JP2006095412A - Method for decomposing/removing heavy oils - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for decomposing/removing heavy oils, by which the soil which is contaminated with heavy oils and contains a large amount of high-concentration heavy oils or a persistent component, can be cleaned under simple control. <P>SOLUTION: This method for decomposing/removing heavy oils is used for cleaning the soil contaminated with heavy oils by decomposing heavy oils by the decomposability of a microbe. A white rot fungus is adopted as the microbe. The contaminated soil is cleaned by using the white rot fungus and a white rot fungus-inoculated culture or a lignin-decomposable enzyme produced from the white rot fungus. When the white rot fungus and its culture are mixed in the soil contaminated with heavy oils and the mixture is cultured for one week to four weeks at 25-30°C, heavy oils can be decomposed/detoxified. Since the white rot fungus has the capacity for decomposing a persistent polycyclic aromatic compound, lignin can be decomposed. The white rot fungus is known as a microbe capable of decomposing dioxins, or the like. Therefore, the polycyclic aromatic compound to be hardly treated by the conventional bioremediation can be decomposed by the white rot fungus. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a method for decomposing and purifying heavy oils that decomposes and purifies contaminated soil contaminated with heavy oils by the resolution of microorganisms.

  When diverting the site of a business establishment that handles petroleum products to other businesses, the soil on these sites may be contaminated with oil or the like, and it is necessary to purify the contaminated soil.

Conventional methods for purifying contaminated soil with petroleum products and the like are classified according to the principle as follows.
(1) A method of chemically decomposing pollutants with heat, catalyst, light or the like.
(2) A method of chemically removing contaminants by adsorption, solidification, and extraction.
(3) A method of shielding the soil and physically containing the contaminants.
(4) A method of biologically degrading contaminants by bioremediation using microorganisms or the like.

Bioremediation is a bioenvironmental remediation (purification) technology, and bioremediation involves biostimulation that activates indigenous microorganisms to enhance and reinforce self-cleaning and introduces (inputs) foreign microorganisms. There is. These purification methods are classified into a method for performing purification treatment at a contaminated site (in situ bioremediation or on-site bioremediation) and a method for performing treatment at a site other than the contaminated site (ex situ bioremediation or offsite bioremediation). Can be classified. In addition, this method is a method in which indigenous microorganisms and the like are activated by adding nutrient salts and supplying oxygen, thereby decomposing and detoxifying heavy oils.
JP 2004-8900 A

  By the way, although the purification methods (1) to (4) can be processed for a relatively short time, they require energy such as fuel and electricity, and kill the soil environment as one ecosystem. For example, the load on the environment is relatively large and the processing cost is high.

  In addition, the bioremediation (4) has a problem that it is difficult to treat highly-contaminated soil, and a problem that it is difficult to decompose hardly decomposable polycyclic aromatics among heavy oil components.

  Furthermore, in the bioremediation of (4), a process of adding nutrient salts and a process of supplying oxygen are necessary, and it is necessary to add nutrient salts and supply oxygen (composting the culture). There was a problem that the cost to manage was high.

  The present invention has been made in order to solve the above-mentioned problems, and can be used to treat high-concentration contaminated soil and heavy oil-contaminated soil containing a large amount of hardly decomposable components with a simple management. It is a technical problem to provide a method for decomposing and purifying water.

The present invention is a method for decomposing and purifying heavy oils, and has the following configuration in order to solve the above technical problems.
That is, the heavy oil decomposition and purification method of the present invention is a heavy oil decomposition and purification method that decomposes and purifies contaminated soil contaminated with heavy oil by the resolution of microorganisms,
Adopting white rot fungi as the microorganism,
The contaminated soil is purified using the white rot fungus, a culture inoculated with the white rot fungus, or a lignin-degrading enzyme produced by the white rot fungus.

  According to this configuration, white rot fungi and cultures thereof are mixed with heavy oil contaminated soil and cultured at 25 ° C. to 30 ° C. for 1 to 4 weeks, thereby decomposing and detoxifying heavy oils.

  In addition, white rot fungi have the ability to degrade persistent polycyclic aromatics and can degrade lignin. Furthermore, white rot fungi are known as microorganisms that degrade dioxins and the like, and can degrade polycyclic aromatics that have been difficult to treat with conventional bioremediation.

