JP2005074289A - Cleaning method for hardly-gas/water-permeable contaminated soil and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method for hardly-gas/water-permeable contaminated soil capable of certainly and efficiently recovering contaminant existing in the hardly-gas/water-permeable layer, and a system. <P>SOLUTION: The cleaning system 1 for the hardly-gas/water-permeable contaminated soil is provided with a high pressure air pressure-introduction mechanism 5 for intermittently feeding high pressure air to a contaminated area 4 contaminated with the contaminant 3 such as oil and dioxins or volatile organic chlorine compounds of the saturated hardly gas/water permeable layer 2 existing at underground water level or lower; and a suction mechanism 13 for sucking the contaminated substance 3 with air after the air intermittently pressure-introduced is floated to an unsaturated gas permeable layer 7 through a saturated water permeable layer 6 as bubbles while the air carries the contaminated substance 3. The high pressure air pressure-introduction mechanism 5 intermittently introduces the high pressure air from an air compressor 12 to the contaminated area 4 through a pressure-introduction pipe 9 and can impart vibration to soil particles in the contaminated area. <P>COPYRIGHT: (C)2005,JPO&NCIPI

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 pollutants 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 it is 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, which sends air in and entrains the 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. High pressure air is intermittently sent, then vibration is applied to the soil particles in the contaminated area by intermittent press-fitting of the high-pressure air, and then the air is made into bubbles while entraining the pollutant in the intermittently press-fitted air. It floats up to the unsaturated air permeable layer, and after that, the pollutant is sucked together with the air to perform the purification treatment.

  Further, in the method for purifying hardly permeable and air permeable contaminated soil according to the present invention, the saturated permeable layer located above the saturated hardly permeable and air permeable layer through which the contaminated area or air entrained by contaminants from the contaminated area floats and passes. Water passing in the horizontal direction is performed in at least one of the inner passage areas, and then the purified water is collected and subjected to purification treatment.

  Further, as described in claim 3, the purification system for hardly permeable and air permeable contaminated soil according to the present invention intermittently applies high-pressure air to a contaminated area contaminated with contaminants in the saturated permeable and air permeable layer. A high-pressure pneumatic injection mechanism that applies vibration to the soil particles in the contaminated area by intermittent injection of the high-pressure air, and sucks together with the air the contaminants that are entrained in the intermittently injected air and float to the unsaturated air-permeable layer And a gas processing facility for performing purification treatment.

  Further, in the purification system for hardly permeable and air permeable contaminated soil according to the present invention, the high pressure / pneumatic injection mechanism includes a press-fit pipe embedded so that a high pressure air outlet is located in a contaminated region of the saturated permeable and air permeable layer. And an air compressor connected to the press-fitting pipe via a pressure vessel and an air tank, and the gas treatment facility is embedded in an unsaturated gas permeable layer extending above the saturated gas permeable layer. A suction pipe, 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, The water treatment facility is connected to the liquid phase space of the gas-liquid separation tank.

  Further, the system for purifying hardly permeable and air permeable contaminated soil according to the present invention includes the saturated permeable layer positioned above the saturated hardly permeable and air permeable layer through which the contaminated area or air entrained by contaminants from the contaminated area floats and passes. A water injection well and a pumping well buried at opposite positions sandwiching at least one of the passage areas inside, and a water treatment facility for purifying the water injected from the water injection well and pumped through the pumping well It is.

  In the purification method and system for hardly permeable and air permeable contaminated soil according to the present invention, high-pressure air is intermittently fed into a contaminated area contaminated with contaminants in the saturated permeable and air-permeable layer with a high-pressure pneumatic injection mechanism. Then, vibration is imparted to the soil particles in the contaminated area by intermittent press-fitting of the high-pressure air.

  In this way, unlike the conventional method of simply entering air pressure, the soil particles collide with each other to create a new gap between the soil particles, the gap becomes larger than the original size, While the skeleton is destroyed, the soil particles are rubbed against each other, so that contaminants attached to the surface of the soil particles are peeled off from the surface.

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

  Therefore, if the contaminants are entrained in the intermittently injected air, the air is lifted as bubbles to the unsaturated air permeable layer, and then the contaminants are sucked together with the air in the gas treatment facility to perform the purification process. Thus, it becomes possible to reliably and efficiently purify the hardly permeable and air permeable contaminated soil, which was 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.

