Test equipment and method for photocatalytic regulation of service performance of permeable reaction barriers

Abstract

The present invention belongs to the field of contaminated groundwater remediation, and discloses a test device and method for photocatalytically regulating the service performance of a permeability reaction barrier. The device can provide a test device for the service performance of a permeability reaction barrier and improve the accuracy of the test. The device includes a contaminated groundwater simulation device, a groundwater inlet device, a permeability reaction barrier, a groundwater outlet device, a water collection device, a metering device, and a monitoring device; the water outlet of the contaminated groundwater simulation device is connected to the water inlet of the groundwater inlet device, and the groundwater inlet device, the permeability reaction barrier, and the groundwater outlet device are connected in sequence, and a sealing plate that can move up and down is provided on the side of the permeability reaction barrier close to the groundwater inlet device; the water outlet of the groundwater outlet device is connected to the water collection device, and the water outlet of the water collection device is connected to the metering device. The monitoring device is respectively connected to the contaminated groundwater simulation device, the groundwater inlet device, the groundwater outlet device, the water collection device, and the metering device.

Description

Technical Field

[0001] The present invention relates to a test device for repairing contaminated groundwater, and in particular to a test device and method for photocatalytically regulating the service performance of a permeability reaction barrier. Background Art

[0002] A permeable reactive barrier is a device used for in-situ remediation of contaminated groundwater. By filling the groundwater downstream with a strip of permeable filler material, the contaminated groundwater undergoes a series of physical and chemical reactions with the filler material, thereby removing or degrading pollutants and controlling the spread of the contamination plume. For groundwater containing high or constant concentrations of pollutants, the permeable reactive barrier significantly improves its removal efficiency by optimizing the filler material's adsorption efficiency and increasing the frequency of filler material replacement. This has led to its successful application in a growing number of groundwater remediation projects at contaminated sites.

[0003] However, for high-concentration organic pollution sites and production enterprise plots in the later stages of remediation, the concentration of groundwater pollutants shows typical fluctuation characteristics. In order to ensure the removal effect of groundwater pollutants in such sites, engineers often select the filler type of the permeability reaction barrier and optimize the design of the filler replacement cycle based on the highest groundwater pollutant concentration over a period of time (for example, one year). This directly leads to an increase in the operating cost of the permeability reaction barrier and a low operating efficiency of the supporting facilities. In order to achieve the optimal design of the photocatalytically regulated permeability reaction barrier, it is urgent to develop a model test device that can simulate the service status of the permeability reaction barrier in the site under laboratory conditions and perform optimized design. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a test device and method for photocatalytically regulating the service performance of a permeable reaction barrier, thereby providing a test device for the service performance of a permeable reaction barrier and improving the accuracy of the test.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] On the one hand, the present invention provides a test equipment for photocatalytic regulation of the service performance of a permeable reaction barrier, the equipment comprising a contaminated groundwater simulation device, a groundwater inlet device, a permeable reaction barrier, a groundwater outlet device, a water collection device, a metering device and a monitoring device, the permeable reaction barrier comprising at least one permeable reaction barrier unit; wherein the water outlet of the contaminated groundwater simulation device is connected to the water inlet of the groundwater inlet device, the groundwater inlet device, the permeable reaction barrier and the groundwater outlet device are connected in sequence, and a sealing plate that can move up and down is provided on the side of the permeable reaction barrier close to the groundwater inlet device, the sealing plate is used to close or open the water flow channel between the groundwater inlet device and the permeable reaction barrier; the water outlet of the groundwater outlet device is connected to the water collection device, the water outlet of the water collection device is connected to the metering device, and the monitoring device is respectively connected to the contaminated groundwater simulation device, the groundwater inlet device, the groundwater outlet device, the water collection device and the metering device.

[0007] As a preferred example, the contaminated groundwater simulation device includes a first water storage unit, a first flow controller, a first water inlet valve, a second water storage unit, a second flow controller, and a second water inlet valve; the first water storage unit is used to store the highest concentration of contaminated groundwater required for the test, and the second water storage unit is used to store the lowest concentration of contaminated groundwater required for the test; the first water storage unit is connected to the first flow controller through the first water inlet valve, and the water outlet of the first flow controller is connected to the groundwater inlet device; the second water storage unit is connected to the second flow controller through the second water inlet valve, and the water outlet of the second flow controller is connected to the groundwater inlet device; the monitoring device is respectively connected to the first water inlet valve, the second water inlet valve, the first flow controller, and the second flow controller.

[0008] As a preferred example, the groundwater inlet device includes a first shell and a first agitator, the first agitator is connected to the first shell, a detection component is provided on the wall of the first shell, and the detection component is connected to the monitoring device; a first drain outlet is provided at the lower part of the first shell, and a first exhaust and water-stop valve is provided on the top of the first shell; the groundwater outlet device includes a second shell and a second agitator, the second agitator is connected to the second shell, a water inlet is provided on the top surface of the second shell, and a second exhaust and water-stop valve is provided on the top of the second shell; the monitoring device is respectively connected to the first agitator and the second agitator.

[0009] As a preferred example, the water outlet of the groundwater outlet device is located on a side of the second shell away from the groundwater inlet device, and there are at least two water outlets, and at least two water outlets are at different heights.

[0010] As a preferred example, the permeable reaction barrier unit includes a hollow third shell, and the two relatively hollow sides of the third shell are sealed with the first shell and the second shell respectively, and the two relatively hollow sides of the third shell are respectively provided with permeable gauze; the third shell is filled with granular filler, and an ultraviolet light band is arranged inside the granular filler, and the two power supply ends of the ultraviolet light band are respectively connected to the positive and negative poles of the external power supply; the granular filler includes translucent glass balls and expanded clay with titanium dioxide loaded on the surface.

[0011] As a preferred example, in each of the permeable reaction barrier units, the embedded length of the ultraviolet light band is determined according to formula (1) and formula (2):

[0012] Formula (1)

[0013] Formula (2)

[0014] Where, Indicates the buried length of the UV light band in cm; It represents the length of the permeability reaction barrier unit in cm; It represents the width of the permeability reaction barrier unit in cm; It represents the height of the permeability reaction barrier unit in cm; Indicates the radial effective irradiation area of ​​a UV light band, in cm 2 ; It represents the reduction factor of the radial effective irradiation area of ​​the ultraviolet light band, dimensionless; Indicates the stacking volume of light-transmitting glass balls, in cm 3 ; Indicates the bulk volume of ceramsite in cm 3 ; It represents the benchmark value of the bulk volume ratio of transparent glass balls and expanded clay, and is dimensionless.

[0015] As a preferred example, the permeability reaction barrier includes N permeability reaction barrier units, which are connected in series. The sealing plate is located on the side where the permeability reaction barrier unit is connected to the groundwater inlet device, and the sealing plate is connected to the permeability reaction barrier unit through a guide rail; N is an integer greater than 1.

