CN112051383B - Simulation experiment device for migration and transformation of pollutants in underground water level fluctuation zone - Google Patents

Abstract

The invention provides a simulation experiment device for the migration and transformation of pollutants in the groundwater level fluctuation zone, which relates to the technical field of groundwater level monitoring and solves the technical problem that the wear-resistant structure in the prior art needs to be replaced frequently. The device comprises a container, a first The pipeline and the second pipeline, wherein: the container is filled with soil samples; the outer surface of the container is connected with a water pressure monitoring part, a moisture content monitoring part, an ORP monitoring part, a soil moisture monitoring part and a soil sample collection part; the interior of the container is provided with The first perforated plate, the first perforated plate and the bottom of the container are provided with a water storage cavity, and the bottom of the container is provided with a discharge port; the first pipeline and the second pipeline are respectively connected to the top and bottom of the container, and the first pipe A first peristaltic pump and a second peristaltic pump are respectively arranged on the road and the second pipeline, and the present invention is used to simultaneously study the physical and chemical environment changes of the vadose zone and the water-saturated zone.

Description

A simulation experiment device for the migration and transformation of pollutants in the groundwater level fluctuation zone

technical field

The invention relates to the technical field of groundwater level monitoring, in particular to a simulation experiment device for the migration and transformation of pollutants in the groundwater level fluctuation zone.

Background technique

Soil and groundwater coupling experiment simulation research is an important research basis in soil and groundwater related research.

Among them, the groundwater level fluctuation zone is the interface between the soil and the saturated groundwater aquifer, and is also the main location for material exchange.

The applicant found that the prior art has at least the following technical problems:

At present, the existing experimental simulation devices for the migration and transformation of pollutants in the groundwater level fluctuation zone pay more attention to the changes in the geochemical environment of the saturated groundwater aquifer during the water level fluctuation process, ignoring the unsaturated environmental changes in the vadose zone. None of the physical migration experimental devices can achieve the scenario simulation of groundwater level fluctuations caused by top precipitation.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an experimental device for simulating the migration and transformation of pollutants in the groundwater level fluctuation zone, so as to solve the existing experimental simulation device for the migration and transformation of pollutants in the groundwater water level fluctuation zone existing in the prior art. The changes in the geochemical environment of the layer in the process of water level fluctuations ignore the unsaturated environmental changes in the vadose zone. In addition, the existing experimental devices for pollutant migration have failed to achieve the technical problem of simulating groundwater level fluctuations caused by top precipitation. The technical effects that can be produced by the preferred technical solutions among the technical solutions provided by the present invention are detailed in the following descriptions.

For achieving the above object, the invention provides the following technical solutions:

The invention provides a simulation experiment device for the migration and transformation of pollutants in the groundwater level fluctuation zone, comprising a container, a first pipeline and a second pipeline, wherein:

The container is filled with soil samples;

The outer surface of the container is connected with a water pressure monitoring unit, a moisture content monitoring unit, an ORP monitoring unit, a soil moisture monitoring unit and a soil sample collection unit;

A first perforated plate is arranged inside the container, a water storage cavity is arranged on the bottom of the first perforated plate and the container, and a discharge port is opened at the bottom of the container;

The first pipeline and the second pipeline are respectively connected to the top and bottom of the container, and the first pipeline and the second pipeline are respectively provided with a first peristaltic pump and a second peristaltic pump.

Preferably, a rainfall leaching device is also included, and the rainfall leaching device is arranged on the top of the container, wherein:

The rainfall leaching device includes a casing, a cover plate arranged on the top of the casing, and a second porous plate, wherein:

A cavity is arranged inside the casing, and the second perforated plate is arranged at the bottom of the cavity, between the rainfall leaching device and the container;

The cover plate is provided with a solution inlet.

Preferably, the moisture content monitoring part, the ORP monitoring part, the soil moisture monitoring part and the soil sample collection part are evenly arranged along the circumference of the outer surface of the container.

