JP2005007344A - Contaminated foundation purification method jointly using in situ stirring and air injection suction, and purification device used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contaminated foundation purification method which can be applied to every foundation of a saturated sand foundation, an unsaturated sand foundation, a saturated viscous foundation and an unsaturated viscous foundation, is high in purification efficiency, and can attain the remarkable shortening of a treatment period, and to provide a purification device used therefor. <P>SOLUTION: In the contaminated foundation purification method, a contaminated foundation in situ is purified by using a stirring apparatus 10 provided with one or more stirring vanes 2 radiately fitted in the lower direction of rotary shafts, air injection ports 3 fitted to the prescribed places in the rotating regions of the stirring vanes 2 and gas suction ports 4 fitted to the prescribed places in the direction upper than the air injection ports 3 in the rotating regions of the stirring vanes 2. In this case, the stirring of in situ soil by the stirring vanes 2 and the injection of air into the rotating regions of the stirring vanes 2 are simultaneously performed, and contaminants are recovered from the gas suction ports 4 to the ground. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applicable to any contaminated ground of saturated sandy ground, unsaturated sandy ground, saturated viscous ground or unsaturated viscous ground, and a contaminated ground purification method using both in-situ agitation and air injection suction. The present invention relates to a purification device used for this.
[0002]
[Prior art]
Volatile organic compounds such as trichlorethylene, which are used in large quantities in the cleaning process of semiconductor manufacturing plants, etc., may contaminate the soil or groundwater due to leakage, etc. There is a problem that the use of groundwater is restricted.
[0003]
As a method for purifying such contaminated soil and contaminated groundwater, conventionally, a well is dug around the contaminated ground area and pumped to pump the pollutants dissolved in the pumped groundwater to an aeration treatment device or activated carbon on the ground. Groundwater pumping method to collect with the adsorption treatment device, soil gas suction method to suck the gaseous pollutants existing in the ground above the groundwater level with low groundwater level and collect the contaminants with the activated carbon adsorption treatment device on the ground ( Non-patent document 1), quick lime mixed stirring method for recovering by gasifying and recovering volatile organic compounds using heat of hydration generated by mixing quick lime with soil (JP-A-8-112586 of Patent Document 1), Air is injected into the injection pipe that reaches the aquifer from the ground, and bubbles that have taken in volatile pollutants are sucked by an extraction pipe separately installed in the unsaturated layer, and then polluted by the activated carbon adsorption treatment device on the ground. Recovery for air sparging (Non Patent Document 2).
[0004]
Further, the hydrate-reactive granular material is gas-transported through a transport passage provided in the tube shaft penetrating into the ground, and sprayed into the rotating region in the stirring blade attached to the tube shaft, and the soil and A soil purification construction method in which the soil is hydrated with the agitation, volatilized harmful components in the soil by the reaction heat, and lifted to the ground together with the transport gas to render it harmless (Japanese Patent Laid-Open No. 10-5737 Gazette), using a stirrer having a shaft and a stirrer fixed to the end of the shaft, the step of stirring the soil, and the step of sucking fluid from the stirred soil, As the shaft, a hollow tube having a through hole is used, and in the suction step, a soil purification method for sucking fluid from the hollow portion of the hollow tube, or in the soil purification method, further gas in the agitated soil A suction well and a gas supply well are provided to expose the soil between the two wells. A method (JP-2000-202425 Patent Document 3) for.
