A comprehensive in-situ stratified collection device and method for seabed sediments

Abstract

The invention discloses a comprehensive in-situ stratified collection device and method for seabed sediments, belonging to the field of in-situ collection of deep-sea sediments. A stratified sample collection chamber is creatively designed to realize the simultaneous in-situ collection and recovery of sediments, microorganisms, pore water and gases at different layers. The sample collection chamber comprises a sediment collection chamber, a pore water collection chamber, a microorganism fixing liquid chamber and a pressure automatic drive chamber. The sediment collection chamber is cylindrical as a whole, and the pressure automatic drive chamber, the pore water collection chamber and the microorganism fixing liquid chamber are arranged on the periphery of the sediment collection chamber to form a circular ring structure surrounding the sediment collection chamber. In combination with designs such as stratified partitions and cutting stratified fans, in-situ stratification of sediments and microorganism samples is realized. In addition, in combination with the design of sliding partitions on both sides of the microorganism fixing liquid chamber, semi-automatic injection of the microorganism fixing liquid is realized. The structural design of the scheme is ingenious, power-saving, simple and effective, and has a wide range of practical application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of in-situ collection of deep-sea sediments, and in particular relates to a device and method for comprehensive in-situ stratified collection of seabed sediments. Background Art

[0002] Marine sediments and their pore water contain a large number of effective indicators such as microorganisms, elemental composition, mineral composition, geological age, ion composition, dissolved gas, etc., which can reveal important geochemical characteristic information and are of great significance in seabed mineral exploration and ecological environment evolution research.

[0003] Currently, there are two methods for collecting sediment pore water:

[0004] One is destructive sampling, that is, non-in-situ pore water extraction, which is mainly carried out by pressing, centrifugation and vacuum filtration; such as a sediment pore water and dissolved gas collection device disclosed in a new patent with authorization announcement number CN207570848U. However, this non-in-situ sampling method will cause changes in the physical and chemical properties of the soil, and the measured data may not be completely consistent with the actual situation.

[0005] The other is in-situ collection, such as the invention patent with application publication number CN106153393A which discloses an in-situ stratified collection device for columnar sediment pore water in shallow water areas, and the invention patent with application publication number CN103105317A which discloses a field in-situ stratified collection device for sediment pore water.

[0006] There are various existing in-situ collection devices for seabed sediment pore water, but generally there are the following problems: most sediment pore water collection devices only consider the in-situ collection and recovery of pore water in sediments, and do not consider the synchronous collection of sediments in the same layer, and the effectiveness of sample data and indication information is low. Moreover, most schemes do not consider the protected collection of microbial samples in sediments. The microbial information in the sediments will be contaminated by the external environment interference and long operation time during the operation of device recovery and sampling, which will affect the actual measurement.

[0007] Therefore, it is necessary to comprehensively consider and develop comprehensive, efficient, and authentic in-situ collection of sediments, microorganisms, pore water, and dissolved gas. Summary of the invention

[0008] In view of the problems that the prior art does not consider the synchronous collection of sediments in the same layer and lacks consideration for the protection and collection of microbial samples, the present invention provides a comprehensive in-situ stratified collection device and method for seabed sediments. The device has a simple structural principle and is easy to operate. It is a sampling device that can simultaneously perform in-situ fidelity stratified collection of sediments, microorganisms, pore water and gas.

[0009] The present invention is implemented by adopting the following technical scheme: a comprehensive in-situ stratified collection device for seabed sediments, comprising a hydraulic drive unit, a control unit and a sample collection cabin, wherein the upper part of the sample collection cabin is connected to the hydraulic drive unit through a mounting seat;

[0010] The hydraulic drive unit includes a boom, a hydraulic cylinder and a first sensing rod. The boom is arranged on the top of the hydraulic cylinder and is used to connect the cable to realize the recovery of the device. The hydraulic cylinder is connected to the mounting seat through the hydraulic cylinder push rod. A counterweight block is also arranged on the periphery of the hydraulic cylinder to be used for rapid sinking of the device and controlling the stability of the device. The first sensing rod is arranged at the bottom of the hydraulic drive unit and on both sides of the sample collection cabin, and the height of the first sensing rod is consistent with the height of the mounting seat.

