Water sample pretreatment device for deep sea water sample filtration and water flow optimization

Abstract

The invention discloses a water sample pretreatment device for deep sea water sample filtration and water flow optimization, and relates to the field of electrochemistry and microfluidics. The water sample pretreatment device comprises a water sample inlet, a flow channel filtering area, a flat plate filter membrane filtering area, an electrochemical detection area and a water sample outlet which are connected with one another. A to-be-detected water sample passes through the flow channel filtering area and passes through a parallel snake-shaped flow channel and a micro-column blocking flow channel in the flow channel filtering area, the water sample containing large-diameter suspended particles is discharged out of the water sample preprocessor through a waste outlet, and the filtered water sample enters the flat plate filter membrane filtering area and is further filtered through a flat plate filter membrane A, a flat plate filter membrane B and a flat plate ultrafiltration membrane. The filtered water sample enters an electrochemical detection area for electrochemical detection, and finally the water sample is discharged through a water sample outlet. The inertial micro-fluidic technology is adopted, and the parallel snake-shaped flow channels and the micro-column blocking flow channels are designed to serve as filtering flow channels, so that primary screening of large suspended particles with the diameter being larger than the micron level is achieved.

Description

Technical Field

[0001] The present invention relates to the fields of electrochemistry and microfluidics, and particularly to a device for filtering water samples and optimizing water flow. Background Art

[0002] Heavy metals generally include transition metals and some main group metals in the periodic table. Common heavy metals are lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr), arsenic (As), nickel (Ni), copper (Cu), zinc (Zn), etc. These metals often exist in the form of minerals in nature and have important industrial uses. Many heavy metal ions are significantly toxic at high concentrations or under long-term exposure and may have adverse effects on different organs and systems. Industrialization and urbanization have accelerated the entry of heavy metal pollutants into water bodies through wastewater discharge, atmospheric deposition, etc. Through infiltration into groundwater or through the scouring of surface water, they ultimately converge into the ocean. In the marine environment, heavy metal ions will be absorbed by marine organisms, and due to the cumulative effect of the food chain, it will affect the survival and reproductive ability of marine organisms and may even lead to the extinction of species. The ocean is an important food source for humans, and many seafood products such as fish and shellfish are one of the main food sources for humans. The accumulation of heavy metal ions through the food chain will ultimately enter the human body through seafood products. Therefore, in-situ detection of heavy metal ions in the ocean can timely discover pollution sources, take corresponding measures, and protect the balance and stability of the marine ecosystem.

[0003] Electrochemical sensors have the characteristics of simple structure, fast response speed, low manufacturing cost, high sensitivity, outstanding specificity and stability. Electrochemical sensors can identify and quantify heavy metal ions by scanning specific potentials, and the current generated at each reduction potential indicates the type and concentration of metal ions, and this process only takes a few minutes.

[0004] The ocean current conditions in the ocean are complex, with different flow velocities at different depths. The flow velocity in the upper layer is significantly higher than that in the lower layer. The complex ocean currents make it impossible for some electrodes modified with sensitive materials to improve the detection performance to directly conduct in-situ detection. In the marine environment, the water body contains a large number of suspended particles, such as organic matter, sediment particles, microplastics, microorganisms, etc. The diameters of these particles range from several hundred micrometers to several micrometers. Among them, large flocs (with a diameter greater than 134 micrometers) account for more than 60% of the total suspended particles and are severely affected by seasons. These suspended particles are easily attached to the electrode surface of the sensor, causing signal distortion and interfering with the normal operation of the sensor. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a pretreatment device for filtering deep sea water samples and stabilizing the flow rate.

