JP3738028B1 - Floating oil purification device and contaminated formation purification method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil purification device that is efficient even for oily contaminants such as engine lubricating oil or small-scale construction, and a contaminated formation purification method using the same.
SOLUTION: A press-fitting well 3 for press-fitting high-pressure washing water 2 into a contaminated formation 1 containing oily contaminants 14, jet nozzles 12a to 12g for jetting high-pressure washing water 2 from the press-fitting well 3, and the injected high pressure The cleaning water 2 stirs and cleans the contaminated formation 1 to collect the oil-water turbid liquid 10 mixed with the oily contaminant 14 while sucking it at a negative pressure, and the edge is horizontal in the vicinity of the groundwater surface W. And the suction port 6 opened upward, the pumping means 90 capable of pumping up the oil-water turbid liquid 10 sucked from the ground, and the oil layer 8 comprising the oily contaminant 14 covering the groundwater surface W, soaking the liquid surface. A float 16 that follows the fluctuation, and a suction port depth adjusting means 30 that maintains the depth D of the suction port 6 in the immediate vicinity of the groundwater surface W by interlocking with the vertical movement thereof.
[Selection] Figure 1

Description

  The present invention relates to an apparatus and method for purifying an in-situ layer contaminated with oily contaminants.

  As an in situ contaminated formation purification method, there is a technology that enables purification processing at low cost without the need to excavate and backfill the pollutant-containing soil on a large scale.

Specifically, a contaminated cleaning liquid for cleaning the contaminated formation by placing an injection hole for injecting ultra-high pressure spray water into the drilled contaminated formation and a pipe having a large number of holes on the outer periphery around the injection hole. A well point to be sucked up, a rod for jetting ultra-high pressure water inserted into the jet hole, an ultra-high pressure jet nozzle for jetting the ultra-high pressure jet water in the vicinity of the tip of the rod, and a range from 100 MPa to 400 MPa. In the contaminated formation purification apparatus comprising an injection pump capable of press-fitting ultrahigh-pressure spray water into the rod, the well point is arranged around the injection hole with a number of placements proportional to the area of the contaminated formation. The track record of a contaminated formation cleaning system characterized by being driven deeper than the formation and a cleaning method using the same (for example, see Patent Document 1) has been highly evaluated.
Japanese Patent No. 3567435 (Claims, Fig. 1)

  However, the contaminated geological layer cleaning system disclosed in Patent Document 1 and the cleaning method using the same are, for example, a large amount of VOCs and heavy metals mainly used when converting a vast factory site that manufactures machinery into an apartment house. Since the system is configured to obtain the highest construction quality and cost-effectiveness, assuming that a large contaminated formation is purified over a construction period of several months, it is not expected to be oily, such as engine lubricating oil. It was not always efficient for contaminants or small-scale construction.

  First, for small-scale and short-term construction, large-scale plants are not suitable due to space and profitability problems, and high-precision, lean and compact equipment is required. Etc. need to be concentrated to a minimum volume.

  Secondly, unlike the former factory site, for example, in the case of an old station such as a gas station or an automobile maintenance factory, the pollutant component is often only high-viscosity engine lubricating oil. From the viewpoint of construction quality and efficiency, There was a problem that a dedicated device was desired.

  Therefore, in order to solve the above problems, the present invention concentrates highly viscous engine lubricating oil and the like in a highly accurate and lean compact device, and the collected sludge and waste liquid are concentrated to a minimum volume. It is an object of the present invention to provide a floating oil purification device that can be completed by construction and a contaminated formation purification method using the same.

