KR100481700B1 - method for aerobic treating soil polluted with oil by decomposing bacteria - Google Patents

Abstract

The present invention relates to aerobic treatment of oil-contaminated soil by oil-degrading bacteria, administering oxygen-producing photosynthetic strains and oil-degrading strains to oil-contaminated soil and supplying light from a light source, but with good dispersion of light to the soil. In order to inject into the soil the optical fiber with the scratches on the cladding part of the optical fiber injected into the soil, the effect is not only small on the ecosystem, but also a remarkable effect that can shorten the period to decompose and stabilize the oil of the contaminated soil. Can be.

Description

Method for aerobic treating soil polluted with oil by decomposing bacteria}

The present invention relates to aerobic treatment of oil-contaminated soil by oil-degrading bacteria, more specifically, by using the oxygen produced from photosynthetic bacteria to increase the activity of oil-degrading strains and indigenous microorganisms in oil-contaminated soils It relates to aerobic treatment of oil contaminated soil by oil decomposition bacteria that can minimize the time taken to purify.

Techniques for treating contaminated soil include physical, chemical and biological treatment techniques.

Physical treatment technology is a shielding method that creates an impervious zone to prevent contaminants from spreading around by the movement of groundwater and a method of blocking groundwater flow by adjusting water pressure, which is inexpensive and compatible with other methods. However, pollutants are not fundamentally removed, and chemical treatment technology separates pollutants adsorbed in the soil from the soil using chemical catalysts to remove pollutants. There is a disadvantage that the air treatment process should be introduced.

On the other hand, biological treatment technology uses a biodegradation process that proceeds in a natural state such as a river or soil, and has an advantage in that microorganisms having excellent adaptability to the environment decompose harmful substances without changing soil type in the soil. Particularly in the proper conditions, the growth rate and the processing speed are very high, and are used in various process forms for the purification of oil contaminated soil.

In particular, among the oils that cause soil pollution, diesel has a relatively low volatility and solubility compared to other oils, so that the spread of pollutants is slow and is mainly vertical through the soil unsaturated layer in a non-aqueous phase liquid (NAPL) state. It tends to migrate and accumulate above groundwater levels. In general, a large amount of accumulated diesel remains between pores of unsaturated soil by capillary action and is a residual saturation state, acting as a long-term source of infiltration or groundwater such as rainwater. It becomes.

As such, since the diesel component is basically low in volatility or solubility, and relatively high in biodegradability, biological treatment is mainly used for the purification of the unsaturated unsaturated soil layer with diesel.

The biological purification method of the contaminated soil is a biodegradation process performed in a natural state such as a river or soil, and artificially improves the processing speed by supplying oxygen separately, providing deficient nutrients, or providing microorganisms suitable for decomposition of pollutants. The method of making is mainly used.

However, in the soil or saturated soils with high pollution, the oil blocks the air layer and transfers oxygen to the air, which adversely affects the growth conditions of aerobic microorganisms. The injection of oxygen, which is an important factor in the composition, has become a problem.

Accordingly, the present invention has been made in view of the above-described conventional problems, and oxygen is produced in order to effectively and efficiently deal with the problem that oxygen is not supplied to soil contaminated with oil and thus requires much time to decompose pollutants. Aerobic treatment of oil-contaminated soil that maximizes the purification effect by stimulating oxygen production of photosynthetic bacteria by artificially transmitting light through optical fiber through artificial fiber through the fiber and supplying excellent oil-decomposing microorganisms separated from nature To provide a method.

A secondary object of the present invention is to provide a clear and clean environment in the future by achieving a faster natural purification by operating the aerobic treatment method of oil-contaminated soil in an optimal state.

The aerobic treatment method of soil contaminated oil by the oil-degrading bacteria of the present invention as described above is to administer oxygen-producing photosynthetic strains and oil-degrading strains to the soil contaminated with oil, supplying light from the light source, but light into the soil It consists of injecting optical fiber into the soil to improve the supply of.

