JP2015057267A - Method of purifying contaminated ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of purifying contaminated ground which eliminates the need of digging to a depth of a lower end of a contaminated region layer in contaminated ground and inserting earth retaining pipes to the depth, and the need of a special sealing member for preventing a fluid for purification injected into the ground from escaping upward.SOLUTION: A purification outer pipe 9 is laid in a ground M so that, in a state where soil in the pipe is removed to be in a hollow condition, its lower end is located closed to a depth Q1 of an upper end of a contaminated region layer Q in the ground M and its upper end appears on a ground surface E. After a purification inner pipe 13 is inserted from the upper end of the purification outer pipe 9 laid in the ground M, the purification inner pipe 13 is penetrated under the lower end of the purification outer pipe 9 and close to a depth Q2 of the lower end of the contaminated region layer Q. A purification fluid is supplied to the purification inner pipe 13 to inject the purification fluid into the contaminated region layer Q of the ground M through an injection hole provided in the lower end part of the purification inner pipe 13.

Description

  The present invention relates to a method for purifying contaminated ground for purifying pollutants existing in the ground, and in particular, a purifying inner pipe inserted into a purifying outer pipe buried in the ground. The present invention relates to a method for purifying contaminated ground that penetrates to a layer and injects a purifying fluid into the contaminated ground through an injection hole provided in the inner pipe for purification.

  In the conventional method for cleaning contaminated ground shown in Patent Document 1, first, a porous tube is inserted and disposed on the inner periphery of a drilled well formed by excavation on the contaminated ground, and then the jet outlet is placed at the tip. The injection well provided in the part is inserted into the porous tube. A packer as a sealing member for preventing the purifying fluid injected from the jet port from escaping upward is attached to the outer periphery of the injection well located above the jet port. Then, while the injection well is slid in the porous tube, the purification fluid is injected into the contaminated ground from the jet outlet to purify the contaminated ground in which the pollutant exists.

Japanese Patent No. 3646589

  However, in the conventional purification method of contaminated ground, since excavation formation to the depth of the lower end of the contaminated area layer in the contaminated ground, and the porous pipe for earth retaining had to be fitted and arranged to that depth, accordingly, The earth retaining tube was long. In addition, it was necessary to attach a packer to the outer periphery of the injection well in order to prevent the purification fluid injected from the jet port from escaping upward. As a result, it has been desired to reduce the cost of materials in the conventional purification method for contaminated ground.

  The present invention has been made to meet such a demand, and it is not necessary to excavate to the depth of the lower end of the contaminated area layer in the contaminated ground and to insert and arrange the earth retaining pipe up to that depth. It is an object of the present invention to provide a method for purifying contaminated ground that does not require a special sealing member for preventing the purifying fluid injected therein from escaping upward.

  In order to achieve this object, the contaminated ground purification method according to the present invention is a hollow state in which the soil in the pipe is removed, the lower end is located near the upper end depth of the contaminated area layer in the ground, and the upper end A purification outer pipe burying step in which the purification outer pipe is buried in the ground so that the surface of the purification outer pipe faces the ground, and the purification outer pipe is inserted from the upper end into the purification outer pipe buried in the ground, and then A purging inner pipe penetration step for penetrating the purifying inner pipe below the lower end of the pipe and near the depth of the lower end of the contaminated area layer, and supplying a purifying fluid into the purifying inner pipe, And a purifying fluid injection step of injecting the purifying fluid into the contaminated region layer in the ground through an injection hole provided at the lower end of the purifying inner pipe.

  The method for purifying contaminated ground according to the invention described in claim 2 is the method for purifying contaminated ground according to claim 1, wherein the purification outer pipe burying step is performed up to a depth near the upper end of the contaminated region layer in the ground. A test tube penetration process for penetrating the test tube into the ground so that the lower end is located and the upper end faces the ground, and the soil in the test tube that has penetrated the ground is removed to make the test tube hollow. And a soil removal step, and a purification outer tube insertion step of inserting the purification outer tube into the hollow borehole.

  According to a third aspect of the present invention, there is provided a purification method for a contaminated ground according to the second aspect, wherein the purification outer pipe burying step further includes the test bore after the purification outer pipe insertion step. A drill tube extracting step for extracting the tube from the ground is provided.

  The method for purifying contaminated ground according to the invention described in claim 4 is the method for purifying contaminated ground according to any one of claims 1 to 3, wherein the purifying fluid uses ozone as a composition gas. The ozone-containing gas, hot water, and water vapor having a temperature higher than that of the hot water, and the purification fluid injection step switches the warm water and a mixed gas obtained by mixing the ozone-containing gas and water vapor with a switching device to alternately perform the purification. It is characterized in that it is supplied into the inner pipe.

  According to the invention of claim 1, after inserting the inner purification tube into the outer tube for purification buried in the ground up to near the depth of the upper end of the contaminated area layer in the ground, below the lower end of the outer tube for purification, In addition, since the inner pipe for purification is penetrated to the depth near the lower end of the contaminated area layer, excavation is formed to the depth of the lower end of the contaminated area layer in the contaminated ground, and the earth retaining pipe is inserted to that depth. There is no need to dispose, and no special sealing member is required to prevent the purifying fluid injected into the ground from escaping upward.

According to the second aspect of the present invention, since the borehole is penetrated into the ground up to the depth near the upper end of the contaminated area layer in the ground, the borehole having a strong drilling member attached to the tip is drilled. By penetrating into the ground with the equipment, even if there are a lot of rocks, large and small stones and gravel between the top of the ground and the vicinity of the depth of the upper end of the contaminated area layer, it can be excavated without any trouble. In addition, since the purification outer tube is inserted into the borehole penetrating into the ground, the purification outer tube can be easily penetrated to a depth near the upper end of the contaminated region layer.
According to the third aspect of the present invention, after the purification outer tube is inserted into the borehole, the borehole is pulled out from the ground, so that the removed borehole can be reused immediately.

