Groundwater tracking detection system and application method for contaminated land restoration

Abstract

The present invention relates to the field of groundwater monitoring for the remediation of contaminated land, and in particular to a groundwater tracking and detection system and application method for the remediation of contaminated land. It includes a comprehensive injection unit and a pumping unit, wherein it also includes an on-site groundwater detection unit; a set of comprehensive injection units is arranged upstream of the groundwater flow, and several sets of pumping units are arranged downstream of the groundwater flow, and the comprehensive injection units and pumping units are distributed in a fan shape, and the on-site groundwater detection unit is located at the center of the fan; the on-site groundwater detection unit includes an outer pipe of a monitoring well and an inner pipe of a monitoring well, and a micro-lifting pump is arranged in the inner pipe of the monitoring well, and the micro-lifting pump sucks the groundwater in the inner pipe of the monitoring well to the wellhead integrated detection equipment. It can track and detect the groundwater in real time, and timely feedback the concentration value of the target pollutant in the groundwater.

Description

Technical Field

[0001] The present invention relates to the field of groundwater monitoring for contaminated land restoration, and in particular to a groundwater tracking and detection system and an application method for contaminated land restoration. Background Art

[0002] After the implementation of the "Law of the People's Republic of China on the Prevention and Control of Soil Pollution", the process of land survey and remediation of polluted land has been accelerated, and the demand for soil and groundwater testing has gradually increased. Groundwater is usually collected and tested in the remediation sites of polluted soil and groundwater, and the effectiveness of remediation of polluted land is judged by the characteristic pollutant indicators in groundwater.

[0003] Normally, to build groundwater monitoring wells in contaminated plots, third-party testing laboratory personnel will go to the site to collect groundwater samples, and then transport, circulate and store the samples for laboratory testing and analysis. The test report cycle is about 15 days. This process is time-consuming and the data feedback is not timely, which greatly wastes the construction time and cost of the construction site. Therefore, there is an urgent need for a technology for timely tracking and testing of groundwater for the remediation of contaminated plots. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and propose a groundwater tracking and detection system and application method for the remediation of contaminated land, which can track and detect groundwater in real time and provide timely feedback on the concentration values ​​of target pollutants in groundwater.

[0005] The technical solution of the present invention is: a groundwater tracking and detection system for the remediation of contaminated land, comprising a comprehensive injection unit and a pumping unit, wherein, it also comprises an on-site groundwater detection unit;

[0006] A set of integrated injection units is arranged upstream of the groundwater flow, and several sets of pumping units are arranged downstream of the groundwater flow. The integrated injection units and pumping units are distributed in a fan shape, and the groundwater detection unit in the field is located in the center of the fan shape.

[0007] The on-site groundwater detection unit includes an outer pipe of the monitoring well and an inner pipe of the monitoring well. A micro lift pump is provided in the inner pipe of the monitoring well. The micro lift pump draws the groundwater in the inner pipe of the monitoring well to the wellhead integrated detection equipment.

[0008] In the present invention, the integrated injection unit comprises an injection well pipe located in the injection well, a sealing well cap is arranged on the top of the injection well pipe, and a well pipe screen seam area is arranged on the bottom of the injection well pipe;

[0009] The outlet end of the water supply pipe passes through the sealing well cap and is inserted into the interior of the injection well pipe. The inlet end of the water supply pipe is connected to the water storage tank through a water injection pipeline. The water injection pipeline is provided with a water injection pump and a water injection control valve.

[0010] The outlet end of the gas injection pipe passes through the sealing well cap and is inserted into the interior of the injection well pipe and is located below the groundwater level. The inlet end of the gas injection pipe is connected to the gas storage device through a gas transmission pipeline, and a first gas transmission pump and a first gas transmission control valve are provided on the gas transmission pipeline.

[0011] The water supply pipe, air injection pipe and sealing well cap are all sealed.

[0012] The pumping unit comprises a pumping well pipe located in the pumping well, a pipe cap is arranged on the top of the pumping well pipe, and a pumping well pipe sieve seam area is arranged on the lower part of the pumping well pipe;

[0013] The water pumping pipe is inserted into the water pumping well pipe through the pipe cap, the water suction port of the water pumping pipe is located at the bottom of the water pumping well pipe, and the water suction port is U-shaped, the water outlet end of the water pumping pipe is connected to the water treatment equipment through the second water delivery pipeline, and the second water delivery pipeline is provided with a second water reduction pump and a second water delivery control valve;

[0014] The air supply pipe passes through the pipe cap and is inserted into the pumping well pipe. The air outlet of the air supply pipe is located in the pumping well pipe and below the stable groundwater level. The air inlet end of the air supply pipe is connected to the gas storage equipment through the third gas pipeline. The third gas pipeline is provided with a third gas pump and a third gas control valve.