Preferably, the water content monitoring part is configured to include a plurality of water content sensors, and the plurality of water content sensors are evenly distributed along the height direction of the container;

The ORP monitoring part is configured to include a plurality of ORP sensors, and the plurality of ORP sensors are evenly distributed along the height direction of the container;

The soil moisture monitoring unit is configured to include a plurality of soil moisture collectors, and the multiple soil moisture collectors are evenly distributed along the height direction of the container;

The soil sample collection part includes a plurality of soil sample collection holes, and the plurality of soil sample collection holes are evenly distributed along the height direction of the container.

Preferably, the water pressure monitoring part is configured to include a water pressure sensor, the water pressure sensor is arranged at the bottom of the plurality of soil sample collection holes, and the water pressure sensor is connected to the plurality of soil sample collection holes, etc. The distances are distributed on the soil sample collection part.

Preferably, it also includes a data collector and an analysis platform, wherein:

The data collector is connected to the water content sensor, the water pressure sensor, the ORP sensor, and the soil moisture collector;

The analysis platform includes a signal receiving device, the data collector includes a signal transmitting device, and the data collector is wirelessly connected to the analysis platform.

Preferably, the container adopts a cylindrical structure, and the bottom of the container is evenly provided with a plurality of supporting feet along the circumferential direction of the container.

Preferably, the top and bottom of the soil sample are provided with quartz sand layers.

Preferably, the cover plate is a transparent cover plate, and a sealing structure is arranged between the cover plate and the casing.

Preferably, the pore diameters of the first porous plate and the second porous plate are both set to be 0.1-0.5 cm.

The present invention provides an experimental device for simulating the migration and transformation of pollutants in the groundwater level fluctuation zone. This device simulates the whole process by monitoring the changes of seepage field and chemical field in real time through the water pressure monitoring unit, the water content monitoring unit, and the ORP monitoring unit, and by monitoring the soil moisture. The water samples in the vadose zone are extracted from the department, and the soil is extracted through the soil sample collection department to monitor the pollutant concentration distribution, the migration and transformation of pollutants, the changes in the seepage field and the chemical environment during the infiltration process of pollutants. The physical and chemical environment changes in the saturated zone, combined with the uniform rainfall infiltration and leaching device, can be used to simulate the real rainfall scenario, and the water migration monitoring in the vadose zone and the water level monitoring in the saturated zone can be completed under different rainfall scenarios.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic structural diagram of an embodiment of an experimental device for simulating the migration and transformation of pollutants in the groundwater level fluctuation zone according to the present invention;

Fig. 2 is the front view structure schematic diagram of the rainfall leaching device of the present invention;

Fig. 3 is the top view structure schematic diagram of the container of the present invention;

Fig. 4 is the structural representation of the moisture content detection part of the present invention;

Fig. 5 is the structural representation of ORP monitoring part of the present invention;

Fig. 6 is the structural representation of the soil moisture monitoring part of the present invention;

Fig. 7 is the structural representation of the soil sample collection part of the present invention;

Fig. 8 is the structural representation of the first porous plate of the present invention;

FIG. 9 is a schematic structural diagram of the second porous plate of the present invention.

In the figure: 1, container; 11, first perforated plate; 12, water storage cavity; 13, discharge port; 14, quartz sand layer; 2, first pipeline; 21, first peristaltic pump; 3, second pipeline; 31, second peristaltic pump; 4, rainfall leaching device; 41, shell; 42, cover plate; 43, second perforated plate; 44, cavity; 45, solution inlet; 5, support structure; 6. Data collector; 7. Analysis platform; 10. Soil moisture monitoring department; 20. ORP monitoring department; 30. Soil sample collection department; 40. Moisture content monitoring department; 101. Soil moisture collector; 201, ORP sensor; 301, a soil sample collection hole; 401, a water content sensor; 501, a water pressure sensor.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The present invention provides a simulation experiment device for the migration and transformation of pollutants in the groundwater level fluctuation zone. FIG. 1 is a schematic structural diagram of this embodiment, as shown in FIG. in:

