• Journal of Environmental Impact Assessment
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• v.9 no.3
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• pp.203-214
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• 2000

Health risk assessment is applied to streamlining LCA(Life Cycle Assessment) using Monte carlo simulation for probabilistic/stochastic exposure and risk distribution analysis caused by data variability and uncertainty. A case study was carried out to find benefits of this application. BTC(Benzene, Trichloroethylene, Carbon tetrachloride mixture alias) personal exposure cases were assumed as production worker(in workplace), manager(in office) and business man(outdoor). These cases were different from occupational retention time and exposure concentration for BTC consumption pattern. The result of cancer risk in these 3 scenario cases were estimated as $1.72E-4{\pm}1.2E+0$(production worker; case A), $9.62E-5{\pm}1.44E-5$(manger; case B), $6.90E-5{\pm}1.16E+0$(business man; case C), respectively. Portions of over acceptable risk 1.00E-4(assumed standard) were 99.85%, 38.89% and 0.61%, respectively. Estimated BTC risk was log-normal pattern, but some of distributions did not have any formal patterns. Except first impact factor(BTC emission quantity), sensitivity analysis showed that main effective factor was retention time in their occupational exposure sites. This case study is a good example to cover that LCA with probabilistic risk analysis tool can supply various significant information such as statistical distribution including personal/environmental exposure level, daily time activity pattern and individual susceptibility. Further research is needed for investigating real data of these input variables and personal exposure concentration and application of this study methodology.

• Membrane Journal
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• v.6 no.1
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• pp.53-57
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• 1996

Polysulfone ultrafiltration membrane was coated with polyisobutylene(PIB) as a top layer to separate chlorinated hydrocarbons. The solubility parameter differences between PIB, water and perchloroethylene(PCE) or trichloroethylene(TCE) show that the solubility parameter difference between PIB and TCE or PCE is similar while that between PIB and water is far less, indicating that PIB is selective to chlorinated hydrocarbons. The pervaporation separation of TCE and PCE shows that TCE is concentrated more than four times, by PIB composite membrane, while PCE is concentrated more than thirteen times. This result shows that PIB composite membrane in this study seems to be an appropriate selective layer for the separation of TCE and PCE from aqueous organic solutions.

• Journal of Environmental Science International
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• v.12 no.9
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• pp.967-976
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• 2003

Volatile organic compounds (VOCs) are present in essentially all natural and synthetic materials from petrol to flowers. In this study, indoor and outdoor VOCs concentrations of houses, offices and internet-cafes were measured and compared simultaneously with personal exposures of each 50 participants in Asan and Seoul, respectively. Also, factors that influence personal VOCs exposure were statistically analyzed using questionnaires in relation to house characteristics, time activities, and health effects. All VOCs concentrations were measured by OVM passive samplers (3M) and analyzed with GC/MS. Target pollutants among VOCs were Toluene, o-Xylene, m/p-Xylene, Ethylbenzene, MIBK, n-Octane, Styrene, Trichloroethylene, and 1,2-Dichlorobenzene. Indoor and outdoor VOCs concentrations measured in Seoul were significantly higher than those in Asan except Ethylbenzene. Residential indoor/outdoor (I/O) ratios for all target compounds ranged from 0.94 to 1.51 and I/O ratios of Asan were a little higher than those of Seoul. Relationship between personal VOCs exposure, and indoor and outdoor VOCs concentrations suggested that time-activity pattern could affect the high exposure to air pollutant. Factors that influence indoor VOCs level and personal exposure with regard to house characteristics in houses were building age, inside smoking and house type. In addition insecticide and cosmetics interestingly affected the VOCs personal exposure. Higher exposure to VOCs might be caused to be exciting increase and memory reduction, considering the relationship between measured VOCs concentrations and questionnaire (p<0.05).

