KR101717126B1 - Soil Treatment System Using Nanobubble and Multi-Stage Washing of Organic Acid - Google Patents

Abstract

The present invention relates to a purification treatment system for contaminated soil using nanobubbles and multi-step organic acid washing, wherein to purify soil contaminated with oil contaminants and heavy metals, heavy metals are removed more efficiently by a chelating action in a multi-step washing with an organic acid while the nanobubbles serve to decompose oils and release the heavy metals. The purification treatment system comprises: a feeding selection unit including a plurality of conveyors which supplies a fixed amount of soil contaminated with oil contaminants and heavy metals, and a contaminated soil selection device which is disposed among the conveyors to perform magnetic selection and particle size selection while sequentially receiving the contaminated soil; a first-step washing unit including a first washing tank which receives the contaminated soil selected by the feeding selection unit to wash the same, and a first bubble generator which is connected to one end of the first washing tank and injects nanobubbles toward the first washing tank to float and separate the oil contaminants and the heavy metals; a second-step washing unit including a second washing tank which receives the contaminated soil having passed through the first-step washing unit to wash the same, and a second bubble generator which is connected to one end of the second washing tank and injects nanobubbles toward the second washing tank to float and separate the oil contaminants and the heavy metals; and an organic acid injection unit which is connected to the first washing tank of the first-step washing unit and the second washing tank of the second-step washing unit, and injects an organic acid into the contaminated soil inside the first washing tank and the second washing tank to remove the heavy metals from the contaminated soil by a chelating action of the organic acid.

Description

Technical Field [0001] The present invention relates to a system for treating a contaminated soils using a nano bubble and an organic acid multi-

The present invention relates to a system for treating a contaminated soil by using nano bubbles and organic acid multi-stage washing, and more particularly, to a system for collecting and purifying soil contaminated with oil pollutants and heavy metals, The present invention relates to a system for treating a complex contaminated soil using a nano bubble and an organic acid multi-stage washing capable of more efficiently removing heavy metals by chelating action through the multi-stage washing of organic acid while proceeding desorption of heavy metals.

In Korea, soil pollution is mainly caused by unauthorized landfill or leakage of liquid wastes. In addition, it is caused by the underground diffusion of ground - level objects left in the course of long - term industrial activities. It is caused by various kinds of chemical species rather than species compounds. Typical complex contaminated soils are complex pollution in the form of oil pollutants such as BTEX, diesel, gasoline and heavy metals, and occur in most industrial activity areas.

Methods for recovering contaminated soil can be classified into physical methods such as soil washing, incineration, solidification, stabilization and solvent extraction, and biological methods such as soil cultivation, composting, bio-venting, and plant restoration. Soil flushing is a technique that has recently come into widespread use as a way to quickly and easily restore contaminated soils.

In general, the soil washing method of contaminated soil is a technique of separating the soil particles from the soil particles by weakening the surface tension of the harmful organic pollutants or changing the heavy metal into the liquid phase by using water or a chemical agent. It has the advantage of being able to remove the substance while applying it regardless of the kind of the pollutant.

The in-situ method is divided into the in-situ method and the ex-situ method. The in-situ method removes the contaminated soil from the washing solution injection well, the washing solution discharge well, the washing effluent treatment facility, Soil flushing is a soil flushing method that circulates a cleaning agent in a contaminated soil to be installed on a polluted site to directly clean the contaminated soil. It is difficult to collect the cleaning agent Of course, since there is a disadvantage that there is no mobility, the soil washing method is mainly applied to the Ex-situ method.

Here, the Ex-situ method is used to grasp the distribution of pollutants in the soil and physical / chemical characteristics of the soil, excavate the contaminated soil to the extent to be treated, and then use the appropriate cleaning agent to remove the contaminated soil excavated (Soil Washing), which is a generalized method.

At this time, acid, base, organic acid, and surfactant are widely used as chemical agents applied to the soil washing technique. In the case of acids and bases, the removal efficiency of heavy metals is good, but due to the oxidation of organic substances in the soil after the treatment, additional processes such as fertilization treatment and pH adjustment are required for reuse, which is not environmentally friendly.

