Shallow groundwater quality change simulation device in multi-supply mode

Abstract

The invention relates to the technical field of underground water simulation, and provides a shallow underground water quality change simulation device in a multi-supply mode, comprising a soil column for storing soil; the high-pressure oxygen-free bottle is used for conveying water to the soil column; one end of the first matrix pipe is communicated with the high-pressure oxygen-free bottle; the soil column is used for conveying water to the low-pressure oxygen-free bottle; and the other end of the second matrix pipe is communicated with the low-pressure oxygen-free bottle. The simulation device can comprehensively simulate lateral replenishment and more truly restore the groundwater replenishment process in the natural environment, through cooperation of the soil columns and the matrix pipes, the water replenishment path and flow can be controlled, observation by researchers is facilitated, and deep understanding of the dynamic change rule of groundwater is facilitated. Wherein the high-pressure oxygen-free bottle and the low-pressure oxygen-free bottle can completely simulate an oxygen-free environment in a real environment. By means of the technical scheme, the problem that in the prior art, the reconstruction precision of the underground reducing environment of an underground water simulation device is insufficient is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of groundwater simulation, and in particular to a device for simulating water quality changes of shallow groundwater in a multi-recharge mode. Background Art

[0002] Groundwater is one of the most important water resources on Earth, and changes in its water quality directly affect drinking water safety, agricultural irrigation, and the health of the ecological environment. As an important medium for the interaction between surface water and groundwater, the water quality characteristics of shallow groundwater are affected by a variety of environmental factors, such as rainfall infiltration, overflow recharge, lateral recharge, and chemical, physical, and biological processes in the underground environment. Especially in the first aquifer of groundwater, water quality changes have significant spatiotemporal dynamic characteristics, and these characteristics are often affected by the complex interaction of water recharge mode, aquifer geological conditions, and redox environment.

[0003] At present, the simulation research on groundwater quality changes mostly adopts the method of combining indoor model experiments, numerical simulation and field monitoring. However, the existing groundwater simulation devices still have the following problems and limitations in water quality research: 1. Insufficient research on the linked water quality effects of multiple recharge methods: Existing devices can usually only simulate a single recharge method (such as rainfall infiltration), and it is difficult to comprehensively reproduce the impact of multiple recharge methods such as rainfall infiltration, overflow recharge and lateral recharge on water quality changes under different combination conditions.

[0004] 2. The reconstruction accuracy of the underground reducing environment is insufficient: The groundwater system is usually in a low-oxygen or even reducing environment. Its chemical reactions (such as the dissolution of iron and manganese, the reduction of nitrates, etc.) play an important role in water quality changes. However, the existing equipment is insufficient in the reconstruction and regulation of the reducing environment, which makes it difficult for the experimental results to accurately reflect the actual groundwater conditions.

[0005] 3. Lack of research on the coupling effect between dynamic changes in water level and water quality: Changes in groundwater head will not only change the flow field distribution of the aquifer, but also affect the migration and transformation of pollutants and water chemical balance. There is a lack of research on the coupling effect of different groundwater recharge sources on water quality.

[0006] 4. Insufficient simulation of groundwater recharge sources: Different recharge conditions such as lateral recharge, infiltration recharge, and overflow recharge have a great impact on groundwater quality changes, but existing devices usually find it difficult to achieve regulation of multiple recharge sources, and most of them are simulation devices for lateral recharge and infiltration recharge, or single overflow recharge simulation devices, which limits the in-depth study of water quality dynamic processes.

[0007] Therefore, there is an urgent need for an innovative device that can comprehensively simulate multiple shallow groundwater recharge mechanisms, accurately control the changes in recharge sources and reduction conditions, and reconstruct the reduction environment of groundwater in order to more realistically simulate the changes in water quality in the groundwater system. Such a device not only helps to deeply reveal the temporal and spatial evolution of water quality under complex recharge conditions, but also provides important technical support for groundwater pollution control, resource protection and management. Summary of the invention

[0008] The present invention proposes a device for simulating changes in shallow groundwater quality under a multi-recharge mode, which solves the problem of insufficient reconstruction accuracy of the underground reduction environment of the groundwater simulation device in the related art.

[0009] The technical solution of the present invention is as follows: The device for simulating shallow groundwater quality changes under multiple recharge modes includes: Soil columns, used to store soil; A high-pressure oxygen-free bottle, used for delivering water to the soil column; A first matrix tube, one end of which is connected to the high-pressure oxygen-free bottle and the other end of which is connected to the soil column; A low-pressure anaerobic bottle, wherein the soil column is used to transport water to the low-pressure anaerobic bottle; The second matrix tube has one end connected to the soil column and the other end connected to the low-pressure oxygen-free bottle.

