JP2002153257A - Microorganism bed mat and method for cleaning soil polluted with persistent injurious substance with the mat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for safely and labor-savingly degrading persistent injurious substances accumulated in the soil polluted with exhaust gas, drainage (waste fluid), incineration ash or the like which is discharged from an incineration facility, a production installation, or the like to the natural world, and to provide a microorganism bed mat used therefor. SOLUTION: This microorganism bed mat contains the microorganism for producing an enzyme for degrading the persistent injurious substances and substances used as the nutritive sources of the microorganism and which is used for degrading the persistent injurious substances. The method for cleaning the soil polluted with the persistent injurious substances is characterized by laying the microorganism bed mat on or in the soil polluted with the persistent injurious substances to degrade the persistent injurious substances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fungus bed mat and a method for purifying soil contaminated with a hardly decomposable harmful substance using the same, and more particularly, a mat containing a hardly decomposable harmful substance decomposing bacterium. And persistent degradable harmful substances contained in soil using the same, for example, specific components in pesticides, specific degradable substances such as specific chemical substances generated during incineration of garbage and industrial waste, and polymer raw materials in the chemical industry. Decomposes and detoxifies hard-to-decompose substances used as chemicals and polymerization terminators or hard-to-decompose substances used as cleaning agents in the paper, pulp industry, precision machinery related industries, etc., and purifies the soil. It is about the method.

[0002]

2. Description of the Related Art Various hard-to-degrade chemicals, which are well known as harmful substances to human bodies, are discharged into the natural world from incineration facilities for municipal solid waste and industrial waste, various combustion facilities, equipment, and the like. In the production process of chemical substances, various organic compounds that have a bad influence on the environment are emitted, which is a major social problem. Among these substances, for example, dioxins are difficult to be decomposed by living organisms, so they are absorbed into many living organisms, and eventually accumulated and concentrated in the animal body by the food chain, resulting in carcinogenic and carcinogenic effects. It is known to have teratogenic or hormone-like effects.

[0003] Therefore, methods for suppressing the generation of dioxins and the like have been studied and proposed. For example, a method of burning exhaust gas and ash from an incinerator or the like at a high temperature has been proposed. However, even in such a method, the generation of dioxins and the like has not yet been sufficiently suppressed. The dioxins and the like released into the atmosphere fall on the ground together with rainwater and snow, and are accumulated in soil and sediment in water bodies. Thus, no effective means has been found for detoxifying dioxins and the like that have been left in the natural world. In addition, for hardly decomposable phenols, adsorption separation with activated carbon and the like, decomposition with activated sludge, etc. are performed, but halogenated phenols, alkyl phenols, bisphenols, and further phthalate esters, etc. There is a problem that it is difficult to be biologically decomposed due to its chemical structure, and it is easy to accumulate in the environment. These compounds are also bio-enriched by the food chain, causing various damages to humans and environmental organisms.

[0004] On the other hand, soil in industrial areas such as paper, pulp industry, and precision machinery-related industries contains halogenated hydrocarbon-based hard-to-decompose harmful substances such as tetrachloroethylene, trichloroethylene and dichloroethylene used as detergents. It is thought that pollution has spread to a considerable extent, and there have been many reports of cases actually detected by environmental surveys and the like. It is said that those hardly decomposable harmful substances remaining in soil are dissolved in groundwater by rainwater or the like and spread throughout the surrounding area. Since these compounds are suspected of being carcinogenic and stable in the environment, the pollution of groundwater used as a drinking water source has become a serious social problem.

[0005] Therefore, purification of an aqueous medium such as contaminated groundwater, soil, and the accompanying gas phase by removing and decomposing hardly decomposable harmful substances is a very important issue from the viewpoint of environmental conservation. Various technologies required for purification have been developed. Among them, the decomposition and purification of harmful substances accumulated in soil and river bottom mud or excess sludge of activated sludge treatment equipment is the most difficult and expensive. Methods for decomposing harmful substances such as soil and sediment include a high-temperature incineration method, a chemical decomposition method using an alkali, a decomposition method using ozone and ultraviolet rays, and a microbial decomposition method. When performing microbial degradation,
A method of activating and decomposing microorganisms living in soil by adding a nutrient to the soil has been practiced at a petroleum pollution site (N. AL-AWADHI et al .: Restoration and rehabil).
itation of the desert environment, 21-40, 1996).

