Device and method for determining volatile organic compounds in soil

Abstract

The invention relates to the technical field of detection equipment, and provides a soil volatile organic compound measuring device and method.The device comprises a pipeline, the pipeline is used for being inserted into soil, a sealable sealing section is formed at the bottom of the pipeline, a side air hole is formed in the side face of the sealing section and covered with a filter screen, and a cover capable of being opened outwards is arranged outside the side air hole; a heating piece is arranged on the cover body; the drill bit is arranged at the lower part of the sealing section; the air pressure control assembly comprises a circulating air pipeline and an air compressor, and the two ends of the circulating air pipeline communicate with the sealing section and the air compressor correspondingly; and the gas collecting bin is communicated with the air compressor. For volatile organic compounds which are low in content or difficult to diffuse in the soil, volatilization of the VOCs is promoted by heating, and then gas containing the VOCs is pumped out, so that whether organic pollutants exist in the soil or not is determined. By changing the insertion position and depth of the device in the soil for multiple times, the spatial distribution condition of VOCs in the polluted site can be quickly judged.

Description

Technical Field

[0001] The invention relates to the technical field of detection equipment, and in particular to a device and method for determining volatile organic matter in soil. Background Art

[0002] Volatile organic compounds (VOCs) in soil refer to organic compounds with a saturated vapor pressure of more than 70.91 Pa or a boiling point of less than 260°C at room temperature. They are the most common pollutants emitted by the petroleum, chemical, pharmaceutical, printing, building materials and spraying industries. Volatile organic compounds in soil have pollution characteristics that are different from other pollutants, such as concealment, unevenness, volatility, and toxicity. They have complex components and great potential dangers, and should be given priority control in soil pollution control.

[0003] Volatile organic compounds in soil are an important pollutant component of major environmental accidents in recent years. In the investigation of soil contaminated sites, traditional technical means are to preset investigation points based on ground conditions, drill undisturbed soil at different depths, and bring them back to the laboratory for testing and analysis. If the spatial distribution of VOCs in contaminated sites can be quickly determined, it will be of great help for further accurate sampling and precise remediation. Summary of the invention

[0004] In order to solve the technical problem of the prior art that the original soil is drilled at different depths according to the preset survey points based on the ground conditions and brought back to the laboratory for testing and analysis, the embodiment of the present invention provides a soil volatile organic compound determination device and method. The technical solution is as follows:

[0005] In one aspect, a device for measuring volatile organic compounds in soil is provided, the device comprising:

[0006] A pipe, the pipe is used to be inserted into the soil, the bottom of the pipe forms a sealable sealing section, the side of the sealing section has a side air hole, the side air hole is covered with a filter screen, the side air hole is provided with a cover body that can be opened outwards, and the cover body has a heating element;

[0007] a drill bit, the drill bit being arranged at the lower part of the sealing section;

[0008] An air pressure control assembly, the air pressure control assembly comprising a circulating air pipeline and an air compressor, wherein two ends of the circulating air pipeline are respectively connected to the sealing section and the air compressor;

[0009] A gas collecting bin is communicated with the air compressor.

[0010] Optionally, the diameter of the drill bit is greater than or equal to the size of the pipeline and the cover body after the cover body is opened.

[0011] Optionally, the filter has a mesh size of 40 to 100 to block soil particles from entering the sealing section while allowing gas to pass through.

[0012] Optionally, the heating element is a heating tile, and the heating tiles are evenly distributed on the inner wall and the outer wall of the cover body.

[0013] Optionally, a controller is further included, and the controller is communicatively connected to the heating element.

[0014] Optionally, the air compressor has a pressure regulating function, and can pressurize or depressurize the gas in the sealing section according to a preset pressure value.

[0015] Optionally, a gas analysis component is further included, which is connected to the gas collection chamber and is used to perform component analysis on the collected gas.

[0016] Optionally, the gas analysis component includes a gas chromatograph and a mass spectrometer, which can simultaneously perform qualitative analysis.

[0017] Optionally, the pipeline includes a plurality of sub-pipes of the same length, and the plurality of sub-pipes are connected in series, which can indicate the depth to which the pipeline is inserted into the soil.

