Underground water remediation system and remediation method

Abstract

The invention belongs to the technical field of groundwater pollution remediation, and particularly discloses a groundwater remediation system and method. The repairing system comprises a pumping well, a circulating well and a water injection well, the pumping well and the circulating well are connected through a first water pipe, and the circulating well and the water injection well are connected through a second water pipe. The circulating well and the water injection well each comprise an inner well pipe, an outer well pipe, a middle packing layer located between the inner well pipe and the outer well pipe and an outer packing layer surrounding the outer side wall of the outer well pipe by a circle. First-stage single-well internal and external dual-circulation systems are formed in the circulation well and the water injection well, second-stage underground water circulation systems are formed between the pumping well and the circulation well and between the circulation well and the water injection well, and a third-stage underground water circulation system of an underground water polluted area is formed between the pumping well and the water injection well in the flowing direction of underground water. The method has the remarkable advantages of high efficiency, high quality, low cost, flexibility, applicability, small work amount, environmental protection, safety and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of groundwater pollution remediation, and in particular relates to a groundwater remediation system and a remediation method. Background Art

[0002] With the continuous development of human economic activities, groundwater pollution has attracted more and more attention. In many countries and regions around the world, groundwater pollution has become one of the main environmental problems caused by urbanization and industrialization. Due to the emission of harmful substances, garbage dumping, oil leakage and other factors caused by human activities such as industry and agriculture, groundwater has been seriously polluted, threatening the water source that should have been clean and available for use.

[0003] Groundwater remediation technologies include ex situ remediation technology and in situ remediation technology. Among them, ex situ remediation technology, also known as remote recharge (P&T), is a technology that extracts contaminated groundwater from underground and transports it to a place far away from the site for treatment and disposal after treatment. The specific operating steps usually include extracting contaminated groundwater, treating it in a treatment facility, and injecting purified water into a clean groundwater area after treatment. Ex situ remediation technology can efficiently remove pollutants from groundwater and is suitable for some contaminated sites that are difficult to effectively treat, such as large-scale, especially deep or uncontrollable pollution sources.

[0004] In recent years, the efficiency and treatment effect of ex situ remediation technology have been further improved, especially with the application of electro-oxidation technology and photocatalytic technology. In this process, groundwater needs to go through multiple steps such as extraction, transportation, treatment and re-injection, which involves certain safety risks and the possibility of secondary pollution. The in situ treatment technology of groundwater, also known as in situ remediation (IST), is a technology that treats the pollution source on site. It carries out the treatment process directly within the groundwater range. Therefore, it has the advantages of not destroying the soil structure, high treatment efficiency and low cost. Compared with ex situ remediation technology, it requires less upstream and downstream control and is more commonly used in practice.

[0005] The main methods of in-situ remediation technology include bioremediation, chemical remediation and physical remediation. Bioremediation uses the interaction between microorganisms and the environment to weaken or remove groundwater pollutants. It has a wide range of applications and low cost. Chemical remediation can change the groundwater environment by injecting redox agents and other anti-pollution materials to cause pollutants to transfer or transform. It is one of the important remediation methods. Physical remediation technology is a groundwater remediation technology based on physical mechanisms to repair pollution. Its purpose is to control the migration and transfer process of groundwater pollutants by changing environmental parameters such as permeability, porosity, medium properties, etc., so that the contaminated groundwater can be purified. Commonly used in-situ physical remediation technologies include activated carbon adsorption, groundwater interception ditches and permeable interception walls. For in-service industrial enterprises, due to the limitations of production operations and ground buildings, in-situ remediation technology is more suitable for the prevention and control of 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 used for groundwater pollutants of different types, sizes and depths, so its application range is wider and more flexible. (2) Can reduce 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 need to pump out the groundwater and then return it, 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 easier and requiring relatively fewer operators. (4) Lower cost: Compared with ex situ remediation technology, the materials and equipment required for in situ remediation technology are simpler, so the cost of governance can be effectively controlled 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, and it is difficult to bear the high economic costs in practical applications. (2) Long treatment cycle: Groundwater is affected by factors such as soil environmental conditions, and it is difficult to completely remove or completely degrade it during the treatment process. It takes months or even years to achieve the expected treatment effect. (3) By-product generation: For some pollutants, some treatment equipment may produce by-products that affect or harm the environment. When using them, attention should be paid to the subsequent disposal of by-products. (4) High operating requirements: Traditional groundwater treatment technology is complex to operate and is easily affected by environmental factors. The process operation level, management level, safety skills and other requirements are relatively strict, and professional personnel are required to participate. (5) It is difficult to monitor the water quality treatment effect: Due to the driving force during the treatment process, strict control is required to prevent external pollution from entering. In summary, although existing groundwater treatment technology has achieved certain achievements, it still needs to continue to explore and innovate in terms of high efficiency, low cost, environmental protection, safety and coordination. Summary of the invention

[0008] One object of the present invention is to provide a groundwater remediation system to effectively solve the problem that existing groundwater treatment technologies are not ideal for removing groundwater pollutants.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0010] A groundwater repair system comprises 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, wherein the pumping well and the circulation well are connected via a first water pipe, and the circulation well and the injection well are connected via a second water pipe.

[0011] The circulation well and the water injection well both include an inner well pipe, an outer well pipe, an intermediate filling layer located between the inner well pipe and the outer well pipe, and an outer filling layer surrounding the outer side wall of the outer well pipe.

[0012] A first-level single-well inside-outside double circulation system is formed in the circulation well and in 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, and a third-level groundwater circulation system is formed in the groundwater contaminated area between the pumping well and the injection well along the groundwater flow.

[0013] Furthermore, the well wall of the pumping well is divided into an impermeable well wall located in the middle and upper part and a permeable well wall located in the lower part, and a plurality of permeable micropores are arranged on the permeable well wall.

