Device for collecting marine micro-layer VOCs gas and estimating sea-air exchange flux

Abstract

This invention discloses a device for collecting VOCs gas in the marine micro-surface layer and estimating air-sea exchange flux, belonging to the field of marine atmospheric pollution monitoring technology. The device includes a gas sampling port, a nitrogen port, and a gas outlet on the inlet cavity and top plate. An underwater drive device is installed in the lower section of the inlet cavity. The gas sampling port is connected to the gas collection device, and the underwater drive device is connected to the bottom of a pontoon to drive the pontoon to move in the sea. Gas collection devices are installed in the first and second sealed cavities within the pontoon, and a water sample collection device is installed in the third sealed cavity. The bottom of the pontoon is connected to the underwater drive device, which is electrically connected to a controller. The controller enables the underwater drive device to move the pontoon in the sea, allowing it to move to the desired collection and measurement location. Therefore, this invention can achieve in-situ collection of marine volatile organic compounds and flexibly change the collection location, keeping the pontoon away from the land or ships, avoiding the influence of human factors on the final measurement results and ensuring measurement accuracy.

Description

Technical Field

[0001] This invention relates to a flux measurement device, and more particularly to a device for collecting VOCs gas in the marine micro-surface and estimating air-sea exchange flux, belonging to the field of marine atmospheric pollution monitoring technology. Background Technology

[0002] Volatile organic compounds (VOCs), after entering the atmosphere, undergo complex reactions to generate ozone and secondary organic aerosols (SOA), which have significant impacts on local and regional air quality and climate change. Oceans cover more than 70% of the Earth's surface and release several important marine biogenic VOCs, including the natural sulfur compound dimethyl sulfide and terpenoids such as isoprene and monoterpenes. High concentrations of isoprene emitted from the ocean can increase marine SOA levels in the boundary layer above the distant ocean. Therefore, quantifying marine VOC emission fluxes is crucial for understanding the ocean's impact on the environment and climate change.

[0003] Most current research on marine volatile organic compound (VOC) emission fluxes is based on numerical models and observations. However, the numerical simulation results differ significantly from the actual situation. This difference may be due to the influence of the ocean surface microlayer. Therefore, there is a need for a device that can measure marine VOC emission fluxes under in-situ conditions. Summary of the Invention

[0004] The main objective of this invention is to overcome the problem that "existing studies on VOCs air-sea exchange flux are based on numerical model estimations, but existing estimation models do not incorporate the key interface of the ocean micro-surface layer and lack parameters for multiple environmental factors such as temperature, light, and wind speed, resulting in the estimated air-sea exchange fluxes failing to fully represent the actual exchange fluxes of volatile organic compounds between the ocean and the lower atmosphere," and to provide a device for collecting VOCs gas in the ocean micro-surface layer and estimating air-sea exchange fluxes.

[0005] The objective of this invention can be achieved by adopting the following technical solution: A device for collecting and estimating the atmospheric-ocean exchange flux of VOCs in the marine micro-surface includes a pontoon, with a first sealing cavity, a second sealing cavity, and a third sealing cavity distributed around the outside of the pontoon, and an inlet cavity installed at the axis of the pontoon. The top and sides of the sea inlet cavity of the pontoon shaft are sealed, while the bottom is open to allow seawater to flow in. The sea inlet cavity and the top plate are equipped with a gas intake port, a nitrogen port and a gas outlet. A support frame is installed around the inner side of the lower section of the sea entry cavity, and an underwater drive device is installed on the axis of the support frame. The gas sampling port is connected to the gas collection device; The underwater drive device is connected to the bottom of the pontoon to drive the pontoon to move in the sea; Gas collection devices are installed in the first and second sealed cavities of the pontoon, and water collection devices are installed in the third sealed cavity.

