An in-situ remediation well and system for treating groundwater pollution

Abstract

The present invention discloses an in-situ remediation well for treating groundwater pollution, which includes an outer wellbore, an inner wellbore, a water purification component, a reaction medium, and a water outlet pipe. Groundwater enters the in-situ remediation well through a first water inlet hole on the outer wellbore, and the sediment in the groundwater is preliminarily filtered by a first filter material. Then, it enters the internal water purification component from the bottom through a second water inlet hole on the inner wellbore, and is filtered again by a second filter material in the water purification unit from bottom to top to remove organic matter and ammonia nitrogen in the treated groundwater. Finally, it is discharged through the water outlet pipe. Further, an in-situ remediation system for treating groundwater pollution is also disclosed. Through the present invention, the polluted groundwater containing ammonia nitrogen and organic matter can be repaired quickly, efficiently, and at low cost. Multiple wells can be combined to repair groundwater alone, or combined with technologies such as permeable reactive barrier technology and in-situ bioremediation technology to form a composite treatment technology, achieving the maximum remediation benefit.

Description

Technical Field

[0001] The present invention relates to the technical field of groundwater remediation, and more specifically, to an in-situ remediation technology for groundwater pollution control. Background Art

[0002] With the development of the national economy and the acceleration of the urbanization process, people's living standards have been greatly improved, but it has brought a lot of environmental pollution problems. In recent years, due to the unreasonable landfill of domestic waste, the illegal discharge of industrial pollutants, and the leakage of underground oil and gas pipelines, a large amount of harmful substances have entered the groundwater system, exceeding the self-purification capacity of the groundwater system, and the groundwater pollution situation has become increasingly serious. Therefore, how to effectively remediate polluted groundwater has become one of the hot research issues for scholars at home and abroad.

[0003] There are more than ten existing groundwater pollution remediation technologies, which can be divided into in-situ remediation and ex-situ remediation according to their remediation locations. Ex-situ remediation technologies generally pump out the polluted water body and transport it to the surface through pipelines for treatment. This method is used when the treatment time limit requirement is relatively tight, the treatment degree requirement is not high, and the pollution source is relatively concentrated. The treatment volume is large in the early stage and the effect is good, but problems such as rebound and significant inefficiency may occur in the later stage, resulting in poor treatment effects. In-situ remediation technology is a technology that remediates polluted groundwater in-situ by omitting the pumping process under artificial intervention. According to different remediation mechanisms, in-situ remediation technology can be further divided into physical remediation, chemical remediation, biological remediation, and permeable reactive barrier remediation technology. Compared with ex-situ remediation, since in-situ remediation technology is carried out in-situ, it can essentially improve the water body properties, enhance the self-purification capacity of the groundwater system, and cause little disturbance to the stratum and groundwater. Since its emergence, it has been widely recognized by all sectors of society and has been applied to various types of groundwater remediation projects to date.

[0004] Since in-situ remediation is carried out underground through reaction media such as reaction agents or fillers, its unpredictability is too strong, and it is difficult to control the replacement of reaction agents or fillers. For example, the permeable reactive barrier technology is to bury a passive reaction zone filled with active reaction media underground, and pollutants are removed from the groundwater through adsorption, precipitation, filtration, degradation, and other effects with the reaction media. If the reaction media expires and the reaction media is not replaced in time, the already adsorbed and saturated reaction media itself will become a pollution source and release pollutants to the surrounding areas. The process of replacing the reaction media must first dig up all the soil layers of the project site, which is equivalent to reconstructing the original in-situ treatment project, consuming time and effort. Summary of the Invention

[0005] To solve the technical problem of difficult replacement of reaction media such as reaction agents or fillers in in-situ remediation technologies, the present invention discloses an in-situ remediation well and system for treating groundwater pollution, which can facilitate the replacement of reaction media such as reaction agents or fillers.

