JP2002018424A - Method for treating pollutant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for treating a pollutant, in which the pollutant is decomposed and treated without necessitating a large amount of bacterial beds and also without scattering contaminated soil in the surroundings. SOLUTION: A bacterial bed such as the bacterial bed of eatable bacteria having decomposing capacity of the pollutant or a waste bacterial bed is crushed and made to a pulverized state. The powdery bacterial bed is injected into polluted soil and added by using a device 5 equipped with a tank 1 housing the powdery bacterial bed, a force-feeding means 2 consisting of a force-feeding pipe 2A and a pump 2B for force-feeding the powdery bacterial bed from the tank 1, a platelike head 3 connected to the tank 1 via the force-feeding means 2 and a plurality of hollow tubular projecting parts 4. When the head 3 is pushed on the soil surface and the head surface is allowed to abut on the soil surface, the tubular projecting parts 4 are inserted into soil by only the projecting length. When the pump 2B is driven in this state, the powdery bacterial bed housed in the tank 1 is injected into soil from the tubular projecting parts 4 through the force-feeding pipe 2A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating contaminants which decomposes hardly decomposable substances contained in contaminated soil and adversely affecting the environment.

[0002]

2. Description of the Related Art In recent years, soil near a waste incineration plant has become a major social problem because it is contaminated with organochlorine compounds such as dioxin, trichloroethylene and tetrachloroethylene contained in incineration ash. In addition to organic chlorine compounds, solvents for cleaning substrates, aromatic carbohydrates such as benzopyrene, and other substances that are contaminated with contaminants that are hardly decomposable substances, such as mercury substances, have also caused problems. is there.

[0003] In addressing this problem, the present inventors have developed a bacterial bed containing a mixture of sawdust, medium additives and water in order to inoculate mushrooms, for example, white-rot fungi, and to grow their hyphae. It has been found that when mixed with contaminated soil containing substances or contaminants, the contaminants are decomposed by the synergistic effect of the growing mycelium and the decomposing enzyme generated by the fungi. In this specification, a bacterial bed for inoculating and growing edible mushrooms is particularly referred to as an edible bacterial bed. In addition, the present inventors have collected used mushrooms grown on the above-mentioned fungus bed, and used the fungus bed, which was conventionally discarded when the waste fungus bed was mixed with the contaminants or contaminated soil. Also found that pollutants were similarly degraded.

[0004] Therefore, it is conceivable to treat the contaminants by pulverizing the bacterium beds such as the edible microbial bed and the waste microbial bed, and mixing and pulverizing the pulverized material with the contaminated soil using a large-sized machine. Can be

[0005]

However, in the conventional method using a large machine, a bacterial bed is mixed with the entire contaminated soil, so that a large amount of the bacterial bed must be mixed with the soil. Was. Further, when the contaminated soil is stirred and mixed using a large-sized machine, there is a problem that the contaminated soil is scattered around.

By the way, as seen in dioxins, many contaminants have high hydrophobicity, so that most of them do not penetrate deep into the soil, but only about 5 to 30
It was found to penetrate only to a depth of cm. From this, it became clear that it was not necessary to mix a large amount of bacterial beds into the entire contaminated soil as in the prior art, and it was only necessary to add it to the surface layer of the soil.

Accordingly, an object of the present invention is to provide a pollutant treatment method capable of decomposing a pollutant without requiring a large amount of bacterial beds and without scattering contaminated soil around.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for inserting one or more tubes into a contaminated soil to a predetermined depth.
A method for treating contaminants by inserting a bacterial bed or a crushed product thereof or a bacterial bed in a suspension form through this tube is proposed. The present invention also proposes a method for treating contaminants by spraying or injecting a solution or suspension of a bacterial bed on contaminated soil. In the above method, the bacterial bed is
It may be an edible bacterial bed or a waste bacterial bed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Example 1 First, a bacterial bed (edible bacterial bed or waste bacterial bed) capable of decomposing contaminants is ground into a powder. For example, as schematically shown in FIG. 1, a tank 1 for accommodating the powdered bacterial bed and a pumping means 2 comprising a pumping pipe 2A and a pump 2B for pumping the powdered bacterial bed from the tank 1. And a plate-shaped head 3 connected to the tank 1 via the pumping means 2 and attached to the end of the arm A of the movable heavy machine M, and a plurality of hollow tubular projections protruding from the head 3 The powdered bacterial bed is injected and added to the contaminated soil by using the apparatus 5 including the section 4. Specifically, when the head 3 is pressed against the soil surface by operating the arm A of the heavy equipment M to bring the head surface into contact with the soil surface, the tubular projection 4 protruding from the head 3 has a protrusion length. Minutes are inserted into the soil. When the pump 2B is driven in this state, the powdered bacterial bed stored in the tank 1 is injected into the soil from the tubular protrusion 4 through the pressure pipe 2A. Here, the length of the tubular projection 4 is about 5 to
The depth is set at 30 cm, preferably about 15 to 25 cm, and the depth at which the powdered bacterial bed is injected is about 5 to 30 cm, preferably about 15 to 25 cm from the ground surface. This is because many contaminants are highly hydrophobic and only exist at a depth of about 5 to 30 cm from the soil surface.

