A device for measuring the rate of emission of greenhouse gases from soil

Abstract

The utility model belongs to the technical field of greenhouse gas collection, concretely is a kind of soil greenhouse gas emission rate measuring device, main body A is the hollow structure of lower end sealing, upper end opening, and main body A is filled with soil for culture;Main body B is the hollow structure of upper end sealing, lower end opening, and the lower end sealing of main body B is fixedly connected with the annular ring for being connected with main body A, and main body B is equipped with suction tube, one end of suction tube is communicated with the inside of main body B, the other end is connected with needle tube, and valve is equipped on suction tube;The lower end of support rod is installed on base, and the upper end of support rod is equipped with hanging rod, and the tank body with culture soil is hung on hanging rod after being connected with cavity.The utility model is applicable to small soil culture test, and the emission rate of soil greenhouse gas can be collected and measured by the measuring device, the culture test demand can be satisfied, it is simple in structure, high in precision, easy to operate, can be reused, and widely applicable.

Description

Technical Field

[0001] This invention belongs to the field of greenhouse gas collection technology, specifically a soil greenhouse gas emission rate measuring device. Background Technology

[0002] Increased concentrations of greenhouse gases (CO2, CH4, N2O) are a major cause of global warming, and soil is a significant source of these gases. Investigating soil greenhouse gas emissions through cultivation experiments is a common technique used by researchers. However, currently used greenhouse gas cultivation devices are mostly made of glass or rigid plastic, which presents several problems, such as: difficulty in gas extraction; easy disturbance to soil conditions and soil microorganisms; small device size when the amount of cultured soil is small, making it difficult to collect sufficient gas for measurement; and the tendency for displacement methods to cause changes in gas concentration within the cultivation device. Therefore, there is an urgent need for a cultivation experimental device that can solve all of the above problems, meet the requirements of cultivation experiments with different amounts of soil, minimize disturbance to the soil conditions within the cultivation device, and simultaneously extract sufficient gas for measurement and analysis. Utility Model Content

[0003] To address the problems of existing devices used for cultivation experiments, such as difficulty in air extraction, significant soil disturbance, and susceptibility of gases within the device to interference, the purpose of this invention is to provide a soil greenhouse gas emission rate measuring device.

[0004] The objective of this utility model is achieved through the following technical solution:

[0005] This utility model includes a tank, a cavity, and a support. The tank includes a main body A, which is a hollow structure with a sealed lower end and an open upper end, and is filled with culture soil. The cavity includes a ring and a deformable main body B, which is also a hollow structure with a sealed upper end and an open lower end. The lower end of the main body B is sealed and fixedly connected to the ring for connection with the main body A. The main body B is provided with an exhaust pipe, one end of which communicates with the interior of the main body B, and the other end of which is connected to a needle tube for collecting greenhouse gases. A valve is provided on the exhaust pipe. The support includes a base, a support rod, and a hanging rod. The lower end of the support rod is mounted on the base, and the upper end of the support rod is provided with a hanging rod. The tank containing the culture soil is connected to the cavity and then suspended on the hanging rod.

[0006] Wherein: the main body A is a cylinder made of transparent glass, and the upper opening of the main body A is provided with external threads.

[0007] The main body B is a cylindrical body made of polyethylene, and the ring is made of glass. The ring is sealed to the inner wall of the lower opening of the main body B, and the inner surface of the ring is provided with internal threads.

[0008] The upper end of the main body B is a PVC sheet, and the upper surface of the PVC sheet is provided with a hanging ring for hanging on a hanging rod.

[0009] The support rod is a telescopic rod that can be height adjusted. Once the height is adjusted to the correct position, it is locked in place by a locking bolt on the telescopic rod.

[0010] The hanging rod includes a vertical rod and multiple horizontal rods. The middle of the vertical rod is fixedly connected to the upper end of the support rod. Multiple horizontal rods are evenly arranged along the length of the vertical rod. Each horizontal rod is an integral structure with the vertical rod, or the middle of each horizontal rod is fixedly connected to the vertical rod. The two ends of each horizontal rod are used to suspend the connected tank and cavity.

[0011] The main body A and the ring partially overlap after being connected.

