• Analytical Science and Technology
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• v.18 no.2
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• pp.120-129
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• 2005

Volatile organic compounds (VOCs) have been recognized as major contributor to air pollution. The catalytic oxidationis is one of the most important processes for VOCs destruction due to the possibility getting high efficiency at low temperature. In this study, monometallic Pt, Ir and bimetallic Pt-Ir were supported to $TiO_2$. In order to distribute metals uniformly, $H_2O-H_2$ treatment method was used. Xylene, toluene and MEK were used as reactants. The monometallic or bimetallic catalysts were prepared by the excess wetness impregnation method and characterized by XRD, XPS, and TEM analysis. Pt catalyst showed higher conversion than Ir catalyst and Pt-Ir bimetallic catalyst showed the highest conversion. The catalysts prepared by $H_2O-H_2$ treatment had better VOC's conversion than that of nothing treatment. In the VOCs oxidation, Pt-Ir bimetallic catalysts had multipoint active sites, so it improved the range of Pt metal state. Therefore, bimetallic catalysts showed higher conversion of VOCs than monometallic ones. $H_2O-H_2$ treatment effected an uniform distribution of Pt particles. In VOCs oxidation was found to follow first order reaetion kinetics. The activation energy of $H_2O-H_2$ treatment catalysts was lower than that of untreated ones. In this study, the a small amount of Ir was used with Pt to promote the oxidation conversion of VOCs.

• Journal of Environmental Science International
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• v.15 no.2
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• pp.101-106
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• 2006

The work of hairdressers includes washing, coloring, bleaching, permanent waving, conditioning, and cutting hair. Hairdressers are subjected to a number of physical and toxicological hazards. The toxicological hazards are those resulting from exposure to a wide range of chemicals that are usually classified active processes. In this study, twenty beauty shops were selected to assess the exposure to indoor air pollutants such as VOCs and particulate matter $(PM_{10})$ during one month from September 1 to September 30, 2003. Indoor air quality of beauty shops might be worse by vehicle emissions because the beauty shops were generally located near roadways. Personal exposures to VOCs and $PM_{10}$ were related to indoor concentrations of beauty shops. According to the questionnaire, hairdressers complained of sore throat, eye irritation, and nervousness as physical symptoms. The measured mean concentrations of respiratory particulates were $30.5ng/m^3$ in indoor, $30.5ng/m^3$ in outdoor and $44.0ng/m^3$ on personal levels. The personal concentration was found higher than indoor and outdoor concentrations. The heavy metals mean concentrations were shown as indoor (Na>Zn>Cr), outdoor (Cr>Zn>Pb), and personal (Na>Cr>Zn) levels. Conclusively, customers as well as workers in the beauty shops might be highly exposed to air pollutants from indoor and outdoor sources. Therefore, proper management should be taken to improve the indoor air quality in beauty shops.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.1
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• pp.113-123
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• 2013

Clothes that retain and emanate body odor feel uncomfortable and unclean; subsequently, the adsorption, desorption and removal amounts of malodorous compounds from fabrics with different polarities were examined. 1-Octen-3-one, octanal and isovaleric acid, which are important malodor compounds from the body, were used as volatile organic compounds (VOC). Samples were prepared with unfinished and ${\beta}$-CD finished cotton, nylon and PET fabrics. The amounts of VOCs retained on the fabrics were measured using headspace GC-MS; in addition, the odor intensity of the samples were evaluated by 10 trained panelists. The amounts adsorbed were estimated by weight gain; however, moisture was found to have a larger effect on the increase in weight than VOCs. The polarity of the VOCs decreased in the order of isovaleric acid, octanal and 1-octen-3-one. Despite the exceptionally large amounts of octanal adsorbed on the nylon sample, the amounts of malodorous compounds adsorbed on fabrics increased with the decreasing VOC molecular weight. The unfinished PET sample adsorbed more VOCs than the unfinished-fabric samples. The odor intensity was mostly weaker in the ${\beta}$-CD finished fabrics than in the unfinished fabrics. The odor intensity of the ${\beta}$-CD finished fabrics was lower than unfinished fabrics. The amount of VOCs that remained on the soiled fabric samples after storing in air for 24 hrs decreased with the increasing VOC vapor pressure. Most VOCs were removed by washing; however, more VOCs were left on the ${\beta}$-CD finished fabrics than unfinished fabrics. The intensity of the odor from the unfinished PET and ${\beta}$-CD finished fabrics was stronger and weaker, respectively, than that of other fabrics, even when the same amounts of VOCs remained.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.87-96
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• 2017

