JP2003245648A - Purification apparatus and method for polluted soil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the work efficiency of the soil purification work by shortening the time taken for the cleaning treatment in a cleaning tank. <P>SOLUTION: A storage part 80 is installed in the upper end part of a cleaning tank 11, so as to make harmful substances such as oils and PCB, which are floating in the liquid surface of a solvent, overflow and be received in the storage part 80. A harmful substance discharge pipe 82 having a discharge pump 81 is joined to the storage part 80 and the harmful substance discharge pipe 82 is joined to an organic substance treatment apparatus 48. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to harmful organic substances such as oil, PCB and dioxin, and heavy metals such as mercury and lead.
The present invention relates to a method and method for cleaning contaminated soil for cleaning soil contaminated with harmful inorganic substances such as cyanides.

[0002]

2. Description of the Related Art In recent years, soil contaminated by domestic wastewater, immersion of drainage from factories, business establishments, etc., and soil contaminated with chemical substances that cannot naturally be decomposed due to soil contamination of factory sites, etc. The increase in groundwater has a serious impact on the soil environment as an ecosystem and social infrastructure. Therefore, various methods for purifying such contaminated soil and groundwater have been proposed. However, the above-mentioned oils, PCBs, dioxins, heavy metals such as mercury and lead,
There is no effective treatment method for cyanides, and the current situation is that measures such as incineration and containment are taken.

In the conventional incineration treatment, soil contaminated with various harmful substances such as oil, PCB and dioxin is incinerated in a high temperature atmosphere by an incinerator such as a rotary kiln to obtain contaminated soil. It incinerates various harmful substances contained in and decomposes them, and returns them to the environment as purified soil. Further, the gas discharged by decomposing various harmful substances in this incineration facility is rendered harmless, and is discharged to the atmosphere as exhaust gas together with the combustion gas.

However, such a large-scale incineration facility has a large energy cost for treating a large amount of contaminated soil, and there is a possibility that waste may be handled due to alteration of the soil after treatment. Therefore, it may be difficult to reuse. On the other hand, the containment treatment of contaminated soil described above is not essentially a purification measure for contaminated soil,
It is a passive method of simply blocking from the natural world.
Therefore, there is a demand for an economically advantageous soil treatment method for properly purifying soil contaminated with various harmful substances such as oil, PCB, and dioxin and returning it to the natural world.

Therefore, the present applicant has applied for Japanese Patent Application No. 2001-282681 "purification device and method for contaminated soil". This "purification device and method for contaminated soil, by pouring the contaminated soil and solvent into the washing tank and dipping and cleaning, to separate the harmful substances contained in this contaminated soil, and then remove the extraction solvent from this cleaning tank. By circulating air in the washing tank while discharging, the residual solvent is removed and the washed soil is dried,
It is discharged from the cleaning tank and returned to the environment.

[0006]

In the above-mentioned application, when the contaminated soil and the solvent are put into the cleaning tank for the immersion cleaning,
By repeating the circulation process of supplying the solvent to the contaminated soil in the cleaning tank from the upper part and discharging it from the lower part for a predetermined time, harmful substances are dissolved and extracted into the solvent. When a certain amount of harmful substances in the contaminated soil are dissolved and extracted, the extraction solvent is discharged and a new solvent is supplied, and the circulation process is repeated for a predetermined time to extract the harmful substances. I'm repeating. However, there are variations in the degree of pollution of the contaminated soil to be treated due to harmful substances, and if the degree of pollution is high, the harmful substances contained in the contaminated soil cannot be reliably dissolved, and the solvent in the cleaning tank cannot be dissolved. The number of repetitions of the circulation work increases and the work time becomes long.

The present invention solves such a problem, and provides a contaminated soil purifying apparatus and method for shortening the time required for the cleaning process in the cleaning tank to improve the work efficiency of the soil cleaning work. The purpose is to provide.

[0008]

In order to achieve the above-mentioned object, the contaminated soil purifying apparatus according to the invention of claim 1 introduces the contaminated soil into the washing tank and supplies the purifying liquid to clean the contaminated soil. In a contaminated soil purification device for separating harmful substances contained in the contaminated soil by immersion cleaning, the harmful substance discharging means for discharging harmful substances floating or settling in the cleaning tank, and the harmful substance discharging means A harmful substance treating means for treating the discharged harmful substance is provided.

In the apparatus for purifying contaminated soil according to the second aspect of the present invention, the harmful substance discharging means stores the harmful substance floating in the washing tank and receives the harmful substance in the storage part. It is characterized in that it has a conveying means for conveying to the substance processing means.

In the apparatus for purifying contaminated soil according to the third aspect of the present invention, a cleaning liquid circulating means for circulating the cleaning liquid in the cleaning tank, and a harmful substance separated from the cleaning liquid circulating by the cleaning liquid circulating means. It is characterized in that a hazardous substance separating means is provided.

In the polluted soil purifying apparatus according to a fourth aspect of the present invention, the harmful substance separating means is an oil separator.

In the polluted soil purifying apparatus according to a fifth aspect of the present invention, the harmful substance separating means is a resin-filled layer for circulating the circulating purifying liquid.

According to a sixth aspect of the present invention, there is provided a device for purifying contaminated soil, wherein a heating means for heating the cleaning liquid is provided.

