배경대기의 PM2.5 내 탄소 성분의 분포특성 연구

Abstract

Routine measurements of organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC) and Humic Like Substance-Carbon (HULIS-C) in PM2.5 were carried out at Anmyeon Island (AI) to understand the characteristics of carbonaceous aerosol at a background area in Korea between 2015 and 2016. Annual average concentrations of OC and EC were 4.01 ± 1.78 ㎍ C m-3 and 0.43 ± 0.21 ㎍ C m-3, respectively. OC and EC concentrations showed different seasonal variation. OC concentrations showed summer minimum and winter maximum. while, EC concentrations showed fall minimum and summer maximum. The composition of OC and EC was consistent (90% of OC and 10% of EC in carbonaceous aerosol). The average concentrations of WSOC and WISOC were 2.27 ± 1.15 ㎍ C m-3 and 1.75 ± 0.87 ㎍ C m-3, respectively, and their composition in OC shows daily variation. WISOC was calculated by subtraction of WSOC from OC and weakly correlation of WISOC with EC was observed. It means that WISOC is derived from primary emissions other than EC. While, WSOC concentrations were highly related with OC concentrations. The results indicate the formation of secondary organic aerosol (SOA) is major factor for the determination of WSOC concentrations in this region. HULIS-C as known one of brown carbon was major component of WSOC which accounts for 29 to 99% in WSOC. The average concentrations of HULIS-C was 1.67 ± 0.79 ㎍ C m-3 and the highest concentration was observed in fall.