[0016] As a preferred example, the water collection device includes a connecting pipe and an outlet valve; one end of the connecting pipe is connected to the outlet of the groundwater outlet device, and the other end is connected to the outlet valve; the metering device includes a flow meter and a collecting device, the outlet of the outlet valve is connected to the flow meter, and the outlet of the flow meter is connected to the collecting device; the monitoring device is connected to the flow meter.

[0017] In a second aspect, the present invention further provides a method for operating the above-mentioned test equipment for photocatalytically regulating the service performance of the permeable reaction barrier, comprising:

[0018] S1. Based on the groundwater survey results of the test prototype contaminated site, determine the change in groundwater pollutant concentration at the location where the permeability reaction barrier is to be constructed within a set time period; based on the change in the groundwater pollutants within the set time period, establish a relationship function between groundwater pollutant concentration and time to obtain the maximum and minimum contaminated groundwater concentration values ​​required for the test;

[0019] S2. Prepare simulated contaminated groundwater with the same type of pollutants and the same maximum concentration as those in the groundwater at the prototype contaminated site, and fill it into the first water storage unit;

[0020] Prepare simulated contaminated groundwater with the same type of pollutants and the same minimum concentration as those in the groundwater at the prototype contaminated site, and fill it into the second water storage unit;

[0021] S3. Close the first water inlet valve, the second water inlet valve, the water outlet valve, and the sealing plate; open the second exhaust and water-stop valve, and inject degassed clean distilled water into the groundwater outlet device through the water inlet until the clean distilled water fills the groundwater outlet device and the permeable reaction barrier. Expel all air from the groundwater outlet device and the permeable reaction barrier by vacuuming, and then close the water inlet and the second exhaust and water-stop valve.

[0022] S4. Open the first water inlet valve, the second water inlet valve, the first exhaust and water-stop valve, and the first agitator; adjust the first flow controller and the second flow controller according to a preset flow ratio to obtain simulated contaminated groundwater of a set concentration; introduce the simulated contaminated groundwater into the groundwater inlet device until the simulated contaminated groundwater fills the groundwater inlet device; close the first exhaust and water-stop valve, and then use the first agitator to evenly mix the simulated contaminated groundwater;

[0023] S5. Obtaining data measured by the detection component located in the groundwater inlet device through the monitoring device; when the data measured by the detection component stabilizes, opening the outlet valve, the sealing plate, and the second agitator, and turning off the ultraviolet light band, allowing the simulated contaminated groundwater to flow through the permeability reaction barrier, the groundwater outlet device, the water collection device, the flow meter, and finally into the collection device;

[0024] The monitoring device records the flow meter's flow reading at set time intervals, thereby regulating the first flow controller and the second flow controller so that the difference between the flow rate measured by the flow meter and the sum of the flows from the first flow controller and the second flow controller is less than or equal to a preset flow difference threshold; samples are taken from the collection device to test the pollutant concentration until a set outlet water volume is reached, thereby obtaining a relationship between the outlet water pollutant concentration and the outlet water volume under the set concentration conditions;

[0025] S6. Close the first water inlet valve, the second water inlet valve, the sealing plate, the water outlet valve, the first agitator, and the second agitator, and drain the simulated contaminated groundwater in the groundwater inlet device through the first drain port. After draining, close the first drain port.

[0026] S7. Return to step S4 according to the next set concentration of simulated contaminated groundwater, and turn on the ultraviolet light band in S5; take samples from the collection device to test the pollutant concentration until the set effluent volume is reached, thereby obtaining the relationship between the effluent pollutant concentration and the effluent volume under the next set concentration condition, until the relationship between the effluent pollutant concentration and the effluent volume under all set concentrations of simulated contaminated groundwater conditions is obtained.

[0027] As a preferred example, the method further includes:

[0028] S8. Close the ultraviolet light strip, the first water inlet valve, the second water inlet valve, the water outlet valve, the first agitator and the second agitator, open the sealing plate, and drain the simulated contaminated groundwater in the groundwater inlet device, the permeability reaction barrier, the groundwater outlet device and the water collection device through the first drain port; drain the simulated contaminated groundwater in the metering device through the drainage hole on the collecting device.

[0029] Compared to existing technologies, the testing equipment and method for photocatalytically regulating the service performance of permeable reaction barriers, described in embodiments of the present invention, provide testing equipment for permeable reaction barrier service performance, improving test accuracy. The equipment includes a contaminated groundwater simulation device, a groundwater inlet device, a permeable reaction barrier, a groundwater outlet device, a water collection device, a metering device, and a monitoring device. The permeable reaction barrier comprises at least one permeable reaction barrier unit. This equipment can complete indoor testing of the service performance of permeable reaction barriers, providing data support for subsequent service performance evaluation and control parameter optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a structural diagram of a device according to an embodiment of the present invention;

[0031] Figure 2 Schematic diagram of the structure of the permeable reaction barrier unit in the device of an embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the structure of the sealing plate and the permeable reaction barrier unit in the device of an embodiment of the present invention;

[0033] Figure 4 It is a top view of the sealing plate and the permeable reaction barrier unit in the device according to an embodiment of the present invention.

[0034] The figure shows: a contaminated groundwater simulation device 1, a first water storage unit 111, a first flow controller 112, a first water inlet valve 113, a second water storage unit 121, a second flow controller 122, a second water inlet valve 123, a groundwater inlet device 2, a first shell 201, a first agitator 202, a detection component 203, a first drain outlet 204, a permeability reaction barrier 3, a third shell 301, a permeable mesh 302, an ultraviolet light strip 303, a transparent glass ball 3041, ceramsite 3042, a sealing plate 305, a guide rail 306, a groundwater outlet device 4, a second shell 401, a second agitator 402, a water inlet 403, a water collection device 5, a water outlet valve 501, a metering device 6, a flow meter 601, a collection device 602, and a monitoring device 7. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is described in detail below. The reagents and materials mentioned above can be obtained from commercial sources unless otherwise specified.

[0036] like Figure 1 As shown, an experimental device for photocatalytically regulating the service performance of a permeable reaction barrier according to an embodiment of the present invention comprises a contaminated groundwater simulation device 1, a groundwater inlet device 2, a permeable reaction barrier 3, a groundwater outlet device 4, a water collection device 5, a metering device 6, and a monitoring device 7. The permeable reaction barrier 3 comprises at least one permeable reaction barrier unit. The outlet of the contaminated groundwater simulation device 1 is connected to the water inlet of the groundwater inlet device 2, and the groundwater inlet device 2, the permeable reaction barrier 3, and the groundwater outlet device 4 are connected in sequence. A sealing plate 305 that can move up and down is provided on the side of the permeable reaction barrier 3 close to the groundwater inlet device 2. The sealing plate 305 is used to close or open the water flow channel between the groundwater inlet device 2 and the permeable reaction barrier 3; the outlet of the groundwater outlet device 4 is connected to the water collection device 5, and the outlet of the water collection device 5 is connected to the metering device 6. The monitoring device 7 is respectively connected to the contaminated groundwater simulation device 1, the groundwater inlet device 2, the groundwater outlet device 4, the water collection device 5, and the metering device 6.

