• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.322-331
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• 2016

Oil budget calculator identifies the removal pathways of spilled oil by both natural and response methods, and estimates the remaining oil required response activities. A oil budget calculator was newly developed as a response tool for Deepwater Horizon oil spill incident in Gulf of Mexico in 2010 to inform clean up decisions for Incident Comment System, which was also successfully utilized to media and general public promotion of oil spill response activities. This study analyzed the theoretical background of the oil budget calculator and explored its future application to Korea. The oil budge calculation of four catastrophic marine pollution incidents indicates that 3~8% of spilled oil was removed mechanically by skimmers, 1~5% by in-situ burning, 4.8~16% by chemical dispersion due to dispersant operation, and 37~56% by weathering processes such as evaporation, dissolution, and natural dispersion. The results show that in-situ burning and chemical dispersion effectively remove spilled oil more than the mechanical removal by skimming, and natural weathering processes are also very effective to remove spilled oil. To apply the oil budget calculator in Korea, its parameters need to be optimized in response to the seasonal characteristics of marine environment, the characteristics of spilled oil and response technologies. A new algorithm also needs to be developed to estimate the oil budget due to shoreline cleanup activities. An oil budget calculator optimized in Korea can play a critical role in informing decisions for oil spill response activities and communicating spill prevention and response activities with the media and general public.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.519-528
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• 1993

The biodegradation experiment, the TOD analysis and the element analysis for dispersant, Bunker-C and dispersant/Bunker-C oil mixtures were conducted for the purposes of evaluating the biodegradability of dispersnat/Bunker-C oil mixtures and studying the consumption of dissolved oxygen with relation to biodegradation in the seawater. The results of biodegradation experiment showed the mixtures with $1:10{\sim}5:10$ mix ratios of dispersant to 4mg/l of Bunker-C oil to be $0.34{\sim}2.06mg/l$ of $BOD_5$ and to be $1.05{\sim}5.47mg/l$ of $BOD_{20}$ in natural seawater. The results of TOD analysis showed 1mg of Bunker-C oil to be 3.16mg of TOD. The results of element analysis showed the contents of carbon and hydrogen to be $87.3\%\;and\;11.5\%$ for Bunker-C oil, respectively, but nitrogen element was not detected in Bunker-C oil. The biodegradability of dispersant/Bunker-C oil mixture shown as the ratio of $BOD_5$/TOD was increased from $3\%\;to\;11\%$ as a mix ratio of dispersant to 4mg/l of Bunker-C oil changed from 1:10 to 5:10, and the mixtures were found to belong in the organic matter group of low-biodegradability. The deoxygenation rates($K_1$) and ultimate oxygen demands($L_o$) obtained through the biodegration experiment and Thomas slope method were found to be $0.072{\sim}0.097/day$ and $1.113{\sim}6.746mg/l$ for the mixtures with $1:10{\sim}5:10$ mix ratios of dispersant to 4mg/l of Bunker-C oil, respectively. The ultimate oxygen demand of mixture was increased as a mix ratio of dispersant to Bunker-C oil changed from 1:10 to 10:5. This means that the more dispersants are applied to the sea for Bunker-C oil cleanup, the more decreases the dissolved oxygen level in the seawater.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.57-64
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• 2020

The IOPC Fund general assembly reported that the International Convention on Liability and Compensation for Damage in Connection with the Carriage of Hazardous and Noxious Substances by Sea (known as the HNS Convention) will meet the requirement for the convention to take ef ect between 2021 and 2022. When the convention comes into effect, the liability-limit insurance of the HNS transport ship will be enforced and the shipper receiving the HNS will pay the share of the contribution from the International Fund for damages exceeding the limit of the ship's liability insurance. Korea is one of the major shipping and shipper countries in the world; thus, this study aimed to the need to analyze the effect of the convention on the related industries. The survey of ships and contribution targets analyzed the research data of the Ministry of Oceans and Fisheries. The P&I premium estimation was reviewed by the Korea Shipping Association and the K P&I as insured ships. In addition, the contribution of the HNS cargo volume was analyzed in an annual report by a representative international association for each cargo. About 1,500 ocean-going and domestic vessels have been identified as ships subject to the convention. The effect of changes in premiums under the convention was minimal for most ships. The effect of the shipping industry is expected, with about 150 domestic tankers expected to increase insurance premiums. In the case of shipper industries, 52 freight terminals were found to be eligible for the payment of the share of the international fund, as the proportion of freight volume in Korea was ranked second to fourth in the world by individual HNS accounts. This implies the obligation to pay contributions according to the convention. Considering the status of HNS transport ships entering and leaving ports and the quantity of HNS cargo, it can be concluded that the validity of Korea's convention is sufficient and that, it is necessary to coordinate with global major shipper countries.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.267-271
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• 2003