[0014] Furthermore, the well wall of the circulation well is divided into a circulation well wall located at the upper part, a watertight circulation well wall located in the middle part and a water-permeable circulation well wall located at the lower part, and the well wall of the circulation well is divided into a first upper watertight well wall and a first lower water-permeable well wall, and the first lower water-permeable well wall and the water-permeable circulation well wall are both provided with a plurality of water-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 injection well wall located at the upper part, an impermeable injection well wall located in the middle part and a permeable injection well wall located at the lower part, and the injection well wall is divided into a second upper impermeable well wall and a second lower permeable well wall, and the second lower permeable well wall and the permeable injection well wall are both provided with a plurality of permeable micropores.

[0017] 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 well wall of the water injection well.

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

[0019] Furthermore, the top of the external filling layer of the water injection well is flush with the top of the second lower permeable well wall, and the bottom of the external filling layer of the water injection well is flush with the bottom of the permeable water 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 middle filler layer of the circulation well and passes through the bottom end of the middle filler layer of the circulation well and then folds 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 sequence against the flow direction of groundwater.

[0021] Furthermore, one end of the second water pipe extends downward through the middle filler layer of the circulation well and then continues to extend 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 middle filler layer of the injection well and passes through the bottom end of the middle filler layer of the injection well and then folds upward into the inner well pipe of the injection well. A second filter, a second water pump, a second water storage tank and a second air dissolved pump are connected in series in sequence on the second water pipe located above the well in the direction of groundwater flow.

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

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

[0024] Another object of the present invention is to provide a groundwater remediation method to effectively solve the problem that existing groundwater treatment technologies are not ideal for removing groundwater pollutants.

[0025] A groundwater remediation method, applied to the groundwater remediation system as described in the above embodiment, comprises the following steps:

[0026] S1. Formation of a circulation loop between the pumping well and the circulation well, and formation of an internal and external double circulation loop of the circulation well.

[0027] A first pump is used to pump water from the pumping well through the first water pipe, and the water enters the first water storage tank after passing through the first filter. The water output from the first water storage tank is compressed and dissolved in water by the first dissolved air pump with air or other gas, and then sent to 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, and part of the water flows downward along the middle packing layer of the circulation well, and the other part of the water 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 re-enters the circulation well under the suction effect of the negative pressure in the circulation well.

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

[0029] A second pump is used to pump water from the circulation well through a second water pipe, and the water enters the second water storage tank after passing through a second filter. The water output from the second water storage tank is compressed and dissolved in water by a second dissolved air pump with air or other gas, and then sent to the inner well pipe of the injection well through the second water pipe. Water flows out from the top of the inner well pipe of the injection well, with part of the water flowing downward along the middle packing layer of the injection well, and the other part of the water 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 re-enters the injection well under the suction effect of the negative pressure in the injection well.

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

[0031] Furthermore, the tail gas from the injection well and the circulation well is introduced into the groundwater in the pumping well, and the tail gas from the pumping well is transported to the tail gas treatment device for treatment and then 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 inner and outer double pipes and a filler layer of the circulation well and the injection well. When the present invention performs three-stage circulation treatment on pollutants in groundwater, the pollutants continuously flow through the filler layer and the soil layer, and can be efficiently purified after physical, chemical or biochemical reactions.

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

[0035] (3) Small amount of work: The present invention repairs groundwater in situ without the need to extract the groundwater for treatment, which reduces the amount of work, is easy to operate, and can effectively reduce treatment costs.

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

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

[0038] In summary, the present invention achieves the purpose of purification by performing three-stage circulation treatment of groundwater using the filler layer and the soil layer as treatment carriers, and has significant advantages such as high efficiency, high quality, low cost, flexible applicability, small engineering workload, environmental protection and safety. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] Figure 1 Schematic diagram of the structure of the groundwater remediation system of the present invention, in which the black solid arrow indicates the direction of water flow.

[0041] In the figure: 1, pumping well; 2, circulation well; 3, injection well; 4, inner well pipe; 5, outer well pipe; 6, middle 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 Permeable 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. Tail gas treatment device; 33. First fan; 34. Second fan. DETAILED DESCRIPTION

[0042] like Figure 1 As shown, a groundwater remediation system is provided. By investigating the contaminated site, the most seriously polluted point is found in the groundwater contaminated area, one or more pumping wells 1 are set near the point, one or more circulation wells 2 are set upstream of the pumping well 1 along the groundwater flow direction, and one or more injection wells 3 are set upstream of the circulation well 2.

[0043] The circulation well 2 and the water injection well 3 both include an inner well pipe 4, an outer well pipe 5, an intermediate filler layer 6 located between the inner well pipe 4 and the outer well pipe 5, and an outer filler layer 7 tightly surrounding the outer side wall of the outer well pipe 5.

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

[0045] The well wall of the circulation well 2 is divided into a circulation well wall located at the upper part, a watertight circulation well wall 11 located in the middle part, and a watertight circulation well wall 12 located at the lower part. The circulation well wall is divided into a first upper watertight well wall 13 and a first lower watertight well wall 14. A plurality of watertight micropores are provided on the first lower watertight well wall 14 and the watertight circulation well wall 12. The top end of the inner well pipe of the circulation well 2 is flush with the bottom end of the first lower watertight 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 watertight circulation well wall 12.

[0046] The top of the outer packing layer of the circulation well 2 is roughly 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 roughly level with the bottom of the permeable circulation well wall 12 .

[0047] The well wall of the water injection well 3 is divided into a well wall of the water injection well located at the upper part, a water-impermeable well wall 16 of the water injection well located in the middle part, and a water-permeable well wall 17 of the water injection well located at the lower part. The well wall of the water injection well is divided into a second upper water-impermeable well wall 18 and a second lower water-permeable well wall 19. A plurality of water-permeable micropores are provided on the second lower water-permeable well wall 19 and the water-permeable well wall 17 of the water injection well. The top end of the inner well pipe of the water injection well 3 is flush with the bottom end of the second lower water-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 water-permeable well wall 17 of the water injection well.

[0048] The top of the outer filling layer of the injection well 3 is roughly level with the top of the second lower permeable well wall 19 , and the bottom of the outer filling layer of the injection well 3 is roughly level with the bottom of the permeable 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 as close to the bottom of the pumping well 1 as possible, and 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 of the middle packing layer of the circulation well 2 and then folds upward into the inner well pipe of the circulation well 2. On the first water pipe 20 located at the upper part of 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 in sequence against the flow direction of groundwater.

