국내 배경지역 대기 미세먼지의 기상현상별 화학조성 비교:2012-2013년 측정

Abstract

The PM10 and PM2.5 samples were collected at Gosan site of Jeju Island, which is one of the background site of Korea, during 2012-2013. Their ionic and elemental species were analyzed, in order to examine the chemical composition characteristics in accordance with the different meteorological phenomena. The mass concentrations of PM10 and PM2.5 were 34.5 and 15.3 μg/m3 and the PM10-2.5 mass concentration was 19.2 μg/m3. In the result of ion balance comparison, the correlation coefficients(r) between the sum of cationic equivalent concentrations and the sum of anionic equivalent concentrations were 0.959 and 0.958, respectively, for coarse (PM10-2.5) and fine (PM2.5) particulate matter, indicating a good correlation. In coarse particles (PM10-2.5), the concentrations of secondary pollutants such as nss-SO4 2-, NO3 -, and NH4 + were 1.60, 1.99 and 0.37 μg/m3, respectively. In fine particles (PM2.5), their concentrations were 5.64, 1.04, and 2.05 μg/m3, respectively, showing 91.3% of those ionic species. Meanwhile, elemental compositions of the coarse particles showed 56.5% for marine (Na, Mg), 21.4% for soil (Al, Fe, Ca), and 18.0% for anthropogenic (S, Pb, Zn), and they were 22.3%, 23.6%, 50.6% for the fine particles. Based on the study of size-segregated particle compositions, the PM10-2.5/PM2.5 concentration ratios of nss-SO4 2- and NH4 + were 0.3, 0.2, respectively, indicating that those species were mostly existed in fine particles. On the other hand, NO3 - was evenly distributed in both fine and coarse particles, and the marine and soil species such as Na+, Cl-, and nss-Ca2+ were rich in coarse particle mode. From the study of source origins by factor analysis, the PM10-2.5 ionic species were mostly originated from marine sources, followed by anthropogenic and soil sources. On the other hand, compositions of the PM2.5 fine particles were influenced mainly by anthropogenic sources, followed by marine and soil sources. During Asian dust periods, the concentrations of nss-Ca2+ and NO3 - were increased highly as 13.5 and 3.2 times in coarse particle mode, and 2.5 and 4.9 times in fine particles, respectively, compared to non-event days. Especially, the concentrations of the crustal species such as Al, Fe, Ca, K, Mn, Ba, and Sr showed a noticeable increase during the Asian dust periods. For the haze events days, the concentrations of secondary pollutants were increased 2.1～3.7 and 3.1～6.5 times in coarse and fine particles, respectively. Futhermore, the remarkable increase of NO3 - concentration was observed in fine particle mode during haze events. The concentrations of the secondary pollutants the mist event days were 2.0～3.4 and 1.5～1.9 times, respectively, in coarse and fine particles than non-event days. The neutralization factors by NH3 were 0.33, 0.16, 0.43, and 0.52, respectively, for non-events, Asian dust, haze and mist days in coarse particles, besides they were 0.86, 0.71, 0.86, and 0.86, respectively, in fine particles. Meanwhile, those by CaCO3 were 0.26, 0.47, 0.24, and 0.22, respectively, in coarse particles, and 0.03, 0.02, 0.01, and 0.02 in fine particles