  According to the fourth aspect of the present invention, the hot water and the mixed gas obtained by mixing the ozone-containing gas and water vapor are switched by the switching device and are alternately supplied into the purification inner pipe. Thus, the supply pipe for supplying the hot water and the mixed gas into the purification inner pipe can be a common pipe. As a result, the piping is simplified accordingly.

FIG. 1 shows a schematic configuration of a purification apparatus that can use the method for purifying contaminated ground according to the first embodiment of the present invention, as viewed from the side with the underground part and the like broken. It is sectional drawing. 2A is a cross-sectional view showing the state of the purification inner pipe of the purification apparatus as viewed from the side, omitting three midway portions, and FIG. 2B is a diagram of FIG. It is sectional drawing of the state seen from the direction which follows the arrow AA line of FIG. 2, (c) The figure of FIG. 2 is sectional drawing of the state seen from the direction which follows the arrow BB line of (a) figure. is there. FIG. 3 is a cross-sectional view of the portion surrounded by the two-dot chain line indicated by X in FIG.

4 (a), 4 (b) and 4 (c) are cross-sectional views showing the state of the operation of penetrating the borehole and the purification outer tube into the ground as viewed from the side in the order of the steps. 5D, 5E, and 5F are cross-sectional views showing the state of the operation of inserting the purification inner pipe into the purification outer pipe penetrating into the ground as viewed from the side in the order of steps. FIG.

FIG. 6 is an external view showing a state in which the state of the operation of penetrating the inner pipe for purification into the ground while striking with the striking device is seen from the side by breaking only in the ground. FIG. 7: is an external view which shows the state which looked at the schematic structure of the purification apparatus which can use the purification method of the contaminated ground which concerns on the 2nd Embodiment of this invention from upper direction.

(First embodiment)
Hereinafter, a first embodiment of a contaminated ground purification method according to the present invention will be described in detail with reference to FIGS. What is indicated by reference numeral 1 in each figure is an example of a purification device for using the method for purifying contaminated ground according to an embodiment of the present invention, and this purification device 1 is a volatile organic compound such as trichlorethylene or tetrachloroethylene. (Volatile organic compounds hereinafter referred to as “VOCs”) is used to purify contaminated soil in the underground M where the soil is contaminated by a pollutant. In FIG. 1, the state which is purifying underground M is shown. In addition, about each figure, on account of drawing, the ratio of the reduced scale of each structural member is shown mutually differently. The purification device 1 includes an ozone-containing gas supply device 3, a hot water supply device 5, and a water vapor supply device 7.

  In FIG. 1, a region surrounded by a two-dot chain line indicated by a symbol Q indicates a contaminated region layer in which soil in the ground M is contaminated, and a symbol 9 indicates a purification outer tube. The purification outer tube 9 includes a plurality of iron purification outer short tubes 11 each having an outer diameter and an inner diameter of 66 mm and 60 mm and a length of 1 to 2 meters, all surfaces including the inner and outer surfaces being galvanized. It is configured as a single long purification outer tube 9 that is connected. As a configuration to be connected, the purification short outer pipes 11 in which the male screw part and the female screw part are respectively engraved at both ends of the purification short outer pipe 11 are connected to each other, and the male screw part of one purification short outer pipe 11 and the other The internal thread portion of the short outer tube 11 for purification is screwed together so as to be connected to each other. In addition, the site | part which connected the short outer tubes 11 for purification | cleaning is airtightly hold | maintained by screwing together firmly.

  The purification outer pipe 9 is inserted into the underground M so that the lower end of the outer pipe 9 for purification reaches the vicinity of the depth (depth) Q1 of the upper end of the contaminated region layer Q in the underground M. A purifying inner tube 13 is inserted into the tube 9. The lower end portion of the purification inner tube 13 protrudes downward from the lower end of the purification outer tube 9 and reaches the vicinity of the depth Q2, which is the lower end of the contaminated region layer Q, specifically, a depth slightly deeper than the depth Q2. The depth is, for example, 5 to 20 meters from the ground E. On the other hand, the upper end portion of the inner purification tube 13 further protrudes from the upper end of the outer purification tube 9 protruding above the ground E.

  As shown in FIG. 2A, the purification inner pipe 13 is connected to the purification short inner pipe 15a constituting the lower end of the purification inner pipe 13 and the upper end of the purification short inner pipe 15a. The short inner pipe 15b for purification connected through the pipe 17 is comprised. An excavation member 19 for excavating the underground M and making a hole in the ground E is barely attached to the lower end of the purification inner short tube 15a. The excavation member 19 is formed in a four-step staircase shape so as to taper in a staircase shape toward the tip side. The short inner pipes 15a and 15b for purification have a length of 2 meters and are constituted by pipes having an outer diameter and an inner diameter of 33 millimeters and 25 millimeters, respectively.

  The purification inner short tube 15a is made of stainless steel, and the purification inner short tube 15b and the connecting tube 17 are made of iron whose entire surface including the inner and outer surfaces is galvanized. Female threaded portions are engraved on the inner peripheral surfaces of both ends of the connecting pipe 17, and these female threaded portions are respectively engraved on the upper end portion of the purification short inner tube 15a and one end portion of the purification short inner tube 15b. The provided male screw portions are joined together to connect the purification inner short pipes 15a and 15b. Further, the male threaded portions engraved at the other end of the purification inner short tube 15b and one end of the other purification inner short tube 15b are respectively fitted to the female threaded portions at both ends of the other connecting tube 17. It is configured to be able to.

  Thus, the single purification inner pipe 13 is constructed by appropriately connecting the purification inner short pipe 15a and two or more purification inner short pipes 15b via the plurality of connection pipes 17. Is done. In addition, the site | part which connected the short inner pipes 15a and 15b for a purification | cleaning, and the connection pipe | tube 17 is airtightly hold | maintained by carrying out the screw connection firmly.

