JP2001347255A - Method for decontaminating soil and groundwater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for decontaminating soil and groundwater which enhances the feed of oxygen into the ground. SOLUTION: This method is for cleaning the soil and the groundwater by improving the feed of oxygen into a saturated layer S by injecting or penetrating a liquid containing fine air bubbles into the saturated layer S. When the feed of oxygen is improved, the activity of microorganisms in the soil is activated and the function of cleaning by microorganisms is improved, and contaminated soil and/or contaminated groundwater are efficiently cleaned by utilizing the microorganisms. The contaminated soil is washed and cleaned by such a flow of the liquid containing fine air bubbles that is generated in the ground by penetrating the liquid containing fine air bubbles into the groundwater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for purifying soil and groundwater for purifying soil and groundwater.

[0002]

2. Description of the Related Art A purification method for purifying contaminated soil and / or contaminated groundwater is roughly classified into a physicochemical treatment method and a biological purification treatment method. Incineration method to incinerate and purify soil,
There are a thermal desorption method in which excavated soil is purified by low-temperature heat treatment using a rotary kiln, etc., and a cleaning method in which excavated soil is washed and purified.The biological purification treatment method also uses excavated soil with high ridges. The high ridge method (bioventing method), in which air is supplied to these high ridges to activate microorganisms in the soil and purifies by the action of these microorganisms, supplies air to the ground to remove microorganisms in the soil. There is an in situ method (eg, an air purging method) that activates and purifies by the action of the microorganism. This in situ method makes it possible to purify contaminated soil and / or contaminated groundwater without excavation, and can reduce the cost of purification treatment because excavation costs are not required. I'm taking a bath.

[0003]

In the in-situ method, when injecting air into the ground, it is difficult to uniformly inject air into a region to be purified as required. There is a problem in that the supply of oxygen to the water is insufficient, and this is one of the causes, and the purification ability is low. An object of the present invention is to provide a method of purifying soil and groundwater that can uniformly inject or infiltrate air into a region in the ground to be purified and improve the supply of air to the region to be purified. .

Another object of the present invention is to provide a method for purifying soil and groundwater which can improve the purification ability.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a liquid containing fine air bubbles is injected or permeated into the ground to make the oxygen supply into the ground uniform, thereby reducing the contaminants contained in the ground. A method for purifying soil and groundwater, comprising decomposing and purifying soil by activating the growth or activity of degrading microorganisms. According to the present invention, a liquid containing fine bubbles is injected or permeated into the ground. Such fine bubbles have a slow rise rate in the ground, and the bubbles contained in the injected or infiltrated liquid diffuse laterally, thereby reducing the oxygen supply to the ground (groundwater and / or underground soil). Uniformity is promoted. If the oxygen supply can be made uniform in this way,
The growth or activity of microorganisms in the ground is activated, the purification action of the microorganisms is enhanced, and contaminated soil and / or contaminated groundwater can be purified efficiently using microorganisms.

Further, the present invention is characterized in that the liquid containing fine bubbles is substantially uniformly dispersed in a region of the ground to be purified. According to the present invention, fine bubbles, for example, bubbles having a size of 1 to 10000 μm, have a low rising speed in the ground and are also diffused in the lateral direction, so that the liquid containing the fine bubbles is substantially located in the area to be purified. By being evenly dispersed and thus dispersed, the growth or activity of the microorganisms present in such areas is activated and can be purified substantially uniformly throughout the area to be purified.

The present invention also relates to a method of injecting or penetrating a liquid containing fine bubbles into the ground, flowing the liquid through an area to be purified in the ground, and containing the liquid in the soil by the flow of the liquid. A soil and groundwater purification method characterized by washing and purifying contaminants adhering to a soil surface and infiltrating fine bubbles and / or oxygen caused by the fine bubbles between small soil particles. According to the present invention, a liquid containing fine bubbles is injected or permeated into the ground. Such fine bubbles have a slow rising speed in the ground, and the liquid containing the fine bubbles flows through the region to be purified. Therefore, the area to be purified by the flow of the liquid and the flow of the fine bubbles contained therein, that is, the contaminants contained in the soil and / or the contaminants attached to the soil surface are washed. These fine bubbles, for example, bubbles having a size of 1 to 1000 μm, are sufficiently small in size and can penetrate between small soil particles by the flow of the liquid, thereby increasing the purification ability.

