A device and method for indoor evaluation and optimization of groundwater pollution remediation test

Abstract

The present invention relates to a device and method for indoor evaluation and optimization of groundwater pollution remediation test, belonging to the technical field of environmental remediation test device. The technical scheme is: the extraction well (04) and the injection well (05) are connected to the extraction system (02) and the gas / liquid injection system (03) respectively; the left side of the test generation device (01) is connected to the water storage tank 2 (29) through the replenishment pipe 2 (26), and the replenishment pipe 2 (26) is provided with a water stop valve 2 (28) and a water level gauge 2 (27); the right side of the test generation device (01) is connected to the water storage tank 1 (24) through the replenishment pipe 1 (21), and the replenishment pipe 1 is provided with a water level gauge 1 and a water stop valve 1. The present invention effectively solves the problems of the lack of indoor simulation test device for the existing contaminated groundwater extraction and treatment technology, the high cost and long time of conducting extraction and treatment pilot tests in the field (constructing monitoring wells to conduct pilot tests), and insufficient optimization of key parameters.

Description

Technical Field

[0001] The invention relates to a device and a method for indoor evaluation and optimization of groundwater pollution remediation tests, belonging to the technical field of environmental remediation test devices. Background Art

[0002] With the acceleration of industrialization, many organic pollution sites have appeared in my country, and groundwater has been polluted to varying degrees. The remediation of organic pollution in groundwater has become increasingly important. Before remediating contaminated groundwater, it is necessary to screen the groundwater remediation technology to determine the proposed remediation technology, and at the same time, it is necessary to carry out indoor tests and field pilot tests to obtain the key parameters of related technologies. Among the many groundwater remediation technologies, extraction and treatment technology is widely used due to its mature technology, relatively high initial extraction efficiency, low cost, and can be applied to emergency treatment. However, at the same time, the cost of groundwater extraction and treatment will change with the changes in factors such as the location of the pumping well, the pumping rate, and the pumping time, and with the increase of time, there will be tailing and rebound problems, resulting in increased remediation costs and longer remediation time. At present, the research on the key parameters of extraction and treatment technology is mostly model simulation research and field pilot test research, which is expensive and time-consuming, and cannot quickly draw conclusions. Therefore, how to evaluate the applicability of extraction and treatment remediation technology indoors, obtain the key parameters of the technology, evaluate the remediation effect of the optimization technology, and obtain the optimal remediation plan is an urgent problem to be solved in this field. At the same time, the tests on extraction and treatment technology are mainly pilot tests and simulation predictions. Pilot tests are mostly field tests, which have the disadvantages of being time-consuming, costly, considering fewer key parameters, and difficulty in evaluating the effects of combination with other technologies. Simulation predictions require a lot of basic data, and a lot of data needs to be collected and investigated. The accuracy of simulation predictions is related to the data collection situation. Therefore, it is difficult to quickly and effectively guide the design of subsequent remediation plans for contaminated groundwater.

[0003] Therefore, there is an urgent need to provide a device and method for indoor evaluation and optimization of groundwater pollution remediation experiments to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a device and method for indoor evaluation and optimization of groundwater pollution remediation tests, which can conduct simulated remediation tests on contaminated groundwater indoors, simulate the real outdoor environment, evaluate and optimize according to the test results, obtain the best remediation plan, and solve the above-mentioned problems existing in the background technology.

[0005] The technical solution of the present invention is:

[0006] A device for indoor evaluation and optimization of groundwater pollution remediation tests, comprising a test generating device, an extraction system and a gas / liquid injection system, wherein the test generating device is filled with sand and gravel adsorbed with pollutants and is filled with polluted groundwater; an extraction well, an injection well and a monitoring well are buried in the sand and gravel with pollutants, the bottoms of the extraction well, the injection well and the monitoring well are connected to the inside of the test generating device, the polluted groundwater in the test generating device enters the extraction well, the injection well and the monitoring well, and the extraction well and the injection well are respectively connected to the extraction system and the gas / liquid injection system;

[0007] The left side of the test generating device is connected to the water storage tank 2 through the supply pipe 2, and the supply pipe 2 is provided with a water stop valve 2 and a water level gauge 2; the right side of the test generating device is connected to the water storage tank 1 through the supply pipe 1, and the supply pipe 1 is provided with a water level gauge 1 and a water stop valve 1;

[0008] The extraction system comprises an extraction pipeline, an extraction pump, a pollutant treatment system and a recovery tank, one end of the extraction pipeline extends into the extraction well, and the other end is connected to the pollutant treatment system and the recovery tank in sequence through the extraction pump;

[0009] The gas injection / liquid injection system comprises an injection pipeline, a liquid storage tank and an ozone generator. One end of the injection pipeline extends into the injection well, and the other end is connected to the gas injection pipeline and the liquid injection pipeline respectively through a three-way valve. The gas injection pipeline is connected to the ozone generator through an gas injection pump, and the liquid injection pipeline is connected to the liquid storage tank through a liquid injection pump.