The container 1 is filled with soil samples; the outer surface of the container 1 is connected with a water pressure monitoring unit, a soil moisture monitoring unit 10, an ORP monitoring unit 20, a soil sample collection unit 30 and a moisture content monitoring unit 40;

The inside of the container 1 is provided with a first perforated plate 11 for water seepage, the first perforated plate 11 and the bottom of the container 1 are provided with a water storage cavity 12 for water storage, and the bottom of the container 1 is provided with a discharge port 13 for The first pipeline 2 and the second pipeline 3 are respectively connected to the top and bottom of the container 1, and the first pipeline 2 and the second pipeline 3 are respectively provided with a first peristaltic pump 21 and a second Peristaltic pump 31 .

This device simulates the whole process by monitoring the seepage field and chemical field changes in real time through the water pressure monitoring unit, the water content monitoring unit 40, and the ORP monitoring unit 20, and extracting water samples in the vadose zone through the soil moisture monitoring unit 10, and collecting soil samples through soil samples. Section 30 extracts the soil, monitors the concentration distribution of pollutants, the migration and transformation of pollutants, the change of seepage field and the change of the chemical environment during the infiltration process of pollutants, and simultaneously studies the changes of the physical and chemical environment in the vadose zone and the saturated zone, and uses them evenly. Rainfall infiltration and leaching device, using the device to simulate real rainfall scenarios, can complete the monitoring of water migration in the vadose zone and the water level in the saturated zone under different rainfall scenarios.

As an optional embodiment, a rainfall leaching device 4 is also included. FIG. 2 is a schematic front view of the rainfall leaching device in this embodiment. As shown in FIG. 2 , the rainfall leaching device 4 is arranged on the top of the container 1. Above the groundwater level fluctuation zone pollutant migration and transformation simulation experimental device, a rainfall leaching matching device is set to simulate the real rainfall process.

Specifically, the rainfall leaching device 4 includes a casing 41 , a cover plate 42 disposed on the top of the casing 41 , and a second porous plate 43 , wherein: the casing 41 is provided with a cavity 44 , and the second porous plate 43 It is arranged at the bottom of the cavity 44 for uniform rainfall, and is located between the rainfall leaching device 4 and the container 1 , and the cover plate 42 is provided with a solution inlet 45 . The simulation experiment device for the migration and transformation of pollutants in the groundwater level fluctuation zone can be used to simulate different rainfall intensity scenarios through the rainfall leaching device 4 . It can also simulate various situations such as the initial infiltration process of pollutants and the change process of polluted soil under rainfall leaching, which is widely used.

As an optional embodiment, FIG. 3 is a schematic top view of the container of this embodiment. As shown in FIG. 3 , the moisture content monitoring unit 40 , the ORP monitoring unit 20 , the soil moisture monitoring unit 10 and the soil sample collection unit 30 are located along the container 1 . The circumferential direction of the outer surface is evenly arranged.

In this embodiment, the container 1 adopts a cylindrical structure with a main body inner diameter of 15 cm and a height of 60 cm. The four sides of the cylindrical body are respectively provided with holes to arrange different sensors and sampling holes, specifically including: water pressure sensor, moisture content sensor, ORP sensor, soil moisture sensor Collector and soil sample collection hole, simulate the whole process, use pressure, moisture content, ORP sensors to monitor seepage field and chemical field changes in real time, and use soil moisture collection instrument to extract water samples in the vadose zone, and pass the soil on the side of the soil column. The soil was extracted from the sample collection hole, and the concentration distribution of pollutants, the migration and transformation of pollutants, the change of seepage field and the change of chemical environment during the infiltration process of pollutants were monitored.

Specifically, FIG. 4 is a schematic structural diagram of the water content detection unit. As shown in FIG. 4 , the water content monitoring unit 40 is configured to include a plurality of water content sensors 401 , and the plurality of water content sensors 401 are evenly distributed along the height direction of the container 1 , In this embodiment, the distance between every two water content sensors 401 is set to be 10 cm, and four water content sensors 401 are arranged from top to bottom to monitor water content information at different locations.

