A soil gas collection device and a collection method

Abstract

The present invention discloses a soil gas collection device and a collection method. The device includes a collection cylinder, a connecting pipe, and a ventilation component; a gas accommodation cavity is arranged inside the collection cylinder, and at least one ventilation channel communicating with the outside is arranged in the gas accommodation cavity; the connecting pipe is arranged inside the ventilation channel; the ventilation component includes a fixed ring cap for connecting with the connecting pipe, a waterproof and breathable membrane sheet, and a support sheet. The fixed ring cap includes a large opening end and a relatively small opening end which are communicated. The fixed ring cap is detachably connected to one end of the connecting pipe through the large opening end. The support sheet is provided with a plurality of through holes. After the waterproof and breathable membrane sheet and the support sheet are attached, they are arranged between the fixed ring cap and the connecting pipe, and are attached to one end of the connecting pipe through the small opening end. Through the collection cylinder, the present invention can be directly buried inside the soil to realize the collection of soil gas at different depths, and is applicable to different types of soil through pre-burial, with a wide application range.

Description

Technical Field

[0001] The present invention relates to the technical field of soil gas research, and in particular to a soil gas collection device and a collection method. Background Art

[0002] The main gases in soil are O 2 , CO 2 , CH 4 , SO 2 , H 2 S, NH 3 , N 2 O, H 2 , H 2 O, Rn, etc. These gases are generated by various complex biochemical processes (mineralization, litter decomposition, soil respiration, anaerobic bacterial decomposition, release of organic fertilizers or chemical fertilizers, etc.) and atmospheric deposition (polluted gas deposition is absorbed by the ground surface and then diffuses into the soil layer). In the fields of soil remediation, plant physiology research, greenhouse gas emission research, prospecting (chemical prospecting for gases such as CO 2 , CH 4 , SO 2 , H 2 S and Hg, etc.), plant nutrition detection, earthquake prediction (measuring H 2 anomalies in soil), and soil radon gas detection before building design (national standard "Code for Indoor Environmental Pollution Control of Civil Building Engineering" (GB 50325-2010)), etc., the detection of soil gases is required.

[0003] The commonly used soil gas collection methods are the static chamber method and the probe method. The static chamber method is mostly used in greenhouse gas emission research. By covering the ground surface with an opaque box of known volume and enriching for a certain period of time, the gas flux per unit time and unit area is analyzed. However, this method cannot collect and study soil gases at different depths. The probe method refers to inserting a hollow probe with a conical drill bit (with a stainless steel filter) at the bottom into the soil at a certain depth, and connecting a syringe, a gas collection bag or a gas pump to extract the gas. However, this method has high requirements for soil properties. It is difficult to insert the probe into hard soil. Hammering will cause soil loosening and blockage of the bottom filter. Wet soil will also cause blockage of the bottom filter, and it cannot filter liquids, resulting in less gas and easy extraction of liquids.

[0004] Therefore, in view of the above problems, it is necessary to propose a further solution to at least solve one of the problems. Summary of the Invention

[0005] The present invention aims to provide a soil gas collection device and a collection method to overcome the deficiencies in the prior art.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A soil gas collection device, comprising a collection cylinder, a connecting pipe provided on the collection cylinder, and a ventilation component connected to the connecting pipe;

[0008] A gas accommodation cavity is provided in the collection cylinder, and at least one ventilation channel communicating with the outside is provided in the gas accommodation cavity;

[0009] The connecting pipe is arranged in the ventilation channel;

[0010] The ventilation component includes a fixed ring cap for connecting with the connecting pipe, a waterproof breathable membrane sheet, and a support sheet. The fixed ring cap includes a large opening end and a relatively small opening end, and the large opening end and the small opening end are through. The fixed ring cap is detachably connected to one end of the connecting pipe through the large opening end. The support sheet is provided with a plurality of through holes. After the waterproof breathable membrane sheet and the support sheet are attached, they are arranged between the fixed ring cap and the connecting pipe, and are attached to one end of the connecting pipe through the small opening end.

[0011] In a preferred embodiment of the present invention, the support sheet is farther from the barrel wall of the collection cylinder than the waterproof breathable membrane sheet.

