한라산 1100고지 대기 미세먼지의 화학조성 및 배출특성

Abstract

The PM_10 and PM_2.5 samples were collected at the 1100 m site of Mt. Halla in Jeju Island, which is a background site located at the atmospheric boundary layer (ABL), during the period of 2012-2013. Their ionic and elemental species were analyzed, in order to examine the chemical compositions and emission characteristics of fine particulate matters in accordance with the different meteorological phenomena. Mass concentrations of the PM_10 and PM_2.5 were 21.1±11.7 and 12.4±6.9 μg/m^3, respectively, during the non-event days. From the comparison of ion balance, the correlation coefficients (r) between the sums of cationic and anionic equivalent concentrations were 0.986 and 0.984, respectively, for PM_10 and PM_2.5 fine particulate matters, indicating the good correlations. In PM_10 fine particulate matters, the concentrations of secondary pollutants such as nss-SO_4^2^-, NH_4^+, and NO_3^- were 5.51, 1.94 and 1.35 μg/m^3, respectively. In PM_2.5 fine particulate matters, their concentrations were 4.41, 1.65, and 0.53 μg/m^3, respectively. Meanwhile, the elemental compositions of PM_10 showed 46.6% for anthropogenic (Zn, Pb, Ni), 31.4% for soil (Al, Fe, Ca) sources. Based on the study of size-fractionated particle compositions, the PM_2.5/PM_10 concentration ratios of nss-SO_4^2 and NH_4^+ were 0.8, 0.9, respectively, indicating that those species were mostly existed in PM_2.5 particles. On the other hand, marine and soil species such as Na^+, Cl^-, Mg^2^+, and nss-Ca^2^+ were rich in PM_10 particles. From the study of source origins by the principal component analysis, the ionic species of PM_10 fine particulate matters were mostly originated from anthropogenic sources, followed next by marine, plant, and mixed soil-anthropogenic sources. While the compositions of PM_2.5 fine particulate matters were influenced mainly by anthropogenic sources, followed next by plant, marine, and mixed soil-anthropogenic sources. During the Asian dust periods, the concentrations of nss-Ca^2^+ and NO_3^- were increased highly as 12.3 and 3.8 times in PM_10, and 3.4 and 5.3 times in PM_2.5, respectively, compared to non-event days. Especially, the concentrations of the crustal species such as Al, Fe, Ca, Mn, Ba, and Sr showed a noticeable increase during the Asian dust periods. For the haze events days, the concentrations of secondary pollutants increased 1.9～5.2 and 1.9～7.6 times in PM_10 and PM_2.5, respectively. Meanwhile, those for the mist event days were 1.6～2.1 and 1.2～2.1 times higher, respectively, in PM_10 and PM_2.5, compared to non-event days.