[Non-Patent Document 1]
Koji Kogure, "Contamination and purification system of the ground environment", published by Gihodo, pages 174 to 177
[Patent Document 1]
JP-A-8-112586 (Claims)
[Non-Patent Document 2]
"Purification technology for persistent organic compounds and heavy metal contamination in soil", issued by NTS, Takashi Yoshida, pp. 179-193
[Patent Document 2]
JP 10-5737 A (Claim 1)
[Patent Document 3]
JP 2000-202425 A (Claims 1 to 4)
[0005]
[Problems to be solved by the invention]
However, the application range and purification efficiency of the groundwater pumping method and soil gas suction method are greatly affected by the ground conditions. That is, the groundwater pumping method and the soil gas suction method are effective methods with good purification efficiency in sandy gravel ground or sandy ground with high water permeability or air permeability, but in viscous ground with low water permeability or air permeability, Since the range of influence of pumping water or gas suction is small and the purification efficiency is poor, the processing cost may be enormous or even difficult to apply. In particular, in ground with a high altitude such as a hill, the groundwater level is deep in the ground, and gaseous pollutants may be present above the groundwater level, and the ground is, for example, sandy ground. However, the groundwater pumping method is not applicable.
[0006]
In addition, the quick lime mixing and stirring method reduces soil saturation and improves air permeability by quick lime mixing and stirring, and then implements soil gas suction, so that the purification efficiency is poor and the processing cost is increased. In addition, the decrease in saturation is small, and the gas permeability may not be sufficiently improved, and the gas recovery efficiency is poor. Furthermore, when applied to saturated viscous ground, the mixing amount of quicklime becomes enormous, the strength of the quicklime mixed ground becomes remarkably high, and the use of the ruins is restricted, and there is a problem of alkali contamination.
[0007]
Also, air sparging cannot be said that the distance between the air inlet and the gas inlet is close. For example, the air is sufficiently recovered after the injected air moves horizontally in the ground water or reaches the unsaturated layer. It may not be done. In this case, there is a risk of expanding groundwater contamination or releasing pollutant gas to the atmosphere. When the injected air moves in the horizontal direction and there is a risk that the pollutant may diffuse, it is necessary to surround the contaminated ground with a water blocking wall or the like, which is uneconomical. In addition, the range of bubbles from a single injection tube varies depending on the amount of injected air, the injection depth, the soil quality of the aquifer, etc. It can be difficult. Thus, in the conventional construction method, it is difficult to say that the contaminated ground can be applied to any of the saturated sandy ground, unsaturated sandy ground, saturated viscous ground, and unsaturated viscous ground. Development of a construction method that has high purification efficiency of pollutants without being affected by the soil quality is desired. In the present specification, the saturated ground refers to the ground where the contaminated ground or the contaminated layer is below the groundwater level, and the unsaturated ground refers to the ground above the groundwater level.
[0008]
In addition, the purification method described in JP-A-10-5737 uses a gap around the tube axis for lifting the transport gas transporting the hydration reactive granular material and the volatile harmful component, Recovery to the ground is not certain. Further, when the supply of the hydration reactive granular material is stopped, the pumping of the transport gas is also stopped, so that the volatile harmful component may not be sufficiently lifted. Moreover, since the soil purification method of Unexamined-Japanese-Patent No. 2000-202425 attracts volatile harmful substances from the agitated soil, it cannot be said that the collection efficiency of volatile harmful substances is sufficient. In order to increase the recovery efficiency of volatile harmful substances, a gas suction well and a gas supply well are provided in the agitated soil. However, the supply air is not recovered sufficiently in the suction well because of the long distance traveled horizontally. Sometimes. Moreover, since the stirring process, the well burying process, and the gas supply / suction process are performed independently, there is a problem that the construction period is prolonged.
[0009]
Therefore, the object of the present invention is to solve the above-mentioned conventional problems, and the contaminated ground is any of saturated sandy ground, unsaturated sandy ground, saturated viscous ground or unsaturated viscous ground. It is an object of the present invention to provide a contaminated ground purification method that can be applied, has high purification efficiency, and can greatly reduce the treatment period, and a purification device used therefor.
[0010]
[Means for Solving the Problems]
In such a situation, the present inventors have intensively studied, and as a result, one or more stirring blades radially attached below the rotation shaft, and an air inlet provided at a predetermined location in the rotation region of the stirring blade, , Using a stirrer provided with a gas suction port or a finned gas suction pipe provided at a predetermined location within the rotation region of the stirring blade and above the air injection port, in-situ stirring and air injection suction were used in combination By adopting the purification method, the present inventors have found that the purification efficiency can be increased and the treatment period can be greatly shortened without being influenced by the soil quality of the contaminated ground, and the treatment cost can be reduced, thereby completing the present invention.
