• Journal of Environmental Science International
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• v.5 no.2
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• pp.113-130
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• 1996

Diurnal variations of air quality for each season over Taeau city were analyzed using the characteristic features of the various synoptic wind fields. The air quality data which were monitored by four stations are the hourly averaged sulfur dioxide($SO_2$), total suspended particulate(TSP) and oxidants ($O_3$) during the period of 1989 to 1992. The various synoptic wind fields obtained from the 850 hPa geopotential height were divided in to four geostrophic wind directions and two geostrophic wind speeds for each seasons. The synoptic weather conditions were again subdivided info two categories using the lotal cloud amounts, The results shows that diurnal and seasonal variations of the air quality over Taegu city, such as sulfur dioxide, total suspended particulate and oxidants reseal the various characteristics under the same synoptic weather conditions.

• Food Science and Preservation
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• v.15 no.6
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• pp.791-795
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• 2008

In order to establish the method to prepare and use the sulfur dioxide gas generating agent in low temperature storage of grape fruits, the $SO_2$ generation capacity from various sulfite compounds was investigated, and the method to regulate $SO_2$ gas generation and to detect the gas was developed. The conidial germination and mycelium growth of Botrytis cinerea which causes gray mold disease during grape fruit storage was completely inhibited at the $SO_2$ gas concentration of 400 ppm and 3200 ppm, respectively. Sodium hydrosulfite generated the most amount of $SO_2$ gas among the investigated 5 different sulfite or bisulfite compounds. By adjusting the number of pinholes on packaging film of the compound or by adding pH adjusting agent, e.g. citric acid or phosphates, it was possible to regulate the amount and duration of $SO_2$ gas generation from the compound. Because malachite green was quantitatively discolored by $SO_2$ gas, the solution or impregnated paper with the compound could be practically utilized as a indicator detecting $SO_2$ gas. Finally, when Muscat Bailey A grape was stored at low temperature with $SO_2$ gas generating agent, the disease incidence was reduced after storage.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.146-151
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• 2013

This paper reveals the performance decrease and recovery of PEMFC when the contaminated fuel gas and air source with sulfur impurities such as hydrogen sulfide and sulfur dioxide were simultaneously introduced to anode and cathode, respectively. Three different GDLs were fabricated with different carbon black and activated carbon to prevent an introduction of sulfur compound impurities into MEA. components. The severity of $SO_2$ and $H_2S$ poisoning was depended on concentrations(3 ppm - 10 ppm) of sulfur impurities. Especially, cell performance degradation rate was rapid when MEA fabricated with CN-2 GDL because it had little porosity on GDL surface. Moreover, the cell performance can be recovered up to 90%-95% only with neat hydrogen and fresh air feeding.. Conclusively, MEA fabricated with porous CN-1 GDL showed the best cell performance and recovery efficiency during exposure to poisoning condition by simultaneous sulfur impurities.

• Carbon letters
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• v.1 no.1
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• pp.31-35
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• 2000

[ $SO_2$ ]and NO gases that come from the flue gases of most of all industrial combustion processes are harmful to everything include person and industrial facilities. For the simplification of the environmental clean-up processes, we studied the decomposition process by microwave. The microwave can destroy molecules into elementary atoms and offers energy to the atoms to react with carbons. Since the microwave is not absorbed into quartz tube and metallic chamber, the air pollution gases can be removed with much lower energy than in the case of conventional methods. We studied the decomposition of $SO_2$ and NO gases on the carbon beds by microwave. In the microwave field, the gases can be decomposed to form other compounds, such as elementary sulfur, nitrogen, carbon monoxide and carbon dioxide. It was found that CO gas is formed at higher temperature than is $CO_2$ gas, so it needs to control the bed temperature depend on products that we want to get.