The invention according to claim 1, the contaminated formation (1) containing oily contaminants (14), the high-pressure cleaning and pressed well of injecting high-pressure washing water (2) (3), the press-fit well into (3) An injection pump (7) for injecting water (2), an injection nozzle (12a-12g) for injecting the high-pressure washing water (2) from the press-fit well (3), and the injected high-pressure washing water (2) And a vacuum well (4) for collecting the oily water turbid liquid (10) mixed with oily contaminants (14) while agitating and washing the contaminated formation (1) while sucking at a negative pressure, and the vacuum well (4 And a vacuum pump (17) connected via an extraction pipe (9) inserted into the vacuum well (4) and capable of maintaining the inside of the vacuum well (4) at a negative pressure, and a concrete coating (which seals the ground surface (GL) surface of the target site) 70), said vacuum wells (4) A suction port (6) whose edge is horizontal and open upward in the vicinity of the sewage surface (W), and a pumping means (90) capable of pumping the oil-water turbid liquid (10) sucked from the suction port (6) to the ground. ), A specific gravity difference separator (40) for separating the oily water turbid liquid (10) pumped up by the pumping means (90) and detoxifying the oily contaminants (14) from harmless water, and the groundwater surface The float (16) immersed in the oil layer (8) composed of the oily contaminant (14) covering (W) and following the fluctuation of the liquid level, and interlocking with the vertical movement of the float (16) Suction port depth adjusting means (30) for maintaining the depth (D) of the suction port (6) in the immediate vicinity of the groundwater surface (W), and sent to the specific gravity difference separator (40) In the oil / water turbid liquid (10), the water was removed and the oil was concentrated to a small volume. While storing serial oily contaminants only (14) temporarily removed treated water (20) is characterized by being configured to re-inject into the press-fit well back into the injection pump (7) (3) A floating oil purifying device (100).

The operation of the invention according to claim 1 is as follows.
When high pressure washing water (2) is injected into the injection well (3) by the injection pump (7), the high pressure washing water (2) injected from the injection nozzles (12a to 12g) stirs and cleans the contaminated formation (1). .
The ground surface (GL) surface of the target site is sealed with a concrete coating (70), and is sucked by a vacuum pump (17) connected via an extraction pipe (9) inserted into a vacuum well (4). By keeping the inside of the vacuum well (4) at a negative pressure, the oil-water turbid liquid (10) diluted with the high-pressure washing water (2) from the surrounding contaminated formation (1) and mixed with the oily contaminant (14) It flows into (9).
That is, the vacuum well (4) collects the high-pressure washing water (2) from the press-fit well (3) while sucking it at a negative pressure.
The oily contaminant (14) mixed in the oil / water turbid liquid (10) extracted in the vacuum well (4) by this negative pressure suction covers the surface layer of the groundwater surface (W) in the state of the oil layer (8). ing.
The suction port (6) whose edge is horizontal and open upward near the groundwater surface (W) is immersed in an oil layer (8) floating on the groundwater surface (W), and the suction port (6) By the action of the suction port depth adjusting means (30), that is, the float (16) following the change in the liquid level, the suction port (6) can be maintained in an open state close to the oil layer (8).
For this reason, only the oily contaminants (14) gathered in the state of the oil layer (8) floating in the ground water surface (W) with a light specific gravity among the oil-water turbid liquid (10) can be efficiently sorted and sucked.
Therefore, the suction port (6), which is a well-side terminal of the pumping means (90), contains a large amount of high-concentration oily contaminants (14) from the oil-water turbid liquid (10) in the vacuum well (4). It is possible to inhale and pump efficiently to the ground.
The oil-water turbid liquid (10) extracted into the extraction pipe (9) of the vacuum well (4) in this way is pumped up by pipe connection from the extraction pipe (9) to the specific gravity difference separator (40) ( 90), it is pumped up to the specific gravity difference separator (40), separated into oily contaminants (14) and harmless water, and detoxified.
At this time, out of the oil / water turbid liquid (10) sent to the specific gravity difference separator (40), only the oily contaminant (14) concentrated to a small volume by removing moisture was temporarily removed. The treated water (20) is returned to the injection pump (7) and reinjected into the injection well (3).
The oily contaminants (14) temporarily stored and collected are highly concentrated and thus have a small volume, and the transportation and disposal costs are low. On the other hand, the treated water (20) can be easily drained to the original location or sewage. Can also be processed.

