A groundwater remediation system and method of remediation

Abstract

The present application belongs to the technical field of groundwater pollution remediation, and specifically discloses a groundwater remediation system and a remediation method. The remediation system comprises a pumping well, a circulation well and an injection well, the pumping well and the circulation well are connected by a first water pipe, and the circulation well and the injection well are connected by a second water pipe. The circulation well and the injection well each comprise an inner well pipe, an outer well pipe, an intermediate filler layer between the inner well pipe and the outer well pipe, and an outer filler layer surrounding the outer side wall of the outer well pipe. A first-stage single-well inner-outer double circulation system is formed in the circulation well and in the injection well, a second-stage groundwater circulation system is formed between the pumping well and the circulation well and between the circulation well and the injection well, and a third-stage groundwater circulation system of a groundwater pollution area is formed between the pumping well and the injection well along the groundwater flow direction. The present application has the advantages of high efficiency, high quality, low cost, flexibility, small engineering quantity, environmental protection and safety.

Description

Technical Field

[0001] This invention belongs to the field of groundwater pollution remediation technology, and particularly relates to a groundwater remediation system and remediation method. Background Technology

[0002] With the continuous development of human economic activities, groundwater pollution has become an increasingly prominent issue. In many countries and regions around the world, groundwater pollution has become one of the major environmental problems brought about by urbanization and industrialization. Due to factors such as the emission of harmful substances, garbage dumping, and oil spills caused by human activities such as industry and agriculture, groundwater has been severely polluted, threatening what should be clean and usable water sources.

[0003] Groundwater remediation technologies include ex-situ remediation and in-situ remediation. Ex-situ remediation, also known as remote recharge (P&T), involves extracting contaminated groundwater, treating it, and then transporting it to a location far from the site for further treatment. Specific operational steps typically include extracting contaminated groundwater, treating it in a treatment facility, and then injecting the treated water into a clean groundwater area. Ex-situ remediation can efficiently remove contaminants from groundwater and is suitable for contaminated sites where effective treatment is difficult to achieve, such as large-scale, especially deep or uncontrollable pollution sources.

[0004] In recent years, the application of electro-oxidation and photocatalysis technologies, in particular, has further improved the efficiency and effectiveness of ex-situ remediation. However, this process involves multiple steps, including extraction, transportation, treatment, and reinjection of groundwater, posing certain safety risks and the possibility of secondary pollution. In-situ groundwater treatment (IST), also known as groundwater remediation, is a technology that treats groundwater at the pollution source, placing the treatment process directly within the groundwater area. Therefore, it offers advantages such as not damaging the soil structure, high treatment efficiency, and low cost. Compared to ex-situ remediation, it requires less upstream and downstream control and is more commonly used in practice.

[0005] In-situ remediation technologies mainly include bioremediation, chemical remediation, and physical remediation. Bioremediation utilizes the interaction between microorganisms and the environment to weaken or remove pollutants from groundwater; it has a wide range of applications and is inexpensive. Chemical remediation alters the groundwater environment by introducing oxidizing and reducing agents and other anti-pollution materials, causing pollutants to transfer or transform; it is an important remediation method. Physical remediation is a groundwater remediation technology based on physical mechanisms. Its purpose is to control the migration and transfer of pollutants in groundwater by changing environmental parameters such as permeability, porosity, and media properties, thereby purifying the contaminated groundwater. Commonly used in-situ physical remediation technologies include activated carbon adsorption, groundwater interception trenches, and permeable barrier walls. For operating industrial enterprises, due to limitations imposed by production operations and surface buildings, in-situ remediation technologies are more suitable for controlling groundwater pollution risks.

[0006] Compared with ex-situ remediation technology, in-situ remediation technology has the following obvious advantages: (1) Wide range of applications: In-situ remediation technology can be applied to groundwater contaminants of different types, sizes and depths, thus its application is more extensive and flexible. (2) Reduced secondary pollution: In ex-situ remediation technology, the treated groundwater needs to be returned to the natural environment, which may cause secondary pollution. In-situ remediation technology does not require the groundwater to be pumped out and then returned, thus avoiding secondary pollution. (3) Simple operation and convenient maintenance: In-situ remediation technology usually involves setting up relatively few wells and pipelines, making its management and operation simpler and easier, and requiring relatively fewer operators. (4) Lower cost: Compared with ex-situ remediation technology, in-situ remediation technology requires simpler materials and equipment, thus effectively controlling treatment costs when using in-situ remediation technology.

[0007] Although existing groundwater treatment technologies have achieved certain results in pollutant removal, they still have the following shortcomings: (1) High treatment costs: Groundwater treatment requires a lot of resources such as electricity, materials and manpower, making it difficult to bear the high economic costs in practical applications. (2) Long treatment cycle: Groundwater is affected by factors such as soil environmental conditions, making it difficult to achieve complete removal or thorough degradation during the treatment process, requiring months or even years to achieve the expected treatment effect. (3) Byproduct generation: For certain pollutants, some treatment equipment may produce byproducts that affect or harm the environment, and attention should be paid to the subsequent disposal of byproducts during application. (4) High operational requirements: Traditional groundwater treatment technologies are complex to operate and easily affected by environmental factors. The requirements for process operation level, management level, safety skills, etc. are relatively strict, requiring the participation of professional personnel. (5) Difficulty in monitoring the water quality treatment effect: Due to the driving force in the treatment process, it is necessary to strictly control the entry of external pollution. In summary, although existing groundwater treatment technologies have achieved certain results, continuous exploration and innovation are still needed in terms of high efficiency, low cost, environmental protection, safety and coordination. Summary of the Invention

[0008] One objective of this invention is to provide a groundwater remediation system that effectively solves the problem that existing groundwater treatment technologies are not ideal in removing groundwater pollutants.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] A groundwater remediation system includes at least one pumping well, at least one circulation well located upstream of the pumping well, and at least one injection well located upstream of the circulation well. The pumping well and the circulation well are connected by a first water pipe, and the circulation well and the injection well are connected by a second water pipe.

[0011] Both the circulation well and the injection well include an inner well pipe, an outer well pipe, an intermediate packing layer located between the inner and outer well pipes, and an outer packing layer surrounding the outer wall of the outer well pipe.

[0012] A first-level single-well internal and external dual circulation system is formed in both the circulation well and the injection well. A second-level groundwater circulation system is formed between the pumping well and the circulation well, and between the circulation well and the injection well. A third-level groundwater circulation system is formed along the groundwater flow direction between the pumping well and the injection well, creating a groundwater pollution zone.

[0013] Furthermore, the well wall of the pumping well is divided into an impermeable pumping well wall located in the upper middle part and a permeable pumping well wall located in the lower part, and the permeable pumping well wall is provided with multiple permeable micropores.

[0014] Furthermore, the well wall of the circulation well is divided into an upper circulation well wall, a middle impermeable circulation well wall, and a lower permeable circulation well wall. The circulation well wall is further divided into a first upper impermeable well wall and a first lower permeable well wall. Both the first lower permeable well wall and the permeable circulation well wall are provided with multiple permeable micropores.

[0015] The top end of the inner well pipe of the circulation well is flush with the bottom end of the first lower permeable well wall, and the bottom end of the inner well pipe of the circulation well is flush with the top end of the permeable circulation well wall.

