Multifunctional sampling device for wetland soil greenhouse gas flux measurement

Abstract

The utility model discloses a multifunctional sampling device for measuring the flux of greenhouse gas in wetland soil. The multifunctional sampling device comprises a flux column, a sampling cover and a fixed lock catch, the flux column is a cylindrical pipe body, the bottom is chamfered so as to be conveniently inserted into soil, a plurality of substance exchange holes in the lower part can maintain the consistency of internal and external water levels and soil physicochemical properties, and an upper graduated scale is used for measuring the water level height and calculating the volume of an air chamber. The sampling cover is hermetically connected and matched with the flux column to form a gas chamber, and is provided with a gas sampling port and a gas pressure balance port which are respectively used for sampling gas and maintaining gas pressure balance. And the flux column exchanges substances with external soil and water through the substance exchange holes. The device is compact in structure and high in portability, is suitable for greenhouse gas flux monitoring of wetland soil such as mangrove forest and peat land, can effectively overcome the limitation of a traditional device in a complex environment, supports real-time measurement and sample collection, is suitable for various analysis methods, and provides an efficient and reliable tool for greenhouse gas emission research of a wetland ecosystem.

Description

Technical Field

[0001] The utility model relates to a gas sampling device, in particular to a multifunctional sampling device used for measuring greenhouse gas flux of wetland soil. Background Art

[0002] Wetland ecosystems are greenhouse gases (such as CO 2 , CH 4 and N 2 O) is an important source of emissions. Traditional greenhouse gas flux measurement devices have problems such as large size, complex operation, and lack of portability. They are difficult to carry in soft wetland swamps or mangrove soils. Therefore, these devices are usually limited to hard land such as forest soil and grassland soil, and are restricted when used in long-term flooded areas, especially in tidal wetlands or flooded environments. Therefore, it is of great significance to develop a portable and adaptable wetland greenhouse gas sampling device.

[0003] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Utility Model Content

[0004] The main purpose of the utility model is to overcome the defects existing in the above-mentioned background technology and provide a multifunctional sampling device for measuring greenhouse gas flux in wetland soil.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A multifunctional sampling device for measuring greenhouse gas flux in wetland soil, comprising:

[0007] The flux column is a cylindrical tube with a chamfered bottom for insertion into the soil. The lower part is provided with multiple holes for material exchange to maintain the consistency of the water level and soil physical and chemical properties inside and outside the flux column. The upper part is provided with a scale to measure the water level and calculate the volume of the air chamber.

[0008] The sampling cover is used to form a sealed connection with the flux column, and has a gas sampling port and a pressure balance port. The gas sampling port is used for gas sampling, and the pressure balance port is used to maintain the pressure balance inside and outside the flux column;

[0009] A fixed lock buckle, used to connect and fix the sampling cover to the flux column;

[0010] The flux column and the sampling cover cooperate to form an air chamber for collecting and measuring greenhouse gases, and the lower part of the air chamber exchanges substances with external soil and water through substance exchange holes.

[0011] Furthermore, the length of the flux column is 300-600 mm, the diameter of the material exchange holes is 25-35 mm, and the vertical spacing between adjacent holes is 45-55 mm.

[0012] Furthermore, the chamfer angle of the bottom of the flux column is 15°~20°.

[0013] Furthermore, the flux column is made of corrosion-resistant transparent acrylic material.

[0014] Furthermore, the air pressure balance port of the sampling cover is detachably connected to an air pressure balance tube, and the length of the air pressure balance tube is not less than 1.5 m.

[0015] Furthermore, the fixed lock includes a sampling cover fixed end, a flux column fixed end and a connecting piece, the connecting piece connects the sampling cover fixed end and the flux column fixed end, the connecting piece is a magnetic component or a Velcro strap, and is used for quick connection and disassembly of the sampling cover and the flux column.

[0016] Furthermore, a gas mixing fan and a battery box assembly are provided inside the sampling cover, and the battery box assembly supplies power to the gas mixing fan.

[0017] Furthermore, a clock is provided on the top of the sampling cover for recording the sampling time to calculate the gas emission flux per unit time.