[0018] On the other hand, a method for determining volatile organic matter in soil is also provided, the method comprising:

[0019] Insert the pipe into the soil to be tested;

[0020] Open the cover outside the side air hole, start the heating element, and heat the area near the cover to promote the release of volatile organic matter in the soil;

[0021] Start the air compressor, circulate downward to apply preset positive and negative pressure, and use the circulating gas to recover the gas in the sealing section and the area near the cover body to the gas collection bin through the circulating air pipeline;

[0022] The collected volatile organic compounds are analyzed to determine the types of the volatile organic compounds.

[0023] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0024] The soil volatile organic compound measuring device provided by the embodiment of the present invention, by providing a sealable sealing section and a heating element, promotes the volatilization of VOCs in the soil by heating for some volatile organic compound components with low content or relatively dispersed distribution in the soil, and then extracts the gas containing VOCs to quickly determine whether the soil is contaminated by organic matter. By repeatedly changing the insertion position and depth of the device in the soil, the spatial distribution of VOCs in the contaminated site can be quickly determined, which is of great help for further accurate sampling and accurate remediation. This measuring device can effectively collect and analyze volatile organic compounds in the soil without destroying the soil structure, providing strong support for research in the fields of environmental science and ecology. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic structural diagram of a soil volatile organic compound determination device provided by an embodiment of the present invention;

[0027] Figure 2 The present invention provides a flow chart of a method for determining volatile organic compounds in soil.

[0028] Reference numerals:

[0029] 1. Pipe; 11. Sealing section; 12. Side air hole; 13. Filter screen; 14. Cover; 15. Air impact mechanism;

[0030] 2. Drill bit;

[0031] 3. Air pressure control assembly; 31. Circulating air pipeline; 32. Air compressor;

[0032] 4. Gas collection chamber;

[0033] 5. Gas analysis components. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0035] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0036] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0037] The embodiment of the present invention provides a soil volatile organic compound determination device, which includes: a pipeline 1, a drill bit 2, an air pressure control component 3 and a gas collection chamber 4. The drill bit 2 is used to dig into the soil and can usually be driven by a ground air impact mechanism 15. For example, the ground air impact mechanism 15 can be an electric pile driver. The pipeline 1 is used to transport gas and accommodate the air pressure control component 3.

[0038] The pipe 1 is used to be inserted into the soil, and the bottom of the pipe 1 forms a sealable sealing section 11 through a partition. The side of the sealing section 11 has a side air hole 12, and the side air hole 12 is covered with a filter 13 to prevent soil particles from entering the sealing section 11 while allowing gas to pass through. A cover 14 that can be opened outward is provided outside the side air hole 12, and a heating element is provided on the cover 14. The heating element may be used to increase the temperature around the side air hole 12 to promote the volatilization of volatile organic compounds (VOCs) in the soil.

[0039] Specifically, the drill bit 2 is arranged at the lower part of the sealing section 11 to assist the pipeline 1 in being inserted into the soil and ensure that the sealing section 11 can correctly and deeply enter the soil layer.

[0040] The air pressure control assembly 3 includes a circulating air pipeline 31 and an air compressor 32. The two ends of the circulating air pipeline 31 are connected to the sealing section 11 and the air compressor 32, respectively, to form a closed gas circulation system. The air compressor 32 is used to provide power to enable the gas to flow in the circulating air pipeline 31, thereby realizing the gas exchange inside and outside the sealing section 11.

[0041] The gas collection chamber 4 is connected to the air compressor 32 and is used to collect VOCs volatilized from the soil and transported through the circulating air pipeline 31.

[0042] It should be noted that VOCs in the soil, mixed with mud and water, are like colloid, and it is difficult to extract them by simply pumping air. Through heating and continuous circulation of negative and positive pressure air, the volatilization of VOCs can be accelerated and mixed into the circulating gas.

