• 한국환경과학회지
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• 제33권2호
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• pp.113-119
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• 2024

In this study, the most suitable sampling methods for the bimodal mass distribution characteristics and individual particle analysis of atmospheric aerosols were investigated. Samples collected in Quartz, Teflon, and Nuclepore filters were analyzed for individual particles using scanning electron microscopy with an energy-dispersive X-ray spectrometer (SEM/EDS). Then, the pore diameter of the filter and the collection flow rate were determined using the theoretical collection efficiency calculation formula for two-stage separation sample collection of coarse and fine particles. The Nuclepore filter was found to be the most suitable filter for identifying the physical and chemical characteristics of atmospheric aerosols since it was able to separate the sample and count the different sized particles better than either Quartz or Teflon. Nuclepore filters with 8.0 ㎛ and 0.4 ㎛ pores were connected in series and exposed to a flow rate of 16.7 L/min for two-stage separation sampling. The results show that it is possible to separate and collect both coarse and fine particles. We expect that the proposed methodology will be used for future individual particle analysis of atmospheric aerosols and related research.

• 한국대기환경학회지
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• 제31권5호
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• pp.437-448
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• 2015

The purpose of this study is to present the source contribution of the fine particles ($PM_{2.5}$) in Chungju area using the CMB (chemical mass balance) method throughout the four seasons in Korea. The Chungju's annual average level of $PM_{2.5}$ was $48.2{\mu}g/m^3$, which exceeded two times higher than standard air quality. Among these particles, the soluble ionic compounds represent 54.2% of fine particle mass. Additionally, the OC concentration in Chungju stayed similar to other domestic cities, while the EC concentration decreased significantly compared to other domestic/international cities. The concentration of sulfur represented the highest composition (8%) among the fine particle compounds. According to the CMB results, the general trend of the $PM_{2.5}$ mass contributors was the following: secondary aerosols (50.5%: ammonium sulfate 26.5% and ammonium nitrate 24.0%) > gasoline vehicle (18.3%) > biomass burning (11.0%) > industrial boiler (6.0%) > diesel vehicles (4.4%). The contribution of the secondary aerosols was the main cause than others. This impact is assumed to be emitted from air pollutants of urban cities or neighbor countries such as China.

• 한국환경과학회지
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• 제26권5호
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• pp.591-600
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• 2017

This study was carried out to elucidate the chemical compositions of water-soluble inorganic ions in $PM_{10}$ and $PM_{2.5}$ aerosols collected during summer and winter in downtown Jejusi city. The ratios of $NO_3^-$ to the total mass of ionic species in $PM_{10}$ and $PM_{2.5}$ aerosols largely increase in winter compared to summer, while $SO_4^{2-}$ ratios in both aerosols appear to follow the opposite trend. Moreover, concentrations of $Na^+$, $Mg^{2+}$, $Ca^{2+}$ and $Cl^-$ in $PM_{10}$ and $PM_{2.5-10}$ aerosols are higher in winter than in summer. The nitrate concentrations in $PM_{10}$ and $PM_{2.5}$ aerosols increase with an identical increase in excess ammonium during winter, however, nitrate formation during summer is not important owing to ammonium-poor conditions.

• 대기
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• 제26권2호
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• pp.289-299
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• 2016

Optical properties of aerosols associated with haze events over Seoul were examined using ground-based skyradiometer and satellite-borne CALIOP and MODIS measurements over the 2009~2010 period. It is shown that aerosol optical thickness (AOT), ${\AA}ngstr{\ddot{o}}m$ exponents (${\alpha}$), and fine-mode particles increase during the haze events. The CALIOP-measured vertical profiles of aerosol during the haze events revealed that most of aerosols are loaded within layers below 4 km altitude. A large portion of these events appear to be related to the long-range transport of aerosols from China; about 35% and 18% of the haze events observed over Seoul were traced back to northern China and southern China, respectively. Compared with optical properties for locally-induced haze events (25%), these long-range transported aerosols are found to have relatively higher AOTs.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2004년도 추계학술대회 논문집
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• pp.461-462
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• 2004

• 분석과학
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• 제28권1호
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• pp.47-57
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• 2015