  If intermittent press-fitting of high-pressure air can exert the above-described action on the soil particles by applying vibration to the soil particles in the contaminated area, the magnitude of the pressure and the duration of the intermittent operation can be, for example, saturated impermeability. What is necessary is just to determine suitably according to the air-permeable coefficient of an air-permeable layer, or its distribution condition.

  Here, it should be reiterated that the air pressure insertion in the present invention is not a mere press-fitting as in the prior art but an intermittent press-fitting. In other words, it is difficult to improve the water permeability and air permeability of the hardly permeable air permeable layer by simply introducing air pressure. Rather, the gap between the soil particles becomes smaller than the original size, and the water permeable and air permeable properties are reduced. It is also conceivable that the value decreases.

  The present applicant has newly found that it is possible to vibrate soil particles by intermittent press-fitting of high-pressure air, thereby causing the above-described action and thus improving the water permeability and air permeability of the hardly air-permeable water-permeable layer. It is a very useful knowledge in the industry and has a remarkable effect as compared with the prior art.

  The configuration of the high pressure / pneumatic injection mechanism and gas processing equipment is arbitrary. For example, the high pressure / pneumatic injection mechanism is a press-fit pipe embedded so that the high-pressure air discharge port is located in the contaminated region of the saturated hardly permeable air permeable layer. And an air compressor connected to the press-fitting pipe via a pressure vessel and an air tank, and the gas treatment facility is embedded in an unsaturated gas permeable layer extending above the saturated gas permeable layer. A suction pipe, 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, It is conceivable to comprise a water treatment facility connected to the liquid phase space of the gas-liquid separation tank.

  In particular, it is possible to divert an apparatus used in the Biopster construction method for the press-fitting pipe and the pressure vessel. The biopster method is a method in which pulsed high-pressure air is sent into the ground at regular intervals to activate the aerobic microorganisms in the ground, and its use or purpose is completely different from the present invention. To.

  As described above, in the method and system for purifying hardly air-permeable and permeable contaminated soil according to the present invention, vibration is imparted to soil particles existing in the contaminated area by intermittently injecting high-pressure air into the saturated and hardly permeable and air-permeable layer. Then, while entraining the pollutant in the intermittently injected air, the air was lifted up to the unsaturated air permeable layer as a bubble, and then the contaminant was sucked together with the air to perform the purification process. When a saturated permeable layer is interposed between the saturated hardly permeable permeable layer and the unsaturated permeable layer, in addition to such a configuration, the pollutant entrained air from the contaminated region or the contaminated region floats and passes. A water injection well and a pumping well embedded in opposite positions sandwiching at least one of the passage regions in the saturated water permeable layer located above the saturated hardly permeable gas permeable layer, and water injected from the water injection well and passing through the water pumping well Pumped A water treatment facility for purifying the collected water, passing water in at least one of the polluted area and the pollutant-entrained air passing area in the horizontal direction, collecting the water after passing the water, and performing the purification process You may do it.

  In this way, when the cleaning water is passed through the contaminated area, when the passed cleaning water flows through the gaps between the soil particles, the flow resistance is greatly reduced by the above-described vibration imparting action, Since contaminants adhering to the soil particles are liberated in the gaps between the soil particles, the contaminants are also easily taken to the wash water.

  Therefore, if cleaning water is passed through the contaminated area, and then the cleaning water entrained with the pollutant is pumped up for purification treatment, it is difficult to achieve with conventional water cleaning and air sparging methods. It becomes possible to more reliably and efficiently purify the air-permeable and water-contaminated soil.

  Contaminants in the contaminated area can be reliably recovered by water washing using water injection wells and pumped wells, and pollutants that cannot be entrained by air, such as cadmium, lead, copper, zinc, nickel, chromium, etc. It is also possible to collect heavy metals by washing with water.

  In addition, if washing water is passed through the passage area in the saturated permeable layer, even if air-entrained contaminants float up and are released in the saturated permeable layer, such contaminants are reliably captured. Can be collected.

  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 oil, dioxins or volatile organic chlorine compounds in the saturated permeable and air permeable layer 2 existing below the groundwater level. The high-pressure pneumatic injection mechanism 5 that intermittently sends high-pressure air to the contaminated area 4 that is contaminated with the contaminant 3, and the intermittently-pressurized air entrains the contaminant 3 as bubbles and passes through the saturated permeable layer 6 and is unsaturated. After rising to the air-permeable layer 7, the gas processing equipment 13 which performs a purification process by sucking the contaminant 3 together with air is provided.