[0011] The sample collection chamber is sealed at the top and includes a sediment collection chamber, a pore water collection chamber, a microorganism fixing liquid chamber and a pressure automatic drive chamber; the sediment collection chamber is cylindrical as a whole, with an open bottom, and a lotus petal drill is arranged at the bottom; the pressure automatic drive chamber, the pore water collection chamber and the microorganism fixing liquid chamber are arranged on the periphery of the sediment collection chamber, forming a circular ring structure surrounding the sediment collection chamber;

[0012] Multiple stratified partitions are evenly arranged along the length direction of the sample collection chamber, and the pressure automatic driving chamber, the pore water collection chamber and the microbial fixed liquid chamber are stratified to form multiple independent stratified chambers respectively, and cutting stratified fans are arranged at corresponding positions in the sediment collection chamber, and the positions and numbers of the stratified partitions and the cutting stratified fans are consistent;

[0013] The first one-way solenoid valve, the second one-way solenoid valve and the third one-way solenoid valve with stainless steel screens are respectively arranged on the inner walls of each layer of pore water collection chamber, the microorganism fixation liquid chamber and the pressure automatic drive chamber. A first interface valve is arranged on the outer wall of each layer of pore water collection chamber; a second interface valve is arranged on the outer wall of each layer of microorganism fixation liquid chamber. The first one-way solenoid valve is directed outwards, and is used for pressing pore water in the sediment into the pore water collection chamber from the sediment collection chamber under the action of pressure difference; the second one-way solenoid valve is directed inwards, and is used for pressing the microorganism fixation liquid into the sediment collection chamber for microorganism fixation; the third one-way solenoid valve is directed outwards, and is used for discharging air at the top of the sediment collection chamber when drilling into the sediment.

[0014] Furthermore, a one-way serrated slide is provided on the inner wall of the microorganism fixing liquid chamber, and the microorganism fixing liquid chamber is separated from the pore water collection chamber and the pressure automatic driving chamber by a sliding partition. The sliding partition can slide along the one-way serrated slide to squeeze the microorganism fixing liquid chamber, and the pore water collection chamber and the pressure automatic driving chamber are separated by a fixed partition.

[0015] Furthermore, a vertical partition plate is provided inside the sediment collection chamber to evenly divide the chamber body of the sediment collection chamber into two parts, for collecting sediment and microbial samples in the sediment respectively. The third one-way solenoid valve is arranged opposite to the vertical partition plate, and the first one-way solenoid valve and the second one-way solenoid valve are arranged on both sides of the vertical partition plate.

[0016] Furthermore, a second sensing rod is provided at the inner top of the sediment collection chamber. After the second sensing rod senses the sediment sample, it triggers the control unit to control the cutting and stratifying fan blades to gradually open in a fan shape, thereby stratifying the columnar sediment in situ.

[0017] Furthermore, the pore water collection chamber, the pressure automatic drive chamber and the microbial fixed liquid chamber are made of high-pressure resistant and corrosion-resistant metal materials, and the sediment collection chamber and the vertical partition plate are made of high-pressure resistant and corrosion-resistant PVC materials.

[0018] The present invention also provides a collection method of a comprehensive in-situ stratified collection device for seabed sediments, comprising the following steps:

[0019] Step A, evacuating the pore water collection chamber, filling the microbial fixative chamber with the microbial fixative, starting the hydraulic drive unit, and lowering the comprehensive in-situ collection device;

[0020] Step B, controlling the sample collection chamber to penetrate into the sediment through the hydraulic drive unit, controlling the cutting and layering sectors of the sediment collection chamber to collect sediments in layers, and realizing the collection of pore water and gas by the pore water collection chamber at the same layer;

[0021] (1) After the hydraulic drive unit is turned on, the entire sample collection chamber is driven to penetrate into the sediment as a whole. At the same time, the control unit turns on the third one-way solenoid valves on the inner wall of the pressure automatic drive chamber, so that the gas in the sediment collection chamber is squeezed into the pressure automatic drive chamber, pushing the sliding partition on one side of the microorganism fixation liquid chamber to slide inward to cause space compression;

[0022] (2) When the first sensing rod at the bottom of the hydraulic drive unit touches the ground, the control unit stops the hydraulic drive, the sample collection chamber stops penetrating, and the sediment reaches the top of the sediment collection chamber, triggering the control unit to control the cutting and stratification fan blades of each layer in the sediment collection chamber to gradually open, so as to accurately stratify the sediment sample. At the same time, the control unit is triggered to close the third one-way solenoid valve on the inner wall of the pressure-automatic drive chamber, so as to stop the gas in the sediment collection chamber from being injected into the chamber;

[0023] (3) The control unit then opens the multiple first one-way solenoid valves on the inner wall of the pore water collection chamber, and the pore water in the sediment sample on one side of the sediment collection chamber passes through the stainless steel screen into the various layers of separation chambers in the pore water collection chamber. After a certain period of time, the first one-way solenoid valve is closed, and the pore water collection is completed; at the same time, due to the increase in pressure in the pore water collection chamber, the sliding partition on one side of the microbial fixed liquid chamber is pushed to slide further inward to squeeze the microbial fixed liquid chamber.