  According to a second aspect of the present invention, as the suction port depth adjusting means (30), the suction port (6) opened in the vacuum well (4) is a J-shaped terminal (J), and the J-shaped terminal ( The floating oil purifying device (100) according to claim 1, further comprising a sliding cylinder (31) that is fitted in J) and is slidable in a vertical direction.

  According to the second aspect of the present invention, the suction port (6), which is a well-side terminal of the pumping means (90), is a J-shaped terminal (J) and is fitted vertically to the J-shaped terminal (J). The sliding cylinder (31) that is freely slidable in the direction follows the fluctuation of the liquid level by the action of the float (16), and thus functions well as the suction port depth adjusting means (30).

  The invention according to claim 3 is a contaminated formation purification method using the floating oil purification device (100) according to claim 1 or 2, wherein the high-pressure washing water (2) is injected into the injection nozzle (12a- 12g), the spraying step (S1) for stirring and washing the contaminated formation (1) by spraying, and the vacuum well (4) as a whole under a negative pressure while the negative pressure application to the pumping means (90) is stopped The extraction step (S2) for extracting the oil / water turbid liquid (10) by applying a negative pressure, stopping the negative pressure application to the whole vacuum well (4), and applying a negative pressure suction force only to the pumping means (90) The pumping step (S3) for pumping the oil-water turbid liquid (10) to the ground, and the intermittent step (S4) for repeating the pumping step (S3) and the extraction step (S2) alternately, It is a contaminated formation purification method.

  In the invention which concerns on Claim 3, a negative pressure is provided to the whole vacuum well (4) by performing an injection process (S1) and an extraction process (S2), Therefore A contaminated formation (1) is formed in the well bottom. The oil-water turbid liquid (10) extracted from is collected.

  In the pumping step (S3) for pumping up the accumulated oil / water turbid liquid (10) to the ground, a pressure higher than the atmospheric pressure on the ground is applied to the underground oil / water turbid liquid (10) to push it up, and a vacuum well (4 ) “Suction method” to suck up from the ground with a strong negative pressure suction force over the negative pressure applied to the whole can be selected.

  Here, when the above “push-up method” is adopted, a positive pressure over the atmospheric pressure is applied to the underground oil / water turbid liquid (10) and a negative pressure is applied to the vacuum well (4). However, since the positive pressure and the negative pressure cancel each other, the effect of pumping up the oil / water turbid liquid (10) to the ground is hindered.

  On the other hand, when the “suction method” is adopted, in order to take in the oil / water turbid liquid (10) from the contaminated formation (1), it was taken into the well bottom against the negative pressure applied to the entire vacuum well (4). If the negative pressure suction force that sucks up the oil / water turbid liquid (10) to the ground is not much stronger, it cannot be sucked up.

  Thus, regardless of which of the “push-up method” and the “pick-up method”, the negative pressure applied to the vacuum well (4) hinders the operation of pumping the oil-water turbid liquid (10) to the ground. The efficiency of the pumping step (S3) can be increased by stopping this and applying a negative pressure suction force only to the pumping means (90).

  In addition, when performing the pumping-up process (S3), since the negative pressure provision to the whole vacuum well (4) is stopped, the extraction process (S2) which extracts an oil-water turbid liquid (10) from a contaminated formation (1) ) Is interrupted.

  These intermittent steps (S4), in which the extraction step (S2) and the pumping step (S3) are alternately repeated, are completed while maintaining the purification efficiency of the contaminated formation high.

According to the invention according to claim 1, firstly, a high-precision and wasteless compact device in a small-scale and short-term construction, which is not suitable for a large-scale plant due to space and profitability problems, An apparatus capable of concentrating recovered sludge and waste liquid to a minimum volume can be provided.
In other words, the oily contaminants that are temporarily stored and collected are highly concentrated and have a small volume, and the transportation and treatment costs are low. On the other hand, the treated water obtained by detoxifying the oil-water turbid liquid is in situ or sewage, etc. It can also be processed easily.
Secondly, for example, when a pollutant component is only a highly viscous engine lubricating oil, such as a gas station or an automobile maintenance shop, a dedicated device with excellent construction quality and efficiency can be provided.