[0006] Preferably, the gas collection device includes a gas collection canister, a gas collection and distribution assembly, a gas collection pipe, and a controller; The gas collection tanks are placed in the first sealed cavity, the gas collection and distribution assembly is set in the second sealed cavity, one end of the gas collection pipe of the gas collection device is connected to the gas collection and distribution assembly, and the other end of the gas collection pipe is connected to the gas collection port on the top plate of the sea inlet cavity. The four-way solenoid valve in the gas collection and distribution assembly is connected to the gas collection tank.

[0007] Preferably, the water sample collection device includes a sampling tube, a small water pump, and a Teflon water sample collection bottle; The small water pump and Teflon water sample collection bottle are set in the third sealed cavity. The sampling tube extends into the water below the water surface inside the sea inlet cavity and collects surface water samples into the Teflon water sample collection bottle through the small water pump.

[0008] Preferably, the perimeter of the sea inlet cavity is made of 316L stainless steel, the top plate is made of transparent borosilicate glass, and the interior of the transparent borosilicate glass top plate is coated with a hydrophobic silica coating.

[0009] Preferably, the sea inlet cavity is equipped with temperature and humidity measuring devices and a fan for headspace air mixing.

[0010] Preferably, a heating wire is provided on the outer wall of the sea entry cavity, and the heating wire controls the temperature of the outer wall of the sea entry cavity.

[0011] Preferably, a stainless steel slide rail is provided between the pontoon and the sea inlet cavity, and the stainless steel slide rail provides a variable volume top gas collection space for the sea inlet cavity.

[0012] Preferably, the underwater drive device includes a first propeller, a second propeller, a first drive component, and a second drive component; The support frame is equipped with a first driving component and a second driving component that rotate in both directions. The output ends of the first driving component and the second driving component are respectively connected to the first propeller and the second propeller for rotation.

[0013] Preferably, the outer side of the pontoon is surrounded by lifting rings, and a handle is mounted around the top plate. The pontoon is made of 316L stainless steel.

[0014] Preferably, a frame is installed at the bottom of the pontoon, casters are installed at the four corners of the frame, and a power supply is installed in the second and third sealed cavities.

[0015] Beneficial technical effects of the present invention: The present invention provides a marine micro-surface VOCs gas collection and air-sea exchange flux estimation device. The bottom of the inlet cavity is open to allow a certain volume of seawater to flow into the inlet cavity. After the device is placed in the seawater, the bottom of the pontoon is below the sea surface. A certain volume of seawater enters from the bottom open of the inlet cavity. The top plate of the inlet cavity is equipped with a collection port, a nitrogen port, and an outlet. When entering the sea, the nitrogen port and outlet controller are turned on. High-purity nitrogen is continuously introduced into the cavity to replace the original gas in the cavity. After the original gas in the cavity is replaced, the cavity is left to stand and wait for the seawater to release volatile organic gases. The outlet is closed and the collection port is opened. One end of the collection pipe is connected to the collection port, and the other end is connected to the Summa tank through a four-way solenoid valve. The device dynamically collects the VOCs mixed gas released by the seawater and realizes the accurate quantification of the VOCs exchange flux at the air-sea interface. Simultaneously, the water sampling device collects surface water samples from the cavity when the equipment is submerged to determine the initial value of VOCs in the water sample. After the gas sampling is completed, it collects surface water samples from the cavity again to determine the concentration value after the water sample has released VOCs, thus achieving synchronous monitoring of VOCs concentration in both gas and liquid states.

[0016] In addition, a vent is provided at the bottom of the sea inlet cavity, which can be connected to a high-pressure gas cylinder to conduct in-situ experiments on specific gases (such as CO2, CH4, O3, etc.).