[0006] The technical solution of the present invention:

[0007] A water sample pretreatment device for deep - sea water sample filtration and water flow optimization, comprising a water sample inlet 2, a flow - channel filtration area 27, a flat - membrane filtration area 26, an electrochemical detection area 25, and a water sample outlet 28 that are connected to each other. The flow - channel filtration area 27 is a hollow area formed by splicing and combining a water sample pre - processor cover 3 and a water sample pre - processor housing 7. The water sample inlet 2 is located at the front end of the water sample pre - processor cover 3 and is directly connected to the flow - channel filtration area 27; the other end of the flow - channel filtration area 27 is respectively connected to a waste outlet 17 and the flat - membrane filtration area 26. The symmetric waste outlet 17 is located at the tail end of the water sample pre - processor housing 7, and the flat - membrane filtration area 26 is located in the central area at the tail end of the water sample pre - processor housing 7. The other end of the flat - membrane filtration area 26 is connected to the electrochemical detection area 25. Three flat - membrane slots 22 are opened along the length direction of the flat - membrane filtration area 26, and a flat - membrane A 9, a flat - membrane B 10, and a flat - ultrafiltration membrane 11 are installed in sequence. The surfaces of the three kinds of membranes are perpendicular to the water flow direction. The electrochemical detection area 25 is a cylindrical area at the tail end of the flat - membrane filtration area 26, and a water sample outlet 28 is provided at the bottom end of the electrochemical detection area 25.

[0008] In the flow - channel filtration area 27, filter plates 5 are arranged in parallel. Parallel serpentine channels 4 and micro - column obstructive channels 6 are sequentially opened on the filter plates 5 from the inlet to the outlet direction. Two or more mutually parallel serpentine channels are provided in each parallel serpentine channel 4. Each cycle is defined as a serpentine unit. At the end of the turning semi - circle of each serpentine unit in a parallel serpentine channel 4, the mutually parallel serpentine channels are open to each other. The outermost serpentine channel at the opening is defined as the outermost channel, and the outlet of the outermost channel is connected to the waste outlet 17, and the other serpentine channels are connected to the micro - column obstructive channels 6.

[0009] Two micro - column arrays are arranged in the micro - column obstructive channels 6. Each micro - column array is in a "<" shape. The micro - column array is composed of several rows of micro - columns. The angle between each row of micro - columns and the axis of the micro - column obstructive channel 6 is an acute angle. In the upstream micro - column array, there is a distance of one row of micro - columns between the outermost row of micro - columns and the wall of the micro - column obstructive channel 6. In the downstream micro - column array, there is a distance of two rows of micro - columns between the outermost row of micro - columns and the wall of the micro - column obstructive channel 6. An outer outlet and an inner outlet are respectively provided at the end of the micro - column obstructive channel 6. The outer outlet is connected to the waste outlet 17, and the inner outlet is connected to the electrochemical detection area 25.

[0010] The water sample to be measured enters the flow channel filtration area 27 of the water sample pre-processor through the water sample inlet 2, passes through the parallel serpentine flow channels 4 and the micro-column obstruction flow channels 6. The water sample containing large-diameter suspended particles is discharged outside the water sample pre-processor through the waste outlet 17. The filtered water sample enters the flat filter membrane filtration area 26 and is further filtered by the flat filter membrane A9, the flat filter membrane B10 and the flat ultrafiltration membrane 11. After filtration, the water sample enters the electrochemical detection area 25 for electrochemical detection, and finally the water sample is discharged through the water sample outlet 28.

[0011] Further, three mutually parallel serpentine flow channels are arranged in each parallel serpentine flow channel 4.

[0012] Further, each micro-column array has 5 - 7 vertical columns, and the two micro-column arrays are 5 - 10 mm apart.

[0013] Further, the included angle between each row of micro-columns and the axis of the micro-column obstruction flow channel 6 is 17 - 22 degrees.

[0014] Further, the parallel serpentine flow channel 4 includes 5 - 8 serpentine units.

[0015] Further, symmetric fixed brackets B21 are provided on both sides of the water sample pre-processor cover 3, and are matched with the fixed threaded holes of the symmetric fixed brackets A19 on both sides of the water sample pre-processor housing 7 through the socket head cap screws 1 to realize the stable connection between the water sample pre-processor cover 3 and the water sample pre-processor housing 7.