[0037] The test equipment of the above embodiment can be used to test the service performance of permeable reaction barriers indoors, providing a reference for optimizing equipment parameters used in practical applications of permeable reaction barriers. The test equipment comprises a contaminated groundwater simulation device 1, a groundwater inlet device 2, a permeable reaction barrier 3, a groundwater outlet device 4, a water collection device 5, a metering device 6, and a monitoring device 7. The contaminated groundwater simulation device 1 is used to simulate actual contaminated groundwater, including the types and concentrations of pollutants. The contaminated groundwater simulation device 1 injects simulated contaminated groundwater into the groundwater inlet device 2. In the groundwater inlet device 2, the simulated contaminated groundwater is stirred to achieve uniform mixing and improve measurement accuracy. The simulated contaminated groundwater flowing out of the groundwater inlet device 2 passes through the permeable reaction barrier 3, which adsorbs all or part of the pollutants in the simulated contaminated groundwater. The simulated contaminated groundwater flowing out of the permeable reaction barrier 3 flows into the groundwater outlet device 4. After being stirred in the groundwater outlet device 4, the simulated contaminated groundwater flows through the water collection device 5 into the metering device 6, which measures the flow rate of the simulated contaminated groundwater flowing out of the water collection device 5. The monitoring device 7 is used to control the opening or closing of the contaminated groundwater simulation device 1, the groundwater inlet device 2, the groundwater outlet device 4, and the water collection device 5. The monitoring device 7 is also used to obtain the flow value measured by the metering device 6.

[0038] Preferably, the contaminated groundwater simulation device 1 includes a first water storage unit 111, a first flow controller 112, a first water inlet valve 113, a second water storage unit 121, a second flow controller 122, and a second water inlet valve 123; the first water storage unit 111 is used to store the highest concentration of contaminated groundwater required for the test, and the second water storage unit 121 is used to store the lowest concentration of contaminated groundwater required for the test. The first water storage unit 111 is connected to the first flow controller 112 via the first water inlet valve 113, and the outlet of the first flow controller 112 is connected to the groundwater inlet device 2. The second water storage unit 121 is connected to the second flow controller 122 via the second water inlet valve 123, and the outlet of the second flow controller 122 is connected to the groundwater inlet device 2. The monitoring device 7 is connected to the first water inlet valve 113, the second water inlet valve 123, the first flow controller 112, and the second flow controller 122, respectively.

[0039] In the above preferred example, based on the groundwater environmental quality survey results of the prototype contaminated site, the change in groundwater pollutant concentration at the proposed permeability reaction barrier location within a set time period is determined. Based on the change in groundwater pollutants within the set time period, the maximum and minimum groundwater pollutant concentrations are obtained. The first water storage unit 111 is used to store contaminated groundwater with the highest concentration required for the test. That is, the pollutant concentration of the simulated contaminated groundwater stored in the first water storage unit 111 is equal to the maximum pollutant concentration in the actual contaminated groundwater. The second water storage unit 121 is used to store contaminated groundwater with the lowest concentration required for the test. That is, the pollutant concentration of the simulated contaminated groundwater stored in the second water storage unit 121 is equal to the minimum pollutant concentration in the actual contaminated groundwater. Thus, by adjusting the flow rates between the first water storage unit 111 and the second water storage unit 121, contaminated groundwater of the set concentration can be obtained. The first water inlet valve 113 controls the opening and closing of the first water storage unit 111. When the first water inlet valve 113 is open, the simulated contaminated groundwater flows out of the first water storage unit 111. When the first water inlet valve 11 is closed, the simulated contaminated groundwater cannot flow out of the first water storage unit 111. The first flow controller 112 is used to control the flow rate of the simulated contaminated groundwater flowing out of the first water storage unit 111. The second water inlet valve 123 controls the opening or closing of the second water storage unit 121. When the second water inlet valve 123 is opened, the simulated contaminated groundwater flows out of the second water storage unit 121. The second flow controller 122 is used to control the flow rate of the simulated contaminated groundwater flowing out of the second water storage unit 121. The monitoring device 7 is used to control the opening and closing of the first water inlet valve 113 and the second water inlet valve 123, as well as to control the flow rates of the first flow controller 112 and the second flow controller 122.

[0040] Preferably, the groundwater inlet device 2 includes a first housing 201 and a first agitator 202. The first agitator 202 is connected to the first housing 201. A detection assembly 203 is provided on the wall of the first housing 201, and the detection assembly 203 is connected to the monitoring device 7. A first drain outlet 204 is provided at the bottom of the first housing 201, and a first exhaust and water-stop valve is provided at the top of the first housing 201. The groundwater outlet device 4 includes a second housing 401 and a second agitator 402. The second agitator 402 is connected to the second housing 401. A water inlet 403 is provided on the top surface of the second housing 401. A second exhaust and water-stop valve is provided at the top of the second housing 401. The monitoring device 7 is connected to the first agitator 202 and the second agitator 402, respectively.

[0041] In the preferred embodiment described above, the simulated contaminated groundwater flowing out of the first water storage unit 111 and the second water storage unit 121 flows into the groundwater inlet device 2, respectively. Opening the first exhaust and water-stop valve allows the simulated contaminated groundwater to flow smoothly into the groundwater inlet device 2 and exhausts the gas within the groundwater inlet device 2. The first agitator 202 stirs the simulated contaminated groundwater in the groundwater inlet device 2, ensuring uniform mixing and more realistic simulation of actual contaminated groundwater. The detection assembly 203 is a combination of existing components and may, for example, include at least two monitoring electrodes for testing pH, conductivity, and redox potential. Preferably, the detection assembly 203 is disposed on at least two walls of the first housing 201. In other words, multiple detection assemblies 203 are provided, each disposed on different walls of the first housing 201. By distributing the detection assemblies 203 at different locations within the first housing 201, detection accuracy is improved. After the detection assembly 203 measures the value of the simulated contaminated groundwater in the groundwater inlet device 2, it transmits the data to the monitoring device 7. After passing through the permeable reaction barrier 3, the simulated contaminated groundwater flows into the groundwater outlet device 4. Because the permeable reaction barrier is a porous medium, the simulated contaminated groundwater flowing through its pores undergoes significant diffusion, resulting in significant variations in contaminant concentrations across the cross-section of the permeable reaction barrier. Therefore, the embodiment of the present invention utilizes a second agitator 402 to achieve more uniform mixing of the simulated contaminated groundwater within the groundwater outlet device 4. A uniform concentration of groundwater contaminants within the groundwater outlet device 4 effectively improves test accuracy. Conventional methods increase test accuracy by increasing the sampling volume, but this requires a significant amount of water collection time. A comparison revealed that when collecting 10 consecutive samples, the coefficient of variation of contaminant concentrations across the 10 samples was 5.2% when the second agitator 402 was on; this coefficient of variation was 32.3% when the second agitator 402 was off. If a coefficient of variation of 5.2% is desired for sample concentrations with the second agitator 402 off, the number of samples should be increased to 32. The water inlet 403 provided on the top surface of the second shell 401 is in a closed state when not in use. A second exhaust and water-stop valve is provided on the top of the second shell 401. By opening the second exhaust and water-stop valve, clean distilled water can be smoothly injected into the sealed body formed by the permeability reaction barrier 3 and the groundwater outlet device 4, and the gas in the sealed body can be discharged. The monitoring device 7 is respectively connected to the first agitator 202 and the second agitator 402, and is used to control the operation of the first agitator 202 and the second agitator 402. By means of the contaminated groundwater simulation device 1 and the groundwater inlet device 2, contaminated groundwater of the required pollution concentration can be simulated. By reasonably setting the flow rates of the first water storage unit 111 and the second water storage unit 121, the simulated contaminated groundwater flowing out of the two can be mixed in the groundwater inlet device 2 to form contaminated groundwater of the required pollution concentration.