[0011]
That is, the present invention (1) includes one or more stirring blades radially attached below the rotation shaft, an air inlet provided at a predetermined location in the rotation region of the stirring blade, and the rotation region of the stirring blade. A method of purifying the contaminated ground in the original position using a stirrer provided with a gas suction port attached to a predetermined location above the air inlet, and stirring the in-situ soil by the stirring blade, An object of the present invention is to provide a contaminated ground purification method characterized by simultaneously injecting air into the rotating region of the stirring blade and collecting the contaminants from the gas suction port to the ground. According to this contaminated ground purification method, since air is injected into the agitated soil, moisture is efficiently blown off, air permeability is increased, volatilization of pollutants is promoted, and agitation promotes gas diffusion. The gas suction effect is further enhanced. Since the stirring, air injection, and gas suction are simultaneously performed, the purification efficiency is high, and the processing period can be greatly shortened. This contaminated ground purification method can be applied to any of the saturated sandy ground, unsaturated sandy ground, saturated viscous ground, and unsaturated viscous ground, but is particularly suitable for unsaturated sandy ground. .
[0012]
Further, the present invention (2) includes one or more stirring blades provided radially below the rotating shaft, an air inlet provided at a predetermined location in the rotation region of the stirring blade, and the rotation region of the stirring blade. A method for purifying contaminated ground in the original position using a stirring device having a finned gas recovery shaft rotatably attached to a predetermined location above the air inlet, wherein the original position by the stirring blade Simultaneously agitating the soil and injecting air into the rotation region of the agitating blade, and passing the contaminants from the gas recovery hood installed on the ground through the gap formed around the outer peripheral surface of the gas recovery shaft The present invention provides a contaminated ground purification method characterized by Conventionally, the fin for forming a gap around the outer peripheral surface of the shaft tube is attached to the stirring shaft (main shaft), but the fin of the present invention is a gas recovery shaft that is separate from the stirring shaft, and has its own A gap suitable for the ground can be formed by controlled rotation or the like. According to the contaminated ground purification method, in addition to the same effects as the above invention, particularly when the contaminated ground is a saturated sandy ground or a saturated viscous ground, the collection of the pollutant is performed around the outer peripheral surface of the gas recovery shaft. It can be efficiently recovered on the ground through the voids formed in Therefore, this contaminated ground purification method can be applied to any of the saturated sandy ground, unsaturated sandy ground, saturated viscous ground, and unsaturated viscous ground. Suitable for viscous ground. In addition, when this contaminated ground purification method is applied to saturated sandy ground or saturated viscous ground, it is possible to inject a volatilization promoter such as quick lime together with air injection, resulting in hydration caused by mixing of quick lime and soil. It is preferable at the point which can accelerate | stimulate gasification of a volatile organic compound using a heat | fever.
[0013]
Further, the present invention (3) includes one or more stirring blades radially attached below the rotation shaft, an air inlet provided at a predetermined position in the rotation region of the stirring blade, and the rotation region of the stirring blade. In addition, the present invention provides a purification device for purifying contaminated ground in the original position, comprising a gas suction port attached to a predetermined location above the air inlet. If this purification apparatus is used, the contaminated ground purification method (1) can be carried out reliably.
[0014]
Further, the present invention (4) includes one or more stirring blades provided radially below the rotating shaft, an air inlet provided at a predetermined location in the rotation region of the stirring blade, and the rotation region of the stirring blade. The present invention also provides a purification device used for purification of contaminated ground in the original position, comprising a finned gas recovery shaft attached to a predetermined location above the air inlet. If this purification device is used, the contaminated ground purification method (2) can be reliably carried out.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, a contaminated ground purification method and a purification device (stirring device) used in the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram for explaining the contaminated ground purification method of this example, FIG. 2 is a schematic diagram of a purification apparatus for performing the contaminated ground purification method of FIG. 1, and FIG. 3 is another example for implementing the contaminated ground purification method of FIG. The schematic of a purification apparatus is shown, respectively.
