JP2017176899A - Decomposition treatment method of oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for facilitating decomposition and oxidation of oil content highly efficiently in a short time without destroying environment with respect to petroleum oil contained in accompanying water, petroleum contaminated soil and the like.SOLUTION: A decomposition treatment method of oil which is the method for decomposing and treating oil consisting of either one side or both of aliphatic hydrocarbon and aromatic compound is characterized in that oil and chlorophylls are brought into contact with each other, thereafter, light is applied and the oil is oxidized according to photocatalytic reaction. Further, the decomposition treatment method is characterized in that the oil oxidized according to photocatalytic reaction and microorganism which degrades a compound having hydroxy group are brought into contact with each other and the oil oxidized according to the photocatalytic reaction is further oxidized by biological treatment.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for decomposing oil. In particular, the present invention relates to a method for decomposing oil for purifying associated water drained in an oil mining process, soil contaminated with oil, or the like.

  In the oil mining process, a large amount of oil-containing water is discharged from the formation along with the production of oil. Such oil-containing water is called accompanying water. Accompanying water contains a large amount of petroleum-based oils including large particles separated from water and fine emulsions. The accompanying water is released into the environment in addition to the return disposal to the oil field, but when the environment is released, the environmental pollution of the oil contained in the accompanying water becomes a problem. In addition, the soil is contaminated with petroleum components in and around the site of oil refining factories and stockpiling bases, as well as in gas station sites.

  As a countermeasure against such environmental pollution, as described in Patent Document 1, bioremediation using biodegradable bacteria (bioremediation, environmental remediation technology by living organisms) has attracted attention. Bioremediation is a method of decomposing petroleum oil by adding petroleum-degrading bacteria to associated water containing petroleum oil or petroleum-contaminated soil. Bioremediation is a resource-saving, inexpensive and less environmental burden compared to treatment methods that use chemicals such as oxidizing agents and flocculants. In addition, there is an advantage that petroleum, which is known as hardly decomposable, can be completely decomposed.

  However, as shown in Patent Literature 1 and Non-Patent Literature 1, the degradation treatment using petroleum degrading bacteria has a drawback that it takes a long time of several weeks. In Non-Patent Document 2, as a cause, petroleum contains an organic compound that is hardly biodegradable, and an oxidation reaction by monooxygenase (an enzyme that introduces one oxygen atom into a compound using oxygen molecules as a substrate) is a rate-limiting step. It is shown that

  As a method for improving this rate-limiting step, for example, Patent Document 2 discloses that a petroleum oil component is partially oxidized using a photocatalyst using titanium dioxide and then decomposed to carbon dioxide by microorganisms. .

  However, in the photocatalyst using titanium dioxide described in Patent Document 2, the oxidation reaction proceeds only on the surface of the object coated with titanium dioxide, and the petroleum-based oil can be efficiently oxidized in the entire treated water. There is a drawback that it is difficult. Further, when sprayed on soil, titanium dioxide does not dissolve in water and does not decompose, which may cause environmental destruction.

JP 2014-61489 A JP-T 6-502340 Kadokura et al., “Safety Evaluation of Petroleum Decomposing Bacteria”, 67th Annual Scientific Lecture Meeting (September 2012), P. 677-P. 678 Nilanjana Das and Preethy Chandran, "Microbial Degradation of Petroleum Hydrocarbon Contaminants: An Overview", SAGE-Hindawi Access to Research, Biotechnology Research International, Volume 2011, Article ID 941810, 13pages.

  In view of the above circumstances, the present invention aims to provide a method for promoting decomposition and oxidation in an efficient manner and in a short time without destroying the environment for oil contained in accompanying water, petroleum-contaminated soil, or the like. To do.

  Oils contained in associated water, petroleum-contaminated soil, and the like contain biopersistent aliphatic hydrocarbons and aromatic compounds. As a method for highly efficiently oxidizing this biopersistent aliphatic hydrocarbon or aromatic compound, it is conceivable to use a photocatalytic reaction with chlorophylls. Chlorophylls are decomposed by microorganisms and light over time, and can be decomposed without using chemicals, etc., so that there is little risk of environmental destruction even if released to the environment.

