An in-situ testing device for chemical and physical parameters of seabed sedimentary environment

Abstract

The application discloses a kind of in-situ testing devices for chemical properties of seabed sediment environment, and is specially designed for seabed drill rig.In the operation process, the device is fixedly installed in the specific test section cavity of the probe rod.The stable displacement in the vertical direction is realized by driving diaphragm pump with electric push rod, the pore water sample is passively collected by the synergistic effect of water-permeable ceramic and one-way valve, and the pore water sample in the detection cavity is updated by pump valve, so that the in-situ continuous detection of pH, H2S, Eh, CO3 2‑ and other key chemical parameters of seabed sediment pore water is realized.The device has the advantages of simple and reliable structure, low disturbance collection, high precision and fast response, strong environmental adaptability, low cost, easy maintenance and high efficiency.It provides high-quality in-situ test data for marine scientific research and resource development, and helps to understand the biogeochemical processes of seabed sediment.

Description

Technical Field

[0001] The present invention belongs to the field of marine geotechnical exploration equipment and relates to the field of in-situ testing technology, in particular to an in-situ testing device for environmental chemical property parameters of a seabed sediment layer. Background Art

[0002] Sediment pore waters contain a wealth of critical geochemical information. This information reflects the physicochemical properties of materials buried contemporaneously with the sedimentation, the rate of deposition, and the diffusion, migration, and chemical reactions between seawater and sediment. These processes further determine the redox environment at the sediment-bottom-water interface. Changes in the chemical composition of sediment pore waters are influenced by the deposition rate, redox potential, and the organic matter content of the sediments, and are of significant biogeochemical significance. Furthermore, the physicochemical properties of seafloor sediments are crucial for marine engineering, resource exploration, and environmental assessment.

[0003] Due to the complexity of the deep-sea environment, traditional sampling methods make it difficult to obtain high-quality undisturbed samples. Therefore, in-situ testing technology for seabed sediments has become an important means of seabed engineering surveys. In the process of in-situ detection of seabed sediment geochemical parameters, the in-situ testing device for the chemical properties of seabed sediments is usually used as a supporting equipment for the seabed drilling rig and fixedly installed in a certain detection cavity of the detection rod. The penetration force of the drilling rig is used to press the device into the seabed sediment layer to achieve in-situ, real-time and efficient measurement of the chemical parameters of the sediment layer. This measurement method can effectively avoid the physical and chemical changes such as the escape of dissolved gases and oxidation of components caused by the drastic temperature and pressure changes from the seabed to the sea surface during the collection of sediment samples, thereby ensuring the accuracy and reliability of the test results.

[0004] In recent years, my country has developed an "in-situ detection simulation system for hydrate geochemical parameters in deep-sea sediments" that uses laser Raman spectroscopy detection technology to detect dissolved CH4, H2S / HS in sediment pore water. - and SO4 2- However, this instrument is large and expensive, and the pore water parameters and depths it can measure are relatively limited. Research into high-precision, rapid detection of chemical parameters using in-situ probes is urgently needed to meet the needs of marine scientific research and resource development. Summary of the Invention

[0005] In order to solve the technical problems of large errors in experimental results and the lack of in-situ, long-term, and time-divided collection, detection and storage of large-depth profiles of sediment pore water in existing in-situ sampling and detection technologies for seabed sediment pore water, the present invention provides an in-situ testing device for chemical physical parameters of seabed sediment environments, thereby realizing rapid in-situ detection of large-depth profiles of pore water chemical parameters in seabed sediment environments. The operation steps are relatively simple, the requirements for operators are relatively low, the detection process has little disturbance to the environment, and the detection efficiency is high.

[0006] The object of the present invention is achieved through the following technical solutions: an in-situ testing device for environmental chemical parameters of submarine sediments, the device comprising a probe rod and an upper electric composite cable, a detection chamber, a diaphragm pump and a lower electric composite cable installed in the probe rod from top to bottom;

[0007] A microelectrode group is installed inside the detection chamber, and the microelectrode group is connected to the upper electric composite cable;

[0008] The two sides of the detection chamber are each connected to a one-way valve chamber; an inlet one-way valve and an outlet one-way valve are respectively installed in the two one-way valve chambers;

[0009] The lower end of the detection chamber is connected to a diaphragm pump, which controls the opening and closing of the inlet and outlet check valves through piston movement to collect and discharge pore water. The lower end of the diaphragm pump is connected to the lower electric composite cable.