In addition, the surfactant has a lower efficiency than the acid and base, and its use is limited because the surfactant itself can act as a contaminant. On the other hand, in the case of organic acid formulations, the removal efficiency of heavy metals from the soil is excellent, and oxalic acid and citric acid are also used as nutrients of microorganisms, except for organic acids which are toxic like NTA or EDTA. .

Korean Patent Registration No. 954206 (Apr. 14, 2010) discloses a method for purifying contaminated soil as described above, wherein high-pressure air is sprayed to a fine soil slurry, and the fine soil slurry to which the high- A reaction tank in which hydrogen peroxide and an alkali solution are introduced and reacted to separate the oil component adhering to the fine soil into which the fine soil slurry to which the high pressure air is applied is inputted and reacted; And a plurality of through holes are formed on the surface of the mountain and the valley portion so as to allow the fine bubbles generated during the reaction to float, and a plurality of through holes Bending plates and the oil component and foreign matter floating on the upper part of the reaction tank by the minute bubbles Wherein the hydrogen peroxide is generated by accelerating the autolysis reaction in the alkaline condition of the alkaline solution to generate the minute bubbles, and when the buoyancy is increased as the minute bubbles are gradually attached to the oil component of the fine soil Wherein the bottom portion of the reaction tank floats in a direction of only the oil component from the fine soil, and the lower portion of the reaction tank has a cone shape having an inclined surface whose sectional area becomes narrower toward the lower side in order to induce sedimentation of the fine soil from which the oil component is separated, An inlet pipe for injecting high-pressure air is disposed through a plurality of through-holes formed along the longitudinal direction of the pipe so that the outlet can be opened when soil is filled with the lower outlet, and the inlet of the inlet pipe is connected to the outside And the high-pressure air is supplied Is connected to a first supply pipe, a second supply pipe through which the hydrogen peroxide is supplied, and a third supply pipe into which the alkali solution flows, through the control valve, and the through-holes of the injection pipe are connected to the air, hydrogen peroxide An alkaline solution, and introducing the selected one into the reaction tank, it is possible to effectively remove the oil component and improve the treatment efficiency of the pollutant, as well as a device for removing oil and heavy metal substances in the contaminated soil.

In addition, Korean Registered Patent No. 1103411 (Dec. 30, 2011) discloses a method in which a waste activated sludge and a washing liquid are put into a soil to be cleaned and stirred, and heavy metals in the soil to be washed are adsorbed and released to the waste activated sludge, A mixing treatment unit for washing and removing heavy metals in the soil to be cleaned with a washing liquid; and a mixing treatment unit connected to the mixing treatment unit and supplied with the washing liquid used in the mixing treatment unit and separated from the soil to be cleaned and the waste activated sludge contained in the washing liquid And a neutralization processing unit connected to the settling unit for receiving the cleansing liquid from the supporter and simultaneously injecting a neutralizing agent into the cleansing liquid to neutralize the cleansing liquid, Removal cost is low and removal efficiency can be increased while eliminating heavy metals Are both heavy metals removal devices are known.

However, since the conventional techniques described above use microbubbles or inorganic acids to remove heavy metals from contaminated soil, they require a large amount of chemicals, and due to the use of high concentrations of chemicals, soil structure destruction, limited use of purified soil Increase).

On the other hand, when the use amount of inorganic acid is reduced or avoided in the purification process of contaminated soil, there is a problem that the purification efficiency is greatly reduced although it is environmentally advantageous.

Korean Registered Patent No. 10-0954206 (Apr. 14, 2010) Korean Registered Patent No. 10-1103411 (December 30, 2011)

In order to solve the above problems, the present invention is configured to perform multi-stage cleaning while injecting nano bubbles and organic acid into a soil contaminated with oil pollutants and heavy metals, so that pollutants and heavy metals in contaminated soil are collectively cleaned It is an object of the present invention to provide a complex contaminated soil purification system using nano bubbles and organic acid multi-stage washing, which can enhance the purification efficiency of contaminated soil through multi-stage washing while benefiting environmentally with organic acids.