[0042] In the above preferred example, the first agitator 202 and the second agitator 402 have the same structure. The first agitator 202 includes a servo motor and a stirring blade, and the stirring blade is connected to the servo motor through a stirring shaft. The servo motor drives the stirring blade to rotate through the stirring shaft. The length of each stirring blade is between 35% and 45% of the minimum length of the length, width and height of the groundwater inlet device 2. This can achieve uniform distribution of pollutants in the inner cavity of the groundwater inlet device 2. If the stirring blade is too short, pollutants will accumulate in the corners of the groundwater inlet device 2, increasing the difference in concentration distribution; if the stirring blade is too long, it will affect the groundwater flow, forming turbulence, resulting in large differences in the adsorption amount of pollutants in different spaces in the permeability reaction device, causing large changes in the concentration of effluent pollutants, and reducing the accuracy of the test.

[0043] Preferably, the water outlet of the groundwater outlet device 4 is located on the side of the second shell 401 away from the groundwater inlet device 2, and there are at least two water outlets, at least two of which are at different heights. The water outlets are arranged at different heights so that the simulated contaminated groundwater at different heights in the groundwater outlet device 4 flows out and converges into the same water collection device 5 for mixing. Although the groundwater outlet device 4 is provided with a second agitator 402, it cannot be guaranteed that the contamination concentration of the simulated contaminated groundwater at different heights in the groundwater outlet device 4 is the same. Therefore, water outlets are arranged at different heights on the side of the groundwater outlet device 4 so that the simulated contaminated groundwater at different heights converges and the concentration of the simulated contaminated groundwater is uniform.

[0044] like Figure 2 As shown, preferably, the permeable reaction barrier unit includes a hollow third shell 301, and the two relatively hollowed-out sides of the third shell 301 are sealedly connected to the first shell 201 and the second shell 401 respectively. The two relatively hollowed-out sides of the third shell 301 are respectively provided with a water-permeable mesh 302. Preferably, the porosity of the water-permeable mesh 302 is greater than 80%. The third shell 301 is filled with granular filler, and an ultraviolet light strip 303 is arranged inside the granular filler, and the two power supply ends of the ultraviolet light strip 303 are respectively connected to the positive and negative poles of the external power supply. The granular filler includes a light-transmitting glass ball 3041 and a ceramsite 3042 with titanium dioxide loaded on the surface.

[0045] In the above preferred example, if the permeability reaction barrier 3 only includes one permeability reaction barrier unit, the two relatively hollowed-out sides of the third shell 301 are sealed with the first shell 201 and the second shell 401 respectively, then the shells of the groundwater inlet device 2, the permeability reaction barrier 3, and the groundwater outlet device 4 form a sealed whole. The seal of the three can isolate the contaminated groundwater from the atmospheric environment, preventing the atmosphere from entering the liquid. The bubbles formed will agglomerate in the filler of the permeability reaction barrier, affecting the contact area between the pollutants and the filler, thereby increasing the test error. In addition, after the simulated contaminated groundwater enters the groundwater inlet device 2, it flows through the permeability reaction barrier 3 and the groundwater outlet device 4 and flows out from the groundwater outlet device 4. In this process, the simulated contaminated groundwater will not overflow, ensuring the balance of water inlet and water outlet during the test, and improving the accuracy of the pollutant concentration test in the test. The simulated contaminated groundwater passes through the permeable gauze 302 located on one side of the permeability reaction barrier unit and flows into the inner cavity of the third shell 301. It flows through the granular filler and out of the permeable gauze 302 on the other side of the permeable reaction barrier unit. During this process, the granular filler adsorbs pollutants in the simulated contaminated groundwater, thereby purifying the groundwater. When the ultraviolet light band 303 is turned on, the granular filler includes transparent glass balls 3041 and ceramsite 3042 with titanium dioxide loaded on the surface. After the ultraviolet light band 303 emits ultraviolet light, the ultraviolet light hits the titanium dioxide surface loaded on the ceramsite 3042, generating electron-hole pairs, which react with water molecules in contact with them to form hydroxyl radicals. These hydroxyl radicals gradually degrade organic pollutants into small molecular intermediates through oxidation, and eventually mineralize into CO2 and H2O. Because the ceramsite 3042 is an opaque material, the propagation distance of ultraviolet light in the permeable reaction barrier is very short, with a maximum distance of approximately 5 times the diameter of the granular filler. Therefore, by adding transparent glass balls 3041 to the filler, the embodiment of the present invention allows ultraviolet light to pass through the transparent glass balls 3041 and refract at their surfaces, significantly increasing the area illuminated by the ultraviolet light and the ceramsite 3042. For example, by mixing ceramsite 3042 and transparent glass balls 3041 at a volume ratio of 1:1, the axial illumination area of ​​a single ultraviolet light strip 303 can be increased by approximately seven times, significantly improving the catalytic efficiency of the light source.

[0046] Fillers with the ability to adsorb pollutants and degrade pollutants through photocatalysis are added to the permeable reaction barrier unit, and an external light source is introduced. When the ultraviolet light band 303 is turned off, when the simulated contaminated groundwater flows through the permeable reaction barrier, the pollutants are adsorbed and fixed in the permeable reaction barrier through the adsorption effect of the filler. When the ultraviolet light band 303 is turned on, when the simulated contaminated groundwater flows through the permeable reaction barrier, on the one hand, the pollutants are adsorbed and fixed in the permeable reaction barrier through the adsorption effect of the filler, and on the other hand, the pollutants released by desorption from the filler are catalytically degraded through the photocatalytic effect. After degradation, the pollutants adsorbed on the filler diffuse back to the groundwater, reducing the frequency of filler replacement. In particular, in sites where organic pollutants in groundwater change frequently, the permeable reaction barrier of this embodiment improves the operating efficiency of the permeable reaction barrier.