A method for purifying contaminated soil according to the invention of claim 7 is
By pouring contaminated soil into the cleaning tank and supplying a cleaning liquid to dip and wash the contaminated soil, the harmful substances contained in the contaminated soil are separated, while the harmful substances floating in the cleaning tank are overflowed. It is characterized by carrying out the discharge processing.

The method for purifying contaminated soil according to the invention of claim 8 is
By pouring contaminated soil into the cleaning tank and supplying a cleaning liquid to dip and wash the contaminated soil, the harmful substances contained in the contaminated soil are separated, while the harmful substances precipitated in the cleaning tank are discharged. It is characterized by being processed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the embodiments described below.

FIG. 1 shows a schematic structure of a contaminated soil purifying apparatus according to a first embodiment of the present invention, and FIG. 2 shows an overall structure of a contaminated soil purifying system showing the contaminated soil purifying apparatus of the present embodiment.

In the contaminated soil purification system of the present embodiment, as shown in FIG. 2, the cleaning tank 11 for introducing the contaminated soil for cleaning treatment is portable, and a large number of cleaning tanks 11 are provided. Transport it to the processing place for use. The tank unit 12 has a refined solvent tank 13, discharge solvent tanks 14 and 15, and a cleaning liquid tank 16. The purification solvent tank 13 stores a solvent (purification liquid) for extracting harmful organic substances (for example, oil, PCB, dioxin, etc.) contained in contaminated soil, and has a purification solvent supply pump 17. It is connected to each cleaning tank 11 via a supply pipe 18. On the other hand, the discharged solvent tank 14,
15 stores a solvent containing an organic substance extracted from contaminated soil in the cleaning tank 11, and is connected to each cleaning tank 11 via a discharge pipe 21 having an operation valve 19 and an extraction solvent discharge pump 20. Has been done. In addition, the supply pipe 17
A circulation pipe 24 having an operation valve 22 and a circulation pump 23 is connected between the exhaust pipe 21 and the exhaust pipe 21.

Therefore, when the refined solvent pump 17 is driven with the operation valves 19 and 22 closed, the refined solvent tank 1
The solvent in 3 can be supplied to each cleaning tank 11 through the supply pipe 18, and when the operation valve 19 is opened and the extraction solvent discharge pump 20 is driven, the extraction solvent in each cleaning tank 11 is discharged. Each of the discharged solvent tanks 14 and 15 through the pipe 21
Can be discharged to. On the other hand, when the circulation pump 23 is driven in a state where the operation valve 19 is closed and the operation valve 22 is opened, the solvent can be circulated and discharged from the cleaning tank 11 through the circulation pipe 24.

The cleaning liquid tank 16 stores a cleaning liquid (cleaning liquid) for dissolving and extracting or decomposing harmful inorganic substances (heavy metals such as mercury and lead, cyanides, etc.) contained in contaminated soil, Each cleaning tank 11 is connected via a supply pipe 26 having a cleaning liquid supply pump 25. A discharge pipe 29 having an operation valve 27 and a cleaning liquid discharge pump 28 is connected to each cleaning tank 11. A circulation pipe 32 having an operation valve 30 and a circulation pump 31 is connected between the supply pipe 26 and the discharge pipe 29.

Therefore, when the cleaning liquid pump 25 is driven with the operation valves 27 and 30 closed, the cleaning liquid in the cleaning liquid tank 16 can be supplied to each cleaning tank 11 through the supply pipe 26, and the operation valves can be operated. When the cleaning liquid discharge pump 28 is driven by opening 27, the extraction cleaning liquid in each cleaning tank 11 can be discharged through the discharge pipe 29. on the other hand,
When the circulation pump 31 is driven in a state where the operation valve 27 is closed and the operation valve 30 is opened, the cleaning liquid can be circulated and discharged from the cleaning tank 11 through the circulation pipe 32.

A concentration sensor 33 for detecting the concentration of harmful organic substances contained in the extraction solvent is attached to the discharge pipe 21, while the concentration of harmful inorganic substances contained in the extraction cleaning liquid is measured in the discharge pipe 29. A concentration sensor 34 for detecting is attached. In this case, it is desirable to provide a plurality of sensors that detect the concentration with high accuracy according to the types of harmful organic substances and inorganic substances.

Further, the purification unit 35 removes organic substances from the extraction solvent discharged from the cleaning tank 11 and stored in the discharge solvent tanks 14 and 15 to purify the solvent by a solvent refining device 3
6, a cleaning liquid purification device 37 that removes and purifies inorganic substances from the extraction cleaning liquid discharged from the cleaning tank 11, and a soil from which organic substances or inorganic substances have been removed by sucking gas into each cleaning tank 11. And a drying device 38 that removes and dries the remaining solvent or cleaning liquid.

The solvent refining device 36 is a distillation device 42 in which a strainer 39 for removing coarse particles such as sand, an oil strainer 40 for removing oil and fat, and a boiler 41 are connected.
It consists of and. Then, the discharged solvent tank 14,
15 and the strainer 39 are connected by a transfer pipe 44 having a transfer pump 43. On the other hand, the distillation device 42 and the purified solvent tank 13 are connected by a return pipe 46. In addition, the strainer 39, the oil strainer 40,
An organic substance treatment device (storage tank, treatment device) 48 is connected to the distillation device 42 via an organic substance discharge pipe 47.