[0006] On the other hand, unlike petroleum cracking, strong degrading microorganisms often do not exist in soil when polluted by hard-to-degrade harmful substances such as dioxin and trichlorethylene, and it is necessary to add degrading bacteria in addition to nutrient sources. is there. In this case, unless the degrading microorganism can use a special nutrient source, it is necessary to grow it on bran or rice bran. Since such organic nutrients serve as nutrients for indigenous microorganisms in addition to the microorganisms to be added, it is difficult to selectively grow the added microorganisms. It is difficult to achieve the purpose unless decomposing microorganisms are proliferated and prioritized. As a method for growing degraded microorganisms, a method is known in which a nutrient source is pelletized and cultured, and the pellet is mixed with soil (APPL. ENVIRON. MICROBIOL. June 1996, 2045-2052).
This method requires an operation of uniformly mixing the pellets with the soil, and there is a risk that a worker working on the contaminated soil may inhale during mixing. In addition, the work itself is difficult on a steep slope or a place where trees are growing on the contaminated area, and a machine cannot be introduced for mixing, so the method is dependent on manual work, which is not economical as a method for treating a large area.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an incineration plant,
The above accumulated in the soil contaminated by exhaust gas, wastewater (waste liquid), incinerated ash, etc., which contains persistently harmful substances discharged into the natural world from manufacturing facilities, etc., sediment in water bodies, or excess sludge in activated sludge treatment facilities A labor-saving and safe method for decomposing hard-to-decompose harmful substances, that is, (1) operation is simple,
(2) Purification can be performed at the pollution site without construction of decomposition facilities, etc. (3) Less secondary pollution due to transportation, (4)
(5) A method for purifying soil and a material used for the method, which can purify the soil while retaining the topography and natural vegetation, and (5) promote the growth of added microorganisms preferentially in the soil and promote the decomposition of hardly decomposable harmful substances. It is intended to do so.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a microorganism producing an enzyme that decomposes a hardly decomposable harmful substance inside a mat, The present inventor has found that a bacterial bed mat containing a substance serving as a nutrient source is effective in decomposing hardly decomposable harmful substances accumulated in soil, and based on these findings, completed the present invention.

That is, the gist of the present invention is as follows. (1) A microbial bed mat for decomposing hard-to-decompose harmful substances, which contains a microorganism that produces an enzyme that decomposes hard-to-decompose harmful substances and a substance that is a nutrient source of the microorganisms inside the mat. (2) The fungal bed mat according to (1), further comprising a water retention agent in addition to a substance serving as a nutrient source of the microorganism. (3) The bacterial bed mat according to (1) or (2), wherein the material of the mat is a natural fiber, a synthetic fiber, or a wire mesh. (4) The hardly decomposable harmful substance is a hardly decomposable aromatic compound having 6 or more carbon atoms, or 1 to 4 carbon atoms and at least 1
The bacterial bed mat according to any one of the above (1) to (3), which is a hardly decomposable halogenated hydrocarbon consisting of two halogen atoms. (5) The hardly decomposable aromatic compound having 6 or more carbon atoms is at least one selected from dioxins, halogenated biphenyls, bisphenols, alkylphenols, halogenated phenols and phthalic esters. ).

(6) The hardly decomposable halogenated hydrocarbon comprising 1 to 4 carbon atoms and at least one halogen atom is monochloromethane, dichloromethane, trichloromethane, tetrachloromethane, monochloroethane, dichloroethane, trichloroethane, Monochloroethylene,
The bacterial bed mat according to the above (4), which is at least one selected from dichloroethylene, trichloroethylene and trichloropropylene. (7) The bacterial bed mat according to any one of the above (1) to (6), wherein the enzyme that decomposes hardly decomposable harmful substances is laccase, lignin peroxidase, manganese peroxidase, monooxygenase or dioxygenase. (8) Microorganisms that produce enzymes that degrade hard-to-decompose harmful substances are Schizophyllum
Genus, Pleurotus, Trametes, Lentinus
us) genus, Rhizoctonia
Genus, Funaria, Pycnoporus, Merulius
ius), Myceliophto (Myceliophto)
ra), Coprinus, Agaricus, Foliota (Pholi)
ota) genus, Flammulina genus,
Genus Ganoderma, Genus Daedaleopsis, Fabolus (Fa)
volus), lyophilum (Lyophyllu)
m) genus or Auricularia
a) The fungal bed mat according to any one of the above (1) to (7), which is a microorganism belonging to the genus.