[0010] A replenisher 2 and a replenisher 1 are respectively provided on the left and right sides of the test generating device. The replenisher 2 and the replenisher 1 have the same structure and are both composed of a plurality of radially arranged water outlet pipes. The water outlet pipes are covered with water outlet holes. The plurality of water outlet pipes on the left are connected to the replenishment pipe 2, and the plurality of water outlet pipes on the right are connected to the replenishment pipe 1.

[0011] A mounting frame 2 and a mounting frame 1 are respectively provided on the left and right sides of the interior of the test generating device, and the mounting frame 2 and the mounting frame 1 divide the left and right sides of the interior of the test generating device into two replenishment areas. Feeder 2 and feeder 1 are respectively arranged in the two replenishment areas, and multiple radially arranged water outlet pipes in feeder 2 are fixed on mounting frame 1, and multiple radially arranged water outlet pipes in feeder 1 are fixed on mounting frame 2.

[0012] The replenisher 2 and the replenisher 1 can slowly replenish water to the test generating device, avoiding concentrated water flow impacting the sand and gravel in the test generating device, causing the sand and gravel to be dispersed, and also avoiding inconsistent concentrations of pollutants in the aquifer during the water replenishment process.

[0013] The second mounting frame and the first mounting frame are in a grid shape, and the water outlet pipes in the two replenishment areas can be fixed on the second mounting frame and the first mounting frame respectively by corresponding cable ties.

[0014] The water storage tank 1 and the water storage tank 2 are both filled with pollution-free deionized water.

[0015] The liquid reservoir is filled with hydrogen peroxide.

[0016] There are multiple monitoring wells, and the multiple monitoring wells are arranged around the extraction well and the injection well.

[0017] The pollutant treatment system is an activated carbon column.

[0018] The test generating device comprises a sand box and a sand box closing cover. The sand box is a rectangular box body with an upper opening. The sand box closing cover is closed at the upper opening of the sand box.

[0019] The extraction pump and the gas injection pump are vacuum pumps or other devices that meet the test conditions, and the liquid injection pump is a peristaltic pump or other devices that meet the test conditions. The extraction rate is changed by adjusting the extraction pump, the gas injection pump and the liquid injection pump.

[0020] A method for indoor evaluation and optimization of groundwater pollution remediation test, using the above-mentioned device for indoor evaluation and optimization of groundwater pollution remediation test, the steps are as follows:

[0021] ① Fill the test generating device with sand and gravel adsorbing pollutants, and fill the test generating device with contaminated groundwater. At the same time, bury the extraction well, injection well and monitoring well in the sand and gravel adsorbing pollutants, seal the test generating device to prevent the pollutants in the sand and gravel from volatilizing and reduce the test error. Connect the feeder 2 and feeder 1 on the left and right sides of the test generating device with the feed pipe 2 and feed pipe 1;

[0022] ②Indoor evaluation and optimization of groundwater pollution remediation tests under three different scenarios can be carried out:

[0023] Evaluation and optimization of the remediation of contaminated groundwater through extraction technology: Use an extraction pump to extract contaminated groundwater from the aquifer of the test generator through the extraction pipeline. The contaminated groundwater is remediated through the pollutant treatment system and eventually enters the recovery pool. In order to fully simulate the changes in the aquifer under natural conditions, when the water level in the aquifer of the test generator drops, stop valves 1 and 2 will open, and non-contaminated deionized water will be replenished into the aquifer in the test generator through replenisher 2 and replenisher 1, so as to fully characterize the tailing and rebound problems existing in the application of extraction treatment technology and simulate the on-site environment. During the experiment, Different extraction rates can be changed to record the test data of different degrees of remediation of contaminated groundwater by the pollutant treatment system at different extraction rates; before, during and after the test, samples of contaminated groundwater in monitoring wells, extraction wells and / or injection wells in different time periods can be collected and tested separately, and the test data can be recorded; through the test data and test data, the time nodes of tailing and rebound of the extraction treatment technology can be clarified, and the removal efficiency of pollutants by the pollutant treatment system at different extraction rates can be estimated and optimized, so as to provide the best extraction rate for subsequent extraction treatment technology and provide a design basis for enhanced research;

[0024] Evaluation and optimization of remediation of contaminated groundwater through extraction and gas injection technology: use an extraction pump to extract contaminated groundwater in the aquifer of the test generating device through the extraction pipeline, and the contaminated groundwater passes through the pollutant treatment system and finally enters the recovery pool; at the same time, use an injection pump to extract the ozone generated in the ozone generator and inject it into the aquifer of the test generating device through the injection well; in order to fully simulate the changes in the aquifer under natural conditions, when the water level in the aquifer of the test generating device decreases, the stop valve 1 and the stop valve 2 will open, and the non-polluted deionized water will be replenished into the aquifer in the test generating device through the replenisher 2 and the replenisher 1, so as to fully characterize the tailing and rebound problems existing in the application of the extraction treatment technology and simulate the field environment; different extraction and treatment methods can be changed during the experiment. Rate and gas injection rate, extraction and gas injection are combined to repair contaminated groundwater, and the test data of pollutant treatment system and ozone repairing contaminated groundwater to different degrees under different extraction rates and gas injection rates are recorded; before, during and after the test, contaminated groundwater samples in monitoring wells, extraction wells and / or injection wells in different time periods can be collected and tested respectively, and the test data can be recorded; through the test data and test data, the time nodes of tailing and rebound of extraction and gas injection treatment technology can be clarified, and the removal efficiency of pollutants by pollutant treatment system and oxides under different extraction rates and gas injection rates can be estimated and optimized, so as to provide the best extraction rate and gas injection rate for subsequent extraction and gas injection treatment technology and provide a design basis for enhanced research;