[0006] The technical solution provided by the present invention is as follows:

[0007] An in-situ remediation well for treating groundwater pollution, comprising an outer wellbore, an inner wellbore, a water purification assembly, reaction media, and a water outlet pipe;

[0008] The outer wellbore is a hollow cylindrical structure that penetrates along the length direction, and a number of first water inlet holes are provided on the barrel wall;

[0009] The inner wellbore is a hollow cylindrical structure that penetrates along the length direction, and a number of second water inlet holes are provided at the bottom of the barrel wall; the inner wellbore and the outer wellbore are designed to be coaxial and of equal height, and a first filter material is arranged between the inner and outer parts;

[0010] The water purification assembly includes a plurality of water purification units arranged in sequence along the length direction of the inner wellbore in the inner wellbore, and a second filter material for treating organic matter and ammonia nitrogen in groundwater is arranged in the water purification units;

[0011] The water outlet pipe is arranged at the upper part of the side wall of the outer wellbore and is communicated with the inner wellbore and the outer wellbore;

[0012] Groundwater enters the in-situ remediation well through the first water inlet holes on the outer wellbore, and the sediment in the groundwater is preliminarily filtered by the first filter material, and then enters the internal water purification assembly from the bottom through the second water inlet holes on the inner wellbore, and is filtered again from bottom to top by the second filter material in the water purification unit to remove organic matter and ammonia nitrogen in the groundwater, and finally is discharged through the water outlet pipe.

[0013] As a preferred solution, the water purification unit is a hollow cylindrical structure, with a plurality of relatively independent packing placement cavities inside, and is equipped with an upper cover plate and a bottom plate. The upper cover plate is provided with lifting lugs and limiting lugs, and a number of holes are provided on the bottom plate and the side wall of the hollow cylinder.

[0014] As a preferred solution, the opening ratio of the holes on the bottom plate and the side wall of the hollow cylinder is 5%, and the hole diameter is 1 cm.

[0015] As a preferred solution, the upper cover plate and the bottom plate are also provided with a connecting mechanism for cooperation to be fixedly connected with adjacent water purification units.

[0016] As a preferred solution, a functional part placement area is provided in the water purification unit, and the functional placement areas of each water purification unit are connected up and down.

[0017] As a preferred solution, the material of the outer wellbore is precast concrete, the material of the inner wellbore is HDPE, and the water purification unit is made of stainless steel material.

[0018] As a preferred solution, the first filter material includes at least one of gravel with a particle size of 3 - 5 cm and quartz sand.

[0019] As a preferred solution, the first water inlet holes include multiple groups evenly distributed along the length direction of the outer wellbore, and each group includes multiple holes evenly distributed along the circumferential direction of the outer wellbore.

[0020] As a preferred solution, the second water inlet holes are distributed on the barrel wall more than two meters below the bottom of the inner wellbore and are evenly distributed in a plum blossom shape.

[0021] As a preferred solution, the outer wellbore has a diameter of 2 m, a well depth of 15 m, and a wall thickness of 8 cm; the inner wellbore has a diameter of 1 m, a well depth of 15 m, and a wall thickness of 8 cm; the water purification unit has a diameter of 0.95 m and a height of 1 m.

[0022] As a preferred solution, the first water inlet holes have a diameter of 2 cm and are arranged in a circle every 3 m along the length direction of the barrel wall; the second water inlet holes have a diameter of 0.8 cm, a hole spacing of 10 cm, and are evenly distributed on the barrel wall more than two meters below the bottom of the inner wellbore.

[0023] The present invention also discloses an in-situ remediation system for treating groundwater pollution, which includes a PRB underground enclosure, an effluent regulation tank, and an in-situ remediation well of any of the above solutions. The PRB underground enclosure is used to guide groundwater to the in-situ remediation well, and the outlet pipe of the in-situ remediation well is connected to the effluent regulation tank.

[0024] The present invention has the following beneficial effects:

[0025] (1) By using the internal water purification components of the in-situ remediation well, it is convenient to replace reaction media such as reaction agents or fillers, and quickly, efficiently, and at low cost, remediate groundwater polluted by ammonia nitrogen and organic matter, etc.

