JP2002018425A - 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 having treatment capacity of the pollutant is crushed and made to a pulverized state. The powdery bacterial bed is charged in the trailer part 2 of a device M and the powdery bacterial bed 1 is disseminated on the surface layer of contaminated soil containing the pollutant in the vicinity of e.g. the incinalation site of waste from a scattering port 3 disposed in the trailer part 2. At the same time as the scattering work, the powdery bacterial bed 1 scattered by using a miniature plough 4 fitted to the trailer part 2 is ploughed in the surface layer part of soil. In this case, ploughing work is performed so that contaminated soil is not scattered in the surroundings.

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 pollutants which decomposes hard-to-degrade pollutants 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, and it has been found that most contaminants do not penetrate deep into the soil but remain near the surface. 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]

According to the present invention, there is provided a method for inserting a fungus bed or a crushed product thereof into a contaminated soil to a predetermined depth, for example, 5 cm to 30 cm, preferably 15 cm to 25 cm from the ground surface, or At the same time as or after spraying or injecting the dissolving solution of the above, only the surface layer of this soil, for example, 5 cm to 30 cm, preferably 15 cm to
We propose a method for treating pollutants by mixing the bacterial bed into contaminated soil by stirring 25 cm. In this method, the bacterial bed may be an edible bacterial bed or a waste bacterial bed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method for treating pollutants of the present invention will be described below. First, a bacterial bed (edible bacterial bed or waste bacterial bed) capable of treating contaminants is pulverized into powder. Then, the powdered bacterial bed 1 is filled in a trailer unit 2 of an apparatus M as shown in FIG. 1, and a spout 3 provided in the trailer unit 2 is used to remove contaminated soil containing contaminants near a waste incineration plant, for example. The powdered bacterial bed 1 is spread on the surface layer. Simultaneously with this spraying operation, the powdered bacterial bed 1 sprayed using the small plows 4 attached to the trailer unit 2 is thrown into the surface layer of the soil. At this time, plowing work is performed so that the contaminated soil does not fly around.

[0010] After several weeks, hyphae grow from the plowed fungal bed, and decomposing enzymes are generated during this growth process. The contaminants present on the surface of the contaminated soil are decomposed and made harmless by the synergistic effect of the grown mycelium 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.

[0011] After plowing the powdered bacterial bed into the contaminated soil,
If the plowing operation is performed again at the time when the hypha grows in the soil, for example, about one month after the application, the mycelium can be evenly distributed in the soil, and the decomposition treatment of the pollutant can be further promoted.

In the above-described embodiment, the structure in which the powdered bacterial bed is sprayed from the spraying port 3 of the apparatus M as shown in FIG. 1 has been described. However, any means capable of spraying the bacterial bed on the surface of the soil can be used. Any one may be used.

Although the plows 4 are used for plowing the scattered bacterial bed, actually, any means can be used as long as the bacterial bed can be plowed into the surface layer of the soil. Is also good. Further, in the above-described embodiment, the bacterial bed crushed into a powder is sprayed. However, a solution in which the bacterial bed is dissolved may be sprayed or injected onto the contaminated soil.

[0014]

According to the structure in which the bacterial bed having the ability to decompose pollutants is sprayed only on the surface layer of the contaminated soil and the sprayed bacterial bed is plowed into the surface layer of the soil, it is not necessary to use a large-sized machine. In addition, the pollutants can be effectively decomposed without scattering the contaminated soil to the surroundings. Also, since the bacterial bed is sprayed only on 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 pollutant treatment method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Powder bed 2 Trailer part 3 Spray port 4 Plow

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hirokazu Tsuji 4-640 Shimoseito, Kiyose-shi, Tokyo F-term in Obayashi Corporation Technical Research Institute Co., Ltd. 4B065 AA57X AC20 BC31 BC50 CA56 4D004 AA41 AB03 AB05 AB06 AB07 AC07 CA15 CA18 CA50 CC07

Claims (2)

[Claims] 1. Inserting a bacterial bed or a crushed product thereof to a predetermined depth into a contaminated soil, or simultaneously spraying or injecting a solution of the bacterial bed, or thereafter, stirring only the surface layer of the soil. A method for treating contaminants, comprising mixing the bacterial bed into contaminated soil. 2. The method according to claim 1, wherein the bacterial bed is an edible bacterial bed or a waste bacterial bed.