JP4410491B2 - Groundwater purification structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a groundwater purification technique, and relates to a groundwater purification structure used for purifying contaminated groundwater.
[0002]
[Prior art]
In recent years, toxic substances and factory effluents flowing from waste disposal sites and illegally dumped wastes have permeated underground and frequently contaminated groundwater, which has become a major social problem. The groundwater contaminated in this way (hereinafter referred to as “contaminated groundwater”) spreads the contaminated area by its flow and causes various environmental pollution. For this reason, various purification techniques have been proposed in order to prevent such contaminated groundwater from flowing into the surrounding area.
[0003]
For example, the applicant of the present invention, as shown in FIG. 6, has one kind of water permeable purifying material 111 in which water permeability is secured in the downstream basin of the contaminated groundwater W1 contaminated by the harmful substance (contamination source) P that has penetrated underground. Is constructed with a permeable groundwater purification wall 110 that is arranged in the ground and a water blocking wall 120, and the permeable purification material 111 is introduced by introducing the contaminated groundwater W1 to the permeable groundwater purification wall 110. Has been developed and put into practical use (see Patent Document 1).
[0004]
[Patent Document 1]
JP 2000-263068 A ([0010]-[0018], FIG. 2)
[0005]
[Problems to be solved by the invention]
However, the contaminated groundwater W1 composed of hazardous substances and factory waste liquids flowing out from waste disposal sites and illegal dumping waste is often contaminated in a complex manner, and the conventional permeable groundwater purification wall 110 is limited. In the case of purifying the contaminated groundwater W1 with one kind of water permeable purification material 111 for the different types of pollutants, there is a problem that the contaminated groundwater cannot be purified.
[0006]
The present invention has been made to solve the above-described problems, and proposes a groundwater purification structure capable of efficiently purifying complex contaminated groundwater.
[0007]
[Means for Solving the Problems]
  In order to solve such a problem, the invention according to claim 1 includes at least two permeable groundwater purification regions in which a wall body having a water permeable purification material or a plurality of pillars are arranged in the ground. The contaminated groundwater contaminated with a plurality of pollutants can pass through each permeable groundwater purification area.So as to cross the direction of flow of the contaminated groundwaterAnd a plurality of the permeable groundwater purification regions corresponding to the plurality of pollutants, wherein the permeable groundwater purification regions include different types of components, and each of the permeable groundwater purification regions is a purification method. Are different and do not mix with each other,Each permeable groundwater purification areaPurifying atmosphereDo not interfere with each otherIt is the groundwater purification structure characterized by being arranged like this.
[0008]
Water-permeable purification materials used for such groundwater purification structures include activated carbon, allophane, chelating materials, those that purify volatile organic compounds, heavy metals, etc. by physical adsorption such as sand layers, biochemical decomposition of microorganisms, etc. That purifies organic chlorine compounds and oils, volatile organic compounds by chemical decomposition by reduction, oxidation, catalytic reaction, etc., metal reducing agents such as iron powder and aluminum powder, oxidizing agents, lime, etc. There are things that purify heavy metals.
[0009]
Such a groundwater purification structure is configured to combine a plurality of permeable groundwater purification regions having different purification effects by the permeable purification material containing the above-described different types of components, and contaminated groundwater passes through the permeable groundwater purification region. As a result, the contaminated groundwater contaminated by the complex is a permeable groundwater purification area corresponding to each pollutant, so that the pollutant can be surely eliminated and environmental destruction is prevented. Here, as the water-permeable purification material containing different types of components, it is usually preferable to use the water-permeable purification material having the above-described different actions, but depending on the case, the water-permeability purification material having the same action of different components may be used. A purification material may be used.
[0010]
  The invention according to claim 2At least two permeable groundwater purification regions comprising a wall body having a water permeable purification material or a plurality of pillars in the ground are provided, and the contaminated groundwater complexly contaminated with a plurality of contaminants is said each permeable water. And a water-permeable purification material containing different types of components in the plurality of water-permeable groundwater purification regions corresponding to the plurality of contaminants, respectively. Each of the permeable groundwater purification areas has different purification methods and is not mixed with each other, so that the purification atmosphere of each other is not affected.Each permeable groundwater purification area is in the direction of flow of the contaminated groundwater.More than 0.5 times the range of influenceIt is characterized by being arranged with gaps at intervals of.
