• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.410-413
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• 2000

Lab-scale trickling bioreactor(TBR) containing the biofilm of Pseudomonas cepacia G4 was developed for the treatment of trichloroethylene(TCE) in a waste gas stream. The effect of phenol feeding on the efficiency of TCE biodegadation in TBR was investigated with the change of inlet phenol concentration from 0 to 4.71 ppm. When 0.94 ppm of phenol was supplied, the best performance of TBR was maintained with the TCE removal efficiency of 58.1%. These results showed that the appropriate supply of phenol could stimulate TCE removal efficiency in TBR.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.578-581
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• 2001

A treatability study was conducted using a hydrocarbon-contaminated soil for the oPtimization of bioremediation strategy best fit to a given set of contamination. The applicability of nutrients, biosurfactant, and oil-degrading microorganisms were examined by monitoring $CO_2$ evolution and oil degradation The addition of inorganic nutrients in the form of slow released fertilizer accelerated the initial rate of $CO_2$ evolution by a factor of 3. The application of oil-degrading microorganisms did not significantly increased $CO_2$ evolution or biodegradation efficiency. Application of a commercial biosurfactant was most effect in terms of the total $CO_2$ evolution and the oil degradation rate. The results indicate that $CO_2$ evolution measurement was found to be a simple and reliable countermeasure of crude oil hydrocarbon mineralization for the rapid determination of the best-fit bioremediation strategy.

• KSBB Journal
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• v.14 no.2
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• pp.136-140
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• 1999

Characteristics of organic acid degradation by isolated yeast strain was investigated. Optimum initial pH was 5. Increase in cell mass was proportional to the decrease in organic acid degradation. Also no accumulation of byproduct was observed during degradation. Acetic acid degraded fast, followed by butyric acid and propionic acid in order. No significant substrate inhibition was observed up to 12 g/L of acetic acid 7 g/L of propionic acid, respectively. However, inhibition of butyric acid was significant above 4 g/L. Cell mass yield was 0.2-0.4 g cell/g acids and decreased at high decreased at high organic acid concentration. 95% of organic acid (7.5 g/L), corresponding to 13,000 ppm, was degraded in 30-40 hours.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.390-392
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• 2003

Organic solvent tolerant bacterium, Pseudomonas savastanoi BCNU 106 could utilize trichloroacetic acid, monochloroacetic acid, trichloroethylene, p-dichlorobenzene as a sole carbon source. But Pseudomonas savastanoi BCNU 106 didn't have tolerance about trichloroacetic acid, monochloroacetic acid, trichloroethylene, p-dichlorobenzene. Strain BCNU 106 could utilize to the extend of 30 mM trichloroacetic acid as a sole carbon source on mineral salt medium.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.386-389
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• 2003

Organic solvent tolerance bacteria, Pseudomonas savastanoi BCNU 106 could utilize a high contentration of benzene, toluene, ethylbenzene, xylene isomers (BTEX) as a sole carbon source. It was founded that strain BCNU 106 transformed o-xylene to 2-methylbenzyl alcohol, 2-methylbenzoic acid through direct oxygenation of methyl residue on GC-MS analysis.

• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.56-60
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• 2001

A kerosene fungus of Cladosporium resinae NK-1 was examined for its ability to degrade individual n-alkanes and aromatic hydrocarbons by gas chromatography-mass spectrometry, and its organic solvent-tolerance was investigated by making use of the water-organic solvent suspension culture method. It grew on a wide range of solvents of varying hydrophobicities and it was found to have tolerance to various kinds of toxic organic solvents (10%, v/v) such as n-alkanes, cyclohexane, xylene, styrene, and toluene. A hydrocarbon degradation experiment indicated that NK-1 had a greater n-alkane degrading ability compared to that of the other selected strains. C. resinae NK-1, which could utilize 8-16 carbon chain-length n-alkanes of medium chain-length as a carbon source, could not assimilate the shorter chain-length n-alkanes and aromatic hydrocarbons tested so far. The n-alkane degrading enzyme activity was found in the mycelial extract of the organism.