[0015] The outer pipe of the monitoring well is arranged in the monitoring well, and the inner pipe of the monitoring well is arranged in the outer pipe of the monitoring well. The outer pipe of the monitoring well and the inner pipe of the monitoring well are nested and fixed through the wellhead cover at the top. The lower part of the outer pipe of the monitoring well is provided with an outer pipe sieve area, and the lower part of the inner pipe of the monitoring well is provided with an inner pipe sieve area.

[0016] A built-in pumping pipe is provided in the gap between the outer pipe of the monitoring well and the inner pipe of the monitoring well. The water suction port of the built-in pumping pipe is located at the bottom of the outer pipe of the monitoring well, and the water suction port is U-shaped. The water outlet of the built-in pumping pipe is connected to the water treatment equipment through a first water delivery pipeline. The first water delivery pipeline is provided with a first dewatering pump and a first water delivery control valve.

[0017] A filtering mechanism is arranged in the inner pipe of the monitoring well, a micro lifting pump is arranged above the filtering mechanism, and the micro lifting pump is connected to the wellhead integrated detection equipment through a groundwater lifting pipe.

[0018] A rain cover is provided on the top outer side of the monitoring well outer tube and the monitoring well inner tube, the wellhead integrated detection equipment and monitoring equipment are arranged in the rain cover, and the top plate of the rain cover is a photovoltaic energy storage panel;

[0019] The water outlet of the wellhead integrated detection equipment is connected to the water treatment equipment through a drainage pipe.

[0020] The filtering mechanism comprises a fiber filtering layer and a sand filtering layer arranged in sequence from top to bottom, the fiber filtering layer and the sand filtering layer are both located above the inner tube sieve slot area, and there is a gap between the fiber filtering layer and the sand filtering layer, and the micro lifting pump is arranged on the top surface of the fiber filtering layer;

[0021] The air outlet of the air blowing pipe is located in the gap between the fiber filter layer and the sand filter layer. The inlet end of the air blowing pipe is connected to the gas storage device through a second gas pipeline. The second gas pipeline is provided with a second gas pump and a second gas control valve.

[0022] The present invention also discloses a method for automatically detecting groundwater using the groundwater tracking and detection system for remediation of contaminated land, comprising the following steps:

[0023] S1. Determine the pollution remediation area and plan the construction location of the groundwater tracking and detection system, and complete the construction of the groundwater tracking and detection system;

[0024] S2. Open the groundwater detection unit on site separately, and use the micro lift pump to pump groundwater to the wellhead integrated detection equipment to obtain initial analysis data;

[0025] S3. Intermittently inject compressed air into the integrated injection unit, and use the pumping unit to treat the underground sewage. After the groundwater flow field is formed, turn on the micro-lifting pump of the groundwater detection unit in the field to pump groundwater to the wellhead integrated detection equipment, and obtain real-time data through detection and analysis.

[0026] In step S3, the first air pump and the first air control valve connected to the integrated injection unit are turned on, and compressed air is intermittently injected into the injection well pipe through the air injection pipe. The second dewatering pump and the third air pump connected to the pumping unit are turned on simultaneously to pump the groundwater inside the pumping well pipe to the water treatment equipment, and the underground sewage is treated by the water treatment equipment.

[0027] In step S3, when the wellhead integrated detection device reports that the groundwater is abnormally turbid, the second air delivery pump and the second air delivery control valve connected to the on-site groundwater detection unit are turned on, and compressed air is used to backwash the sand filter layer through the air blowing pipe; the first dewatering pump and the first water delivery control valve connected to the on-site groundwater detection unit are turned on simultaneously, and the turbid groundwater is pumped to the water treatment equipment through the built-in pumping pipe of the on-site groundwater detection unit to treat the turbid groundwater;

[0028] When groundwater is scarce, turn on the water injection pump and water injection control valve connected to the integrated injection unit, and replenish the clean water in the water storage tank to the land through the water supply pipe to enhance the fluidity of groundwater.

[0029] The present invention also discloses a method for detecting the injection influence radius of an in-situ injection remediation process using the above-mentioned groundwater tracking and detection system for remediation of contaminated land, comprising the following steps:

[0030] S1. Select an area in the contaminated land where the soil layer has not been disturbed and level the surface;

[0031] S2, constructing a comprehensive injection unit in the center of the leveled area obtained in step S1;

[0032] S3. With the integrated injection unit as the center, build groundwater detection units on site at intervals of 1m, 2m, and 3m in the four positive directions of east, south, west, and north;

[0033] S4. Inject specific reagents or color developers into the integrated injection unit, and analyze and determine the injection impact radius based on the detection results of the wellhead integrated detection equipment of the on-site groundwater detection unit.

