KR100988047B1 - Soil pollutant cleaning method and system - Google Patents

Abstract

The present invention relates to a contaminant washing method and system for removing soil by washing soil contaminated with oil and various heavy metals.

This embodiment of the present invention is a stirring step of mixing and mixing the mixed detergent in the contaminated soil; A first to fourth classification and washing step of separating soil particles while washing the stirred contaminated soil; 1 to 3 fine particle washing step of washing by mixing the mixed detergent is washed with a washing liquid and a high pressure; Primary and secondary particulate solids separation step of separating the large particle size soil particles in the soil; A sedimentation step of putting a mixed detergent into the soil and precipitating soil particles; It comprises a; purification step of filtering the washing liquid separated in the settling step.

Soil, pollutants, washing, classification, dewatering, purification, particulates, sedimentation

Description

Pollutants in the soil washing method and system

The present invention relates to a method and system for cleaning pollutants in soil for removing contaminants by washing soil contaminated with oil and various heavy metals. More specifically, the present invention provides a chemically friendly mixed detergent for contaminated soil. Mixing and stirring to promote the decomposition reaction of the pollutants, and according to the particle size of the contaminated soil in order to perform the classification, washing process, fine particle washing process, fine particle solids separation process in order to effectively remove and remove contaminants from the soil, The pollutants and washing liquid separated from the particles are purified through the purification process and then recycled into discharged or process water, which effectively removes contaminants from the contaminated soil and restores the soil and makes it available as aggregate. It relates to a cleaning method and system.

In general, environmental pollution can be classified into air pollution, water pollution, and soil pollution. Among them, soil pollution can be a very serious threat to food production, and it causes pollution of drinking water sources through surface water as well as groundwater pollution. Contaminated soil needs to be cleaned up quickly.

In recent years, soil pollution in Korea is mainly caused by unauthorized landfill or leakage accident of liquid waste. In addition, it is caused by underground diffusion of ground stocks left over long periods of industrial activities. It is caused by several kinds of chemical species rather than a single compound, and representative compound pollution occurs in most industrial areas in the form of oils and heavy metals.

Recently, methods for restoring contaminated soils include physicochemical methods such as soil washing, incineration, solidification, stabilization and solvent extraction, and biological methods such as soil cultivation, composting, bioventing, and plant restoration. Among these methods, a relatively easy and quick way to restore the polluted soil is the soil washing method.

The method of washing contaminated soil is a technique to reduce the surface tension of harmful organic pollutants bound to soil particles by using an appropriate cleaning agent or to separate heavy metals into liquid phase to separate them from soil particles. On the other hand, there is an advantage that can be applied regardless of the type of pollutants.

Soil washing method is classified into in-situ method and ex-situ method, and in-situ treatment method does not excavate contaminated soil and does not excavate contaminated soil. Effluent treatment facilities, pumps, instrumentation facilities, and volatile material treatment facilities are installed on the contaminated site to circulate the wash water in the contaminated soil to treat the contaminated soils directly. Because of this, soil cleaning is usually applied off-site.

The off-site treatment method identifies the distribution of contaminants in the soil and the physical and chemical characteristics of the soil, excavates the contaminated soil in the range to be treated, and then cleans the excavated contaminated soil with a cleaning device using an appropriate cleaning solution. As a method of washing, it is used as a recently generalized soil washing method.

It is a technology to restore soil by removing various contaminants including oil and heavy metals attached to contaminated soil by selecting and washing soil contaminated by the conventional soil washing method in multiple stages. Domestic Patent No. 10-0534067 (Restoration of polluted soil) Soil washing methods and apparatus for the control and screening process are presented.

The prior art is to screen the contaminated soil through a dry sorting step, a high pressure sprinkling sorting step, and then washed in a primary washing tank and discharged into a floating soil containing a large amount of contaminants and a sedimented soil containing a small amount of contaminants. In addition, the sedimented soil is washed in the secondary washing tank and discharged into fine soil and granulated soil at the same time, and the granulated soil is dehydrated and reduced to restoration soil. And it is a technology to make the contaminated sludge for disposal through the dehydration process, the contaminated washing water to neutralize and recycle.