[0016]
The purification apparatus 10 used in the contaminated ground purification method according to the first embodiment includes, for example, three stirring blades 2, 2, 1 shaft attached radially below the two rotating shafts 1, 1, 2, the air inlets 3, 3 attached to one blade of the lowermost stirring blade in the rotation region of the stirring blades 2, 2, and the rotation region of the stirring blades 2, 2, 2 And a gas suction port 4 provided above the upper stirring blade. Further, the other side blades of the lowermost stirring blade are further provided with volatilization promoter inlets 7 and 7 which are optional components. In addition, an air supply pipe 5 and a volatile promoter supply pipe 6 are attached to a space in the rotary shafts 1 and 1 which are hollow pipes, and one end of the air supply pipe 5 communicates with the air inlet 3 and others. The end is connected to the compressed air supply means 20. One end of the volatile accelerator supply pipe 6 communicates with the volatile accelerator inlet 7, and the other end is connected to the volatile accelerator supply means 30. A thermometer 14 that measures the temperature of the agitated soil, which is an optional component, is provided at the center lower portion of the gas suction port 4. The installation place of the air inlets 3 and 3 only needs to be within the rotation region of the stirring blades 2, 2 and 2 of the purification device 10, and is directly attached to the lower part of the rotating shafts 1 and 1 other than the stirring blades. It may be done. In the figure, reference numeral 13 denotes an auger, reference numeral 9 denotes a tip excavation bit, and reference numeral 15 denotes an unsaturated sandy ground including a contaminated layer.
[0017]
In the present invention, the installation form of the gas suction port 4 is not particularly limited, and is a transverse member having an inverted triangular cross section provided in a stretched manner between the two rotary shafts 1 and 1, and both side surfaces of the transverse member. In addition, a filter is installed in the opening and a gas suction pipe 8 is connected to the central portion of the upper surface (FIG. 2), and a part of the two rotary shafts 1 and 1 are formed as openings 4a and 4a. The installation form (FIG. 3) etc. which attached the filter to this opening are mentioned. In the installation form of FIG. 2, the gas suction port 4 is arranged so as to cross the rotation region of the stirring blades 2, 2, and 2, and the opening surface of the gas suction port 4 is also directed substantially downward, so that the gas is recovered. It becomes easy to do. In the installation form of FIG. 3, the installation of the gas suction pipe 8 can be omitted, and the gas flow path becomes a space portion in the rotary shafts 1, 1. The gas suction parts 4 and 4a are located above the air inlets 3 and 3 and are as close as possible, so that even when a large amount of air is injected, a large amount of injected air is reliably sucked together with the contaminated gas. As a result, it is preferable in that it prevents diffusion of the injected air in the horizontal direction, which has been a problem in the prior art, and significantly improves the purification efficiency and shortens the construction period. Further, since the air inlets 3 and 3 and the gas suction ports 4 and 4a are close and fixed, even if the purification device 10 is moved in the depth direction or moved to the original position (moved in the horizontal direction), the arrangement relationship Is constant, and reliable gas suction can be performed without causing gas diffusion.
[0018]
The air supplied to the purification device 10 is supplied from the compressed air supply means 20 on the ground, and the volatilization promoter supplied to the purification device 10 is supplied from the ground volatilization promoter supply means 30. Contaminated gas from the suction ports 4, 4 a is recovered by the contaminated gas recovery means 50, and the contaminated gas rising in the rotating region of the stirring blade of the purification device 10 is recovered by the remaining contaminated gas purification and recovery means 40.
