• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.176-179
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• 2003

The objective of this study was to investigate reductive dechlorination of aromatic hydrocarbons using zero valent metals (ZVMs) and catalysts as reactive materials for permeable reactive barriers (PRBs). A group of small aromatic hydrocarbons such as monochlorophenols, phenol, benzene were readily reduced with palladium catalyst and zero valent iron. Poly-aromatic hydrocarbons (PAHs) were also tested with the catalysts and zero valent metal combinations. The aromatic rings were reduced and partly reduced PAHs were found as the daughter compounds. Current preliminary study implicate that ZVMs and modified catalysts can be successfully applied for PRBs which currently applicable for halogenated organic compounds and some inorganic contaminants including chromium(Ⅵ) and nitrate.

• Bulletin of the Korean Chemical Society
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• v.24 no.2
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• pp.246-248
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• 2003

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.79-79
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• 2004

• Journal of Environmental Science International
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• v.8 no.4
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• pp.473-477
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• 1999

The purpose of this study was to investigate the characteristics of removal efficiency for aromatic hydrocarbons using a high-temperature fiber filter on a laboratory scale. The main elemental compositions of a high-temperaure fiber filter are aluminium and silica, which can act as the catalysts. Benzene, toluene and o-xylene among aromatic hydrocarbons were used in this experiment. For 3cm thickness of fiber filter, these compounds were removed more than 90% at the face velocities of 3cm/sec and 5cm/sec above 45$0^{\circ}C$. For 4cm thickness of it, the removal efficiencies of these compounds were almost 90% from 40$0^{\circ}C$ at the same face velocities, suggesting that it may be due to increasing the contact time between the fiber filter and aromatic hydrocarbons. The pressure droop ranged from 22 to 48mmH2O for 3cm thickness of fiber filter. However, for 4cm thickness of it, it was about two times(41~89mm$H_2O$) higher than that for 3cm fiber thickness.

• Advances in environmental research
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• v.6 no.3
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• pp.189-202
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• 2017

This study examines the concentrations of particulate-phase polycyclic aromatic hydrocarbons (PAHs) and gas-phase PAHs in sidestream cigarette smoke. Sixteen PAHs were determined for four brands of cigarettes. The volume of the experimental room is approximately $66m^3$. The air samples in the room were collected before and after smoking. The median total of particulate-phase and gas-phase PAH concentrations before smoking $3.13ng/m^3$and $48.0ng/m^3$, respectively. The median concentrations of them after smoking were $10.0ng/m^3$ and $79.6ng/m^3$. The median increases in the total of 16 PAH concentrations per cigarette during smoking were 271 ng for the particulate-phase PAHs and 1960 ng for the gas-phase PAHs. According to the relationship between particulate-phase and gas-phase PAHs after smoking, the two- to four-ring gas-phase PAHs and the higher molecular weight particulate-phase PAHs were probably formed from similar precursors. The relationship between the total suspended particulate (TSP) concentration and the increase in the total particulate-phase concentration of the 16 PAHs per cigarette during smoking were significantly positive. The increase in the total gas-phase concentration of the 16 PAHs tended to increase as the TSP concentration increased. This may indicates that decreasing the amount of TSP produced inhibit the production of PAHs during smoking.

• Mass Spectrometry Letters
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• v.2 no.2
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• pp.41-44
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• 2011

Molecular compositions of two types of heavy oil were studied using positive atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Vacuum gas oil (VGO) was generated from vacuum distillation of atmospheric residual oil (AR), and slurry oil (SLO) was generated from catalytic cracking of AR. These heavy oils have similar boiling point ranges in the range of 210-$650^{\circ}C$, but they showed different mass ranges and double-bond equivalent (DBE) distributions. Using DBE and carbon number distributions, aromatic ring distributions, and the extent of alkyl side chains were estimated. In addition to the main aromatic hydrocarbon compounds, those containing sulfur, nitrogen, and oxygen heteroatoms were identified using simple sample preparation and ultra-high mass resolution FT-ICR MS analysis. VGO is primarily composed of mono- and di-aromatic hydrocarbons as well as sulfur-containing hydrocarbons, whereas SLO contained mainly polyaromatic hydrocarbons and sulfur-containing hydrocarbons. Both heavy oils contain polyaromatic nitrogen components. SLO inludes shorter aromatic alkyl side chains than VGO. This study demonstrates that APPI FT-ICR MS is useful for molecular composition characterization of petroleum heavy oils obtained from different refining processes.