(9) The bacterial bed mat according to any one of (1) to (8) is laid on the surface or inside the soil contaminated with the hardly decomposable harmful substance to decompose the hardly decomposable harmful substance. A method for purifying soil contaminated with a hardly degradable harmful substance. (10) A plurality of the bed mats according to any one of (1) to (8) above are laid at intervals on the surface or inside of soil contaminated with the hardly degradable harmful substance, and A method for purifying soil contaminated with a hardly decomposable harmful substance, comprising decomposing a hardly decomposable harmful substance contained in the soil by an enzyme produced by a microorganism that decomposes the substance. (11) The above-mentioned (9), wherein the hardly decomposable harmful substance is a hardly decomposable aromatic compound having 6 or more carbon atoms or a hardly decomposable halogen hydrocarbon comprising 1 to 4 carbon atoms and at least one halogen atom. ) Or the method for purifying soil according to (10). (12) The method for purifying soil according to the above (10) or (11), wherein the enzyme produced by the microorganism that degrades the hardly decomposable harmful substance is laccase, lignin peroxidase, manganese peroxidase, monooxygenase or dioxygenase.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a hard-to-decompose harmful substance comprising a microorganism which produces an enzyme for decomposing a hard-to-decompose harmful substance and a substance serving as a nutrient source of the microorganism inside the mat. It is a bacterial bed mat for decomposition. Further, the present invention provides a hard-to-decompose harmful substance characterized in that the above-mentioned bacterial bed mat is laid on or in the surface of soil contaminated with the hard-to-decompose harmful substance to decompose the hard-to-decompose harmful substance. It is a method of purifying contaminated soil. Here, the “soil” in the present invention means soil, bottom mud of a water area (for example, a river or a lake), or excess sludge of an activated sludge treatment facility. Further, the present invention also provides a plurality of the above-mentioned bacterial bed mats at intervals on the surface or inside soil contaminated with a hardly degradable harmful substance, and an enzyme produced by a microorganism that degrades the hardly degradable harmful substance. A method for purifying soil contaminated with a hardly decomposable harmful substance, characterized by decomposing a hardly decomposable harmful substance contained in soil.

The term "mat" used in the present invention means that the material is a natural fiber, a synthetic fiber or a wire mesh,
The plate-shaped or net-shaped product is further formed into a bag shape so that a substance serving as a nutrient source for microorganisms, in particular, a solid plant nutrient source can be contained therein. The mat used in the present invention contains a substance serving as a nutrient source of microorganisms therein, and then adds microorganisms. Therefore, a material that can withstand sterilization treatment, for example, at least 60 ° C for heat treatment, preferably 100 ° C or more. It must be made of a material that can withstand the temperatures of Preferred specific examples of the mat include hemp bags, cotton bags, cotton nets, coconut garnets, polyurethane nets, synthetic fibers or non-woven fabrics of natural fibers,
Wire mesh and the like. The substance serving as a nutrient source of the microorganism used in the present invention includes sawdust, wood chips, rice straw, barley straw, bran, rice bran, corn bran, whole soybean,
Such as citrus skin, grape skin, tea grounds and starch, the use of such solid plant nutrients is advantageous in handling. Liquid nutrient sources such as meat extract, molasses, and molasses can also be used by impregnating them with water retention agents such as charcoal, zeolite, and attapulgite. Accordingly, some of the fungus bed mats of the present invention further contain a water retention agent in addition to the microorganisms and a substance serving as a nutrient source of the microorganisms inside the mat. As the water retention agent, charcoal, zeolite, attapulgite, water-absorbing polymers such as crosslinked starch, crosslinked carboxymethylcellulose, crosslinked polyaspartic acid, powdered or granular materials such as crosslinked polyglutamic acid, and the like can be used. A water absorbing agent such as polyacrylamide may be used.

Before adding a microorganism that produces an enzyme that decomposes a persistent harmful substance, the mat containing a substance serving as a nutrient source of the microorganism (and a water retention agent) in the inside of the mat is inoculated with a microorganism (seed fungus). Before sterilization. Sterilization may be performed by any of wet heat sterilization, dry heat sterilization, chemical sterilization (gas sterilization, use of a sterilizing agent), and physical sterilization (radiation, electron beam sterilization). In the present invention, usually, the cultured microorganism (inoculum) is inoculated into a molded mat containing a substance serving as a nutrient source of the microorganism, and the sterilized nutrient source is cooled, and the microorganism is added to mold the mat. Is also good. Further, a mat may be formed by adding the solid medium to a seed bacterium that has been sufficiently grown on the solid medium. At this time, the solid medium may or may not be sterilized. Cultivation of the microorganism (seed fungus) is carried out at 10 to 60 ° C, preferably at 20 to 40 ° C. The medium has a water content of 30 to 90%, preferably 5 to 90%.
0 to 80%, and the number of culture days is 3 to 60 days. If the culture days are short, the bacteria will not grow sufficiently, and if the culture days are long, it will be costly and disadvantageous. By inoculating a nutrient source of the microorganisms in the mat with a microorganism that produces an enzyme that degrades hardly degradable harmful substances, the microorganisms proliferate and form a bacterial bed mat.

