JP3970108B2 - Purification of groundwater contaminated with oil - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for purifying groundwater contaminated with oil, and more specifically, jets compressed air using a stirring member, peels off oil adhering to soil adjacent to groundwater, and floats it in groundwater. The present invention relates to a method for purifying groundwater contaminated with oil by collecting groundwater and separating the oil.
[0002]
[Prior art]
Oil such as solvent and oil leaks into the waste liquid tank and the like, penetrates into the soil with rainwater and the like, contaminates the groundwater, and further adheres to or is impregnated into surrounding soil particles adjacent to the groundwater. Oil that has once adhered to soil particles does not easily flow into groundwater, and oil that has floated in groundwater can be removed, but oil that has adhered to soil adjacent to groundwater cannot be removed. . However, since it oozes into groundwater for a long period of time, it is impossible to ensure the safety of groundwater without removing the oil adhering to the soil. Therefore, a method and an apparatus for removing oil adhering to soil are desired.
[0003]
Conventionally, many methods and apparatuses for purifying groundwater contaminated with oil have been proposed. Generally, a method and an apparatus are used in which a well is provided in a contaminated area and the contaminated ground water is pumped from the well to remove oil. In this case, a suction pump for pumping up ground water and an oil / water separator are used, and the ground water containing the sucked oil is separated into oil and water by the oil / water separator. The separated water can be returned as groundwater. In-situ purification by installing a well in the aquifer of groundwater, dissolving methane, etc. in the groundwater, purifying the gas by suctioning the gas at the top of the well, and returning the purified groundwater to the aquifer. A method and apparatus have also been proposed.
[0004]
However, when the groundwater is contaminated with oil as described above, the oil is adsorbed by adsorbing or impregnating the soil near the aquifer, and does not easily flow out into the groundwater. There was a problem that the purification could not be performed. In addition, when performing work such as suctioning and returning purified water using a well, abruptly increasing or decreasing the groundwater level may cause land subsidence. Feeding must be done at a very slow rate. Therefore, the purified water is not distributed over a wide area in the groundwater, and it cannot be said that the purification efficiency is good. Further, although the number of wells can be increased to increase the purification efficiency, there is a problem that the number or capacity of the suction pumps needs to be increased and the processing capacity of the oil / water separator needs to be increased. .
[0005]
In view of the above-described problems, a method and an apparatus have been proposed that facilitate the separation of oil from soil particles and efficiently purify contaminated groundwater by supplying air to the groundwater and activating microorganisms. For example, the method and apparatus disclosed in Japanese Patent Application Laid-Open No. 2001-129545 discloses that ultra-high pressure air is intermittently injected into groundwater from an injection well located in the lower layer of an aquifer by pulsing it at short intervals. It is characterized by floating the oil adsorbed on the soil particles, collecting the groundwater mixed with the floating oil, separating the oil and water, and then reducing it to the groundwater again. In Japanese Patent Laid-Open No. 2001-129545, it is easy to exfoliate oil from soil particles with the momentum when ultrahigh pressure air is blown into the lower layer portion of the aquifer instantaneously at a predetermined intermittent timing, and groundwater is extracted by ultrahigh pressure air. It is disclosed to purify contaminated groundwater with oil by promoting biodegradation by microorganisms in an aerobic state.
[0006]
However, the method and apparatus disclosed in Japanese Patent Application Laid-Open No. 2001-129545 needs to form an injection well and a pumping well in advance, and injects ultrahigh pressure air in a pulsed manner at short intervals. However, although it is possible to spread the purified water over a wide area, the oil adhering to the soil on the side surface of the aquifer cannot be effectively separated, and the purified water is further removed from the groundwater. Could not be sufficiently dispersed.