[0016] Further, the O-ring B20 is installed at the groove at the rear end of the water sample pre-processor cover 3 to seal the joint between the water sample pre-processor cover 3 and the water sample pre-processor housing 7;

[0017] Further, 6 to 8 filter plates 5 are provided;

[0018] Further, the electrochemical detection cavity 16 is located on the outer periphery of the flat filter membrane filtration area 26 and the electrochemical detection area 25 to play a protective role. The hexagon head bolt 8 fixes the electrochemical detection cavity 16 and the water sample pre-processor housing 7 through the screw hole A23 and the hexagon extra-thin nut 18.

[0019] Further, the socket head cap screw 12 fixes the electrochemical detection cavity cover 13 and the electrochemical detection cavity 16 through the screw hole B24. The electrochemical three-electrode jack 14 is located at the center of the electrochemical detection cavity cover 13. The O-ring A15 is installed at the groove of the electrochemical detection cavity cover 13 to seal the electrochemical detection cavity 16;

[0020] Further, two groups of parallel serpentine flow channels 4 are arranged in each filter plate 5, which are symmetric with respect to the central axis of the filter plate 5.

[0021] Further, the inlet width and depth of each serpentine flow channel are 0.5 - 1 mm.

[0022] Further, the opening positions between the three mutually parallel serpentine flow channels are set within the range of 0 - 90 degrees at the tail end of the rotating semi - circle and within the range of 0 - 1 mm of the connected straight flow channel.

[0023] Further, the diameter of each micro - pillar of the micro - pillar array is 200 - 400 microns, the height is 500 - 1000 microns, and the horizontal and vertical spacings between the micro - pillars are both 300 - 600 microns.

[0024] Further, the water sample is an in - situ ocean water sample. Natural seawater contains a large number of suspended particles, including biological particles (particulate carbon), sediment, sediment, micro - plastics, and flocs, etc. The particle size of these suspended particles spans a wide range, from several hundred microns to several microns. Some ultra - fine suspended particles such as biological metabolites, fine mineral particles, and marine aerosols generated by wave action have a diameter of less than 1 micron.

[0025] Further, flat membrane A9 is a large - pore membrane with a pore size range of 1 to 10 microns, flat membrane B10 is a medium - pore membrane with a pore size range of 0.1 to 1 micron, and flat ultra - filtration membrane 11 is a small - pore membrane with a pore size range of 0.01 to 0.1 micron. The material of the flat membrane is one of metal membrane, organic membrane, and ceramic membrane.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) By adopting inertial microfluidics technology, parallel serpentine flow channels and micro - pillar obstructive flow channels are designed as filtration flow channels to achieve preliminary screening of large suspended particles with a diameter above the micron level.

[0028] (2) By adopting multi - stage filtration, parallel serpentine flow channels as the first - stage filtration, micro - pillar obstructive flow channels as the second - stage filtration, and flat membranes as the third - stage filtration, it can effectively separate suspended solid particles in the in - situ ocean water sample and precisely filter particles with different particle sizes.

[0029] (3) The parallel serpentine flow channels and micro - pillar obstructive flow channels can share the filtration pressure for the flat membrane and extend the service life of the device.

[0030] (4) The designed flow channels can reduce the flow rate of the water sample when it finally enters the detection chamber and provide a more stable detection environment for electrochemical detection.

[0031] (5) The device has a simple structure, is easy to operate, and is convenient for large - scale production and manufacturing. Description of the Drawings

[0032] Figure 1An exploded view of a water sample pretreatment device for deep sea water sample filtration and water flow optimization.

[0033] Figure 2 A cross-sectional view of a water sample pretreatment device for deep sea water sample filtration and water flow optimization.

[0034] Figure 3 A schematic diagram of the filtration flow channels on the filter plate.

[0035] Figure 4 A schematic diagram of the micro-column obstructive flow channel.

[0036] Figure 5 A simulation diagram of the particle trajectories in the parallel serpentine flow channel.

[0037] Figure 6 A histogram of the particle position distribution at the outlet of the parallel serpentine flow channel.