  As shown in FIG. 1, the upper end portion of the purification inner short tube 15 b constituting the upper end portion of the purification inner tube 13 is connected to one end portion of the purification fluid supply tube 23 via a connector 21, The other end of the working fluid supply pipe 23 is connected to a switching device 25 that switches the type of the purifying fluid to be supplied. Further, the switching device 25 is supplied with the other end of the hot water supply pipe 29 whose one end is connected to the electric pump 27 of the hot water supply device 5 installed on the ground E, and a mixed gas supply for supplying a mixed gas described later. One end of the tube 31 is connected.

  The other end of the mixed gas supply pipe 31 is connected to an ejector 33. The other end of an ozone-containing gas supply pipe 35 having one end connected to the ozone-containing gas supply device 3 installed on the ground E is connected to the ejector 33, and further, water vapor installed on the ground E The other end of the water vapor supply pipe 39 having one end connected to the pressure regulating valve 37 of the supply device 7 is connected.

  A main body 41 of the hot water supply device 5 is connected to the electric pump 27 of the hot water supply device 5 through a connecting pipe. An electric heater 41a is provided in the main body 41, and water stored in the hot water supply apparatus main body 41 is raised to a predetermined temperature by energizing the electric heater 41a. Note that hot water may be generated by a gas water heater instead of the electric heater 41a. Examples of the predetermined temperature include any one of 30 ° C. to 100 ° C. The electric pump 27 is driven by an electric motor (not shown), and hot water is supplied to the hot water supply pipe 29 by the electric pump 27 at a predetermined pressure. As the predetermined pressure, for example, any pressure from 1 MPa (megapascal) to 30 MPa can be mentioned.

  The ozone-containing gas supply device 3 is connected to an oxygen cylinder 43 containing oxygen gas via an oxygen gas supply pipe 45, and the oxygen gas in the oxygen cylinder 43 is introduced into the ozone-containing gas supply device 3. . Ozone is generated by silent discharge by the discharge tube inside the ozone-containing gas supply device 3, and ozone is mixed with oxygen at a predetermined ratio to generate ozone-containing gas. As the ozone-containing gas, for example, a gas in which ozone is 1% to 10% by volume and the remainder is oxygen can be used. The ozone-containing gas generated in this way is injected into the ejector 33 through the ozone-containing gas supply pipe 35 from the ozone-containing gas supply device 3 at a pressure of, for example, 0.8 MPa (megapascal) to 1.1 MPa.

  The pressure adjusting valve 37 of the water vapor supply device 7 is disposed on an upper portion of a gas heating boiler 47 constituting the main body of the water vapor supply device 7, and the pressure of the water vapor supplied from the boiler 47 to the water vapor supply pipe 39 is adjusted. It has a function to adjust to be constant. The constant pressure includes, for example, any pressure from 0.1 MPa (megapascal) to 0.5 MPa, and the temperature of the water vapor at that time is any temperature from 120 ° C. to 150 ° C. It has become. In addition, there is a correlation between the pressure of water vapor and the temperature, and when the pressure is determined, the temperature is also determined according to the pressure.

  As shown in FIG. 3, the ejector 33 includes a suction part main body 49 having a suction chamber 49 a formed therein, and is inserted into both ends of the suction part main body 49 and fixed to the suction part main body 49. 49a includes a discharge-side nozzle 51 and a suction-side nozzle 53 arranged so as to face each other with a certain gap. The suction part main body 49, the discharge side nozzle 51, and the suction side nozzle 53 are all made of stainless steel. The discharge-side nozzle 51 and the suction-side nozzle 53 are both tapered at the tip portions facing each other, and the suction-side nozzle 53 is formed more gently than the discharge-side nozzle 51 in the taper inclination. Further, the hole diameter at the tip of the discharge side nozzle 51 is formed smaller than the hole diameter at the tip of the suction side nozzle 53. For example, the hole diameter of the discharge side nozzle 51 is 6 mm and the hole diameter of the suction side nozzle 53 is 6 as an example. A dimension of .7 millimeters can be mentioned.

  The end of the water vapor supply pipe 39 is connected to the discharge-side nozzle 51 of the ejector 33 via a connector 55, the end of the ozone-containing gas supply pipe 35 is connected to the suction part main body 49, and the mixed gas supply pipe 31 The end portion is connected to the suction side nozzle 53 of the ejector 33 via the connector 57. Thus, the ozone-containing gas supplied from the ozone-containing gas supply device 3 and passing through the ozone-containing gas supply pipe 35 and flowing into the suction chamber 49a of the ejector 33 is converted from the water vapor generated by the water vapor supply device 7 to the discharge side nozzle. 51 is sucked into the suction side nozzle 53 by the negative pressure generated when it is discharged from the suction side 53 and flows into the suction side nozzle 53 and mixed with water vapor by the turbulent flow generated in the suction chamber 49a to generate a mixed gas, The mixed gas is sent to the mixed gas supply pipe 31 through the suction side nozzle 53.

  On the other hand, as shown in FIGS. 2 (b) and 2 (c), there are a plurality of tip ends (lower ends in FIG. 2) of the purification inner short tube 15a constituting the lower end of the purification inner tube 13. Injection holes 59 are formed. As can be seen from FIGS. 2A to 2C, four injection holes 59 are formed at the same position in the longitudinal direction of the pipe 15a at a position near the lower end of the purification inner short pipe 15a. Four holes are drilled at the same position in the longitudinal direction of the tube 15a above the portion by a dimension L (for example, 1 meter).

  Each of these four injection holes 59 is drilled at an equal angular interval of 90 degrees around the axis O as viewed from the direction along the axis O, and the purification inner short tube 15a. The angle between the four injection holes 59 drilled near the lower end and the four injection holes 59 drilled above is shifted by 45 degrees around the axis O. As a result, a mixed gas of ozone-containing gas and steam and hot water are injected into the underground M from substantially the horizontal direction through the injection holes 59. The positions of the injection holes 59 to be drilled may be arranged in a straight line at the same position along the axis O of the short inner tube 15a for purification without shifting the angle by 45 degrees, and are arbitrarily set. be able to.