[0025] Evaluation and optimization of remediation of contaminated groundwater through extraction and injection technology: use an extraction pump to extract contaminated groundwater from the aquifer of the test generating device through the extraction pipeline, and the contaminated groundwater passes through the pollutant treatment system and finally enters the recovery pool; at the same time, use an injection pump to extract chemical oxidants or microbial liquid in the liquid storage tank and inject it into the aquifer of the test generating device through the injection well; in order to fully simulate the changes in the aquifer under natural conditions, when the water level in the aquifer of the test generating device decreases, the stop valve 1 and the stop valve 2 will open, and the non-polluted deionized water will be replenished into the aquifer in the test generating device through the replenisher 2 and the replenisher 1, so as to fully characterize the tailing and rebound problems existing in the application of the extraction treatment technology and simulate the field environment; different extraction speeds can be changed during the experiment The extraction and injection rates are combined to repair the contaminated groundwater, and the test data of the pollutant treatment system and the oxidants or microbial liquids to repair the contaminated groundwater to different degrees under different extraction rates and injection rates are recorded; before, during and after the test, samples of contaminated groundwater in the monitoring wells, extraction wells and / or injection wells in different time periods can be collected and tested respectively, and the test data can be recorded; through the test data and test data, the time nodes of tailing and rebound of the extraction and injection treatment technology can be clarified, and the removal efficiency of pollutants by the pollutant treatment system and oxidants under different extraction rates and injection rates can be estimated and optimized, so as to provide the best extraction rate and injection rate for subsequent extraction and injection treatment technology and provide a design basis for enhanced research;

[0026] 3) After the test, the total reduction rate of pollutants in the contaminated groundwater in the test device is used to judge the removal effect of the pollutants in the contaminated groundwater. Combined with risk control and remediation goals, the site conditions, water treatment capacity and level, operating costs and cycles are comprehensively considered to determine the optimal remediation plan.

[0027] The number and positions of the extraction wells, injection wells and monitoring wells are set according to test requirements.

[0028] The present invention has the following functions: (1) Establishing a three-dimensional model of the intensified extraction-treatment technology for the remediation of contaminated groundwater in different contaminated sites, realizing simulation of different sites from a three-dimensional perspective, and evaluating whether the technology is suitable for the remediation of contaminated groundwater in the site in a short time; (2) Realizing the medium-sized test of three-dimensional simulation of extraction-treatment for the remediation of contaminated groundwater indoors, studying and obtaining key parameters such as the extraction (liquid / gas) rate, injection (liquid / gas) rate, extraction / injection time, and location of extraction / injection wells of the extraction-treatment technology, and providing a design reference for the engineering implementation of the extraction-treatment technology; (3) Realizing the evaluation and optimization of the remediation effect of the extraction-treatment technology for the remediation of contaminated groundwater indoors. The influence of changes in key parameters such as the extraction mode (continuous / intermittent extraction), extraction time, extraction rate, and location of the extraction well on the remediation effect and remediation cost can be simulated and optimized indoors, thereby improving the remediation efficiency; the influence of the combined use of remediation technologies such as extraction treatment + in-situ injection (injection of chemical oxidants, microbial liquids), extraction treatment + natural monitoring attenuation can be simulated indoors. (4) At the same time, the test device and method of the present invention can be applied to pilot tests of extraction treatment outdoors through the same scale design.

[0029] Positive effects of the invention: The invention effectively solves the problems of the lack of indoor simulation test equipment for the existing contaminated groundwater extraction and treatment technology, high cost and long time for field extraction and treatment pilot tests (construction of monitoring wells for pilot tests), and insufficient optimization of key parameters. It realizes indoor and outdoor simulation and optimization of key parameters of the extraction and treatment technology and simulation of the effects of combination with other remediation technologies, which helps to improve the remediation efficiency of the extraction and treatment technology, shorten the remediation time, and reduce the remediation cost. It can better provide a more detailed design basis for subsequent pilot tests and remediation projects of the extraction and treatment technology of contaminated groundwater, and obtain the optimal modification plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the installation structure of the mounting frame 1 and the feeder 1 of the present invention;

[0032] In the figure: test generating device 01, extraction system 02, gas injection / liquid injection system 03, extraction well 04, injection well 05, monitoring well 06, extraction pipeline 13, extraction pump 14, pollutant treatment system 15, recovery tank 16, injection pump 17, liquid storage tank 18, ozone generator 19, feeder 120, supply pipeline 121, water level gauge 122, water stop valve 123, water storage tank 124, feeder 25, supply pipeline 26, water level gauge 27, water stop valve 28, water storage tank 29, injection pipeline 30, gas injection pipeline 31, liquid injection pipeline 32, sand box 33, mounting frame 134, mounting frame 235, sand box closing cover 36, gas injection pump 37, water outlet pipe 38, water outlet hole 39. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0034] A device for indoor evaluation and optimization of groundwater pollution remediation experiments comprises a test generating device 01, an extraction system 02 and a gas / liquid injection system 03. The test generating device 01 is filled with sand and gravel adsorbed with pollutants and is filled with contaminated groundwater.

