KR101269213B1 - Method for removing hydro carbon from contaminated soil - Google Patents

Abstract

The present invention relates to a method for removing hydrocarbons in soil: a hopper sorting step (S10) for filtering foreign matter into the sorting hopper 10 equipped with a bar screen on the soil introduced; Iron material separation step (S20) for filtering the magnetic material to the magnetic separator 20 in the soil passed through the hopper screening step (S10); Log washers disposed between the dehydration screen 33 and the precision screen 37 while removing the suspended solids in the specific gravity than the soil of the iron material separation step (S20), supplying the cleaning water to the spray nozzle ( 35) crush the mass in the soil, filter the soil 100 ~ 300mm in diameter with the drying screen 31 and then pass through the dewatering screen 33, and through the dewatering screen 33 using a precision screen 37 Particle selection step (S30) to filter the soil more than one diameter 4mm to collect the soil of the particulate; The sand is recovered and re-injected into the hydraulic cyclone 40 to be suspended by the centrifugal force by spraying high-pressure water to the particulate soil after the fine particle selection step (S30), and equipped with a stirrer equipped with an impeller in the tank structure A hydrocarbon removal step (S40) of removing hydrocarbons contained in the particulate soil by friction with the treatment cell 45; And a purifying step (S50) of adding a washing solution to the finely divided soil having undergone the hydrocarbon removing step (S40) and generating dried sludge.
Accordingly, it is based on a closed circuit that minimizes the use of water, and reuses suspended solids or filtrates to maintain high treatment efficiency in an environmentally friendly continuous process.

Description

Method for removing hydro carbon from contaminated soil}

The present invention relates to a method for removing hydrocarbon pollution of soil, and more specifically, based on a closed circuit minimizing the use of water and reusing suspended solids or filtrates, so that hydrocarbon pollution of soil can be maintained in an environmentally friendly continuous process. It relates to a removal method.

The Soil Environment Conservation Act provides standards for soil pollution that requires measures against soil pollution by exceeding the standards of concern and hindering human health, property and growth of animals and plants. As such, interest in the soil is increased as a component of the most basic environment along with water and air, and technology development for preventing and restoring soil pollution along with precautionary measures for soil pollution is actively progressing. In particular, prior art related to the removal of hydrocarbons, including oil in the soil, "Oil Pollution Soil Restoration Method and Apparatus Used in Korean Patent Publication No. 0755910", "Pollution Soil Washing Separator" in Korean Patent Publication No. 0988942 "," Method for cleaning oil and heavy metal contaminated soil "of Korean Patent Publication No. 0526993 and the like are known.

Korean Patent Publication No. 0755910 restores oil contaminated soil to an appropriate particle size, and then restores it by washing with high pressure spraying the washing water, and separating and recovering the washed soil into regenerated coarse aggregate and fine aggregate. The oil separated from the oil is separated and collected, and the washing water can be used repeatedly, so that the cost and time required for the restoration work can be greatly reduced without fear of secondary environmental pollution during the restoration process. .

Korean Patent Publication No. 0988942 introduces contaminated soil containing oil or petrochemical contaminants or various heavy metals into a washing facility, and then sprays the washing water at high pressure to cause collision and friction between particles of contaminated soil. By removing contaminants adsorbed on the soil particles, sorting and separating the washed soil, and chemically treating the contaminants remaining in the washing water to separate sludge and purifying the washing water used for sorting. It is expected to reduce the odor while implementing the cleaning equipment cheaply and simply.

Korean Registered Patent Publication No. 0526993 excavates and collects contaminated soil, and washes the soil, which is discharged in stages from the largest to the smallest, in the original collection location or reused for reclamation at other places. And, in order to prevent secondary contamination by the washed water that has washed the contaminated soil, it provides a method to purify the used wash water and reuse it as the wash water. In particular, it is expected that the secondary pollution will not be generated by the contaminated washing water by reprocessing the contaminated washing water.

However, according to the preceding patents, in addition to the quantitative and qualitative capacity of the soil pollution purification, in consideration of economics and eco-friendliness, etc., there is a limit to complex implementation of the main technical features.

An object of the present invention for improving the conventional problems as described above, is based on a closed circuit minimizes the use of water and removes hydrocarbon contamination of the soil that can maintain a high processing efficiency in an environmentally friendly continuous process by reusing suspended solids or filtrate To provide a way.

