System and method for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation

Abstract

Abstract The present invention discloses a system and method for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation, and belongs to the technical field of in- situ sampling devices for interstitial water and gaseous organic matters from wetland sediments in multilayer profiles. This system includes a sampling head, a sample tube adapter, a filter membrane, an injector, a vacuum bottle to which a Teflon capillary tube is connected, a water inlet with a foam float, a starcone-shaped sampling head cap, and a perforated iron wire mesh, etc. In the method, after a device is prepared, the sample tube adapter drives the sampling head to sink to a target position, and the sampling head is rotated to be detached from the starcone-shaped sampling head cap to start the sampling; interstitial water enters the sampling head through the perforated iron wire mesh; a three-way valve is switched, and aqueous phase samples and gaseous phase samples are collected by an aqueous phase sampling bottle and the vacuum bottle to which the Teflon capillary tube is connected, respectively; and after sampling, a drag-reduction connection cord drags a cap flip to drive the sampling head to move upward. This system and method are mainly used for the in-situ extraction of organic matters in multilayer profiles of a wetland ecosystem, and can collect aqueous phase samples and gaseous phase samples synchronously. Abstract 20 26 20 01 41 09 J an 2 02 6 A b s t r a c t 2 0 2 6 2 0 0 1 4 1 0 9 J a n 2 0 2 6

Description

TECHNICAL FIELD

[0001] The present invention belongs to the technical field of in-situ sampling devices for interstitial water and gaseous organic matters from wetland sediments in multilayer profiles. BACKGROUND

[0002] Wetland sediments are important carriers of material cycling and energy exchange in ecosystems, and dissolved organic matters and volatile gases contained in their pores are of great significance for studying the interaction mechanism of sediments and organisms. The in-situ collection and analysis of such substances is a key link in understanding the functions of wetland ecosystems, but there are still many limitations in existing collection technologies.

[0003] The previous methods for collecting sediment-related samples may be classified into four categories. The first category is to collect sediment columns by using a gravity tube or a multitube sampler, transport them back to a laboratory, and then separate them for extraction. This method will destroy an anaerobic environment of wetland sediments, resulting in the deterioration of dissolved organic matters, and at the same time, volatile gases are easy to diffuse and overflow during the transfer process, resulting in flux estimation loss. The transfer of sediments under atmospheric pressure for gas testing will cause sample overflow and signal distortion. The second category is a cup-type sampler, which can extract samples through vacuum extraction in combination with void ceramics, but can only collect liquid samples and cannot acquire gaseous phase samples, so that dissolved organic matters cannot match gaseous signals for analysis. The third category is a needle-type interstitial water sampler, which employs a porous filter head filled with a specific material, which is not only expensive and non-recyclable, but also has a fragile sampling head structure, making it difficult to achieve deep sampling, and cannot carry out large-capacity sample collection to meet subsequent analysis needs. The fourth category is a drilling extraction method, which requires supporting mechanical equipment, and silty sediments in the wetland are easy to reset after drilling, cannot maintain a sampling channel, and are thus not suitable for a soft environment of the wetland. At present, there is no commercial equipment on the market that can implement deep in-situ extraction of multilayer profiles in wetland ecosystems and is difficult to meet the needs of synchronous collection of dissolved organic matters and 2026200141   31 Aug 2026 volatile gases and high-fidelity preservation of sample characteristics, thereby limiting the research progress in related fields. SUMMARY

[0004] The present invention attempts to provide a system and method for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation, which are used to solve the problem that the prior art cannot synchronously collect dissolved organic matters and volatile gas samples from wetland sediments in multilayer profiles, making it difficult to achieve deep in-situ sampling.

[0005] In order to fulfill the above objective, the present invention provides the following technical solution.

[0006] In a first aspect, the present invention provides a device for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation. The device includes a sampling head, a sample tube adapter, a filter membrane, a first syringe, a second syringe, a first Teflon capillary tube, a vacuum bottle to which the first Teflon capillary tube is connected, a water inlet with a foam float, a starcone-shaped sampling head cap, a perforated iron wire mesh, a first three-way valve, a second three-way valve, an aqueous phase sampling bottle, a second Teflon capillary tube, a screw and a drag-reduction connection cord, wherein the sampling head is equipped with the perforated iron wire mesh and the starcone-shaped sampling head cap; the upper end of the sampling head is connected to the sample tube adapter; the sample tube adapter is connected to a water pipe and the second Teflon capillary tube by means of the second three-way valve; the water pipe is connected to the aqueous phase sampling bottle and the water inlet with the foam float, respectively; the filter membrane is arranged at a water outlet of the aqueous phase sampling bottle; the first syringe (7) is connected to the output of the vacuum bottle (9) to which the first Teflon capillary tube is connected, and the second syringe (7) is connected to the output of the aqueous phase sampling bottle (6) via the filter membrane (5) by means of the second three-way valve ; the starcone-shaped sampling head cap is connected to the sampling head through the screw; and the sampling head is connected to an external traction structure through the drag-reduction connection cord.

