KR102122772B1 - Remediation apparatus for polluted soil and Water by Multi-Phase Extraction - Google Patents

Abstract

Disclosed is a device for purifying contaminated soil and groundwater by a vacuum multiple extracting method capable of increasing extracting efficiency by an increase in negative pressure while purifying the contaminated soil and the groundwater. The device for purifying contaminated soil and groundwater by a multiple extracting method comprises: a jet pump which inserts a tube casing into an extracting hole which is perforated deeper than a groundwater level in the ground, and is installed inside the tube casing; an extracting pipe which is connected to an upper end of the jet pump and is extended to the ground; a high-pressure water supplying unit which supplies high-pressure water to the jet pump; a gas-liquid separating device which is connected to the extracting pipe and accommodates an extract; an oil-water separating device which is connected to the gas-liquid separating device; and a waterproof airtight sheet which covers the ground of a surrounding unit around the tube casing to maintain airtightness of the surroundings of the tube casing.

Description

Remediation apparatus for polluted soil and Water by Multi-Phase Extraction}

The present invention relates to a contaminated soil groundwater purification apparatus by a vacuum multi-extraction method capable of increasing the extraction efficiency by increasing the negative pressure during a contaminated soil groundwater purification process.

In general, as a physical extraction technology for the purification treatment of soil contaminated with oil, vapors of ground (soil), namely volatile organic compounds (VOCs) and oil contaminants (TPH; total petroleum hydrocarbon) and lightly hydrophobic liquids in groundwater Multi-Phase Extraction (MPE), which simultaneously extracts (LNAPL), is known.

Multi-Phase Extraction (MPE) is a general term for the technique of simultaneously extracting vapors (VOCs) of unsaturated zones and dissolved and free-phase oils (LNAPL) in groundwater. )It is a method of realizing multiphase extraction by applying vacuum (negative pressure) in a closed extraction (pipe) well by combining steam extraction and groundwater pump-treatment facilities.

The basic principle of polyphase extraction generally includes a portion of the well screen extending to the unsaturation zone above the water surface and applied to the well. That is, since the water is pumped from the ground level or below the ground level, extraction of the liquid phase (oil dissolved in the groundwater, free phase oil) is performed, and vacuum applied to the well extracts soil vapor and increases the pressure gradient while increasing the amount of groundwater extraction. Increase. The vacuum action does not significantly lower the groundwater level from the well being pumped, effectively increasing the hydraulic slope in the well being pumped (EPA USA, 1999).

1 shows a basic concept showing the effect of applying vacuum in a water well. The static water level without vacuum and no pumping (see 1), the water level drop when pumping only without vacuum (see 2), and the drop in water at this time are the result of the pumping of groundwater. Wells affected by vacuum result in a rise in water level corresponding to the applied vacuum pressure (Δh=specific gravity of vacuum pressure water) (see 3), vacuum is negative gauge pressure (less than atmospheric pressure) and produces a negative slope towards the well do. In addition, the effective water level drop when multiple pumping and vacuum are applied simultaneously is the sum of the water level drop generated by the vacuum action and the depression of the ground water level (shown in 4). As a result, an increase in the hydraulic pumping rate (extraction rate) is realized because the hydraulic gradient increases (Suthersan, 1997). In the case of laminar flow in the permeable porous medium, Darcy's Law is applied, and it is known that the flow through the aquifer is directly proportional to the hydraulic slope (i) under the same conditions (Q=kiA). When the water level drops below the control level, it is extracted mainly in the gas phase, so the amount of liquid pumping is reduced, and the groundwater level, which has dropped, converges, so that the hydraulic gradient is no longer increased. However, when negative pressure (vacuum) is applied to the extraction well, the hydraulic slope can be effectively increased without additional drop in water level. Therefore, the hydraulic pressure load increases the hydraulic slope and consequently the groundwater extraction rate (Suthersan, 1997).