  According to the second aspect of the present invention, the suction port depth adjusting means that follows the liquid level fluctuation functions well.

  According to the third aspect of the present invention, since the pumping process and the extracting process cancel each other out when they are executed simultaneously, the purification efficiency of the contaminated formation can be maintained high by executing the intermittent process that is alternately repeated one by one.

  Hereinafter, the configuration and operation of a floating oil purification device (hereinafter referred to as a “floating oil purification device”) according to an embodiment of the present invention will be described together. FIG. 1 is a schematic diagram of a floating oil purification device 100. A vacuum well 3 is excavated in the center of a contaminated formation 1 and a plurality of holes (see FIG. 3) are excavated so as to surround the injection well 3. 4 is provided.

  An extraction pipe 9 is inserted into the vacuum well 4, and a vacuum pump 17 is connected via a pipe at the upper end of the extraction pipe 9, so that the inside of the vacuum well 4 can be maintained at a negative pressure. Further, the pumping means 90 is configured to surely pump up the oil / water turbid liquid 10 accumulated at the bottom of the vacuum well 4 to the specific gravity difference separator 40 on the ground.

  The oil / water turbid liquid 10 pumped up in this manner mainly contains highly viscous oily contaminants 14 such as engine lubricating oil, and the oil / water turbid liquid 10 is separated from the oily contaminants 14 by the specific gravity difference separator 40. Therefore, the contaminated formation 1 can be purified by the floating oil purification device 100 because the harmless moisture is separated and detoxified.

  The pumping means 90 sucks into the oil / water recovery pump 50 the oil / water turbid liquid 10 via the recovery pipes 18a and 18b communicating with the J-shaped terminal J opened upward just below the groundwater surface W accumulated at the bottom of the vacuum well 4. Then, when discharged from the oil / water recovery pump 50, it is configured to be sent to the specific gravity difference separator 40 via the recovery pipe 18c.

  Of the oil / water turbid liquid 10 sent to the specific gravity difference separator 40, only the oily contaminants 14 which have been removed from the water and concentrated to a small volume are discharged from the recovery pipe 18d and temporarily stored in the waste oil container 41, while being removed. The treated water 20 is returned to the injection pump 7 and reinjected into the injection well 3. In addition, since the sludge 44 contained in the oil / water turbid liquid 10 accumulates at the bottom of the specific gravity difference separator 40 with the operation of the floating oil purification device 100, the sludge 44 is scraped out by the screw conveyor 42 and temporarily stored in the sludge container 43.

  Then, as shown only in FIG. 3 and omitted from FIG. 1, the ground surface GL is provided with a concrete coating 70 to maintain an airtight state. Moreover, although the high-pressure washing water 2 inject | poured into the injection well 3 with the injection pump 7 is injected to the contaminated formation 1 from the injection nozzles 12a-12g, the injection pressure and the amount of injection water are comprised so that it can adjust suitably. .

  2 is a cross-sectional view of the main part of the suction port depth adjusting means, in which the encircled portion indicated by a two-dot broken line in FIG. 1 is enlarged, (a) shows a high water level state and (b) shows a low water level state. . The suction port 6 of the J-shaped terminal J shown in FIG. 2 opens upward just below the ground water surface W accumulated at the bottom of the vacuum well 4, and the J-shaped terminal J is slidable in the vertical direction. The cylinder 31 is fitted, and the sliding cylinder 31 is interlocked with the vertical movement of the float 16 to constitute the suction depth adjusting means 30 for maintaining the depth D of the inlet 6 close to the groundwater surface W. .

  The edge of the suction port 6 opens horizontally and upward in the vicinity of the groundwater surface W of the vacuum well 4. The oil / water turbid liquid 10 sucked from the suction port 6 can be pumped to the ground by the pumping means 90. Here, since the float 16 floats together with the sliding cylinder 31 on the groundwater surface W, the sliding cylinder 31 follows the fluctuation of the liquid level by immersing it in the oil layer 8 composed of the oily contaminant 14 covering the groundwater surface W. To do.

