Tide simulation device and method

Abstract

The application discloses a kind of tidal simulation device and method, the device includes mud column, water tank, water inlet peristaltic pump, water outlet peristaltic pump, external tide circulating pump, support frame, time control switch and valve;And by designing the structure and installation position of mud column and water tank, so that mud column can realize the circulation of overlying water under the action of external tide circulating pump, the pressure generated by mud column in closed space;And the device not only can realize more abundant, more real, tidal simulation is more controllable, little influence on sediment, stratified sampling and monitoring is more convenient, but also can study the influence of tidal action on hydroxyl radical in sediment, by additionally adding supplementary water tank, so that its device is suitable for simulating long-period tidal action, suitable for studying the influence of different tidal simulation on sediment.

Description

Technical Field

[0001] This invention relates to the technical field of environmental engineering, and specifically to a tidal simulation device and method. Background Technology

[0002] Sediments in coastal wetlands, lake shores, farmland and wetlands, and rivers are easily affected by factors such as sunlight, temperature, oxygen concentration, microorganisms, metal elements and organic matter in the overlying water, and tidal cycles, making it difficult to monitor and study the changing trends of hydroxyl radicals in these environments.

[0003] Currently, research on the generation of hydroxyl radicals at the redox interface in sediments mainly relies on simulating tidal processes through simple water level fluctuations. To enhance tidal circulation and enrich the simulation conditions to better reflect real-world environments, circulation pumps are often introduced. For example, the tidal simulation system for studying material cycling in application number 202210664726.X incorporates a built-in tidal circulation pump with inlet, outlet, and outlet located near the bottom of the sandbox. This allows water to circulate within the sandbox, simulating horizontal migration and controlling the intensity of tidal circulation. However, this setup causes significant disturbance to the sediment surface, making it difficult to ensure that water at different heights undergoes tidal circulation. Consequently, it suffers from poor realism in tidal simulation, difficulty in monitoring tidal conditions, and reduced reliability of research data.

[0004] In addition, during long-term cycles, tidal simulation devices are susceptible to the cumulative effects of water evaporation and water loss from components, and there is also the problem that long-term tidal cycle research cannot be carried out.

[0005] Therefore, there is an urgent need to develop a tidal simulation device that provides richer and more realistic tidal simulation, more controllable tidal cycle processes, more convenient stratified sampling and monitoring, and can study the effects of tidal action on hydroxyl radicals in sediments. Summary of the Invention

[0006] In order to overcome the problems existing in the prior art, the purpose of this invention is to provide a tide simulation device and method.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, the present invention provides a tide simulation device, including a mud column, a water tank, an inlet peristaltic pump, an inlet and outlet control valve, an external tide circulation pump, a time control switch, a support frame, an overlying water outlet control valve, and an overlying water inlet control valve.

[0009] The support frame has at least two layers, with the mud pillar and the water tank respectively located in the upper and lower layers of the support frame.

[0010] The mud column includes a mud column shell and a plug for sealing the mud column. A water inlet is provided at the bottom of the mud column shell. At least two sampling ports located at different horizontal planes are provided on the lower half of the side wall of the mud column shell.

[0011] The upper half of the side wall of the mud column shell is provided with an overlying water outlet and an overlying water inlet located at different horizontal planes.

[0012] The water tank includes a water tank body, a water inlet, a circulating water outlet, and a circulating water inlet;

[0013] The water inlet of the water tank is connected to the inlet and outlet peristaltic pump, the inlet and outlet control valve and the inlet of the mud column through pipelines to simulate the process of high tide and low tide.

[0014] The circulating water outlet of the water tank is connected in sequence to the external tidal circulation pump, the overlying water inlet control valve, and the overlying water inlet of the mud column via pipelines. The overlying water outlet of the mud column is connected in sequence to the overlying water outlet control valve and the circulating water inlet of the water tank via pipelines, in order to simulate the overlying water circulation process.

[0015] The time control switch is connected to the inlet / outlet peristaltic pump and the external tidal circulation pump via circuits, respectively, and is used to control the type of tidal simulation and the operating cycle of the overlying water circulation.

[0016] In some embodiments of the present invention, the top of the mud column is covered; the sampling port is equipped with a stopper of matching size (e.g., silicone stopper, wooden stopper, glass stopper).

[0017] Specifically, in the mud column, the water inlet corresponds to the "inlet and outlet" in this embodiment of the invention, meaning a component or through-hole that enables water inflow and outflow. Each inlet and outlet on the mud column is equipped with a valve or plug, allowing the mud column to be temporarily in a relatively closed state within the tidal simulation device. This enables the simulated tidal device to achieve effective circulation of overlying water under the action of a single pump and the internal pressure of the mud column. Simultaneously, the overlying water outlet and inlet are positioned on different horizontal planes to improve the effectiveness of overlying water circulation. Furthermore, by placing the water inlet at the bottom of the mud column, disturbance to the sediment is reduced. It should be noted that, because the mud column is relatively closed, under the action of the external circulation pump, after the overlying water enters the mud column through the pipe, the mud column will, in order to maintain internal pressure balance, allow some of the overlying water to flow out through the overlying water outlet and back into the water tank.

[0018] In some embodiments of the present invention, the water tank further includes an aeration hole, a sensor hole, a water supply inlet, and a cover for fixing components and sealing; the aeration hole, the sensor hole, and the circulating water outlet are all disposed on the cover;

[0019] The circulating water inlet is located on the side wall of the water tank body, at a distance of 0.1 to 0.5 cm from the top of the water tank body. The water inlet and water supply inlet of the water tank are both located on the side wall of the water tank body, at a distance of 0.1 to 0.5 cm from the bottom of the water tank body.

[0020] The tidal simulation device also includes an oxygen generator, a flow regulating valve, and an aeration head, wherein the aeration head is installed inside the water tank body;

[0021] The oxygen generator is connected to a flow regulating valve, aeration holes and aeration heads via pipelines. The oxygen generator is also connected to a time control switch to regulate the dissolved oxygen content of the liquid inside the water tank.

[0022] In some preferred embodiments of the present invention, the number of sensor holes is 2 to 10.

[0023] In some more preferred embodiments of the present invention, a conduit for fixing a water pipe is installed on the aeration hole.

[0024] Specifically, the water tank has at least the following functions: (1) water storage function, (2) providing overlying water or circulating water, (3) providing space for regulating and monitoring overlying water, and (4) being connected to compensation water tanks and one-way valves set at different heights, and having the function of automatically replenishing water.

[0025] In some embodiments of the present invention, the oxygen generating device includes at least one of an oxygen cylinder and an oxygen pump.

[0026] In some embodiments of the present invention, the tidal simulation device further includes a lighting system, a data detection system, a data display and control system, and a moving electrode system;

[0027] The lighting system is installed on the top of the support frame and connected to a time control switch to irradiate the mud column and simulate different lighting conditions.

[0028] The data detection system is installed on the water tank and is used to detect the amount of water covering the tank.

[0029] The movable electrode system is used to detect the potential signal of sediments in a mud column;

[0030] The data detection system and the mobile electrode system are respectively connected to the data display and control system, and are used to directly display and feed back the detected data on the display and control system's monitor, so as to facilitate the monitoring and control of sediment and overlying water conditions.

[0031] In some embodiments of the present invention, the data detection system includes a water level sensor, a dissolved oxygen sensor, a pH sensor, a temperature sensor, and a redox potential sensor.

[0032] In some embodiments of the present invention, the movable electrode system includes a reference electrode and a working electrode.

[0033] In some embodiments of the present invention, the reference electrode is a calomel electrode and the working electrode is a platinum electrode.

[0034] In some preferred embodiments of the present invention, the data detection system includes a water level sensor, a dissolved oxygen sensor, a pH sensor, a temperature sensor, and a redox potential sensor, and all the sensors in the data detection system are installed on the water tank through sensor ports on the lid of the water tank.

[0035] In some preferred embodiments of the present invention, the water level sensor is selected from at least one of a float level sensor and an optical level sensor.

[0036] Specifically, the available sensors are as follows:

[0037] The water level sensor includes at least one of the following: Littelfuse 59630 float level sensor, Cynergy 3 OLS500D3 optical level sensor, Keyence FL-CP120 level sensor, and Keyence FL-CP100 level sensor.

[0038] The dissolved oxygen sensor includes at least one of the following: Leici JPBJ-608 dissolved oxygen sensor, Leici JPBJ-607A dissolved oxygen sensor, German AMER online dissolved oxygen meter OOM223, German AMER online dissolved oxygen meter OOM253; and Mettler Toledo InPro6050 dissolved oxygen sensor.

[0039] The pH sensor includes at least one of the following models: InPro4800, InPro3100 / 120 Pt100, and InPro3100 / 150 Pt100; the manufacturer of the pH sensor is Mettler Toledo.

[0040] The redox potential sensor includes at least one of Mettler Tolle's redox potential (ORP) composite electrode LE501 and Mettler Tolle's redox electrode InLab Redox Ag805.