Fig. 2 shows the concept of the restoration of oil-contaminated ground (EPA, New England, 2002). The ground layer is made of porous sand, gravel layer, and clay layer, which is an impermeable layer, and groundwater flows in a laminar flow. It flows into the river. Oil leaks from old oil storage facilities on the ground, or there is an illegal landfill of LNAPL pollutants and the soil is contaminated. An extraction well was installed for purification, and a physical barrier (sheet pile) was installed next to the stream to prevent the contaminant LNAPL from entering the stream directly.

In addition, as a prior art, there is disclosed a prior art document "Patent Registration 10-1830288 Oil Pollution Groundwater Purification Device". However, in the prior art, treatment of effluent, reduction of the effect of vacuum applied to the extraction well, increase of the drop in the groundwater level and insufficient effect of reducing the smear zone (ground hazard, pollution diffusion factor), outflow of contaminated water, etc. There was a problem.

In addition, there is a conventional technique of re-injecting (reducing) the treated effluent into the basement by installing an injection well in a contaminated area without discharging it into a nearby water system. Although it has the effect of blocking urea, the treated effluent is re-injected to its original position without being completely 100% purified, so a small amount of residual contaminants in the injection water form a scum on the filter of the injection well and periodically clean it ( Surging) or economic loss such as periodic injection well reinstallation, and re-supplying contaminants that have not been completely 100% purified to ground water, there is a problem that the residual pollutants need to be purified as much as possible before reaching the ground water.

Registered patent 10-1830288

The object of the present invention is to solve this problem, a multi-phase extraction type oil pollution groundwater extraction device capable of simultaneously extracting groundwater and light-hydrophobic liquids and volatile organic compounds in a well, and controlling and maintaining the groundwater level at a required location. It is possible, and there are few restrictions on application according to geological conditions such as permeability and breathability, it can maintain the vacuum pressure inside the well, and it can recover a lot of groundwater with less power than the existing method and maximize the comprehensive area per extraction well It has the characteristics that it can be applied to emergency treatment for the purification and diffusion prevention of groundwater pollution, and it can physically control the required water level and extract polluted vapor and supply air to a large area of unsaturated zone. ), and to provide a groundwater purification system for polluted soil by a vacuum multiple extraction method that can make the most of the self-cleaning ability of the smear zone.

As a specific means for achieving the above object, the present invention, a well casing is inserted into the extraction hole drilled deeper than the groundwater level on the ground, a jet pump installed inside the well casing; An extraction pipe connected to the upper end of the jet pump and extending to the ground; High pressure water supply means for supplying high pressure water to the jet pump; A gas-liquid separator connected to the extraction tube to receive the extract; An oil-water separator connected to the gas-liquid separator; And a watertight airtight sheet installed to cover the ground of the periphery around the well casing so that airtightness is maintained in the unsaturated soil layer around the well casing.

At this time, the buried space part which is a space that partially protrudes from the bottom of the ground may be formed on the top of the well casing so that the top end of the well casing does not protrude to the top of the ground so that the waterproof airtight sheet can be kept in close contact with the ground.

At this time, a protective cap may be installed on the wall surface of the buried space portion to protect the buried space portion from soil.

At this time, the extraction pipe and the high-pressure water supply means may extend from the buried space portion to the end of the waterproof airtight sheet and then extend to the ground.

At this time, an airtight groove is formed at the end of the waterproof airtight sheet, and the end of the waterproof airtight sheet can be fixed to the airtight groove.

At this time, the waterproof airtight sheet may be fixed to the airtight groove by filling with soil, filling with water, injecting treated water, or whipping tiles.

At this time, a jet pump for ground may be installed between the extraction pipe and the gas-liquid separator for the purpose of increasing vacuum pressure.

At this time, the jet pump installed inside the well casing may be installed in a double connection with the first jet pump and the second jet pump.

According to the present invention as described above has the following effects.

