JP4374951B2 - Purification method and system for hardly air permeable and contaminated soil - Google Patents

Description

  The present invention relates to a purification method and system for recovering and purifying contaminants present in hardly permeable and air permeable contaminated soil.

  Various pollutants such as volatile organic chlorine compounds such as trichlorethylene, fuel oils and machine oils, dioxins, and heavy metals such as cadmium, lead, copper, zinc, nickel and chromium are found in the soil of the factory site. May be in the soil.

  If the contaminated soil contaminated with such contaminants is left as it is, the contaminants mixed in the soil will diffuse to the surroundings, hindering the lives of the surrounding residents, and if they are released from the soil particles by rainwater In addition, it may cause contamination of groundwater by contaminating water quality. Therefore, the soil contaminated with the above-mentioned pollutants must be cleaned using various methods.

Various methods have been developed to purify pollutants in the soil in-situ, so-called water-cleaning methods that use the soil gas suction method, injecting water into the contaminated soil, pumping it up, and treating it on the ground. Various methods, such as the so-called bubble entrainment purification method, in which air is introduced and entrained pollutants in the bubbles, the air sparging method that combines pneumatic injection and gas suction, and the bioremediation method that utilizes the microbial activity of soil fungi The method is known.
JP 2002-119952 A JP 2001-205248 A

  However, when the pollutant is present in a hardly air permeable water permeable layer such as a clay layer or a silt layer, the above-described method cannot be employed. That is, since these hardly permeable air permeable layers have poor air permeability and water permeability, there is relatively little concern about the entry of contaminants. However, once the contaminants are mixed into the hardly permeable air permeable layer, as described above. On the other hand, the poor tempering and water permeability impeded purification, which caused the problem that it was very difficult to recover the pollutants from the hardly permeable air permeable layer.

  The present invention has been made in consideration of the above-described circumstances, and provides a purification method and system for hardly permeable and air permeable contaminated soil capable of reliably and efficiently recovering contaminants present in the hardly permeable and air permeable layer. For the purpose.

In order to achieve the above object, the method for purifying hardly permeable and air permeable contaminated soil according to the present invention, as described in claim 1, is applied to a contaminated area contaminated with contaminants in the saturated permeable and air permeable layer. An oscillating body is embedded, and vibrations are applied to the soil particles in the contaminated area by driving the oscillating body, and air is injected into the contaminated area, and then the contaminant is entrained in the injected air. Air is allowed to rise as an air bubble to the unsaturated air permeable layer that extends above the hardly-saturated air permeable layer , and then the contaminants are embedded in the unsaturated air permeable layer along with the air so as to extend in the horizontal direction. A suction process is performed by performing suction with a suction pipe .
Further, in the method for purifying hardly air-permeable and permeable contaminated soil according to the present invention, the vibrator is composed of a pile or a sheet pile whose lower end is embedded in the contaminated area and a vibro hammer attached to the upper end of the pile or sheet pile. It is composed.

  Moreover, the purification method of the hardly permeable and air permeable contaminated soil according to the present invention is such that the vibrator is configured by a vibrator.

Further, purification system NanToruki permeability contaminated soils according to the present invention as described in claim 4, among the saturated flame permeability aquifer, the buried driven operation in contaminated areas which are contaminated with pollutants A vibrating body that imparts vibrations to the soil particles in the contaminated area, an air pressure injecting mechanism that injects air into the contaminated area, and an unsaturation that is entrained in the injected air and spreads above the saturated hardly permeable air permeable layer. A gas processing facility for performing a purification process by sucking contaminants floating up to the air permeable layer together with the air by a suction pipe embedded in the unsaturated air permeable layer so as to extend in the horizontal direction is provided.

Further, in the purification system for hardly permeable and air permeable contaminated soil according to the present invention, the air pressure insertion mechanism is a press-fit pipe embedded so that an air discharge port is located in a contaminated region of the saturated hardly permeable and air permeable layer, An air compressor connected to the press-fitting pipe through an air tank, and the gas treatment facility, a suction pipe embedded in an unsaturated gas permeable layer extending above the saturated gas permeable layer, A gas-liquid separation tank connected to the suction pipe, a suction blower connected to the gas phase space of the gas-liquid separation tank, a harmful substance removing device connected to the suction blower, and the gas-liquid separation tank It is composed of a water treatment facility connected to the liquid phase space .
In the purification method and system for hardly permeable and air permeable contaminated soil according to the present invention, a vibrating body is embedded in a contaminated area contaminated with a contaminant in the saturated permeable and air permeable layer, and the driving operation of the vibrating body is performed. Thus, vibration is applied to the soil particles in the contaminated area, and air is press-fitted into the contaminated area using an air pressure inserting mechanism.