[0041] In some embodiments of the present invention, the tide simulation device further includes a compensation water tank and a one-way valve; the compensation water tank is disposed on the upper layer of the support frame;

[0042] The compensation water tank is equipped with a water outlet, and the water outlet of the compensation water tank is connected to a one-way valve and the water supply port of the water tank in sequence through a pipeline. The one-way valve is connected to a data display and control system through a line to replenish the water volume in a timely manner.

[0043] In some preferred embodiments of the present invention, the support frame has a three-layer structure (upper, middle, and lower), with the lighting system located in the upper layer, the mud column in the middle layer, and the water tank and compensation water tank in the lower layer.

[0044] In some preferred embodiments of the present invention, the outlet of the compensation water tank is located on the side wall at a distance of 0.1cm to 0.5cm from the bottom of the compensation water tank.

[0045] In some embodiments of the present invention, the diameter of the outlet of the compensation water tank is 0.1 cm to 1 cm.

[0046] In some embodiments of the present invention, the compensation tank includes a compensation tank body and a cover.

[0047] In some embodiments of the present invention, the ratio of the volume of the water tank to the volume of the compensation water tank is (6~10):1.

[0048] In some embodiments of the present invention, the lower half of the side wall of the mud column shell is provided with 6 to 20 sampling ports located at different horizontal planes.

[0049] In some preferred embodiments of the present invention, the sampling port on the outer shell of the mud column is a circular through hole, and the ratio of the diameter of the sampling port to the length of the height of the mud column is (0.005~0.03):1.

[0050] In some preferred embodiments of the present invention, 2-4 circular sampling ports are provided on each horizontal plane of the lower half of the side wall of the mud column shell; the sampling ports are provided on at least 4-15 horizontal planes, and the diameter of the sampling ports is 0.2cm-0.6cm.

[0051] In some preferred embodiments of the present invention, the circular through holes are evenly distributed in layers on the sidewall of the inlay, for a total of 6 to 15 layers.

[0052] In some embodiments of the present invention, the water outlet of the mud column shell is located above the water inlet of the mud column, and the water outlet of the mud column is located at a vertical distance of 0.1 to 4 cm from the top of the mud column.

[0053] In some preferred embodiments of the present invention, the vertical distance between the upper water outlet and the upper water inlet is 5-8 cm.

[0054] In some embodiments of the present invention, the mud column further includes an inlay, the inlay being selected from a cuboid or a cylinder.

[0055] In some preferred embodiments of the present invention, the mud column further includes an inlay, which is cylindrical, hollow and without a cap; the inner side of the inlay has cylindrical gauze, and the side wall of the inlay has several through holes.

[0056] Specifically, the cylindrical inlay can be referred to as an "inlaid cylinder".

[0057] In some embodiments of the present invention, the interior of the mud column shell is cylindrical; the difference between the inner diameter of the mud column shell and the outer diameter of the embedded cylinder is ≤0.5cm.

[0058] In some embodiments of the present invention, the ratio of the height of the inlay to the height of the mud column shell is (0.3~0.6):1.

[0059] In some preferred embodiments of the present invention, the through hole on the side wall of the inlay is the same size as the sample port.

[0060] In some preferred embodiments of the present invention, the cylindrical gauze has a mesh count of 100 to 300.

[0061] Specifically, the cylindrical gauze is used to reduce the impact of simulated tides on sediments (including sediment loss), while the embedded cylinder is used to fix the sediment wrapped in the cylindrical gauze to the bottom of the mud column. Meanwhile, since the water inlet of the mud column is located at the bottom, during simulated high and low tides, water is transported through the holes in the embedded cylinder to carry overlying water.

[0062] In some embodiments of the present invention, the outer shell of the mud column further includes a flange structure, and the flange structure consists of an upper flange and a lower flange, with the water inlet at the bottom of the mud column respectively located at the center of the lower flange.

[0063] Specifically, the flange structure can be fixed with screws, and the flange structure is designed to facilitate the filling of an insert containing deposits wrapped in gauze.

[0064] In some embodiments of the present invention, the flange structure is connected and fixed by screws.

[0065] In some embodiments of the present invention, the ratio of the internal volume of the inlay to the volume of the outer shell of the mud column is 1:(1.5~3).

[0066] In some preferred embodiments of the present invention, the through hole on the side wall of the embedded cylinder is a circular through hole, and the ratio of the diameter of the through hole to the length of the height of the mud column is (0.005~0.03):1.

[0067] In some embodiments of the present invention, the ratio of the volume of the mud column to the volume of the water tank is (4~6):1.

[0068] In some preferred embodiments of the present invention, both the mud column and the embedded cylinder are made of transparent plexiglass, which facilitates observation, sampling and research.

[0069] In some more preferred embodiments of the present invention, the inner diameter of the mud column shell is equal to the outer diameter of the embedded cylinder, and the difference between the inner diameter and the outer diameter of the embedded cylinder is 0.1~0.5cm.

[0070] Specifically, by designing a reasonable inner diameter of the mud column shell and the outer and inner diameters of the embedded cylinder, the contact surface and friction between the mud column shell and the embedded cylinder can be increased, so that the embedded cylinder and the sediment located inside the embedded cylinder can be well fixed to the bottom inside the mud column shell; it can also control the path of the overlying water.

[0071] In some embodiments of the present invention, the ratio of the volume of the mud column to the volume of the water tank is (4~6):1.

[0072] In some embodiments of the present invention, the mud column, the water tank, and the compensation water tank are all made of transparent material, which facilitates observation, sampling, and monitoring.

[0073] In some embodiments of the present invention, the water tank is selected from a cuboid or a cylinder; the compensation water tank is selected from a cuboid or a cylinder.

[0074] In some embodiments of the present invention, the cover of the water tank is selected from a cuboid or a cylinder; the cover of the compensation water tank is selected from a cuboid or a cylinder.

[0075] In some preferred embodiments of the present invention, the lid of the water tank and the lid of the compensation water tank are screw caps, and the screw caps are 0.5~5cm high.

[0076] In some embodiments of the present invention, the transparent material is selected from at least one of inorganic glass, plexiglass, and transparent plastic.

[0077] In some embodiments of the present invention, the inlet / outlet water control valve, the overlying water outlet control valve, and the overlying water inlet water control valve are connected to a time control switch, which can improve the controllability of the tide simulation device.

[0078] In some embodiments of the present invention, the time control switch is connected to a data display and control system, which can improve the linkage of the device.

[0079] Specifically, the time control switch and data display and control system can be replaced with devices that have time control switch function and display function, such as mobile phones, computers, tablets, etc.

[0080] Secondly, the present invention also provides a tide simulation method, wherein the method uses the above-mentioned tide simulation device for simulation.

[0081] In some embodiments of the present invention, the tide simulation method includes the following steps:

[0082] S1: Monitor and regulate the overlying water in the tank;

[0083] After mixing the overlying water with the sediment, wrap the mixture with gauze and fill it inside the inlay. Then install and fix the inlay to the bottom of the mud column.

[0084] The operating cycles of the lighting system, inlet and outlet peristaltic pumps, and external tidal circulation pump are controlled by setting a timer switch;

[0085] S2: The process of tidal bore is simulated by using inlet and outlet peristaltic pumps to transport overlying water from the water tank to the mud column;

[0086] S3: After the high tide process is over, the mud column is sealed by valves and plugs, and then the overlying water outlet and inlet of the mud column are opened. The overlying water is circulated by the water tank, the external tidal circulation pump and the pressure inside the mud column.

[0087] S4: Turn off the external tidal circulation pump, open the inlet and outlet water control valves, and use the inlet and outlet water peristaltic pumps to transport the overlying water back to the water tank to simulate the receding tide process.

[0088] In some embodiments of the present invention, the installation of the inlay in S1 is specifically as follows: the position of the through hole on the inlay needs to be aligned with the sampling port, which facilitates the sampling of interstitial water in the stratified sediments and the pretreatment operation for the study of microorganisms in each layer of sediments. The cross-section of the silicone plug is the same as the shape and size of the through hole on the inlay cylinder, which can be used to fix the inlay cylinder at the bottom, which facilitates sampling and research, reduces the loss of sediments caused by high tide, low tide and circulating water turbulence, and ensures that the mud column can undergo a longer simulation process.

[0089] In some embodiments of the present invention, the ratio of the height of the sediment to the height of the mud column is (0.8~1.2):1.

[0090] Specifically, the inlet and outlet peristaltic pumps, external tidal circulation pumps, and lighting systems can be controlled by setting the aforementioned time control switch to simulate different lighting conditions, different intertidal zone locations (high tide, mid-tide, low tide), different tidal types (semi-diurnal tide, diurnal tide), and tidal levels (high tide, mid-tide, low tide). Further analysis shows that different tidal conditions can be simulated by setting the following conditions, as detailed in Table 1.

[0091] Table 1. Correspondence between the conditions for time-controlled switch control and tidal types

[0092]

[0093] Note: A day in Table 1 is calculated in 24-hour increments. Different tidal levels can be set according to the amount of sediment and the height of the mud column.