Therefore, when the transfer pump 43 is driven and the extraction solvent in the discharge solvent tanks 14 and 15 is sent to the solvent refining device 36 through the transfer pipe 44, the solvent is replaced with oil,
The organic solvent such as PCB and dioxin is removed, and the purified solvent is passed through the return pipe 46 to the purified solvent tank 13
Can be returned to. On the other hand, the organic substance removed by the solvent refining device 36 is sent to the organic substance treatment device 48 through the organic substance discharge pipe 47, where it can be stored and stored for detoxification treatment.

The cleaning liquid purifying device 37 comprises a sand filtration tower 49 and a resin adsorption tower 50. The downstream end of the cleaning liquid discharge pipe 29 is connected to the sand filtration tower 49, and the resin adsorption tower 50 and the cleaning liquid tank are connected. 16 is connected by a return pipe 51, and an inorganic substance treatment device 53 is connected to the sand filtration tower 49 and the resin adsorption tower 50 via an inorganic substance discharge pipe 52.

Therefore, when the cleaning liquid discharge pump 28 is driven and the extracted cleaning liquid is sent from each cleaning tank 11 to the cleaning liquid purifying device 37 through the discharge pipe 29, here, heavy metals such as mercury and lead, cyanide, etc. are discharged from the cleaning liquid. The cleaning liquid from which the inorganic substances have been removed and which has been purified can be returned to the cleaning liquid tank 16 through the return pipe 51. On the other hand, the cleaning liquid purification device 3
The inorganic substance removed in 7 is sent to the inorganic substance treatment device 53 through the inorganic substance discharge pipe 52, where it can be detoxified or concentrated.

The drying device 38 takes in air containing solvent (mist) discharged from the cleaning tank 11 and separates the contained mist, a knockout pot 54, a heat exchanger 55 for cooling the air, and a solvent. It is composed of an activated carbon tower 56 for adsorbing steam and a blower 57. Cleaning tank 1
1 is a knockout pot 54 via an air exhaust pipe 58.
The activated carbon tower 57 is connected to the cleaning tank 11 via an air supply pipe 59. The knockout pot 54 and the heat exchanger 55 are connected to the discharged solvent tank 15 via a return pipe 65 having a solvent return pump 64.

Therefore, the blower 56 is operated to activate the cleaning tank 11.
When the air inside is sucked, the air is knocked out of the knockout pot 54.
The solvent mist contained therein is separated, and the heat exchanger 5
The solvent vapor is liquefied by cooling in 5, and is further purified by the activated carbon tower 57 and supplied to the cleaning tank 11, and the solvent remaining in the cleaning tank 11 can be evaporated and removed from the soil.

A boiler unit 61, a cooling unit 62, a compressor unit 63 and the like are provided as the utility unit 60. The boiler unit 61 is for heating the air supplied to the cleaning tank 11 as needed, and the cooling unit 62 is for the heat exchanger 55.
The compressor unit 63 is for cooling the air discharged from the cleaning tank 11 to condense the solvent vapor.
Is for operating various pumps.

A solvent for extracting harmful organic substances such as oil, PCB, and dioxin contained in the contaminated soil, and heavy metals such as mercury and lead contained in the contaminated soil, and harmful inorganic substances such as cyanides are contained in the contaminated soil. It is necessary to set the type of the cleaning solution to be dissolved, extracted or decomposed and washed according to the content or concentration of the harmful substances contained in the contaminated soil by conducting an investigation of the contaminated soil in advance. In this case, the solvent is preferably a hydrophilic solvent such as alcohol, and the cleaning liquid is preferably water, an alkaline liquid or an acidic liquid. Specifically, it is necessary to provide an alcohol storage tank, a water tank, an alkaline liquid tank, and an acidic liquid tank.

As to the concrete structure of the cleaning tank 11, as shown in FIG. 1, the cleaning tank 11 is composed of a tank main body 71 having an opening at the top and a lid 72, and supply ports 73 and 74 are provided at the upper and lower portions.
And a discharge port 75 is formed in the lower part. In addition, a lattice-shaped support portion 76 is integrally formed in the tank main body 71 and is located below, and a filtration filter 77 is laid on the support portion 76. And supply pipe 1
8 is branched and the upper and lower supply ports 7 are operated through the operation valves 78 and 79.
3, while the discharge pipe 21 is connected to the discharge port 75.
Are connected. Although the solvent supply / discharge equipment has been described here, the cleaning agent supply / discharge equipment has the same configuration.

Further, a storage portion 80 is provided outside the upper end of the cleaning tank 11 along the circumferential direction, and overflows harmful substances such as oil and PCB floating on the liquid surface of the solvent to store the storage portion 80. Can be accepted by. A toxic substance discharge pipe (conveying means) 82 having a discharge pump 81 is connected to the storage section 80, and the toxic substance discharge pipe 82 is connected to the organic substance treating apparatus (toxic substance treating means) 48 described above. There is. In this case, the storage part 80, the discharge pump 81, and the harmful substance discharge pipe 82 constitute a harmful substance discharge means. The cleaning tank 11 has a control valve 22, a circulation pump 23, and a circulation pipe 2 as a cleaning liquid circulation means.
4 is provided, and a steam heater (which may be an electric heater or a heat exchanger) 83 is provided as a heating means for heating the solvent flowing through the circulation pipe 24.

In this case, as shown in FIG.
A concentration sensor 84 for detecting the concentration (content rate) of harmful substances contained in the contaminated soil put therein is provided. Therefore, when the concentration of the harmful substance detected by the concentration sensor 84 is equal to or higher than the solubility in the solvent, it is determined that the insoluble substance such as oil or PCB floats on the liquid surface of the solvent in the cleaning tank 11, and the cleaning is performed. By increasing the amount of solvent supplied into the tank 11 and causing it to overflow, floating substances such as oil and PCB are discharged to the storage section 80, and the discharge pump 81 discharges the harmful substances through the harmful substance discharge pipe 82 to the organic substance processing apparatus. I am sending it to 48.