Further, in the present invention, groundwater is used as a liquid containing fine bubbles, a pumping hole is provided in relation to a region to be purified, and fine bubbles are contained in the groundwater pumped from the pumping hole. It is subsequently injected or penetrated into the ground and circulates groundwater through the area to be purified.
According to the invention, pumping holes are dug in connection with the area where the soil is to be purified, and groundwater in the ground is pumped from the pumping holes.
As the liquid to be injected or permeated into the ground, groundwater from this pumping hole is used, and the groundwater contains fine bubbles and is injected or permeated into the ground. In this way, groundwater is circulated through the area to be purified, and the area to be purified using groundwater, that is, contaminated soil and / or contaminated groundwater can be purified as required.

Further, the present invention is characterized in that nutrients of degrading microorganisms are added to groundwater pumped from a pumping hole and then injected or permeated into the ground. According to the present invention, the nutrient of the decomposing microorganism is added to the groundwater, so that the groundwater containing the nutrient is injected or permeated into the ground. Therefore, nutrients are given to the microorganisms in the soil, the growth or activity of such microorganisms is further activated, and the purifying action of the microorganisms can be further enhanced.

Further, the present invention is characterized in that a decompression pump is used to depressurize the pumping hole, groundwater is pumped in a decompressed state by the decompression pump, and the pumped groundwater is injected or permeated into the ground. According to the present invention, a vacuum pump is used when pumping groundwater from the pumping hole, and the inside of the pumping hole is maintained in a reduced pressure state by the vacuum pump. A large amount of groundwater can be pumped by pumping under reduced pressure using a vacuum pump.

In the present invention, the groundwater pumped from the pumping hole is passed through a heavy metal treatment device and an oil removing device, and the heavy metal contained in the groundwater is removed by the heavy metal treatment device. The oil content is removed, and air is contained in the groundwater from which heavy metals and oil have been removed. According to the present invention, the pumped groundwater is treated by a heavy metal treatment device and an oil removal device. The heavy metal removal device removes heavy metals in groundwater, and the oil removal device removes oil components in groundwater. By injecting or infiltrating the groundwater thus purified into the ground, the area to be purified can be further improved. Can be purified.

In the present invention, an air supply pipe for supplying air and a liquid supply pipe for supplying liquid are buried in the ground, and a tip of the air supply pipe is connected to a tip of the liquid supply pipe. The liquid flowing through the liquid supply pipe is mixed with the air flowing through the air supply pipe, and the liquid containing fine bubbles is injected into the ground. According to the present invention, the tip of the air supply pipe is connected to the tip of the liquid supply pipe, and at the tip of the liquid supply pipe, in other words, the air supply pipe is connected to the liquid flowing through the liquid supply pipe immediately before injection into the soil. The flowing air is mixed to produce a liquid containing fine bubbles, which can then be injected into the ground in the form of fine bubbles.

Further, in the present invention, an air supply pipe for supplying air is disposed radially inward of the liquid supply pipe for supplying liquid and buried in the ground, and the liquid supply pipe is provided at a tip end of the liquid supply pipe. The liquid flowing through the pipe is mixed with the air flowing through the air supply pipe, and the liquid containing fine bubbles is injected into the ground. According to the present invention,
An air supply pipe is arranged radially inward of the liquid supply pipe, and at the tip of the liquid supply pipe, in other words, the air flowing through the air supply pipe is mixed with the liquid flowing through the liquid supply pipe immediately before being injected into the soil. A liquid containing fine bubbles is generated, and can thus be injected into the ground in the form of fine bubbles.