[0017] The bottom of the pontoon is connected to an underwater drive unit, which is electrically connected to a controller. The controller enables the underwater drive unit to move the pontoon in the sea, allowing it to move to the desired measurement location. Therefore, this invention enables in-situ collection of marine volatile organic compounds and allows for flexible changes in the collection location, keeping the buoy away from the ground or ships, thus avoiding the influence of human factors on the measurement results and ensuring the accuracy of the measurements. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a preferred embodiment of the marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to the present invention; Figure 2 This is a top view of the internal structure of a preferred embodiment of the marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to the present invention; Figure 3 This is a side view of a preferred embodiment of the marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to the present invention; Figure 4 This is a bottom view of a preferred embodiment of the marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to the present invention; Figure 5 This is a top view of a preferred embodiment of the marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to the present invention.

[0019] In the diagram: 1. Float; 11. First sealing cavity; 12. Second sealing cavity; 13. Third sealing cavity; 2. Sea inlet cavity; 21. Top plate; 211. Gas intake port; 212. Nitrogen inlet; 213. Gas outlet; 22. Temperature and humidity monitor; 23. Fan; 25. Heating wire; 26. Water temperature probe; 3. Underwater propulsion device; 31. First propeller; 32. Second propeller; 33. First drive component; 34. Second drive component; 35. Support frame; 4. Controller; 5. Gas sampling device; 51. Suma canister; 52. Four-way solenoid valve; 53. Gas sampling pipe; 54. Controller; 6. Water sampling device; 61. Sampling tube; 62. Small water pump; 63. Teflon water sample collection bottle; 64. Controller; 7. Stainless steel slide rails; 8. Frame; 81. Casters; 82. Lifting rings; 83. Handles; 9. Power supply. Detailed Implementation

[0020] To enable those skilled in the art to understand the technical solution of the present invention more clearly, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0021] Example: Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the marine micro-surface VOCs gas collection and air-sea exchange flux estimation device provided in this embodiment includes a pontoon 1. A first sealing cavity 11, a second sealing cavity 12 and a third sealing cavity 13 are arranged around the outside of the pontoon 1. An inlet cavity 2 is installed on the axis of the pontoon 1. The top and sides of the sea inlet cavity 2 of the pontoon 1 axis are sealed, and the bottom is an open opening to allow seawater to flow in. The sea inlet cavity 2 and the top plate 21 are provided with a gas intake port 211, a nitrogen port 212 and a gas outlet 213. A support frame 35 is installed around the inner side of the lower frame 8 of the sea inlet cavity 2, and an underwater drive device 3 is installed on the axis of the support frame 35. The gas sampling port 211 is connected to the gas collection device 5; The underwater drive device 3 is connected to the bottom of the pontoon 1 to drive the pontoon 1 to move in the sea; Gas collection devices 5 are installed in the first sealed cavity 11 and the second sealed cavity 12 inside the float box 1, and water sample collection devices 6 are installed in the third sealed cavity 13.

[0022] The gas collection device 5 includes a gas collection tank 51, a gas collection and distribution assembly 52, a gas collection pipe 53, and a controller 54. The gas collection tanks 51 are placed in the first sealed cavity 11, the gas collection and distribution assembly 52 is set in the second sealed cavity 12, one end of the gas collection pipe 53 of the gas collection device 5 is connected to the gas collection and distribution assembly 52, and the other end of the gas collection pipe 53 is connected to the gas collection port 211 on the top plate of the sea inlet cavity 2. The four-way solenoid valve in the gas collection and distribution assembly 52 is connected to the gas collection tanks 51.

[0023] The water sample collection device 6 includes a sampling tube 61, a small water pump 62, and a Teflon water sample collection bottle 63; The small water pump 62 and the Teflon water sample collection bottle 63 are set in the third sealed cavity 13. The sampling tube 61 extends into the water surface inside the sea inlet cavity 2 and collects surface water samples into the Teflon water sample collection bottle 63 through the small water pump 62.

[0024] The sea inlet cavity 2 is made of 316L stainless steel on all sides, and the top plate 21 is made of transparent borosilicate glass plate. The transparent borosilicate glass top plate 21 is sprayed with a silica hydrophobic coating inside.

[0025] The sea inlet cavity 2 is equipped with a temperature and humidity measuring device 22 and a fan 23 for mixing headspace air.