[0034] The beneficial effects of the present invention are:

[0035] (1) The present invention sets up an on-site groundwater detection unit and utilizes the wellhead integrated detection equipment therein to fully automatically detect indicators such as heavy metals, VOCs, SVOCs, pH, COD, petroleum, ammonia nitrogen, total phosphorus, chromaticity, chemical oxygen demand, sulfate, dissolved oxygen, total hardness, conductivity, etc. in the incoming water sample and timely feedback the data to the APP software system. According to the data values ​​detected, the groundwater can be tracked and detected in real time, and the concentration values ​​of target pollutants in the groundwater can be timely fed back. Compared with the existing technology, the detection time is saved, thereby greatly shortening the construction period at the construction site and reducing the construction cost;

[0036] (2) Through this application, the injection impact radius of the in-situ injection remediation process site can also be determined, and the number and spacing of injection wells, pumping wells and detection wells at the construction site can be determined based on the injection impact radius. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of a fan-shaped arrangement of a groundwater tracking and detection system for remediation of contaminated land in Example 1;

[0038] Figure 2 It is a schematic diagram of the cross-sectional structure of the integrated injection unit;

[0039] Figure 3 It is a schematic diagram of the cross-sectional structure of the groundwater detection unit on site;

[0040] Figure 4 Schematic diagram of the cross-section structure of the pumping unit

[0041] Figure 5This is a schematic diagram of the connection of water and gas transmission of the system of the present invention in Example 1;

[0042] Figure 6 It is a schematic diagram of the plan layout when the system of the present invention is used to detect the injection impact radius in Example 3.

[0043] In the figure: 1 integrated injection unit; 101 sealing well cap; 102 injection well pipe; 103 sieve slot; 104 water supply pipe; 105 air injection pipe; 106 surface sealing layer; 2 on-site groundwater detection unit; 201 rain cover; 202 monitoring well outer pipe; 203 monitoring well inner pipe; 204 built-in pumping pipe; 205 outer pipe sieve slot area; 206 inner pipe sieve slot area; 207 sand filter layer; 208 fiber filter layer; 209 air blowing pipe; 210 micro lift pump; 211 groundwater lift pipe; 212 wellhead integrated detection equipment; 213 monitoring equipment; 214 drainage pipe; 3 pumping unit; 301 pipe cap; 302 pumping well pipe; 303 water extraction pipe; 304 air supply pipe; 4 gas storage equipment; 401 first gas pipeline; 402 first gas pump; 403 first gas control valve; 404 second gas pipeline; 405 second gas pump; 406 second gas control valve; 407 third gas pipeline; 408 third gas pump; 409 third gas control valve; 5 water treatment equipment; 501 first water pipeline; 502 first dewatering pump; 503 first water control valve; 504 second water pipeline; 505 second dewatering pump; 506 second water control valve; 6 water storage tank; 601 water injection pipeline; 602 water injection pump; 603 water injection control valve. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0045] In the following description, specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0046] Example 1

[0047] The present invention discloses a groundwater tracking and detection system for the remediation of contaminated land, comprising a comprehensive injection unit 1, an on-site groundwater detection unit 2, a pumping unit 3, a gas storage device 4, a water treatment device 5, and a water storage tank 6. The comprehensive injection unit 1 is connected to the gas storage device 4 and the water storage tank 6. The on-site groundwater detection unit 2 is connected to the gas storage device 4 and the water treatment device 5. The pumping unit 3 is connected to the gas storage device 4 and the water treatment device 5.

[0048] like Figure 1As shown, the integrated injection unit 1, the on-site groundwater detection unit 2, and the pumping unit 3 are arranged in a 45° fan-shaped arrangement. One set of integrated injection units 1 is arranged upstream of the groundwater flow, and three sets of pumping units 3 are arranged downstream of the groundwater flow. One set of integrated injection units 1 and three sets of pumping units 3 form a 45° fan-shaped arrangement. The on-site groundwater detection unit 2 is located at the center of the fan-shaped arrangement.

[0049] According to different hydrogeological conditions, the well spacing between the integrated injection unit 1 and the pumping unit 3 of the silt clay / clay plot is 10-15m. The well spacing between the integrated injection unit 1 and the pumping unit 3 of the miscellaneous fill / silt sand plot is 15-25m. According to the depth of groundwater pollution in different plots, the well depth of the groundwater detection system 2 and the well depth of the pumping unit 3 can be adjusted. When the groundwater pollution depth is deep, the well depth of the groundwater detection system 2 and the well depth of the pumping unit 3 can be adjusted to twice the well depth of the integrated injection unit 1.

