JPH07112176A - Contaminated soil restoration device and contaminated soil restoration method using the same - Google Patents

Abstract

(57) [Summary] [Purpose] Contaminated soil can be treated efficiently and safely in situ by using microorganisms without the need for adsorption treatment with activated carbon. [Constitution] In the contaminated soil remediation device 10, a submersible pump 14 for pumping groundwater in the shaft 12 is installed in the groundwater.
A vacuum pump 16 for sucking the air in the shaft 12 is arranged on the wall surrounding the opening 2. The vacuum pump 16 is
A gas phase bioreactor 20 containing a microorganism having a function of decomposing pollutants is connected to a lower portion of a treatment tank 22 installed therein via a blower 18. Also,
The submersible pump 14 is connected to the upper part of the processing tank 22 by a pipe 24. The pollutants in the air and groundwater supplied into the treatment tank 22 by these are decomposed by coming into contact with the gas phase bioreactor 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contaminated soil remediation apparatus and an efficient contaminated soil remediation method using the same.

[0002]

2. Description of the Related Art In recent years, as a solution to the environmental pollution problem, various attempts have been made to remove pollutants from soil contaminated with organic substances and restore the soil. A method has been proposed in which a substance is sucked using a vacuum pump and treated with activated carbon.

However, according to the vacuum suction method, contaminants are adsorbed and removed by activated carbon, so that the adsorption efficiency is low, and it is difficult to treat a substance containing a large amount of water.
Efficient treatment was difficult due to the problem of reprocessing used activated carbon that adsorbed pollutants.

[0004]

The object of the present invention is that treatment of contaminated soil can be performed efficiently and without the problem of secondary contamination by using microorganisms without the need for treatment with activated carbon. An object of the present invention is to provide an apparatus and an efficient method for repairing contaminated soil using the apparatus.

[0005]

[Means for Solving the Problems] Claim 1 according to the present application
The described invention comprises a submersible pump for pumping groundwater containing pollutants in the shaft and a vacuum pump for sucking air in the shaft, and the groundwater and pollutants contained in the air extracted by the vacuum pump A treatment tank in which a gas phase bioreactor for decomposing is installed, and a liquid transfer means for supplying the groundwater from the upper portion of the treatment tank,
The present invention relates to a contaminated soil remediation device including a blower for supplying the air from the lower part of the treatment tank.

According to the second aspect of the present invention, the groundwater containing pollutants is pumped up by an underwater pump, and the air containing the pollutants in the soil is sucked by a vacuum pump to decompose the groundwater into pollutants. Is supplied from the upper part of a treatment tank in which a gas phase bioreactor containing microorganisms is installed to contact the gas phase bioreactor, and the air is supplied from the lower part of the treatment tank by a blower to contact the gas phase bioreactor, and ground water And a method for remediating contaminated soil, characterized by decomposing contaminated organic substances in air and discharging treated water and air.

[0007]

The polluted soil remediation device of the present invention pumps up groundwater containing pollutants in the shaft by means of a submersible pump. Further, the air in the vertical shaft is sucked by the vacuum pump. Next, the ground water supplied from the upper part and the air supplied by the blower from the lower part are brought into contact with the gas phase bioreactor in the treatment tank in which the gas phase bioreactor containing the microorganism that decomposes pollutants is installed. As a result, pollutants are decomposed, and then liquid components and air are discharged, so that organic components such as trichlorethylene, which is particularly problematic as a harmful substance, are efficiently extracted from the soil,
Can be processed. Furthermore, since the pollutants are treated by utilizing the decomposition action of microorganisms, there is no problem of secondary pollution.

[0008]

The present invention will be described in more detail below. (Example 1) The contaminated soil restoration apparatus of the present invention will be described in detail.

FIG. 1 is a schematic diagram of a contaminated soil restoration device 10. The contaminated soil restoration device 10 of this embodiment includes a vertical shaft 12
A submersible pump 14 for pumping the groundwater therein is disposed in the groundwater. Also, on the wall body surrounding the opening of the vertical shaft 12,
A vacuum pump 16 for sucking air in the shaft 12 is provided. Further, the vacuum pump 16 is connected via a blower 18 to a lower portion of a treatment tank 22 in which a gas phase bioreactor 20 containing a microorganism having a function of decomposing contaminants is installed. The submersible pump 14 is connected to the upper portion of the processing tank 22 by a pipe 24. The air sucked by the vacuum pump 16 is blower 1
8 is blown into the treatment tank 22 from the lower portion of the treatment tank 22, and groundwater flows through the gas phase bioreactor 20 by flowing down from the upper portion and circulates in the treatment tank 22 to come into contact with the gas phase bioreactor 20.

A publicly known double vacuum extraction device or the like may be used as an example of the contaminant extraction device in which the submersible pump 14 and the vacuum pump 16 are combined.