[0010] Optionally, the first matrix tube and the second matrix tube have the same structure, and both include: There are a plurality of transverse tubes, wherein the plurality of transverse tubes are arranged vertically, one end of the transverse tube is connected to the soil column, and the other end is connected to the high-pressure anaerobic bottle or the low-pressure anaerobic bottle; Also includes: A plurality of valves are provided in the transverse tube, and the valves are used to open or close the transverse tube.

[0011] Optionally, the high-pressure anaerobic bottle and the low-pressure anaerobic bottle have the same structure, and both include: Barrel; A partition is arranged in the barrel body, the partition divides the barrel body into a first water storage chamber and a second water storage chamber, water in the second water storage chamber overflows into the first water storage chamber, and the transverse pipe is connected to the second water storage chamber; A barometer is arranged on the barrel body, and is used to detect the air pressure in the first water storage cavity and the second water storage cavity.

[0012] Optionally, the second water storage chamber of the high-pressure anaerobic bottle has a water inlet, the first water storage chamber of the low-pressure anaerobic bottle has a water outlet, the bottom end of the second water storage chamber of the low-pressure anaerobic bottle has a water replenishment port, and the high-pressure anaerobic bottle further includes: The first pump body is arranged in the first water storage chamber, and the first pump body is used to introduce the water in the first water storage chamber into the second water storage chamber.

[0013] Optionally, it also includes: There are several pressure stabilizers, which are arranged on the high-pressure anaerobic bottle, the soil column and the low-pressure anaerobic bottle. The pressure stabilizers are used to adjust the pressure balance of the high-pressure anaerobic bottle, the soil column and the low-pressure anaerobic bottle.

[0014] Optionally, the voltage stabilizer includes: First gas cylinder; A first pipeline, one end of which is connected to the first gas cylinder, and the other end of which is connected to the high-pressure anaerobic bottle, the soil column or the low-pressure anaerobic bottle; The first pressure reducing valve, the second pressure reducing valve and the first pressure regulating valve are arranged in sequence on the first pipeline, and the first pressure reducing valve, the second pressure reducing valve and the first pressure regulating valve are used for pressure regulation.

[0015] Optionally, the bottom end of the soil column has a permeable layer, the permeable layer has a water inlet, and further comprises: A water storage tank is communicated with the water inlet.

[0016] Optionally, the water storage tank comprises: Second gas cylinder; A second pipeline, one end of which is connected to the second gas cylinder, and the other end of which is connected to the water filling port; The third pressure reducing valve and the second pressure regulating valve are arranged in sequence on the second pipeline, and the third pressure reducing valve and the second pressure regulating valve are used for pressure regulation.

[0017] Optionally, the top of the high-pressure anaerobic bottle, the soil column or the low-pressure anaerobic bottle is provided with an exhaust valve.

[0018] Optionally, it also includes: A mounting plate, arranged in the soil column, the mounting plate having a plurality of spray ports; A rainfall box, arranged in the soil column; The second pump body is arranged in the soil column, and the rain box is connected with the spray port through the second pump body.

[0019] The working principle and beneficial effects of the present invention are: In the present invention, first, a soil column of suitable size is prepared, and the soil sample to be studied is filled inside. The high-pressure anaerobic bottle is connected to the soil column through the first matrix tube, and the low-pressure anaerobic bottle is connected to the soil column through the second matrix tube. First, nitrogen or argon is filled into the connected system to take out the oxygen in the system. The first matrix tube adopts corrosion-resistant and well-sealed pipes. An appropriate amount of water is injected into the high-pressure anaerobic bottle in advance. The water level height can be adjusted according to the experimental requirements, and it is ensured that there is enough pressure in the bottle to transport water to the soil column. The pressure can be provided by an external pressure source. The low-pressure anaerobic bottle is connected to the soil column through the second matrix tube, and the sealing and stability of the connection must also be ensured. The low-pressure anaerobic bottle is used to receive water seeping out of the soil column. During the experiment, the passage between the high-pressure anaerobic bottle and the soil column is opened, so that water enters the soil column through the first matrix tube to simulate the lateral recharge and infiltration recharge process. At the same time, the drainage of the soil column to the low-pressure anaerobic bottle is observed to simulate the lateral recharge process. By controlling the water supply pressure and flow rate of the high-pressure oxygen-free bottle and the soil characteristics of the soil column, the water quality in the groundwater level fluctuation zone can be studied.