Oxygen-producing photosynthetic strains used in the aerobic treatment of oil-contaminated soils by oil-degrading bacteria of the present invention are isolated from rivers, inoculated in sterilized medium and incubated in lamp-equipped incubators. Rhodobacter sphaeroides sp.).

The oil degradation strain is Pseudomonas aeruginosa (Pseudomonas aeruginosa) F722 isolated from the oil-contaminated soil and cultured in LB medium. In addition, the oil degradation strain is characterized in that it is Acinetobacter calcoaceticus OM1 isolated from the ocean and cultured in LB medium.

The oil degradation strain used in the present invention is preferably used by mixing Pseudomonas arginosa F722 and Acinetobacter carcoeistikus OM1 in a 1: 1 ratio.

Lactobacillus strain Pseudomonas arginosa F722 used in the present invention Cinetobacter Carcoesticus OM1 is a strain found in the Microbiology Laboratory, Department of Environmental Engineering, Chonnam National University. On May 8, 2002, it was deposited with KACC as P02-019 and P02-020. The accession numbers are "KACC 91005" and "KACC 91006".

In addition, the present invention is to the cladding portion of the optical fiber that is injected into the soil so that the optical fiber is injected into the oil contaminated soil for the photosynthetic action of the oxygen-producing photosynthetic strain to have a good dispersion of light in the soil. It is characterized by forming a scratch.

In the aerobic treatment method of oil-contaminated soil by oil-degrading bacteria of the present invention, the light emitted from the light source and supplied to the medium is 1,000 to 2,000 lux at the end of the optical fiber injected into the soil.

The aerobic treatment method of oil contaminated soil of the present invention schematically enhances the oxygen generation amount of photosynthetic strains producing oxygen, and the oil decomposition strain removes oil contamination using the generated oxygen as follows. .

First, photosynthetic and oil degradation strains are administered to oil contaminated soil.

The photosynthetic strain is selected from among algae-type photosynthetic strains that release oxygen. In the present invention, it is preferable to select and use Rhodobacter sphaeroides that are easily available as photosynthetic agents.

Rhodobacter sphaeroides species are isolated from the river and inoculated in a growth medium of pH 6.8, and the growth medium is yeast extract 1.0g, ethanol 0.5ml, sodium succinate 5.0ml, KH2PO4 0.5g, MgSO4 · 7H2O 0.4g, NaCl 0.4g, NH4Cl 0.4g, CaCl2 · 2H2O It is made up of 0.05 g, 1.0 ml of trace element solution SL-6, and 1.0 L of distilled water.

In addition, the trace element solution SL-6 is 0.1 g of ZnSO 4 · 7H 2 O, 0.03 g of MnCl 2 · 4H 2 O, 0.02 g of CoCl 2 · 6H 2 O, 0.01 g of CuCl 2 · 2H 2 O, 0.02 g of NiCl 2 · 6H 2 O, 0.03 g of Na 2 MoO 4 · 2H 2 O, and 1.0 L of distilled water. It is created.

Table 2 below shows the growth medium of Rhodobacter sphaeroides.

Yeast extract 1.0 g Trace element solution SL-6 ethanol 0.5 ml Sodium succinate 5.0 ml KH2PO4 0.5g MgSO4, 7H2O 0.4g ZnSO4, 7H2O 0.1g NaCl 0.4g MnCl2, 4H2O 0.03 g NH4Cl 0.4g CoCl2, 6H2O 0.02 g CaCl2 · 2H2O 0.05g CuCl2 · 2H2O 0.01 g Trace element solution SL-6 1.0 ml NiCl2, 6H2O 0.02 g Distilled water 1.0L Na2MoO4, 2H2O 0.03 g pH 6.8 Distilled water 1.0L

The growth medium thus prepared is placed in a screw capped bottle and nitrogen gas is injected for 1 to 2 minutes and then sealed with a rubber diaphragm. The sealed screw cap bottle is kept at 120-125 ° C. for 12-17 minutes to sterilize the growth medium.

