KR101059851B1 - Physical treatment system for dnapl-contaminated sites - Google Patents

Abstract

PURPOSE: A physical processing system for dense non-aqueous phase liquid(DNAPL) contaminated region is provided to extract underground water contaminated with DNAPL using a pumping and treating process and chemically and physically purify the water according to the characteristics of contamination. CONSTITUTION: A gas-liquid separator(120) separates contaminated underground water into liquid materials and gaseous materials. A precipitating bath(130) eliminates solid materials from the liquid materials. A DNAPL/water separator(140) receives the liquid materials without the solid materials and eliminates light non-aqueous phase liquid(LNAPL) and DNAPL. A degassing bath(150) receives the liquid materials through the DNAPL/water separator and eliminates volatile materials by contacting the liquid materials with air.

Description

Physical treatment system for DNAPL-contaminated sites

The present invention relates to a technology for purifying soil or groundwater in a DNA non-aqueous phase liquid (DNAPL) contaminated area, and more specifically, the DNAPL / water separator and air A physical treatment system for a DNAPL contaminated area that can be purified using a physical treatment system comprising a degassing tank.

DNAPL is a high-density chlorinated organic pollutant, and representative materials include TCE (Tricloroethylene) and PCE (Perchloroethylene). These organic chloride pollutants generally have high volatility and low flammability, and they dissolve various organic solvents quickly, mainly degreasing metals, cleaning agents for electronic components, making paints and adhesives, and removing caffeine from coffee. It has also been used as a cleaner for film films, refrigerants, dehydration of alcohols, thickening additives, anesthetics, and sedatives. It exists only as a pure substance at the time of manufacture, but after use it may be mixed and spilled with substances such as oils and grease. Recently, the problems of soil and groundwater contamination caused by TCE and PCE have been frequently reported in Korea. Because of the characteristics of TCE and PCE, it is mainly found in soil and groundwater in industrial areas.

In addition, DNAPL is defined as a comprehensive meaning that includes more than 70 kinds of substances with various chemical properties. In this case, it is impossible to generalize the toxicity by each chemical substance. Research and treatment of these substances is being conducted. In general, TCE hardly accumulates in organisms, while PCE accumulates in organisms, but TCE and PCE affect the nervous system in the same way, and when these two components are present, toxicity is known to increase. .

On the other hand, the flow characteristics in the soil are as follows.

Light non-aqueous phase liquid (LNAPL) components, such as BTEX, have a lower specific gravity than water, so when they enter the groundwater they are present in the upper groundwater and move with the groundwater flow. In general, LNAPL has a characteristic of contaminating soil and groundwater simultaneously while maintaining its shape when it is discharged underground, and shows various mobility according to the amount and characteristics of the soil. If a small amount of LNAPL is leaked, it will be collected in the soil pores and there will be no further movement, but if a large amount is continuously supplied from the ground, it will be collected in the soil pores and exceed the capillary pressure of the soil pores. Will move.

On the other hand, DNAPL exists in the soil in free phase DNAPL and residual DNAPL. When a large amount of DNAPL is released into the soil, gravity moves to the free phase DNAPL state. Free phase DNAPL is present in saturated soils and is capable of migration between pores. This mobility goes down due to gravity and is not captured between the soil layers. After this movement, the remaining residual DNAPL remains in the form of spherical or crystalline phases in the soil and is trapped in the soil by capillary pressure, which causes little mobility or flows slowly underground for a very long time. It goes down. Slowly moving DNAPLs meet the impermeable layer and create a DNAPL pool by moving horizontally, not vertically, in the soil. DNAPLs make large pools while descending vertically, but move downward, making thin horizontal lenses under the influence of soil particles and structure during migration. The state of these residual DNAPLs is influenced by the nature of the lipids and DNAPL itself, and the release history (frequency, intensity, duration, volume, location). Therefore, DNAPL has a larger vertical contamination range than a horizontal contamination range and fluidity is governed by the structure of the strata. However, since the structure of the strata is not easily understood from the ground, the estimation of the contamination range is not easy.