• Journal of environmental and Sanitary engineering
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• v.15 no.1
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• pp.69-76
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• 2000

폐수거품은 전 세계의 폐수처리장에서 악취생산과 BOD의 증가 및 부유고형물의 원인과 같은 수많은 문제들을 야기시킨다. Actinomycetes가 폐수거품에 존재하는 주요 미 생물군으로 알려져있다. Hexadecane은 폐수, 토양, 바닷물과 같은 자연환경에서 오염물질로 고려되는 복잡한 기름 성분의 대표적인 구성성분이다. Hexadecane은 폐수로부터 얻어진 폐수거품에 의한 분해가능성을 평가하기 위한 대표적인 모델 화합물로서 사용되었다. Gas chromatography (GC)/mass (MS)가 시료중에 있는 hexadecane의 분석을 위해 사용되었다. 본 연구를 통해서, hexadecane은 폐수거품에 의해 분해될 수 있는 것으로 사료된다. 멸균시킨 폐수거품시료를 포함하고 있는 control시료에서, hexadecane은 거의 분해되지 않았다. 반면에, 같은 방법에 의해 멸균되지 않은 폐수시료에서, hexadecane은 급속히 분해되었다. 덧붙여서, 농축폐수거품이 들어있는 시료는 3주 동안 건조된 폐수거품의 시료보다 hexadecane을 분해하는 데 더욱 효과가 높았다. 그러나, 3주 후에는 농축폐수거품의 시료에 남아있는 hexadecane의 농도는 건조된 폐수거품시료의 농도와 유사하였다. 요약컨대, 농축된 폐수거품시료와 건조된 폐수거품시료는 control시료와 비교했을 때, hexadecane의 급속한 분해를 보여주었다. 그러므로 본 연구의 실험결과를 통해서 건조된 폐수거품시료가 hexadecane을 비롯한 다른 chemical들로 오염된 장소를 정화하는 데 실제적으로 적용될 수 있을 것으로 사료된다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.73-76
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• 2004

Rusted iron could retain activity to redox-sensitive pollutants in batch reactor. Flow-through columns packed with permeable reactive iron filings (Fe$^{0}$ ) between soil and sand layers were used to evaluate the applicability of bio-enhanced iron barriers to treat explosives-contaminated groundwater. One column was bioaugmented with municipal anaerobic sludge to evaluate the enhancement of biodegradation. Military contaminants (RDX, HMX, TNT, 2,4DNT, 2,6DNT), which coexist in soils at military sites, were completely removed in the bioaugmented Fe$^{0}$ layer after 8 months of operation. Overall, this research suggests that Fe$^{0}$ barriers can effectively clean up groundwater contaminated with military explosives, and that treatment efficiency can be enhanced by bioaugmentation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.153-157
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• 2004

다양한 혐기성 조건에서 다환방향족탄화수소(PAHs)로 오염된 토양의 미생물 분해 연구를 수행하였다. 대표적인 다환방향족탄화수소인 phenanthrene과 fluorene을 토양과 물에 오염시켜서 약 100일 동안 저감정도를 관찰하였고, 실제 다환방향족탄화수소로 오염된 현장 토양을 이용 혐기성하에서 다환방향족탄화수소의 생분해 가능성을 확인하였다. 미생물 접종원은 혐기성 조건에서 다환방향족탄화수소에 노출시킨 슬러리가 사용되었다. 황산염 환원조건, 질산염 환원조건, 메탄생성조건 등의 다양한 혐기성 조건에서 실험을 수행한 결과, 메탄생성조건 > 질산염 환원조건 > 황산염 환원조건의 순서로 분해가 잘 일어났다. 또한 현장오염토양의 경우 34일간 처리 후 메탄생성조건에서 최대 72%의 분해율을 보였다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.62-65
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• 2002

Permeable reactive barriers (PRBs) are in-situ barriers constructed in a subsurface to treat contaminated groundwater using various reactive media. The common reactive medium used in PRB is zero-valent iron, which has been widely used to treat chlorinated solvents (i.e., PCE, TCE). A disadvantage of iron media is high cost. In this study, waste foundry sands were tested to determine the feasibility of their use as a low cost reactive medium. Batch and column tests were conducted with TCE to determine transport parameters and reactivity of the foundry sands. The reactivities of foundry sands for common groundwater contaminants are comparable to or slightly higher than those for Peerless iron, a common medium used in PRBs. In addition, the TOC and clay in foundry sands can significantly retard the movement of target contaminant, which may result in lower effluent concentration of contaminant due to biodegradation. In general, PRBs 1-m thick can be constructed with many foundry sands to treat TCE provided the zero-valent iron content in the foundry sand is higher than 1%.