  Therefore, the inventor mixed the chlorophylls with water or soil containing oils of aliphatic hydrocarbons or aromatic compounds, brought the oils into contact with the chlorophylls, and then irradiated the light to thereby produce the oils by photocatalysis. It was found that the oxidation of can be promoted.

  In addition, the inventor mixed a liquid such as water containing oil partially decomposed by the photocatalytic reaction of chlorophylls with a degrading bacterium that decomposes alcohol and brought the oil and the decomposing bacteria into contact with each other. It has been found that the decomposed oil can be further decomposed.

  As a result, the inventor can decompose the biodegradable aliphatic hydrocarbons and oils of aromatic compounds with high efficiency and in a short period of time by combining the partial oxidation by the photocatalytic reaction of chlorophylls with the decomposing bacteria that decompose alcohol. I got the knowledge.

  The present invention has been completed based on these findings and provides a method for decomposing oil as follows.

  The method for decomposing oil according to the first invention is a method for decomposing oil comprising either one or both of an aliphatic hydrocarbon and an aromatic compound, wherein after the oil is brought into contact with chlorophylls, light is irradiated. Irradiating and oxidizing the oil by photocatalytic reaction.

  The method for decomposing oil according to the second invention is the method for decomposing oil according to the first invention, wherein the oil oxidized by the photocatalytic reaction is contacted with a microorganism that decomposes the compound having a hydroxy group, and is oxidized by the photocatalytic reaction. The oil is further oxidized by biological treatment.

  The oil decomposition treatment method of the third invention is the oil decomposition treatment method according to the first or second invention, wherein the chlorophylls are chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll d, chlorophyll f. Any one of or a combination of two or more is characterized.

  According to the method for decomposing oil according to the present invention, by utilizing the photocatalytic reaction of chlorophylls for oils of biodegradable aliphatic hydrocarbons and aromatic compounds contained in petroleum-containing water and petroleum soil contamination. , Can promote oxidation and decompose. In addition, due to this and in combination with alcohol-degrading bacteria, it is possible to decompose oil of aliphatic hydrocarbons and aromatic compounds that are hardly biodegradable in a short time with high efficiency without causing environmental destruction. The problem of environmental pollution such as petroleum soil pollution can be solved.

Results of FTIR analysis after light irradiation in a dichloromethane solution in which chlorophyll a was dissolved (dotted line in Fig. (A)), results of FTIR analysis after light irradiation in dichloromethane solution in which n-dodecane was dissolved (in Fig. (A), Solid line), FTIR analysis after light irradiation in a dichloromethane solution in which chlorophyll a and n-dodecane are dissolved (Figure (b)). It is a result of gas chromatography analysis after light irradiation and comparison of a dichloromethane solution in which chlorophyll a and n-dodecane are dissolved, a dichloromethane solution in which chlorophyll a is dissolved, and a dichloromethane solution in which n-dodecane is dissolved. It is the result of FTIR analysis after light irradiation for phenanthrene with and without chlorophyll a being mixed. It is the result of FTIR analysis after light irradiation, with and without chlorophyll a being mixed for pyrene. It is the result of FTIR analysis after light irradiation for diluted crude oil with and without chlorophyll a. It is the result of light irradiation, gas chromatographic analysis, and comparison of diluted crude oil with and without chlorophyll a mixing. It is the result of irradiating light to the liquid mixture of the diluted crude oil and the algal ethanol crude extract and the mixed liquid of the diluted crude oil and ethanol, respectively, and comparing by gas chromatography analysis.

  Hereinafter, an embodiment of an oil decomposition treatment method according to the present invention will be described.

<Oil decomposition method according to the first embodiment>
The method for decomposing oil according to the first embodiment of the present invention includes a liquid typified by associated water discharged along with the production of oil in the oil mining process, particularly aliphatic hydrocarbons contained in water. This is a method for decomposing an aromatic compound oil.

