KR100892689B1 - Bioremediation of seaside soil polluted with oil - Google Patents

Abstract

A bioremediation method of oil-polluted seaside soil is provided to purify the oil-polluted seaside soil stably by mixing a porous carrier with an oxygen generating agent or a slow release fertilizer. A bioremediation method of oil-polluted seaside soil comprises the following steps of: absorbing a microorganism on a porous carrier for immobilization of microorganism; mixing an 10 ~ 100 weight% of an oxygenator, 10 ~ 500 weight% of a time-released nutrient or 10 ~ 100 weight% of the oxygenator, 10 ~ 500 weight% of a time-released with the microorganism-adsorbed porous carrier; and reclaiming a mixture on the seaside soil.

Description

Bioremediation of Seaside Soil Polluted with Oil}

The present invention relates to bioremediation of oil-contaminated coastal soils. Specifically, when the intertidal zone soil of the coast is contaminated by oil, the soil soil that has been continuously contaminated with oil for a long time without being lost to the sea water by adsorbing microorganisms having oil degradation ability to the carrier and landfilling them. It relates to a method that can be biologically purified. The present invention further has an advantage of improving the oil resolution of the microorganism by further including an oxygen generator or a sustained-release nutrient.

Recently, all living organisms in the global ecosystem including human beings are threatened by the release of pollutants that transcend the self-cleaning ability of the ecosystem following industrialization and urbanization. In particular, in most countries, the pollution problem caused by oil used in the petrochemical industry and heavy chemical industry, which is the national infrastructure industry, is expanding from the local problem to the international problem. In particular, the oil pollution of the marine and coastal soils due to the oil spill accident in the ocean has been constantly. Oil pollutants are various types of petroleum hydrocarbon compounds contained in oil such as crude oil, diesel and gasoline, and the physical and chemical methods of contaminating soil and groundwater contaminated by these pollutants are also limited. Therefore, it is urgent to develop a new type of environmental purification method that can replace or supplement the existing method. A new type of environmental purification is bioremediation, which uses the inherent ability of microorganisms to decompose or detoxify oil.

Bioremediation method optimizes environmental factors affecting the metabolic activity of indigenous microorganisms in nature, artificially administers microorganisms with special environmental purification ability to the environment, or decomposes various pollutants through a combination of both treatments. By restoring the polluted environment to its original state. Compared to physical and chemical methods, this technology uses natural processes and is economical because it uses less energy, and the environment that hardly causes secondary pollution because it completely decomposes or detoxifies harmful compounds into carbon dioxide and water by metabolism of microorganisms. It's a friendly way. In addition, this method is applicable in the field, and thus has the advantage that it can be effectively used to clean the area where contaminants have already been widely spread.

As a bioremediation method for the purification of pollution by oil, microorganisms such as Korean Patent Application Nos. 1019990045835, 1020000027486, 1019940026352, 1019940026351, 1020030018913, 1020020018122, etc. have been found. Methods such as Korean Patent Application Nos. 1020020031429 and 1020000035283 have been devised.

However, the above methods are all subject to soil pollution caused by oil leakage in inland plant areas, and it is not applicable to coastal intertidal soil where it is difficult to expect stable purification of microorganisms by waves and high tide and low tide. impossible.

Specifically, the above-described low tide soil has a problem that the microorganisms for oil decomposition is easily wiped out as the sea water is continuously brought out by tides or tidal tides as mentioned above. This inevitably lowers the concentration of microorganisms, which significantly reduces the decomposition rate. This problem is similarly applied to the nutrients added for the growth of the microorganisms, even if the microorganisms are not washed in the sea water, it is difficult to obtain the optimum growth conditions due to the lack of nutrients.

In addition, the purified microorganisms that ultimately convert oil into carbon dioxide and water are aerobic microorganisms, and the low tide soils are blocked by the sea due to seawater, and the oxygen supply necessary for the growth of these microorganisms is not smooth, and this problem is more severe at high tide. Become.

