JPH11347533A - Bioremediation apparatus for dioxins - Google Patents

Abstract

PROBLEM TO BE SOLVED: To treat stably a soil contaminated by a PCB and dioxin by applying a microorganism of a bacillus subtilis or the like to a place contaminated by the PCB.dioxin of a low concentration over a wide area. SOLUTION: Microorganism decomposition by a thermophinlic bacteria microorganism such as a bacillus subtilis or the like is accelerated by irradiating a soil and an incimeration ash which contain PCB and dioxin with ultraviolet rays. Further, in order to accelerate further the microorganism decomposition, a more effective aerobic fermentation is enabled by using a transfer type rotary roller and a stirring paddle. In execution, treatment material is entered about 100 cm from a surface soil, stirred by cutting back 20 to 80 cm part from the surface soil to make ventilation of air good, and an apparatus which executes efficiently the aerobic fermentation is used. The dioxin becomes thereby decomposable by microorganism by allowing a thermophilic bacteria to act thereon in the place without carrying the contaminated soil to an apparatus assembled at another place, and a dioxin concentration existing in the soil is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This technology is used for the purpose of restoring the original safe standard by using microorganisms on soil degraded or contaminated with chemical substances such as dioxin by incinerators and the like. SUMMARY OF THE INVENTION It is an object of the present invention to effectively perform bioremediation in a site that is contaminated with a low concentration of PCB / dioxin over a wide range.

[0002]

2. Description of the Related Art In general, dioxin-contaminated soil is generally excavated or slurried and then solidified using a technique such as supercritical water or incinerated. However,
From a cost-effective point of view, this method is suitable for small areas of high concentration, but not for low concentration of widely distributed areas. Also, incineration has a problem that the structure of the furnace is difficult and it is difficult for the residents to persuade. In order to solve these problems, various bioremediation degradation methods have been devised.

[0003] These bioremediation is a method in which oxygen and nutrients are given to decomposing bacteria in the environment to activate them.
There is a method to select and spray bacteria with high resolution, but PCB
And the ability to decompose dioxins is insufficient. Optimum conditions and methods and equipment for decomposition have not been established

[0004]

[Problems to be Solved by the Invention] Dioxins used in the Vietnam War are still present after decades, and it is reported in the news that they are afflicting the people of Vietnam. On the other hand, it is true that dioxin is gradually decomposed year by year. This is because natural microorganisms that live in hot areas are decomposing. These high-temperature bacteria active at high temperatures are mixed in the building having the structure as shown in FIG.
It aims to decompose dioxin efficiently.

[0005]

Means for Solving the Problems 1) Microorganisms can be actively decomposed by irradiating ultraviolet rays to soil or incineration ash containing PCB / dioxin.

Action 1 In the present invention, it has been confirmed that when a high-temperature bacterium adheres to a polymer compound whose surface has been hydrophilized by irradiating an ultraviolet lamp as shown in FIG. 1, microbial decomposition is promoted.

[0006]

Means for Solving the Problems 2) Aerobic and high-temperature microorganisms are converted to PCB
・ By adding to dioxin-containing soil, the decomposition ability is enhanced and the reaction speed is increased.

[Action 2] It has been demonstrated that thermophilic microorganisms such as Bacillus subtilis used in the present invention can decompose rubber foamed at a high temperature using a freeze-thaw apparatus.

[0007]

Means for Solving the Problems 3 In order to further promote microbial decomposition, more efficient aerobic fermentation can be performed by using a movable rotary roller or a stirring paddle.

[Function 3] In the present invention, as shown in FIG. 1, a treated material is put in about 100 cm from the topsoil, and a portion of 20 to 80 cm from the topsoil is cut back to stir to improve air ventilation and efficiently perform aerobic fermentation. The device was realized.

[0008]

Means for Solving the Problems 4 Soil contaminated with PCB and dioxin is to be treated on site.

[Function 4] By constructing and using a prefabricated reaction tank as shown in FIG. 1, microorganisms can be decomposed and contaminated soil can be returned to safe soil. As a result, the dioxin can be microbially decomposed by the action of thermophilic bacteria on the spot without transporting the contaminated soil to a device assembled elsewhere, thereby reducing the dioxin concentration in the soil.

[0009]

Means for Solving the Problems 5 In order to more stably treat soil contaminated with PCB / dioxin, a secondary material or a fermentation promoter is administered.

[Function 5] By adding a substance mainly composed of lignin as an auxiliary, the microorganisms increase the decomposition rate.

[Brief description of the drawings]

FIG. 1 is a simple configuration diagram of the present invention.

[Explanation of symbols]

 (1) Ultraviolet lamp (for night use) (2) Ultraviolet transparent sheet or glass (3) Exhaust port (3) Exhaust port (4) Stirring paddle (self-feeding type or chain drive)

Claims (5)

[Claims] 1. A microorganism such as Bacillus subtilis bacterium is
Used for decomposition of CB / dioxin. 2. A process according to claim 1, wherein the reaction device shown in FIG. 1 is prepared and used so that the contaminated soil is processed without moving. 3. In the treatment according to claim 1, PCBs and dioxins containing trace amounts can be uniformly treated by using the apparatus shown in FIG. 4. The processing according to claim 1, wherein
By using an ultraviolet ray transmitting sheet or glass shown in (2), ultraviolet rays from the sun are transmitted and used effectively. At night or on rainy days, an ultraviolet lamp shown in FIG. 1A is used. 5. In the treatment according to claim 1, it is possible to treat incineration ash discharged from the incinerator by using the apparatus shown in FIG.