[0035] In this embodiment: the test device 1 is a three-dimensional glass sand box, with a length, width and height of 80cm×60cm×40cm respectively. The three-dimensional glass sand box is made of 5mm thick glass material, which is used to store quartz sand and machine-contaminated groundwater, and is equipped with extraction wells, injection wells and detection wells to carry out experimental research. The three-dimensional glass sand box is provided with a glass sand box closing cover, which is closed at the opening at the upper end of the three-dimensional glass sand box to prevent the organic pollutants in the quartz sand from volatilizing and reduce experimental errors.

[0036] There are 7 monitoring wells, evenly distributed upstream and downstream of the pumping wells and injection wells, for observing the changing relationship between the water level and water quality of contaminated groundwater and the extraction rate and injection rate during the operation of the test device.

[0037] The extraction well 04, injection well 05 and monitoring well 06 are buried in sand and gravel with pollutants. The bottoms of the extraction well 04, injection well 05 and monitoring well 06 are connected to the inside of the test generating device 01. The contaminated groundwater in the test generating device 01 enters the extraction well 04, injection well 05 and monitoring well 06. The extraction well 04 and injection well 05 are connected to the extraction system 02 and the gas / liquid injection system 03 respectively.

[0038] In this embodiment, the extraction well 04 and the injection well 05 are glass tubes with a water outlet hole, a wall thickness of 1.5 mm, an inner diameter of 2 cm, and a length of 40 cm. The extraction well 04 is used to extract groundwater contaminated by volatile / semi-volatile organic matter. The injection well 05 is used to inject chemical oxidants and microbial bacterial liquid.

[0039] The left and right sides of the test generating device 01 are respectively provided with a mounting frame 2 35 and a mounting frame 1 34. Both the mounting frame 1 34 and the mounting frame 2 35 are in a grid shape. The mounting frame 2 35 and the mounting frame 1 34 divide the left and right sides of the test generating device 01 into two replenishment areas. The replenisher 2 25 and the replenisher 1 20 are respectively arranged in the two replenishment areas. The replenisher 2 25 and the replenisher 1 20 have the same structure, and are both composed of a plurality of radially arranged water outlet pipes 38. The water outlet pipes 38 are covered with water outlet holes 39, and the water outlet pipes 38 are hoses. The plurality of radially arranged water outlet pipes 38 in the replenisher 2 25 are fixed to the mounting frame 1 34 by fixing parts such as cable ties. The ends of the plurality of radially arranged water outlet pipes 38 in the replenisher 2 25 are gathered together and connected to one end of the replenishment pipe 2 26. The other end of the replenishment pipe 2 26 is connected to the water storage tank 2 29. The replenishment pipe 2 26 is provided with a water stop valve 2 28 and a water level gauge 2 27. Multiple radially arranged water outlet pipes in the replenisher 20 are fixed to the mounting frame 235 by means of fixing parts such as cable ties, and the ends of the multiple radially arranged water outlet pipes in the replenisher 20 are gathered together and connected to one end of a replenishment pipe 21, and the other end of the replenishment pipe 21 is connected to a water storage tank 24. A water level gauge 22 and a water stop valve 23 are provided on the replenishment pipe 21.

[0040] In this embodiment: the water tank 1 24 and the water tank 2 29 are both filled with pollution-free deionized water. The water outlet pipe is made of PVC material, and the wall of the water outlet pipe is covered with water outlet holes. Multiple water outlet pipes are radially arranged on the left and right sides of the test generating device 01, and the water outlet holes are uniformly injected into the test generating device 01 to fully simulate the outdoor environment, so as to fully describe the tailing and rebound problems existing in the process of applying the extraction treatment technology. The water stop valve 1 23 and the water stop valve 2 28 are both one-way water stop valves.

[0041] The extraction system 02 includes an extraction pipeline 13, an extraction pump 14, a pollutant treatment system 15 and a recovery tank 16. One end of the extraction pipeline 13 extends into the extraction well 04, and the other end is connected to the pollutant treatment system 15 and the recovery tank 16 in sequence through the extraction pump 14.