[0018] Furthermore, the lower part of the sampling cover has a sealing edge, and the sealing edge is a circular ring, and the outer diameter of the ring matches the inner diameter of the flux column.

[0019] Furthermore, the gas sampling port is detachably mounted with a gas sampling tube, and the gas sampling tube is connected to a gas sampling needle tube with a Luer connector via a three-way valve with a Luer connector, so as to realize gas collection and transmission.

[0020] The utility model has the following beneficial effects:

[0021] The utility model provides a multifunctional sampling device for measuring greenhouse gas flux in wetland soil. The device optimizes the problems of large size, complex operation and insufficient portability of traditional greenhouse gas flux measuring devices in wetland environments. The split design achieves the characteristics of compact structure and light weight, which is convenient for monitoring greenhouse gas emission or absorption flux in wetland soils such as mangroves and peatlands. The bottom chamfer design of the flux column is convenient for insertion into the soil. The combination of the flux column and the sampling cover forms an air chamber, which can effectively maintain the consistency of internal and external water levels and soil physical and chemical properties. At the same time, the material exchange with the external soil and water body is achieved through the material exchange holes to ensure the stability of the sampling environment. In addition, the device supports real-time measurement and sample collection, adapts to a variety of analysis methods, and has strong environmental adaptability. It can be used in complex environments such as tidal wetlands. It is not only easy to carry in the field, but also can be quickly installed and maintained. It effectively overcomes the limitation of traditional devices that are not easy to carry in tidal wetland environments, and provides an efficient and convenient solution for measuring greenhouse gas flux in wetland soil.

[0022] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1A and Figure 1B They are schematic structural diagrams of the sampling cover of an embodiment of the utility model from two different perspectives.

[0024] Figure 2A and Figure 2B They are schematic structural diagrams of the flux column of an embodiment of the utility model from two different perspectives.

[0025] Figure 3 This is an exploded structural diagram of the multifunctional sampling device according to an embodiment of the utility model. DETAILED DESCRIPTION

[0026] The following is a detailed description of the implementation of the utility model. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the utility model.

[0027] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

[0028] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0030] See also Figures 1A to 3 The embodiment of the utility model provides a multifunctional sampling device for measuring greenhouse gas flux in wetland soil, including a flux column 14, a sampling cover 1 and a fixed lock: the flux column 14 is a cylindrical tube, the bottom of which is provided with a chamfer 17 for inserting into the soil, and the lower part is provided with a plurality of material exchange holes 15 for maintaining the water level and soil physical and chemical properties inside and outside the flux column consistent, and the upper part is provided with a scale 16 for measuring the water level height and calculating the volume of the air chamber; the sampling cover 1 is used to form a sealed connection with the flux column 14, and has a gas sampling port 2 and an air pressure balance port 3, the gas sampling port 2 is used for gas sampling, and the air pressure balance port 3 is used to maintain the air pressure balance inside and outside the flux column; the fixed lock is used to connect and fix the sampling cover 1 to the flux column 14; the flux column 14 and the sampling cover 1 cooperate to form an air chamber for collecting and measuring greenhouse gases, and the lower part of the air chamber exchanges materials with the external soil and water through the material exchange holes 15.

[0031] This device adopts a split design of flux column and sampling cover, which is convenient for rapid deployment and maintenance in complex terrain, greatly improving the portability and operational flexibility of the device. The chamfered design of the bottom of the flux column is convenient for insertion into the soil. The combination of the flux column and the sampling cover forms an air chamber, which can effectively maintain the consistency of internal and external water levels and soil physical and chemical properties. At the same time, it realizes material exchange with external soil and water bodies through material exchange holes to ensure the stability of the sampling environment. The structural design of the air chamber combined with the air pressure balance port can maintain internal and external air pressure balance during the sampling process. This device is not only easy to carry in the field, but also can be quickly installed and maintained, effectively overcoming the limitation of traditional devices that are not easy to carry in tidal wetland environments. It is especially suitable for wetland soil greenhouse gas flux determination in complex environments such as mangroves and peatlands, providing an efficient and reliable solution for greenhouse gas emission monitoring.

