe connector. The liquid transfer pipe penetrates out of the coarse filter cylinder and is connected to an inlet pipe connector through a telescopic pipe. The inlet pipe connector is provided with a pressure relief hole.

[0008] In a second aspect, the present invention provides a filtration device for nearshore marine environmental monitoring, comprising a support frame and a filtration cylinder as described in any of the above claims. Multiple filtration cylinders are provided and disposed on the upper end of the support frame. A collection bottle is provided at the lower end of the support frame. The upper end of the collection bottle is connected to a suction mechanism via a suction pipe. The suction mechanism is a filtration pump. The lower end of the collection bottle is connected to the lower end of the filtration cylinder via a filtrate pipe. A magnetic stirrer is connected to the upper end of the filtration cylinder via a liquid inlet pipe. A water outlet pipe is also provided at the lower end of the collection bottle.

[0009] Furthermore, the filter cylinders are arranged in a circumferential array on the upper end of the support frame, and the filter cylinders are erected vertically. A fixing component is provided on the cylinder body, and a bracket is fixedly provided on the upper end of the support frame. The driving component includes a support column provided on the support frame, a rotating shaft provided on the support column, a motor provided on the upper end of the bracket to drive the rotating shaft to rotate, and an inclined disk fixedly provided on the rotating shaft. The portion of the liquid transfer tube that penetrates through the coarse filter cylinder is connected to a driving groove facing the rotating shaft. The inclined disk is provided in the driving groove, and the inclined disk drives the liquid transfer tube to slide up and down inside the piston by rotating.

[0010] Furthermore, the fixing assembly includes an upper fixing plate and a lower fixing plate. The upper fixing plate has a first insertion hole for inserting the transfer tube, and the lower fixing plate has a second insertion hole for inserting the filter tube connector.

[0011] Furthermore, the bracket is provided with a lifting assembly, which includes a base on the bracket, an ejector seat on the base, a locking arm on the base for engaging with the liquid inlet pipe connector, an ejector arm on the ejector seat for engaging with the liquid inlet pipe, and an electric push rod inside the ejector seat for driving the ejector seat to spring up.

[0012] Furthermore, the upper part of the liquid collection bottle is provided with a gap partition, and the inner side wall of the liquid collection bottle is provided with a water pressure sensing line from top to bottom, and a water pressure sensor is provided on the water pressure sensing line.

[0013] Furthermore, the filtration device includes a controller, a first solenoid valve is provided on the inlet pipe, a second solenoid valve is provided on the filtrate pipe, and the controller is electrically connected to a magnetic stirrer, a filtration pump, a motor, an electric push rod, a water pressure sensor, the first solenoid valve, and the second solenoid valve.

[0014] Thirdly, the present invention provides a filtration method for nearshore marine environmental monitoring, comprising:

[0015] The controller controls the magnetic stirrer to open, the controller opens the first solenoid valve and the second solenoid valve, the controller starts the motor in the drive assembly, the transfer tube slides in the piston, and the water sample flows into the inlet area of ​​the suction filter through the inlet tube;

[0016] The transfer tube moves up and down, causing the coarse filter to move up and down as well. The impurities on the coarse filter are shaken, and the water sample flows through the coarse filter into the coarse filtration zone.

[0017] The water sample is transferred to the transfer zone through the transfer hole and the connecting hole. The piston moves downward and applies pressure towards the filter membrane to the water sample in the transfer zone. Under the action of the piston pressure and the negative pressure in the suction filtration zone, the water sample in the transfer zone is filtered through the filter membrane and enters the suction filtration zone and flows into the collection bottle.

[0018] When the water pressure sensor detects that the water level has reached the set value, it transmits a signal to the controller. The controller then controls the closure of the first solenoid valve, the second solenoid valve, the magnetic stirrer, and the filtration pump, stops the motor, and simultaneously controls the electric push rod to lift the ejector seat, thereby detaching the inlet pipe from the inlet pipe connector and completing the filtration process.

[0019] In summary, the present invention has the following beneficial technical effects:

[0020] The beneficial effects of this invention

[0021] 1. The present invention proposes a filtration cylinder, filtration device, and filtration method for nearshore marine environmental monitoring, which significantly improves filtration efficiency and reduces the frequency of filter membrane replacement. The filtration cylinder is equipped with a double-layer filtration structure of coarse filter plates and filter membrane. The coarse filter plates can pre-intercept larger particulate impurities such as suspended fine sand in seawater, so that the filter membrane mainly undertakes the task of fine filtration, extending the service life of the filter membrane and avoiding rapid clogging of the filter membrane due to nearshore seawater turbidity. This reduces the need for frequent filter membrane replacement and improves the overall filtration efficiency.

[0022] 2. The filtration device of the present invention has multiple filtration cylinders arranged in a circumferential array, which can simultaneously filter multiple water samples. Alternatively, two sets can be turned on while the other two sets are turned off for filtration. Then, the two sets that are turned on and off can be switched for comparative experiments. Compared with the filtration method of a single filter in the prior art, the parallel processing capability is significantly enhanced, and it has a certain degree of flexibility.

[0023] 3. In this invention, the piston pressure and negative pressure work together to drive the piston to move inside the cylinder, applying pressure towards the filter membrane to the liquid in the liquid transfer zone. At the same time, the suction zone forms a negative pressure through the suction mechanism. This dual power mechanism of "positive pressure pushing + negative pressure attracting" can accelerate the speed at which the liquid passes through the filter membrane and reduce the time spent on suction filtration.

[0024] 4. The coarse filter disc shaking and impurity removal function of this invention, when the transfer tube moves up and down, drives the coarse filter disc to move synchronously, causing the impurities trapped on the coarse filter disc to shake and fall off, thus avoiding the accumulation of impurities on the surface of the coarse filter disc and clogging the pores to a certain extent. The detachable cylinder structure of this invention allows for the disassembly and connection of each part, facilitating targeted cleaning and maintenance of different areas after filtration, reducing the impact of impurity residue on subsequent testing.