[0043] When the device is inserted into the soil, for fluid or colloidal soil, it will immediately wrap around the outer wall of the pipe 1, so that the outer wall of the pipe 1 and the soil are sealed. The device is surrounded by mud and water, which tightly surrounds the pipe 1. After the cover 14 is opened, the space outside the cover 14 forms a local closed air cavity. The heating element on the cover 14 is turned on to increase the air temperature around the side air holes 12 and promote the volatilization of VOCs in the soil. At the same time, the air compressor 32 is started, and the external air is introduced into the air cavity through the circulating air pipeline 31, and the gas containing VOCs in the air cavity is extracted and transported to the gas collection bin 4. The function of the filter 13 is to prevent soil particles from entering the circulation system and keep the system clean and efficient. The gas sample finally collected by the gas collection bin 4 can be further determined by chemical analysis and other methods to determine the VOCs therein.

[0044] After the pipe 1 is inserted into the soil at a certain depth along with the drill bit 2, the side air hole 12 at the bottom of the pipe 1 is opened, and then the heating element starts to heat. At the same time, the upper air compressor 32 drives the circulating air, which is sometimes high pressure and sometimes low pressure, to flow through the closed air cavity formed by the underground side air hole 12 and the outer space thereof. Through the tension and suction of the air, the gas molecules are diffused and recovered in the underground closed space, thereby driving the volatile organic compounds to mix into the circulating gas and collect them. Furthermore, the above-mentioned volatile organic compounds can be detected in a variety of ways, for example, they can be quickly detected by a handheld PID (VOCs rapid detector).

[0045] The soil volatile organic compound measuring device provided by the embodiment of the present invention, by providing a sealable sealing section 11 and a heating element, promotes the volatilization of VOCs in the soil by heating for some volatile organic compound components with low content or relatively dispersed distribution in the soil, and then extracts the gas containing VOCs to quickly determine whether the soil is polluted by organic matter. By repeatedly changing the insertion position and depth of the device in the soil, the spatial distribution of VOCs in the contaminated site can be quickly determined, which is of great help for further accurate sampling and accurate remediation. This measuring device can effectively collect and analyze volatile organic compounds in the soil without destroying the soil structure, providing strong support for research in the fields of environmental science and ecology.

[0046] During the investigation of soil contamination sites, for soils at a certain depth, for example, 1m, 1.5m, 2m, etc., it is possible to quickly determine whether VOCs pollution exists.

[0047] It should be noted that the power of the drill bit 2 is the ground air impact mechanism 15, which is connected to the pipeline 1. Driven by the ground air impact mechanism 15, the sub-pipe and the connected drill bit 2 are pushed underground together. In one embodiment provided by the present invention, the diameter of the drill bit 2 is greater than or equal to the size of the pipeline 1 and the cover body 14 after the cover body 14 is opened, so that the hole drilled by the drill bit 2 is larger than the diameter of the pipeline 1, and the space larger than the pipeline 1 can form a space for opening the cover body 14. Moreover, in the process of inserting and removing the pipeline 1, the larger diameter of the drill bit 2 can more effectively remove obstacles in the soil, such as tree roots, stones, etc., and reduce the risk of soil blockage.

[0048] Furthermore, the cover 14 is opened outward and downward, and this structure is used to automatically close the cover 14 based on the pressure of the soil when the device is lifted up after the measurement is completed.

[0049] Furthermore, in an embodiment provided by the present invention, the mesh size of the filter screen 13 is 40 to 100 meshes, so as to prevent soil particles from entering the sealing section 11 while allowing gas to pass through.

[0050] The 40-mesh mesh is relatively small and can effectively block most soil particles from entering the sealing section 11. As the mesh size increases, that is, the mesh becomes smaller, the effect of blocking soil particles will also increase. However, too small a mesh may increase the resistance when gas passes through, affecting the efficiency of gas exchange. Therefore, a mesh size that meets the requirements can be selected as needed, and this embodiment does not limit this.

[0051] In one embodiment provided by the present invention, the heating element is a heating tile, and the heating tile is evenly distributed on the inner wall and the outer wall of the cover 14, which can ensure that the temperature distribution of the cover 14 and its surrounding environment is more uniform, and can avoid problems such as local overheating or uneven temperature. This helps to promote the volatile organic compounds (VOCs) in the soil to volatilize more evenly, thereby improving the accuracy and reliability of the measurement.

[0052] As a heating element, the heating tile has the characteristics of fast heating speed and high thermal efficiency. By properly controlling the power and heating time of the heating tile, the temperature of the cover body 14 and its surrounding environment can be quickly increased, thereby accelerating the volatilization process of VOCs.