  When the soil particles are thus vibrated, unlike the conventional air sparging method and bubble entrainment purification method, the soil particles collide with each other in the contaminated region of the saturated hardly permeable air permeable layer. Contamination that has adhered to the surface of the soil particles as a result of new gaps between the particles, the gap being larger than the original size, the skeleton of the soil particles being destroyed, and the soil particles rubbing against each other Material peels from the surface.

  In such a state, when the injected air flows through the gaps between the soil particles, the flow resistance is greatly reduced, and contaminants attached to the soil particles are released into the gaps between the soil particles. , Pollutants are also easily taken to the air.

  Therefore, while entraining the pollutant in the injected air, the air is lifted as an air bubble to the unsaturated air permeable layer, and after that, the contaminant is sucked together with the air in the gas processing facility to perform the purification process. This makes it possible to reliably and efficiently purify the hardly permeable and air permeable contaminated soil, which is impossible with the conventional air sparging method or the like.

  Contaminants mainly include oil and volatile organic compounds (including volatile organic chlorine compounds), but any substance that can be air-entrained, such as dioxins, is included in the contaminants referred to in the present invention. .

  The hardly permeable air permeable layer in the saturated permeable air permeable layer mainly means a silt layer or a clay layer, but because of its poor air permeability and water permeability, conventional methods such as water washing, gas suction, air sparging method, etc. Then, if the pollutant cannot be recovered, a soil layer containing sand in addition to silt or clay is naturally included in the hardly permeable air permeable layer referred to in the present invention.

The configuration of the pneumatic injection mechanism and the gas processing equipment is arbitrary. For example, the pneumatic injection mechanism includes a press-fitting pipe embedded with an air discharge port located in a contaminated region of the saturated hardly permeable air permeable layer, and an air An air compressor connected to the press-fitting pipe through a tank, and the gas treatment facility, a suction pipe embedded in an unsaturated air permeable layer extending above the saturated hardly air permeable water layer, A gas-liquid separation tank connected to the suction pipe; a suction blower connected to the gas-phase space of the gas-liquid separation tank; a hazardous substance removing device connected to the suction blower; and a liquid in the gas-liquid separation tank It is conceivable that the water treatment equipment is connected to the phase space .
The present applicant has newly found that the soil particles can be vibrated by a vibrating body, thereby causing the above-described action, and thus improving the water permeability and air permeability of the hardly permeable air permeable layer. In addition, it is an extremely useful knowledge in the industry, and it has a remarkably effective effect as compared with the prior art.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a purification method and system for hardly permeable and air permeable contaminated soil according to the present invention will be described with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.

(First embodiment)
FIG. 1 is a view showing a purification system for hardly air permeable and contaminated soil according to the present embodiment. As shown in the figure, the hardly permeable and air permeable contaminated soil purification system 1 according to the present embodiment includes a steel sheet pile 20 as a vibrating body, a vibro hammer 10 attached to the upper end of the steel sheet pile, and a groundwater level. An air pressure injection mechanism 5 for injecting air into a contaminated area 4 contaminated with a pollutant 3 such as oil, dioxins or volatile organic chlorine compounds in the saturated hardly permeable air permeable layer 2 present below, The steel sheet pile 20 is saturated at the lower end of the steel sheet pile 20 with a gas treatment facility 13 that sucks together with the air the contaminant 3 that has been entrained in the air and has floated up to the unsaturated air permeable layer 7 through the saturated water permeable layer 6. It is embedded in the contaminated area 4 of the hardly air-permeable permeable layer 2, and the vibration can be imparted to the soil particles in the contaminated area 4 by driving the vibro hammer 10.

  The saturated hardly air permeable water permeable layer 2 is made of soil mainly composed of silt, clay, or clay soil, so that it is inferior in air permeability and water permeability. On the other hand, the saturated water permeable layer 6 and the unsaturated air permeable layer 7 are soil layers made of sandy soil having water permeability and air permeability, respectively.