[0038] Figure 7 A simulation diagram of the particle trajectories in the micro-column obstructive flow channel.

[0039] Figure 8 A histogram of the particle position distribution at the outlet of the micro-column obstructive flow channel.

[0040] In the figure: 1 - Round head socket head cap screw; 2 - Water sample inlet; 3 - Water sample preprocessor cover; 4 - Parallel serpentine flow channel; 5 - Filter plate; 6 - Micro-column obstructive flow channel; 7 - Water sample preprocessor housing; 8 - Hexagon head bolt; 9 - Flat filter membrane A; 10 - Flat filter membrane B; 11 - Flat ultrafiltration membrane; 12 - Round head socket head cap screw; 13 - Electrochemical detection chamber cover; 14 - Electrochemical three-electrode jack; 15 - O-ring A; 16 - Electrochemical detection chamber; 17 - Waste outlet; 18 - Hexagon extra thin nut; 19 - Fixed bracket A; 20 - O-ring B; 21 - Fixed bracket B; 22 - Flat filter membrane slot; 23 - Threaded hole A; 24 - Threaded hole B; 25 - Electrochemical detection area; 26 - Flat filter membrane filtration area; 27 - Flow channel filtration area; 28 - Water sample outlet. Detailed implementation manners

[0041] To further illustrate the present invention, the present invention will be described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the protection scope of the present invention.

[0042] The present invention is a water sample pretreatment device for deep sea water sample filtration and water flow optimization, wherein the flow channel filtration area 27 and the flat filter membrane filtration area 26 constitute multi-stage filtration, the parallel serpentine flow channel 4 filters suspended particles with a particle size of more than 200 microns, the microcolumn obstruction flow channel 6 filters suspended particles larger than microns and simultaneously reduces the flow rate of the water sample entering the flat filter membrane filtration area 26.

[0043] Example 1

[0044] The present invention discloses a water sample pretreatment device for deep sea water sample filtration and water flow optimization, which is used to filter suspended particles with a huge particle size range in water samples in an ocean in-situ environment, while reducing the flow rate of the water sample to provide a more stable detection environment for electrochemical detection.

[0045] Combination Figure 1 , 2 , 3, and 4 illustrate a specific embodiment of the present invention, a water sample pretreatment device for deep sea water sample filtration and water flow optimization, comprising a water sample inlet 2, a flow channel filtration area 27, a flat filter membrane filtration area 26, an electrochemical detection area 25, and a water sample outlet 28 that are interconnected. The flow channel filtration area 27 is a hollow area formed by the splicing and combination of the water sample pretreatment device cover 3 and the water sample pretreatment device housing 7. The water sample inlet 2 is located at the front end of the water sample pretreatment device cover 3 and is directly connected to the flow channel filtration area 27; the other end of the flow channel filtration area 27 is respectively connected to the waste outlet 17 and the flat filter membrane filtration area 26, the symmetrical waste outlet 17 is located at the rear end of the water sample pretreatment device housing 7, and the flat filter membrane filtration area 26 is located in the central area of ​​the rear end of the water sample pretreatment device housing 7. The other end of the flat membrane filtration area 26 is connected to the electrochemical detection area 25. The flat membrane filtration area 26 has three flat membrane slots 22 along the length direction, and the flat membrane A9, the flat membrane B10 and the flat ultrafiltration membrane 11 are installed in sequence. The surfaces of the three membranes are perpendicular to the water flow direction. The electrochemical detection area 25 is a cylindrical area located at the tail end of the flat membrane filtration area 26, and a water sample outlet 28 is provided at the bottom of the electrochemical detection area 25.

[0046] The flow channel filtration area 27 is provided with filter plates 5 assembled in parallel, and the filter plates 5 are provided with parallel serpentine flow channels 4 and micro-column obstruction flow channels 6 in sequence from the inlet to the outlet. Three mutually parallel serpentine flow channels are provided in each parallel serpentine flow channel 4, and each cycle is set as a serpentine unit. In a parallel serpentine flow channel 4, at the end of the semicircle of each serpentine unit, the openings of the three mutually parallel serpentine flow channels are interconnected, and the serpentine flow channel with the opening located at the outermost side is defined as the outermost flow channel, and the outlet of the outermost flow channel is connected to the waste outlet 17, and the other two serpentine flow channels are connected to the micro-column obstruction flow channel 6.