[0010] Furthermore, the probe rod is cylindrical with a hollow cavity inside. There are two holes on the wall of the probe rod. The upper electrocompatibility cable, electrode fixing part, microelectrode group, microelectrode connector, detection chamber, diaphragm pump, connecting sleeve, and lower electrocompatibility cable are all placed in the probe rod. The probe rod only has detection and sensing functions. During operation, the upper end needs to be connected to the data acquisition and communication module, and the lower end needs to be connected to other test units or directly connected to the drill bit.

[0011] Furthermore, the electrode fixing part is an irregular wedge shape, hollow inside, square on the top like a bolt, with a groove on the shoulder. After being connected to the microelectrode connector, vulcanized rubber is poured in. After being thoroughly air-dried, a sealing ring is placed in the groove position, passing through the opening above the detection chamber from bottom to top, and the contact surface between the electrode fixing part and the detection chamber is tightened by tightening the nut, leaving only the upper electrical composite cable exposed.

[0012] Furthermore, one end of the one-way valve chamber is connected to the detection chamber, and the other end is connected to one side of the perforated cover; the lower edge of the other side of the perforated cover is pressed onto the probe rod; the upper edge of the perforated cover is connected to one side of the ceramic filter, and the other side of the ceramic filter is connected to the pressure cover.

[0013] Furthermore, threads are provided at both ends of the one-way valve chamber, and circular grooves are provided on both sides of the central protrusion; a sealing ring is installed in the groove position at one end of the one-way valve chamber, and is connected to the detection chamber through threads to prevent pore water from seeping into the probe rod.

[0014] Furthermore, the diaphragm pump is composed of a diaphragm, a piston, a ball, a telescopic rod, a micro pump and an exhaust hole;

[0015] The upper end of the diaphragm pump is connected to the lower end of the detection chamber, and the diaphragm is installed between the diaphragm pump and the detection chamber; one end of the telescopic rod is connected to the piston, and the other end is connected to the micro pump, and an exhaust hole is provided on the wall of the diaphragm pump; a ball bearing is installed between the piston and the inner wall of the diaphragm pump; the lower end of the diaphragm pump is connected to the upper end of the motor through a connecting sleeve; the lower end of the motor leads to a lower electric composite cable.

[0016] Furthermore, silicone gaskets are installed on both sides of the diaphragm of the diaphragm pump, and the lower part of the detection chamber presses the upper part of the diaphragm pump and is tightly connected by screws.

[0017] Furthermore, the detection chamber, diaphragm pump, and motor are installed and combined in sequence, and then placed into the probe rod, ensuring that the one-way valve chambers on both sides are precisely aligned with the two holes on the probe rod wall; the perforated cover is a hollow structure, and a sealing ring is put on before installation, and then pressed into the hole and tightened to the one-way valve chamber; the ceramic filter is embedded in the perforated cover, and then pressed with a pressure cap, and the hexagonal screw is tightened to complete the fixation.

[0018] Furthermore, the microelectrode group is a combination of one or more of a pH electrode, an Ag / AgCl electrode, an Ag / Ag2S electrode, an Eh electrode, a dissolved oxygen electrode, a sulfate electrode, a carbonate electrode or a temperature electrode, which is fixed to the lower end of the microelectrode connector by welding or epoxy resin bonding, and is used for in-situ detection of various chemical parameters of the pore water environment of marine sediments.

[0019] Furthermore, the motor drives the piston to reciprocate up and down. When the piston moves upward, the diaphragm deflects upward due to the increase in pressure, the inlet one-way valve opens, and the outlet one-way valve closes. The pore water is filtered through the ceramic filter and flows into the water inlet tank, and is passively collected into the detection tank. Conversely, the piston moves downward, the diaphragm deflects downward due to the decrease in pressure, the inlet one-way valve closes, and the outlet one-way valve opens. The pore water flows from the detection tank through the water outlet tank and is discharged from the probe rod.