[0050] like Figure 2 As shown, the integrated injection unit 1 includes an injection well pipe 102 located in the underground soil layer, and a sealing well cap 101 is provided on the top of the injection well pipe 102, and the sealing well cap 101 and the injection well pipe 102 are sealed. A well pipe sieve area 103 is provided in the middle and lower part of the injection well pipe 102. The groundwater in the injection well enters the injection well pipe through the well pipe sieve area 103. A water supply pipe 104 and an air injection pipe 105 are provided on the sealing well cap 101, and the outlet ends of the water supply pipe 104 and the air injection pipe 105 pass through the sealing well cap 101 and are inserted into the interior of the injection well pipe 102, and the outlet end of the water supply pipe 104 must be located below the stable groundwater level. The water supply pipe 104 and the air injection pipe 105 are both sealedly connected to the sealing well cap 101. The inlet end of the water supply pipe 104 is connected to the water storage tank 6, and clean water or repair agents can be injected into the injection well through the water storage tank 6. The inlet end of the gas injection pipe 105 is connected to the gas storage device 4, and compressed air is injected into the injection well through the gas storage device 4. The compressed air can accelerate the injection and diffusion of clean water or repair agents in the upstream injection well pipe into the groundwater.

[0051] In this embodiment, the construction depth of the injection well is 3m. The nominal diameter of the injection well pipe 102 is DN50, and its length is 3.5m, and it is made of UPVC material. The height of the well pipe screen seam area 103 is 1m, and the well pipe screen seam area 103 is 0.2m away from the bottom of the injection well pipe. Its screen seam width is 1mm, and the screening rate is 50%. A circular surface sealing layer 106 needs to be constructed in the injection well head area. The surface sealing layer 106 uses concrete with a model of C30 and a thickness of 10cm. The injection well pipe 102 is taken as the center of the circle, and its construction radius is 1.5m.

[0052] A water injection pipeline 601 is provided at the water outlet of the water storage tank 6, and the water injection pipeline 601 is connected to the water supply pipe 104. A water injection pump 602 and a water injection control valve 603 are provided on the water injection pipeline 601. The water injection pump 602 pumps the clean water in the water storage tank 6 into the injection well pipe 102 through the water supply pipe 104. A first gas delivery pipeline 401 is provided at the gas outlet of the gas storage device 4, and the first gas delivery pipeline 401 is connected to the gas injection pipe 105. A first gas delivery pump 402 and a first gas delivery control valve 403 are provided on the first gas delivery pipeline 401. The first gas delivery pump 402 delivers compressed air into the injection well pipe 102 through the gas injection pipe 105.

[0053] In this embodiment, the water storage tank 6 is a PE material tank with a volume of 2m 3 , built on the surface, the nominal diameter of its water injection pipeline 601 is DN15. The gas storage equipment 4 is a steel tank with a volume of 2m 3 , built on the surface, the nominal diameter of the first gas pipeline 401 is DN8.

[0054] like Figure 3 As shown, the on-site groundwater detection unit 2 includes a monitoring well outer tube 202 and a monitoring well inner tube 203 located in the underground soil layer. The monitoring well inner tube 203 is located in the tube cavity of the monitoring well outer tube 202. In this embodiment, the monitoring well outer tube 202 and the monitoring well inner tube 203 are coaxially arranged. A wellhead cover is fixed on the top of the monitoring well outer tube 202 and the monitoring well inner tube 203. The monitoring well outer tube 202 and the monitoring well inner tube 203 are nested and fixed through the wellhead cover. An outer tube sieve area 205 is provided at the lower part of the monitoring well outer tube 202. The groundwater in the monitoring well enters the monitoring well outer tube 202 through the outer tube sieve area 205. An inner tube sieve area 206 is provided at the lower part of the monitoring well inner tube 203. The groundwater entering the monitoring well outer tube 202 enters the monitoring well inner tube 203 through the inner tube sieve area 206.

[0055] In this embodiment, the construction depth of the monitoring well is 6m, the nominal diameter of the monitoring well outer pipe 202 is DN200, the length is 6.3m, and it is made of carbon steel. The height of the outer pipe sieve slot area 205 is 0.8m, the sieve slot width is 1.5mm, and the screening rate is 50%. The nominal diameter of the monitoring well inner pipe 203 is DN150, the length is 5.3m, and it is made of carbon steel. The height of the inner pipe sieve slot area 206 is 1m, the sieve slot width is 1.5mm, and the screening rate is 50%.

