System for observing and simulating aquifer

Abstract

The utility model relates to a system for observing and simulating an aquifer, which comprises a micro-fluidic chip, an injection device, a recovery device and an imaging device, the injection device and the recovery device are respectively connected with a liquid inlet and a liquid outlet of the micro-fluidic chip, a medium is filled in the micro-fluidic chip, and the structure of the aquifer is simulated. The injection device injects a solution into the micro-fluidic chip, and the solution flows through the micro-fluidic chip and is collected by the recovery device after flowing out; the imaging device is arranged on the outer side of the micro-fluidic chip, and the change in the micro-fluidic chip is observed or photographed through the transparent shell. The system for observing and simulating the aquifer can be used for researching the distribution of pollutants in the pores of the aquifer and evaluating the tracing effect of the tracer agent, and has great significance in researching the distribution rule of the pollutants in the aquifer and developing a novel tracer agent.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of environment technology, especially a system for observing simulation aquifer. BACKGROUND

[0002] Heavy non-aqueous phase liquids are typical groundwater organic pollutants, mainly including trichloroethylene, tetrachloroethylene, polycyclic aromatic hydrocarbons and the like. Due to its environmental persistence, difficulty in biodegradation, continuous release and toxic and harmful to human and animals and plants, its research on environmental problems such as groundwater pollution has become a research hotspot in today's environmental science. When organic pollutants are released into the environment, organic pollutants infiltrate from the surface to the aquifer, and under the scouring action of groundwater, they migrate horizontally with groundwater. In this process, organic pollutants will contact with underground aquifer medium (quartz sand, etc.), and under the action of adhesion and shear force, various residual organic pollutants in the form of occurrence are formed and retained in the pores of the aquifer, and continuously dissolved and released into groundwater. Research and detection of the occurrence form of organic pollutants in the pores of the aquifer medium are research hotspots in today's environmental science. Direct observation of the migration and distribution of organic pollutants in the pores from the microscopic point of view, monitoring the detection effect of tracers on residual organic pollutants in the pores, is helpful to study the distribution and retention law of organic pollutants in the pores, and is also conducive to the development of organic pollutant tracing technology and remediation technology. SUMMARY

[0003] To solve the above technical problems, the utility model provides a kind of system for observing simulation aquifer organic pollutant distribution and application in tracing detection.

[0004] The technical scheme adopted by the utility model is: a system for observing simulation aquifer, comprising,

[0005] Microfluidic chip, loading pore medium, for simulating aquifer;

[0006] Injection device, in communication with microfluidic chip, capable of injecting solution into microfluidic chip;

[0007] Recovery device, in communication with microfluidic chip, solution flows out of microfluidic chip into recovery device;

[0008] Imaging device, arranged on the side of microfluidic chip, capable of observing and / or photographing images in microfluidic chip.

[0009] Preferably, the microfluidic chip includes a transparent shell, two ends are provided with a screen, and the shell is loaded with a pore medium between the two screens. The upstream hose and the downstream hose are provided through the two ends of the shell.

[0010] Preferably, the pore medium has a particle size of 200-500 μm.

[0011] Preferably, the injection device is a syringe pump, and the syringe pump is connected to the upstream hose.

[0012] Preferably, the upstream hose of the microfluidic chip is connected to the syringe pump through a luer adapter.

[0013] Preferably, the imaging device is a microscope, including an ocular lens and / or an imaging system.

[0014] Preferably, the imaging device is a laser scanning confocal microscope, including an ocular lens and an imaging system, and has a fluorescence imaging function.

[0015] Preferably, the transparent shell is high-transmittance quartz glass.

[0016] Preferably, the microfluidic chip is filled with a liquid, and the liquid level is higher than the packing height of the porous medium.

[0017] Preferably, the liquid includes one or more of a combination of water, simulated groundwater, and simulated pollutants.