[0020] The advantages and positive effects of the present invention are:

[0021] 1. Low disturbance: The in-situ testing device for the environmental chemical properties of seabed sediments designed in the present invention is a test rod of a sediment drilling rod with a small diameter. During the insertion into the seabed sediment, the device has little impact and disturbance on the surrounding environment of the sediment.

[0022] 2. Reliable Structure: The in-situ testing device for environmental chemical properties of submarine sediments designed in this invention boasts a robust design. Its core component is a piston-driven micro-diaphragm pump. This pump utilizes the reciprocating motion of the piston / diaphragm, driven by a motor, to change the pump chamber volume. This precisely controls the minute pressure differential between the probe chamber inside the probe and the sediment layer outside. This, in conjunction with a one-way valve, enables active sampling of sediment pore water and discharge of waste liquid.

[0023] 3. Low cost: The in-situ testing device for environmental chemical properties of seabed sediments designed in the present invention is easy to process and assemble, and its parts processing technology is simple and low-cost. The connection method mostly adopts fixed connection of bolts and nuts, or uses vulcanized rubber bonding, and uses silicone materials, sealing rings and other materials to ensure the sealing performance of the device. Assembly and disassembly are simple and efficient, easy to maintain and replace, and highly economical and practical.

[0024] 4. Easy replacement of parts: The in-situ testing device for environmental chemical properties of seabed sediments designed in the present invention does not have complicated transmission components, and parts replacement is convenient. The microelectrode group and the microelectrode connector are connected by welding or epoxy resin bonding, and damaged parts can be replaced independently: If the microelectrode is damaged, the original microelectrode can be removed by heating, melting and chemically washing, and replaced with a new one.

[0025] 5. High efficiency: The in-situ testing device for environmental chemical properties of seabed sediments designed in this invention adopts miniaturized motor drive technology to ensure stable and reliable output of the motor during operation. The diaphragm pump piston of the device effectively reduces frictional resistance through the ball design, lowering the requirement for motor power, making it adaptable to low-power motors and further optimizing the energy consumption and performance of the device. During the sample replacement process, the diaphragm pump works in conjunction with the one-way valve to achieve rapid sample replacement, significantly improving test efficiency, and thus better meeting the needs of in-situ testing of seabed sediments.

[0026] 6. High precision: When the detection chamber of the in-situ testing device for the environmental chemical properties of seabed sediments designed by the present invention collects pore water samples, the water samples enter through the openings on both sides of the probe rod. Since the aperture of these openings is small, the disturbance to the sediments during the collection process is minimal, and the in-situ nature of the water samples can be ensured. By accurately recording the depth to which the probe rod descends into the sediment layer, the depth position of the water sample being tested can be clearly known. This design enables the device to accurately detect the distribution of sediment pore water profiles, providing reliable data support for the study of the chemical properties of seabed sediments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 This is a full cross-section of the front view of the in-situ testing device for environmental chemical properties of seabed sediments.

[0029] Figure 2 This is a full cross-section of the rear view of the in-situ testing device for environmental chemical properties of seabed sediments.

[0030] Figure 3 Schematic diagram of the in-situ testing device for environmental chemical properties of seabed sediments.

[0031] Figure 4 for Figure 3 A is a partial enlargement of the figure.

[0032] Figure 5 for Figure 3 A partial enlargement of Figure B.

[0033] Figure 6 This is an overhead view of the in-situ testing device for environmental chemical properties of seabed sediments.

[0034] Figure 7 This is a front view of the in-situ testing device for environmental chemical properties of seabed sediments.

[0035] Figure 8 This is the main appearance diagram of the in-situ testing device for environmental chemical properties of seabed sediments.

[0036] Figure 9 This is a diagram of the internal structure of the in-situ testing device for environmental chemical properties of seabed sediments.