It should be noted that the surface of the solvent in the cleaning tank 11 may be oil or PCB.
The determination that the overflow of the solvent is necessary for the floating of the like is the concentration of the harmful substance contained in the contaminated soil detected by the concentration sensor 84, but the oil and PCB generated on the liquid surface of the solvent in the cleaning tank 11 It is also possible to use an optical sensor (transmittance sensor, refractive index sensor) or a camera for detecting the presence or absence of floating substances such as

Here, a method for purifying the contaminated soil according to the above-described embodiment will be described. In this case, the soil contamination status of the soil will be investigated in advance, necessary equipment and treatment agents will be prepared, and various equipment will be transported to the site and assembled to install the purification equipment.
Further, the concentration sensor 84 is used to measure the concentration of harmful substances contained in the contaminated soil to be purified in the cleaning tank 11. The number of cleaning tanks 11 to be installed is set according to the size of the treatment site and the amount of contaminated soil to be purified. Then, when the equipment for purifying the contaminated soil is installed, as shown in FIG. 2, first, a predetermined amount of the contaminated soil is put into each cleaning tank 11 using a power shovel or the like, and the tank body 7 is used.
The lid 72 is fixed to 1 to seal the contaminated soil, and the purification treatment work for harmful substances is started.

Then, as shown in FIGS. 1 and 2, with the operation valves 19 and 21 of the cleaning tank 11 closed, the solvent (alcohol) in the refined solvent tank 13 is supplied from the refined solvent pump 17 through the supply pipe 18. Is supplied to each cleaning tank 11.
In this case, the operation valve 78 is closed and the operation valve 79 is opened, the solvent is supplied into the cleaning tank 11 from the lower supply port 74 to make the filtration filter 77 submerged, and here, the operation valve 79 is closed and the operation valve 78. Open the tank and wash the solvent from the upper supply port 73.
It is possible to suppress clogging due to the adherence of suspended soil particles to the filtration filter 77 by supplying the air to the inside of 1 to immerse the contaminated soil. Then, the solvent is supplied until the contaminated soil in the cleaning tank 11 is immersed.

When the solvent is put into the cleaning tank 11 in this way, the refined solvent pump 17 is stopped, the operation valve 22 is opened, the circulation pump 23 is operated, and the circulation pipe 24
By circulating the solvent through the cleaning tank 11 for a predetermined time,
Organic substances contained in polluted soil, that is, oil, PCB, and dioxin can be extracted. At this time, when the concentration of the harmful substance detected by the concentration sensor 84 is equal to or higher than the solubility in the solvent, harmful substances such as oil and PCB that cannot be dissolved on the liquid surface of the solvent during the circulation of the solvent to the cleaning tank 11 are removed from the soil particles. Peel and float. Therefore, the purification solvent pump 1
7 is operated to supply the solvent in the refined solvent tank 13 to the supply pipe 18
And is supplied to each of the cleaning tanks 11 to increase the circulation amount. In this case, it is desirable to open the operation valve 78 to supply the solvent just below the suspended matter, but the operation valve 79 may be opened to supply the solvent.

Then, the liquid level of the solvent in the cleaning tank 11 rises, and the oil floating above the liquid level has a solubility higher than that of the solvent, PCB.
Hazardous substances such as are overflowed in a liquid state to be discharged to the storage section 80, and the discharge pump 81 sends the harmful substances to the organic substance processing device 48 through the harmful substance discharge pipe 82. It can be detoxified. In this case, by heating the circulating solvent by the steam heater 83 to raise the temperature, the solubility of the harmful substance can be improved, and the viscosity of the harmful substance adhered to the soil particles can be lowered to promote separation. it can.

Then, the solvent is circulated and discharged into and from the cleaning tank 11 for a predetermined time to extract the oil, PCB, and dioxin contained in the contaminated soil, and the harmful substance whose concentration is higher than the solubility of the solvent is discharged. While the valve 22 is closed and the circulation pump 23 is stopped, the operation valve 19 is opened to operate the extraction solvent discharge pump 20, and the extraction solvent in each cleaning tank 11 is discharged via the discharge pipe 21 to the discharge solvent tanks 14, 15 To discharge. Then, as described above, a new solvent in the refined solvent tank 13 is supplied to the cleaning tank 11 and is circulated and discharged for a predetermined time to extract the organic substance. While doing this work for several preset cycles, the oil in the discharged solvent,
The concentrations of PCB and dioxin are measured by the concentration sensor 33. When the measured value of the concentration sensor 33 becomes equal to or lower than a preset predetermined value, it is assumed that the residual amount of the organic substance contained in the soil of the cleaning tank 11 becomes equal to or lower than the reference value determined by the official method. Finish the cleaning work.

When harmful organic substances are removed from the soil in the cleaning tank 11, the blower 56 is operated to operate the cleaning tank 11.
By sucking the gas inside, the solvent remaining in the soil in the cleaning tank 11 is evaporated and discharged together with air to dry the soil. Then, the discharged air is collided with the partition wall in the knockout pot 54 to separate the mist of the solvent, and the heat exchanger 55 cools the solvent vapor to condense the solvent vapor. The solvent of the activated carbon tower 5
Adsorb at 7. Then, the residual solvent removed by the knockout pot 54 and the heat exchanger 55 is returned to the discharged solvent tank 15 by the solvent return pump 64 via the return pipe 65.