In the present invention, as the hardly decomposable harmful substance, a hardly decomposable aromatic compound having 6 or more carbon atoms, a hardly decomposable halogenated carbon comprising 1 to 4 carbon atoms and at least one halogen atom. Hydrogen and the like. Examples of the hardly decomposable aromatic compound having 6 or more carbon atoms include dioxins, halogenated biphenyls, bisphenols, alkylphenols, halogenated phenols, and phthalic esters. Dioxins are dioxins having one or more chlorine atoms or bromine atoms, and are compounds in which hydrogen atoms in two benzene rings of dibenzo-p-dioxin or dibenzofuran are replaced by chlorine atoms or bromine atoms. . A wide variety of compounds are included depending on the number of substitution of the chlorine atom or bromine atom and the substitution position on the benzene ring.

Among these dioxins, polychlorinated compounds having four or more chlorine atoms in one molecule are particularly highly toxic to the human body. As such compounds, for example, 2,3,7,8-tetra Chlorodibenzo-p-dioxin, 1,2,3,7,8-pentachlorodibenzo-
p-dioxin, 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin, 1,2,3,4,6,
7,8-heptachlorodibenzo-p-dioxin, 1,
2,3,4,6,7,8,9-octachlorodibenzo-
polychlorinated products of dibenzo-p-dioxin such as p-dioxin; 2,3,7,8-tetrachlorodibenzofuran, 1,2,3,7,8-pentachlorodibenzofuran, 2,3,4,7,8 -Pentachlorodibenzofuran, 1,2,3,4,7,8-hexachlorodibenzofuran, 1,2,3,6,7,8-hexachlorodibenzofuran, 1,2,3,7,8,9-hexachlorodibenzofuran, 2,3,4,6,7,8-hexachlorodibenzofuran, 1,2,3,4,6,7,8-heptachlorodibenzofuran, 1,2,3,4,6,7,8,9-
There are polychlorinated products of dibenzofuran such as octachlorodibenzofuran.

Further, as the halogenated biphenyls,
For example, there is coplanar (Coplanar) PCB in which a chlorine atom is substituted at a position other than the ortho position.
3 ', 4,4'-tetrachlorobiphenol, 3,
3 ', 4,4', 5-pentachlorobiphenol, 3,
Compounds such as 3 ′, 4,4 ′, 5,5′-hexachlorobiphenol are exemplified. Among the chlorinated compounds, the most toxic compound is 2,3,7,8-tetrachlorodibenzo-p-dioxin. Further, examples of bisphenols include compounds such as 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4-hydroxyphenyl) cyclohexane. Among these compounds, those suitable for the method of the present invention include:
2,2-bis (4-hydroxyphenyl) propane is exemplified.

The alkylphenols include nonylphenol, pentylphenol, octylphenol,
Compounds such as tert-butyl phenol are included. Examples of halogenated phenols include compounds such as dichlorophenol, trichlorophenol, tetrachlorophenol, and pentachlorophenol. Further, examples of the phthalic acid esters include compounds such as dibutyl phthalate, butylbenzyl phthalate, and di-2-ethylhexyl phthalate. In the present invention, examples of the hardly decomposable halogenated hydrocarbon comprising 1 to 4 carbon atoms and at least one halogen atom include mono-, di-, tri- and tetra-halogenated methane, and 1 to 5 halogen atoms , Halogenated ethylene having 1 to 3 halogen atoms, halogenated propylene having 2 to 3 halogen atoms, and the like. Specifically, monochloromethane,
Examples include dichloromethane, trichloromethane, tetrachloromethane, monochloroethane, dichloroethane, trichloroethane, monochloroethylene, dichloroethylene, trichloroethylene, and trichloropropylene.

The hardly decomposable harmful substance in the present invention includes:
It is a so-called extrinsic endocrine disrupter that has acute toxicity, carcinogenicity, teratogenicity, or is likely to accumulate in the body of animals and cause various problems. These endogenous endocrine disrupters are ubiquitous in the environment, exhibit a similar effect to hormones, and refer to chemicals that disrupt endocrine.Even in trace amounts, damage to animal ecology and human health,
For example, it has a great influence on the immune system, endocrine system, and nervous system. Therefore, it is desired to decompose such exogenous endocrine disrupting substances to render them harmless.

