• Journal of Soil and Groundwater Environment
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• v.7 no.2
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• pp.35-44
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• 2002

In order to determine the contamination of the aromatic hydrocarbons in soil, a fiber-optic sensing technique with fluorescence detector has been proposed. Previous researches have shown that the optimal condition for detecting benzene, toluene, ethylbenzene, xylene (BTEX) was 260 nm /290 nm (excitation/emission wavelength). However, broader fluorescence spectra of BTEX-polluted soil sample ranging from 300 nm to 600 nm were observed. Additionally, the intensity of fluorescence increased with increasing BTEX concentration, which was conspicuous in the fine-particle soil, The overall results indicated that the suggested technique could be useful for in-situ monitoring system for subsurface oil-storage tank.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.185-195
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• 2006

Phytoremediation is an economical and environmentally friendly bioremediation technique using plants which can increase the microbial population in soil. Unlike other pollutants such as heavy metals, poly-chlorinated biphenyl, trichloroethylene, perchloroethylene and so on, petroleum hydrocarbons are relatively easily degradable by soil microbes. For successful phytoremediation of soil contaminated with petroleum hydrocarbons, it is important to select plants with high removal efficiency through microbial degradation. In this study, we clarified the roles of plants and rhizobacteria and identified their species effective on phytore-mediation by reviewing the papers previously reported. Plants and rhizobacteria can degrade and remove the petroleum hydrocarbons directly and indirectly by stimulating each other's degradation activity. The preferred plant species are alfalfa, ryegrass, tall fescue, poplar, corn, etc. The microorganisms with a potential to degrade hydrocarbons mostly belong to Pseudomonas spp., Bacillus spp., and Alcaligenes spp. It has been reported that the elimination efficiency of hydrocarbons by soil microorganisms can be improved when plants were simultaneously applied. For more efficient restoration, it's necessary to understand the plant-rhizobacteria interaction and to select the suitable plant and microorganism species.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.1
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• pp.27-35
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• 2014

The headspace solid-phase microextraction (HS-SPME) followed by gas chromatography/mass spectrometry procedure has been developed for the simultaneous determination of petroleum aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) and polycyclic aromatic hydrocarbons (PAHs) in seawater. The advantages of SPME compared to traditional methods of sample preparation are ease of operation, reuse of fiber, portable system, minimal contamination and loss of the sample during transport and storage. SPME fiber, extraction time, temperature, stirring speed, and GC desorption time were key extraction parameters considered in this study. Among three kinds of SPME fibers, i.e., PDMS ($100{\mu}m$), CAR/PDMS ($75{\mu}m$), and PDMS/DVB ($65{\mu}m$), a $65{\mu}m$ PDMS/DVB fiber showed the most optimal extraction efficiencies covering molecular weight ranging from 78 to 202. Other extraction parameters were set up using $65{\mu}m$ PDMS/DVB. The final optimized extraction conditions were extraction time (60 min), extraction temperature (50), stirring speed (750 rpm) and GC desorption time (3 min). When applied to artificially contaminated seawater like water accommodated fraction, our optimized HS-SPME-GC/MS showed comparable performances with other conventional method. The proposed protocol can be an attractive alternative to analysis of BTEX and PAHs in seawater.

• Journal of the Korean GEO-environmental Society
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• v.11 no.8
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• pp.25-32
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• 2010

Contamination of soil and groundwater by the compounds of hydrocarbon petroleum has been widely accepted as the main cause that harms the environments and health. To remove those pollutants, absorbing clothes, activated carbons, or oil-water separation devices with the gravity method are employed for treatment. However, those materials and devices cannot remove the emulsion pollutants despite of their efficiency for removing free products. Therefore, we investigated the problems which occur during the groundwater treatment for the highly concentrated suspended solid particles, which can be resulted from excavation, and to propose methods to remove TPH(Total Petroleum Hydrocarbon). After coagulation experiment with high molecular polymers, the concentration of SS(Suspended Solids) and COD(Chemical Oxygen Demand) turned to satisfy the groundwater quality criteria within 5 minutes while the concentration of TPH failed to meet the water quality standard of effluent. Consequently, the water quality criteria for effluent could not be met by single DAF(Dissolved Air Flotation) process. However all water quality criteria could be satisfied after 20 minutes when coagulation reactions are carried out simultaneously in the DAF reactor.

• Journal of Life Science
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• v.19 no.5
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• pp.659-663
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• 2009

Bacterial stain 3Y was isolated from a site that was contaminated with diesel for more than 15 years. The strain could grow on various petroleum using hydrocarbons as the sole carbon source. The strain grew not only on aliphatic hydrocarbons but also on aromatic hydrocarbons. 3Y grew on aliphatic petroleum hydrocarbons hexane or hexadecane, and aromatic petroleum hydrocarbons BTEX, phenol, biphenyl, or phenanthrene. The strain showed aromatic ring dioxygenase and meta-cleavage dioxygenase activities as determined by tests using indole and catechol. Aromatic ring dioxygenase is involved in the initial step of biodegradation of aromatic hydrocarbons while meta-cleavage dioxygenase catalyzes the cleavage of the benzene ring. Based on a nucleotide sequence analysis of its 16S rRNA gene, 3Y belongs to the genus Sphingomonas. A phylogenetic tress was constructed based on the nucleotide sequences of closest relatives of 3Y and petroleum hydrocarbon degrading sphingomonads. 3Y was in a cluster that was different from the cluster that contained well-known sphingomonads. The results of this study suggest that 3Y has the potential to cleanup oil-contaminated sites. Further investigation is warranted to optimize conditions to degrade petroleum hydrocarbons by the strain to develop a better bioremediation strategy.

