A device for measuring water-atmosphere interface greenhouse gases during water level drawdown and methods of use thereof

Abstract

Reservoirs, as an important way of human transforming nature, account for 4% of CO2 and 20% of CH4 in anthropogenic emissions. According to the operation characteristics of reservoirs and the generation rules of greenhouse gases in sediments, CO2 and CH4 generated in sediments will be released obviously during the drainage period, and the annual greenhouse gas emissions of reservoirs are mainly from this period. Therefore, the patent is about a device and a measuring method for accurately quantifying greenhouse gas emissions during the water level drawdown process, which will provide technical support for reservoir carbon cycle. A device for measuring greenhouse gases at the water-air interface during the water level drawdown process, comprising a columnar body, one side of the columnar body is provided with a scale, the inner wall of the columnar body is provided with a foam plate, the foam plate is connected with a water pumping port, the water pumping port is connected with a TPU pipe inlet, one end of a water pump is connected in parallel with a water quality analyzer and an inlet of a water-gas separation device, and a gas outlet of the water-gas separation device is connected with a gas analyzer.

Description

Technical Field

[0001] This invention relates to the field of carbon cycling in aquatic ecosystems, and more specifically to an apparatus and method for measuring greenhouse gases at the water-air interface during water level decline. Background Technology

[0002] CO2 and CH4 are important greenhouse gases in reservoir water, mainly originating from sediments. However, the release of greenhouse gases into the atmosphere is closely related to changes in water level. Normally, a small portion of greenhouse gases produced by sediments is transported to the water-air interface and released into the atmosphere. However, a drop in water level significantly promotes the upward diffusion of greenhouse gases or their upward transport in the form of bubbles.

[0003] Currently, there is no device that can accurately quantify the amount of greenhouse gas released at the water-air interface in response to changes in water level. Studies have shown that anthropogenic greenhouse gas emissions are a major cause of frequent extreme weather events. Of these, reservoir CO2 accounts for approximately 4% of anthropogenic emissions, while CH4 accounts for as much as 20%. Therefore, this device was invented to measure the amount of greenhouse gases released when reservoir water levels drop, providing a scientific basis for carbon emission reduction in reservoirs.

[0004] Reference article for water-gas separator 15: A fast-response automated gas equilibrator (FaRAGE) for continuous in situ measurement of CH4 and CO2 dissolved in water. Summary of the Invention

[0005] This invention aims to solve the problem of accurately measuring the maximum total emission and maximum emission rate of greenhouse gases CO2 and CH4 from sediments during water level drops. It also addresses the issue of measurement deviations caused by device leakage during sediment greenhouse gas emissions.

[0006] To solve the above problems, this application provides the following technical solution:

[0007] A device for measuring greenhouse gases at the water-air interface during water level drop includes a columnar body with a scale on one side. A foam board is installed on the inner wall of the columnar body, and the foam board is connected to a water inlet. The water inlet is connected to the inlet of a TPU tube, and the detection outlet of the TPU tube is connected to the inlet of a water pump. One end of the water pump outlet is connected in parallel to the inlet of a water quality analyzer and a water-gas separator. The gas outlet of the water-gas separator is connected to the gas analyzer.

[0008] The water inlet is connected to a spiral telescopic coiled TPU tube to adjust the height of the water inlet when the water level drops.

[0009] The inner wall of the column is attached to the outer wall of the foam board.

[0010] The foam board is equipped with a counterweight, which is connected to the water inlet.

[0011] The TPU tube has a retractable spring tube at one end.

[0012] One end of the atmospheric branch of the TPU tube is connected to a three-way valve.

[0013] The weight of the counterweight accounts for 10% to 12% of the drainage capacity of the foam board.

[0014] The counterweight is made of stainless steel.

[0015] The method of using the device for measuring greenhouse gases at the water-air interface during water level drop includes the following steps:

[0016] S1. After mixing the sediment, put it into an acrylic column 3 and let it stand.

[0017] S2. Use a syringe to add water to the upper surface of the sediment along the inner wall of columnar body 3;

[0018] S3. Place the water inlet 10 on the foam board into contact with the water surface;

[0019] S4. Turn on water pump 13 to pump water. When there are no air bubbles in the water pipe, turn on the multi-parameter water quality analyzer 14, water-gas separation device 15 and greenhouse gas analyzer 17 to measure the concentration of CO2 and CH4 in the water, and simultaneously time and measure the distance of water level drop.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. This invention generates CO2 and CH4 through sediments, and slowly pumps water to achieve a uniform drop in water level. This allows the water level to reflect the CO2 and CH4 emissions from the water surface during the drop, thereby accurately assessing the carbon emissions from the reservoir.

[0022] 2. This invention can accurately and in real time reflect the response relationship between water level changes and the concentration of greenhouse gases at the water-air interface and time.

[0023] 3. This invention can explore the relationship between the concentration of greenhouse gases on the water surface and the specific numerical changes in water level drop. It accurately quantifies the distance of water level drop and the corresponding concentration of greenhouse gases on the water surface;

[0024] 4. This invention uses an acrylic device with a known regular shape and size, which facilitates the calculation of greenhouse gas flux over water surfaces.