[0007]
[Problems to be solved by the invention]
The present invention has been made to solve the above-described problems, and can excavate to a position where groundwater in soil exists, and can supply ground air and agitate groundwater. Using the agitating member, the oil attached to the soil adjacent to the groundwater is separated by the supplied compressed air, and the oil can be separated and purified from the groundwater containing the floating oil, and the agitating member is rotated. The purpose of the present invention is to provide a method for purifying groundwater contaminated with oil that makes it possible to promote the purification of the entire groundwater by moving the groundwater up and down and dispersing the water from which oil has been removed over a wide range. To do.
[0008]
[Means for Solving the Problems]
The above object of the present invention is achieved by providing a method for purifying groundwater contaminated with the oil of the present invention.
[0009]
That is, according to the invention of claim 1 of the present invention, the step of excavating the soil by rotating the stirring member provided with the cutting member at the tip, and immersing the stirring member in the groundwater present in the soil;
Injecting compressed air from the agitating member toward the periphery of the agitating member, and jetting the compressed air from the agitating member and rotating the agitating member to adhere to the soil adjacent to the groundwater Separating the oil and floating in the ground water;
A method for purifying groundwater contaminated with oil is provided, comprising: recovering groundwater containing the suspended oil and separating the oil.
[0010]
According to the second aspect of the present invention, there is provided a method for purifying groundwater contaminated with oil, comprising the step of returning the water from which the oil has been separated in the step of separating the oil to the groundwater.
[0011]
According to invention of Claim 3 of this invention, the said stirring member is provided in the front pipe | tube provided with the said cutting member in the front-end | tip part, the hollow shaft body to which the said front pipe | tube is connected, and the circumference of the said shaft body. The spiral blade, a plurality of projecting members disposed on the upper surface and the lower surface of the spiral blade, and the inside of the shaft body, through the shaft body, toward the edge of the spiral blade The injection pipe for supplying the compressed air and water separated from the oil component,
The shaft is provided with a method for purifying groundwater contaminated with oil, wherein the shaft is formed to have a large diameter at the center along the length direction and a small diameter at both ends.
[0012]
According to the invention of claim 4 of the present invention, there is further provided a method for purifying groundwater contaminated with oil, comprising the step of injecting compressed air from the tip conduit through the inside of the shaft portion.
[0013]
According to a fifth aspect of the present invention, there is provided a method for purifying groundwater contaminated with oil, wherein the step of injecting the compressed air injects the compressed air at a pressure of 200 kPa to 1000 kPa. Is done.
[0014]
According to the invention of claim 6 of the present invention, in the step of separating the oil component, the groundwater containing the suspended oil component is collected through a pumping hole reaching the groundwater from the ground surface. A method for the purification of contaminated groundwater is provided.
[0015]
According to the seventh aspect of the present invention, there is provided a method for purifying groundwater contaminated with oil, wherein the step of returning to the groundwater intermittently injects water from which the oil has been separated. .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. The method for purifying groundwater contaminated with oil according to the present invention is a method for purifying contaminated groundwater by infiltrating the soil with rainwater or the like together with leakage of waste liquid containing oil such as solvent and oil. The groundwater purification method of the present invention is particularly suitable for removing oil adhering to the soil adjacent to the groundwater. The present invention provides an effect of intermittently injecting compressed air into the soil adjacent to the groundwater by injecting the compressed air while rotating in the groundwater using the stirring member, and also by injecting the compressed air from the previous conduit. In addition, oil adhering to the bottom soil of groundwater can be peeled off and suspended in groundwater. Moreover, this invention can make compressed air collide with soil in the state of a fine bubble, and collision can be repeated by the intermittent injection mentioned above, and an oil component can be peeled from a soil particle. The separated oil adheres to the bubbles due to the surface tension of the bubbles, and moves toward the upper layer of the groundwater together with the bubbles. In the groundwater purification method of the present invention, a part of groundwater containing suspended oil is sucked in the upper layer of the groundwater, the oil and water are separated in the oil-water separator, and the separated water is again passed through the stirring member to the groundwater. You can put it back in. By repeating this, the oil is gradually removed from the groundwater and the soil adjacent to the groundwater, and the groundwater is purified.