(1) In the present invention, since the air inflow is prevented through the pores of the soil layer around the extraction well by the waterproof airtight sheet, a strong vacuum pressure is maintained in the extraction hole, and when water is extracted, the water level is maintained or raised to enable continuous extraction. .

(2) The present invention provides a very stable extraction effect because the smear zone in which residual oil remains is not enlarged by controlling the change in groundwater level according to extraction.

1 is a conceptual diagram for a vacuum effect of a general pumping well.
2 is a general NAPL restoration conceptual diagram.
3 is a schematic diagram of a soil purification apparatus for soil soil by a multiple extraction method according to a first embodiment of the present invention.
4 is a schematic diagram of a watertight airtight sheet and well casing of a contaminated soil underground water purification apparatus by a multiple extraction method according to a first embodiment of the present invention.
5 is a schematic diagram of the equipment installed on the ground of the apparatus for purifying soil soil by the multiple extraction method according to the first embodiment of the present invention.
6 is a cross-sectional view showing an example of a weaving tile that can be applied to an apparatus for purifying soil soils by a multiple extraction method according to a first embodiment of the present invention.
7 is a schematic diagram of an apparatus for purifying contaminated soil groundwater by a multiple extraction method according to a second embodiment of the present invention.
8 is a schematic diagram of a watertight airtight sheet and a well casing of a contaminated soil underground water purification apparatus by a multiple extraction method according to a second embodiment of the present invention.
9 is a schematic diagram of equipment installed on the ground of the soil purification apparatus for soil pollution by the multiple extraction method according to the third embodiment of the present invention.
10 is a schematic diagram of a watertight airtight sheet and well casing of a contaminated soil underground water purification apparatus by a multiple extraction method according to a third embodiment of the present invention.
11 is a schematic diagram for explaining the difference in effectiveness between the soil soil purification apparatus and the prior art by the multiple extraction method according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily practice. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. In the drawings, parts not related to the description are omitted in order to clearly describe the present invention, and the same reference numerals are attached to the same or similar elements throughout the specification.

In this specification, terms such as “include” or “have” are intended to indicate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, and that one or more other features are present. It should be understood that the existence or addition possibilities of fields or numbers, steps, actions, components, parts or combinations thereof are not excluded in advance. In addition, when a part such as a layer, film, region, plate, etc. is said to be "above" another part, this includes not only the case "directly above" the other part but also another part in the middle. Conversely, when a portion of a layer, film, region, plate, or the like is said to be “under” another portion, this includes not only the case “underneath” another portion, but also another portion in the middle.

Hereinafter, an apparatus for purifying soil soil by multiple extraction methods according to an embodiment of the present invention will be described in detail with reference to the drawings.

A contaminated soil underground water purification apparatus by a multiple extraction method according to a first embodiment of the present invention, referring to FIGS. 3 to 5, a jet pump 20, an extraction pipe 42, a high pressure water supply means (boost pump, 30), a gas-liquid separator 40, an oil-water separator 50, a waterproof airtight sheet 70, a buried space portion 80, and a hermetic 90.

Referring to FIGS. 1 to 3, the jet pump 20 may have a well casing inserted into an extraction hole drilled deeper than the groundwater level in the ground, and installed inside the well casing.

At this time, the extraction hole (2) can be drilled using a conventional auger drill, it is preferable to puncture to the depth of the periphery designed in accordance with the depth of the ground water level and the ground level of the previously explored.

At this time, the well casing 10 is installed so that the lower end is located below the constant ground water level and the upper end protrudes into the buried space 80. The well casing 10 includes a well casing body constituting an upper half, a well screen having an upper end coupled to a lower end of the well casing body, a well plug 11 closing the bottom of the well well, and the well casing body It includes a well cap 12 to close the top. The outer diameter of the well casing main body and the well screen of the well casing 10 is formed smaller than the inside diameter of the extraction hole 2 so that a gap is formed between the inner peripheral surface of the extraction hole 2 and the well and the outer peripheral surface of the well. It is composed. The well casing body is configured such that the upper end protrudes from the buried space part, and the lower end is located above the constant ground water level, and the well screen is configured such that the upper end is located above the constant ground water level and the bottom is located below the constant ground water level. do. The well casing body and the well screen can be joined by welding, the well screen and well plug 11 can be coupled by interference fitting and welding, and the well casing body and well cap 12 are well-defined casing The male screw portion formed on the outer circumferential surface of the body and the female screw portion formed on the inner circumferential surface of the well cap 12 can be screwed. Between the well casing body and the well cap (12) is configured to fit the O-ring to maintain airtightness.