[0012] In a preferred embodiment of the present invention, the ventilation component further includes an adapter ring for connecting with the connecting pipe and located between the collection cylinder and the fixed ring cap. The adapter ring includes opposite end face one and end face two. The end face one cooperates with the corresponding part of the collection cylinder, and the end face two cooperates with the end face of the large opening end.

[0013] In a preferred embodiment of the present invention, the adapter ring is sleeved on the connecting pipe, and the fixed ring cap is threadedly connected to the connecting pipe.

[0014] In a preferred embodiment of the present invention, an air extraction pipe is further included. An air extraction channel is provided in the gas accommodation cavity, and the air extraction pipe is detachably connected to the air extraction channel.

[0015] In a preferred embodiment of the present invention, the collection cylinder includes a cylinder body part and a cover body part for sealing the cylinder body part. The cylinder body part and the cover body part are detachably connected, and the gas accommodation cavity is formed between the cylinder body part and the cover body part.

[0016] In a preferred embodiment of the present invention, two ventilation components are included. The connecting pipe penetrates through the ventilation channel, and the two ventilation components are symmetrically arranged at both ends of the connecting pipe.

[0017] In a preferred embodiment of the present invention, two of the ventilation channels are symmetrically arranged in the gas accommodation chamber.

[0018] In a preferred embodiment of the present invention, the air extraction channel is arranged at the lower end of the collection cylinder.

[0019] In a preferred embodiment of the present invention, the ventilation channels are away from the air extraction channel.

[0020] In a preferred embodiment of the present invention, the volume of the gas accommodation chamber is 1000 cm 3 -2000 cm 3 .

[0021] In a preferred embodiment of the present invention, the waterproof and breathable membrane and the support sheet are adhesively bonded in part, and the unbonded part of the waterproof and breathable membrane and the support sheet communicates with the small opening end.

[0022] In a preferred embodiment of the present invention, the material of the support sheet is a rigid material.

[0023] In a preferred embodiment of the present invention, the aperture of the through hole of the support sheet is 0.3 - 0.6 mm..

[0024] In a preferred embodiment of the present invention, the wall thickness of the collection cylinder is 0.8 - 1.5 cm.

[0025] In a preferred embodiment of the present invention, the material of the collection cylinder is acrylic or polycarbonate.

[0026] In a preferred embodiment of the present invention, the inner diameter of the small opening end is not less than 1 cm.

[0027] In a preferred embodiment of the present invention, the material of the waterproof and breathable membrane is ePTFE.

[0028] The present invention also provides a method for collecting soil gas, using any of the soil gas collection devices, and comprising the following steps:

[0029] Place a gas analyzer and / or connect an air extraction pipe in the collection cylinder;

[0030] Embed one or more of the soil gas collection devices into the soil according to requirements;

[0031] After a certain period of time, extract the gas in the collection cylinder to complete the sampling.

[0032] In a preferred embodiment of the present invention, a plurality of the soil gas collection devices are buried at different positions at the same depth or at different depths at the same position in the soil.

[0033] In a preferred embodiment of the present invention, the air extraction channel of the collection cylinder is placed away from the soil surface.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] (1) The present invention can directly bury the collection cylinder into the soil to collect soil gases at different depths, and is applicable to different types of soils through pre-burial, with a wide range of applications. At the same time, through the cooperation of the connecting pipe and the ventilation component, the ventilation channel can be blocked in a limited way, the soil can be blocked and filtered by the support sheet, and the liquid can be blocked by the waterproof breathable membrane sheet to prevent the liquid from entering the gas chamber and affecting the sampling detection.

[0036] (2) The present invention supports the flexible waterproof breathable membrane sheet through the support sheet, enabling it to be fixed and flattened, ensuring comprehensive waterproofing of the ventilation channel.

[0037] (3) By setting the volume of the gas chamber, the present invention meets the gas extraction requirements, enables the soil gas to form a relatively stable state in the gas chamber, and provides a relatively sufficient extraction volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 is a three-dimensional schematic diagram of the present invention;

[0040] Figure 2 is a partial exploded schematic diagram of the present invention;

[0041] Figure 3 is an enlarged exploded schematic diagram of the connecting pipe and the ventilation component in the present invention;

[0042] Figure 4 is a schematic diagram of the usage state in Embodiment 1 of the present invention;

[0043] Figure 5 is a schematic diagram of the usage state in Embodiment 2 of the present invention;

[0044] Figure 6 is a schematic diagram of the usage state in Embodiment 3 of the present invention.