[0047] There are 2 micro-column arrays arranged in the micro-column obstructed flow channel 6. Each micro-column array is in the shape of "<", and each micro-column array has 6 vertical columns. The two micro-column arrays are 7 mm apart. The micro-column array is composed of several rows of micro-columns. The angle between each row of micro-columns and the axis of the micro-column obstructed flow channel 6 is 17 degrees. In the upstream micro-column array, there is a distance of one row of micro-columns between the outermost row of micro-columns and the wall of the micro-column obstructed flow channel 6. In the downstream micro-column array, there is a distance of two rows of micro-columns between the outermost row of micro-columns and the wall of the micro-column obstructed flow channel 6. An outer outlet and an inner outlet are respectively arranged at the end of the micro-column obstructed flow channel 6. The outer outlet is connected to the waste outlet 17, and the inner outlet is connected to the electrochemical detection area 25.

[0048] The water sample to be tested enters the flow channel filtration area 27 of the water sample pre-processor through the water sample inlet 2, passes through the parallel serpentine flow channel 4 and the micro-column obstructed flow channel 6. The water sample containing large-diameter suspended particles is discharged outside the water sample pre-processor through the waste outlet 17. The filtered water sample enters the flat membrane filtration area 26 and is further filtered by the flat membrane A9, the flat membrane B10 and the flat ultrafiltration membrane 11. The filtered water sample enters the electrochemical detection area 25 for electrochemical detection, and finally the water sample is discharged through the water sample outlet 28.

[0049] The described parallel serpentine flow channel 4 includes 8 serpentine units. There are 8 filter plates 5.

[0050] Symmetric fixed brackets B21 are provided on both sides of the water sample pre-processor cover 3, and are matched with the M5 fixed threaded holes of the symmetric fixed brackets A19 on both sides of the water sample pre-processor housing 7 through the M5 round head socket head cap screws 1 to achieve a firm connection between the water sample pre-processor cover 3 and the water sample pre-processor housing 7.

[0051] The O-ring B20 is installed at the groove at the rear end of the water sample pre-processor cover 3 for sealing the joint between the water sample pre-processor cover 3 and the water sample pre-processor housing 7;

[0052] The electrochemical detection cavity 16 is located on the outer periphery of the flat membrane filtration area 26 and the electrochemical detection area 25 to play a protective role. The M5 hexagon head bolt 8 fixes the electrochemical detection cavity 16 and the water sample pre-processor housing 7 through the M5 screw hole A23 and the M5 hexagon special flat nut 18.

[0053] The M4 round head socket head cap screw 12 fixes the electrochemical detection cavity cover 13 and the electrochemical detection cavity 16 through the M4 screw hole B24. The electrochemical three-electrode jack 14 is located at the center of the electrochemical detection cavity cover 13. The O-ring A15 is installed at the groove of the electrochemical detection cavity cover 13 for sealing the electrochemical detection cavity 16;

[0054] Two groups of parallel serpentine flow channels 4 are arranged in each filter plate 5, which are symmetric with respect to the central axis of the filter plate 5.

[0055] The inlet width and depth of each serpentine flow channel are 0.9 mm and 1 mm respectively.

[0056] The opening positions between the 3 mutually parallel serpentine flow channels are set at the tail of the rotating semi-circle. The outer two flow channels are set in the 10 - 55 degree interval, and the opening positions of the inner two flow channels are set in the 0 - 45 degree interval and continue for 0.5 mm in the straight flow channel.

[0057] The diameter of each micro-column of the micro-column array is 200 microns, the height is 1000 microns, and the horizontal and vertical spacings between the micro-columns are both 300 microns.