[0007] In a possible embodiment, the perforated iron wire mesh is a multilayer tubular iron wire filter screen; the perforated iron wire mesh is communicated with an internal channel of the sampling head and arranged in a tangential penetration structure; the screw is fixed at one end of 2026200141   31 Aug 2026 the sampling head connected to the starcone-shaped sampling head cap; and the screw is connected to a corresponding position of the starcone-shaped sampling head cap.

[0008] In a possible embodiment, the starcone-shaped sampling head cap is equipped with a starshaped protrusion; during sampling, the rotating sampling head can make the starcone-shaped sampling head cap detached from the screw; and after sampling, the sampling head can be pulled up, and the drag-reduction connection cord can drag the starcone-shaped sampling head cap to flip.

[0009] In a possible embodiment, the sample tube adapter is a flat plate structure; the sample tube adapter is fixedly connected to the sampling head; the sample tube adapter can be pressed manually to drive the sampling head to sink; the water inlet with the foam float is fixed at the lower end of the sampling head; and the water inlet with the foam float is communicated with the internal channel of the sampling head.

[0010] In a possible embodiment, the water pipe is a metal steel pipe; the first Teflon capillary tube is embedded inside the metal steel pipe; both ends of the first Teflon capillary tube are hermetically connected to the first three-way valve and the vacuum bottle to which the first Teflon capillary tube is connected, respectively; the vacuum bottle to which the first Teflon capillary tube is connected is a gaseous phase sampling bottle; and the gaseous phase sampling bottle is arranged to correspond to a headspace air domain from a liquid level inside the sampling head.

[0011] In a possible embodiment, the aqueous phase sampling bottle is communicated with the internal channel of the sampling head; the filter membrane is fixed at a port of the aqueous phase sampling bottle close to the second syringe; and the filter membrane is used to filter interstitial water entering the second syringe.

[0012] In a possible embodiment, the second three-way valve has three connecting ports, which are respectively connected to the sample tube adapter, the water pipe and the second Teflon capillary tube in a one-to-one correspondence manner, and can be switched to different connecting paths by rotating the second three-way valve; the first syringe is connected to one of the ports of the first three-way valve; and a pressure in the connecting paths of the second three-way valve can be adjusted by operating the first syringe.

[0013] In a second aspect, the present invention provides a method for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation. The method includes the following steps:

[0014] preparing the device as described above; driving, by the sample tube adapter, the sampling head to sink to a target sampling position; 2026200141   31 Aug 2026

[0015] operating the sampling head to start the sampling, such that interstitial water in a sediment enters into the sampling head;

[0016] switching paths through the first and second three-way valves, collecting aqueous phase samples using the aqueous phase sampling bottle, and collecting gaseous phase samples using the vacuum bottle to which the first Teflon capillary tube is connected; and

[0017] after the sampling is completed, dragging the starcone-shaped sampling head cap by the drag-reduction connection cord to drive the sampling head upward to be detached from the sediment.

[0018] In a possible embodiment, after the preparation is completed, the sample tube adapter is fixedly connected to the upper end of the sampling head, and the sample tube adapter is pressed manually to drive the sampling head to sink to the target sampling position;

[0019] the step of operating the sampling head to start the sampling, such that interstitial water in the sediment enters into the sampling head includes: rotating the sampling head, such that the starcone-shaped sampling head cap is detached from the screw, wherein the starcone-shaped sampling head cap is equipped with a star-shaped protrusion; enabling the interstitial water in the sediment after detachment to tangentially permeate into the internal channel of the sampling head through the perforated iron wire mesh under the action of water pressure; forming a supernatant from the interstitial water inside the sampling head under the action of self-sedimentation, sucking the supernatant through the water inlet with the foam float and conveying the supernatant to the water pipe; and

[0020] the step of switching paths through the second three-way valve, and collecting aqueous phase samples using the aqueous phase sampling bottle includes: rotating the second three-way valve, such that the second three-way valve communicates the internal channel of the sampling head with the water pipe; and enabling the supernatant to flow through the water pipe to the aqueous phase sampling bottle, and after being filtered by the filter membrane, to enter into the second syringe to complete the collection of the aqueous phase samples.

