JPH0823965A - Proliferation factor of microorganism made hydrophobic - Google Patents

Abstract

PURPOSE:To effectively decompose spilled pollutant oil with an microorganism without secondary environmental pollution by using a specific proliferation factor of microorganism made hydrophobic by coating it with a solid and hydrophobic organic compound. CONSTITUTION:A proliferation factor of a microorganism capable of decomposing oil such as of Pseudomonas bacterium is coated with a solid and hydrophobic organic compound such as paraffin wax or the like to obtain the objective proliferation factor. A microorganism capable of decomposing oil and this proliferation factor composition are scattered to the spilled oil contaminating sea and river or applied to the soil in the construction site penetrated with the pollutant oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the treatment of oil spilled into the sea, rivers, lake water, drainage pits, etc. and oil spilled into soil such as oil storage bases and construction sites.

[0002]

2. Description of the Related Art Oil is leaked to the sea due to a tanker accident or the like, which often causes great damage. Also on land, there are frequent accidents where oil spills and contaminates water and soil. Methods for removing such spilled oil are roughly classified into three types.

The first method is to absorb and remove oil with a special mat. The removal of oil by this method is rapid and effective in removing crude oil. However, this method cannot remove oil adhering to the quay, sand, rocks, etc., or oil that has infiltrated into the soil. In addition, there is no method for treating a mat that has absorbed oil except incineration, and there is a problem that soot and harmful gas are generated by treating this.

The second method is a method in which an oil is emulsified and dispersed in water by using a chemical, and it is advantageous that the oil can be easily treated. However, although it is considered that oil dispersed in water is decomposed by microorganisms living in nature, the behavior of dispersed oil is unknown in reality. In addition, there are concerns about the effects of chemicals on aquatic plants and animals.

The third method is a method of decomposing and removing oil by utilizing a microorganism having oil degrading ability.
In the oil treatment technology utilizing microorganisms, it is an advantage that there is no concern about secondary contamination as in the case of treatment with chemicals. Microorganisms are also effective in removing oils that the adsorption mat cannot use, such as oils that have infiltrated the soil. For these reasons, great expectations have been placed on oil removal technology using microorganisms.

In order to decompose and remove oil by microorganisms, it is necessary to bring a growth factor essential for microorganisms into contact with oil. However, since these growth factors are water-soluble, they diffuse into water, and the oil-degrading bacteria cannot effectively use the growth factors. In order to overcome such problems, a method has been proposed in which a growth factor is enclosed in a w / o emulsion to prevent outflow (Japanese Patent Publication No. 61-11590).
Reference). However, in this method, the emulsion is relatively easily broken by an external impact or the like, so that the growth factor may diffuse into water. Further, in order to form an emulsion, it is necessary to add a chemical such as an activator, which may cause secondary environmental pollution.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above problems in the art, and provides a technique for efficiently treating spilled contaminated oil with microorganisms having an oil decomposing ability and preventing secondary environmental pollution. It was made to do.

[0008]

That is, the present invention provides a hydrophobizing growth factor for microorganisms comprising a growth factor for oil-degrading microorganisms coated with a solid hydrophobic organic compound, and an outflow of the hydrophobizing growth factor. The present invention relates to a method for treating spilled contaminated oil, which comprises contacting contaminated oil in the presence of the microorganism.

The hydrophobized growth factor according to the present invention is prepared by coating a microbial growth factor having oil degradability with a solid hydrophobic organic compound. As the solid hydrophobic organic compound used in the present invention, various waxes (for example, paraffin wax, montan wax,
Carnauba wax etc.), higher saturated fatty acids (eg lauric acid, myristic acid, palmitic acid, stearic acid etc.), animal oils (eg beef tallow, lard etc.) and the like.

Growth factors coated with these hydrophobic organic compounds are microorganisms having oil degrading ability, for example, Pseudomonas spp., Arthrobacter spp.
(Artrobacter), Acinetobacte genus (Acinetobacte
r), a bacterium of the genus Corynebacterium (Corynebacterium), a genus of Flavobacterium (Flavobacterium), or the like, and may be any growth factor, but is not particularly limited. , Phosphates such as disodium phosphate and ammonium phosphate, nitrogen-containing compounds such as ammonium nitrate, sodium nitrate, potassium nitrate, urea, amino acids, peptides and proteins,
Examples include vitamins such as biotin, pantothenic acid, folic acid, niacin, aminobenzoic acid, pyridoxine, riboflavin and thiamine. It should be noted that microorganisms having such oil-degrading properties are generally widely present in natural soil, and those skilled in the art can easily culture and utilize the microorganisms if desired.