[0026] A heating wire 25 is provided on the outer wall of the sea inlet cavity 2, and the heating wire 25 controls the temperature of the outer wall of the sea inlet cavity 2.

[0027] A stainless steel slide rail 7 is provided between the pontoon 1 and the sea inlet cavity 2, and the stainless steel slide rail 7 provides a variable volume top gas collection space for the sea inlet cavity 2.

[0028] The underwater drive device 3 includes a first propeller 31, a second propeller 32, a first drive component 33, and a second drive component 34. The support frame 35 is equipped with a first driving member 33 and a second driving member 34 that rotate in both directions. The output ends of the first driving member 33 and the second driving member 34 are respectively connected to the first propeller 31 and the second propeller 32 for rotation.

[0029] The outer side of the float 1 is surrounded by lifting rings 82, and the top plate 21 is surrounded by handles 83. The float 1 is made of stainless steel 316L.

[0030] The bottom of the float box 1 is equipped with a frame 8, and casters 81 are installed at the four corners of the frame 8. Power supplies 9 are installed in the second sealing cavity 12 and the third sealing cavity 13.

[0031] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the underwater drive device 3 drives the pontoon 1 to move in the sea through the controller 54, enabling the pontoon 1 to move to the required collection position. The bottom of the pontoon 1 is below the sea surface, allowing a certain volume of seawater to enter the sea inlet cavity 2. The top plate 21 of the sea inlet cavity is equipped with a gas sampling port 211, a nitrogen port 212, and a gas outlet 213, which are controlled by solenoid valves. When entering the sea, the nitrogen port 212 and the gas outlet 213 are opened, and high-purity nitrogen is continuously introduced into the top of the cavity to replace the original gas in the cavity. After the original gas in the cavity is replaced, it is left to stand and wait for the seawater to release volatile organic gases. The gas outlet 213 is closed, and the gas sampling port 211 is opened. The end of the gas sampling port 211 is connected to the first end of the gas sampling pipe 53 through a four-way solenoid valve, and the second end of the gas sampling pipe is connected to the Summa tank 51. The mixed gas of VOCs released by the seawater is dynamically collected, realizing the precise quantification of the VOCs exchange flux at the sea-air interface. Simultaneously, when the equipment is launched into the water, a small water pump 62 is remotely controlled to collect surface water samples inside the sea cavity to determine the initial value of VOCs in the water sample. After the sampling is completed, the small water pump 62 is remotely controlled again to collect surface water samples inside the sea cavity to determine the concentration value after the water sample has released VOCs, thus realizing synchronous monitoring of "gas-liquid" VOCs concentration.

[0032] In this embodiment, the top plate 21 is made of transparent borosilicate glass, and the inner side of the top plate 21 is coated with a silica hydrophobic coating. The transparent borosilicate glass plate can ensure that the seawater inside the sea inlet cavity 2 is exposed to sunlight, and the hydrophobic coating can prevent water vapor inside the cavity from condensing on the top plate, so that the test results of the near-sea-air interface gas collection device of the present invention are more in line with reality.

[0033] In this embodiment, a thermometer, a hygrometer, and a small fan are installed on the top side of the inner side of the sea inlet cavity. The thermometer and hygrometer are used to monitor the temperature and humidity inside the cavity during the sampling process, and the small fan is used to mix the air and VOCs released from the seawater inside the cavity to ensure the quality of the sampling.

[0034] To avoid the influence of the materials of the pontoon 1 and the sea inlet cavity 2 on the measurement results, in this embodiment, both the pontoon and the sea inlet cavity are made of stainless steel plates. Stainless steel has good corrosion resistance and is relatively stable in seawater. It will not react with seawater to produce volatile organic compounds, thus ensuring the accuracy of the measurement results. Specifically, both the pontoon and the sea inlet cavity are made of 316L stainless steel plates.