  The air pressure input mechanism 5 includes an air compressor 12, an air tank 11 that intermediately stores air supplied from the air compressor, and an air discharge port 8 connected to the air tank 11 that is formed of the saturated hardly permeable air permeable layer 2. The press-in pipe 9 is embedded so as to be located in the contaminated area 4, and air from the air compressor 12 can be press-fitted into the contaminated area 4 through the press-in pipe 9.

  The gas treatment facility 13 includes a suction pipe 14 embedded in the unsaturated gas permeable layer 7 that extends above the saturated hardly-permeable gas permeable layer 2, a gas-liquid separation tank 15 connected to the suction pipe, and the gas-liquid separation. A suction blower 16 connected to the gas phase space of the tank, an activated carbon filter tank 17 as a harmful substance removing device connected to the suction blower, and a water treatment facility connected to the liquid phase space of the gas-liquid separation tank 18.

  In order to install the purification system 1 of the hardly permeable and air permeable contaminated soil according to the present embodiment, first, the pneumatic injection mechanism 5 is placed in the contaminated area 4 of the saturated permeable and air permeable layer 2 that is contaminated with the contaminant. A press-fitting pipe 9 is installed.

  When the press-fit pipe 9 is installed, the corresponding position is bored in advance, and then the press-fit pipe 9 is inserted into the bore hole, and then the press-fit pipe 9 and the bore hole are prevented so that the air discharge port 8 is not blocked. In order to fix the press-fitting pipe 9 in between, a mortar, bentonite, etc. are filled in a space shallower than the air discharge port 8 in order to fix the press-fitting pipe 9.

  Next, an air tank 11 and an air compressor 12 are sequentially connected to the upper end of the press-fit pipe 9.

  The steel sheet pile 20 is driven so as to penetrate into the unsaturated gas permeable layer 7 and the saturated water permeable layer 6 before and after the installation of the press-fit pipe 9, and the lower end of the saturated gas permeable layer 2 is contaminated. The vibratory hammer 10 is attached to the upper end of the steel sheet pile 20 after being buried in the contaminated area 4 contaminated with the substance. The steel sheet pile 20 may be driven with the vibro hammer 10.

  On the other hand, a suction pipe 14 is embedded in the unsaturated gas permeable layer 7 and a gas-liquid separation device 15 is connected to the suction pipe. Thereafter, as described above, the suction blower 16 and activated carbon are communicated with the gas phase space. The filter tank 17 is sequentially connected, and the water treatment facility 18 is connected so as to communicate with the liquid phase space.

  In order to purify the hardly permeable and water-permeable contaminated soil, that is, the contaminated region 4 of the saturated permeable and permeable water-permeable layer 2 in this embodiment, using the purification system 1 installed in this way, first, the vibro hammer 10 is driven. Thus, the soil particles in the contaminated region 4 are vibrated through the steel sheet pile 20, and the air compressor 12, the air tank 11, and the pressure vessel 10 are appropriately operated to contaminate the saturated hardly permeable air permeable layer 2. Air is pressed into region 4.

  In this way, unlike the conventional air sparging method and bubble entrainment purification method, soil particles collide with each other in the contaminated region 4 of the saturated hardly permeable air permeable layer 2 and a new gap is formed between the soil particles. Or the gap becomes larger than the original size, the skeleton of the clay soil is destroyed, and the soil particles rub against each other, so that the contaminants attached to the surface of the soil particles are peeled off from the surface. .

  FIG. 2 shows an example of the case where the skeletal fracture of the viscous soil occurs, and FIG. 2A shows the skeleton of the viscous soil before the driving operation of the vibro hammer 10. b) schematically shows the skeleton of the cohesive soil after such a driving operation.

  As can be seen from these figures, the skeleton of the viscous soil is broken by the driving operation of the vibro hammer 10 so that the soil particles are separated, the voids 21 are newly formed, and the contaminant 3 attached to the surface of the soil particles 3 Peels from the soil particles.

  Even when the skeleton is not destroyed, a new gap is generated by the driving operation of the vibro hammer 10 or the original gap is increased. Thus, the air 22 press-fitted through the press-fitting pipe 9 is When flowing through the gaps 21 between the soil particles, the flow resistance is greatly lowered and the flow is facilitated, and the contaminant 3 adhering to the soil particles is released in the gaps 21 between the soil particles. 3 is also easily taken to the air 22.