[0021] In a possible embodiment, the step of switching paths through the second three-way valve, and collecting gaseous phase samples using the vacuum bottle to which the second Teflon capillary tube is connected includes: after the gas-liquid balance inside the sampling head, rotating the second three-way valve, such that the second three-way valve communicates the headspace air domain from the liquid level inside the sampling head with the second Teflon capillary tube; enabling gas to enter into the vacuum bottle through the second Teflon capillary tube under the action of a negative pressure inside the vacuum bottle to which the first Teflon capillary tube is 2026200141   31 Aug 2026 connected so as to complete the collection of gaseous phase samples; if the pressure in the paths is insufficient during the collection process, operating the first syringe to adjust the pressure in a connecting channel of the second three-way valve to assist sample flowing; and

[0022] the step of, after the sampling is completed, dragging the starcone-shaped sampling head cap by the drag-reduction connection cord to drive the sampling head upward to be detached from the sediment includes: connecting one end of the drag-reduction connection cord to the starconeshaped sampling head cap, and enabling the other end of the drag-reduction connection cord to extend to an external operating end; pulling the drag-reduction connection cord upward, and dragging the starcone-shaped sampling head cap to flip to reduce the upward resistance; and continuing to pull the drag-reduction connection cord to drive the sampling head upward to be detached from the sediment.

[0023] Compared with the prior art, the present invention has the following beneficial effects: from the perspective of structure and mode of action, the system is connected to the aqueous phase sampling bottle and the vacuum bottle to which the first Teflon capillary tube is connected respectively through the first and second three-way valves, and in combination with the corresponding layout of the second Teflon capillary tube and the headspace air domain from the liquid level inside the sampling head, dissolved organic matters and volatile gas samples can be collected synchronously in situ, which solves the problem that the existing cup-type sampler and the needle-type interstitial water sampler can only collect single phase samples, so that signals for aqueous phase samples and gaseous phase samples can be used for matching analysis.

[0024] The starcone-shaped sampling head cap mounted on the sampling head is equipped with a star-shaped protrusion, which is fixed by a screw and may be detached by rotation, and the sample tube adapter with a flat plate structure needs only to be pressed manually to drive the sampling head to sink to a deep position, without relying on mechanical equipment, thereby avoiding the defects of easy resetting and inability to maintain the sampling channel in wetland silty sediments in a drilling method. After sampling, by using the drag-reduction connection cord to drag the cap to flip, the upward resistance can be further reduced, enabling convenient field operations.

[0025] The multilayer tubular iron wire filter screen is arranged inside the sampling head in a tangential permeation structure, which can not only intercept solid particles in the sediment, but also ensure the high-throughput entry of interstitial water, and in combination with the selfsedimentation process inside the sampling head, a large volume of supernatant samples can be acquired, thereby overcoming the shortcomings of expensive and non-recyclable filter heads of needle-type interstitial water samplers and limited sampling capacity. 2026200141   31 Aug 2026

[0026] At the same time, the entire sampling process is completed in situ without the transfer of sediments or samples, which effectively avoids the deterioration of dissolved organic matters, volatile gas overflow and signal distortion caused by sample transfer in the existing gravity tube sampler, and ensures the high fidelity of sample characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0027] For clearer descriptions of the technical solutions in the embodiments of the present invention, the following briefly describes the accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description show merely some embodiments of the present application, and other drawings may be derived by a person of ordinary skill in the art from these accompanying drawings without creative efforts.

[0028] FIG. 1 is a schematic diagram of an overall structure of a system for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation according to an embodiment of the present invention;

[0029] FIG. 2 is a schematic diagram of a partial structure of a sampling head of the system for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation according to an embodiment of the present invention;

[0030] FIG. 3 is a schematic top view of a partial structure of a sampling head cap of the system for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation according to an embodiment of the present invention; and

[0031] FIG. 4 is a schematic structural diagram of a partial structure of the sampling head of the system for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation in a rising process according to an embodiment of the present invention.