[0026] (2) The in-situ remediation well can not only be used alone or in combination with multiple wells to remediate groundwater, but also be combined with technologies such as permeable reaction barrier technology (PRB) and in-situ bioremediation technology (ISB) to form a composite treatment technology, thereby maximizing the remediation benefit.

[0027] (3) In this in-situ remediation well, groundwater can flow hydraulically through gravity and its own pressure, without the need to additionally add a power device for hydraulic distribution and flow, saving energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the in-situ remediation well structure disclosed in the embodiment;

[0029] Figure 2 It is a schematic diagram of the outer wellbore structure disclosed in the embodiment, where: (a) is the front view of the outer wellbore, and (b) is the top view of the outer wellbore;

[0030] Figure 3 It is a schematic diagram of the inner wellbore structure disclosed in the embodiment, where: (a) is the front view of the outer wellbore, and (b) is the top view of the outer wellbore;

[0031] Figure 4 It is a schematic diagram of the water purification unit structure disclosed in the embodiment, where: (a) is the structure diagram of the upper cover plate of the water purification unit, (b) is the front view of the water purification unit, and (c) is the structure diagram of the bottom plate of the water purification unit;

[0032] Figure 5 It is a schematic diagram of the water flow direction of the in-situ remediation well disclosed in the embodiment, where the arrows indicate the water flow direction;

[0033] Figure 6 It is a schematic plan layout of the composite treatment technology in the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To further understand the content of the present invention, the following will be described in conjunction with the drawings and specific embodiments.

[0035] Combined with Figures 1 to 5 As shown, an in-situ remediation well (hereinafter referred to as the in-situ remediation well) for treating groundwater pollution is disclosed in the embodiment, which mainly includes an outer wellbore 1, an outer filter material 2, an inner wellbore 3, a water purification component 4, a filler 5, and a water outlet pipe 6.

[0036] As Figure 2 shown, the outer wellbore 1 is a hollow cylindrical structure that penetrates up and down, and its material is precast concrete. Several water inlet holes 11 are evenly distributed on the barrel wall. In specific applications, its wellbore diameter, depth, wall thickness, and the size distribution of the water inlet holes on the barrel wall can be determined according to actual situations. In this embodiment, the diameter of the outer wellbore 1 is 2 meters, the well depth is 15 meters, the wall thickness is 8 centimeters, a circle of water inlet holes 11 is arranged every 3 meters along the length direction of the barrel wall, each circle of water inlet holes is arranged in a "cross" pattern (8 water inlet holes in each circle), and the diameter of each water inlet hole is 2 centimeters. As Figure 2As shown, the outer wellbore 1 is the initial water inlet and water distribution point of the entire in-situ remediation well. After the groundwater enters the remediation well through the water inlet holes 11 of the outer wellbore 1, it seeps into the outer filter material 2. The outer filter material 2 can be selected from gravel, quartz sand or various other filter materials, and the particle size of the filter material depends on the specific situation. In this embodiment, the outer filter material 2 is selected as gravel with a particle size of 3 - 5 cm. The outer filter material 2 will filter out most of the pollutants such as sediment in the groundwater and preliminarily treat the groundwater.

[0037] As Figure 3 shown, the inner wellbore 3 is also a cylindrical structure, coaxial and at the same height as the outer wellbore 1, made of HDPE, and several water inlet holes 31 are evenly distributed within the range of 1 - 2 meters from the bottom of the barrel wall. In specific applications, its wellbore diameter, depth, wall thickness and the size distribution of the water inlet holes on the barrel wall can be determined according to the actual situation. In this embodiment, the wellbore diameter is 1 meter, the well depth is 15 meters, the wall thickness is 8 cm, and several water inlet holes 31 are evenly distributed in a plum blossom shape within 1 meter from the bottom of the barrel wall, with a hole spacing of 10 cm, and the diameter of each water inlet hole 31 is 0.8 cm. The groundwater filtered by the outer filter material 2 enters the internal water purification component 4 from the bottom of the inner wellbore 3.