  Next, after the injected air 22 floats up to the unsaturated gas permeable layer 7 as a bubble while entraining the pollutant 3, the pollutant 3 is sucked together with the air 22 by the gas processing equipment 13 to perform a purification process. Suction is performed by operating the suction blower 16.

  Next, the sucked pollutant entrained air is separated into liquid and gas in the gas-liquid separation tank 15, and the gas is passed through the activated carbon filter tank 17 to adsorb the pollutant 3 on the activated carbon, and then released to the atmosphere. At the same time, for the liquid, the pollutant 3 is removed by the water treatment facility 18 and then discharged into a river or the like.

  Even in the case of the unsaturated air permeable layer 7, the substance to be sucked is not only gas but also moisture is sucked in some amounts depending on weather conditions such as rainfall, and therefore the gas-liquid separation tank 15 is interposed. Needless to say, it is desirable to install the water treatment facility 18.

  As described above, according to the purification method and system for hardly permeable and air permeable contaminated soil according to the present embodiment, unlike the conventional air sparging method and bubble entrainment purification method, the steel sheet pile 20 is interposed. By applying vibration to the contaminated area 4 by the vibro hammer 10, the soil particles collide with each other to create a new gap between the soil particles, the gap becomes larger than the original size, or the soil particle skeleton is destroyed. At the same time, the soil particles rub against each other, so that the contaminant 3 attached to the surface of the soil particles is peeled off from the surface.

  In such a state, when the injected air 22 flows through the gap between the soil particles, the flow resistance is greatly reduced, and the contaminant 3 attached to the soil particles is released into the gap between the soil particles. Therefore, the contaminant 3 is also easily taken to the air 22.

  For this reason, if the injected air 22 entrains the pollutant 3 and rises to the unsaturated air permeable layer 7 as bubbles, then the pollutant 3 is sucked together with the air 22 to perform a purification process. It becomes possible to reliably and efficiently purify the saturated hardly permeable air permeable layer 2 which was impossible by the law.

  In the present embodiment, the steel sheet pile 20 is employed as a member that transmits the excitation force of the vibro hammer 10 to the contaminated region 4. However, any material can be used as long as vibration can be imparted to the soil particles in the contaminated region 4. Such a member may be used. For example, a pile can be used instead of the steel sheet pile 20.

(First Reference Example )
FIG. 3 is a view showing a purification system for hardly air permeable and contaminated soil according to the first reference example . As can be seen in the figure, as shown in the figure, the purification system 31 for the hardly permeable and air permeable contaminated soil according to the present reference example , as in the first embodiment, is a steel sheet pile 20 as a vibrating body and the steel product. A vibro hammer 10 attached to the upper end of the sheet pile is provided, and the lower end of the steel sheet pile 20 is a pollutant such as oil, dioxins or volatile organic chlorine compounds in the saturated hardly permeable air permeable layer 2 existing below the groundwater level. 3 is embedded in the contaminated area 4 that is contaminated, and by driving the vibro hammer 10, vibration can be imparted to the soil particles in the contaminated area 4.

Moreover, the purification system 31 of the hardly air-permeable and permeable contaminated soil according to the present reference example is located in the contaminated area 4 and the infiltrated area 34 in the saturated permeable layer 6 that is located above the contaminated area and into which contaminants enter. A water injection well 32 and a water pumping well 33 buried in opposite positions across the water, and a water treatment facility 8 for purifying the water pumped through the water pumping well 33 and circulatingly pumping the purified treated water to the water injection well 32 Prepare.

  As in the first embodiment, the purification system 31 in which the steel sheet pile 20 and the vibro hammer 10 are installed is used to purify the hardly permeable and permeable contaminated soil, in this embodiment, the contaminated region 4 of the saturated permeable and permeable permeable layer 2. First, by driving the vibro hammer 10, vibration is imparted to the soil particles in the contaminated region 4 through the steel sheet pile 20, and the treated water from which the contaminant 3 has been removed is used as washing water. The water is pumped from the water treatment facility 18 to the water injection well 32, and the washing water is pumped through a pumping pump (not shown) installed at the bottom of the pumping well 33.

  In this way, unlike the conventional air sparging method and bubble entrainment purification method, by applying vibration to the contaminated region 4 by the vibro hammer 10 via the steel sheet pile 20, the soil particles collide with each other and There was a new gap between the soil particles, the gap became larger than the original size, the skeleton of the clay soil was destroyed, and the soil particles were rubbed together and adhered to the surface of the soil particles Contaminants are stripped from the surface.