[0050] The circulation well 2 and the water injection well 3 are connected by a second water pipe 25. One end of the second water pipe 25 passes downward through the middle packing layer of the circulation well 2 and then continues to extend downward into the inner bottom of the outer well pipe of the circulation well 2. The other end of the second water pipe 25 extends downward into the middle packing layer of the water injection well 3 and passes through the bottom end of the middle packing layer of the water injection well 3 and then folds upward into the inner well pipe of the water injection well 3. The second filter 26, the second water pump 27, the second water storage tank 28 and the second dissolved air pump 29 are connected in series in sequence on the second water pipe 25 located in the upper part of the well in the reverse direction of the groundwater flow. 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] The wellheads of the pumping well 1, the circulation well 2 and the injection well 3 are all provided with a sealed manhole cover 30, and a gas collection pipeline 31 is provided on the sealed manhole cover 30. In some specific embodiments, one end of the gas collection pipeline on the sealed manhole cover of the circulation well 2 and one end of the gas collection pipeline on the sealed manhole cover of the injection well 3 both extend downward into the pumping well 1, and the gas collection pipeline on the sealed manhole cover of the pumping well 1 is connected to the tail gas treatment device 32. In this embodiment, the gas collection pipeline on the sealed manhole cover of the injection well 3 merges with the gas collection pipeline on the sealed manhole cover of the circulation well 2 to input the tail gas into the groundwater of the pumping well 1 together, and a first fan 33 is provided on the merged gas collection pipeline to improve the tail gas transportation efficiency. A second fan 34 is provided on the gas collection pipeline on the sealed manhole cover of the pumping well 1. Under the action of the second fan 34, the tail gas in the pumping well 1 is collected and transported to the tail gas treatment device 32 through the gas collection pipeline on the sealed manhole cover of the pumping well 1 for treatment and discharge.

[0052] The groundwater remediation system provided by the present invention adopts a three-level groundwater circulation system, specifically including: (1) a first-level single-well internal and external dual circulation system, that is, a single-well internal and external circulation formed by groundwater in the circulation well 2 and in the injection well 3. (2) A second-level 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-level groundwater circulation system formed along the groundwater flow to the 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 a circulation loop between the pumping well 1 and the circulation well 2 and the formation of an internal and external double circulation loop of the circulation well 2.

[0055] A first water pump 22 is used to pump water from the pumping well 1 through the first water pipe 20, and then enters the first water storage tank 23 after passing through the first filter 21. The water discharged from the first water storage tank 23 is compressed and dissolved in water by the first dissolved air pump 24, and then sent to the bottom of the inner well pipe of the circulation well 2 through the first water pipe 20, and the dissolved air water is injected upward into the inner well pipe of the circulation well 2. While 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, and the water at the bottom of the circulation well 2 is sucked into the inside of the inner well pipe of the circulation well 2. With the help of the internal and external pressure difference of the inner well pipe of the circulation well 2 and the density difference of the gas and water fluids, the water at the bottom of the circulation well 2 flows rapidly upward along the inside of the inner well pipe of the circulation well 2 along with the dissolved air water injected by the first water pipe.

[0056] Water flows out from the top of the inner well pipe of the circulation well 2, part of which flows downward along the middle packing layer of the circulation well 2, and the other part of the water flows to the outer packing layer of the circulation well 2 through the first lower permeable well wall 14, and then the water flows from top to bottom through the permeable circulation well wall 12 and re-enters the circulation well 2 under the suction effect of the negative pressure in the circulation well 2. After the dissolved air water enters the circulation well 2, it drives the well water to form a double circulation loop inside and outside the circulation well 2, and the contaminated groundwater is purified after physical, chemical or biological effects in the process of continuous circulation through the packing layers inside and outside the circulation well 2.

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

[0058] S2, the formation of a circulation loop between the water injection well 3 and the circulation well 2 and the formation of an internal and external double circulation loop of the water injection well 3.

[0059] A second pumping pump 27 is used to pump water from the circulation well 2 through the second water pipe 25, and the water enters the second water storage tank 28 after passing through the second filter 26. The water discharged from the second water storage tank 28 is compressed and dissolved in water by the second dissolved air pump 29, and then sent to the inner well pipe of the water injection well 3 through the second water pipe 25, and the dissolved air water is injected upward into the inner well pipe of the water injection well 3. While 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 water injection well 3, and the water at the bottom of the water injection well 3 is sucked into the inside of the inner well pipe of the water injection well 3. With the help of the internal and external pressure difference of the inner well pipe of the water injection well 3 and the density difference of the gas and water fluids, the water at the bottom of the water injection well 3 flows rapidly upward along the inside of the inner well pipe of the water injection well 3 along with the dissolved air water injected from the second water pipe 25.

[0060] Water flows out from the top of the inner well pipe of the injection well 3, part of which flows downward along the middle packing layer of the injection well 3, and the other part of the water flows to the outer packing layer of the injection well 3 through the second lower permeable well wall 19, and then the water flows from top to bottom through the permeable injection well wall 17 and re-enters the injection well 3 under the suction effect of the negative pressure in the injection well 3. After the dissolved air water enters the injection well 3, it drives the well water to form a double circulation loop inside and outside the injection well 3, and the contaminated groundwater is purified after physical, chemical or biological action in the process of continuous circulation through the packing layers inside and outside the injection well 3.

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

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

[0063] S4, the tail gas from the injection well 3 and the circulation well 2 is introduced into the groundwater in the pumping well 1 through their respective gas collecting pipelines, and the tail gas from the pumping well 1 is transported to the tail gas treatment device 32 through the gas collecting pipeline of the pumping well for treatment and then discharged.

