Vertical stratified sampling device for vertical flow constructed wetland in laboratory

Abstract

The invention discloses a vertical stratified sampling device for a vertical flow constructed wetland in a laboratory, which comprises a stratified sampling assembly and a support seat, and the stratified sampling assembly is arranged on the support seat. According to the vertical stratified sampling device for the vertical flow constructed wetland in the laboratory, the filler and the three-phase separator are arranged in the experimental cylinder in a stratified manner, and the environment of water, solid and gas three-phase synergistic effect in the constructed wetland is truly simulated in combination with a vertical flow water inlet mode; fixed-point and non-disturbance stratified sampling of water at different depths is achieved through sampling pipes arranged at equal intervals, gas produced by all layers is collected through cooperation of independent gas guide pipes and gas collection bags, and cross contamination of water and gas is effectively avoided; meanwhile, pressure balance of the system is maintained through the air outlet pipe, stable operation is ensured, synchronous, accurate and in-situ monitoring of the degradation process of pollutants in the constructed wetland and microbial metabolic activity in the vertical direction is achieved through the design, and the reliability of experimental data is remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of wetland stratified sampling, and more particularly to a vertical stratified sampling device for a laboratory vertical flow constructed wetland. Background Technology

[0002] Constructed wetlands, as an eco-friendly and low-cost wastewater treatment technology, are widely used for treating domestic sewage, agricultural drainage, and some industrial wastewater. Their purification efficiency mainly relies on the complex physical, chemical, and biological synergistic effects between the packing material, microorganisms, plants, and water body. Especially in vertical flow constructed wetlands, the pollutant removal process exhibits significant vertical spatial differentiation—dissolved oxygen concentration, redox potential, microbial community structure, and metabolic products (such as gases) all show obvious gradient changes at different depths. Therefore, vertically stratified, in-situ, and simultaneous water-air two-phase sampling within the wetland is a key prerequisite for deeply revealing the mechanisms of pollutant migration and transformation, and optimizing wetland structural design and operating parameters.

[0003] However, existing laboratory simulation devices generally suffer from problems such as crude sampling methods, strong interference, and insufficient data representativeness. Traditional methods often use overall water sampling or single-point sampling, which cannot reflect dynamic changes in the vertical direction. Although some improved devices are equipped with multiple sampling ports, sampling requires stopping the machine, opening the cover, or inserting the probe, which seriously disturbs the packing structure and water flow state, affecting the accuracy of the data. More importantly, gases are important products of microbial metabolism (such as methane, carbon dioxide, nitrogen, etc.), and their generation location and flux directly reflect the functional activity of each layer. However, existing devices generally lack the ability to collect gases independently in each layer, often collecting all the gases in the column together, which masks the spatial heterogeneity of the gas production process and makes it difficult to correlate the correspondence between water phase quality and gas phase metabolism. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, one objective of this application is to provide a vertical stratified sampling device for a vertical flow constructed wetland in the laboratory. By stratifying packing material and a three-phase separator in the experimental cylinder and combining it with vertical flow water inlet, the device can realistically simulate the synergistic effect of water, solid and gas in a constructed wetland. It can achieve undisturbed stratified water quality sampling by using equidistant sampling tubes, and collect the gas from each layer separately with independent gas guide tubes and gas collection bags to avoid cross-contamination and significantly improve the reliability of experimental data.

[0006] To achieve the above objectives, a first aspect of this application provides a vertical stratified sampling device for a laboratory vertical flow constructed wetland, comprising a stratified sampling component and a support base. The stratified sampling component is mounted on the support base. The stratified sampling component includes an experimental cylinder mounted on the support base. Multiple sampling tubes are equidistantly arranged on the experimental cylinder. Multiple three-phase separators are disposed inside the experimental cylinder, and the multiple three-phase separators are staggered with the multiple sampling tubes. An inlet pipe is fixedly installed on the experimental cylinder on the side opposite to the sampling tubes. An outlet pipe is fixedly installed on the experimental cylinder above the multiple sampling tubes. An outlet pipe is fixedly installed on the surface of the experimental cylinder at a slightly above position on the side opposite to the outlet pipe. Air guide pipes are fixedly installed on the tops of the multiple separators. An air collection bag is provided at the top of each of the multiple air guide pipes.

[0007] In addition, the vertical stratified sampling device for constructed wetlands with vertical flow in the laboratory proposed in this application may also have the following additional technical features: In one embodiment of this application, a plurality of the gas guide tubes sequentially pass through a three-phase separator located above the gas guide tubes and extend through the gas guide tubes to the outside of the experimental cylinder.

