• Journal of Korean Society for Atmospheric Environment
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• v.31 no.3
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• pp.239-254
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• 2015

Little information on HUmic-Like Substances (HULIS) in ambient particulate matter has been reported yet in Korea. HULIS makes up a significant fraction of the water-soluble organic mass in the atmospheric aerosols and influence their water uptake properties. In this study 24-hr $PM_{2.5}$ samples were collected between December 2013 and October 2014 at an urban site in Gwangju and analyzed for organic carbon (OC), elemental carbon (EC), water-soluble OC (WSOC), HULIS, and ionic species, to investigate possible sources and formation processes of HULIS. HULIS was separated using solid phase extraction method and quantified by total organic carbon analyzer. During the study period, HULIS concentration ranged from 0.19 to $5.65{\mu}gC/m^3$ with an average of $1.83{\pm}1.22{\mu}gC/m^3$, accounting for on average 45% of the WSOC (12~ 73%), with higher in cold season than in warm season. Strong correlation of WSOC with HULIS ($R^2=0.91$) indicates their similar chemical characteristics. On the basis of the relationships between HULIS and a variety of chemical species (EC, $K^+$, $NO_3{^-}$, $SO_4{^{2-}}$, and oxalate), it was postulated that HULIS observed during summer and winter were likely attributed to secondary formation and primary emissions from biomass burning (BB) and traffics. Stronger correlation of HULIS with $K^+$, which is a BB tracer, in winter ($R^2=0.81$) than in summer ($R^2=0.66$), suggests more significant contribution of BB emissions in winter to the observed HULIS. It is interesting to note that BB emissions may also have an influence on the HULIS in summer, but further study using levoglucosan that is a unique organic marker of BB emissions is required during summer. Higher correlation between HULIS and oxalate, which is mainly formed through cloud processing and/or photochemical oxidation processes, was found in the summer ($R^2=0.76$) than in the winter ($R^2=0.63$), reflecting a high fraction of secondary organic aerosol in the summer.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.555-569
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• 2004

Size -segregated measurements of aerosol composition using 8-stage DRUM impactor are used to determine the transport of natural and anthropogenic aerosols at Gosan site from 29 March to 30 May in 2002. Separation of ambient aerosols by DRUM impactor offers many Advantages over other standard filtration techniques. Some of the most important advantages are the ability to segregate into details by particle tire, to better preserve chemical integrity since the air stream doesn＇t pars through the deposit, to collect samples as a function of time, and to have a wide variety of impaction surfaces available to match analytical needs. Although the transport of Yellow sand is a well-known phenomenon in springtime, the result of measurement shows that not only soil dust but also anthropogenic aerosols, including sulfur, enriched trace metals such as Pb, Ni, Zn. Cu, Cr, As, Se, Br, are transported to Gosan in springtime. This study combines the size- and time-resolved aerosol composition measurements with isentropic, backward air-mass trajectories in order to identify some potential source regions of anthropogenic aerosols. As a result, during the NYS period, the average concentration of PM$_{10}$ was 46$\mu\textrm{g}$/㎥, Si, Al. S, Fe, Cl, K, Ca were higher than 1,000 ng/㎥ and Ti was about 100 ng/㎥. The concentrations of Zn, Mn, Cu. Pb, Br, Rb, V, Cr, Ni. At, Se ranged between 1 and 70 ng/㎥. More than 50% typical soil elements, tuck as Al, Si, Fe, Cd. Ti, Cr, Cu, Br. were distributed in a coarse particle range(5.0-12${\mu}{\textrm}{m}$). In other hand, anthropogenic pollutants, luck as S, N, Vi, were mainly distributed in a fine particle range (0.09-0.56${\mu}{\textrm}{m}$). During the YS period, PM$_{10}$ increased about 8 times than NYS period, and main soil elements, such as Al, Si, S, K, V, Mn, Fe also doubled in coarse particle range (1.15-12${\mu}{\textrm}{m}$). But Zn, As, Pb, Cu and Se, which distributed in the time aerosols (0.09-0.56${\mu}{\textrm}{m}$), were on the same level with or decreased than NYS period. Finally. except the YS Period, coarse particles (2.5-12${\mu}{\textrm}{m}$) are inferred to be influenced by soil, coal combustion, waste incineration, ferrous and nonferrous sources through similar pathways with Yellow Sand. But fine particles have different sources, such as coal combustion, gasoline vehicle, biomass burning, oil or coal combustion, nonferrous and ferrous metal sources, which are transported from China, Korea peninsula and local sources.ces.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.719-731
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• 2003