[0058] The water sample mentioned above is an in-situ seawater sample. Natural seawater contains a large number of suspended particles, including biological particles (particulate carbon), sediment, sediment, microplastics, and flocs, etc. The particle size of these suspended particles spans a wide range, from several hundred microns to several microns. Some ultra-fine suspended particles such as biological metabolites, fine mineral particles, and marine aerosols generated by wave action have a diameter of less than 1 micron.

[0059] The flat filter membrane A9 is a large-pore filter membrane with a pore size range of 10 microns. The flat filter membrane B10 is a medium-pore filter membrane with a pore size range of 1 micron. The flat ultrafiltration membrane 11 is a small-pore filter membrane with a pore size range of 0.1 micron. The material of the flat filter membrane is one of metal membrane, organic membrane, and ceramic membrane.

[0060] The water sample enters the filter plate 5 through the water sample inlet 2, and passes through the parallel serpentine flow channel 4 and the micro-column obstacle flow channel 6. The suspended particles in the water sample are subject to a net lift force F in the direction perpendicular to the movement direction in the flow channel L , including the wall effect lift force F W and the shear gradient lift force F S .

[0061]

[0062] where ρ is the fluid density, V m is the velocity of the suspended particle, d is the diameter of the suspended particle, D h is the hydraulic diameter of the flow channel, C W is the wall lift coefficient, C S is the shear lift coefficient.

[0063] F D = 3πμdU D

[0064]

[0065] Among them, F D is the Dean drag, μ is the viscosity of the fluid, U D is the cross-flow velocity of the secondary flow, D eThe Dean number for describing the eddy current intensity, R e is the Reynolds number, H is the channel width, and R is the radius of curvature of the channel.

[0066] Under the action of the net lift force F L , suspended particles of different particle sizes will reach different equilibrium positions. In a curved channel, the fluid motion is subjected to radial centrifugal acceleration, thus forming opposite vortices called Dean vortices in the upper and lower parts of the channel cross-section. Suspended particles in the fluid reach the equilibrium position faster under the combined action of F L and the Dean drag force F D generated by the Dean vortices. A communication area is provided at the turning point of the parallel serpentine channel 4. Suspended particles with a particle size greater than 200 microns are more likely to be subjected to centrifugal action and converge to the outer channels in the communication area, entering the waste outlet 17. In the micro-column obstructed channel 6, suspended particles in the water sample are guided by the micro-column array to converge to the edge and enter the waste outlet 17, and the remaining water sample enters the flat membrane filtration area 26 at a low flow rate. Suspended particles with small particle sizes in the water sample are filtered step by step. After filtration, the water sample enters the electrochemical detection area and is discharged from the water sample outlet 28 after electrochemical detection.

[0067] Example 2

[0068] A water sample pretreatment device for deep sea water sample filtration and water flow optimization of the present invention is used to filter suspended particles with a huge particle size span in the water sample in the in-situ marine environment, and at the same time reduce the flow rate of the water sample to provide a more stable detection environment for electrochemical detection. In this example, the finite element simulation of the filtration channel is carried out by using the computational fluid dynamics module and the particle tracking module of the COMSOL multi-physics simulation software to verify its filtration effect on suspended particles at different inlet flow rates.