[0024] Step C, fixing the microbial flora in each layer of sediment collected by the sediment collection chamber;

[0025] The control unit opens a plurality of second one-way solenoid valves on the inner wall of the microorganism fixing liquid chamber, and the microorganism fixing liquid in the microorganism fixing liquid chamber is injected into the sediment sample on one side of the sediment collection chamber through the second one-way solenoid valve to fix the microbial flora in the sediment;

[0026] Step D: After the collection is completed, the comprehensive in-situ stratified collection device is recovered to achieve the simultaneous preservation of sediments, pore water, microorganisms and gases.

[0027] Compared with the prior art, the advantages and positive effects of the present invention are:

[0028] This scheme designs a vertical partition plate in the sediment collection chamber, which automatically divides the sediment column sample into two parts when the device is drilled in. One part is used as the physical and chemical property test and analysis of the sediment column sample, and the other part is used to fix the microbial flora in the sediment with a microbial fixative for microbial molecular biology test and analysis. At the same time, through the design of multiple upper and lower cutting and stratifying fan blades, the in-situ stratification of sediment and microbial samples can be achieved, and the cross-layer problem of pore water and microbial flora in the sediment can be effectively prevented.

[0029] In addition, by designing a circular integrated sample collection chamber, the sediment collection chamber is set inside the ring, and the annular pore water collection chamber and microbial fixed liquid chamber are set outside through the partition, so that the sediments, microorganisms, pore water and gas in different layers can be collected and recovered in situ at the same time. The multi-dimensional data of four types of samples in the same layer can be compared and analyzed to obtain more comprehensive and comprehensive geochemical information and environmental indications.

[0030] At the same time, the pressure of the original gas in the sediment collection chamber is collected to automatically drive the chamber and the pore water collection chamber with increased injection pressure due to pore water collection to squeeze the sliding partitions on both sides of the microbial fixative chamber, thereby realizing semi-automatic injection of the microbial fixative, saving power, being simple and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a comprehensive in-situ layered collection device according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of a sample collection cabin according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of a cross section of a sample collection chamber (with the fan blade not opened) according to an embodiment of the present invention;

[0034] Figure 4 It is a schematic diagram of a cross section of a sample collection chamber (with the fan blades opened) according to an embodiment of the present invention;

[0035] Among them: 1. suspension rod; 2. hydraulic cylinder; 3. counterweight; 4. first sensing rod; 5. mounting seat; 6. sample collection cabin; 7. pressure automatic drive chamber; 8. microorganism fixed liquid chamber; 9. pore water collection chamber; 10. sediment collection chamber; 11. lotus petal drill; 12. first one-way solenoid valve; 13. second one-way solenoid valve; 14. layered partition; 15. first interface valve; 16. transmission line; 17. second interface valve; 18. sliding partition; 19. fixed partition; 20. cutting layered fan blades; 21. one-way toothed slideway, 22. third one-way solenoid valve; 23. vertical dividing plate. DETAILED DESCRIPTION

[0036] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and therefore, the present invention is not limited to the specific embodiments disclosed below.

[0037] Embodiment 1: A comprehensive in-situ stratified collection device for seafloor sediments, such as Figure 1-2 As shown, it includes a hydraulic drive unit, a control unit and a sample collection cabin. The upper part of the sample collection cabin is connected to the hydraulic drive unit through a mounting seat 5. The sample collection cabin is driven by the hydraulic drive unit to drill into the sediment. The control unit is used to control the switch of the hydraulic drive unit and the switch of each collection valve of the sample collection cabin.

[0038] The hydraulic drive unit includes a boom 1, a hydraulic cylinder 2, a counterweight 3 and a first sensing rod 4. The hydraulic cylinder 2 is connected to a mounting seat 5 via a hydraulic cylinder push rod. The boom 1 is used to connect a cable to recover the device. The hydraulic cylinder 2 and the hydraulic cylinder push rod are core components of the hydraulic drive unit. The counterweight 3 is used to quickly sink the device and control the stability of the device. The first sensing rod 4 includes two rods, which are arranged at the bottom of the hydraulic drive unit and on both sides of the sample collection cabin 6. The height of the first sensing rod 4 is consistent with the height of the mounting seat 5.