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.14-21
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• 2000

DEAE-Toyopearl 650S, Superdex pg-75, Poros HQ, Superdex H200의 각종 칼러크로마토그래피를 이용하여 C.bifermentans DPH-1균주로부터 테트라클로로에틸렌(PCE) 분해 효소를 정제했다. 이 PCE 분해효소 (PCE dehalogenase)는 PCE를 환원적 탈염소화 반응에 의해 시스디클로로에딜렌 (cis-1,2-dichloroethylene)에 전환 가능하여, 이 때의 Vmax 및 Km 치는 각각 73 nmol/h.mg protein, 12$\mu$M이었다. 본 PCE dehalogenase의 겔여과 분자량 Maker Kit를 이용한 분석결과(70kDa)는 SDS-PAGE에 나타난 분자량(35kDa)의 약 2배인 것으로 확인되었다. 따라서 본 효소는 분자량 70kDa의 이량체(Homo dimer)인 것으로 추정되었다. 본 효소의 최적온도 및 pH는 각각 35$^{\circ}C$ 및 8.0 이었다. 또한 본 효소는 PCE외의 트리클로로에틸렌, 디클로로에틸렌 이성체, 1,2-디클로로에템, 1,2-디클로로프로판, 1,1,2-트리클로로에탄에 대하여도 활성을 타나내었다. N-말단 아미노산 분석결과에서도 본 효소는 현재 알려진 PCE dehalogenase와 그 배열이 전혀 다른 것으로 나타나 각종 유기염소 화합물의 분해능을 보유한 신종의 PCE 분해효소인 것이 확인되었다.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.229-239
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• 2002

The objective of this study was to design an optimal electro-remediation system for TCE contaminated water using zero talent iron (ZVI) and direct current (DC). A series of column experiments were conducted to evaluate the effects of electrode arrangement and the location of permeable iron barrier in the column on the TCE removal efficiency and iron corrosion process. In twelve different combinations of ZVI and/or DC application in the test columns, the rate of reductive degradation of TCE was improved with simultaneous application of both ZVI and DC compared to that used ZVI only. The moot effective arrangement of electrode and ZVI for TCE removal from water was a column set with ZVI and cathode installed at the down gradient, respectively.

• Journal of Soil and Groundwater Environment
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• v.18 no.6
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• pp.32-37
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• 2013

The scope of this study was to develop, design, and build an ex-situ remediation system of using the heating and water sparging treatment for the highly volatile DNAPL (Dense Non-Aqueous Phase Liquid) contaminated groundwater, and to conduct pilot testing at the site contaminated with DNAPL. The TCE (Trichloroethylene) removal was at the highest rate of 94.6% with the water sparging at $70^{\circ}C$ in the lab-scale test. The pilot-scale remediation system was developed, designed, and fabricated based on the results of the lab-scale test conducted. During the pilot-scale testing, DNAPL-contaminated groundwater was detained at heat exchanger for the certain period of time for pre-heating through the heat exchanger using the thermal energy supplied from the heater. The heating system supplies thermal energy to the preheated DNAPL-contaminated groundwater directly and its highly volatile TCE, $CCl_4$ (Carbontetrachloride), Chloroform are vaporized, and its vaporized and treated water is return edback to the heat exchanger. In the pilot testing the optimum condition of the HWSRS was when the water temperature at the $40^{\circ}C$ and operated with water sparging concurrently, and its TCE removal rate was 90%. The efficiency of the optimized HWSRS has been confirmed through the long-term performance evaluation process.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.2
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• pp.140-148
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• 2012

Objectives: This study was performed to provide harmonized guidelines on health and environmental classification criteria and its results of chemicals in Korea. Methods: Firstly, The history of GHS implementation in UN and Korea was reviewed. Secondly, the differences in classification criteria on health and environmental hazards among UN GHS and two Korean government agencies, Korea Ministry of Employment and Labour (KMoEL) and Korea Ministry of Environmental (KMoE). The classification results were compared between classifications of Korea Occupational Safety and Health Agency (KOSHA) based on KMoEL and classifications of Korea National Institute of Environmental Research (KNIER) based on KMoE. Finally, an inter-agency harmonization on the classification criteria and the results was suggested by comparing the classification results of 5 chemicals; Benzene, carbon disulfide, formaldehyde, toluene-2,4-diisocyanate, and trichloroethylene. Results: KMoEL and KMoE revised regulations on chemical management and published a Notices on GHS classification criteria according to UN GHS document. However, the hazard to the ozone layer contained in the latest edition of UN GHS document published in 2011 was not included yet. The differences in classifications of 5 chemicals between KOSHA and KNIER were 36.2% in health hazards and 23.4% in environmental hazards, respectively. In conclusion, we suggested that a new revision be needed to include newly contained hazard and inter-agency working party be organized to harmonize classification results.