Further, the present invention is characterized in that a microbubble generating member having a large number of micropores is provided at a tip of a pipe for injecting a liquid containing microbubbles into the ground. According to the present invention, since the microbubble generating member is provided at the tip of the pipe for injecting the liquid, when the liquid including the air bubbles is injected through the microbubble generating member, the air bubbles are further miniaturized and smaller. The liquid can be injected into the ground in the form of bubbles.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for purifying soil and groundwater according to the present invention will be described with reference to the accompanying drawings. First Embodiment First, a first embodiment of a soil and groundwater purification method according to the present invention will be described with reference to FIGS. FIG. 1 shows a first embodiment of a soil and groundwater purification system to which the first embodiment of the soil and groundwater purification method according to the present invention is applied.
FIG. 2 is a plan view schematically showing the embodiment of FIG.
BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the purification system of soil and groundwater simply.

1 and 2, the soil and groundwater purification system according to the first embodiment includes an air injection mechanism 6, and the air injection mechanism 6 is provided at a predetermined portion of a region 8 to be cleaned. Are provided at the four corners of a square region 8 having a side of about 20 m. This air injection mechanism 6
A liquid containing fine air bubbles, in this embodiment, water containing fine air is injected into the ground as described later. The air injection mechanism 6 can be appropriately provided in consideration of the purification ability and the like.

The illustrated air injection mechanism 6 includes a main liquid supply pipe 1 for supplying a liquid such as water, and first and second branched liquid supply pipes 2 and 4 extending from the main liquid supply pipe 1. Most of these branched liquid supply pipes 2 and 4 are buried in the ground. In this embodiment, the first branch liquid supply pipe 2 is formed shorter than the second branch liquid supply pipe 4. As shown in FIG. 2, the surface portion of the ground has an unsaturated layer R having voids between soil particles on its surface, and a saturated layer S in which the space between the soil particles is occupied by groundwater below the unsaturated layer R. Exists. For example, when the soil of the saturated layer S is contaminated, the first branch liquid supply pipe 2 is buried so as to extend downward in the ground to a relatively shallow portion of the saturated layer S, and the second branch liquid supply pipe 4 Is buried so as to extend downward in the ground to a relatively deep portion of the saturated layer. The burying length L1 of the first liquid supply pipe 2 is set to, for example, about 3000 mm, and by setting in this manner, the liquid (described later) from the first liquid supply pipe 2 is supplied to the saturated layer S from its leading end inlet. It is injected into a relatively shallow part. Further, the buried length L2 of the second air supply pipe 4 is set to, for example, about 7000 mm, and by setting such, the liquid from the second air supply pipe 4 is supplied to the relatively deep portion of the saturated layer S from the tip inlet. Is injected into. The main liquid supply pipes 1 of the four air injection mechanisms 6 are connected via a connection pipe (not shown), and are connected via this connection pipe to a liquid supply source (not shown) such as a liquid supply pump. .

The first and second branch liquid supply pipes 2 and 4 of each air injection mechanism 6 are connected to first and second air supply pipes 5 and 7 for supplying air as a gas. The second air supply pipes 5, 7 are connected to an air supply (not shown) such as an air compressor. The air from the first air supply pipe 5 is supplied to the first branch liquid supply pipe 2, and the liquid containing fine bubbles formed by mixing air with the liquid is supplied to the first branch liquid supply pipe 2.
Is injected into a relatively shallow portion of the saturated layer S. Further, the air from the second air supply pipe 7 is supplied to the second branch liquid supply pipe 4, and the liquid containing fine bubbles is injected into a relatively deep portion of the saturated layer S through the second branch liquid supply pipe 4. Is done.

As the liquid to be injected, water from rivers and ponds, groundwater, tap water, and the like can be used, and the size (diameter) of bubbles contained therein is 1 to 10000 μm.
When the size of the bubbles exceeds 10000 μm, the rising speed of the bubbles in the ground, in this embodiment, in the saturated layer S increases, and the amount of air staying in the saturated layer S decreases. Therefore, the supply of air into the ground cannot be made uniform, and the degree of improvement of the purifying action described later decreases. The smaller the size of the bubbles contained in the liquid, the more effective, for example, 1 to 10
Desirably, it is 00 μm, and such a size allows air bubbles to penetrate between narrow soil particles. As the liquid containing fine bubbles, for example, a well-known premix nozzle that mixes air into the liquid to generate a liquid having bubbles can be used.