[0037] Among them: 1 is the probe rod, 2 is the upper electrocompatibility cable, 3 is the electrode fixing part, 4 is the fastening nut, 5 is the sealing ring, 6 is the microelectrode group, 7 is the one-way valve chamber, 8 is the outlet one-way valve, 9 is the water outlet chamber, 10 is the ceramic filter, 11 is the diaphragm pump, 11-1 is the diaphragm, 11-2 is the piston, 11-3 is the ball, 11-4 is the telescopic rod, 11-5 is the micro pump, 11-6 is the exhaust hole, 12 is the connecting sleeve, 13 is the motor, 14 is the lower electrocompatibility cable, 15 is the detection chamber, 16 is the perforated cover, 17 is the inlet one-way valve, 18 is the water inlet chamber, 19 is the pressure cover, and 20 is the microelectrode connector. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] like Figures 1-9 As shown, the present invention provides an in-situ testing device for environmental chemical property parameters of seabed sediments, which includes a probe rod 1, an upper electric composite cable 2, an electrode fixing part 3, a fastening nut 4, a sealing ring 5, a microelectrode group 6, a one-way valve compartment 7, an outlet one-way valve 8, a water outlet compartment 9, a ceramic filter 10, a diaphragm pump 11, a diaphragm 11-1, a piston 11-2, a ball 11-3, a telescopic rod 11-4, a micro pump 11-5, an exhaust hole 11-6, a connecting sleeve 12, a motor 13, a lower electric composite cable 14, a detection compartment 15, a perforated cover 16, an inlet one-way valve 17, a water inlet compartment 18, a pressure cover 19 and a microelectrode connector 20.

[0040] The probe rod 1 is cylindrical with a hollow cavity inside. There are two holes on the wall of the probe rod 1. The upper electric composite cable 2, electrode fixing part 3, microelectrode group 6, microelectrode connector 20, detection chamber 15, diaphragm pump 11, connecting sleeve 12, and lower electric composite cable 14 are all placed in the probe rod 1. The probe rod 1 only has detection and sensing functions. During operation, the upper end needs to be connected to the data acquisition and communication module, and the lower end is connected to other test units or directly connected to the drill bit.

[0041] The microelectrode group 6 is mounted on the microelectrode connector 20 and leads to the upper electric communication composite cable 2 through the microelectrode connector 20; the microelectrode group 6 is a combination of one or more of a pH electrode, an Ag / AgCl electrode, an Ag / Ag2S electrode, an Eh electrode, a dissolved oxygen electrode, a sulfate electrode, a carbonate electrode, or a temperature electrode, and is fixed to the lower end of the microelectrode connector 20 by welding or epoxy resin bonding, and is used for in-situ detection of various chemical parameters of the pore water environment of marine sediments;

[0042] like Figure 6 and Figure 9 As shown, the electrode fixing member 3 is installed on the outer wall of the microelectrode connector 20 and connected to the upper end of the detection chamber 15; the electrode fixing member 3 is an irregular wedge shape, hollow inside, with a square top like a bolt, and a groove on the shoulder. After being connected to the microelectrode connector 20, vulcanized rubber is poured in. After being thoroughly air-dried, a sealing ring 5 is placed in the groove position, passed through the opening above the detection chamber 15 from bottom to top, and the contact surface between the electrode fixing member 3 and the detection chamber 15 is compressed by tightening the nut 4, leaving only the upper electrical composite cable 2 exposed;

[0043] like Figure 9As shown, the two sides of the detection chamber 15 are each connected to one end of a one-way valve chamber 7, and the two one-way valve chambers 7 are respectively installed with an inlet one-way valve 17 and an outlet one-way valve 8, and the other end of the one-way valve chamber 7 is connected to one side of the perforated cover 16; the two ends of the one-way valve chamber 7 are provided with threads, and circular grooves are respectively provided on both sides of the middle protrusion; a sealing ring 5 is installed in the groove position of one end of the one-way valve chamber 7, which is connected to the detection chamber 15 through threads to prevent pore water from seeping into the probe rod 1; the lower edge of the other side of the perforated cover 16 is pressed onto the probe rod 1; one side of the ceramic filter 10 is connected to the upper edge of the perforated cover 16, and the other side is connected to the pressure cover 19;