[0011]
Such a groundwater purification structure plays a role regardless of whether the permeable groundwater purification regions are in contact with each other or separated from each other as long as contaminated groundwater reliably passes through each permeable groundwater purification region.
However, in order to purify contaminated groundwater more effectively, for example, when the flow rate of contaminated groundwater is fast and the contaminated groundwater passes through the permeable groundwater purification area without obtaining a sufficient purification effect, It is good also as a structure which changes the layer thickness of each permeable groundwater purification area | region according to the flow velocity of contaminated groundwater, or a structure which provides a space | interval between each permeable groundwater purification area | region. Also, depending on the type of water permeable purification material, if they are placed close to each other, the materials will react and coalesce so that the effect can not be obtained sufficiently, or in the permeable groundwater purification area and anaerobic atmosphere that keeps the aerobic atmosphere In some cases, it is better to separate them so that they do not interfere with each other as in the area of water-permeable groundwater purification that is maintained. There may be a structure in which each permeable groundwater purification region is provided and separated from the permeable groundwater purification region, and can remain in the permeable groundwater purification region for a sufficient time that the contaminated groundwater can be purified.
In other words, the groundwater purification structure according to the present invention determines the layer thickness and interval of each permeable groundwater purification region according to the flow velocity and flow rate of the groundwater at each installation location, the geology, the stratum, etc., and more effectively purifies contaminated groundwater. Is.
[0012]
  The invention according to claim 3At least two permeable groundwater purification regions comprising a wall body having a water permeable purification material or a plurality of pillars in the ground are provided, and the contaminated groundwater complexly contaminated with a plurality of contaminants is said each permeable water. And a water-permeable purification material containing different types of components in the plurality of water-permeable groundwater purification regions corresponding to the plurality of contaminants, respectively. The permeable groundwater purification areas are arranged so that the purification methods are different and are not mixed with each other.Including the predetermined microorganism as the water-permeable purification material, the first water-permeable groundwater purification region maintained in an aerobic atmosphere, and the second water-permeable groundwater purification region maintained in an anaerobic atmosphere, The first permeable groundwater purification region is arranged on the upstream side of the contaminated groundwater flow from the second permeable groundwater purification region.
[0013]
With such a groundwater purification structure, a water-permeable groundwater purification region with an aerobic atmosphere such as bioremediation (hereinafter sometimes referred to as “aerobic purification region”) and a water-permeable groundwater purification region with an anaerobic atmosphere such as iron powder and aluminum powder. (Hereinafter sometimes referred to as “anaerobic purification region”), decomposition of organic and oil components in the aerobic purification region, suspended solids (SS), dioxin (DXN), biochemical oxygen demand (BOD) In addition, reduction of chemical oxygen demand (COD), etc., and decomposition and adsorption of volatile organic compounds (VOC), heavy metals, agricultural chemicals and the like by an anaerobic purification region can be performed. In other words, by combining these permeable groundwater purification areas, it becomes possible to purify contaminated groundwater that is contaminated in a complex manner, such as hazardous substances flowing from waste disposal sites and illegally dumped waste and factory waste liquid. Here, the arrangement of the aerobic purification region upstream of the flow of groundwater removes substances that adhere to the reducing agent in the anaerobic purification region such as oil and reduce the reduction action in advance, and therefore anaerobic purification. This is preferable because the purification function of the region can be sufficiently exhibited.
[0014]
The invention which concerns on Claim 4 is the groundwater purification structure of any one of Claim 1 thru | or 3, Comprising: The water-permeable purification material of each said water-permeable groundwater purification area | region is exchangeable in the ground It is arranged.
[0015]
Such a groundwater purification structure is constructed such that the permeable groundwater purification area is constructed by filling the permeable purification material of the permeable groundwater purification area into a bag or a cartridge-like container and burying it in the ground and replacing it. Even if there is a possibility that the purification function may be impaired by purifying contaminated groundwater over a long period of time, it is possible to easily replace the water permeable purification material, so it can be used for a long time without impairing the purification function. Is possible.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted. Also, in the following explanation, the outflow surface downstream of the groundwater from the groundwater purification structure is referred to as the front surface, the inflow surface upstream is referred to as the rear surface, and the left and right directions are as seen from the outflow surface of the groundwater purification structure in front view. .