[0042] The gas injection / liquid injection system 03 comprises an injection pipeline 30, a liquid storage tank 18 and an ozone generator 19. One end of the injection pipeline 30 extends into the injection well 05, and the other end is connected to the gas injection pipeline 31 and the liquid injection pipeline 32 through a three-way valve. The gas injection pipeline 31 is connected to the ozone generator 19 through a gas injection pump 37, and the liquid injection pipeline 32 is connected to the liquid storage tank 18 through a liquid injection pump 17. The liquid storage tank 18 is provided with a chemical oxidant or a microbial liquid to evaluate the effect of repairing contaminated groundwater.

[0043] In this embodiment: the extraction pipe 13 and the injection pipe 30 are both PVC hoses, which can be directly inserted into the extraction well and the injection well without gaps; the extraction pump and the gas injection pump are liquid injection pumps, and the extraction rate is changed by adjusting the liquid injection pump. The chemical oxidant in the liquid storage tank 18 is an in-situ chemical oxidant, such as hydrogen peroxide. The pollutant treatment system 15 is a glass column filled with coconut peel and activated carbon, with a diameter of 6 cm and a length of 20 cm. The gas / liquid enters the gas recovery tank after adsorption. The extraction pump 14 and the gas injection pump 37 are vacuum pumps, which provide power for extraction and gas injection, and the ozone generator can produce catalysts such as ozone. The power of the liquid injection system is the liquid injection pump, and the liquid storage tank 18 can store chemical agents and microbial bacterial liquid.

[0044] Specific test process and method of the present invention:

[0045] 1) Fill the test generating device 01 with quartz sand with a particle size of about 1-5 mm that absorbs pollutants (the filler can be replaced according to the specific situation), and fill the test device 01 with contaminated groundwater. At the same time, the extraction well 04, the injection well 05, and the seven monitoring wells 06 are pre-buried in the contaminated quartz sand, and the test generating device 01 is covered with a sand box closing cover 36 to prevent the organic pollutants in the quartz sand from volatilizing and reduce the test error.

[0046] 2) This experimental device can carry out experiments under four different scenarios: single extraction scenario, extraction and injection of gas oxidant (ozone) scenario, and extraction and injection of liquid chemical oxidant or microbial solution.

[0047] In the extraction scenario: only the extraction well 04 is used to carry out the test of liquid phase extraction treatment and remediation technology. The extraction pump 14 is used to extract the contaminated groundwater in the aquifer of the test generating device 01 through the extraction pipeline 13. The contaminated groundwater passes through the pollutant treatment system 15 and finally enters the recovery pool 16. In order to fully simulate the changes in the aquifer under natural conditions, a feeder 1 20 and a feeder 2 25 with uniform water outlet holes are added on both sides of the device. When the water level in the aquifer decreases, the stop valve 1 23 and the stop valve 2 28 will open, and the non-polluted deionized water will be replenished into the aquifer through the feeder 1 20 and the feeder 2 25, so as to fully describe the tailing and rebound problems existing in the application of the extraction treatment technology. Before, during and after the test, different extraction rates can be changed, and contaminated groundwater samples can be collected from seven monitoring wells 06, extraction well 04 and injection well 05 for testing to determine the extraction effect of the extraction and treatment technology under different extraction rates, and to identify the time nodes when tailing and rebounding of the extraction and treatment technology occur, so as to provide the best extraction rate for subsequent extraction and treatment technology and provide a design basis for intensified research.

[0048] In the extraction / gas injection scenario: In this scenario, extraction well 04 and injection well 05 are used to carry out the enhanced test of liquid phase extraction treatment and remediation technology. The injection pump 14 is used to extract the contaminated groundwater in the aquifer of the test generating device 01 through the extraction pipeline 13. The contaminated groundwater passes through the pollutant treatment system 15 and finally enters the recovery pool 16; at the same time, the ozone generated in the ozone generator 19 is extracted by the gas injection pump 37 and injected into the aquifer through the injection well 05. In order to fully simulate the changes in the aquifer under natural conditions, a feeder 1 20 and a feeder 2 25 with uniform water outlet holes are added on both sides of the device. When the water level in the aquifer decreases, the stop valve 1 23 and the stop valve 2 28 will open, and the non-polluted deionized water will be replenished into the aquifer through the feeder 1 20 and the feeder 2 25, so as to fully describe the tailing and rebound problems existing in the application of extraction treatment technology. In this scenario, key parameters such as the extraction rate, injection rate, and combination of extraction and injection can be changed. Before, during, and after the experiment, contaminated groundwater samples can be collected from the seven monitoring wells 06, extraction well 04, and injection well 05 for testing to determine the optimal extraction / injection rate, extraction and injection method, and number of extraction wells and injection wells in this scenario to increase the extraction efficiency.