[0012] The advantages and positive effects of this utility model are as follows:

[0013] When collecting gas from the measuring device, the polyethylene body B deforms and shrinks to ensure that the gas pressure inside the device matches the external pressure, thus avoiding any impact on the soil and soil microorganisms. Simultaneously, almost all the gas inside the device can be extracted for gas measurement, making extraction easy and minimizing interference with the gas concentration. After gas extraction, the device can be reset. Furthermore, the overall cylindrical shape of the device allows for the calculation of gas production volume using a known internal volume. This invention features a simple overall structure, is reusable, and can be used for cultivation experiments involving 5-600g of soil, meeting the needs of most cultivation experiments. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the tank and cavity of this utility model;

[0015] Figure 2 for Figure 1 A schematic diagram of the structure of the glass ring in the middle;

[0016] Figure 3 This is a schematic diagram of the structure of the bracket of this utility model;

[0017] Wherein: 1 is the tank body, 11 is the main body A, 12 is the external thread; 2 is the cavity, 21 is the main body B, 22 is the glass ring, 23 is the internal thread, 24 is the lifting ring, 25 is the PVC (polyvinyl chloride) sheet, 26 is the valve, 27 is the air extraction pipe; 3 is the bracket, 31 is the base, 32 is the locking bolt, 33 is the support rod, 34 is the hanging rod, 35 is the vertical rod, and 36 is the horizontal rod. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] like Figures 1-3 As shown, this utility model includes a tank 1, a cavity 2, and a support 3. The tank 1 includes a main body A11, which is a hollow structure with a sealed lower end and an open upper end. The main body A11 is filled with culture soil. The cavity 2 includes a ring 22 and a deformable main body B21, which is a hollow structure with a sealed upper end and an open lower end. The lower end of the main body B21 is sealed and fixed with a ring 22 for connecting to the main body A11. The main body B21 is provided with an exhaust pipe 27. One end of the exhaust pipe 27 is connected to the interior of the main body B21, and the other end of the exhaust pipe 27 is connected to a needle for collecting greenhouse gases. A valve 26 is provided on the exhaust pipe 27. The support 3 includes a base 31, a support rod 33, and a hanging rod 34. The lower end of the support rod 33 is installed on the base 31, and the upper end of the support rod 33 is provided with a hanging rod 34. The tank 1 containing culture soil is connected to the cavity 2 and then suspended on the hanging rod 34.

[0020] In this embodiment, the main body A11 is a cylinder made of transparent glass, with a height of 3-7cm and a diameter of 2-5cm. The upper opening of the main body A11 is provided with an external thread 12. The container 1 can be filled with a maximum of 600g of culture soil.

[0021] The main body B21 in this embodiment is a cylindrical material made of polyethylene, which has good flexibility and deformability, with a height of 9-18cm and a diameter of 2-5cm.

[0022] In this embodiment, the ring 22 is made of glass, with a height of 1-2 cm and a diameter of 2-5 cm. The ring 22 is sealed to the inner wall of the lower opening of the main body B21, and the inner surface of the ring 22 is provided with internal threads 23. The upper end of the main body B21 is a PVC sheet 25 with a diameter of 2-5 cm; a hanging ring 24 for suspending on the hanging rod 34 is provided in the middle of the upper surface of the PVC sheet 25.

[0023] In this embodiment, one end of the air extraction pipe 27 is located at the middle position in the height direction of the main body B21, and the opening and closing of the air extraction pipe 27 is controlled by the valve 26.

[0024] In this embodiment, the support rod 33 is a telescopic rod that can be height adjusted. Once the height is adjusted to the correct position, it is locked by the locking bolt 32 on the telescopic rod.

[0025] The hanging rod 34 in this embodiment includes a vertical rod 35 and multiple horizontal rods 36. The middle of the vertical rod 35 is fixedly connected to the upper end of the support rod 33. Multiple horizontal rods 36 are evenly arranged along the length of the vertical rod 35. Each horizontal rod 36 is an integral structure with the vertical rod 35, or the middle of each horizontal rod 36 is fixedly connected to the vertical rod 35. The two ends of each horizontal rod 36 are used to suspend the connected tank 1 and cavity 2.

[0026] The measurement method of the soil greenhouse gas emission rate measuring device of this utility model is as follows:

[0027] When collecting greenhouse gases (such as CO2, CH4, N2O), culture soil is placed in the main body A11 of tank 1. Then, cavity 2 is installed above tank 1. The internal thread 23 on the lower ring 22 of cavity 2 is threaded to the external thread 12 on the upper end of main body A11, with partial overlap between main body A11 and ring 22 (overlap can be 0.5 cm). Valve 26 is closed, and the assembled tank 1 and cavity 2 are suspended from the crossbar 36 of hanging rod 34 via hanging ring 24 and placed in an incubator for a set incubation time. Afterward, valve 26 is opened, and gas is collected from inside cavity 2 through a syringe and extraction tube 27. Since the incubation experiment is conducted in an incubator, the temperature recorded during gas collection is the incubator's set temperature. The collected gas is used to determine greenhouse gas concentrations. By measuring the greenhouse gas concentrations collected over a specific incubation period, the soil greenhouse gas emission rate during the incubation experiment can be calculated. The formula for calculating the soil greenhouse gas emission rate during the incubation experiment is:

[0028]

[0029] F: Emission rate of greenhouse gases (CO2, CH4, N2O) from soil (μg g) -1 h -1 );

[0030] A1: Concentration (ppm) of greenhouse gases (CO2, CH4, N2O) in cavity 2 after soil incubation;

[0031] A2: Concentration (ppm) of greenhouse gases (CO2, CH4, N2O) in cavity 2 at the start of soil incubation;

[0032] P: Atmospheric pressure (Pa) of the soil culture environment;

[0033] P0: Standard atmospheric pressure (Pa);

[0034] 273: Conversion factor between Kelvin temperature (K) and Celsius temperature (°C);

[0035] T: Temperature inside the incubator (°C);

[0036] B: Molecular weight (g / mol) of greenhouse gases (CO2, CH4, N2O) -1 );

[0037] 22.4: Molar volume of a gas under standard conditions (L mol) -1 );

[0038] 3.14: The value of pi (π) is retained to the first two digits;

[0039] R: Radius of the main body B21 (cm);

[0040] G: The height (cm) from the top layer of soil filled in the main body A11 to the top of the PVC sheet 25 of the main body B21;

[0041] 10 -3 : The coefficient for converting cubic centimeters to liters;

[0042] M: Weight of soil filled (g, dry soil);

[0043] H: Incubation time (h).

[0044] Experimental Example 1

[0045] Culture soil was filled into the main body A11, which was 3.5 cm high and 2 cm in radius; the soil weight was 45 g, and the field bulk density of the soil at the time of collection was 1.2 g / cm³. 3 To maintain the same bulk density as the field soil, the soil in the main body A11 was compacted to a filling height of 3cm.

[0046] After the soil filling is completed, connect the internal thread 23 of the lower ring 22 of the main body B21 to the external thread 12 of the upper part of the main body A11, with the connection overlapping by 0.5cm. The radius of the main body B21 is 2cm and the height is 9cm. The measuring device is in a sealed state, and valve 26 is closed. Suspend the assembled measuring device on the crossbar 36 of the hanging rod 34 through the hanging ring 24, and place it in an incubator for incubation. The temperature inside the incubator is 25℃. After incubation for 5 hours, collect the gas inside the cavity 2 through the exhaust pipe 27, measure the N2O concentration of the collected gas, and calculate the soil N2O emission rate using the following formula:

[0047]

[0048] Before incubation, the gas in the apparatus was air, and the N2O concentration A2 was the N2O concentration in the air (0.3 ppm). After 5 hours of incubation, the N2O concentration A1 was 1.3 ppm. The laboratory was located at a low altitude, so the default P / P0 = 1. The incubator temperature was 25℃, and the molecular weight of N2O was 44 g mol. -1 The radius of the main body B21 is 2cm, the height is 9cm, the soil mass is 45g, and the cultivation time is 5h. Substituting the above parameters, the calculation is as follows:

[0049]

[0050] Experiment Example 2

[0051] Culture soil was filled into the main body A11, which was 3.5 cm high and 2 cm in radius; the soil weight was 45 g, and the field bulk density of the soil at the time of collection was 1.2 g / cm³.3 To maintain the same bulk density as the field soil, the soil in the main body A11 was compacted to a filling height of 3cm.

[0052] After the soil filling is completed, connect the internal thread 23 of the lower ring 22 of the main body B21 to the external thread 12 of the upper part of the main body A11, with the connection overlapping by 0.5cm. The radius of the main body B21 is 2cm and the height is 9cm. The measuring device is in a sealed state, and valve 26 is closed. Suspend the assembled measuring device on the crossbar 36 of the hanging rod 34 through the hanging ring 24, and place it in an incubator for incubation. The temperature inside the incubator is 25℃. After incubation for 5 hours, collect the gas inside the cavity 2 through the exhaust pipe 27, measure the CO2 concentration of the collected gas, and calculate the soil N2O emission rate using the following formula:

[0053]

[0054] Before incubation, the gas inside the apparatus was air, and the CO2 concentration A2 was the CO2 concentration in the air (450 ppm). After 5 hours of incubation, the CO2 concentration A1 was 830 ppm. The laboratory was located at a low altitude, so P / P0 was assumed to be 1. The incubator temperature was 25℃, and the molecular weight of CO2 was 44 g mol. -1 The radius of the main body B21 is 2cm, the height is 9cm, the soil mass is 45g, and the cultivation time is 5h. Substituting the above parameters, the calculation is as follows:

[0055]

[0056] Experimental Example 3

[0057] Culture soil was filled into the main body A11, which was 3.5 cm high and 2 cm in radius; the soil weight was 45 g, and the field bulk density of the soil at the time of collection was 1.2 g / cm³. 3 To maintain the same bulk density as the field soil, the soil in the main body A11 was compacted to a filling height of 3cm.