[0008] In one embodiment of this application, a rubber stopper is provided on the plurality of sampling tubes for sealing the sampling tubes.

[0009] In one embodiment of this application, a separation mechanism is provided at the top of the plurality of air guide pipes; the separation mechanism includes an exhaust pipe installed on the air guide pipes; a connecting pipe is fixedly installed at one end of the exhaust pipe; a plurality of push springs are fixedly installed on the surface of the exhaust pipe near the air guide pipe; a sealing disc is fixedly installed at one end of the plurality of push springs; a plurality of connecting rods are fixedly installed on the surface of the sealing disc; a sealing disc is fixedly installed at one end of the plurality of connecting rods; and a plurality of flow holes are provided on the exhaust pipe.

[0010] In one embodiment of this application, one end of the air guide pipe is located inside the exhaust pipe, and the diameter of the air guide pipe is smaller than the diameter of the exhaust pipe.

[0011] In one embodiment of this application, the sealing disc is sleeved on the surface of the air guide tube, and the sealing disc is slidably connected to the air guide tube.

[0012] In one embodiment of this application, the sealing disc is located above the plurality of flow holes, and the sealing disc is in a sealing sliding connection with the exhaust stack.

[0013] In one embodiment of this application, a return pipe is fixedly installed on the exhaust pipe, and a one-way valve is fixedly installed at the bottom end of the return pipe; a control valve is fixedly installed at the top end of the return pipe.

[0014] In one embodiment of this application, the bottom end of the return pipe is fixedly connected to the bottom end of the air guide pipe through the one-way valve, and the top end of the return pipe is fixedly connected to the sealing disc.

[0015] The laboratory vertical flow constructed wetland vertical stratified sampling device of this application embodiment simulates the environment of water, solid, and gas synergistic interaction in constructed wetlands by stratifying packing materials and three-phase separators in the experimental cylinder and combining them with a vertical flow water inlet method. It achieves fixed-point, undisturbed stratified sampling of water quality at different depths by using equidistantly arranged sampling tubes, and collects gas generated in each layer separately with independent gas guide pipes and gas collection bags, effectively avoiding cross-contamination between water and gas. At the same time, the system pressure balance is maintained through the gas outlet pipe to ensure stable operation. This design realizes synchronous, accurate, and in-situ monitoring of pollutant degradation processes and microbial metabolic activities in the vertical direction inside the constructed wetland, which significantly improves the reliability of experimental data.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of a vertical stratified sampling device for a laboratory vertical flow constructed wetland according to an embodiment of this application; Figure 2 This is a perspective view of an experimental tube according to an embodiment of this application; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 This is a cross-sectional view of a separation mechanism according to an embodiment of this application; Figure 5 for Figure 4 Enlarged view of section B in the middle.

[0018] As shown in the figure: 10. Layered sampling assembly; 101. Experimental cylinder; 102. Sampling tube; 103. Three-phase separator; 104. Water inlet pipe; 105. Water outlet pipe; 106. Gas outlet pipe; 107. Gas guide pipe; 108. Gas collection bag; 20. Support base; 30. Separation mechanism; 301. Exhaust pipe; 302. Connecting pipe; 303. Push spring; 304. Sealing plate; 305. Connecting rod; 306. Sealing plate; 307. Flow hole; 40. Return pipe; 41. One-way valve; 42. Control valve. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0020] The following description, in conjunction with the accompanying drawings, describes a laboratory vertical flow constructed wetland vertical stratification sampling device according to an embodiment of this application.

[0021] like Figure 1 - Figure 5 As shown in the embodiment of this application, the vertical stratified sampling device for a laboratory vertical flow constructed wetland includes a stratified sampling component 10 and a support base 20. The stratified sampling component 10 is disposed on the support base 20. The stratified sampling component 10 includes an experimental cylinder 101 mounted on the support base 20. Multiple sampling tubes 102 are equidistantly arranged on the experimental cylinder 101. Multiple three-phase separators 103 are disposed inside the experimental cylinder 101, and the multiple three-phase separators 103 are connected to the multiple sampling tubes 102. Sample tubes 102 are arranged in an alternating manner; an inlet pipe 104 is fixedly installed on the experimental cylinder 101 on the side opposite to the sampling tubes 102; an outlet pipe 105 is fixedly installed on the experimental cylinder 101 above the plurality of sampling tubes 102; an outlet pipe 106 is fixedly installed on the surface of the experimental cylinder 101 at a position slightly above the side opposite to the outlet pipe 105; a gas guide pipe 107 is fixedly installed on the top of the plurality of separators 103; and a gas collection bag 108 is provided at the top of each of the plurality of gas guide pipes 107.