In order to maintain and manage ambient air quality, it is necessary to identify sources and to apportion its sources for ambient particulate matters. The receptor methods were one of the statistical methods to achieve reasonable air pollution strategies. Also, receptor methods, a field of chemometrics, is based on manifold applied statistics and is a statistical methodology that analyzes the physicochemical properties of gaseous and particulate pollutant on various atmospheric receptors, identifies the sources of air pollutants, and quantifies the apportionment of the sources to the receptors. The objective of this study was 1) after obtaining results from the PMF modeling, the existing sources of air at the study area were qualitatively identified and the contributions of each source were quantitatively estimated as well. 2) finally efficient air pollution management and control strategies of each source were suggested. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols, the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided quantitative source contributions (scaled G matrix) and source profiles (scaled F matrix). The results of the PMF modeling showed that the sources were apportioned by secondary aerosol related source 28.8 ％, soil related source 16.8％, waste incineration source 11.5%, field burning source 11.0%, fossil fuel combustion source 10%, industry related source 8.3％, motor vehicle source 7.9%, oil/coal combustion source 4.4％, non-ferrous metal source 0.3％. and aged sea- salt source 0.2％, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.1
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• pp.94-102
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• 2010

Water content of $PM_{2.5}$ (particles in the atmosphere with a diameter of less than or equal to a nominal $2.5{\mu}m$) was estimated by using a gas/aerosol equilibrium model, SCAPE2, for the particles collected at Seoul and Gosan, Korea. From measured and analyzed characteristics of the particles, the largest difference between Seoul and Gosan is the proportions of total ammonia (t-$NH_3$=gas phase $NH_3$+particle phase ${NH_4}^+$), total nitric acid (t-$HNO_3$=gas phase $HNO_3$+particle phase ${NO_3}^-$) and sulfuric acid ($H_2SO_4$). Even though both sites have sufficient t-$NH_3$ to neutralize acidic species such as $H_2SO_4$, t-$HNO_3$, and t-HCl (total chloric acid=gas phase HCl+particle phase $Cl^-$), equivalent fraction of t-$NH_3$ and t-$HNO_3$ are higher at Seoul and $H_2SO_4$ is higher at Gosan. Based on the modeling result, it is identified that the $PM_{2.5}$ at Seoul is more hygroscopic than Gosan if the meteorological conditions are the same. To reduce water content of $PM_{2.5}$, and thus, mass concentration, control measures for ammonia and nitrate reduction are needed for Seoul, and inter-governmental cooperation is required for Gosan.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.604-613
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• 2006

The chemical composition of $PM_{2.5}$ such as ${SO_4}^{2-},\;{NO_3}^-,\;Cl^-,\;{NH_4}^+,\;Ca^{2+},\;K^+,\;Na^+,\;Mg^{2+}$, OC, and EC and the concentrations of reactive trace gases including $O_3,\;CO,\;NOx,\;SO_2,\;and\;H_2O_2$ were measured at Gosan in Jeju Island during March $13{\sim}30$, as a part of the Atmospheric Brown Clouds-East Asian Regional Experiment 2005(ABC-EAREX2005). The average mass concentrations of $PM_{2.5}$ was 27.3 ${\mu}g/m^3$, of which OC showed the highest concentration as 4.22 ${\mu}g/m^3$ and nss ${SO_4}^{2-}$ was the second highest as 3.34 ${\mu}g/m^3$. During that period, average concentrations of CO and $O_3$ was about 300 ppbv and 56 ppbv, respectively. For the whole experiment, the correlations of CO with ${SO_4}^{2-}$ and EC were very good, which suggests that CO can be used as tracer for the formation of fine aerosols. Several pollution and dust episodes were identified by the enhancement of CO, OC, EC, nss ${SO_4}^{2-},\;or\;Ca^{2+}$ concentrations or their ratios. In conjunction with factor analysis, air trajectory analysis, and comparison with emission inventories, these results indicate the spring aerosols collected at Gosan was strongly influenced by Asian outflows.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.5
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• pp.469-484
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• 2016

HR-ToF-AMS was applied for a seasonal and size-distributional measurements for inorganic ($SO{_4}^{2-}$, $NO_3{^-}$, $NH_4{^+}$, $Cl^-$) and organic components in Baegryung Island Super Site. The average concentration of $PM_{1.0}$ remarks $12.9{\mu}g/m^3$ while $14.5{\mu}g/m^3$ in Spring time, $14.2{\mu}g/m^3$ in Winter, $13.1{\mu}g/m^3$ in Summer and $9.86{\mu}g/m^3$ in Autumn. The mass of measured $PM_{1.0}$ shows 54.6% of $PM_{2.5}$ which is similar to those of Beijing and Lanzhou, China. The highest portion of Chemical composition is $SO{_4}^{2-}$ marking 41.0%, 31.8% by organics, 13.5% by $NH_4{^+}$, 12.8% by $NO_3{^-}$ and 1% by $Cl^-$. In every seasons, except winter, $SO{_4}^{2-}$ remarks the highest level, organic components take place the highest in winter time. The size-distribution of $PM_{1.0}$ components scattered at accumulation mode of 200 nm~800 nm which means the influence of primary emission is low. In case of air stream from the industrialized area of Sandung, Shanghai, China, the concentrations of such components were distributed a bit higher.