[0045] Specifically, 1. Soil gas collection device; 2. Soil; 3. Gas analyzer;

[0046] 100, Collection cylinder; 110, Gas accommodation chamber; 120, Ventilation passage; 130, Air extraction passage; 101, Cylindrical body part; 102, Cover body part;

[0047] 200, Connecting pipe;

[0048] 300, Ventilation component; 310, Fixed ring cap; 311, Large opening end; 312, Small opening end; 320, Support piece; 321, Through hole; 330, Waterproof and breathable membrane; 340, Adaptation ring; 341, First end face; 342, Second end face;

[0049] 400, Air extraction pipe joint. Specific implementation manner

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0051] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0052] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the protection scope of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0053] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] As Figure 1 shown, a soil gas collection device 1 includes a collection cylinder 100, a connection pipe 200 provided on the collection cylinder 100, and a ventilation assembly 300 connected to the connection pipe 200. By directly burying the collection cylinder 100 into the soil, the present invention can collect soil gases at different depths, and by pre-burying, it is applicable to different types of soil, such as conventional soil, industrial and mining polluted sites, bottom mud, sediment, wetland, marsh, etc., with a wide range of applications.

[0055] Specifically, as Figure 2 shown, a gas accommodation chamber 110 is provided inside the collection cylinder 100, and at least one ventilation channel 120 communicating with the outside is provided in the gas accommodation chamber 110. The ventilation channel 120 is preferably not provided at the lower end of the collection cylinder 100 to avoid the ventilation channel 120 being flooded by accumulated water for a long time under the condition of excessive soil moisture. The collection cylinder 100 may include a cylinder part 101 and a cover part 102 for sealing the cylinder part 101. The cylinder part 101 and the cover part 102 are detachably connected, and the gas accommodation chamber 110 is formed between the cylinder part 101 and the cover part 102. The ventilation channel 120 is opened on the cylinder part 101. The cylinder part 101 is preferably cylindrical to facilitate digging and burying. The connection pipe 200 is inserted into the ventilation channel 120. Preferably, two ventilation channels 120 are symmetrically provided in the gas accommodation chamber 110 to accelerate gas convection and achieve rapid collection. The wall thickness of the cylinder wall of the collection cylinder 100 is preferably 0.8 - 1.5 cm to enhance the strength and be suitable for being buried in the soil. Further, the material of the collection cylinder 100 is acrylic or polycarbonate. In a specific embodiment, the material of the cover part 102 is acrylic or polycarbonate or other corrosion-resistant materials, with an outer diameter of 120 mm, an inner diameter of 110 mm, and a height of 20 mm. The material of the cylinder part 101 is acrylic or polycarbonate or other corrosion-resistant materials, with an outer diameter of 110 mm, an inner diameter of 100 mm, and a height of 200 mm, so as to form a gas accommodation chamber 110 with an appropriate volume and have a suitable strength for being buried in various types of soil and not being easily damaged.

[0056] As Figure 3As shown, the ventilation component 300 includes a fixed ring cap 310 for connecting with the connecting pipe 200, a waterproof and breathable membrane 330, and a support sheet 320. By cooperating the connecting pipe 200 with the ventilation component 300, a restricted blocking of the ventilation passage 120 is achieved. The soil is blocked and filtered by the support sheet 320, and the liquid is blocked by the waterproof and breathable membrane 330, preventing the liquid from entering the gas accommodation cavity and affecting the sampling detection. The material of the waterproof and breathable membrane 330 is preferably ePTFE. ePTFE is the general term for materials with special functions obtained by processing polytetrafluoroethylene (PTFE) materials, and has excellent waterproof and breathable properties.

[0057] Preferably, the device includes two ventilation components 300. The connecting pipe 200 penetrates through the ventilation passage 120, and the two ventilation components 300 are symmetrically arranged at both ends of the connecting pipe 200 to enhance the filtration of soil impurities and liquid, improve the dryness of the gas in the gas accommodation cavity 110, and facilitate sampling.