[0038] The water purification component 4 is the core part of the remediation well for treating groundwater, and the water purification component 4 can be made into various forms according to the actual situation. As Figure 4As shown in the figure, the water purification component in this embodiment has functions such as hoisting, limiting, and replaceability, and various filter materials are placed inside the component. Specifically, the internal water purification component is divided into 15 water purification units, each of which is a 316L stainless steel hollow cylinder structure with a height of 1 meter and a diameter of 0.95 meters, mainly including a cylindrical body 41, an upper cover plate 42, and a bottom plate 43. The inside of the cylindrical body 41 is divided into four equally sized packing placement chambers 44 and a functional component installation area 45. The functional component installation area 45 is arranged at the central position of the cylindrical body 41, and the packing placement chambers 44 are evenly arranged circumferentially around the functional component installation area 45. Among them, each packing placement chamber 44 and the functional component installation area 45 penetrate through the upper cover plate 42 and the bottom plate 43 along the length direction of the cylindrical body 41. The upper cover plate 42 is mainly used for the connection and installation of two adjacent water purification units, and is configured with lifting lugs 46 and limiting lugs 47 at the edge, which can facilitate the placement of the water purification unit into the well and extraction from the well. Each water purification unit can be connected to each other or not. When connection is required, a matching connection mechanism can be set on the upper cover plate 42 and the bottom plate 43. The positions of the upper cover plate 42 corresponding to the packing placement chambers 44 and the functional component installation area 45 are hollow structures, so that the packing can be loaded and unloaded without opening the cover. The position of the bottom plate 43 corresponding to the functional component installation area 45 is a hollow structure, so that the upper and lower parts of each functional component installation area 45 are connected. A plurality of uniformly distributed water inlet holes 48 are opened on the side wall and the bottom plate 43 of the cylindrical body 41, the opening ratio is 5%, and the opening diameter is 1 cm. In the design of this water purification unit in the embodiment, the cylindrical body 41, the upper cover plate 42, and the bottom plate 43 can be integrally formed. There are multiple packing placement chambers inside the water purification unit. Of course, in addition, other designs can also be used, as long as the packing 5 inside each water purification unit can contact the external sewage. The functional component installation area 45 can also be designed according to requirements, including whether it is in the central position, the space size, etc., and can be used to place aeration pipes, sensors, and detectors. In each packing placement chamber 44 of each water purification unit, packing 5 for treating organic matter and ammonia nitrogen in groundwater, such as adsorption materials such as zeolite and manganese sand, is assembled. In actual application, the water purification component inside the in-situ remediation well can be lifted out by a crane in cooperation with the lifting lugs to replace the packing, thus solving the technical problem of difficult replacement of reaction media such as reaction agents or packing in the in-situ remediation technology.

[0039] An outlet pipe 6 is horizontally arranged at the upper part of the in-situ remediation well. The outlet pipe 6 communicates with the inner wellbore 3 and the outer wellbore 1. The groundwater entering from the bottom of the internal water purification component 4 is discharged from the in-situ remediation well through the upper outlet pipe 6 after being treated by the packing 5. In the embodiment, the relative elevation of the lowest water surface of the groundwater is 2.3 meters below the ground surface, and the central axis elevation of the outlet pipe 6 of the in-situ remediation well is selected to be 2.8 meters below the ground surface.

[0040] As Figure 6As shown in the figure, the embodiment also discloses an in-situ remediation system for treating groundwater pollution, which includes a PRB underground enclosure 7, a regulating tank 8, and an in-situ remediation well 9 of any of the above solutions. After the water outlet pipe 6, it can be connected to a regulating tank 8 through a pipeline for caching the remediated groundwater.

[0041] Furthermore, the in-situ remediation well in this embodiment can also be combined with the funnel-and-gate PRB technology and the bioremediation technology to form a composite treatment technology. The contaminated groundwater enters the in-situ remediation well acting as a funnel through the PRB underground enclosure 7. After being remediated by the in-situ remediation well combined with adsorption and bioremediation technologies, it enters the downstream.

[0042] Finally, it should be noted that although the embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Under the inspiration of this specification, those of ordinary skill in the art can, without departing from the scope protected by the present invention, design structural forms and embodiments similar to this technical solution without creative efforts, which should all fall within the protection scope of the present invention.