  As a result, when the water injected from the water injection well 32 flows through the gaps between the soil particles in the contaminated region 4 of the saturated hardly permeable air permeable layer 2, the flow resistance is greatly reduced and the water is easily flown. Since the pollutant 3 adhering to the particles is liberated in the gaps between the soil particles, the pollutant 3 is also easily taken into the injected water. As for the saturated water permeable layer 6, even if the contaminant 3 from the saturated hardly permeable air permeable layer 2, for example, a volatile organic chlorine compound, enters the saturated water permeable layer, the pollutant has no problem in the injected water. Taken away.

  That is, in such water injection and pumping, the water injection well 32 and the water pumping well 33 are embedded in opposing positions sandwiching the contaminated area 4 and the intrusion area 34 as described above, and both the contaminated area 4 and the intrusion area 34 are water-permeable. Washed. Therefore, the pumped water includes not only the pollutant 3 in the polluted area 4 but also the pollutant 3 that has entered the saturated water permeable layer 6 from the polluted area.

  Next, the water passed through the saturated hardly permeable air permeable layer 2 and the saturated permeable water layer 6 is pumped from the pumping well 33 and purified by the water treatment facility 18, and then the treated water is returned to the water injection well 32. The surplus is discharged as appropriate.

As described above, according to the purification method and system for hardly permeable air permeable contaminated soil according to this reference example , unlike the conventional air sparging method and bubble entrainment purification method, the steel sheet pile 20 is interposed. By applying vibration to the contaminated area 4 by the vibro hammer 10, the soil particles collide with each other to create a new gap between the soil particles, the gap becomes larger than the original size, or the soil particle skeleton is destroyed. As the soil particles rub against each other, the contaminant 3 attached to the surface of the soil particles is peeled off from the surface.

  In such a state, when the injected water flows through the gaps between the soil particles, the flow resistance is greatly reduced, and the contaminant 3 attached to the soil particles is released into the gaps between the soil particles. For this reason, the pollutant 3 is also easily taken to the injected water.

  Therefore, by pumping water from the pumping well 33 while entraining the pollutant 3 in the water poured from the water pouring well 32, it is possible to surely purify the saturated hardly permeable air permeable layer 2 that was impossible with the conventional air sparging method and the like. It becomes possible to carry out efficiently. In this case, it goes without saying that heavy metals such as cadmium, lead, copper, zinc, nickel, and chromium can also be recovered.

Further, according to the purification method and system for hardly permeable and air permeable contaminated soil according to this reference example , the contaminant 3 enters the saturated permeable layer 6 by washing both the contaminated area 4 and the intrusion area 34 with water. Even if it happens, this can be reliably recovered, and purification in the contaminated area 4 can be performed more reliably and efficiently.

In this reference example , both the contaminated area 4 and the intrusion area 34 are washed with water. However, if there is no need to wash the intrusion area 34 with water, only the contaminated area 4 is washed with water. It doesn't matter.

( Second Embodiment)
Next, a second embodiment will be described. Note that components that are substantially the same as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 4 is a diagram showing a purification system for hardly air permeable and contaminated soil according to the second embodiment. As shown in the figure, a hardly permeable and air permeable contaminated soil purification system 41 according to the present embodiment includes a vibrator 42 as a vibrating body and an oil and a saturated permeable and air permeable layer 2 existing below a groundwater level. An air pressure injection mechanism 5 for injecting air into the contaminated area 4 contaminated with the contaminant 3 such as dioxins or volatile organic chlorine compounds, and the contaminant 3 entrained in the injected air and rising to the unsaturated air-permeable layer 7 And a gas treatment facility 13 that performs a purification process by sucking the air together with the air, and the vibrator 42 is embedded in the contaminated area 4 of the saturated hardly permeable air permeable layer 2 and operates the vibrator to operate the contaminated area. Vibration can be imparted to the soil particles in 4.

  The saturated hardly air permeable water permeable layer 2 is made of soil mainly composed of silt, clay, or clay soil, so that it is inferior in air permeability and water permeability. On the other hand, the unsaturated air permeable layer 7 is a soil layer made of sandy soil having air permeability, for example.