[0035] To prevent the stainless steel cavity from cooling down after entering the sea, which could cause water vapor to condense on the inner wall of the cavity and lead to a secondary reaction of VOCs, in this embodiment, a heating wire 25 and a water temperature probe are installed on the outer wall above the waterline of the cavity. The temperature of the stainless steel wall of the cavity is adjusted according to the seawater temperature by the water temperature probe.

[0036] Specifically, when forward movement is required, the controller adjusts the first drive member 33 and the second drive member 34 to rotate clockwise at the same speed. When turning is required, the controller adjusts the rotation direction of the first drive member 33 to be opposite to the rotation direction of the second drive member 34. When backward movement is required, the controller adjusts the first drive member 33 and the second drive member 34 to rotate counterclockwise at the same speed.

[0037] To facilitate the control of the movement of the pontoon 1, in this embodiment, the marine micro-surface VOCs gas collection and air-sea exchange flux estimation device and in-situ experimental system include a wireless receiving device and a wireless transmitting device. The wireless receiving device is fixedly connected to the pontoon 1, and both the wireless receiving device and the wireless transmitting device are connected to the controller signal.

[0038] The position of the float 1 and the working status of the gas collection device 5 and the water sample collection device 6 are adjusted by a wireless receiver and a wireless transmitter.

[0039] In summary, the marine micro-surface VOCs gas collection and air-sea exchange flux estimation device and in-situ experimental system of the present invention includes a buoy 1, an inlet cavity 2, an underwater drive device 3, and a controller 4. The bottom of the buoy 1 is located below the sea surface, allowing a certain volume of seawater to enter the inlet cavity 2. The top plate 21 of the inlet cavity is equipped with a gas collection port, a nitrogen port, and a gas outlet, which are controlled by electromagnetic valves. When entering the sea, the nitrogen port 212 and the gas outlet 213 are opened. High-purity nitrogen is continuously introduced into the top of the cavity to replace the original gas in the cavity. After the original gas in the cavity is replaced, the cavity is left to stand and wait for the seawater to release volatile organic gases. The gas outlet 213 is closed, and the gas collection port 211 is opened. The end of the gas collection port 211 is connected to the first end of the gas collection pipe through a four-way solenoid valve. The second end of the gas collection pipe is connected to the Summa tank 51. The mixed gas of VOCs released by the seawater is dynamically collected, realizing the accurate quantification of the VOCs exchange flux at the air-sea interface. Furthermore, the bottom of the pontoon 1 is connected to the underwater drive device 3, which is electrically connected to the controller 54. The controller 54 enables the underwater drive device 3 and the pontoon 1 to move in the sea, allowing the pontoon 1 to move to the required sampling and measurement position. Therefore, the near-shore-air interface gas collection device 5 of the present invention can realize in-situ collection of marine volatile organic compounds. At the same time, the gas collection port 1 can be connected to relevant detection equipment to realize in-situ measurement of water-air exchange of marine volatile organic compounds. Furthermore, the sampling position can be flexibly changed so that the buoy 1 is far away from the ground or ships, avoiding the influence of human factors on the final measurement results and ensuring the accuracy of the measurement.

[0040] Simultaneously, when the equipment is launched into the water, a small water pump is remotely controlled to collect surface water samples inside the sea cavity to determine the initial value of VOCs in the water sample. After the sampling is completed, the small water pump 62 is remotely controlled again to collect surface water samples inside the sea cavity to determine the concentration value after the water sample has released VOCs, thus realizing synchronous monitoring of "gas-liquid" VOCs concentration.

[0041] In addition, a vent is provided at the bottom of the sea inlet cavity, which can be connected to a high-pressure gas cylinder to conduct in-situ experiments on specific gases such as CO2, CH4, and O3.