As microorganisms producing enzymes used for decomposing difficult-to-decompose harmful substances, microorganisms having a high laccase productivity, for example, schizophyllum
m) genus, Pleurotus genus, Trametes genus, Lentinas (Lent)
inus), Rhizoctonia
a) genus, Funaria, Pycnoporus, Merulis
lius, Myceliopht
ora), Coprinus, Agaricus, Foliota (Phol)
iota) genus, Flammulina
Genus, Ganoderma, Daedaleopsis, Fabolus, Lyophilm
lum) genus, Auricularia
a) A microorganism belonging to the genus or the like can be used.

The laccase produced by the above-mentioned microorganisms includes those produced together with laccase and lignin peroxidase, manganese peroxidase, monooxygenase, dioxygenase and the like. Examples include laccase, lignin peroxidase, manganese peroxidase, monooxygenase and dioxygenase. Microorganisms that produce enzymes that degrade hard-to-degrade harmful substances used in the present invention are filamentous fungi. It can be regarded as "Sumika (house)" of filamentous fungi,
On the basis of this, it is possible to intermittently or continuously produce an enzyme for spreading hyphae into the soil or decomposing hardly decomposable harmful substances.

When purifying contaminated soil using the cell mat of the present invention, the cell mat is laid horizontally or vertically on or in the soil. The number of cell mats to be laid depends on the area and depth of the soil, and the number is not limited. Usually, the cell mat of the present invention is laid in plural or plural layers according to the depth of the contaminated soil. The space between the fungus mats laid on the soil surface or inside the soil is 3-80c
m, preferably 5 to 40 cm. If the interval is too wide, the decomposition of harmful substances in the soil in the middle part will be slow, and if it is too narrow, it will be disadvantageous because it is expensive.

The cell mat laid on the surface of the contaminated soil is:
The upper portion of the cell mat may be covered with a sheet of paper or the like for moisture retention. The water content of the cell mat is preferably 20 to 80%, and when the water content is less than 20%, the bacteria are not killed but the growth is slowed down, and the decomposition of harmful substances is slow. It is not necessary to sterilize the soil before treating the soil with the cell mat, but if necessary, the soil can be heated or the like to suppress indigenous bacteria. If necessary, plant seeds can be placed in the cell mat. When plant seeds are added, the runoff of the soil can be suppressed to a small extent by the roots of the plants generated later. It is more preferable that the plant can decompose the hardly decomposable substance, such as horseradish. When a substance serving as a nutrient source for microorganisms is placed in the mat, usually, the nutrient source substance is directly placed in the mat. After wrapping in a water-soluble polymer film (for example, water-soluble polyvinyl alcohol film, starch film, etc.) or non-woven fabric,
You may put it in a mat.

Further, a liquid or solid nutrient substance may be added again after the production of the fungus bed mat, so that the fungus can grow more vigorously in the soil when the fungus body mat is laid on the soil. Good. The manufactured bed mat is transferred as it is or after drying to a contaminated site having contaminated soil. Alternatively, control the moisture and temperature and store until use.

[0025]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 (1) Molding of a nutrient-containing mat A bran 3 is added to 10 parts by weight of chips (2 to 15 mm) of kunugi.
Parts by weight, 2 parts by volume of corn bran, 1 dried citrus skin
The volumes were mixed, and tap water was added to make the water content 75%. This nutrient source was placed in a hemp bag of 30 cm x 40 cm and 3 cm thick, and the inlet was sewn with hemp. 30 mats (mat A) were manufactured. (2) Sterilization of mat The obtained nutrient-containing mat (mat A) was placed in an aluminum vat with a lid large enough to accommodate one mat, and was sterilized in a large autoclave at 121 ° C for 60 minutes. (3) Cultivation of Seed Bacterium 100 g of a liquid medium containing 20 g of an oatmeal medium and 5 g of carboxycellulose per 1 liter of tap water was placed in a 500 ml Mayer flask, and sterilized in an autoclave at 121 ° C. for 15 minutes. A laccase-producing microorganism was inoculated into this medium, and cultured at 28 ° C. with shaking for 7 days. In Example 1, Schizophillum commune (IFO6505) was used as a microorganism. (4) Manufacture of a bacterial bed mat The above inoculum cultivated from the top of a sterilized nutrient-containing mat (sterilized mat A) is sprayed and inoculated, covered with an aluminum lid, cultured at 28 ° C. for 14 days, and cultured. A mat (A) was produced.