  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 high-pressure / pneumatic injection mechanism 5 includes an air compressor 12, an air tank 11 that intermediately stores high-pressure air sent from the air compressor, and a pressure that adjusts the pressure of the high-pressure air sent from the air tank 11. It is composed of a container 10 and a press-fitting pipe 9 that is connected to the pressure container and embedded so that the high-pressure air discharge port 8 is located in the contaminated region 4 of the saturated hardly permeable air permeable layer 2. High-pressure air is intermittently pressed into the contaminated area 4 through the press-fitting pipe 9, and vibration can be imparted to the soil particles in the contaminated area.

  Here, as the press-fitting pipe 9 and the pressure vessel 10, it is possible to divert an apparatus used in the Biopster construction method.

  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 for the hardly permeable and air permeable contaminated soil according to the present embodiment, first, the high pressure / pneumatic injection mechanism 5 is placed in the contaminated area 4 of the saturated hardly permeable and permeable water layer 2 that is contaminated with contaminants. The press-in 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 are prevented from being blocked. While a predetermined amount of sand is pre-filled between the holes, the gap with the bore hole is filled with mortar, bentonite, etc. at a location shallower than the high-pressure air outlet 8 in order to prevent the press-fitting pipe 9 from shaking. .

  Next, the pressure vessel 10 is attached to the upper end of the press-fit pipe 9, and the air tank 11 and the air compressor 12 are sequentially connected.

  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 contaminated soil, in this embodiment, the contaminated region 4 of the saturated hardly permeable water permeable layer 2 using the purification system 1 installed in this way, first, an air compressor 12 and an air tank 11 are used. And by operating the pressure vessel 10 as appropriate, high-pressure air is intermittently sent to the contaminated region 4 of the saturated hardly permeable air permeable layer 2 and vibration is imparted to the soil particles in the contaminated region 4 by intermittent press-fitting of the high-pressure air.

  In this way, unlike the conventional simple air pressure insertion, the intermittent press-fitting of high-pressure air causes the soil particles to collide with each other, resulting in a new gap between the soil particles, or a gap larger than the original size. As the soil becomes larger or the skeleton of the clay soil is destroyed, the soil particles are rubbed 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 a skeletal fracture of cohesive soil occurs. Fig. 2 (a) shows intermittent press-fitting of high-pressure air, and Fig. 2 (b) Fig. 2 (c) shows the state of the viscous soil skeleton after intermittent high-pressure air injection.

  As can be seen from these figures, the clay skeleton is broken by intermittent press-fitting of high-pressure air and the soil particles are separated, and voids 21 are newly generated, and the contaminant 3 attached to the surface of the soil particles is Peel from the soil particles.

  Even when the skeleton is not destroyed, there is no change in that a new gap is generated by the intermittent press-fitting of high-pressure air, or the original gap is increased. Thus, the intermittently press-fitted air 22 is a gap 21 between soil particles. The flow resistance is greatly reduced when flowing through the soil, and it becomes easy to flow, and the contaminant 3 adhering to the soil particles is released in the gap 21 between the soil particles, so the contaminant 3 is also entrained in the air 22. It becomes easy to be done.

  Next, after the intermittently press-fitted air 22 floats up to the unsaturated gas permeable layer 7 while entraining the pollutant 3, the pollutant 3 is sucked together with the air 22 by the gas treatment 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 gas 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 method of simply entering air pressure, the soil particles collide with each other, Contaminant 3 attached to the surface of the soil particles due to the formation of a new gap, the gap becoming larger than the original size, the skeleton of the soil particles being destroyed, and the soil particles rubbing against each other Peels from the surface.

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

  For this reason, if the intermittently injected air 22 entrains the pollutant 3 and rises to the unsaturated air permeable layer 7 as a bubble and then sucks the pollutant 3 together with the air 22, the conventional air sparging method or the like It becomes possible to reliably and efficiently purify the saturated hardly permeable air permeable layer 2 that has been impossible.