• Resources Recycling
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• v.6 no.3
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• pp.28-35
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• 1997

Adsorption properities of hcavy metals (Cd, Cu, Fe, Mn, Pb, Zn) and organic compounds (Trichloroethylene and T Tetrachroethy len려 on sh$\xi$1I( oyster and ark shell) were investigated using wat$\xi$r treatment matenals, The shell powder (m띠or C crystal structurc is calcium hydroxide) showed the preference adsorption for heavy metals in order of Mn > Zn > Fe > Cd > eu > P Pb. The high removal capacities of heavy metals arc helicved to be largely due to precipitation by foonation of metal c carhonat,잃 and hydroxides at high pH caused by the $Ca(OH)_2$ component of sl1ell, immobilizatIon of heavy metals in a solid I matrix by calcium‘ and fixation by insoluble organic materials in the oystcr and ark shell. The use of sh려I in water treatment h has the potential to bc benefIcial as a source of inexpensive matcrials‘ moreover, not only treatment of waste but also e environmcntal business including environmental-purification ceramics could be better off by utili낌ng high-valued waste and d developed puri'fication ceramics and media.

• Advances in environmental research
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• v.3 no.2
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• pp.151-162
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• 2014

Among the combination of 4 different second metals and 3 different noble metals, Ni 10%-Pd 1%/hematite (Ni(10)-Pd(1)/H) showed best tetrachloroethylene (PCE) removal (75.8%) and production of non-toxic products (39.8%) in closed batch reactors under an anaerobic condition. The effect of environmental factors (pH, contents of Ni and Pd in catalyst, and hydrogen gas concentration) on the reductive dechlorination of PCE by Pd-Ni/hematite catalysts was investigated. PCE was degraded less at the condition of Ni(5)/H (13.7%) than at the same condition with Ni(10)/H (20.6%). Removals of PCE were rarely influenced by the experimental condition of different Pd amounts (Pd(1)/H and Pd(3)/H). Acidic to neutral pH conditions were favorable to the degradation of PCE, compared to the alkaline condition (pH 10). Increasing Ni contents from 1 to 10% increased the PCE removal to 89.8% in 6 hr. However, the removal decreased to 74.2% at Ni content of 20%. Meanwhile, increasing Pd contents to 6% showed no difference in PCE removal at Pd content of more than 1%. Increasing H2 concentration increased the removal of PCE until 4% H2 which was maximumly applied in this study. Chlorinated products such as trichloroethylene, 1,1-dichloroethylene, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, and vinyl chloride were not observed while PCE was transformed to acetylene (24%), ethylene (5%), and ethane (11%) by Ni(10)-Pd(1)/H catalyst in 6hr.

• Journal of IKEEE
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• v.23 no.2
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• pp.431-437
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• 2019

This work was carried out ozone generation and TCE decomposition characteristics using dielectric ball materials filled barrier discharge reactor and catalyst's reactor for ozone decomposition. Ozone concentration generated from $Al_2O_3$ or $TiO_2$ filled barrier discharge reactor was so high compared with non-filled discharge reactor. This reactor is good discharge structure for generating the high ozone concentration. In addition, TCE decomposition rate and COx conversion rate increased using $MnO_2$ filled discharge reactor, because ozone was decomposed at the same discharge space on the surface of $MnO_2$ catalysts. To identify the $MnO_2$ catalytic effects, TCE decomposition rate reached to 100[%] by the decomposition of ozone at $MnO_2$ catalyst's reactor by the arrangement of $Al_2O_3$ filled discharge reactor and $MnO_2$ catalyst reactor. Finally, $MnO_2$ catalyst is good materials for the decomposition of ozone and this process will be useful for decomposing VOCs such as TCE.