[0058] The support sheet 320 is provided with a number of through holes 321 to allow the gas to pass through, and the flexible waterproof and breathable membrane 330 is supported by the support sheet 320 so that it can be fixed in a flattened posture to ensure comprehensive waterproofing of the ventilation passage 120. The material of the support sheet 320 is preferably a rigid material to form an effective support effect. Preferably, the support sheet 320 is farther from the wall of the collection cylinder 100 than the waterproof and breathable membrane 330 to block soil fragments and protect the waterproof and breathable membrane 330. Preferably, the waterproof and breathable membrane 330 and the support sheet 320 are partially bonded and adhered, and the unbonded part of the waterproof and breathable membrane 330 and the support sheet 320 communicates with the small opening end 312 to provide a gas circulation channel. The aperture of the through hole 321 of the support sheet 320 is preferably 0.3 - 0.6 mm. In a specific embodiment, the material of the waterproof and breathable membrane 330 is ePTFE, with an adhesive backing, and can be pasted on the support sheet 320. The outer diameter of the waterproof and breathable membrane 330 is 25 mm, and the inner diameter (referring to the breathable part, the rest is the adhesive) is 10 mm. The waterproof and breathable membrane 330 only allows gas to pass through and does not allow water to pass through. The material of the support sheet 320 is stainless steel, which has excellent characteristics such as high strength and corrosion resistance, and is the same diameter as the breathable membrane, that is, the diameter is 25 mm, the aperture is 0.5 mm, and the thickness is 0.3 mm. The holes are arranged in concentric circles, so as to support the waterproof and breathable membrane 330.

[0059] The fixed ring cap 310 includes a large open end 311 and an opposite small open end 312, and the large open end 311 and the small open end 312 are through. The large open end 311 and the small open end 312 refer to their relative sizes. The fixed ring cap 310 is detachably connected to one end of the connecting pipe 200 through the large open end 311. After the waterproof and breathable membrane 330 and the support sheet 320 are attached, they are arranged between the fixed ring cap 310 and the connecting pipe 200, and are attached to one end of the connecting pipe 200 through the small open end 312 of the fixed ring cap 310. The inner diameter of the small open end 312 is not less than 1 cm.

[0060] In a preferred embodiment of the present invention, as Figure 2 and Figure 3 shown, the ventilation assembly 300 further includes an adapter ring 340. The adapter ring 340 is connected to the connecting pipe 200 and is located between the collection cylinder 100 and the fixed ring cap 310. The adapter ring 340 includes opposite end faces 341 and 342. The end face 341 cooperates with the corresponding part of the collection cylinder 100, and the end face 342 cooperates with the end face of the large open end 311, thereby enhancing the sealing performance between the collection cylinder 100 and the fixed ring cap 310, especially when the contact surface of the collection cylinder 100 and / or the fixed ring cap 310 is non-planar.

[0061] Preferably, the adapter ring 340 is sleeved on the connecting pipe 200, and the fixed ring cap 310 is threadedly connected to the connecting pipe 200. Specifically, the connecting pipe 200 is provided with an external thread, and the large open end 311 of the fixed ring cap 310 is provided with a matching internal thread, so that the two are threadedly connected. The inner ring of the adapter ring 340 is a smooth curved surface, so that after it is connected to the connecting pipe 200, it can rotate freely so that its end face fits with the corresponding part of the collection cylinder 100, so as to achieve the seal between the collection cylinder 100 and the fixed ring cap 310, preventing external soil and other sundries from entering the collection cylinder 100 and affecting gas collection. In particular, sundries are likely to cover the gas analyzer 3, resulting in inaccurate detection, or block the suction pipe, making it impossible to complete the sampling.

[0062] When the device includes two ventilation assemblies 300, the connecting pipe 200 penetrates through the ventilation channel 120, and the two ventilation assemblies 300 are symmetrically arranged at both ends of the connecting pipe 200, that is, an adapter ring 340 abuts against both the inner and outer walls of the collection cylinder 100. At this time, the end face 341 of one adapter ring 340 cooperates with the outer wall of the collection cylinder 100, and the end face 341 of the other adapter ring 340 cooperates with the inner wall of the collection cylinder 100.