  In the present embodiment, the high-pressure / pneumatic injection mechanism 5 includes an air compressor 12, an air tank 11 that intermediately stores high-pressure air supplied from the air compressor, and high-pressure air supplied from the air tank 11. The pressure vessel 10 is configured to adjust the pressure, and the press-fit pipe 9 is connected to the pressure vessel and embedded so that the high-pressure air discharge port 8 is located in the contaminated region 4 of the saturated hardly permeable air permeable layer 2. Any configuration may be used as long as vibration can be imparted to the soil particles in the contaminated region 4 by intermittent press-fitting of air.

(Second Embodiment)

  Next, a second embodiment will be described. In addition, this embodiment adds the structure which performs water flow washing | cleaning in addition to the structure of 1st Embodiment, attaches | subjects the same code | symbol about the same component as 1st Embodiment, and the description. Is omitted.

  FIG. 3 is a diagram showing a purification system for hardly air permeable and contaminated soil according to the second embodiment. As can be seen from the figure, the hardly permeable and air permeable contaminated soil purification system 31 according to the present embodiment includes oil and dioxin in the saturated permeable and air permeable layer 2 existing below the groundwater level as shown in the figure. High-pressure pneumatic injection mechanism 5 that intermittently sends high-pressure air to the contaminated area 4 that is contaminated with the pollutant 3 such as volatile organic chlorine compounds, and the intermittently injected air is saturated as bubbles while entraining the pollutant 3 After ascending to the unsaturated air permeable layer 7 through the water permeable layer 6, the gas treatment facility 13 for sucking the pollutant 3 together with the air, and the contaminated area 4 and the air entrained by the pollutant from the contaminated area float and pass through. The water treatment facility 18 of the gas treatment facility 13 includes a water injection well 32 and a pumping well 33 that are embedded in opposed positions across the passage region 34 in the saturated water permeable layer 6 located above the air permeable layer 2. 3 It is configured to also serve as a water treatment facility for purifying pumping water through the water injection pumping wells 33.

  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 31 installed in the same manner as in the first embodiment, first, the air compressor 12. By operating the air tank 11 and the pressure vessel 10 as appropriate, high-pressure air is intermittently sent to the contaminated area 4 of the saturated hardly permeable air-permeable layer 2 and the high-pressure air is intermittently pressed to vibrate the soil particles in the contaminated area 4. Is granted.

  In this way, unlike the conventional simple air pressure insertion, the intermittent press-fitting of high-pressure air causes the soil particles to collide with each other, resulting in a new gap between the soil particles, or a gap larger than the original size. As the soil becomes larger or the skeleton of the clay soil is destroyed, the soil particles rub against each other and the contaminants attached to the surface of the soil particles are peeled off from the surface.As a result, as in the first embodiment, When the intermittently press-fitted air 22 flows through the gaps 21 between the soil particles, the flow resistance thereof is greatly reduced and the air 22 becomes easy to flow, and the pollutant 3 attached to the soil particles enters the gaps 21 between the soil particles. Since it is free, the pollutant 3 is also easily taken to the air 22.

  Next, after the intermittently press-fitted air 22 floats up to the unsaturated gas permeable layer 7 while entraining the pollutant 3, the pollutant 3 is sucked together with the air 22 by the gas treatment 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.

  On the other hand, the treated water from which the pollutant 3 has been removed is pumped as washing water from the water treatment facility 18 to the water injection well 32, and the washing water is passed through the contaminated area 4 and the passing area 34, and then to the bottom of the pumping well 33. Water is pumped through an installed pump (not shown).

  In such water injection and pumping, the water injection well 32 and the water pumping well 33 are embedded in opposing positions across the contaminated area 4 and the passing area 34 as described above, and both the contaminated area 4 and the passing area 34 are washed with water. The Therefore, the pumped water includes not only the contaminant 3 in the contaminated area 4 but also the contaminant 3 released from the contaminant entrained air 22. In addition, about the pumped water, the pollutant 3 is removed with the water treatment equipment 18 similarly to 1st Embodiment, and it discharges to a river etc. after that.

  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 method of simply entering air pressure, the soil particles collide with each other, Contaminant 3 that adheres to the surface of the soil particles due to the formation of a new gap, the gap becoming larger than the original size, the skeleton of the soil particles being destroyed, and the soil particles rubbing each other. Peels from the surface.