[0094] In some preferred embodiments of the present invention, step S1 of the tidal simulation method includes: first incubating the sediment in the dark at a temperature of 25~35°C for 10~20 days, and then adjusting the water content of the sediment to 30%~50% with overlying water.

[0095] In particular, incubation in the dark is to facilitate the study of changes in the amount of hydroxyl radicals generated in the sediments. Adjusting the water content of the sediments beforehand can reduce the loss of overlying water during the simulation process and is beneficial for monitoring the changing trends of other sediment data.

[0096] In some preferred embodiments of the present invention, the tidal simulation method further includes: S2, S3 and S4 can run cyclically for several cycles.

[0097] In some preferred embodiments of the present invention, the tidal simulation method includes a pre-run process, which includes performing the S1 process once, performing the S2, S3 and S4 processes 1 to 5 times, and then starting data monitoring and recording.

[0098] In some embodiments of the present invention, the tidal simulation method further includes: using a moving electrode system inserted into a sampling port on a mud column to detect sediments at different locations in different mud columns.

[0099] In some embodiments of the present invention, the tidal simulation method further includes: removing the silicone rubber stopper and using a sampler to collect sediment or interstitial water samples at different locations in the mud column at the sampling port position on the mud column.

[0100] Specifically, samples extracted using a moving electrode system and sampler can be used to detect the content of ferrous iron, dissolved organic carbon, and hydroxyl radicals in sediments at different locations, thereby enabling the study of the effects of different tidal forces on hydroxyl radicals in sediments.

[0101] In some embodiments of the present invention, the tidal simulation method further includes: monitoring the dissolved oxygen content in the overlying water in the tank using a data detection system, and quantitatively supplying oxygen to the overlying water in the tank by controlling the pipeline connected by an oxygen pump, a flow regulating valve and an aeration head.

[0102] Specifically, by using a data monitoring system, oxygen pump, flow control valve, and aeration head, the influence of dissolved oxygen on hydroxyl radicals in sediments can be investigated, and the dissolved oxygen level in the tank can be controlled in a timely manner. Furthermore, by using the data monitoring system, oxygen pump, flow control valve, aeration head, mud column, tank, and moving electrode system together, the effects of multiple factors such as organic matter, microorganisms, iron, potential, and dissolved oxygen on hydroxyl radicals in sediments can be further investigated.

[0103] In some embodiments of the present invention, the tidal simulation method further includes: before tidal simulation, detecting the initial water level in the tank using a water level sensor in the data detection system; after a tidal simulation cycle ends, detecting the water level in the tank after tidal simulation, and replenishing the water level in the tank as needed.

[0104] Specifically, when the initial water level is greater than the water level after the tide simulation, the one-way valve is opened by the time control switch, and the compensation tank delivers the overlying water to the tank through the action of gravity and pressure difference, and replenishes the water level in the tank to the initial water level;

[0105] In other cases, the one-way valve remains closed.

[0106] Specifically, the setting of the compensation tank can extend the operating time of the tidal simulation device, reduce the impact of water loss (e.g., evaporation) on the tidal simulation, and improve the accuracy of the research data and the realism of the simulation.

[0107] In some preferred embodiments of the present invention, when the initial water level is greater than the water level after tidal simulation ±1cm, a one-way valve is opened by a time-controlled switch to compensate the water tank by gravity and pressure difference to deliver overlying water to the water tank and replenish the water level in the water tank to the initial water level.

[0108] In some embodiments of the present invention, the sediment is at least one of coastal wetland sediments, lake shore sediments, underground sediments of farmland, and river sediments.

[0109] In some embodiments of the present invention, the overlying water is at least one of artificial seawater and ultrapure water.

[0110] In some embodiments of the present invention, the overlying water is at least one of artificial seawater and ultrapure water.

[0111] The beneficial effects of this invention are as follows: The tidal simulation device of this invention, through the design of the structure and installation position of the mud column and water tank, as well as the connection method of each device, not only achieves richer and more realistic tidal simulation, more controllable tidal cycle processes, and more convenient stratified sampling and monitoring, with minimal impact on sediments, but also enables the study of the effects of tidal action on hydroxyl radicals and other parameters in sediments. Furthermore, by adding a supplementary water tank, the device can be adapted to simulate long-period or long-duration tidal actions, making it suitable for studying the effects of different tidal simulations on sediments. Specifically:

[0112] (1) The circulation process of the overlying water in the tidal simulation device of the present invention mainly utilizes the effect of an external circulation pump and pressure difference;

[0113] Specifically, when the mud column is in a submerged state, the use of a plug allows for a closed vacuum inside the mud column. Under the action of an external tidal circulation pump and the internal pressure of the mud column, the overlying water flows from the water tank into the mud column through the overlying water inlet. The internal pressure of the mud column then forces the overlying water in the mud column to flow back into the water tank through the overlying water outlet, thus achieving the circulation process of the overlying water. This not only ensures that the circulation of the overlying water is controllable and does not easily cause disturbance to the sediment surface, which is beneficial for research, but also allows for the control of the circulation intensity of the overlying water during the tidal process by controlling the flow rate of the external tidal circulation pump.

[0114] (2) The tidal simulation device of the present invention is more in line with the actual tidal process. The tidal simulation operation system achieves bottom water intake through mud column and introduces external water inlet and outlet peristaltic pump to achieve circulation and reduce disturbance, which can reduce disturbance to the surface of sediment, reduce the impact on the sampling and measurement of the experiment, facilitate the research, and add a light system. These three points are more in line with the actual tidal process.

[0115] (3) The tidal simulation device of the present invention can simulate different intertidal zone locations (high tide zone, mid tide zone, low tide zone), different tidal types (semi-diurnal tide, diurnal tide), tidal height (high tide level, mid tide level, low tide level), different overlying water circulation intensity conditions, overlying water dissolved oxygen conditions, and different regional light conditions.

[0116] (3) The tidal simulation device of the present invention is convenient for sampling and monitoring. By designing sampling ports with different horizontal planes in the mud column, it is convenient to conduct in-situ monitoring or sampling of interstitial water and related physicochemical properties of sediments at different horizontal planes.

[0117] (4) The tidal simulation device of the present invention, by designing the bottom flange structure of the mud column shell, not only facilitates the placement and fixation of sediments, but also allows the sediments to be removed without damaging the layered structure of the sediments, making the pretreatment operation for the layered study of sediment microorganisms more convenient.

[0118] (5) The tidal simulation device of the present invention can realize direct real-time monitoring and control of relevant indicators of the overlying water during operation.

[0119] (6) The tidal simulation device of the present invention is equipped with an automatic evaporation water replenishment system, which can realize multi-cycle tidal operation research, reduce experimental errors caused by evaporation during long-term operation, and improve the accuracy of the research.

[0120] (7) The present invention provides a method for tidal simulation, which includes first adjusting the water content of sediments with overlying water to reduce the impact of subsequent overlying water on sediments during transport. Attached Figure Description

[0121] Figure 1 This is a schematic diagram of the tidal simulation device in an embodiment of the present invention.

[0122] Figure 2 This is a schematic diagram of the structure of the mud column, the outer shell of the mud column, and the inner cylinder of the mud column in an embodiment of the present invention.

[0123] Figure 3 This is a schematic diagram of the structure of a mud column without sediment and a mud column filled with sediment in an embodiment of the present invention.

[0124] Figure 4 This is a schematic diagram of a structure for monitoring the state of sediments in a mud column using a moving electrode system in an embodiment of the present invention.

[0125] Figure 5 This is a schematic diagram of the circulating water tank in an embodiment of the present invention.

[0126] Figure 6This is a graph showing the monitoring data of the redox potential of interstitial water in the surface sediments of the intertidal zone in Example 1.

[0127] Figure 7 Fe in the interstitial water of surface sediments in the intertidal zone sediments of Example 1 2+ The results of monitoring data on the content are shown in the figure.

[0128] Figure 8 This is a graph showing the monitoring data results of hydroxyl radical content in intertidal sediments from Example 1.

[0129] Figure label:

[0130] 1 mud column, 1-1 mud column shell, 1-2 embedded cylinder, 1-1' sampling port, 1-2' upper water outlet, 1-3' upper water inlet, 1-4' inlet and outlet, 1-5' upper flange, 1-6' lower flange;

[0131] 2. Water tank, 2-1 aeration hole, 2-2 sensor hole, 2-3 circulating water outlet, 2-4 circulating water inlet, 2-5 water tank inlet and outlet, 2-6 water supply inlet, 2-7 water tank cap, 2-8 water tank body.

[0132] 3. Inlet and outlet peristaltic pumps; 4. Inlet and outlet control valves; 5. External tidal circulation pump; 6. Oxygen pump; 7. Flow regulating valve; 8. Aeration head; 9. Lighting system; 10. Time control switch;

[0133] 11 Data detection system, 11-1 Water level sensor, 11-2 Dissolved oxygen sensor, 11-3 pH sensor, 11-4 Temperature sensor, 11-5 Oxidation-reduction potential sensor;

[0134] 12 Data display and control system; 13 Compensation tank; 14 One-way valve; 15 Support frame; 16 Moving electrode system, 16-1 Working electrode (platinum electrode), 16-2 Reference electrode (calomel electrode); 17 Overhead water outlet control valve; 18 Overhead water inlet control valve; The remaining parts are pipelines and wires. Detailed Implementation

[0135] The present invention will be further described in detail below through specific embodiments.

