(주)에이피엠엔지니어링

화학적·광학적·분광학적 방법을 이용한 광주 도심지역 여름철 초미세먼지의 특성

Characterization of fine particulate matter during summer at an urban site in Gwangju

using chemical, optical, and spectroscopic methods

Abstract 

Daily PM2.5 was collected during summer period in 2020 in Gwangju to investigate its chemical and light absorption properties.

In addition, real-time light absorption coefficients were observed using a dual-spot 7-wavelength aethalometer. During the

study period, SO4^2- was the most important contributor to PM2.5, accounting for on average 33% (10-64%) of PM2.5.

The chemical form of SO4^2- was appeared to be combination of 70% (NH4)2SO4 and 30% NH4HSO4. Concentration-weighted

trajectory (CWT) analysis indicated that SO4^2- particles were dominated by local pollution, rather than regional transport from

China. A combination of aethalometer-based and water-extracted brown carbon (BrC) absorption indicated that light absorption

of BrC due to aerosol particles was 1.6 times higher than that due to water-soluble BrC, but the opposite result was found in

absorption Ångström exponent (AAE) values. Lower AAE value by aerosol BrC particles was due to the light absorption of aerosol

BrC by both water-soluble and insoluble organic aerosols. The BrC light absorption was also influenced by both primary sources

(e.g., traffic and biomass burning emissions) and secondary organic aerosol formation. Finally the ATR-FTIR analysis confirmed

the presence of NH4+, C-H groups, SO4^2-, and HSO4^2-. The presence of HSO4^2- supports the result of the estimated
composition ratio of inorganic sulfate ((NH4)2SO4) and bisulfate (NH4HSO4).

Key word

PM2.5, (NH4)2SO4, NH4HSO4, CWT, BrC light absorption, and ATR-FTIR

▶출처 : Particle and Aerosol Research 제 17 권 제 4 호