  In the case of the accompanying water, the aliphatic hydrocarbon oil contained in the water includes, for example, alkane-based and cycloalkane-based hydrocarbons, and the petroleum-based oil component of the aromatic compound includes benzene rings such as benzene, toluene, and xylene. One compound, and polycyclic aromatic hydrocarbons such as naphthalene and phenanthrene. Such petroleum oil has biodegradability.

  And in the case of accompanying water, since sand and mud are mixed, before separating oil with a photocatalyst, oil separation which removes these is performed. This is because the load of the oxidation treatment caused by the inclusion of sand or mud can be reduced. In the oil separation process, oil separation means such as a physical separation method using a specific gravity difference, a mechanical treatment method using a device such as a centrifuge, and a treatment method using a precipitant are used.

  Subsequently, chlorophylls or chlorophyll-containing materials are added to the accompanying water from which sand, mud, and the like have been removed, and the oil and chlorophylls contained in the accompanying water are brought into contact with each other and irradiated with light. And by the photocatalytic reaction of chlorophylls, it is possible to partially oxidize aliphatic hydrocarbons or oils of aromatic compounds contained in the accompanying water to alcohols or phenols having a hydroxy group, or to further promote the oxidation.

  The chlorophyll can be composed of any one or a combination of two or more of chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll d, and chlorophyll f.

  Moreover, in order to raise | generate a photocatalytic reaction efficiently, it is suitable for the wavelength of light to be an ultraviolet ray and visible ray of 250 nm-700 nm. Sunlight can be used when disassembling outdoors.

  Since the oxidation of oil by photocatalysis occurs on the surface of chlorophylls irradiated with light, in order to oxidize the oil efficiently, the accompanying water is stirred under aerobic conditions after the addition of chlorophylls. It is preferable to irradiate light while mixing chlorophylls.

  The oil contained in the accompanying water is oxidized and purified by the photocatalytic reaction of chlorophylls, but the time required for the oxidation is 24 hours or less, and the oil can be oxidized in a short time.

  As mentioned above, although the decomposition | disassembly processing method of the petroleum-type oil component contained in accompanying water was mainly demonstrated, the decomposition | disassembly processing method of the oil which concerns on the 1st Embodiment of this invention is not limited to accompanying water. Needless to say, even contaminated water containing petroleum oils can be applied and decomposed.

  If necessary, the oil decomposed by the above method can be further decomposed chemically by an oxidizing agent or ozone reaction or biologically by microorganisms to further purify water. This is additionally performed when the above-described oxidation of the chlorophylls by the photocatalytic reaction alone is insufficient, but will be described in detail later.

  The purified water can be discharged into rivers, seas or, if necessary, injected into a well if necessary. Chlorophylls may also be released into rivers and the like as necessary. This is because chlorophylls are decomposed with time and there is little risk of environmental destruction.

<Oil decomposition method according to the second embodiment>
In the method for decomposing oil according to the second embodiment of the present invention, the soil contaminated with petroleum-based oils composed of aliphatic hydrocarbons or aromatic compounds is used as a material to be treated. It is a method of decomposing oil contained in.

  The oil-contaminated soil according to the present invention is not particularly limited as long as it is soil that can be purified by the method of the present invention. For example, soil contaminated with gasoline, kerosene, heavy oil, lubricant, engine oil and the like can be mentioned. Examples of such soil include soil in factory sites, factory sites, gas station sites, oil pollution accident sites, and the like.

  In the method for decomposing oil according to the second embodiment of the present invention, chlorophylls are sprayed and added to petroleum-contaminated soil, and the oil and chlorophylls contained in the soil are brought into contact with each other and irradiated with light. And the oil of the aliphatic hydrocarbon and aromatic compound contained in soil can be partially oxidized to the alcohol and phenols which have a hydroxyl group, or oxidation can be further promoted.