[0032] Reference symbols represent the following components: 1-wetland sediment; 2-sampling head; 3-sample tube adapter; 4-sample tube; 5-filter membrane; 6-secondary sedimentation bottle; 7-syringe; 8-three-way valve; 9-vacuum bottle to which a Teflon capillary tube is connected; 10-water inlet with foam float; 11-starcone-shaped sampling head cap; 12-multilayer iron wire mesh; 13-screw; 14-drag-reduction connection cord; and 15-Teflon capillary tube. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some embodiments, rather 2026200141   31 Aug 2026 than all embodiment, of the present application. Based on the embodiments in the present application, all other embodiments derived by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0034] Embodiments:

[0035] It should be noted that the terms “comprise / include” and “having” and any variants thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or are inherent to such processes, methods, products, or devices.

[0036] The present embodiment provides a device for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation. The device includes a sampling head, a sample tube adapter, a filter membrane, a first syringe, a second syringe, a first Teflon capillary tube, a vacuum bottle to which the first Teflon capillary tube is connected, a water inlet with a foam float, a starcone-shaped sampling head cap, a perforated iron wire mesh, a first three-way valve, a second three-way valve, an aqueous phase sampling bottle, a second Teflon capillary tube, a screw and a drag-reduction connection cord, wherein the sampling head is equipped with the perforated iron wire mesh and the starcone-shaped sampling head cap; the upper end of the sampling head is connected to the sample tube adapter; the sample tube adapter is connected to a water pipe and the second Teflon capillary tube by means of the second three-way valve, respectively; the water pipe is connected to the aqueous phase sampling bottle and the water inlet with the foam float, respectively; the filter membrane is arranged at a water outlet of the aqueous phase sampling bottle; the first syringe is connected to the output of the vacuum bottle to which the first Teflon capillary tube is connected, and the second syringe is connected to the output of the aqueous phase sampling bottle via the filter membrane by means of the second three-way valve; the starcone-shaped sampling head cap is connected to the sampling head through the screw; and the sampling head is connected to an external traction structure through the drag-reduction connection cord.

[0037] In one embodiment, the perforated iron wire mesh is a multilayer tubular iron wire filter screen; the perforated iron wire mesh is communicated with an internal channel of the sampling head and arranged in a tangential penetration structure; the screw is fixed at one end of the sampling head connected to the starcone-shaped sampling head cap; and the screw is connected to a corresponding position of the starcone-shaped sampling head cap.

[0038] In one embodiment, the starcone-shaped sampling head cap is equipped with a star-shaped protrusion; during sampling, the rotating sampling head can make the starcone-shaped sampling 2026200141   31 Aug 2026 head cap detached from the screw; and after sampling, the sampling head can be pulled up, and the drag-reduction connection cord drags the starcone-shaped sampling head cap to flip.

[0039] In one embodiment, the sample tube adapter is a flat plate structure; the sample tube adapter is fixedly connected to the sampling head; the sample tube adapter can be pressed manually to drive the sampling head to sink; the water inlet with the foam float is fixed at the lower end of the sampling head; and the water inlet with the foam float is communicated with the internal channel of the sampling head.

[0040] In one embodiment, the water pipe is a metal steel pipe; the second Teflon capillary tube is embedded inside the metal steel pipe; both ends of the second Teflon capillary tube are hermetically connected to the second three-way valve and the vacuum bottle to which the first Teflon capillary tube is connected, respectively; the vacuum bottle to which the first Teflon capillary tube is connected is a gaseous phase sampling bottle; and the gaseous phase sampling bottle is arranged to correspond to a headspace air domain from a liquid level inside the sampling head.

[0041] In one embodiment, the aqueous phase sampling bottle is communicated with the internal channel of the sampling head; the filter membrane is fixed at a port of the aqueous phase sampling bottle close to the second syringe; and the filter membrane is used to filter interstitial water entering the second syringe.

[0042] In one embodiment, the second three-way valve has three connecting ports, which are respectively connected to the sample tube adapter, the water pipe and the second Teflon capillary tube in a one-to-one correspondence manner, and can be switched to different connecting paths by rotating the second three-way valve; the second syringe is connected to one of the ports of the second three-way valve; and a pressure in the connecting paths of the second three-way valve can be adjusted by operating the first syringe.

[0043] The present embodiment further provides a method for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation. The method includes the following steps.

[0044] In step 1: the device as described above is prepared; and the sampling head is driven by the sample tube adapter to sink to a target sampling position.