[0025] 5. This invention features simultaneous filtration and standardized operation, allowing multiple filtration cylinders to process parallel samples for quality control at the same time. This avoids the cumbersome operation of changing membranes one by one in existing technologies, effectively reducing inconsistencies in parallel sample test results due to operational differences, and improving the reliability and comparability of test data. The device is equipped with a controller, enabling fully automated operation from water sample inflow and filtration to the end of filtration. When the water pressure sensor detects that the water level in the collection bottle has reached the set value, the system can automatically stop filtration and perform subsequent operations such as disassembling the inlet pipe, reducing manual intervention costs and improving the convenience and stability of operation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the filter cylinder in Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the upward movement of the transfer tube in the vacuum filter cylinder of Embodiment 1 of the present invention;

[0028] Figure 3 This is a schematic diagram of the downward movement of the transfer tube in the filtration cylinder of Embodiment 1 of the present invention;

[0029] Figure 4 This is a schematic diagram of the filtration device according to Embodiment 2 of the present invention;

[0030] Figure 5 This is another structural schematic diagram of the filtration device according to Embodiment 2 of the present invention;

[0031] Figure 6 This is Embodiment 2 of the present invention. Figure 4 A magnified view of part A in the image;

[0032] Figure 7 This is the internal structure of the liquid collection bottle of the filtration device in Embodiment 2 of the present invention.

[0033] The components include: 1. Cylinder body; 101. Liquid inlet zone; 102. Coarse filtration zone; 103. Liquid transfer zone; 104. Vacuum filtration zone; 105. Coarse filter cylinder; 106. Liquid transfer cylinder; 107. Fine filter cylinder; 108. Filtration pipe connector; 2. Liquid transfer pipe; 201. Liquid inlet section; 202. Liquid transfer section; 203. Liquid inlet hole; 204. Liquid transfer hole; 205. Connecting hole; 206. Lower pressure plate; 207. Upper lifting plate; 208. Telescopic pipe; 209. Liquid inlet pipe connector; 210. Pressure relief hole; 211. Drive tank; 3. Filter membrane; 301. Coarse filter plate; 302. Piston; 4. Drive assembly; 401. Support column; 402. 1. Motor; 403. Inclined disc; 5. Support frame; 501. Bracket; 6. Fixing assembly; 601. Upper fixing plate; 602. First insertion hole; 603. Lower fixing plate; 604. Second insertion hole; 7. Lifting assembly; 701. Base; 702. Ejector seat; 703. Snap-fit ​​arm; 704. Ejector arm; 8. Collection bottle; 801. Filter pipe; 802. Water outlet pipe; 803. Water pressure sensing line; 804. Second solenoid valve; 805. Gap partition; 9. Vacuum pump; 901. Air extraction pipe; 10. Magnetic stirrer; 1001. Liquid inlet pipe; 1002. First solenoid valve; 11. Controller. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings.

[0035] Example 1

[0036] Reference Figure 1 This embodiment of a nearshore marine environmental monitoring filtration cylinder includes a cylinder body 1. A filter membrane 3 is detachably mounted on the lower end of the cylinder body 1, and a coarse filter 301 is detachably mounted on the upper end of the cylinder body 1. A piston 302 is provided inside the cylinder body 1, and a liquid transfer tube 2 is provided on the piston 302. The liquid transfer tube 2 is connected to a drive assembly 4. The cylinder body 1 is divided into an inlet zone 101, a coarse filtration zone 102, a liquid transfer zone 103, and a filtration zone 104 by the coarse filter 301, the piston 302, and the filter membrane 3. The drive assembly 4 drives the liquid transfer tube 2 to slide inside the piston 302, and at the same time drives the piston 302 to move inside the cylinder body 1. Liquid is transferred from the coarse filtration zone 102 to the liquid transfer zone 103. At the same time, the piston 302 applies pressure to the liquid towards the filter membrane 3. The filtration zone 104 forms a negative pressure through a suction mechanism, so that the liquid is drawn from the liquid transfer zone 103 to the filtration zone 104.

[0037] Reference Figure 2 and Figure 3 The liquid transfer tube 2 has an inlet section 201 and a transfer section 202. The inlet section 201 has an inlet hole 203 on its side wall, and the transfer section 202 has a transfer hole 204 on its side wall. The bottom of the transfer section 202 has a connecting hole 205. The coarse filter 301 is fixedly connected to the liquid transfer tube 2. The liquid transfer tube 2 penetrates the cylinder 1 and can slide at the end of the cylinder 1 and inside the piston 302, thereby driving the coarse filter 301 to slide inside the cylinder 1. The transfer section 202 has a lower pressure plate 206 and an upper lifting plate 207 distributed on both sides of the piston 302. The drive assembly 4 drives the liquid transfer tube 2 to slide inside the piston 302. The liquid is transferred from the coarse filtration zone 102 to the transfer zone 103 through the transfer hole 204 and the connecting hole 205.

[0038] The cylinder 1 includes a coarse filter cylinder 105, a liquid transfer cylinder 106 detachably connected to the coarse filter cylinder, and a fine filter cylinder 107 detachably connected to the liquid transfer cylinder 106. The lower end of the fine filter cylinder 107 is provided with a filtrate pipe 801 connector 108. The liquid transfer pipe 2 penetrates out of the coarse filter cylinder 105 and is connected to an inlet pipe 1001 connector 209 through a telescopic pipe 208. The inlet pipe 1001 connector 209 is provided with a pressure relief hole 210.