[0020] The simulation device can comprehensively simulate lateral recharge and more realistically restore the groundwater recharge process in the natural environment. Through the coordination of soil columns and matrix pipes, the water recharge path and flow rate can be controlled, which is convenient for researchers to observe and helps to gain a deeper understanding of the dynamic changes of groundwater. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The preferred implementation modes will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0022] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the structure of the water storage tank of the present invention; Figure 3 This is a schematic diagram of the structure of the voltage stabilizer of the present invention; Figure 4 It is a schematic diagram of the process of the present invention.

[0023] In the figure: 1, soil column, 2, high-pressure anaerobic bottle, 3, first matrix tube, 4, low-pressure anaerobic bottle, 5, second matrix tube, 51, horizontal tube, 52, valve, 21, barrel, 22, partition, 23, first water storage chamber, 24, second water storage chamber, 25, barometer, 26, water inlet, 27, water outlet, 28, water replenishment port, 29, first pump body, 6, pressure stabilizer, 61, first gas cylinder, 62, first pipeline, 63, first pressure reducing valve, 64, second pressure reducing valve, 65, first pressure regulating valve, 11, permeable layer, 111, water filling port, 12, water storage tank, 121, second gas cylinder, 122, second pipeline, 123, third pressure reducing valve, 124, second pressure regulating valve, 13, exhaust valve, 7, mounting plate, 8, rainfall box, 9, second pump body. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, they can also be understood as further technical solutions without creative work. In some figures, components with the same structure or function are only schematically illustrated, or only one of them is marked. In this article, "one" not only means "only one", but also means "more than one", and "several" includes "two" and "more than two".

[0025] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0027] Reference Figure 1~Figure 2 , which is the first embodiment of the present invention, proposes a shallow groundwater quality change simulation device under a multi-recharge mode, wherein a soil column 1 is used to store soil; a high-pressure anaerobic bottle 2 is used to transport water to the soil column 1; one end of a first matrix tube 3 is connected to the high-pressure anaerobic bottle 2, and the other end is connected to the soil column 1; a low-pressure anaerobic bottle 4 soil column 1 is used to transport water to the low-pressure anaerobic bottle 4; one end of a second matrix tube 5 is connected to the soil column 1, and the other end is connected to the low-pressure anaerobic bottle 4.

[0028] In this embodiment, first, a soil column 1 of suitable size is prepared, and the soil sample to be studied is filled inside. The high-pressure anaerobic bottle 2 is connected to the soil column 1 through the first matrix tube 3, and the low-pressure anaerobic bottle 4 is connected to the soil column 1 through the second matrix tube 5. First, nitrogen or argon is filled into the connected system to remove the oxygen in the system. The first matrix tube 3 adopts corrosion-resistant and well-sealed pipes. An appropriate amount of water is injected into the high-pressure anaerobic bottle 2 in advance. The water level height can be adjusted according to the experimental requirements, and it is ensured that there is enough pressure in the bottle to transport the water to the soil column 1. The pressure can be provided by an external pressure source. The low-pressure anaerobic bottle 4 is connected to the soil column 1 through the second matrix tube 5, and the sealing and stability of the connection must also be ensured. The low-pressure anaerobic bottle 4 is used to receive the water seeping out of the soil column 1. During the experiment, the passage between the high-pressure anaerobic bottle 2 and the soil column 1 is opened, so that water enters the soil column 1 through the first matrix tube 3, simulating the lateral recharge and infiltration recharge process. At the same time, the drainage of the soil column 1 to the low-pressure anaerobic bottle 4 is observed to simulate the lateral recharge process. By controlling the water supply pressure and flow rate of the high-pressure oxygen-free bottle 2 and the soil characteristics of the soil column 1 and other parameters, the water quality in the groundwater level fluctuation zone can be studied.

[0029] The simulation device can comprehensively simulate lateral recharge and more realistically restore the groundwater recharge process in the natural environment. Through the cooperation of the soil column 1 and the matrix tube, the water recharge path and flow rate can be controlled, which is convenient for researchers to observe and helps to gain a deeper understanding of the dynamic changes of groundwater. The high-pressure anaerobic bottle 2 and the low-pressure anaerobic bottle 4 can completely simulate the anaerobic environment in the real environment.

[0030] Furthermore, the first matrix tube 3 and the second matrix tube 5 have the same structure, there are a plurality of transverse tubes 51, and the plurality of transverse tubes 51 are arranged vertically, one end of the transverse tube 51 is connected to the soil column 1, and the other end is connected to the high-pressure anaerobic bottle 2 or the low-pressure anaerobic bottle 4; there are a plurality of valves 52, which are arranged in the transverse tube 51, and the valves 52 are used to open or close the transverse tube 51.

