• Analytical Science and Technology
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• v.17 no.2
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• pp.130-144
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• 2004

Recently, the air pollution in A and B industrial area has become one of the most important issues, then 60 VOCs in the area were measured using a highly sensitive method. The VOCs were adsorbed onto Carbotrap using air sampler and subsequently desorbed by a thermal desorber system into gas chromatograph-mass spectrometry (TDS-GC-MS). The peaks of all compounds had good chromatographic properties and offered very sensitive response for the EI-MS (SIM). Method detection limits (MDL) ranged from 0.01 to 0.1 ppt(v/v), and linearities of calibration curves were over 0.995. We analyzed total 90 atmosphere air samples of A and B industrial complex using the method. Benzene, toluene, ethylbenzene, xylene, n-hexane, fluorotrichloromethane, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, styrene, 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, sec-butylbenzene and naphthalen were identified as the major compounds in the air, and their average concentrations were 0.81, 5.02 1.30, 3.0, 0.81, 37.9, 0.07, 0.15, 0.15, 0.79, 0.06, 0.33, 0.03, 0.12, 0.23, and 0.35 ppb(v/v), respectively. The concentrations of VOCs were low in summer and high in fall or winter. When the concentrations detected in air compare with WHO's norm, no case exceed it.

• Journal of Soil and Groundwater Environment
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• v.11 no.5
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• pp.35-42
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• 2006

The following results were obtained in the reductive degradation of hexachloroethane (HCA), and surface characteristics by using iron sulfide ($FeS,\;FeS_{2}$) mediators. HCA was degraded to pentachloroethane (PCA), tetrachloroethylene(PCE), trichloroethylene(TCE) and cis-l,2-dichloroethylene (cis-1,2-DCE) by complicated pathways such as hydrogenolysis, dehaloelimination and dehydrohalogenation. FeS had more rapid degradation rates of organic solvent than $FeS_{2}$. In liquidsolid reaction, the reaction rates of organic solvents were investigated to explain surface characteristics of FeS and $FeS_{2}$.. To determine surface characteristics of FeS and $FeS_{2}$, the specific surface area and surface potential of each mineral was determined and the hydrophilic site ($N_{s}$) was calculated. The specific surface area ($107.0470m^{2}/g\;and\;92.6374m^{2}/g$) and the $pH_{ZPC}$ of minerals ($FeS\;PH_{ZPC}=7.42,\;FeS_{2},\;PH_{ZPC}=7.80$) were measured. The results showed that the Ns of FeS and $FeS_{2}$ were $0.053\;site/mm^{2}\;and\;0.205\;site/mm^{2}$, respectively. $FeS_{2}$ had more hydrophilic surface than FeS. In other words, FeS have more hydrophobic surface site than $FeS_{2}$.

• Clean Technology
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• v.7 no.3
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• pp.195-202
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• 2001

In this study the trace of chlorinated organic compound in aqueous solution was separated by pervaporation process using crosslinked PDMS (polydimethylsiloxane) membrane. The flux of trichloroethylene(TCE) increased linearly with feed composition but the flux of water was slightly increased. The partial flux of TCE was greater than that of tetrachloroethylene(PCE). The partial flux of TCE was not changed with operating temperature, but increased rapidly with feed flow rates. High crosslinking density causes the reduction of solubility and diffusivity for target component. The reduction of flux and selectivity for TCE is due to the chain immobilization and reduction of diffusivity with crosslinking density.

