• 환경위생공학
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• 제22권3호
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• pp.13-26
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• 2007

Changes in the characteristics of dissolved organic matter was studied at selected stations in the Nakdong river basin using physical and chemical methods. Characteristics of dissolved organic matters were analysed and assessed. Production of disinfection byproducts were also investigated. 1. Result of relatedness study among each items of analyses showed that relatedness on BOD values were highest with cattle excrement treatment facilities where there is no synthetic organic materials and relatedness on $COD_{Mn}$ were highest at the mainstream Nakdong river. In case of $COD_{Cr}$ (which has more oxidative power than $COD_{Mn}$), the values were higher in the sidestreams indicating the higher content of recalcitrant compounds. The relatedness values for the $UV_{254}$ also showed higher values in the sidestreams and treatment facilities than mainstream indicating the presence of organic aromatic compounds. 2. Ratio of DOC on total organic carbon were higher in the mainstream which is attributable to the influent particulate organic materials produced by agricultural activities. The values were 10-15% higher in the mainstream compared with sidestreams. 3. Result of biodegradability test indicate that concentrations of recalcitrant DOC were higher in the sidestreams than in the mainstream. The values of recalcitrant DOC were higher with the forest stream indicating the effect of soil oriented humic substances. 4. Result of THM production test carried out at 10 stations in the Nakdong river show that $CHCl_3$ was detected with the highest value and the value was highest at Waekwan station.

• 한국토양환경학회지
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• 제3권3호
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• pp.87-92
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• 1998

The effect of chemically oxidized intermediates of Polynuclear Aromatic Hydrocarbon (PAH) compounds on the degradation of the parent PAHs was characterized and evaluated for the context of cooxidation. Anthracene and pyrene exhibited extensive degradation (mean percent removal of 57.5%) after 28 days of incubation by introducing the Fenton oxidation intermediate of the PAH compounds, while unoxidized anthracene and pyrene exhibited 12.5% removal The chemical oxidation products can serve as a structually similar analogue substrates for a consortia of soil microorganisms and as a metabolic intermediates in the biodegradation sequence of the parent PAH compounds. These results may be interpreted in the context of cooxidation mechanism whereby high recalcitrant PAH compounds are biodegraded in the soil and suggest a potential tool for bioremediation of PAHs contaminated soils and protection of groundwater.

• Mycobiology
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• 제39권1호
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• pp.64-66
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• 2011

Most fungi possess several hydrogen peroxide-generating enzymes, glucose oxidase and pyranose oxidase. Pyranose oxidase can use glucose as its substrate to generate hydrogen peroxide. White rot fungi, which degrade diverse recalcitrant compounds, contain lignin-degrading enzymes, and lignin peroxidase and manganese peroxidase require hydrogen peroxide for their enzymatic reactions. In this study, we isolated a cDNA fragment of pyranose oxidase from Phlebia tremellosa using PCR and examined its expression under the degradation conditions of diethylphthalate (DEP). Pyranose oxidase expression was enhanced up to 30% by the addition of DEP, and this result supports the possible involvement of pyranose oxidase in the degradation of recalcitrant compounds.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.287-292
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• 2002

본 연구에서는 경안천 유역에 있는 주유소 오염토양으로부터 대표적인 아조계 염료 congo-red분해능이 우수한 토양 방선균, SMA-2를 분리 선별하고, SMA-2의 배양조건을 최적화하여 2,4-dichlorophenol의 산화에 관여하는 actinomycetes lignin peroxidase(ALiP)의 활성도에 대한 특성을 규명하였다. 기존에 보고된 방선균 유래 ALiP와는 달리, SMA-2유래 ALiP효소는 pH6에서 최고의 활성을 보였으며, 2,4-DCP와 $H_2$$O_2$에 대한 Km값이 각각 0.21mM과 8.5mM로 측정되었다. 또한 최적화된 배지에서 성장한 SMA-2의 배양액은 2,4-dichlorophenol 뿐만 아니라 2-chlorophenol, 2,4,6-trichlorophenol, 2,6-dichlorophenol, phenol, 4-chloropheno떼 대해서도 산화능을 보임으로써, 토양 방선균을 이용한 염화 페놀계 화합물이 포함된 오염 토양의 생복원 가능성을 제시하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 총회 및 춘계 학술발표회 논문집
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• pp.53-60
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• 1998

The effect of chemically oxidized intermediated of PAH compounds on the degradation of the parent PAHs was characterized and evaluated for the context of cooxidation. Anthracene and pyrene exhibited extensive degradation (mean percent removal of 57.5%) after 28 days of incubation by introducing the Fenton oxidation intermediate of the PAH compounds, while unoxidized anthracene and pyrene exhibited 12.5% removal. Dehydrogenase activities for the oxidized PAH studies ware enhanced two to five folds to the unoxidized PAHs studies. The chemical oxidation products can serve as a structually very similar analogue substrates for a consortia of soil microorganisms and as a metabolic intermediates in the biodegradation sequence of the parent PAH compounds. These results may be interpreted in the context of cooxidation mechanism whereby high recalcitrant PAH compounds are biodegraded in the soil and suggest a potential tool for bioremediation of PAHs contaminated soils and protection of groundwater.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.467-470
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• 2003