[0049] In the extraction / injection scenario: In this scenario, extraction well 04 and injection well 05 are used to carry out experiments on the combination of liquid extraction treatment and remediation technology with other remediation technologies such as in-situ chemical oxidation and microbial remediation. The extraction pump 14 is used to extract the contaminated groundwater in the aquifer of the test generating device 01 through the extraction pipeline 13. The contaminated groundwater passes through the pollutant treatment system 15 and finally enters the recovery pool 16. At the same time, the injection pump 17 is used to extract the chemical oxidant or microbial liquid in the liquid storage tank 18 and inject it into the aquifer through the injection well 05. In order to fully simulate the changes in the aquifer under natural conditions, a feeder 20 and a feeder 25 with uniform water outlet holes are added on both sides of the device. When the water level in the aquifer decreases, the stop valve 1 23 and the stop valve 2 28 will open, and the non-polluted deionized water will be replenished into the aquifer through the feeder 1 20 and the feeder 2 25, so as to fully describe the tailing and rebound problems existing in the application of the extraction treatment technology. In this scenario, key parameters such as extraction rate, injection rate, combination of extraction and injection, number and location of extraction / injection wells can be changed. Before, during and after the test, groundwater samples can be collected from seven monitoring wells 06, extraction well 04 and injection well 05 for testing to determine the best extraction / injection rate method in this scenario, so as to increase the extraction efficiency and solve the problems of tailing and rebound.

[0050] Extraction / gas injection / liquid injection (gas injection and liquid injection are performed alternately) scenario: In this scenario, extraction well 04 and injection well 05 are used to carry out experiments on the combination of liquid phase extraction treatment and remediation technology with other remediation technologies such as in-situ chemical oxidation and microbial remediation. The extraction pump 14 is used to extract the contaminated groundwater in the aquifer of the test generating device 01 through the extraction pipeline 13. The contaminated groundwater passes through the pollutant treatment system 15 and finally enters the recovery tank 16. At the same time, the gas injection pump 37 is used to extract the ozone generated in the ozone generator 19 and inject it into the aquifer through the injection well 05. When it reaches a certain level, the gas injection pump 37 is turned off, the gas injection is stopped, the liquid injection pump 17 is turned on, and the chemical oxidant or microbial liquid in the liquid storage 18 is extracted by the liquid injection pump 17 and injected into the aquifer through the injection well 05. In order to fully simulate the changes in the aquifer under natural conditions, a replenisher 20 and a replenisher 25 with uniform water outlet holes are added on both sides of the device. When the water level in the aquifer drops, the stop valve 23 and the stop valve 28 will open, and the non-polluted deionized water will be replenished into the aquifer through the replenisher 20 and the replenisher 25, so as to fully describe the tailing and rebound problems existing in the application of extraction treatment technology. In this scenario, the best combination of the three methods of extraction / gas injection / liquid injection can be explored, and the simultaneous and alternating injection of hydrogen peroxide liquid, microbial bacterial solution and ozone can be studied to explore the best injection method, injection rate, and the effect of injecting oxidizing gas, oxidizing liquid and microbial bacterial solution.

[0051] 3) After the test, the removal effect of groundwater pollutants is judged based on the distribution of groundwater pollution at different times, the removal efficiency of a single well, the comprehensive groundwater extraction rate and the total pollutant reduction rate. Combined with risk control and remediation goals, the extraction flow rate and optimized extraction plan are determined by comprehensively considering site conditions, water treatment capacity and level, operating costs and cycles.

[0052] Among them: The single well removal efficiency can be calculated using formula (A.1):

[0053] m i =q i c i Formula (A.1)

[0054] In the formula, m i is the extraction efficiency of well i, mg / d; q i is the amount of water pumped per unit time by well i, m 3 / d;c i is the target pollutant concentration in the water extracted from well i, mg / m 3 .

[0055] The comprehensive groundwater extraction rate can be calculated using formula (A.2):

[0056] Formula (A.2)

[0057] Where M R It is the total extraction efficiency of the target pollutant of the entire extraction system, mg / d; other parameters are the same as above.

[0058] The total pollutant reduction rate can be calculated using formula (A.3):

[0059] Formula (A.3)

[0060] Where M0 is the total mass of the target pollutant in the entire extraction system, mg; other parameters are the same as above.

[0061] The present invention solves the problem that the research on key parameters can only be model simulation research and field pilot test research, which results in high research costs, long time, and inability to quickly draw conclusions by establishing a three-dimensional simulation model of the treatment technology of extraction, gas injection and liquid injection, thereby achieving indoor evaluation of the applicability of the extraction treatment and remediation technology, obtaining the key parameters of the technology, and evaluating the remediation effect of the optimization technology. The test device and method can carry out three-dimensional simulation tests of the treatment technology alone for the treatment of contaminated groundwater and the treatment technology combined with other remediation technologies to obtain the key parameters of the groundwater extraction and treatment technology (extraction rate, extraction well location, number of extraction wells, etc.), and provide parameter design basis for actual contaminated groundwater remediation projects. The test device and method simulate and strengthen the remediation effect of the extraction and treatment technology from a three-dimensional perspective, depict the three-dimensional distribution of the pollution plume, continuously optimize its key parameters, and obtain the best solution for the treatment of contaminated groundwater. It effectively solves the problems of pilot tests and simulation prediction tests of extraction and treatment technology, such as long time consumption, high test costs, few key parameters considered, difficulty in evaluating the effect of combination with other technologies, need for a lot of basic data, and difficulty in ensuring the effectiveness of simulation prediction accuracy and simulation prediction schemes. It provides a more detailed design basis for subsequent pilot tests and remediation projects of contaminated groundwater with extraction and treatment technology in a faster, more effective and lower-cost manner.