[0019]
The compressed air supply means 20 includes a dry compressor 21 and a ground pipe 22. The ground pipe 22 is connected to and integrated with the air supply pipe 5 of the purification device 10. The compressed air supplied to the contaminated ground is not particularly limited, and examples include normal temperature air, warm air, and hot air. Further, the air injection amount is not particularly limited, and since the air injection port and the gas suction port are close to each other, the injection can be performed up to several hundred times as much as the conventional air sparging injection amount.
[0020]
The volatilization promoter supply means 30 includes a dry compressor 31, a volatilization promoter supply machine 32, and a ground pipe 33. The ground pipe 33 is connected to and integrated with the volatilization promoter supply pipe 6 of the purification device 10. The volatilization promoter is not particularly limited, and examples thereof include a hydration reactive material such as quicklime. Volatilization promotion refers to the action of heat of hydration generated by mixing the drug with soil increasing the volatility of the pollutant. Moreover, since quicklime absorbs a water | moisture content, air permeability improves, there exists an effect as an air permeability improvement agent, and gas suction efficiency improves further. Further, an air permeability improving agent such as sand and crushed stone may be injected into the rotation region of the stirring blade in combination with or alone with the volatilization promoter.
[0021]
The polluted gas recovery means 50 processes a mixture of a large amount of exhaust air containing most of the pollutants in the contaminated ground and a small amount of water, and separates it into treated water and clean gas. That is, the contaminated gas recovery means 50 includes a separation tower 51, a drainage storage tank 52, a vacuum blower 53, a pump 54, a ground pipe 55, and a gas adsorption tower 56, and the ground pipe 55 is the purifier shown in FIG. In the case of 10, it is connected to the gas suction pipe 8 and integrated.
[0022]
The remaining pollutant gas collecting means 40 collects and processes the remaining pollutant that is not sucked from the gas suction ports 4 and 4a of the purifier 10 and rises in the rotating region of the stirring blade 2, and is thus treated in the present invention. Is an optional component. That is, the remaining pollutant gas recovery means 40 includes a gas recovery hood 12 that collects gas rising from the ground, a bag filter 43, a blower 42, and a gas adsorption tower 41. By using the pollutant gas recovery means 50 and the remaining pollutant gas recovery means 40 in combination, the pollutants in the contaminated ground can be recovered almost completely.
[0023]
The installation location of the thermometer 14 may be in the vicinity of the rotation region of the stirring blade of the purifier and in the vicinity thereof. For example, both the plate surfaces of the gas suction port 4 and the two rotary shafts 1 and 1 are connected in addition to the above position. The accompanying prevention board 19 etc. are mentioned. The thermometer 14 is connected to the monitoring means on the ground so that the temperature of the agitated soil can be known on the ground. Thereby, the supply of the hydration reactive material such as quicklime is stopped, the injection amount is increased and decreased, the rotation speed of the stirring blade 2 is adjusted, and the volatilization state of the pollutant can be monitored and controlled.
[0024]
The contaminated ground purification method using the purification device 10 of the first embodiment can be applied to any of saturated sandy ground, unsaturated sandy ground, saturated viscous ground, or unsaturated viscous ground. These grounds are preferably sandy ground. Further, the purification device 10 of this example may be a purification device having a single-axis rotation shaft. Moreover, the purification apparatus 10 of this example may use the volatilization promoter supply means 30 and separately inject the heat generation accelerator together with the volatilization promoter or the heat generation accelerator separately. In the case of single injection of the heat generation accelerator, a heat generation accelerator supply means may be provided separately and injected from the means. The separate heat generation accelerator supply means may be the same device as the volatilization promoter supply means 30, and similarly, a heat generation accelerator supply pipe may be provided in the space in the rotating shaft. If this exothermic accelerator is used in combination with a volatile accelerator such as quicklime, the amount of quicklime injected can be suppressed while maintaining the exothermic effect. Thereby, the ground strength accompanying the excessive injection | pouring of quicklime becomes high more than necessary, and there is no restriction | limiting of use of a ruins, and alkali elution decreases.