[0016] Furthermore, the well wall of the water injection well is divided into an upper water injection well wall, a middle impermeable water injection well wall, and a lower permeable water injection well wall. The well wall of the water injection well is further divided into a second upper impermeable well wall and a second lower permeable well wall. Both the second lower permeable well wall and the permeable water injection well wall are provided with multiple permeable micropores.

[0017] The top end of the inner well pipe of the water injection well is level with the bottom end of the second lower permeable well wall, and the bottom end of the inner well pipe of the water injection well is level with the top end of the permeable water injection well wall.

[0018] Furthermore, the top end of the outer packing layer of the circulation well is flush with the top end of the first lower permeable well wall, and the bottom end of the outer packing layer of the circulation well is flush with the bottom end of the permeable circulation well wall.

[0019] Furthermore, the top end of the outer packing layer of the injection well is flush with the top end of the second lower permeable well wall, and the bottom end of the outer packing layer of the injection well is flush with the bottom end of the permeable injection well wall.

[0020] Furthermore, one end of the first water pipe extends downward into the pumping well, and the other end of the first water pipe extends downward into the intermediate packing layer of the circulation well and passes through the bottom end of the intermediate packing layer of the circulation well before folding upward into the inner well pipe of the circulation well. On the first water pipe located above the well, a first filter, a first pumping pump, a first water storage tank, and a first dissolved air pump are connected in series in the opposite direction to the groundwater flow.

[0021] Furthermore, one end of the second water pipe passes downward through the intermediate packing layer of the circulation well and continues downward into the inner bottom of the outer well pipe of the circulation well; the other end of the second water pipe extends downward into the intermediate packing layer of the injection well and passes through the bottom end of the intermediate packing layer of the injection well before folding upward into the inner well pipe of the injection well. On the second water pipe located above the well, a second filter, a second water pump, a second water storage tank, and a second dissolved air pump are connected in series in the opposite direction to the groundwater flow.

[0022] Furthermore, the wellheads of the pumping well, the circulating well, and the injection well are all equipped with sealed well covers, and the sealed well covers are equipped with gas collection pipelines.

[0023] Furthermore, one end of the gas collection pipe on the sealing cover of the circulation well and one end of the gas collection pipe on the sealing cover of the water injection well both extend downward into the pumping well, and the gas collection pipe on the sealing cover of the pumping well is connected to the exhaust gas treatment device.

[0024] Another objective of this invention is to provide a groundwater remediation method that effectively solves the problem that existing groundwater treatment technologies are not ideal in removing groundwater pollutants.

[0025] A groundwater remediation method, applied to the groundwater remediation system described in the above embodiments, includes the following steps:

[0026] S1. The formation of the circulation loop between the pumping well and the circulation well, and the formation of the internal and external double circulation loops of the circulation well.

[0027] Water is pumped from the pumping well through the first water pipe using the first pumping pump. After passing through the first filter, the water enters the first water storage tank. The water from the first water storage tank is then compressed and dissolved into the water by the first dissolved air pump, and then sent into the inner well pipe of the circulation well through the first water pipe. The water flows out from the top of the inner well pipe of the circulation well. Part of the water flows downward along the middle packing layer of the circulation well, and the other part flows through the first lower permeable well wall to the outer packing layer of the circulation well. Then the water flows from top to bottom through the permeable circulation well wall and is sucked back into the circulation well by the negative pressure inside the circulation well.

[0028] S2, the formation of the circulation loop between the injection well and the circulation well, and the formation of the internal and external double circulation loops of the injection well.

[0029] Water is pumped from the circulation well through the second water pipe using the second pump. After passing through the second filter, the water enters the second water storage tank. The water from the second water storage tank is then compressed and dissolved into the water by the second dissolved air pump, and then sent into the inner well pipe of the injection well through the second water pipe. The water flows out from the top of the inner well pipe of the injection well. Part of the water flows downward along the middle packing layer of the injection well, and the other part flows through the second lower permeable well wall to the outer packing layer of the injection well. Then the water flows from top to bottom through the permeable injection well wall and is sucked back into the injection well by the negative pressure inside the injection well.

[0030] S3. The formation of a circulation loop between pumping wells and injection wells along the direction of groundwater flow.

[0031] Furthermore, the exhaust gas from the injection well and the circulation well is introduced into the groundwater in the pumping well, and the exhaust gas from the pumping well is transported to an exhaust gas treatment device for treatment before being discharged.

[0032] Compared with the prior art, the beneficial technical effects of the present invention are:

[0033] (1) High-efficiency purification: The groundwater remediation system of the present invention forms a three-stage circulation treatment system by setting up a pumping well, a circulation well, an injection well, and an inner and outer double pipe and a filling layer for the circulation well and the injection well. When the pollutants in the groundwater are treated in the three-stage circulation, they continuously flow through the filling layer and the soil layer and are purified through physical, chemical or biochemical processes.

[0034] (2) Flexible application: The groundwater remediation system and method provided by the present invention can flexibly change the type of filler in the filler layer and adjust the type of additives added to the well and the operation method according to the type of pollutants in the groundwater to achieve the treatment purpose, thereby adapting to different groundwater pollution situations.

[0035] (3) Small workload: This invention remediates groundwater in situ, eliminating the need to extract and treat the groundwater, thus reducing the workload, making the operation convenient, and effectively reducing treatment costs.

[0036] (4) Environmental protection and safety: Since the invention does not require the extraction and treatment of groundwater, it can avoid the generation of secondary pollution. At the same time, it does not require large-scale transportation and disposal of waste and pollutants, making it more environmentally friendly and safe.

[0037] (5) Long-lasting treatment effect: The present invention can treat groundwater pollution through a three-stage cycle treatment method and maintain a good long-lasting effect, thus providing an easy and effective solution for protecting groundwater resources.

[0038] In summary, this invention achieves purification by using a filler layer and a soil layer as treatment carriers to carry out three-stage recycling treatment of groundwater. It has significant advantages such as high efficiency, high quality, low cost, flexibility, small engineering workload, and environmental safety. Attached Figure Description

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0040] Figure 1 This is a schematic diagram of the groundwater remediation system of the present invention. In the diagram, the solid black arrows indicate the direction of water flow.

[0041] In the diagram: 1. Pumping well; 2. Circulation well; 3. Injection well; 4. Inner well casing; 5. Outer well casing; 6. Intermediate packing layer; 7. Outer packing layer; 8. Impermeable pumping well wall; 9. Permeable pumping well wall; 11. Impermeable circulation well wall; 12. Permeable circulation well wall; 13. First upper impermeable well wall; 14. First lower permeable well wall; 16. Impermeable injection well wall; 17. Permeable injection well wall; 18. Second upper impermeable well wall. 19. Second lower permeable well wall; 20. First water pipe; 21. First filter; 22. First water pump; 23. First water storage tank; 24. First dissolved air pump; 25. Second water pipe; 26. Second filter; 27. Second water pump; 28. Second water storage tank; 29. ​​Second dissolved air pump; 30. Sealed well cover; 31. Gas collection pipeline; 32. Exhaust gas treatment device; 33. First fan; 34. Second fan. Detailed Implementation

[0042] like Figure 1 As shown, a groundwater remediation system involves investigating a contaminated site, identifying the most severely polluted location within the area where groundwater is contaminated, setting up one or more pumping wells 1 near the location, setting up one or more circulation wells 2 upstream of the pumping wells 1 along the direction of groundwater flow, and setting up one or more injection wells 3 upstream of the circulation wells 2.