[0025] 5. The three-way valve configured in this invention can prevent backflow of the water quality analyzer and water-air separation device, and facilitates venting, which is conducive to ensuring the airtightness of the entire system by setting the water inlet to be close to the water surface. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the device for measuring changes in sediment water level and greenhouse gas emissions according to the present invention.

[0027] Figure 2 This is a schematic diagram of the device for measuring changes in sediment water level and greenhouse gas emissions after water injection, according to the present invention.

[0028] Figure labels: Sediment 1, Sediment-water interface 2, Columnar body 3, Water body 4, Scale 5, Direction of water level drop 6, Water surface 7, Foam board 8, Counterweight 9, Pump outlet 10, Water flow direction 11, TPU pipe 12, Three-way valve 1201, Spring tube 1202, Atmospheric branch pipe 1203, Water pump 13, Water quality analyzer 14, Water-gas separator 15, Airflow direction 16, Gas analyzer 17. Detailed Implementation

[0029] Example 1

[0030] like Figures 1-2 As shown, sediment 1, sediment-water interface 2, columnar body 3 is a regularly shaped acrylic columnar body, filtration water 4, scale 5, water level drop direction 6, water surface 7, foam board 8 has an outer diameter slightly smaller than the inner diameter of the regularly shaped acrylic columnar body 3, counterweight 9, water inlet 10, water flow direction 11, TPU pipe 12, water pump 13 is a water pump with a fixed flow rate, water quality analyzer 14 is a multi-parameter water quality analyzer, water-gas separation device 15, airflow direction 16, and gas analyzer 17 is a greenhouse gas analyzer.

[0031] like Figure 1 The diagram shows a device for measuring greenhouse gases at the water-air interface during water level drop. Sediment 1 produces greenhouse gases; the sediment-water interface 2 is the interface through which greenhouse gases from the sediment enter the water body; regularly shaped acrylic columnar bodies 3 facilitate the calculation of sediment and water volumes and the verification of water level drop distance; filtered water 4 acts as a carrier for greenhouse gases to be transported to the water surface; a scale 5 is used to accurately monitor the water level drop distance; the water surface 7 is the interface through which greenhouse gases enter the atmosphere; a foam board 8 connects to the pump inlet 10 to prevent greenhouse gas leakage; a counterweight 9 ensures that the foam board 8 completely covers and contacts the water surface 7; TPU tubing 12 connects the various components to ensure no leakage of water or gas; a fixed-flow water pump 13 pumps water; a multi-parameter water quality analyzer 14 monitors the physicochemical properties of the water; and a combination of a water-air separation device 15 and a greenhouse gas analyzer 17 is used to indirectly measure the concentration of greenhouse gases at the water surface.

[0032] An apparatus for measuring greenhouse gases at the water-air interface during water level drop includes a columnar body 3, a scale 5 on one side of the columnar body 3, a foam board 8 on the inner wall of the columnar body 3, the foam board 8 being connected to a water inlet 10, the water inlet 10 being connected to the inlet of a TPU tube 12, the detection outlet of the TPU tube 12 being connected to the inlet of a water pump 13, one end of the outlet of the water pump 13 being connected in parallel to the inlet of a water quality analyzer 14 and a water-gas separator 15, and the gas outlet of the water-gas separator 15 being connected to a gas analyzer 17.

[0033] The water inlet 10 is connected to a spiral telescopic coiled TPU tube 12 to adapt to the height adjustment of the water inlet 10 when the water level drops.

[0034] The inner wall of the columnar body 3 is attached to the outer wall of the foam board 8.

[0035] The foam board 8 is equipped with a counterweight 9, which is connected to the water inlet 10.

[0036] The TPU tube 12 has a retractable spring tube 1202 at one end.

[0037] One end of the atmospheric branch pipe 1203 of the TPU tube 12 is connected to a three-way valve 1201.

[0038] The weight 9 accounts for 10% to 12% of the drainage capacity of the foam board 8.

[0039] The counterweight 9 is made of stainless steel.

[0040] A method for using an apparatus for measuring greenhouse gases at the water-air interface during a water level drop, comprising the following steps:

[0041] S1. After mixing the sediment to be tested, put it into an acrylic columnar body 3 and let it stand for 7 days.

[0042] S2. Use a syringe to add water to the upper surface of the sediment along the inner wall of columnar body 3;

[0043] S3. Place the water inlet 10 on the foam board into contact with the water surface;

[0044] S4. Turn on water pump 13 to pump water. When there are no air bubbles in the water pipe, turn on the multi-parameter water quality analyzer 14, water-gas separation device 15 and greenhouse gas analyzer 17 to measure the concentration of CO2 and CH4 in the water, and simultaneously time and measure the distance of water level drop.

[0045] In this invention, the water level in columnar body 3 is 1m to 1.5m.