The sterilized growth medium is inoculated with Rhodobacter sp. Spp. Sp. Using a sterile injector, and cultured in an incubator equipped with a lamp. At this time, the lamp is a light source for supplying photosynthesis of Rhodobacter sp. Sp. Sp. Sp., It is preferable to incubate for 2-3 days with a light of 3,000 to 5,000 lux using a tungsten lamp.

Oil-degrading strains used in the aerobic treatment of oil-contaminated soils by oil-degrading bacteria of the present invention as on-site microorganisms that are adapted to contaminated soil field conditions Many known microorganisms can be used, such as algae, bacteria, and fungi, which degrade hydrocarbons.

However, in view of the oil removal efficiency, in the present invention, it is most preferable to use Pseudomonas arginosa F722 and Acinetobacter carcoeistikus OM1 distributed in Chonnam National University of Environmental Engineering and Microbiology Laboratory as oil degradation strains.

The Pseudomonas arginosa F722 is well grown at 30 ~ 35 ℃, Acinetobacter Karkoeistikus OM1 is characterized by growing well at 25 ℃ or more incubated by inoculating each strain in LB medium.

In order to store the pure microorganisms as described above for a long time, it is stored in a freezer (DF 9014, Ilshin Lab Co., Ltd.) maintained at -70 ° C by mixing an enrichment culture solution and glycerol, and frequently The microorganism to be used is preferably used while smearing in an LB solid medium composed of 1 L of deionized water, 10 g of tryptone, 5 g of yeast extract, and 10 g of sodium chloride.

When each Pseudomonas arginosa F722 and Acinetobacter Carkoeistikus OM1 cultured were inoculated into oil-contaminated soil as a single strain, Pseudomonas Arginosa F722 showed a large difference in reproducibility and Acinetobacter car Coeistikus OM1 has a 75% removal rate after 7 days. On the other hand, when inoculated with the strain of Pseudomonas arginosa F722 and Acinetobacter Carcoesticus OM1 in the oil-contaminated soil, the removal rate of 95% after 2 weeks is investigated.

Pseudomonas Arginosa F722 and Ashineto have the above oil removal efficiency. Bacter carcoastigus OM1 is administered to oil contaminated soil along with photosynthetic strains.

The optical fiber is injected into the soil to which the photosynthetic strain and the oil degradation strain are administered, and light is supplied from the light source to improve the supply of light to the soil through the optical fiber. At this time, since the conductivity of light varies according to the material and thickness of the optical fiber, it is important to adjust the intensity of the original light source differently according to the optical fiber, but to be 1,000 to 2,000 lux at the end of the optical fiber injected into the soil.

The optical fiber developed by advanced science is also called optical fiber, and some of them are made of synthetic resin, but mainly made of glass with good transparency. Originally developed as a material for communication cables, it has been applied to outdoor lighting and indoor lighting in recent years by using beautiful and annular light transmission.

Referring to the structure of the optical fiber in Fig. 1, a portion called a core (1) in the center has a double cylinder shape in which a portion called a cladding (2) is wrapped around. The outside is coated with one or two coats of synthetic resin to protect it from impact. The total size excluding the protective coating is 100 to several hundred micrometers in diameter (1 micrometer is 1/1000 mm), and the refractive index of the core 1 portion is higher than that of the cladding 2, so that the light L is the core ( 1) Focused on the part, you can proceed without going well.

At this time, the end cladding (2) portion of the optical fiber to improve the dispersion efficiency of the light transmitted to the soil by the optical fiber by injecting the scratches (3) into the soil.

Photosynthetic bacteria administered in the soil efficiently use the optical fiber as a medium It is possible to use the light that is dispersed and supplied, and as a result, photosynthesis is actively promoted to promote oxygen generation.

As described above, oxygen generated by photosynthetic bacteria is used in the decomposition process of hydrocarbons by aerobic oil decomposition strains to promote the decomposition of oils.

In addition, compost is mixed for the biodegradation of oil contaminants by the oil degradation strain so that the nutrients of carbon, nitrogen, phosphorus can be sufficiently supplied.