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

  For this reason, intermittently injected air 22 entrains the contaminant 3 and rises to the unsaturated air permeable layer 7 as bubbles, and then sucks the contaminant 3 together with the air 22, which is impossible with the conventional air sparging method or the like. It was possible to perform the purification of the saturated hardly permeable air permeable layer 2 reliably and efficiently.

  Moreover, according to the purification method and system of the hardly permeable and air permeable contaminated soil according to the present embodiment, it is possible to wash both the contaminated area 4 and the passing area 34 with water, and further purify the contaminated area 4. This can be performed reliably and efficiently, and even if the pollutant 3 is separated from the entrained air 22 and enters the saturated water permeable layer 6, it can be reliably recovered. Moreover, it becomes possible to collect contaminants that cannot be entrained by air, such as heavy metals such as cadmium, lead, copper, zinc, nickel, and chromium, by washing with water.

  In the present embodiment, the high-pressure / pneumatic injection mechanism 5 includes an air compressor 12, an air tank 11 that intermediately stores high-pressure air that has been supplied from the air compressor, and high-pressure air that has been supplied from the air tank 11. The pressure vessel 10 is configured to adjust the pressure, and the press-fit pipe 9 is connected to the pressure vessel and embedded so that the high-pressure air discharge port 8 is located in the contaminated region 4 of the saturated hardly permeable air permeable layer 2. Any configuration may be used as long as vibration can be imparted to the soil particles in the contaminated region 4 by intermittent press-fitting of air.

  In this embodiment, both the contaminated area 4 and the passing area 34 are washed with water. However, if there is no need to wash the passing area 34 with water, only the contaminated area 4 is washed with water. Alternatively, the direct purification of the contaminated area 4 may be performed exclusively by the entrainment action of high-pressure air, and the indirect purification of the contaminated area 4 may be performed by washing only the passage area 34 with water.

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 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,31 Purification system 2 of hardly permeable air permeable contaminated soil 2 Saturated permeable air permeable layer 3 Pollutant 4 Contaminated area 5 High-pressure pneumatic insertion mechanism 7 Unsaturated permeable layer 9 Press-in pipe 10 Pressure vessel 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 facility 32 Water injection well 33 Pumping well 34 Passage area

Claims (5)

High-pressure air is intermittently sent to a contaminated area that is contaminated with a pollutant in the saturated hardly permeable air-permeable layer, and then vibration is applied to the soil particles in the contaminated area by intermittent injection of the high-pressure air, The air is caused to rise to the unsaturated air permeable layer as air bubbles while entraining the pollutant in the intermittently injected air, and then the purification is performed by sucking the pollutant together with the air. A purification method for hardly air permeable and contaminated soil. The pollutant entrainment air from the contaminated area or the contaminated area floats and passes through at least one of the passing areas in the saturated permeable layer located above the saturated hardly permeable permeable layer, The method for purifying hardly permeable and air permeable contaminated soil according to claim 1, wherein the purified water is collected by purifying the water after passing water. A high-pressure pneumatic injection mechanism that intermittently sends high-pressure air to a contaminated area contaminated with a pollutant in the saturated hardly-permeable air-permeable layer and applies vibration to the soil particles in the contaminated area by intermittent injection of the high-pressure air; And a gas treatment facility for purifying the contaminants entrained in the intermittently injected air and floating up to the unsaturated air permeable layer together with the air. Purification system. The high pressure / pneumatic injection mechanism includes a press-fit pipe embedded so that a high-pressure air discharge port is located in a contaminated region of the saturated hardly-permeable air-permeable layer, and an air connected to the press-fit pipe via a pressure vessel and an air tank. A compressor and a suction pipe embedded in the unsaturated air permeable layer extending above the saturated hardly permeable air permeable layer, a gas-liquid separation tank connected to the suction pipe, and A suction blower connected in communication with the gas-phase space of the gas-liquid separation tank, a harmful substance removing device connected to the suction blower, and a water treatment facility connected in communication with the liquid-phase space of the gas-liquid separation tank. The purification system for hardly permeable and air permeable contaminated soil according to claim 3. A water injection well embedded in an opposing position sandwiching at least one of the contaminated area or a passing area in the saturated permeable layer located above the saturated hardly permeable permeable layer through which the contaminant-entrained air from the contaminated area floats and passes. And a water treatment facility for purifying water pumped from the water injection well and pumped through the water pumping well.

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