  Here, if the suction port 6 is held at a depth D slightly lower than the groundwater surface W of the contaminated formation 1, and the suction port 6 is opened close to the oily contaminant 14, the water will be removed. However, it is possible to efficiently extract only the oily contaminant 14 having a light specific gravity and a floating property.

  First, when the underground water surface W is at a depth D and is in the high water level state shown in FIG. 2A, the sliding cylinder 31 that is immersed in the oil layer 8 and follows the fluctuation of the liquid level has the suction port 6 on the bottom surface of the oil layer 8. The oil-water turbid liquid 10 in which the oily contaminant 14 covering the ground water surface W is sucked in at a high concentration can be sent from the J-shaped terminal J to the ground specific gravity difference separator 40. it can.

  Next, when the groundwater surface W is at the depth D ′ and the low water level state shown in FIG. 2 (b), the sliding cylinder 31 that follows the fluctuation of the lowered liquid level similarly has the suction port 6 at the bottom surface of the oil layer 8. The oil-water turbid liquid 10 in which the oily contaminant 14 covering the ground water surface W is sucked in at a high concentration can be sent from the J-shaped terminal J to the ground specific gravity difference separator 40. it can.

  By such an action of the suction depth adjusting means 30, it is possible to inhale at a high concentration until all of the oily contaminant 14 disappears without sucking air or water unnecessarily. That is, if the suction port depth adjustment mechanism 30 automatically adjusts so that the depth of the suction port 6 matches the depth D slightly lower than the lower surface of the oil layer 8 floating in water, the height from the contaminated formation 1 is increased. Since only the oily contaminant 14 having the concentration can be sucked out in a short time, the oily contaminant 14 can be efficiently recovered. As a result, it is possible to complete the purification while suppressing the oil / water turbid waste liquid 10 requiring treatment to a small volume.

3A and 3B are explanatory views of a well, wherein FIG. 3A is a plan layout view, FIG. 3B is a vertical cross-sectional view taken along line AA in FIG. 3A, and FIG. 3C is a vertical cross-sectional view of one vacuum well. In addition, the mm dimension in a figure only showed the Example which obtained the favorable result.
As shown in FIG. 3 (a), each of the wells of the vacuum wells 4 and 4 is disposed at the four corners of a square having a side of 4 m, and the press-fit well 3 is excavated at the center connecting the diagonals.

  One extraction tube 9 is inserted into each of the vacuum wells 4 and 4. The extraction tube 9 has an inner diameter of about 10 to 50 cm (implemented at 25 cm), and is arranged in a grid pattern with a vertical and horizontal interval of 1 to 6 m, and an oil-water turbid liquid 10 (see FIG. 1) in which the contaminated formation is washed. Suck up.

  Since the press-in well 3 is used as the injection hole 5 as shown in FIG. 3A, the press-in rod 11 shown in FIG. 3B can be inserted at an appropriate depth aiming at the core of the contaminated formation 1 or its vicinity. A swivel (not shown) is disposed near the upper end of the press-fitting rod 11, and this swivel supports the press-fitting rod 11 so that it can freely rotate by the perforation indicated by R, and the high-pressure washing water 2 is press-fitted into the press-fitting rod 11. Is possible. In the vicinity of the press-fit rod 11, injection nozzles 12a to 12g are opened in the direction perpendicular to the axis. If this press-fitting rod 11 is inserted into the contaminated formation 1 from the tip, it is possible to inject the high-pressure washing water 2 injected from the swivel into the contaminated formation 1.

  As shown in FIG. 3 (c), the outer periphery of the extraction pipe 9 in the middle and high portions and in the vicinity of the bottom is a non-porous pipe portion 92 in which no slit is perforated. Further, the oil-water turbid liquid 10 (see FIG. 1) diluted from the surrounding contaminated formation 1 to the high-pressure washing water 2 is passed through the screen tube portion 91 having slits drilled in the outer periphery of the middle and lower portions of the extraction tube 9. Flow into. A filter sand 93 is embedded so as to surround the outer periphery of the underground portion of the extraction pipe 9.