[0022] It should be noted that a valve body is installed at the top of the air duct 107, which can be opened or closed to control whether or not data is collected.

[0023] It should be noted that the main design parameters of the hierarchical sampling component 10 are as follows: 1. Dimensions (diameter * height): D150mm * 1200mm 2. Packing height: 1000mm 3. Filler type: gravel (5-10mm in diameter) 4. Plant type: Windmill grass (similar growth, planting density 9-25 plants / m2), roots buried 250mm into the substrate to ensure good growth. 5. Water inlet method: bottom inlet, top outlet, peristaltic pump, consistent wetland residence time (3 days), flow rate is 2.33L / day 6. Inlet & Outlet (from bottom to top): 0mm - Inlet, 1000mm - Outlet 7. Medium and water sampling ports (from bottom to top): A sampling port (D30mm) is set at 100mm intervals. 8. Gas sampling port: One port is installed 1050mm from the bottom (D50mm, equipped with a gas collection bag). 9. Top gas collection device (diameter * height): sealing cover D200mm*1000mm, equipped with a gas pressure balancing device and a thermometer.

[0024] In one embodiment of this application, such as Figure 1 and Figure 2 As shown, multiple air guide tubes 107 sequentially pass through the three-phase separator 103 located above the air guide tube 107 and extend through the air guide tube 107 to the outside of the experimental cylinder 101.

[0025] It should be noted that a label is installed at one end of the air delivery tube 107. The label is used to record the connection position of the air delivery tube 107, so as to facilitate the identification of specimens sampled from different positions.

[0026] In one embodiment of this application, such as Figure 1 and Figure 2 As shown, rubber stoppers are provided on the multiple sampling tubes 102 for sealing the sampling tubes 102.

[0027] Specifically, in the actual process, the simulated artificial wetland packing material is first filled into the experimental cylinder 101, and three-phase separators 103 are installed at equal intervals. Water is continuously or intermittently injected from the bottom of the experimental cylinder 101 or at a designated height through the inlet pipe 104, and flows vertically upward through the packing layer under the action of gravity, simulating the operating environment of water, solid (packing material and biofilm), and gas (gases produced by microbial metabolism, such as methane and carbon dioxide) coexisting in a real vertical flow artificial wetland. During the upward flow of water, the water quality (such as COD, ammonia nitrogen, dissolved oxygen, etc.) at different depths shows a vertical gradient change due to microbial degradation, adsorption and sedimentation. At this time, fixed-point stratified sampling can be carried out through sampling pipes 102 located at different elevations. Before sampling, the rubber stopper on the corresponding sampling pipe 102 is removed, and negative pressure is used to pump the water. Water samples from this layer are obtained by suction or natural outflow. After sampling, the rubber stopper is re-tightened to maintain the airtightness of the sampling tube 102. At the same time, the gas generated by the microbial activity in each layer is effectively intercepted by the three-phase separator 103 above and collected at its top. Then, it is discharged upward through the gas guide tubes 107 connected to each layer. Since each gas guide tube 107 passes through all the three-phase separators 103 above it and extends to the outside of the experimental tube 101, gas mixing between layers is avoided, ensuring that the gas generated in each layer is collected independently. The gas collection bag 108 connected to the top of the gas guide tube 107 can store the gas generated at different depths, which is convenient for subsequent gas composition and yield analysis. The treated water is finally discharged from the water outlet pipe 105 at the top, and excess or accumulated gas can also be released through the high-level gas outlet pipe 106 to maintain pressure balance.

[0028] By layering packing material and a three-phase separator within the experimental chamber, combined with a vertical water inlet method, the synergistic effect of water, solids, and gas in an constructed wetland is realistically simulated. Equidistant sampling tubes are used to achieve targeted, undisturbed, stratified sampling of water quality at different depths. Independent gas delivery pipes and gas collection bags are used to collect gas generated from each layer separately, effectively avoiding cross-contamination between water samples and gases. Simultaneously, the gas outlet pipe maintains system pressure balance, ensuring stable operation. This design enables synchronous, precise, and in-situ monitoring of pollutant degradation processes and microbial metabolic activities within the constructed wetland in the vertical direction, significantly improving the reliability and depth of experimental data. It provides an efficient and practical experimental platform for exploring the mechanisms and optimizing the processes of constructed wetlands.