  In order to install the purification system 41 of the hardly permeable and air permeable contaminated soil according to the present embodiment, first, the pneumatic injection mechanism 5 is placed in the contaminated area 4 contaminated with the contaminants in the saturated permeable and permeable water permeable layer 2. A press-fitting pipe 9 is installed.

  When the press-fit pipe 9 is installed, the corresponding position is bored in advance, and then the press-fit pipe 9 is inserted into the bore hole, and then the press-fit pipe 9 and the bore hole are prevented so that the air discharge port 8 is not blocked. In order to fix the press-fitting pipe 9 in between, a mortar, bentonite, etc. are filled in a space shallower than the air discharge port 8 in order to fix the press-fitting pipe 9.

  Next, an air tank 11 and an air compressor 12 are sequentially connected to the upper end of the press-fit pipe 9.

  Before and after the installation of the press-fit pipe 9, an appropriate number of vibrators 42 are embedded in the contaminated region 4 contaminated with the pollutant in the saturated hardly permeable air permeable layer 2, and the respective vibrators are not shown. Connect to.

  On the other hand, a suction pipe 14 is embedded in the unsaturated gas permeable layer 7 and a gas-liquid separation device 15 is connected to the suction pipe. Thereafter, as described above, the suction blower 16 and activated carbon are communicated with the gas phase space. The filter tank 17 is sequentially connected, and the water treatment facility 18 is connected so as to communicate with the liquid phase space.

  In order to purify the hardly air permeable and contaminated soil, in this embodiment, the contaminated region 4 of the saturated hardly permeable and air permeable layer 2 using the purification system 41 thus installed, first, the vibrator 42 is driven and operated. Thus, vibration is applied to the soil particles in the contaminated region 4 and air is pressed into the contaminated region 4 of the saturated hardly permeable air permeable layer 2 by appropriately operating the air compressor 12, the air tank 11 and the pressure vessel 10.

  In this way, unlike the conventional air sparging method and bubble entrainment purification method, soil particles collide with each other in the contaminated region 4 of the saturated hardly permeable air permeable layer 2 and a new gap is formed between the soil particles. Or the gap becomes larger than the original size, the skeleton of the clay soil is destroyed, and the soil particles rub against each other, so that the contaminants attached to the surface of the soil particles are peeled off from the surface. .

  For example, the skeleton of the viscous soil is broken by the driving operation of the vibrator 42, and the soil particles are separated, voids are newly generated, and the contaminant 3 attached to the surface of the soil particles is separated from the soil particles.

  Even when the skeleton is not destroyed, a new gap is generated by the driving operation of the vibrator 42, or the original gap is increased, and thus the air press-fitted through the press-fitting pipe 9 becomes soil particles. When flowing through the gaps between them, the flow resistance is greatly reduced and the flow is facilitated, and the contaminants 3 adhering to the soil particles are released in the gaps between the soil particles. It becomes easy to be taken.

  Next, after the injected air floats up to the unsaturated air permeable layer 7 as bubbles while entraining the pollutant 3, the pollutant 3 is sucked together with the air by the gas processing facility 13 to perform the purification process. Suction is performed by operating the suction blower 16.

  Next, the sucked pollutant entrained air is separated into liquid and gas in the gas-liquid separation tank 15, and the gas is passed through the activated carbon filter tank 17 to adsorb the pollutant 3 on the activated carbon, and then released to the atmosphere. At the same time, for the liquid, the pollutant 3 is removed by the water treatment facility 18 and then discharged into a river or the like.

  Even in the case of the unsaturated air permeable layer 7, the substance to be sucked is not only gas but also moisture is sucked in some amounts depending on weather conditions such as rainfall, and therefore the gas-liquid separation tank 15 is interposed. Needless to say, it is desirable to install the water treatment facility 18.

  As described above, according to the purification method and system for hardly permeable and air permeable contaminated soil according to the present embodiment, the contaminated region 4 due to the vibrator 42 is different from the conventional air sparging method and bubble entrainment purification method. By applying vibration to the soil particles, the soil particles collide with each other, and a new gap is generated between the soil particles, the gap becomes larger than the original size, or the skeleton of the soil particles is destroyed. As a result of rubbing, the contaminant 3 adhering to the surface of the soil particles is peeled off from the surface.

  In such a state, when the injected air flows through the gaps between the soil particles, the flow resistance is greatly reduced, and the contaminant 3 attached to the soil particles is released into the gaps between the soil particles. Therefore, the contaminant 3 is also easily taken to the air.