[0039] The coarse filter cartridge 105 in the cylinder 1, as the uppermost structure of the suction filter, mainly undertakes the functions of preliminary filtration and water sample introduction. It is detachably connected to the transfer cylinder 106 for easy disassembly and cleaning during maintenance. The transfer tube 2 penetrates the top of the coarse filter cartridge 105 and is connected to the inlet pipe 1001 connector 209 through the telescopic tube 208, forming the inlet channel for the water sample. The coarse filter plate 301 is detachably installed at the upper part of the interior to initially intercept the seawater and separate large suspended particles (such as silt and debris), reducing the burden on the subsequent filter membrane 3. At the same time, the coarse filter plate 301 is fixedly connected to the transfer tube 2 and moves up and down with the transfer tube 2 inside the cylinder 1. The impurities on the coarse filter plate 301 are shaken, which facilitates faster filtration of the water sample.

[0040] The liquid transfer cylinder 106 in the cylinder 1 connects the coarse filter cylinder 105 and the fine filter cylinder 107 to form the liquid transfer zone 103, realizing the transfer of water samples and pressure drive. A piston 302 is set inside, and the piston 302 is slidably connected to the liquid transfer tube 2. The piston 302 is driven to move up and down by the drive component 4.

[0041] Reference Figure 2 and Figure 3The transfer section 202 of the transfer tube 2 passes through the piston 302, and the side wall is provided with a transfer hole 204 and the bottom is provided with a connecting hole 205. When the transfer tube 2 slides, the water sample of the coarse filtration zone 102 can be introduced into the transfer zone 103 through the transfer hole 204 and the connecting hole 205. The connecting hole 205 transmits negative pressure to the entire cylinder 1, so that the water sample can be smoothly drawn from the container storing the water sample into the cylinder 1. The lower pressure plate 206 and the upper lifting plate 207 on the liquid transfer section 202 are distributed on both sides of the piston 302. The lower pressure plate 206 and the upper lifting plate 207 can drive the piston 302 to move up and down. When the piston 302 is lifted, the liquid transfer hole 204 is placed in the coarse filtration zone 102, and the connecting hole 205 is always placed in the liquid transfer zone 103. The water sample in the coarse filtration zone 102 can flow in through the liquid transfer hole 204 and then flow out from the connecting hole. At this time, because the connecting hole 205 and the transfer hole connect the coarse filtration zone 102 and the liquid transfer zone 103, the piston 302 will not encounter any resistance during the upward pulling process.

[0042] Reference Figure 2 and Figure 3 When piston 302 is pressed down, transfer hole 204 is placed in transfer zone 103, and water sample can flow out from transfer hole 204 and connecting hole 205. The downward pressure of piston 302 applies pressure towards filter membrane 3 to the water sample in transfer zone 103. Because piston 302 is in a closed state at this time, connecting hole 205 and transfer hole cannot connect coarse filtration zone 102 and transfer zone 103. The pressure can only be directed towards the inner wall of cylinder 1 and filter membrane 3. Since the water sample always flows into suction filtration zone 104 through filter membrane 3, the pressure will be conducted through filter membrane 3, accelerating filtration. Under the combined action of negative pressure on the lower side of filter membrane 3 and positive pressure brought by piston 302 on the upper side of filter membrane 3, water sample passes through filter membrane 3 faster.

[0043] The fine filter cartridge 107 in the cylinder 1 serves as the bottom structure of the suction filter cartridge, enabling fine filtration of water samples and filtrate extraction. A filter membrane 3 is detachably installed at the lower end to trap fine particles, chlorophyll, and other monitoring targets in the seawater. A filtrate tube 801 connector 108 is provided at the bottom, which connects to the collection bottle 8 through the filtrate tube 801, through which the filtered liquid flows into the collection bottle 8. It is detachably connected to the transfer cylinder 106 for easy replacement of the filter membrane 3 or cleaning of internal residual impurities.

[0044] The coarse filter 301 in the cylinder 1 acts as a primary filtration element, intercepting large particles of impurities in seawater, protecting the filter membrane 3 and extending its service life. It is fixedly connected to the transfer tube 2, and can shake off surface impurities as it slides up and down with the transfer tube 2 to prevent clogging; its pore size is larger than that of the filter membrane 3, allowing smaller particles of water sample to pass through, while only intercepting large suspended solids.

[0045] The filter membrane 3 in the cylinder 1 is the core filtration element, enabling fine filtration of water samples for pretreatment before testing for indicators such as suspended solids and chlorophyll. It is detachably installed at the lower end of the fine filter cylinder 107, allowing for easy replacement of filter membranes 3 with different pore sizes (such as 0.45μm cellulose acetate membrane) according to testing needs. Under the combined action of the pressure of the piston 302 and the negative pressure of the suction filtration zone 104, it efficiently retains target substances, ensuring that the filtrate meets the testing requirements.

[0046] The liquid transfer tube 2 in the cylinder 1 is the water sample transfer channel, and it is also driven to move up and down to control the filtration process.

[0047] The inlet section 201 is located inside the coarse filter cartridge 105, with an inlet hole 203 on its side wall. After the water sample flows into the coarse filter cartridge 105 through the inlet pipe 1001 connector 209, it enters the interior of the transfer pipe 2 through the inlet hole 203. The transfer section 202 passes through the piston 302, with a transfer hole 204 on its side wall and a connecting hole 205 at the bottom. When the transfer pipe 2 slides, the water sample from the coarse filter zone 102 enters the transfer pipe 2 through the transfer hole 204 and is then introduced into the transfer zone 103 through the connecting hole 205. The transfer pipe 2 is fixedly connected to the coarse filter 301. When it slides, it causes the coarse filter 301 to shake, allowing the impurities on it to be removed from the coarse filter 301 to a certain extent due to inertia. The lower pressure plate 206 and the upper lifting plate 207 of the transfer section 202 cooperate with the piston 302 to push the piston 302 up and down, applying pressure to the water sample in the transfer zone 103.