After the harmful organic substances are removed from the contaminated soil in the cleaning tank 11, the cleaning liquid pump 2
5, the cleaning liquid (for example, water) in the cleaning liquid tank 16 is supplied to each cleaning tank 11 through the supply pipe 26, and the contaminated soil in the cleaning tank 11 is obtained by the same method as the method for extracting the organic substance by the solvent described above. Is immersed in the liquid. Then, the liquid is washed by the circulation pump 31 through the circulation pipe 32 into the cleaning tank 11.
By circulating it, the harmful inorganic substances contained in the contaminated soil are dissolved. Then, when the liquid is circulated in the cleaning tank 11 for a predetermined time, the circulation of the liquid is stopped, and the extract liquid in each cleaning tank 11 is discharged to the cleaning liquid purification device 37 by the cleaning agent discharge pump 28. Then, again, a new liquid is supplied to the cleaning tank 11 and circulated, and a harmful inorganic substance is extracted by circulating and discharging this liquid for a predetermined time. While performing this operation for several cycles, the concentration of the harmful substance in the discharged liquid is measured by the concentration sensor 34. Then, when the measured value of the concentration sensor 34 becomes less than or equal to a preset predetermined value, the cleaning tank 1
When the residual amount of harmful substances contained in the soil (1) falls below the standard value specified by the official law, the cleaning work is completed.

After the cleaning process of the contaminated soil with the liquid is completed, the alkaline liquid is similarly circulated and supplied to and from the cleaning tank 11 for a predetermined time, and this process is repeated for several cycles to remove harmful inorganic substances contained in the contaminated soil. Remove material. Further, the acidic liquid is circulated and fed into and out of the cleaning tank 11 for a predetermined time, and this treatment is performed for several cycles to remove harmful inorganic substances contained in the contaminated soil. In this case, the cleaning treatment with the acidic liquid may be performed first, and then the cleaning treatment with the alkaline liquid may be performed.

On the other hand, the extraction solvent (alcohol) in the discharge solvent tanks 14 and 15 is transferred by the transfer pump 43 to the transfer pipe 44.
To the solvent refining device 36, where the solvent removes oil,
Organic substances such as PCB and dioxin are removed, and the purified solvent is returned to the purified solvent tank 13. On the other hand, the organic substance removed by the solvent refining device 36 is sent to the organic substance treatment device 48 through the organic substance discharge pipe 47, where it is detoxified. In this case, the oil is incinerated and the PCB is hydrothermally decomposed. Further, in the cleaning liquid purification device 37, the cleaning liquid (water,
Remove harmful inorganic substances from alkaline and acidic solutions,
The purified cleaning liquid is returned to the cleaning liquid tank 16. On the other hand, the harmful inorganic substance removed by the cleaning liquid purification device 37 is sent to the inorganic substance treatment device 53 through the inorganic substance discharge pipe 52,
Here, detoxification processing is performed.

Thereafter, the blower 56 is operated as necessary to suck the gas in the cleaning tank 11 to evaporate the moisture remaining in the soil in the cleaning tank 11 to dry it.

When the harmful organic substances and inorganic substances are separated and removed from the contaminated soil in the washing tank 11 by the above-mentioned treatment, the purified soil is discharged from the washing tank 11, and the separating device 82 separates the washed soil by the specific gravity separation. After the particle size adjusting agent is separated and removed, it can be returned to the natural world and reused.

As described above, in the contaminated soil purification system of this embodiment, the storage section 80 is provided at the upper end of the cleaning tank 11 to overflow harmful substances such as oil and PCB floating on the liquid surface of the solvent. The storage section 80 can be received by the storage section 80, and the storage section 80 is connected to a harmful substance discharge pipe 82 having a discharge pump 81.
2 is connected to the organic substance processing apparatus 48.

Therefore, the concentration sensor 84 detects the concentration of the harmful substance contained in the contaminated soil put into the cleaning tank 11, and when the detected concentration of the harmful substance is equal to or higher than the solubility in the solvent, Oil or PC that cannot be dissolved in the solvent surface
Judging that harmful substances such as B float, the cleaning tank 11
By increasing the amount of solvent supplied to the interior and causing it to overflow, floating substances such as oil and PCB are discharged to the storage unit 80, and the discharge pump 81 passes through the harmful substance discharge pipe 82 to the organic substance processing apparatus 48. To send. That is, the cleaning tank 1
The amount of harmful substances that cannot be dissolved by the solvent of No. 1 is separately taken out and detoxified by the organic substance processing device 48.
It is possible to reduce the number of times of repeating the solvent circulation work in the cleaning tank 11 to shorten the work time and improve the work efficiency of the soil purification work.

Further, in the contaminated soil purification system of the present embodiment, the purified solvent tank 13 and the cleaning liquid tank 16 are connected to the plurality of cleaning tanks 11, and the contaminated soil put into each cleaning tank 11 is First, the solvent in the purified solvent tank 13 is supplied and immersed for a predetermined time to separate organic substances (for example, oil, PCB, dioxin, etc.) contained in the contaminated soil, and then the solvent in the cleaning tank 11 is removed. After discharging, the cleaning liquid in the cleaning liquid tank 16 is supplied and dipped for a predetermined time to separate inorganic substances (heavy metals such as mercury and lead, cyanides, etc.) contained in the contaminated soil.

