• Journal of Korean Society for Atmospheric Environment
• /
• v.32 no.4
• /
• pp.435-447
• /
• 2016

Anthropogenic emissions of $PM_{2.5}$ in Chuncheon are considered to be low according to the national emissions inventory; however, the atmospheric $PM_{2.5}$ concentrations have been reported to be higher than or at least similar to those measured in metropolitan (e.g. Seoul) and/or in industrial cities (e.g. Incheon, Ulsan). In this study, the concentrations of $PM_{2.5}$ and its ionic and carbonaceous compounds were measured from Jan. 2013 to Dec. 2014 in Chuncheon, Korea to identify the characteristics of high $PM_{2.5}$ concentration event. Average $PM_{2.5}$ concentration was $34.6{\mu}g/m^3$, exceeding the annual air quality standard ($25{\mu}g/m^3$). The most abundant compound was organic carbon (OC), comprising 26% of $PM_{2.5}$ mass, followed by $SO_4{^{2-}}$. Among 14 high concentration events, three events showed clearly enhanced contributions of OC, $SO_4{^{2-}}$, $NO_3{^-}$ and $NH_4{^+}$ to $PM_{2.5}$ under the fog events. One event observed in summer showed high concentration of $SO_4{^{2-}}$ while the high wind speeds and the low $PM_{2.5}/PM_{10}$ ratios were observed for the two high concentration events. These results indicate that the secondary aerosol formation under the fog events and high atmospheric temperature as well as the regional and/or the long-range transport were important on enhancing $PM_{2.5}$ concentration in Chuncheon. Cluster analysis based on back trajectories also suggested the significant impacts of regional transport from China and metropolitan areas of Korea on $PM_{2.5}$ in Chuncheon.

• Applied Chemistry for Engineering
• /
• v.10 no.8
• /
• pp.1129-1135
• /
• 1999

The reduction of $SO_2$ by CO over supported cobalt catalysts was investigated within the temperature range of $350{\sim}550^{\circ}C$, initial $SO_2$ concentration of 1000~10000 ppm, $CO/SO_2$ molar ratio of 1.0~3.0 and space velocity of $5000{\sim}15000h^{-1}$. Several types of supports such as ${\gamma}-Al_2O_3$, $TiO_2$ were tested. The $SO_2$ conversion and selectivity to elemental sulfur were investigated using a differential fixed bed reactor at atmospheric pressure. The catalyst prepared by wet impregration of 5 wt % cobalt on ${\gamma}-Al_2O_3$ showed $SO_2$ conversion higher than 90% and COS yield lower than 6% at temperature above $400^{\circ}C$. The optimum $CO/SO_2$ molar ratio was investigated as 2.0. At higher $CO/SO_2$ molar ratio, the $SO_2$ conversion became higher but the main product was COS. The effect of $SO_2$ concentration and space velocity over $SO_2$ conversion and COS yield was not appreciable in the experimental range. The activated cobalt phase was detected as $CoS_2$ and the $CoS_2$ phase unchanged even after reaction.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.2052-2057
• /
• 2010

In December 2006, the Ministry of Environment in Korea established the "Indoor Air Quality Management Guidelines in Public Transportation." As the items of the guideline, $CO_2$(Carbon dioxide) and PM10(Particulate matter). Therefore, the air quality inside the train is supposed to be ruled by this guideline. This study calculated the increase or decrease rate of the $CO_2$ concentration by using the data measured in accordance with flap operation. In case of flap close or open, the calculated $CO_2$ concentration variation was 6.32ppm/min. The $CO_2$ concentration prediction equation was derived from the general equation and the actual measured value are compared with the predicted $CO_2$ concentration suggested during the KyungBu high speed railway construction. The predicted value show good agreement with the measured data.