[0064] The present invention adopts a low-cost, efficient, safe and convenient treatment method and system for in-situ remediation. Compared with the prior art, the treatment cycle is effectively shortened, the treatment cost is reduced, and the treatment efficiency is improved. The present invention can adapt to different types of groundwater pollution problems, and can achieve the best treatment effect by flexibly changing the type of packing layer and the operation method, thereby improving the scope of application. The present invention sets a pumping well 1, a circulation well 2 and an injection well 3, and sets a packing layer inside and outside the circulation well 2 and the injection well 3, so that the contaminated groundwater is circulated in three stages and treated by physical, chemical or biochemical effects of the packing layer and the soil layer, so as to achieve the purpose of purifying the groundwater.

[0065] The present invention is described in detail below by way of examples.

[0066] Embodiment 1:

[0067] By investigating the contaminated site, in the area where the groundwater is contaminated by diesel, find the point where the groundwater is most seriously polluted within the pollution range, 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.

[0068] The groundwater remediation system of the present invention is used for setting.

[0069] In this embodiment, the middle filler layer of the circulation well uses columnar activated carbon particles as filler, and the outer filler layer of the circulation well uses volcanic rock as filler. The middle filler layer of the water injection well uses columnar activated carbon particles as filler, and the outer filler layer of the circulation well uses volcanic rock as filler. 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 Item Test Data Parameter Item Test Data Iodine value 800-1200mg / g strength 90-95％ Specific surface area <![CDATA[850-1300m 2 / g]]> Methylene blue 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 Related parameters of volcanic rocks

[0073] Parameter Item Test Data Parameter Item 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] A first water pump is used to pump water from a pumping well through a first water pipe, and the water enters a first water storage tank after passing through a first filter. The water output from the first water storage tank is compressed and dissolved in water by a first dissolved air pump, and then sent to the bottom of an inner well pipe of a circulation well through the first water pipe, and the dissolved air water is ejected upward into the inner well pipe of the circulation well. While 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, and the water at the bottom of the circulation well is sucked into the interior of the inner well pipe of the circulation well. 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 gas and water fluids, the water at the bottom of the circulation well flows rapidly upward along the inside of the inner well pipe of the circulation well along with the dissolved air water ejected from the first water pipe.

[0075] Water flows out from the top of the inner well pipe of the circulation well, part of which flows downward along the middle packing layer of the circulation well, and the other part of the water flows through the first lower permeable well wall to the outer packing layer of the circulation well, and then the water flows from top to bottom through the permeable circulation well wall and re-enters the circulation well under the suction effect of the negative pressure in the circulation well. After the dissolved air water enters the circulation well, it oxygenates the well water and drives the well water to form a double circulation loop inside and outside the circulation well. The polluted groundwater continuously circulates through the packing layers inside and outside the circulation well, and the pollutants are adsorbed on the packing layers. As the oxygenated groundwater continuously flows through the packing layers, a variety of microorganisms gradually attach and grow on the packing layers. The microorganisms in the packing can perform respiratory metabolism faster and form a large number of microbial communities. The diesel adsorbed on the packing layer and dispersed in the groundwater are degraded by the degradation action of the microorganisms.

[0076] A second water pump is used to pump water from the circulation well through a second water pipe that penetrates deep into the bottom of the circulation well, and then enters the second water storage tank after passing through a second filter. The water discharged from the second water storage tank is compressed and dissolved in water by a second dissolved air pump, and then sent to the inner well pipe of the water injection well through the second water pipe, and the dissolved air water is injected upward into the inner well pipe of the water injection well. While 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 water injection well, and the water at the bottom of the water injection well is sucked into the inside of the inner well pipe of the water injection well. With the help of the internal and external pressure difference of the inner well pipe of the water injection well and the density difference of the gas and water fluids, the water at the bottom of the water injection well flows rapidly upward along the inside of the inner well pipe of the water injection well along with the dissolved air water injected from the second water pipe.

[0077] Water flows out from the top of the inner well pipe of the injection well, part of which flows downward along the middle packing layer of the injection well, and the other part of the water flows through the second lower permeable well wall to the outer packing layer of the injection well, and then the water flows from top to bottom through the permeable injection well wall and re-enters the injection well under the suction effect of the negative pressure in the injection well. After the dissolved air water enters the injection well, it drives the well water to form a double circulation loop inside and outside the injection well. During the continuous circulation of the contaminated groundwater through the packing layer inside and outside the injection well, the pollutants are adsorbed on the packing layer. As the oxygenated groundwater continuously flows through the packing layer, a variety of microorganisms gradually attach and grow on the packing layer. In an aerobic environment, the microorganisms in the packing can perform respiratory metabolism faster and form a large number of microbial communities. The diesel adsorbed on the packing layer and dispersed in the groundwater are degraded by the degradation action of the microorganisms.

[0078] During the tertiary circulation of groundwater in 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 in the circulating groundwater is degraded by the microorganisms in the filler and soil, thereby achieving the effect of groundwater purification.

[0079] Embodiment 2:

[0080] By investigating the contaminated sites, in the area where the groundwater is contaminated by benzene, the points with the most serious groundwater pollution are found within the pollution range, one or more pumping wells are set up near the points, one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow, and one or more injection wells are set up upstream of the circulation wells.

[0081] The groundwater remediation system of the present invention is used for setting.

[0082] In this embodiment, ozone catalyst particles are used as fillers in both the middle and outer filler layers of the circulation well. 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 middle filler layer of the water injection well uses columnar activated carbon particles as fillers. The relevant parameters of the columnar activated carbon particles are shown in Table 1. The outer filler layer of the water injection well uses volcanic rock as filler. The relevant parameters of the volcanic rock are shown in Table 2.

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

[0084]

[0085]

[0086] A first pumping pump is used to pump water from a pumping well through a first water pipe, and the water enters a first water storage tank after passing through a first filter. The water from the first water storage tank is compressed and dissolved in water by a first dissolved air pump, and then sent to the bottom of an inner well pipe of a circulation well through the first water pipe, and the dissolved air water is ejected upward into the inner well pipe of the circulation well. While 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, and the water at the bottom of the circulation well is sucked into the inside of the inner well pipe of the circulation well. 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 gas and water fluids, the water at the bottom of the circulation well flows rapidly upward along the inside of the inner well pipe of the circulation well along with the dissolved air water ejected from the first water pipe.