[0058] After the soil filling is completed, connect the internal thread 23 of the lower ring 22 of the main body B21 to the external thread 12 of the upper part of the main body A11, with the connection overlapping by 0.5cm. The radius of the main body B21 is 2cm and the height is 9cm. The measuring device is in a sealed state, and valve 26 is closed. Suspend the assembled measuring device on the crossbar 36 of the hanging rod 34 through the hanging ring 24, and place it in an incubator for incubation. The temperature inside the incubator is 25℃. After incubation for 30 hours, collect the gas inside the cavity 2 through the exhaust pipe 27, measure the CH4 concentration of the collected gas, and calculate the soil CH4 emission rate using the following formula:

[0059]

[0060] Before incubation, the gas in the apparatus was air, and the CH4 concentration A2 was the CH4 concentration in the air (0 ppm). After 30 hours of incubation, the CH4 concentration A1 was 45 ppm. The laboratory was located at a low altitude, so the default P / P0 = 1. The incubator temperature was 25℃, and the molecular weight of CH4 was 16 g mol. -1 The radius of the main body B21 is 2cm, the height is 9cm, the soil mass is 45g, and the cultivation time is 5h. Substituting the above parameters, the calculation is as follows:

[0061]

[0062] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural exchanges made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A soil greenhouse gas emission rate measurement device, characterized by: The system includes a tank (1), a cavity (2), and a support (3). The tank (1) includes a main body A (11), which is a hollow structure with a sealed lower end and an open upper end. The main body A (11) is filled with soil for cultivation. The cavity (2) includes a ring (22) and a deformable main body B (21), which is a hollow structure with a sealed upper end and an open lower end. The lower end of the main body B (21) is sealed and fixed with a ring (22) for connecting to the main body A (11). The main body B (21) is provided with an air extraction pipe. 27), one end of the exhaust pipe (27) is connected to the interior of the main body B (21), and the other end of the exhaust pipe (27) is connected to a needle tube for collecting greenhouse gases. A valve (26) is provided on the exhaust pipe (27); the bracket (3) includes a base (31), a support rod (33) and a hanging rod (34). The lower end of the support rod (33) is installed on the base (31), and the upper end of the support rod (33) is provided with a hanging rod (34). The tank (1) containing the culture soil is connected to the cavity (2) and then suspended on the hanging rod (34).

2. The soil greenhouse gas emission rate measuring device according to claim 1, characterized in that: The main body A (11) is a cylinder made of transparent glass, and the upper opening of the main body A (11) is provided with an external thread (12).

3. The soil greenhouse gas emission rate measuring device according to claim 1, characterized in that: The main body B (21) is a cylindrical body made of polyethylene, and the ring (22) is made of glass. The ring (22) is sealed to the inner wall of the lower opening of the main body B (21), and the inner surface of the ring (22) is provided with internal threads (23).

4. The soil greenhouse gas emission rate measuring device according to claim 1, characterized in that: The upper end of the main body B (21) is a PVC sheet (25), and the upper surface of the PVC sheet (25) is provided with a hanging ring (24) for hanging on the hanging rod (34).

5. The soil greenhouse gas emission rate measuring device according to claim 1, characterized in that: The support rod (33) is a telescopic rod that can be height adjusted. When the height is adjusted to the correct position, it is locked by the locking bolt (32) on the telescopic rod.

6. The soil greenhouse gas emission rate measuring device according to claim 1, characterized in that: The hanging rod (34) includes a vertical rod (35) and multiple horizontal rods (36). The middle of the vertical rod (35) is fixed to the upper end of the support rod (33). Multiple horizontal rods (36) are evenly arranged along the length of the vertical rod (35). Each horizontal rod (36) is an integral structure with the vertical rod (35), or the middle of each horizontal rod (36) is fixed to the vertical rod (35). The two ends of each horizontal rod (36) are used to suspend the connected tank (1) and cavity (2).

7. The soil greenhouse gas emission rate measuring device according to claim 1, characterized in that: The main body A (11) and the ring (22) partially overlap after being connected.

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