[0046] If the counterweight 9 is too heavy (more than 12%), it will not be conducive to the reset of the spring tube 1202. If the counterweight 9 is too light, the water will not be able to adhere to the water inlet 10 and the foam board 8. As a result, when the water level drops during the measurement process, the foam board 8 will be suspended in the air while adhering to the inner wall of the columnar body 3. When the foam board 8 is suspended, it will tilt downward and cause side leakage, resulting in air leakage.

[0047] A retractable spring tube 1202 is provided at one end of the TPU tube 12, allowing the TPU tube 12 to descend along the water surface while adhering to the surface, ensuring airtightness during the measurement process. One end of the spring tube 1202 is connected to the suction port and the counterweight 9, ensuring that the foam board is in close contact with the water surface below, preventing air leakage and making the measurement results more accurate. A three-way valve 1201 is connected to one end of the TPU tube 12; after the test is completed, the three-way valve 1201 is rotated to open the atmospheric branch pipe 1203 of the TPU tube 12 to the atmosphere.

[0048] Preferably, column 3 is purchased from Henan Shengyu Plastics Co., Ltd., model: large acrylic column tube. The inner diameter of column 3 is 490mm. Preferably, the inner wall of column 3 is made of acrylic material.

[0049] Preferably, the counterweight 9 is purchased from Shenzhen Kede Technology Co., Ltd., with a diameter of 200mm, a thickness of 10mm, and is made of stainless steel.

[0050] Preferably, foam board 8 was purchased from Jiaozuo Xinlv Foam Board Co., Ltd., with a diameter of 488mm and a thickness of 20mm.

[0051] Preferably, TPU tube 12 was purchased from Shunping County Zhongxing Plastic Products Co., Ltd., made of TPU material, model: diameter 10mm, thickness 2mm.

[0052] Preferably, the water pump 13 is purchased from Grundfos Water Pumps (Suzhou) Co., Ltd., with a flow rate of 0ml / min to 2000ml / min.

[0053] Preferably, the multi-parameter water quality analyzer 14 was purchased from Xylem Inc. in the United States, model YSI EXO.

[0054] Preferably, the gas analyzer 17 is purchased from Picarro Corporation of the United States, model G2201-i greenhouse gas analyzer.

[0055] Preferably, the water pump 13, water quality analyzer 14, water-gas separator 15 and gas analyzer 17 are powered by an external power source.

[0056] This invention can be applied to the measurement of sludge sediment at the bottom of reservoirs, and can also be used for the detection of CO2 and CH4 in the decomposition process of other organic matter. The detection is convenient and the data is accurate.

[0057] The device in this invention can calculate the change in greenhouse gas flux based on greenhouse gas concentration data, the inner diameter of a regularly shaped acrylic column, the distance of water level drop, and the corresponding time data, so as to reflect its response relationship with the distance of water level drop.

Claims

1. An apparatus for measuring greenhouse gases at the water-air interface during a drop in water level, comprising a columnar body (3), characterized in that, A scale (5) is provided on one side of the column (3), and a foam board (8) is installed on the inner wall of the column (3). The foam board (8) is connected to the water inlet (10). The water inlet (10) is connected to the inlet of the TPU tube (12). The detection outlet of the TPU tube (12) is connected to the inlet of the water pump (13). One end of the outlet of the water pump (13) is connected in parallel to the inlet of the water quality analyzer (14) and the water-gas separator (15). The gas outlet of the water-gas separator (15) is connected to the gas analyzer (17). The water inlet (10) is connected to a spiral telescopic coiled TPU tube (12) to adapt to the height adjustment of the water inlet (10) when the water level drops; a counterweight (9) is installed on the foam board (8), and the counterweight (9) is connected to the water inlet (10); the mass of the counterweight (9) accounts for 10% to 12% of the drainage of the foam board (8).

2. The apparatus for measuring greenhouse gases at the water-air interface during a water level drop, as described in claim 1, is characterized in that... The inner wall of the column (3) is attached to the outer wall of the foam board (8).

3. The apparatus for measuring greenhouse gases at the water-air interface during a water level drop, as described in claim 1, is characterized in that... The TPU tube (12) has a retractable spring tube (1202) at one end.

4. The apparatus for measuring greenhouse gases at the water-air interface during a water level drop, as described in claim 1, is characterized in that... One end of the atmospheric branch pipe (1203) of the TPU tube (12) is connected to a three-way valve (1201).

5. The apparatus for measuring greenhouse gases at the water-air interface during a water level drop, as described in claim 1, is characterized in that... The counterweight (9) is made of stainless steel.

6. A method of using the apparatus for measuring greenhouse gases at the water-air interface during a water level drop, as described in any one of claims 1 to 5, characterized in that... Includes the following steps: S1. After mixing the sediment, put it into the column (3) and let it stand. S2. Use a syringe to add water to the upper surface of the sediment along the inner wall of the columnar body (3); S3. Place the water inlet (10) on the foam board into contact with the water surface; S4. Turn on the water pump (13) to pump water. When there are no air bubbles in the water pipe, turn on the multi-parameter water quality analyzer (14), water-gas separation device (15), and gas analyzer (17) to measure the concentration of CO2 and CH4 in the water, and simultaneously time and measure the distance of water level drop.

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