[0063] The device preferably further includes an exhaust pipe. An exhaust passage 130 is provided in the gas accommodation chamber 110, and the exhaust pipe is detachably connected to the exhaust passage 130. Specifically, the exhaust passage 130 is formed in the wall of the collection cylinder 100. Further, an exhaust pipe joint 400 is provided in the exhaust passage 130 to stably and quickly connect the exhaust pipe and achieve stable sampling. The exhaust pipe joint 400 can adopt a Luer joint to achieve universality. Further, the exhaust pipe joint 400 adopts a Luer joint with a detachable Luer plug. The exhaust passage 130 is preferably provided at the lower end of the collection cylinder 100 so that when exhausting, the lower gas is first exhausted, and the upper gas is mixed due to gravity sedimentation, thereby improving the uniformity of the extracted gas components and reducing the detection error. Further preferably, the ventilation passage 120 is arranged away from the exhaust passage 130. This "away" refers to the height direction and / or the horizontal direction. Optimally, the ventilation passage 120 and the exhaust passage 130 are located on the diagonal of the cross-section of the collection cylinder 100, that is, the two are the farthest apart, so that the gas flow path is the longest and the disturbance of the external soil gas of the collection cylinder 100 is reduced.

[0064] In a preferred embodiment of the present invention, the volume of the gas accommodation chamber 110 is 1000 cm 3 -2000 cm 3 , to meet the gas extraction requirements, so that the soil gas can form a relatively stable state in the gas accommodation chamber 110 and provide a relatively sufficient extraction amount; at the same time, the disturbance to the soil during burial is reduced, that is, the excessive exchange of gas in the atmosphere and the gas in the soil caused by human influence is reduced, affecting the authenticity of the soil gas sample. This volume is also adapted to the size of the current gas analyzer 3 so that it can be placed in.

[0065] The present invention also provides a method for collecting soil gas, using any soil gas collection device 1, and including the following steps:

[0066] Place the gas analyzer 3 and / or connect the exhaust pipe in the collection cylinder 100. It can be understood that one end of the exhaust pipe is connected to the exhaust passage 130, that is, buried in the soil, and the other end is exposed outside the soil to collect the soil gas. The exhaust pipe is not shown in the figure.

[0067] Pre-bury one or more soil gas collection devices 1 into the soil according to requirements.

[0068] After a certain period of time, extract the gas in the collection cylinder 100 to complete the sampling. The time can be artificially determined. It is beneficial to bury for one week. At the same time, the sampling time interval can also be artificially determined. For example, sample once at a fixed time every day after burying for one week. If there is no change in the gas concentration in the sample, it may be that the gas has not been exchanged yet, and the time can be postponed for a period of time and sampled again.

[0069] Preferably, multiple soil gas collection devices 1 are buried at different positions at the same depth in the soil, that is, multiple soil gas collection devices 1 are pre-buried in the soil at parallel intervals. Or multiple soil gas collection devices 1 are buried at the same position in the soil at different depths, that is, multiple soil gas collection devices 1 are pre-buried vertically stacked in the soil.

[0070] Preferably, when the soil gas collection device 1 is buried in the soil, the ventilation component 300 is perpendicular to the horizontal plane, so as to prevent the soil from blocking the ventilation component 300 due to gravity extrusion.

[0071] Preferably, the air extraction channel 130 of the collection cylinder 100 is placed away from the soil surface. This placement method can ensure that air is extracted from the lower part of the gas accommodation cavity 110, so as to obtain relatively uniformly mixed soil gas. Specifically, the gas at the bottom is first extracted, and the gas at the upper part sinks and mixes due to the action of gravity, thereby improving the gas uniformity.

[0072] To extend the length of the gas flow path and reduce the disturbance to the soil gas outside the collection cylinder, it is preferable to use a collection cylinder 100 with a relatively large distance between the ventilation channel 120 and the air extraction channel 130.

[0073] Example 1:

[0074] As Figure 4 shown, a gas analyzer 3 (recorder) is built into the collection cylinder 100 to analyze and record soil gas in real time.