[0136] It should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", "horizontal", "vertical", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0137] Unless otherwise specified, "overlying water" in the embodiments refers to "circulating water"; the water storage tank 2 in the embodiments functions as both a water storage tank and a circulating water tank; the materials in the mud column 1, water tank 2, and compensation water tank 13 are all transparent materials (e.g., inorganic glass, plexiglass, plastic, etc.), allowing for easy observation of the overall device's operation; the tide simulation device or accessories in the embodiments are all as described above. Figures 1-4 As shown; in this invention, "overlapping time" refers to the time when the sediment in mud column 1 is covered with overlapping water, and "exposed time" refers to the time when the sediment in mud column 1 is exposed to air or other gases; the electrodes, sensors, pumps, switches, and flow meters in this invention are all commercially available.

[0138] A schematic diagram of the tidal simulation device in this embodiment of the invention is shown below. Figure 1 As shown in the diagram. This embodiment of the invention uses a moving electrode system to monitor the state of sediments in a mud column. Figure 4 As shown. A schematic diagram of the structure of the mud column 1 in this embodiment of the invention is shown below. Figure 2 As shown in (a) in the diagram; a structural schematic diagram of the mud column shell 1-1, as shown in the diagram. Figure 2 As shown in (b) of the diagram; a schematic diagram of the structure of the embedded cylinder 1-2 of the mud column, as shown in the diagram. Figure 2 As shown in (c) of the figure. A schematic diagram of the structure of a mud column without sediment and a mud column filled with sediment in an embodiment of the present invention is shown below. Figure 3 As shown in the diagram. A schematic diagram of the structure of the water tank 2 in this embodiment of the invention is shown below. Figure 5 As shown in (a), this is a schematic diagram of the structure of the water tank 2 with aeration heads and a data detection system. Figure 5 As shown in (b) of the diagram.

[0139] Tidal simulation device:

[0140] In some embodiments, combined with Figures 1-5 The tidal simulation device includes a tidal simulation operation system, an intelligent monitoring and control system, and an automatic evaporation water replenishment system;

[0141] The tidal simulation operation system includes a mud column 1, a water tank 2, an inlet and outlet peristaltic pump 3, an inlet and outlet control valve 4, an external tidal circulation pump 5, an oxygen pump 6, a flow regulating valve 7, an aeration head 8, a lighting system 9, a support frame 15, an overlying water outlet control valve 17, and an overlying water inlet control valve 18.

[0142] The support frame 15 has three layers, from top to bottom: the first layer, the second layer, and the third layer.

[0143] The lighting system 9 is placed on the first layer to ensure that the light from the lighting system 9 can illuminate the mud column 1;

[0144] The mud column 1, the external tidal circulation pump 5 and the compensation water tank 13 are set on the second layer of the support frame 15, and the water tank 2 is placed on the third layer. This not only ensures that the mud column 1 can circulate water in a closed environment through pressure difference and external circulation pump, but also facilitates that the compensation water tank 13 in the automatic evaporation water replenishment system can replenish the water tank 2 in a timely manner through gravity and pressure difference.

[0145] The inlet and outlet 2-5 of the bottom of the water tank 2 are connected in sequence to the inlet and outlet peristaltic pump 3, the inlet and outlet control valve 4, and the inlet and outlet 1-4' of the mud column 1 through pipelines, which are used to control the inlet and outlet water volume of the mud column 1 to achieve the function of rising tide and receding tide.

[0146] Water tank 2 is connected to external tidal circulation pump 5, overlying water inlet control valve 18, and overlying water inlet 1-3' in mud column 1 via pipeline through circulating water outlet 2-3. Then, overlying water outlet 1-2' in mud column 1 is connected to water tank 2 via overlying water outlet control valve 17 and circulating water inlet 2-4, thereby enabling control of the overlying water conditions in mud column 1 (e.g., overlying water turbulence, composition of overlying water, circulation cycle of overlying water, etc.).

[0147] The oxygen pump 6 is connected to the aeration head 8 located in the water tank 2 via the flow regulating valve 7, the aeration hole 2-1 in the water tank 2, and the pipeline, which can control the dissolved oxygen content of the overlying water in the water tank 2.

[0148] Multiple sampling ports 1-1' are provided on the side wall of the lower half of the mud column 1, which can be connected to the movable electrode system 16, and can ensure the airtightness of the mud column 1 and monitor the condition of sediments at different heights; each sampling port 1-1' is equipped with a corresponding silicone rubber plug.

[0149] The automatic evaporation water replenishment system includes a compensation water tank 13 and a one-way valve 14.

[0150] The compensation water tank 13 is set on the second layer of the support frame 15, and the water outlet at the bottom of the compensation water tank 13 is connected to the one-way valve 14 and the water supply port 2-6, so as to realize the function of automatic water replenishment by relying solely on gravity and the one-way valve. At the same time, when used in conjunction with the water level sensor 11-1, it can effectively control the amount of water in the water tank 2.

[0151] The intelligent monitoring and control system includes a time control switch 10, a data detection system 11, a data display and control system 12, and a mobile electrode system 16, which are used to realize real-time monitoring and control of relevant physicochemical indicators of the overlying water during operation.

[0152] The time control switch 10 is connected to the lighting system 9, the external tidal circulation pump 5, the inlet and outlet water peristaltic pump 3, and the oxygen pump 6 respectively, and is used to control the inlet and outlet water volume, lighting time, circulation cycle of the overlying water and oxygen content of the overlying water in the tidal simulation operation system.

[0153] The water level sensor 11-1, dissolved oxygen sensor 11-2, pH sensor 11-3, temperature sensor 11-4, and oxidation-reduction potential sensor 11-5 in the data detection system 11 are inserted below the liquid surface of the water tank 2 through sensor holes 2-2 to detect the water level, dissolved oxygen content, pH value, temperature, and oxidation-reduction potential in the water tank 2. At the same time, the data detection system 11 is connected to the data display and control system 12, which is in turn connected to the one-way valve 14, so that the water tank 2 can be replenished with appropriate amounts of water in a timely manner during the long-term operation of the device.

[0154] The working electrode 16-1 and reference electrode 16-2 in the mobile electrode system 16 are connected to the data display and control system 12. Since the electrode system is movable, it can conveniently sample and monitor the conditions of sediments at different heights in the mud column 1 (e.g., the potential signal of redox potential, and this electrical signal can be used for physicochemical property analysis, thereby quantitatively or qualitatively analyzing the conditions of ferrous iron and dissolved organic carbon (DOC) in sediments or interstitial water at different locations in the mud column).

[0155] The mud column 1 is also equipped with an embedded cylinder 1-2, which can facilitate the maintenance of sediment stability. The embedded cylinder 1-2 is a hollow cylinder, and the wall of the embedded cylinder 1-2 has multiple through holes. When the through holes correspond to the sampling port 1-1', it is convenient for the experimenter to sample (water sample or sediment sample) from the sampling port 1-1', and it is also convenient to use the movable electrode system 16 to conduct in-situ monitoring and research on the sediment wrapped in gauze.

[0156] The overlying water inlet 1-3' and the overlying water outlet 1-2' in the mud column 1 are both located on the side wall of the upper half of the mud column 1, and it must be ensured that the overlying water outlet 1-2' is located above the overlying water inlet 1-3'.

[0157] In the movable electrode system 16, the working electrode 16-1 is a platinum electrode, the reference electrode 16-2 is a calomel electrode, and the reference electrode 16-2 is connected to the negative terminal of the potentiometer, the working electrode 16-1 is connected to the positive terminal of the potentiometer, and the potentiometer is then connected to the data display and control system 12.

[0158] In some embodiments, the tidal simulation device is further equipped with a time control switch 10, a data detection system 11, and a data display and control system 12 connected together. The time control switch 10 can control the operation of various sensors in the data detection system 11 and transmit the data to the data display and control system 12 in real time. This enables the timing of the tidal simulation operation system to be correlated with the data monitored by the data display and control system 12 in the intelligent monitoring and control system, thereby further realizing the synchronous activation of the monitoring and simulation system. This makes the real-time monitoring of relevant indicators of the overlying water and the control of dissolved oxygen in the overlying water more accurate during operation.

[0159] In some embodiments, the inlet / outlet water control valve 4, the overlying water outlet control valve 17, and the overlying water inlet control valve 18 in the tidal simulation device can all be connected to the time control switch 10, thereby further improving the intelligence level of the device.

[0160] Mud column 1:

[0161] It should be noted that, considering the specific parameters of the device, the key feature of the tidal simulation device in the embodiments of the present invention is that it provides a mud column 1 (see...). Figures 2-4 The device includes: a mud column shell 1-1 with a cap on top, a hollow, capless embedded cylinder 1-2 with multiple through holes, nine silicone rubber plugs (diameter: 0.4cm) that match the size of the sample port 1-1', and a cylindrical gauze of 200 mesh. The mud column shell 1-1 and the embedded cylinder 1-2 are both made of transparent plexiglass, which is convenient for observation, sampling and research.