[0043] Both the circulation well 2 and the injection well 3 include an inner well pipe 4, an outer well pipe 5, an intermediate packing layer 6 located between the inner well pipe 4 and the outer well pipe 5, and an outer packing layer 7 tightly attached to the outer side wall of the outer well pipe 5.

[0044] The well wall of the pumping well 1 is divided into an impermeable pumping well wall 8 located in the upper middle part and a permeable pumping well wall 9 located in the lower part. The permeable pumping well wall 9 is provided with multiple permeable micropores.

[0045] The well wall of the circulation well 2 is divided into an upper circulation well wall, a middle impermeable circulation well wall 11, and a lower permeable circulation well wall 12. The circulation well wall is further divided into a first upper impermeable well wall 13 and a first lower permeable well wall 14. Both the first lower permeable well wall 14 and the permeable circulation well wall 12 are provided with multiple permeable micropores. The top end of the inner well pipe of the circulation well 2 is flush with the bottom end of the first lower permeable well wall 14, and the bottom end of the inner well pipe of the circulation well 2 is flush with the top end of the permeable circulation well wall 12.

[0046] The top of the outer packing layer of the circulation well 2 is approximately level with the top of the first lower permeable well wall 14, and the bottom of the outer packing layer of the circulation well 2 is approximately level with the bottom of the permeable circulation well wall 12.

[0047] The well wall of the water injection well 3 is divided into an upper water injection well wall, a middle impermeable water injection well wall 16, and a lower permeable water injection well wall 17. The water injection well wall is further divided into a second upper impermeable well wall 18 and a second lower permeable well wall 19. Both the second lower permeable well wall 19 and the permeable water injection well wall 17 are provided with multiple permeable micropores. The top end of the inner well pipe of the water injection well 3 is flush with the bottom end of the second lower permeable well wall 19, and the bottom end of the inner well pipe of the water injection well 3 is flush with the top end of the permeable water injection well wall 17.

[0048] The top of the outer filler layer of the water injection well 3 is approximately level with the top of the second lower permeable well wall 19, and the bottom of the outer filler layer of the water injection well 3 is approximately level with the bottom of the permeable water injection well wall 17.

[0049] The pumping well 1 and the circulation well 2 are connected by a first water pipe 20. One end of the first water pipe 20 extends downward into the pumping well 1 and is as close as possible to the bottom of the pumping well 1. The other end of the first water pipe 20 extends downward into the middle packing layer of the circulation well 2 and passes through the bottom end of the middle packing layer of the circulation well 2 before turning upward into the inner well pipe of the circulation well 2. On the part of the first water pipe 20 located above the well, a first filter 21, a first pumping pump 22, a first water storage tank 23 and a first dissolved air pump 24 are connected in series against the direction of groundwater flow.

[0050] The circulation well 2 and the injection well 3 are connected by a second water pipe 25. One end of the second water pipe 25 extends downward through the intermediate packing layer of the circulation well 2 and continues downward into the bottom of the outer well pipe of the circulation well 2. The other end of the second water pipe 25 extends downward into the intermediate packing layer of the injection well 3 and passes through the bottom end of the intermediate packing layer of the injection well 3 before folding upward into the inner well pipe of the injection well 3. A second filter 26, a second water pump 27, a second water storage tank 28, and a second dissolved air pump 29 are connected in series against the direction of groundwater flow on the upper part of the second water pipe 25. In this embodiment, the second water pipe 25 and the first water pipe 20 in the circulation well 2 are arranged opposite to each other.

[0051] Each of the pumping well 1, circulating well 2, and injection well 3 has a sealed well cover 30 at its opening, and a gas collection pipe 31 is provided on the sealed well cover 30. In some specific embodiments, one end of the gas collection pipe on the sealed well cover of the circulating well 2 and one end of the gas collection pipe on the sealed well cover of the injection well 3 both extend downward into the pumping well 1, and the gas collection pipe on the sealed well cover of the pumping well 1 is connected to the exhaust gas treatment device 32. In this embodiment, the gas collection pipe on the sealed well cover of the injection well 3 and the gas collection pipe on the sealed well cover of the circulating well 2 merge and together input the exhaust gas into the groundwater of the pumping well 1. A first fan 33 is provided on the merged gas collection pipe to improve the exhaust gas transportation efficiency. A second fan 34 is provided on the gas collection pipe on the sealed well cover of the pumping well 1. Under the action of the second fan 34, the exhaust gas in the pumping well 1 is collected and transported through the gas collection pipe on the sealed well cover of the pumping well 1 to the exhaust gas treatment device 32 for treatment before being discharged.

[0052] The groundwater remediation system provided by this invention adopts a three-stage groundwater circulation system, specifically including: (1) a first-stage single-well internal and external dual circulation system, namely, groundwater forming a single-well internal and external circulation in the circulation well 2 and the injection well 3. (2) a second-stage groundwater circulation system formed between the pumping well 1 and the circulation well 2, and between the circulation well 2 and the injection well 3. (3) a third-stage groundwater circulation system along the groundwater flow direction, forming a groundwater contaminated area between the pumping well 1 and the injection well 3.

[0053] The method for groundwater remediation using the groundwater remediation system of this embodiment specifically includes the following steps:

[0054] S1, the formation of the circulation loop between pumping well 1 and circulation well 2, and the formation of the inner and outer double circulation loops of circulation well 2.

[0055] Water is pumped from the pumping well 1 using the first water pump 22 through the first water pipe 20. After passing through the first filter 21, the water enters the first water storage tank 23. The water from the first water storage tank 23 is then pumped through the first dissolved air pump 24 to compress and dissolve air or other gases into the water. The dissolved air water is then sent to the bottom of the inner well pipe of the circulation well 2 through the first water pipe 20. The dissolved air water is injected upward into the inner well pipe of the circulation well 2. As the dissolved air water releases tiny bubbles and flows rapidly upward with the water flow, a negative pressure vacuum is formed at the bottom of the inner well pipe of the circulation well 2. This draws the water at the bottom of the circulation well 2 into the inner well pipe of the circulation well 2. With the help of the pressure difference between the inside and outside of the inner well pipe of the circulation well 2 and the density difference between the air and water fluids, the water at the bottom of the circulation well 2 flows rapidly upward along the inner well pipe of the circulation well 2 with the dissolved air water sprayed out by the first water pipe.

[0056] Water is ejected from the top of the inner well pipe of circulation well 2. Part of the water flows downwards along the middle packing layer of circulation well 2, while the other part flows through the first lower permeable well wall 14 to the outer packing layer of circulation well 2. Then, the water flows downwards through the permeable circulation well wall 12 and is drawn back into circulation well 2 by the negative pressure within it. After entering circulation well 2, the dissolved air water drives the well water to form a double circulation loop inside and outside circulation well 2. The contaminated groundwater is purified through physical, chemical, or biological processes as it continuously circulates through the packing layers inside and outside circulation well 2.

[0057] The dissolved gas pressure of the first dissolved gas pump 24 is 0.3-0.5 MPa.

[0058] The formation of the circulation loop between S2, injection well 3 and circulation well 2, and the formation of the inner and outer double circulation loops of injection well 3.