• Journal of Life Science
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• v.19 no.5
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• pp.659-663
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• 2009

Bacterial stain 3Y was isolated from a site that was contaminated with diesel for more than 15 years. The strain could grow on various petroleum using hydrocarbons as the sole carbon source. The strain grew not only on aliphatic hydrocarbons but also on aromatic hydrocarbons. 3Y grew on aliphatic petroleum hydrocarbons hexane or hexadecane, and aromatic petroleum hydrocarbons BTEX, phenol, biphenyl, or phenanthrene. The strain showed aromatic ring dioxygenase and meta-cleavage dioxygenase activities as determined by tests using indole and catechol. Aromatic ring dioxygenase is involved in the initial step of biodegradation of aromatic hydrocarbons while meta-cleavage dioxygenase catalyzes the cleavage of the benzene ring. Based on a nucleotide sequence analysis of its 16S rRNA gene, 3Y belongs to the genus Sphingomonas. A phylogenetic tress was constructed based on the nucleotide sequences of closest relatives of 3Y and petroleum hydrocarbon degrading sphingomonads. 3Y was in a cluster that was different from the cluster that contained well-known sphingomonads. The results of this study suggest that 3Y has the potential to cleanup oil-contaminated sites. Further investigation is warranted to optimize conditions to degrade petroleum hydrocarbons by the strain to develop a better bioremediation strategy.

• Asian Journal of Atmospheric Environment
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• v.10 no.2
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• pp.90-98
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• 2016

Total suspended particulates (TSP) in the atmosphere were collected for 2 weeks during winter in Muroran, Hokkaido, Japan, a typical iron-manufacturing city. The concentrations of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in TSP were determined by high-performance liquid chromatography (HPLC) using fluorescence and chemiluminescence detectors, respectively. No relationship was observed between the atmospheric PAH and NPAH concentration, or the atmospheric PAH and TSP concentration. However, there was a tendency that the atmospheric PAH concentration was higher when the wind blew from the coke-oven plant. Furthermore, the concentration ratios of 1-nitropyrene to pyrene, which is a suitable indicator of the contribution made by automobiles and coal combustion systems to urban air particulates, were smaller in Muroran and the values were close to those observed in particulates from coal combustion systems. Therefore, these results show that the PAH and NPAH compositions for Muroran are characteristic of an iron-manufacturing city.

• Asian Journal of Atmospheric Environment
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• v.9 no.1
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• pp.57-65
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• 2015

We measured the concentrations of five aromatic hydrocarbons (benzene, toluene, ethylbenzene, m,p-xylene, and styrene) in the atmosphere during four seasonal campaigns at Deokjeok and Jeju Islands in the Yellow Sea from October 2005 to June 2006. Toluene was the most abundant aromatic hydrocarbon, with median of 0.24 ppb at Deokjeok and 0.20 ppb at Jeju, followed by benzene (0.21 ppb, 0.15 ppb) and m,p-xylene (0.06 ppb, 0.06 ppb). Aromatic hydrocarbon measurements exhibited the typical seasonality of the major emission sources, such as vehicle exhaust, solvent evaporation, and regional circulation patterns. The ratios of m,p-xylene/ethylbenzene of 1.57 at Deokjeok and 1.05 at Jeju reflected the degree of proximity to outflows of each source region, South Korea and China. The toluene/benzene ratios of 1.0 were consistently both on field observations and on the 3-D chemical model simulation, which is slightly higher than that in the Western Pacific area. It implied that the air over the Yellow Sea was influenced to a great extent by the surrounding areas. We confirmed that current emission inventories of aromatic hydrocarbons in Northeast Asia reasonably reproduced temporal and spatial variations of toluene and benzene over the Yellow Sea.

• Journal of Environmental Health Sciences
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• v.38 no.5
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• pp.386-392
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• 2012

Objectives: This study aims to evaluate the blood concentrations and dietary intake for 24-hour food duplicate of low level polycyclic aromatic hydrocarbons (PAHs). Design: The geometric means of the blood concentrations and dietary intake of 16 PAHs in college student candidates were simply compared with instrumental detection. Methods: The concentrations of 16 PAHs in venous blood and 24-hour food duplicates were analyzed with head-space solid phase microextraction (HS-SPME) of gas chromatography-mass spectrometry. Results: Naphthalene, acenaphthylene, pyrene, benz(a)anthracene, chrysene, and acenaphthene among the 16 analyzed PAHs were simultaneously detected both in venous blood and 24-hour food duplicate samples. Conclusion: The main exposure source of the six PAHs is thought to be oral intake from food through low level non-occupational exposure.