At this time, the jet pump 20 is composed of a jet pump body 21, a tapered expansion pipe 22, a jet nozzle 23, and a high pressure water supply pipe 32, on the top of the jet pump body 21 A tapered expansion pipe 22 that is connected and gradually expands while going upwards, and a jet nozzle 23 that upwardly jets high pressure water toward the bottom of the tapered expansion pipe 22 in the jet pump body 21, and , High pressure water supply pipe 32 for supplying high pressure water to the jet nozzle (23). The high pressure water supply pipe 32 penetrates the side surface of the protection cap 81 and is installed over the interior of the buried space portion 80 and the well casing 10.

At this time, a check valve is installed at the lower end of the jet pump body 21 to allow the groundwater, light-hydrophobic liquid and volatile organic compounds sucked from the lower end of the jet pump body 21 to flow upward, but in the reverse direction. It can be configured so that it cannot flow in the direction.

The extraction pipe 42 is connected to an upper end of the tapered expansion pipe 22. At this time, the extraction pipe 42 penetrates the well cap 12 of the well casing 10 and extends to the buried space portion 80.

At this time, the extraction pipe 42 and the high pressure water supply pipe 32 may be extended from the buried space portion 80 to the end of the waterproof airtight sheet 70 and then exposed to the ground.

The gas-liquid separator 40 may use a conventional gas-liquid separator for separating groundwater, light-hydrophobic liquid, and volatile organic compounds from the three-phase mixture extracted through the extraction pipe 42.

The gas-liquid separator 40 is a three-phase mixture inlet connected to the extraction pipe 42, a ground water outlet connected to the high-pressure water supply means, a volatile organic compound discharge unit and ground water and light to discharge volatile organic compounds It may include a two-phase mixture transport for transporting the hydrophobic liquid.

The high-pressure water supply means may include a boost pump 30 having a discharge end connected to the high-pressure water supply pipe 32 and a suction end connected to a gas-liquid separator 40.

At this time, the suction end of the boost pump 30 may be connected to the ground water outlet of the gas-liquid separator 40.

Here, the ground water stored in the gas-liquid separator 40 and the light-hydrophobic liquid form the upper layer of the light-hydrophobic liquid due to the difference in specific gravity, and the ground water forms the lower layer, and the ground water forming the lower layer is jetted by a high-pressure water supply means. It can be supplied as high pressure water to the jet nozzle 23 of the pump 20.

The oil-water separator 50 is an inlet connected to the two-phase mixture transfer unit of the gas-liquid separator 40, a light-hydrophobic liquid discharge unit for discharging the separated light-hydrophobic liquid, and a volatile organic compound for discharging remaining volatile organic compounds It may include a compound discharge portion, and a ground water discharge portion for discharging the separated ground water.

The discharge tank 60 may include an inlet connected to the ground water discharge unit of the oil-water separator 50 and a discharge unit for discharging the introduced ground water.

3 to 4, the waterproof airtight sheet 70 may be installed to cover the ground of the periphery around the well casing 10 so that airtightness around the well casing 10 is maintained.

At this time, the waterproof airtight sheet 70 may be applied with a waterproof cloth or waterproof vinyl.

At this time, in order to keep the waterproof hermetic sheet 70 in close contact with the ground 1, the upper portion of the well casing 10 is partially above the ground 1 so that the upper end of the well casing 10 does not protrude to the ground. A buried space portion 80 that is a protruding space may be formed. Due to the configuration of the buried space portion 80, the waterproof airtight sheet 70 can properly function.