[0048] Example 2

[0049] Reference Figure 4 and Figure 5 This embodiment of a nearshore marine environmental monitoring filtration device includes a support frame 5 and a filtration cylinder as described above. Multiple filtration cylinders are provided and are arranged on the upper end of the support frame 5. A collection bottle 8 is provided at the lower end of the support frame 5. The upper end of the collection bottle 8 is connected to a suction mechanism via a suction pipe 901. The suction mechanism is a filtration pump 9. The lower end of the collection bottle 8 is connected to the lower end of the filtration cylinder via a filtrate pipe 801. A magnetic stirrer 10 is connected to the upper end of the filtration cylinder via a liquid inlet pipe 1001. A water outlet pipe 802 is also provided at the lower end of the collection bottle 8.

[0050] Reference Figure 4 The support frame 5 serves as the basic support structure of the device, bearing components such as the filtration cylinders, collection bottles 8, and drive assembly 4, ensuring overall stability. The upper end has a circular or polygonal structure, used to fix multiple filtration cylinders and arrange them in a circular array for parallel filtration. The lower end provides mounting positions for the collection bottles 8, which are fixed by brackets or slots. The support column 401 and bracket 501 are fixed to the upper end of the support frame 5, providing a mounting base for the drive assembly 4 and lifting assembly 7.

[0051] Reference Figure 4 and Figure 6The filter cylinders are arranged in a circular array on the upper end of the support frame 5. The filter cylinders are vertically erected. The cylinder body 1 is provided with a fixing component 6. The upper end of the support frame 5 is fixedly provided with a bracket 501. The driving component 4 includes a support column 401 provided on the support frame 5, a rotating shaft provided on the support column 401, a motor 402 provided on the upper end of the bracket 501 to drive the rotating shaft to rotate, and an inclined disk 403 fixedly provided on the rotating shaft. The portion of the liquid transfer tube 2 that penetrates through the coarse filter cylinder 105 is connected to a driving groove 211 facing the rotating shaft. The inclined disk 403 is provided in the driving groove 211. The inclined disk 403 drives the liquid transfer tube 2 to slide up and down in the piston 302 by rotation.

[0052] The drive assembly 4 drives the transfer tube 2 to slide via mechanical transmission, thereby enabling the piston 302 to move and the water sample to be transferred. The motor 402 on the bracket 501 drives the rotating shaft to rotate, which in turn drives the tilting disk 403 to rotate. The tilting disk 403 is embedded in the drive groove 211 at the end of the transfer tube 2. When rotating, the eccentric structure pushes the transfer tube 2 to slide up and down. The support column 401 is fixed to the support frame 5. The bracket 501 supports the motor 402 and the rotating shaft, ensuring the stable operation of the drive assembly 4.

[0053] The telescopic tube 208 and the inlet tube 1001 connector 209 connect to the external inlet tube 1001 to introduce water samples. The telescopic tube 208 is flexible, allowing the transfer tube 2 to slide up and down while maintaining pipeline continuity. The filter tube 801 connector 108 connects the fine filter cartridge 107 to the collection bottle 8 to discharge the filtered liquid. The filter tube 801 connector 108 is fixedly connected to the lower end of the fine filter cartridge 107 to ensure smooth flow of the filtrate into the collection bottle 8.

[0054] The filtration zone 104 generates negative pressure. Air is drawn from the filtration zone 104 by the filtration pump 9, creating this negative pressure. The filtration zone 104 is connected to the collection bottle 8 via the suction pipe 901. The collection bottle 8 is connected to the filtration pump 9 above, forming a negative pressure conduction path. Simultaneously, the negative pressure is transmitted through the entire cylinder 1 and the inlet pipe 1001. A sealing ring is provided on the edge of the piston 302 to ensure the sealing of the transfer zone 103 during sliding. A seal is provided where the transfer pipe 2 penetrates the cylinder 1 to prevent water sample leakage or external air intrusion that could affect the negative pressure environment.

[0055] The fixing component 6 includes an upper fixing plate 601 and a lower fixing plate 603. The upper fixing plate 601 has a first insertion hole 602 for inserting the transfer tube 2, and the lower fixing plate 603 has a second insertion hole 604 for inserting the filter tube 801 connector 108.

[0056] The fixing component 6 fixes the suction filter cylinder and guides the connection path of the transfer tube 2 and the filtrate tube 801. The upper fixing plate 601 is located at the upper end of the support frame 5 and has a first insertion hole 602. After the transfer tube 2 penetrates the coarse filter cylinder 105, it is inserted into the hole, which restricts the upward displacement of the suction filter cylinder and ensures the coaxiality of the vertical sliding of the transfer tube 2. The lower fixing plate 603 is located near the lower end of the support frame 5 and has a second insertion hole 604. The connector 108 of the filtrate tube 801 is inserted into the hole, which fixes the bottom of the fine filter cylinder 107, restricts the downward displacement of the suction filter cylinder, and guides the filtrate tube 801 to communicate with the collection bottle 8.

[0057] The bracket 501 is provided with a lifting assembly 7, which includes a base 701 on the bracket 501 and an ejector seat 702 on the base 701. The base 701 is provided with a snap-fit ​​arm 703 that snaps into the connector 209 of the liquid inlet pipe 1001. The ejector seat 702 is provided with an ejector arm 704 that snaps into the liquid inlet pipe 1001. An electric push rod for driving the ejector seat 702 to spring up is provided inside the ejector seat 702.

[0058] The lifting assembly 7 automatically connects and disconnects the inlet pipe 1001 and its connector 209, enhancing the automation and ease of operation of the device. The base 701 is fixed to the bracket 501, and the locking arm 703 secures the inlet pipe 1001 connector 209, ensuring stability during connection. An electric push rod is installed inside the ejector seat 702, and the ejector arm 704 engages the end of the inlet pipe 1001. When a signal is received from the controller 11, the electric push rod drives the ejector seat 702 to spring up, pulling the inlet pipe 1001 upwards via the ejector arm 704, achieving automatic pipe disconnection. After filtration, the electric push rod activates, and the ejector seat 702 springs up, separating the inlet pipe 1001 from its connector 209. The pressure relief hole 210 can release negative pressure in advance, making it easier to pull out. The lifting assembly 7 also prevents manual contact with damp pipes.