Example 2 (1) Molding of a nutrient-containing mat 10 parts by weight of cherry sawdust (2 to 5 mm), barley whole grain 0.5
Parts by weight, 1 part by weight of rice bran, 1 part by weight of bran, 1 part by weight of dried grape cake, and 1 part by weight of oolong tea grounds were mixed and adjusted to 70% water by adding tap water. This nutrient source was put into a 30 cm × 40 cm cotton net (mesh size 1 mm) to a thickness of 5 cm, and the inlet was sewn with cotton thread. 30 mats (mat B) were manufactured. (2) Sterilization of mat The obtained nutrient-containing mat (mat B) was placed in an aluminum vat with a lid large enough to accommodate one mat, and was sterilized in a large autoclave at 121 ° C for 60 minutes. (3) Cultivation of inoculum Trametes versicolor [IFO4] instead of Schizophyllum commune used in Example 1
937], except for using the same components, conditions,
The inoculum was cultured using the method. (4) Production of bacterial bed mat The above-described inoculum cultured above the sterilized nutrient-containing mat (sterilized mat B) was sprayed and inoculated. This mat was placed in an aluminum vat, covered with an inner lid, and cultured at 30 ° C. for 20 days to produce a bacterial bed mat (B).

Example 3 Instead of the hemp bag in Example 1, a coconut garment (thickness: 3 mm) was used, and two newspapers were laid on the coconut garage mat, thereby sandwiching the nutrient source to a thickness of 4 cm from above and from below. A fungus bed mat (C) was produced using exactly the same materials and method as in Example 1 except that the periphery thereof was stitched with hemp.

Example 4 10 parts by weight of beech sawdust, 3 parts by weight of bran and 1 part by weight of potato starch were added, and 7 parts by weight of tap water were added and mixed. This nutrient source is 10 mm in diameter and 10 mm in length with a pelletizer.
Granulated to １５15 mm. This pellet is 40cm × 60
The aluminum bat with a lid of cm × 10 cm was spread to a depth of 4 cm and sterilized in an autoclave at 121 ° C. for 20 minutes. Next, 200 ml of the inoculum cultivated in Example 1 was added from the upper surface of the aluminum bat to a humidity of 100% and a temperature of 2%.
It was placed in a constant-humidity and constant-temperature room at 8 ° C., and cultured for 14 days to produce a seed inoculum. Next, 5 parts by weight of the obtained inoculum in pellet form was mixed with 100 parts by weight of black stalks (54% moisture). The mixture was packed in a hemp bag of 30 cm × 40 cm to a thickness of 5 cm, and the inlet was sewn with hemp to produce a fungus bed mat (D).

Example 5 3 parts by weight of a sugar-granule having a water content of 80% were mixed with 5 parts by weight of calcined attapulgite having a particle size of 2 to 3 mm. To this mixture, 10 parts by weight of a mixture of zelkova, arakashi, marebashii, and ground pruned tree (5 to 20 mm), 3 parts by weight of bran, and 2 parts by weight of dried citrus are mixed, and tap water is added to reduce the water content to 65%. Was adjusted. This nutrient source is 40cm x 50
Using a wire mesh having a mesh opening of 1 cm and a thickness of 5 cm from the upper and lower parts, the surroundings were folded to produce a nutrient-containing mat. Next, the mat was sterilized, cultivated by the inoculum, and inoculated with the inoculum in the same manner as in the method of sterilizing the mat and the method of cultivating the inoculum performed in Example 1 to produce a bacterial bed mat (E).

Examples 6 to 16 and Comparative Examples 1 to 5 A polyethylene net having an aperture of 1 mm was stretched on the bottom of a container (30 cm × 40 cm × 30 cm) having one hole (diameter: 5 mm) per 25 cm ^{2 on the} bottom surface. . In this container, soil contaminated with dioxin (2340 picog, TEQ / g soil) was spread to various thicknesses (a
layer). The fungal bed mats produced in Examples 1 to 5 were laid on this and pressed lightly. Contaminated soil was further placed on the fungus bed mat spread in the same manner (layer b), and the fungus bed mat was overlaid thereon. Further, in the case of using a section (layer c) in which soil was stacked, a bacterial bed mat was placed on the top. Large container (50cm × 60c)
Each container was placed on nine glass supports so that a space was formed at the bottom of the container (m × 20 cm), so that water leaked from the bottom at the time of watering did not flow away. A boiler was installed and controlled in the greenhouse so that the minimum temperature did not drop below 20 ° C. The temperature rise during the day was not particularly controlled. The daytime temperature reached a maximum of 36 ° C. 1 water
Once a week, water was sprinkled from the top and given until there was a slight run off of water from the bottom.

