제주시 도로변 미세먼지의 입경별 이온성분 분포 특성

Abstract

In the roadside environment the aerosol particles can affect not only pedestrians but also residents in the immediate vicinity. Furthermore, depending on the size, aerosol particles can affect on human and nature. There have been no studies on the roadside aerosol in Jeju area. Therefore, this study was carried out to figure out the characteristics of size distribution of roadside aerosol in Jeju City. In this study, aerosol particles have been collected from July 2018 to May 2019 at the roadside area of Jeju City by using two samplers with an 8 stage cascade impactor. Cation (Na+, NH4+, K+, Mg2+, Ca2+) and anion (Cl-, NO3-, SO42-) contained in aerosols at the roadside environment were analyzed by ion chromatography. The average mass concentration of aerosol was 29.087 ㎍/㎥, and the that of PM2.1 and PM9 was 14.38 ㎍/㎥ and 26.88 ㎍/㎥, respectively. The size distribution for aerosol mass showed bimodal distribution with the peaks in the rang of 0.7∼1.1 ㎛ and 3.3∼4.7 ㎛. The water-soluble ionic components in aerosol accounted for 42% of total mass of aerosol and SO42-, NO3-, and NH4+ were dominant in ionic components, mainly in fine particle mode. NO3- and K+ showed bi-modal distribution and SO42- and NH4+ showed an uni-modal distribution with peak in the rang of 0.7∼1.1 ㎛ for all seasons. Ca2+ and Mg2+ and Cl- also showed a bimodal distribution for all seasons, The size distribution of Na+ showed bi-modal in fall and uni-modal in winter and spring. Mg2+, Ca2+, Na+ and Cl- were basically accumulated in the coarse particle mode in all seasons. Based on the results for calculation of marine enrichment factor in this study, it can be found that, in Jeju City, Mg2+ and Cl- in roadside aerosol were considerably affected by the sea, while Ca2+ was largely influenced by other origin rather than the sea. However, K+ and SO42contained in the coarse particles were influenced by the sea. The correlation - vi coefficients of NH4+ with SO42­ and NO3­ were 0.945 and 0.367 in the fine particles, respectively, and 0.603 and 0 in the coarse particles, respectively. The correlation coefficient for Na+, Mg2+, and Ca2+ showed a value of 0.5 or greater. Thus, these ions are thought to have similar origins.