  In addition, a concrete coating 70 for sealing is applied to the surface GL of the target site, and only the upper end portion of the extraction pipe 9 protrudes and is connected to the specific gravity difference separator 40 (see FIG. 1).

  FIG. 4 is a flowchart showing the steps of the contaminated formation purification method. In the contaminated formation purification, the high-pressure washing water 2 is injected from the injection nozzles 12a to 12g into the contaminated formation 1 through the injection holes 5, and the contaminated formation 1 is agitated. It starts when the spraying step (S1) for cleaning is turned on. However, the injection step (S1) is ON / OFF controlled so that the groundwater surface W of the vacuum well 4 does not become too high. The groundwater surface W is monitored by a water level sensor or a monitoring camera (not shown) and reflected in the control.

  The extraction step (S2) is also executed in conjunction with the injection step (S1) being turned on, but at the timing of the extraction step (S2) being turned on by applying a negative pressure to the entire vacuum well 4 and extracting the oil / water turbid liquid 10, the pumping means 90 The pumping step (S3) for pumping up the oil / water turbid liquid 10 to the ground by applying a negative pressure suction force to is turned off. If it does so, a negative pressure will be given to the whole vacuum well 4, and the oil-water turbidity liquid 10 extracted from the contaminated formation 1 will accumulate on the bottom of the well.

  Next, the pumping process (S3) is turned on at the timing of the extraction process (S2) being turned off. If it does so, the negative pressure provision to the whole vacuum well 4 will be stopped, and the oil-water turbidity liquid 10 which accumulated on the bottom of the well will be pumped up to the ground. As described above, when the pumping step (S3) is performed, since the negative pressure application to the entire vacuum well 4 is stopped, the extraction step (S2) for extracting the oil / water turbid liquid 10 from the contaminated formation 1 is interrupted. The

  If the pumping process (S3) is turned ON at the same time as the extraction process (S2) is turned ON, the negative pressure applied to the entire vacuum well 4 to take in the oil / water turbid liquid 10 from the contaminated formation 1 is brought to the bottom of the well. If the negative pressure suction force that sucks up the captured oil-water turbid liquid 10 to the ground is not particularly strong, it cannot be recovered. That is, since the pumping step (S3) and the extraction step (S2) are offset or reduced when executed simultaneously, the purification efficiency of the contaminated formation can be maintained high by executing an intermittent step that is alternately repeated one by one.

  For this reason, the application of negative pressure to the entire vacuum well 4 hinders the operation of pumping up the oil / water turbid liquid 10 to the ground and tries to pull it back, so that this is stopped and the negative pressure suction force is applied only to the pumping means 90. It is possible to increase the efficiency of the pumping step (S3) by acting.

  By performing the intermittent process (S4) in which the extraction process (S2) and the pumping process (S3) are alternately repeated, it is possible to complete the process while maintaining high purification efficiency of the contaminated formation.

  If the contaminated formation 1 is purified using the compact floating oil purification device 100 as described above, oily contaminants 14 such as engine lubricating oil remaining on a small-scale site of a gas station or an automobile maintenance factory are removed. Complete recovery in a short time. Moreover, the oily contaminants 14 collected in the waste oil container 41 shown in FIG. 1 are highly concentrated and thus have a small volume, and the carrying out and processing costs are low. In addition, as a result of purifying the treated water 20, if it passes the official inspection, it can be easily treated by pouring it into the original position or sewage.