For comparison, a decomposition experiment was conducted in the same manner except that a mat not inoculated with dioxin-decomposing bacteria was used. After 30 days, the soil in each of the layers a to c was mixed and homogenized, and the residual dioxin concentration was measured.
The results of the measurement were as follows.

Bacterial bed mat used Thickness of soil Layer Dioxin content in soil (cm) (pico g / g soil) Example 6 Example 13 3a 1290 Example 7 ５ 5 a 1450 Example 8 １０ 10 a 1530 Example 9 〃 20 a 1750 Example 10 〃 30 a 1770 Example 11 〃 10 a 1580 １０ 10 b 1560 Example 12 ７ 7 a 1690 〃 ｂ b 1520 〃 ｃ c 1440 Comparative Example 1 Example 1 (Bacteria) 7 a 2130 〃 b 2150 〃 c 2090 Example 13 Example 2 10 a 1710 １０ 10 b 1490 １０ 10 c 1510 Comparative Example 2 Example 2 (no bacterial inoculation) 10 a 2210 １０ 10 b 2160 １０ 10 c 2090 Example 14 Example 3 10 a 1670 １０ 10 b 1580 １０ 10 c 1530 Comparative Example 3 Example 3 (cell-free inoculum) 10 a 2180 〃 10 b 2210 〃 10 c 2140

Bacterial bed mat used Thickness of soil Layer Dioxin content in soil (cm) (pico g / g soil) Example 15 Example 4 10 a 1750 １０ 10 b 1680 １０ 10 c 1630 Comparative Example 4 Example 4 (no inoculation of cells) 10 a 2290 １０ 10 b 2150 〃 10 c 2140 Example 16 Example 5 10 a 1650 〃 10 b 1620 １０ 10 c 1340 Comparative Example 5 Example 5 (no inoculation of cells) 10 a 2280 〃 10 b 2040 〃 10 c 2090

Example 17 and Comparative Example 6 Dioxin was decomposed in the same manner as in Example 13 except that the soil used was heated at 85 ° C. for 3 hours.

Bacterial bed mat used Thickness of soil Layer Dioxin content in soil (cm) (pico g / g soil) Example 17 Example 13 10 a 1590 １０ 10 b 1380 １０ 10 c 1310 Comparative Example 6 Example 6 13 (no inoculation of bacterial cells) 10 a 2240 １０ 10 b 2160 １０ 10 c 2180

Example 18 and Comparative Example 7 Bisphenol A, octylphenol, hexachlorophenol and butyl phthalate were each added to acetone in a quantity of 25%.
It was dissolved at a rate of 0 mg / l. Black soil (moisture 1
8%) 40kg is put into a stainless steel V-shaped mixer,
Add 1 liter of acetone solution once every 3 minutes,
A total of 4 liters was added. After the addition of the acetone solution,
Mixing was continued for 1 hour. A metal mesh with an aperture of 1 mm was stretched on the bottom of a stainless steel container (30 cm × 40 cm × 20 cm) having one hole (diameter: 2 mm) per 4 cm ² on the bottom. This container was placed on nine glass supports so that a space was formed at the bottom of a large stainless steel container (40 cm × 55 cm × 25 cm). Next, 15 kg of soil containing a hardly decomposable harmful substance was put into this internal stainless steel container, and two identical sections were used. The container was left outdoors for 48 hours with a roof to evaporate the acetone. Thereafter, the fungus bed mat prepared in Example 3 was spread on the top of one of the soils, tap water was sprinkled gradually from the top of the net, and added over 4 hours until water leaked from the bottom of the internal stainless steel vat. For comparison, a mat to which no hard-to-decompose harmful substance-decomposing bacteria was added was similarly spread.

The two containers were placed in a constant temperature bath at 28 ° C., and water was sprayed once a week to such an extent that water was slightly dropped from the bottom. This has been going on for two months,
The upper mat was removed and the soil was mixed evenly. The soil was dried to a moisture content of 18%, 100 g was extracted with 1 liter of dichloromethane, and the same operation was repeated three times. Similarly, extraction operation was performed on two 100 g soil samples. The dichloromethane extract was analyzed by high performance liquid chromatography, and the average of three samples was determined. The results were as follows.