In the prior art, after screening soil particles having a particle size of 10 mm or more in the dry sorting step and the sprinkling screening step, as the washing process is performed, the overall soil and the flotation soil generated in the washing process cannot be washed. Since the waste is made of contaminated sludge for disposal, the waste disposal costs are excessive, and other environmental pollution is caused. In particular, there is a problem in that the contaminants adsorbed in the soil of particulates cannot be effectively removed.

The present invention is a technique devised to improve the problems according to the conventional method of cleaning the contaminated soil, to effectively clean the contaminants in the contaminated soil to restore the soil and at the same time to use a natural mixed cleaner in the contaminated soil to use as aggregate. Mixing and stirring promotes the decomposition reaction of pollutants, and according to the particle size of the contaminated soil, performs classification, washing process, fine particle washing process, and fine particle solids separation process to effectively wash and remove contaminants from soil and separate them from soil particles. The contaminants and washing liquids are purified through the purification process and then recycled to discharged or process water.In particular, the contaminated soil of the particles generated in the classification and washing process is agitated, mixed with the mixed detergent, washing the fine particles and solid particulate separation process. Pollutants in soil where pollutants are effectively washed and removed To provide a method and system to the primary purpose.

The present invention is to realize the desired object as described above,

Adding a mixing detergent to the contaminated soil and stirring the mixing step; A first to fourth classification and washing step of separating soil particles while washing the stirred contaminated soil; 1 to 3 fine particle washing step of washing by mixing the mixed detergent is washed with a washing liquid and a high pressure; Primary and secondary particulate solids separation step of separating the large particle size soil particles in the soil; A sedimentation step of putting a mixed detergent into the soil and precipitating soil particles; Including the purification step of filtering the washing liquid separated in the settling step is implemented a method for washing the soil contaminants according to an embodiment of the present invention.

In addition, the soil pollutant cleaning system according to an embodiment of the present invention, the first to fourth classification and washing apparatus for separating soil particles having a large particle size while washing the soil contaminated with a mixed detergent, and the soil and the mixed detergent A first to third fine particle washing apparatus for washing the mixed and mixed soil in a stirrer by spraying the washing liquid with a high pressure; Primary and secondary particulate solid-liquid separation device for separating the large grain particles in the soil; A sedimentation tank in which soil and a mixed detergent are added and soil particles are precipitated; It comprises a; purifying apparatus that is introduced into the washing solution separated from the immersion tank and filtered.

According to an embodiment of the present invention, a natural friendly chemical mixing agent (Chemical) is mixed with the contaminated soil, and stirred to promote the decomposition reaction of the contaminants adsorbed to the contaminated soil while classifying them sequentially according to the particle size of the contaminated soil. And cleaning process, particulate cleaning process, and particulate solid solution separation process to effectively remove and remove contaminants from contaminated soil, and contaminants and washing liquid separated from soil particles are purified through purification process and then recycled into discharged or process water. In addition, it effectively removes contaminants from contaminated soil and restores the soil, while providing the effect of being used as aggregate.

In particular, an embodiment of the present invention is that the contaminated soil is effectively washed and removed through the stirring process, the fine particle washing step and the fine particle solids separation step of mixing the mixed soil of the fine soil.

In the embodiment of the present invention will be described in detail with reference to Figures 1 and 2 shown in the figure for cleaning the soil contaminants.

Contaminant washing method of the soil according to an embodiment of the present invention, a stirring step of mixing and mixing the mixed detergent in the contaminated soil; A first classification and washing step of separating soil particles of 50 to 200 mm or more while washing the stirred contaminated soil; A second classification and washing step of separating soil particles of 8 to 50 mm or more while washing the soil from which the particles of 50 to 200 mm or more are separated in the first classification and washing step; A stirring step of mixing and mixing a mixed detergent into the soil in which particles of 8 to 50 mm or more are separated in the secondary classification and washing step; Primary particulate washing step of washing the stirred soil by spraying with a washing liquid and a high pressure; Tertiary classification and washing to separate soil particles 3 to 8 mm or more while washing the soil transported from the primary particulate washing step; A fourth classification and washing step of separating soil particles of 1 to 3 mm or more while washing the soil in which the particles of 3 to 8 mm or more are separated in the third classification and washing step; A stirring step of mixing and mixing a mixed detergent into the soil in which particles of 1 to 3 mm or more are separated in the fourth classification and washing step; A secondary particulate washing step of washing the stirred soil by spraying with a washing liquid and a high pressure; A primary particulate solid-liquid separation step of separating soil particles of 0.02-1 mm or more from the soil transferred from the secondary particulate washing step; A mixing step of adding a mixed detergent to the soil in which the particles of 0.02 to 1 mm or more are separated in the first particulate solid-liquid separation step; A third particulate washing step of washing the mixed soil by spraying the washing liquid with a high pressure; A sedimentation step of putting a mixed detergent into the soil transferred from the third particulate washing step and precipitating soil particles; Secondary particulate solid-liquid separation step of dewatering the precipitated soil to separate the soil particles of 0.02mm or less; It comprises a; purification step of filtering the washing liquid separated from the soil precipitated in the settling step.