[0162] The inner diameter of the outer shell of the mud column 1-1 is 3 cm, its height is 22 cm, and its volume is approximately 168.3 cm³. 3 The outer diameter of the embedded cylinder 1-2 is 3cm, the inner diameter is 2.8cm, and the height is 10cm. This increases the contact area and friction between the mud column shell 1-1 and the embedded cylinder 1-2, so that the embedded cylinder 1-2 and the sediment inside the embedded cylinder 1-2 can be well fixed at the bottom inside the mud column shell 1-1.

[0163] The sidewall of the embedded cylinder 1-2 has evenly distributed circular through holes with a diameter of 0.4 cm. The holes are evenly distributed in layers on the sidewall, with a total of 10 layers. When using it, the position of the circular holes of the embedded cylinder 1-2 should be aligned with the sampling port 1-1' to facilitate the sampling of interstitial water in the stratified sediments and to facilitate the pretreatment operation for the study of microorganisms in each layer of sediments. The cross-section of the silicone plug is the same as the shape and size of the through holes on the embedded cylinder 1-2, which can be used to fix the embedded cylinder 1-2 at the bottom, which facilitates sampling and research, reduces the loss of sediments by the rising tide, falling tide and circulating water turbulence, and ensures that the mud column can undergo a longer simulation process.

[0164] The cylindrical gauze is designed to prevent sediment from leaking out through the holes in the embedded, uncovered cylinder. During simulated high tide, water enters from the bottom of the sediment and slowly seeps into it through the through-holes on the side walls of the embedded cylinder 1-2, achieving bottom water inflow for highly viscous soil. This allows for bottom water inflow and outflow during operation to control the high and low tide processes, reducing disturbance to the surface soil and minimizing the impact on measurements. During simulated low tide, the gauze reduces the impact of pumping on the state of the sediment layers, acting as a buffer.

[0165] The mud column shell 1-1 also includes 9 sampling ports 1-1', an overlying water outlet 1-2', an overlying water inlet 1-3', an inlet and outlet 1-4', and a flange structure, which includes an upper flange plate 1-5' and a lower flange plate 1-6';

[0166] Nine sampling ports 1-1' are set on the side wall of 1-1 with a height ≤10cm. Taking the upper surface of the upper flange 1-5' as a reference, one sampling port 1-1' with an inner diameter of 0.4cm is opened every 2cm from bottom to top. During sampling, the silicone plug of the desired sampling position is removed, and the sample is taken or the electrical signal of the position is tested in situ using a syringe or the movable electrode system 16. It can also analyze the physicochemical properties of sediments at different locations and the interstitial water of each sediment layer (e.g., dissolved organic carbon (DOC) index, ferrous iron content index).

[0167] The upper flange 1-5' and the lower flange 1-6' are located at the bottom of the mud pillar housing 1-1, and both are detachable.

[0168] When flange 1-5' and lower flange 1-6' are separated, it is convenient to put or take out the sediment (shape: cylindrical) wrapped in 200-mesh gauze and the embedded cylinder 1-2 (purpose: support, used to keep the sediment cylindrical) from the bottom of the mud column shell 1-1, thereby reducing the loss of sediment during operation and improving the sampling accuracy.

[0169] When the upper flange 1-5' and the lower flange 1-6' are connected by screws, the bottom surface of the lower flange 1-6' is provided with a single cylindrical inlet / outlet 1-4' (inner diameter: 0.4cm, length: 1cm). Since the inlet / outlet is relatively small, it can increase the airtightness of the mud column shell 1-1, creating conditions for the circulation process of the overlying water to be realized by utilizing the pressure difference and the water tank 2.

[0170] On the side wall of the mud column shell 1-1, at positions 11.5cm and 18cm away from the upper flange 1-5', respectively, there are upper water inlet 1-3' and upper water outlet 1-2' with an inner diameter of 0.3 mm, which are used to realize the circulation process of the upper water.

[0171] In some embodiments, after a specific tidal simulation process, the unique structure of the cylindrical gauze facilitates the study of microorganisms in each layer of sediment. The embedded cylinders 1-2 containing sediment are directly removed from the mud column 1 and then frozen at -80°C. The open holes on the sidewalls of the uncovered embedded cylinders 1-2, spaced 1 cm apart, allow for direct cutting, sampling, and testing, thereby improving the efficiency of microbial research in each layer of sediment.

[0172] In summary, by utilizing the sampling port 1-1' of the mud column 1 and the layered perforated structure of the embedded cylinder 1-2 in the tidal simulation system, the physicochemical properties of interstitial water in sediments can be determined, and sampling is convenient. Combined with a mobile electrode system, the oxygen reduction potential of different sediment layers can be measured directly in situ. In the mud column 1, the flange structure at the bottom of the embedded cylinder 1-2 and the mud column shell 1-1 facilitates the removal of sediments without damaging the layered structure, making the pretreatment operation for sediment microbial stratification studies more convenient.

[0173] Sink 2:

[0174] A schematic diagram of the structure of the water tank 2 in this embodiment of the invention is shown below. Figure 5 As shown in (a), this is a schematic diagram of the structure of the water tank 2 with aeration heads and a data detection system. Figure 5 As shown in (b) of the diagram.

[0175] It should also be noted that the tidal simulation device (see Figure 5 The water tank 2 in the ) has multiple functions. It can be used to store water, can be used with pump 3 to simulate the rise and fall of tides, can be used with mud column 1 to simulate the circulation process of overlying water, and can also be connected to other gas devices (e.g., oxygen, nitrogen, carbon dioxide generators) to regulate the dissolved oxygen content in tidal liquid and overlying water.

[0176] Specifically, based on specific parameters, the water tank 2 of the tide simulation device is 7cm × 7cm × 5cm (volume: 245cm). 3 A lidded cuboid container, comprising a water tank body 2-8 and a screw cap 2-7 1 cm high, capable of sealing, storing, and providing top-covering water.

[0177] The water tank body 2-8 has water inlet and outlet 2-5 and water supply inlet 2-6 on its left and right sides, respectively, and the water inlet and outlet 2-5 and water supply inlet 2-6 are all located 0.2cm away from the bottom of the water tank body 2-8.

[0178] A circulating water inlet 2-4 is provided on the upper right side of the water tank body 2-8, and the circulating water inlet 2-4 is located 0.2cm away from the top of the water tank body 2-8; the circulating water inlet 2-4 and the water supply inlet 2-6 are located on the side wall of the water tank body 2-8, and close to the side of the data detection system 11, so as to ensure that water can be replenished in time according to the water level detected by the data detection system, which is conducive to extending the service life of the data detection system 11;

[0179] From the inlet / outlet 2-5 of the water tank to the replenishment inlet 2-6, the water tank cap 2-7 is provided with aeration holes 2-1 (diameter: 0.3cm), circulating water outlet 2-3 (diameter: 0.3cm), and 5 sensor holes 2-2 (diameter: 0.3cm) in sequence. Since the circulating water outlet 2-3 is located between the sensor holes 2-2 and the aeration holes 2-1, it is connected to an external circulating peristaltic pump 3 through a water pipe, which can be used to circulate the overlying water and quickly adjust the dissolved oxygen content in the mud column 1.

[0180] A glass tube 1.5cm long and 0.3cm in diameter passes through the aeration hole 2-1 and is glued to the screw cap 2-7 of the water tank. Both ends of the glass tube are connected to hoses. One end is connected to the flow regulating valve 7 through a hose, and the other end is connected to the aeration head 8 through a hose, thereby fixing the pipeline connected to the oxygen pump 6 and thus being able to stably control the dissolved oxygen in the overlying water.

[0181] Five sensor holes 2-2 are used to house a water level sensor 11-1, a dissolved oxygen sensor 11-2, a pH sensor 11-3, a temperature sensor 11-4, and a redox potential sensor 11-5, respectively, for real-time monitoring of the physicochemical properties of the overlying water in the water tank 2.

[0182] Compensation tank 13:

[0183] The compensation tank 13 is used to store a certain volume of artificial seawater or ultrapure water and to serve as a supplementary water source for the water evaporated during tidal operation.

[0184] The compensating water tank 13 is a covered rectangular container with dimensions of 3.5cm in length, 3.5cm in width, and 2.5cm in height (volume: 30.625cm²). 3 It includes a compensating water tank body and a matching screw cap (1cm high), which can achieve a seal;

[0185] On the left side of the compensation water tank 13, there is a water outlet with a length of 0.5cm and a diameter of 0.15cm, located 0.1cm from the bottom. This water outlet is connected to the one-way valve 14 and the water supply inlet 2-6 of the water tank 2 to replenish the water tank 2.