• Asian Journal of Atmospheric Environment
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• v.6 no.1
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• pp.41-52
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• 2012

Particulate sulfate in $PM_{2.5}$, sulfur dioxide ($SO_2$) and size-segregated aerosol particle number concentrations were measured at a site ($32^{\circ}19'N$, $129^{\circ}59'E$) on the southwestern Japan coast from 5 March to 10 April, 2010. Results show frequent episodic increases of sulfate and $SO_2$. Compared to the average concentration of sulfate $4.4{\pm}2.7\;{\mu}g\;m^{-3}$ in the whole observation period, episodic sulfate reached $10.5-20.1\;{\mu}g\;m^{-3}$. The variation of sulfate always synchronized with aerosol particles in the size range of $0.1-0.5 {\mu}m$, indicating the episodic sulfate was a consequence of the increase of the sub-micron particles. $SO_2$ did not have remarkable increase in any episodes of sulfate increase. During the passage of low pressure systems which loaded Asian dust in postfrontal air, concentrated sulfate appeared right behind the front but before dust arrival, suggesting the dominance of dust-free particulate sulfate. Weather and backward trajectory analyses revealed that air parcels with high sulfate passed eastern and northeastern China or Korean peninsula before arriving at the site. In contrast, those with high $SO_2$ passed an active volcano, Mt. Sakurajima, about 100 km in the south, suggesting the $SO_2$ was more likely from the volcanic emission. The ratio of sulfate to total sulfur compounds $({SO_4}^{2-})/({SO_4}^{2-}+SO_2)$ was 0.31-0.89 in continentally originated air while was 0.25-0.43 in the air having passed the volcano, showing more efficient conversions of $SO_2$ to sulfate in the air from the continent. The close dependence of the conversion on humidity in the continentally originated air was confirmed.

• Journal of Environmental Impact Assessment
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• v.8 no.1
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• pp.29-40
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• 1999

This study focuses on one of typical energy-intensive industries, the cement industry. The purpose of the study is to propose $SO_2$ emission reduction measures in the cement industry. This study partially employed and modified AIM(Asia-Pacific Integrated Model) developed by Japan National Environmental Research Institute to develop AIM/KOREA SULFUR model for simulation. In the study, a base scenario, and mitigation scenarios(a use of low-sulfur contain fuel, fuel conversion to cleaner energy, an induction of desulfurization systems, and energy saving) were employed. The results of the simulation are summarized below: The sulphur dioxide emission from the cement industry in 1992 was estimated to be 106,000 metric tons; however, according to base scenario, sulphur dioxide emission is expected to be increased to 219,000 metric tons, which is 2.1 times greater than that in 1992 by year 2020. To alleviate such increasement, simulation results under various scenarios proved that some degrees of reduction may be possible by an induction of desulfulization systems although there may be numerous ways to interpretate the simulation results.

• Journal of Environmental Science International
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• v.5 no.2
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• pp.131-140
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• 1996

Analysis of hourly variations of sulfur dioxide ($SO_2$) concentrations affected by regional climates for the period of yellow sandy dusts was carried out from March 31 through April 9, 1993. The concentration of 50, at a coastal city, Kangnung city, was much higher than that at an inland city Wonju in the west, but the hourly distrbutions of $SO_2$ concentrations show a similar tendency at both cities. Under the prevailing synoptic-scale westerly winds blowing over a high Mt. Taegualyang in the west toward Kangnung city in the eastern coastal region, the $SO_2$ at Kangnung is trapped by an easterly sea-breeze during the day and under prevailing easterly winds, it is also isolated by the high wall of Mt. Taegualyang, with its high concentration from 14 to 16 LST. Furthermore, when the westerly winds were dominent all day long the high $SO_2$ concentrations at Kangnung were produced by its intrusion from a urban city, Wonju or China in the west into a mountainous coastal city, Kangnung, to some extent, and when the air becomes rapidly cooled down at the clear daytime or the nighttime, their concentrations are also increased by a great amount of heating fuel combustion. Especilly, its maximum concentrations were shown in Wonju and Kangnung from 08 LST through 10 LST, due to the increase of auto vehicles near the beginning time of office hour and were detected again after sunset due to both increases of vehicles at the end of office hour and heating fuel combustion. During the period of Yellow Sandy Dusts which are transported from China into Korea, the $SO_2$ concentrations on rainy days at Wonju and Kangnung were much lower than the monthly mean values of $SO_2$, and their low concentrations could be caused by the scavenging process of rain.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.103.1-103.1
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• 2003