[0087] Water flows out from the top of the inner well pipe of the circulation well, part of which flows downward along the middle packing layer of the circulation well, and the other part of the water flows through the first lower permeable well wall to the outer packing layer of the circulation well, and then the water flows from top to bottom through the permeable circulation well wall and re-enters the circulation well under the suction effect of the negative pressure in the circulation well. After the dissolved air water enters the circulation well, the groundwater carries ozone and drives the well water to form a double circulation loop inside and outside the circulation well. The contaminated groundwater continuously circulates through the catalyst packing layer inside and outside the well, and the pollutants are adsorbed on the packing layer. As the groundwater filled with ozone continuously flows through the catalyst packing layer, the benzene series is oxidized and decomposed into small molecular organic matter, carbon dioxide and water under the catalytic oxidation of ozone.

[0088] A second water pump is used to pump water from the circulation well through a second water pipe that penetrates deep into the bottom of the circulation well, and then enters the second water storage tank after passing through a second filter. The water discharged from the second water storage tank is compressed and dissolved in water by a second dissolved air pump, and then sent to the inner well pipe of the water injection well through the second water pipe, and the dissolved air water is injected upward into the inner well pipe of the water injection well. While 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 water injection well, and the water at the bottom of the water injection well is sucked into the inside of the inner well pipe of the water injection well. With the help of the internal and external pressure difference of the inner well pipe of the water injection well and the density difference of the gas and water fluids, the water at the bottom of the water injection well flows rapidly upward along the inside of the inner well pipe of the water injection well along with the dissolved air water injected from the second water pipe.

[0089] Water flows out from the top of the inner well pipe of the injection well, part of which flows downward along the middle packing layer of the injection well, and the other part flows to the outer packing layer of the injection well through the second lower permeable well wall, and then the water flows from top to bottom through the permeable injection well wall and re-enters the injection well under the suction effect of the negative pressure in the injection well. After the dissolved air water enters the injection well, a double circulation loop is formed inside and outside the well. The contaminated groundwater continuously circulates through the packing layer inside and outside the well, and the pollutants are adsorbed on the packing layer. As the oxygenated groundwater continuously flows through the packing layer, a variety of microorganisms gradually attach and grow on the packing layer. In an aerobic environment, the microorganisms in the packing can perform respiratory metabolism faster and form a large number of microbial communities. The remaining organic pollutants adsorbed on the packing layer and dispersed in the groundwater are degraded by the degradation action of microorganisms.

[0090] During the tertiary circulation of groundwater in the polluted area, the groundwater contaminated by benzene is first treated through ozone catalytic oxidation, and the benzene in the groundwater is oxidized and decomposed. The remaining organic pollutants in the groundwater are then removed through filler adsorption and microbial degradation. Through repeated ozone catalytic oxidation and biodegradation, the groundwater is purified during the tertiary circulation process.

[0091] Embodiment 3:

[0092] By investigating the contaminated sites, in the area where the groundwater is contaminated by PAHs, the points with the most serious groundwater pollution are found within the pollution range, one or more pumping wells are set up near the points, one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow, and one or more injection wells are set up upstream of the circulation wells.

[0093] The groundwater remediation system of the present invention is used for setting.

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

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

[0096]

[0097] A first pumping pump is used to pump water from a pumping well through a first water pipe, and the water enters a first water storage tank after passing through a first filter. Sodium percarbonate is added to the first water storage tank. The water discharged from the first water storage tank is compressed and dissolved in water by a first dissolved air pump, and then sent to the bottom of an inner well pipe of a circulation well through the first water pipe. The dissolved air water is ejected upward into the inner well pipe of the circulation well. While 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, and the water at the bottom of the circulation well is sucked into the interior of the inner well pipe of the circulation well. 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 gas and water fluids, the water at the bottom of the circulation well flows rapidly upward along the inside of the inner well pipe of the circulation well along with the dissolved air water ejected from the first water pipe.

[0098] Water flows out from the top of the inner well pipe of the circulation well, part of which flows downward along the middle filler layer of the circulation well, and the other part of the water flows through the first lower permeable well wall to the outer filler layer of the circulation well. Then the water flows from top to bottom through the permeable circulation well wall and re-enters the circulation well under the suction effect of the negative pressure in the circulation well.

[0099] After the dissolved air water 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 filler layer inside and outside the well. The polycyclic aromatic hydrocarbons in the groundwater are oxidized and decomposed into small molecular organic matter, carbon dioxide and water under the strong oxidizing action of a series of highly active oxidative free radicals produced by iron-carbon micro-electrolysis and iron-carbon activation of sodium percarbonate.

[0100] A second pump is used to pump water from the circulation well through a second water pipe that penetrates into the bottom of the circulation well, and then enters the second water storage tank after passing through a second filter. The water discharged from the second water storage tank is compressed and dissolved in water by a second dissolved air pump, and then sent to the inner well pipe of the injection well through the second water pipe, and the dissolved air water is injected upward into the inner well pipe of the injection well. While 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, and the water at the bottom of the injection well is sucked into the inside of the inner well pipe of the injection well. With the help of the internal and external pressure difference of the inner well pipe of the injection well and the density difference of the gas and water fluids, the water at the bottom of the injection well flows rapidly upward along the inside of the inner well pipe of the injection well along with the dissolved air water injected from the second water pipe.

[0101] Water flows out from the top of the inner well pipe of the injection well, part of which flows downward along the middle packing layer of the injection well, and the other part flows to the outer packing layer of the injection well through the second lower permeable well wall, and then the water flows from top to bottom through the permeable injection well wall and re-enters the injection well under the suction effect of the negative pressure in the injection well. After the dissolved air water enters the injection well, the groundwater is loaded with ozone and 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 layer inside and outside the well, and the pollutants are adsorbed on the packing layer. As the groundwater filled with ozone continuously flows through the catalyst packing layer, the pollutants are oxidized and decomposed under the catalytic oxidation of ozone.