[0029] In one embodiment of this application, such as Figure 4 and Figure 5 As shown, a separation mechanism 30 is provided at the top of the plurality of air guide pipes 107; the separation mechanism 30 includes an exhaust pipe 301 installed on the air guide pipe 107; a connecting pipe 302 is fixedly installed at one end of the exhaust pipe 301; a plurality of push springs 303 are fixedly installed on the surface of the exhaust pipe 301 near the air guide pipe 107; a sealing disc 304 is fixedly installed at one end of the plurality of push springs 303; a plurality of connecting rods 305 are fixedly installed on the surface of the sealing disc 304; a sealing disc 306 is fixedly installed at one end of the plurality of connecting rods 305; and a plurality of flow holes 307 are opened on the exhaust pipe 301.

[0030] In one embodiment of this application, there is another case where the connecting pipe 302 is configured as a retractable and extendable pipe, and the connecting pipe 302 is connected to the sealing plate 306. When the sealing plate 306 moves down, one end of the connecting pipe 302 is connected to one end of the gas guide pipe 107, so that the gas can directly enter the gas collection bag 108 through the connecting pipe 302.

[0031] In one embodiment of this application, such as Figure 4 and Figure 5 As shown, one end of the air guide pipe 107 is located inside the exhaust pipe 301, and the diameter of the air guide pipe 107 is smaller than the diameter of the exhaust pipe 301.

[0032] In one embodiment of this application, such as Figure 4 and Figure 5 As shown, the sealing disc 304 is sleeved on the surface of the air guide tube 107, and the sealing disc 304 is slidably connected to the air guide tube 107.

[0033] In one embodiment of this application, such as Figure 4 and Figure 5As shown, the sealing disc 306 is located above the plurality of flow holes 307, and the sealing disc 306 is in a sealing sliding connection with the exhaust pipe 301.

[0034] In one embodiment of this application, such as Figure 3 and Figure 4 As shown, a return pipe 40 is fixedly installed on the exhaust pipe 301, and a one-way valve 41 is fixedly installed at the bottom end of the return pipe 40; a control valve 42 is fixedly installed at the top end of the return pipe 40.

[0035] It should be noted that the control unit of the control valve 42 is located outside the exhaust stack 301. Before each sampling, the control valve 42 can be opened by the control unit and can also be closed after opening. The end of the return pipe 40 located inside the exhaust stack 301 is a spring-loaded pipe that can elastically contract and extend, so that it will not be affected by the return pipe 40 when the sealing disc 304 moves up and down.

[0036] In one embodiment of this application, such as Figure 3 and Figure 4 As shown, the bottom end of the return pipe 40 is fixedly connected to the bottom end of the air guide pipe 107 through the one-way valve 41, and the top end of the return pipe 40 is fixedly connected to the sealing disc 304.

[0037] Specifically, in actual use, due to the relatively long length of the gas guide tube 107, a certain amount of gas will remain in the gas guide tube 107 after each stage of sampling, which will affect the subsequent sampling accuracy.

[0038] When sampling is required, first open the control valve 42, so that the liquid above the sealing plate 304 enters the bottom of the gas guide pipe 107 through the return pipe 40 and the one-way valve 41. Then, the control valve body opens. At this time, under the action of the gas, the liquid at the bottom of the gas guide pipe 107 is pushed upward, and the gas above the liquid is pushed upward. The gas will be discharged through the flow hole 307. When the liquid flows to the top of the gas guide pipe 107, the liquid will flow into the exhaust pipe 301 and press down on the sealing plate 304, causing the sealing plate 304 to move downward. The downward movement of the sealing plate 304 will drive the connecting rod 305 and the sealing plate 306 to move downward, so that the sealing plate 306 seals the flow hole 307.

[0039] Before sampling, the control valve is opened, and the inside of the gas guide tube is flushed with liquid to completely push out the residual gas from the previous sampling and discharge it through the flow hole. When the flushing liquid reaches the top of the exhaust stack, its own weight presses down on the sealing plate, driving the sealing plate to automatically close the flow hole and achieve airtight isolation. This process not only thoroughly removes pipeline residues and ensures the independence and accuracy of each gas sampling, but also significantly improves the accuracy of vertical stratified gas sampling.