In order to achieve the above object, the present invention provides a method for removing hydrocarbons in the soil: hopper sorting step of filtering the foreign matter into the sorting hopper equipped with a bar screen; An iron material separation step of filtering the magnetic material with a magnetic separator in the soil which has undergone the hopper selection step; Remove the suspended solids in the soil of the iron material separation step than the soil, supplying the cleaning water to the spray nozzle, crushing the mass in the soil with a log washer disposed between the dehydration screen and the precision screen, drying screen Particle selection step of filtering the soil having a diameter of 100 ~ 300mm and permeate the dehydration screen, and collecting the soil of the particulate by filtering the soil more than 4mm in diameter through the dewatering screen using a precision screen; The high pressure water is injected into the particulate soil which has undergone the fine particle selection step, and the sand is recovered and re-injected into a hydrocyclone that is suspended by centrifugal force, and by friction with an attrition cell having an agitator equipped with an impeller in the tank structure. A hydrocarbon removal step of removing hydrocarbons contained in the particulate soil; And a purifying step of adding a washing liquid to the finely divided soil having undergone the hydrocarbon removing step and generating dried sludge.

In addition, according to the present invention, the fine particle sorting step is characterized by separating sand with a diameter of 4 mm or less using a log washer with a plurality of screens.

At this time, the fine particle selection step is characterized in that using a drying screen, a dehydration screen, a precision screen sequentially.

In addition, according to the present invention, the hydrocarbon removing step is characterized in that to recover the sand using a hydrocyclone, and to remove the hydrocarbon using an attrition cell.

In addition, according to the present invention, the purifying step is characterized in that the cleaning solution is mixed with lime and / or NaOH and mixed with a nonionic surfactant.

According to the present invention as described above, it is based on a closed circuit minimized the use of water, there is an effect that can maintain a high processing efficiency in an environmentally friendly continuous process by reusing suspended solids or filtrate.

1 is a block diagram of a main installation for the implementation of the method according to the invention.
2 is a block diagram showing the main process flow of the method according to the invention.

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

The present invention relates to a method for removing hydrocarbons in soil. According to the method according to the invention the hopper penalty step (S10), iron material separation step (S20), fine particle selection step (S30), hydrocarbon removal step (S40), purification step (S50) is performed in sequence. As shown in FIG. 1, the sorting hopper 10, the magnetic separator 20, the log washer 35, the hydraulic cyclone 40, the attention cell 45, the controller 50, the filter press 55, etc. are utilized. It is not necessarily limited to this, but may be partially performed manually.

Hopper penalty step (S10) of the present invention is a process of filtering foreign matter from the soil. It is preferable to use the sorting hopper 10 with the conveyor belt in the hopper penalty step (S10). The sorting hopper 10 first removes rocks, wood, and other foreign matter using a fixed bar screen and discharges them onto the conveyor belt 15 downward.

In addition, the iron material separation step (S20) of the present invention is a process of filtering the magnetic material in the soil. It is preferable to use the magnetic separator 20 with the conveyor belt in the iron material separation step (S20). The magnetic separator 20 removes magnetic materials, including iron materials, which may cause damage to the equipment of subsequent processes.

In addition, the fine particle sorting step (S30) of the present invention is a process of filtering out material having a lower specific gravity than the soil and removing the soil having a predetermined diameter or more. Substances with a lower specific weight than soil mean organic substances such as small pieces of wood, and high molecular compounds. Soil having a diameter exceeding a predetermined value may be contaminated by washing or washing liquid only while being transferred through a separate conveyor belt 15.

At this time, the fine particle sorting step (S30) is to separate the sand of less than 4mm in diameter using a log washer 35 with a plurality of screens. In the fine particle sorting step (S30), the drying screen 31, the dehydration screen 33, the precision screen 37 are used sequentially. The soil having a diameter of 100 to 300 mm is filtered out from the first drying screen 31, and the soil having a diameter of 4 to 100 mm is filtered out from the final precision screen 37. A log washer 35 tilts the resistor-coated cross blade stirrer to crush the lumps in the soil and discharge the low specific gravity suspended matter through the drying screen. Of course, the washing water may be sprayed through the spray nozzle from the top of the log washer 35. The log washer 35 is preferably disposed between the dewatering screen 33 and the precision screen 37, but is not necessarily limited thereto.