[0039] Continue to refer Figure 2The sample collection chamber 6 is closed at the top and includes a sediment collection chamber 10, a pore water collection chamber 9, a microorganism fixing liquid chamber 8 and a pressure automatic drive chamber 7. The sediment collection chamber 10 is cylindrical as a whole, with an open bottom and is connected to a lotus petal drill 11 to prevent the sediment from falling and causing loss during the recovery process of the device; wherein the pressure automatic drive chamber 7, the pore water collection chamber 9 and the microorganism fixing liquid chamber 8 are arranged on the periphery of the sediment collection chamber 10 to form a circular ring structure surrounding the sediment collection chamber 10, the microorganism fixing liquid chamber 8 is separated from the pore water collection chamber 9 and the pressure automatic drive chamber 7 by a sliding partition 18, and the pore water collection chamber 9 is separated from the pressure automatic drive chamber 7 by a fixed partition 19, and a vertical partition plate 23 is arranged inside the sediment collection chamber 10 to evenly divide the chamber of the sediment collection chamber into two parts to collect sediment and microorganism samples in the sediment respectively.

[0040] In addition, a plurality of stratified partitions 14 are evenly arranged along the length direction of the sample collection chamber 6, and the pressure automatic driving chamber 7, the pore water collection chamber 9 and the microorganism fixed liquid chamber 8 are stratified at the same time, and a cutting stratification fan 20 is arranged at a corresponding position in the sediment collection chamber 10, and the position and number of the stratified partitions 14 and the cutting stratified fan 20 are consistent, and the stratification interval distance is set according to the sampling resolution; the pore water collection chamber 9, the microorganism fixed liquid chamber 8 and the pressure automatic driving chamber 7 are divided into a plurality of independent stratified chambers by the stratified partitions 14, and a stainless steel strip is arranged on the inner wall of each stratified chamber of the pore water collection chamber 9 A first one-way solenoid valve 12 of the sieve, a first interface valve 15 is provided on the outer wall of each pore water collection chamber 9, a second one-way solenoid valve 13 with a stainless steel sieve is provided on the inner wall of the stratified chamber of each microbial fixed liquid chamber 8, a second interface valve 17 is provided on the outer wall of the chamber of each microbial fixed liquid chamber 8, a third one-way solenoid valve 22 with a stainless steel sieve is provided on the inner wall of the stratified chamber of each pressure automatic drive chamber 7, and the third one-way solenoid valve 22 is provided opposite to the vertical partition plate 23, and the first one-way solenoid valve 12 and the second one-way solenoid valve 13 are provided on both sides of the vertical partition plate 23.

[0041] It can be seen that in this embodiment, the sample collection chamber 6 is divided into two layers, the inner and outer layers, wherein the outer cavity wall (pore water collection chamber 9, pressure automatic drive chamber 7 and microorganism fixing liquid chamber 8) is made of high pressure resistant and corrosion resistant metal material, and the inner cavity wall (sediment collection chamber) is made of high pressure resistant and corrosion resistant PVC material, and the inner wall size is adapted to the inner diameter of the outer wall metal cavity. An O-ring is provided on the top side of the PVC cavity to fix the inner and outer cavities and relieve material friction. The PVC cavity can be removed from the metal outer cavity for subsequent lossless transfer of sediment samples. By vertically arranging a layer of vertical partition plate 23 of the same material along the center line inside the PVC cavity, the columnar sample is divided into two when penetrating the sediment and the original sequence is kept intact, half of which is mainly used for microbial sample collection and molecular testing analysis, and the other half is mainly used for original sediment collection and physical and chemical property analysis. In the sediment sample chamber 10, with the vertical dividing plate 23 as the central axis, a group of cutting and stratifying fans 20 are respectively arranged in each layer. The position, height and number of the cutting and stratifying fans 20 are consistent with the stratified partition 14 of the outer cavity wall of the sample collection chamber 6. A second sensing rod is arranged at the top of the sediment collection chamber 10. After the second sensing rod senses the sediment sample, it will trigger the control unit to control the cutting and stratifying fans to gradually open in a fan shape, so as to accurately stratify the columnar sediment in situ. At the same time, these cutting and stratifying fans also have a good separation effect of preventing pore water from crossing layers when collecting pore water and preventing microbial flora from crossing layers when injecting microbial fixative.