[0075] For example, a portable gas analyzer 3 for CO 2 and / or O 2 is turned on, the recording time interval is set, and it is placed in the collection cylinder 100. If there is an air extraction channel 130, the air extraction channel 130 is closed, and then it is vertically buried in the soil 2. The soil gas will analyze and record the soil gas components and concentrations at preset times.

[0076] Example 2:

[0077] As Figure 5 shown, soil gas is collected at different positions at the same depth.

[0078] Taking a soil remediation site as an example, the soil gas collection devices 1 are respectively buried in the soil 2 at the same depth at different positions, and the air extraction pipes are respectively connected. After air extraction and sampling, they are taken to the laboratory for further analysis. This method can timely understand whether the dosage of the remediation agent (such as an oxidant) is insufficient or not uniform enough.

[0079] Example 3:

[0080] As Figure 6 shown, soil gas is collected at the same position at different depths.

[0081] Taking the study of soil carbon emissions as an example, there are differences in soil temperature and soil microbial populations at different depths, which in turn affect carbon emissions (soil respiration). After stacking the soil gas collection devices 1 one by one, they are vertically buried in the soil 2 at different depths at the same site, connected to the suction pipes respectively, and the soil gases at different depths are extracted respectively and taken to the laboratory for further analysis.

[0082] By using this method, soil gases can be collected in-situ at fixed times and locations for long-term monitoring experiments.

[0083] In summary, the collection cylinder of the present invention can be directly buried inside the soil to achieve the collection of soil gases at different depths, and is applicable to different types of soil through pre-burial, with a wide range of applications; at the same time, through the cooperation of the connecting pipe and the ventilation component, the ventilation channel is blocked in a limited way, the soil is blocked and filtered by the support sheet, and the liquid is blocked by the waterproof and breathable membrane to prevent the liquid from entering the gas cavity and affecting the sample detection.

[0084] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0085] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A soil gas collection device, characterized in that, it includes a collection cylinder, a connecting pipe arranged on the collection cylinder, and a ventilation component connected to the connecting pipe; a gas accommodation cavity is arranged in the collection cylinder, and at least one ventilation channel communicating with the outside is arranged in the gas accommodation cavity; the connecting pipe is arranged in the ventilation channel; the ventilation component includes a fixed ring cap for connecting with the connecting pipe, a waterproof breathable membrane, and a support sheet. The fixed ring cap includes a large opening end and a relatively small opening end, and the large opening end and the small opening end are penetrated. The fixed ring cap is detachably connected to one end of the connecting pipe through the large opening end. The support sheet is provided with a plurality of through holes. After the waterproof breathable membrane and the support sheet are attached, they are arranged between the fixed ring cap and the connecting pipe, and are attached to one end of the connecting pipe through the small opening end; the ventilation component further includes an adapter ring, which is used to connect with the connecting pipe and is located between the collection cylinder and the fixed ring cap. The adapter ring includes opposite end face one and end face two. The end face one cooperates with the corresponding part of the collection cylinder, and the end face two cooperates with the end face of the large opening end; the adapter ring is sleeved on the connecting pipe, and the fixed ring cap is threadedly connected to the connecting pipe; it further includes an extraction pipe. An extraction channel is arranged in the gas accommodation cavity, and the extraction pipe is detachably connected to the extraction channel; the extraction channel is arranged at the lower end of the collection cylinder; the ventilation channel is far away from the extraction channel.

2. The soil gas collection device according to claim 1, characterized in that, the support sheet is farther away from the cylinder wall of the collection cylinder than the waterproof breathable membrane.

3. The soil gas collection device according to claim 1, characterized in that, it includes two of the ventilation components, the connecting pipe penetrates through the ventilation channel, and the two ventilation components are symmetrically arranged at both ends of the connecting pipe.

4. A soil gas collection method, characterized in that, using the soil gas collection device according to any one of claims 1-3, and including the following steps: placing a gas analyzer and / or connecting an extraction pipe in the collection cylinder; embedding one or more of the soil gas collection devices into the soil according to requirements; extracting the gas in the collection cylinder after a certain period of time to complete sampling.

5. The soil gas collection method according to claim 4, characterized in that, placing the extraction channel of the collection cylinder away from the soil surface.

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