[0017]
FIG. 1 is a perspective view showing an example of a stirring member that can be used in the groundwater purification method of the present invention. The stirring member 1 shown in FIG. 1 can also be used as a soil excavation member. The stirring member 1 shown in FIG. 1 includes a tip conduit 3 having a cutting member 2 at the tip, a shaft body 4 having a central portion with a larger diameter along the length direction and a smaller diameter at both ends, The spiral blade 5 is provided around the outer surface of the shaft body 4 and a plurality of projecting members 6 provided on the upper and lower surfaces of the spiral blade 5. The leading conduit 3 shown in FIG. 1 is connected to a shaft body 4 and a connecting member such as a flange 7, and the cutting member 2 is provided on the flange 7 in the same manner as the leading conduit 3. The cutting member 2 shown in FIG. 1 has a sharply pointed tip, and can cut hard soil or stone. The shaft body 4 shown in FIG. 1 has a shape in which cones are connected to both sides of a cylinder, and spiral blades 5 are provided around the outer surface. The diameter of the spiral blade 5 is also the largest in the portion disposed in the central portion of the shaft body 4 and is formed so that the diameter decreases toward both ends of the shaft body 4, similarly to the shaft body 4. ing. The shaft body 4 has a hollow inside, and is used for inserting a pipe into the hollow portion of the shaft body 4 or injecting compressed air from the front conduit 3. The spiral blade 5 shown in FIG. 1 is provided with projecting members 6 at predetermined positions on the upper surface and the lower surface, and injection tubes 8 and 9 taken out from the inside through the shaft body 4 are the edges of the spiral blade 5. It is arranged toward the part.
[0018]
The stirring member 1 shown in FIG. 1 is provided with a rotating means (not shown) for connecting the end of the shaft body 4 to which the leading conduit 3 is not connected and for rotating the stirring member 1. The tip pipe 3 is excavated by bringing it into contact with the soil while rotating. A stirring member 1 shown in FIG. 1 includes a cutting member 2 at the tip, a shaft 4 having a diameter increased from the tip toward the center, and a spiral having a diameter increased toward the center together with the diameter of the shaft 4. The shaped blade 5 makes it possible to excavate smoothly into the ground. The agitating member 1 shown in FIG. 1 uses an air compressor or an air cylinder (not shown), and injects compressed air from a leading conduit 3 provided at the tip of the agitating device 1. The soil can be excavated. The compressed air used for excavation can be used to reduce impact on the ground during excavation and to give the agitating member 1 a rocking agitation effect to facilitate excavation. Further, the projecting member 6 provided on the spiral blade 5 is a rectangular plate, and a plurality of protrusion members 6 are disposed on the upper surface and the lower surface of the spiral blade 5. The projecting member 6 shown in FIG. 1 is provided such that the rectangular surface faces in the radial direction, and the agitating member 1 can smoothly rotate when excavating or agitating the soil, thereby preventing the generation of soil. It is hard to happen.
