대기경계층 미세먼지의 화학조성 특성 : 2012년 가을 집중측정

Abstract

The collection of PM10 and PM2.5 samples for the intensive study was made at the 1100 Site of Mt. Halla of Jeju Island in Korea, which is a background Site located at the atmospheric boundary layer (ABL), during October and November of 2012. The ionic and elemental species were analyzed, in order to investigate the chemical composition characteristics. The mass concentrations of PM10 and PM2.5 fine particulate matter were 22.4 and 13.9 μg/m3 respectively, and that of PM10-2.5 was 8.5 μg/m3. The concentrations of the secondary pollutants nss-SO4 2-, NH4+ and NO3- in PM10 were 6.11, 2.36, and 2.18 μg/m3, respectively. Furthermore, the elemental compositions of PM10 occupied 91.1%, 40.6% for anthropogenic (S, Pb, Zn), 33.7% for soil (Al, Ca, Fe), and 16.8% for marine (Na, Mg) sources. The concentrations of nss-SO4 2-, NH4+, and NO3- were 4.81, 1.97, and 1.23μg/m3 in PM2.5 fine particles, showing 91.7% of the total ionic components. On the other hand, their concentrations were 0.63, 0.21 and 1.10 μg/m3 in PM10-2.5 coarse particles. The comparative study of size distribution resulted that NH4+, nss-SO4 2-, K+, and CH3COO- were mostly existed in fine particles, and NO3- was distributed in both fine and coarse particles, but Na+, Cl-,Mg2+, nss-Ca2+ were in coarse particle mode. The acidity contributions by sulfuric and nitric acids were 76.5% and 21.1% in PM10, and those in PM2.5 were 80.6% and 16.1%, respectively. Meanwhile the acidity contributions by formic and acetic acids were 1.8% in PM10, and 2.4% in PM2.5, respectively. On the other hand, the neutralization factors by ammonia and calcium carbonate were 76.5% and 9.9% in PM10, and those in PM2.5 were 86.2% and 3.8%, respectively. Based on the factor analyses for the examination of the source origins, the PM10-2.5 coarse particles were influenced mainly by marine sources, followed by soil and anthropogenic sources. On the other hand, PM2.5 fine particles were influenced mostly by both anthropogenic and soil sources, followed by marine sources. The comparison between mountainous Mt. Halla-1100 Site and coastal Gosan Site showed that the coarse particles at the atmospheric boundary layer were influenced less than at coastal area.