Claims

1. A device for indoor evaluation and optimization of groundwater pollution remediation experiments, characterized in that: The invention comprises a test generating device (01), an extraction system (02) and a gas / liquid injection system (03); the test generating device (01) is filled with sand and gravel adsorbed with pollutants and is filled with contaminated groundwater; an extraction well (04), an injection well (05) and a monitoring well (06) are buried in the sand and gravel adsorbed with pollutants; the bottoms of the extraction well (04), the injection well (05) and the monitoring well (06) are connected to the inside of the test generating device (01); the contaminated groundwater in the test generating device (01) enters the extraction well (04), the injection well (05) and the monitoring well (06); the extraction well (04) and the injection well (05) are connected to the extraction system (02) and the gas / liquid injection system (03) respectively; The left side of the test generating device (01) is connected to the water storage tank 2 (29) through the supply pipe 2 (26), and the supply pipe 2 (26) is provided with a water stop valve 2 (28) and a water level gauge 2 (27); the right side of the test generating device (01) is connected to the water storage tank 1 (24) through the supply pipe 1 (21), and the supply pipe 1 (21) is provided with a water level gauge 1 (22) and a water stop valve 1 (23); The extraction system (02) comprises an extraction pipeline (13), an extraction pump (14), a pollutant treatment system (15) and a recovery tank (16); one end of the extraction pipeline (13) extends into the extraction well (04), and the other end is connected to the pollutant treatment system (15) and the recovery tank (16) in sequence through the extraction pump (14); The gas injection / liquid injection system (03) comprises an injection pipeline (30), a liquid storage tank (18) and an ozone generator (19); one end of the injection pipeline (30) extends into the injection well (05), and the other end is connected to the gas injection pipeline (31) and the liquid injection pipeline (32) respectively through a three-way valve; the gas injection pipeline (31) is connected to the ozone generator (19) through a gas injection pump (37); the liquid injection pipeline (32) is connected to the liquid storage tank (18) through a liquid injection pump (17); and the liquid storage tank (18) is filled with hydrogen peroxide; The test generating device (01) is provided with a second replenisher (25) and a first replenisher (20) on the left and right sides, respectively. The second replenisher (25) and the first replenisher (20) have the same structure, and are both composed of a plurality of radially arranged water outlet pipes (38). The water outlet pipes (38) are covered with water outlet holes (39). The plurality of water outlet pipes (38) located on the left side are connected to the second replenishing pipe (26), and the plurality of water outlet pipes (38) located on the right side are connected to the first replenishing pipe (21); The left and right sides of the interior of the test generating device (01) are respectively provided with a second mounting frame (35) and a first mounting frame (34). The second mounting frame (35) and the first mounting frame (34) divide the left and right sides of the interior of the test generating device (01) into two replenishment areas. The second replenisher (25) and the first replenisher (20) are respectively arranged in the two replenishment areas. The plurality of radially arranged water outlet pipes in the second replenisher (25) are fixed on the first mounting frame (34), and the plurality of radially arranged water outlet pipes in the first replenisher (20) are fixed on the second mounting frame (35).

2. The device for indoor evaluation and optimization of groundwater pollution remediation test according to claim 1, characterized in that: The second mounting frame (35) and the first mounting frame (34) are in a grid shape, and the water outlet pipes in the two replenishment areas can be fixed to the second mounting frame (35) and the first mounting frame (34) respectively by corresponding cable ties.

3. The device for indoor evaluation and optimization of groundwater pollution remediation test according to claim 1, characterized in that: The water storage tank 1 (24) and the water storage tank 2 (29) are both filled with pollution-free deionized water.

4. The device for indoor evaluation and optimization of groundwater pollution remediation test according to claim 1, characterized in that: There are a plurality of monitoring wells, and the plurality of monitoring wells are arranged around the extraction well (04) and the injection well (05).

5. The device for indoor evaluation and optimization of groundwater pollution remediation test according to claim 1, characterized in that: The pollutant treatment system (15) is an activated carbon column.