[0019]
The agitating member 1 shown in FIG. 1 is supplied with compressed air through an injection pipe 8 provided in a hollow interior of the shaft body 4, and oil is separated by an oil / water separator through the injection pipe 9 to be purified without containing oil. Water can be returned to groundwater. Further, compressed air is supplied through a gap between the injection pipes 8 and 9 inside the shaft body 4 shown in FIG. Compressed air is injected from the tip conduit 3 provided at the tip of the stirring member 1 shown in FIG. 1 and can be smoothly cut by the cutting member 2. As shown in FIG. 1, at least two injection pipes 8 and 9 can be provided for supplying compressed air and purified water separately. In the present invention, the injection pipes 8 and 9 can supply compressed air and purified water through the same injection pipe, or a plurality of injection pipes for compressed air and a plurality of purified water. It is also possible to provide two or more injection tubes for each of the injection tubes. Moreover, it can also be branched and supplied from a plurality of locations. Furthermore, in this invention, it can also be set as the triple pipe structure arrange | positioned like the shaft body 4, a 1st injection pipe, a 2nd injection pipe from the outer side pipe | tube. In this case, the purified water in the second injection pipe, the compressed air injected into the ground water between the first injection pipe and the second injection pipe, the shaft 4 and the first injection pipe In between, it can be supplied separately such as compressed air used during excavation. The first injection tube and the second injection tube may be branched and supplied from two or more locations. In the present invention, the stirring member 1 is substantially intermittently supplied with respect to the predetermined direction. In this case, although depending on the number of the injection pipes 8 and 9 and the number of rotations of the stirring member 1, the period for supplying the compressed air and the purified water to the predetermined direction in order to properly separate the oil component is 0. .5 s ^{−1 to} 3 s ⁻¹ . In the present invention, the compressed air may be any pressure as long as it can be supplied to the groundwater, but can be, for example, 200 kPa to 1000 kPa. The purified water may be at any pressure as long as it can be returned to the groundwater, but can be supplied at a pressure of 200 kPa to 1000 kPa as with the compressed air.
[0020]
The stirring member 1 shown in FIG. 1 can be pulled up from the soil while rotating in a direction opposite to the direction of rotation when excavating. By doing in this way, when raising and lowering while rotating in the soil, the generation of soil removal can be suppressed. In addition, by stirring the stirring member 1 while raising and lowering it several times up and down and supplying compressed air and purified water from the injection pipes 8 and 9, the purified water is also supplied to the upper layer and the lower layer of the groundwater in the original position. It can be dispersed and the oil adhering to soil at any depth can be separated and suspended in groundwater. In the present invention, the agitation member 1 is once pulled up, installed in another position, excavated, and compressed air is injected as described above, so that the oil content attached to the soil covering the groundwater without using an additional excavating means. Can be removed by peeling.
[0021]
The tip conduit 3 used in the stirring member 1 shown in FIG. 1 may be a pipe having any diameter and length. Further, the cutting member 2 may have any shape, structure and material as long as it can excavate the soil appropriately. In the case of the cutting member 2 as shown in FIG. 1, any number may be provided. Further, the shaft body 4 is of any size as long as the diameter of the central portion in the length direction is increased, the diameters of both end portions are decreased, hollow, and provided with the spiral blades 5. May be. Further, the spiral blade 5 may be provided with any circumference in the length direction of the shaft body 4 as shown in FIG. In this invention, since the stirring member 1 is immersed in water, it can be produced using a material that does not rust. For example, stainless steel or Teflon (registered trademark) processed material can be used. Further, any number of the protruding members 6 may be provided, and the shape of the protruding member 6 is not the rectangular plate shape described above, but the rectangular plate is bent along the spiral shape of the spiral blade 5. May be. In the present invention, the extension shaft member is connected to the shaft body 4 in accordance with the depth of excavating the soil, and the groundwater existing at a predetermined depth can be purified.
[0022]
The stirring member 1 described above will be described in detail with reference to FIGS. 2 and 3. FIG. 2 is a side view and a cross-sectional view of the stirring member 1 shown in FIG. The stirring member 1 shown in FIG. 2 is provided with a leading conduit 3 for excavating soil, and a plurality of cutting members 2 are provided at the tip of the leading conduit 3. The cutting member 2 has a sharp pointed tip, and a plurality of cutting members 2 are provided in the circumferential direction of the tip of the tip conduit 3. Further, the leading conduit 3 is connected to the shaft body 4 by a flange 7 and is provided on the flange 7 so that a cutting member 2b similar to the cutting member 2a provided on the leading conduit 3 faces in the same direction as the direction of the cutting member 2a. It has been. The cutting member 2 shown in FIG. 2 can be joined to the leading conduit 3 and the flange 7 by welding or the like.