Therefore, despite the above problems, there is an urgent need for a technique for stably purifying coastal soils from oil pollution.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a bioremediation method for purifying oil-polluted low tide coastal soil by adsorbing microorganisms having oil resolution on a porous carrier and embedding them. .

Another object of the present invention is to provide a bioremediation method for stably purifying oil-contaminated coastal soils for a long time by mixing an oxygen generating agent or a sustained-release nutrient with the porous carrier.

In order to achieve the object as described above, the biological restoration method of the oil-contaminated coastal soil of the present invention,

(A) adsorbing microorganisms having oil resolution to the porous carrier for fixing the microorganisms; And

(B) embedding the porous carrier adsorbed on the microorganisms in coastal soil

Characterized in that it comprises a.

In addition, the porous carrier of step (B) may be embedded by mixing with 10 to 1000 parts by weight of the oxygen generator per 100 parts by weight of the porous carrier.

In addition, the porous carrier of step (B) may be embedded by mixing with 10 to 500 parts by weight of slow release fertilizer (SRF) per 100 parts by weight of the porous carrier.

In addition, the porous carrier of step (B) may be embedded by mixing with 10 to 1000 parts by weight of the oxygen generating agent and 10 to 500 parts by weight sustained-release nutrient per 100 parts by weight of the porous carrier.

Further, the porous carrier of step (B), a mixture thereof with the oxygen generating agent, a mixture thereof with the sustained-release nutrient, or a mixture thereof with the oxygen generating agent and the sustained-release nutrient, may have a grid size of 0.2 to 10 It is also possible to bury in mm mesh bags.

In addition, the embedding of the step (B) is a porous carrier of the step (B), a mixture of it and the oxygen generating agent, and a mixture of the sustained-release nutrient in the inside of the hole of 10 to 200 cm length having a plurality of holes Alternatively, a mixture of the oxygen generator and the sustained-release nutrient can be added to bury the pores.

In addition, in the embedding of the step (B), it is also possible to put the mesh bag in the inside of the hole of 10 to 200 cm length formed with a plurality of through holes, and to fill the hole.

In addition, apart from the embedding of the step (B), from the culture medium of the microorganism having the oil resolution, the microorganism fixed porous carrier, the porous carrier to which the microorganisms are adsorbed, the oxygen generator, the sustained-release nutrient, and mixtures thereof It is preferable to further include the step of further spraying the selected coastal soil.

In addition, the method may further include the step of further spreading the coastal soil after spraying the coastal soil.

In addition, it is preferable that the microorganism having the oil resolution has flame resistance and low temperature activity.

In addition, the microorganism having the oil resolution is Rhodococcus sp. YHLT-2 (KCTC 10203BP).

In addition, the microbial fixation porous carrier may be selected from the group consisting of Celite, Vermiculite, Peat Moss, and mixtures thereof.

In addition, the oxygen generator may be selected from the group consisting of MgO ₂ , CaO ₂ , H ₂ O ₂ , KMnO ₄ and mixtures thereof.

In addition, the mesh bag, perforated pipe, or mesh bag and perforated pipe is preferably a material that is biodegraded by microorganisms.

In addition, the porous carrier is preferably an inorganic material or a material biodegraded by microorganisms.

Further, before the landfill of step (C), before further spraying on the coastal soil, or before landfilling of the step (C) and before further spraying on the coastal soil, a mesh bag containing the porous carrier adsorbed by the microorganism, the oil The culture medium of the microorganism having a resolution, the microorganism is adsorbed porous carrier may be further included for 1 to 5 days at 1 to 5 days.

Biocontamination method of the oil-contaminated coastal soil of the present invention has the advantage that the microorganisms are buried in a state in which the microorganisms are adsorbed on the porous carrier so that the microorganisms are not easily lost by waves or high water, and thus stable oil decomposition for a long time is possible. This advantage can be further increased by embedding the porous carrier adsorbed by the microorganisms in a mesh bag, or by embedding the porous carrier or the mesh bag containing the same in a hole formed with a plurality of holes.