• Clean Technology
• /
• v.24 no.3
• /
• pp.212-220
• /
• 2018

Oxy-fuel combustion is considered as a promising greenhouse gas reduction technology in power plant. In this study, the behaviors of NO and $SO_2$ were investigated under the condition that in-furnace $deNO_x$ and $deSO_x$ methods are applied in oxy-fuel circulating fluidized bed combustion condition. In addition, the generation trends of $SO_3$, $NH_3$ and $N_2O$ were observed. For the purpose, limestone and urea solution were directly injected into the circulating fluidized bed combustor. The in-furnace $deSO_x$ method using limestone could reduce the $SO_2$ concentration in exhaust gas from ~403 to ~41 ppm. At the same experimental condition, the $SO_3$ concentration in exhaust gas was also reduced from ~3.9 to ~1.4 ppm. This trend is mainly due to the reduction of $SO_2$. The $SO_2$ is the main source of the formation of $SO_3$. The negative effect of $CaCO_3$ in limestone, however, was also appeared that it promotes the NO generation. The NO concentration in exhaust gas reduced to ~26 - 34 ppm by appling selective non-catalytic reduction method using urea solution. The $NH_3$ concentration in exhaust gas was appeared up to ~1.8 ppm during injection of urea solution. At the same time, the $N_2O$ generation also increased with increase of urea solution injection. It seems that the HNCO generated from pyrolysis of urea converted into $N_2O$ in combustion atmosphere. From the results in this study, the generation of other pollutants should be checked as the in-furnace $deNO_x$ and $deSO_x$ methods are applied.

• Journal of Korean Society for Atmospheric Environment
• /
• v.15 no.1
• /
• pp.53-61
• /
• 1999

Acid aerosol and gas concentrations ($SO_4^{2-}$, $NO_3^-$, $HNO_3$, $SO_2$, and $NH_3$) were measured at Chunchon and Seoul, Korea using filter pack method during one year from October 1996 to september 1997. The samples were collected during 24 hours every Wednesday in a week from 10 A.M. with 10$\ell$/min of sample flow. Concentration of $HNO_3$, $SO_2$ and $NH_3$ gases showed typical seasonal variation. The $HNO_3$ showed the highest in summer and annual mean concentrations were 0.42 ppb and 0.57 ppb at Chunchon and Seoul, respectively. The $SO_2$ showed the highest in winter and annual mean concentration was 5.59 ppb at Chunchon. The $NH_3$ showed the highest in early summer and annual mean concentration were 5.15 ppb and 6.28 ppb at Chunchon and Seoul, respectively.

• Applied Biological Chemistry
• /
• v.6
• /
• pp.57-59
• /
• 1965

According to the result of the observations on the effect of the reagents, $CuSO_4{\cdot}5H_2O$, $ZnSO_4{\cdot}7H_2O$ $MnSO_4{\cdot}4H_2O$, $HgCl_2$, upon the mycelial growth of psalliota campestris $HgCl_2$ showed the strongest effect on checking the mycelial growth $(,.008{\sim}0.01%)$ $CuSO_4{\cdot}5H_2O(0.030%)$, $ZnSO_4{\cdot}7H_2O(0.080%)$, came next and the $MnSO_4{\cdot}4H_2O(0.100%)$ was the weakest. Writer also found that showed the promoting effect of the mycelial growth in appropriate Concentration (at $0.015%\;CuSO_4{\cdot}5H_2O$, $0.030%ZnSO_4{\cdot}7H_2O$).