  The chlorophyll can be composed of any one or a combination of two or more of chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll d, and chlorophyll f.

  Moreover, in order to raise | generate a photocatalytic reaction efficiently, it is suitable for the wavelength of light to be an ultraviolet ray and visible ray of 250 nm-700 nm. Sunlight can be used when disassembling outdoors.

  As described above, the second embodiment has been described. Furthermore, as described later, oil contained in soil can be oxidized and additionally decomposed by microorganisms.

<Oil Decomposition Treatment Method According to Third Embodiment>
As described in the method for decomposing oil according to the first embodiment or the method for decomposing oil according to the second embodiment, the biodegradable aliphatic hydrocarbon or aromatic compound oil is included. Oil can be decomposed using photocatalytic reaction by adding chlorophylls to dead water or soil, bringing oil and chlorophylls into contact and irradiating light.

  However, the oxidation of chlorophylls by photocatalytic reaction alone may not be sufficient. Therefore, in such a case, oxidation treatment by microorganisms can be additionally performed. The method will be described below.

  In the method for decomposing oil according to the third embodiment of the present invention, chlorophylls are added to water or soil containing oils of biodegradable aliphatic hydrocarbons or aromatic compounds, and the oil and chlorophylls. In the photocatalytic reaction process where the oil is partially oxidized by photocatalytic reaction, the microorganism is added to water or soil containing the partially oxidized oil to bring the oil and the microorganism into contact with each other. A process to decompose and oxidize oil is added.

  The microorganism is preferably a microorganism that degrades a compound having a hydroxy group. This is because the oil contained in water and soil is decomposed into at least alcohol and phenol by the photocatalytic reaction of chlorophylls. Examples of the microorganism that degrades the compound having a hydroxy group include bacteria of the genus Pseudomonas and the genus Gordonia. In the method for decomposing oil according to the third embodiment of the present invention, any microorganism may be used or a combination thereof may be used. A microorganism that degrades a compound having a hydroxy group can be cultured by using a medium for assimilating methanol.

  Since the oil partially oxidized to the compound having a hydroxy group by the photocatalytic reaction has biodegradability, it can be easily decomposed and oxidized in a short time by using the microorganism.

  As described above, by combining photocatalytic reaction of chlorophylls and decomposition by microorganisms, water and soil containing biodegradable aliphatic hydrocarbons and oils of aromatic compounds can be purified in 2 to 3 days. Is possible.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

<1. Decomposition of oil by photocatalysis>
(1) Decomposition of aliphatic hydrocarbons by photocatalytic reaction of chlorophylls Experiments were carried out using chlorophyll a as chlorophylls and n-dodecane of aliphatic hydrocarbons as oil.

That is, about 0.45 mg of chlorophyll a (Chlorophyll Research Laboratories) was dissolved in a solvent of dichloromethane (Nacalai Tesque) to prepare a 5 mM chlorophyll a solution. The mixture was added to 10 μl (7.5 mg) of the solution and stirred to mix chlorophyll a and n-dodecane. Thereafter, the mixture of chlorophyll a and n-dodecane was irradiated with LED light (white, peaks at 450 nm and 570 nm, about 1000 μmol photon · m− ² · s ⁻¹ ) at 25 ° C. for 24 hours.

  In addition, as a control experiment (control experiment), a solution in which 100 μl of dichloromethane was mixed with 10 μl of n-dodecane and 5 mM chlorophyll a solution without addition of n-dodecane were used.

  And after irradiating light as mentioned above, the reaction material was dissolved in the dichloromethane. A Fourier transform infrared spectrophotometer (referred to herein as “FTIR”) analysis (apparatus: manufactured by JASCO, model FTIR-4000) and gas chromatography analysis (apparatus body: Shimadzu GC-2014, column: The reaction was evaluated by Rxi-5ms (RESTEK), detection: FID).