[0017]
(First embodiment)
FIG. 1 is a perspective view of a groundwater purification structure according to the first embodiment. Reference numeral 1 denotes a groundwater purification structure composed of a three-layer permeable groundwater purification region and a water blocking wall. 10 shows the septic tank which accommodates each permeable groundwater purification area | region, 20 shows a water stop wall. W1 indicates contaminated groundwater before purification, and W2 indicates treated water after purification by the groundwater purification structure 1.
[0018]
As shown in FIG. 1, the septic tank 10 is formed in a box shape which is a horizontally long and hollow rectangular parallelepiped by a concrete outer wall 11, and a composite water-permeable groundwater purification region containing three types of components therein ( (Hereinafter referred to as “composite purification region”) 30 is accommodated. Further, in the septic tank 10, two horizontal inner walls 12 erected at a predetermined interval in the transverse direction of the groundwater so as to partition each permeable groundwater purification region and two sheets erected at a predetermined interval in the longitudinal direction. A vertical inner wall 13 is provided. A water-permeable screen 15 is provided at a predetermined position on each of the outer wall 11, the horizontal inner wall 12, and the vertical inner wall 13. On the other hand, the water blocking wall 20 is made of a steel sheet pile and is close to the rear surface of the septic tank 10 so as to be wider than the maximum width of the contaminated groundwater W1 so as to guide the contaminated groundwater W1 generated from the contamination source to the septic tank 10. It extends on both sides. Here, the space | interval of the horizontal inner wall 12 is determined by the layer thickness of each permeable groundwater purification area | region determined by the flow velocity of local groundwater.
[0019]
2 shows a cross-sectional view of the septic tank 10 shown in FIG. 1, wherein (a) is a plane cross-sectional view and (b) is a vertical cross-sectional view. As shown in FIG.2 (b), the top part of the septic tank 10 protrudes a little from the ground surface GL, and the top is covered with the top end covering sheet 16, and the structure which prevents inflow to the septic tank 10 of rainwater, surface water, etc. It has become. Further, the bottom portion of the septic tank 10 is formed by digging a predetermined depth from the impermeable layer line RL such as a rock so that at least the upper surface of the bottom plate 14 is equal to or less than the impermeable layer line RL. Built to prevent spilling through underneath. The height of the top of the combined purification area 30 is set to be equal to or higher than the height of the groundwater level WL, and the contaminated groundwater W1 is constructed so as to surely pass through the combined purification area 30.
[0020]
As shown in FIG. 2 (b), the screen 15 provided on the outer wall 11 and the lateral inner wall 12 allows the groundwater W1 that has flowed in to pass through the combined purification region 30 in the septic tank 10 while going up and down. The screens 15 provided on the outer wall 11 and the lateral inner wall 12 adjacent to each other in the flow direction are staggered in a side view, that is, the rear outer wall 11a is a lower portion, the rear lateral inner wall 12a is an upper portion, and the front lateral inner wall 12b is a lower portion. The front outer wall 11b is provided so as to be an upper part. Further, the screens 15 are also provided on the vertical inner wall 13 so as to alternate between the upper part and the lower part similarly to the horizontal inner wall 12 (see FIG. 1). Here, the upper end of the screen 15 provided in the upper part is provided so that it may be located below the groundwater level WL. Further, the screen 15 is formed of a wire net having a mesh so that the water-permeable groundwater purification regions of the composite purification region 30 are not mixed.
[0021]
As shown in FIG. 2 (a), the septic tank 10 has three tanks divided by the horizontal inner wall 12, and the composite purification region 30 has water permeable purification materials having components having different purification actions in each tank. The groundwater purification area is filled. The composite purification region 30 of the present embodiment includes an aerobic purification region such as bioremediation in which a sand layer is maintained in an aerobic atmosphere as a first purification region 31 and microorganisms are present therein, and a sand layer as a second purification region 32 from the rear surface. The three types of water-permeable purification materials are the sand filtration region and the third purification region 33, which are anaerobic purification regions that are maintained in an anaerobic atmosphere and contain iron powder and silica sand inside. It is arranged as a wall. Further, each permeable groundwater purification region is divided into three regions in the transverse direction in order to facilitate exchange of each permeable groundwater purification region by the vertical inner wall 13 as described later. Each of the water-permeable purification materials divided into the three regions is filled in a cartridge-like container so that the water-permeable groundwater purification region can be easily replaced.