In the embodiment of the present invention, the mixed washing agent (Chemical) mixed in the contaminated soil is less toxic and it is preferable to use the surfactant as a natural friendly composition using microorganisms to prevent the second environmental pollution, the conventional surfactant Prior art discloses Korean Patent No. 10-0337953 (microbial surfactant composition for soil contamination restoration and soil restoration method using the same).

Surfactants used as mixed detergents enhance desorption in soil particles by decomposition reactions of oils and heavy metals, and increase the decomposition rate of pollutants by soil microorganisms. Environmental pollution can be prevented.

In the soil contaminant washing method according to an embodiment of the present invention, the stirring step is to increase the washing efficiency of the contaminants by mixing and stirring the mixed washing agent in the contaminated soil to homogenize the concentration of the soil and decomposing the mixed washing agent. After sufficient stirring, contaminated soil is washed through the first classification and washing stages, and the second classification and washing stages, and soil particles having a large particle size are sequentially separated.

Soil particles with large particle size are easily cleaned due to relatively weak adsorption power of contaminants, so soil particles of 50 ~ 200mm or more are separated and washed in the primary classification and washing stages, and soil particles of 8 ~ 50mm or more are washed in the secondary classification and washing stages. And separated, wherein the separated washing gravel can be utilized as aggregate.

Soil separated from particles of 8 ~ 50mm or more in the second classification and washing stage is mixed and mixed with the mixed detergent in the stirring stage again, and after being sufficiently stirred, it is sprayed with washing liquid and high pressure in the first fine particle washing stage and adsorbed to the soil particles. As the contaminant is desorbed, the washing process is performed.

The soil that has undergone the first fine particle washing step is washed through the third classification and washing step, the fourth classification and washing step, and the soil particles of 3 to 8 mm or more and soil particles of 1 to 3 mm or more are separated from each other. Cleaned gravel and sand can be utilized as aggregate.

Soil separated from particles 1 ~ 3mm or more in the 4th classification and washing stage is mixed and mixed with the mixed washing agent in the stirring stage again, and after being sufficiently stirred, it is sprayed with the washing liquid and high pressure in the secondary particulate washing stage and adsorbed to the soil particles. As the contaminant is desorbed, the washing process is performed.

The soil that has undergone the secondary particulate washing step is separated from the soil particles of 0.02 ~ 1mm or more in the first particulate solid-liquid separation step, and then the mixed washing agent is mixed in the mixing step, wherein the mixed washing agent is used for the oil contaminants adsorbed on the soil particles. This function promotes the decomposition reaction and adjusts the input amount considering the reaction degree.

Soil mixed with the mixed detergent is sprayed with the washing liquid and high pressure in the 3rd particulate washing stage, and the contaminants adsorbed to the soil particles are desorbed.Then, the washing process is carried out and then supplied to the settling stage where the mixed detergent is added. Here, the precipitated soil is separated from the soil particles of 0.02 mm or less through the dehydration process in the secondary particulate solid-liquid separation step, and the washed fine sand and dehydrated cake separated in the primary particulate solid-liquid separation step and the secondary particulate solid-liquid separation step (Cake) can be used as aggregate.

The washing liquid separated from the soil precipitated in the sedimentation stage is purified through a plurality of filters in the purification stage, filtered, and the purified washing liquid is discharged or recycled into process water.

In addition, as a method for increasing the cleaning effect of the pollutants adsorbed to the soil particles in the soil pollutant washing method according to an embodiment of the present invention, after the first fine particle washing step is performed to rub the soil particles mutually adsorbed to the soil particles A tribological cleaning step may be performed to wash the contaminated material.