[0031] In this embodiment, when making the first matrix tube 3 and the second matrix tube 5, the diameter of the transverse tube 51 is selected according to the water flow required for the experiment to ensure a certain strength and corrosion resistance. A plurality of transverse tubes 51 are assembled in a vertical arrangement, and a sealing joint is used at the connection between the transverse tube 51 and the soil column 1 and the high-pressure anaerobic bottle 2 (or the low-pressure anaerobic bottle 4) to prevent water leakage. A valve 52 is installed in each transverse tube 51. The valve 52 can be a solenoid valve. The solenoid valve is convenient for remote control and automatic operation. The installation position of the valve 52 should ensure that it can effectively control the on and off of the transverse tube 51, and the operation is flexible and there is no jamming. A master control switch is connected to a plurality of valves 52, and the opening and closing of a plurality of valves 52 is controlled by the master control switch. During the experiment, different simulated working conditions can be achieved by controlling the opening and closing state of the valve 52 according to the needs of the experimental design.

[0032] Generally, the aquicludes of the sampled soil in different areas of the soil column 1 are at different heights. In the lateral recharge experiment, the valve 52 below the horizontal plane of the aquiclude should be closed. At the same time, the lateral recharge water flow will not fill the soil column 1, so the corresponding high valve 52 can also be closed to make the water flow more efficient.

[0033] Furthermore, the high-pressure anaerobic bottle 2 and the low-pressure anaerobic bottle 4 have the same structure, a barrel body 21; a partition 22 is arranged in the barrel body 21, and the partition 22 divides the barrel body 21 into a first water storage chamber 23 and a second water storage chamber 24, and the water in the second water storage chamber 24 overflows into the first water storage chamber 23, and the cross pipe 51 is connected to the second water storage chamber 24; a barometer 25 is arranged on the barrel body 21, and the barometer 25 is used to detect the air pressure in the first water storage chamber 23 and the second water storage chamber 24.

[0034] In this embodiment, when manufacturing the high-pressure anaerobic bottle 2 and the low-pressure anaerobic bottle 4, a high-strength, corrosion-resistant material is used to make the barrel body 21. The barrel body 21 is generally in the shape of a rectangular parallelepiped, and is designed according to the actual use scenario and space requirements. Its volume is determined according to the amount of water and pressure range required for the experiment. A partition 22 is installed in the barrel body 21, and the partition 22 is welded or sealed to the inner wall of the barrel body 21 to ensure that the first water storage chamber 23 and the second water storage chamber 24 are completely isolated. The height of the partition 22 is less than the height inside the barrel body 21, so that the water in the second water storage chamber 24 can overflow into the first water storage chamber 23 after reaching a certain height.

[0035] The barometer 25 is installed on the top of the barrel 21, and is connected to the first water storage chamber 23 and the second water storage chamber 24 through a sealed interface. The accuracy of the barometer 25 should meet the requirements of the experiment for pressure measurement. Generally, a pressure gauge with an accuracy of kilopascals is selected. During the experiment, the data of the barometer 25 can be read in real time to understand the pressure changes in the bottle so as to adjust the water supply pressure or negative pressure. The connection between the transverse tube 51 and the second water storage chamber 24 allows the transverse tube 51 to smoothly take water, and the connection method uses a sealed pipe joint to prevent water leakage and air leakage.

[0036] The design of the partition 22 in the bottle and the installation of the barometer 25 make it possible to better control the water pressure and water level in the bottle. By monitoring the air pressure, the water supply pressure can be accurately adjusted according to the experimental requirements to ensure the stable supply or collection of water.

[0037] Furthermore, the second water storage chamber 24 of the high-pressure anaerobic bottle 2 has a water inlet 26, the first water storage chamber 23 of the low-pressure anaerobic bottle 4 has a water outlet 27, the bottom end of the second water storage chamber 24 of the low-pressure anaerobic bottle 4 has a water replenishment port 28, and the first pump body 29 is arranged in the first water storage chamber 23. The first pump body 29 is used to introduce the water in the first water storage chamber 23 into the second water storage chamber 24.

[0038] In this embodiment, a water inlet 26 is provided at a suitable position on the top of the second water storage chamber 24 of the high-pressure anaerobic bottle 2, and the water inlet 26 is connected to an external water supply pipe. A water outlet 27 is provided at the bottom or side of the first water storage chamber 23 of the low-pressure anaerobic bottle 4, and the water outlet 27 is connected to a drainage pipe, which can lead to a collection device. A water replenishment port 28 is provided at the bottom end of the second water storage chamber 24 of the low-pressure anaerobic bottle 4, and the water replenishment port 28 is connected to an external water replenishment device. In order to speed up the experimental efficiency, this solution adds a certain amount of water to the low-pressure anaerobic bottle 4 through the water replenishment port 28. Although there is water in both the high-pressure anaerobic bottle 2 and the low-pressure anaerobic bottle 4, there is still a corresponding pressure difference.