[0022]
The groundwater purification structure 1 according to the first embodiment includes a composite purification region 30 including a three-layer permeable groundwater purification region including a first purification region 31, a second purification region 32, and a third purification region 33. , Organic substances having high volatility such as benzene are decomposed by biochemical decomposition of microorganisms living in the aerobic purification region of the first purification region 31, and solid particles are separated in the sand filtration region of the second purification region 32. It is possible to effectively purify the contaminated groundwater W1 that is contaminated in a complex manner by performing removal and reducing heavy metals and the like by the reducing action of the metal reducing agent in the anaerobic purification region of the third purification region 33. It has become. The aerobic purification region of the first purification region 31 is for purifying with microorganisms having the property of aerating air and oxygen and decomposing specific types of pollutants, and aeration is performed by a vacuum extraction method or an injection method. The anaerobic purification region made of iron powder in the third purification region 33 is effective for stabilizing heavy metals and the like by the reductive decomposition method. In addition, the water permeability coefficient of each water permeable purification material shall be equal to or greater than the water permeability coefficient of the surrounding ground.
[0023]
Moreover, since each water-permeable purification material of the composite purification area | region 30 is filled in the inside of the cartridge-shaped container arrange | positioned in the inside divided by the horizontal inner wall 12 and the vertical inner wall 13, it is a purification function by long-term utilization. In the case where the water content is lowered, by replacing these cartridge-like containers individually, it becomes possible to replace each permeable groundwater purification region in a short time with a simple operation. Also, in this replacement work, each permeable groundwater purification area is divided into three areas, so by replacing one place at a time, the remaining two places can continue purification, so the function of purifying contaminated groundwater W1 is achieved. It is possible to perform the replacement work without stopping.
[0024]
Moreover, the passage time of each permeable groundwater purification area | region is lengthened by providing the screen 15 in the horizontal inner wall 12 and the vertical inner wall 13 so that it may alternate, and raising and lowering the flow in the purification tank 10 of the contaminated groundwater W1. Thus, the contaminated groundwater W1 can be effectively purified. That is, by adjusting the positions of the outer wall 11, the horizontal inner wall 12, and the screen 15 provided on each of the outer wall 11, it is possible to ensure the time and distance necessary for the purification of harmful substances contained in the contaminated groundwater W1 in the vertical direction. It is possible to reduce the required space and the required material, which is economical.
[0025]
(Second embodiment)
FIG. 3 is a cross-sectional view of the groundwater purification structure according to the second embodiment, where (a) is a plan cross-sectional view and (b) is a vertical cross-sectional view.
[0026]
As shown in FIG. 3A, the groundwater purification structure 1 according to the second embodiment includes a composite purification region 30 having three types of water-permeable groundwater purification regions arranged horizontally, and the composite purification region 30. It consists of the outer wall 11 and the water stop wall 20 which consist of the steel sheet pile provided in the right and left.
[0027]
In the second embodiment, as a combined purification region 30 substantially equivalent to the first embodiment, an aerobic purification region is provided in the first purification region 31, a sand filtration region is provided in the second purification region 32, and a third purification region is provided. The anaerobic purification region 33 is provided to effectively purify the contaminated groundwater W1 contaminated in a complex manner. The first purification region 31 is provided with an air supply hole 35 connected to an air supply blower (not shown) so that oxygen can be supplied periodically. Here, the layer thickness of each permeable groundwater purification area is determined by the flow rate of the local groundwater, and the permeable coefficient of each permeable purification material is equal to or greater than the permeable coefficient of the surrounding ground.
[0028]
The groundwater purification structure 1 according to the present embodiment does not construct a septic tank made of a box-shaped concrete structure as the septic tank 10, but uses temporary earth retaining sheet piles 21 on four sides in a horizontally long rectangular parallelepiped shape. The shaft is excavated up to the impermeable layer, the bottom plate 14 is installed on the bottom, and the three layers of permeable groundwater purification region are arranged on the bottom in parallel to the groundwater flow without any gaps. In this case, the top cover 34 is provided. When the construction of the composite purification region 30 and the soil covering 34 is completed, the temporary earth retaining sheet piles 21 provided before and after the composite purification region 30 are removed. At this time, the temporary earth retaining sheet pile 21 on the side surface is left as the outer wall 11, and the contaminated groundwater W <b> 1 is guided so as to be reliably purified in the combined purification region 30. Further, the water blocking walls 20 are extended on both side surfaces of the combined purification region 30 so as to guide the contaminated groundwater W1 generated from the contamination source to the purification tank 10 as in the first embodiment.