[0056] An internal pumping pipe 204 is provided between the inner wall of the monitoring well outer tube 202 and the outer wall of the monitoring well inner tube 203. The water suction port at the bottom of the internal pumping pipe 204 is U-shaped. In this embodiment, the distance between the water suction port of the internal pumping pipe 204 and the bottom of the monitoring well outer tube 202 is 0.3 m. The top of the internal pumping pipe 204 is a water outlet, and its water outlet is connected to the water treatment equipment 5 through the first water delivery pipeline 501. The first water delivery pipeline 501 is provided with a first water delivery control valve 503 and a first dewatering pump 502. When the first dewatering pump 502 is started, the groundwater in the monitoring well outer tube 202 can be pumped to the water treatment equipment 5, and the underground sewage can be treated by the water treatment equipment 5.

[0057] A fiber filter layer 208 and a sand filter layer 207 are arranged in the cavity of the inner tube 203 of the monitoring well from top to bottom, and the fiber filter layer 208 and the sand filter layer 207 are both located above the inner tube sieve seam area 206. There is a certain gap between the fiber filter layer 208 and the sand filter layer 207, and a micro lift pump 210 is arranged on the top surface of the fiber filter layer 208, and the micro lift pump 210 is located below the stable groundwater level. Under the suction action of the micro lift pump 210, the groundwater entering the inner tube 203 of the monitoring well flows from bottom to top, and passes through the sand filter layer 207 and the fiber filter layer 208 in turn during the flow process to filter the groundwater. The sand filter layer 207 is used to filter large impurities such as mud and sand in the groundwater, and the fiber filter layer 208 is used to filter small impurities in the groundwater. Through the above filtering process, it can not only ensure that the groundwater entering the wellhead integrated detection equipment 212 will not cause damage to the detection equipment due to impurities, but also ensure the accuracy of the detection data.

[0058] In this embodiment, the thickness of the sand filter layer 207 is 0.4m, and the filler is quartz sand with a particle size of 2-3mm. The thickness of the fiber filter layer 208 is 0.2m, and the filler is fiber with a diameter of 1-2mm. The distance between the sand filter layer 207 and the fiber filter layer 208 is 6cm.

[0059] A rain cover 201 is provided on the upper outer side of the outer tube 202 of the monitoring well. A monitoring device 213 and a wellhead integrated detection device 212 are provided inside the rain cover 201. In this embodiment, the rain cover 201 adopts a rectangular steel structure with a size of 5×6×3.5m, and the top plate of the rain cover 201 is set as a photovoltaic energy storage panel. The monitoring device 213 and the wellhead integrated detection device 212 are connected to the APP software system and the wireless network system. The wellhead integrated detection device 212 in this embodiment includes a plurality of detection devices connected in series, and the corresponding index parameters of groundwater are detected and analyzed through each detection device.

[0060] An air blowing pipe 209 and a groundwater lifting pipe 211 are provided in the inner pipe 203 of the monitoring well, and both the air blowing pipe 209 and the groundwater lifting pipe 211 pass through the outer pipe of the monitoring well and the wellhead cover on the top of the inner pipe of the monitoring well. The air outlet of the air blowing pipe 209 is located in the gap between the sand filter layer 207 and the fiber filter layer 208, and the inlet end of the air blowing pipe 209 is connected to the gas storage device 4 through the second gas pipeline 404. A second gas pump 405 and a second gas control valve 406 are provided on the second gas pipeline 404. The second gas pump 405 can blow the compressed air in the gas storage device 4 into the inner pipe 203 of the monitoring well through the air blowing pipe 209 to backwash the sand filter layer 207 to avoid blockage and repeated replacement of the sand filter layer 207. In this embodiment, the nominal diameter of the second gas pipeline 404 is DN8.

[0061] The micro lift pump 210 is connected to the wellhead integrated detection device 212 through the groundwater lift pipe 211. The micro lift pump 210 pumps the filtered groundwater in the monitoring well inner tube 203 to the wellhead integrated detection device 212 on the ground surface through the groundwater lift pipe 211 for index detection and analysis. The wellhead integrated detection device 212 can automatically detect the heavy metals, VOCs, SVOCs, pH, COD, petroleum, ammonia nitrogen, total phosphorus, chromaticity, chemical oxygen demand, sulfate, dissolved oxygen, total hardness, conductivity and other indicators in the water sample, and feed back the data to the APP software system. The wellhead integrated detection device 212 discharges the waste liquid to the water treatment device 5 through the drainage pipe 214.

[0062] like Figure 4 As shown, the pumping unit 3 includes a pumping well pipe 302, and a pumping well pipe sieve area is provided at the bottom of the pumping well pipe 302. Groundwater enters the pumping well pipe 302 through the pumping well pipe sieve area. A pipe cap 301 is fixed to the top of the pumping well pipe 302. In this embodiment, the construction depth of the pumping well is 6m, the nominal diameter of the pumping well pipe 302 is DN50, the length is 6.3m, and it is made of UPVC material. The height of the pumping well pipe sieve area is 1.5m, the width of the sieve is 1mm, and the screening rate is 50%.