  FIG. 1 shows the results of FTIR analysis. (A) is n-dodecane (solid line) after light irradiation, chlorophyll a (dotted line) after light irradiation, and (b) is a spectrum after light irradiation to a mixture of n-dodecane and chlorophyll a. FIG. 2 shows the results of gas chromatography analysis. (A) is dichloromethane, (b) is n-dodecane after light irradiation, (c) is chlorophyll a after light irradiation, (d) is n-dodecane mixed with n-dodecane and chlorophyll a after light irradiation. It is a result. The light irradiation time is 24 hours in both FIG. 1 and FIG.

  From the results of FIG. 1 and FIG. 2, it can be seen that n-dodecane is completely decomposed after light irradiation as compared with the control experiment. Furthermore, it was not possible to confirm hydrocarbon-based decomposition products. Presumably, it has been reduced in molecular weight and volatilized.

(2) Decomposition of aromatic compounds by photocatalytic reaction of chlorophylls Using chlorophyll a as chlorophylls, experiments were conducted using aromatic compounds phenanthrene (Nacalai Tesque) and pyrene (Nacalai Tesque) as oils. It was.

That is, about 0.45 mg of chlorophyll a (manufactured by Chlorophyll Laboratories) is dissolved in a solvent of dichloromethane (manufactured by Nacalai Tesque) to prepare a 5 mM chlorophyll a solution, and this is used as a final concentration of 5% (w / v) The mixture was added to 100 μl of a dichloromethane solution in which phenanthrene was dissolved and mixed. Further, the 5 mM chlorophyll a solution described above was added to 100 μl of a dichloromethane solution in which 5% (w / v) pyrene was dissolved at a final concentration, and the mixture was stirred and mixed. Then, these mixed liquids were irradiated with LED light (white, peaks at 450 nm and 570 nm, about 1000 μmol photon · m− ² · s ⁻¹ ) at 25 ° C. for 24 hours.

  As a control experiment, 100 μl of a dichloromethane solution containing 5% (w / v) phenanthrene or 5% (w / v) pyrene was used.

  And after irradiating light as mentioned above, the reaction material was dissolved in the dichloromethane. Then, the reaction product was evaluated by FTIR analysis (apparatus: manufactured by JASCO Corporation, model FTIR-4000).

  The results of FTIR analysis for phenanthrene and pyrene are shown in FIGS. 3 and 4, respectively. In both cases, (a) is the result of FTIR analysis of the control experiment, and (b) is the result of FTIR analysis by mixing chlorophyll a and irradiating with light. In both (a) and (b), the light irradiation time is 24 hours.

  From the results of FIGS. 3 and 4, it can be seen that when chlorophyll a is mixed and irradiated with light, phenanthrene and pyrene are significantly decomposed.

(3) Decomposition of crude oil by photocatalytic reaction of chlorophylls Chlorophyll a was used as chlorophylls, and as oil, mud and water were removed from the crude oil provided by Akiba-ku, Niigata Prefecture, and dichloromethane (manufactured by Nacalai Tesque) ) And a crude oil diluted three times (in the present specification and drawings, this diluted crude oil is referred to as “diluted crude oil”).

That is, about 0.45 mg of chlorophyll a (Chlorophyll Research Laboratories) is dissolved in a solvent of dichloromethane to prepare a 5 mM chlorophyll a solution. This chlorophyll a solution is added to 30 μl of diluted crude oil and stirred to mix chlorophyll a and diluted crude oil. Were mixed. Thereafter, this mixed solution was irradiated with LED light (white, peaks at 450 nm and 570 nm, about 1000 μmol photon · m− ² · s ⁻¹ ) at 25 ° C. for 24 hours.

In addition, as a control experiment, a solution obtained by mixing 100 μl of dichloromethane with 10 μl of diluted crude oil and 5 mM of chlorophyll a solution without addition of diluted crude oil were used.
After irradiation with light as above, the reaction was dissolved in dichloromethane. The reactants were evaluated by FTIR analysis (device: JASCO, model FTIR-4000) and gas chromatography analysis (device body: Shimadzu GC-2014, column: Rxi-5ms (RESTEK), detection: FID). .