The aerobic treatment method of oil-contaminated soil according to the present invention is to produce oxygen using photosynthesis of bacteria by light in the soil, and thus the possibility of self-delivery in the soil with respect to oxygen respiration required for biological restoration of oil-contaminated soil. It is an aerobic treatment method of oil-contaminated soil that supplies and effectively purifies the excellent oil-decomposing microorganisms separated from nature.

Hereinafter, preferred embodiments of the present invention will be described in detail.

<Example>

1. Photosynthetic strain culture

① Strain Rhodobacter sphaeroides were isolated from the stream.

② ZnSO4 · 7H2O 0.1g, MnCl2 · 4H2O 0.03g, CoCl2 · 6H2O 0.02g, CuCl2 · 2H2O 0.01g, NiCl2 · 6H2O 0.02g, Na2MoO4 · 2H2O 0.03g, 1.0L of distilled water, mixed with trace element solution SL-6 It was made.

③ yeast extract 1.0g, ethanol 0.5ml, sodium succinate 5.0ml, KH2PO4 0.5g, 0.4 g of MgSO 4 · 7H 2 O, 0.4 g of NaCl, 0.4 g of NH 4 Cl, 0.05 g of CaCl 2 · 2H 2 O, 1.0 ml of the trace element solution SL-6, and 1.0 L of distilled water were mixed to form a growth medium having a pH of 6.8.

④ 400 ml of the growth medium of ③ in a 500 ml screw cap bottle, and nitrogen gas was blown for 2 minutes and sealed with a rubber diaphragm.

⑤ ④ screwed bottle was sterilized for 15 minutes at 121 ℃ temperature to create an anaerobic medium.

Aseptic injector was inoculated with Rhodobacter sphaeroides isolated from the stream in the medium of ⑤ and incubated in an incubator equipped with a tungsten lamp for 2 days.

2. Culture of oil degradation strains

① As a microbial preparation, Pseudomonas arginosa F722 isolated from oil-contaminated soil and Ashinebacter karkoeistikus OM1 isolated from the ocean were distributed in Chonnam National University Department of Environmental Engineering and Microbiology.

② Pseudomonas arginosa F722 was inoculated in LB medium and incubated for 12 hours at 32 ℃.

③ Acinetobacter Karkoeistikus OM1 was inoculated in LB medium and incubated at 25 ° C. for 12 hours.

Pseudomonas arginosa F722 of ④ and Acinetobacter carcoeistiticus OM1 of ③ were mixed at a 1: 1 ratio.

3. Measurement of oil decomposition rate

① Produce reactor in size that can be tested in laboratory Prepared standard yarns were mixed with 3% diesel and artificially contaminated.

② Inoculated with compost (as a nutrient) and photosynthetic microorganisms and mixed strain 1% in the standard yarn contaminated with diesel, put in a constant temperature room at 30 ℃ was observed for two weeks.

1) Cumulative Oxygen Respiration

As described above, one reactor containing the standard yarn contaminated with 3% diesel was injected with only compost, and the other reactor was a mixed strain of Pseudomonas arginosa F722, which is an oil-decomposing microorganism, and Acinetobacter carcoesticus OM1. 1% was added.

After 14 days of experiment, the cumulative oxygen respiration rate of the two samples was measured using a respirometer, and the sample injected with compost showed a cumulative oxygen respiration amount of about 1,100 mg-O2 / kg-sand. The cumulative oxygen respiration rate of about 19,000 mg-O2 / kg-sand was observed in the sample to which the mixed oil-degrading microorganisms adapted to the oil contaminated sample were added.

Compost only Add 1% oil decomposition microorganism 1,100mg-O2 / kg-sand 19,000mg-O2 / kg-sand

As a result of the above experiment, it was found that the respiratory rate was much higher in the sample to which the oil-degrading microbe was added than in the sample to which the oil-degrading microbe was not added.

