• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
• /
• pp.315-317
• /
• 2004

Henry's law constants of trichloroethylene (TCE) and tetrachloroethylene (PCE) in air-aqueous surfactant systems were determined by gas chromatography headspace analysis of closed system. The effect of surfactant type and concentration was investigated.

• 한국환경농학회:학술대회논문집
• /
• 한국환경농학회 2011년도 30주년 정기총회 및 국제심포지엄
• /
• pp.290-290
• /
• 2011

• Tuberculosis and Respiratory Diseases
• /
• 제76권2호
• /
• pp.75-79
• /
• 2014

Trichloroethylene (TCE) is a toxic chemical commonly used as a degreasing agent, and it is usually found in a colorless or blue liquid form. TCE has a sweet, chloroform-like odor, and this volatile chlorinated organic chemical can cause toxic hepatitis, neurophysiological disorders, skin disorders, and hypersensitivity syndromes. However, the hypersensitivity pneumonitis (HP) attributed to TCE has rarely been reported. We hereby describe a case of HP associated with TCE in a 29-year-old man who was employed as a lead welder at a computer repair center. He was installing the capacitors on computer chip boards and had been wiped down with TCE. He was admitted to our hospital with complaints of dry coughs, night sweats, and weight losses for the past two months. HP due to TCE exposure was being suspected due to his occupational history, and the results of a video-associated thoracoscopic biopsy confirmed the suspicions. Symptoms have resolved after the steroid pulse therapy and his occupational change. TCE should be taken into consideration as a potential trigger of HP. Early recognition and avoidance of the TCE exposure in the future is important for the treatment of TCE induced HP.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.168-171
• /
• 2003

This research was conducted to assess the performance of the mixed reactive materials with sand, iron filings, and HDTMA-bentonite for trichloroethylene (TCE) and chromate removal under controlled groundwater flow conditions. TCE and chromate removal rates with the mixtures of iron filing/HDTMA-bentonite were highest among four columns due to reduction by iron filings and sorption by HDTMA-bentonite. The greater capacity of the mixed iron filing/HDTMA-bentonite compared HDTMA-bentonite was due to an enhanced chromate reduction in addition to chromate sorption. The presence of chromate caused greater inhibition of TCE removal in the column with iron filings, while the presence of TCE caused less inhibition of TCE. Also, nitrate caused the decrease in TCE removal relative to chloride. Nitrate ions may also significantly affect TCE reduction rates by competing for electrons with the chlorinated compounds. The anion and co-existed contaminants competing effects should be considered when designed permeable reactive barriers (PRBs) composed of zero valent iron for field applications to remediate TCE and chromate.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2002년도 추계학술발표회
• /
• pp.362-365
• /
• 2002

토양의 물리/화학적 특성에 따른 토양의 유기오염물 흡착능 변화를 규명하기 위하여, 토양 내 clay 함량 및 유기물 함량변화, 수용액 내 TCE 농도변화에 따른 TCE 의 토양내 흡착량 변화를 측정하였다. 수용액의 pH와 실내온도는 일정하게 유지시켰으며 clay는 표면적이 다른 Ca-montmorillonite, Na-montmorillonite, kaolin을 이용하였고, 유기물질로는 활성탄을 사용하였다. 일정한 토양성분과 실제토양에 대해 수용액 내 TCE의 농도를 변화시켜 농도변화에 따른 흡착량 변화를 측정하였다. 실험결과 유기물과 점토함량의 증가에 따라 흡착량은 모두 증가하였으나 활성탄에 의한 TCE 흡착량이 점토에 비해 매우 높았으므로 유기물에 의한 TCE 흡착영향이 점토에 의한 흡착 영향보다 큰 것으로 나타났다. TCE 농도변화에 따른 흡착결과는 실제토양과 모사토양에서 모두 농도가 증가함에 따라 흡착 증가율이 증가하다가 감소하는 Langmuir isotherm 형태를 보여 주었다.