A general method of coating a growth factor for microorganisms with the above solid hydrophobic organic compound is to add the growth factor and a solid hydrophobic organic compound such as wax to the melting point of the hydrophobic organic compound. This is a method of mixing at the above temperature.
The thickness of the coating layer of the hydrophobic organic compound may be appropriately selected according to the type of the hydrophobic organic compound, the type of the contaminated oil to be treated, the place or time when the contaminated oil flows out, and is not particularly limited. However, it is generally 0.001 to 1 mm, preferably 0.0
It is 1 to 0.1 mm. If the coating layer is too thin, the microbial growth factor will flow out, and if it is too thick, the microorganism will not be able to utilize it. When the growth factor is a liquid or when the growth factor is used as a solution, the growth factor may be microencapsulated using the above hydrophobic organic compound by a microencapsulation method known per se. If desired, the solid hydrophobic organic compound and the growth factor may be used in combination of two or more kinds. The particle size of the hydrophobizing growth factor for microorganisms according to the present invention is not particularly limited, but is usually 0.05 to 5 mm, preferably 0.1 to 1 mm. If the particle size is too small, the relative content of microbial growth factor decreases,
On the other hand, if it is too large, the utilization efficiency by microorganisms decreases.

The method for treating spilled contaminated oil using the hydrophobizing growth factor for microorganisms according to the present invention is roughly classified into two. The first aspect is a method of spraying a contaminated oil that has flowed out to the sea, rivers, etc., with the above-mentioned microorganism having an oil-degrading property and the hydrophobizing growth factor according to the present invention. The second aspect is a method of spraying the contaminated oil that has infiltrated into the soil such as an oil storage base or a construction site with the hydrophobizing growth factor according to the present invention (in this case, a microorganism having an oil degrading property is present in the soil). However, cultured microorganisms may be sprayed if desired).

Although the hydrophobized growth factor according to the present invention can be directly applied to the spilled contaminated oil, it is usually used as a suspension in which it is dispersed and suspended in an aqueous medium. The dispersed concentration of the growth factor is not particularly limited, but is generally 10
-70% by weight, especially 30-50% by weight. The amount of such an aqueous suspension of hydrophobized growth factor to be sprayed may be appropriately selected according to the type and amount of the contaminated oil to be treated, the place and the time when the contaminated oil flows out, and is not particularly limited. Is 40 to 50% by weight, for example, 200 to 1000 ml per liter of contaminated oil spilled. The hydrophobized growth factor according to the present invention is not easily destroyed by an external impact (e.g., wave), and the growth factor is gradually released in spilled contaminated oil over time and supplied to a microorganism having oil degradability. Therefore, the spilled oil is efficiently decomposed because the microorganisms are effectively propagated. Further, since the hydrophobic organic compound as a growth factor coating agent is dissolved in the spilled contaminated oil and decomposed by microorganisms, secondary environmental pollution is not brought about.

[0014]

EXAMPLES The present invention will be described below with reference to examples. Example 1 Ammonium nitrate 5 g, monopotassium phosphate 0.4 g, disodium phosphate 1.7 g, magnesium sulfate heptahydrate 0.5 g
The hydrophobized growth factor according to the invention was prepared by mixing and 4 g of paraffin under heat (60-80 ° C.). After adding 0.5 ml of D-spindle oil to 50 ml of distilled water, 1 g of the above-mentioned hydrophobizing growth factor was added (the oil floating on the water surface was absorbed by the hydrophobizing growth factor). No ammonium ion, phosphate ion, potassium ion, sodium ion or magnesium ion was detected in the aqueous layer after the mixture was vigorously shaken for about 5 minutes.