The gas-phase bioreactor 20 in the treatment tank 22 used in this embodiment is preferably one in which microorganisms having a function of decomposing pollutants extracted from soil are immobilized.

The immobilization material used in the gas phase bioreactor 20 may be selected appropriately depending on the microorganism.
For example, organic porous materials such as peat moss and polyurethane resin can be used. The immobilization material preferably has a porous structure such as a filter in order to improve the contact area with the gas-liquid that has extracted the contaminants, but a spherical immobilization material is used and held by a holder through which the gas-liquid can pass. It is also possible to use the prepared one. The bioreactor using the microorganisms immobilized on the immobilization material may be used as one layer, but it is preferable that the bioreactor form multiple layers in terms of processing efficiency.

Next, the method for repairing contaminated soil according to the present invention will be described in detail. In recent years, pollution with persistent substances, especially organic chlorides such as trichlorethylene, has become more serious year by year, and it has been desired to establish a treatment method using microorganisms.
The treatment method using the contaminated soil restoration device 10 of the present embodiment is
Particularly effective for trichlorethylene. Trichlorethylene accumulates in soil, but it can be extracted from soil in the gas phase by vacuum extraction. Therefore, the submersible pump 14 installed in the underground water system in the vertical shaft 12 is used to pump up the groundwater containing trichlorethylene, and at the same time, the vacuum pump 16 is used to pump the trichlorethylene in the soil.
Aspirate with the air inside.

Ground water containing pollutants is pumped by a pump 14
It is pumped up by the pump, pressure-fed in the pipe 24, and supplied to the upper portion of the processing tank 22. When groundwater or the like flows down in the treatment tank 22, it comes into contact with the gas phase bioreactor 20 and decomposes trichlorethylene. The supply of the groundwater into the treatment tank 22 is preferably performed so as to be dispersed over a wide area by a sprinkler or the like in order to increase the contact area with the gas phase bioreactor 20. If desired, a pump, a pipe or the like for recirculating the liquid phase from the bottom of the processing tank 22 to the upper supply port may be installed. The treated liquid component is discharged after the biosensor 26 confirms that trichlorethylene is decomposed and removed. Air is blown into the treatment tank 22 from the lower portion of the treatment tank 22 by the blower 18, circulates in the treatment tank 22 and comes into contact with the gas phase bioreactor 20, and trichlorethylene existing in a gas state in the air is decomposed. The gas phase from which trichlorethylene has been decomposed and removed is exhausted to the atmosphere.

The microorganisms used in the gas phase bioreactor include, for example, Pseudomonas putida, a type of Pseudomonas bacterium.
), Pseudomonas cepacia
) Etc. are known. As a material used for immobilizing microorganisms, a peat moss porous body or the like is preferably used.
According to this method, soil can be efficiently repaired in-situ without the need for large-scale excavation, and since trichlorethylene is decomposed and removed by microorganisms, conventional physical adsorption such as activated carbon is not required. As with the removal, the treatment of the adsorbent itself does not pose a problem and there is no problem of secondary contamination accompanying the treatment.

[0016]

EFFECTS OF THE INVENTION By carrying out the method for remediating contaminated soil using the contaminated soil remediation apparatus of the present invention, excavation and movement of soil and treatment with activated carbon are not required, and the use of microorganisms also causes the problem of secondary contamination. In other words, it shows an excellent effect that the contaminated soil can be efficiently treated in situ.

[Brief description of drawings]

FIG. 1 is a schematic view of a contaminated soil restoration device.

[Explanation of symbols]

 10 Contaminated Soil Restoration Device 14 Submersible Pump 16 Vacuum Pump 18 Blower 20 Gas Phase Bioreactor 22 Treatment Tank 24 Pipe (Liquid Transfer Means)

Claims (2)

[Claims] 1. A submersible pump for pumping groundwater containing pollutants in the shaft, and a vacuum pump for sucking air in the shaft. The groundwater and pollutants contained in the air extracted by the vacuum pump are provided. A treatment tank in which a gas phase bioreactor for decomposing is installed, and a liquid transfer means for supplying the groundwater from the upper portion of the treatment tank,
And a blower for supplying the air from the lower part of the treatment tank. 2. A gas phase bioreactor containing microorganisms that decompose pollutants into groundwater by pumping groundwater containing pollutants with a submersible pump and sucking air containing soil pollutants with a vacuum pump. The gas is supplied from the upper part of the treatment tank and brought into contact with the gas-phase bioreactor, and the air is supplied from the lower part of the treatment tank by a blower and brought into contact with the gas-phase bioreactor,
A method for remediating contaminated soil, which comprises decomposing contaminated organic substances in groundwater and air and discharging the treated water and air.