[0044] like Figure 3-Figure 5 As shown, the upper end of the diaphragm pump 11 is connected to the lower end of the detection chamber 15, the diaphragm 11-1 is installed between the diaphragm pump 11 and the detection chamber 15, silicone gaskets are installed on both sides of the diaphragm 11-1 of the diaphragm pump 11, and the lower part of the detection chamber 15 presses the upper part of the diaphragm pump 11 and is tightly connected by screws; one end of the telescopic rod 11-4 is connected to the piston 11-2, and the other end is connected to the micro pump 11-5, and an exhaust hole 11-6 is provided on the wall of the diaphragm pump 11; a ball 11-3 is installed between the piston 11-2 and the inner wall of the diaphragm pump 11; the lower end of the diaphragm pump 11 and the upper end of the motor 13 are connected by a connecting sleeve The motor 13 is connected to the cylinder 12; the lower end of the motor 13 leads to the lower electric composite cable 14; the motor 13 drives the piston 11-2 to reciprocate up and down. When the piston 11-2 moves upward, the diaphragm 11-1 deflects upward due to the increase in pressure, the inlet check valve 17 opens, the outlet check valve 8 closes, and the pore water flows from the detection chamber 15 through the water outlet chamber 9 through the detection chamber 15 and is discharged from the probe rod 1;

[0045] The detection chamber 15, diaphragm pump 11, and motor 13 are installed and combined in sequence, and then placed into the probe rod 1, ensuring that the one-way valve chambers 7 on both sides are accurately aligned with the two holes on the wall of the probe rod 1; the perforated cover 16 is a hollow structure. Before installation, the sealing ring 5 is first put on, then pressed into the hole, and tightened to the one-way valve chamber 7; the ceramic filter 10 is embedded in the perforated cover 16, and then pressed with the pressure cap 19, and the hexagonal screws are tightened to complete the fixation.

[0046] The working principle of the present invention is:

[0047] Motor 13 drives piston 11-2 to reciprocate up and down, precisely controlling the tiny pressure differential between the outside of the probe rod 1 and the inside of the detection chamber 15, enabling the active collection and discharge of sedimentary pore water samples. When motor 13 drives piston 11-2 upward, the diaphragm 11-1 expands upward due to the increase in internal pressure. At this time, the inlet check valve 17 opens and the outlet check valve 8 closes. Under the action of pressure, the sedimentary pore water passes through the fine filtration of the ceramic filter 10, flows into the water inlet chamber 18, and is actively collected in the detection chamber 15. After the microelectrode group 6 contacts the pore water, the collected signal is transmitted to the data acquisition module terminal via the upper electric communication composite cable 2, completing the process of measuring the environmental chemical parameters of the sedimentary pore water.

[0048] When motor 13 drives piston 11-2 downward, diaphragm 11-1 expands downward due to reduced internal pressure, creating a negative pressure in detection chamber 15 within probe rod 1. This closes inlet check valve 17 and opens outlet check valve 8, draining pore water from detection chamber 15. This structural design enables efficient collection and real-time monitoring of pore water in sedimentary layers, ensuring the accuracy and reliability of test data.

[0049] Application examples of the present invention are:

[0050] When conducting in-situ testing of sediment pore water environmental chemical parameters in nearshore waters, the probe rod 1 and its accompanying test rod are installed on the drilling rig. All connecting components of the probe rod 1 (such as the upper electric cable 2, the detection chamber 15, the motor 13, and the diaphragm pump 11) are securely connected. The motor 13, the diaphragm pump 11, and the microelectrode assembly 6 are also checked for proper operation. Using a positioning system such as GPS or acoustic positioning, the drilling rig is precisely positioned at the target sedimentary area. The propulsion mechanism is activated, slowly driving the probe rod 1 into the seafloor sediment. Driven by the propulsion mechanism, the probe rod 1 slowly and steadily penetrates the seafloor sediment. According to a pre-set program, the motor 13 begins to drive the piston 11-2 in an upward and downward reciprocating motion. As the motor 13 drives the piston 11-2 upward, the diaphragm 11-1 expands upward due to the increased internal pressure, opening the inlet check valve 17 and closing the outlet check valve 8. Under pressure, pore water in the sedimentary layer outside the probe 1 passes through the ceramic filter 10, where it is filtered and desilted before flowing into the inlet chamber 18 and actively collected in the detection chamber 15. As the pore water enters the detection chamber 15, the microelectrode assembly 6 immediately begins operation, measuring various chemical parameters of the pore water (such as pH, dissolved oxygen concentration, and redox potential) in real time. The collected signals are transmitted via the upper electric communication composite cable 2 to the data acquisition module terminal, completing the measurement of the environmental chemical parameters of the pore water in the sedimentary layer. After the test is completed, the motor 13 drives the piston 11-2 downward. At this point, the diaphragm 11-1 expands downward due to the reduced internal pressure, creating a negative pressure within the detection chamber 15. The inlet check valve 17 closes, and the outlet check valve 8 opens, allowing the pore water in the detection chamber 15 to pass through the outlet chamber 9 and out of the probe 1, ready for the next collection.