[0045] During the preparation of the device as described above, the perforated iron wire mesh is arranged inside the sampling head and communicated with the internal channel of the sampling head; the starcone-shaped sampling head cap is fixedly connected to the sampling head through the screw; the second Teflon capillary tube is embedded in the water pipe, and both ends of the second Teflon capillary tube are connected to the second three-way valve and the vacuum bottle 2026200141   31 Aug 2026 to which the first Teflon capillary tube is connected, respectively; the first syringe is connected to the output of the vacuum bottle to which the first Teflon capillary tube is connected, and the second syringe is connected to the output of the aqueous phase sampling bottle via the filter membrane by means of the second three-way valve ; the filter membrane is fixed at a port of the aqueous phase sampling bottle close to the second syringe; and the aqueous phase sampling bottle is connected to the second three-way valve through the water pipe.

[0046] After the preparation is completed, the sample tube adapter is fixedly connected to the upper end of the sampling head, and the sample tube adapter is pressed manually to drive the sampling head to sink to the target sampling position.

[0047] In step 2, the sampling head is operated to start the sampling, such that interstitial water in the sediment enters into the sampling head.

[0048] The step of operating the sampling head to start the sampling, such that interstitial water in the sediment enters into the sampling head includes: rotating the sampling head, such that the starcone-shaped sampling head cap is detached from the screw, wherein the starcone-shaped sampling head cap is equipped with a star-shaped protrusion; enabling the interstitial water in the sediment after detachment to tangentially permeate into the internal channel of the sampling head through the perforated iron wire mesh under the action of water pressure; forming a supernatant from the interstitial water inside the sampling head under the action of self-sedimentation, sucking the supernatant through the water inlet with the foam float and conveying the supernatant to the water pipe.

[0049] In step 3, paths are switched through the first and second three-way valves, aqueous phase samples are collected using the aqueous phase sampling bottle, and gaseous phase samples are collected using the vacuum bottle to which the first Teflon capillary tube is connected.

[0050] The step of switching paths through the second three-way valve, and collecting aqueous phase samples using the aqueous phase sampling bottle includes: rotating the second three-way valve, such that the second three-way valve communicates the internal channel of the sampling head with the water pipe; and enabling the supernatant to flow through the water pipe to the aqueous phase sampling bottle, and after being filtered by the filter membrane, to enter into the second syringe to complete the collection of the aqueous phase samples.

[0051] The step of switching paths through the second three-way valve, and collecting gaseous phase samples using the vacuum bottle to which the first Teflon capillary tube is connected includes: after the gas-liquid balance inside the sampling head, rotating the second three-way valve, such that the second three-way valve communicates the headspace air domain from the 2026200141   31 Aug 2026 liquid level inside the sampling head with the second Teflon capillary tube; enabling gas to enter into the vacuum bottle through the second Teflon capillary tube under the action of a negative pressure inside the vacuum bottle to which the first Teflon capillary tube is connected so as to complete the collection of gaseous phase samples; if the pressure in the paths is insufficient during the collection process, operating the first syringe to adjust the pressure in the connecting channel of the second three-way valve to assist sample flowing.

[0052] In step 4: after the sampling is completed, dragging the starcone-shaped sampling head cap by the drag-reduction connection cord to drive the sampling head upward to be detached from the sediment.

[0053] the step of dragging the starcone-shaped sampling head cap by the drag-reduction connection cord to drive the sampling head upward to be detached from the sediment includes: connecting one end of the drag-reduction connection cord to the starcone-shaped sampling head cap, and enabling the other end of the drag-reduction connection cord to extend to an external operating end; pulling the drag-reduction connection cord upward, and dragging the starconeshaped sampling head cap to flip to reduce the upward resistance; and continuing to pull the dragreduction connection cord to drive the sampling head upward to be detached from the sediment.

[0054] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with accompanying drawings in the embodiments of the present invention.