[0039] A first pump body 29 is installed in the first water storage chamber 23 of the high-pressure oxygen-free bottle 2. The pump body can be a peristaltic pump. The appropriate model and power are selected according to the experimental requirements for water flow and pressure. The inlet and outlet of the first pump body 29 are connected to the first water storage chamber 23 and the second water storage chamber 24 through a pipeline. The connection of the pipeline must be firm and sealed to ensure that water can be pumped smoothly from the first water storage chamber 23 to the second water storage chamber 24. During the experiment, when it is necessary to maintain the water level of the second water storage chamber 24, the first pump body 29 is started to introduce the water in the first water storage chamber 23 into the second water storage chamber 24.

[0040] The design of the water inlet 26 and the first pump body 29 of the high-pressure anaerobic bottle 2 facilitates the replenishment and adjustment of the water volume and water pressure in the bottle, can meet the experimental needs of long-term and different working conditions, ensure the continuity and stability of water supply during the experiment, and is of great significance for studying the fluctuation law of groundwater level under continuous recharge conditions. The design of the water outlet 27 and the water replenishment port 28 of the low-pressure anaerobic bottle 4 enables the collected water to be discharged in time and the appropriate amount of water to be replenished, so as to maintain the relative stability of the negative pressure in the bottle, which is conducive to accurately simulating the changes in the groundwater level during the lateral recharge process, improves the authenticity of the simulation experiment, and provides strong support for in-depth research on the interaction between groundwater and the surrounding environment.

[0041] Furthermore, there are several pressure stabilizers 6 arranged on the high-pressure anaerobic bottle 2 , the soil column 1 and the low-pressure anaerobic bottle 4 , and the pressure stabilizers 6 are used to adjust the pressure balance among the high-pressure anaerobic bottle 2 , the soil column 1 and the low-pressure anaerobic bottle 4 .

[0042] In this embodiment, the pressure stabilizer 6 can effectively eliminate the pressure fluctuations caused by water flow, temperature changes or other factors during the experiment, ensuring that the pressures in the high-pressure anaerobic bottle 2, the soil column 1 and the low-pressure anaerobic bottle 4 are always in a relatively stable state, thereby improving the reliability and repeatability of the experimental data. For the study of groundwater level fluctuations, a stable pressure environment can more accurately simulate the flow and water level changes of groundwater under natural conditions, reduce experimental errors caused by unstable pressure, and help researchers to deeply analyze the inherent relationship between groundwater recharge and water level fluctuations, providing more accurate experimental conditions for groundwater dynamics research.

[0043] Further, one end of the first pipeline 62 is connected to the first gas cylinder 61, and the other end is connected to the high-pressure anaerobic bottle 2, the soil column 1 or the low-pressure anaerobic bottle 4; the first pressure reducing valve 63, the second pressure reducing valve 64 and the first pressure regulating valve 65 are arranged in sequence on the first pipeline 62, and the first pressure reducing valve 63, the second pressure reducing valve 64 and the first pressure regulating valve 65 are used for pressure regulation. The adjustment range of the first pressure reducing valve 63 is 0-15mpa, the adjustment range of the second pressure reducing valve 64 is 0-0.25mpa, and the adjustment range of the first pressure regulating valve 65 is 0-6kpa.

[0044] In this embodiment, the gas filled in the first gas cylinder 61 is generally an inert gas such as nitrogen to prevent chemical reactions with water or other substances in the experimental device. One end of the first pipeline 62 is connected to the gas outlet of the first gas cylinder 61, and a one-way valve is installed at the connection to prevent the gas from flowing back into the gas cylinder; the other end is connected to the gas inlet interfaces on the high-pressure anaerobic bottle 2, the soil column 1 and the low-pressure anaerobic bottle 4 through branch pipelines, and stop valves are installed on the branch pipelines to independently control the gas supply to each part.

[0045] The first pressure reducing valve 63, the second pressure reducing valve 64 and the first pressure regulating valve 65 are sequentially installed on the first pipeline 62. The first pressure reducing valve 63, the second pressure reducing valve 64 and the first pressure regulating valve 65 should be selected with high precision and stable regulation performance, and the selection should be made according to the pressure range and regulation precision required for the experiment. The first pressure reducing valve 63 is used to initially reduce the pressure of the high-pressure gas output by the gas cylinder and adjust it to a relatively stable intermediate pressure value; the second pressure reducing valve 64 further fine-tunes the gas pressure after passing through the first pressure reducing valve 63 to make it closer to the working pressure range required by the experimental device; the first pressure regulating valve 65 is used to accurately adjust the gas pressure entering each part to stabilize it at the set pressure value. During the experiment, according to the pressure data of each part monitored by the pressure sensor, the opening of the three valves 52 is adjusted by the automatic control system to achieve accurate control and balanced regulation of the pressure in the high-pressure oxygen-free bottle 2, the soil column 1 and the low-pressure oxygen-free bottle 4.