Next, a system for implementing a method for washing contaminants in soil according to an embodiment of the present invention includes: a stirrer 11 in which contaminated soil and a mixed washing agent are mixed; A primary classification and washing apparatus (10) for separating soil particles having a large particle size while washing the contaminated soil; A secondary classification and washing apparatus 20 for separating soil particles having a large particle size while washing the soil supplied from the feed; Primary fine particle cleaning device 30 for mixing and stirring the transported soil and mixed washing agent and spraying the stirred soil at a high pressure with the washing liquid; A tertiary classification and washing apparatus 40 for separating soil particles having a large particle size while washing the soil transported from the soil; A fourth classification and washing device (50) for separating soil particles having a large particle size while washing the soil transferred from the soil; Secondary fine particle cleaning device 60 for mixing and stirring the transported soil and mixed washing agent and spraying the stirred soil at a high pressure with the washing liquid; Primary particulate solid-liquid separation device 70 for separating the soil particles having a large particle size in the soil transported from the; Tertiary particulate washing device (80) for washing by spraying the soil mixed with the mixed detergent and transported with the washing liquid and high pressure; A sedimentation tank 90 in which the soil and the mixed washing agent are transferred and the soil particles are precipitated; Secondary particulate solid-liquid separator 100 for separating the soil particles by dehydrating the soil precipitated in the sedimentation tank (90); It comprises a; purification device 110 is filtered by the inflow of the washing liquid separated from the soil precipitated in the sedimentation tank (90).

The main constitution of the soil pollutant cleaning system according to an embodiment of the present invention, as shown in Figures 3 to 6, the first to fourth classification and separating the soil particles having a large particle size while washing the contaminated soil with a stirrer; A washing apparatus and a first to third particulate washing apparatus for washing by spraying the soil mixed with the washing agent with a washing liquid at a high pressure; Primary and secondary particulate solid-liquid separation device for separating the large grain particles in the soil; A sedimentation tank in which soil particles are precipitated; It consists of a purifying device in which the washing liquid separated from the sedimentation tank is introduced and filtered.

In the above main configuration, the stirrer 11 mixes the mixed washing agent to the contaminated soil, and agitates it to uniformly contaminate the contaminant concentration of the soil. It is preferable to apply a type stirrer.

The primary classification and washing apparatus 10 includes a screw conveyor 12 for transferring the contaminated soil sufficiently stirred in the stirrer 11, and a screw classifier 13 for separating soil particles having a large particle size while washing the transferred contaminated soil. ), The contaminated soil is transferred through the screw conveyor (12) to a certain degree of washing process, the washing liquid is sprayed at a high pressure in the screw classifier (13), the soil is washed 50 ~ 200mm or more Are separated.

On the other hand, the secondary classification and washing device 20 is a feeder 21 for transporting and supplying soil from which particles of 50 to 200 mm or more are separated from the primary classification and washing device 10, and the grains are large while washing the soil to be supplied. It consists of a vibrating dewatering screen 22 for separating the soil particles, the washing liquid is sprayed with high pressure to the soil supplied through the conveyor 21, the washing process proceeds to separate the soil particles of more than 8 ~ 50mm.

In addition, the primary particulate washing device 30 is composed of a stirring tank 31, the soil and the mixed washing agent is mixed and stirred, and a soil washer 32 for washing by spraying the stirred soil at a high pressure with the washing liquid, where the stirring tank ( 31) the stirring blade is rotated by the driving of the motor to sufficiently agitate the soil and the mixed washing agent transferred from the secondary classification and washing device 20 evenly, the stirred soil is a high-pressure jet of the washing liquid from the pump in the soil washing machine (32) As it is sucked into the venturi tube being sprayed with a high pressure with the washing liquid, the contaminants adsorbed to the soil particles are desorbed and washed.

The tertiary classification and washing device 40 may apply a dewatering screen 42, and separates soil particles of 3 to 8 mm or more from the soil transferred from the primary particulate washing device 30, and vibrates and dehydrates the soil particles. As the soil particles rub against each other during the separation process, the adsorbed pollutants are desorbed and washed.