Example 18 Residual amount (mg) per 40 kg of soil Bisphenol A 128 Octylphenol 320 Hexachlorophenol 520 Butyl phthalate 472 Comparative Example 7 Bisphenol A 632 Octylphenol 724 Hexachlorophenol 880 Butyl phthalate 872

[0039]

EFFECT OF THE INVENTION By using the fungus bed mat according to the present invention, the hard-to-decompose harmful substances accumulated in the soil contaminated by exhaust gas, wastewater (waste liquid), incineration ash and the like containing the hard-to-decompose harmful substances can be saved in a labor-saving manner. Since it can be safely decomposed and rendered harmless, it is very effective when applied to actual soil contamination sites.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C12N 11/04 (C12N 1/14 F (C12N 1/14 C12R 1: 645) C12R 1: 645) (C12N 9/02 (C12N 9/02 C12R 1: 645) C12R 1: 645) B09B 3/00 ZABE F term (reference) 4B029 AA08 AA21 BB09 CC02 CC03 GA08 GB10 4B033 NA13 NB33 NB45 NB65 NB69 NC06 ND04 ND10 ND20 4050 DD05 DD14 LL10 4B065 AA71X AC20 BB23 BB26 BB27 BC42 BC46 BC50 CA28 CA56 4D004 AA41 AB05 AB06 AB07 AC07 CA20 CB03 CB50 CC07

Claims (12)

[Claims] 1. A bacterial bed mat for decomposing hard-to-decompose harmful substances, characterized in that the mat contains a microorganism producing an enzyme that decomposes hard-to-decompose harmful substances and a substance serving as a nutrient source of the microorganisms. . 2. The fungal bed mat according to claim 1, further comprising a water retention agent in addition to a substance serving as a nutrient source of the microorganism. 3. The fungus bed mat according to claim 1, wherein the material of the mat is a natural fiber, a synthetic fiber, or a wire mesh. 4. The hardly decomposable harmful substance is a hardly decomposable aromatic compound having 6 or more carbon atoms or a hardly decomposable halogenated hydrocarbon comprising 1 to 4 carbon atoms and at least one halogen atom. The bacterial bed mat according to any one of claims 1 to 3. 5. The hardly decomposable aromatic compound having 6 or more carbon atoms is at least one selected from dioxins, halogenated biphenyls, bisphenols, alkylphenols, halogenated phenols and phthalic esters. Item 8. The fungal bed mat according to Item 4. 6. The hardly decomposable halogenated hydrocarbon comprising 1 to 4 carbon atoms and at least one halogen atom is monochloromethane, dichloromethane, trichloromethane, tetrachloromethane, monochloroethane, dichloroethane, trichloroethane, monochloromethane. The bacterial bed mat according to claim 4, which is at least one selected from ethylene, dichloroethylene, trichloroethylene, and trichloropropylene. 7. The bacterial bed mat according to claim 1, wherein the enzyme that decomposes hardly decomposable harmful substances is laccase, lignin peroxidase, manganese peroxidase, monooxygenase, or dioxygenase. 8. The microorganism producing an enzyme that decomposes a hardly decomposable harmful substance is Schizophillum.
um), Pleurotus, Trametes, Lentinas (Len)
tinus, Rhizoctonia
a) genus, Funaria, Pycnoporus, Merulis
lius, Myceliopht
ora), Coprinus, Agaricus, Foliota (Phol)
iota) genus, Flammulina
Genus, Ganoderma, Daedaleopsis, Fabolus, Lyophilm
lum) or Auricularia (Auricular)
The fungal bed mat according to any one of claims 1 to 7, which is a microorganism belonging to the ia) genus. 9. Decomposing the hard-to-decompose harmful substance by laying the fungal bed mat according to any one of claims 1 to 8 on or inside soil contaminated with the hard-to-decompose harmful substance. A method for purifying soil contaminated with a hardly decomposable harmful substance. 10. A hard-to-decompose bacterium mat according to any one of claims 1 to 8, which is laid at intervals on the surface or inside soil contaminated with hard-to-degrade harmful substances. A method for purifying soil contaminated with hard-to-degrade harmful substances, comprising decomposing hard-to-degrade harmful substances contained in soil by enzymes produced by microorganisms that degrade harmful substances. 11. The hardly decomposable harmful substance is a hardly decomposable aromatic compound having 6 or more carbon atoms or a hardly decomposable halogen hydrocarbon comprising 1 to 4 carbon atoms and at least one halogen atom. The method for purifying soil according to claim 9 or 10. 12. The method for purifying soil according to claim 10, wherein the enzyme produced by the microorganism that decomposes the persistent harmful substance is laccase, lignin peroxidase, manganese peroxidase, monooxygenase or dioxygenase.