• 미생물학회지
• /
• 제46권2호
• /
• pp.183-191
• /
• 2010

본 연구에서는 성장기질로써 다양한 방향족 화합물을 첨가하여 TCE 분해 균주를 분리하고 고효율 TCE 분해 균주에 의한 고농도의 TCE 분해 특징에 대해 연구하였다. TCE에 오염된 토양 및 폐수로부터 시료를 채취하였고 성장기질로써 벤젠(Benzene), 페놀(Phenol), 에틸벤젠(Ethylbenzene), 아닐린(Aniline), 큐멘(Cumene), 톨루엔(Toluene) 등을 사용하여 TCE에 내성을 가지는 179 균주를 순수 분리하였다. 순수 분리된 균주들을 TCE 농도 30 mg/L, 성장기질 농도 0.2 g/L, $30^{\circ}C$, pH 7, 균 농도 1.0 g/L (w/v)의 호기적 조건으로 21일 동안 분해효율을 측정한 결과, 아닐린을 성장기질로 이용한 EK2 균주가 74.4%의 가장 높은 효율을 보여주었다. EK2 균주는 형태학적 특징, 생화학적 특징 및 분자적 특징을 분석한 결과 Delftia acidovorans로 동정되었다. D. acidovorans EK2의 TCE 분해는 TCE 농도 10에서 200 mg/L까지 성장 및 분해할 수 있었으나 250 mg/L 이상의 농도에서는 성장과 분해가 보이지 않았다. 저농도(1.0 mg/L) 분해 실험을 위하여 D. acidovorans EK2를 각 0.01 g/L, 0.03 g/L, 0.05 g/L로 적용한 결과, 모든 조건에서 12일 동안 99.9%의 분해효율을 보였다. 고농도(200 mg/L)를 분해하기 위한 최적 배양조건은 균 농도 1.0 g/L, 아닐린 농도 0.5 g/L, pH 7, 온도 $30^{\circ}C$로 확인되었으며, 21일 동안 호기적으로 배양 시 71.0%의 가장 높은 TCE 분해효율을 보여주었고, 분해속도는 94.7 nmol/h이었다. 결과적으로 본 연구에서 개발된 D. acidovorans EK2를 이용하여 고농도의 TCE로 오염된 토양 및 지하수의 생물학적 처리에 효율적으로 이용될 수 있을 것으로 사료된다.

• 한국대기환경학회지
• /
• 제18권2호
• /
• pp.149-159
• /
• 2002

The objective of this study was to evaluate the formation characteristics of CBs and CPs from TCE, aliphatic compound. The experiment was carried out in a fixed reactor during 30 min under the oxidation condition at the range of temperature, 300~$700^{\circ}C$. MSWI fly ash was used as catalyst in this study. Total amount of CBs formed greater magnitude than that of CPs overall range of reaction temperature. It is proposed that the formation of CPs was caused from hydroxylation of CBs. According to increasing temperature to $600^{\circ}C$, the yield of CBs and CPs increased but significantly decreased at $700^{\circ}C$. It is suggested that decomposition rate was faster than formation rate at the high temperature. In the homologue distribution of CBs, DCBs were major products at 30$0^{\circ}C$ and the amount of higher chlorinated compound increased to $600^{\circ}C$. Because they were formed by chlorination of lower chlorinated compounds. In case of CPs, the amount of DCPs was 90% of total amounts in both thermal formation and catalytic reaction. On the other hand it was clearly observed that the chlorination rate in catalytic reaction was higher than in thermal formation with TCE only.