• Journal of Environmental Health Sciences
• /
• v.32 no.4 s.91
• /
• pp.324-335
• /
• 2006

Five sampling sites were selected to investigate the distribution characteristics of air pollutants with pollution sources and weather conditions in Ulsan. $SO_2,\;NO_2,\;O_3,\;CO,\;PM_{10}$ concentrations and weather conditions with time were analyzed by using several statistical methods. Also, the distribution characteristics of ambient air quality were estimated by pollution-rose and multi-regression analysis. As a result of the analysis, $NO_2,\;CO\;and\;PM_{10}$ concentrations were high in winter season, whereas $SO_2\;and\;O_3$ concentrations were high in summer season. This concentration distribution was caused by the unfavorable geographical location, which the residential area was located at the downwind direction to industrial area. From the pollution-rose, we confirmed that each pollutant influenced the downwind residential areas because of seasonal wind direction. $SO_2$ concentration has shown positive correlation of $0.2{\simm}0.3$ for $NO_2,\;PM_{10}$ and temperature, while $O_3$ concentration has shown negative correlation. Also, $NO_2$ and CO concentrations, pollutants generated by combustion, have shown positive correlation, while $O_3$ concentration and temperature have shown negative correlation. Therefore, it could be suggested that a seasonal air quality policy and a new guideline of air quality was necessary in each season with wind directions to reduce the air pollution level in Ulsan.

• Fashion & Textile Research Journal
• /
• v.6 no.3
• /
• pp.384-392
• /
• 2004

The purpose of this study is in development of effective filter-type polymer adsorbent for removal of pollutants from wastewater by UV irradiation graft polymerization. Photografting of acrylic acid (AA) on polypropylene (PP) nonwoven fabric using benzophenone (BP) as a photosensitizer was investigated. Inhibition of homopolymerization was achieved by adding various concentrations of $FeSO_4{\cdot}7H_2O$, $CuSO_4{\cdot}5H_2O$ and Mohr's salt. As AA concentration was increased, the degree of grafting was increased as to a specific value and then decreased, and the effect of BP concentration showed the same tendency. It was also found that the degree of grafting increased with reaction time and reaction temperature. Addition of the polyfunctional monomers and $H_2SO_4$ to the grafting system accelerated the photografting. The melting temperature, molecular weight and breaking stress and breaking strain were decreased with the increase in the degree of grafting.

• Fashion & Textile Research Journal
• /
• v.6 no.3
• /
• pp.377-383
• /
• 2004

Photografting of styrene (St) on polypropylene (PP) nonwoven fabric using benzoin ethyl ether (BEE) as a photosensitizer was investigated. Inhibition of homopolymerization was achieved by adding various concentrations of $FeSO_4{\cdot}7H_2O$, $CuSO_4{\cdot}5H_2O$ and Mohr's salt. As St concentration was increased, the degree of grafting was increased as to a specific value and then decreased, and the effect of BEE concentration showed the same tendency. It was also found that the degree of grafting increased with reaction time and reaction temperature. Addition of the polyfunctional monomers and $H_2SO_4$ to the grafting system accelerated the photografting. The melting temperature, molecular weight, tensile strength and elongation were decreased with the increase in the degree of grafting.

• Journal of Environmental Science International
• /
• v.4 no.1
• /
• pp.41-52
• /
• 1995

The effects of reaction temperature, SO2 and CO2 concentration in an air gas stream, particle sizes of limestone on the reactivity and capacity of SO2 removal have been determined in a thermogravimetric analyser(TGA). The apparent reaction order of sulfation reaction of pre-calcined lime(CaO) with respect to SO2 is found to be close to unity. The apparent activation energies are found to be 17,000 kcal/kmol for sulfation of pre-calcined lime and 19,500 kcal/kmol for direct sulfation of limestone(CaCO3). The initial sulfation reaction rate of pre-calcined lime increases with increasing temperature, whereas the sulfur capture capacity exhibits a maximum value at 90$0^{\circ}C$. In direct sulfation of limestone, sulfation reactivity and sulfur capature capacity of sorbent increase with increasing temperature and decreasing CO2 concentration in a gas bulk stream. The main pare of pre-calcined lime is shifted to the larger pore sizes and pore volume decreases with increasing sulfation time and temperature. The surface area of lime decreases with increasing calcination temperature under an air atmosphere, whereas is yearly constant under a CO2(5, 10%) atmosphere in a gas stream.