Furthermore, the present invention can optimize the growth conditions of microorganisms by including a sustained-release nutrient that can last a long time as the release is controlled, as well as to the microorganisms that are easily blocked by the sea by adding oxygen generators. There is an advantage that can provide an aerobic environment.

Hereinafter, preferred embodiments of the present invention will be described in detail. In addition, in the following description there are shown a number of specific details such as specific components, which are provided only to help a more comprehensive understanding of the present invention, it is common in the art that the present invention may be practiced without these specific details. It is self-evident to those who have knowledge of the world. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Bioremediation of oil-contaminated coastal soils of the present invention starts with the step of adsorbing microorganisms having a resolution of the oil on a carrier for fixing microorganisms.

Since the object of the present invention is the biological restoration of pollution due to oil, the microorganism used in the present invention is also required to have the ability to convert oil such as crude oil into products that are harmless to the environment such as carbon dioxide.

Further, since the application region of the present invention is a low tide coastal soil, it is preferable to have flame resistance and low temperature activity in addition to the oil resolution.

Any microorganism having the above characteristics can be used in the present invention without limitation, in particular, Rhodococcus sp. YHLT-2 (KCTC 10203BP) is preferred. Oil resolution of the strain is disclosed in the applicant's patent publication (Korean Patent Publication No. 435231).

The microorganism of the present invention is adsorbed on a porous carrier capable of fixing it, through which a primary loss prevention is achieved. That is, as adsorbed on the carrier, it is possible to lower the possibility of being lost to sea water compared to the conventional method of spraying the soil directly in the form of a culture solution or lyophilized powder.

The porous carrier used in the present invention is not limited as long as it can adsorb and immobilize microorganisms, and it is preferable that the porous carrier is made of an inorganic material or a material that can be decomposed by microorganisms. In the present invention, it is particularly preferred to be selected from celite, vermiculite, peat and mixtures thereof.

The adsorption amount of the microorganisms in the carrier is preferably 10 ³ to 10 ¹¹ CFU per gram of carrier, if less than 10 ³ CFU, oil degradation efficiency is lowered, and if it exceeds 10 ¹¹ CFU, the culture itself is difficult as well as excessive microbial concentration itself Due to the disadvantage that the growth is reduced.

The porous carrier to which the microorganisms are adsorbed is then buried in the low tide coastal soil contaminated by the oil to initiate bioremediation of the contamination. In order to minimize the possibility of sea water loss due to the characteristics of the present application region called the coastal low tide soil, in addition to improving the contact efficiency of the microorganisms having oil resolution as the substrate, the landfill instead of spraying to be.

The landfill may bury the porous carrier by burying the coastal soil, and more preferably through the known method associated with the landfill, such as by filling up the coastal soil with a tractor or the like, then burying the porous carrier and covering the coastal soil again. It may be done.

In addition, the carrier to which the microorganisms are adsorbed may then be embedded in a mesh bag having a grid size of 0.2 to 10 mm. As a result, the microorganism of the present invention is provided with another means for preventing its loss in addition to landfill, and as a result, it is possible to stably purify oil such as crude oil over a long period of time. If the grid size of the mesh bag is less than 0.2 mm may be in contact efficiency between the oil and microorganisms, and if it exceeds 10 mm the carrier itself may be lost it is difficult to achieve the object of the present invention.

The mesh bag used in the present invention is not limited in size, for example, 25 L onion mesh may be used. More preferably, the bag itself is made of a material that can be biodegraded by microorganisms to prevent the occurrence of contamination due to the net bag itself.

Furthermore, in order to achieve a more stable embedding of microorganisms, it is also possible to use a spike method using a perforated tube. This is a method in which the porous carrier to which the microorganisms are adsorbed or the mesh bag containing the same is placed in a hole tube having a plurality of through holes, and the hole tube is buried.