[0046] Furthermore, the bottom end of the soil column 1 is provided with a water-permeable layer 11 , the water-permeable layer 11 is provided with a water inlet 111 , and the water storage tank 12 is connected with the water inlet 111 .

[0047] In this embodiment, a permeable layer 11 is laid at the bottom of the soil column 1. The permeable layer 11 can be made of gravel, coarse sand and other materials with good water permeability. The thickness is generally between several centimeters and more than ten centimeters. The particle size and gradation are determined according to experimental requirements to ensure that water can smoothly pass through the permeable layer 11 into the soil column 1 or seep out of the soil column 1. A water inlet 111 is set at a suitable position of the permeable layer 11.

[0048] The design of the aquifer 11 and the water storage tank 12 at the bottom of the soil column 1 increases the simulation dimension of the groundwater recharge mode, and can study the effects of lateral recharge and overflow recharge on groundwater level fluctuations. By controlling the water flow and water level of the water storage tank 12, bottom recharge conditions of different intensities and durations can be simulated, providing richer experimental data for a comprehensive understanding of the mechanism of groundwater level fluctuations.

[0049] Further, the second gas cylinder 121; one end of the second pipeline 122 is connected to the second gas cylinder 121, and the other end is connected to the water inlet 111; the third pressure reducing valve 123 and the second pressure regulating valve 124 are arranged in sequence on the second pipeline 122, and the third pressure reducing valve 123 and the second pressure regulating valve 124 are used for pressure regulation. The adjustment range of the third pressure regulating valve 123 is 0-15mpa and the adjustment range of the second pressure regulating valve 124 is 0-0.25mpa.

[0050] In this embodiment, a third pressure reducing valve 123 and a second pressure regulating valve 124 are sequentially installed on the second pipeline 122. The selection and installation methods of the third pressure reducing valve 123 and the second pressure regulating valve 124 are similar to those of the pressure reducing valve and the pressure regulating valve on the first pipeline 62, and are used to accurately adjust the gas pressure output from the gas cylinder, thereby controlling the water flow and pressure entering the permeable layer 11 at the bottom of the soil column 1 through the water inlet 111. The third pressure reducing valve 123 first reduces the high-pressure gas in the gas cylinder to a suitable intermediate pressure range, and the second pressure regulating valve 124 further accurately adjusts the pressure on this basis to meet the requirements of the experiment for the bottom water pressure.

[0051] The other end of the second pipeline 122 is connected to the water inlet 111 of the permeable layer 11 at the bottom of the soil column 1. The connection part adopts a joint with good sealing performance to ensure that gas and water will not leak. During the experiment, by adjusting the opening of the third pressure reducing valve 123 and the second pressure regulating valve 124, the gas pressure in the gas cylinder is controlled, and then the water supply pressure and flow rate of the water storage tank 12 to the bottom of the soil column 1 are adjusted to achieve accurate simulation and control of the bottom recharge process.

[0052] Furthermore, the top of the high-pressure anaerobic bottle 2 , the soil column 1 or the low-pressure anaerobic bottle 4 is provided with an exhaust valve 13 .

[0053] In this embodiment, an exhaust valve 13 is installed at a suitable position on the top of the high-pressure anaerobic bottle 2, the soil column 1 and the low-pressure anaerobic bottle 4. The exhaust valve 13 is a valve 52 that is corrosion-resistant, has good sealing properties and can withstand a certain pressure. The interface of the exhaust valve 13 is tightly connected to the bottle body or the top of the soil column 1 by welding or threaded connection to ensure that there is no leakage at the connection. The caliber of the exhaust valve 13 is determined according to the volume of the experimental device and the demand for gas discharge, which can not only ensure that the gas can be discharged smoothly when exhaust is required, but also prevent excessive air from entering the device due to the excessive diameter of the exhaust valve 13 and affecting the experimental results. During the experiment, when the pressure in the bottle or the soil column 1 rises to a certain level due to water flow, temperature changes or other factors, the exhaust valve 13 can be opened manually or automatically to discharge excess gas, maintain the pressure in the device stable, and ensure the safety and stability of the experiment.