Therefore, the contaminated soil in the cleaning tank 11 is immersed in the solvent to separate the contained organic substances, and the cleaning liquid is immersed in the separated inorganic substances to separate the contaminated soil from the solvent and the contaminated soil. By soaking and separating the cleaning solution and the cleaning liquid without stirring, the separation process does not take a long time due to the atomization of soil, and the filter does not become clogged. Can be done properly.

In the purification system for polluted soil of the above-mentioned embodiment, the hydrophilic solvent (for example, alcohol) is used as the solvent, and water, the alkaline liquid, and the acidic liquid are used as the cleaning liquid. In addition to alcohol, ketone or the like can be used, and as a solvent, other than a hydrophilic solvent,
Hydrocarbons, aromatics and the like can be used as the hydrophobic solvent. In addition, the hydrophilic solvent (alcohol, ketone, etc.) and the hydrophobic solvent (hydrocarbons, aromatics, etc.) are used to dehydrate the water in the water-contaminated soil with the hydrophilic solvent, and then the organic substance Alternatively, a harmful organic substance contained in the contaminated soil may be extracted and removed with a hydrophobic solvent having a high extraction / dissolution capacity, and the inorganic substance may be dissolved / decomposed with a cleaning agent to be removed. In this case, the treatment time can be shortened by using a mixed solvent obtained by mixing a hydrophilic solvent and a hydrophobic solvent. Further, the structure of the cleaning tank 11 described above is not limited to the embodiment described above.

FIGS. 3 to 5 show a schematic structure of a contaminated soil purifying apparatus according to second to fourth embodiments of the present invention.
It should be noted that members having the same functions as those described in the above-described embodiment are designated by the same reference numerals, and redundant description will be omitted.

In the contaminated soil purification device of the second embodiment,
As shown in FIG. 3, a storage unit 80 is provided at the upper end of the cleaning tank 11.
The storage section 80 is provided with an organic substance processing apparatus 4 via a harmful substance discharge pipe 82 having a discharge pump 81.
Connected to eight. In addition, the circulation pipe 24 of the cleaning tank 11
In addition to the steam heater 83, an oil separator (toxic substance separating means) 85 and a feed pump 86 wider than the cleaning tank 11 are provided.

Therefore, by operating the circulation pump 23 and circulating the solvent through the circulation pipe 24 into the cleaning tank 11 for a predetermined time, the organic substances contained in the contaminated soil, that is, oil, PC
Extract harmful substances such as B and dioxin. At this time, the extraction solvent is fed to the oil separator 85, where harmful substances such as oil, PCB, and dioxin that have been separated from the soil particles float up to form a layer. Then, the solvent from which the harmful substances have been separated by the oil separator 85 is returned to the cleaning tank 11 by the feed pump 86. In this case, in order to promote the formation of the floating layer of the harmful substance in the oil separator 85, the circulation flow rate of the solvent by the circulation pump 23 and the feed pump 86 is set to be equal to or lower than the floating speed of the harmful substance, so that the solvent and the harmful substance are separated from each other. It is desirable to allow the phase separation of.

When the concentration of the harmful substance detected by the concentration sensor 84 is equal to or higher than the solubility in the solvent, the harmful substance such as oil or PCB which cannot be dissolved in the cleaning tank 11 is separated from the soil particles and floats. The circulating amount of the solvent to the cleaning tank 11 is increased to overflow the harmful substances such as oil and PCB that are floating, and are discharged to the storage unit 80 to be separately treated by the organic substance treatment device 48. Further, the harmful substance floating in the oil separator 85 is also fed to the organic substance treatment device 48 by the discharge pump 81 for treatment.

Thus, the oil and PC floating in the washing tank 11
B, dioxin, and other harmful substances are overflowed and discharged to the storage section 80, separately processed by the organic substance processing device 48, and the extraction solvent is sent to the oil separator 85 to separate oil, PCB, and dioxin from the soil particles. Hazardous substances such as are floated and separated, and solvent is washed again 1
Since the solvent is circulated and the contaminated soil is purified, the extraction solvent can be purified, and the number of times the solvent circulation work is repeated in the cleaning tank 11 is reduced to improve the work efficiency of the soil purification work. Can be improved.

In the polluted soil purifying apparatus of the third embodiment,
As shown in FIG. 4, a storage unit 80 is provided at the upper end of the cleaning tank 11.
Further, the circulation pipe 24 of the cleaning tank 11 is provided with a harmful substance separating device 87 and a feed pump 88. The harmful substance separating device 87 has a resin-filled layer 89 through which a circulating solvent is circulated.
9 is composed of a resin filler having an affinity for harmful substances. Then, the storage section 80 is provided with the harmful substance separating device 87 via the harmful substance discharge pipe 91 having the discharge pump 90.
Are linked to.

Therefore, the circulation pump 23 and the circulation pipe 24
By circulating the solvent through the cleaning tank 11 for a predetermined period of time, organic substances contained in the contaminated soil, that is, harmful substances such as oil, PCB, and dioxin are extracted. At this time, the circulation amount of the solvent to the cleaning tank 11 is increased, and the harmful substances such as floating oil and PCB are overflowed and discharged to the storage section 80, and the discharge pump 90 is operated to be harmful by the harmful substance discharge pipe 91. The substance is fed to the substance separation device 87. Further, the extraction solvent is also fed to the harmful substance separating device 87 and flows through the resin-filled layer 89, so that the droplet-like harmful substance floats and becomes a layer. Then, the solvent from which the harmful substances have been separated by the harmful substance separating device 87 is returned to the cleaning tank 11 by the feed pump 88.