[0047] The permeable reaction barrier has two functions: one is to adsorb pollutants in the groundwater; the other is to degrade and remove pollutants that were previously adsorbed on the filler and may be released into the groundwater again through the catalytic effect of ultraviolet light. In other words, in order to prevent the released pollutants from migrating downstream again, the embodiment of the present invention proposes a permeable reaction barrier with a photocatalytic regulation function, which catalytically degrades the pollutants after they are desorbed from the filler, preventing the pollutants from returning to the water flow. In this way, the filler in the permeable reaction barrier unit can not only adsorb pollutants in the simulated contaminated groundwater, but also degrade the pollutants and release them into the groundwater again.

[0048] Preferably, in each of the permeable reaction barrier units, the embedded length of the ultraviolet light band (303) is determined according to formula (1) and formula (2):

[0049] Formula (1)

[0050] Formula (2)

[0051] Where, represents the embedded length of the ultraviolet light tape 303, in cm; It represents the length of the permeability reaction barrier unit in cm; It represents the width of the permeability reaction barrier unit in cm; It represents the height of the permeability reaction barrier unit in cm; Indicates the radial effective irradiation area of ​​a UV light band 303, in cm 2 ; represents the reduction coefficient of the radial effective irradiation area of ​​the ultraviolet light band 303, dimensionless; Indicates the stacking volume of the light-transmitting glass balls 3041, in cm 3 ; Indicates the bulk volume of ceramsite 3042, in cm 3 ; It represents the reference value of the stacking volume ratio of the transparent glass balls 3041 and the ceramsite 3042, and is dimensionless. The value range is 0.8~2.3.

[0052] In the preferred embodiment described above, by adjusting the embedded length of the UV light strip 303, quantitative data support can be provided for optimizing the performance of the permeable reaction barrier. For example, when the granular filler material changes, the UV light strip length must also be adjusted accordingly. This maximizes the catalytic effect of the UV light and reduces energy input.

[0053] like Figure 3 and Figure 4 As shown, preferably, the permeability reaction barrier 3 includes N permeability reaction barrier units, which are connected in series, and the sealing plate 305 is located on the side where the permeability reaction barrier unit is connected to the groundwater inlet device 2, and the sealing plate 305 is connected to the permeability reaction barrier unit through a guide rail 306; N is an integer greater than 1.

[0054] In the preferred embodiment described above, when the permeability reaction barrier 3 comprises multiple permeability reaction barrier units, the units are connected in series, i.e., the third shells 301 of the multiple permeability reaction barrier units are sealed together in sequence, and the third shell 301 of each permeability reaction barrier unit contains granular filler. The third shell 301 of the permeability reaction barrier unit located at the outermost end of the permeability reaction barrier 3 is sealed together with the first shell 201; the third shell 301 of the permeability reaction barrier unit located at the outermost end of the permeability reaction barrier 3 is sealed together with the second shell 401. In this way, the shells of the groundwater inlet device 2, the permeability reaction barrier 3, and the groundwater outlet device 4 form a sealed whole. The entire device is provided with only one sealing plate 305. The sealing plate 305 is connected to the third shell 301 of the permeability reaction barrier unit directly connected to the first shell 201. The sealing plate 305 is connected to the permeability reaction barrier unit via a guide rail 306. The sealing plate 305 is movable up and down along the guide rail 306. By moving the sealing plate 305 , the contaminated groundwater flow channel between the groundwater inlet device 2 and the permeable reaction barrier 3 is controlled to be opened or closed.

[0055] like Figure 1As shown, preferably, the water collection device 5 includes a connecting pipe and an outlet valve 501; one end of the connecting pipe is connected to the outlet of the groundwater outlet device 4, and the other end is connected to the outlet valve 501. The water collection device 5 is used to collect liquid flowing out of the outlets at different locations of the groundwater outlet device 4 into one channel and inject it into the metering device 6. The number of outlets of the groundwater outlet device 4 is equal to the number of connecting pipes. One connecting pipe is connected to one outlet of the groundwater outlet device 4. Through one outlet valve 501, the simulated contaminated groundwater in all the connecting pipes is collected into one channel. The concentration of the simulated contaminated groundwater flowing out of the outlets at different locations may be different. This preferred embodiment can improve the uniformity of the concentration of the simulated contaminated groundwater flowing out of the groundwater outlet device 4. For example, the groundwater outlet device 4 is provided with four outlets, one near each of the four corners. The metering device 6 includes a flowmeter 601 and a collection device 602. The outlet of the outlet valve 501 is connected to the flowmeter 601, and the outlet of the flowmeter 601 is connected to the collection device 602. The flow meter 601 is used to measure the flow data of the simulated contaminated groundwater flowing out of the outlet valve 501 and transmit the data to the monitoring device 7.

[0056] The present invention further provides a method for operating a test device for photocatalytically regulating the service performance of a permeable reaction barrier using the above embodiment or preferred example, comprising:

[0057] S1. Based on the groundwater survey results of the test prototype contaminated site, determine the changes in the groundwater pollutant concentration at the location where the permeability reaction barrier is to be constructed within a set time period; based on the changes in the groundwater pollutants within the set time period, establish a relationship function between the groundwater pollutant concentration and time to obtain the maximum concentration value of the contaminated groundwater required for the test and the minimum concentration value of the contaminated groundwater required for the test.

[0058] Before the test equipment is operational, groundwater survey results from the prototype contaminated site are obtained. The proposed study period is divided into several subintervals, each lasting 0.5 to 1 month. The average pollutant concentration measured during each subinterval is used as the representative pollutant concentration for that subinterval. For example, for the past year, the types and concentrations of groundwater pollutants at the prototype contaminated site are obtained on a monthly basis. The arithmetic mean of the daily measured groundwater pollutant concentrations is used as the representative monthly groundwater pollutant concentration. Based on the groundwater survey results from the prototype contaminated site, a function is established that relates groundwater pollutant concentration to time. This function represents the changing characteristics of groundwater pollutant concentration within a specific time period. Those skilled in the art typically design permeable reaction barriers conservatively, designing them based on the maximum pollutant concentration. This design approach results in wasteful filler and increases the operating cost of the permeable reaction barrier. In sites with significant groundwater pollutant concentration variability, this function can be used to divide the pollutant concentration into several time periods. The embedded length of the UV light strip 303 can then be adjusted based on the pollutant concentration values ​​for each time period, thereby improving the performance of the permeable reaction barrier.

[0059] Before the test equipment is put into operation, install the test equipment. Fill the permeability reaction barrier unit with saturated granular filler. Connect the contaminated groundwater simulation device 1, groundwater inlet device 2, permeability reaction barrier 3, groundwater outlet device 4, water collection device 5, and metering device 6 in sequence. Also, connect the monitoring device 7 to the contaminated groundwater simulation device 1, groundwater inlet device 2, groundwater outlet device 4, water collection device 5, and metering device 6, respectively.

[0060] S2. Prepare simulated contaminated groundwater with the same type of pollutants and the same maximum concentration as those in the test prototype contaminated site, and load it into the first water storage unit 111; prepare simulated contaminated groundwater with the same type of pollutants and the same minimum concentration as those in the test prototype contaminated site, and load it into the second water storage unit 121.