  FIG. 5 shows the results of FTIR analysis, and FIG. 6 shows the results of gas chromatography analysis. In both cases, (a) is the result for the diluted crude oil in the control experiment, and (b) is the result after light irradiation of the mixed liquid of chlorophyll a and the diluted crude oil. From the results of FIGS. 5 and 6, it is possible to confirm a decrease in petroleum components of aliphatic hydrocarbons and aromatic compounds in the diluted crude oil. The light irradiation time is 24 hours.

(4) Decomposition of crude oil by photocatalytic reaction using algal ethanol crude extract An experiment was conducted using a crude algal ethanol extract as chlorophylls and diluted crude oil as oil.

  That is, a few drops of diluted crude oil were dropped on the petri dish, and a few drops of the algal ethanol crude extract were dropped thereon. Algae ethanol crude extract is a solution obtained by suspending about 1 g of Spirulina tablets (Japan Alger Co., Ltd.) in about 10 ml of ethanol and removing insolubles. The algal ethanol crude extract contains chlorophylls. In the control experiment, ethanol was added dropwise instead of the algal ethanol crude extract.

  The petri dish on which the above-described diluted crude oil and crude algal ethanol extract were dropped was allowed to stand in the sunlight for about 3 hours, and then the hydrocarbon components were extracted into hexane, followed by gas chromatography (device main unit: Shimadzu GC-2014, column: The reaction was analyzed by Rxi-5ms (RESTEK), detection: FID).

  The results of gas chromatography analysis are shown in FIG. From the result of FIG. 7, it can be seen that the hydrocarbon component is halved by the photocatalytic reaction using the algal ethanol crude extract.

<2. Decomposition of oil by photoreaction and biological treatment>
(1) Isolation of microorganisms As described above, bacteria that further decompose the partially decomposed product of crude oil partially decomposed by the photocatalytic reaction of chlorophylls were isolated. Specifically, a microorganism having an ability to assimilate 1-octadecanol, an aliphatic alcohol (higher alcohol), was searched from the soil of Akiba-ku, Niigata City.

First, M9 (-) medium (500 ml, 1.28 g Na ₂ HPO ₄ , 0.3 g KH ₂ PO _4, 0.05 g NaCl, 0.1 g NH ₄ Cl, 0.12 g MgSO ₄ .7H ₂ O, 5.5 mg CaCl ₂ The soil sample was diluted with 0.1 mg FeSO ₄ · 7H ₂ O) and seeded on M9 agar medium supplemented with 1-octadecanol (manufactured by Nacalai Tesque) (final concentration 0.1%). Incubate at 30 ° C, collect genomic DNA from the resulting large number of colonies, and amplify the 16S ribosomal RNA sequence using primers 16SrRNA8F: 5'-AGAGTTTGATCCTGGCTCAG-3 'and 16SrRNA1492R: 3'-GGTTACCTTGTTACGACTT-3' did. The base sequences of these primers are shown in SEQ ID NO: 1 and SEQ ID NO: 2, respectively.

  As a result, there were two types of microorganisms that could be isolated and had the base sequences shown in SEQ ID NO: 3 and SEQ ID NO: 4, respectively. As a result of the homology search, all of them were new species belonging to the genus Psudomonas, and were found to be closely related to Psudomonas knackmussii B13 having bisphenol resolution and Psudomonas taeanensis MS-3 having oil resolution, respectively.