[0059] The upper part of the liquid collection bottle 8 is provided with a gap partition 805, and the inner side wall of the liquid collection bottle 8 is provided with a water pressure sensing line 803 from top to bottom, and a water pressure sensor is provided on the water pressure sensing line 803.

[0060] Reference Figure 7 The high-position interface design of the upper gap partition 805 of the collection bottle 8 and the suction pipe 901 prevents the filtrate from being drawn back into the suction pump 9, thus protecting the equipment.

[0061] The filtration device includes a controller 11, a first solenoid valve 1002 is provided on the inlet pipe 1001, and a second solenoid valve 804 is provided on the filtrate pipe 801. The controller 11 is electrically connected to the magnetic stirrer 10, the filtration pump 9, the motor 402, the electric push rod, the water pressure sensor, the first solenoid valve 1002, and the second solenoid valve 804.

[0062] As the control core of the device, the controller 11 coordinates the operation of various components to achieve full-process automated control. The controller 11 receives the water level signal from the water pressure sensor to determine the filtration status.

[0063] The controller 11 outputs commands to control the start and stop of the magnetic stirrer 10 to ensure the homogenization of the water sample, controls the switch of the filtration pump 9 to adjust the negative pressure, controls the speed of the motor 402 to drive the reciprocating motion of the transfer tube 2, controls the extension and retraction of the electric push rod to realize the automatic disassembly and assembly of the inlet pipe 1001, and controls the switch of the first and second solenoid valves 804 to adjust the inlet and filtrate passages.

[0064] In this embodiment, multiple filter cartridges are arranged in a circumferential array, allowing for the simultaneous processing of multiple water samples. This improves efficiency several times compared to single-cartridge filtration, making it particularly suitable for the simultaneous filtration of parallel samples in batch quality control. This embodiment presents a scenario with four filter cartridges. Two cartridges can be selected to operate while the first solenoid valve 1002 and the second solenoid valve 804 of the other two are closed. After the experiment, the two filter cartridges that were not previously in operation are replaced to perform the filtration, making the process convenient and quick.

[0065] The collection bottle 8 collects the filtered liquid and also serves as a negative pressure conduction channel and a water level monitoring unit. An upper gap partition 805 isolates the suction pipe 901 from the liquid surface, preventing backflow of liquid into the filtration pump 9 during filtration. A water pressure sensing line 803 and a sensor are arranged along the inner wall from top to bottom to monitor the liquid level in real time. When the water level reaches a set value, a signal is sent to the controller 11 to trigger a shutdown procedure. The lower outlet pipe 802 is used to discharge the filtrate from the collection bottle 8, facilitating subsequent sampling or waste disposal. The upper end is connected to the filtration pump 9 via the suction pipe 901, creating a negative pressure environment. The filtration pump 9 provides negative pressure to the filtration zone 104, working in conjunction with the piston 302 to accelerate water sample filtration.

[0066] The function of the magnetic stirrer 10 is to mix the water sample in the inlet pipe 1001 to ensure water quality uniformity and avoid suspended solids from settling and affecting the representativeness of the test. It is connected to the upper end of the filter cylinder through the inlet pipe 1001 and starts stirring under the command of the controller 11 to keep the water sample entering the filter cylinder in a suspended state. It is especially suitable for the homogenization treatment of turbid seawater near the coast.

[0067] The inlet pipe 1001 and the first solenoid valve 1002 control the flow of water sample into the filter cartridge, realizing automated liquid inlet and shut-off. The first solenoid valve 1002 is installed on the inlet pipe 1001 and is controlled by the signal of the controller 11. When it is open, it allows water sample to flow in, and when it is closed, it cuts off the liquid inlet passage.

[0068] The filter tube 801 is connected to the filter cylinder and the collection bottle 8 via the second solenoid valve 804. This controls the filtrate discharge path and enables automatic shut-off. The second solenoid valve 804 is installed on the filter tube 801. When the controller 11 is turned on, the filtrate flows into the collection bottle 8 through the connector 108 of the filter tube 801 and the filter tube 801. After the detection is completed, the solenoid valve is closed to prevent filtrate backflow or leakage.

[0069] The outlet pipe 802 is used to discharge the filtrate in the collection bottle 8, which facilitates sampling and testing or waste liquid treatment.

[0070] Example 3: This example describes a filtration method for nearshore marine environmental monitoring, comprising:

[0071] The controller 11 controls the magnetic stirrer 10 to open, the controller 11 opens the first solenoid valve 1002 and the second solenoid valve 804, the controller 11 starts the motor 402 in the drive assembly 4, the transfer tube 2 slides in the piston 302, and the water sample flows into the inlet area 101 of the suction filter through the inlet tube 1001.

[0072] The transfer tube 2 moves up and down, causing the coarse filter 301 to move up and down. The impurities on the coarse filter 301 are shaken, and the water sample flows through the coarse filter 301 into the coarse filtration zone 102.

[0073] The water sample is transferred to the transfer zone 103 through the transfer hole 204 and the connecting hole 205. The piston 302 moves downward to apply pressure towards the filter membrane 3 to the water sample in the transfer zone 103. Under the action of the piston 302 pressure and the negative pressure of the suction filtration zone 104, the water sample in the transfer zone 103 is filtered through the filter membrane 3 and enters the suction filtration zone 104 and flows into the collection bottle 8.

[0074] When the water pressure sensor detects that the water level has reached the set value, it transmits a signal to the controller 11. The controller 11 controls the closure of the first solenoid valve 1002, the second solenoid valve 804, the magnetic stirrer 10, and the filtration pump 9, stops the operation of the motor 402, and simultaneously controls the electric push rod to make the ejector seat 702 pop up, driving the inlet pipe 1001 to be removed from the inlet pipe 1001 connector 209, thus completing the filtration.