[0061] Step S2 is to prepare simulated contaminated groundwater based on the maximum and minimum groundwater pollutant concentrations obtained in step S1. In the first water storage unit 111, simulated contaminated groundwater is prepared, containing the same types of groundwater pollutants and the same maximum concentration as the groundwater at the test prototype contaminated site. In the second water storage unit 121, simulated contaminated groundwater is prepared, containing the same types of groundwater pollutants and the same minimum concentration as the groundwater at the test prototype contaminated site. By regulating the flow rates of the first and second water storage units 111, 121 in subsequent steps, simulated contaminated groundwater of the desired contamination concentration and type is obtained in the groundwater inlet device 2.

[0062] S3. Close the first water inlet valve 113, the second water inlet valve 123, the water outlet valve 501, and the sealing plate 305; open the second exhaust and water-stop valve, and inject degassed clean distilled water into the groundwater outlet device 4 through the water inlet 403 until the clean distilled water fills the groundwater outlet device 4 and the permeability reaction barrier 3, and exhaust the air in the groundwater outlet device 4 and the permeability reaction barrier 3 by vacuuming, and then close the water inlet 403 and the second exhaust and water-stop valve.

[0063] S4. Open the first water inlet valve 113, the second water inlet valve 123, the first exhaust and water-stop valve, and the first agitator 202, and adjust the first flow controller 112 and the second flow controller 122 according to the preset flow ratio to obtain simulated contaminated groundwater with a set pollutant concentration; introduce the simulated contaminated groundwater into the groundwater inlet device 2, and fill the groundwater inlet device 2 with the simulated contaminated groundwater; close the first exhaust and water-stop valve, and then use the first agitator 202 to evenly mix the simulated contaminated groundwater.

[0064] S5. The monitoring device 7 obtains data measured by the detection component 203 located in the groundwater inlet device 2. When the data measured by the detection component 203 stabilizes, the outlet valve 501, the sealing plate 305, and the second agitator 402 are opened, and the ultraviolet light band 303 is turned off. The simulated contaminated groundwater is allowed to flow sequentially through the permeability reaction barrier 3, the groundwater outlet device 4, the water collection device 5, the flow meter 601, and finally into the collection device 602.

[0065] The monitoring device 7 records the flow reading of the flow meter 601 at set time intervals, thereby regulating the first flow controller 112 and the second flow controller 122 so that the difference between the flow measured by the flow meter 601 and the sum of the flows flowing out of the first flow controller 112 and the second flow controller 122 is less than or equal to a preset flow difference threshold; samples are taken from the collection device 602 to test the pollutant concentration until the set water outlet volume is reached, thereby obtaining the relationship between the water outlet pollutant concentration and the water outlet volume under the set concentration conditions.

[0066] S6. Close the first water inlet valve 113, the second water inlet valve 123, the sealing plate 305, the water outlet valve 501, the first agitator 202 and the second agitator 402, and discharge the simulated contaminated groundwater in the groundwater inlet device 2 through the first drain outlet 204. After draining, close the first drain outlet 204.

[0067] S7. Return to step S4 according to the next set concentration of simulated contaminated groundwater, and turn on the ultraviolet light band 303 in S5; take samples from the collection device 602 to test the pollutant concentration until the set effluent volume is reached, thereby obtaining the relationship between the effluent pollutant concentration and the effluent volume under the next set concentration condition, until the relationship between the effluent pollutant concentration and the effluent volume under all set concentrations of simulated contaminated groundwater is obtained.

[0068] In the above method, in step S3, the first water inlet valve 113, the second water inlet valve 123, the water outlet valve 501, and the sealing plate 305 are closed. In this way, the groundwater outlet device 4 and the permeable reaction barrier 3 form a closed body, and the groundwater inlet device 2 forms another closed body. The second exhaust and water-stop valve is opened, and clean distilled water is filled into the groundwater outlet device 4 and the permeable reaction barrier 3. In step S4, the groundwater inlet device 2 is filled with simulated contaminated groundwater. In step S5, when the sealing plate 305 is opened, since the closed bodies on both sides of the sealing plate 305 are filled with liquid, there is no pressure difference on both sides. Under the control of the first flow controller 112 and the second flow controller 122, the simulated contaminated groundwater flows at a uniform speed from the groundwater inlet device 2 through the permeable reaction barrier 3, the groundwater outlet device 4, and flows into the water collection device 5. The permeable reaction barrier 3 is a porous medium, and the contaminated groundwater flowing through it will produce a diffusion phenomenon, resulting in significant differences in the concentration of pollutants in the groundwater across the cross section of the permeable reaction barrier 3. The degree of diffusion and migration of groundwater pollutants is directly related to the groundwater flow rate, that is, the greater the groundwater flow rate, the greater the difference in the distribution of pollutant concentrations across the cross-section of the permeability reaction barrier 3. Therefore, during the test, the flow rate of the simulated contaminated groundwater needs to be strictly controlled to minimize the negative impact of the diffusion and migration of pollutants in the contaminated groundwater on the test results. In the above method, in step S4, since the concentration of contaminated groundwater simulated at different times is different, the flow rates of the first water storage unit 111 and the second water storage unit 121 are controlled by adjusting the first flow controller 112 and the second flow controller 122 to obtain simulated contaminated groundwater with a set pollutant concentration.

[0069] In the above method, in step S5, the monitoring device 7 obtains data measured by the detection component 203 located in the groundwater inlet device 2. The detection component 203 measures detection data of the simulated contaminated groundwater at different locations in the groundwater inlet device 2. When the data measured by each detection component 203 stabilizes, for example, the difference between the same parameter measured by each detection component 203 is less than a preset threshold, it can be considered that the simulated contaminated groundwater in the groundwater inlet device 2 is evenly mixed and has the desired concentration of simulated contaminated groundwater. The outlet valve 501, the sealing plate 305, the second agitator 402, and the ultraviolet light band 303 are opened, so that the simulated contaminated groundwater flows through the permeable reaction barrier 3, the groundwater outlet device 4, the water collection device 5, the flow meter 601, and is collected in the collection device 602. In the permeable reaction barrier 3, the filler adsorbs all or part of the pollutants in the simulated contaminated groundwater. The ultraviolet light band 303 is used to release the pollutants adsorbed by the filler from the filler and degrade them. In the groundwater outlet device 4, the simulated contaminated groundwater is stirred by the second agitator 402, so that the simulated contaminated groundwater is mixed more evenly. The simulated contaminated groundwater flowing out of the groundwater outlet device 4 is gathered into one path by the water collection device 5 and directed to the flow meter 601. The flow meter 601 records the flow of the simulated contaminated groundwater flowing through it and transmits the flow data to the monitoring device 7. The monitoring device 7 records the flow reading of the flow meter 601 at a set time interval, thereby regulating the first flow controller 112 and the second flow controller 122 so that the difference between the flow measured by the flow meter 601 and the sum of the flows flowing out of the first flow controller 112 and the second flow controller 122 is less than or equal to the preset flow difference threshold, and the water flow is stable. This also ensures that the simulated contaminated groundwater flows at a uniform speed in the groundwater inlet device 2, the permeability reaction barrier 3 and the groundwater outlet device 4. If the difference between the two is greater than the preset flow difference threshold, the water flow is unstable, affecting the accuracy of the test. Samples are taken from the collection device 602 to test the pollutant concentration, and the service performance test results of the permeability reaction barrier 3 under the set groundwater pollutant concentration conditions are obtained.