[0063] The water pumping pipe 303 and the air supply pipe 304 are both inserted into the water pumping well pipe 302 through the pipe cap 301. The air outlet of the air supply pipe 304 is located in the water pumping well pipe 302 and below the stable groundwater level. The air inlet end of the air supply pipe 304 is connected to the gas storage device 4 through the third gas transmission pipeline 407. The third gas transmission pipeline 407 is provided with a third gas transmission pump 408 and a third gas transmission control valve 409. The compressed air in the gas storage device 4 enters the water pumping well pipe 302 through the air supply pipe 304, and the compressed air can accelerate the pressurized extraction of groundwater in the downstream water pumping well pipe.

[0064] The water inlet of the pumping pipe 303 is located at the bottom of the pumping well pipe 302, and the water inlet is U-shaped. In this embodiment, the distance between the water inlet of the pumping pipe 303 and the bottom of the pumping well pipe 302 is 0.3m. The water outlet of the pumping pipe 303 is connected to the water treatment equipment 5 through the second water delivery pipeline 501. The second water delivery pipeline 501 is provided with a second dewatering pump 505 and a second water delivery control valve 506. Starting the second dewatering pump 505 can pump the groundwater in the pumping well pipe 302 to the water treatment equipment 5, and the underground sewage is treated by the water treatment equipment 5.

[0065] like Figure 5 As shown, the gas storage device 4 in this embodiment can simultaneously supply gas to the integrated injection unit 1, the groundwater detection unit 2 and the pumping unit 3. The water treatment device 5 can simultaneously treat the groundwater extracted by the groundwater detection unit 2 and the pumping unit 3.

[0066] Example 2

[0067] This embodiment is the first application method of the groundwater tracking and detection system for remediation of contaminated land described in Embodiment 1, and specifically is a method for automatic groundwater detection using the above system, which includes the following steps.

[0068] The first step is to investigate the hydrogeological conditions before construction begins, determine the groundwater flow direction, stable water level, soil conditions, etc. Determine the pollution remediation area and plan the construction location of the groundwater tracking and detection system described in the present invention.

[0069] The second step is to construct the comprehensive injection unit 1, the on-site groundwater detection unit 2, and the pumping unit 3, complete the connection between the comprehensive injection unit 1, the on-site groundwater detection unit 2, the pumping unit 3 and the gas storage equipment 4, the water treatment equipment 5, and the water storage tank 6, and complete the debugging.

[0070] The third step is to start the on-site groundwater detection unit 2 separately during the hydrogeological survey stage and the initial stage of the repair construction, and use the micro lift pump 210 to extract groundwater to the wellhead integrated detection equipment 212, and use the computer or mobile phone APP software system connected to the wellhead integrated detection equipment 212 to obtain initial analysis data.

[0071] The fourth step is to start the first air pump 402 and the first air control valve 403 connected to the integrated injection unit 1 in the middle and late stages of construction, and intermittently inject compressed air into the injection well pipe 102 through the air injection pipe 105. Simultaneously, start the second dewatering pump 502 and the third air pump 408 connected to the pumping unit 3 to pump the groundwater inside the pumping well pipe 302 to the water treatment equipment 5, and treat the underground sewage through the water treatment equipment 5.

[0072] After the groundwater flow field is formed, the micro lift pump 210 of the groundwater detection unit 2 in the field is turned on to pump groundwater to the wellhead integrated detection equipment 212 to obtain detection and analysis data.

[0073] When the wellhead integrated detection device 212 reports that the groundwater is abnormally turbid, the second air delivery pump 405 and the second air delivery control valve 406 connected to the on-site groundwater detection unit 2 are turned on, and the compressed air blown out by the air blowing pipe 209 is used to backwash the sand filter layer 207. The first dewatering pump 502 and the first water delivery control valve 503 connected to the on-site groundwater detection unit 2 are turned on simultaneously, and the turbid groundwater is pumped to the water treatment device 5 through the built-in pumping pipe 204 of the on-site groundwater detection unit 2 to treat the turbid groundwater.

[0074] When groundwater is scarce, clean water is stored in the water storage tank 6, and the water injection pump 602 and the water injection control valve 603 connected to the integrated injection unit 1 are turned on, and clean water is added to the plot through the water supply pipe 104 to enhance the fluidity of groundwater.

[0075] Example 3

[0076] A groundwater remediation site in Xuzhou, Jiangsu Province, used multiphase extraction technology to remediate contaminated soil above 2m above the surface and contaminated groundwater 8m deep. The pollutant in the site was 1,2-dichloroethane, and the soil remediation volume was 2000m 3 、Groundwater restoration area 10000m 2 .