[0059] Water is pumped from the circulation well 2 using the second water pump 27 through the second water pipe 25. After passing through the second filter 26, the water enters the second water storage tank 28. The water from the second water storage tank 28 is then compressed and dissolved into the water by the second dissolved air pump 29, and then sent into the inner well pipe of the injection well 3 through the second water pipe 25. The dissolved air water is injected upward into the inner well pipe of the injection well 3. As the dissolved air water releases tiny bubbles and flows rapidly upward with the water flow, a negative pressure vacuum is formed at the bottom of the inner well pipe of the injection well 3, which draws the water at the bottom of the injection well 3 into the inner well pipe of the injection well 3. With the help of the pressure difference between the inside and outside of the inner well pipe of the injection well 3 and the density difference between the air and water fluids, the water at the bottom of the injection well 3 flows rapidly upward along the inner well pipe of the injection well 3 with the dissolved air water sprayed out by the second water pipe 25.

[0060] Water is ejected from the top of the inner well pipe of injection well 3. Part of the water flows downwards along the middle packing layer of injection well 3, while the other part flows through the second lower permeable well wall 19 to the outer packing layer of injection well 3. Then, the water flows downwards through the permeable injection well wall 17 and is drawn back into injection well 3 by the negative pressure inside. After entering injection well 3, the dissolved air water drives the well water to form a double circulation loop inside and outside injection well 3. The contaminated groundwater is purified through physical, chemical, or biological processes as it continuously circulates through the packing layers inside and outside injection well 3.

[0061] The dissolved gas pressure of the second dissolved gas pump 29 is 0.3-0.5 MPa.

[0062] S3. Formation of a circulation loop between pumping well 1 and injection well 3 along the direction of groundwater flow.

[0063] S4. The exhaust gas from the injection well 3 and the circulation well 2 is fed into the groundwater in the pumping well 1 through their respective gas collection pipelines. The exhaust gas from the pumping well 1 is then transported to the exhaust gas treatment device 32 for treatment before being discharged.

[0064] This invention employs a low-cost, efficient, safe, and convenient treatment method and system for in-situ remediation. Compared to existing technologies, it effectively shortens the treatment cycle, reduces treatment costs, and improves treatment efficiency. This invention can adapt to different types of groundwater pollution problems and can achieve optimal treatment results by flexibly changing the type of filler layer and operating methods, thus expanding its applicability. This invention involves setting up a pumping well 1, a circulation well 2, and an injection well 3, with filler layers installed inside and outside the circulation well 2 and the injection well 3. This allows the contaminated groundwater to undergo a three-stage circulation process, being treated by the physical, chemical, or biochemical processes of the filler layers and soil layers, thereby purifying the groundwater.

[0065] The present invention will be described in detail below through embodiments.

[0066] Example 1:

[0067] By investigating the contaminated site, within the area where groundwater is contaminated by diesel, the point with the most severe groundwater contamination is located within the contaminated area. One or more pumping wells are set up near the point, and one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow. One or more injection wells are set up upstream of the circulation wells.

[0068] The groundwater remediation system of the present invention is constructed using the construction method of the present invention.

[0069] In this embodiment, columnar activated carbon particles are used as the intermediate packing layer in the circulation well, and volcanic rock is used as the outer packing layer. Similarly, columnar activated carbon particles are used as the intermediate packing layer in the injection well, and volcanic rock is used as the outer packing layer in the circulation well. The relevant parameters of the columnar activated carbon particles are shown in Table 1, and the relevant parameters of the volcanic rock are shown in Table 2.

[0070] Table 1. Relevant parameters of columnar activated carbon particles.

[0071] Parameter Items Test data Parameter Items Test data iodine value 800-1200mg / g strength 90-95％ Specific surface area <![CDATA[850-1300m 2 / g]]> AFC Champions League Value 120-150mg / g Total pore volume <![CDATA[>0.8cm 3 / g]]> Formaldehyde adsorption rate 60-100％ Filling density <![CDATA[0.35-0.55g / cm 3 ]]> Specifications (diameter) 2-8mm

[0072] Table 2 Relevant parameters of volcanic rocks

[0073] Parameter Items Test data Parameter Items Test data Porosity 50-70％ aperture 3-5μm Specific surface area <![CDATA[50-200m 2 / g]]> density <![CDATA[1.8-2.0g / cm 3 ]]> Bulk density <![CDATA[0.8-1.4g / cm 3 ]]> Pickling rate >＝98％ Particle size 10-30mm compressive strength 60N

[0074] Water is pumped from the well through the first water pipe using the first water pump. After passing through the first filter, the water enters the first water storage tank. The water from the first water storage tank is then compressed and dissolved into the water by the first dissolved air pump. The dissolved air water is then sent to the bottom of the inner well pipe of the circulation well through the first water pipe. The dissolved air water is injected upward into the inner well pipe of the circulation well. As the dissolved air water releases tiny bubbles and flows rapidly upward with the water flow, a negative pressure vacuum is formed at the bottom of the inner well pipe of the circulation well. This draws the water at the bottom of the circulation well into the inner well pipe. With the help of the pressure difference between the inside and outside of the inner well pipe of the circulation well and the density difference between the air and water fluids, the water at the bottom of the circulation well flows rapidly upward along the inner well pipe of the circulation well with the dissolved air water injected by the first water pipe.

[0075] Water is ejected from the top of the inner well pipe of the circulation well. Part of the water flows downwards along the middle packing layer of the circulation well, while the other part flows through the first lower permeable well wall to the outer packing layer of the circulation well. Then, the water flows downwards through the permeable circulation well wall and is drawn back into the circulation well by the negative pressure within the well. After dissolved air water enters the circulation well, it oxygenates the well water and creates a double circulation loop inside and outside the well. The contaminated groundwater continuously circulates through the packing layers inside and outside the circulation well, adsorbing pollutants onto the packing layers. As the oxygenated groundwater continues to flow through the packing layers, various microorganisms gradually attach and grow on them. These microorganisms can rapidly respire and metabolize, forming a large microbial community. Through the degradation action of these microorganisms, the diesel fuel adsorbed on the packing layers and dispersed in the groundwater is broken down.

[0076] Water is pumped from the circulation well using a second water pump through a second water pipe extending near the bottom of the circulation well. After passing through a second filter, the water enters a second water storage tank. Water from the second water storage tank is then pumped through a second dissolved air pump to compress and dissolve air in the water before being sent into the inner well pipe of the injection well via the second water pipe. The dissolved air water is then injected upwards into the inner well pipe of the injection well. As the dissolved air water releases tiny bubbles that flow rapidly upwards with the water flow, a negative pressure vacuum is created at the bottom of the inner well pipe, drawing water from the bottom of the injection well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe and the density difference between the air and water fluids, the water at the bottom of the injection well flows rapidly upwards along the inner well pipe of the injection well with the dissolved air water ejected from the second water pipe.

[0077] Water is ejected from the top of the inner well pipe of the injection well. Part of the water flows downwards along the middle packing layer of the injection well, while the other part flows through the second lower permeable well wall to the outer packing layer. Then, the water flows downwards through the permeable injection well wall and is drawn back into the injection well by the negative pressure inside. After entering the injection well, the dissolved air water creates a double circulation loop inside and outside the well. As the contaminated groundwater continuously circulates through the packing layers inside and outside the injection well, pollutants are adsorbed onto the packing layers. With the continuous flow of oxygenated groundwater through the packing layers, various microorganisms gradually attach and grow on the packing layers. In an aerobic environment, these microorganisms can more quickly respire and metabolize, forming a large microbial community. Through the degradation action of these microorganisms, the diesel fuel adsorbed on the packing layers and dispersed in the groundwater is broken down.