Thus, the oil and PC floating in the washing tank 11
B, dioxin and other harmful substances are overflowed and discharged to the storage part 80 and sent to the harmful substance separation device 87, and the extraction solvent is also sent to the harmful substance separation device 87 and oil separated from the soil particles, PCB , Hazardous substances such as dioxins are floated and separated, and the solvent is returned to the washing tank 11 again, and the solvent can be circulated to purify the contaminated soil to purify the extraction solvent. It is possible to improve the work efficiency of the soil purification work by reducing the number of repetitions of the solvent circulation work of.

In the contaminated soil purification apparatus of the fourth embodiment,
As shown in FIG. 5, a harmful substance treatment device 94 is connected to the lower end of the cleaning tank 11 via a harmful substance discharge pipe 93 having a discharge pump 92. Further, the circulation pipe 24 of the cleaning tank 11 is provided with a harmful substance separating device 95 and a feed pump 96.

Therefore, by operating the circulation pump 23 and circulating the solvent through the circulation pipe 24 into the cleaning tank 11 for a predetermined time, the harmful substances contained in the contaminated soil are extracted. At this time, harmful substances that cannot be dissolved in the washing tank 11 are separated from the soil particles, but harmful substances having a specific gravity heavier than the specific gravity of the solvent are precipitated. Therefore, the discharge pump 92 is operated to remove the precipitated harmful substances from the harmful substance discharge pipe. It is discharged to the harmful substance processing device 94 by 93, and is detoxified here. In addition, the extraction solvent is fed to the harmful substance separating device 95, where the harmful substance having a high specific gravity separated from the soil particles is precipitated, and the solvent from which the harmful substance has been separated is returned to the cleaning tank 11 by the feed pump 96.

Thus, the harmful substances precipitated in the cleaning tank 11 are discharged and separately processed by the organic substance processing device 94, and the extraction solvent is sent to the harmful substance separating device 95 to remove the harmful substances separated from the soil particles. The solvent is circulated again by precipitating and separating, and the solvent is returned to the washing tank 11. The solvent can be circulated to purify the contaminated soil and the extraction solvent can be purified. Can be reduced to improve the work efficiency of soil remediation work.

In the above embodiment, the cleaning tank 11 is used.
A harmful organic substance contained in contaminated soil by supplying a solvent into the contaminated soil to separate harmful organic substances (for example, oil, PCB, dioxin, etc.) and supplying a cleaning liquid into the cleaning tank 11. Although it has been designed to separate heavy metals such as mercury and lead, cyanides, etc., the processing order may be reversed, and only the solvent or the cleaning solution may be used depending on the type of harmful substances contained in the contaminated soil. You may supply only and may perform a purification process.

[0064]

As described above in detail in the embodiment, according to the polluted soil purifying apparatus of the invention of claim 1,
Floating or settling in the cleaning tank in the cleaning device for the contaminated soil that separates harmful substances contained in the contaminated soil by pouring the contaminated soil into the cleaning tank and supplying the cleaning liquid to dip and wash the contaminated soil. Since the harmful substance discharging means for discharging the harmful substance and the harmful substance treating means for treating the harmful substance discharged by the harmful substance discharging means are provided, the cleaning liquid liquid in the cleaning tank during the cleaning process of the contaminated soil. Since harmful substances that cannot be dissolved on the surface float or precipitate, this harmful substance is discharged by the harmful substance discharge means and detoxified by the harmful substance treatment means, thereby shortening the cleaning treatment time in the cleaning tank, The work efficiency of soil purification work can be improved.

According to the polluted soil purifying apparatus of the second aspect of the present invention, the harmful substance discharging means is a storage part for receiving the floating harmful substance overflowed from the washing tank, and the harmful substance in the storage part is treated with the harmful substance. Since it is configured with the transporting means for transporting to the means, it is possible to overflow the harmful substances floating on the surface of the cleaning liquid in the cleaning tank and easily discharge them to the storage part, and at the same time, transport the harmful substances in the storage part by the transfer means. It can be quickly transported to the hazardous substance processing means.

According to the polluted soil purifying apparatus of the third aspect of the present invention, the purifying liquid circulating means for circulating the purifying liquid in the cleaning tank, and the harmful substance for separating the harmful substance from the purifying liquid circulating by the purifying liquid circulating means. Since the separation means is provided, the purification treatment of the extraction purification liquid can be performed during the cleaning work of the contaminated soil by circulating the purification liquid, and the number of repetitions of the purification liquid circulation work in the cleaning tank can be reduced to reduce the soil. The work efficiency of the cleaning work can be improved.

In the polluted soil purifying apparatus according to the fourth aspect of the present invention, since the harmful substance separating means is the oil separator, the harmful substance can be easily separated from the extracted and purified liquid with a simple structure.

According to the contaminated soil purifying apparatus of the fifth aspect of the present invention, since the harmful substance separating means is a resin-filled layer for circulating the circulating purifying liquid, extraction is performed with a simple structure without increasing the installation area. It is possible to easily separate harmful substances from the cleaning liquid.