[0077] According to actual needs, a total of 1 set of the system of the present invention was built, among which the construction depth of the comprehensive injection unit was 4.5m, the construction depth of the on-site groundwater detection unit was 9m, and the construction depth of the pumping unit was 9m. The present invention was used for automatic groundwater detection multiple times in the early, middle and late stages of the construction process, and a detection data curve was formed. During the implementation period, the system described in this application operated well, saving about 50 calendar days of construction time and about 500,000 yuan in third-party laboratory testing costs.

[0078] Example 4

[0079] This embodiment is a second application method of the groundwater tracking and detection system for contaminated land remediation described in Example 1. Specifically, it is a method of using the above system to detect the injection influence radius of the in-situ injection remediation process. This method mainly uses the comprehensive injection unit 1 and the on-site groundwater detection unit 2 in the detection system. The method includes the following steps.

[0080] The first step is to select an area in a polluted plot where the soil layer is not disturbed and level the surface. The leveling area is about 50m 2 .

[0081] In the second step, a comprehensive injection unit 1 is constructed in the center of the leveled area obtained in the first step. In this embodiment, the injection well can be constructed to a depth of 5 m.

[0082] The third step is to construct on-site groundwater detection units 2 with the integrated injection unit 1 as the center in the four positive directions of east, south, west and north at intervals of 1m, 2m and 3m respectively. In this embodiment, the construction depth of the monitoring well can be 5m.

[0083] In the fourth step, the comprehensive injection unit 1 injects a specific agent or a color developer, and the injection impact radius is determined by analysis by the on-site groundwater detection unit 2.

[0084] When the wellhead integrated detection device of the on-site groundwater detection unit 2 can detect a specific agent or color developer, it means that the injection influence radius can reach the distance range where the on-site groundwater detection unit 2 is located; when the wellhead integrated detection device of the on-site groundwater detection unit 2 cannot detect a specific agent or color developer, it means that the injection influence radius cannot reach the distance range where the on-site groundwater detection unit 2 is located. Thus, the injection influence radius is determined.

[0085] The groundwater tracking detection system and detection method for the remediation of contaminated land provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined in this article can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this article, but will conform to the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A groundwater tracking and detection system for contaminated land remediation, comprising an integrated injection unit and a pumping unit, characterized in that: Also included is an on-site groundwater testing unit; A set of integrated injection units is arranged upstream of the groundwater flow, and several sets of pumping units are arranged downstream of the groundwater flow. The integrated injection units and pumping units are distributed in a fan shape, and the groundwater detection unit in the field is located in the center of the fan shape. The on-site groundwater detection unit includes an outer pipe of the monitoring well and an inner pipe of the monitoring well. A micro lift pump is provided in the inner pipe of the monitoring well to pump the groundwater in the inner pipe of the monitoring well to the wellhead integrated detection equipment; The outer pipe of the monitoring well is arranged in the monitoring well, and the inner pipe of the monitoring well is arranged in the outer pipe of the monitoring well. The outer pipe of the monitoring well and the inner pipe of the monitoring well are nested and fixed through the wellhead cover at the top. The lower part of the outer pipe of the monitoring well is provided with an outer pipe sieve area, and the lower part of the inner pipe of the monitoring well is provided with an inner pipe sieve area. A built-in pumping pipe is provided in the gap between the outer pipe of the monitoring well and the inner pipe of the monitoring well. The water suction port of the built-in pumping pipe is located at the bottom of the outer pipe of the monitoring well, and the water suction port is U-shaped. The water outlet of the built-in pumping pipe is connected to the water treatment equipment through a first water delivery pipeline. The first water delivery pipeline is provided with a first dewatering pump and a first water delivery control valve. A filtering mechanism is provided in the inner pipe of the monitoring well, and a micro lifting pump is provided above the filtering mechanism. The micro lifting pump is connected to the wellhead integrated detection equipment through a groundwater lifting pipe; A rain cover is provided on the top outer side of the monitoring well outer tube and the monitoring well inner tube, the wellhead integrated detection equipment and monitoring equipment are arranged in the rain cover, and the top plate of the rain cover is a photovoltaic energy storage panel; The water outlet of the wellhead integrated detection equipment is connected to the water treatment equipment through a drainage pipe; The filtering mechanism comprises a fiber filtering layer and a sand filtering layer arranged in sequence from top to bottom, the fiber filtering layer and the sand filtering layer are both located above the inner tube sieve slot area, and there is a gap between the fiber filtering layer and the sand filtering layer, and the micro lifting pump is arranged on the top surface of the fiber filtering layer; The air outlet of the air blowing pipe is located in the gap between the fiber filter layer and the sand filter layer. The inlet end of the air blowing pipe is connected to the gas storage device through a second gas pipeline. The second gas pipeline is provided with a second gas pump and a second gas control valve.