In addition, since the organic acid used for washing contaminated soil is recycled to be recycled as a cleaning agent, the present invention can purify a complex contaminated soil using nano bubbles and organic acid multi-stage washing that can greatly reduce the amount of organic acid required for washing contaminated soil Processing system.

The complex contaminated soil purification system using nano bubbles and organic acid multi-stage washing proposed by the present invention includes a plurality of conveyance conveyors for supplying a soil contaminated with oil pollutants and heavy metals in a complex manner, And a contaminated soil sorter for sequentially performing magnetic force sorting and particle size sorting while sequentially accommodating the contaminated soil sorter; A first washing tank connected to one end of the first washing tank and configured to float the oil pollutant and heavy metal adsorbed on the contaminated soil toward the first washing tank to selectively filter contaminated soil selected from the feeding sorting unit; A first bubble generator for injecting nano bubbles; A second washing tank connected to the one end of the second washing tank and configured to float the oil pollutants and heavy metals adsorbed on the contaminated soil toward the second washing tank A second bubble generator for injecting nano bubbles; The first washing tank of the first washing stage and the second washing tank of the second washing stage, and the organic acid is injected into the contaminated soil in the first washing tank and the second washing tank, and the chelate action of the organic acid And an organic acid injection unit for removing heavy metals.

The contaminated soil sorter of the feeding sorting unit includes a magnetic separator for sorting and separating magnetic soil having magnetic force among the contaminated soil and a vibration separator for sorting contaminated soil having a certain particle diameter through the magnetic separator, The contaminated soil to be introduced into the first washing tank of the single washing unit is selected to be within the range of 0.04 to 2 mm in particle size.

Wherein the contaminated soil is disposed between the first-stage washing unit and the second-stage washing unit, and the contaminated soil containing the organic acid after the first washing is received from the first-stage washing unit, And a scraper conveyor for supplying the contaminated soil to the second second cleaning tank.

The first organic acid regeneration unit regenerates the organic acid of the wash water separated from the scraper conveyor by adding sodium sulfide (Na ₂ S) so that the organic acid can be reused in the first-stage washing unit.

The first organic acid regeneration unit may include a first reaction tank in which sodium sulfide (Na ₂ S) is injected into the internal washing water and stirred, and a second reaction tank in which a flocculant polymer is added to the washing water stirred in the first reaction tank and then stirred to form a heavy metal sulfide And a first regenerating sedimentation tank for regenerating the heavy metal sulfide from the washing water containing the heavy metal sulfide introduced from the first flocculating tank, while regenerating the heavy metal sulfide with the organic acid washing water.

And a dewatering screen for supplying depleted soil containing organic acid after the second washing step from the second step washing part to dewatering the washing water containing organic acid in the contaminated soil.

And a second organic acid regeneration unit for regenerating the organic acid of the washing water separated from the dewatering screen by adding sodium sulfide (Na ₂ S) so as to be reused in the second-stage washing unit.

The second organic acid regeneration unit includes a second reaction tank for mixing sodium sulphide (Na ₂ S) into the internal washing water and stirring the mixture, and a second reaction tank for adding a flocculant polymer to the washing water stirred in the second reaction tank and stirring to form a heavy metal sulfide And a second regenerating sedimentation tank for regenerating the heavy metal sulfide from the washing water containing the heavy metal sulfide introduced from the second flocculating tank, while regenerating the heavy metal sulfide with the organic acid washing water.

The organic acid in the organic acid injecting unit may be one selected from the group consisting of oxalic acid, citric acid, acetic acid, and malic acid.

According to the composite contaminated soil purification system using nano bubbles and organic acid multi-stage washing according to the present invention, the pollutants and the soil contaminated with heavy metals are purified simultaneously to shorten the cleaning time, and no oxidizing agent and inorganic acid are used Accordingly, it is possible to reduce environmental pollution, reduce environmental pollution, reduce environmental pollution, reduce environmental pollution, reduce environmental pollution,

In addition, the complex contaminated soil purification system using nano bubbles and organic acid multi-stage washing according to the present invention recycles organic acids from the washing wastewater used for cleaning contaminated soil, thereby reducing the amount of organic acid injected in the washing process, There is an effect that can be.