[0040] In summary, the laboratory vertical flow constructed wetland vertical stratified sampling device of this application, by stratifying packing materials and three-phase separators within the experimental cylinder and combining them with a vertical flow water inlet method, realistically simulates the synergistic environment of water, solids, and gas in a constructed wetland. It utilizes equidistantly arranged sampling tubes to achieve fixed-point, undisturbed stratified sampling of water quality at different depths, and employs independent gas guide pipes and gas collection bags to collect gas generated from each layer separately, effectively avoiding cross-contamination between water and gas. Simultaneously, the gas outlet pipe maintains system pressure balance, ensuring stable operation. This design achieves synchronous, precise, and in-situ monitoring of pollutant degradation processes and microbial metabolic activities within the constructed wetland in the vertical direction, significantly improving the reliability of experimental data.

[0041] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0042] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0043] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A vertical flow constructed wetland vertical stratification sampling device in a laboratory, characterized in that, It comprises a hierarchical sampling assembly (10) and a support base (20), wherein, The hierarchical sampling assembly (10) is arranged on the support base (20); The hierarchical sampling assembly (10) comprises an experimental cylinder (101) mounted on the support base (20); A plurality of sampling tubes (102) are arranged equidistantly on the experimental cylinder (101); A plurality of three-phase separators (103) are arranged in the experimental cylinder (101), and the plurality of three-phase separators (103) are arranged alternately with the plurality of sampling tubes (102); A water inlet pipe (104) is fixedly mounted on the experimental cylinder (101) and located on the opposite side of the sampling tube (102); A water outlet pipe (105) is fixedly mounted on the experimental cylinder (101) and located above the plurality of sampling tubes (102); An air outlet pipe (106) is fixedly mounted on the surface of the experimental cylinder (101) and located on the opposite side of the water outlet pipe (105) and upward; A plurality of gas guide pipes (107) are fixedly mounted on the top of the plurality of separators (103); A plurality of gas collection bags (108) are arranged at the top of the plurality of gas guide pipes (107).

2. The vertically stratified sampling device for laboratory-scale vertical flow constructed wetlands according to claim 1, characterized in that The plurality of gas guide pipes (107) sequentially penetrate the three-phase separators (103) above the gas guide pipes (107) and extend to the outside of the experimental cylinder (101) through the gas guide pipes (107).

3. The vertically stratified sampling device for laboratory-scale vertical flow constructed wetlands according to claim 1, wherein, A plurality of rubber plugs are arranged on the plurality of sampling tubes (102) to seal the sampling tubes (102).

4. The vertically stratified sampling device for laboratory-scale vertical flow constructed wetlands according to claim 1, wherein, A plurality of separation mechanisms (30) are arranged on the top of the plurality of gas guide pipes (107); The separation mechanism (30) comprises an exhaust cylinder (301) mounted on the gas guide pipe (107); A connecting pipe (302) is fixedly mounted on one end of the exhaust cylinder (301); A plurality of push springs (303) are fixedly mounted on the surface of the exhaust cylinder (301) close to the gas guide pipe (107); A sealing disc (304) is fixedly mounted on one end of the plurality of push springs (303); A plurality of connecting rods (305) are fixedly mounted on the surface of the sealing disc (304); A blocking disc (306) is fixedly mounted on one end of the plurality of connecting rods (305); A plurality of flow holes (307) are arranged on the exhaust cylinder (301).

5. The vertically stratified sampling device for laboratory-scale vertical flow constructed wetlands according to claim 4, characterized in that One end of the gas guide pipe (107) is located in the interior of the exhaust cylinder (301), and the caliber of the gas guide pipe (107) is smaller than the caliber of the exhaust cylinder (301).

6. The vertically stratified sampling device for laboratory-scale vertical flow constructed wetlands according to claim 4, characterized in that, The sealing disc (304) is sleeved on the surface of the gas guide pipe (107), and the sealing disc (304) is in sealed sliding connection with the gas guide pipe (107).

7. The vertically stratified sampling device for laboratory-scale vertical flow constructed wetlands according to claim 4, characterized in that, The blocking disc (306) is located above the plurality of flow holes (307), and the blocking disc (306) is in sealed sliding connection with the exhaust cylinder (301).

8. The vertically stratified sampling device for laboratory-scale vertical flow constructed wetlands according to claim 4, characterized in that, A backflow pipe (40) is fixedly mounted on the exhaust cylinder (301), and a one-way valve (41) is fixedly mounted on the bottom end of the backflow pipe (40); A control valve (42) is fixedly mounted on the top end of the backflow pipe (40).

9. The vertically stratified sampling device for laboratory-scale vertical flow constructed wetlands according to claim 8, characterized in that, The bottom end of the backflow pipe (40) is fixedly connected with the bottom end of the air guide pipe (107) through the one-way valve (41), and the top end of the backflow pipe (40) is fixedly connected with the sealing disc (304).

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