  Further, as shown in FIG. 2, the injection holes 59 are formed by slits that are long in the longitudinal direction of the purification inner short tube 15a, and have a width dimension of 0.3 millimeters to 1 millimeter (length of the purification inner short tube). 15a is a long hole having a length of 10 mm to 20 mm, and is formed by irradiation with a high-density laser beam. In addition, since the ozone-containing gas is mixed in the mixed gas supplied to the purifying inner pipe 13 via the purifying fluid supply pipe 23, the mixed gas becomes the purifying inner short pipe 15a of the purifying inner pipe 13. When being injected into the ground M through the rim, the periphery of the small injection hole 59 is particularly susceptible to corrosion. For this reason, the purification inner short tube 15a is made of stainless steel which is not easily corroded.

  Further, one end portion of the recovery pipe 63 that communicates the gap 61 (see FIG. 1) between the inner peripheral surface of the purification outer tube 9 and the outer peripheral surface of the purification short inner tube 15b and the outside above the ground E is for purification. The other end of the recovery pipe 63 is connected to a contaminated water recovery tank 65 for recovering the contaminated water recovered from the underground M. An open / close valve 67 that opens and closes the pipe line is disposed in the middle of the recovery pipe 63 in the longitudinal direction. In addition, a sealing member 69 is mounted in a liquid-tight manner between the inner peripheral surface of the upper end portion of the purification outer tube 9 and the outer peripheral surface of the purification inner short tube 15b. The clearance 61 between the peripheral surface and the outer peripheral surface of the purification inner short tube 15b and the outside above the ground E are communicated only by the recovery tube 63.

  The ozone-containing gas supply device 3, the switching device 25, the electric motor of the electric pump 27, the pressure adjusting valve 37, the electric heater 41a, the ignition device of the boiler 47, and the on-off valve 67 are controlled so that their operations are appropriately controlled. Each is electrically connected to a control device 68 installed on the ground E via an electric wire (not shown).

(Purification procedure)
Next, a work procedure for purifying the contaminated region layer Q of the underground M using the above-described purification device 1 will be described in detail.
(Trial drilling)
As shown in FIG. 4 (a), first, a borehole 71 having a drilling member 72 attached to the tip is penetrated into the underground M where the contaminated region layer Q exists by a drilling device (not shown). The region and depth on the ground E where the contaminated region layer Q is present have been previously determined by a ground drill and a survey of the soil sampled by the borehole. Based on the results of this ground survey, the borehole 71 is connected to the ground M Intrude into. The borehole 71 is configured as one long borehole 71 by connecting a plurality of short steel boreholes 71a having an outer diameter and an inner diameter of 114 millimeters and 100 millimeters and lengths of 1 to 2 meters, respectively. . As the bore of the borehole 71 penetrates the ground M, if the bore of the borehole 71 becomes insufficient, the borehole 71 is penetrated into the ground M while connecting the borehole 71a.

  As a structure to be connected, the short bore pipes 71a in which the male screw portion and the female screw portion are respectively engraved at both ends of the short bore tube 71a are connected to each other, and the male screw portion of one of the short bore tubes 71a and the other short bore tube 71a. The female screw part is screwed together so as to be connected to each other. The soil that enters the borehole 71 when penetrating the borehole 71 into the ground M interrupts the penetration when the borehole 71 is penetrated to some extent by the excavator, and the ground M The soil collecting device 73 is inserted into the borehole 71 in a state of penetrating into the borehole and collected (see FIG. 4B). At this time, the soil collection device 73 is inserted into the borehole 71 while rotating in one direction and vibrating in the vertical direction.

  The soil recovery device 73 includes a cylindrical recovery unit 75 provided in a lower portion and a shaft member 77 that is detachably attached to the upper end of the recovery unit 75. The folding | returning part 75a which has the function to take in is provided. As a specific work for collecting the soil, the soil collecting device 73 is pushed into the borehole 71 by a pressing device (not shown) and the soil is taken into the collecting portion 75 of the soil collecting device 73, and then the soil collecting device. 73 is taken out on the ground E. Then, by removing the shaft member 77 from the collection unit 75, one end of the collection unit 75 is opened, and the soil is taken out from the opening. The extracted soil is inspected for the presence or absence of contaminants and the type and concentration of the contaminants by an inspection device (not shown).

  After the soil in the borehole 71 is removed by the soil collecting device 73, the drilling device is operated again to penetrate the borehole M into the underground M, and the borehole 71a according to the depth of the borehole 71 to penetrate. Proceed with drilling work. The depth of the borehole 71 that penetrates is determined based on the result of the above-described ground survey, and is set in the vicinity of the depth Q1 at the upper end of the contaminated region layer Q. Therefore, when the lower end of the borehole 71 reaches the depth, the borehole operation is stopped.

  Contaminants usually pass through the gap between the aquifer formed by the presence of a lot of rocks, large and small stones, gravel and sand in the ground, together with the groundwater, and the aquifer and the clay layer below it. And the silt layer where the contaminants are retained is the contaminated region layer Q. The formation from the ground E to the lower end of the aquifer (corresponding to the depth Q1) contains a lot of rocks, large and small stones, and gravel. It is possible to excavate without any trouble by penetrating the underground bore 71 into the underground M by the excavating device, with the drilling pipe 71 having a strong excavating member 72 attached to the part.

(Embedding work of outer pipe 9 for purification)
When soil remains in the borehole 71 that has penetrated to the vicinity of the depth Q1 of the underground M, the soil is again removed by the soil recovery device 73, and then as shown in FIG. 4 (c). In addition, the outer tube 9 for purification is inserted into the borehole 71 until the lower end thereof reaches the vicinity of the depth Q1 of the underground M. At this time, when the length of the purification outer tube 9 is insufficient, the plurality of purification outer short tubes 11 are appropriately connected to each other, and the shaft cores of the purification outer tube 9 and the test tube 71 are connected to each other. Are inserted into the borehole 71 so that the two substantially coincide with each other.