[0025]
Next, a method for purifying the contaminated ground in the original position using the purification device 10 will be described. First, the purification device 10 and various means 20, 30, 40, 50 attached thereto are installed at predetermined positions. When the purifier 10 is inserted or withdrawn, the in-situ soil is stirred by the stirring blade 2 and air is injected into the rotation region of the stirring blade 2 at the same time. It collect | recovers on the ground from the suction ports 4 and 4a, or collect | recovers to the gas collection | recovery hood 12 as needed. Moreover, when quick lime is used as a volatilization promoter, the thermometer 14 is turned ON and the temperature of the stirred soil is monitored. In other words, when it is determined that the ground has no rise in temperature even when quick lime is injected and there is no pore water, the quick lime injection is stopped, and the pollutant is recovered by stirring the in situ soil and injecting air. On the other hand, when the stirring temperature rises and the temperature does not rise despite the presence of interstitial water, the rotational speed of the stirring blade 2 is increased or the amount of quicklime injected is increased. Thus, the volatilization state of the pollutant can be monitored by monitoring the thermometer 14 on the ground. The purification device 10 is moved in the horizontal direction by once lifting the purification device 10 to the ground and horizontally moving it to a predetermined position. According to the contaminated ground purification method of the present embodiment, since air is injected into the agitated soil, moisture is efficiently blown off, air permeability is increased, volatilization of pollutants is promoted, and agitation is performed by gas. The gas suction effect is further enhanced to promote diffusion. Further, since the gas is collected at both the gas suction ports 4 and 4a and the gas recovery hood 12 on the ground, the pollutant is not diffused on the ground. In addition, this contaminated ground purification method can be applied to any of the saturated sandy ground, unsaturated sandy ground, saturated viscous ground or unsaturated viscous ground, but especially to unsaturated sandy ground. Suitable.
[0026]
Next, the contaminated ground purification method in 2nd Embodiment is demonstrated with reference to FIG. FIG. 4 is a schematic diagram for explaining the contaminated ground purification method of this example. 4, the same components as those in FIG. 1 are denoted by the same reference numerals, description thereof is omitted, and different points are mainly described. That is, the second embodiment is a method suitable for purifying the saturated sandy ground 16 using the purification device 10 similar to the first embodiment. Specifically, the saturated sandy ground is previously lowered using a pumping means so that the groundwater level is below the contaminated layer, and then the contaminated ground by the method described with reference to FIG. To purify. In order to lower the groundwater level, a pumping well 61 may be dug around the contaminated ground area and pumped at a suction point 62 such as a deep well. According to the second embodiment, by using the conventional groundwater pumping method, the same effect as that of the first embodiment can be obtained for the saturated sandy contaminated ground.
[0027]
Next, the contaminated ground purification method in the third embodiment will be described with reference to FIG. FIG. 5 is a schematic diagram for explaining the contaminated ground purification method of this example. In FIG. 5, the same components as those in FIG. That is, the third embodiment is a method suitable for purifying saturated viscous contaminated ground using the purification device 10 similar to that of the first embodiment. Specifically, the saturated viscous ground 16a is lowered in advance by using a pumping means so that the groundwater level is below the contaminated layer, and then contaminated by the method described with reference to FIG. Purify the ground. The viscous ground 16a has, for example, a water passage layer 17 below the viscous soil layer 16b. In order to lower the groundwater level of the saturated viscous ground 15, a large number of water flow columns 71 such as sand piles and crushed stone piles are formed at an appropriate pitch to improve the permeability of the viscous soil layer 16b. A method of installing a suction point 62 such as a deep well in the water flow layer portion 63 and pumping up groundwater from the pumping well 61 can be applied. According to the third embodiment, by using the conventional groundwater pumping method, the same effects as those of the first embodiment can be obtained for the saturated viscous contaminated ground. Can be recovered from the three paths of the gas absorption port 4, the gas recovery hood 12 and the pumping well 61.