[0055] Referring to FIG. 1, the present embodiment provides a system for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation. The system includes a sampling head 2, a sample tube adapter 3, a filter membrane 5, a fine particle sedimentation cell, a syringe 7, a vacuum bottle (i.e., a gaseous phase sampling bottle 9) to which the first Teflon capillary tube is connected, a water inlet 10 with a foam float, a perforated iron wire mesh 11, a starcone-shaped sampling head cap 12, and a screw 13. Before use, the starcone-shaped sampling head cap 12 of the sampling head 2 is tightly screwed and fixed with the screw 13, the flat plate structure of the sample tube adapter 3 is pressed manually, and the sample tube adapter 3 drives the sampling head 2 to sink gradually; and when the sampling head 2 reaches a specified position, the sampling head 2 contacts the sediment 1. Then, the sampling head 2 is rotated by one circle, the starcone-shaped sampling head cap 12 is then detached from the screw 13, and the interstitial water in the sediment 1 enters into the sampling head 2 through the multilayer perforated iron wire mesh 11 by means of tangential penetration. The water inlet 10 with the foam float at the lower end of the sampling head 2 is connected to the sample tube adapter 3, and the sample tube adapter 3 is also connected 2026200141   31 Aug 2026 to the water pipe through the three-way valve 8. The water pipe is connected to the aqueous phase sampling bottle 6 and the gaseous phase sampling bottle 9 at the same time, and the filter membrane 5 is arranged at a water outlet of the aqueous phase sampling bottle 6.

[0056] In the present embodiment, referring to FIG. 2, in order to avoid excessive resistance during deep profile sampling, the sampling head 2 is protected by the starcone-shaped sampling head cap 12. The starcone-shaped structure is configured to reduce the resistance during the sinking process, so that the system can allow independent field sampling operations without mechanical assistance. The water pipe to which the sampling head 2 is connected is a metal steel pipe, and the water inlet 10 with the foam float is connected to the lower end of the water pipe. The water inlet 10 with the foam float can readily suck the supernatant formed after the self-sedimentation occurs inside the sampling head 2.

[0057] More specifically, in the present embodiment, the starcone-shaped sampling head cap 12 with the star-shaped protrusion is connected to the sampling head 2 through the screw 13. This connection mode not only protects the sampling head 2 but also increases the resistance endurance of the sampling head 2 during the sinking process. Referring to FIG. 3, the star-shaped protrusion is arranged on the starcone-shaped sampling head cap 12. When the sampling head 2 reaches a specified depth, the water pipe made of a metal steel pipe is rotated, and the water pipe is moved up by 1 cm at the same time to achieve non-contact start of underwater sampling. The starconeshaped sampling head cap 12 is pressed and placed in the wet sediment, and its star-shaped protrusion will lead to pores in the surrounding sediment. The interstitial water penetrates into the perforated iron wire mesh 11 under the action of water pressure. Solid particles in the sediment are intercepted by the perforated iron wire mesh 11. The multilayer perforated iron wire mesh 11 adopts a tangential flow structure to achieve high-throughput water passage, and pure interstitial water can be obtained from the liquid level inside the sampling head 2 after self-sedimentation. The interstitial water flows upward through the connected water pipe, flows through the filter membrane 5 to be filtered, and is then sucked into the second syringe 7.

[0058] More specifically, referring to FIG. 4, after the sampling operation is completed, the sampling head 2 is pulled upward, and the bottom end of the starcone-shaped head cap 12 will be dragged by the connection cord to flip. The flipped starcone-shaped sampling head cap 12 can significantly reduce the upward resistance, so that the sampling head 2 can move up at low resistance to be detached from the sediment.

[0059] On this basis, the gaseous phase sampling bottle 9 is communicated with the headspace air domain from the liquid level inside the sampling head 2, and after the gas-liquid balance is 2026200141   31 Aug 2026 achieved inside the sampling head 2, the connection between the gaseous phase sampling bottle 9 and the second Teflon capillary tube 15 can be achieved by rotating the three-way valve 8. In the present embodiment, the second Teflon capillary tube 15 is used as a gas transport channel, and the second Teflon capillary tube 15 is embedded in a metal tube of the sampling head 2. This structure can keep the headspace air volume extremely small, so as to effectively prevent the contamination to the samples by exogenous air. The gaseous matters and the solid-liquid system reach a balance in situ, and then the flux of the gaseous organic matters including microbubbles can be obtained. After balance with atmospheric pressure, the three-way valve 8 is rotated, and a negative pressure inside the gaseous phase sampling bottle 9 will allow the balanced gas to enter the bottle, achieving parallel collection of gas and liquid samples eventually.

[0060] In the present embodiment, the spill flux of gas including microbubbles can also be calculated by accumulating sampling time, thereby providing more comprehensive data support for subsequent analysis.

