• 상하수도학회지
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• 제29권1호
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• pp.39-46
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• 2015

The degradation characteristics of perchloroethylene by ferrate(VI) oxidation have been studied. The degradation efficiency of perchloroethylene in aqueous solution was investigated at various values of ferrate(VI) dosage, pH, initial concentration of perchloroethylene and aqueous solution temperature. GC-ECD has been used to analyze the changes of perchloroethylene concentration. The optimum conditions of perchloroethylene degradation were obtained at pH 7.0 and $25^{\circ}C$ of aqueous solution temperature. Also, the experimental results showed that perchloroethylene removal efficiency increased with the decrease of initial concentration of perchloroethylene. Lastly intermediate products were identified by GC-MS techniques. Trichloroethylene and chloroform were identified as reaction intermediates.

• 한국응용과학기술학회지
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• 제22권2호
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• pp.136-141
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• 2005

This paper presents applicability of Fenton oxidation to perchloroethylene(PCE) contaminated soil. The initial concentration of PCE was 187mg/kg and Fenton oxidation conditions were 1.0M $H_2O_2$ and 0.5M $Fe^{2+}$. More than 97% of PCE decomposition and 98% of dechlorination were obtained within 5 hrs. It was found that the decomposition of PCE by Fenton oxidation was followed pseudo first order and its reaction coefficient was 0.78 $hr^{-1}$. GC-MS and GC-ECD analysis of reaction intermediates confirmed only the presence of trichloroacetic acid(i.e., 1.0% of initial PCE concentration). Under Fenton oxidation conditions, it was proposed that PCE was decomposed not simultaneously but one by one.

• 한국염색가공학회지
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• 제6권3호
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• pp.37-43
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• 1994

Commercial Poly(ethylene terephthalate) (PET) filaments were treated in solvents mixtures such as benzyl alcohol/perchloroethylene(BA/PER), benzyl alcohol/trichloroethylene(BA/TRI), benzyl alcohol/ethylene chloride(BA/EC), metha nol/perchloroethylene(ME/PER), and methanol/trichloroethyle(ME/TRI). Swelling of PET in solvent mixtures showed rapidly in the middle range of mixture ratio. Contribution of swelling of each component to total swelling of binary mixtures with increasing treated time was generally showed in proportion to the mixture ratio of the each component in dependence of the extend of swelling.

• 한국환경보건학회지
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• 제40권5호
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• pp.397-406
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• 2014

Objectives: Perchloroethylene (PCE) is a volatile chemical widely used as a solvent in the dry-cleaning and textile processing industries. It was evaluated as Group 2 "probably carcinogenic to humans" by the Integrated Risk Information System (IRIS) of the United State Environmental Protection Agency (U.S. EPA) in 2012. In order to provide a scientific basis for establishing risk management measures for chemicals on the national priority substances list, aggregate risk assessment was conducted for PCE, included in the top-10 substances. Methods: We conducted the investigation and monitoring of PCE exposure (e.g., exposure scenario, detection levels, and exposure factors, etc.) and assessed its multi-media (e.g., outdoor air, indoor air, and ground water) exposure risk with a deterministic and probabilistic approach. Results: In human risk assessment (HRA), the level of human exposure was higher in the younger age group. The exposure level through inhalation at home was the highest among the exposure routes. Outdoor air or uptake of drinking water represented less than 1% of total contributions to PCE exposure. These findings suggested that the level of risk was negligible since the Hazard Index (HI) induced by HRA was below one among all age groups, with a maximum HI value of 0.17 when reasonable maximum exposure was applied. Conclusion: In conclusion, it was suggested that despite low exposure risk, further studies are needed considering main sources, including occupational exposure.

• 미생물학회지
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• 제41권4호
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• pp.281-286
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• 2005

울산, 여수 등 공단지역의 토양, 하천의 저니, 해양의 준설토 둥을 이용하여 난분해성 염소화합물인 PCE (perchloroethylene)및 TCE (trichloroethylene)의 혐기성 탈염소화에 관련하는 미생물을 탐색하고 이들의 탈염소화 효율을 조사하였다. 혐기성 상호대사에 의한 탈염소화 효율을 조사하기 위해 전자공여체로 acetate를 사용하여 혐기성 회분식 실험을 실시하였으며, 이와 병행하여 분자생물학적인 기법인 16S rDNA의 PCR-Double Gradient DGGE (DG-DGGE)를 이용하여 미생물의 군집을 분석하였다. 그 결과 울산 태화강 및 여수 하남천의 저니를 접종한 경우 PCE는 $70\%,\;65\%$, TCE는 $50\%,\;45\%$의 높은 탈염소화 효율을 나타내었다. 또한 16S rDNA의 PCR을 이용한 DG-DGGE로 미생물 군집을 분석한 결과, 탈염소화 효율이 높은 지역의 저니에는 Desulfovibrio sup.의 미생물이 주로 존재함을 확인하였다.