[0028]
Next, a contaminated ground purification method and a purification device used therefor according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a schematic diagram for explaining the contaminated ground purification method of this example, and FIG. 7 is a schematic view of a purification apparatus for implementing the contaminated ground purification method of FIG. In FIG. 7, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted. That is, the purification device 10b of the present example is different from the purification device 10 of the first embodiment in that the gas suction port 4 and the gas suction pipe 8 of the purification device 10 are omitted and the rotation shafts 1 and 1 are connected. Thus, a gas recovery shaft 81 with fins 82 and 83 is provided above the air inlet 3. Since the gas recovery shaft 81 with such fins 82 and 83 rotates when the purification device 10b is inserted or pulled out, a gap corresponding to the width of the fin is formed around the gas recovery shaft 81. It becomes a flow path. For this reason, the purification apparatus 10b can be suitably used for saturated viscous contaminated ground. In this case, as shown in FIG. 6, the ground pollutant gas recovery means 50 can be omitted.
[0029]
Next, a method for purifying the contaminated ground in the original position using the purification device 10b will be described. First, the purification device 10b and various means 20, 30, and 40 attached thereto are installed at predetermined positions. When the purification device 10b is inserted or withdrawn, the in situ soil is stirred by the stirring blade 2 and air is injected into the rotation region of the stirring blade 2 at the same time. The gas is recovered in the gas recovery hood 12 through the gap. In the contaminated ground purification method of the present embodiment, it is particularly preferable to inject a volatilization accelerator such as quicklime from the viewpoint that the air permeability of the viscous ground can be improved. According to the fourth embodiment, the saturated viscous contaminated ground has the same effect as the first embodiment, and a large amount of air can be injected into the stirred soil. The amount of the gas containing the pollutant is also large, and the exhaust gas can be reliably recovered on the ground through the gap formed around the finned gas recovery pipe 81.
[0030]
【The invention's effect】
According to the contaminated ground purification method of the present invention, since air is injected into the agitated soil, moisture is efficiently blown off, air permeability is increased, volatilization of contaminants is promoted, and agitation promotes gas diffusion. Therefore, the gas suction effect is further enhanced. Since the stirring, air injection, and gas suction are simultaneously performed, the purification efficiency is high, and the processing period can be greatly shortened. Further, this contaminated ground purification method can be applied to any ground of saturated sandy ground, unsaturated sandy ground, saturated viscous ground, or unsaturated viscous ground. In addition, if combined with the injection of a volatilization accelerator such as quicklime, the heat of hydration generated by the mixing of quicklime and soil can be used to promote gasification of volatile pollutants, and from the ability of quicklime to absorb moisture Further, the air permeability is increased, and the gas suction efficiency is further improved. Moreover, if the groundwater pumping method is used in combination, it can also be applied to the purification of saturated contaminated ground. Moreover, since the purification apparatus of the present invention only needs to slightly improve the mechanical stirring and mixing treatment apparatus used in the conventional ground improvement method, it is possible to suppress an increase in equipment cost.
[Brief description of the drawings]
FIG. 1 is a schematic diagram for explaining a contaminated ground purification method according to a first embodiment.
FIG. 2 is a schematic view of a purification apparatus that implements the contaminated ground purification method of FIG. 1;
FIG. 3 is a schematic view of another purification apparatus that implements the contaminated ground purification method of FIG. 1;
FIG. 4 is a schematic diagram for explaining a contaminated ground purification method according to a second embodiment.
FIG. 5 is a schematic diagram for explaining a contaminated ground purification method according to a third embodiment.
FIG. 6 is a schematic diagram for explaining a contaminated ground purification method according to a fourth embodiment.
7 is a schematic view of a purification apparatus for implementing the contaminated ground purification method of FIG. 6. FIG.