[0078] During the three-stage circulation of groundwater within the contaminated area, the oxygenated groundwater circulates in the filler layers inside and outside the well and in the underground soil, promoting the growth of a large number of microorganisms in the filler and soil. The diesel fuel in the circulating groundwater is degraded by the microorganisms in the filler and soil, thereby achieving the effect of groundwater purification.

[0079] Example 2:

[0080] By investigating the contaminated site, within the area where groundwater is contaminated by benzene series compounds, the point with the most severe groundwater contamination is located within the contaminated area. One or more pumping wells are set up near the point, and one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow. One or more injection wells are set up upstream of the circulation wells.

[0081] The groundwater remediation system of the present invention is constructed using the construction method of the present invention.

[0082] In this embodiment, both the intermediate and outer packing layers of the circulation well use ozone catalyst particles as packing material. The ozone catalyst is activated carbon particles loaded with metal oxides such as titanium, zirconium, or manganese. The parameters of the activated carbon particles are shown in Table 3. The intermediate packing layer of the injection well uses columnar activated carbon particles as packing material. The relevant parameters of the columnar activated carbon particles are shown in Table 1. The outer packing layer of the injection well uses volcanic rock as packing material. The relevant parameters of the volcanic rock are shown in Table 2.

[0083] Table 3. Relevant parameters of activated carbon particles.

[0084]

[0085]

[0086] Water is pumped from the well through the first water pipe using the first water pump. After passing through the first filter, the water enters the first water storage tank. The water from the first water storage tank is then pumped through the first dissolved air pump to compress and dissolve ozone in the water. The dissolved air water is then sent to the bottom of the inner well pipe of the circulation well through the first water pipe. The dissolved air water is injected upward into the inner well pipe of the circulation well. As the dissolved air water releases tiny bubbles and flows rapidly upward with the water flow, a negative pressure vacuum is formed at the bottom of the inner well pipe of the circulation well. This draws the water at the bottom of the circulation well into the inner well pipe. With the help of the pressure difference between the inside and outside of the inner well pipe of the circulation well and the density difference between the air and water fluids, the water at the bottom of the circulation well flows rapidly upward along the inner well pipe of the circulation well with the dissolved air water injected from the first water pipe.

[0087] Water is ejected from the top of the inner well pipe of the circulation well. Part of the water flows downwards along the middle packing layer of the circulation well, while the other part flows through the first lower permeable well wall to the outer packing layer of the circulation well. Then, the water flows downwards through the permeable circulation well wall and is drawn back into the circulation well by the negative pressure within the well. After the dissolved air water enters the circulation well, the groundwater is loaded with ozone, creating a double circulation loop inside and outside the well. The contaminated groundwater continuously circulates through the catalyst packing layers inside and outside the well, adsorbing pollutants onto the packing layers. As the ozone-filled groundwater continues to flow through the catalyst packing layers, benzene compounds are oxidized and decomposed into small molecule organic matter, carbon dioxide, and water under the catalytic oxidation of ozone.

[0088] Water is pumped from the circulation well using a second water pump through a second water pipe extending near the bottom of the circulation well. After passing through a second filter, the water enters a second water storage tank. Water from the second water storage tank is then pumped through a second dissolved air pump to compress and dissolve air in the water before being sent into the inner well pipe of the injection well via the second water pipe. The dissolved air water is then injected upwards into the inner well pipe of the injection well. As the dissolved air water releases tiny bubbles that flow rapidly upwards with the water flow, a negative pressure vacuum is created at the bottom of the inner well pipe, drawing water from the bottom of the injection well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe and the density difference between the air and water fluids, the water at the bottom of the injection well flows rapidly upwards along the inner well pipe of the injection well with the dissolved air water ejected from the second water pipe.

[0089] Water is ejected from the top of the inner well pipe of the injection well. Part of the water flows downwards along the middle packing layer of the injection well, while the other part flows through the second lower permeable well wall to the outer packing layer. Then, the water flows downwards through the permeable injection well wall and is drawn back into the injection well by the negative pressure inside. After entering the injection well, dissolved air water forms a double circulation loop inside and outside the well. The contaminated groundwater continuously circulates through the packing layers inside and outside the well, adsorbing pollutants onto them. As the oxygenated groundwater continues to flow through the packing layers, various microorganisms gradually attach and grow on them. In an aerobic environment, these microorganisms can more quickly respire and metabolize, forming a large microbial community. Through the degradation action of these microorganisms, the remaining organic pollutants adsorbed on the packing layers and dispersed in the groundwater are degraded.

[0090] During the three-stage circulation of groundwater within the contaminated area, the groundwater contaminated with benzene compounds is first pre-treated through ozone catalytic oxidation, where the benzene compounds are oxidized and decomposed. The remaining organic pollutants in the groundwater are then removed through adsorption by packing material and degradation by microorganisms. Through repeated ozone catalytic oxidation and biodegradation, the groundwater is purified during the three-stage circulation process.

[0091] Example 3:

[0092] By investigating the contaminated site, within the area where groundwater is contaminated by polycyclic aromatic hydrocarbons, the point of most severe groundwater contamination is located within the contaminated area. One or more pumping wells are set up near the point of contamination, and one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow. One or more injection wells are set up upstream of the circulation wells.

[0093] The groundwater remediation system of the present invention is constructed using the construction method of the present invention.

[0094] In this embodiment, both the intermediate packing layer and the outer packing layer of the circulation well are made of iron-carbon packing, and the parameters of the iron-carbon packing are shown in Table 4.

[0095] Table 4. Relevant parameters of iron-carbon packing.

[0096]

[0097] Water is pumped from the well through the first water pipe using the first water pump. After passing through the first filter, the water enters the first water storage tank, where sodium percarbonate is added. Water from the first water storage tank is then pumped through the first dissolved air pump to compress and dissolve air in the water before being sent to the bottom of the inner well pipe of the circulation well through the first water pipe. The dissolved air water is then injected upwards into the inner well pipe of the circulation well. As the dissolved air water releases tiny bubbles and flows rapidly upwards with the water flow, a negative pressure vacuum is formed at the bottom of the inner well pipe of the circulation well, drawing the water from the bottom of the circulation well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe of the circulation well and the density difference between the air and water fluids, the water at the bottom of the circulation well flows rapidly upwards along the inner well pipe of the circulation well with the dissolved air water injected from the first water pipe.

[0098] Water is ejected from the top of the inner well pipe of the circulation well. Part of the water flows downward along the middle packing layer of the circulation well, while the other part flows through the first lower permeable well wall to the outer packing layer of the circulation well. Then, the water flows from top to bottom through the permeable circulation well wall and is drawn back into the circulation well by the negative pressure inside the circulation well.

[0099] After the dissolved air carrying sodium percarbonate enters the circulation well, it drives the well water to form a double circulation loop inside and outside the circulation well. The contaminated groundwater continuously circulates through the iron-carbon packing layer inside and outside the well. The polycyclic aromatic hydrocarbons in the groundwater are oxidized and decomposed into small molecule organic matter, carbon dioxide and water under the strong oxidizing action of a series of highly active free radicals generated by iron-carbon micro-electrolysis and iron-carbon activated sodium percarbonate.