At this time, a protective cap 81 may be installed on the wall surface of the buried space portion 80 to protect the buried space portion 80 from soil. In addition, the upper surface of the protective cap 81 may be covered by a manhole (82).

At this time, an end of the waterproof airtight sheet 70 is formed with a trench 90 for airtight treatment, and the end of the waterproof airtight sheet 70 may be fixed to the airtight 90 for airtight processing.

At this time, the waterproof airtight sheet 70 may be fixed to the airtight ditch 90 by filling the soil 91, filling water, injecting treated water, or a weaving tile.

Referring to FIG. 3, an apparatus for purifying contaminated soil underground water by a multiple extraction method according to a first embodiment of the present invention is illustrated. As shown, the extraction hole 2 is excavated under the buried space portion 80, and a well casing is installed in the extraction hole 2. A jet pump 20 is installed inside the well casing 10. The upper end of the well casing 10 is exposed so as to protrude to the buried space portion 80, but is located below the ground 1 so as not to interfere with the action of the waterproof airtight sheet 70. From the inside of the well casing 10, the extraction pipe 42 and the high-pressure water supply pipe 32 are installed to be horizontally buried and then passed through the trench 90 for airtight treatment and then extended to the ground. The high pressure water passes through the high pressure water supply pipe 32 from the boost pump 30 through the distributor 31 and is then supplied to the nozzle 23 inside the well casing 10, and the extracted groundwater mixture is extracted pipe 42 ) And the distributor 41 to move to the gas-liquid separator 40. The equipment installed on the ground is almost identical to the existing technology.

Referring to Figure 4, it can be seen in detail the portion of the watertight airtight sheet 70 is installed in the soil purification apparatus for soil contamination by the multiple extraction method according to the first embodiment of the present invention. The high pressure water is supplied by the pump 30 to the nozzle 23 through the high pressure water supply pipe 32, and extraction of ground water is performed by the operation of the jet pump 20. At this time, in the case of the conventional case where there is no waterproof airtight sheet 70, air easily penetrates into the extraction well from the surface, and a vacuum pressure is generated to show the water level in the form of A level, but the upper surface of the extraction well as in the present invention. Because it is hermetically sealed, the vacuum pressure is strongly provided, and the water level appears in the form of B level. That is, around the well casing 10, vacuum pressure is applied by the operation of the jet pump 20, and in this state, the air on the ground is not immediately absorbed by the waterproof airtight sheet 70, and the storage membrane located far from the extraction well Since it is supplied through (92), a strong vacuum pressure is added, and groundwater will continue to be extracted while maintaining the level of B level.

Referring to Figures 4 and 5, but has a configuration almost similar to the existing equipment, there is a difference in that the discharge line 61 in the discharge tank 60 is connected to the ditch 90 for airtightness. By connecting the effluent to the airtight 90 for the airtightness, it is possible to increase the vacuum pressure effect by forming the water film 92 by the effluent and rainwater to maintain airtightness as shown in FIG. 6.

Referring to Figure 11, it shows the effect of the conventional and the present invention in a schematic diagram. As shown, in the conventional case of (a), during actual action, air flows through the pores of the soil layer, and the vacuum in the extraction hole 2 cannot be maintained. Difficulties in continuous extraction are expected, the smear zone where residual oil remains increases, and VAC _p <IN _p , resulting in a longer dead head period. In the case of the present invention in Fig. 11 (b), since the air inflow is controlled by the waterproof airtight sheet 70 and the sealing film 92, the vacuum in the extraction hole 2 is continuously maintained, and the negative pressure (-) This increases, and when water is extracted, the water level is maintained or raised to enable continuous extraction, and at the same time, the expansion of the smear zone where residual oil is left is prevented, and very stable extraction is achieved, and VAC _p >> IN _p becomes effective. Can be seen.