Most of them are mobile free-phase DNAPL pools, except for large amounts of DNAPL, which are released from petrochemical plants, oil pipelines and tanks. The location of these free-phase DNAPL pools is difficult to find and difficult to remove completely.

Therefore, in view of the above characteristics of DNAPL, there is a need for a method of purifying groundwater or soil contaminated with DNAPL.

In connection with the above-mentioned problems, the problem to be solved by the present invention is to extract the groundwater contaminated with DNAPL by using a ground pump (pump & treat), physical and chemical Or to provide a physical treatment system for a DNAPL contaminated area that can be biologically purified.

In addition, another problem to be solved by the present invention is to protect the ecosystem by removing harmful substances such as DNAPL and to reduce the enormous purification cost that will be caused by flowing into the ecosystem.

In addition, another object of the present invention is to secure mobility and efficiency by mounting a physical treatment system for a DNAPL contaminated area in a container.

Problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In accordance with another aspect of the present invention, there is provided a physical treatment system for a DNAPL contaminated area, including: an extraction distributor configured to extract and distribute contaminated groundwater in a well using an underwater pump; A gas-liquid separator which receives the contaminated groundwater from the extracting distributor and separates it into a liquid substance and a gaseous substance; A settling tank receiving the liquid material separated by the gas-liquid separator to remove the solid material from the liquid material; A DNAPL / water separator receiving the liquid material from which the solid material has been removed from the settling tank, and removing LNAPL (Light Non-Aqueous Phase Liquid) and DNAPL (Dense Non-Aqueous Phase Liquid) present in the liquid material; And a liquid degassing tank (Air Stripping System) for receiving the liquid substance passed through the DNAPL / water separator and contacting the conveyed liquid substance to remove volatile contaminants remaining in the liquid substance. (DNAPL) A physical treatment system for a contaminated area,
A cyclone that removes the foreign matter contained in the gas phase material separated by the gas-liquid separator using centrifugal force; And a gas-liquid activated carbon adsorption tank for adsorbing contaminants remaining in the gaseous substance using activated carbon and then discharged into the atmosphere.
The gas-liquid separator is provided with a liquid storage tank for collecting a liquid substance at a lower portion and a gaseous substance at an upper portion thereof, and detecting that the liquid substance is accumulated at a predetermined amount or more by a water level sensor attached to the liquid storage tank. Transferred to the settling tank,
The sedimentation tank is equipped with a detection sensor to discharge by using the detection sensor when the solid material sedimented in the lower portion of the sedimentation tank is collected more than a predetermined amount,
The DNAPL / water separator has a space separated into three stages, the lower portion of each space discharge port for discharging LNAPL and DNAPL present in the liquid material; And a plate pack (plate pack) for promoting the settling of the LNAPL and DNAPL is installed,
The air degassing tank includes a flow regulating tank at an upper end and a lower end, respectively, and a circulation pump is installed between the two flow adjusting tanks to repeat air degassing of the liquid substance, and a heating wire is installed in the two flow adjusting tanks. To increase the volatilization rate and speed for the liquid material, wherein the air degassed liquid material is transferred to the rear side from the physical processing system by a pressure pump,
The volatile contaminants include VOCs, PCE, TCE and BTEX.

Specific details of other embodiments are included in the detailed description and the drawings.

According to the physical treatment system for the DNAPL contaminated area according to the embodiment of the present invention as described above, at least one of the following effects exist.

First, it is possible to extract groundwater contaminated with DNAPL by using the ground pump & treat method, and it can be purified physically, chemically or biologically according to the groundwater contamination type and the characteristics of the contaminated area.

Second, by eliminating harmful substances such as DNAPL, it can protect the ecosystem and reduce the enormous purification cost that will be caused by flowing into the ecosystem.

