• 한국환경과학회지
• /
• 제12권10호
• /
• pp.1043-1054
• /
• 2003

During the period from April to September 2002, the size distributions of ambient aerosol were measured at the coastal site at Hamduk in Jeju Island. Na$\^$+/, K$\^$+/, Mg$\^$2+/, Ca$\^$2+/and Cl$\^$-/ exhibited mostly a bimodal coarse mode size distribution, while ammonium and sulfate were mainly in the fine size range, with maximum at around 0.54$\mu\textrm{m}$. The average molar concentration ratio of ammonium to sulfate for fine particles was equal to 2.0${\pm}$0.9. Nitrate was evenly found in both the coarse and fine modes. Elements like Al, Fe, Cu, Mg, Na, Ti, Sr and Mn were dominant in coarse particles, with the maximum at around 5.25$\mu\textrm{m}$. S and Pb were mainly in the submicrometer size range. Other elements with a fine and coarse modes were V, Ni, Cu, Ba and Mo. The patterns of the size distributions of trace elements measured at the downtown in Jeju City were very similar to those at the coastal site in Hamduk. However, the amplitude of size fractional concentrations at Jeju City was narrower than that at Hamduk. While the mass median diameters for the chemical species originated from the natural origin such as marine and crust were relatively large, those for ammonium, sulfate, S and Pb were very small.

• 한국입자에어로졸학회지
• /
• 제9권1호
• /
• pp.7-21
• /
• 2013

Twelve-hour size-resolved atmospheric aerosols were measured to determine size distributions of water-soluble organic carbon(WSOC) during daytime and nighttime, and to investigate sources and formation pathways of WSOC in individual particle size classes. Mass, WSOC, ${NO_3}^-$, $K^+$, and $Cl^-$ at day and night showed mostly bimodal size distributions, peaking at the size range of $0.32-0.55{\mu}m$(condensation mode) and $3.1-6.2{\mu}m$(coarse mode), respectively, with a predominant condensation mode and a minor coarse mode. While ${NH_4}^+$ and ${SO_4}^{2-}$ showed unimodal size distributions which peaked between 0.32 and $0.55{\mu}m$. WSOC was enriched into nuclei mode particles(< $0.1{\mu}m$) based on the WSOC-to-mass and WSOC-to-water soluble species ratios. The sources and formation mechanisms of WSOC were inferred in reference to the size distribution characteristics of inorganic species(${SO_4}^{2-}$, ${NO_3}^-$, $K^+$, $Ca^{2+}$, $Na^+$, and $Cl^-$) and carbon monoxide. Nuclei mode WSOC was likely associated with primary combustion sources during daytime and nighttime. Among significant sources contributing to the condensation mode WSOC were homogeneous gas-phase oxidation of VOCs, primary combustion emissions, and fresh(or slightly aged) biomass burning aerosols. The droplet mode WSOC could be attributed to aqueous oxidation of VOCs in clouds, cloud-processed biomass burning aerosols, and small contributions from primary combustion sources. From the correlations between WSOC and soil-related particles, and between WSOC and sea-salt particles, it is suggested that the coarse mode WSOC during daytime is likely to condense on the soil-related particles($K^+$ and $Ca^{2+}$), while the WSOC in the coarse fraction during nighttime is likely associated with the sea-salt particles($Na^+$).

• 공업화학
• /
• 제7권1호
• /
• pp.83-90
• /
• 1996

AO-AOT계내에서 S/D의 증가에 따라 흡수 및 형광 spectra의 변화 양상이 감소하다가 증가함을 알 수 있으며 회합 및 해리가 일어남을 알 수 있다. 그리고 온도 상승에 따라 순수한 AO계에서는 흡광도가 증가하나 premicellar영역(S/D=10, 20, 50 및 80)내에서는 흡광도가 오히려 점차 감소한다. 한편 AO-AOT계에 첨가한 염의 농도가 증가함에 따라 metachromasy 소멸도는 증가하나 $NaNO_3$의 경우는 이와 반대로 나타난다. 이러한 염의 양이온에 대한 metachromasy 소멸도의 증가 순서는 $Li^+$, $Na^+$ > $Mg^{2+}$ > $Ca^{2+}$이며, 염의 음이온에 대해서는 $Cl^-$ > $SO_4{^{2-}}$ > $NO_3{^-}$로 나타남을 알 수 있었다.