(2) Decomposition of alcohol by microorganisms (2-1) Aliphatic alcohol (higher alcohol)
M9 (-) medium supplemented with 1-dodecanol (manufactured by Nacalai Tesque) or 1-octadecanol (manufactured by Nacalai Tesque) (final concentration 0.1%) has the nucleotide sequences shown in SEQ ID NO: 3 and SEQ ID NO: 4. As a result of inoculating microorganisms and incubating at 30 ° C for 12 hours, white turbidity suggesting the growth of microorganisms was observed, and the supernatant was gas chromatographically analyzed (system unit: Shimadzu GC-2014, column: Rxi-5ms (RESTEK) Detection: FID) As a result, it was revealed that 1-dodecanol and 1-octadecanol completely disappeared.
On the other hand, white turbidity was not observed in the control in which 1-dodecanol or 1-octadecanol was not added or in the control in which no bacteria were inoculated. In addition, even in the control to which only n-dodecane was added, no cloudiness was observed, and gas chromatography analysis (equipment body: Shimadzu GC-2014, column: Rxi-5ms (RESTEK), detection: FID) was performed. -The disappearance of dodecane could not be confirmed.

(2-2) Aromatic alcohol (phenols)
Inoculating microorganisms having the nucleotide sequences shown in SEQ ID NO: 3 and SEQ ID NO: 4 into M9 (-) medium supplemented with aromatic alcohol (phenols) phenanthrol (manufactured by Nacalai Tesque) (final concentration 0.1%) And incubated at 30 ° C. for 12 hours. Phenanthrol was insoluble in water and precipitated or floated as fine aggregates before incubation, but after incubation, cloudiness suggesting bacterial growth was observed, and phenanthrol aggregates almost disappeared.

  On the other hand, in the control to which phenanthrene having no hydroxyl group (manufactured by Nacalai Tesque) or pyrene (manufactured by Nacalai Tesque) was added, white turbidity was not observed, and no apparent decrease in phenanthrene or pyrene aggregates was confirmed.

  As described above, it can be seen that the isolated microorganism is effective for decomposing aliphatic alcohols (higher alcohols) and aromatic alcohols (phenols), and decomposes them at high speed.

(3) Decomposition of oil by photoreaction and biological treatment using algal ethanol crude extract A two-stage crude oil decomposition experiment by photoreaction and biological treatment using algal ethanol crude extract was performed as follows.

By leaving the crude oil provided by Akiba-ku, Niigata Prefecture, the mud settled and the supernatant was collected. The crude oil supernatant contains water or a water-soluble substance in addition to containing about 0.1 to 1% of the oil component. The crude oil supernatant was put into a 10 ml transparent glass container, and the above-mentioned algal ethanol crude extract (about 1 g of Spirulina tablets (Japan Alger) was suspended in about 10 ml of ethanol and insoluble matter was removed. 1 ml of the solution) was added, and the solution was left under sunlight (about 1000 to 2000 μmol photon · m- ² · s- ¹ ) for 2 hours. As a result of repeating the addition of the algal ethanol crude extract and the sunlight irradiation 3 to 4 times, it was confirmed by visual observation that the oil component almost disappeared. This light irradiated crude oil supernatant had high turbidity and low transparency due to insoluble matters and colored substances derived from petroleum degradation products and algae ethanol crude extract-derived components.

  However, when the microorganisms having the nucleotide sequences shown in SEQ ID NO: 3 and SEQ ID NO: 4 were inoculated and allowed to stand for half a day, they could be separated into a colorless and highly transparent supernatant and precipitate. Thereby, the oil component was able to be decomposed | disassembled.

  The method for decomposing oil according to the present invention can be used in the field and in the technical field for purifying the associated water taken out when oil or natural gas is produced or soil contaminated with oil. is there.

Claims (3)

A method for decomposing oil comprising either one or both of an aliphatic hydrocarbon and an aromatic compound,
A method for decomposing oil, which comprises contacting the oil with chlorophylls, irradiating light, and oxidizing the oil by a photocatalytic reaction.   2. The oil according to claim 1, wherein the oil oxidized by the photocatalytic reaction is contacted with a microorganism that decomposes a compound having a hydroxy group, and the oil oxidized by the photocatalytic reaction is further oxidized by biological treatment. Decomposition method. The oil according to claim 1 or 2, wherein the chlorophyll is composed of any one or a combination of two or more of chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll d, and chlorophyll f. Decomposition method.

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