[0100] Water is pumped from the circulation well using a second water pump through a second water pipe extending near the bottom of the circulation well. After passing through a second filter, the water enters a second water storage tank. Water from the second water storage tank is then pumped through a second dissolved air pump to compress and dissolve ozone in the water before being sent into the inner well pipe of the injection well via the second water pipe. The dissolved air water is then injected upwards into the inner well pipe of the injection well. As the dissolved air water releases tiny bubbles and flows rapidly upwards with the water flow, a negative pressure vacuum is created at the bottom of the inner well pipe, drawing water from the bottom of the injection well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe and the density difference between the air and water fluids, the water at the bottom of the injection well flows rapidly upwards along the inner well pipe of the injection well with the dissolved air water ejected from the second water pipe.

[0101] Water is ejected from the top of the inner well pipe of the injection well. Part of the water flows downwards along the middle packing layer of the injection well, while the other part flows through the second lower permeable well wall to the outer packing layer of the injection well. Then, the water flows downwards through the permeable injection well wall and is drawn back into the injection well by the negative pressure inside. After the dissolved air water enters the injection well, the groundwater is loaded with ozone, creating a double circulation loop inside and outside the well. The contaminated groundwater continuously circulates through the catalyst packing layers inside and outside the well, adsorbing pollutants onto the packing layers. As the ozone-filled groundwater continues to flow through the catalyst packing layers, the pollutants are oxidized and decomposed under the catalytic oxidation of ozone.

[0102] During the three-stage circulation of groundwater within the contaminated area, the groundwater contaminated with polycyclic aromatic hydrocarbons (PAHs) is first initially treated through the strong oxidizing effect of iron-carbon activated sodium percarbonate coupled with iron-carbon micro-electrolysis. The PAHs in the groundwater are initially decomposed. The remaining organic pollutants in the groundwater are then removed through adsorption by packing material and microbial degradation. Through repeated chemical oxidation, electrochemical decomposition, and biodegradation, the groundwater is purified during the three-stage circulation process.

[0103] Example 4:

[0104] By investigating the contaminated site, within the area where groundwater is contaminated by chlorinated hydrocarbons, the most severely contaminated point is located within the contaminated area. One or more pumping wells are set up near the point, and one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow. One or more injection wells are set up upstream of the circulation wells.

[0105] The groundwater remediation system of the present invention is constructed using the construction method of the present invention.

[0106] In this embodiment, both the intermediate and outer packing layers of the circulation well are made of ferrous sulfide particles, and the parameters of the ferrous sulfide particles are shown in Table 5. Both the intermediate and outer packing layers of the injection well are made of ozone catalyst particles, which are activated carbon particles loaded with metal oxides such as titanium, zirconium, or manganese. The parameters of the activated carbon particles are shown in Table 3.

[0107] Table 5. Relevant parameters of ferrous sulfide particles.

[0108]

[0109]

[0110] Water is pumped from the well through the first water pipe using the first water pump. After passing through the first filter, the water enters the first water storage tank, where potassium persulfate is added. Water from the first water storage tank is then pumped through the first dissolved air pump to compress and dissolve air in the water before being sent to the bottom of the inner well pipe of the circulation well through the first water pipe. The dissolved air water is then injected upwards into the inner well pipe of the circulation well. As the dissolved air water releases tiny bubbles and flows rapidly upwards with the water flow, a negative pressure vacuum is formed at the bottom of the inner well pipe of the circulation well, drawing water from the bottom of the circulation well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe of the circulation well and the density difference between the air and water fluids, the water at the bottom of the circulation well flows rapidly upwards along the inner well pipe of the circulation well with the dissolved air water injected from the first water pipe.

[0111] Water is ejected from the top of the inner well pipe of the circulation well. Part of the water flows downward along the middle packing layer of the circulation well, while the other part flows through the first lower permeable well wall to the outer packing layer of the circulation well. Then, the water flows from top to bottom through the permeable circulation well wall and is drawn back into the circulation well by the negative pressure inside the circulation well.

[0112] After dissolved air water enters the circulation well, it drives the well water to form a double circulation loop inside and outside the well. The contaminated groundwater continuously circulates through the ferrous sulfide packing layer inside and outside the well. Chlorinated hydrocarbons are adsorbed onto the packing layer. The ferrous sulfide activates potassium persulfate to generate highly oxidizing sulfate radicals and hydroxyl radicals, which oxidize and decompose the chlorinated hydrocarbons in the groundwater. Dissolved oxygen can promote the reaction between ferrous sulfide and potassium persulfate, making the reaction rate faster and increasing the number of free radicals generated. Secondly, dissolved oxygen also has an important influence on free radical reactions. Free radicals can react with oxygen to form oxidizing substances such as hydroxyl ions, improving the removal efficiency of chlorinated hydrocarbons.

[0113] Water is pumped from the circulation well using a second water pump through a second water pipe extending near the bottom of the circulation well. After passing through a second filter, the water enters a second water storage tank. Water from the second water storage tank is then pumped through a second dissolved air pump to compress and dissolve ozone in the water before being sent into the inner well pipe of the injection well via the second water pipe. The dissolved air water is then injected upwards into the inner well pipe of the injection well. As the dissolved air water releases tiny bubbles and flows rapidly upwards with the water flow, a negative pressure vacuum is created at the bottom of the inner well pipe, drawing water from the bottom of the injection well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe and the density difference between the air and water fluids, the water at the bottom of the injection well flows rapidly upwards along the inner well pipe of the injection well with the dissolved air water ejected from the second water pipe.

[0114] Water is ejected from the top of the inner well pipe of the injection well. Part of the water flows downwards along the middle packing layer of the injection well, while the other part flows through the second lower permeable well wall to the outer packing layer of the injection well. Then, the water flows downwards through the permeable injection well wall and is drawn back into the injection well by the negative pressure inside. After the dissolved air water enters the injection well, a double circulation loop is formed inside and outside the well. The groundwater, loaded with ozone, drives the well water to form a double circulation loop inside and outside the injection well. The contaminated groundwater continuously circulates through the catalyst packing layers inside and outside the well, and the pollutants are adsorbed onto the packing layers. As the ozone-filled groundwater continues to flow through the catalyst packing layers, the pollutants are oxidized and decomposed under the catalytic oxidation of ozone.

[0115] During the three-stage circulation of groundwater within the contaminated area, the groundwater contaminated with chlorinated hydrocarbons is first adsorbed onto the packing layer and preliminarily treated by the oxidation of potassium persulfate activated by ferrous sulfide. The remaining organic pollutants in the groundwater are then removed by ozone catalytic oxidation. Through repeated adsorption and advanced oxidation, the groundwater contaminated with chlorinated hydrocarbons is purified during the three-stage circulation process.

[0116] Example 5:

[0117] By investigating the contaminated site, in the area where groundwater is contaminated by iron, manganese and ammonia nitrogen, find the point of most severe groundwater contamination within the contaminated area, set up one or more pumping wells near it, set up one or more circulation wells upstream of the pumping wells along the direction of groundwater flow, and set up one or more injection wells upstream of the circulation wells.

[0118] The groundwater remediation system of the present invention is constructed using the construction method of the present invention.

[0119] In this embodiment, both the intermediate and outer packing layers of the circulating well are made of strip-shaped ZSM-5 zeolite packing, and the parameters of the strip-shaped ZSM-5 zeolite packing are shown in Table 6. Both the intermediate and outer packing layers of the injection well are made of columnar activated carbon particles, and the parameters of the columnar activated carbon particles are shown in Table 1.