[0070] In step S6, since simulated contaminated groundwater with different concentrations needs to be replaced, the simulated contaminated groundwater from the previous simulation needs to be drained from the groundwater inlet device 2. However, the simulated contaminated groundwater from the previous simulation still remains in the permeability reaction barrier 3 and the groundwater outlet device 4. This ensures that the simulation is continuous in time and more realistically reflects the real scene.

[0071] In step S7, the process returns to step S4 and configures simulated contaminated groundwater of the desired concentration for this test. In step S5, the ultraviolet light band 303 is turned on. The ultraviolet light band 303 is used to release the contaminants adsorbed by the filler in the previous simulation and decompose the contaminants. This restores the filler's adsorption capacity for contaminants while preventing contaminants from returning to the groundwater and contaminating downstream groundwater. The process proceeds to step S6, where samples are taken from the collection device 602 to test the contaminant concentration until the set effluent volume is reached, thereby obtaining the relationship between the effluent contaminant concentration and the effluent volume under the next set concentration condition. By varying the flow rates of the first flow controller 112 and the second flow controller 122, as well as the concentration of the simulated contaminated groundwater, the effluent contaminant concentration of the groundwater outlet device 4 is tested at different flow rates, obtaining the relationship between the effluent contaminant concentration and the effluent volume, and obtaining the service performance test results of the permeable reaction barrier 3. Based on the relationship between time and groundwater contaminant concentration determined in the groundwater contaminant concentration-time relationship function obtained in step S1, a corresponding number of simulations are performed according to time. Each simulation uses the groundwater contaminant concentration corresponding to the time. Repeat steps S4-S7 until the relationship between the effluent pollutant concentration and the effluent volume under all set concentrations of simulated contaminated groundwater conditions is obtained.

[0072] After the test is completed, preferably, the working method further includes:

[0073] S8. Close the ultraviolet light strip 303, the first water inlet valve 113, the second water inlet valve 123, the water outlet valve 501, the first agitator 202 and the second agitator 402, open the sealing plate 305, and drain the simulated contaminated groundwater in the groundwater inlet device 2, the permeability reaction barrier 3, the groundwater outlet device 4, and the water collection device 5 through the first drain port 204; drain the simulated contaminated groundwater in the metering device 6 through the drainage hole on the collection device 602.

[0074] After the test, the UV light strip 303, first water inlet valve 113, second water inlet valve 123, water outlet valve 501, first agitator 202, and second agitator 402 are closed, and the sealing plate 305 is opened. At this point, the groundwater inlet device 2, permeable reaction barrier 3, and groundwater outlet device 4 form a whole. The simulated contaminated groundwater in the groundwater inlet device 2, permeable reaction barrier 3, groundwater outlet device 4, and water collection device 5 is drained through the first drain port 204 located on the groundwater inlet device 2.

[0075] In the devices and methods of the above-described embodiments, a fully enclosed housing design—namely, the first housing 201, the third housing 301, and the second housing 401—is connected to form a closed unit, enabling precise control of the simulated contaminated groundwater flow rate and realistically simulating groundwater flowing through a permeable reaction barrier at a constant rate. In a non-enclosed housing, the groundwater flow process is simulated by the water level difference upstream and downstream of the permeable reaction barrier. In this case, the groundwater flow rate is subject to dynamic changes, resulting in significant variations in the collected effluent pollutant concentrations, significantly different from the actual environment and inaccurate data.

[0076] In the equipment and methods of the above embodiments, the adsorption, desorption and degradation processes of the ceramsite with titanium dioxide loaded on the surface are regulated by photocatalysis. The service performance of the permeable reaction barrier under the condition of drastic changes in groundwater pollution concentration is tested through indoor experiments, providing data support for the optimized design of the service performance of the permeable reaction barrier.

[0077] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are only intended to further illustrate the principles of the present invention. Various changes and improvements are possible without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the invention as claimed.

Claims

1. A test device for photocatalytic regulation of the service performance of a permeable reaction barrier, characterized in that: The device comprises a contaminated groundwater simulation device (1), a groundwater inlet device (2), a permeability reaction barrier (3), a groundwater outlet device (4), a water collection device (5), a metering device (6) and a monitoring device (7), wherein the permeability reaction barrier (3) comprises at least one permeability reaction barrier unit; wherein, The water outlet of the contaminated groundwater simulation device (1) is connected to the water inlet of the groundwater inlet device (2); the groundwater inlet device (2), the permeability reaction barrier (3), and the groundwater outlet device (4) are connected in sequence; and a sealing plate (305) that can move up and down is provided on a side of the permeability reaction barrier (3) close to the groundwater inlet device (2); the sealing plate (305) is used to close or open the water flow channel between the groundwater inlet device (2) and the permeability reaction barrier (3); the water outlet of the groundwater outlet device (4) is connected to the water collection device (5), and the water outlet of the water collection device (5) is connected to the metering device (6); and the monitoring device (7) is respectively connected to the contaminated groundwater simulation device (1), the groundwater inlet device (2), the groundwater outlet device (4), the water collection device (5), and the metering device (6); The groundwater inlet device (2) comprises a first shell (201) and a first agitator (202), the first agitator (202) being connected to the first shell (201), a detection component (203) being provided on the wall of the first shell (201), and the detection component (203) being connected to the monitoring device (7); a first drain port (204) being provided at the lower portion of the first shell (201), and a first exhaust and water-stop valve being provided at the top of the first shell (201); The groundwater outlet device (4) comprises a second shell (401) and a second agitator (402), the second agitator (402) being connected to the second shell (401), a water inlet (403) being provided on the top surface of the second shell (401), and a second exhaust and water-stop valve being provided on the top of the second shell (401); The monitoring device (7) is connected to the first stirrer (202) and the second stirrer (402) respectively; The permeable reaction barrier unit comprises a hollow third shell (301), wherein two opposite hollow sides of the third shell (301) are sealedly connected to the first shell (201) and the second shell (401), respectively, and two opposite hollow sides of the third shell (301) are provided with a water-permeable gauze (302); the third shell (301) is filled with a granular filler, wherein an ultraviolet light strip (303) is provided inside the granular filler, and two power supply ends of the ultraviolet light strip (303) are respectively connected to the positive and negative poles of an external power supply; the granular filler comprises a light-transmitting glass ball (3041) and ceramsite (3042) with titanium dioxide loaded on the surface.