In this study, 4 gases containing typical chlorinated volatile organic compounds (VOCs) were treated by ultraviolet (UV) irradiation. The typical chlorinated VOCs are dichloromethane (DCM), trichloromethane (TCM), carbon tetrachloride (CTC) and trichloroethylene (TCE). The removal efficiency (RE) and the products of chlorinated VOCs by UV irradiation are investigated. At this time, 2 types of background gas (air and nitrogen) were used to figure out the RE by photooxidation and photolysis. The specification of UV-lamp used in this study was low-pressure mercury lamp emitting wavelength of 185~254 nm. The experimental conditions were set as initial VOC concentration of $180{\pm}10ppm$, empty bed retention time (EBRT) of 53 s, temperature of $23{\pm}2^{\circ}C$ and relative humidity of $65{\pm}5%$. In the photolysis condition with nitrogen ($N_2$) as background gas, the averaged RE of the 4 types of chlorinated VOCs was about 24% higher than that with photooxidation; and the REs of VOCs except CTC were confirmed as >99%. The composition of off-gases after UV photooxidation in air was investigated and several intermediates from DCM, TCM and TCE were detected by GC/MS. Among them, phosgene which is a toxics was detected as an intermediate of TCM. In addition, the concentration of carbon dioxide ($CO_2$) in the off-gases was measured to calculate the mineralization rate (MR). With the photooxidation, TCE showed the highest RE (>99%) while MR was the lowest (17%); and the MR of DCM was the highest (86%). In addition, particulate matters (PM) in the off-gases was also detected and high concentrated $PM_{10}$ ($21,580{\mu}g{\cdot}m^{-3}$) and $PM_{2.5}$ ($6,346{\mu}g{\cdot}m^{-3}$) were detected in TCE off-gas. More than 99% of the chlorinated VOCs could be removed using UV254-185 nm lamp, while it is necessary to conduct further studies on the production and treatment of secondary pollutants.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.435-445
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• 2012

The aim of this study is to understand the characteristics of volatile oranic compounds (VOCs) and provide information about the present Indoor Air Quality (IAQ) at residential apartments. All samples were collected in 60-min interval using the tenax absorption trap between May, 2011 and February, 2012. And the effects of environmental factors such as temperature, humidity and construction characteristics were analyzed in relation to the measured concentrations. The results of this study showed that the mean concentration of VOCs was lower than the Ministry of the Environment's standards for maintenance of indoor air quality. The correlation analysis showed that ethylbenzene and xylene (r=0.916, p<0.01), toluene and ehtylbenzene (r=0.810, p<0.01), toluene and xylene (r=0.803, p<0.01) and toluene and styrene (r=0.588, p<0.01) were significant. The result of regression analysis was found that the influenece factors associated with the concentration of VOCs were the age and location of the apartment, remodeling, the temperature and the season.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.24 no.1
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• pp.44-55
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• 1995

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.241-242
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• 2003

국내의 대규모 석유화학산단지역은 석유정제 및 석유화학 관련 사업장으로서 공정별 저장탱크나 밸브, 플랜지 및 폐수처리장 등에서 다량의 VOCs 물질이 배출되고 있다. 여수산단은 1969년 종합적인 석유화학단지로 조성되기 시작하여 현재 93개 업체가 입주하여 가동 중에 있고, 이중 석유화학 관련 사업장이 51개사로서 VOCs 배출과 관련하여 환경부에 매년 배출량을 보고하고 있다. 도시지역의 VOCs 배출은 주로 자동차나 유기용제 사용 등으로 외국에서는 이에 대한 연구가 진행되어 도시지역 특성에 따른 기여도가 대략 산출되어 관리방안 등이 마련되고 있다. (중략)

• KSBB Journal
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• v.15 no.6
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• pp.578-583
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• 2000

Biofiltration has been identified as a promising method of odor, VOCs and air toxic removal from waste gas streams because of low capital and operating cost, low energy requirements and an absence of residual products requiring further treatment of disposal. Because biofiltration units are microbial systems in-corporationg microorganisms grown on a porous solid media like compost, peat, soil and mixtures of these materials, there is a need to study of the adsorptive behavior of these supports. The purpose of this study was to investigate the major parameters of adsorptive process. We adsorbed VOCs onto peats and bark, and examined the correlations between the interphase mass transfer coefficients and transfer units, at different stream flow rates, VOCs inlet concentrations and bed lengths.

• Journal of Environmental Science International
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• v.16 no.9
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• pp.1019-1026
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• 2007

This study was performed in 30 selected apartments in Seoul, Asan and Daegu area which were constructed within 4 years and over 4 years, to measure the concentration of VOCs(benzene, toluene, xylene) from July, 2004 to September. Mean ratios of indoor to outdoor VOCs concentrations in the construction under 4 years were higher in 1 than average, I/O ratio of over 4 years were lower in 1. This was considered that the VOCs density influences indoor pollutant. For the indoor air quality estimation, the deposition constant and the source strength factor of toluene were $1.49{\pm}2.05\;hr^{-1}\;and\;36.95{\pm}52.26\;ppb/h$, respectively.

• Analytical Science and Technology
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• v.16 no.5
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• pp.407-417
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• 2003

In this study, we measured the concentration of VOCs in ambient air and landfill gas (LFG) in a midsize municipal landfill site. The LFG flux values of VOCs were computed using a total of fifteen VOCs determined by GC-PID system. To understand relative contribution of these 15 VOCs to the total carbon budget, their concentration and flux estimates were compared to those of non-methane hydrocarbons (NMHC) measured concurrently. It was also found that there were systematic differences in absolute VOC concentration levels between LFG and air samples above landfill surface. The VOC concentrations in LFG samples were high enough to reach above a few tens of ppm that are 10 to 100 times higher than those in air above landfill surface. If the LFG flux values were computed using the LFG concentration data of 15 VOCs and NMHC with exit ventilation speed, the magnitude of emissions in the study area is estimated to be 8.6 and 103 ton C/yr, respectively. In the meantime, large fraction of those speciated VOC emissions is accounted for by BTEX.