[Explanation of symbols]
1 Rotating shaft
2 Stirring blade
3 Air inlet
4, 4a Gas suction port
5 Air supply pipe
6 Volatilization accelerator supply pipe
7 Volatilization accelerator inlet
8 Gas suction pipe
9 Tip drill bit
10, 10a, 10b Purification device
11 Fin
12 Gas recovery hood
13 Auger
14 Thermometer
15 Unsaturated sandy ground
16 Saturated sandy ground
16a Viscous ground
16b Cohesive soil layer
17 Water flow layer
20 Compressed air supply means
21, 31 Dry compressor
22, 33, 44, 55 Piping
30 Volatilization accelerator supply means
32 Volatilization accelerator feeder
40 Remaining pollutant gas purification and recovery means
41, 56 Gas adsorption tower
42, 53 Blower
43 Bug Filter
50 Contaminated gas recovery means
51 Separation tower
52 Wastewater storage tank
54 Pump
61 Pumping well
62 Suction points
71 Water flow pillar
81 Gas recovery pipe
82, 83 fins
WL Groundwater level

Claims (11)

One or more stirring blades radially attached below the rotating shaft; an air inlet provided at a predetermined location in the rotating region of the stirring blade; and within the rotating region of the stirring blade and above the air inlet A method of purifying contaminated ground in situ using a stirrer provided with a gas suction port attached to a predetermined location of the agitator, wherein the agitating blade stirs the soil in situ and the air into the rotation region of the agitating blade A contaminated ground purification method characterized by simultaneously performing injection and collecting the pollutant from the gas suction port to the ground. One or more stirring blades radially attached below the rotating shaft; an air inlet provided at a predetermined location in the rotating region of the stirring blade; and within the rotating region of the stirring blade and above the air inlet A method for purifying contaminated ground in situ using a stirring device comprising a finned gas recovery shaft rotatably attached to a predetermined location, comprising: stirring the in situ soil with the stirring blade; and Contaminated soil purification characterized by simultaneously injecting air into the rotation area and collecting pollutants from the gas recovery hood installed on the ground through the gap formed around the outer peripheral surface of the gas recovery shaft Construction method. 2. The contamination according to claim 1, wherein the collection of the pollutant to the ground uses a method of collecting from a gas collection hood installed on the ground in addition to the method of collecting from the gas suction port. Ground purification method. The stirrer further provided with a volatilization promoter injection port at a predetermined location in the rotation region of the stirring blade, and further injecting the volatilization promoter into the rotation region of the stirring blade. 3. The contaminated ground purification method according to any one of 3 above. The volatilization accelerator is a hydration-reactive material, injects the hydration-reactive material into the rotation region of the stirring blade, and a thermometer attached to and around the rotation region of the stirring blade of the stirring device The contaminated ground purification method according to claim 4, further comprising monitoring the temperature of the soil. The contaminated ground purification method according to claim 1, wherein the contaminated ground is a saturated sandy ground, an unsaturated sandy ground, a saturated viscous ground, or an unsaturated viscous ground. The contaminated ground purification method according to claim 2, wherein the contaminated ground is a saturated viscous ground. A method for purifying saturated ground, characterized in that the groundwater level is lowered in advance using a pumping means so as to be lower than the contaminated layer, and then the contaminated site purification method according to claim 1 is performed. Contaminated site purification method. One or more stirring blades radially attached below the rotating shaft; an air inlet provided at a predetermined location in the rotating region of the stirring blade; and within the rotating region of the stirring blade and above the air inlet A purification device comprising a gas suction port attached to a predetermined portion of the first purification device, wherein the purification device is used for purification of in-situ contaminated ground. One or more stirring blades radially attached below the rotating shaft; an air inlet provided at a predetermined location in the rotating region of the stirring blade; and within the rotating region of the stirring blade and above the air inlet A purification apparatus comprising: a finned gas recovery shaft attached to a predetermined position of the purification site, for use in purification of in situ contaminated ground. The purification apparatus according to claim 9 or 10, further comprising a volatilization accelerator injection port provided at a predetermined position in the rotation region of the stirring blade.

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