[0042] In this embodiment, three holes (corresponding to the first one-way solenoid valve 12, the second one-way solenoid valve 13 and the third one-way solenoid valve 22) are set on the PVC and metal cavity walls of each layer of samples, and a stainless steel screen and a one-way solenoid valve are set on the holes of the inner metal cavity wall. A sealing ring is fixed on the outer ring of each hole in the PVC cavity wall to prevent the pore water, microbial fixative and gas from overflowing when passing through. Among them, the first one-way solenoid valve 12 is connected to the pore water collection chamber 9, and the first one-way solenoid valve 12 is directed outward, which is used for the pore water in the sediment to be pressed into the pore water collection chamber 9 by the sediment collection chamber 10 under the action of pressure difference. The second one-way solenoid valve 13 is connected to the microbial fixative liquid chamber 8, and the second one-way solenoid valve 13 is directed inward, which is used to press the microbial fixative liquid into the sediment collection chamber for microbial fixation. The third one-way solenoid valve 22 is connected to the pressure automatic drive chamber 7, and the third one-way solenoid valve 22 is directed outward, which is used to discharge the air at the top of the sediment collection chamber when drilling into the sediment.

[0043] Combination Figure 3 and Figure 4As shown, in this embodiment, the cross section of the pore water collection chamber 9 is 1 / 3 annular, which is used for collecting and storing pore water and in-situ gas in sediments. Before the overall collection operation of the device, the pore water collection chamber 9 is in a high vacuum state, and the top and bottom of the chamber are completely closed. The pore water collection chamber 9 is divided into a plurality of layered chambers by a layered partition 14 at a certain distance in the vertical direction, and each layered chamber is in an independent high vacuum state. A first one-way solenoid valve 12 with a stainless steel screen is provided on the inner wall of each layered chamber. The stainless steel screen is air-permeable and water-permeable, and the liquid flows outward. The first one-way solenoid valve 12 is controlled by a control unit. When the first one-way solenoid valve 12 is opened, the pore water in the sediment of the sediment collection chamber 10 will pass through the stainless steel screen and be pressed into the high vacuum annular pore water collection chamber 9 under the pressure difference between the inside and outside of the chamber. The collection ends when the control valve is closed. A first interface valve 15 is provided on the outer wall of each layered chamber, which is used for transferring and storing pore water samples through external pipelines and sample bottles after subsequent device recovery. At the same time, the pressure-maintaining gas in the pore water can also be stored through the interface valve to connect the pressure-resistant pipe valve and the airtight pressure-resistant sample tank.

[0044] The cross section of the pressure automatic driving chamber 7 is 1 / 3 of a ring, and is used to collect the original gas at the top of the sediment collection chamber 10 when the sample collection chamber 6 drills into the sediment. The top and bottom of the chamber are completely closed, and the pressure automatic driving chamber 7 is also provided with a layered partition 14 at a certain distance in the vertical direction to be divided into multiple layered chambers. A third one-way solenoid valve 22 with a stainless steel screen is provided on the inner wall of each layered chamber. The switch of the third one-way solenoid valve 22 is controlled by the control unit, and the center of the stainless steel screen opening is aligned with the vertical partition plate 23 position of the sediment collection chamber 10, so that the stainless steel screen opening and the space on both sides of the sediment collection chamber 10 can be connected. The stainless steel screen is air-permeable and water-impermeable, and the gas flows outward. Before the operation of the whole device, the chamber is filled with normal pressure air. When the sample collection chamber 6 drills downward into the sediment, the columnar sediment will squeeze the original gas at the top of the sediment collection chamber 10. The gas will enter the pressure automatic drive chamber 7 under the squeeze, and push the sliding partition on one side of the microorganism fixation liquid chamber 8 to squeeze the microorganism fixation liquid chamber 8 through the one-way toothed slide 21, thereby completing the automatic collection and driving of pressure.