[0053] Furthermore, the heating element may be connected to a control switch for operation and control by an operator.

[0054] In a further embodiment, the maximum heating temperature of the heating element may be adjusted according to the boiling point of the potential contaminants.

[0055] In one embodiment provided by the present invention, a controller is further included, and the controller is in communication with the heating element. The heating power and temperature of the heating tile can be accurately controlled by the controller, thereby realizing accurate regulation of the heating process. This helps to adjust the heating intensity and time according to actual needs to meet the needs under different measurement conditions.

[0056] Furthermore, the maximum heating temperature of the heating element can be set by the controller, for example, it can be set to 80° C. to avoid the vaporization of water in the soil due to too high a temperature.

[0057] In one embodiment provided by the present invention, the air compressor 32 has a pressure regulating function, and can pressurize or depressurize the gas in the sealing section 11 according to a preset pressure value, so that the circulating air can be diffused or recovered in the soil to better mix the VOCs and take them out. Through the air compressor 32, the sealing section 11 at the bottom of the device can be under positive pressure or negative pressure to accelerate the exchange of gas with soil gas. Through the pressure regulating function, the air compressor 32 can accurately control the gas pressure in the cavity. During the process of pressurization or decompression, the fluidity and diffusivity of the gas will change. By accurately adjusting the pressure, the air compressor 32 can optimize the exchange efficiency of the gas between the soil and the cavity, thereby more effectively collecting and analyzing volatile organic compounds (VOCs) in the soil.

[0058] Moreover, different soil types and depths may have different requirements for gas pressure. The air compressor 32 with pressure regulation function can be adjusted according to actual soil conditions to meet the needs of different measurement scenarios.

[0059] Specifically, the gas collection bin 4 is made of PC (Polycarbonate) material, and the gas collection bin 4 is detachably connected to the air compressor 32 .

[0060] In one embodiment provided by the present invention, a gas analysis component 5 is further included. The gas analysis component 5 is connected to the gas collection chamber 4 and is used to perform component analysis on the collected gas.

[0061] The main function of the gas analysis component 5 is to perform component analysis on the gas collected from the gas collection chamber 4 to identify and quantify volatile organic compounds (VOCs) and other possible components therein.

[0062] The gas analysis component 5 may use a variety of analysis techniques, including but not limited to gas chromatography (GC), mass spectrometry (MS), infrared spectroscopy (IR), or a combination thereof (such as GC-MS). These techniques can provide highly sensitive and specific analysis, helping to accurately identify different components in the gas.

[0063] Furthermore, in an embodiment provided by the present invention, the gas analysis component 5 includes a gas chromatograph and a mass spectrometer, which can simultaneously perform qualitative analysis.

[0064] Specifically, gas chromatography is a technology that separates different substances based on the difference in distribution coefficients between the stationary phase and the mobile phase. In the application of soil volatile organic compound determination, the gas chromatograph can efficiently separate the volatile organic compounds in the soil from other components, providing a clear chromatogram for subsequent analysis. The working principle of the gas chromatograph is to use a carrier gas to bring the sample into the chromatographic column. The different components in the sample are separated by the interaction force between the stationary phase and the mobile phase in the chromatographic column. The separated components are detected by a detector and a corresponding chromatogram is generated.

[0065] A mass spectrometer is a high-precision instrument that can measure the relative molecular mass and relative abundance of various elements, isotopes, compounds, etc. in a sample. In the application of soil volatile organic compound determination, the mass spectrometer can further identify the various components separated by the gas chromatograph. The working principle of the mass spectrometer is to use an ion source to ionize the sample molecules, and then separate and detect the ions through a mass analyzer. Ions of different masses have different motion trajectories in an electric or magnetic field, thereby achieving ion separation. The separated ions are detected by a detector and a corresponding mass spectrum is generated.

[0066] The identification of the individual components separated by mass spectrometry can determine the types of volatile organic compounds present in the soil. This is usually done by comparing the mass spectrum with the mass spectra of known compounds.