[0032] In a preferred embodiment, the length of the flux column 14 is 300-600 mm, the diameter of the material exchange hole 15 is 25-35 mm, and the vertical spacing between adjacent holes is 45-55 mm. The chamfer 17 at the bottom of the flux column 14 has an angle of 15°-20°. The flux column 14 is made of corrosion-resistant transparent acrylic material.

[0033] See also Figure 1A to Figure 1B In a preferred embodiment, the lower part of the sampling cover 1 has a sealing edge 11, and the sealing edge 11 is a circular ring, and the outer diameter matches the inner diameter of the flux column 14. The air pressure balance port 3 of the sampling cover 1 is connected to the air pressure balance tube 4 in a detachable manner, and the length of the air pressure balance tube 4 is not less than 1.5m. The gas sampling port 2 is detachably installed with a gas sampling tube 5, and the gas sampling tube 5 is connected to a gas sampling needle tube 10 with a Luer connector through a three-way valve 9 with a Luer connector, which is used to realize gas collection and transmission. A gas mixing fan 12 and a battery box assembly 13 are provided inside the sampling cover 1, and the battery box assembly 13 is powered by the gas mixing fan 12. A clock 6 is provided on the top of the sampling cover 1 for recording the sampling time to calculate the gas emission flux per unit time.

[0034] In a preferred embodiment, the fixing lock comprises a sampling cover fixing end 7, a flux column fixing end 18 and a connector 8, wherein the connector 8 connects the sampling cover fixing end 7 and the flux column fixing end 18, and the connector 8 is a magnetic component or a Velcro tape, which is used for the rapid connection and disassembly of the sampling cover 1 and the flux column 14. The device has a compact structure and is suitable for outdoor carrying, rapid installation and maintenance.

[0035] The specific embodiments of the present utility model are further described below.

[0036] like Figures 1A to 3 As shown, a multifunctional sampling device for measuring greenhouse gas flux in wetland soil is mainly composed of a flux column 14 and a sampling cover 1. A plurality of material exchange holes 15 are provided at the lower part of the flux column to ensure that the water level and soil physical and chemical properties inside and outside are consistent. A scale 16 is attached to the upper part, which can be used for water level measurement and air chamber volume calculation. The sampling cover includes a sealing edge 11, a gas sampling port 2 and a pressure balance port 3. A gas mixing fan 12, a battery box assembly 13 and a clock 6 are provided inside. The gas sampling port 2 can be detachably installed with a gas sampling tube 5. The gas sampling tube 5 is connected to a gas sampling needle tube 10 through a three-way valve 9 with a Luer connector. The pressure balance port 3 can be detachably installed with a pressure balance tube 4. The utility model has a compact structure and is easy to operate. It is suitable for the measurement of greenhouse gas flux in wetland soil such as mangroves. It can be quickly deployed in the field and achieve efficient sampling.

[0037] More specifically, the flux column 14 is a cylindrical tube with a length of 300 to 600 mm. The lower half of the flux column is provided with a plurality of material exchange holes 15 with a diameter of 25 to 35 mm, and the vertical spacing of the holes is 45 to 55 mm to ensure that the water level inside and outside the flux column and the physical and chemical properties of the soil are consistent. A scale 16 is attached to the upper part of the flux column for measuring the water level and calculating the volume of the air chamber. A chamfer 17 of 15° to 20° is provided at the bottom of the flux column for insertion into the soil. The flux column is made of corrosion-resistant transparent acrylic material, which is not easy to heat up under sunlight, can be deployed in seawater flooded areas for a long time, and is not easy to react chemically with seawater and barnacle glue.