[0075] Example 3: This example describes a filtration method for nearshore marine environmental monitoring, comprising:

[0076] The controller 11 controls the magnetic stirrer 10 to open, the controller 11 opens the first solenoid valve 1002 and the second solenoid valve 804, the controller 11 starts the motor 402 in the drive assembly 4, the transfer tube 2 slides in the piston 302, and the water sample flows into the inlet area 101 of the suction filter through the inlet tube 1001.

[0077] The transfer tube 2 moves up and down, causing the coarse filter 301 to move up and down. The impurities on the coarse filter 301 are shaken, and the water sample flows through the coarse filter 301 into the coarse filtration zone 102.

[0078] The water sample is transferred to the transfer zone 103 through the transfer hole 204 and the connecting hole 205. The piston 302 moves downward to apply pressure towards the filter membrane 3 to the water sample in the transfer zone 103. Under the action of the piston 302 pressure and the negative pressure of the suction filtration zone 104, the water sample in the transfer zone 103 is filtered through the filter membrane 3 and enters the suction filtration zone 104 and flows into the collection bottle 8.

[0079] When the water pressure sensor detects that the water level has reached the set value, it transmits a signal to the controller 11. The controller 11 controls the closure of the first solenoid valve 1002, the second solenoid valve 804, the magnetic stirrer 10, and the filtration pump 9, stops the operation of the motor 402, and simultaneously controls the electric push rod to make the ejector seat 702 pop up, driving the inlet pipe 1001 to be removed from the inlet pipe 1001 connector 209, thus completing the filtration.

[0080] Specific implementation steps:

[0081] S1. Initial Status Check and System Startup

[0082] After confirming the hardware connection, check whether the fixing components 6 (upper fixing plate 601 and lower fixing plate 603) of the filter cylinder and support frame 5 are locked tight, and ensure that the liquid transfer tube 2 and the filter tube 801 connector 108 are accurately positioned; confirm that the liquid inlet tube 1001 and the liquid inlet tube 1001 connector 209 are firmly connected by the ejector arm 704, the filter tube 801 is connected to the lower end of the collection bottle 8, and the air extraction tube 901 is connected and sealed to the filter pump 9.

[0083] S2. Controller 11 is initialized and the power is turned on. Controller 11 starts the self-test program to check whether the water pressure sensor is normal (scans the initial water level of the collection bottle 8 through the water pressure sensing line 803), tests the opening and closing status of the first solenoid valve 1002 and the second solenoid valve 804, and runs the motor 402 (drive component 4) to confirm that the transfer tube 2 slides without jamming.

[0084] S3. Parameter preset: Set the water level threshold (e.g., 80% of the capacity of the collection bottle 8), motor speed 402 (adjust according to the turbidity of the seawater, recommended 20-30 r / min), and negative pressure value of the filtration pump 9 (usually -0.04 to -0.06 MPa) through the controller 11 interface.

[0085] S4. Water sample inlet and coarse filtration stage: Water sample inlet control, controller 11 turns on magnetic stirrer 10, and simultaneously opens first solenoid valve 1002 and second solenoid valve 804, and turns on suction pump 9. Water sample flows into inlet zone 101 of suction filter cylinder through inlet pipe 1001. Magnetic stirrer 10 runs at a speed of 200-300 r / min to ensure that water sample entering inlet zone 101 is uniformly mixed and to prevent suspended solids from settling.

[0086] S5. Controller 11 starts drive assembly 4 motor 402, the rotating shaft drives the tilting disk 403 to rotate, drives the liquid transfer tube 2 to slide up and down in the piston 302 at a frequency of 1 time / second, the liquid transfer tube 2 drives the coarse filter 301 to move up and down synchronously, the larger particles of impurities trapped on the surface of the coarse filter 301 fall off due to the shaking, avoiding clogging of the filter holes, the water sample flows through the coarse filter 301 (pore size 50-100μm) into the coarse filtration zone 102, and the initial filtration is completed.

[0087] S6. In the stage of combined liquid transfer and pressure filtration, when the liquid transfer tube 2 slides, the inlet hole 203 of the inlet section 201 is connected to the coarse filtration zone 102. The water sample enters the interior of the liquid transfer tube 2 through the inlet hole 203 and can also flow into the liquid transfer zone 103 through the connecting hole 205. When the liquid transfer tube 2 moves downward, the liquid transfer hole 204 of the liquid transfer section 202 is aligned with the liquid transfer zone 103. The water sample flows into the liquid transfer zone 103 through the liquid transfer hole 204 and the connecting hole 205. At this time, the piston 302 is closed. When the liquid transfer tube 2 drives the piston 302 to move downward, the lower pressure plate 206 pushes the piston 302 to apply positive pressure to the water sample in the liquid transfer zone 103, accelerating the water sample to flow out towards the filter membrane 3. The water sample in the liquid transfer zone 103 quickly passes through the filter membrane 3 (pore size 0.45μm), and suspended solids, chlorophyll and other target substances are intercepted. The filtrate enters the suction filtration zone 104 and flows into the collection bottle 8 through the filtrate tube 801.

[0088] S7. Intelligent monitoring and automatic shutdown stage: real-time water level monitoring; water pressure sensing line 803 on the inner wall of collection bottle 8 senses the liquid level height; water pressure sensor transmits real-time data to controller 11; when the filtrate water level reaches a preset threshold (e.g., 80% capacity), the sensor sends a shutdown signal to controller 11.

[0089] After receiving the signal, the controller 11 closes the first solenoid valve 1002 to cut off the liquid inlet passage, closes the second solenoid valve 804 to stop the filtrate from flowing into the collection bottle 8, shuts off the magnetic stirrer 10 to avoid dry running, shuts off the vacuum pump 9, releases the negative pressure in the vacuum filtration zone 104, stops the motor 402 from running, and the transfer pipe 2 and piston 302 stop moving.