Burkholderia sp. D5, a polyaromatic hydrocarbons(PAHs)-degrading bacterium, was isolated from oil-contaminated soil. The bacterium could utilize phenanthrene (Phe) as a sole carbon source but could not use pyrene (Pyr). However, the strain could degrade Pyr when a cosubstrate such as yeast extract (YE) was supplemented. The PAH degradation rate of the bacterium was enhanced by the addition of other organic materials such as YE, peptone and glucose. YE was a particularly effective additive in stimulating cell growth as well as PAH degradation. When 1 g-YE/L was supplemented into the basal salt medium (BSM) with 215 mg-Phe/L, the specific growth rate (0.28 h-1) and Phe-degrading rate (29.30 μmol/L/h) were enhanced approximately ten and two times more than those obtained in the BSM with 215 mg-Phe/L, respectively. Through kinetic analysis, the maximum specific growth rate (μmax) and PAH degrading rate (Vmax) for Phe were obtained as 0.34/h and 289 ${\mu}mol$/L/h, respectively. Also, μmax and Vmax for Pyr were 0.27 h-1 and 50 ${\mu}mol$/L/h, respectively. The degradation rates for each Phe (2.20 μmol/L/h) and Pyr (2.18 μmol/L/h) were lower in mixture substrates than in a single substrate (29.30 ${\mu}mol$/L/h and 9.58 ${\mu}mol$/L/h, respectively). Burkholderia sp. D5 can degrade Phe and Pyr contained in soil, and the PAH degradation rates in soil were 20.03 ${\mu}mol$/L/h for Phe and 1.09 ${\mu}mol$/L/h for Pyr.

• Journal of Life Science
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• v.24 no.9
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• pp.988-994
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• 2014

The effluents of chemical and petroleum industries often contain non-biodegradable aromatic compounds, with phenol being one of the major organic pollutants present among a wide variety of highly toxic organic chemicals. Phenol is toxic upon ingestion, contact, or inhalation, and it is lethal to fish even at concentrations as low as 0.005 ppm. Phenol biodegradation has been studied in detail using bacterial strains. However, these microorganisms suffer from substrate inhibition at high concentrations of phenol, whereby growth is inhibited. A phenol-degrading bacterium, P21, was isolated from oil-contaminated soil. The phenotypic characteristics and a phylogenetic analysis indicated the close relationship of strain P21 to Rhodococcus pyridinovorans. Phenol biodegradation by strain P21 was studied under shaking condition. The optimal conditions for phenol biodegradation by strain P21 were 0.09% $KNO_3$, 0.1% $K_2HPO_4$, 0.3% $NaH_2PO_4$, 0.015% $MgSO_4{\cdot}7H_2O$, 0.001% $FeSO_4{\cdot}7H_2O$, initial pH 9, and $20-30^{\circ}C$, respectively. When 1,000 ppm of phenol was added to the optimal medium, the strain P21 completely degraded it within two days. Rhodococcus pyridinovorans P21 could grow in up to 1,500 ppm of phenol as the sole carbon source in a batch culture, but it could not grow in a medium containing above 2,000 ppm. Moreover, strain P21 could utilize toxic compounds, such as toluene, xylene, and hexane, as a sole carbon source. However, no growth was detected on chloroform.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.407-419
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• 2022

Soil(vadose zone) gas compositions were measured for about 3 days to suggest a method for monitoring and interpreting soil gas data collected around wells from which methane(CH₄) is outflowing. The vadose zone gas samples were collected within 1 m around two test wells(TB2 and TB3) at Pohang and analyzed for CO₂, CH₄, N₂ and O₂ concentrations in situ. CO₂ flux was measured beside TB2. In addition, gas samples from well head in TB2 and atmospheric air samples were collected for comparison. Carbon isotopes of CO₂(δ¹³C_CO2) of samples collected on the last day of the study period were analyzed in the laboratory. The two test wells (TB2 and 3) were 12.7 m apart and only TB3 was cemented to the surface. According to the bio-geochemical process-based interpretation, the relationships between CO₂ and O₂, N₂, and N₂/O₂ of vadose zone gas were plotted between the lines of CH₄ oxidation and CO₂ dissolution. In addition, the CH₄ concentrations of gas samples from the wellhead of the uncemented well (TB2) were 5.2 times higher than the atmospheric CH₄ concentration. High CO₂ concentrations (average 1.148%) of vadose zone gas around TB2 seemed to be attributed to the oxidation of CH₄. On the other hand, the vadose zone CO₂ around the cemented well(TB3) showed a relatively low concentration(0.136%). This difference indicates that the vadose zone gas(including CO₂) around the CH₄ outflowing well were strongly affected by well completion(cementing). This study result can be used to establish strategies for environmental monitoring of soil around natural gas sites, and can be used to monitor leakage around injection and observation wells for CO₂ geological storage. In addition, the method of this study is useful for soil monitoring in natural gas storage and oil-contaminated sites.