[0051] During in-situ testing of sediment pore water environmental chemical parameters in deep-sea waters, the probe rod 1 and its accompanying test rod are installed on the drilling rig. All connecting components of the probe rod 1 (such as the upper electric cable 2, the detection chamber 15, the motor 13, and the diaphragm pump 11) are securely connected. The motor 13, the diaphragm pump 11, and the microelectrode assembly 6 are also checked for proper operation. Using a positioning system such as GPS or acoustic positioning, the drilling rig is precisely positioned at the target sedimentary area. The propulsion mechanism is activated, slowly driving the probe rod 1 into the seafloor sediment. Driven by the propulsion mechanism, the probe rod 1 slowly and steadily penetrates the seafloor sediment. According to a pre-set program, the motor 13 begins to drive the piston 11-2 in an upward and downward reciprocating motion. As the motor 13 drives the piston 11-2 upward, the diaphragm 11-1 expands upward due to the increased internal pressure, opening the inlet check valve 17 and closing the outlet check valve 8. Under pressure, pore water in the sedimentary layer outside the probe 1 passes through the ceramic filter 10, where it is filtered and desilted before flowing into the inlet chamber 18 and actively collected in the detection chamber 15. As the pore water enters the detection chamber 15, the microelectrode assembly 6 immediately begins operation, measuring various chemical parameters of the pore water (such as pH, dissolved oxygen concentration, and redox potential) in real time. The collected signals are transmitted via the upper electric communication composite cable 2 to the data acquisition module terminal, completing the measurement of the environmental chemical parameters of the pore water in the sedimentary layer. After the test is completed, the motor 13 drives the piston 11-2 downward. At this point, the diaphragm 11-1 expands downward due to the reduced internal pressure, creating a negative pressure within the detection chamber 15. The inlet check valve 17 closes, and the outlet check valve 8 opens, allowing the pore water in the detection chamber 15 to pass through the outlet chamber 9 and out of the probe 1, ready for the next collection.

[0052] The embodiments described above relate only to preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Any changes and improvements made to the technical solutions of the present invention by persons skilled in the art without departing from the design concept of the present invention are intended to fall within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims and any equivalents thereof.