The ground surface 12 in the area 8 to be purified of the ground is covered with, for example, a sheet 10 so that the air injected into the saturated layer S does not rise and is not released from the surface 12 to the atmosphere. When the saturated layer S is contaminated, the contaminant is a volatile organic compound (V
This is because, in the case of OCs) or the like, there is a risk that such contaminants may be released into the atmosphere due to the rise of the injected air. A suction tube 14 is provided in combination with the sheet 10. The suction tube 14 is formed of a hollow tube member, and is provided with a number of suction holes (not shown) at intervals in the axial direction. In this embodiment, the suction pipe 14 is arranged in a rectangular shape on the outer periphery of the region 8 to be treated, and a suction pipe 16 is connected to a part of the suction pipe 14.
And a connection pipe 20 connected to an adsorption tower (not shown). The adsorption tower includes, for example, a known activated carbon adsorption tower or the like. This suction pipe 14 is buried near the surface of the unsaturated layer R as shown in FIG. Therefore, the air that has risen from the saturated layer S through the unsaturated layer R is supplied to the suction device 1.
8, the liquid is sucked from the suction hole of the suction pipe 14, and is supplied to an adsorption tower (not shown) through the suction pipe 14, the suction pipe 16, and the connection pipe 20 as shown by an arrow 22. After pollutants such as VOCs are completely removed, they are released into the atmosphere.

In this purification system, a liquid such as water is supplied to the main liquid supply pipe 1 of each air injection mechanism 6 via a connecting pipe (not shown), and the first and second liquids are supplied from the main liquid supply pipe 1. Two-branch liquid supply pipes 2, 4
Sent to The air is supplied to the first branch liquid supply pipe 2 through the first air supply pipe 5 and is supplied to the second branch liquid supply pipe 4 through the second air supply pipe 7. Since the liquid and the air are supplied in this manner, the liquid mixed with the air in the first branch liquid supply pipe 2, that is, the liquid containing fine bubbles, is supplied from the inlet at the tip (lower end) of the saturated layer S. The liquid injected into the relatively shallow portion and mixed with air in the second branch air supply pipe 4, that is, the liquid containing fine bubbles, flows from the inlet at the tip (lower end) of the saturated layer S into the relatively thin portion. Injected into the deep part. Since the bubbles contained in the liquid are fine, the rising speed in the saturated layer is low, and therefore the residence time in the saturated layer is long, which can promote uniform air supply to the saturated layer. . As a result, the injected air activates the growth or activity of the endogenous bacteria in the soil of the saturated layer S, that is, the decomposing microorganisms that decompose the contaminants, and utilizes the action of the endogenous bacteria to in the soil and / or groundwater. It can decompose contaminants in the water and promote the purification of soil and groundwater. In addition, fine bubbles easily penetrate into the saturated layer, penetrate into narrow soil particles, promote the penetration of air into the saturated layer, and further diffuse into the saturated layer due to lateral diffusion and the like. Can be substantially evenly dispersed, whereby
The region 8 to be purified can be purified almost uniformly.
Further, the soil and / or groundwater is also cleaned by the flow of the liquid injected into the saturated layer S and the bubbles contained therein.

Second Embodiment Next, a second embodiment of the method for purifying soil and groundwater according to the present invention will be described with reference to FIG. FIG. 3 is a sectional view schematically showing a part of a second embodiment of a soil and groundwater purification system to which the second embodiment of the soil and groundwater purification method according to the present invention is applied. , The suction tube and the sheet are omitted. In the following description, members that are substantially the same as those in the first embodiment are given the same numbers, and descriptions thereof are omitted.