For example, 10 to 50 cm in diameter and 10 to 200 cm in length are formed in a plurality of holes having a diameter of 0.1 to 1 cm at intervals of 2 to 10 cm perpendicular to contaminated coastal soil, and the inner coastal soil is removed as necessary. After the microorganisms are adsorbed, the porous carrier or the net bag containing the same can be embedded in a way to cover the coastal soil.

As a result, the oil-decomposing microorganisms used in the present invention can more stably perform purification in coastal soils. These perforated pipes may be made of biodegradable materials by microorganisms, or may be recovered and reused from the purified coastal soils even if they are not.

The amount of embedding of the porous carrier adsorbed by the microorganism, the mesh bag or the perforated pipe containing the microorganisms depends on the degree of contamination of the coastal soil. For example, a porous carrier or a mesh bag containing 1 to 5 kg of microorganisms adsorbed per 1 m ^{2 of} coastal soil may be embedded, or a porous hole may be embedded at intervals of 2 to 10 m in width.

On the other hand, the porous carrier that adsorbed the microorganism is more preferably used alone or in combination with the oxygen generator.

As described above, aerobic conditions are required for hydrocarbons such as oil to be completely decomposed into carbon dioxide and water, but the coastal soils of low tide are more likely to be blocked from the atmosphere by seawater than inland soils, which directly leads to a decrease in purification efficiency. .

This problem can be overcome by providing a separate oxygen generating agent with the microorganisms, the oxygen generating agent that can be used for this purpose is MgO ₂ , CaO ₂ , H ₂ O ₂ (200 to 1000 ppm aqueous solution), KMnO ₄ And mixtures thereof. The above-described oxygen generating agent is provided in the form of granules or powder, or in the case of H ₂ O ₂ is provided as a liquid to continuously generate oxygen, the generated oxygen is supplied to the microorganism used in the present invention.

The amount of the oxygen generating agent is preferably 10 to 1000 parts by weight per 100 parts by weight of the porous carrier, and may be increased or decreased depending on the probability of contact with the atmosphere. That is, a relatively large amount may be added when the area is buried or deeply buried in the sea, and a relatively small amount of oxygen generating agent may be added when the area is inland or shallowly buried. There is a possibility that oxygen is depleted in the second half of the purification process due to insufficient oxygen generation amount, and if it exceeds 1000 parts by weight, the economic efficiency may be reduced.

On the other hand, the porous carrier of the present invention can also be mixed and used with sustained-release nutrients. As described above, the loss of microorganisms due to seawater has been applied to nutritional substances for the growth of the microorganisms, and thus the purification efficiency has been drastically reduced. This may be the same even when the release is a controlled nutrient, it is preferable in the present invention to include a sustained release nutrient is released slowly through the control of the release.

These sustained-release nutrients include Woodace (Vigoro Industries), Customblen® (Sierra Chemical Co.), MaxBac (Grace Sierra), Inipol EAP 22 (Elf Aquataine Company), Osmocote® (The Scotts Miracle-Gro Co.), Lecitina de soja (Geminis), MgNH ₄ PO ₄ , S-200 (International Environmental Products, LLC), VB591 Water (BioNutraTech, Inc.), Vitabug (BioNutraTech, Inc.), and once fertilizer (shipbuilding fertilizer).

The added amount of the sustained-release nutrient is preferably 10 to 500 parts by weight per 100 parts by weight of the porous carrier, and when less than 10 parts by weight, the meaning of adding the nutrient can be halved.

The oxygen generating agent, the slow nutrient, or the oxygen generating agent and the slow nutrient may be mixed with the porous carrier to which the microorganism is adsorbed, and embedded in the mesh bag or the pore tube in the mixed state.

Coastal soil bioremediation method of the present invention is a porous carrier adsorbed the microorganisms, the culture medium of the microorganisms having the oil decomposition ability, the porous carrier for fixing the microorganisms, the porous microorganisms are adsorbed separately from the embedding of the net bag or perforated tube containing the microorganisms It may further comprise the step of further spraying the contaminated coastal soil with one selected from a carrier, the oxygen generator, the sustained nutritional agent, and mixtures thereof.