제주도 고산지역에서 2010~2011년에 대기 에어로졸을 입경별로 채취하여 산성화와 중화 특성을 조사하였다. 인위적 기원의 $NH_4{^+}$와 nss-$SO_4{^{2-}}$은 일반적으로 $0.7{\sim}1.1{\mu}m$의 극미세 입자에서 높은 농도를 보였으나, 황사 시에는 $4.7{\sim}5.8{\mu}m$의 조대입자 범위에서도 함께 농도가 높은 이산형 분포를 나타내어 황사와 비황사 간에 서로 다른 분포 패턴을 보였다. nss-$Ca^{2+}$과 $NO_3{^-}$은 $3.3{\sim}4.7{\mu}m$의 조대입자에서 높은 농도를 보였으며, 특히 $NO_3{^-}$은 미세입자와 조대입자 영역에서 농도가 높은 이산형 분포를 나타내었다. 고산지역 대기 에어로졸의 산성화는 황산과 질산 등 무기산에 의한 영향이 대부분이며, 유기산인 포름산과 아세트산은 1.6~6.4% 정도 산성화에 기여하는 것으로 확인되었다. 또한 암모니아, 탄산칼슘, 탄산마그네슘 등이 대기 에어로졸의 산성 물질 중화에 주로 관여하고 있으며, 특히 암모니아에 의한 중화는 비황사와 황사 기간 모두 미세입자 영역에서 훨씬 더 높은 기여도를 보였으나, 탄산칼슘은 조대입자 영역에서 더 큰 중화 기여도를 보였다.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E3호
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• pp.87-94
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• 2005

Wet scavenging by rain drops is a most important removal process of air pollutants. In order to study the scavenging mechanisms of aerosol particles, the characteristics of chemical components in the rain water were examined as a function of the amount of rainfall. Rain water were collected continuously and separated into the soluble and insoluble components. The elemental concentrations in both components were determined by a PIXE analysis. The physical and chemical characteristics of atmospheric aerosols during the rainfall events were measured simultaneously. The elemental concentrations in rain water decreased substantially just after rain started and then gradually declined in subsequential rain fall exceeding 1.0 mm. The large particles were scavenged more easily than the fine particles. Fe, Ti and Si in rain water were in high insoluble state. Contrarily, almost whole of S was dissolved in rain water.

• 한국대기환경학회지
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• 제13권6호
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• pp.475-486
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• 1997

The characteristics of atmospheric aerosols were investigated as a function of particle size and water solubility. The atmospheric aerosols were sampled with classifying into 12 size ranges by the use of Andersen low-pressure impactor. Collected aerosol particles were extracted by ultrapure water and filtered to be separated into water-soluble and insoluble components. The concentrations 12 elements in both components were determined by PIXE analysis. And the concentrations of 8 ions in the soluble component were analyzed by ion chromatography. In general, the mass size distribution of particulate matter was represented as a bimodal distribution. The mass size distributions of S$(SO_4^{2-}), K(K^+), Zn and NH_4^+$ skewed to the smaller size range and those of Si, Ca$(Ca^{2+}), Fe, Na^+ and Mg^{2+}$ skewed to the larger size range. They had roughly one peak in the fine and coarse particle region,respectively. On the other hand, the mass size distribution of Ti, Mn, Ni, Cu, $Cl^- and NO_3^-$ were represented as the bimodal distribution. Fe and Si in the aerosol particles extracted into pure water are existing in high insoluble state. Conversely, almost the whole of S is dissolved in water.

• 한국대기환경학회지
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• 제25권3호
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• pp.219-236
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• 2009

Particle-phase organic tracers (molecular markers) have been shown to be an effective method to assess and quantify the impact of sources of carbonaceous aerosols. These molecular markers have been used in chemical mass balance (CMB) models to apportion primary sources of organic aerosols in regions where the major organic aerosol source categories have been identified. As in the case of all CMB models, all important sources of the tracer compounds must be included in a Molecular Marker CMB (MM-CMB) model or the MMCMB model can be subject to biases. To this end, the application of the MM-CMB models to locations where reasonably accurate emissions inventory of organic aerosols are not available, should be performed with extreme caution. Of great concern is the potential presence of industrial point sources that emit carbonaceous aerosols and have not been well characterized or inventoried. The current study demonstrates that emissions from industrial point sources in the St. Louis, Missouri area can greatly bias molecular marker CMB models if their emissions are not correctly addressed. At a sampling site in the greater St. Louis Area, carbonaceous aerosols from industrial point sources were found to be important source of carbonaceous aerosols during specific time periods in addition to common urban sources (i.e. mobile sources, wood burning, and road dust). Since source profiles for these industrial sources have not been properly characterized, method to identify time periods when point sources are impacting a sampling site, needs to avoid obtaining biases source apportionment results. The use of real time air pollution measurements, along with molecular marker measurements, as a screening tool to identify when point sources are impacting a receptor site is presented.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2006년도 춘계학술대회 논문집
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• pp.298-299
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• 2006