  Next, sand S is put into the gap formed between the outer periphery of the outer tube 9 for purification and the inner periphery of the borehole 71 to a depth of 1 to 3 meters above the depth Q1, and the shaft core of the borehole 71 is placed. On the other hand, after stabilizing so that the shaft core of the purification outer tube 9 does not shift in a direction perpendicular to these shaft cores, the borehole 71 is pulled out from the ground M by a pulling device (not shown). A hole in the underground M formed around the traced outer pipe 9 from which the borehole 71 has been pulled out is filled with swellable bentonite or a mixture of the bentonite and sand. As a result, there is no gap around the purification outer tube 9, and the purification outer tube 9 is stably embedded in the underground M. As a result, the state shown in FIG.

(Penetration work of inner pipe 13 for purification)
Next, as shown in FIG. 5 (e), the purification inner short tube 15a constituting the lower end of the purification inner tube 13 is inserted into the purification outer tube 9 buried in the underground M. . Since the purification outer tube 9 reaches the depth M1 near the underground M, the purification inner short tube 15a can be easily inserted to the depth Q1 vicinity. At that time, the purification inner short tube 15b is inserted through the connection tube 17 while being appropriately connected so that the lower end of the purification inner short tube 15a reaches the vicinity of the depth Q1.

  The fact that the lower end of the purification inner short tube 15a has reached the depth Q1 of the underground M can be seen by the lower end of the purification inner short tube 15a striking the soil surface at the bottom of the hole of the purification outer tube 9. Next, as shown in FIG. 6, the purging inner pipe 13 penetrates into the ground M while striking the purging short inner pipe 15 b constituting the upper end portion of the purifying inner pipe 13 with the striking device 79. The striking device 79 includes a pedestal 81 for installing the striking device 79 on the ground E, and a column member installed in a standing state on the pedestal 81 with tension applied by a wire rope 83 connected to the pedestal 81. 85, a striking mechanism portion 87 attached to the pillar member 85 and movable along the longitudinal direction of the pillar member 85 to apply a striking load to the cleaning inner short tube 15b, and an upper end portion of the striking mechanism portion 87 A rope winding device 91 that changes the height position of the striking mechanism portion 87 by appropriately adjusting the winding length of the other end side of the wire rope 89 that is connected to one end side thereof, and the column member 85 that is covered from above. And a pulley device 93 attached to the upper end of the pulley. The rope winding device 91 is fixed on a pedestal 81.

  A midway portion of the wire rope 89 is stretched between a pair of pulleys 93 a and 93 a of the pulley device 93. On the ground E in the vicinity of the side of the impact device 79, when the hydraulic oil whose pressure has been increased to high pressure is supplied via the flexible hydraulic oil supply pipe 95a, the process and the supplied hydraulic oil are supplied to the flexible hydraulic oil. A hydraulic oil supply device 97 that repeatedly performs the step of returning via the return pipe 95b to the striking mechanism 87 is installed. The hydraulic oil supply device 97 includes an electric motor 99a and a hydraulic pump 99b driven by the electric motor 99a, and hydraulic oil stored in a hydraulic oil storage tank (not shown) is blown by the hydraulic pump 99b. 87 is supplied at high pressure.

  When the cleaning short inner pipe 15b is being hit by the hitting device 79, the position detecting device 101 for detecting when the hitting mechanism portion 87 is lowered to a predetermined lower limit position is a lower part of the column member 85. It is arranged. By the detection of the position detection device 101, the rotation of the electric motor 99a of the hydraulic oil supply device 97 is stopped, and the striking operation of the striking mechanism 87 is stopped. The electric motor 99a and the position detection device 101 of the hydraulic oil supply device 97 are electrically connected to a control device 103 installed on the ground E via electric wires (not shown). The joint member 105 connected to the upper end of the purification inner short tube 15b is given a striking load by the striking mechanism 87, so that the excavation member 19 has a hole in the ground M deeper than the depth Q1 of the ground M. Is worn.

  As described above, since the formation from the ground E to the lower end of the aquifer (corresponding to the depth Q1) is rich in rocks, large and small stones and gravel, it must be excavated with a strong excavation member corresponding to it. There is. On the other hand, since the silt layer of the contaminated region layer Q is a soft formation without rocks, stones and gravel, a strong excavation member such as an excavation member attached to the borehole 71 is not necessary, and The inner pipe 13 for purification can be easily penetrated into the underground M with a relatively small impact load by the impact device 79. Further, since the outer peripheral surface of the purification inner pipe 13 that has penetrated into the silt layer of the contaminated region layer Q is completely adhered and covered with the soft soil of the silt layer, the ozone-containing gas injected into the underground M A special sealing member for preventing the mixed gas of hot water and steam and the hot water from escaping upwards as they are becomes unnecessary.

  As the depth of penetration of the purifying inner pipe 13 into the underground M becomes deeper, another purifying inner short pipe 15b is connected to the upper end of the purging inner short pipe 15b protruding from the ground E with the connecting pipe 17 It will be added through. The depth of the purging inner pipe 13 penetrating is determined based on the result of the ground investigation described above, and is set near the depth Q2 at the upper end of the contaminated region layer Q, specifically, slightly below the depth Q2. Therefore, the penetration operation is stopped when the lower end of the purification inner pipe 13 reaches the depth. As a result, the state shown in FIG.

  After penetrating the inner purification tube 13, a purification fluid is supplied to the upper end portion of the purification inner short tube 15 b constituting the upper end portion (portion protruding above the ground E) of the purification inner tube 13 via the connector 21. One end of the tube 23 is connected while the other end is connected to the switching device 25. The switching device 25 includes a hot water supply pipe 29 having one end connected to the electric pump 27 of the hot water supply apparatus 5, and another end of the mixed gas supply pipe 31 having one end connected to the ejector 33. Connect. The ejector 33 includes an ozone-containing gas supply pipe 35 having one end connected to the ozone-containing gas supply apparatus 3, and a water vapor supply pipe 39 having one end connected to the pressure regulating valve 37 of the water vapor supply apparatus 7. Is connected to the other end.