[0067] In one embodiment provided by the present invention, the pipeline 1 includes a plurality of sub-tubes of the same length, and the plurality of sub-tubes are connected in series, which can indicate the depth of the pipeline 1 inserted into the soil, so that the operator can monitor and adjust in real time during the insertion process to ensure that each insertion reaches the predetermined depth requirement. The pipeline 1 is a quick-detachable multi-section structure, and the length of each sub-tube can be set as needed, for example, it can be 50cm or 100cm, which is not limited in this embodiment. The gas path and the electric circuit can be led through the pipeline 1. Based on the above structure, the sampling depth of the determination of volatile organic compounds in the soil can be accurately controlled, thereby ensuring that the conditions of each determination are as consistent as possible, improving the accuracy and comparability of the measurement results, and improving work efficiency.

[0068] It should be noted that a sealable sealing section 11 is formed inside the sub-tube at the bottom, and the end is connected to the drill bit 2. Among them, the ground air impact mechanism 15 is connected to the sub-tube at the top. Driven by the ground air impact mechanism 15, the sub-tube and the connected drill bit 2 are pushed underground together. And a simple quick pull-out device is configured. In the investigation of soil sites, the investigation depth is often 1-5 meters, or even deeper. Based on this multi-section convenient disassembly structure, the device is easy to carry and transport, and the use process is also very convenient.

[0069] In one embodiment provided by the present invention, a condenser is provided inside the gas collection chamber 4 for condensing and removing water vapor in the collected gas to improve the accuracy of gas analysis.

[0070] In the process of soil volatile organic compound determination, the collected gas often contains a certain amount of water vapor. If this water vapor is not removed, it may interfere with the subsequent gas analysis and affect the accuracy of the measurement results. The setting of the condenser can effectively condense the water vapor in the gas into liquid water and remove it through an appropriate discharge device, thereby ensuring the accuracy of subsequent analysis.

[0071] By removing water vapor, the condenser can reduce interference factors in the gas analysis process, making the analysis results more accurate and reliable. This is especially important for application scenarios that require high-precision measurements, such as environmental monitoring, food safety testing, and other fields.

[0072] The soil volatile organic compound measuring device provided in the embodiment of the present invention, by providing a sealable sealing section 11 and a heating element, promotes the volatilization of VOCs in the soil by heating some volatile organic compound components with low content or relatively dispersed distribution in the soil, and then extracts the gas containing VOCs to quickly determine whether the soil is polluted by organic matter. This measuring device can quickly determine whether there are organic pollutants in the soil, effectively collect and analyze volatile organic compounds in the soil, and provide strong support for research in the fields of environmental science, ecology, etc.

[0073] The present invention also provides a method for determining volatile organic compounds in soil, the method comprising:

[0074] 201. Insert the pipe 1 into the soil to be tested.

[0075] Specifically, the drill bit 2 and the pipe 1 connected together can be impacted into the soil at a certain depth by the air impact mechanism 15 .

[0076] 202. Open the cover 14 outside the side air hole 12, start the heating element, and heat the area near the cover 14 to promote the release of volatile organic matter in the soil.

[0077] The purpose of heating is to promote the release of volatile organic compounds in the soil into the air for subsequent collection and analysis. The specific heating temperature and time can be adjusted according to specific measurement requirements and soil characteristics.

[0078] 203 . Start the air compressor 32 , circulate downward to apply preset positive pressure and negative pressure, and use the circulating gas to recover the gas in the area near the sealing section 11 and the cover body 14 to the gas collection bin 4 through the circulating air pipeline 31 .

[0079] Specifically, the upper air compressor 32 drives the circulating air with sometimes positive pressure and sometimes negative pressure to flow through the underground side air holes 12 and the closed space outside the cover body 14, and through the tension and suction of the air, the gas molecules are diffused and recovered in the underground closed space.

[0080] Specifically, when the air compressor 32 applies positive pressure, the gas molecules diffuse into the soil, promoting the diffusion of volatile organic matter in the soil into the air; when the air compressor 32 applies negative pressure, the gas in the sealing section 11 and the enclosed space is recovered to the ground, and the circulating air is finally collected in the gas collection bin 4.

[0081] The purpose of this step is to collect air containing volatile organic compounds for subsequent analysis.

[0082] During this process, the working state of the air compressor 32 needs to be controlled to maintain the air pressure in the air cavity within a preset range, which can ensure the stability and accuracy of gas collection.