Leaking underground storage tanks are a major source of groundwater contamination by petroleum hydrocarbons. Aerobic bioremediation has been highly effective in the remediation of many fuel releases. However, Bioremediation of aromatic hydrocarbons in groundwater and sediments is ofen limited by the inability to provide sufficient oxygen to the contaminated zones due to the low water solubility of oxygen. Nitrate can also serve as an electron acceptor and results in anaerobic biodegradation of organic compounds via the processes of nitrate reduction and denitrification. Because nitrate is less expensive and more soluble than oxygen. it may be more economical to restore fuel-contaminated aquifers using nitrate rather than oxygen. And denitrifying bacteria are commonly found in the subsurface and in association with contaminated aquifer materials. These studies have shown that BTEX and MTBE can be degraded by the nitrate-amended microcosms under aerobic and anaerobic conditons. Biodegradation of the toluene and ethylbenzne compounds occurred very quickly under denitrifying conditions. MTBE, benzene and p-xylene were recalcitrant under denitrifying conditions in this study, But finally Biodegradaton was observed for all of the test compounds.

• 한국환경과학회지
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• 제9권6호
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• pp.523-529
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• 2000

Attempts have been made to use Supercritical fluids for industrial purpose in a variety of fields and some of them, are already in practice. However, basic chemical properties of supercritical fluids have not been understood well. The present pater presents the results of physicochemical studies on Supercritical fluids as well as the application of supercritical fluids to industry. The detail is as follows PCB and organic compounds.

• Journal of the Korean Wood Science and Technology
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• 제32권3호
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• pp.52-58
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• 2004

The use of N-hydroxyphthalimide (NHPI) as a mediator for laccase has proven to be comparable to N-hydroxybenzotriazole (HBT) for the delignification of kraft pulp, and the transformation of a number of industrial dyes. The advantages of NHPI derivatives are the biodegradation of these compounds compared to HBT, which has been shown to be recalcitrant in the environment, and the more reasonable cost of synthetic process.

• 환경생물
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• 제34권3호
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• pp.201-207
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• 2016

The hazards associated with the polycyclic aromatic hydrocarbons (PAHs) are known to be recalcitrant by their structure, but white rot fungi are capable of degrading recalcitrant organic compounds. Phlebia brevispora KUC9045 isolated from Korea was investigated its efficiency of degradation of four PAHs, such as phenanthrene, anthracne, fluoranthene, and pyrene. And the species secreted extracellular laccase and MnP (Manganese dependent peroxidase) during degradation. P. brevispora KUC9045 demonstrated effective degradation rates of phenanthrene (66.3%), anthracene (67.4%), fluoranthene (61.6%), and pyrene (63.3%), respectively. For enhancement of degradation rates of PAHs by the species, Remazol Brilliant Blue R (RBBR) was preferentially supplemented to induce ligninolytic enzymes. The biodegradation rates of the three PAHs including phenanthrene, fluoranthene, and pyrene were improved as higher concentration of Remazol Brilliant Blue R was supplemented. However, anthracene was degraded with the highest rate among four PAHs after two weeks of the incubation without RBBR addition. According to the previous study, RBBR can be clearly decolorized by P. brevispora KUC9045. Hence, the present study demonstrates simultaneous degradation of dye and PAHs by the white rot fungus. And it is considered that the ligninolytic enzymes are closely related with the degradation. In addition, it indicated that dye waste water might be used to induce ligninolytic enzymes for effective degradation of PAHs.

• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1230-1239
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• 2010

Five bacterial species, capable of degrading the recalcitrant organic compounds (ROCs) diethyleneglycol monomethylether (DGMME), 1-amino-2-propanol (APOL), 1-methyl-2-pyrrolidinone (NMP), diethyleneglycol monoethylether (DGMEE), tetraethyleneglycol (TEG), and tetrahydrothiophene 1,1-dioxide (sulfolane), were isolated from an enrichment culture. Cupriavidus sp. catabolized $93.5{\pm}1.7$ mg/l of TEG, $99.3{\pm}1.2$ mg/l of DGMME, $96.1{\pm}1.6$ mg/l of APOL, and $99.5{\pm}0.5$ mg/l of NMP in 3 days. Acineobacter sp. catabolized 100 mg/l of DGMME, $99.9{\pm}0.1$ mg/l of NMP, and 100 mg/l of DGMEE in 3 days. Pseudomonas sp.3 catabolized $95.7{\pm}1.2$ mg/l of APOL and $99.8{\pm}0.3$ mg/l of NMP. Paracoccus sp. catabolized $98.3{\pm}0.6$ mg/l of DGMME and $98.3{\pm}1.0$ mg/l of DGMEE in 3 days. A maximum $43{\pm}2.0$ mg/l of sulfolane was catabolized by Paracoccus sp. in 3 days. When a mixed culture composed of the five bacterial species was applied to real wastewater containing DGMME, APOL, NMP, DGMEE, or TEG, 92~99% of each individual ROC was catabolized within 3 days. However, at least 9 days were required for the complete mineralization of sulfolane. Bacterial community diversity, analyzed on the basis of the TGGE pattern of 16S rDNA extracted from viable cells, was found to be significantly reduced in a conventional bioreactor after 6 days of incubation. However, biodiversity was maintained after 12 days of incubation in an electrochemical bioreactor. In conclusion, the electrochemical reduction reaction enhanced the diversity of the bacterial community and actively catabolized sulfolane.