In the early stages of contamination, an excess of contaminants may cause microorganisms to inhibit the substrate, and later in the contamination, the loss or consumption of microorganisms, oxygen or nutrients may occur. Therefore, if the above signs are captured through monitoring of the purification efficiency, it is desirable to restore the purification efficiency by supplying additional components through the spraying or landfill form.

Of course, it is also possible to improve the contact efficiency with the source of pollution by plowing the coastal soil with a tractor or the like and then covering it again.

On the other hand, microorganisms having oil resolution of the present invention is preferably adapted to relatively low temperature coastal soil and seawater by storing for 1 to 5 days at a low temperature of 2 to 15 ℃ before landfilling or spreading, through which Saving time can speed up biological recovery through oil degradation.

Although the above has been illustrated and described with respect to the preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, those skilled in the art without departing from the gist of the present invention various modifications Of course, implementation is possible. Therefore, the scope of the present invention should not be construed as being limited to the above embodiments, but should be defined by the claims below and equivalents thereof.

Claims (11)

(A) adsorbing microorganisms having oil resolution to the porous carrier for fixing the microorganisms; And (B) 10 to 1000 parts by weight of the oxygen generator, 10 to 500 parts by weight of slow release fertilizer (SRF), or 10 to 1000 parts by weight of the oxygen generator and 10 to 500 parts by weight of the sustained nutrient per 100 parts by weight of the porous carrier. Buried in the coastal soil by mixing with a porous carrier adsorbed by the microorganisms Biocontamination method of the oil-contaminated coastal soil comprising a. delete The method according to claim 1, The porous carrier of step (B), a mixture thereof with the oxygen generator, a mixture thereof with the sustained nutrient, or a mixture thereof with the oxygen generator and the sustained nutrition agent, having a grid size of 0.2 to 10 mm Biocontamination method of oil-contaminated coastal soil characterized in that the landfill in a net bag. The method according to claim 1, The embedding of the step (B) is a porous carrier of the step (B), a mixture of it and the oxygen generator, a mixture of the sustained-release nutrient and the inside of the hole of 10 to 200 cm length having a plurality of holes, or And a mixture of the oxygen generating agent and the sustained-release nutrient, and embedding the pores of the oil. The method according to claim 3, Reclamation of the step (B) is a bio-contamination method of oil-contaminated coastal soil, characterized in that the mesh bag is put into the inside of the hole of 10 to 200 cm length formed with a plurality of holes, the hole is embedded. The method according to any one of claims 1 or 3 to 5, Apart from the landfill of the step (B), selected from the culture medium of the microorganism having the oil resolution, the microorganism fixed porous carrier, the porous carrier to which the microorganisms are adsorbed, the oxygen generator, the sustained-release nutrient, and mixtures thereof Biocontamination method of the oil-contaminated coastal soil, characterized in that further comprising the step of further spraying the coastal soil. The method according to claim 6, Biospray method of the oil-contaminated coastal soil, characterized in that further comprising the step of spraying the coastal soil and then the coastal soil. The method according to any one of claims 1 or 3 to 5, The microorganism having the oil resolving power is bio-contaminated method of the oil-contaminated coastal soil, characterized in that it has flame resistance and low temperature activity. The method according to any one of claims 1 or 3 to 5, The microorganism having the oil resolving ability is Rhodococcus sp. Bioremediation of oil-contaminated coastal soils, characterized in that YHLT-2 (KCTC 10203BP). The method according to any one of claims 1 or 3 to 5, The microbial fixation porous carrier is Celite (Celite), Vermiculite (Vermiculite), peat (Peat Moss), and bio-contaminated method of biocontaminated coastal soil, characterized in that selected from the group consisting of. The method according to any one of claims 1 or 3 to 5, The oxygen generator is MgO ₂ , CaO ₂ , H ₂ O ₂ , KMnO ₄ And biocontamination method of the oil-contaminated coastal soil, characterized in that selected from the group consisting of.