[0120] Table 6 shows the relevant parameters of strip-shaped ZSM-5 zeolite packing.

[0121] Parameter Items Test data Parameter Items Test data Silicon-to-aluminum ratio 35 diameter 2-3mm Crystallinity 95％ length 5-10mm Specific surface area <![CDATA[300-360m 2 / g]]> compressive strength Greater than 150N aperture 0.3-0.58nm / /

[0122] Water is pumped from the well through the first water pipe using the first water pump. After passing through the first filter, the water enters the first water storage tank, where potassium persulfate is added. Water from the first water storage tank is then pumped through the first dissolved air pump to compress and dissolve air in the water before being sent to the bottom of the inner well pipe of the circulation well through the first water pipe. The dissolved air water is then injected upwards into the inner well pipe of the circulation well. As the dissolved air water releases tiny bubbles and flows rapidly upwards with the water flow, a negative pressure vacuum is formed at the bottom of the inner well pipe of the circulation well, drawing water from the bottom of the circulation well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe of the circulation well and the density difference between the air and water fluids, the water at the bottom of the circulation well flows rapidly upwards along the inner well pipe of the circulation well with the dissolved air water injected from the first water pipe.

[0123] Water is ejected from the top of the inner well pipe of the circulation well. Part of the water flows downward along the middle packing layer of the circulation well, while the other part flows through the first lower permeable well wall to the outer packing layer of the circulation well. Then, the water flows from top to bottom through the permeable circulation well wall and is drawn back into the circulation well by the negative pressure inside the circulation well.

[0124] After dissolved air water enters the circulation well, it drives the well water to form a double circulation loop inside and outside the well. The contaminated groundwater continuously circulates through the zeolite packing layer inside and outside the well. The micropores of ZSM-5 zeolite can adsorb ferrous and manganese ions and prevent them from further dissolving into the water. Oxygen in the groundwater comes into contact with the ferrous and manganese ions in the water to produce an oxidation reaction, generating water-insoluble Fe(OH)3 and MnO2, which are removed from the groundwater. The crystal defect sites of ZSM-5 zeolite have high acidic active sites. In the presence of ammonia in the water, it can undergo selective adsorption and ion exchange reactions, adsorbing ammonia nitrogen in the water onto its surface, effectively improving the ammonia nitrogen removal efficiency. In an oxygen-loaded groundwater environment, it can accelerate the process of aerobic microbial transformation and removal of ammonia nitrogen.

[0125] Water is pumped from the circulation well using a second water pump through a second water pipe extending near the bottom of the circulation well. After passing through a second filter, the water enters a second water storage tank. Water from the second water storage tank is then pumped through a second dissolved air pump to compress and dissolve air in the water before being sent into the inner well pipe of the injection well via the second water pipe. The dissolved air water is then injected upwards into the inner well pipe of the injection well. As the dissolved air water releases tiny bubbles that flow rapidly upwards with the water flow, a negative pressure vacuum is created at the bottom of the inner well pipe, drawing water from the bottom of the injection well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe and the density difference between the air and water fluids, the water at the bottom of the injection well flows rapidly upwards along the inner well pipe of the injection well with the dissolved air water ejected from the second water pipe.

[0126] Water is ejected from the top of the inner well pipe of the injection well. Part of the water flows downwards along the middle packing layer of the injection well, while the other part flows through the second lower permeable well wall to the outer packing layer of the injection well. Then, the water flows downwards through the permeable injection well wall and is drawn back into the injection well by the negative pressure inside. After the dissolved air water enters the injection well, a double circulation loop is formed inside and outside the well. The surface of the activated carbon particles has numerous adsorption sites that can adsorb iron and manganese ions. As the oxygen-laden groundwater flows through the activated carbon packing layer, the oxygen in the groundwater reacts with the iron and manganese ions in the water, producing insoluble Fe(OH)3 and MnO2, which are removed from the groundwater. Simultaneously, in the presence of ammonia in the water, the activated carbon particles can undergo selective adsorption, adsorbing ammonia nitrogen on their surface, effectively removing ammonia nitrogen. In an oxygen-laden groundwater environment, this accelerates the aerobic microbial process of removing ammonia nitrogen.

[0127] During the three-stage circulation of groundwater within the contaminated area, the groundwater contaminated with iron, manganese, and ammonia nitrogen is first initially removed by adsorption and oxidation from ZSM-5 zeolite, and then further removed by adsorption and oxidation from activated carbon. Through repeated adsorption, oxidation, and microbial action, the groundwater contaminated with iron, manganese, and ammonia nitrogen is purified during the three-stage circulation process.

[0128] Example 6

[0129] By investigating the contaminated site, within the area where groundwater is contaminated with thiocyanate, the point of most severe groundwater contamination is located within the contaminated area. One or more pumping wells are set up near the point of contamination, and one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow. One or more injection wells are set up upstream of the circulation wells.

[0130] The groundwater remediation system of the present invention is constructed using the construction method of the present invention.

[0131] In this embodiment, both the intermediate and outer packing layers of the circulation well are made of copper-loaded spherical molecular sieves, and the relevant parameters of the spherical molecular sieves are shown in Table 7. Both the intermediate and outer packing layers of the injection well are made of copper-loaded columnar activated carbon particles, and the parameters of the columnar activated carbon particles are shown in Table 1.

[0132] Table 7. Relevant parameters of spherical molecular sieves.

[0133]

[0134]

[0135] Water is pumped from the well through the first water pipe using the first water pump. After passing through the first filter, the water enters the first water storage tank, where potassium persulfate is added. Water from the first water storage tank is then pumped through the first dissolved air pump to compress and dissolve oxygen in the water before being sent to the bottom of the inner well pipe of the circulation well through the first water pipe. The dissolved air water is injected upwards into the inner well pipe of the circulation well. As the dissolved air water releases tiny bubbles and flows rapidly upwards with the water flow, a negative pressure vacuum is formed at the bottom of the inner well pipe of the circulation well, drawing the water from the bottom of the circulation well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe of the circulation well and the density difference between the air and water fluids, the water at the bottom of the circulation well flows rapidly upwards along the inner well pipe of the circulation well with the dissolved air water injected from the first water pipe.

[0136] Water is ejected from the top of the inner well pipe of the circulation well. Part of the water flows downward along the middle packing layer of the circulation well, while the other part flows through the first lower permeable well wall to the outer packing layer of the circulation well. Then, the water flows from top to bottom through the permeable circulation well wall and is drawn back into the circulation well by the negative pressure inside the circulation well.

[0137] After dissolved air water enters the circulation well, it drives the well water to form a double circulation loop inside and outside the well. The contaminated groundwater continuously circulates through the zeolite packing layer inside and outside the well. The micropores of ZSM-5 zeolite can adsorb thiocyanate ions and prevent them from further dissolving into the water. Under the action of copper-containing active sites on the zeolite surface, oxygen molecules are excited into free radicals. At the same time, thiocyanate ions react with the free radicals and are oxidized into harmless substances such as CO2, H2O, and N2. The copper ions in the catalytic process can repeatedly undergo redox cycles, thereby accelerating the reaction.