• 대기
• /
• 제26권3호
• /
• pp.357-372
• /
• 2016

Northeast Asian regions have recently become the main source of anthropogenic and natural aerosols. Measurement of aerosols on the sea in these regions have been rarely conducted since the experimental campaigns such as ACE-ASIA (Asian Pacific Regional Aerosol Characterization Experiment) in 2001. Research vessel observations of aerosol mass and chemical composition were performed on the Yellow and south sea around the Korean peninsula. The ship measurements showed six representative cases such as aerosol event and non-event cases during the study periods. On non-event cases, the anthropogenic chemical and natural soil composition on the Yellow sea were greater than those on the south sea. On aerosol event cases such as haze, haze with dust, and dust, the measured mass concentrations of anthropogenic chemical and element compositions were clearly changed by the events. In particular, methanesulfonate ($MSA^-$, $CH_3SO_3^-$), a main component of natural oceanic aerosol important for sulfur circulation on Earth, was first observed by the vessel in Korea, and its concentration on the Yellow sea was three times that on the south sea during the study period. Sea salt concentration important to chemical composition on the sea is related to wind speed. Coefficients of determination ($R^2$) between wind speed and sea salt concentration were 0.68 in $PM_{10}$ and 0.82 in $PM_{2.5}$. Maximum wave height was not found to be correlated to the sea salt concentration. When sea-salt comes into contact with pollutants, the total sea-salt mass is reduced, i.e., a loss of $Cl^-$ concentration from NaCl, the main chemical composing sea salt, is estimated by reaction with $HNO_3$(gas) and $H_2SO_4$(gas). The $Cl^-$ concentration loss by $SO_4^{2-}$ and $NO_3^-$ more easily increased for $PM_{10}$ compared to $PM_{2.5}$. The results of this study will be applied to verifying a dust-haze forecasting model. In addition, continued vessel measurements of aerosol data will become important to research for climate change studies in the future.

• 한국환경과학회지
• /
• 제10권3호
• /
• pp.201-208
• /
• 2001

To investigate the physio-chemical components and properties of aerosol particles in urban area sampling of aerosol particles was carried out in the campus of Hokkaido University, Sapporo, Japan, during snowfall. Aerosol particles were collected on millipore filter papers using a low volume air sampler. Their shapes, sizes and chemical components were analyzed by a SEM(Scanning Electron Microscope) and an EDX(Energy Dispersive X-ray). As a results, ice crystals of dendrite and column types were predominantly shown at mature and developing stage of snowfall intensity. The denerite and sector plate types of ice crystals were mainly originated from the sea but column types were come from soil. Scavenging effect by snowfall was greatly also shown at dendrite type ice crystals that embryo was fully developd. Al, Si elements were shown at high frequencies as compared with others. Na, Cl components were especially shown at high frequencies under the sea-breeze wind during snowfall. Anthropogenic aerosol particles had shown with irregular shapes and sizes, relatively. Mainly 3-7$\mu$m aerosol particles were abundant and coarse particles also could be seen during snowfall. Ca, Zn, Fe components mainly caused by spike tires from vehicles in winter season were dominant before snowfall, however the element S mainly caused by human activity was rich after snowfall. The pH values of snow in Sapporo city were higher than those at coastal area. The concentration of chemical components in aerosol particles was also affected by surface winds. Aerosol particles in urban area, Sapporo were mainly affected by human activities like vehicles and combustion with wind system. And their types were related with snowfall intensity.

• 한국환경보건학회지
• /
• 제22권4호
• /
• pp.55-61
• /
• 1996

Measurements of the seasonal variations of concentration and size distribution of TSP, $SO_4^{2-}, NO_3^-, Cl^-, NH_4^+, Na^+, K^+, Ca^{2+}$ and $Mg^{2+}$ were made by Andersen air sampler from May 1995 to April 1996 in Seoul. The size distribution of these ions was divided into four patterns. 1) Distribution was concentrated on fine particles over a year such as $NO_3^-$ component, 2) Distribution was predominated in coarse particles fraction over a year such as $Mg^{2+}$ and $Ca^{2+}$ components, 3) Distribution was differerent from various seasons such as $NH_4^+, SO_4^{2-}, Cl^-$ and $K^+$ components, 4) Distribution was bi-modal such as $Na^+$.