FIG. 5 is a schematic structural diagram of the ORP monitoring part. As shown in FIG. 5 , the ORP monitoring part 20 is configured to include multiple ORP sensors 201 , and the multiple ORP sensors 201 are evenly distributed along the height direction of the container 1 . The distance between the two ORP sensors 201 is 10cm, and a total of five ORP sensors 201 are arranged from top to bottom to monitor ORP information at different positions;

FIG. 6 is a schematic structural diagram of the soil moisture monitoring unit. As shown in FIG. 6 , the soil moisture monitoring unit 10 is configured to include a plurality of soil moisture collectors 101 , and the multiple soil moisture collectors 101 are evenly distributed along the height direction of the container 1 . In the embodiment, the distance between every two soil moisture collectors 101 is set to be 10 cm, and five soil moisture collectors 101 are arranged from top to bottom to collect soil moisture information at different locations;

FIG. 7 is a schematic diagram of the structure of the soil sample collection part. As shown in FIG. 7 , the soil sample collection part 30 includes a plurality of soil sample collection holes 301 , and the plurality of soil sample collection holes 301 are evenly distributed along the height direction of the container 1 . This embodiment , the distance between every two soil sample collection holes 301 is set to be 10 cm, and a total of five soil sample collection holes 301 are set from top to bottom to collect soil samples at different positions.

As an optional embodiment, the water pressure monitoring part is configured to include a water pressure sensor 501, the water pressure sensor 501 is arranged at the bottom of the plurality of water content sensors 401, and the water pressure sensor 501 and the plurality of water content sensors 401 are equidistantly distributed in the The water content monitoring part 40 is used for monitoring the water pressure.

As an optional embodiment, it also includes a data collector 6 and an analysis platform 7. The real-time monitoring data of the sensor is connected to the signal transmitting device through the data collector 6, uploaded to the cloud platform through a wireless network, and the data is remotely read for analysis.

Wherein: the data collector 6 is connected to the water content sensor 401, the water pressure sensor 501, the ORP sensor 201, and the soil moisture collector 101; the analysis platform 7 includes a signal receiving device, the data collector includes a signal transmitting device, and the data collector 6 is connected to The analysis platform 7 is connected wirelessly.

In use, the water pressure sensor 501 , the water content sensor 401 , and the ORP sensor 201 in this embodiment are all connected to the data collector through a data cable, connect to a signal transmitter, and upload data to the cloud platform through a wireless network. The soil moisture collector 101 collects samples through an air pump. The experimental data results can be further used for model building and fitting analysis through numerical simulation.

As an optional embodiment, the container 1 adopts a cylindrical structure, and a plurality of supporting structures 5 are evenly arranged at the bottom of the container 1 along the circumferential direction of the container 1 to support the device, keep a certain distance from the ground, and facilitate the discharge port 13 Drain or connect to other external devices.

As an optional implementation, the top and bottom of the soil sample are provided with a quartz sand layer 14. In this embodiment, the quartz sand layer 14 is coarse-grained quartz sand with a diameter of 0.5 cm, and the thickness of the quartz sand layer 14 is set to 1 cm. In the embodiment, the height of the actual filling soil sample is 50cm.

As an optional embodiment, the cover plate 42 adopts a transparent cover plate for easy observation, and a sealing structure, such as a sealing ring, is arranged between the cover plate 42 and the casing 41 to ensure that the rainfall leaching device 4 has good sealing performance.

As an optional embodiment, the apertures of the first porous plate 11 and the second porous plate 43 are both set to 0.1-0.5 cm, and the thicknesses of the first porous plate 11 and the second porous plate 43 are both 1 cm. Preferably, FIG. 8 is a schematic structural diagram of the first porous plate in this embodiment. As shown in FIG. 8 , the aperture of the first porous plate 11 is set to 0.5 cm. FIG. 9 is a schematic diagram of the second porous plate in this embodiment. Schematic diagram of the structure, as shown in FIG. 9 , the aperture of the second porous plate 43 is set to 0.5 cm or 0.2 cm.