[0069] Combined Figure 5 , 6 , 7, 8 to illustrate the specific implementation manners of the present invention. As Figure 5 shown, a two-dimensional model is used to simulate the parallel serpentine channel 4, simulating the channel area occupied by the fluid, and the fluid density is set to 1000 kg / m ^3 , and the inlet flow rate of the fluid is 0.4 m / s. The particle tracking module sets the density of the particles to 1100 kg / m ^3 , the diameter of the particles is evenly distributed in the range of 50 to 250 microns, and 200 particles are released at the same time. The particles are set to be subjected to the drag force and lift force exerted by the fluid, and the reaction force of the particles on the fluid is ignored. The two-dimensional model is refined with a mesh divided by the physical field, and the model is solved by using the iterative solver GMRES. As Figure 6As shown, the x-axis represents the position of the particles at the outlet in mm, the y-axis represents the particle diameter in microns, and the z-axis represents the number of particles. It is statistically obtained that 93.2% of the particles with a diameter greater than 200 microns flow out from the outlet at a position of 3 - 4 mm, that is, into the waste outlet 17. As Figure 7 shown, a two-dimensional model is used to simulate the micro-column obstructing the flow channel 6, and the flow channel area occupied by the fluid is simulated. The fluid density is set to 1000 kg / m ^3 , and the inlet velocity of the fluid is 0.2 m / s. The particle tracking module sets the density of the particles to 1100 kg / m ^3 , the particle diameter is evenly distributed in the range of 1 to 200 microns, and 200 particles are released simultaneously. The drag force and lift force exerted by the fluid on the particles are set, and the reaction force of the particles on the fluid is ignored. The two-dimensional model is refined by physical field-controlled mesh generation, and the model is solved using the iterative solver GMRES. As Figure 8 shown, the x-axis represents the position of the particles at the outlet in mm, the y-axis represents the particle diameter in microns, and the z-axis represents the number of particles. It is statistically obtained that 95.68% of the particles flow out from the outlet at a position of 6 - 8 mm, that is, into the waste outlet 17.

Claims

1. A water sample pretreatment device for deep sea water sample filtration and water flow optimization, characterized in that: The invention comprises a water sample inlet (2), a flow channel filtration area (27), a flat filter membrane filtration area (26), an electrochemical detection area (25) and a water sample outlet (28) which are interconnected; the flow channel filtration area (27) is a hollow area formed by splicing and combining a water sample preprocessor cover (3) and a water sample preprocessor shell (7); the water sample inlet (2) is located at the front end of the water sample preprocessor cover (3) and is directly connected to the flow channel filtration area (27); the other end of the flow channel filtration area (27) is respectively connected to a discarded object outlet (17) and a flat filter membrane filtration area (26); the symmetrical discarded object outlet (17) is located outside the water sample preprocessor. The flat filter membrane filtration area (26) is located at the rear end of the water sample preprocessor housing (7); the other end of the flat filter membrane filtration area (26) is connected to the electrochemical detection area (25); the flat filter membrane filtration area (26) is provided with three flat filter membrane slots (22) along the length direction, and the flat filter membrane A (9), the flat filter membrane B (10) and the flat ultrafiltration membrane (11) are installed in sequence respectively, and the surfaces of the three filter membranes are perpendicular to the water flow direction; the electrochemical detection area (25) is a cylindrical area located at the rear end of the flat filter membrane filtration area (26); and the bottom end of the electrochemical detection area (25) is provided with a water sample outlet (28); A filter plate (5) assembled in parallel is arranged in the flow channel filtering area (27), and a parallel serpentine flow channel (4) and a micro-column obstruction flow channel (6) are sequentially provided on the filter plate (5) from the inlet to the outlet; more than two parallel serpentine flow channels are arranged in each parallel serpentine flow channel (4), and each cycle is set as a serpentine unit. In a parallel serpentine flow channel (4), at the end of the semicircle of each serpentine unit, the parallel serpentine flow channels are opened to communicate with each other, and the serpentine flow channel with the opening located at the outermost side is defined as the outermost flow channel, and the outlet of the outermost flow channel is connected to the waste outlet (17), and the other serpentine flow channels are connected to the micro-column obstruction flow channel (6); Two micro-column arrays are arranged in the micro-column obstruction channel (6), each micro-column array is in a "<" shape, the micro-column array is composed of a plurality of rows of micro-columns, each row of micro-columns and the axis of the micro-column obstruction channel (6) are at an acute angle, in the upstream micro-column array, the outermost row of micro-columns are separated from the wall of the micro-column obstruction channel (6) by a distance of one row of micro-columns, and in the downstream micro-column array, the outermost row of micro-columns are separated from the wall of the micro-column obstruction channel (6) by a distance of two rows of micro-columns; an outer outlet and an inner outlet are respectively arranged at the ends of the micro-column obstruction channel (6), the outer outlet is connected to the waste outlet (17), and the inner outlet is connected to the electrochemical detection area (25); The water sample to be tested enters the flow channel filtration area (27) of the water sample preprocessor through the water sample inlet (2), passes through the parallel serpentine flow channel (4) and the micro-column obstruction flow channel (6), and the water sample containing large-diameter suspended particles is discharged to the outside of the water sample preprocessor through the discard outlet (17). The filtered water sample enters the flat filter membrane filtration area (26) and is further filtered using the flat filter membrane A (9), the flat filter membrane B (10) and the flat ultrafiltration membrane (11). The filtered water sample enters the electrochemical detection area (25) for electrochemical detection, and finally the water sample is discharged through the water sample outlet (28).