• Journal of Environmental Science International
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• v.24 no.1
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• pp.97-115
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• 2015

For the purpose of protecting the health of citizens and creating a delightful environment, the Government shall establish the environmental standards, and make such standards keep their propriety according to any changes in environmental conditions. The Special Metropolitan City, Metropolitan City or Do may, in case where deemed necessary in view of the speciality of regional environments, set forth the separate environmental standards which are more expanded and strengthened than the environmental standards by the Municipal Ordinance of the relevant City/Do. The purpose of this study was for the management of stream waters of Jeju Island and proposed the appropriate Jeju local river environmental standards. Jeju-Do and Daejeon-si applies the Local River Environmental Standards in Korea. While each nation? circumstances and environment are different, for the most part, environmental standards and purposes of use are similar to those in Korea. Proposed Jeju River Local Environment Standards followed The River Environment Standards of Nation(Korea) for Living Environment Standards. Newly Strengthened Value is Cd, Carbon tetrachloride, 1,2-dichloroethene, Tetrachloroethylene(PCE) and add Items is Fluorine, Selenium, Phenol and Toluene for Human Health Protection.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.108-111
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• 2000

FeS/FeS$_2$ minerals have been known to be potentially useful reductant to the removal of common organic contaminants in groundwater and soil. This research is aimed at improving our understanding of factors affecting the pathways and rates of reductive transformation of Hexachloroethane by catalytical iron minerals in natural system. Hexachloroethane is reduced by FeS/FeS$_2$ minerals under anaerobic condition to tetrachloroethylene and trichloroethylene with pentachloroethyl radical as the intermediate products. The kinetics of reductive transformations of the Hexachloroethane have been investigated in aqueous solution containing FeS, FeS$_2$. The proposed reduction mechanism for the adsorbed nitrobenzene involves the electron donor-acceptor complex as a precursor to electron transfer. The adsorbed Hexachloroethane undergo a series of electron transfer, proton transfer and dehydration to achieve complete reduction. It can be concluded that the reductive transformation reaction takes place at surface of iron-bearing minerals and is dependent on surface area and pH. Nitrobenzene reduction kinetics is affected by reductant type, surface area, pH, the surface site density, and the surface charge. FeS/FeS$_2$-mediated reductive dechlorination may be an important transformation pathway in natural systems.

• Journal of Soil and Groundwater Environment
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• v.21 no.5
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• pp.1-7
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• 2016

The removal of non-aqueous phase liquids (NAPLs) from groundwater using pure water, via pump and treat, is quite ineffective due to their low solubility and hydrophobicity. Therefore, the objectives of pilot tests were to select potentially suitable surfactants that solubilize tetrachloroethylene (PCE) and trichloroethylene (TCE) present as contaminants and to evaluate the optimal range of process parameters that can increase the removal efficiency in surfactant-enhanced soil flushing (SESF). Used experimental method for surfactant selection was batch experiments. The surfactant solution parameters for SESF pilot tests were surfactant solution concentration, surfactant solution pH, and the flow rate of surfactant solution in the SESF pilot system. Based on the batch experiments for surfactant selection, DOSL (an anionic surfactant) was selected as a suitable surfactant that solubilizes PCE and TCE present as contaminants. The highest recovery (95%) of the contaminants was obtained using a DOSL surfactant in the batch experiments. The pilot test results revealed that the optimum conditions were achieved with a surfactant solution concentration of 4% (v/v), a surfactant solution pH of 7.5, and a flow rate of 30 L/min of surfactant solution (Lee and Woo, 2015). The maximum removal of contaminants (89%) was obtained when optimum conditions were simultaneously met in pilot-scale SESF operations. These results confirm the viability of SESF for treating PCE and TCE-contaminated groundwater.

• Environmental Analysis Health and Toxicology
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• v.15 no.3
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• pp.81-91
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• 2000

Residents who live near petrochemical industrial areas are exposed to a variety of petrochemicals, including benzene or benzene-containing liquids. It is a serious concern because some VOCs are carcinogens naturally present in petroleum and gasoline. The aim of this study was to assess the exposure to VOCs, measured by personal/indoor/outdoor air sampling, and to estimate the relationship between the air samples and biological monitoring data. Through biological monitoring, we investigated VOCs in blood and s-phenylmercapturic acid (s-PMA) , minor urinary metabolites of benzene. The external benzene exposure of subjects was measured using passive dosimeters and urinary s-PMA and blood-benzene were determined by GC/MS. More than 80% of subjects were detected for m-xylene, ethylbenzene, and toluene in blood samples and not detected at all for chloroform, 1 , 1 , 1 -trichloroethylene, and tetrachloroethylene. The mean concentration of benzene in the breathing zone of residents was 6.3 $\mu\textrm{g}$/m$^3$, personal, indoor and outdoor concentrations were strongly correlated to each other. s-PMA detected in all subject samples was affected by personal exposure (p< 0.05) and the level was different by age (p< 0.01). Blood benzene was not affected by external benzene during these periods .