  In addition, as a culture substrate in the culture in the method for decomposing and purifying heavy oils of the present invention, a woody material is adopted, and the culture is prepared without composting the woody material. The woody material is a pruning material containing leaves.

  Furthermore, in the method for decomposing and purifying heavy oils of the present invention, the lignin-degrading enzyme produced by the white rot fungus is manganese peroxidase, laccase and lignin peroxidase.

  Still further, when preparing the culture, no nutrient salt is added.

  The present invention is capable of treating highly contaminated soil, and managing the addition of nutrients and oxygen supply (composting the culture) to heavy oil contaminated soil containing a large amount of persistent components. It can be purified. For this reason, it is possible to reduce the labor cost required for management and cope with high-concentration contamination, so that the scope of purification can be greatly expanded.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a heavy oil decomposition and purification method according to the present invention will be described in detail with reference to the drawings.

  The method for decomposing and purifying heavy oils according to this embodiment is a method for purifying heavy oils (contaminated soil), and lignin-degrading enzymes produced by white rot fungi and their cultures or white rot fungi. To purify. The lignin-degrading enzymes produced by this white rot fungus are manganese peroxidase, laccase and lignin peroxidase.

  In this embodiment, as heavy oils, C heavy oil with the largest amount of non-volatile components is the target. Moreover, the wood flour (beech defatted wood flour) is used as a culture substrate in the culture in this embodiment without composting. Further, this woody material is a pruning material containing leaves. Furthermore, YK-624 and Kawaratake are used as white rot fungi (mushrooms).

  That is, inoculate wood flour (beech defatted wood flour: heavy oil concentration 15000 ppm) impregnated with C heavy oil with white rot fungi (YK-624 or Kawaratake) and leave at 30 ° C. for 1 to 4 weeks. Incubation was performed and the degradation effect was confirmed.

  FIG. 1 is a graph showing the state of decomposition of heavy oils (C heavy oil). In FIG. 1, the vertical axis represents the amount of residual oil (%), and the horizontal axis represents the elapsed time.

  In FIG. 1, when YK-624 is used as a white rot fungus, the residual oil amount (%) changes rapidly to 15% after 2 weeks from the start, and after 6 weeks, the residual oil amount (%) Changed to 8%. In addition, when Kawaratake was used as the white rot fungus, the residual oil amount (%) changed to 8% after 6 weeks from the start.

  This shows that C heavy oil can be decomposed and purified using white rot fungi (YK-624, Kawaratake, etc.). Moreover, even if the same white rot fungus is compared with YK-624 and Kawaratake, YK-624 can be decomposed and purified more efficiently than Kawaratake.

  In addition, according to this embodiment, when YK-624 was used as the white rot fungus, it was confirmed that about a half (about 50%) of heavy C heavy oil was decomposed in about one week. Therefore, this embodiment makes it possible to use conventional microorganisms that could not cope with a high concentration of C heavy oil, and it is unnecessary to make compost (such as switching back by static culture) that has been conventionally performed. It was suggested that it can be efficiently decomposed and detoxified.

  FIG. 2 is a graph showing the decomposition state of each of A heavy oil, B heavy oil, and C heavy oil using white rot fungi (YK-624) that can be efficiently decomposed and purified. In FIG. 2, the vertical axis represents the amount of residual oil (%), and the horizontal axis represents the elapsed time.

  In FIG. 2, when A heavy oil was decomposed and purified using YK-624 as a white rot fungus, the residual oil amount (%) changed rapidly to 10% after 2 weeks from the start, and after another 6 weeks, The oil amount (%) changed to 5%. When heavy oil B is decomposed and purified using white rot fungus with YK-624, the residual oil amount (%) changes rapidly to 10% after 2 weeks from the start, and after 6 weeks, the residual oil amount (%) Changed to 5%. In the case of C heavy oil, the residual oil amount (%) changed rapidly to 15% after 2 weeks from the start, and after 6 weeks, the residual oil amount (%) changed to 8%.