[0090] At this time, the inlet pipe 1001 is automatically disassembled, the controller 11 triggers the electric push rod to be energized, the push rod extends upward to drive the ejector seat 702 to pop up; the ejector seat 702 drives the ejector arm 704 to move upward, pulling the inlet pipe 1001 out of the inlet pipe 1001 connector 209, completing the pipe separation.

[0091] S8. Subsequent processing and maintenance steps: filtrate sampling and testing. Open the water outlet pipe 802 at the lower end of the collection bottle 8, connect the filtrate to the sampling bottle, and use the filtered water sample to measure heavy metals and nutrients, etc.

[0092] Remove the coarse filter 301 and filter membrane 3. Weigh the impurities, suspended solids, and chlorophyll retained by filter membrane 3. Measure the chlorophyll content of all four filter membranes 3 to obtain the chlorophyll content of the total filtered water. After filtration, dry the four filter membranes 3 plus the four coarse filter 31 (including impurities and fine sand). Subtract the original dry weight of the four filter membranes plus the four coarse filter 31 from this total weight to obtain the suspended solids content of the total filtered water. The coarse filter 301 is reusable, but the filter membrane 3 is not.

[0093] For cleaning the suction filter cartridge and replacing the filter membrane 3, disassemble the coarse filter cartridge 105, the liquid transfer cartridge 106, and the fine filter cartridge 107. Take out the coarse filter plate 301 and the filter membrane 3. After weighing the coarse filter plate 301 and impurities, rinse the surface impurities with clean water. It can be reused. Store the filter membrane 3 according to the detection requirements. For example, the filter membrane 3 for suspended solids detection needs to be dried and weighed. Replace with a new filter membrane 3 and install it into the fine filter cartridge 107. Reset the system and put it into standby mode.

[0094] When motor 402 is running but the filtration flow rate drops significantly (more than 50% lower than the initial value), controller 11 determines that filter membrane 3 may be clogged and automatically starts the high-frequency shaking mode of coarse filter 301 (shaking frequency increased to 2 times / second). If the flow rate does not recover after 30 seconds, it prompts to stop the machine and clean coarse filter 301.

[0095] Negative pressure abnormality protection: If the negative pressure value of the filter pump 9 does not reach the set range during operation, the controller 11 will automatically shut down the filter pump 9 and alarm, prompting the user to check whether the air extraction pipe 901 is leaking or blocked.

[0096] If a comparative experiment is required, the first round of the experiment can be conducted by activating the first solenoid valve 1002 and the second solenoid valve 804, allowing water samples to flow into two sets of filtration cylinders. After the first round of the experiment, the second round of the experiment can be initiated by replacing the collection bottle 8 and controlling the flow of water samples into the other two sets of filtration cylinders via the first solenoid valve 1002 and the second solenoid valve 804, preventing them from flowing into the filtration cylinders from the first round of the experiment. Controlling the same filtration time and filtration volume, among other limiting conditions, can be used as variables for the comparative experiment. This ensures the consistency of the collected parallel samples and improves the quality control level of marine environmental monitoring sampling.

[0097] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A filter cartridge for nearshore marine environmental monitoring, characterized in that, The device includes a cylindrical body (1), a filter membrane (3) detachably mounted on the lower end of the inner cavity of the cylindrical body (1), a coarse filter plate (301) detachably mounted on the upper end of the inner cavity of the cylindrical body (1), a piston (302) disposed inside the cylindrical body (1) between the filter membrane (3) and the coarse filter plate (301), a liquid transfer pipe (2) mounted on the piston (302), and a drive assembly (4) connected to the liquid transfer pipe (2). The inner cavity of the cylindrical body (1) is divided by the coarse filter plate (301), the piston (302) and the filter membrane (3) to form a liquid inlet. The filter consists of a coarse filtration zone (101), a coarse filtration zone (102), a liquid transfer zone (103), and a vacuum filtration zone (104). The drive assembly (4) drives the liquid transfer tube (2) to slide inside the piston (302), while simultaneously driving the piston (302) to move inside the cylinder (1). The liquid is transferred from the coarse filtration zone (102) to the liquid transfer zone (103). At the same time, the piston (302) applies pressure to the liquid towards the filter membrane (3). The vacuum filtration zone (104) forms a negative pressure through the suction mechanism, causing the liquid to be drawn from the liquid transfer zone (103) to the vacuum filtration zone (104). The transfer pipe (2) has an inlet section (201) and a transfer section (202). The inlet section (201) has an inlet hole (203) on its side wall, and the transfer section (202) has a transfer hole (204) on its side wall. The bottom of the transfer section (202) has a connecting hole (205). The coarse filter (301) is fixedly connected to the transfer pipe (2). The transfer pipe (2) penetrates the upper end of the cylinder (1) and can pass through the cylinder (1). The upper end slides inside the piston (302), thereby driving the coarse filter (301) to slide inside the cylinder (1). The liquid transfer section (202) is provided with a lower pressure plate (206) and an upper lifting plate (207) distributed on both sides of the piston (302). The driving assembly (4) drives the liquid transfer tube (2) to slide inside the piston (302). The liquid is transferred from the coarse filtration zone (102) to the liquid transfer zone (103) through the liquid transfer hole (204) and the connecting hole (205). In use, the water sample flows into the inlet area of ​​the suction filter cylinder through the inlet hole on the side wall of the inlet section. The drive component drives the transfer tube to slide up and down on the piston. The transfer tube drives the coarse filter to move up and down synchronously. The water sample passes through the coarse filter and flows into the coarse filtration area, completing the initial filtration. When the transfer tube slides, the transfer hole of the transfer section is connected to the coarse filtration area. The water sample enters the interior of the transfer tube through the transfer hole and also flows into the transfer area through the connecting hole. When the transfer tube moves downward, the transfer hole of the transfer section is aligned with the transfer area. The water sample flows into the transfer area through the transfer hole and the connecting hole. At this time, the piston is closed. When the transfer tube drives the piston to move downward, the lower pressure plate pushes the piston to apply positive pressure to the water sample in the transfer area, accelerating the water sample to flow out towards the filter membrane. The water sample in the transfer area quickly passes through the filter membrane, and the filtrate enters the suction filtration area.