  Therefore, if the injected air floats up to the unsaturated air permeable layer 7 as a bubble while entraining the pollutant 3, and then the contaminant 3 is sucked together with the air to perform the purification process, the conventional air sparging method, etc. Thus, it becomes possible to reliably and efficiently purify the saturated hardly permeable air permeable layer 2 that was impossible.

( Second reference example )
Next, a second reference example will be described. Incidentally, this reference example, instead of the washing with air injection and gas suction of the second embodiment is obtained by adopting the configuration in which the water flow washing, the same reference numerals for the second embodiment and the same parts, etc. The description is omitted.

FIG. 5 is a view showing a purification system for hardly air permeable and contaminated soil according to a second reference example . As can be seen in the figure, as shown in the figure, the hardly permeable and permeable contaminated soil purification system 51 according to this reference example includes a vibrator 42 as a vibrating body, as in the second embodiment. Of the saturated hardly permeable air permeable layer 2 existing below the groundwater level, it is buried in the contaminated area 4 contaminated with the pollutant 3 such as oil, dioxins or volatile organic chlorine compounds, and operates the vibrator 42 By doing so, vibration can be imparted to the soil particles in the contaminated area 4.

Moreover, the purification system 51 of the hardly air-permeable and permeable contaminated soil according to this reference example includes a water injection well 32 and a pumping well 33 embedded in opposed positions across the contaminated area 4, and water pumped through the pumping well 33. And a water treatment facility 8 that circulates and pumps the purified treated water to the water injection well 32.

In order to purify the hardly permeable air permeable contaminated soil, in this reference example , the contaminated region 4 of the saturated permeable air permeable layer 2 using the purification system 51 in which the vibrator 42 is installed as in the second embodiment, By driving the vibrator 42, the soil particles in the contaminated area 4 are vibrated, and the treated water from which the pollutants 3 have been removed is pumped from the water treatment facility 18 to the water injection well 32, and the treated water is pumped up. Water is pumped through a pumping pump (not shown) installed at the bottom of the well 33.

  In this way, unlike the conventional air sparging method and bubble entrainment purification method, the vibration applied to the contaminated region 4 by the vibrator 42 causes the soil particles to collide with each other, resulting in a new gap between the soil particles. This occurs, the gap becomes larger than the original size, the skeleton of the viscous soil is destroyed, and the soil particles rub against each other, so that the contaminants attached to the surface of the soil particles are peeled off from the surface.

  As a result, when the water injected from the water injection well 32 flows through the gaps between the soil particles in the contaminated region 4 of the saturated hardly permeable air permeable layer 2, the flow resistance is greatly reduced and the water is easily flown. Since the pollutant 3 adhering to the particles is liberated in the gaps between the soil particles, the pollutant 3 is also easily taken into the injected water.

  That is, in such water injection and pumping, the water injection well 32 and the water pumping well 33 are embedded in the opposite positions across the contaminated area 4 as described above, and the contaminated area 4 is washed with water. Contaminant 3 in the contaminated area 4 is included.

  Next, after the water pumped from the pumping well 33 is purified by the water treatment facility 18, the treated water is returned to the water injection well 32, and the surplus is discharged appropriately.

As explained above, according to the purification method and system for hardly permeable and air permeable contaminated soil according to this reference example , unlike the conventional air sparging method and bubble entrainment purification method, the contaminated area 4 by the vibrator 42 is obtained. By applying vibration to the soil particles, the soil particles collide with each other, and a new gap is generated between the soil particles, the gap becomes larger than the original size, or the skeleton of the soil particles is destroyed. As a result of rubbing, the contaminant 3 adhering to the surface of the soil particles is peeled off from the surface.

  In such a state, when the injected water flows through the gaps between the soil particles, the flow resistance is greatly reduced, and the contaminant 3 attached to the soil particles is released into the gaps between the soil particles. For this reason, the pollutant 3 is also easily taken to the injected water.

  Therefore, by pumping water from the pumping well 33 while entraining the pollutant 3 in the water poured from the water pouring well 32, it is possible to surely purify the saturated hardly permeable air permeable layer 2 that was impossible with the conventional air sparging method and the like. It becomes possible to carry out efficiently. In this case, it goes without saying that heavy metals such as cadmium, lead, copper, zinc, nickel, and chromium can also be recovered.