Third, mobility and efficiency can be secured by installing a physical treatment system in a container for a DNAPL contaminated area.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is an overall configuration diagram of a physical treatment system for a DNAPL contaminated area according to an embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the present embodiments merely make the disclosure of the present invention complete, and are common in the art to which the present invention pertains. It is provided to fully inform those skilled in the art of the scope of the invention, which is to be defined only by the scope of the claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, “comprises” and / or “comprising” refers to the presence of one or more other components, steps, operations and / or elements. Or does not exclude additions. Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. Like reference numerals refer to like elements throughout.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to describe the present invention in more detail.

1 is an overall configuration diagram of a physical treatment system for a DNAPL contaminated area according to an embodiment of the present invention.

Referring to FIG. 1, it can be seen that the system for cleaning the DNAPL contaminated area is largely composed of a physical processing system 100, a biological / chemical processing system 200, and a post-treatment processing system 300. In the embodiment of the present invention, a technique for purifying DNAPL contamination mainly based on the function of the physical processing system 100 will be proposed.

The physical processing system 100 shown in FIG. 1 is an extraction distributor 110, a gas-liquid separator 120, a settling tank 130, a DNAPL / water separator 140, an air degassing tank 150, a cyclone 160. ), A decompression device 170 and a gas-liquid activated carbon adsorption tank 180, the biological / chemical treatment system 200 includes a chemical reaction tank 210 and a biological reaction tank 220, the post-treatment processing system 300 ) Is configured to include a pH adjusting tank 310, a sand filter 320, the liquid activated carbon adsorption tank 330.

First, the extraction distributor 110 serves to extract the contaminated groundwater in the well by using a submersible pump to inject into the gas-liquid separator 120.

The gas-liquid separator 120 receives the contaminated groundwater from the extraction distributor 110 and separates the liquid and gaseous substances. The gas-liquid separator 120 is provided with a liquid storage tank for collecting a liquid material at the bottom and a gaseous material at the top, and detects that the liquid material has accumulated a predetermined amount or more by a water level sensor attached to the liquid storage tank. Transfer to the settling tank 130 to be described later.

The settling tank 130 receives the liquid material separated by the gas-liquid separator 120 and serves to remove the solid material from the liquid material. At this time, when the solid material precipitated in the lower portion of the settling tank 130 is collected by a predetermined amount or more is discharged by using a sensor.

The DNAPL / water separator 140 receives the liquid material from which the solid material has been removed from the settling tank 130, and serves to remove LNAPL and DNAPL present in the liquid material.

DNAPL / water separator 140 according to an embodiment of the present invention has a space separated into three stages, a DNAPL outlet for discharging the DNAPL present in the liquid material may be installed in the lower portion of each space.

In addition, the DNAPL / water separator 140 may be provided with a plate pack for promoting the separation of the LNAPL and DNAPL.

The air degassing tank 150 receives the liquid material passed through the DNAPL / water separator 140 and contacts the air with the transferred liquid material, thereby remaining volatile contaminants, ie, VOCs, PCE, TCE, It is responsible for removing BTEX.

Air degassing tank 150 according to an embodiment of the present invention includes a flow adjusting tank at the top and bottom, respectively, between the two flow adjusting tank is installed a circulation pump to repeat the air degassing for the liquid material, A heating wire may be installed in the two flow rate adjusting tanks to increase the volatilization rate and the speed of the liquid substance.

Meanwhile, the liquid substance treated by the air degassing tank 150 is transferred to the pH adjusting tank 310 through the chemical reaction tank 210 and the biological reaction tank 220 at the rear end by a pressure pump.

The cyclone 160 performs a function of removing the foreign matter contained in the gaseous substance separated by the gas-liquid separator 120 using centrifugal force.

Roots blower (170) is a device that moves gaseous substances from low pressure to high pressure and generates vacuum pressure to extract contaminated groundwater.