Referring to FIG. 3, in the system according to the second embodiment, a pumping well 32 as a pumping hole is dug in connection with an area to be purified (see FIG. 2). It is excavated to a deep part. Pumping well 32
One or more is provided in the area to be purified and / or adjacent to the area to be purified, for example in the embodiment shown in FIG. . In the second embodiment, the groundwater collected in the pumping well 32 is used as a liquid containing fine bubbles. The suction pipe 4 is placed in the groundwater 46 accumulated in the pumping well 32.
The suction pipe 48 is connected to a suction pump 50, and the liquid supply pipe 5 connected to the suction pump 50 is connected to the suction pipe 48.
2 extends downward in the ground to a relatively deep part of the saturated layer. The air supply pipe 54 extends downward in the ground substantially in parallel with the liquid supply pipe 52, and its tip (lower end) is connected to the tip (lower end) of the liquid supply pipe 52. The other end of the air supply pipe 54 is connected to, for example, an air compressor (not shown), and air from the air compressor is supplied to the distal end of the liquid supply pipe 54. Other configurations of the second embodiment are substantially the same as those of the above-described first embodiment.

In the second embodiment, the suction pump 50
Groundwater 46 accumulated in the pumping well 32 by the suction action of
The groundwater 46 thus pumped is supplied to the liquid supply pipe 52 through the suction pipe 48.
Air is supplied from an air compressor (not shown),
This air is supplied to the distal end of the liquid supply pipe 54 through the air supply pipe 54. At the distal end of the liquid supply pipe 52, the air flowing through the air supply pipe 54 is mixed with the liquid flowing through the liquid supply pipe 52, and thus mixed to generate water containing fine bubbles. It is injected into the ground from the tip injection port of the pipe 52. As described above, water (groundwater) containing fine bubbles is injected into the saturated layer in the same manner as described above, so that the air supply into the ground can be made uniform. And / or purify groundwater.

The second embodiment further has the following characteristic in relation to utilizing groundwater collected in the pumping well 32 as the liquid to be injected. That is, since the liquid to be injected is groundwater, it can be easily and inexpensively obtained, and the processing cost of the purification system can be reduced. Further, the groundwater in the saturated layer accumulates in the pumping well 32, and the accumulated groundwater is re-injected into the saturated layer together with fine bubbles, so that the groundwater circulates through the area of the ground to be purified. It can be purified as required using circulating groundwater. In particular, as shown in FIG. 3, by circulating groundwater, water containing air bubbles (groundwater) flows through the area to be purified,
By this flow, contaminants contained in the soil and / or adhering to the soil surface can be washed away. In addition, the flow of groundwater allows fine air bubbles to reach between soil particles that cannot be reached by air bubbles alone, thereby further promoting purification of contaminants in the ground. In addition, in the second embodiment, since the mixing of the groundwater and the air is performed immediately before the injection into the saturated layer, the oxygen supply to the ground is made more uniform, and the soil and / or the groundwater are mixed. The purifying action can be further enhanced.

Third Embodiment Next, a third embodiment of the method for purifying soil and groundwater according to the present invention will be described with reference to FIG. FIG. 4 is a sectional view schematically showing a part of a third embodiment of a soil and groundwater purification system to which the third embodiment of the soil and groundwater purification method according to the present invention is applied. Also, the suction tube and sheet are omitted in FIG. 4, in the purification system according to the third embodiment, the inner diameter of the liquid supply pipe 82 buried in the saturated layer is larger than the outer diameter of the air supply pipe 84 for supplying air, and the diameter of the liquid supply pipe 82 An air supply pipe 84 is disposed on the inner side in the direction, and the liquid supply pipe 82 and the air supply pipe 8
4 extends to the saturated layer. A connection pipe 86 connected to the suction pump 50 is connected to a base side (upper end side) of the liquid supply pipe 82, and an air supply pipe 84 is connected to an air compressor (not shown). Other configurations of the third embodiment are substantially the same as those of the above-described second embodiment.

In the third embodiment, the groundwater 46 in the pumping well 32 is pumped by the suction action of the suction pump 50, and the pumped groundwater is supplied through the connection pipe 86 and the liquid supply pipe 82, and is compressed by air. Air from the machine (not shown)
Supplied through. Immediately before being injected into the saturated layer in the ground, air from the air supply pipe 84 blows out into the groundwater supplied through the liquid supply pipe 82, and these are mixed to generate water containing fine bubbles. The water containing bubbles is injected into the saturated layer from the inlet of the liquid supply pipe 82, and the same operation and effect as in the third embodiment can be achieved with this configuration.