[0023]
The shaft body 4 shown in FIG. 2 is formed such that the diameter of the central portion is increased, the center portion has a constant diameter at a predetermined length, and the diameter decreases toward the both end portions at a constant rate. ing. The shaft body 4 is hollow inside, and a spiral blade 5 formed in a spiral shape on the outer surface of the shaft body 4 is provided around the shaft body 4. The spiral blade 5 is formed so that the diameter of the spiral blade 5 increases toward the center of the shaft body 4, and a plurality of projecting members 6 are provided on the upper and lower surfaces of the spiral blade 5. . Similar to the shaft body 4, the spiral blade 5 is formed so that the diameter of the blade increases from both ends of the shaft body 4 in the length direction toward the center portion, and smoothly agitates in the soil up and down. It has a structure that can be done. For example, the shaft body 4 has a constant diameter of 0.8 m in length and a length of 0.16 m in the center, and a diameter of 0.14 m to 0.4 m in the range of 0.32 m at both ends in the length direction. The structure can be enlarged at a certain rate. In the case of the shaft body 4 described above, the taper angle that expands at a constant rate is preferably 22 °. The spiral blade 5 disposed in the central portion having a constant diameter of the shaft body 4 is formed to be a blade having a constant diameter.
[0024]
The protruding member 6 shown in FIG. 2 has a rectangular plate shape, and is disposed so that the rectangular surface faces the shaft body 4. Further, the protruding member 6 is provided on the edge of the spiral blade 5 and the inner edge near the shaft body 4 and has a structure in which rectangular corners are chamfered. By adopting a structure in which the corners on the side facing the rotation direction of the rectangular plate-like projecting member 6 are chamfered, the spiral blade 5 can be smoothly rotated and effectively stirred in soil and groundwater. be able to. In the stirring member 1 shown in FIG. 2, when excavating the soil, the protruding member 6 provided on the lower surface of the spiral blade 5 sharply stirs the soil and effectively agitates the soil, and the protruding member 6 provided on the upper surface. Can smoothly feed the cut and agitated earth and sand, and even if the soil contains stones and the like, it is difficult to chew. When the stirring device 1 is pulled up from the groundwater toward the ground surface, the protruding member 6 provided on the upper surface of the spiral blade 5 effectively cuts and stirs, and the protruding member 6 provided on the lower surface Smooth earth and sand can be sent backward. Therefore, when excavating soil using the stirring member 1 shown in FIG. 2, the excavated earth and sand are not discharged to the ground.
[0025]
The agitating member 1 shown in FIG. 2 includes an injection pipe 8 for passing compressed air through a hollow interior of the shaft body 4 and an injection pipe 9 for supplying purified water from which oil has been separated in an oil / water separator. Are inserted so that compressed air can pass through the space excluding the injection pipes 8 and 9. As mentioned above, compressed air and purified water are supplied at a pressure that can be supplied to groundwater, which releases the purified water farther and adheres to the soil adjacent to the groundwater. Remove oil and float in groundwater. The purified water is dispersed in the groundwater, reducing the oil concentration in the groundwater. In the stirring member 1 shown in FIG. 2, injection pipes 8 and 9 are inserted into the shaft body 4 on the upper and lower surfaces of the spiral blade 5, and the spiral blade is passed through the vicinity of the central portion of the shaft body 4. It is arranged toward the edge of 5. The compressed air and the purified water are supplied toward the circumferential direction of the stirring member 1 through the injection pipes 8 and 9 in the rotating stirring member 1. Further, the compressed air injected from the front conduit 3 gives a swinging effect to the agitating member 1 and can detach and float the oil adhering to the impervious layer at the bottom of the groundwater. In the present invention, the compressed air injected from the front conduit 3 suppresses the heat generation of the cutting member 2 and excludes the soil entering the shaft body 4 when excavating hard soil before reaching the groundwater. it can.