It is a schematic diagram of a floating type oil purification apparatus. It is principal part sectional drawing of an inlet-port depth adjustment means, and the circled part of the dashed-two dotted line in FIG. 1 is expanded, (a) A high water level state and (b) A low water level state are shown. It is explanatory drawing of a well, (a) is a plane | planar arrangement | positioning drawing, (b) is the AA line longitudinal cross-sectional view in (a), (c) is a longitudinal cross-sectional view of one vacuum well. It is a flowchart which shows the process of a contaminated formation purification method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Contaminated stratum 2 High pressure washing water 3 Pressurization well 4 Vacuum well 5 Injection hole 6 Suction port 7 Injection pump 8 Oil layer 9 Extraction pipe 10 Oil-water turbid liquid 11 Injection rod 12, 12a-12g Injection nozzle 14 Oily contaminant 16 Float 17 Vacuum pump 18, 18a to 18d Recovery pipe 19 Injection pipe 20 Treated water 30 Suction port depth adjustment means 31 Telescopic cylinder 40 Specific gravity difference separator 41 Waste oil container 42 Screw conveyor 43 Sludge container 44 Sludge 50 Oil water recovery pump 70 Concrete coating 90 Pumping means 91 Screen pipe part 92 Non-porous pipe part 93 Filter sand 94 Sand pool 100 Floating oil purifier D, D 'Depth of (inlet) J J terminal R Direction of rotation of press-fit rod GL Ground surface W Groundwater surface

Claims (3)

An injection well (3) for injecting high-pressure washing water (2) into a contaminated formation (1) containing oily contaminants (14);
An injection pump (7) for injecting the high-pressure washing water (2) into the injection well (3);
Injection nozzles (12a to 12g) for injecting the high-pressure washing water (2) from the injection well (3);
The vacuum well that collects the oily water turbid liquid (10) mixed with the oily contaminant (14) while sucking and sucking the contaminated formation (1) by stirring and washing the contaminated formation (1) by the jetted high pressure washing water (2) (4) and
A vacuum pump (17) connected via an extraction tube (9) inserted into the vacuum well (4) and capable of maintaining the inside of the vacuum well (4) at a negative pressure;
A concrete cover (70) for sealing the surface (GL) surface of the target site;
A suction port (6) whose edge is horizontal and open upward in the vicinity of the groundwater surface (W) of the vacuum well (4);
Pumping means (90) capable of pumping the oil-water turbid liquid (10) sucked from the suction port (6) to the ground;
A specific gravity difference separator (40) for separating the oily water turbid liquid (10) pumped by the pumping means (90) and detoxifying the oily contaminants (14) from harmless water;
A float (16) that is immersed in an oil layer (8) comprising the oily contaminant (14) covering the groundwater surface (W) to follow the fluctuation of the liquid level;
A suction port depth adjusting means (30) for maintaining the depth (D) of the suction port (6) in the immediate vicinity of the groundwater surface (W) by interlocking with the vertical movement of the float (16). ,
Of the oil-water turbid liquid (10) sent to the specific gravity difference separator (40), only the oily contaminant (14) concentrated to a small volume by removing moisture was temporarily removed while being removed. The floating oil purification device (100) is characterized in that the treated water (20) is returned to the injection pump (7) and reinjected into the injection well (3 ). As the inlet depth adjusting means (30),
The suction port (6) opening in the vacuum well (4) is a J-shaped terminal (J),
The floating oil purification device (100) according to claim 1, further comprising a sliding cylinder (31) that is fitted to the J-shaped terminal (J) and is slidable in a vertical direction. A contaminated formation purification method using the floating oil purification device (100) according to claim 1 or 2,
An injection step (S1) of stirring and cleaning the contaminated formation (1) by injecting the high-pressure cleaning water (2) from the injection nozzles (12a to 12g);
An extraction step (S2) for extracting the oil-water turbid liquid (10) by applying a negative pressure to the entire vacuum well (4) in a state where the application of the negative pressure to the pumping means (90) is stopped;
A pumping step (S3) of stopping the application of negative pressure to the entire vacuum well (4) and applying a negative pressure suction force only to the pumping means (90) to pump the oil-water turbid liquid (10) to the ground;
Contaminated formation purification method characterized by including each process of the intermittent process (S4) which repeats the said pumping process (S3) and the said extraction process (S2) alternately.

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