The process of a complete infiltration experiment of pollutants in the groundwater level fluctuation zone in this embodiment is as follows:

1. Install the water pressure sensor 501, the water content sensor 401, the ORP sensor 201 and the soil moisture collector 101, prepare soil samples, and compress them in layers.

2. Deionized water saturates the sand column from bottom to top, and the water filling process is: open the water stop valve of the first peristaltic pump 21, inject the simulated groundwater from the bottom of the sand column with the first peristaltic pump 21, and keep the first peristaltic pump 21. The rotation speed of 21 is 5mL/min to ensure that the permeability meets the requirements, and the water supply is stopped when the water in the experimental sand column is full. Stable for 2 hours after saturation.

3. Turn on the first peristaltic pump 21 and slowly pump water until the water level is at 10cm. After 2 hours of stabilization, conventional indicators of soil moisture were collected. Obtain physicochemical parameter distributions under natural conditions.

4. Taking this start as time 0, then turn on the first peristaltic pump 21 and the second peristaltic pump 31 at the same time, the upper infiltration volume is greater than the lower drainage volume, and the water level rises slowly. After the water level stabilized, the soil moisture was collected and tested. Obtain the physical and chemical environmental effects of rising water levels under natural conditions.

5. Reduce rainfall, the water level gradually drops to 10cm, and stabilizes for 2 hours.

6. Pump the prepared pollutant solution, the upper infiltration amount is greater than the lower excretion amount, and the water level rises slowly. After the water level stabilized, the soil moisture was collected and tested. Obtained pollutants infiltration with rainfall, the impact of water level rise on the physical and chemical environment.

7. Reduce rainfall, the water level gradually drops to 10cm, and stabilizes for 2 hours. At this point the column is completely contaminated. Collect soil moisture and soil samples.

It solves the problem of synchronously monitoring seepage field and chemical field in vadose zone and saturated zone. Through sensor arrangement and sampling device, the effect of synchronously studying multi-field parameters of groundwater level fluctuation zone is achieved. Secondly, the simulation problem of the groundwater level fluctuation scenario caused by the infiltration of pollutants with rainfall is solved. The invention designs a matching rainfall leaching device, taking into account the influence of rainfall on the fluctuation of groundwater level.

The whole device controls the rise and fall of the water level through the upper precipitation and the bottom outflow flow. After obtaining a stable seepage field, for the scenario where the pollutants infiltrate from the surface through the vadose zone and enter the saturated zone, a fixed concentration of heavy metals (or other pollutants) is used. Contamination) solution continues to leaching from the upper part of the model, simulating the scenario of pollutant infiltration affecting soil and groundwater.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (7)