[0045] The cross section of the microorganism fixing liquid chamber 8 is 1 / 3 of a ring shape, and is used to store microorganism fixing liquid. The inner wall of the chamber is vertically divided into multiple layered chambers by a layered partition 14 at a certain distance. A second one-way solenoid valve 13 with a stainless steel screen is provided on the inner wall of each layered chamber, which is water-permeable but air-tight, and the liquid flows inward. The second one-way solenoid valve 13 is controlled by the control unit and is used to inject the microorganism fixing liquid into half of the sediment collection chamber 10 to fix the microbial flora in the sediment. The partitions on both sides of the microorganism fixing liquid chamber 8 on the inner wall of each layered chamber are slidable partitions, and one-way toothed slideways 21 are provided on both sides of the cavity of the microorganism fixing liquid chamber 8, which are used to slide the sliding partition inward. A second valve interface is provided on the outer wall of each layered chamber for the injection of microorganism fixing liquid during preparation. When the overall sample collection cabin 6 drills into the sediment, the original gas in the sediment collection chamber 10 will enter the pressure automatic driving chamber 7 under the pressure of the sediment, pushing the sliding partition on one side of the microorganism fixing liquid chamber 8 to squeeze, but this part of the pressure is not enough to make the pressure in the microorganism fixing liquid chamber 8 higher than the pressure in the sediment collection chamber 10. When the sediment drilling is completed, the vacuum pore water collection chamber 9 will collect the pore water in the sediment in the sediment collection chamber 10 under the internal and external pressure difference, and at the same time increase the pressure in the pore water collection chamber, further promote the sliding partition on one side of the microorganism fixation liquid chamber 8 to slide and squeeze, so that the pressure in the microorganism fixation liquid chamber 8 is higher than that in the sediment collection chamber 10, and the microorganism fixation liquid will automatically enter the sediment sample through the second one-way solenoid valve 13 for microorganism fixation, realizing semi-automatic and unmanned high-efficiency operation.

[0046] During specific operation, the sample collection chamber 6 is penetrated as a whole into the seabed sediment through the hydraulic drive unit. When the first sensing rod 4 contacts the seabed sediment, the first sensing rod 4 transmits a trigger signal to the control unit. The control unit immediately stops the hydraulic drive and opens the first one-way solenoid valve 12 on the inner wall of the pore water collection chamber 9 to start pore water collection. The collection time can be set to 30 seconds. After 30 seconds, the control unit closes the first one-way solenoid valve 12 to stop pore water collection, and then the device starts the recovery process.

[0047] Example 2: Based on the comprehensive in-situ stratified collection device proposed in Example 1, this example proposes a collection method of a comprehensive in-situ stratified collection device for seabed sediments, which specifically includes the following steps:

[0048] Step A, evacuate the pore water collection chamber 9, fill the microorganism fixing liquid chamber 8 with the microorganism fixing liquid, start the hydraulic drive unit, and lower the comprehensive in-situ collection device;

[0049] (1) Evacuating the pore water collection chamber 9: Before the in-situ integrated stratified collection device is put into water, multiple first interface valves 15 on the outer wall of each stratified chamber in the pore water collection chamber 9 are connected to a vacuum pump through a multi-way valve, and all first interface valves 15 are opened to evacuate the pressure in each stratified chamber of the pore water collection chamber 9 to a vacuum state of 200 Pa, and then all first interface valves 15 are closed.

[0050] (2) Fill the microbial fixative liquid chamber 8 with the microbial fixative liquid through the second valve interface 17, place the PVC inner chamber of the sediment collection chamber 10 into the metal outer chamber of the sample collection chamber 6 according to the position of the side hole opening, and assemble the lotus petal drill bit 11 at the bottom;

[0051] (3) Connect the top boom 1 of the in-situ integrated layered collection device to the cable on the ship and place it in the seawater. Set the time for the control unit to start the hydraulic drive unit according to the water depth and the weight of the device. The start time of the hydraulic drive unit should be longer than the time it takes for the collection device to reach the seabed.

[0052] Step B, controlling the sample collection chamber 6 to penetrate into the sediment through the hydraulic drive unit, controlling the cutting and layering sectors 20 of the sediment collection chamber 10 to collect sediment in layers, and realizing the collection of pore water and gas by the pore water collection chamber 9 at the same layer;

[0053] (1) After the hydraulic drive unit is turned on, the entire sample collection chamber 6 is driven to penetrate into the sediment as a whole. At the same time, the control unit opens the multiple third one-way solenoid valves 22 on the inner wall of the pressure automatic drive chamber 7, so that the gas in the sediment collection chamber 10 is squeezed into the pressure automatic drive chamber 7, pushing the sliding partition 18 on one side of the microorganism fixation liquid chamber 8 to slide inward to cause space compression. When the first sensing rod 4 at the bottom of the hydraulic drive unit touches the ground, the signal is transmitted to the control unit, and the control unit immediately stops the hydraulic drive, and the sample collection chamber 6 stops penetrating. At the same time, the sediment will reach the second sensing rod at the top of the sediment collection chamber 10, triggering the control unit to control the cutting and stratification fan blades 20 of each layer in the sediment collection chamber 10 to gradually open, and perform accurate stratification of the sediment sample. At the same time, the control unit is triggered to close the third one-way solenoid valve 22 on the inner wall of the pressure automatic drive chamber 7, and stop the gas in the sediment collection chamber 10 from being injected inward.