• 한국의류학회지
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• 제12권3호
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• pp.383-390
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• 1988

To investigate the soil-redeposition and color change on dry-cleaning, the white and, dyed, fabrics of cotton, silk, polyester and viscose rayon were put into ordinary commercial dry-cleaning machine with soiled cloths. The solvents used were hydrocarben, perchloroethylene and fluorocarbon. From the result, we obtained the following conclusions by examining soil-redeposition, color difference of fabrics and tenacity of cotton fabric. 1. In case of white fabrics, as a whole, perchloroethylene shows the lowest soil redeposition. When distillation process is adopted, the rate of soil redeposition is lowered. with hydrocarbon sdvent. The order of soil redeposition rate of fibers are following; cotton> viscose rayon> silk> polyester. 2. In case of dyed fabrics, the color difference between soil redeposited fabrics and originals ($\delta\;E_1$) is similar with white fabrics in pattern, and the order is cotton, viscose rayon, silk and polyester. The color difference between fabrics, treated by pure solvents and originals ($\delta\;E_2$ ) is also validated as a little. It seems to be due to the bleeding of dyestuffs from fabrics. 3. There is a little change of tenacity of cotton fabrics by dry-cleaning with perchloroethylene solvent. It is supposed that the damage is more influenced the repetitive mechanical action during dry-cleaning than by acidity of the solvent having the acid value of 0,14.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1734-1739
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• 2006

The degradation of perchloroethylene (PCE) was investigated with the serial treatment of biological reaction after dechlorination using Fenton's reagent. The dechlorination of PCE was expressed using $D_m$ (dechlorination value), calculated from ${\Delta}Cl^-mol/{\Delta}PCE$ mol, and was 2.58 with 5 mM of $H_2O_2$ and $Fe^{3+}$. The $150{\mu}M$ of PCE was transformed to $37{\mu}M$ of dichloroacetic acid (DCAA). Biological treatment with Delftia sp. N6 was applied after degradation of PCE by the Fenton reaction. The optical densities indicating cell growth were 0.53/0.10 with/without the Fenton reaction after one day, respectively. The N6 strain degraded 95% of the DCAA produced from PCE by the Fenton reaction within one day. Consequently, it seemed that the serial treatment of a Fenton reaction and biological reaction was effective in the removal of not only PCE, but also DCAA, one of the major metabolites of PCE.

• 한국산업보건학회지
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• 제1권2호
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• pp.192-199
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• 1991

Biological exposure indices (BEI) of toluene, perchloroethylene (PCE) and methyl ethyl ketone (MEK) for Korean workers were studied respectively. Environmental exposures in workplace to organic solvent were measured by personal sampling. Blood toluene, blood perchloroethylene, urinary trichloroacetic acid and urinary MEK were determined by headspace gas chromatography. Urinary hippuric acid were determined by HPLC and corrected by creatinine. BEIs for Korean workers were calculated as the levels of determinants which are correspond to permissible exposure limits in Korea. Blood toluene level of 2.2mg/l and urinary hippuric acid level of 1.7g/g creatinine are correspond to an exposure of 100 ppm toluene. Blood PCE concentration of 1.6mg/l and urinary trichloroacetic acid concentration of 2.9mg/l are correspond to an exposure of 50ppm PCE. Urinary MEK concentration of 1.0mg/l is correspond to an exposure of 200ppm of MEK. BEIs for Korean workers determined in this study are very different to ACGIH's BEI as urinary determinants are much lower and blood determinants are much higher than ACGIH's BEI.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2002년도 봄 학술발표대회 발표논문집
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• pp.55-56
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• 2002

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.250-253
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• 2002

Remediation of groundwater using zero valent iron filings has received considerable attention in recent years. However, zero valent iron is gradually transformed to iron(III) oxides at permeable reactive barriers, so the reduction of iron(III) oxides can enhance the longevity of the reactive barriers. In this study, microbial reduction of Fe(III) was performed in anaerobic condition. A medium contained nutrients similar to soil solution. The medium was autoclaved and deoxygenated by purging with 99.99% $N_2$ and pH was buffered to 6, while the temperature was regulated as 2$0^{\circ}C$. Activity of iron reducing bacteria were not affected by chlorinated organics but affected by iron(III) oxide. Although perchloroethylene(PCE) was not degraded with only ferric oxide, PCE was reduced to around 50% with ferric oxide and microorganism. It shows that reduced iron can dechlorinate PCE.