[0029]
The aerobic purification region of the first purification region 31 decomposes highly volatile organic substances such as benzene, removes solid particles in the sand filtration region of the second purification region 32, iron powder of the third purification region 33, etc. By stabilizing heavy metals and the like in the anaerobic purification region consisting of the above, it becomes possible to effectively purify the contaminated groundwater W1 contaminated in a complex manner. Moreover, since it is not necessary to construct a special structure without using special heavy machinery and materials for construction, it becomes possible to construct a groundwater purification structure more easily.
[0030]
(Third embodiment)
FIG. 4 is a cross-sectional view showing a third embodiment, where (a) is a plan cross-sectional view and (b) is a vertical cross-sectional view.
[0031]
In 3rd Embodiment, three types of water permeability of 1st purification | cleaning area | region 31 ', 2nd purification | cleaning area | region 32', and 3rd purification | cleaning area | region 33 'by the aggregate | assembly of a plurality of cylindrical pile-shaped water-permeable purification materials. A complex purification region 30 composed of a groundwater purification region is constructed, and the contaminated groundwater W1 contaminated in a complex manner is purified by passing through each permeable groundwater purification region. Similar to the groundwater purification structure according to the second embodiment, the outer wall 11 and the water blocking wall 20 made of steel sheet piles are provided on the side surface of the combined purification region 30 so that the contaminated groundwater W1 does not flow out. ing.
[0032]
Each permeable groundwater purification area is formed by filling the hole drilled with a casing pipe (not shown) while preventing the collapse of the natural ground, and ½ to 5 times the pile diameter They are arranged in a row perpendicular to the contaminated groundwater at intervals, and in a staggered manner with respect to the flow direction of the contaminated groundwater. Here, the interval and the number of columns of the permeable purification material in the columnar pile shape are determined by the flow rate of the groundwater in the field, and the permeability coefficient of the permeable purification material in the columnar pile shape is 10 of the permeability coefficient of the surrounding ground. Double or more so that contaminated groundwater is guided to each pile-shaped purification material. In addition, the drilling hole is to be dug by a predetermined depth from the impermeable layer line RL such as bedrock, and constructed so that the lower end of each pile-shaped water permeable purification material is equal to or less than the impermeable layer line RL. It is constructed so as to prevent it from flowing out under the composite purification region 30. Further, a cover soil 34 is provided on the combined purification region 30 to prevent inflow of rainwater and ground surface water.
[0033]
Each permeable groundwater purification region of the combined purification region 30 is constructed as an aerobic purification region as a first purification region 31 ′ from the upstream side of the groundwater, and purifies oil and organic components by the ability of microorganisms to be decomposed. A sand filtration area is constructed as the area 32 'and turbidity treatment is performed, and a heavy metal / volatile organic compound (VOC) is purified by the anaerobic purification area containing iron powder as the third purification area 33'. Thus, the contaminated groundwater W1 contaminated in combination is effectively purified.
In addition, the columnar pile-shaped water-permeable purification material in each water-permeable groundwater purification area is disposed in consideration of its purification power because its purification power substantially extends not only to the cross-sectional area but also to the outer area. Determine the interval. By arranging them at predetermined intervals in this way, it is possible to reduce the amount of purification material to be installed, and it is possible to construct a groundwater purification structure 1 that is excellent in economic efficiency.