[0186] In a specific embodiment, the information of the sensor used is as follows:

[0187] Water level sensor 11-1 (type: optical liquid level sensor, model: Cynergy 3 OLS500D3); dissolved oxygen sensor 11-2 (manufacturer: Leici, model: JPBJ-608); pH sensor 11-3 (manufacturer: Mettler Toledo, model: InPro4800); redox potential sensor 11-5 (manufacturer: Mettler Toledo, model: ORP composite electrode LE501).

[0188] Specifications and instructions for other original components:

[0189] Inlet / outlet peristaltic pump 3: Simulates water inflow by pumping water into the mud column to achieve tidal level changes; simulates receding tide by pumping away the overlying water in the mud column to achieve tidal level changes. The inlet and outlet water flow is controlled by adjusting the clockwise and counterclockwise rotation direction of the peristaltic pump.

[0190] Inlet / outlet control valve 4: For tidal processes, after water intake is complete, tighten the stop valve to maintain the airtightness of the mud column and prevent backflow of the overlying water. Open the stop valve when pumping. For cyclic processes, close the stop valve at the end of the cyclic process and open the stop valve at the beginning of the cyclic process.

[0191] External tidal circulation pump 5: Simulates ocean wave fluctuations to control flow rate. The external circulation pump can reduce disturbance to the surface soil of sediment in the mud column and facilitates control of oxygen concentration.

[0192] Oxygen pump 6: Provides oxygen to the overlying water.

[0193] Flow regulating valve 7: The concentration of dissolved oxygen is controlled by adjusting the gas flow rate.

[0194] Aeration head 8: Placed below the liquid surface of water tank 2 for aeration.

[0195] Lighting system 9: Controlled by time switch 10, used to simulate lighting.

[0196] Time control switch 10: controls the inlet and outlet peristaltic pump 3, external tidal circulation pump 5, lighting system 9, and one-way valve 14 to achieve intelligent operation. By controlling the different running times of the pumps, it simulates the intertidal zone position by controlling different tidal types, the ratio of water cover time to exposure time, and the lighting system to simulate the changes in sunlight time in different seasons in the actual environment.

[0197] The data detection system 11 includes a water level sensor 11-1 inserted into the water tank 2, a dissolved oxygen sensor 11-2, a pH sensor 11-3, a temperature sensor 11-4, and a redox potential sensor 11-5, used to monitor changes in relevant indicators of the circulating overlying water during operation. Simultaneously, by utilizing the data monitored by the water level sensor 11-1 and the data display and control system 12, it can control the compensation tank 13 to replenish the water evaporated from the mud column by the one-way valve 14 during operation, and achieve automatic replenishment of evaporated water. Furthermore, by using the dissolved oxygen sensor 11-2, the data display and control system 12, the oxygen pump 6, the flow regulating valve 7, and the aeration head 8 in combination, the dissolved oxygen level of the overlying water can be controlled.

[0198] The data display and control system 12 is used in conjunction with the data detection system 11 to display the operating status of the sensors in the data detection system 11.

[0199] One-way valve 14: can only flow from compensation tank 13 to storage tank 2, is connected to the water level sensor in the monitoring system, and its opening and closing are controlled by the water level sensor.

[0200] Support frame 15: has a 3-layer structure for placing components.

[0201] Simulation operation method of tide simulation device:

[0202] The tide simulation device of this invention can at least realize the following simulation process:

[0203] Controlling dissolved oxygen levels at different concentrations, tidal processes such as high and low tides, the circulation of overlying water, the automatic water replenishment process, and different light conditions.

[0204] (1) Controlling the dissolved oxygen content of different dissolved oxygen levels: The oxygen pump 6 is opened and closed by controlling the time control switch 10, and the dissolved oxygen value of the liquid in the water tank 2 is monitored by the data detection system 11 and the data display and control system 12. The flow regulating valve 7 in the tidal simulation operation system is adjusted according to the dissolved oxygen value of the liquid to control the concentration of dissolved oxygen, thereby realizing the control simulation of dissolved oxygen conditions of the overlying water.

[0205] (2) Tidal process: Taking mud column 1 as the key body, mud column 1 is connected to inlet and outlet peristaltic pump 3 through water pipe, and then connected to inlet and outlet control valve 4 and inlet and outlet 2-5 of the bottom of water tank 2. The rise and fall of the tidal process is controlled by the operation and rotation direction of inlet and outlet peristaltic pump 3.

[0206] Meanwhile, the inlet and outlet peristaltic pump 3 is designed to be connected to the time control switch 10. Different high tide and low tide times can be set through the time control switch 10, thereby realizing the control and simulation of different intertidal zone positions (high tide zone, mid tide zone, low tide zone), different tidal types (semi-diurnal tide, diurnal tide), and tidal heights (high tide level, mid tide level, low tide level).

[0207] The different intertidal zone locations and different tidal types are achieved by controlling the flooding time and exposure time. The flooding time to exposure time in the high tide zone is 1:2, the flooding time to exposure time in the mid-tide zone is 1:1, and the flooding time to exposure time in the low tide zone is 2:1.

[0208] Within a tidal cycle, the flooding time and exposure time of a semi-diurnal tide should be set to 6 hours and 6 hours respectively, while the flooding time and exposure time of a diurnal tide should be set to 12 hours and 12 hours respectively.

[0209] The tidal level is achieved by controlling the overlying water height of the sediment in mud column 1. The overlying water height is set to 7-10 cm for high tide, 5-7 cm (excluding 7 cm) for mid-tidal level, and 3-5 cm (excluding 5 cm) for low tide.

[0210] The illumination system 9 is also controlled by the time switch 10. During the ebb and flow of the tide, the simulation of illumination conditions is introduced, which not only more closely reflects the actual tidal operation process, but also allows for the study of the impact of illumination on sediments and tides during actual operation.

[0211] (3) The circulation process of the overlying water: the overlying water inlet 1-3' of the mud column 1 is connected to the overlying water inlet control valve 18 and the external tidal circulation pump 5, and the connected water pipe is placed below the liquid surface through the circulating water outlet 2-3 of the water tank 2. At the same time, the overlying water outlet 1-2' is directly connected to the data display and control system 12 and the circulating water inlet 2-4 through the water pipe.

[0212] Since the inlet and outlet peristaltic pump 3 and the external tidal circulation pump 5 are both connected to the time control switch 10, after the tidal process controlled by the inlet and outlet peristaltic pump 3 ends, the mud column 1 is in a relatively sealed state through the cover of the mud column 1 and the rubber stopper of the sampling port 1-1'. Then, the time control switch 10 is used to start the operation of the external tidal circulation pump 5. Under the action of the pressure difference, the overlying water flows out from the circulating water outlet 2-3 of the water tank 2, flows into the mud column 1 through the overlying water inlet 1-3', and then flows out of the mud column 1 through the overlying water outlet 1-2'. Then, the overlying water flows back into the water tank 2 through the circulating water outlet 2-4, thereby realizing the simulation of the circulation process of the overlying water.

[0213] (4) Automatic water replenishment process: The initial water level is automatically recorded by the water level sensor 11-1 inserted in the water tank 2 and the data display and control system 12. After one or more tidal simulation processes, the water level in the water tank 2 is replenished to the same level as the initial water level by the data display and control system 12 according to the water level measured by the water level sensor 11-1 in the water tank 2. The water level in the water tank 2 is replenished to the same level as the initial water level, that is, the automatic water replenishment process is realized during operation.

[0214] The automatic water replenishment process can ensure the long-term operation of the tidal simulation device and reduce experimental errors caused by evaporation during long-term operation, which is conducive to improving the accuracy of the research.

[0215] (5) Different lighting conditions: Different lighting cycles can be set by the time control switch 10 to simulate lighting conditions at different latitudes and longitudes, which helps to improve the realism of the simulation and the accuracy of the research data.

[0216] In some embodiments of the present invention, the circulation process of the overlying water in the tidal simulation device mainly utilizes the principle of pressure difference. Since the mud column 1 is in a water-covered state and plugged, the interior of the mud column 1 presents a relatively closed vacuum. When overlying water flows into the mud column 1 through ports 1-3', the internal pressure of the mud column forces the overlying water in the mud column 1 to flow back into the water tank 2 through the water pipe circulation outlets 2-4 from ports 1-2'. This achieves the circulation process of the overlying water through internal pressure. This method allows for controllable circulation of the overlying water and minimizes disturbance to the sediment surface, facilitating research.

[0217] In some embodiments of the present invention, the tidal simulation device of the present invention can also control the circulation intensity of the overlying water during the tidal process by controlling the flow rate of the external tidal circulation pump 5.

[0218] In summary, the present invention can achieve the circulation process of the overlying water by designing the mud column 1 to be water-intake from the bottom and introducing an external tidal circulation pump 5, which can reduce the disturbance to the surface of the sediment, not affect the sampling and measurement of the experiment, and facilitate the research; and by introducing the lighting system 9, it can simulate the changes in the amount of sunlight in different seasons in the actual environment, making the tidal simulation device of the present invention more closely resemble the actual tidal process.