[0054] The setting of the exhaust valve 13 provides a way for the experimental device to release pressure, effectively avoiding potential safety hazards caused by excessive internal pressure, such as bottle rupture, soil column 1 deformation, etc., ensuring the safety and reliability of the experimental process. By timely exhausting excess gas, the pressure in the high-pressure anaerobic bottle 2, soil column 1 and low-pressure anaerobic bottle 4 can be maintained within a reasonable range, ensuring the stability of the experimental conditions, reducing the impact of abnormal pressure fluctuations on the simulation results of the groundwater level, making the experimental data more accurate and reliable, and helping researchers to better study the changing laws of the groundwater level fluctuation zone.

[0055] Furthermore, the mounting plate 7 is arranged in the soil column 1, and the mounting plate 7 has a plurality of spray ports; the rain box 8 is arranged in the soil column 1; the second pump body 9 is arranged in the soil column 1, and the rain box 8 is connected with the spray ports through the second pump body 9.

[0056] In this embodiment, according to the size of the soil column 1 and the experimental requirements, a mounting plate 7 of suitable size is designed and manufactured, and a number of spray ports are evenly distributed on the mounting plate 7. The spray ports can be adjusted according to the intensity requirements of the simulated rainfall. The distribution of the spray ports should ensure that a relatively uniform rainfall effect can be formed in the soil column 1. A rain box 8 is installed at a suitable position in the soil column 1. The volume of the rain box 8 is determined according to the rainfall amount and rainfall duration required by the experiment. The rain box 8 has good sealing to prevent water leakage. The rain box 8 is connected to the mounting plate 7 through a second pump body 9. The second pump body 9 can be a small peristaltic pump. The appropriate model and power are selected according to the experimental requirements for rainfall intensity and flow rate. The inlet of the second pump body 9 is connected to the rain box 8, and the outlet is connected to the spray port of the mounting plate 7. The water in the rain box 8 is pressurized and transported to the spray port through the second pump body 9 to realize the simulated rainfall process. During the experiment, according to the rainfall scheme designed by the experiment, the flow rate and running time of the second pump body 9 can be controlled to adjust the intensity, duration and frequency of the simulated rainfall, and study the impact of rainfall recharge on groundwater level fluctuations.

[0057] The design of the device adds the simulation function of rainfall recharge mode, which can more comprehensively study the fluctuation of groundwater level under various recharge conditions, enrich the simulation scenarios of the experiment, make the simulation results closer to the actual natural situation, and provide more complete data support for groundwater research. This scheme can close the drop recharge and / or overflow recharge as needed to achieve accurate simulation.

[0058] The soil column 1 is filled with soil samples of the study area, and the soil samples of the first aquifer group and the second aquifer group are filled in layers. The high-pressure anaerobic bottle 2 and the low-pressure anaerobic bottle 4 are located on both sides of the soil column 1. The high-pressure anaerobic bottle 2 and the low-pressure anaerobic bottle 4 are respectively connected to the master control switch. The groundwater levels on both sides are controlled by the master control switch, and the water pressure on both sides is controlled by the voltage stabilizer 6. It is assumed that the voltage stabilizer 6 of the soil column 1 adjusts the air pressure of the soil column 1 to X1kpa, the highest point of the water level in the soil column 1 is Z1cm (from the bottom of the soil column 1), the air pressure of the high-pressure anaerobic bottle 2 is X2kpa, the height of the partition 22 is Z2cm, and the low-pressure anaerobic bottle 4 is X3kpa. Assuming that the design head difference is Y, Y=X2-X3, X1 should be set to X2+(Z2-Z1)kpa (X1 needs to be between 0-60kpa). The simulation of groundwater overflow recharge is carried out by controlling the water pressure from the water storage tank 12. The water head size is the groundwater overflow recharge water pressure minus the air pressure of the soil column 1 from the precision barometer 25 on the water transfer tank. If the flow rate needs to be controlled, a large flow meter and a small flow meter are installed at the outlet 27 of the water storage tank 12. The flow simulation range is determined by the specific soil layer.

[0059] The water samples used were pure water, water samples from the first aquifer group in the study area, and water samples from the second aquifer group in the study area. The water sample used for the rainfall device was pure water. The water samples from the first aquifer group in the study area were placed in the high-pressure oxygen-free bottle 2, and the water samples from the second aquifer group in the study area were placed in the water storage device. The lateral recharge groundwater samples were added from the water inlet 111 of the high-pressure oxygen-free bottle 2, and the water overflowed from the partition 22 to the bottom of the peristaltic pump body (in the first water storage chamber 23) after the second water storage chamber 24 was filled. When the sample was first added, the water sample from the first aquifer group in the study area was placed in the first water storage chamber 23 of the low-pressure oxygen-free bottle 4, and the excess sample was discharged. When the second aquifer of soil column 1 was first sampled, the valve 52 of the water storage device was opened, the air valve of soil column 1 was opened, and water was added into the second aquifer of soil column 1. After the aquifer water sample was filled and the gas was discharged, the devices were connected at the same time and operated for three days before sampling and measurement began.