[0138] Water is pumped from the circulation well using a second water pump through a second water pipe extending near the bottom of the circulation well. After passing through a second filter, the water enters a second water storage tank. Water from the second water storage tank is then pumped through a second dissolved air pump to compress and dissolve oxygen in the water before being sent into the inner well pipe of the injection well via the second water pipe. The dissolved air water is injected upwards into the inner well pipe of the injection well. As the dissolved air water releases tiny bubbles and flows rapidly upwards with the water flow, a negative pressure vacuum is created at the bottom of the inner well pipe, drawing water from the bottom of the injection well into the inner well pipe. Utilizing the pressure difference between the inside and outside of the inner well pipe and the density difference between the air and water fluids, the water at the bottom of the injection well flows rapidly upwards along the inner well pipe of the injection well with the dissolved air water ejected from the second water pipe.

[0139] Water is ejected from the top of the inner well pipe of the injection well. Part of the water flows downward along the middle packing layer of the injection well, while the other part flows through the second lower permeable well wall to the outer packing layer of the injection well. Then, the water flows from top to bottom through the permeable injection well wall and is drawn back into the injection well by the negative pressure inside the injection well.

[0140] After dissolved air water enters the injection well, a dual circulation loop is formed inside and outside the well. The surface of the activated carbon particles has numerous adsorption sites that can adsorb thiocyanate ions. As the oxygen-loaded groundwater flows through the activated carbon packing layer, oxygen molecules are excited into free radicals by the copper-containing active sites on the activated carbon surface. Simultaneously, thiocyanate ions react with these free radicals and are oxidized into harmless substances such as CO2, H2O, and N2. The copper ions in this catalytic process can repeatedly undergo redox cycles, thereby accelerating the reaction.

[0141] In the process of three-stage circulation within the contaminated area, groundwater contaminated with thiocyanate is first initially removed by adsorption and catalytic oxidation of copper-loaded ZSM-5 zeolite, and then further removed by adsorption and catalytic oxidation of copper-loaded activated carbon. Through repeated adsorption and catalytic oxidation, the groundwater contaminated with thiocyanate is purified in the three-stage circulation process.

[0142] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A groundwater remediation system, characterized in that, It includes at least one pumping well, at least one circulation well located upstream of the pumping well, and at least one injection well located upstream of the circulation well. The pumping well and the circulation well are connected by a first water pipe, and the circulation well and the injection well are connected by a second water pipe. Both the circulation well and the injection well include an inner well pipe, an outer well pipe, an intermediate packing layer located between the inner well pipe and the outer well pipe, and an outer packing layer surrounding the outer wall of the outer well pipe. A first-level single-well internal and external dual circulation system is formed in both the circulation well and the injection well. A second-level groundwater circulation system is formed between the pumping well and the circulation well, as well as between the circulation well and the injection well. A third-level groundwater circulation system is formed between the pumping well and the injection well along the groundwater flow direction, creating a groundwater pollution zone. The well wall of the pumping well is divided into an impermeable pumping well wall located in the upper middle part and a permeable pumping well wall located in the lower part. The permeable pumping well wall is provided with multiple permeable micropores. The well wall of the circulation well is divided into an upper circulation well wall, a middle impermeable circulation well wall, and a lower permeable circulation well wall. The well wall of the circulation well is further divided into a first upper impermeable well wall and a first lower permeable well wall. Both the first lower permeable well wall and the permeable circulation well wall are provided with multiple permeable micropores. The top end of the inner well pipe of the circulation well is flush with the bottom end of the first lower permeable well wall, and the bottom end of the inner well pipe of the circulation well is flush with the top end of the permeable circulation well wall. The well wall of the water injection well is divided into an upper water injection well wall, a middle impermeable water injection well wall, and a lower permeable water injection well wall. The well wall of the water injection well is further divided into a second upper impermeable well wall and a second lower permeable well wall. Both the second lower permeable well wall and the permeable water injection well wall are provided with multiple permeable micropores. The top end of the inner well pipe of the water injection well is flush with the bottom end of the second lower permeable well wall, and the bottom end of the inner well pipe of the water injection well is flush with the top end of the permeable water injection well wall. The top of the outer packing layer of the circulation well is flush with the top of the first lower permeable well wall, and the bottom of the outer packing layer of the circulation well is flush with the bottom of the permeable circulation well wall. The top of the outer filler layer of the injection well is flush with the top of the second lower permeable well wall, and the bottom of the outer filler layer of the injection well is flush with the bottom of the permeable injection well wall. One end of the first water pipe extends downward into the pumping well, and the other end of the first water pipe extends downward into the middle packing layer of the circulation well and passes through the bottom end of the middle packing layer of the circulation well before turning upward into the inner well pipe of the circulation well. The first water pipe located above the well is connected in series with a first filter, a first pumping pump, a first water storage tank and a first dissolved air pump in the opposite direction of groundwater flow. One end of the second water pipe passes downward through the intermediate packing layer of the circulation well and continues downward into the bottom of the outer well pipe of the circulation well; the other end of the second water pipe extends downward into the intermediate packing layer of the injection well and passes through the bottom end of the intermediate packing layer of the injection well before turning upward into the inner well pipe of the injection well. On the second water pipe located above the well, a second filter, a second water pump, a second water storage tank and a second dissolved air pump are connected in series against the direction of groundwater flow. The wellheads of the pumping well, circulating well, and injection well are all equipped with sealed well covers, and gas collection pipelines are installed on the sealed well covers; One end of the gas collection pipe on the sealing cover of the circulating well and one end of the gas collection pipe on the sealing cover of the water injection well both extend downward into the pumping well. The gas collection pipe on the sealing cover of the pumping well is connected to the exhaust gas treatment device.

2. A groundwater remediation method, characterized in that, The groundwater remediation system described in claim 1 includes the following steps: S1. The formation of the circulation loop between the pumping well and the circulation well, and the formation of the internal and external double circulation loops of the circulation well; Water is pumped from the pumping well through the first water pipe using the first pumping pump. After passing through the first filter, the water enters the first water storage tank. The water from the first water storage tank is compressed and dissolved into the water by the first dissolved air pump, and then sent into the inner well pipe of the circulation well through the first water pipe. The water flows out from the top of the inner well pipe of the circulation well. Part of the water flows down along the middle packing layer of the circulation well, and the other part flows through the first lower permeable well wall to the outer packing layer of the circulation well. Then the water flows from top to bottom through the permeable circulation well wall and is sucked back into the circulation well by the negative pressure inside the circulation well. S2, the formation of the circulation loop between the injection well and the circulation well, and the formation of the internal and external double circulation loops of the injection well; Water is pumped from the circulation well through the second water pipe using the second water pump. After passing through the second filter, the water enters the second water storage tank. The water from the second water storage tank is then compressed and dissolved into the water by the second dissolved air pump, and then sent into the inner well pipe of the injection well through the second water pipe. The water flows out from the top of the inner well pipe of the injection well. Part of the water flows downward along the middle packing layer of the injection well, and the other part flows through the second lower permeable well wall to the outer packing layer of the injection well. Then the water flows from top to bottom through the permeable injection well wall and is sucked back into the injection well by the negative pressure inside the injection well. S3. The formation of a circulation loop between pumping wells and injection wells along the direction of groundwater flow.

3. The groundwater remediation method according to claim 2, characterized in that, The exhaust gas from the injection well and circulation well is introduced into the groundwater in the pumping well, and the exhaust gas from the pumping well is transported to an exhaust gas treatment device for treatment before being discharged.

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