[0219] Simultaneously, the start and stop of the inlet and outlet peristaltic pump 3 are controlled by the time control switch 10 to simulate different intertidal zone positions (high tide zone, mid-tide zone, low tide zone), different tidal types (semi-diurnal tide, diurnal tide), and tidal heights (high tide level, mid-tide level, low tide level). The circulation intensity of the overlying water and the dissolved oxygen conditions of the overlying water are controlled by controlling the flow rate of the external tidal circulation pump 5 and the oxygen pump 6. Therefore, the tidal simulation equipment in this invention has strong controllability, more types of tidal simulation conditions, is closer to the real simulation environment, and is suitable for studying the generation process of hydroxyl radicals under different tidal conditions.

[0220] Example 1

[0221] This embodiment uses the aforementioned tide simulation device to perform the tide simulation process (i.e., the tide simulation method), and the structure of the tide simulation device is as follows: Figure 1 As shown, the specifications and connection methods of the remaining components are as described above. The manufacturers and models of the sensors in this embodiment are shown in Table 2.

[0222] Table 2 Information on the sensor and moving electrode system in Example 1

[0223]

[0224] Note: The temperature and dissolved oxygen sensors in Table 2 are both based on the Leici JPBJ-608 sensor, which can simultaneously measure both temperature and dissolved oxygen. Figure 1 and Figure 3 The initial dissolved oxygen concentration in the overlying water was set to 6-8 ppm, and the circulation intensity was set to medium (i.e., the operating speed of the external tidal circulation pump 5 was 2 mL / min). Taking the mid-tidal zone (overlying time: exposure time = 1:1, i.e., overlying time: 12h, exposure time: 12h) and high tide level (overlying water height: 10cm) of a diurnal tide (tidal cycle of 24h) as an example, this embodiment was set according to the tidal timetable published on the official website https: / / www.chaoxibiao.net / , and the mangrove sediments of Hailing Island, Yangjiang City, Guangdong Province were used to monitor the tidal simulation process and related data.

[0225] This embodiment provides a method for operating a tide simulation device, including the following steps:

[0226] (1) Preparations for tidal simulation:

[0227] Artificial seawater was used as the overlying water, and coastal wetland sediments were used as the sediments.

[0228] After pre-incubating the coastal wetland sediments for 12-14 days, the sediments were mixed with the overlying water and the water content of the sediments was adjusted to 40%. Then, 200-mesh cylindrical gauze was placed inside the embedded cylinder 1-2, and the sediments with a water content of 40% were filled into the cylindrical gauze, so that the sediments filled the entire hollow cavity of the embedded cylinder 1-2. The sediments were then slowly inserted into the outer shell 1-1 of the mud column 1 through the opening at the upper flange 1-5' of the mud column 1.

[0229] After aligning the position of the circular through hole of the embedded cylinder 1-2 with the position of the sample measuring port 1-1', connect the flange structure of the mud column 1 with screws, and then follow the instructions. Figure 1 Place mud column 1 back onto support frame 15;

[0230] The rest according to Figure 1 Connect all components of the tide simulation device with wires and pipes, and keep them closed or powered off.

[0231] (2) The operation process of tidal simulation:

[0232] Taking one tidal simulation cycle (24 hours) as an example,

[0233] S1: Monitoring and adjustment of initial state: Turn on the data detection system 11 and the data display and control system 12 to measure the parameters of initial water level, dissolved oxygen content, temperature, redox potential and pH value of the liquid in the water tank 2, and use 16 to test the initial state of the sediment;

[0234] Turn on the oxygen pump 6, and use the flow regulating valve 7, aeration head 8 and data display and control system 12 to adjust the dissolved oxygen in the water tank 2 to 6~8 ppm;

[0235] The switching time of the lighting system 9, the running time and direction of the inlet and outlet peristaltic pumps 3, and the running time of the external tidal circulation pump 5 are set by using the time control switch 10 to control the simulated tidal lighting time of 12h, the darkness time of 12h, the water covering time of 12h, the exposure time of 12h, and the water covering circulation time.

[0236] S2: Simulate the high tide process: Open the inlet and outlet water control valve 4 and remove the silicone rubber plug from the mud column 1. Set the flow direction of the inlet and outlet water peristaltic pump 3 to water inlet and the flow rate of water inlet to 2mL / min. Control the water inlet time through the time control switch 10 so that the water height in the mud column 1 reaches 10cm. Then close the inlet and outlet water control valve 4 and install the silicone rubber plug back on the mud column 1 so that the mud column 1 is in a relatively sealed state.

[0237] S3: Simulate the overlying water circulation process: Open the overlying water outlet control valve 17 and the overlying water inlet control valve 18, and control the water inlet of the external tidal circulation pump 5 through the time control switch 10, so that the overlying water can be set to the overlying water circulation cycle, and use the data detection system 11 and the data display and control system 12 to monitor various physicochemical parameters in the overlying water.

[0238] Meanwhile, through the time control switch 10, oxygen pump 6, flow regulating valve 7 and aeration head 8, the dissolved oxygen content of the overlying water is maintained at 6~8 ppm during the overlying period, and the dissolved oxygen content of the overlying water is controlled only during the overlying period.

[0239] S4: Simulate the ebb tide process: Open the inlet and outlet water control valve 4, set the flow direction of the inlet and outlet water peristaltic pump 3 to outlet water and the outlet water flow rate to 2mL / min, and control the outlet water time through the time control switch 10 to discharge the overlying water in the mud column 1, thereby completing the ebb tide process.

[0240] S5: Automatic water replenishment process: Before starting the next tidal cycle, the one-way valve 14 is controlled by the water level sensor 11-1 in the water tank 2 to compensate the water in the water tank 13 under the action of gravity and pressure to compensate the water in the water tank 2. Finally, the water in the water tank 2 can be maintained at the initial water level in S1 before starting the next tidal cycle.

[0241] The incubation process in S1 is as follows: the sediment is placed in a light-proof glass bottle and placed in an incubator at 30°C for incubation.

[0242] The single run time of the inlet and outlet peristaltic pumps 3 in S2 and S4 is 35 minutes, and the running cycle of the inlet and outlet peristaltic pumps 3 is 12 hours.

[0243] It should be noted that the S2~S5 processes in the operation method of the tidal simulation device in this embodiment can be performed multiple times to realize the process of multiple tidal simulation cycles. The electrodes of the movable electrode system 16 can monitor the physicochemical properties of sediments or interstitial water at different locations at any time.

[0244] The method for monitoring data during operation in this embodiment is as follows:

[0245] (1) Determination of the amount of hydroxyl radicals generated: After the initial state, single cycle or continuous cycle, take 2g of sediment samples after the end of high tide and surface sediment samples after the end of low tide, add 10mM scavenging agent (sodium benzoate solution), react for 24 hours, take out 1mL of suspension, add an equal volume of methanol to quench the reaction, and then perform the determination on liquid phase.

[0246] (2) Determine relevant factors of overlying water: Activate the intelligent control module of the data detection system 11 to obtain real-time data of dissolved oxygen, pH value, temperature and other parameters of overlying water during the tidal process, which are obtained directly from the data display system of the one-way valve 14.

[0247] (3) Real-time monitoring of redox potential of sediment stratification: Using a moving electrode system 16 connected to a mud column (1), data is obtained from the data display system through a one-way valve 14;

[0248] (4) Indicators of ferrous iron and dissolved organic carbon (DOC) in interstitial water: stratified sampling can be achieved by using a syringe to sample from the sampling port 1-1' of mud column 1. Then, the dissolved organic carbon (DOC) value is determined by a total organic carbon analyzer (TOC). The ferrous iron content of the sample is determined by the standard method of "HJ / T345-2007 Determination of Iron in Water Quality - o-phenanthroline Spectrophotometric Method" to obtain the relevant index results.

[0249] Data monitoring method and results of Example 1

[0250] Because the apparatus and method of the present invention can effectively reduce the disturbance and impact of tidal processes on the surface of sediments, facilitate sampling, and improve the stability of data monitoring, the advantages of the apparatus and method of the present invention will be specifically illustrated by taking the tidal simulation process under the operating conditions of Example 1 to monitor the physicochemical properties of the outermost layer of sediments.

[0251] 1. Monitoring results of redox potential

[0252] Measurement location: the outermost layer of the sediment, i.e., the position where the height of the embedded cylinder is 10 cm.

[0253] Test method: After two pre-run cycles of the tidal device and method in Example 1, relevant data were measured and recorded using the moving electrode system 16. After analysis, the monitoring data of the redox potential of interstitial water in the surface sediments of the intertidal zone under diurnal tidal conditions were plotted as follows: Figure 6 As shown in the figure, the error bars represent the differences between multiple sets of parallel mud columns.

[0254] Depend on Figure 6 It can be known that: Figure 6The sediment measurements were initiated after two pre-run cycles (i.e., two cycles of high tide, overlying water circulation, and low tide). Following the two-week pre-run, formal experimental data were acquired. Data recorded at 0h represents the initial state of the sediments after two tidal cycles; data recorded at 12h represents the state of the sediments after 12 hours of overlying water following high tide; and data recorded at 24h represents the state of the sediments after 12 hours of low tide. The cycle is 24 hours. This graph objectively reflects the changing trend of redox potential over three consecutive cycles. This demonstrates that the structure of the movable electrode system 16 and the mud column 1 allows for in-situ stratified measurement of sediments.