6. A method for indoor evaluation and optimization of groundwater pollution remediation experiments, using the device for indoor evaluation and optimization of groundwater pollution remediation experiments according to any one of claims 1 to 5, characterized in that Follow these steps: ① Fill the test generating device (01) with sand and gravel adsorbing pollutants, and fill the test generating device (01) with contaminated groundwater. At the same time, bury the extraction well (04), injection well (05) and monitoring well (06) in the sand and gravel adsorbing pollutants, seal the test generating device (01) to prevent the pollutants in the sand and gravel from volatilizing and reduce the test error. Connect the feeder 2 (25) and feeder 1 (20) on the left and right sides of the test generating device (01) to the feeder pipe 2 (26) and the feeder pipe 1 (21); ②Indoor evaluation and optimization of groundwater pollution remediation tests under three different scenarios can be carried out: Evaluation and optimization of the remediation of contaminated groundwater by extraction technology: Use an extraction pump (14) to extract contaminated groundwater from the aquifer of the test generating device (01) through the extraction pipe (13), and the contaminated groundwater is remediated through the pollutant treatment system (15) and finally enters the recovery pool (16); in order to fully simulate the changes in the aquifer under natural conditions, when the water level in the aquifer of the test generating device (01) decreases, the stop valve 1 (23) and the stop valve 2 (28) will open, and non-contaminated deionized water will be replenished into the aquifer in the test generating device (01) through the replenisher 2 (25) and the replenisher 1 (20), so as to fully characterize the tailing and rebound problems existing in the application of the extraction treatment technology; different extraction rates can be changed during the experiment, and records can be made. Test data on the different degrees of remediation of contaminated groundwater by the pollutant treatment system (15) at different extraction rates; before, during and after the test, samples of contaminated groundwater in the monitoring well (06), extraction well (04) and / or injection well (05) at different time periods can be collected and tested respectively, and the test data can be recorded; through the test data and test data, the time nodes of tailing and rebound of the extraction treatment technology can be clearly identified, and the removal efficiency of the pollutant treatment system (15) at different extraction rates can be estimated and optimized, so as to provide the best extraction rate for subsequent extraction treatment technology and provide a design basis for enhanced research; Evaluation and optimization of the remediation of contaminated groundwater by combining extraction and gas injection technology: using an extraction pump (14) to extract contaminated groundwater from the aquifer of the test generating device (01) through an extraction pipe (13), the contaminated groundwater passes through a pollutant treatment system (15) and finally enters a recovery pool (16); at the same time, using a gas injection pump (37) to extract ozone generated in an ozone generator (19) and inject it into the aquifer of the test generating device (01) through an injection well (05); in order to fully simulate the changes in the aquifer under natural conditions, when the water level in the aquifer of the test generating device (01) decreases, stop valve one (23) and stop valve two (28) will open, and non-contaminated deionized water will be replenished into the aquifer in the test generating device (01) through replenisher two (25) and replenisher one (20), so as to fully characterize the tailing and Rebound problem; During the experiment, different extraction rates and gas injection rates can be changed, and the contaminated groundwater can be repaired by combining extraction and gas injection. The experimental data of the pollutant treatment system (15) and ozone repairing the contaminated groundwater to different degrees at different extraction rates and gas injection rates can be recorded; Before, during and after the experiment, contaminated groundwater samples can be collected from the monitoring well (06), extraction well (04) and / or injection well (05) in different time periods and tested separately, and the test data can be recorded; Through the test data and test data, the time nodes of the tailing and rebound of the extraction and gas injection treatment technology can be clarified, and the removal efficiency of the pollutant treatment system (15) and oxides for pollutants at different extraction rates and gas injection rates can be estimated and optimized, providing the best extraction rate and gas injection rate for subsequent extraction and gas injection treatment technology and providing a design basis for enhanced research; Evaluation and optimization of the remediation of contaminated groundwater by combining extraction and injection technology: using an extraction pump (14) to extract contaminated groundwater from the aquifer of the test generating device (01) through an extraction pipe (13), the contaminated groundwater passes through a pollutant treatment system (15) and finally enters a recovery pool (16); at the same time, using an injection pump (17) to extract chemical oxidants or microbial liquid from a liquid storage tank (18) and inject them into the aquifer of the test generating device (01) through an injection well (05); in order to fully simulate the changes in the aquifer under natural conditions, when the water level in the aquifer of the test generating device (01) decreases, stop valve 1 (23) and stop valve 2 (28) will open, and non-contaminated deionized water will be replenished into the aquifer in the test generating device (01) through replenisher 2 (25) and replenisher 1 (20), so as to fully characterize the tailing and Rebound problem; During the experiment, different extraction rates and injection rates can be changed, and the contaminated groundwater can be repaired by combining extraction and injection. The experimental data of the pollutant treatment system (15) and oxidants or microbial liquids repairing the contaminated groundwater to different degrees at different extraction rates and injection rates can be recorded; Before, during and after the experiment, contaminated groundwater samples can be collected from the monitoring well (06), extraction well (04) and / or injection well (05) in different time periods and tested separately, and the test data can be recorded; Through the test data and test data, the time nodes of the tailing and rebound of the extraction and injection treatment technology can be clarified, and the removal efficiency of the pollutant treatment system (15) and oxidants for pollutants at different extraction rates and injection rates can be estimated and optimized, so as to provide the optimal extraction rate and injection rate for subsequent extraction and injection treatment technology and provide a design basis for enhanced research; ③ After the test, the total reduction rate of pollutants in the contaminated groundwater in the test generating device (01) is used to judge the removal effect of the pollutants in the contaminated groundwater. Combined with risk control and remediation goals, the site conditions, water treatment capacity and level, operating costs and cycles are comprehensively considered to determine the optimal remediation plan.

7. A method for indoor evaluation and optimization of groundwater pollution remediation experiments according to claim 6, characterized in that: The number and positions of the extraction wells (04), injection wells (05) and monitoring wells (06) are set according to test requirements.

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