• Journal of Life Science
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• v.10 no.3
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• pp.300-306
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• 2000

Several bacterial strains utilizing crude oil as their sole carbon and energy source were isolated from polluted marine by crude oil. One of the strains, named KCL-2 showed strong degradation activity for crude oil. This strain was identified as a Klebsiella sp. based on the morphological, biochemical, and physiological characteristics. The optimum cultural conditions were as follows; $27^{\circ}C$~$37^{\circ}C$ for temperature and 7.0 for initial pH. Additionally, the optimal concentration of sodium chloride was 3.0%, confirming indicating that this strain was derived from sea water.The strain KCL-2 could use several kinds of n-alkane hydrocarbones from octadecane to octacosane as a sole carbon source. The emulsifying activity by KCL-2 was the highest after 3 days of cultivation under the condition of 3.0% sodium chloride, pH 7.0 and 32$^{\circ}C$. This strain had several criptic plasmids.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.721-730
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• 2006

The effects of compost amendment on the removal of petroleum hydrocarbons and the activities of microorganisms in soil ecosystem have been studied in bioremediation of diesel contaminated soil. The relation between biological activities and removal of petroleun hydrocarbon was determined by ATP(Adenisine Triphosphate), n-alkanes and TPH concentration analysis. After 80 days of bioremediation, the removal of TPH in soil amended with compost increased more than 10% compared with control soil which was tilled in the same condition without compost addition. The biodegradations of n-alkanes having 12 to 20 moles of carbon were distinctive. As the soil was contaminated with more diesel, the ATP has decreased rapidly. When the TPH amounted to 80,000 mg diesel/kg, the ATP decreased to 4 ng/g from initial concentration of 65 ng/g. While the ATP in the compost amended soil increased to 112 ng/g after tilling for 6 days, the ATP in the control increased to merely 36 ng/g after tilling for 14 days. Also while the control soil showed a lag time in ATP increase, the compost amended soil did not show that but showed a rapid ATP increase within a short time. The patterns of changes in ATP concentration were similar to those in daily removals of TPH with time difference of about 7 days.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.28-34
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• 2005

The aim of this article is to assess the application characteristics of the site by remediating oil-contaminated area using DSB (Deep-site Biopile) system. In the contaminated area, the soil was composed of penetrable sand and the leaked oil was spread widely (total 7,201 cubic meters) through 2.5 meter deep underground water flow. DSB system was operated for 30 minutes intervals for 24 hours in a day (30 minutes opεration and 30 minutes stop). To check contamination level change in the contaminated area after DSB system was operated, samples were taken. The result from the site shows that BTEX/TPH contamination level was dropped 50% after 30-day operation of DSB system, and that contamination level was dropped below contamination level check standard after 165 days and the remediation was completed. Unlike traditional biological remediation methods DSB system could efficiently process soil and water which were contaminated by high levels of oil compounds.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.3 s.3
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• pp.83-92
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• 2001

Field investigations for subsurface soil and groundwater at a gas station showed that the site was severely contaminated and even petroleum compounds as free liquid state were observed. Pilot-scale soil flushing and soil vapor extraction process(SVE) were applied to evaluate the effectiveness of pollutants removal. Surfactant solution, Tween 80, was used to enhance the solubility of petroleum compounds and resulted in about 10 times increase on TPH(Total Petroleum Hydrocarbon) concentration. As for SVE method, maximum concentration of TPH and BTEX reached within 24 hours of extraction and then continuously decreased. Considerations on the groundwater level and the kinetic limitation for volatilization of contaminants have to be taken into account for the effective application of SVE process.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.57-61
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• 2001

일반적으로 Asphaltene은 원유뿐만 아니라 화석연로원(Fessil Fuel Sources)에도 포함되어 있는 것으로 알려져 있으며 난분해성으로 탄화수소(Hydrocarbon)와 Heterocyclic 또는 N-, S-, 산소를 포함하는 화합물이다. 그리고 금속성 물질이 Asphaltene Fraction에 농축되어 있는 것으로 알려져 있다. 한편 이러한 metallo-complex는 Asphaltene의 구조화합물중 방향족계 sheet 사이에 Self-association 상태로 존재한다. Asphaltene의 분해는 일반 TPH나 BTEX계 유류의 분해 기작과는 매우 상이하며 현재까지 Asphaltene으로 오염된 토양의 복원 기술을 매우 미미한 것으로 알려져 있다. 따라서 본 연구는 Asphalteme으로 오염된 토양의 복원 기숙을 개발하기 위한 전단계로 Asphaletene의 구성물질과 저분자화 작용기작을 구명하여 효과적 복원기술 개발을 위하여 Arabian Light Oil에서 Oil 자체와 Oil에서 분리해낸 Asphaltene을 사용하여 용매조건과 처리제별로 저분자화 과정을 조사하였다.