1 is a block diagram schematically illustrating an embodiment according to the present invention;
Fig. 2 is an overall configuration diagram showing an embodiment according to the present invention; Fig.
3 is a schematic view showing a first stage washing unit according to an embodiment of the present invention.
4 is a view showing a two-stage washing unit according to an embodiment of the present invention.
5 is a view schematically showing a first organic acid regeneration section in an embodiment according to the present invention.
FIG. 6 is a schematic view showing a second organic acid regeneration section in an embodiment according to the present invention. FIG.

The present invention relates to a method and apparatus for collecting contaminated soil, which comprises a plurality of conveying conveyors for supplying a soil contaminated with oil pollutants and heavy metals in a quantitative manner, and a contaminated soil sorter disposed between the conveying conveyors for sequentially sorting contaminated soil, A feeding selector configured to include a feeder; A first washing tank connected to one end of the first washing tank and configured to float the oil pollutant and heavy metal adsorbed on the contaminated soil toward the first washing tank to selectively filter contaminated soil selected from the feeding sorting unit; A first bubble generator for injecting nano bubbles; A second washing tank connected to the one end of the second washing tank and configured to float the oil pollutants and heavy metals adsorbed on the contaminated soil toward the second washing tank A second bubble generator for injecting nano bubbles; The first washing tank of the first washing stage and the second washing tank of the second washing stage, and the organic acid is injected into the contaminated soil in the first washing tank and the second washing tank, and the chelate action of the organic acid And an organic acid injecting unit for removing heavy metals. The system is characterized by comprising a nano bubble and an organic acid multi-stage washing system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown.

As shown in FIGS. 1 and 2, an embodiment of a system for cleaning a composite contaminated soil using nano bubbles and organic acid multi-stage washing according to the present invention includes a feeding sorting unit 10, a first stage washing unit 20, A two-stage washing section 30, and an organic acid injecting section 40.

The feed sorting unit 10 is configured to feed and feed the soil contaminated with oil pollutants and heavy metals to the first stage washing unit 20 while sorting the soil into a washable type. The feeding conveyor 11 and the polluted soil And a selector (13).

The feeding sorting unit 10 includes a raw hopper 5 capable of feeding contaminated soil excavated from a separate excavation equipment.

A plurality of the conveying conveyors 11 are provided on a conveyance path toward the one-stage washing unit 20, and the contaminated soil introduced into the raw hopper 5 is conveyed so as to be supplied in a predetermined amount.

The contaminated soil sorter 13 is disposed between the plurality of conveying conveyors 11 and sequentially scans the contaminated soil supplied by a predetermined amount for each divided list.

In the contaminated soil sorter 13, the contaminated soil is sequentially received, and the magnetic force is sorted and the particle size is sorted. That is, the contaminated soil sorter 13 includes a magnetic force separator 13a for sorting and separating magnetic soil having magnetic force among the contaminated soil, a vibration separator 13a for sorting the contaminated soil transferred through the magnetic separator 13a at a predetermined particle size, (13b).

The contaminated soil to be introduced into the first washing tank 21 of the one-stage washing unit 20 is selected within the range of 0.04 to 2 mm in particle diameter by the vibration discriminator 13b.

The first stage washing unit 20 performs a primary washing operation on the pollutants and heavy metals in the contaminated soil selected through the magnetic force sorting and particle size selection process of the feeding sorting unit 10.

As shown in FIGS. 2 and 3, the first-stage washing unit 20 includes a first washing tank 21 for receiving the contaminated soil in a detachable manner, a second washing tank 21 for injecting a nano bubble toward the first washing tank 21, 1 bubble generator 23.

The first washing tank 21 is provided with a stirrer which is always movable to clean the contaminated soil contained therein and a pH meter for confirming the hydrogen ion concentration of the contaminated soil.

Since the hydrogen ion concentration in the first washing tank 21 is maintained in the range of pH 3 to 7, the removal efficiency of heavy metals due to organic acids can be improved.

The first bubble generator 23 is connected to one end of the first washing tank 21 and injects nano bubbles toward the first washing tank 21.