2. The groundwater tracking and detection system for contaminated land restoration according to claim 1 is characterized in that: The integrated injection unit comprises an injection well pipe located in the injection well, a sealing well cap is arranged on the top of the injection well pipe, and a well pipe screen seam area is arranged on the bottom of the injection well pipe; The outlet end of the water supply pipe passes through the sealing well cap and is inserted into the interior of the injection well pipe. The inlet end of the water supply pipe is connected to the water storage tank through a water injection pipeline. The water injection pipeline is provided with a water injection pump and a water injection control valve. The outlet end of the gas injection pipe passes through the sealing well cap and is inserted into the interior of the injection well pipe and is located below the groundwater level. The inlet end of the gas injection pipe is connected to the gas storage device through a gas transmission pipeline, and a first gas transmission pump and a first gas transmission control valve are provided on the gas transmission pipeline. The water supply pipe, air injection pipe and sealing well cap are all sealed.

3. The groundwater tracking and detection system for contaminated land restoration according to claim 1 is characterized in that: The pumping unit comprises a pumping well pipe located in the pumping well, a pipe cap is arranged on the top of the pumping well pipe, and a pumping well pipe sieve seam area is arranged on the lower part of the pumping well pipe; The water pumping pipe is inserted into the water pumping well pipe through the pipe cap, the water suction port of the water pumping pipe is located at the bottom of the water pumping well pipe, and the water suction port is U-shaped, the water outlet end of the water pumping pipe is connected to the water treatment equipment through the second water delivery pipeline, and the second water delivery pipeline is provided with a second water reduction pump and a second water delivery control valve; The air supply pipe passes through the pipe cap and is inserted into the pumping well pipe. The air outlet of the air supply pipe is located in the pumping well pipe and below the stable groundwater level. The air inlet end of the air supply pipe is connected to the gas storage equipment through the third gas pipeline. The third gas pipeline is provided with a third gas pump and a third gas control valve.

4. A method for automatically detecting groundwater using the groundwater tracking and detection system for remediation of contaminated land as described in any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Determine the pollution remediation area and plan the construction location of the groundwater tracking and detection system, and complete the construction of the groundwater tracking and detection system; S2. Open the groundwater detection unit on site separately, and use the micro lift pump to pump groundwater to the wellhead integrated detection equipment to obtain initial analysis data; S3. Intermittently inject compressed air into the integrated injection unit, and use the pumping unit to treat the underground sewage. After the groundwater flow field is formed, turn on the micro-lifting pump of the groundwater detection unit in the field to pump groundwater to the wellhead integrated detection equipment, and obtain real-time data through detection and analysis.

5. The automatic groundwater detection method according to claim 4, characterized in that: In step S3, the first air pump and the first air control valve connected to the integrated injection unit are turned on, and compressed air is intermittently injected into the injection well pipe through the air injection pipe. The second dewatering pump and the third air pump connected to the pumping unit are turned on simultaneously to pump the groundwater inside the pumping well pipe to the water treatment equipment, and the underground sewage is treated by the water treatment equipment.

6. The automatic groundwater detection method according to claim 4, characterized in that: In step S3, when the wellhead integrated detection device reports that the groundwater is abnormally turbid, the second air delivery pump and the second air delivery control valve connected to the groundwater detection unit on site are turned on, and compressed air is used to backwash the sand filter layer through the air blowing pipe; the first dewatering pump and the first water delivery control valve connected to the groundwater detection unit on site are turned on simultaneously, and the turbid groundwater is pumped to the water treatment equipment through the built-in pumping pipe of the groundwater detection unit on site to treat the turbid groundwater; When groundwater is scarce, turn on the water injection pump and water injection control valve connected to the integrated injection unit, and replenish the clean water in the water storage tank to the land through the water supply pipe to enhance the fluidity of groundwater.

7. A method for detecting the injection influence radius of an in-situ injection remediation process using the groundwater tracking and detection system for contaminated land remediation according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Select an area in the contaminated land where the soil layer has not been disturbed and level the surface; S2, constructing a comprehensive injection unit in the center of the leveled area obtained in step S1; S3. With the integrated injection unit as the center, build groundwater detection units on site at intervals of 1m, 2m, and 3m in the four positive directions of east, south, west, and north; S4. Inject specific reagents or color developers into the integrated injection unit, and analyze and determine the injection impact radius based on the detection results of the wellhead integrated detection equipment of the on-site groundwater detection unit.

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