[0054] (2) The control unit then opens the multiple first one-way solenoid valves 12 on the inner wall of the pore water collection chamber 9, and the pore water in the sediment sample on one side of the sediment collection chamber 10 will pass through the stainless steel screen into the various layers of separation chambers of the pore water collection chamber 9. After 30 seconds, the first one-way solenoid valve 12 is closed, and the pore water collection is completed. At the same time, due to the increase in pressure in the pore water collection chamber 9, the sliding partition 18 on one side of the microorganism fixed liquid chamber 8 is pushed to slide further inward to squeeze the microorganism fixed liquid chamber 8.

[0055] Step C, fixing the microbial flora in each layer of sediment collected by the sediment collection chamber 10;

[0056] The control unit opens multiple second one-way solenoid valves 13 on the inner wall of the microbial fixation liquid chamber 8, and the microbial fixation liquid in the microbial fixation liquid chamber 8 is injected into the sediment sample of each layer on one side of the sediment collection chamber 10 through the second one-way solenoid valve 13. The control unit is set to automatically close the second one-way solenoid valve 13 after 30 seconds, and the fixation of the microbial flora in the sediment is completed.

[0057] Step D: After the collection is completed, the comprehensive in-situ stratified collection device is recovered to achieve the simultaneous preservation of sediments, pore water, microorganisms and gases;

[0058] Recover the device to the deck, connect the first interface valve 15 on the outer wall of the pore water collection chamber 9 to the pressure-resistant pipeline and the airtight pressure-resistant sample bottle. After manually opening the first interface valve 15, the pore water and gas will be transferred to the sample bottle for sealed storage for the determination of gas components and pore water composition information.

[0059] The PVC tube of the sediment collection chamber 10 is taken out for cutting and sampling, wherein half of the sediment sample injected with microbial fixative is mainly used for molecular testing and analysis of microorganisms, and the other half of the sediment sample with pore water extracted is mainly used for testing and analysis of physical and chemical properties of sediments.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A comprehensive in-situ stratified sampling device for seabed sediments, comprising a hydraulic drive unit, a control unit and a sample collection chamber, wherein the upper portion of the sample collection chamber is connected to the hydraulic drive unit via a mounting seat, and characterized in that: The sample collection chamber is sealed at the top and includes a sediment collection chamber, a pore water collection chamber, a microorganism fixative liquid chamber and a pressure automatic drive chamber; the sediment collection chamber is cylindrical in shape as a whole, and the bottom is open, and a lotus petal drill is arranged at the bottom, and a vertical partition plate is arranged inside the sediment collection chamber to evenly divide the chamber of the sediment collection chamber into two parts, respectively collecting sediment and microorganism samples in the sediment; The pressure automatic driving chamber, the pore water collection chamber and the microorganism fixed liquid chamber are arranged on the periphery of the sediment collection chamber, forming a circular ring structure surrounding the sediment collection chamber; a one-way toothed slideway is arranged on the inner wall of the microorganism fixed liquid chamber, and the microorganism fixed liquid chamber is separated from the pore water collection chamber and the pressure automatic driving chamber by a sliding partition, and the sliding partition can slide along the one-way toothed slideway to squeeze the microorganism fixed liquid chamber, and the pore water collection chamber and the pressure automatic driving chamber are separated by a fixed partition; Multiple stratified partitions are evenly arranged along the length direction of the sample collection chamber, and the pressure automatic driving chamber, the pore water collection chamber and the microbial fixed liquid chamber are stratified to form multiple independent stratified chambers respectively, and cutting stratified fans are arranged at corresponding positions in the sediment collection chamber, and the positions and numbers of the stratified partitions and the cutting stratified fans are consistent; The inner walls of each layer of pore water collection chamber layered chamber, microbial fixed liquid chamber layered chamber and pressure automatic drive chamber layered chamber are respectively provided with a first one-way solenoid valve, a second one-way solenoid valve and a third one-way solenoid valve with a stainless steel screen, the third one-way solenoid valve is arranged opposite to the vertical partition plate, the first one-way solenoid valve and the second one-way solenoid valve are arranged on both sides of the vertical partition plate, and a first interface valve is arranged on the outer wall of the cavity of each layer of pore water collection chamber; a second interface valve is arranged on the outer wall of the cavity of each layer of microbial fixed liquid chamber.