[0038] The sampling cover 1 includes a cover body, a gas sampling port 2, an air pressure balance port 3 and a sealing edge 11. The gas sampling port 2 is a hole with a diameter of 6 mm, and a gas sampling tube 5 is detachably installed. The gas sampling tube 5 with a Luer connector is connected to a gas sampling needle tube 10 through a three-way valve 9 with a Luer connector, and in-situ sampling can be performed through the gas sampling needle tube 10. The air pressure balance port 3 is a hole with a diameter of 6 mm, and a pressure balance tube 4 is detachably connected to achieve air pressure balance inside and outside the device. The pressure balance tube 4 is detachable and made of Teflon tube material with low volatility, odorlessness and non-adsorbability, with a length of not less than 1.5m to ensure that gas turbulence interference is avoided when the air pressure is balanced. A gas mixing fan 12 and a battery box assembly 13 are provided inside the sampling cover, and a clock 6 is provided on the top of the sampling cover to record the sampling time. A gas mixing fan 12 with a power of 2-4 W is hung on the inside of the sampling cover, which is kept at a distance of more than 30 mm from the top of the cover to ensure that the gas in the gas chamber is mixed. The battery box assembly 13 is equipped with three 18650 batteries, which provide a 12V voltage and can provide the gas mixing fan 12 with a working time of not less than 10 hours. The sealing edge 11 at the bottom of the sampling cover is an acrylic ring with an outer diameter slightly smaller than the inner diameter of the flux column 14. It can be inserted into the flux column 14 to achieve basic sealing. After sealing, it can effectively reduce the convection exchange between the internal and external gases of the device.

[0039] The fixed lock comprises a sampling cover fixed end 7, a flux column fixed end 18 and a connector 8. The connector 8 can be a magnetic component or a Velcro tape, and its two ends can be fixed to the sampling cover fixed end 7 and the flux column fixed end 18 respectively, so as to realize the rapid connection and disassembly of the sampling cover and the flux column.

[0040] The three-way valve 9 is used on the gas collection pipe 5, which can be rinsed before gas collection to discharge 10-15mL of gas to prevent the gas at the inlet pipe from being effectively mixed with the gas in the box. Rinsing is usually performed 10-20 seconds before gas collection. First, the three-way valve is twisted to the upper and lower connections to draw 10-15mL of gas. Then the three-way valve is twisted to the upper side and connected to the branch to discharge the gas; during the period when no gas is collected, the valve can seal the gas path.

[0041] The pressure balance port 3 is connected to the pressure balance pipe 4 to prevent the convection exchange between the external air and the internal air (air leakage in the box). Collecting gas in a completely closed state will generate negative pressure, resulting in the generation of a "pump effect", which will accelerate the discharge of gas in the soil, thereby causing an overestimation of the emission. The combination of the pressure balance port and the pressure balance pipe can effectively avoid the generation of negative pressure, and at the same time, the pressure balance pipe can increase the length of the pipeline and avoid gas exchange (air leakage in the box).

[0042] Application examples:

[0043] Using a multifunctional sampling device, the flux column is deployed in wetland soil for a long period of time, and the sampling cap is connected to the needle tube for needle sampling.

[0044] (1) Device deployment

[0045] At least one day before the first experiment, the lower part of the flux column 14 is vertically inserted into the soil of the sample plot (the sample plot can be a mangrove wetland, salt marsh, long-term flooded forest, beach, etc.), ensuring that the material exchange hole 15 is covered by soil or submerged by water, so as to keep the internal and external water levels and soil physical and chemical properties consistent. The chamfer 17 design at the bottom of the flux column 14 helps it to be smoothly inserted into the soil and improve stability; if the material exchange hole 15 cannot be completely submerged, a flux column of a lower size can be selected according to the actual situation.

[0046] (2) Preparation before measurement.

[0047] Before conducting the experiment, it is necessary to fix one end of the connector 8 to the fixed end 7 of the sampling cover, and read the scale 16 data according to the soil or water level to determine the air chamber height H, and calculate the air chamber volume V in combination with the size of the flux column bottom area S. The measurement can only be started when H is greater than 15 cm. Install several batteries in the battery box assembly 13, and ensure that the gas mixing fan 12 can operate normally. Connect the gas sampling pipe 5 to the gas sampling port 2, and the gas sampling pipe 5 is connected to the three-way valve 9 with a Luer connector, and close the valve to ensure a certain air tightness. Connect the air pressure balance pipe 4 to the air pressure balance port 3 to balance the air pressure inside and outside the sampling device. Record the temperature T and pressure P inside the box at the time of sampling.