The first bubbling generator 23 injects nano bubbles into the first washing tank 21 so that the pollutants and heavy metals adsorbed on the contaminated soil can be selected by floating. The nano bubbles are injected into the first washing tank 21 under a strong pressure, 1 nano bubble in the washing tank 21 can be injected with a strong spraying force. That is, the fine bubble-shaped nano bubbles come in contact with the first bubble generator 23 to float the oil contaminants and heavy metals, thereby separating the oil contaminants and heavy metals from the contaminated soil.

Organic acid is injected into the first washing tank 21 of the first stage washing unit 20 through the organic acid injecting unit 40 together with the nano bubbles through the first bubble generator 23, Remove heavy metals.

The contaminated soil firstly washed in the first-stage washing unit 20 is transferred to the second-stage washing unit 30, and the washing water discharged together with the contaminated soil from the first- And constitutes a scraper conveyor 25 for separation.

The scraper conveyor 25 is disposed between the first stage washing unit 20 and the second stage washing unit 30 and receives the contaminated soil containing organic acid after the first washing from the first stage washing unit 20 do.

The scraper conveyor 25 separates the contaminated soil from the washing water. The contaminated soil is separated from the washing water mixed with the organic acid supplied from the first-stage washing unit 20, 30 to the second washing tank 31.

Also, the washing water separated from the scraper conveyor 25 is discharged, and the first organic acid regenerating unit 50, which is injected from the first-stage washing unit 20 and regenerated to reuse the organic acid mixed in the washing water.

The first organic acid regeneration unit 50 is for regenerating sodium sulfate (Na ₂ S) added to the washing water so that the organic acid used in the first-stage washing unit 20 can be reused. As shown in FIGS. 2 and 5 As shown, the first reaction tank 51, the first flocculation tank 53, and the first regeneration tank 55 are provided.

The first reaction tank 51 is connected to a chemical storage tank CT for storing sodium sulfide so that sodium sulfide is injected into the inner wash water and is stirred so as to react sodium hydroxide on the wash water. That is, in the first reaction tank 51, the heavy metal-organic acid compound in the washing water is mixed with sodium sulfide.

The first flocculation tank 53 is connected to a polymer storage tank PT storing the flocculating polymer. The flocculant polymer is added to the washing water stirred in the first reaction tank 51 and stirred to form a heavy metal sulfide.

The first regenerating sedimentation tank 55 recovers the heavy metal sulfide from the washing water containing the heavy metal sulfide introduced from the first flocculating tank 53 and removes it by the organic acid washing water. That is, in the first regeneration sedimentation tank 55, the heavy metal sulfide is precipitated in the washing water, and the organic acid washing water and the heavy metal sulfide are fed and supplied respectively, while the heavy metal sulfide is supplied to the separate sludge storage tank ST. The organic acid washing water is supplied to and stored in a separate process water tank WT1 for supplying the washing water to the first bubble generator 23 of the washing unit 20 and the vibration discriminating unit 13b of the contaminated soil sorter 13.

The two-stage washing unit 30 performs a function of washing the pollutants and heavy metals in the contaminated soil, which have been washed through the first-stage washing unit 20, again.

As shown in FIGS. 2 and 4, the two-stage washing unit 30 includes a second washing tank 31 for receiving contaminated soil again after the first-stage washing unit 20, And a second bubble generator (33) connected to one end of the second washing tank (31) and injecting nano bubbles toward the second washing tank (31) so as to float the oil pollutant and heavy metal adsorbed on the contaminated soil.

The structures of the second washing tank 31 and the second bubbling generator 33 are the same as those of the first washing tank 21 and the first bubbling generator 23 described above, Is omitted.

The contaminated soil secondly washed in the second-stage washing section 30 constitutes a dehydration screen 35 that can be dehydrated and separated into final treated soil.

The dewatered screen 35 is supplied with contaminated soil containing organic acid from the second washing tank 31 of the two-stage washing unit 30, and the dewatered washing water containing organic acid in the contaminated soil is dehydrated, Thereby obtaining the treated soil.

The second organic acid recovery unit 60 discharges the washing water separated from the dewatering screen 35 and recycles the organic acid mixed in the washing water to be reused by the second washing unit 30.