The activated carbon adsorption tank 180 for gas-liquid serves to discharge contaminants remaining in the gaseous substance to the atmosphere after the adsorption using activated carbon.

The pH adjusting tank 310 receives a liquid material from which volatile contaminants such as VOCs, PCE, and TCE have been removed from the air degassing tank 150 and adjusts the acidity of the transferred liquid material as a discharge limit of water pollutants. Do this.

The sand filter 320 performs a function of removing impurities or microorganisms from the surface of the four layers through the passage of impurities.

Liquid activated carbon adsorption tank 330 serves to discharge the liquid material from the pH adjustment tank 310 when the acidity satisfies the above discharge limit.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be appreciated that one embodiment is possible. Accordingly, the true scope of the present invention should be determined by the technical idea of the claims.

100: physical processing system 110: dispenser for extraction
120: gas-liquid separator 130: sedimentation tank
140: DNAPL / water separator 150: air degassing tank
160: cyclone 170: decompression device
180: activated carbon adsorption tank for gas-liquid 200: biological / chemical treatment system
210: chemical reactor 220: biological reactor
300: aftertreatment process system 310: pH adjusting tank
320: sand filter 330: liquid activated carbon adsorption tank

Claims (11)

An extraction distributor configured to extract and distribute the contaminated groundwater in the well by using a submersible pump; A gas-liquid separator which receives the contaminated groundwater from the extracting distributor and separates it into a liquid substance and a gaseous substance; A settling tank receiving the liquid material separated by the gas-liquid separator to remove the solid material from the liquid material; A DNAPL / water separator receiving the liquid material from which the solid material has been removed from the settling tank, and removing LNAPL (Light Non-Aqueous Phase Liquid) and DNAPL (Dense Non-Aqueous Phase Liquid) present in the liquid material; And a liquid degassing tank (Air Stripping System) for receiving the liquid substance passed through the DNAPL / water separator and contacting the conveyed liquid substance to remove volatile contaminants remaining in the liquid substance. (DNAPL) A physical treatment system for a contaminated area,
A cyclone that removes the foreign matter contained in the gas phase material separated by the gas-liquid separator using centrifugal force; And a gas-liquid activated carbon adsorption tank for adsorbing contaminants remaining in the gaseous substance using activated carbon and then discharged into the atmosphere.
The gas-liquid separator is provided with a liquid storage tank for collecting a liquid material at the bottom and a gaseous material at the top, and detecting the liquid material by detecting a certain amount or more accumulated by a water level sensor attached to the liquid storage tank. Transferred to the settling tank,
The sedimentation tank is equipped with a detection sensor to discharge by using the detection sensor when the solid material sedimented in the lower portion of the sedimentation tank is collected more than a predetermined amount,
The DNAPL / water separator has a space separated into three stages, the lower portion of each space discharge port for discharging LNAPL and DNAPL present in the liquid material; And a plate pack (plate pack) for promoting the settling of the LNAPL and DNAPL is installed,
The air degassing tank includes a flow regulating tank at an upper end and a lower end, respectively, and a circulation pump is installed between the two flow adjusting tanks to repeat air degassing of the liquid substance, and a heating wire is installed in the two flow adjusting tanks. To increase the volatilization rate and speed for the liquid material, wherein the air degassed liquid material is transferred to the rear side from the physical processing system by a pressure pump,
The volatile contaminants include VOCs, PCE, TCE, and BTEX. delete The method of claim 1,
Behind the physical processing system for the DNAPL contaminated area,
Chemical reactors and biological reactors;
A pH adjusting tank for receiving the liquid material from which the volatile contaminants have been removed from the air degassing tank and adjusting the acidity of the transferred liquid material to a discharge limit of water pollutants;
Sand filter; And
And a liquid activated carbon adsorption tank for receiving and discharging the liquid material from the pH adjusting tank when the acidity satisfies the emission limit.
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