Fourth Embodiment Next, a fourth embodiment of the method for purifying soil and groundwater according to the present invention will be described with reference to FIG. FIG. 5 is a sectional view schematically showing a main part of a fourth embodiment of a soil and groundwater purification system to which a fourth embodiment of the soil and groundwater purification method according to the present invention is applied. In FIG. 5, in the purification system of the fourth embodiment, an oil removing device 92 for removing an oil component contained in groundwater, and a heavy metal treatment device for removing a heavy metal component contained in groundwater. 94 are provided, and a supply pump 96 is provided between them. A feed pipe 100 from the suction pump 50 is connected to the oil removing device 92.
2 and a heavy metal processing apparatus 94 are connected via a feed pipe 98, and a feed pump 96 is provided on the feed pipe 98.

In the fourth embodiment, the suction pump 50
The groundwater pumped up from the pumping well 32 is supplied to the oil removing device 92 through the supply pipe 100. The oil removing device 92 removes the oil component contained in the groundwater, and the groundwater from which the oil component has been removed passes through a feed pipe 98 by the action of a supply pump 96 to treat the heavy metal treatment device 94.
Sent to The heavy metal treatment device 94 removes the heavy metal component contained in the groundwater, and the groundwater from which the oil component and the heavy metal component have been removed is passed through the feed pipe 104 by the feed pump 102, for example, in the second embodiment of FIG. The liquid is supplied to the liquid supply pipe 52 and then mixed with air and injected into the saturated layer in a state containing fine bubbles as described above.

By using the groundwater from which the oil component and the heavy metal component have been removed as a liquid containing fine bubbles, purification of the groundwater is remarkably promoted, whereby the saturated layer can be more efficiently purified. . In particular, since the groundwater pumped from the pumping well 32 is circulated through the area to be purified and the groundwater is used for the injection into the ground, the purification action of the soil and / or groundwater is significantly improved. In order to promote the purification action of the saturated layer, a purification or purification promoting substance may be added to the liquid (tap water, groundwater, etc.) injected into the saturated layer. Such a purification or purification promoting substance is a nutrient component for activating indigenous bacteria in soil or an adsorbent for adsorbing metal components in soil.

In the second to fourth embodiments, in order to increase the pumping capacity of the groundwater in the pumping well 32, for example, a configuration shown in FIG. 6 can be used. That is, the casing tube 132 is inserted into the pumping well 32, and a sand pool 134 is provided at the bottom (tip) of the casing tube 132. The lower portion 136 of the casing tube 132 has a slightly smaller outer diameter, and a slit tube 138 is provided so as to cover the periphery of the lower portion 136.
Are provided with a large number of slits 140 at intervals in the axial direction (vertical direction in FIG. 6). An inflow port 142 is provided at the bottom of the casing tube 132. A pump 144 is provided in a lower portion 136 of the casing tube 132.
The suction pipe 48 is connected to the water pump 144.

In such a configuration, when pumping groundwater, the inside of the pumping well 32 sealed on the ground surface is depressurized by a decompression pump (not shown) to maintain a state close to a vacuum, and the pumping amount is reduced by the vacuum effect. Can be increased. When the pump 144 is operated and sucked in such a reduced pressure or vacuum state, the groundwater in the pumping well 32 flows into the inside through the many slits 140 of the slit tube 138, and further flows through the inlet 142 of the casing tube 132. The groundwater that has flowed in is sucked by the pump 144 and is drawn by the suction pipe 48.
Flows downstream as indicated by the arrow. At this time,
When flowing through the slit 140 of the slit tube 132, the inflow of air contained in the groundwater is substantially blocked, and the groundwater from which the air has been separated is sent to the pump 144.
This will increase the pumping efficiency and pump up large volumes of groundwater. Compared with the conventional pumping of groundwater by gravity drainage, the forced drainage using atmospheric pressure is performed, so the consolidation dewatering effect is large and the water collecting capacity is large, so that a large volume of groundwater can be pumped.