Quaternary classification and washing device 50 is the primary storage tank 51 is accommodated in the soil transported from the tertiary classification and washing device 40, while washing the soil supplied from the primary storage tank (51) The primary hydro cyclone 52 for separating the soil of the fine particles, and the dewatering screen 55 for separating the soil particles having a large particle size while washing the soil transported from the hydro cyclone (52).

The soil mixed with the washing liquid through the pump in the primary storage tank (51) is injected into the primary hydro cyclone (52), the washing process by the vortex in the primary hydro cyclone (52) as the soil of the particulate The soil is separated and the fine particles are separated is supplied to the dehydration screen 55, the soil particles are separated by 1 to 3mm or more, and the contaminants are desorbed and washed by friction.

The fourth classification and washing device 50 is a method for effectively separating the soil of the fine particles, the secondary storage tank 53 is the soil is accommodated in the primary hydro cyclone 52 and the secondary storage tank ( A secondary hydro cyclone 54 may be applied that separates the soil of particulates while washing the soil supplied from 53.

In addition, in the soil pollutant washing system according to an embodiment of the present invention, the secondary particulate washing device 60 is agitated with a stirring tank 61 in which the soil and the mixed washing agent are mixed and washed by spraying the stirred soil with a washing liquid and a high pressure. Is composed of a soil washer 62, wherein the stirring tank 61 is agitated by the rotation of the motor blades and stirred evenly enough to evenly mix the soil and the mixed detergent transported from the fourth classification and washing apparatus 50, Soil is sucked into the venturi tube in which the washing liquid is injected at a high pressure from the pump in the soil washing machine 62, and the contaminants adsorbed to the soil particles are removed by washing with the washing liquid at a high pressure.

Meanwhile, the primary particulate solid-liquid separator 70 includes a storage tank 71 in which the soil transferred from the secondary particulate washing device 60 is accommodated, and soil particles having a large particle size in the soil supplied from the storage tank 71. It may be composed of a screw decanter 72 for separating, from the screw decanter 72 is separated from the soil particles of 0.02 ~ 1mm or more.

In addition, the tertiary particulate washing device 80 is a mixing tank 81 in which the soil and the mixed detergent mixed in the primary particulate solid-liquid separator 70 are mixed, and the soil washer is sprayed and washed with the washing liquid and high pressure. It may be composed of (82), the soil mixed with the mixed detergent in the mixing tank 81 is sucked from the pump in the soil washer 62 is a high pressure sprayed with the washing liquid from the pump to the high pressure sprayed with the washing liquid and the soil particles Contaminants adsorbed on the desorption are washed.

The sedimentation tank 90 is accommodated in the soil and washing liquid transferred from the tertiary particulate washing device 80, and provided with a large capacity to accommodate the large amount of soil particles and washing liquid as possible, the mixed detergent is added to the contaminant It accelerates the decomposition reaction and sediments of heavy soil particles are precipitated down.

In addition, the secondary particulate solid-liquid separation apparatus 100 may apply a filter press, and the soil precipitated in the sedimentation tank 90 is supplied to the filter press through a pump, and dehydrated in the filter press to soil particles of 0.02 mm or less. Disconnect.

Purification apparatus 110 for filtering the washing liquid generated in the above device is composed of a sand filter 111, a carbon filter 112, 114, a process water storage tank 113, the washing liquid is a plurality of sand Contaminants are adsorbed and removed while passing through the filter 111 and the carbon filters 112 and 114, and the purified washing liquid is discharged and accommodated in the process water storage 113 to be recycled as process water of the washing system.

In the above, the first to fourth classification and washing apparatus, and the washing gravel, washing sand, washing fine sand, dehydrated cake washed in the first and second particulate solid-liquid separator can be utilized as aggregate.

In addition, as a method for increasing the cleaning effect of the contaminants adsorbed to the soil particles in the soil contaminant washing system according to an embodiment of the present invention, the soil transported from the primary particulate washing device 30 is rotated by a double screw The particles may be configured to be supplied to a friction cleaner 41 for desorbing and cleaning the adsorbed contaminants by mutually rubbing the particles, and the contaminants adsorbed by the friction action of the soil particles are desorbed and washed in the friction cleaner 41.

The preferred embodiments of the present invention have been described above with reference to the present invention, and are not limited to the above embodiments, and those skilled in the art through the above embodiments do not depart from the gist of the present invention. Can be implemented in a variety of changes.