• Analytical Science and Technology
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• v.23 no.4
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• pp.371-382
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• 2010

TSP and PM2.5 atmospheric aerosols have been collected at Gosan site of Jeju Island, and their compositions were analyzed to understand the pollution characteristics. The composition ratios of nss (non-sea salt)-$SO_4^{2-}$ and $NH_4^+$ were higher in Gosan site than those in other Korean background and urban sites. However the composition ratio of $NO_3^-$ was conversely lower in Gosan site. From the study of aerosol components according to particle sizes, the anthropogenic nss-$SO_4^{2-}$, $NO_3^-$ and $NH_4^+$ components were mostly existed in the fine particles. But the nss-$Ca^{2+}$, $Na^+$, $Cl^-$ and $Mg^{2+}$ originated from soil and marine sources were distributed relatively in the coarse particles. In the seasonal comparison, the concentrations of nss-$Ca^{2+}$, Al, Fe, Ca and $NO_3^-$ increased in spring season, and nss-$SO_4^{2-}$ showed higher concentration in summer and spring seasons. Based on the factor analysis, the atmospheric aerosols in Gosan site have been found to be influenced largely by anthropogenic sources, and next by marine and soil sources. The backward trajectory analyses showed that the concentrations of nss-$SO_4^{2-}$, $NO_3^-$, Pb and nss-$Ca^{2+}$ increased when the air mass moved from Chinese continent to Jeju area. On the other hand, their concentrations decreased when the air mass moved in from the North Pacific Ocean.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.4
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• pp.567-587
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• 2018

A severe haze event occurred in October 2015 in Gwangju, Korea. In this study, the driving chemical species and the formation mechanisms of $PM_{2.5}$ pollution were investigated to better understand the haze event. Hourly concentrations of $PM_{2.5}$, organic and elemental carbon, water-soluble ions, and elemental constituents were measured at the air quality intensive monitoring station in Gwangju. The haze event occurred was attributed to a significant contribution (72.3%) of secondary inorganic species concentration to the $PM_{2.5}$, along with the contribution of organic aerosols that were strongly attributed to traffic emissions over the study site. MODIS images, weather charts, and air mass backward trajectories supported the significant impact of long-range transportation (LTP) of aerosol particles from northeastern China on haze formation over Gwangju in October 2015. The driving factor for the haze formation was stagnant atmospheric flows around the Korean peninsula, and high relative humidity (RH) promoted the haze formation at the site. Under the high RH conditions, $SO{_4}^{2-}$ and $NO_3{^-}$ were mainly produced through the heterogenous aqueous-phase reactions of $SO_2$ and $NO_2$, respectively. Moreover, hourly $O_3$ concentration during the study period was highly elevated, with hourly peaks ranging from 79 to 95ppb, suggesting that photochemical reaction was a possible formation process of secondary aerosols. Over the $PM_{2.5}$ pollution, behavior and formation of secondary ionic species varied with the difference in the impact of LTP. Prior to October 19 when the influence of LTP was low, increasing rate in $NO_3{^-}$ was greater than that in $NO_2$, but both $SO_2$ and $SO{_4}^{2-}$ had similar increasing rates. While, after October 20 when the impact of haze by LTP was significant, $SO{_4}^{2-}$ and $NO_3{^-}$ concentrations increased significantly more than their gaseous precursors, but with greater increasing rate of $NO_3{^-}$. These results suggest the enhanced secondary transformation of $SO_2$ and $NO_2$ during the haze event. Overall, the result from the study suggests that control of anthropogenic combustion sources including vehicle emissions is needed to reduce the high levels of nitrogen oxide and $NO_3{^-}$ and the high $PM_{2.5}$ pollution occurred over fall season in Gwangju.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.485-494
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• 2018

This study aims to identify the characteristics of oxidation and chemical composition of PM in winter season, 2017 at Incheon area. The mean concentration of air pollutants were $46{\pm}22{\mu}g/m^3-PM_{10}$, $29{\pm}18{\mu}g/m^3/-PM_{2.5}$, $5{\pm}3ppb-SO_2$, $0.56{\pm}0.24ppm-CO$, $21{\pm}13ppb-O_3$ and $28{\pm}17ppb-NO_2$, respectively. The dominant ion of the $PM_{1.0}$ chemical component were organic with $3.2{\mu}g/m^3$ and nitrate with $1.9{\mu}g/m^3$. The day and night variation of the $PM_{1.0}$ chemical components was higher in nighttime than those of daytime. The averaged nitrate oxidation rate (SOR) was 0.06 and sulfate oxidation rate was 0.11 during the field campaign. In the high mass loading period, nitrate oxidation rate (NOR) was up to 0.6 and also the nitrate in $PM_{1.0}$ was increased. The averaged ratio of $NO_x/SO_2$ was 8.7 and nitrate/sulfate was 3.1, respectively. In this results, the nitrate component in $PM_{1.0}$ was influenced by NOx from the stationary source as power plant and the mobile source around the measurement site.