(Purification work at the deepest depth by the purification device 1)
Next, the work procedure for purifying the contaminated area layer Q using the purifying apparatus 1 installed on the ground where the contaminated area layer Q exists will be described in detail. First, the ozone-containing gas supply device 3 is operated to generate ozone-containing gas, the hot water supply device main body 41 is energized with the heater 41a to generate high-temperature hot water, and the boiler 47 of the water vapor supply device 7 is operated. Produces high-temperature and high-pressure steam. The ozone-containing gas generated by the operation of the ozone-containing gas supply device 3 is supplied to the ejector 33 through the ozone-containing gas supply pipe 35. The ozone-containing gas and water vapor are mixed in the ejector 33 to generate a mixed gas, and the mixed gas is sent to the switching device 25 through the mixed gas supply pipe 31.

  On the other hand, high-temperature hot water generated by energizing the electric heater 41 a of the hot water supply device body 41 is sent to the switching device 25 via the hot water supply pipe 29 by the electric pump 27 of the hot water supply device 5. The switching device 25 is switch-controlled by the control device 68 so that either the hot water supply pipe 29 or the mixed gas supply pipe 31 is selectively connected to the purification fluid supply pipe 23. As the switching timing, for example, the communication connection time between the hot water supply pipe 29 and the purification fluid supply pipe 23 is 5 minutes, and the communication connection time between the mixed gas supply pipe 31 and the purification fluid supply pipe 23 is 25. There is a timing of minutes. Then, the control device 68 performs switching control so that these communication connection times are alternately repeated a predetermined number of times.

  The mixed gas and hot water of the ozone-containing gas and water vapor, which are selectively controlled by the switching device 25 and sent out to the purification fluid supply pipe 23, pass through the purification fluid supply pipe 23, and pass through the purification inner pipe 13. It is injected toward the contaminated region layer Q in the ground M from an injection hole 59 formed at the tip of the purification inner short tube 15a.

  In this case, compared with a mixed gas in which ozone-containing gas, which is a gas, and water vapor are mixed, warm water, which is a liquid, has greater kinetic energy due to jetting, so the hot water reaches far away from the ground M, A passage is formed in the underground route that has passed. Therefore, by injecting warm water into the underground M before the mixed gas of ozone-containing gas and water vapor, the mixed gas can easily pass through the underground M passage formed by the warm water. Can reach far away in the ground.

  As a result, volatile organochlorine compounds such as trichlorethylene of VOCs remaining in the soil of the contaminated area layer Q of the underground M are oxidatively decomposed into chlorine, hydrogen chloride, dichloroacetic acid, etc. by ozone and are soluble in water. Thus, it dissolves in hot water or groundwater injected from the injection holes 59 of the purification inner short tube 15a. Chlorine and hydrogen chloride dissolved in warm water and groundwater cause a chemical reaction with minerals contained in the soil of the underground M and become harmless compounds.

  At this time, contaminants in the soil around the injection hole 59 of the purification inner short tube 15a are exposed not only to hot water but also to steam at a higher temperature than that, so that the temperature rises. Chemical reactions with minerals are actively carried out. That is, unlike warm water, which can be raised only up to 100 ° C., water vapor can be raised to a temperature several tens of degrees higher than 100 ° C., so that the chemical reaction by ozone is caused by such high-temperature steam. This is because the temperature of the environment to be performed can be further increased.

  Further, the mixed gas of the ozone-containing gas and water vapor or hot water is injected into the underground M at a high pressure from the injection hole 59 of the purification inner short tube 15a, thereby increasing the pressure of the underground M. For this reason, if the on-off valve 67 is opened, a part of the pollutant dissolved in the hot water or the ground water becomes contaminated water, and the inner peripheral surface of the purifying outer pipe 9 and the purifying short are caused by the pressure in the underground M. It is pushed out onto the ground surface E through the gap 61 with the outer peripheral surface of the inner pipe 15 b and is further collected in the contaminated water collection tank 65 through the collection pipe 63. Thereafter, biological treatment with microorganisms is performed by adding microbial mixed water generated by the growth of microorganisms to the contaminated water collected in the contaminated water collection tank 65, and the pollutants in the contaminated water are decomposed into carbon dioxide and water. And you may make it completely harmless.

(Purification work at other depths by the purification device 1)
After performing the above-described purification operation for a certain period of time, all the operations of the ozone-containing gas supply device 3, the hot water supply device 5 and the water vapor supply device 7 are stopped, and the purification inner pipe 13 is moved from the underground M to about 50 cm. Pull up. Then, when the ozone-containing gas supply device 3, the hot water supply device 5 and the water vapor supply device 7 are actuated again, this time, at a position about 50 centimeters above the lower end (depth Q2) of the contaminated region layer Q of the underground M. The mixed gas of the ozone-containing gas and water vapor and the hot water, which are alternatively sent to the purification fluid supply pipe 23, pass through the purification fluid supply pipe 23 and pass through the purification inner short pipe 15 a of the purification inner pipe 13. It is injected from the injection hole 59...

  The mixed gas of ozone-containing gas and water vapor over the entire depth of the contaminated region layer Q (from the depth Q2 to the depth Q1) by performing the purification operation performed by changing the depth upward about 50 centimeters in this way. And hot water are injected from the injection holes 59 of the purification inner short tube 15a of the purification inner tube 13. In addition, ozone-containing gas with a low specific gravity tends to rise underground M due to its buoyancy, but it was injected when the purification work was performed first by changing the depth upward and performing the purification work. Since the ozone-containing gas spreads over a wider depth region of the contaminated region layer Q, the ozone-containing gas is utilized for purification without waste.