[0083] 204. Analyze the volatile organic compounds collected in the gas collection chamber 4 to determine the types of the volatile organic compounds.

[0084] The gas collected in the gas collection chamber 4 is sent to analytical instruments such as a gas chromatograph and a mass spectrometer for analysis.

[0085] The type and content of volatile organic compounds can be determined by analytical instruments. This step is the core part of the measurement and the key to obtaining the measurement results.

[0086] The method for determining volatile organic compounds in soil provided by the embodiment of the present invention, by providing a sealable sealing section 11 and a heating element, promotes the volatilization of VOCs in the soil by heating for some volatile organic components with low content or relatively dispersed distribution in the soil, and then extracts the gas containing VOCs to quickly determine whether the soil is contaminated by organic matter. By repeatedly changing the insertion position and depth of the device in the soil, the spatial distribution of VOCs in the contaminated site can be quickly determined, which is of great help for further accurate sampling and accurate remediation. This measuring device can effectively collect and analyze volatile organic compounds in the soil without destroying the soil structure, providing strong support for research in the fields of environmental science and ecology.

[0087] Furthermore, the cover 14 is opened outward and downward, and this structure is used to automatically close the cover 14 when the device is lifted up after the measurement is completed.

[0088] The heating element is turned off, and the cover 14 on the side air hole 12 is closed, and the device is pulled out from the soil. In the implementation process, even if the cover 14 cannot be completely closed under the condition of soil blocking, it can be forcibly closed under the soil pressure on both sides during the pulling process.

[0089] It should be understood that the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding.

[0090] In the present invention, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0091] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0092] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A device for measuring volatile organic compounds in soil, characterized in that: The device comprises: A pipe, the pipe is used to be inserted into the soil, the bottom of the pipe forms a sealable sealing section, the side of the sealing section has a side air hole, the side air hole is covered with a filter screen, the side air hole is provided with a cover body that can be opened outwards, and the cover body has a heating element; a drill bit, the drill bit being arranged at the lower part of the sealing section; An air pressure control assembly, the air pressure control assembly comprising a circulating air pipeline and an air compressor, wherein two ends of the circulating air pipeline are respectively connected to the sealing section and the air compressor; A gas collecting bin is communicated with the air compressor.

2. The soil volatile organic compound measuring device according to claim 1, characterized in that: The diameter of the drill bit is greater than or equal to the size of the pipeline and the cover body after the cover body is opened.

3. The soil volatile organic compound measuring device according to claim 1 or 2, characterized in that: The filter has a mesh size of 40 to 100 to block soil particles from entering the sealing section while allowing gas to pass through.

4. The soil volatile organic compound measuring device according to claim 1, characterized in that: The heating element is a heating tile, and the heating tiles are evenly distributed on the inner wall and the outer wall of the cover body.

5. The soil volatile organic compound measuring device according to claim 1, characterized in that: A controller is also included, and the controller is communicatively connected with the heating element.

6. The soil volatile organic compound measuring device according to claim 1, characterized in that: The air compressor has a pressure regulating function and can pressurize or depressurize the gas in the sealing section according to a preset pressure value.

7. The soil volatile organic compound measuring device according to claim 1, characterized in that: It also includes a gas analysis component, which is connected to the gas collection chamber and is used to perform component analysis on the collected gas.

8. The soil volatile organic compound measuring device according to claim 7, characterized in that: The gas analysis component includes a gas chromatograph and a mass spectrometer, which can simultaneously perform qualitative analysis.

9. The soil volatile organic compound measuring device according to claim 1, characterized in that: The pipeline includes a plurality of sub-pipes of the same length, and the plurality of sub-pipes are connected in series, so as to indicate the depth of the pipeline inserted into the soil.

10. A method for determining volatile organic compounds in soil, characterized in that: The method comprises: Insert the pipe into the soil to be tested; Open the cover outside the side air hole, start the heating element, and heat the area near the cover to promote the release of volatile organic matter in the soil; Start the air compressor, circulate downward to apply preset positive and negative pressure, and use the circulating gas to recover the gas in the sealing section and the area near the cover body to the gas collection bin through the circulating air pipeline; The collected volatile organic compounds are analyzed to determine the types of the volatile organic compounds.

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