Further, in order to further reduce the size of the bubbles contained in the liquid, the tip of the liquid supply pipe (2, 4, etc.), in other words, at the inlet of the pipe for injecting the liquid containing bubbles into the ground, It is preferable to provide a microbubble generating member (not shown) having a large number of micropores. By providing the microbubble generating member, a liquid containing fine bubbles can be supplied to the liquid supply pipe when injected into the ground. 2, 4, etc.) and injected into the ground through many fine holes of the fine bubble generating member, and the bubbles in the liquid are fragmented by passing through the fine bubble generating member, thus further miniaturizing the bubbles in the liquid. Can be achieved. The microbubble generating member can be formed from sintered steel, a resin plate, a resin film, or the like, and can be widely applied to the above-described first to fourth embodiments and the like.

Although the embodiment of the method for purifying soil and groundwater according to the present invention has been described above, the present invention is not limited to such an embodiment, and various modifications and alterations can be made without departing from the scope of the present invention. is there. For example, in the second to fourth embodiments, a pumping well 32 as a pumping hole is excavated, and groundwater collected in the pumping well 32 is pumped up.
It is not always necessary to excavate the pumping well 32, but a pumping pipe may be buried in the ground, a pumping hole may be formed by the pumping pipe, and groundwater may be pumped from the pumping hole.

Further, for example, in the above-described embodiment, the liquid containing fine bubbles is injected into the ground through the tip (inlet) of the liquid supply pipe (2, 4 or the like). The liquid may be penetrated into the ground.

[0036]

According to the method for purifying soil and groundwater of claim 1 of the present invention, a liquid containing fine bubbles is injected or permeated into the ground, so that the rising speed of the fine bubbles in the ground is reduced. It is slow and diffuses laterally through the ground, which promotes a uniform oxygen supply into the ground. As a result, the growth or activity of microorganisms in the ground is activated, the purification action of the microorganisms is enhanced, and contaminated soil and / or contaminated groundwater can be efficiently purified using microorganisms.

Further, according to the method for purifying soil and groundwater according to the second aspect of the present invention, the liquid containing fine bubbles is substantially uniformly dispersed in the region to be purified. The growth or activity of the existing microorganisms is activated and can be purified substantially uniformly over the entire area to be purified.

According to the method for purifying soil and groundwater of claim 3 of the present invention, a liquid containing fine bubbles is injected or permeated into the ground, so that the rising speed of the bubbles in the ground is low, Liquid containing fine bubbles flows through the area to be purified. Therefore, the area to be purified by the flow of the liquid and the flow of the fine bubbles contained therein, that is, the contaminants contained in the soil and / or the contaminants attached to the soil surface are washed. In addition, the fine bubbles enter between the small soil particles due to the flow of the liquid, and the purification ability can be enhanced. According to the method for purifying soil and groundwater of claim 4 of the present invention, groundwater is circulated through the area to be purified, and the area to be purified using groundwater, that is, contaminated soil and / or contaminated groundwater is required. Can be purified on the street.

According to the method for purifying soil and groundwater of claim 5 of the present invention, nutrients added to groundwater are given to microorganisms in the soil, and the growth or activity of such microorganisms is further activated. Purification action by microorganisms can be further enhanced. Further, according to the method for purifying soil and groundwater of the sixth aspect of the present invention, groundwater is pumped under reduced pressure using a vacuum pump, so that a large amount of groundwater can be pumped.

Further, according to the method for purifying soil and groundwater of claim 7 of the present invention, the heavy metals in the groundwater are removed by the heavy metal treatment device, the oil in the groundwater is removed by the oil removing device, and the groundwater removed therefrom is removed. Is injected or permeated into the ground, so that the area to be purified can be more effectively purified. Further, according to the method for purifying soil and groundwater according to claims 8 and 9 of the present invention, air bubbles in a liquid containing air bubbles can be injected into the ground in a fine state. Furthermore,
According to the method for purifying soil and groundwater according to claim 10 of the present invention, since the microbubble generating member is provided at the tip of the pipe into which the liquid is injected, the air bubbles in the liquid are further reduced to a finer state. Can be injected.

[Brief description of the drawings]

FIG. 1 shows a first method of purifying soil and groundwater according to the present invention.
1 is a plan view schematically showing a first embodiment of a soil and groundwater purification system to which the example of the present invention is applied.