[0026]
FIG. 3 is a plan view of the stirring member 1 as viewed from the direction of the front conduit 3 shown in FIG. In the stirring member 1 shown in FIG. 3, the tip conduit 3 is connected to the tip of the shaft body 4 shown in FIGS. 1 and 2 via a flange 7, and the cutting member 2 a is disposed at the tip of the tip conduit 3. Has been. A plurality of cutting members 2a are provided at a predetermined interval in the circumferential direction of the tip conduit 3, and the tip portion when excavating the soil has a sharp pointed shape. A plurality of cutting members 2b similar to the cutting member 2a are provided at predetermined intervals in the circumferential direction of the flange 7. The soil can be excavated by rotating the stirring member 1 by the cutting members 2a and 2b. A spiral blade 5 is provided around the outer surface of the shaft body 4 shown in FIGS. 1 and 2, and the diameter of the blade from the end in the length direction of the shaft body 4 toward the center as shown in FIG. 3. Is getting bigger. As the diameter of the spiral blade 5 increases, the force to hold down the sand and water increases, but the resistance increases in soil and groundwater. In particular, the resistance becomes remarkable in the spiral blade 5 provided around the central portion of the shaft body 4, and the damage of the spiral blade 5 becomes remarkable. As shown in FIG. 3, by increasing the diameter at the central portion of the shaft body 4, the shaft body 4 shown in FIGS. 1 and 2 can be strengthened and hardly damaged.
[0027]
The spiral blade 5 shown in FIG. 3 is provided with a plurality of rectangular plate-like projecting members 6, and the rectangular surface is shown in FIG. 1 and so that the stirring by the rotation of the stirring member 1 can be promoted. It arrange | positions so that it may face the shaft 4 shown in FIG. Further, the projecting member 6 provided on the lower surface of the spiral blade 5 shown in FIG. 3 can effectively agitate the soil while excavating the soil sharply. By using the stirring member 1 shown in FIG. 3, the earth and sand can be excavated and stirred without being discharged to the ground. In the present invention, the protruding member 6 can smoothly rotate the spiral blade 5 not only in the soil but also in the water.
[0028]
The method for purifying groundwater contaminated with oil according to the present invention will be described in detail with reference to FIGS. The groundwater purification method of the present invention can be carried out using a stirring member as shown in FIGS. FIG. 4 is a view showing a state where the traveling means connected to the stirring member 1 is installed at a predetermined position of the soil and the soil is excavated. The agitating member 1 shown in FIG. 4 is connected to the traveling means 10 via connecting means. The traveling means 10 shown in FIG. 4 includes wheels 11 and can freely move on the ground surface 12. Moreover, the traveling means 10 is provided with an elevating means 14 via an arm 13 so that the clamping means 15 can be moved up and down. In the embodiment shown in FIG. 4, the wheel 11 is moved to a predetermined position, the angle of the arm 13 is adjusted, and the elevating means 14 is set to be perpendicular to the ground surface 12. Further, the intermediate rod 16 is rotatably held by the holding means 15 arranged to be lifted by the raising / lowering means 14, the stirring member 1 is arranged below the intermediate rod 16, and the holding means 15 is hydraulically driven or the like. Thus, the intermediate rod 16 is rotated in both forward and reverse directions. The intermediate rod 16 serves as a drive shaft that transmits the rotation of the clamping means 15 to the stirring member 1 at the tip. Injection pipes 8 and 9 for passing compressed air and purified water are connected to an injection pipe connecting member 17 connected to the upper part of the intermediate rod 16. The injection pipes 8 and 9 are an air compressor or an air cylinder (not shown), and oil water. The separator 18 is connected.