2. The filter cartridge for nearshore marine environmental monitoring according to claim 1, characterized in that, The cylinder (1) includes a coarse filter cylinder (105), a liquid transfer cylinder (106) detachably connected to the coarse filter cylinder, and a fine filter cylinder (107) detachably connected to the liquid transfer cylinder (106). The lower end of the fine filter cylinder (107) is provided with a filtrate pipe (801) connector (108). The liquid transfer pipe (2) penetrates out of the coarse filter cylinder (105) and is connected to an inlet pipe (1001) connector (209) through a telescopic pipe (208). The inlet pipe (1001) connector (209) is provided with a pressure relief hole (210).

3. A filtration device for nearshore marine environmental monitoring, comprising a filtration cylinder and a support frame (5) as described in claim 2, wherein multiple filtration cylinders are provided and are arranged on the upper end of the support frame (5), and a collection bottle (8) is provided at the lower end of the support frame (5). The upper end of the collection bottle (8) is connected to a suction mechanism through a suction pipe (901), and the suction mechanism is a filtration pump (9). The lower end of the collection bottle (8) is connected to the lower end of the cylinder body (1) of the filtration cylinder through a filtrate pipe (801). The upper end of the cylinder body (1) is connected to a magnetic stirrer (10) through a liquid inlet pipe (1001). The lower end of the collection bottle (8) is also provided with a water outlet pipe (802).

4. The filtration device for nearshore marine environmental monitoring according to claim 3, characterized in that, The filter cylinders are arranged in a circular array on the upper end of the support frame (5). The filter cylinders are erected vertically. The cylinder body (1) is provided with a fixing component (6). The upper end of the support frame (5) is fixedly provided with a bracket (501). The driving component (4) includes a support column (401) on the support frame (5), a rotating shaft on the support column (401), a motor (402) on the upper end of the bracket (501) to drive the rotating shaft to rotate, and an inclined disc (403) fixedly provided on the rotating shaft. The portion of the liquid transfer tube (2) that penetrates through the coarse filter cylinder (105) is connected to a driving groove (211) facing the rotating shaft. The inclined disc (403) is provided in the driving groove (211). The inclined disc (403) drives the liquid transfer tube (2) to slide up and down in the piston (302) by rotating.

5. The filtration device for nearshore marine environmental monitoring according to claim 4, wherein the fixing component (6) includes an upper fixing plate (601) and a lower fixing plate (603), wherein the upper fixing plate (601) has a first insertion hole (602) for inserting the transfer pipe (2), and the lower fixing plate (603) has a second insertion hole (604) for inserting the filtrate pipe (801) connector (108).

6. The filtration device for nearshore marine environmental monitoring according to claim 5, wherein the bracket (501) is provided with a lifting assembly (7), the lifting assembly (7) includes a base (701) provided on the bracket (501), an ejector seat (702) provided on the base (701), a snap-fit ​​arm (703) provided on the base (701) for snapping with the inlet pipe (1001) connector (209), an ejector arm (704) provided on the ejector seat (702) for snapping with the inlet pipe (1001), and an electric push rod for driving the ejector seat (702) to spring up is provided inside the ejector seat (702).

7. The filtration device for nearshore marine environmental monitoring according to claim 6, wherein the upper part of the collection bottle (8) is provided with a gap partition (805), the inner sidewall of the collection bottle (8) is provided with a water pressure sensing line (803) from top to bottom, and a water pressure sensor is provided on the water pressure sensing line (803).

8. The filtration device for nearshore marine environmental monitoring according to claim 7, wherein the filtration device includes a controller (11), a first solenoid valve (1002) is provided on the inlet pipe (1001), a second solenoid valve (804) is provided on the filtrate pipe (801), and the controller (11) is electrically connected to a magnetic stirrer (10), a filtration pump (9), a motor (402), an electric push rod, a water pressure sensor, the first solenoid valve (1002), and the second solenoid valve (804).

9. A filtration method for nearshore marine environmental monitoring, characterized in that, Including the use of the filtration apparatus as described in claim 8: The controller (11) controls the magnetic stirrer (10) to open, the controller (11) opens the first solenoid valve (1002) and the second solenoid valve (804), the controller (11) starts the motor (402) in the drive assembly (4), the transfer tube (2) slides in the piston (302), and the water sample flows into the inlet area (101) of the suction filter tube through the inlet tube (1001); The transfer tube (2) moves up and down, causing the coarse filter (301) to move up and down. The impurities on the coarse filter (301) are shaken, and the water sample flows through the coarse filter (301) into the coarse filtration zone (102). The water sample is transferred to the transfer zone (103) through the transfer hole (204) and the connecting hole (205). The piston (302) moves downward to apply pressure towards the filter membrane (3) to the water sample in the transfer zone (103). Under the action of the piston (302) pressure and the negative pressure of the suction filtration zone (104), the water sample in the transfer zone (103) is filtered through the filter membrane (3) and enters the suction filtration zone (104) and flows into the collection bottle (8). When the water pressure sensor detects that the water level has reached the set value, it transmits the signal to the controller (11). The controller (11) controls the closure of the first solenoid valve (1002), the second solenoid valve (804), the magnetic stirrer (10), and the filtration pump (9), stops the motor (402) from running, and controls the electric push rod to make the ejector seat (702) pop up, driving the inlet pipe (1001) to be removed from the inlet pipe (1001) connector (209) to complete the filtration.

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