FIG. 2 is a cross-sectional view schematically illustrating the soil and groundwater purification system of FIG.

FIG. 3 shows a second method of purifying soil and groundwater according to the present invention.
It is sectional drawing which shows a part of 2nd Embodiment of the purification system of the soil and the groundwater to which Example of this is applied simply.

FIG. 4 is a diagram illustrating a third method of purifying soil and groundwater according to the present invention;
It is sectional drawing which shows a part of 3rd Embodiment of the purification system of the soil and the groundwater to which Example of this is applied simply.

FIG. 5 shows a fourth method of purifying soil and groundwater according to the present invention.
It is sectional drawing which shows a part of 4th Embodiment of the purification system of the soil and the groundwater to which Example of this is applied simply.

FIG. 6 is a sectional view schematically showing a modified form of a pumping section of a pumping well.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main liquid supply pipe 2, 4 Branch liquid supply pipe 5, 7 Air supply pipe 6 Air injection mechanism 8 Area to be purified 32 Pumping well 46 Groundwater 52, 82 Liquid supply pipe 54, 84 Air supply pipe 92 Oil removal device 94 Heavy metal Processing equipment

Claims (10)

[Claims] 1. A liquid containing fine air bubbles is injected or penetrated into the ground to make oxygen supply into the ground uniform, thereby activating the growth or activity of microorganisms that decompose pollutants contained in the ground. A method for purifying soil and groundwater, comprising decomposing and purifying soil. 2. The method for purifying soil and groundwater according to claim 1, wherein the liquid containing fine air bubbles is substantially uniformly dispersed in an area of the ground to be purified. 3. Injecting or infiltrating a liquid containing fine bubbles into the ground, flowing said liquid through an area of the ground to be purified, said liquid being contained in the soil and / or
Alternatively, a method for purifying soil and groundwater, comprising cleaning and purifying contaminants adhering to the surface of soil and causing fine bubbles and / or oxygen caused by the fine bubbles to permeate between small soil particles. 4. Using groundwater as a liquid containing fine bubbles, providing a pumping hole in relation to an area to be purified, and allowing the groundwater pumped from the pumping hole to contain fine bubbles and then into the ground. The method for purifying soil and groundwater according to any one of claims 1 to 3, wherein groundwater is circulated through a region to be injected or permeated and purified. 5. The method for purifying soil and groundwater according to claim 4, wherein a nutrient substance of a decomposing microorganism is added to the groundwater pumped from the pumping hole and then injected or permeated into the ground. 6. The pump according to claim 4, wherein a decompression pump is used to depressurize the pumping hole, the groundwater is pumped in a decompressed state by the decompression pump, and the pumped groundwater is injected or permeated into the ground. The method for purifying soil and groundwater according to the above. 7. The groundwater pumped from the pumping hole flows through a heavy metal treatment device and an oil removal device, and the heavy metal treatment device removes heavy metals contained in the groundwater, and the oil removal device removes oil contained in the groundwater. The method for purifying soil and groundwater according to any one of claims 4 to 6, wherein the groundwater from which heavy metals and oil are removed contains air. 8. An air supply pipe for supplying air and a liquid supply pipe for supplying liquid are buried in the ground, and a tip of the air supply pipe is connected to a tip of the liquid supply pipe. The method for purifying soil and groundwater according to any one of claims 1 to 7, wherein the air flowing through the air supply pipe is mixed with the liquid flowing through the ground, and the liquid containing fine bubbles is injected into the ground. 9. An air supply pipe for supplying air is disposed radially inward of a liquid supply pipe for supplying liquid and buried in the ground, and a liquid flowing through the liquid supply pipe at a tip end of the liquid supply pipe. The method for purifying soil and groundwater according to any one of claims 1 to 7, wherein air flowing through the air supply pipe is mixed with the air, and a liquid containing fine bubbles is injected into the ground. 10. A microbubble generating member having a large number of micropores is provided at a tip of a pipe for injecting a liquid containing fine bubbles into the ground. 3. The method for purifying soil and groundwater according to item 1.