1. an experimental method utilizing a groundwater level fluctuation band pollutant migration and transformation simulation experimental device, is characterized in that, its device structure comprises a container, a first pipeline, a second pipeline, wherein: The container is filled with soil samples, and the top and bottom of the soil samples are provided with quartz sand layers; The outer surface of the container is connected with a water pressure monitoring section, a water content monitoring section, an ORP monitoring section, a soil moisture monitoring section, and a soil sample collection section, a water content monitoring section, an ORP monitoring section, a soil moisture monitoring section, and a soil sample collection section. uniformly arranged along the circumference of the outer surface of the container; A first perforated plate is arranged inside the container, a water storage cavity is arranged on the bottom of the first perforated plate and the container, and a discharge port is opened at the bottom of the container; The first pipeline and the second pipeline are respectively connected to the top and the bottom of the container, and the first pipeline and the second pipeline are respectively provided with a first peristaltic pump and a second peristaltic pump; Also includes a rainfall leaching device, the rainfall leaching device is arranged on the top of the container, wherein: The rainfall leaching device includes a casing, a cover plate arranged on the top of the casing, and a second porous plate, wherein: A cavity is arranged inside the casing, and the second perforated plate is arranged at the bottom of the cavity, between the rainfall leaching device and the container; The cover plate is provided with a solution inlet; The water content monitoring part is configured to include a plurality of water content sensors, and the plurality of water content sensors are evenly distributed along the height direction of the container; The soil moisture monitoring unit is configured to include a plurality of soil moisture collectors, and the multiple soil moisture collectors are evenly distributed along the height direction of the container; The experimental method includes the following steps: 1). Install the water pressure sensor, water content sensor, ORP sensor and soil moisture collector, prepare soil samples, and compact them in layers; 2). Deionized water saturates the sand column from bottom to top. The water filling process is as follows: open the water stop valve of the first peristaltic pump, inject the simulated groundwater from the bottom of the sand column with the first peristaltic pump, and keep the first peristaltic pump The rotation speed is 5mL/min to ensure that the permeability meets the requirements. When the water in the experimental sand column is full, the water supply is stopped, and it is stable for 2 hours after saturation; 3). Turn on the first peristaltic pump, slowly pump water to a water level of 10cm, and after 2 hours of stability, collect routine indicators for soil moisture testing, and obtain the distribution of physical and chemical parameters under natural conditions; 4). Take this time as time 0, then turn on the first peristaltic pump and the second peristaltic pump at the same time, the upper infiltration volume is greater than the lower excretion volume, and the water level rises slowly. The effect of conditional water level rise on the physical and chemical environment; 5). Reduce rainfall, the water level gradually drops to 10cm, and stabilizes for 2 hours; 6). Pump the prepared pollutant solution, the upper infiltration amount is greater than the lower excretion amount, and the water level rises slowly. After the water level is stable, the soil moisture is collected and tested to obtain the infiltration of pollutants with rainfall. environmental impact; 7). Reduce the rainfall, the water level gradually drops to 10cm, and stabilizes for 2 hours. At this time, the column has been completely polluted, and the soil moisture and soil samples are collected. 2. a kind of experiment method utilizing groundwater level fluctuation zone pollutant migration and transformation simulation experiment device according to claim 1, is characterized in that: The ORP monitoring part is configured to include a plurality of ORP sensors, and the plurality of ORP sensors are evenly distributed along the height direction of the container; The soil sample collection part includes a plurality of soil sample collection holes, and the plurality of soil sample collection holes are evenly distributed along the height direction of the container. 3 . The experimental method of utilizing a groundwater water level fluctuation zone pollutant migration and transformation simulation experimental device according to claim 2 , wherein the water pressure monitoring unit is configured to include a water pressure sensor, and the water pressure sensor is configured to include a water pressure sensor. 4 . at the bottom of the plurality of soil sample collection holes, and the water pressure sensor and the plurality of soil sample collection holes are equidistantly distributed on the soil sample collection part. 4. a kind of experiment method utilizing groundwater level fluctuation zone pollutant migration and transformation simulation experiment device according to claim 3, is characterized in that: also comprises data collector and analysis platform, wherein: The data collector is connected to the water content sensor, the water pressure sensor, the ORP sensor, and the soil moisture collector; The analysis platform includes a signal receiving device, the data collector includes a signal transmitting device, and the data collector is wirelessly connected to the analysis platform. 5 . The experimental method according to claim 1 , characterized in that: the container adopts a cylindrical structure, and the bottom of the container is along the circumference of the container. Set up multiple feet evenly. 6 . The experimental method according to claim 1, characterized in that: the cover plate adopts a transparent cover plate, and the cover plate and the shell are connected to each other. A sealing structure is provided between. 7. A kind of experiment method utilizing groundwater level fluctuation zone pollutant migration and transformation simulation experiment device according to claim 1 or 6, it is characterized in that: the aperture of described first porous plate and described second porous plate All are set to 0.1-0.5cm.

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