Meanwhile, referring to FIGS. 7 and 8, an apparatus for purifying contaminated soil underground water by a multiple extraction method according to a second embodiment of the present invention is illustrated. The difference from the first embodiment is to connect the new second extraction pipe 121 between the well casing 10 and the distributor 41 into the well casing 10, but before going to the distributor 41 from the ground, a jet pump. One more 120 is installed. That is, the ground jet pump 120 is added. In order to increase the negative pressure in the extraction hole 2, a jet pump 120 is added. This is possible because the airtight airtight sheet 70 and the water-repellent membrane 92 are installed, so that the amount of air flowing into the extraction hole 2 from the ground is controlled. Of course, the new jet pump 120 is connected to the distributor 31 through the new line 122 and receives high pressure water.

On the other hand, referring to Figures 9 and 10, there is shown a pollution soil underground water purification apparatus by a multiple extraction method according to a third embodiment of the present invention. The difference from the second embodiment is that the extraction pipe 42 of the jet pump 20' installed inside the well casing 10 is connected to a new line 122 and is installed in a double (direct heat) with the second jet pump. will be. Here, the first jet pumps 21', 22', 23' are connected to the distributor 41 through the second jet pumps 22", 23", and the second jet pumps 22", 23" are distributors. The high pressure water supply pipe 132 connected to the 31 is added.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art to understand the spirit of the present invention may add elements within the scope of the same spirit. However, other embodiments may be easily proposed by changing, deleting, adding, or the like, but this will also be considered to be within the scope of the present invention.

1: Ground
2: Extraction hole 10: Well casing
11: Plug 12: Well cap
20: jet pump 21: jet pump body
22: tapered expansion tube 23: nozzle
30: pump 31: distributor
32: high pressure water supply pipe 40: gas-liquid separator
41: distributor 42: extraction tube
50: Oil-water separator 60: Discharge tank
70: waterproof airtight sheet 80: buried space
81: protective cap 82: manhole
90: ditch 91: fill the soil
92: curtain

Claims (6)

A well casing is inserted into an extraction hole drilled deeper than the groundwater level in the ground, and a jet pump installed inside the well casing;
An extraction pipe connected to the upper end of the jet pump and extending to the ground;
High pressure water supply means for supplying high pressure water to the jet pump;
A gas-liquid separator connected to the extraction tube to receive the extract;
An oil-water separator connected to the gas-liquid separator;
A waterproof airtight sheet installed to cover the ground of the periphery around the well casing so that airtightness around the well casing is maintained;
Including,
In order to keep the waterproof airtight sheet in close contact with the ground, a buried space portion, which is a space that partially protrudes from the bottom of the ground, is formed on the top of the well casing so that the top end of the well casing does not protrude to the top of the ground,
An airtight groove is formed at the end of the waterproof airtight sheet, and the end of the waterproof airtight sheet is fixed to the airtight groove, and the waterproof airtight sheet is formed at the bottom of the airtight groove by rainwater or discharge water. The end is fixed to the airtight groove,
A protective cap is installed on the wall surface of the buried space portion to protect the buried space portion from soil, and the upper surface of the protective cap is sealed by a manhole,
The extraction pipe and the high-pressure water supply means extend from the buried space part to the end of the waterproof airtight sheet and then extend the exposure to the ground so as not to interfere with the watertight airtight sheet. delete delete According to claim 1,
The watertight airtight sheet is soil filling, water filling, injecting treated water, or contaminated soil underground water purification device by a multiple extraction method fixed to the hermetic ditches by a whipping tile. According to claim 1,
An apparatus for purifying contaminated soil underground by a multiple extraction method in which a jet pump for ground is installed between the extraction pipe and the gas-liquid separator. The method of claim 1 or 5,
The jet pump installed inside the well casing is a first jet pump and a second jet pump connected to the pollution soil underground water purification device by a multiple extraction method installed in duplicate.

Images