This study was carried out to investigate sulfur dioxide in herb drugs.(Puerariae Radix, Lycii Fructus, Platycodi Radix, Dioscoreae Rhizoma, Mori Radicis Cortex, Nelumbo Seed, Paeoniae Radix, Remotiflori Radix, Astragali Radix, Polygonatum Rhizome) Experimental subjects included 105 cases of 10 species of herb drugs collected in Kyung-dong market from December in 2001 to February in 2002. Sulfur dioxide was determined by Optimized Monier-Wiliams method. In 65 cases(61.9%) of the 105 cases, we detected $SO_2$ over 10mg/kg. (omitted)

• Herbal Formula Science
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• v.17 no.2
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• pp.53-63
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• 2009

Objective : To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after a decoction. Methods : The heavy metal contents before/after a decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and mercury analyzer. In order to analyze pesticides in 4 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide ($SO_2$) were performed by Monier-Williams distillation method. Results: 1. The mean values of heavy metal contents (mg/kg) for the samples were as follows: Jaeumganghwa-tang (before decoction - Pb; 1.190, Cd; 0.184, As; 0.099 and Hg; 0.028, after decoction - Pb; .033, Cd; 0.003, As; 0.005 and Hg; 0.001), Yukmijiwhang-tang (before decoction - Pb; 0.484, Cd; 0.133, As; 0.053 and Hg; 0.009, after decoction - Pb; 0.065, Cd; 0.008, As; 0.007 and Hg; not detected), Bojungikgi-tang (before decoction - Pb; 0.863, Cd; 0.197, As; below 0.016 and Hg; 0.011, after decoction - Pb; 0.071, Cd; 0.009, As; 0.004 and Hg; 0.001) and Ssangwha-tang (before decoction - Pb; 1.511, Cd; 0.212, As; 0.094 and Hg; 0.016, after decoction - Pb; 0.029, Cd; 0.006, As; 0.005 and Hg; 0.0004). 2. Contents (mg/kg) of sulfur dioxide ($SO_2$) before a decoction in Jaeumganghwa-tang, Yukmijiwhang-tang and Ssangwha-tang exhibited 22.7, 107.3 and 5.5, respectively. However, contents of sulfur dioxide after a decoction in all samples were not detected. 3. Contents (mg/kg) of residual pesticides before/after a decoction in all samples were not detected. Conclusion : These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• The Korea Journal of Herbology
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• v.24 no.1
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• pp.111-119
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• 2009

Objectives : To compare the contents of hazardous substances before/after a decoction. Methods : The heavy metal contents before/after a decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and mercury analyzer. In order to analyze pesticides in 6 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide (SO2) were performed by Monier-Williams distillation method. Results : 1. The mean values of heavy metal contents (mg/kg) for the samples were as follows: Samchulkunbi-tang (before decoction - Pb; 1.592, Cd; 0.155, As; 0.055 and Hg; 0.014, after decoction - Pb; 0.036, Cd; 0.002, As; not detected and Hg; 0.001), Yijin-tang (before decoction - Pb; 0.830, Cd; 0.077, As; 0.045 and Hg; 0.015, after decoction - Pb; 0.193, Cd; 0.010, As; not detected and Hg; 0.002), Banhabaikchulcheunma-tang (before decoction - Pb; 0.976, Cd; 0.164, As; 0.167 and Hg; 0.019, after decoction - Pb; 0.031, Cd; 0.003, As; 0.006 and Hg; 0.005), Pyungwi-san (before decoction - Pb; 2.162, Cd; 0.128, As; 0.061 and Hg; 0.018, after decoction - Pb; 0.080, Cd; 0.006, As; not detected and Hg; 0.005), Leejung-tang (before decoction - Pb; 1.480, Cd; 0.294, As; 0.034 and Hg; 0.012, after decoction - Pb; 0.064, Cd; 0.007, As; 0.007 and Hg; 0.002) and Kwibi-tang (before decoction - Pb; 0.907, Cd; 0.193, As; 0.085 and Hg; 0.020, after decoction - Pb; 0.072, Cd; 0.006, As; 0.004 and Hg; 0.002). 2. Contents (mg/kg) of sulfur dioxide ($SO_2$) before a decoction in Banhabaikchulcheunma-tang, Pyungwi-san, Leejung-tang and Kwibi-tang exhibited 3.5, 3.4, 3.8 and 12.4, respectively. However, contents of sulfur dioxide after a decoction in all samples were not detected. 3. Contents (mg/kg) of residual pesticides before/after a decoction in all samples were not detected. Conclusions : These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.