[0010] After several weeks, hyphae grow from the bacterial bed mixed with the waste, and decomposing enzymes are generated during this growth process. The contaminants in the waste are decomposed and made harmless by the synergistic effect of the grown hypha and the decomposing enzyme. For example, in the case of anthracene, pyrene and phenanthrene, 200 ppm is reduced by 90% in one month, and in case of benzpyrene, it is reduced by 60%. For dioxin, 20,000 pgTEQ / g is reduced by about 60% in 2 months.

In this embodiment, by operating the arm A, the angle of the head 3 provided with the tubular protrusion 4 can be changed arbitrarily, so that even if the target soil is inclined as shown in FIG. Can be supplied.

Example 2 First, a bacterial bed (edible bacterial bed or waste bacterial bed) capable of decomposing contaminants is ground into a powder. Then, as shown in FIG.
cm, preferably about 15 to 25 cm, is inserted into the surface of contaminated soil containing contaminants near the waste incineration plant by using a sheep foot roller 7 having a plurality of protrusions 6 having a depth of about 5 cm. After drilling a hole of 〜30 cm, preferably about 15-25 cm, a powdery bacterial bed is inserted into this hole. In this embodiment, as in the first embodiment, the contaminants in the contaminated soil can be decomposed by the synergistic effect of the hypha and the decomposing enzyme grown from the bacterial bed.

<< Example 3 >> A bacterial bed (edible bacterial bed or waste bacterial bed) capable of decomposing contaminants is pulverized into powder, which is dissolved in water to prepare a suspension. The suspension is then spread on the surface of contaminated soil containing contaminants near the waste incineration plant using a ripping chiller used to spray liquid fertilizer to penetrate the surface layer of the soil.
After the spraying, if necessary, the surface of the soil may be leveled by using means such as a rake so that the contaminated soil does not scatter around. In this embodiment, as in the first embodiment, the contaminants in the contaminated soil can be decomposed by the synergistic effect of the hypha and the decomposing enzyme grown from the bacterial bed.

[0014]

According to the configuration of the present invention in which a bacterial bed having a capability of decomposing contaminants is injected, inserted or penetrated from the surface of the contaminated soil to a predetermined depth, it is not necessary to use a large-sized machine. The contaminants can be effectively decomposed without being scattered around. Further, since the bacterial bed is supplied only to the surface layer of the contaminated soil, the amount of the bacterial bed can be reduced and the operation can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a method for treating contaminants of the present invention.

FIG. 2 is a schematic view showing another embodiment of the method for treating pollutants of the present invention.

FIG. 3 is a schematic view showing still another embodiment of the method for treating contaminants of the present invention.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiya Okada 4-640 Shimoseito, Kiyose-shi, Tokyo F-term in Obayashi Corporation Technical Research Institute Co., Ltd. 4B065 AA71X BB04 BC41 BC50 CA27 CA56 4D004 AA41 AB03 AB05 AB06 AB07 AC07 CA18 CA50 CC07

Claims (3)

[Claims] 1. A method comprising inserting one or more tubes into a contaminated soil to a predetermined depth, and injecting a bacterial bed or a crushed product thereof, or a solution or suspension of the bacterial bed through the tubes. Pollutant treatment method. 2. A method for treating contaminants by spraying or pouring a solution or suspension of a bacterial bed onto contaminated soil. 3. The method according to claim 1, wherein the bacterial bed is an edible bacterial bed or a waste bacterial bed.