Comparative Example 1 5 g of ammonium nitrate, 0.4 g of monopotassium phosphate, 1.7 g of disodium phosphate and 0.5 g of magnesium sulfate heptahydrate were dissolved in distilled water to prepare an aqueous solution of 100 g in total. By mixing 40 g of the aqueous solution, 20 g of oleic acid, 4 mol of lauryl alcohol / ethylene oxide adduct and 10 g of butoxyethanol, W / O
A type emulsion was prepared. After adding 1 g of the emulsion to 100 ml of distilled water and shaking vigorously for about 5 minutes, centrifugation treatment (3000 g) was applied for 10 minutes, and ammonium ion and phosphate ion in the aqueous layer were analyzed and found to be about 91%.
It was confirmed that ammonium ion and about 96% of phosphate ion were transferred into the aqueous layer.

Example 2 8 g of casein and 2 g of paraffin were heated (60 to 80).
Hydrophobicized growth factor was prepared by mixing at (° C). 100 ml of sterilized seawater or tap water, D-spindle oil, kerosene, naphthenic machine oil, C heavy oil or crude oil 1
The strain Pseudomonas fluorescens (Pseudomonas fluorescens), which has oil-degrading ability, was added to a mixture containing 0 to 500 mg.
ens) (ATCC31483) or a mixture obtained by further adding 100 mg of the above-mentioned hydrophobizing growth factor to the mixture, the strain was inoculated, and shaking culture was carried out at 30 ° C. for 1 week. After culturing, the oil was extracted using a 6: 4 mixed solvent of n-hexane and toluene, the solvent was removed, and the weight of the extracted oil was measured. The results are shown in Table 1.

[0017]

[Table 1]

Example 3 Ammonium nitrate 5 g, monopotassium phosphate 0.4 g, disodium phosphate 1.7 g, magnesium sulfate heptahydrate 0.5
g, yeast extract 1 g and paraffin 2 g under heating (60-
The hydrophobized growth factor was prepared by mixing at 80 ° C. After inoculating a mixture obtained by adding 500 mg of machine oil or naphthenic machine oil and 500 mg of the above-mentioned hydrophobizing growth factor to 50 ml of tap water, a strain Pseudomonas fluorescens (ATCC31483) having an oil degrading ability was inoculated,
Static culture was performed at ℃. After 1 month, 2 months and 3 months, an oil component was extracted using a 6: 4 mixed solvent of n-hexane and toluene, the solvent was removed, and then the weight of the extracted oil component was measured. 2 shows.

[0019]

[Table 2]

Comparative Example 2 Measurement was carried out according to the same procedure as in Example 3 except that paraffin was not used. Table 2 shows the results.

Comparative Example 3 Example 3 except that growth factors and paraffin were not used.
The measurement was carried out according to the same procedure as in. Table 2 shows the results
Shown in

Example 4 Ammonium nitrate 5 g, monopotassium phosphate 0.4 g, disodium phosphate 1.7 g, magnesium sulfate heptahydrate 0.5
g, yeast extract 1 g and stearic acid 2 g under heating (70
Hydrophobized growth factors were prepared by mixing at ~ 80 ° C). About 30 ml of the soil collected in the sample tube was impregnated with 500 mg of D-spindle oil or naphthenic machine oil, and 0.5 ml of a suspension obtained by suspending 5 g of the hydrophobizing growth factor in 10 ml of tap water was added thereto. After allowing the sample to stand at 25 ° C. for 2 months, an oil component was extracted using a 6: 4 mixed solvent of n-hexane and toluene, the solvent was removed, and the weight of the extracted oil component was measured. The results are shown in Table 3.

[0023]

[Table 3]

Comparative Example 4 Measurement was carried out according to the same procedure as in Example 4 except that stearic acid was not used. The results are shown in Table 3.

Comparative Example 5 Measurement was carried out according to the same procedure as in Example 4 except that growth factors and stearic acid were not used. The results are shown in Table 3.

[0026]

EFFECTS OF THE INVENTION By using the hydrophobizing growth factor according to the present invention, it becomes possible to efficiently decompose spilled contaminated oil by microorganisms without causing secondary environmental pollution.

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Claims (3)

[Claims] 1. A hydrophobizing growth factor for microorganisms, which is obtained by coating a growth factor for oil-degrading microorganisms with a solid hydrophobic organic compound. 2. The hydrophobized growth factor according to claim 1, wherein the solid hydrophobic organic compound is wax or higher saturated fatty acid. 3. A method for treating spilled contaminated oil, which comprises contacting the hydrophobized growth factor according to claim 1 or 2 with the spilled contaminated oil in the presence of a microorganism capable of degrading oil.