• Safety and Health at Work
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• v.3 no.3
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• pp.166-180
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• 2012

This review summarizes the epidemiology of cancer of the female reproductive system and associated lifestyle factors. It also assesses the available evidence for occupational factors associated with these cancers. Cervical, endometrial, and ovarian cancers are relatively common, and cause significant cancer morbidity and mortality worldwide, whereas vulvar, vaginal, fallopian tube cancers, and choriocarcinomas are very rare. As several lifestyle factors are known to play a major role in the etiology of these cancers, very few published studies have investigated possible relationships with occupational factors. Some occupational exposures have been associated with increased risks of these cancers, but apart from the available evidence on the relationships between asbestos fibers and ovarian cancer, and tetrachloroethylene and cervical cancer, the data is rather scarce. Given the multifactorial nature of cancers of the female reproductive system, it is of the utmost importance to conduct occupational studies that will gather detailed data on potential individual confounding factors, in particular reproductive history and other factors that influence the body's hormonal environment, together with information on socio-economic status and lifestyle factors, including physical activity from multiple sources. Studies on the mechanisms of carcinogenesis in the female reproductive organs are also needed in order to elucidate the possible role of chemical exposures in the development of these cancers.

• Journal of the Korean Society of Clothing and Textiles
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• v.2 no.2
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• pp.245-252
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• 1978

In order to obtain some information for solvent dyeing, polyethylene terephthalate (PET) was treated with water, tetrachloroethylene yarn (TCE), and water/TCE emulsion for three hours at the temperatures from $40^{\circ}$ to $140^{\circ}C$. The change of fine structure of substratum by measuring the shrinkage, the degree of crystallinity, the stress relacxation modulus and Young's modulus. The P.E.T. film was also treated in water (at $140^{\circ}C$) for 4 hours to stabilize the substratum. By means of film roll cyliderical method, the Disperse Blue 27 was diffused. Then, calculated the diffusion coefficient and examined the application of WLF equation. However, the temperature dependence of the shrinkage could be explain with WLF equation, the diffusion coefficient couldn't be applied the WLF equation when the substratum was stabilized. From the result, the effects on shrinkage were in the order of water

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.136-139
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• 2003

The combined effect of bioaugmentation of dechlorinating bacterial cultures and addition of iron powder (Fe$^{0}$ ) on reductive dechlorination of tetrachloroethylene (PCE) and other chlorinated ethylenes in a artificially contaminated soil slurry (60$\mu$mo1es PCE/kg soil) were tested. Two different anaerobic bacterial cultures, a pure bacterial culture of Desulfitobacterium sp. strain Y-51 capable of dechlorinating PCE to cis-1, 2-dechloroethylene (cis-DCE) and the other enrichment culture PE-1 capable of dechlorinating PCE completely to ethylene, were used for the bioaugmentation test. Both treatments introduced with the strain Y-51 and PE-1 culture (3mg dry cell weight/kg soil) showed conversion of PCE to cis-DCE within 40 days. The treatments added with Fe$^{0}$ (0.1 -1.0 %(w/w)) alone to the soil slurry resulted in extended PCE dechlorination to ethylene and ethane and the, dechlorination rate depended on the amount of Fe$^{0}$ added. The combined use of the bacterial cultures with Fe$^{0}$ (0.1-1.0%) showed the higher PCE dechlorination rate than the separated application and the pattern of PCE dechlorination and end-product formation was different from those of the separated application. These results suggested that the combined application of Fe$^{0}$ and the bactrial culture, specially the complete dechlorinating enrichment culture such as PE-1 culture, would be practically effective for remediation of PCE contaminated soil.