1 is a block diagram showing a process of the soil washing method according to an embodiment of the present invention.

Figure 2 is a block diagram showing another process of the soil washing method according to an embodiment of the present invention.

Figure 3 is a block diagram showing a soil washing system according to an embodiment of the present invention.

Figure 4 is a block diagram showing a primary particulate washing apparatus and tertiary classification and washing apparatus in a soil washing system according to an embodiment of the present invention.

Figure 5 is a block diagram showing a fourth classification and washing apparatus in a soil washing system according to an embodiment of the present invention.

Figure 6 is a block diagram showing a secondary particulate washing apparatus in a soil washing system according to an embodiment of the present invention.

{Description of symbols for main parts of the drawing}

10: Primary classification and washing device 11: Agitator

12: screw conveyor 20: secondary classification and washing apparatus

21: conveyor 22: vibration dewatering screen

30: 1st particulate cleaning device 31: Stirring tank

32: Soil washer 40: 3rd classification and washing device

41: friction cleaner 42: dewatering screen

50: 4th classification and washing device 51: 1st storage tank

52: primary hydro cyclone 53: secondary storage tank

54: secondary hydro cyclone 55: dewatering screen

60: secondary particulate cleaning device 61: stirring tank

62: soil washer 63: storage tank

64: screw decanter 70: 3rd particulate cleaning device

71: mixing tank 72: soil washer

73: tide tank 74: filter press

80: purifier 81: sand filter

82: carbon filter 83: process water storage tank

Claims (8)

delete delete delete delete A stirrer (11) in which contaminated soil and a mixed washing agent are mixed; A primary classification and washing apparatus (10) for separating soil particles having a large particle size while washing the contaminated soil; A secondary classification and washing apparatus 20 for separating soil particles having a large particle size while washing the soil supplied from the feed; Primary fine particle cleaning device 30 for mixing and stirring the transported soil and mixed washing agent and spraying the stirred soil at a high pressure with the washing liquid; A tertiary classification and washing apparatus 40 for separating soil particles having a large particle size while washing the soil transported from the soil; A fourth classification and washing device (50) for separating soil particles having a large particle size while washing the soil transferred from the soil; Secondary fine particle cleaning device 60 for mixing and stirring the transported soil and mixed washing agent and spraying the stirred soil at a high pressure with the washing liquid; Primary particulate solid-liquid separation device 70 for separating the soil particles having a large particle size in the soil transported from the; Tertiary particulate washing device (80) for washing by spraying the soil mixed with the mixed detergent and transported with the washing liquid and high pressure; A sedimentation tank 90 in which the soil and the mixed washing agent are transferred and the soil particles are precipitated; Secondary particulate solid-liquid separator 100 for separating the soil particles by dehydrating the soil precipitated in the sedimentation tank (90); In the soil contaminant washing system comprising a; purifying apparatus 110 is filtered and introduced into the washing liquid separated from the soil precipitated in the sedimentation tank 90, The soil of the soil, characterized in that it comprises a friction cleaner 41 for rotating the soil transported from the primary particulate washing device 30 by rotating double screw to rub the soil particles to desorb and wash the adsorbed contaminants. Pollutant Cleaning System. The method of claim 5; 4th classification and washing device (50), A primary storage tank 51 in which soil is accommodated, a primary hydro cyclone 52 for separating the soil of fine particles while washing the soil supplied from the primary storage tank 51, and the primary hydro cyclone 52 Soil contaminant washing system comprising a dewatering screen (55) for separating soil particles having a large particle size while washing the soil transported from. The method of claim 6; The quaternary classification and washing apparatus 50 cleans the soil of the particulates while washing the soil supplied from the secondary storage tank 53 in which the soil is accommodated in the primary hydrocyclone 52 and the secondary storage tank 53. Soil contaminant cleaning system comprising a secondary hydro cyclone (54) for separating. The method of claim 5; The primary particulate cleaning device 30 and the secondary particulate cleaning device 60, Washing contaminants in the soil, characterized in that it comprises a stirring tank (31) (61) is mixed and stirred soil and mixed detergent, and soil washer (32, 62) for spraying the stirred soil at a high pressure with the washing liquid system.

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