[0034]
The groundwater purification structure according to the present invention has been described above, but the present invention is not limited to this, and various modifications can be made according to the spirit of the invention. For example, FIG. 5 shows an example in which the above-described embodiments are combined and modified. FIG. 5A shows a case in which a box-shaped outer wall 11 is constructed and a septic tank is constructed by providing an inner wall 12 as in the first embodiment, but the first purification region 31 is air sparged into a sand layer. The aerobic purification region is maintained to maintain an aerobic atmosphere by providing an air supply hole 35 and an exhaust hole 36 of an air supply blower (not shown), and air can be circulated to activate microorganisms and effectively perform purification. It is configured as follows. The air supply holes 35 are arranged in a row perpendicular to the ground water at intervals of 0.5 to 1 times in consideration of the influence range D due to the air blowing ability of the air supply blower, and maintained in an aerobic atmosphere. Like that. A predetermined number (four in this embodiment) of exhaust holes 36 are arranged at a predetermined position outside the influence range D of each air blower. In addition, the water blocking walls 20 extending on both sides close to the rear surface of the septic tank 10 are so that each tip end is wider than the maximum width of the flow of the contaminated groundwater W1 in the diagonally rearward direction on the left and right in plan view. It is extended and constructed so as to guide the contaminated groundwater W1 generated from the contamination source to the septic tank 10. Here, the layer thickness of each permeable groundwater purification area is determined by the flow rate of the local groundwater, and the permeable coefficient of each permeable groundwater purification area is equal to or greater than the permeability coefficient of the surrounding ground.
[0035]
  FIG. 5B shows an aerobic purification region 32 ″, in which oxygen release compound (hereinafter referred to as “ORC”) is injected into the sand layer to maintain an aerobic atmosphere as the first purification region 31 ″. As in the third embodiment, the sand filtration region composed of a sand layer and the third purification region 33 ″ are an anaerobic purification region formed by a cylindrical pile-shaped assembly made of a water-permeable purification material containing iron powder. This is the structure provided. The first purification region 31 ″ is formed by an aggregate of pillar piles that are provided with a plurality of injection holes 37 for injecting ORC into the sand filtration region and are constructed by the influence range D of the ORC injected from the injection holes 37. The injection holes 37 are arranged in rows at intervals of 1.0 to 1.5 times the influence range D of the ORC, and inhabit the sand filtration region by periodically injecting the ORC from the injection holes 37. The microorganisms to be activated are activated so that the purification ability of the first purification region 31 ″ can be maintained. ORC is a drug developed by Regenesis of the United States, whose main component is magnesium peroxide. Since oxygen is released when it comes into contact with water, it can maintain the state of supplying necessary oxygen for a long period of time. (See Chemical Formula 1). The pollutants to be purified by this agent are all aerobic and decomposed substances and are very suitable because they cover a wide range such as gasoline, light oil, vinyl chloride, MTBE (a kind of ether). In the third purification region 33 ", when contaminated groundwater and iron powder come into contact and oxidize, volatile organic compounds are reduced and decomposed into harmless substances. Here, the intervals between the column piles in the third purification region 33" Similarly to the third embodiment, the number of rows is determined from the flow velocity of the local groundwater, and in this embodiment, the number of rows is set to two rows in a staggered manner. In addition, since the third purification region is an anaerobic atmosphere,The influence of the aerobic atmosphereSince it should not be received, the interval between the first purification region and the third purification region is 0.5 times or more the influence range D from the injection hole 37 of the first purification region. Here, the water permeability coefficient of each permeable groundwater purification area shall be 10 times or more of the water permeability coefficient of the surrounding ground.
[0036]
[Chemical 1]
MgO₂+ H₂O → 1 / 2O₂+ Mg (OH)₂
[0037]
Further, in each of the above-described embodiments, the steel sheet pile is used for the water blocking wall. However, the present invention is not limited to this, and the form is limited as long as similar effects such as continuous underground wall and chemical injection can be obtained. Is not to be done.
Further, in the first embodiment, each permeable groundwater purification area is divided into three in the transverse direction by the inner wall. However, this is not a limitation, and the workability is further considered in replacing each permeable groundwater purification area. For example, the number of divisions is not limited.
Moreover, although the composite purification area was constructed by combining three types of permeable groundwater purification areas, it is not limited to this, and the permeable groundwater purification area corresponding to the harmful substances of the contaminated contaminated groundwater. The number of purification regions can be set freely by combining the above.
In addition, the three types of water-permeable groundwater purification areas can be changed not only by the above-described combination but also by a harmful substance contained in the contaminated groundwater. Further, the order is not limited.
In the above-described embodiment, the screen of the septic tank is arranged in two stages up and down, but this is not a limitation, and the layout is appropriately determined depending on the structure of the septic tank.