[0060] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A device for simulating shallow groundwater quality changes under multiple recharge modes, characterized in that: include: A soil column (1) for storing soil; A high-pressure oxygen-free bottle (2) for conveying water to the soil column (1); A first matrix tube (3), one end of which is connected to the high-pressure oxygen-free bottle (2) and the other end of which is connected to the soil column (1); A low-pressure anaerobic bottle (4), wherein the soil column (1) is used to transport water to the low-pressure anaerobic bottle (4); A second matrix tube (5) has one end connected to the soil column (1) and the other end connected to the low-pressure oxygen-free bottle (4).

2. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 1, characterized in that: The first matrix tube (3) and the second matrix tube (5) have the same structure, and both comprise: A plurality of transverse tubes (51) are provided, wherein the plurality of transverse tubes (51) are arranged vertically, and one end of the transverse tube (51) is connected to the soil column (1), and the other end is connected to the high-pressure anaerobic bottle (2) or the low-pressure anaerobic bottle (4); Also includes: A plurality of valves (52) are arranged in the transverse tube (51), and the valves (52) are used to open or close the transverse tube (51).

3. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 2, characterized in that: The high-pressure anaerobic bottle (2) and the low-pressure anaerobic bottle (4) have the same structure, and both include: Barrel (21); a partition (22) disposed in the barrel body (21), the partition (22) dividing the barrel body (21) into a first water storage chamber (23) and a second water storage chamber (24), water in the second water storage chamber (24) overflows into the first water storage chamber (23), and the transverse pipe (51) is in communication with the second water storage chamber (24); A barometer (25) is arranged on the barrel body (21), and the barometer (25) is used to detect the air pressure in the first water storage chamber (23) and the second water storage chamber (24).

4. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 1, characterized in that: The second water storage chamber (24) of the high-pressure anaerobic bottle (2) has a water inlet (26), the first water storage chamber (23) of the low-pressure anaerobic bottle (4) has a water outlet (27), and the bottom end of the second water storage chamber (24) of the low-pressure anaerobic bottle (4) has a water replenishment port (28). The high-pressure anaerobic bottle (2) further comprises: The first pump body (29) is arranged in the first water storage chamber (23), and the first pump body (29) is used to introduce water in the first water storage chamber (23) into the second water storage chamber (24).

5. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 1, characterized in that: Also includes: A plurality of pressure stabilizers (6) are provided on the high-pressure anaerobic bottle (2), the soil column (1) and the low-pressure anaerobic bottle (4); the pressure stabilizers (6) are used to adjust the pressure balance among the high-pressure anaerobic bottle (2), the soil column (1) and the low-pressure anaerobic bottle (4).

6. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 5, characterized in that: The voltage stabilizing element (6) comprises: First gas cylinder (61); A first pipeline (62), one end of which is connected to the first gas cylinder (61), and the other end of which is connected to the high-pressure anaerobic bottle (2), the soil column (1) or the low-pressure anaerobic bottle (4); A first pressure reducing valve (63), a second pressure reducing valve (64) and a first pressure regulating valve (65) are arranged in sequence on the first pipeline (62); the first pressure reducing valve (63), the second pressure reducing valve (64) and the first pressure regulating valve (65) are used for pressure regulation.

7. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 1, characterized in that: The bottom end of the soil column (1) is provided with a water permeable layer (11), the water permeable layer (11) has a water inlet (111), and further comprises: The water storage tank (12) is in communication with the water inlet (111).

8. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 7, characterized in that: The water storage tank (12) comprises: Second gas cylinder (121); A second pipeline (122), one end of which is connected to the second gas cylinder (121) and the other end of which is connected to the water filling port (111); The third pressure reducing valve (123) and the second pressure regulating valve (124) are arranged in sequence on the second pipeline (122); the third pressure reducing valve (123) and the second pressure regulating valve (124) are used for pressure regulation.

9. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 1, characterized in that: The top of the high-pressure anaerobic bottle (2), the soil column (1) or the low-pressure anaerobic bottle (4) is provided with an exhaust valve (13).

10. The device for simulating shallow groundwater quality changes under multi-recharge mode according to claim 1, characterized in that: Also includes: A mounting plate (7) disposed in the soil column (1), the mounting plate (7) having a plurality of spray ports; A rainfall box (8) arranged in the soil column (1); The second pump body (9) is arranged in the soil column (1), and the rain box (8) is connected to the spray port through the second pump body (9).

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