  From this, it can be confirmed that when the white rot fungus is decomposed and purified using YK-624, the A heavy oil and the B heavy oil can be further decomposed and purified more efficiently than the C heavy oil.

Next, examples of the heavy oil decomposition and purification method according to the present invention will be described.
In this example, simulated soil obtained by adding C heavy oil to sandy soil at 5000 to 50000 mg / kg was used as heavy oil contaminated soil. Moreover, in this Example, as mentioned above, it is used without composting wood-based material wood flour (beech defatted wood flour).

  Furthermore, YK-624 is used as a white rot fungus (mushroom fungus). In this example, three types (5000ppm, 20000ppm, 50000ppm) of simulated soil impregnated with C heavy oil were inoculated with white rot fungi, left to stand at 25 ° C for 3 weeks, and simulated with C heavy oil added. The soil was decomposed and purified.

  FIG. 3 is a graph showing the decomposition state of each of three types (5000 ppm, 20000 ppm, 50000 ppm) of simulated soil impregnated with C heavy oil. In FIG. 3, the vertical axis indicates the amount of residual oil (%), and the horizontal axis indicates the elapsed time.

In Fig. 3, when the simulated soil of 5000ppm is decomposed and purified using white rot fungi, the residual oil amount (%) changes rapidly to 18% after one week from the start, and after another three weeks, the residual oil amount (%) Changed to 8%. In addition, when 20,000 ppm simulated soil was decomposed and purified using white rot fungi, the remaining oil amount (%) changed rapidly to 20% after one week from the start, and after another three weeks, the remaining oil amount (% ) Changed to 15%. In addition, when 50,000 ppm simulated soil was decomposed and purified using white-rot fungi, the remaining oil amount (%) changed rapidly to 20% after 1 week from the start, and after another 3 weeks, the remaining oil amount (% ) Changed to 15%. That is, it was confirmed that the heavy oil decomposition and purification method of the present invention can be decomposed and purified to 10% to 15% in 3 weeks even for heavy oils of high concentration (for example, 50000 ppm).

  When the simulated soil of 5000ppm was decomposed and purified using conventional bioremediation, as shown in Fig. 3, the remaining oil amount (%) changed to 85% after 1 week from the start, and when 3 weeks passed, The oil amount (%) changed to 65%.

  According to the results of this example, when the decomposition and purification method for heavy oils of the present invention was used, the conventional bioremediation was able to decompose and purify only about 65% over 3 weeks. Can be decomposed and purified to 10% to 15%.

  Further, in the method for decomposing and purifying heavy oils according to the present invention, since no nutrient salt is added at the time of preparing a culture, management can be simplified. Furthermore, since it is not necessary to compost (reversed by static culture, etc.) which has been conventionally performed, management can be simplified, and decomposition and detoxification can be efficiently performed.

The decomposition state of heavy oil (C heavy oil) is represented with a graph. The decomposition state of each of A heavy oil, B heavy oil, and C heavy oil is graphically represented using white rot fungi (YK-624) that can be efficiently decomposed and purified. The decomposition state of each of three types (5000 ppm, 20000 ppm, 50000 ppm) of simulated soil impregnated with C heavy oil is represented by a graph. It is a perspective view of an aggregation reaction tube.

Claims (5)

A method for decomposing and purifying heavy oils by decomposing and purifying contaminated soil contaminated with heavy oils by the resolution of microorganisms,
Adopting white rot fungi as the microorganism,
A method for decomposing and purifying heavy oils, wherein the contaminated soil is purified using the white rot fungus, a culture inoculated with the white rot fungus, or a lignin-degrading enzyme produced by the white rot fungus. As a culture substrate in the culture, a woody material is adopted,
The method for decomposing and purifying heavy oils according to claim 1, wherein the culture is prepared without composting the woody material.   The method for decomposing and purifying heavy oils according to claim 2, wherein the woody material is a pruning material containing leaves.   The method for decomposing and purifying heavy oils according to any one of claims 1 to 3, wherein the lignin-degrading enzyme produced by the white rot fungus is manganese peroxidase, laccase and lignin peroxidase.   The method for decomposing and purifying heavy oils according to any one of claims 1 to 4, wherein no nutrient salt is added when the culture is prepared.

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