2. A water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: Each parallel serpentine flow channel (4) is provided with three mutually parallel serpentine flow channels; each microcolumn array has 5-7 vertical columns, two microcolumn arrays are 5-10 mm apart, and the angle between each row of microcolumns and the axis of the microcolumn obstruction flow channel (6) is 17-22 degrees.

3. A water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: The parallel serpentine flow channel (4) comprises 5 to 8 serpentine units; and 6 to 8 filter plates (5) are provided.

4. A water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: Symmetrical fixing brackets B (21) are provided on both sides of the water sample preprocessor cover (3), which cooperate with the fixing threaded holes of the symmetrical fixing brackets A (19) on both sides of the water sample preprocessor shell (7) through round head hexagon socket screws (1) to achieve a stable connection between the water sample preprocessor cover (3) and the water sample preprocessor shell (7); O-ring B (20) is installed in the groove at the rear end of the water sample preprocessor cover (3) to seal the joint between the water sample preprocessor cover (3) and the water sample preprocessor shell (7).

5. The water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: The electrochemical detection chamber (16) is located at the periphery of the flat filter membrane filtration area (26) and the electrochemical detection area (25) to play a protective role; the hexagonal head bolt (8) fixes the electrochemical detection chamber (16) and the water sample preprocessor housing (7) through the screw hole A (23) and the hexagonal special flat nut (18).

6. A water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: The round head hexagon socket screw (12) fixes the electrochemical detection chamber cover (13) and the electrochemical detection chamber (16) through the screw hole B (24); the electrochemical three-electrode jack (14) is located at the center of the electrochemical detection chamber cover (13); and the O-ring A (15) is installed in the groove of the electrochemical detection chamber cover (13) to seal the electrochemical detection chamber (16).

7. A water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: Two groups of parallel serpentine flow channels (4) are arranged in each filter plate (5) and are symmetrical with respect to the central axis of the filter plate (5).

8. The water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: The inlet width and depth of each serpentine flow channel are 0.5-1mm; the opening positions between the three parallel serpentine flow channels are set within the 0-90 degree range of the tail end of the rotating semicircle and within the 0-1mm range of the connected straight flow channel; the diameter of each microcolumn in the microcolumn array is 200-400 microns, the height is 500-1000 microns, and the horizontal and vertical spacings between the microcolumns are both 300-600 microns.

9. A water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: The water sample is an in-situ ocean water sample. Natural seawater contains a large amount of suspended particulate matter, including biological particles, silt, sediment, microplastics and flocculants. The particle size of these suspended particles ranges widely, from hundreds of microns to several microns. Some ultrafine suspended particles such as biological metabolites, fine mineral particles and marine aerosols generated by waves have a diameter of less than 1 micron.

10. The water sample pretreatment device for deep sea water sample filtration and water flow optimization according to claim 1, characterized in that: The flat filter membrane A (9) is a large-pore filter membrane with a pore size ranging from 1 to 10 microns, the flat filter membrane B (10) is a medium-pore filter membrane with a pore size ranging from 0.1 to 1 microns, and the flat ultrafiltration membrane (11) is a small-pore filter membrane with a pore size ranging from 0.01 to 0.1 microns; the material of the flat filter membrane is one of a metal membrane, an organic membrane, and a ceramic membrane.

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