[0038]
【The invention's effect】
According to the first aspect of the present invention, contaminated groundwater contaminated in a complex manner can be reliably purified, and environmental destruction can be prevented.
[0039]
Further, according to the invention according to claim 2, it is possible to determine the interval between the permeable groundwater purification regions based on the flow velocity and flow rate of the groundwater at each installation location, the geology, the geological formation, etc., and to purify the contaminated groundwater more effectively. It was.
[0040]
Further, according to the invention according to claim 3, due to the combination of the aerobic purification region and the anaerobic purification region, harmful substances and factory waste liquids flowing out from the waste treatment plant and illegal dumping waste were mixed and contaminated. It became possible to purify contaminated groundwater.
[0041]
Further, according to the invention of claim 4, since the water-permeable purification material can be easily exchanged, it can be used for a long time without impairing the purification function.
[Brief description of the drawings]
FIG. 1 is a perspective view of a groundwater purification structure according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the groundwater purification structure according to the first embodiment of the present invention, (a) is a plan cross-sectional view, and (b) is a vertical cross-sectional view.
FIG. 3 is a cross-sectional view of a groundwater purification structure according to a second embodiment of the present invention, (a) is a plan cross-sectional view, and (b) is a vertical cross-sectional view.
FIG. 4 is a cross-sectional view of a groundwater purification structure according to a third embodiment of the present invention, (a) is a plan cross-sectional view, and (b) is a vertical cross-sectional view.
FIG. 5 is a plan sectional view of still another modification of the groundwater purification structure of the present invention.
FIG. 6 is a plan view of a conventional groundwater purification structure.
[Explanation of symbols]
1 Groundwater purification structure
10 Septic tank
11 Exterior wall
12 Horizontal inner wall
13 Vertical inner wall
14 Bottom plate
15 screens
16 Cover sheet
20 Water barrier
30 Complex purification area
31 1st purification area
32 Second purification zone
33 Third purification zone
34 Covering soil
35 Air supply holes
W1 contaminated groundwater
W2 treated water
GL Ground surface
WL Groundwater level
RL impermeable layer wire

Claims (4)

At least two permeable groundwater purification regions comprising a wall having a water permeable purification material or a plurality of pillars disposed in the ground,
The contaminated groundwater contaminated by a plurality of pollutants is disposed so as to cross the direction of flow of the contaminated groundwater so that the permeable groundwater purification area can be permeated.
A plurality of permeable groundwater purification regions corresponding to the plurality of contaminants are arranged with permeable purification materials containing different types of components,
Each of the permeable groundwater purification regions has a different purification method and does not mix with each other, and is disposed so as not to interfere with the purification atmosphere of each of the permeable groundwater purification regions . At least two permeable groundwater purification regions comprising a wall having a water permeable purification material or a plurality of pillars disposed in the ground,
The contaminated groundwater contaminated with a plurality of pollutants is arranged so as to be able to permeate each permeable groundwater purification area,
A plurality of permeable groundwater purification regions corresponding to the plurality of contaminants are arranged with permeable purification materials containing different types of components,
Each permeability groundwater purification region without purification method is mutual mixing with different, so that there is no influence on the purification atmosphere of one another, before Symbol influence the flow direction of the water-permeable ground water purification area the contaminated groundwater groundwater purifying structure characterized by being arranged with a gap of 0.5 times or more intervals ranging. At least two permeable groundwater purification regions comprising a wall having a water permeable purification material or a plurality of pillars disposed in the ground,
The contaminated groundwater contaminated with a plurality of pollutants is arranged so as to be able to permeate each permeable groundwater purification area,
A plurality of permeable groundwater purification regions corresponding to the plurality of contaminants are arranged with permeable purification materials containing different types of components,
Each permeable groundwater purification area is arranged so that it does not mix with each other with different purification methods,
The first permeable groundwater purification region containing a predetermined microorganism as the permeable purification material and maintained in an aerobic atmosphere, and the second permeable groundwater purification region maintained in an anaerobic atmosphere ,
The groundwater purification structure according to claim 1, wherein the first permeable groundwater purification region is disposed upstream of the second permeable groundwater purification region in the flow of the contaminated groundwater.   The groundwater purification structure according to any one of claims 1 to 3, wherein the water-permeable purification material in each of the water-permeable groundwater purification regions is exchangeably disposed in the ground.

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