(주)에이피엠엔지니어링

2014년과 2020년 대전지역 대기 중 미세먼지 화학조성 변화에 따른 가시거리 악화 특성 비교 Comparison of Visibility Impairment Due to the Change in PM2.5 Chemical Compositions in Daejeon between 2014 and 2020

Abstract 

The visibility impairment caused by air pollutants and aerosol water is a major environmental problem in our society. This research investigates the impacts of chemical composition of PM2.5 and aerosol water on visibility impairment in Daejeon, Korea between 2014 and 2020. Light scattering and absorption coefficients were measured by a nephelometer and an aethalometer, respectively whereas light extinction coefficient was calculated from PM2.5 chemical composition and relative humidity (RH) using the IMPROVE algorithm. Good agreement of light extinction coefficients was observed between measured and calculated ones with a slope of 0.99 and R2 of 0.95. Decreases in annual average concentrations of (NH4)2SO4, organic mass (OM), elemental carbon (EC), and sea-salt (SS) were observed in 2020 comparing to those in 2014 whereas NH4NO3 was increased. During the period of poor visibility (Worst 20%), light extinction coefficient decreased 16.9% in 2020 compared to that in 2014, resulted in 23.2% increase in visibility. The contribution to the total light extinction coefficient decreased from 34.4% (2014) to 22.6% (2020) for (NH4)2SO4 and from 18.0% (2014) to 10.8% (2020) for OM whereas increased from 36.8%(2014) to 59.9%(2020) for NH4NO3. During the Worst 20% visibility period, the contribution of aerosol water to the total light extinction coefficient increased from 48.4% in 2014 to 53.5% in 2020, indicating that aerosol water is important contributor to visibility impairment. This research indicates that reducing NH4NO3 was a significant factor in the deterioration of visibility.

Key words 

Visibility, Light extinction coefficient, PM2.5 chemical compositions, Relative humidity

▶출처 : 한국대기환경학회지 제 38권 제 5 호, 2022.10 p.702-715