The second organic acid regeneration unit 60 is configured to add sodium sulfide (Na ₂ S) to the washing water so that the organic acid used in the second-stage washing unit 30 can be reused. 2 and 6, the second organic acid regeneration unit 60 includes a second reaction tank 61, a second flocculation tank 63, and a second regeneration sedimentation tank 65.

The second reaction tank (61) is connected to the chemical storage tank (CT) so as to mix the sodium sulfide with the inner wash water, and is formed so as to be able to stir sodium sulfide to the wash water. That is, in the second reaction tank 61, the heavy metal-organic acid compound in the washing water is mixed with sodium sulfide.

The second flocculation tank 63 is connected to the polymer storage tank PT to introduce the flocculating polymer therein. The flocculant polymer is stirred in the washing water stirred in the second reaction tank 61 to form a heavy metal sulfide.

The second regeneration sedimentation tank 65 separates the heavy metal sulfide from the washing water containing the heavy metal sulfide introduced from the second flocculation tank 63 to regenerate the organic acid washing water while removing the heavy metal sulfide. That is, in the second regeneration settling tank 65, the heavy metal sulfide is precipitated in the washing water to feed the organic acid washing water and the heavy metal sulfide, respectively, and the heavy metal sulfide is supplied to the sludge storage tank ST. The organic acid washing water is supplied to and stored in a separate process water tank WT2 for supplying the washing water to the second bubble generator 33 of the first unit 30.

2, the organic acid injector 40 stores the organic acid in the organic acid injector 40, and the organic acid is injected into the first washing tank 21 of the first stage washing unit 20 and the second washing tank 21 of the second stage washing unit 30, (31), and organic acid is injected.

The organic acid injecting unit 40 injects organic acid into the contaminated soil in the first washing tank 21 and the second washing tank 31 to remove heavy metals in the contaminated soil by chelating action of the organic acid. In other words, due to the influence of nano bubbles, the pollutants are decomposed from contaminated soil and heavy metals are desorbed and heavy metals are removed by chelating action of organic acids.

The organic acid used herein is one selected from the group consisting of oxalic acid, citric acid, acetic acid, and malic acid.

Hereinafter, the result of the treatment of the complex contaminated soil purification system using nano bubbles and organic acid multi-stage washing according to the present invention was evaluated through the following examples.

[Complex contaminated soil treatment]

As a result of the purification treatment using nano bubbles + organic acid (citric acid) as the result of purification treatment using only nano bubbles using the same contaminated soil in the same area, nano bubble + organic acid (citric acid) + multi- The results of the purification treatment were respectively measured and the results are shown in Table 1 below.

division Removal rate (%) Nano bubble 54.3 Nano bubble + organic acid 400mM 65.2 Nano bubble + organic acid 400mM + multi-stage washing 87.7

As a result of evaluating the removal rate according to the contents of Table 1, the lowest treatment efficiency was obtained when only the nano bubbles were applied, and the treatment efficiency was slightly improved when the organic acid was injected together with the nano bubbles. It was confirmed that the highest treatment efficiency was obtained in the case of multi-stage washing.

[Regeneration of Organic Acid Washing Water]

Following the introduction of nano-bubbles, and organic acid to the compound contaminated soils were respectively measured (Comparative Example) An organic acid dose and removal efficiency, while the first composite contamination after cleaning by injecting the organic acid in the cleaning process of soil washing the organic acid is mixed wastewater Na ₂ S was injected to regenerate the organic acid washing water, and then the organic acid washing water was applied to the washing process of the contaminated soil, and the organic acid injection amount and the removal efficiency were measured (Examples).

division Organic acid injection amount (g) Removal rate (%) Comparative Example 0.06 85.3 Example 0.04 85.7

When the organic acid washing water was regenerated from the washing wastewater, the amount of organic acid injected was reduced by about 1/3 in the cleaning process for the contaminated soil. I could confirm.

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, And it is also within the scope of the present invention.