[0018] The simulation system has the advantages and positive effects that: a simulation system of an underground aquifer organic pollutant is constructed, can be used for simulating and analyzing the formation of groundwater pollution, evaluating the utility of tracers, and is beneficial to the development of organic pollutant tracer technology; has great significance for studying the distribution law of aquifer organic pollutants and developing new tracers;

[0019] The laboratory platform constructed can take photos of multiple slices, and after post-synthesis, three-dimensional pictures can be obtained, which can more directly and stereoscopically express the simulation of environmental pollution and the tracer marking, accurately reflect the utility of the tracer, and make the data more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The system structure schematic diagram for observing the simulated aquifer; 1 injection device; 2 microfluidic chip; 3 recovery device; 41 ocular lens; 42 imaging system; 43 laser emission module;

[0021] Figure 2 The images before and after the tracer marks the distribution of residual organic pollutants; (a1-d1) mark the positions of the organic pollutants through the experimental platform before injecting the tracer, (a2-d2) mark the positions of the organic pollutants after injecting the tracer, a, b, c, and d are different test points. DETAILED DESCRIPTION

[0022] The embodiments of the utility model will be described below in combination with the drawings.

[0023] The utility model relates to a system for observing simulation aquifer, can simulate groundwater layer structure, can be used for evaluating groundwater pollutant tracer effect. The system for observing simulation aquifer includes micro -fluidic chip 2, injection device 1, recovery device 3 and imaging device, as shown in Figure 1 Injection device 1 and recovery device 3 are connected respectively on the upstream and downstream of micro -fluidic chip 2, and micro -fluidic chip 2 is filled with pore medium, simulates underground structure, injection device 1 injects solution into micro -fluidic chip 2, and the solution flows through micro -fluidic chip and is collected by recovery device 3 after flowing out. The shell of micro -fluidic chip 2 is transparent material, can observe its inside scene, and the imaging device is arranged on the outside of micro -fluidic chip 2, and the change in it is observed or photographed through the transparent shell.

[0024] In some embodiments of the utility model, the material of the visual micro -fluidic chip is quartz, which is formed by sintering quartz glass. The quartz glass has no obvious absorption in the ultraviolet, visible and infrared regions, so it will not absorb the fluorescence signal and can reduce the observation error. The pore medium in the two-dimensional micro -fluidic chip is filled by wet method, and the medium material is glass sand or quartz sand. The particle size of the pore medium is 200-500 μm. The micro -fluidic chip is provided with a screen at both ends to prevent the pore medium from being washed away by the flowing liquid solution during the experiment. The upstream and downstream hoses are sealingly arranged at both ends of the micro -fluidic chip and can be connected with the upstream and downstream injection devices and recovery devices respectively. The visual micro -fluidic chip can be placed on a stage, which has a three-layer structure. The upper and lower surfaces are formed by quartz glass to form a light transmission surface, and the middle layer is filled with pore medium. The total thickness is not greater than 3000 μm, and the length and width are not limited, so that it can be placed on a microscope stage.

[0025] The micro -fluidic chip 2 is filled with liquid, and the liquid level is higher than the filling height of the pore medium. The liquid flowing through the micro -fluidic chip includes water, simulated groundwater and one or more combinations of simulated pollutants. According to the experimental purpose and experimental stage, deionized water, simulated groundwater, model pollutant or tracer solution can be continuously injected into the micro -fluidic chip 2 through the injection device 1. The liquid is recovered by the recovery device 3 after passing through the micro -fluidic chip 2. The recovery device 3 can be a recovery barrel or other open or sealed container. The injection device 1 can be a syringe or an injection pump. The upstream hose of the micro -fluidic chip 2 is connected to the injection pump through a luer connector.

[0026] The imaging device is arranged above the micro -fluidic chip and can observe and / or photograph the image in the micro -fluidic chip through the transparent shell. The imaging device can be a microscope, which includes an eyepiece 41 and an imaging system 42. The eyepiece 41 is used to adjust the position and find the appropriate observation site, and the imaging system 42 is used to take pictures. When observing the simulated aquifer structure in the micro -fluidic chip using a laser scanning confocal fluorescence microscope, the scanning is performed layer by layer with a unit of 10 μm and compressed into one image.

[0027] The prepared system for observing the simulated aquifer can be used for experimental research on the aquifer, such as the direction of the aquifer particle migration, the pore structure, the formation reason of the blockage, etc. On one hand, the state of the aquifer under different environmental conditions can be simulated through the cooperation of the microfluidic chip and the injection device. On the other hand, the imaging device can shoot and record the simulation in the microfluidic chip.