2) Oxygen production of Rhodobacter sphaeroids according to moisture content

In order to determine the oxygen production of the Rhodobacter spheroid species used in the embodiment of the present invention, the Rhodobacter spheroid species was added to the standard yarn contaminated with the 3% diesel. After injecting 10 wt% and 20 wt% of water into each of the two reactors, the amount of oxygen generated per hour was observed.

10% water addition 20% water addition 70.7mg-O2 / kg / hr 124.2mg-O2 / kg / hr

As a result of comparing the two samples, an average of 70.7 mg-O2 / kg / hr of oxygen was generated in a reactor injected with 10 wt% of water, and an average of 124.2 mg-O2 / in a reactor injected with 20 wt% of water. Kg / hr was measured.

As a result, it was found that the higher the moisture content, the better the growth of the bacteria, thereby producing a large amount of oxygen.

3) Oxygen utilization rate and microbial population according to moisture content

Mixed with standard sand, compost, 3% diesel, Pseudomonas arginosa F722, and Acinetobacter carcoastiticus OM1. Injected samples were prepared to check the microbial population and oxygen utilization per hour.

Water content 0wt% 10wt% 20wt% Water content of the sample (%) 11.8% 19% 25% Microbial entity count (CFUs / g) 6.4 × 107 2 × 109 2.5 × 109 Oxygen utilization rate (mg-O2 / kg / hr) 53 118 163

As a result of the above experiment, it was found that as the water content of the sample increased, the microbial population and oxygen utilization increased.

As a result, the oxygen respiration rate of the microorganisms necessary for biological restoration in oil-contaminated soils increased as the moisture content increased, and the oxygen respiration rate increased and the period for stabilizing the contaminated soil was also shortened. .

As described above, the aerobic treatment method of the oil-contaminated soil of the present invention not only has less impact on the ecosystem than any other method of purifying oil-contaminated soil, but also shortens the period for decomposing and stabilizing the oil of the contaminated soil. A significant effect can be obtained.

Furthermore, it can meet the domestic and international trends that increase awareness of the current environment, thereby securing competitiveness in the global environmental market and helping to acquire foreign currency.

1 is a configuration diagram briefly showing the configuration of an optical fiber,

Figure 2 is a block diagram of an optical fiber used in the aerobic treatment method of oil contaminated soil by oil decomposition bacteria of the present invention.

<Explanation of symbols for main parts of drawing>

1: core 2: cladding

3: scratches L: light

Claims (7)

Oil by photosynthetic strains and oil degradation strains are administered to oil contaminated soil, and optical fiber is injected into the soil to supply light from the light source and to provide light to the soil. Aerobic treatment of contaminated soil. [Claim 2] The soil contaminated by oil-producing bacteria according to claim 1, wherein the oxygen-producing photosynthetic strain is Rhodobacter sphaeroides, which is inoculated in a sterilized medium and cultured in an incubator equipped with a lamp. Aerobic treatment method. The method of claim 1, wherein the oil degradation strain is Pseudomonas aeruginosa F722 isolated from the oil contaminated soil and cultured in an LB medium. The aerobic treatment of oil-contaminated soil by oil-degrading bacteria according to claim 1, wherein the oil-degrading strain is Acinetobacter calcoaceticus OM1 isolated from the ocean and cultured in LB medium. Way. The aerobic treatment of oil-contaminated soil by the oil-degrading bacteria of claim 1, wherein the oil-decomposing strain is a mixture of Pseudomonas arginosa F722 and Acinetobacter carcoeisticus OM1 in a 1: 1 ratio. Way. The method of claim 1, wherein the optical fiber injected into the oil contaminated soil to transmit light for active photosynthesis of the photosynthetic strain is formed in the cladding portion of the optical fiber injected into the soil so that the light scattering power in the soil is good The aerobic treatment method of the oil-contaminated soil by the oil-decomposing bacteria, characterized in that. The method of claim 1, wherein the light irradiated from the light source and supplied to the medium is 1,000 to 2,000 lux at the end of the optical fiber injected into the soil.