• 한국대기환경학회지
• /
• 제13권1호
• /
• pp.31-40
• /
• 1997

본 연구는 페놀산화미생물을 주입한 입상활성탄 biofilter를 이용하여, 기체 상태의 트리클로로에틸렌(TCE)과 테트라클로로에틸렌(PCE)을 생분해시키는 것과 임계미셀농도(CMC)값 이하에서의 계면활성제가 TCE와 PCE의 처리효율에 미치는 영향을 조사하기 위해 수행하였다. 기체 상태의 TCE와 PCE를 처리하기 위하여, 두 개의 개별적 biofilter를 체류시간이 1.5~7분이 되게 운전하였다. 기체 TCE는 체류시간 7분과 평균 유입농도 85ppm에서 100% 처리되는 것으로 조사되었다. 그리고, 기체 PCE는 체류시간 4~7분과 평균 유입농도 47~84ppm에서 100% 처리되었다. 활성탄에 의한 흡착은 TCE와 PCE 처리에 영향을 적게 준 것으로 나타났다. 기체 상태의 TCE와 PCE의 transformation yield값은 체류시간에 따라 각각 8~48g of TCE/g of phenol과 6~25g of PCE/g of phenol으로 조사되었으며, 액체 상태의 TCE 값과 비교하면 1~2차수 작게 나타났다. Biofilter에 계면활성제의 농도를 5~50mg/L 이하로 주입한 결과, 기체 상태의 TCE와 PCE의 처리효율은 계면활성제를 주입하지 않을 때 보다 약간 증가하였으나, 큰 차이를 발견할 수는 없었다.

• Environmental Engineering Research
• /
• 제18권1호
• /
• pp.21-28
• /
• 2013

In this study, the applicability of visible light-emitting-diodes (LEDs) to the photocatalytic degradation of indoor-level trichloroethylene (TCE) and perchloroethylene (PCE) over N-doped $TiO_2$ (N-$TiO_2$) was examined under a range of operational conditions. The N-$TiO_2$ photocatalyst was calcined at $650^{\circ}C$ (labeled N-650) showed the lowest degradation efficiencies for TCE and PCE, while the N-$TiO_2$ photocatalysts calcined at $350^{\circ}C$, $450^{\circ}C$, and $550^{\circ}C$ (labeled as N-350, N-450, and N-550, respectively) exhibited similar or slightly different degradation efficiencies to those of TCE and PCE. These results were supported by the X-ray diffraction patterns of N-350, N-450, N-550, and N-650. The respective average degradation efficiencies for TCE and PCE were 96% and 77% for the 8-W lamp/N-$TiO_2$ system, 32% and 20% for the violet LED/N-$TiO_2$ system, and ~0% and 4% for the blue LED/N-$TiO_2$ system. However, the normalized photocatalytic degradation efficiencies for TCE and PCE for the violet LED-irradiated N-$TiO_2$ system were higher than those from the 8-W fluorescent daylight lamp-irradiated N-$TiO_2$ system. Although the difference was not substantial, the degradation efficiencies exhibited a decreasing trend with increasing input concentrations. The degradation efficiencies for TCE and PCE decreased with increasing air flow rates. In general, the degradation efficiencies for both target compounds decreased as relative humidity increased. Consequently, it was indicated that violet LEDs can be utilized as energy-efficient light sources for the photocatalytic degradation of TCE and PCE, if operational conditions of N-$TiO_2$ photocatalytic system are optimized.

• 한국대기환경학회지
• /
• 제17권1호
• /
• pp.97-104
• /
• 2001

Decomposition of trichloroethlyene(TCE) in electron beam irradiation was examined on order to obtain information on the treatment of VOC in air. Air containing vaporized TCE has been studied in a flow reactor with different reaction environments, at various initial TCE concentration and in the presence and absence of water vapor. Maximum decomposition was observed in oxygen reaction environment and the degree of decomposition was about 99% at 20kGy for 2,000ppm initial TCE. The concentration of TCE exponentially decreased with dose in air and pure oxygen. The effect of water vapor on TCE decomposition efficiency was examined. The decomposition rate of TCE in the presence of water vapor (5,600 ppm) was approximately 10% higher than that in the absence of water vapor. Dichloroacetic acid, dichloroacethyl chloride and dichloroethyl ester acid were identified as primary products of this reaction adn were decomposed and oxidized to yield CO and $CO_2$. Perchloroethylene, hexachloroethane, chloroform and carbon tetrachloride were also observed as highly chlorinat-ed by products.