• 환경위생공학
• /
• 제17권2호
• /
• pp.63-70
• /
• 2002

We investigated the concentration degree of VOCs for ambient air in the air environment control area of Kyonggi-do in 2001. The VOCs showing higher concentration were in the ascending order of Toluene > n-Butane > 1-Butene > Benzene > n-Hexane. The concentration distribution ratio mentioned above showed almost same pattern in each city. The relative concentration ratio of Benzene, Toluene, Ethylbenzene, Xylenes which are aromatic VOCs were 1 : 6.3 : 0.6 : 1.6. It was similar to the pattern in 1999 but different from the pattern in 2000. In the aspect of seasons, the highest B.T.E.X concentration was indicated in fall and in the aspect of areas, the higher concentration showed in the ascending order of Buchon > Ansan > Kwangmyong > Shihung > Sungnam. The average concentration of target VOCs for ambient air in the air environment control area of Kyonggi-do showed lower concentration than the metropolis of Seoul but higher concentration than Kwang-ju city and Dae-gu city. The amount of total VOCs was increasing, comparing with it last year and the more increasing tendency is anticipated so that it will need to establish the proper regulative criteria.

• Asian Journal of Atmospheric Environment
• /
• 제10권4호
• /
• pp.169-178
• /
• 2016

Measurements of $SO_2$, $NO_2$ and benzene, toluene, ethylbenzene, and xylenes BTEX concentrations using passive tubes were carried out at five locations featuring educational and light industrial activities in south western Kuwait City during 2014. The five selected sites, chosen to be statistically representative of land use in the study area, were monitored to evaluate the impacts of traffic and light industrial activities on pollutant concentrations. The recorded mean concentrations of $NO_2$, $SO_2$ and BTEX were 40.3, 28.1 and $3.72{\mu}g/m^3$, respectively. The lowest concentrations were recorded in the educational area. Comparisons between the measured concentrations and the applicable air quality standards from the Kuwait Environment Public Authority showed that the gas concentrations were lower than the allowable limits.

• Journal of Microbiology and Biotechnology
• /
• 제17권4호
• /
• pp.668-672
• /
• 2007

A microcosmal experiment using a metagenomic technique was designed to assess the effect of BTEX (benzene, toluene, ethylbenzene, and xylenes) on an indigenous bacterial community in a Daejeon forest soil. A compositional shift of bacterial groups in an artificial BTEX-contaminated soil was examined by the 16S rDNA PCR-DGGE method. Phylogenetic analysis of 16S rDNAs in the dominant DGGE bands showed that the number of Actinobacteria and Bacillus populations increased. To confirm these observations, we performed PCR to amplify the 23S rDNA and 16S rDNA against the sample metagenome using Actinobacteria-targeting and Bacilli-specific primer sets, respectively. The result further confirmed that a bacterial community containing Actinobacteria and Bacillus was affected by BTEX.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
• /
• pp.115-118
• /
• 2006

The partitioning tracer method has been studied as an alternative method for characterizing aquifers contaminated by nonaqueous phase liquids (NAPLs). Accurate partition coefficients of tracers partitioning between NAPL and water are needed to improve the reliability of the partitioning tracer method. In this research, partition coefficients of alcohol tracers partitioning between benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds and water are estimated from using the approach of equivalent alkane carbon number (EACN). General agreement was observed in between the measured and estimated partition coefficients. Based on these results we can verify that the EACN approach is suitable for estimating the partition coefficient.

• 한국안전학회지
• /
• 제11권4호
• /
• pp.79-83
• /
• 1996

In this study, in attempt to develop a new application technique of discharge plasma, we employed a kind of discharging method called SPCP ( short for Surface discharge induced Plasma Chemical Process). Applications of SPCP have been widely used for years. Compact ozonizers to deodorize household equipments like refrigerators we a part of such applications. We took advantages of the compactness and durability of the SPCP electrode to set up an experimental apparatus for decompositing vapor of aromatic hydrocarbons such as toluene, benzene and xylenes, which are major substances given off In painting or washing processes and aggravate working conditions. Results obtained from this study are summarized as follows. 1) Aromatic hydrocarbon vapors of up to 2,000ppm were almost thoroughly decomposed at the flow rate of 4ℓ/min or lower under the discharge with electric power of 400 Watts. 2) In dry air, as the decomposition progresses, tar-like substance deposits on the discharging areas, which deteriorated the decomposition rate in the end. This substance, however, was almost thoroughly removed by keeping discharge in dry air containing no solvent vapor.

• 한국환경과학회지
• /
• 제14권8호
• /
• pp.785-792
• /
• 2005

In order to reduce roadside and indoor air pollution for volatile organic compounds VOC), it may be necessary to apply photocatalyst-coated construction materials. This study evaluated the technical feasibility of the application of $TiO_2$ photocatalysis for the removal of VOC present in roadside or indoor air. The photocatalytic removal of five target VOC was investigated: benzene, toluene, ethyl benzene and o,m,p-xylenes. Variables tested for the current study included ultraviolet(UV) light intensity coating materials, relative humidity (RH), and input concentrations. Prior to performing the parameter tests, adsorption of VOC onto the current experiment was surveyed, and no adsorption was observed. Stronger UV intensity provided higher photocatalytic destruction(PCD) efficiency of the target compounds. For higher humidity, higher PCD efficiency was observed. The PCD efficiency depended on coating material. Contrary to certain previous findings, lower PCD efficiencies were observed for the experimental condition of higher input concentrations. The current findings suggested that the four parameters tested in the present study should be considered for the application of photocatalyst-coated construction materials in cleaning VOC of roadside or indoor air.