[0028] In some embodiments of the utility model, the imaging device is a laser scanning confocal microscope, which comprises an ocular lens and an imaging system and has a fluorescence imaging function. The microfluidic chip is arranged on the object table of the laser scanning confocal microscope. The laser scanning confocal microscope has a laser emission module 43, which can emit different wavelengths and take pictures of different fluorescent markers. Based on this function, the system for observing the simulated aquifer can perform specific observation on different fluorescent markers. By marking different injected solutions with fluorescence, the excitation wavelength of the laser scanning confocal microscope can be switched to observe the residual situation of different to-be-detected substances in the microfluidic chip or investigate the action relationship between different to-be-detected substances.

[0029] The utility model is further described in connection with specific embodiments.

[0030] Embodiment 1

[0031] A system for observing a simulated aquifer, comprising a microfluidic chip, an injection device, a recovery device and an imaging device. The visual microfluidic chip material is quartz material, 4cm long, 1cm wide, 3000μm thick, and is sintered by two pieces of quartz glass with a thickness of 1mm from top to bottom. The effective optical path of the microfluidic chip is 1000μm. The microfluidic chip is filled with glass sand by wet method. The upstream hose and the downstream hose are respectively sealed and connected at both ends of the microfluidic chip. The hose material is polytetrafluoroethylene. A screen is arranged at the hose connection position, and the material is polytetrafluoroethylene. The outer diameter of the hose is equal to the inner diameter of the microfluidic chip liquid inlet and outlet, and the sealing is realized by vacuum silicone grease and polytetrafluoroethylene tape. The upstream hose is connected with the syringe through a luer joint, and the downstream hose is connected with the recovery device. The liquid injection rate is 5-50μL / min.

[0032] The imaging device is a laser scanning confocal fluorescence microscope, which comprises an ocular lens and an imaging system. The microfluidic chip is fixed on the microscope object table. When shooting, the appropriate position is adjusted through the ocular lens, so as to facilitate shooting the image of the fixed position in the microfluidic chip, and then the imaging system is converted to monitor or periodically shoot the position. When shooting, the layers are scanned and compressed into an image in units of 10μm.

[0033] In use, the liquid medium simulating the groundwater is first injected into the microfluidic chip through the injection device. The syringe should inject the liquid slowly and keep the liquid level higher than the pore medium to prevent gas from entering the flow channel. The injection device continuously injects the same or different liquid medium, thereby simulating the underground aquifer.

[0034] Example 2:

[0035] On the basis of the system for observing the simulated aquifer constructed in Example 1, the simulated groundwater is first injected through the syringe, and the injection flow rate can be 5 μL / min. The simulated groundwater is converted into the model pollutant (in this example, trichloroethylene is selected as the model pollutant), and the injection flow rate is 5 μL / min, and the continuous injection time is 3 h. Then the model pollutant is converted into the simulated groundwater, and the injection flow rate is 30 μL / min, and the injection time is 3 h, thereby flushing the trichloroethylene in the microfluidic chip medium pores, and thus the underground aquifer with trichloroethylene occurrence state is simulated.

[0036] Example 3:

[0037] Dissolve 3 g of carbon black nanoparticles in 120 mL of tetrahydrofuran, add 6 g of 4,4-azobis-4-cyanopentanoic acid and mix uniformly, heat and stir in an oil bath at 70°C for 24 h, cool and reflux, centrifuge, and vacuum dry at 100°C for 48 h to obtain product 1 solid, which is used after vacuum drying.

[0038] Dissolve 200 mg of product 1 in 500 mL of dimethyl sulfoxide, ultrasonically disperse, add 150 mL of a polyvinyl alcohol dimethyl sulfoxide solution (concentration 40 g / L), mix uniformly, then add 2 g of N,N-dicyclohexyl carbodiimide and 0.2 g of 4-dimethylaminopyridine, seal, stir at room temperature for 24 h, and after reaction, use an ultrafiltration device (ultrafiltration membrane molecular weight cutoff 100 kD) to transfer the ultrafiltration liquid to a dialysis bag (dialysis bag molecular weight cutoff 100 kD) for dialysis in deionized water for 5 days to obtain a product 2 solution.