[0061] In the description of the present specification, the description of referring terms such as “an embodiment”, “some embodiments”, “an example”, “a specific example” and “some examples” integrate particular features, structures, materials or characteristics described in combination with the embodiments or examples and included in at least one embodiment or example of the present invention. In the description, the schematic description of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the described particular features, structures, materials or characteristics can be integrated with any one or more embodiments or examples in a proper manner. In addition, in the absence of contradiction, a person skilled in the art can integrate and combine different embodiments or examples described in this specification and the features of different embodiments or examples.

[0062] The above embodiments are only to illustrate the technical conception and characteristics of the present invention, and are intended to enable a person of ordinary skill in the art to understand the content of the present invention and to implement it accordingly, but not intended to limit the protection scope of the present invention. The equivalent changes or modifications made according to the essence of the present invention shall be covered by the protection scope of the present invention.

[0063] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that such prior art forms part of the common general knowledge. 2026200141   31 Aug 2026

[0064] It will be understood that the terms “comprise” and “include” and any of their derivatives (e.g. comprises, comprising, includes, including) as used in this specification, and the claims that follow, is to be taken to be inclusive of features to which the term refers, and is not meant to exclude the presence of any additional features unless otherwise stated or implied.

[0065] In some cases, a single embodiment may, for succinctness and / or to assist in understanding the scope of the disclosure, combine multiple features. It is to be understood that in such a case, these multiple features may be provided separately (in separate embodiments), or in any other suitable combination. Alternatively, where separate features are described in separate embodiments, these separate features may be combined into a single embodiment unless otherwise stated or implied. This also applies to the claims which can be recombined in any combination. That is a claim may be amended to include a feature defined in any other claim. Further a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

[0066] It will be appreciated by those skilled in the art that the disclosure is not restricted in its use to the particular application or applications described. Neither is the present disclosure restricted in its preferred embodiment with regard to the particular elements and / or features described or depicted herein. It will be appreciated that the disclosure is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope as set forth and defined by the following claims.

Claims

1. A device for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation, comprising a sampling head, a sample tube adapter, a filter membrane, a first syringe, a second syringe, a first Teflon capillary tube, a vacuum bottle to which the first Teflon capillary tube is connected, a water inlet with a foam float, a starcone-shaped sampling head cap, a perforated iron wire mesh, a first three-way valve, a second three-way valve, an aqueous phase sampling bottle, a second Teflon capillary tube, a screw and a drag-reduction connection cord, wherein the sampling head is equipped with the perforated iron wire mesh and the starcone-shaped sampling head cap; the upper end of the sampling head is connected to the sample tube adapter; the sample tube adapter is connected to a water pipe and the second Teflon capillary tube by means of the second three-way valve, respectively; the water pipe is connected to the aqueous phase sampling bottle and the water inlet with the foam float, respectively; the filter membrane is arranged at a water outlet of the aqueous phase sampling bottle; the first syringe is connected to the output of the vacuum bottle to which the first Teflon capillary tube is connected, and the second syringe is connected to the output of the aqueous phase sampling bottle via the filter membrane by means of the second three-way valve ; the starcone-shaped sampling head cap is connected to the sampling head through the screw; and the sampling head is connected to an external traction structure through the drag-reduction connection cord.

2. The device for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation according to claim 1, wherein the perforated iron wire mesh is a multilayer tubular iron wire filter screen; the perforated iron wire mesh is communicated with an internal channel of the sampling head and arranged in a tangential penetration structure; the screw is fixed at one end of the sampling head connected to the starcone-shaped sampling head cap; and the screw is connected to a corresponding position of the starcone-shaped sampling head cap.

3. The device for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation according to either claim 1 or claim 2, wherein the starcone-shaped sampling head cap is equipped with a star-shaped protrusion; during sampling, the rotating sampling head can make the starcone-shaped sampling head cap detached from the screw; and after sampling, the2026200141   31 Aug 202615 sampling head can be pulled up, and the drag-reduction connection cord drags the starcone-shaped sampling head cap to flip.

4. The device for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation according to any one of claims 1 to 3, wherein the sample tube adapter is a flat plate structure; the sample tube adapter is fixedly connected to the sampling head; the sample tube adapter can be pressed manually to drive the sampling head to sink; the water inlet with the foam float is fixed at the lower end of the sampling head; and the water inlet with the foam float is communicated with the internal channel of the sampling head.