• 한국대기환경학회지
• /
• 제20권1호
• /
• pp.59-68
• /
• 2004

In this study, we investigated the concentrations of volatile organic compounds (VOC) in the ambient air of a small scale municipal waste landfill site. Seasonal sampling was carried out simultaneously at two sites, i.e. one in the center of the landfill area, and the other at a boundary site. Among 38 target VOC, toluene appeared to be the most dominant compound, followed by benzene. and xylenes. The higher levels of BTX imply that paint -containing materials and/or organic solvents are the most significant sources of the VOC in the landfill environment. Seasonal variations for the samples collected at the landfill site indicated that the VOC concentrations tend to be higher in the spring and fall season and lower in the winter season. In addition, night- time concentrations appeared to be generally higher than day-time. Such daily variation might be due to more stabilized atmosphere during the night-time. Similar patterns were also found in samples collected at a boundary site. This study demonstrated that the municipal landfill, although it is small -scaled, could be an important emission source of atmospheric VOC, particularly in the vicinities of the landfill. Thus, an appropriate control strategy is required to prevent any undesirable secondary pollutions from the environmental sanitary facilities such as landfill.

• 분석과학
• /
• 제24권5호
• /
• pp.352-359
• /
• 2011

용매를 사용하지 않고 반복적으로 막 추출한 후 저온농축과 GC-MS로 물 중 BTEX를 분석하는 방법을 시도하였다. 물로부터 비공성막의 silicone 막을 투과한 BTEX를 He 기체를 통해 $-100^{\circ}C$의 저온 농축장치로 보낸 후 열 탈착과 GC-MS로 분석하였다. 물 시료(30 mL)는 10 mL/min로 흘려주었고, 한 번 추출된 시료는 다시 되돌려서 두 번 더 추출하였다. Benzene에 대한 회수율은 가장 높아 약 80%인 반면에, ethylbenzene과 xylenes에 대한 회수율은 3.5-10%로 낮은 편이었다. 그렇지만, RSD는 모두 10% 미만이었고 검량선의 직선성($r^2$)도 0.9976-0.9997로 높은 편이었으며, 방법검출한계도 1.8 ${\mu}g$/L 이었다. 이 방법은 짧은 추출 시간, 용매의 미사용 및 분석의 편의성의 장점을 갖고 있다.

• 한국물환경학회지
• /
• 제27권2호
• /
• pp.167-177
• /
• 2011

Oil이나 Gas생산시 발생하는 Produced water의 양은 미국 내에서만 연간 수십억 배럴에 육박한다. 이러한 Produced water의 재이용을 위한 첫 번째 과제는 유해 유기물질을 제거하는 것으로, 본 연구에서는 수중의 BTEX를 가스상태로 변화시킨 후 Vapor phase biofilter (VPB)로 분해, 제거 효능을 평가하였다. VPB 시스템은 짧은 기간의 시스템 shutdown에는 거의 영향을 받지 않는 것으로 나타났다. 그러나 주입 되는 농도가 Peak 형태를 가질때는 제거효능의 저하가 관찰 되었으며, 이중 Benzene이 가장 민감하게 반응하였다. 이를 위한 해결책으로 GAC로 충진된 Buffering Column이 사용되었으며, 이는 peak 형태의 유입농도 Profile을 완만한 형태로 buffering하는 역할을 하였다. 현장 적용을 통하여, 본 시스템이 Produced water내에 존재하는 용존 BTEX를 효과적으 로 제거할 수 있음을 확인하였다.

• 환경영향평가
• /
• 제20권4호
• /
• pp.497-507
• /
• 2011

This research studied human health risk assessment of benzene from industrial complexes of Chungcheong Province (Seosan industrial complex) and Jeonla Province (Iksan industrial complex and Yeosoo industrial complex). The residents near the industrial complexes areas can be often exposed to volatile organic compounds (e.g., benzene, toluene, xylenes) through a number of exposure pathways, including inhalation of the organic pollutant via various environmental matrices (air, water and soil), contaminated water, and soil intake. Benzene is well known to be a common carcinogenic and toxic compound that is produced from industrial and oil refinery complexes. In this study, a number of samples from water, air, and soil were taken from the residential settings and public school zones located near the industrial complex sites. Based on the carcinogenic risk assessment, the risk estimates were slightly above $10{\times}10^{-6}$ at all three industrial sites. According to deterministic risk assessment, inhalation was the most important route. The distribution of benzene in the environment would be dependent on vapor pressure, and the physical property influencing the extent of the potential risks. Non-carcinogenic risk assessment of benzene shows that the values of Hazard Index(HI) were much lower than 1.0 at all industrial complexes. Therefore, benzene was not a cause of concern in terms of non-carcinogenic risk posed to the residents near the sites. When compared to probabilistic risk assessment, the CTE(central tendency exposure) cancer risk values of deterministic risk assessment were close to the mean values predicted by the probabilistic risk assessment. The RME(reasonable maximum exposure) values fell within the range of 95% to 99.9% estimated by the probabilistic risk assessment. Since the values of carcinogenic risk assessment were higher than $10{\times}10^{-6}$, further detailed monitoring and refined risk assessment for benzene may be warranted to estimate more reliable and potential inhalation risks to receptors near the industrial complexes.