In addition, the hydrocarbon removal step (S40) of the present invention is a process of removing hydrocarbons by recovering and re-inserting sand in the permeated particulate soil. Hydrocarbons are removed by physical and chemical treatment of particulate soils less than 4 mm in diameter. It improves eco-friendliness by recirculating soil during pollution treatment.

At this time, the hydrocarbon removal step (S40) is to recover the sand by using the hydrocyclone 40, and remove the hydrocarbon by using an attrition cell (45). Hydrocyclone 40 is disposed in the downward direction of the precision screen 37, and the high-pressure water is injected to generate a centrifugal force while separating the floating fine soil to proceed to recover. Attrition cell 45 has a stirrer equipped with an impeller coated with a resistor in a tank structure lined up to perform physical contamination by friction. The screen dryer 48 is disposed in the downward direction of the attrition cell 45, and a continuous circulation process is performed in a purification step S50 to be described later to remove hydrocarbons and discharge the recovered sand.

In addition, the purifying step (S50) of the present invention is a process of adding the cleaning liquid to the soil of the fine granules from which the permeated sand is separated and dried sludge. In the purification step S50, it is preferable to use the controller 50 and the filter press 55. The controller 50 controls the content and capacity of the cleaning liquid added in the purification step S50, in addition to operating the above-described main equipment. Dry sludge is produced through the filter press 55 and the screen dryer 48.

At this time, the purifying step (S50) is introduced into the cleaning solution mixed with a nonionic surfactant based on any one or more selected from lime or NaOH. The cleaning solution is based on any one or more selected from lime or NaOH, and is used by selecting from water-soluble polymers, water-soluble phosphonates, water-soluble biocides and biodispersants, and water-soluble anti-foaming agents. Surfactants use, but are not limited to, nonionic surfactants such as ethoxylated aliphatic alcohols, ethoxylated alkylphenols, ethoxylated amines, diels, amides and the like. The components and the capacity of the cleaning liquid are determined according to the type of hydrocarbon such as gasoline, lubricating oil, aviation oil, lubricating oil and wax, the components of the soil and the content of the hydrocarbon.

On the other hand, the cleaning water used in the method of the present invention is preferably purified through a sand filter and an active filter. The sand filter can be automatically backwashed, thereby improving economics.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined by the appended claims. It is therefore intended that such variations and modifications fall within the scope of the appended claims.

10: sorting hopper 15: conveyor belt
20: magnetic separator 31: drying screen
33: Dewatering Screen 35: Log Washer
37: Precision Screen 40: Hydrocyclone
45: Attrition cell 48: Screen dryer
50: controller 55: filter press

Claims (5)

In the method of removing hydrocarbons from the soil:
Hopper screening step (S10) to filter the foreign matter into the screening hopper (10) equipped with a bar screen the input soil;
Iron material separation step (S20) for filtering the magnetic material to the magnetic separator 20 in the soil passed through the hopper screening step (S10);
Log washers disposed between the dehydration screen 33 and the precision screen 37 while removing the suspended solids in the specific gravity than the soil of the iron material separation step (S20), supplying the cleaning water to the spray nozzle ( 35) crush the mass in the soil, filter the soil 100 ~ 300mm in diameter with the drying screen 31 and then pass through the dewatering screen 33, and through the dewatering screen 33 using a precision screen 37 Particle selection step (S30) to filter the soil more than one diameter 4mm to collect the soil of the particulate;
The sand is recovered and re-injected into the hydraulic cyclone 40 to be suspended by the centrifugal force by spraying high-pressure water to the particulate soil after the fine particle selection step (S30), and equipped with a stirrer equipped with an impeller in the tank structure A hydrocarbon removal step (S40) of removing hydrocarbons contained in the particulate soil by friction with the treatment cell 45; And
And a purifying step (S50) of adding a washing liquid to the finely divided soil having passed through the hydrocarbon removing step (S40) and generating the dried sludge. delete delete delete The method of claim 1,
The purifying step (S50) is a method for removing hydrocarbon contamination of soil, characterized in that the cleaning solution is mixed with a nonionic surfactant based on any one selected from lime or NaOH.

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