[0102] During the tertiary circulation of groundwater in the contaminated area, the groundwater contaminated by PAHs is first treated through the strong oxidation of iron-carbon micro-electrolysis coupled with iron-carbon activated sodium percarbonate, and the PAHs in the groundwater are preliminarily decomposed. The remaining organic pollutants in the groundwater are then removed through filler adsorption and microbial degradation. Through repeated chemical oxidation, electrochemical decomposition and biodegradation, the groundwater is purified during the tertiary circulation process.

[0103] Embodiment 4:

[0104] By investigating the contaminated sites, in the area where the groundwater is contaminated by chlorinated hydrocarbons, the points with the most serious groundwater pollution are found within the pollution range, one or more pumping wells are set up near the points, one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow, and one or more injection wells are set up upstream of the circulation wells.

[0105] The groundwater remediation system of the present invention is used for setting.

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

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

[0108]

[0109]

[0110] A first water pump is used to pump water from a pumping well through a first water pipe, and the water enters a first water storage tank after passing through a first filter. Potassium persulfate is added to the first water storage tank. The water discharged from the first water storage tank is compressed and dissolved in water by a first dissolved air pump, and then sent to the bottom of an inner well pipe of a circulation well through the first water pipe. The dissolved air water is ejected upward into the inner well pipe of the circulation well. While 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, and the water at the bottom of the circulation well is sucked into the inside of the inner well pipe of the circulation well. 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 gas and water fluids, the water at the bottom of the circulation well flows rapidly upward along the inside of the inner well pipe of the circulation well along with the dissolved air water ejected from the first water pipe.

[0111] Water flows out from the top of the inner well pipe of the circulation well, part of which flows downward along the middle filler layer of the circulation well, and the other part of the water flows through the first lower permeable well wall to the outer filler layer of the circulation well. Then the water flows from top to bottom through the permeable circulation well wall and re-enters the circulation well under the suction effect of the negative pressure in the circulation well.

[0112] After the dissolved air water 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 ferrous sulfide filler layer inside and outside the well. Chlorinated hydrocarbons are adsorbed on the filler layer. Ferrous sulfide activates potassium persulfate to produce highly oxidizing sulfate radicals and hydroxyl radicals to oxidize and decompose the chlorinated hydrocarbons in the groundwater. Dissolved oxygen can promote the reaction of 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, thereby improving the removal effect of chlorinated hydrocarbons.

[0113] A second pump is used to pump water from the circulation well through a second water pipe that penetrates into the bottom of the circulation well, and then enters the second water storage tank after passing through a second filter. The water discharged from the second water storage tank is compressed and dissolved in water by a second dissolved air pump, and then sent to the inner well pipe of the injection well through the second water pipe, and the dissolved air water is injected upward into the inner well pipe of the injection well. While 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, and the water at the bottom of the injection well is sucked into the inside of the inner well pipe of the injection well. With the help of the internal and external pressure difference of the inner well pipe of the injection well and the density difference of the gas and water fluids, the water at the bottom of the injection well flows rapidly upward along the inside of the inner well pipe of the injection well along with the dissolved air water injected from the second water pipe.

[0114] Water flows out from the top of the inner well pipe of the injection well, part of which flows downward along the middle packing layer of the injection well, and the other part flows to the outer packing layer of the injection well through the second lower permeable well wall, and then the water flows from top to bottom through the permeable injection well wall and re-enters the injection well under the suction effect of the negative pressure in the injection well. After the dissolved air water enters the injection well, a double circulation loop is formed inside and outside the well. The groundwater carries ozone and 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 layer inside and outside the well, and the pollutants are adsorbed on the packing layer. As the groundwater filled with ozone continuously flows through the catalyst packing layer, the pollutants are oxidized and decomposed under the catalytic oxidation of ozone.

[0115] During the tertiary circulation of groundwater in the contaminated area, the groundwater contaminated by chlorinated hydrocarbons is first adsorbed on 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. The groundwater contaminated by chlorinated hydrocarbons is purified through repeated adsorption and advanced oxidation during the tertiary circulation process.

[0116] Embodiment 5:

[0117] By investigating the contaminated sites, in the area where the groundwater is contaminated by iron, manganese and ammonia nitrogen, the points with the most serious groundwater pollution are found within the pollution range, one or more pumping wells are set up near them, one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow, and one or more injection wells are set up upstream of the circulation wells.

[0118] The groundwater remediation system of the present invention is used for setting.

[0119] In this embodiment, the middle packing layer and the outer packing layer of the circulation well are both made of strip ZSM-5 zeolite packing, and the parameters of the strip ZSM-5 zeolite packing are shown in Table 6. The middle packing layer and the outer packing layer of the water injection well are both made of columnar activated carbon particles, and the parameters of the columnar activated carbon particles are shown in Table 1.

[0120] Table 6 Relevant parameters of strip ZSM-5 zeolite filler.

[0121] Parameter Item Test Data Parameter Item 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 More than 150N Aperture 0.3-0.58nm / /

[0122] A first water pump is used to pump water from a pumping well through a first water pipe, and the water enters a first water storage tank after passing through a first filter. Potassium persulfate is added to the first water storage tank. The water discharged from the first water storage tank is compressed and dissolved in water by a first dissolved air pump, and then sent to the bottom of an inner well pipe of a circulation well through the first water pipe. The dissolved air water is ejected upward into the inner well pipe of the circulation well. While 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, and the water at the bottom of the circulation well is sucked into the inside of the inner well pipe of the circulation well. 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 gas and water fluids, the water at the bottom of the circulation well flows rapidly upward along the inside of the inner well pipe of the circulation well along with the dissolved air water ejected from the first water pipe.

[0123] Water flows out from the top of the inner well pipe of the circulation well, part of which flows downward along the middle filler layer of the circulation well, and the other part of the water flows through the first lower permeable well wall to the outer filler layer of the circulation well. Then the water flows from top to bottom through the permeable circulation well wall and re-enters the circulation well under the suction effect of the negative pressure in the circulation well.