10: Feeding selector 11: Feed conveyor
13: contaminated soil sorter 13a: magnetic force sorter 13b: vibration sorter
20: first stage washing unit 21: first washing tank 23: first bubble generator
25: scraper conveyor 30: second stage washing section
31: second washing tank 33: second bubble generator
35: Dewatering screen 40: Organic acid injection unit 50: First organic acid regeneration unit
51: first reaction tank 53: first flocculation tank 55: first regeneration tank
60: Second organic acid regeneration unit 61: Second reaction tank 63: Second aggregation tank
65: Second regeneration sedimentation tank WT1, WT2: Process tank CT: Medication tank
PT: Polymer storage tank ST: Sludge storage tank

Claims (9)

A plurality of conveying conveyors for supplying the soil contaminated with oil pollutants and heavy metals in a complex manner and a contaminated soil sorter disposed between the conveying conveyors for sequentially sorting the contaminated soil, A feeder selection unit configured to feed the feeder; And a pH meter for confirming the concentration of hydrogen ions to maintain the hydrogen ion concentration in the range of pH 3 to 7, wherein the contaminated soil selected from the feeding selector is washably received, A first bubble generator connected to one end of the first washing tank and configured to inject nano bubbles toward the first washing tank to float the oil pollutant and heavy metal adsorbed on the contaminated soil; ; And a pH meter for confirming the concentration of hydrogen ions to maintain the hydrogen ion concentration in the range of pH 3 to 7, wherein the pH of the contaminated soil is in the range of 3 to 7, A second bubble generator connected to one end of the second washing tank and configured to inject nano bubbles toward the second washing tank to float the oil pollutant and heavy metal adsorbed on the contaminated soil; ; The first washing tank of the first washing stage and the second washing tank of the second washing stage, and the organic acid is injected into the contaminated soil in the first washing tank and the second washing tank, and the chelate action of the organic acid And an organic acid injection unit for removing heavy metals,
The contaminated soil sorter of the feeding sorter includes a magnetic separator for selectively separating magnetic soil having a magnetic force from the contaminated soil and a vibration separator for sorting contaminated soil having a predetermined particle diameter through the magnetic separator, The contaminated soil to be introduced into the first washing tank of the first washing step is selected to have a particle diameter within a range of 0.04 to 2 mm,
Wherein the contaminated soil is disposed between the first-stage washing unit and the second-stage washing unit, and the contaminated soil containing the organic acid after the first washing is received from the first-stage washing unit, And a scraper conveyor for supplying the contaminated soil to the second secondary cleaning tank,
And a first organic acid regeneration unit for regenerating the organic acid of the wash water separated from the scraper conveyor by adding sodium sulfide (Na ₂ S) so as to be reused in the first-stage washing unit, wherein the first organic acid regeneration unit and a first reaction vessel for stirring by introducing the sodium (Na ₂ S), a first agglomeration tank and the first aggregated flows from the tank to form a heavy metal sulfide is stirred and then added to agglomerated polymer in the stirred wash water from the first reactor Wherein the organic acid washing water recovered in the first regeneration settling tank is supplied to the first bubbler generator and the first bubbler in the first regeneration settling tank, and the first regenerating tank is regenerated with organic acid washing water while precipitating heavy metal sulfides from the washing water containing the heavy metal sulfide, To the vibration discriminator of the soil separator,
And a dewatering screen for supplying depleted soil containing organic acid after the second washing step from the second step washing part to dewatering the washing water containing organic acid in contaminated soil,
And a second organic acid regeneration unit for regenerating the organic acid of the wash water separated from the dewatering screen by adding sodium sulfide (Na ₂ S) so that the organic acid can be reused in the second-stage washing unit, and a second reaction vessel for stirring by introducing the sodium (Na ₂ S), the second agglomeration tank and the second aggregated flows from tank to form a heavy metal sulphide with stirring and then added a cohesive polymer to the wash water was stirred in the second reactor And a second regenerating sedimentation tank for regenerating the heavy metal sulfide from the washing water containing the heavy metal sulfide and regenerating the organic acid washing water while precipitating and removing the heavy metal sulfide from the washing water containing the heavy metal sulfide and supplying the organic acid washing water regenerated in the second regeneration settling tank to the second bubble generator Lt; / RTI >
Wherein the organic acid in the organic acid injection unit is one selected from the group consisting of oxalic acid, citric acid, acetic acid and malic acid. Processing system.
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