2. The comprehensive in-situ stratified collection device for seabed sediments according to claim 1 is characterized by: The hydraulic drive unit includes a boom, a hydraulic cylinder and a first sensing rod. The boom is arranged on the top of the hydraulic cylinder and is used to connect the cable to realize the recovery of the device. The hydraulic cylinder is connected to the mounting seat through the hydraulic cylinder push rod. A counterweight block is also arranged on the periphery of the hydraulic cylinder to be used for rapid sinking of the device and controlling the stability of the device. The first sensing rod is arranged at the bottom of the hydraulic drive unit and on both sides of the sample collection cabin, and the height of the first sensing rod is consistent with the height of the mounting seat.

3. The comprehensive in-situ stratified collection device for seabed sediments according to claim 1 is characterized in that: A second sensing rod is arranged at the inner top of the sediment collection chamber. After the second sensing rod senses the sediment sample, it triggers the control unit to control the cutting and stratifying fan blades to open gradually in a fan shape, so as to stratify the columnar sediment in situ.

4. The comprehensive in-situ stratified collection device for seabed sediments according to claim 1 is characterized by: The pore water collection chamber, the pressure automatic drive chamber and the microorganism fixed liquid chamber are made of high-pressure resistant and corrosion-resistant metal materials, and the sediment collection chamber and the vertical partition plate are made of high-pressure resistant and corrosion-resistant PVC materials.

5. The comprehensive in-situ stratified collection device for seabed sediments according to claim 1 is characterized by: The first one-way solenoid valve is directed outwards, and is used to press the pore water in the sediment into the pore water collection chamber under the action of pressure difference; the second one-way solenoid valve is directed inwards, and is used to press the microbial fixation pressure into the sediment collection chamber for microbial fixation; the third one-way solenoid valve is directed outwards, and is used to discharge the air at the top of the sediment collection chamber when drilling into the sediment.

6. A collection method based on the comprehensive in-situ stratified collection device for seabed sediments according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step A, evacuating the pore water collection chamber, filling the microbial fixative chamber with the microbial fixative, starting the hydraulic drive unit, and lowering the comprehensive in-situ collection device; Step B, controlling the sample collection chamber to penetrate into the sediment through the hydraulic drive unit, controlling the cutting and layering sectors of the sediment collection chamber to collect sediments in layers, and realizing the collection of pore water and gas by the pore water collection chamber at the same layer; (1) After the hydraulic drive unit is turned on, the entire sample collection chamber is driven to penetrate into the sediment as a whole. At the same time, the control unit turns on the third one-way solenoid valves on the inner wall of the pressure automatic drive chamber, so that the gas in the sediment collection chamber is squeezed into the pressure automatic drive chamber, pushing the sliding partition on one side of the microorganism fixation liquid chamber to slide inward to cause space compression; (2) When the first sensing rod at the bottom of the hydraulic drive unit touches the ground, the control unit stops the hydraulic drive, the sample collection chamber stops penetrating, and the sediment reaches the top of the sediment collection chamber, triggering the control unit to control the cutting and stratification fan blades of each layer in the sediment collection chamber to gradually open, so as to accurately stratify the sediment sample. At the same time, the control unit is triggered to close the third one-way solenoid valve on the inner wall of the pressure-automatic drive chamber, so as to stop the gas in the sediment collection chamber from being injected into the chamber; (3) The control unit then opens the multiple first one-way solenoid valves on the inner wall of the pore water collection chamber, and the pore water in the sediment sample on one side of the sediment collection chamber passes through the stainless steel screen into the partition chambers of each layer of the pore water collection chamber. After a certain period of time, the first one-way solenoid valve is closed, and the pore water collection is completed; at the same time, due to the increase in pressure in the pore water collection chamber, the sliding partition on one side of the microorganism fixed liquid chamber is pushed to slide further inward to squeeze the microorganism fixed liquid chamber; Step C, fixing the microbial flora in each layer of sediment collected by the sediment collection chamber; The control unit opens a plurality of second one-way solenoid valves on the inner wall of the microorganism fixing liquid chamber, and the microorganism fixing liquid in the microorganism fixing liquid chamber is injected into the sediment sample on one side of the sediment collection chamber through the second one-way solenoid valve to fix the microbial flora in the sediment; Step D: After the collection is completed, the comprehensive in-situ stratified collection device is recovered to achieve the simultaneous preservation of sediments, pore water, microorganisms and gases.

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