[0029]
In FIG. 4, a pumping hole 19 is provided at a position different from a position where excavation is performed using the stirring member 1, and a suction pump 20 is connected to the pumping hole 19. The pumping hole 19 shown in FIG. 4 may have any diameter, and may be used as a passage for sucking together with the groundwater 20 the oil that has been separated by the air jetted from the stirring member 1 and floated in the groundwater 20. it can. In the present invention, a suction pipe extending to the groundwater 20 may be inserted into the pumping hole 19, and the suction pump 21 may be connected to the suction pipe. Further, the groundwater 20 sucked by the suction pump 21 is supplied to the oil / water separator 18 and separated into floating oil and water. The separated water is returned to the groundwater again as purified water. In this case, the pressure can be returned through the injection tube 9 after being set to a predetermined pressure by a supply pump (not shown).
[0030]
In the embodiment shown in FIG. 4, compressed air is injected through the inside of the intermediate rod 16 and the inside of the stirring member 1 from an air compressor or the like (not shown), and the stirring member 1 is rotated by rotating the intermediate rod 16. be able to. The agitating member 1 can lower the clamping means 15 by the elevating means 14 to lower it in the direction indicated by the arrow A and excavate the soil. When the length of the intermediate rod 16 is insufficient when purifying the soil at a predetermined depth in the original position, the rotation of the intermediate rod 16 is stopped and another intermediate rod 16 is added to extend the length. it can. In the present invention, as long as the intermediate rod 16 can be rotated in both forward and reverse directions, the holding means 15 and the injection pipe connecting member 17 may have any structure, and any means can be used.
[0031]
FIG. 5 is a view showing a state where the stirring member 1 is immersed in the groundwater 20 existing at a predetermined depth, and compressed air is supplied through the injection pipe 8 and purified water is supplied through the injection pipe 9. By the rotation of the stirring member 1 shown in FIG. 5, the compressed air is intermittently injected into the soil 22 adjacent to the groundwater 20, and the oil component attached to the soil is peeled off. The peeled oil component is suspended in the groundwater 20 along the flow of stirring when the groundwater is stirred by the rotation of the stirring member 1. Moreover, the compressed air injected from the stirring member 1 will be intermittently injected in the position of the same soil 22, and the injected compressed air will collide with the soil 22 as a fine bubble, and it will be between soil particles. Or, soil particles and bubbles repeatedly contact, and the oil is separated from the soil particles. In addition, the compressed air injected from the front conduit 3 peels off the oil adhering to the impermeable layer 23 at the bottom of the groundwater 20 and causes the oil to float in the groundwater 20. In this way, the groundwater 20 in which the oil component is suspended is sucked by the suction pump 21 through the pumping hole 19 and supplied to the oil-water separator 18. In the oil / water separator 18, the oil and water are separated as described above, and can be returned to the groundwater 20 again through the injection pipe 9. In the injection pipe 9, as in the injection pipe 8, the injection is performed in a wide area toward the side of the aquifer where the groundwater 20 stays. In the embodiment shown in FIG. 5, an arrow passes through the injection pipes 8 and 9 shown in FIGS. 1 to 3 provided along the spiral blade 5 toward the groundwater 20 existing around the shaft body 4 of the stirring device 1. Compressed air and purified water are jetted in the direction indicated by line B. Compressed air and purified water injected toward the periphery of the stirring member 1 are supplied through the inside of the stirring member 1 through the rotation of the spiral blade 5 and the intermediate rod 16 from an air compressor and a supply pump (not shown). The mixture is agitated and agitated by the compressed air and is agitated with the groundwater 20 existing around the agitating member 1 to disperse around the agitating member 1.
[0032]
In the embodiment shown in FIG. 5, as indicated by an arrow C, the agitation member 1 is moved up and down to raise and lower the oil adhering to the soil 22 at each depth in the original position. Can be peeled off. Thereby, the oil adhering to the ground water 20 and the soil adjacent to the ground water 20 can be separated efficiently and sufficiently, and the purification rate and the work efficiency can be improved.