[0124] After the dissolved air water 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 zeolite packing layer inside and outside the well. The micropores of ZSM-5 zeolite can adsorb divalent iron and divalent manganese ions and prevent them from further dissolving into the water. The oxygen in the groundwater contacts the iron and manganese ions in the water to produce an oxidation reaction, generating Fe(OH)3 and MnO2 that are difficult to dissolve in water and are removed from the groundwater. The crystal defect sites of ZSM-5 zeolite have higher acidic active sites. In the presence of ammonia in water, it can undergo selective adsorption and ion exchange reactions, adsorbing ammonia nitrogen in the water on its surface, effectively improving the removal efficiency of ammonia nitrogen. In the groundwater environment loaded with oxygen, it can accelerate the process of aerobic microbial transformation and removal of ammonia nitrogen.

[0125] A second water pump is used to pump water from the circulation well through a second water pipe that penetrates deep into the bottom of the circulation well, and then enters the second water storage tank after passing through a second filter. The water discharged from the second water storage tank is compressed and dissolved in water by a second dissolved air pump, and then sent to the inner well pipe of the water injection well through the second water pipe, and the dissolved air water is injected upward into the inner well pipe of the water injection well. While 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 water injection well, and the water at the bottom of the water injection well is sucked into the inside of the inner well pipe of the water injection well. With the help of the internal and external pressure difference of the inner well pipe of the water injection well and the density difference of the gas and water fluids, the water at the bottom of the water injection well flows rapidly upward along the inside of the inner well pipe of the water injection well along with the dissolved air water injected from the second water pipe.

[0126] Water flows out from the top of the inner well pipe of the injection well, part of which flows downward along the middle packing layer of the injection well, and the other part flows to the outer packing layer of the injection well through the second lower permeable well wall, and then the water flows from top to bottom through the permeable injection well wall and re-enters the injection well under the suction effect of the negative pressure in the injection well. After the dissolved air water enters the injection well, a double circulation loop is formed inside and outside the well. There are a large number of adsorption sites on the surface of the activated carbon particles, which can adsorb iron and manganese ions. In the process of oxygen-loaded groundwater flowing through the activated carbon packing layer, the oxygen in the groundwater contacts the iron and manganese ions in the water to produce an oxidation reaction, generating Fe(OH)3 and MnO2 that are insoluble in water and removed from the groundwater; at the same time, in the presence of ammonia in water, the activated carbon particles can undergo a selective adsorption reaction, adsorbing ammonia nitrogen in the water on their surface, effectively removing ammonia nitrogen, and in the oxygen-loaded groundwater environment, it can accelerate the process of aerobic microbial transformation and removal of ammonia nitrogen.

[0127] During the tertiary circulation of groundwater in the polluted area, the groundwater contaminated by iron, manganese and ammonia nitrogen is first removed by adsorption and oxidation by ZSM-5 zeolite, and then further removed by adsorption and oxidation by activated carbon. The groundwater contaminated by iron, manganese and ammonia nitrogen is purified through repeated adsorption, oxidation and microbial action during the tertiary circulation process.

[0128] Example 6

[0129] By investigating the contaminated sites, in the area where the groundwater is contaminated by thiocyanate, the points with the most serious groundwater pollution are found within the pollution range, one or more pumping wells are set up near them, one or more circulation wells are set up upstream of the pumping wells along the direction of groundwater flow, and one or more injection wells are set up upstream of the circulation wells.

[0130] The groundwater remediation system of the present invention is used for setting.

[0131] In this embodiment, the middle packing layer and the outer packing layer of the circulation well are both made of copper-loaded spherical molecular sieves, and the relevant parameters of the spherical molecular sieves are shown in Table 7. The middle packing layer and the outer packing layer of the water injection well are both 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] A first water pump is used to pump water from a pumping well through a first water pipe, and the water enters a first water storage tank after passing through a first filter. Potassium persulfate is added to the first water storage tank. The water discharged from the first water storage tank is compressed and dissolved in water by a first dissolved air pump, and then sent to the bottom of an inner well pipe of a circulation well through the first water pipe. The dissolved air water is ejected upward into the inner well pipe of the circulation well. While 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, and the water at the bottom of the circulation well is sucked into the inside of the inner well pipe of the circulation well. 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 gas and water fluids, the water at the bottom of the circulation well flows rapidly upward along the inside of the inner well pipe of the circulation well along with the dissolved air water ejected from the first water pipe.

[0136] Water flows out from the top of the inner well pipe of the circulation well, part of which flows downward along the middle filler layer of the circulation well, and the other part of the water flows through the first lower permeable well wall to the outer filler layer of the circulation well. Then the water flows from top to bottom through the permeable circulation well wall and re-enters the circulation well under the suction effect of the negative pressure in the circulation well.

[0137] After the dissolved gas water 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 zeolite packing layer inside and outside the well. The micropores of ZSM-5 zeolite can adsorb thiocyanate and prevent them from further dissolving into the water. Under the action of the copper-containing active sites on the surface of the zeolite, oxygen molecules are excited into free radicals, and at the same time, thiocyanate ions react with 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] A second water pump is used to pump water from the circulation well through a second water pipe that penetrates deep into the bottom of the circulation well, and then enters the second water storage tank after passing through a second filter. The water discharged from the second water storage tank is compressed and dissolved in oxygen in the water by a second dissolved air pump, and then sent to the inner well pipe of the injection well through the second water pipe, and the dissolved air water is injected upward into the inner well pipe of the injection well. While 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, and the water at the bottom of the injection well is sucked into the inside of the inner well pipe of the injection well. With the help of the internal and external pressure difference of the inner well pipe of the injection well and the density difference of the gas and water fluids, the water at the bottom of the injection well flows rapidly upward along the inside of the inner well pipe of the injection well along with the dissolved air water injected from the second water pipe.

[0139] Water flows out from the top of the inner well pipe of the injection well, part of which flows downward along the middle filler layer of the injection well, and the other part of the water flows through the second lower permeable well wall to the outer filler layer of the injection well. Then the water flows from top to bottom through the permeable injection well wall and re-enters the injection well under the suction effect of the negative pressure in the injection well.