[0255] Meanwhile, the standard deviation of the multiple sets of data in the figure represents the range of the error bars; Figure 6 The standard deviation of the data ranged from 4.949 to 7.071 (unit: mV), indicating that the relative deviation and standard deviation among the measured data sets were small. This tidal simulation device and method cause little disturbance to the sediment surface, which is beneficial for in-depth monitoring and research on the physicochemical properties of sediments and sediment interstitial water.

[0256] 2. Measurement location: The outermost layer of the sediment, i.e., the location where the height of the embedded cylinder is 10 cm.

[0257] Sampling and Measurement Methods: After two pre-run cycles of the tidal device and method in Example 1, interstitial water from the sediment was directly extracted from the sampling port 1-1' of the mud column using a syringe. Multiple parallel groups were set up, and the content of divalent iron was determined using the "HJ / T 345-2007 Determination of Iron in Water Quality - o-phenanthroline Spectrophotometric Method". The test and recorded data are as follows: Figure 7 As shown.

[0258] Depend on Figure 7 It can be known that: Figure 7 The data recorded at 0h represents the initial state of the sediments after two tidal cycles; the data recorded at 12h represents the state of the sediments after 12 hours of flooding following high tide; and the data recorded at 24h represents the state of the sediments after 12 hours of receding tide. Figure 7 The error bars in the table also represent the standard deviation of the test sample, indicating the difference between parallel mud columns, with ≥3 parallel samples.

[0259] and, Figure 7 The standard deviation of the sample was 0.0686~0.214 mol / L (sediment), and the content of ferrous iron in the cyclic test showed obvious periodicity and variation.

[0260] This demonstrates that the tidal simulation device and method of the present invention not only facilitates the portability of the samples but also results in smaller deviations and higher reliability of the tested samples, which is beneficial for studying changes in the surface materials of sediments.

[0261] 3. Hydroxyl radical content

[0262] Measurement location: the outermost layer of the sediment, i.e., the position where the height of the embedded cylinder is 10 cm.

[0263] Sampling and Measurement Methods: After two pre-run cycles of the tidal apparatus and method in Example 1, 2g samples of sediment were taken after high tide and surface sediment after low tide, in the initial state, after a single cycle, or after a continuous cycle. A 10mM scavenging agent (i.e., sodium benzoate solution) was added, and after reacting for 24 hours, 1mL of the suspension was taken out, and an equal volume of methanol was added to quench the reaction. Subsequently, liquid chromatography was used to determine and analyze the hydroxyl radical content of the sample, and the results are as follows: Figure 8 As shown.

[0264] Depend on Figure 8 It can be known that: Figure 8 The data recorded at 0h represents the amount of hydroxyl radicals generated in the sediment after two pre-cycles; the data recorded at 12h represents the amount of free radicals generated in the sediment 12 hours after high tide; and the data recorded at 24h represents the amount of free radicals generated in the sediment after low tide. 0–24h constitutes one cycle, and this figure shows the effect of three consecutive cycles. Meanwhile, Figure 8 The standard deviation range is 0.0707~0.283 μmol / kg (sediment). Since the tidal simulation method of this invention involves incubating the sediment in darkness, the content of hydroxyl radicals on the sediment surface can, to a certain extent, reflect the amount of hydroxyl radicals generated in the sediment. Therefore, the tidal simulation device and method of this invention can effectively monitor hydroxyl radicals on the sediment surface, which is beneficial for studying the generation and variation trends of hydroxyl radicals at the aerobic and anaerobic interface during tidal processes.

[0265] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A tide simulation device, characterized in that: Includes mud column, water tank, inlet peristaltic pump, inlet and outlet control valve, external tidal circulation pump, timer switch, support frame, overlying water outlet control valve and overlying water inlet control valve; The support frame has at least two layers, with the mud pillar and the water tank respectively located in the upper and lower layers of the support frame. The mud column includes a mud column shell and a plug for sealing the mud column. A water inlet is provided at the bottom of the mud column shell. At least two sampling ports located at different horizontal planes are provided on the lower half of the side wall of the mud column shell. The upper half of the side wall of the mud column shell is provided with an overlying water outlet and an overlying water inlet located at different horizontal planes. The water tank includes a water tank body, a water inlet, a circulating water outlet, and a circulating water inlet; The water inlet of the water tank is connected to the inlet and outlet peristaltic pump, the inlet and outlet control valve, and the inlet of the mud column through pipelines to simulate the process of high tide and low tide. The circulating water outlet of the water tank is connected in sequence to the external tidal circulation pump, the overlying water inlet control valve, and the overlying water inlet of the mud column via pipelines. The overlying water outlet of the mud column is connected in sequence to the overlying water outlet control valve and the circulating water inlet of the water tank via pipelines, in order to simulate the overlying water circulation process. The time control switch is connected to the inlet / outlet peristaltic pump and the external tidal circulation pump via circuits, respectively, and is used to control the type of tidal simulation and the operating cycle of the overlying water circulation.

2. The tide simulation device according to claim 1, characterized in that: The water tank also includes aeration holes, sensor holes, water supply inlets, and a cover for fixing components and sealing. The aeration holes, sensor holes, and circulating water outlets are all located on the cover; The circulating water inlet is located on the side wall of the water tank body, at a distance of 0.1 to 0.5 cm from the top of the water tank body. The water inlet and water supply inlet of the water tank are both located on the side wall of the water tank body, at a distance of 0.1 to 0.5 cm from the bottom of the water tank body.

3. The tide simulation device according to claim 2, characterized in that: The tidal simulation device also includes an oxygen generator, a flow regulating valve, and an aeration head, wherein the aeration head is installed inside the water tank body; The oxygen generator is connected to a flow regulating valve, aeration holes and aeration heads via pipelines. The oxygen generator is also connected to a time control switch to regulate the dissolved oxygen content of the liquid inside the water tank.

4. The tide simulation device according to claim 2, characterized in that: The tidal simulation device also includes a lighting system, a data detection system, a data display and control system, and a moving electrode system; The lighting system is installed on the top of the support frame and connected to a time control switch to irradiate the mud column and simulate different lighting conditions. The data detection system is installed on the water tank and is used to detect the amount of water covering the tank. The movable electrode system is used to detect the potential signal of sediments in a mud column; The data detection system and the mobile electrode system are respectively connected to the data display and control system, and are used to directly display and feed back the detected data on the display and control system's monitor, so as to facilitate the monitoring and control of sediment and overlying water conditions.

5. The tide simulation device according to claim 4, characterized in that: The tidal simulation device also includes a compensating water tank and a one-way valve; The compensation water tank is located on the upper layer of the support frame; The compensation water tank is equipped with a water outlet, and the water outlet of the compensation water tank is connected to a one-way valve and the water supply port of the water tank in sequence through a pipeline. The one-way valve is connected to a data display and control system through a line to replenish the water volume in a timely manner.

6. The tide simulation device according to claim 1 or 2, characterized in that: The mud column also includes an inlay, which is cylindrical, hollow and without a cap; the inner side of the inlay has cylindrical gauze, and the side wall of the inlay has several through holes; The interior of the mud column shell is cylindrical; the difference between the inner diameter of the mud column shell and the outer diameter of the embedded cylinder is ≤0.5cm; The ratio of the height of the inlay to the height of the mud column shell is (0.3~0.6):

1.

7. The tide simulation device according to claim 6, characterized in that: The outer shell of the mud column also includes a flange structure, which consists of an upper flange and a lower flange. The water inlets at the bottom of the mud column are respectively located at the center of the lower flange.

8. The tide simulation device according to claim 6, characterized in that: The ratio of the internal volume of the inlay to the volume of the outer shell of the mud column is 1:(1.5~3); the ratio of the volume of the mud column to the volume of the water tank is (4~6):

1.

9. A method for simulating tides, characterized in that, The simulation is performed using the tidal simulation device described in any one of claims 1 to 8.

10. The tidal simulation method according to claim 9, characterized in that, Includes the following steps: S1: Monitor and regulate the overlying water in the tank; After mixing the overlying water with the sediment, wrap the mixture with gauze and fill it inside the inlay. Then install and fix the inlay to the bottom of the mud column. The operating cycles of the lighting system, inlet and outlet peristaltic pumps, and external tidal circulation pump are controlled by setting a timer switch; S2: The process of tidal bore is simulated by using inlet and outlet peristaltic pumps to transport overlying water from the water tank to the mud column; S3: After the high tide process is over, the mud column is sealed by valves and plugs, and then the overlying water outlet and inlet of the mud column are opened. The overlying water is circulated by the water tank, the external tidal circulation pump and the pressure inside the mud column. S4: Turn off the external tidal circulation pump, open the inlet and outlet water control valves, and use the inlet and outlet water peristaltic pumps to transport the overlying water back to the water tank to simulate the receding tide process.

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