[0039] Take 500 mL of product 2 solution, add 20 mg of Nile red solid, ultrasonically avoid light for 0.5 h, stir at room temperature for 24 h, filter the solution using a 0.22 μm filter membrane to obtain a deionized water solution of the nano-tracer, and use a UV spectrophotometer to quantitatively determine the concentration of the nano-carrier, and dilute to 75 mg / L for standby use.

[0040] In the embodiment 2, the underground aquifer simulating the existence state of trichloroethylene is constructed, first, the first fluorescent label is used to simulate the pollutant, the trichloroethylene is dissolved in the cyanine series fluorescent dye in advance, the concentration is 10 mg / L, the solution is used as the model pollutant, and the microfluidic chip is continuously injected; after simulating the large flow flushing of the underground water, part of the fluorescent labeled trichloroethylene remains in the pore of the pore medium, and the distribution of the trichloroethylene labeled by the cyanine series fluorescent dye can be observed under the excitation condition of the laser scanning confocal microscope (the excitation wavelength is 633 nm, the pinhole is 1 AU, and the gain value is 200);

[0041] The tracer solution carrying the second fluorescent label (the Nile red signal molecule) is continuously injected into the microfluidic chip, the second fluorescent substance is labeled to the residual trichloroethylene, for example, the tracer carrying the Nile red is used, the tracer flowing through the position of the residual trichloroethylene labels the Nile red signal molecule to the residual trichloroethylene, and the labeling condition of the tracer to the residual trichloroethylene can be observed under the conversion laser scanning confocal microscope excitation condition (the excitation wavelength is 543 nm, the pinhole is 1 AU, and the gain value is 500), so that the efficacy of the tracer is determined. Figure 2 As shown in Figure 2 The green fluorescence in (a1-d1) shows the residual trichloroethylene, after the tracer is injected, the residual trichloroethylene is labeled with the Nile red under the action of the tracer, and the position of the residual trichloroethylene labeled by the tracer can be observed after the excitation wavelength of the microscope is switched, as shown in Figure 2 The red fluorescence in (a2-d2) is shown, and by comparing with Figure 2 (a1-d1), it can be judged that the tracer has better tracing ability.

[0042] The above embodiment of the utility model is described in detail, but the content is only the preferred embodiment of the utility model, and cannot be considered as limiting the scope of the utility model. Any equivalent change and improvement within the scope of the utility model application should still belong to the patent coverage range of the utility model.

Claims

1. A system for observing an analogue aquifer, characterised in that: For evaluating tracer utility, including, A microfluidic chip is filled with a porous medium for simulating an aquifer; a liquid is injected into the microfluidic chip, the liquid level being higher than the filling height of the porous medium, the liquid comprising deionized water, simulated groundwater, simulated pollutants and tracer solution; the simulated pollutants are first fluorescently labeled, and the tracer carries a second fluorescent label; An injection device is in communication with the microfluidic chip and is capable of injecting a solution into the microfluidic chip; A recovery device is in communication with the microfluidic chip and is capable of recovering a solution from the microfluidic chip into the recovery device; An imaging device is arranged on the side of the microfluidic chip and is capable of observing and / or photographing an image in the microfluidic chip; the imaging device is a laser scanning confocal microscope, which comprises an ocular lens and an imaging system and has a fluorescent imaging function; the microfluidic chip is arranged on the stage of the laser scanning confocal microscope; the laser scanning confocal microscope has a laser emission module and is capable of emitting different wavelengths.

2. The system for observing an analog aquifer of claim 1, wherein: The microfluidic chip comprises a transparent shell, both ends of which are provided with screens; the porous medium is filled between the two screens in the shell; upstream and downstream hoses are provided through both ends of the shell.

3. The system for observing an analog aquifer of claim 2, wherein: The porous medium has a particle size of 200-500 μm.

4. The system for observing an analog aquifer of claim 2, wherein: The injection device is an injection pump, which is in communication with the upstream hose.

5. The system for observing an analog aquifer of claim 4, wherein: The upstream hose of the microfluidic chip is connected to the injection pump through a luer adapter.

6. The system for observing an analog aquifer of claim 2, wherein: The transparent shell is high-transmittance quartz glass.

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