Claims

1. An in-situ remediation well for treating groundwater pollution, characterized in that: It includes an outer wellbore, an inner wellbore, a water purification component, a reaction medium, and a water outlet pipe; The outer wellbore is a hollow cylindrical structure that penetrates along the length direction, and several first water inlet holes are opened on the barrel wall; The first water inlet holes include multiple groups that are equally spaced along the length direction of the outer wellbore, and each group includes multiple holes that are evenly distributed along the circumferential direction of the outer wellbore; The inner wellbore is a hollow cylindrical structure that penetrates along the length direction, and several second water inlet holes are opened at the bottom of the barrel wall; The inner wellbore and the outer wellbore are designed to be coaxial and of the same height, and a first filter material is arranged between them; The water purification component includes multiple water purification units arranged in sequence along the length direction of the inner wellbore within the inner wellbore, and a second filter material for treating organic matter and ammonia nitrogen in groundwater is arranged within the water purification units; The water outlet pipe is arranged at the upper part of the side wall of the outer wellbore and is connected to the inner wellbore and the outer wellbore; Groundwater undergoes hydraulic flow through gravity and its own pressure, enters the in-situ remediation well through the first water inlet holes on the outer wellbore, is preliminarily filtered for sediment in the groundwater by the first filter material, then enters the internal water purification component from the bottom through the second water inlet holes on the inner wellbore, and is filtered again from bottom to top by the second filter material in the water purification units to remove organic matter and ammonia nitrogen in the groundwater, and finally is discharged through the water outlet pipe; The water purification unit is a hollow cylindrical structure, with multiple relatively independent packing placement cavities inside, and is equipped with an upper cover plate and a bottom plate. The upper cover plate is provided with lifting lugs and limiting lugs, and several holes are provided on the bottom plate and the side wall of the hollow cylinder; 2. The in-situ remediation well according to claim 1, wherein The opening ratio of the holes on the bottom plate and the side wall of the hollow cylinder is 5%, and the hole diameter is 1 centimeter.

3. The in-situ repair well according to claim 1, wherein The upper cover plate and the bottom plate are also provided with a connecting mechanism for cooperative use to be fixedly connected to adjacent water purification units.

4. The in-situ remediation well according to claim 1, wherein There is a functional component placement area in the water purification unit, and the functional placement areas of each water purification unit are connected up and down.

5. The in-situ remediation well according to claim 1, characterized in that, The material of the outer wellbore is precast concrete, the material of the inner wellbore is HDPE, and the water purification unit is made of stainless steel material.

6. The in-situ remediation well according to claim 1, wherein The first filter material includes at least one of gravel and quartz sand with a particle size of 3 - 5 centimeters.

7. The in-situ remediation well according to claim 1, wherein, The second water inlet holes are distributed on the barrel wall more than two meters below the bottom of the inner wellbore and are evenly distributed in a plum blossom shape.

8. The in-situ remediation well according to claim 1, wherein, The diameter of the outer wellbore is 2 meters, the well depth is 15 meters, and the wall thickness is 8 centimeters; The diameter of the inner wellbore is 1 meter, the well depth is 15 meters, and the wall thickness is 8 centimeters; The diameter of the water purification unit is 0.95 meters, and the height is 1 meter; The diameter of the first water inlet holes is 2 centimeters, and one circle is arranged every 3 meters along the length direction of the barrel wall; The diameter of the second water inlet holes is 0.8 centimeters, and the hole spacing is 10 centimeters, and they are evenly distributed on the barrel wall more than two meters below the bottom of the inner wellbore.

9. An in-situ remediation system for treating groundwater pollution, characterized in that: It includes a PRB underground enclosure, an effluent regulation pond, and an in-situ remediation well for treating groundwater pollution as described in any one of claims 1 to 8. The PRB underground enclosure is used to guide groundwater to the in-situ remediation well, and the water outlet pipe of the in-situ remediation well is connected to the effluent regulation pond.

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