5. The device for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation according to any one of claims 1 to 4, wherein the water pipe is a metal steel pipe; the second Teflon capillary tube is embedded inside the metal steel pipe; both ends of the second Teflon capillary tube are hermetically connected to the second three-way valve and the vacuum bottle to which the first Teflon capillary tube is connected, respectively; the vacuum bottle to which the first Teflon capillary tube is connected is a gaseous phase sampling bottle; and the gaseous phase sampling bottle is arranged to correspond to a headspace air domain from a liquid level inside the sampling head.

6. The device for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation according to any one of claims 1 to 5, wherein the aqueous phase sampling bottle is communicated with the internal channel of the sampling head; the filter membrane is fixed at a port of the aqueous phase sampling bottle close to the second syringe; and the filter membrane is used to filter interstitial water entering the second syringe.

7. The device for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation according to any one of claims 1 to 6, wherein the second three-way valve has three connecting ports, which are respectively connected to the sample tube adapter, the water pipe and the second Teflon capillary tube in a one-to-one correspondence manner, and can be switched to different connecting paths by rotating the second three-way valve; the first syringe is connected to2026200141   31 Aug 2026one of the ports of the first three-way valve; and a pressure in the connecting paths of the second three-way valve can be adjusted by operating the first syringe.

8. A method for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation, comprising the following steps:preparing the device according to any one of claims 1 to 7; driving, by the sample tube adapter, the sampling head to sink to a target sampling position;operating the sampling head to start the sampling, such that interstitial water in the sediment enters into the sampling head;switching paths through the first and second three-way valves, collecting aqueous phase samples using the aqueous phase sampling bottle, and collecting gaseous phase samples using the vacuum bottle to which the first Teflon capillary tube is connected; andafter the sampling is completed, dragging the starcone-shaped sampling head cap by the drag-reduction connection cord to drive the sampling head upward to be detached from the sediments.

9. The method for in-situ extraction of organic matters in multilayer profiles based on selfsedimentation according to claim 8, whereinafter the preparation is completed, the sample tube adapter is fixedly connected to the upper end of the sampling head, and the sample tube adapter is pressed manually to drive the sampling head to sink to the target sampling position;the step of operating the sampling head to start the sampling, such that interstitial water in the sediment enters into the sampling head includes: rotating the sampling head, such that the starcone-shaped sampling head cap is detached from the screw, wherein the starcone-shaped sampling head cap is equipped with a star-shaped protrusion; enabling the interstitial water in the sediment after detachment to tangentially permeate into the internal channel of the sampling head through the perforated iron wire mesh under the action of water pressure; forming a supernatant from the interstitial water inside the sampling head under the action of self-sedimentation, sucking the supernatant through the water inlet with the foam float and conveying the supernatant to the water pipe; andthe step of switching paths through the second three-way valve, and collecting aqueous phase samples using the aqueous phase sampling bottle includes: rotating the second three-way2026200141   31 Aug 2026valve, such that the second three-way valve communicates the internal channel of the sampling head with the water pipe; and enabling the supernatant to flow through the water pipe to the aqueous phase sampling bottle, and after being filtered by the filter membrane, to enter into the second syringe to complete the collection of the aqueous phase samples.

10. The method for in-situ extraction of organic matters in multilayer profiles based on self-sedimentation according to either claim 8 or claim 9, wherein the step of switching paths through the second three-way valve, and collecting gaseous phase samples using the vacuum bottle to which the first Teflon capillary tube is connected comprises: after the gas-liquid balance is achieved inside the sampling head, rotating the second three-way valve, such that the second threeway valve communicates the headspace air domain from the liquid level inside the sampling head with the second Teflon capillary tube; enabling gas to enter into the vacuum bottle through the second Teflon capillary tube under the action of a negative pressure inside the vacuum bottle to which the first Teflon capillary tube is connected so as to complete the collection of gaseous phase samples; if the pressure in the paths is insufficient during the collection process, operating the first syringe to adjust the pressure in a connecting channel of the second three-way valve to assist sample flowing; andthe step of, after the sampling is completed, dragging the starcone-shaped sampling head cap by the drag-reduction connection cord to drive the sampling head upward to be detached from the sediment comprises: connecting one end of the drag-reduction connection cord to the starconeshaped sampling head cap, and enabling the other end of the drag-reduction connection cord to extend to an external operating end; pulling the drag-reduction connection cord upward, and dragging the starcone-shaped sampling head cap to flip to reduce the upward resistance; and continuing to pull the drag-reduction connection cord to drive the sampling head upward to be detached from the sediment.

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