[0042] The above description is merely a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A device for collecting and estimating the atmospheric-ocean exchange flux of VOCs in the marine micro-surface layer, comprising a pontoon (1), wherein a first sealing cavity (11), a second sealing cavity (12) and a third sealing cavity (13) are arranged around the outside of the pontoon (1), and an inlet cavity (2) is installed on the axis of the pontoon (1). Its features are: The top and sides of the sea inlet cavity (2) of the pontoon (1) are sealed, while the bottom is open to allow seawater to flow in. The sea inlet cavity (2) and the top plate (21) are provided with a gas intake port (211), a nitrogen port (212) and a gas outlet (213). A support frame (35) is installed around the inner side of the lower frame (8) of the sea-entry cavity (2), and an underwater drive device (3) is installed on the axis of the support frame (35). The gas sampling port (211) is connected to the gas collection device (5); The underwater drive device (3) is connected to the bottom of the pontoon (1) to drive the pontoon (1) to move in the sea; Gas collection devices (5) are installed in the first sealed cavity (11) and the second sealed cavity (12) of the float (1), and water sample collection devices (6) are installed in the third sealed cavity (13).

2. The marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to claim 1, characterized in that: The gas collection device (5) includes a gas collection tank (51), a gas collection and distribution assembly (52), a gas collection pipe (53), and a controller (54). The gas collection tanks (51) are placed in the first sealed cavity (11), the gas collection and distribution assembly (52) is set in the second sealed cavity (12), one end of the gas collection pipe (53) of the gas collection device (5) is connected to the gas collection and distribution assembly (52), and the other end of the gas collection pipe (53) is connected to the gas collection port (211) on the top plate of the sea inlet cavity (2). The four-way solenoid valve in the gas collection and distribution assembly (52) is connected to the gas collection tank (51).

3. The marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to claim 1, characterized in that: The water sample collection device (6) includes a sampling tube (61), a small water pump (62), and a Teflon water sample collection bottle (63). The small water pump (62) and the Teflon water sample collection bottle (63) are set in the third sealed cavity (13). The sampling tube (61) extends into the water surface inside the sea cavity (2) and collects surface water samples into the Teflon water sample collection bottle (63) through the small water pump (62).

4. The marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to claim 3, characterized in that: The sea inlet cavity (2) is made of stainless steel 316L around its perimeter, and the top plate (21) is made of transparent borosilicate glass plate. The transparent borosilicate glass top plate (21) is sprayed with a silica hydrophobic coating inside.

5. The marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to claim 4, characterized in that: The sea inlet cavity (2) is equipped with a temperature and humidity measuring device (22) and a fan (23) for mixing headspace air.

6. The marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to claim 5, characterized in that: Heating wire (25) is provided on the outer wall of the sea inlet cavity (2), and the heating wire (25) controls the temperature of the outer wall of the sea inlet cavity (2).

7. The device for collecting marine micro-surface VOCs gas and estimating air-sea exchange flux according to claim 1, characterized in that: A stainless steel slide rail (7) is provided between the pontoon (1) and the sea inlet cavity (2), and the stainless steel slide rail (7) provides a variable volume top gas collection space for the sea inlet cavity (2).

8. The device for collecting marine micro-surface VOCs gas and estimating air-sea exchange flux according to claim 1, characterized in that: The underwater drive device (3) includes a first propeller (31), a second propeller (32), a first drive component (33), and a second drive component (34); The support frame (35) is equipped with a first driving member (33) and a second driving member (34) for forward and reverse rotation. The output ends of the first driving member (33) and the second driving member (34) are respectively connected to the first propeller (31) and the second propeller (32) for rotation.

9. The marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to claim 8, characterized in that: The outer side of the float (1) is surrounded by lifting rings (82), and the top plate (21) is surrounded by a handle (83). The float (1) is made of stainless steel 316L.

10. The marine micro-surface VOCs gas collection and air-sea exchange flux estimation device according to claim 9, characterized in that: The bottom of the pontoon (1) is equipped with a frame (8), and casters (81) are installed at the four corners of the frame (8). Power supplies (9) are installed in the second sealed cavity (12) and the third sealed cavity (13).

Images