[0033]
Although the present invention has been described in detail with the above-described embodiment, the method for purifying groundwater contaminated with oil according to the present invention is not limited to the above-described embodiment, and similar effects can be obtained. As long as it is a thing, the stirring member is not limited to the shape described above, and may have any size and any number of spiral blades, and an injection pipe for supplying compressed air and an injection for returning water from which oil has been separated. The pipes may be arranged in any number and number, and any material that does not corrode can be used as the material of the portion that comes into contact with the compressed air and water. Further, in the present invention, groundwater can be purified by separating and removing any liquid contaminants and solid contaminants, not oil in the groundwater.
[0034]
【The invention's effect】
As described above, by using the stirring member used in the method for purifying groundwater contaminated with oil according to the present invention, it is possible to stir the groundwater and supply compressed air to peel the oil attached to the soil. In addition, it is possible to purify the groundwater by returning the water from which the oil has been separated. In addition, by providing a method for purifying groundwater contaminated with oil according to the present invention, by moving the groundwater up and down while rotating the stirring member, the oil adhering to the soil adjacent to the groundwater of a predetermined depth is removed. It is possible to exfoliate and promote the purification of the entire groundwater.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a stirring member that can be used in the method for purifying groundwater contaminated with oil according to the present invention.
FIG. 2 is a side view and a cross-sectional view of the stirring member shown in FIG.
FIG. 3 is a plan view of the stirring member shown in FIG.
FIG. 4 is a diagram showing a state where soil is excavated using a stirring member that can be used in the method for purifying groundwater contaminated with oil according to the present invention.
FIG. 5 is a view showing a state where compressed air and water separated from oil are injected into groundwater using a stirring member that can be used in the method for purifying groundwater contaminated with oil according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Stirring member 2, 2a, 2b ... Cutting member 3 ... Lead pipe 4 ... Shaft body 5 ... Spiral blade 6 ... Protruding member 7 ... Flange 8, 9 ... Injection pipe 10 ... Running means 11 ... Wheel 12 ... Ground surface 13 ... arm 14 ... lifting means 15 ... clamping means 16 ... intermediate rod 17 ... injection pipe connecting member 18 ... oil / water separator 19 ... suction hole 20 ... ground water 21 ... suction pump 22 ... soil 23 ... impervious layer

Claims (6)

A tip conduit provided with a cutting member at a tip portion, a hollow shaft body formed so that the tip conduit is connected, the diameter is large at the central portion along the length direction, and the diameter is small at both end portions; A spiral blade disposed around the shaft body, a plurality of projecting members disposed on an upper surface and a lower surface of the spiral blade, and passes through the shaft body to penetrate the spiral body Rotating a stirring member provided with an injection pipe disposed toward the edge of the blade to excavate the soil, and immersing the stirring member in groundwater present in the soil;
Injecting compressed air from the injection pipe of the stirring member toward the periphery of the stirring member;
Separating the oil adhering to the soil adjacent to the groundwater by causing the compressed air to be jetted from the injection pipe and rotating the stirring member, and floating in the groundwater;
Recovering groundwater containing the suspended oil, and separating the oil. A method for purifying groundwater contaminated with oil. The method for purifying groundwater contaminated with oil according to claim 1, comprising the step of returning the water from which the oil has been separated to the groundwater through the injection pipe in the step of separating the oil. The method for purifying groundwater contaminated with oil according to claim 1 , further comprising the step of injecting compressed air from the tip conduit through the inside of the shaft portion. Step is characterized by injecting the compressed air at a pressure of 200KPa～1000kPa, purification method of contaminated groundwater by oil of claim 1 to 3 for injecting the compressed air. The oil component according to any one of claims 1 to 4 , wherein in the step of separating the oil component, groundwater containing the suspended oil component is collected through a pumping hole reaching the groundwater from the ground surface. Purification method for groundwater contaminated by water. The method for purifying groundwater contaminated with oil according to claim 2 , wherein in the step of returning the groundwater, water from which the oil is separated is intermittently injected.

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