• 대한기계학회논문집B
• /
• 제28권9호
• /
• pp.1066-1074
• /
• 2004

With a diode corona charger, which is a component of ELPI(Electrical Low Pressure Impactor), aerosol particles are charged to make electrical detection possible before they are collected by the impactor. We designed and evaluated two cylindrical corona chargers, each of which had a central corona needle electrode. For the performance evaluation of each corona charger the polydisperse dioctyl sebacate(DOS) particles, with diameters of 0.1∼0.8 $\mu$m and NaCl particles, smaller than 0.1$\mu$m, were used. The particles were then led through an electrostatic classifier (TSI model 3081) to classify monodisperse aerosol with minimal size deviation. After evaluating the wall loss of the particles in the corona charger, we measured the product of penetration and number of charges, Pㆍn, to evaluate the corona charger efficiency at high positive voltages of 4, 5, 6 kV.

• 한국환경과학회지
• /
• 제12권5호
• /
• pp.541-549
• /
• 2003

Aerosol measurement were carried out to investigate the characteristics of its chemical composition directly affected by the local emissions of Jeju City, Jeju Island by using an eight-stage cascade impactor from Dec. 1999 to Aug. 2000. The ambient aerosol concentrations measured at Jeju City were generally very low but the fine particle concentrations were to be higher than the US standard of PM2.5. The majority of sulfate were non sea salt and contained in the fine particles. In the fine particles, the concentrations of Na$\^$+/, K$\^$+/, Mg$\^$2+/, Ca$\^$2+/, Cl$\^$-/ and NO$\sub$3$\^$-/ had a tendency to increase during the springtime rather than the other seasons. However, the springtime sulfate and ammonium concentrations in the fine particles were slightly lower than those during the other seasons. On the other hand, associated with the coarse particles, the concentrations of ionic species except potassium and ammonium were elevated during the springtime. The calcium concentrations in the coarse particles were increased up to 8 times relative to the other seasons.

• 한국환경과학회지
• /
• 제11권7호
• /
• pp.669-677
• /
• 2002

This study was conducted to investigate the characteristics of role of transport on aerosol concentration at Crate Lake, Oregon USA for 1988.3~1999. 5. The IMPROVE program is a cooperative measurement effort governed by a steering committee composed of representatives from USA federal and regional-state organizations. Also IMPROVE sampler is designed to obtain a complete signature of the composition of the airborne particles affecting visibility. According to 10-day backward isentropic trajectory analysis, the frequency of local, marine and Asian trajectory showed 33.1%(335 cases), 47%(478 cases), 5.2%(53 cases) respectively. The monthly variation of nss $SO_4^{2-}$, nss S, $NO_3^-$, K and C showed the double peak pattern, high in April~May and August~september and showed the lowest concentration in Winter. The other constituents concentration except for Cl$^{[-10]}$ , Na, Mg was high in local trajectory than marine trajectory. A ratio nss $SO_4^{2-}$ to $SO_4^{2-}$ was 90.5% in marine trajectory and 98% in local trajectory. It suggest that the aerosol in Crater Lake was effected by salt. The annual mean concentration of nss $SO_4^{2-}$ and nss S decreased but the springtime concentration increased.

• 한국환경과학회지
• /
• 제29권1호
• /
• pp.79-93
• /
• 2020

To determine the size distributions of water-soluble inorganic ionic species (WSIS) in roadside aerosols, sampling experiments were carried out in the urban roadside area of Jeju City on August 2018 and January 2019 by using the eight-stage cascade impactor sampler. The mass of roadside aerosols were partitioned at 57% in fine fraction, 36-37% in coarse fraction, and 6-7% in giant fraction, regardless of summer and winter. The mass concentrations of WSIS except for Na+ and SO42- in roadside aerosols were higher in winter than in summer. The size distributions of Na⁺, Mg²⁺, Ca²⁺ and Cl^- were characterized by bimodal types with coarse particle mode peaking around 3.3-4.7 ㎛ and 5.8-9.0 ㎛. The size distributions of NO₃^- and K⁺ shifted from a single fine mode peaking around 0.7-1.1 ㎛ in winter to bimodal and/or trimodal types with peaks around coarse mode in summer. SO₄^2- and NH₄⁺ showed a single fine mode peaking around 0.7-1.1 ㎛. The MMAD of roadside aerosols was lower than that of Na⁺, Mg²⁺, Ca²⁺ and Cl-. Based on the marine enrichment factors and the ratio values of WSIS and the corresponding value for sea water, the composition of roadside aerosols in Jeju City may be practically affected by terrestrial sources rather than marine source.