When the purification inner pipe 13 is pulled up from the underground M when the purification operation is performed with the depth changed upward, if the length protruding above the ground E becomes longer, the purification fluid supply pipe 23 is connected. The connector 21, the sealing member 69, and the recovery pipe 63 are removed from the upper end portion of the purification inner tube 13, and the purification inner short tube 15 b and the connection tube 17 constituting the upper end portion of the purification inner tube 13 are 1 Remove the books completely. Then, after adjusting the amount of penetration of the purification inner pipe 13 into the underground M, the connector 21, the sealing member 69 and the recovery pipe 63 to which the purification fluid supply pipe 23 is connected are again connected to the purification inner pipe 13. Attach to the upper end of the plate and restart the purification process.
By the purification operation described above, purification is performed over the entire depth of the contaminated region layer Q.

  According to the purification method of the contaminated ground according to the first embodiment as described above, the purification is performed in the outer pipe 9 for purification buried in the underground M to the vicinity of the depth Q1 at the upper end of the contaminated area layer Q in the underground M. After the inner pipe 13 is inserted, the inner pipe 13 for purification is penetrated to the depth of the underground M below the lower end of the outer pipe 9 for purification (depth slightly lower than the depth Q2). It is not necessary to excavate and form the depth Q2 at the lower end of the region layer Q and to insert and dispose the purification outer tube 9 as a soil retaining tube up to that depth, and the purification fluid injected into the underground M remains as it is. There is also no need for a special sealing member to prevent it from escaping immediately.

  Further, the underground M pollutant dissolved in the ozone-containing gas, hot water and water vapor and dissolved in the hot water is recovered on the ground E through the gap 61 between the purification outer tube 9 and the purification inner tube 13. Therefore, the underground M pollutant can be recovered with a simple configuration.

  Further, since the borehole 71 is penetrated into the underground M to the vicinity of the depth Q1 at the upper end of the contaminated region layer Q in the ground M, the borehole 71 having a strong excavating member attached to the tip portion is removed by the drilling device. By penetrating the underground M, even if there are many rocks, large and small stones and gravel between the ground E and the vicinity of the depth Q1 at the upper end of the contaminated zone Q, it is possible to excavate to the depth Q1 without any trouble. it can. Further, since the purification outer tube 9 is inserted into the borehole 71 penetrating into the underground M, the purification outer tube 9 can be easily penetrated to the vicinity of the depth Q1 at the upper end of the contaminated region layer Q. .

  In addition, after inserting the purification outer tube 9 into the borehole 71, the borehole 71 is removed from the ground M, so that the removed borehole 71 can be reused immediately.

  Furthermore, since the hot water and the mixed gas obtained by mixing ozone-containing gas and water vapor are switched by the switching device 25 and are alternately supplied into the purification inner pipe 13, they are connected to the purification inner pipe 13 and The supply pipe for supplying the hot water and the mixed gas into the purification inner pipe 13 can be a common pipe. As a result, the piping is simplified accordingly.

(Second Embodiment)
Hereinafter, a second embodiment of the method for purifying contaminated ground according to the present invention will be described in detail with reference to FIG. What is shown by the code | symbol 107 in FIG. 7 is the purification apparatus for using the purification method of the contaminated ground which concerns on the 2nd Embodiment of this invention. In this figure, members that are the same as or equivalent to those described in the first embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.

  In the purification method for contaminated ground in the first embodiment described above, an example has been shown in which the purification outer pipe 9 and the purification inner pipe 13 are penetrated into the underground M one by one to purify the contaminated ground. In the method for purifying contaminated ground according to the second embodiment, an example is shown in which the outer 12 for purification 9 and the inner pipe 13 for purification are penetrated into the underground M 12 by 12 to purify the contaminated ground.

  A plurality of outer pipes 9 for purification are penetrated at appropriate intervals so as to reach the depth of the contaminated area layer Q and the depth (depth) of the underground area M of the contaminated area layer Q, and all of these are purified. Purifying inner pipes 13 are inserted into the outer pipes 9. In addition, as described in the first embodiment, the drill tube 71 penetrates the borehole 71 into the ground M in the work steps until the purification outer pipes 9 and the purification inner pipes 13 are inserted. And the process of pulling out the drilled pipe 71 that has penetrated from the underground M are included as the preceding process.

  The purification fluid supply pipes 23 connected to the respective purification inner pipes 13 and the recovery pipes 63 extending from the upper ends of the respective purification outer pipes 9 are finally assembled as one collection pipe. Then, it is connected to the switching device 25 and the contaminated water recovery tank 65, respectively.

(Purification work by the purification device 107)
Next, an operation procedure for purifying the contaminated area layer Q using the purifying apparatus 107 installed on the ground where the contaminated area layer Q exists will be described in detail. In the purification apparatus 107, only one of the plurality of purification inner pipes 13... (The purification inner pipe 13 inserted into the purification outer pipe 9 indicated by the arrow Y in FIG. 7). A mixed gas of ozone-containing gas and water vapor and hot water are supplied in the same manner as in the first embodiment. At this time, the first on-off valve 109 disposed corresponding to the purification inner tube 13 in the purification outer tube 9 indicated by the arrow Y is opened and disposed corresponding to the purification outer tube 9. The second on-off valve 111 is closed. On the other hand, the other first on-off valve 109 is closed and the second on-off valve 111 is opened.

  A mixed gas of ozone-containing gas and water vapor and hot water are respectively injected into the underground M at high pressure from the injection holes 59 of the inner short purification tube 15a constituting the lower end portion of the inner purification tube 13. The pressure of M increases. Part of the pollutant dissolved in the hot water or ground water due to the increased pressure of the underground M is treated as contaminated water, and passes through the gap 61 between each of the purification outer tubes 9 and each of the purification inner tubes 13 on the ground E. It tries to be pushed out.