[0140] After the dissolved air water enters the injection well, a double circulation loop is formed inside and outside the well. There are a large number of adsorption sites on the surface of the activated carbon particles, which can adsorb thiocyanate ions. In the process of oxygen-loaded groundwater flowing through the activated carbon filler layer, the oxygen molecules are excited into free radicals under the action of the copper-containing active sites on the surface of the activated carbon. At the same time, the thiocyanate ions react with the free radicals and are oxidized into harmless CO2, H2O, N2 and other substances. The copper ions in the catalytic process can repeatedly undergo redox cycles, thereby accelerating the reaction.

[0141] During the tertiary circulation flow of groundwater contaminated by thiocyanate in the contaminated area, it is first 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. The groundwater contaminated by thiocyanate is purified through repeated adsorption and catalytic oxidation during the tertiary circulation flow.

[0142] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential 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: The invention comprises 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, wherein the pumping well and the circulation well are connected via a first water pipe, and the circulation well and the injection well are connected via a second water pipe; The circulation well and the water injection well both include 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-level single-well inside-outside double circulation system is formed in the circulation well and in 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, and a third-level groundwater circulation system is formed in the groundwater contaminated area between the pumping well and the injection well along the groundwater flow.

2. The groundwater remediation system according to claim 1, characterized in that: The well wall of the pumping well is divided into an impermeable well wall located in the middle and upper part and a permeable well wall located in the lower part. The permeable well wall is provided with a plurality of permeable micropores.

3. The groundwater remediation system according to claim 2, characterized in that: The wall of the circulation well is divided into a circulation well wall located at the upper part, a watertight circulation well wall located in the middle part and a watertight circulation well wall located at the lower part, the circulation well wall is divided into a first upper watertight well wall and a first lower watertight well wall, and the first lower watertight well wall and the watertight circulation well wall are both provided with a plurality of watertight 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.

4. The groundwater remediation system according to claim 3, characterized in that: The well wall of the water injection well is divided into a well wall of the water injection well located at the upper part, a well wall of the water-impermeable water injection well located in the middle part, and a well wall of the water-permeable water injection well located at the lower part. The well wall of the water injection well is divided into a second upper water-impermeable well wall and a second lower water-permeable well wall. The second lower water-permeable well wall and the well wall of the water-permeable water injection well are both provided with a plurality of water-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 well wall of the water injection well.

5. The groundwater remediation system according to claim 3, characterized in that: The top of the outer filling layer of the circulation well is flush with the top of the first lower permeable well wall, and the bottom of the outer filling layer of the circulation well is flush with the bottom of the permeable circulation well wall.

6. The groundwater remediation system according to claim 4, characterized in that: The top of the external filling layer of the water injection well is flush with the top of the second lower permeable well wall, and the bottom of the external filling layer of the water injection well is flush with the bottom of the permeable well wall.

7. The groundwater remediation system according to claim 5 or 6, characterized in that: 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 filler layer of the circulation well and passes through the bottom end of the middle filler layer of the circulation well and then folds upward into the inner well pipe of the circulation well. A first filter, a first pumping pump, a first water storage tank and a first dissolved air pump are connected in series in sequence on the first water pipe located above the well, counter to the flow direction of groundwater.

8. The groundwater remediation system according to claim 7, characterized in that: After one end of the second water pipe passes downward through the middle packing layer of the circulation well, it continues to extend 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 middle packing layer of the injection well and passes through the bottom end of the middle packing layer of the injection well and then folds upward into the inner well pipe of the injection well. A second filter, a second water pump, a second water storage tank and a second dissolved air pump are connected in series in sequence on the second water pipe located above the well, counter to the flow direction of groundwater.

9. The groundwater remediation system according to claim 8, characterized in that: The wellheads of the pumping well, the circulation well and the injection well are all provided with sealed well covers, and the sealed well covers are provided with gas collecting pipelines.

10. The groundwater remediation system according to claim 9, characterized in that: One end of the gas collection pipeline on the sealed manhole cover of the circulation well and one end of the gas collection pipeline on the sealed manhole cover of the water injection well both extend downward into the pumping well, and the gas collection pipeline on the sealed manhole cover of the pumping well is connected to the exhaust gas treatment device.

11. A method for groundwater remediation, characterized in that: The groundwater remediation system as claimed in claim 10 comprises the following steps: S1. Formation of a circulation loop between the pumping well and the circulation well and formation of an internal and external double circulation loop of the circulation well; A first pumping pump is used to pump water from a pumping well through a first water pipe, and the water enters a first water storage tank after passing through a first filter. The water from the first water storage tank is compressed and dissolved in water by a first dissolved air pump, and then sent to an inner well pipe of a circulation well through the first water pipe. Water flows out from the top of the inner well pipe of the circulation well, and a part of the water flows downward along the middle packing layer of the circulation well, and another part of the water flows through the first lower permeable well wall to the outer packing layer of the circulation well, and then the water flows from top to bottom through the permeable circulation well wall and re-enters the circulation well under the suction effect of the negative pressure in the circulation well; S2, the formation of a circulation loop between the injection well and the circulation well and the formation of an internal and external double circulation loop of the injection well; A second pump is used to pump water from the circulation well through a second water pipe, and the water enters the second water storage tank after passing through a second filter. The water from the second water storage tank is compressed and dissolved in water by a second air dissolving pump, and then sent to the inner well pipe of the water injection well through the second water pipe. The water flows out from the top of the inner well pipe of the water injection well, and part of the water flows downward along the middle packing layer of the water injection well, and the other part of the water flows to the outer packing layer of the water injection well through the second lower permeable well wall, and then the water flows from top to bottom through the permeable water injection well wall and re-enters the water injection well under the suction effect of the negative pressure in the water injection well; S3. The formation of a circulation loop between the pumping well and the injection well along the groundwater flow direction.

12. The groundwater remediation method according to claim 11, characterized in that: The tail gas from the injection well and the circulation well is introduced into the groundwater in the pumping well, and the tail gas from the pumping well is transported to the tail gas treatment device for treatment and then discharged.

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