Claims

1. An in-situ testing device for environmental chemical parameters of submarine sediments, characterized by: The device comprises a probe (1) and an upper electric composite cable (2), a detection chamber (15), a diaphragm pump (11) and a lower electric composite cable (14) installed in the probe rod (1) from top to bottom; The probe rod (1) is cylindrical and has a hollow cavity inside. Two holes are provided on the wall of the probe rod (1). The upper electric composite cable (2), the electrode fixing member (3), the microelectrode group (6), the microelectrode connector (20), the detection chamber (15), the diaphragm pump (11), the connecting sleeve (12), and the lower electric composite cable (14) are all placed in the probe rod (1). The probe rod (1) only has a detection and sensing function. During operation, the upper end needs to be connected to the data acquisition and communication module, and the lower end needs to be connected to other test units or directly connected to the drill bit; the detection chamber (15), the diaphragm pump (11), and the motor (13) are installed and combined in sequence to form a whole, and then placed in the probe rod (1) to ensure that the one-way valves on both sides The chamber (7) is precisely aligned with the two holes on the wall of the probe rod (1); one end of the one-way valve chamber (7) is connected to the detection chamber (15), and the other end is connected to one side of the perforated cover (16); the lower edge of the other side of the perforated cover (16) is pressed onto the probe rod (1); the upper edge of the perforated cover (16) is connected to one side of the ceramic filter (10), and the other side of the ceramic filter (10) is connected to the pressure cover (19); the perforated cover (16) is a hollow structure, and before installation, the sealing ring (5) is first put on, and then pressed into the hole and tightened to the one-way valve chamber (7); the ceramic filter (10) is embedded in the perforated cover (16), and then pressed with the pressure cover (19), and the hexagonal screw is tightened to complete the fixation; A microelectrode group (6) is installed inside the detection chamber (15), and the microelectrode group (6) is connected to the upper electric composite cable (2); The detection chamber (15) is connected to a one-way valve chamber (7) on each side; an inlet one-way valve (17) and an outlet one-way valve (8) are installed in the two one-way valve chambers (7), respectively; the one-way valve chamber (7) is provided with threads at both ends, and circular grooves are provided on both sides of the central protrusion; a sealing ring (5) is installed in the groove position at one end of the one-way valve chamber (7), which is connected to the detection chamber (15) through threads to prevent pore water from seeping into the probe rod (1); The lower end of the detection chamber (15) is connected to a diaphragm pump (11). The diaphragm pump (11) controls the opening and closing of the inlet check valve (17) and the outlet check valve (8) by driving the piston to move up and down. The lower end of the diaphragm pump (11) is connected to the lower electric composite cable (14). When the inlet check valve (17) is opened and the outlet check valve (8) is closed, the pore water is filtered by the ceramic filter (10) and flows into the water inlet chamber (18) and is passively collected into the detection chamber (15). On the contrary, when the inlet check valve (17) is closed and the outlet check valve (8) is opened, the pore water flows from the detection chamber (15) through the water outlet chamber (9) and is discharged from the probe rod (1).

2. The in-situ testing device for environmental chemical parameters of seabed sediments according to claim 1, characterized in that: The electrode fixing part (3) is an irregular wedge-shaped part, hollow inside, square on the top like a bolt, and provided with a groove on the shoulder. After being connected to the microelectrode connector (20), vulcanized rubber is poured in. After being thoroughly air-dried, a sealing ring (5) is placed in the groove position, and passes through the opening above the detection chamber (15) from bottom to top. The contact surface of the electrode fixing part (3) and the detection chamber (15) is tightened by tightening the nut (4), leaving only the upper electric composite cable (2) exposed.

3. The in-situ testing device for environmental chemical properties of seabed sediments according to claim 1, characterized in that: The diaphragm pump (11) is composed of a diaphragm (11-1), a piston (11-2), a ball bearing (11-3), a telescopic rod (11-4), a micro pump (11-5) and an exhaust hole (11-6); The upper end of the diaphragm pump (11) is connected to the lower end of the detection chamber (15), and the diaphragm (11-1) is installed between the diaphragm pump (11) and the detection chamber (15); one end of the telescopic rod (11-4) is connected to the piston (11-2), and the other end is connected to the micro pump (11-5), and an exhaust hole (11-6) is provided on the wall of the diaphragm pump (11); a ball (11-3) is installed between the piston (11-2) and the inner wall of the diaphragm pump (11); the lower end of the diaphragm pump (11) is connected to the upper end of the motor (13) through a connecting sleeve (12); and a lower electric composite cable (14) is led out from the lower end of the motor (13).

4. The in-situ testing device for environmental chemical parameters of seabed sediments according to claim 1, characterized in that: Silicone gaskets are installed on both sides of the diaphragm (11-1) of the diaphragm pump (11), and the lower part of the detection chamber (15) is pressed against the upper part of the diaphragm pump (11) and is tightly connected by screws.

5. The in-situ testing device for environmental chemical parameters of seabed sediments according to claim 1, characterized in that: The microelectrode group (6) is a combination of one or more of pH, Ag / AgCl, Ag / Ag2S, Eh, dissolved oxygen, sulfate, carbonate microelectrodes or temperature electrodes, and is fixed to the lower end of the microelectrode connector (20) by welding or epoxy resin bonding, and is used for in-situ detection of multiple chemical parameters of the marine sediment pore water environment.

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