In this reference example, it is assumed that the saturated hardly permeable air permeable layer 2 is distributed at a relatively shallow position, and the vibrator 42 is selected as the vibrator, and the unsaturated permeable air permeable layer 2 is placed on the saturated hardly permeable air permeable layer 2. In the case where the air permeable layer 7 is present, but the saturated water permeable layer 6 exists between the saturated hardly permeable air permeable layer 2 and the unsaturated air permeable layer 7, the contamination region 4 and the contamination region are positioned above the contamination region 4. What is necessary is just to embed the water injection well 32 and the pumping well 33 in the position which opposes the penetration | invasion area | region 34 in the saturated permeable layer 6 to perform, and to wash | clean both the contamination area | region 4 and the penetration | invasion area | region 34 with water.

  According to such a configuration, even if the pollutant 3 is a volatile organochlorine compound that floats up and enters the saturated water permeable layer 6, it can be reliably recovered, Can be more reliably and efficiently performed.

Schematic of the purification system of the hardly air permeable water-contaminated soil which concerns on 1st Embodiment. The schematic diagram which showed an example of the effect | action of the purification method of the hardly air permeable permeation | contamination soil which concerns on 1st Embodiment. Schematic of the purification system of the hardly air permeable water-contaminated soil which concerns on a 1st reference example . Schematic of the purification system of the hardly air permeable water-contaminated soil which concerns on 2nd Embodiment. Schematic of the purification system of the hardly air permeable water-contaminated soil which concerns on a 2nd reference example .

Explanation of symbols

1,31,41,51 Purification system for hardly air permeable and permeable contaminated soil 2 Saturated hardly permeable and air permeable layer 3 Pollutant 4 Contaminated area 5 Pneumatic inlet mechanism 7 Unsaturated air permeable layer 9 Press-in pipe 10 Vibro hammer (vibrating body)
11 Air tank 12 Air compressor 13 Gas processing equipment 14 Suction pipe 15 Gas-liquid separation tank 16 Suction blower 17 Activated carbon filter tank (Toxic substance removal device)
18 Water treatment equipment 20 Steel sheet pile (vibrating body)
32 Water injection well 33 Pumping well 34 Intrusion area 42 Vibrator (vibrating body)

Claims (5)

Of the saturated hardly permeable air permeable layer, a vibrating body is embedded in a contaminated area contaminated with a pollutant, and vibration is applied to the soil particles in the contaminated area by driving the vibrating body and air is passed through the contaminated area. Then, the air is bubbled up to the unsaturated air permeable layer spreading above the saturated hardly air permeable water layer while entraining the air pollutant in the injected air, and then the pollutant A method for purifying hardly air-permeable and water-contaminated soil, wherein the air is sucked together with the air by a suction pipe embedded in the unsaturated air- permeable layer so as to extend in the horizontal direction . Said vibrating body, and a pile or sheet pile bottom is embedded in the contaminated region, purification method of claim 1 Symbol placement poorly air permeability permeability contaminated soils was constituted by a vibro-hammer over to be attached to the upper end of該杭or sheet pile . Purification method of flame permeability permeability contaminated soils of the vibrating body according to claim 1 Symbol placement was composed of vibrator. Of the saturated hardly permeable air permeable layer, a vibrator embedded in a contaminated area contaminated with a pollutant and imparting vibration to soil particles in the contaminated area by a driving operation, and an air pressure inlet for injecting air into the contaminated area A mechanism and a contaminant that is entrained in the injected air and floats up to the unsaturated air permeable layer that extends above the saturated hardly permeable air permeable layer, along with the air , extend in the horizontal direction to the unsaturated air permeable layer. A system for purifying hardly air-permeable and permeable contaminated soil, comprising: a gas treatment facility for performing purification treatment by suction with a buried suction pipe . The air pressure insertion mechanism includes a press-fit pipe embedded so that an air discharge port is located in a contaminated region of the saturated hardly permeable air permeable layer, and an air compressor connected to the press-fit pipe via an air tank. together, the gas processing facility, before and Ki吸引管, a gas-liquid separation tank connected to the suction pipe, a suction blower, which is communicatively connected to the gas-phase space of the gas-liquid separation tank, to the suction blower The system for purifying hardly permeable and air permeable contaminated soil according to claim 4 , comprising a connected harmful substance removing device and a water treatment facility connected to the liquid phase space of the gas-liquid separation tank.

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