2. The test equipment for photocatalytic regulation of permeability reaction barrier service performance according to claim 1, characterized in that: The contaminated groundwater simulation device (1) comprises a first water storage unit (111), a first flow controller (112), a first water inlet valve (113), a second water storage unit (121), a second flow controller (122), and a second water inlet valve (123); the first water storage unit (111) is used to store contaminated groundwater of the highest concentration required for the test, and the second water storage unit (121) is used to store contaminated groundwater of the lowest concentration required for the test; The first water storage unit (111) is connected to the first flow controller (112) via a first water inlet valve (113), and the water outlet of the first flow controller (112) is connected to the groundwater inlet device (2); The second water storage unit (121) is connected to the second flow controller (122) via a second water inlet valve (123), and the water outlet of the second flow controller (122) is connected to the groundwater inlet device (2); The monitoring device (7) is respectively connected to the first water inlet valve (113), the second water inlet valve (123), the first flow controller (112), and the second flow controller (122).

3. The test equipment for photocatalytic regulation of permeability reaction barrier service performance according to claim 1, characterized in that: The water outlet of the groundwater outlet device (4) is located on a side of the second shell (401) away from the groundwater inlet device (2), and there are at least two water outlets, and at least two water outlets are at different heights.

4. The test equipment for photocatalytic regulation of permeability reaction barrier service performance according to claim 1, characterized in that: In each of the permeable reaction barrier units, the embedded length of the ultraviolet light band (303) is determined according to formula (1) and formula (2): Formula (1) Formula (2) Where, represents the buried length of the ultraviolet light band (303), in cm; It represents the length of the permeability reaction barrier unit in cm; It represents the width of the permeability reaction barrier unit in cm; It represents the height of the permeability reaction barrier unit in cm; Indicates the radial effective irradiation area of ​​a UV band (303), in cm 2 ; represents the reduction factor of the radial effective irradiation area of ​​the ultraviolet light band (303), dimensionless; Indicates the stacking volume of transparent glass balls (3041) in cm 3 ; Indicates the bulk volume of ceramsite (3042) in cm 3 ; It represents the reference value of the bulk volume ratio of transparent glass balls (3041) and ceramsite (3042), dimensionless.

5. The test equipment for photocatalytic regulation of permeability reaction barrier service performance according to claim 1, characterized in that: The permeability reaction barrier (3) comprises N permeability reaction barrier units, the N permeability reaction barrier units are connected in series, a sealing plate (305) is located on the side where the permeability reaction barrier unit is connected to the groundwater inlet device (2), and the sealing plate (305) is connected to the permeability reaction barrier unit via a guide rail (306); N is an integer greater than 1.

6. The test equipment for photocatalytic regulation of permeability reaction barrier service performance according to claim 2, characterized in that: The water collection device (5) comprises a connecting pipe and a water outlet valve (501); one end of the connecting pipe is connected to the water outlet of the groundwater outlet device (4), and the other end is connected to the water outlet valve (501); The metering device (6) includes a flow meter (601) and a collecting device (602); the water outlet of the water outlet valve (501) is connected to the flow meter (601), and the water outlet of the flow meter (601) is connected to the collecting device (602); The monitoring device (7) is connected to the flow meter (601).

7. A method for operating the test equipment for photocatalytically regulating the service performance of a permeable reaction barrier according to claim 6, characterized in that: The method comprises: S1. Based on the groundwater survey results of the test prototype contaminated site, determine the change in groundwater pollutant concentration at the location where the permeability reaction barrier is to be constructed within a set time period; based on the change in the groundwater pollutants within the set time period, establish a relationship function between groundwater pollutant concentration and time to obtain the maximum and minimum contaminated groundwater concentration values ​​required for the test; S2, preparing simulated contaminated groundwater with the same type of groundwater pollutants and the same maximum concentration as those in the prototype contaminated site, and loading it into the first water storage unit (111); Prepare simulated contaminated groundwater with the same type of groundwater pollutants and the same minimum concentration as those in the prototype contaminated site, and fill it into the second water storage unit (121); S3. Close the first water inlet valve (113), the second water inlet valve (123), the water outlet valve (501), and the sealing plate (305); open the second exhaust and water-stop valve, and inject degassed clean distilled water into the groundwater outlet device (4) through the water inlet (403) until the clean distilled water fills the groundwater outlet device (4) and the permeable reaction barrier (3); exhaust the air in the groundwater outlet device (4) and the permeable reaction barrier (3) by vacuuming, and then close the water inlet (403) and the second exhaust and water-stop valve; S4, opening the first water inlet valve (113), the second water inlet valve (123), the first exhaust and water-stop valve, and the first agitator (202); adjusting the first flow controller (112) and the second flow controller (122) according to a preset flow ratio to obtain simulated contaminated groundwater of a set concentration; introducing the simulated contaminated groundwater into the groundwater inlet device (2), so that the simulated contaminated groundwater fills the groundwater inlet device (2); closing the first exhaust and water-stop valve, and then using the first agitator (202) to uniformly mix the simulated contaminated groundwater; S5. Obtaining data measured by the detection component (203) located in the groundwater inlet device (2) through the monitoring device (7); when the data measured by the detection component (203) is stable, opening the outlet valve (501), the sealing plate (305) and the second agitator (402), and closing the ultraviolet light band (303), so that the simulated contaminated groundwater flows through the permeability reaction barrier (3), the groundwater outlet device (4), the water collection device (5), the flow meter (601) in sequence, and is collected into the collection device (602); The monitoring device (7) records the flow reading of the flow meter (601) at set time intervals, thereby regulating the first flow controller (112) and the second flow controller (122) so that the difference between the flow measured by the flow meter (601) and the sum of the flows flowing out of the first flow controller (112) and the second flow controller (122) is less than or equal to a preset flow difference threshold; sampling is performed from the collection device (602) to test the pollutant concentration until a set water outlet volume is reached, thereby obtaining a relationship between the water outlet pollutant concentration and the water outlet volume under the set concentration condition; S6. Close the first water inlet valve (113), the second water inlet valve (123), the sealing plate (305), the water outlet valve (501), the first agitator (202), and the second agitator (402), and discharge the simulated contaminated groundwater in the groundwater inlet device (2) through the first drain port (204). After the water is drained, close the first drain port (204); S7. Return to step S4 according to the next set concentration of simulated contaminated groundwater, and turn on the ultraviolet light band (303) in S5; take samples from the collection device (602) to test the pollutant concentration until the set effluent volume is reached, thereby obtaining the relationship between the effluent pollutant concentration and the effluent volume under the next set concentration condition, until the relationship between the effluent pollutant concentration and the effluent volume under all set concentrations of simulated contaminated groundwater is obtained.

8. The working method of the test equipment for photocatalytic regulation of permeability reaction barrier service performance according to claim 7, characterized in that: Also includes: S8. Close the ultraviolet light strip (303), the first water inlet valve (113), the second water inlet valve (123), the water outlet valve (501), the first agitator (202), and the second agitator (402), open the sealing plate (305), and drain the simulated contaminated groundwater in the groundwater inlet device (2), the permeability reaction barrier (3), the groundwater outlet device (4), and the water collection device (5) through the first drain port (204); drain the simulated contaminated groundwater in the metering device (6) through the drain hole on the collecting device (602).

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