  However, since the second on-off valve 111 disposed corresponding to the purification outer tube 9 indicated by the arrow Y is closed, it passes through the other open second on-off valve 111 and the recovery pipe 63 to cause contamination. Contaminated water is recovered in the water recovery tank 65. In this embodiment as well, the purification inner pipe 13 is moved upward or the purification inner short pipe 15b is removed one by one by the same procedure as in the purification work according to the first embodiment. A mixed gas of ozone-containing gas and water vapor and hot water are injected from the injection holes 59 of the purification inner pipe 15a of the purification inner pipe 13 over the entire depth of the region layer Q (from the depth Q2 to the depth Q1). To.

  After the injection operation by the purification inner tube 13 inserted in the purification outer tube 9 indicated by the arrow Y is completed, the injection is inserted into another purification outer tube 9 (the purification outer tube 9 indicated by the arrow Z in FIG. 7). In order to supply only the purified inner pipe 13 with the mixed gas of ozone-containing gas and water vapor and hot water, the first on-off valve 109 disposed corresponding to the inner pipe 13 for purification is opened. At this time, the first on-off valve 109 disposed corresponding to the purification inner pipe 13 in the purification outer pipe 9 indicated by the arrow Y is closed and arranged corresponding to the purification outer pipe 9 indicated by the arrow Z. The provided second on-off valve 111 is also closed, and the other second on-off valves 111 are opened, so that they pass through the opened second on-off valve 111 and the recovery pipe 63 to the contaminated water recovery tank 65. Contaminated water is collected.

  After the injection operation by the purification inner tube 13 inserted in the purification outer tube 9 indicated by the arrow Z is completed, the same injection operation is performed for the other purification inner tubes 13 that are not performing the injection operation, By performing the injection operation for all the purification inner pipes 13, the soil contaminants can be reliably purified over the entire contamination area layer Q of the underground M.

  The first on-off valve 109 and the second on-off valve 111 are all constituted by solenoid valves and are configured to be automatically opened and closed automatically by the automatic control by the control device 68. The opening / closing operation may be performed manually.

  According to the contaminated ground purification method according to the second embodiment as described above, the purification inner tube 13 inserted into any one of the plurality of purification outer tubes 9. Injecting a mixed gas of ozone-containing gas and water vapor and hot water into the ground M through the atmosphere, and dissolving the mixed gas of ozone-containing gas and water vapor and water in the ground water and dissolved in the hot water and ground water Method for recovering the water on the ground E through a gap 61 between another purification outer tube 9 of the plurality of purification outer tubes 9 and the purification inner tube 13 inserted into the purification outer tube 9. Since the purification outer tube 9 and the like to be injected and recovered are appropriately changed, the purification can be reliably performed over a wide area of the ground M with a simple configuration.

  Note that the second embodiment described above can provide the same operations and effects as the first embodiment described above, and the same or equivalent components as those of the first embodiment are the first. It goes without saying that the same structural change as in the embodiment can be made.

Moreover, each embodiment mentioned above is an example for demonstrating this invention, This invention is not limited to each said embodiment, and can be read from the whole of a claim and a specification. The method can be appropriately changed without departing from the gist or concept of the invention, and the method for purifying contaminated ground after such change is also included in the technical scope of the present invention.
For example, in each of the above-described embodiments, examples have been shown in which fixed pressures and temperatures, and inner diameters, outer diameters, lengths, and materials related to various members and components are used. Any value, dimension, and material may be used.

  Moreover, in each embodiment mentioned above, after inserting the outer tube | pipe 9 for purification | cleaning in the borehole 71 penetrated into the underground M, the borehole 71 was pulled out from the underground M, but it replaces with this. The borehole 71 may be substituted for the outer tube 9 for purification without pulling out the borehole 71 from the underground M. In this case, the purifying inner pipe 13 is inserted into the borehole 71 penetrating the underground M. By doing in this way, the outer pipe | tube 9 for purification | cleaning becomes unnecessary.

DESCRIPTION OF SYMBOLS 1 Purifying device 9 Purifying outer tube 13 Purifying inner tube 25 Switching device 59 Injection hole 71 Borehole M Underground Q Contaminated area layer Q1 Depth Q2 Depth

Claims (4)

In the hollow state where the soil in the pipe is removed, the outer pipe for purification is buried in the ground so that the lower end is located close to the depth of the upper end of the contaminated layer layer in the ground and the upper end faces the ground. Outer pipe burying process,
After the inner purification tube is inserted from the upper end into the outer purification tube buried in the ground, the inner purification tube is placed below the lower end of the outer purification tube and near the depth of the lower end of the contaminated area layer. An inner pipe penetration process for purification,
Purifying fluid injection for supplying a purifying fluid into the purifying inner pipe and injecting the purifying fluid into the contaminated region layer in the ground through an injection hole provided at a lower end portion of the purifying inner pipe. A method for purifying contaminated ground comprising a process. In the purification method of the contaminated ground of Claim 1,
The purifying outer pipe embedding step is a drilling tube penetration step of penetrating the borehole into the ground so that the lower end is located to the depth near the upper end of the contaminated region layer in the ground, and the upper end faces the ground,
Removing the soil in the borehole penetrating into the ground to make the inside of the borehole hollow; and
A subsurface contamination purification method comprising a purification outer tube insertion step of inserting the purification outer tube into the hollow borehole. In the ground purification method of Claim 2,
The subsurface contamination purification method, wherein the purification outer pipe embedding step further includes a test tube extraction step for extracting the test tube from the ground after the purification outer tube insertion step. In the purification method of the contaminated ground according to any one of claims 1 to 3,
The purification fluid includes an ozone-containing gas containing ozone as a composition gas, hot water, and water vapor having a temperature higher than the hot water,
In the purifying fluid injection step, the warm water and a mixed gas obtained by mixing the ozone-containing gas and water vapor are switched by a switching device and alternately supplied into the purifying inner pipe. Pollution purification method.

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