[0048] (3) Gas sampling and concentration measurement.

[0049] After turning on the power of the gas mixing fan 12 on the sampling cover 1, align the fixed end 7 of the sampling cover with the fixed end 18 of the flux column, then insert the sealing edge 11 of the sampling cover 1 into the top of the flux column 14, and fix the other end of the connector 8 to the fixed end 18 of the flux column to ensure that the sampling cover is firmly connected to the flux column (the fixing lock plays a key role). Read the time t shown on the clock 6 and record it. At t+60s, insert the gas sampling needle with a Luer connector into the three-way valve, open the valve and collect 30ml of gas and immediately close the valve, inject the gas into the pre-vacuumed sample bottle, and record the sample number; repeat the above operation at t+300 s, t+600s, t+900s, and t+1200s. Store the sample in a dark place and bring it back to the laboratory to measure the gas concentration (CO 2 , CH 4 and N 2 O). Based on the concentration and sampling time, the rate of change of gas concentration over time can be obtained. This rate of change can be used to calculate the greenhouse gas exchange at the water-air interface.

[0050] The above content is a further detailed description of the utility model in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the utility model is limited to these descriptions. For ordinary technicians in the technical field to which the utility model belongs, without departing from the concept of the utility model, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the utility model. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the scope of protection of the patent application.

Claims

1. A multifunctional sampling device for measuring greenhouse gas flux in wetland soil, characterized in that: include: The flux column is a cylindrical tube with a chamfered bottom for insertion into the soil. The lower part is provided with multiple holes for material exchange to maintain the consistency of the water level and soil physical and chemical properties inside and outside the flux column. The upper part is provided with a scale to measure the water level and calculate the volume of the air chamber. The sampling cover is used to form a sealed connection with the flux column, and has a gas sampling port and a pressure balance port. The gas sampling port is used for gas sampling, and the pressure balance port is used to maintain the pressure balance inside and outside the flux column; A fixed lock buckle, used to connect and fix the sampling cover to the flux column; The flux column and the sampling cover cooperate to form an air chamber for collecting and measuring greenhouse gases, and the lower part of the air chamber exchanges substances with external soil and water through substance exchange holes.

2. The multifunctional sampling device according to claim 1, characterized in that: The length of the flux column is 300-600 mm, the diameter of the material exchange holes is 25-35 mm, and the vertical spacing between adjacent holes is 45-55 mm.

3. The multifunctional sampling device according to claim 1, characterized in that: The chamfer angle of the bottom of the flux column is 15°~20°.

4. The multifunctional sampling device according to claim 1, characterized in that: The flux column is made of corrosion-resistant transparent acrylic material.

5. The multifunctional sampling device according to claim 1, characterized in that: The air pressure balance port of the sampling cover is connected to the air pressure balance tube in a detachable manner, and the length of the air pressure balance tube is not less than 1.5m.

6. The multifunctional sampling device according to claim 1, characterized in that: The fixed lock includes a sampling cover fixed end, a flux column fixed end and a connecting piece, wherein the connecting piece connects the sampling cover fixed end and the flux column fixed end, and the connecting piece is a magnetic component or a Velcro strap, which is used for quick connection and disassembly of the sampling cover and the flux column.

7. The multifunctional sampling device according to claim 1, characterized in that: A gas mixing fan and a battery box assembly are arranged inside the sampling cover, and the battery box assembly supplies power to the gas mixing fan.

8. The multifunctional sampling device according to claim 1, characterized in that: A clock is arranged on the top of the sampling cover for recording the sampling time so as to calculate the gas emission flux per unit time.

9. The multifunctional sampling device according to claim 1, characterized in that: The lower part of the sampling cover is provided with a sealing edge, and the sealing edge is a circular ring, and the outer diameter of the sealing edge matches the inner diameter of the flux column.

10. The multifunctional sampling device according to claim 1, characterized in that: The gas sampling port is detachably mounted with a gas sampling tube, and the gas sampling tube is connected to a gas sampling needle tube with a Luer connector via a three-way valve with a Luer connector, so as to realize gas collection and transmission.

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