울산시 미세먼지 입경별 이온 분포와 오염원 추정

Abstract

In this study, the size distributions of airborne particulate matter (PM) associated ionic species (Cl-, NO3-, SO42-, Na+, NH4+, K+, Mg2+, and Ca2+) and pollution sources were investigated. PM samples were collected using two micro-orifice uniform deposit impactors (MOUDIs) with 11stage cut-sizes (0.056, 0.10, 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6, 10.0, and 18.0 µm) at residential and industrial sites in Ulsan, Korea. At both sites, anthropogenic ions (SO42-, NO3-, and NH4+) contributed to over 60% of the total ion concentrations in PM and were dominant in fine particles. During the high PM episodes, SO42- (42%) was the main ion at the industrial site due to the influence of petrochemical and non-ferrous industries, whereas the contribution of NH4+ (24%) was relatively high at the residential site. The levels of both ions (SO42- and NH4+) were directly influenced by major wind directions. Natural ions (Cl-, Na+, and Mg2+) derived from the earth’s crust and the ocean were prevalent in coarse particles. Based on this study, comprehensive monitoring of ions will be conducted in Ulsan.