According to the contaminated soil purifying apparatus of the invention of claim 6, since the heating means for heating the cleaning liquid is provided, the cleaning liquid circulated by the heating means is heated to raise the temperature, thereby removing harmful substances. The solubility can be improved, and the viscosity of the harmful substance attached to the soil particles can be reduced to promote peeling.

According to the method for purifying contaminated soil of the seventh aspect of the present invention, the harmful substance contained in the contaminated soil is obtained by introducing the contaminated soil into the cleaning tank and supplying the cleaning liquid to dip and wash the contaminated soil. While separating the pollutants, the harmful substances floating in the cleaning tank were overflowed and discharged.Therefore, during the cleaning process of contaminated soil, the harmful substances floating on the surface of the cleaning liquid in the cleaning tank can be easily discharged. By performing the detoxification process by using the detoxification process, the cleaning process time in the cleaning tank can be shortened and the work efficiency of the soil cleaning work can be improved.

According to the method for purifying contaminated soil of the eighth aspect of the present invention, the harmful substance contained in the contaminated soil is obtained by introducing the contaminated soil into the washing tank and supplying the cleaning liquid to dip and wash the contaminated soil. While separating the toxic substances, the harmful substances that precipitate in the cleaning tank are discharged and treated.Therefore, the harmful substances that precipitate in the cleaning tank should be easily discharged during the cleaning process of contaminated soil to detoxify them. Thus, it is possible to shorten the cleaning treatment time in the cleaning tank and improve the work efficiency of the soil cleaning work.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a contaminated soil purification device according to a first embodiment of the present invention.

FIG. 2 is an overall schematic diagram of a contaminated soil purification system showing a contaminated soil purification apparatus of the present embodiment.

FIG. 3 is a schematic configuration diagram showing a contaminated soil purifying apparatus according to a second embodiment.

FIG. 4 is a schematic configuration diagram showing a contaminated soil purification device according to a third embodiment.

FIG. 5 is a schematic configuration diagram showing a contaminated soil purifying apparatus according to a fourth embodiment.

[Explanation of symbols]

11 washing tank 13 Refining solvent tank 14,15 Dissolved solvent tank 16 Cleaning solution tank 18 Supply piping 21 Discharge pipe 24 Circulation piping (cleaning liquid circulation means) 35 Purification unit 36 Solvent Purifier 37 Cleaning solution purifier 38 Dryer 48 Organic substance treatment equipment (hazardous substance treatment means) 71 tank body 72 Lid 77 Filtration filter 80 Storage part (hazardous substance discharge means) 81 discharge pump 82 Hazardous substance discharge pipe (transportation means) 83 Steam heater (heating means) 84 Concentration sensor 85 Oil separator (means for separating harmful substances) 87,95 Hazardous substance separation device 89 Resin-filled layer 94 Hazardous substance processing equipment

Continued front page    (72) Inventor Hideo Suzuki             1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo             No. Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Naoyuki Uejima             2-1-1 Niihama, Arai-cho, Takasago City, Hyogo Prefecture             Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Akihiro Hamasaki             2-1-1 Niihama, Arai-cho, Takasago City, Hyogo Prefecture             Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Taku Arikawa             2-1-1 Niihama, Arai-cho, Takasago City, Hyogo Prefecture             Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. F-term (reference) 4D004 AA41 AB02 AB06 AB07 CA40                       CA42 CC03 CC04 CC12                 4D051 AA01 AA02 AB02 BA10                 4D056 AB03 AB08 AB17 AC06 AC21                       AC22 BA11 CA03 CA11 CA17                       CA20 CA22 CA26 CA27 CA34                       CA39 CA40 DA05

Claims (8)

[Claims] 1. A contaminated soil purifying device for separating harmful substances contained in the contaminated soil by dipping and cleaning the contaminated soil by feeding the contaminated soil into the cleaning tank and supplying the cleaning liquid. A polluted soil characterized by comprising a harmful substance discharging means for discharging a harmful substance floating or settling in the washing tank, and a harmful substance treating means for treating the harmful substance discharged by the harmful substance discharging means. Purification device. 2. The harmful substance discharging means according to claim 1, wherein the harmful substance discharging means conveys the floating harmful substance overflowed from the cleaning tank to the harmful substance processing means. An apparatus for purifying contaminated soil, comprising: a transportation means. 3. The cleaning liquid circulating means according to claim 1, wherein the cleaning liquid is circulated in the cleaning tank, and the harmful substance separating means for separating harmful substances from the cleaning liquid circulated by the cleaning liquid circulating means. A device for purifying contaminated soil, which is characterized by being provided. 4. The apparatus for purifying contaminated soil according to claim 3, wherein the harmful substance separating means is an oil separator. 5. The apparatus for purifying contaminated soil according to claim 3, wherein the harmful substance separating means is a resin-filled layer for circulating the circulating cleaning fluid. 6. The purification apparatus for contaminated soil according to claim 1, further comprising heating means for heating the purification liquid. 7. The toxic substance contained in the contaminated soil is separated by pouring the contaminated soil into the cleaning tank and supplying a cleaning liquid to dip and wash the contaminated soil, while floating in the cleaning tank. A method for purifying contaminated soil, characterized in that toxic substances that are discharged are overflowed and discharged. 8. The toxic substance contained in the contaminated soil is separated by pouring the contaminated soil into the cleaning tank and supplying a cleaning liquid to dip and wash the contaminated soil, while precipitating in the cleaning tank. A method for purifying contaminated soil, which comprises discharging and treating harmful substances.