AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Temporal Variation of PAHs and n-Alkanes Concentrations in Atmospheric PM2.5 of a Background Site in South Korea: Evaluation of Fossil Fuel Combustion Contribution
KI AE KIM, Soo Bin Hong, Jong Sik Lee, Eun Sil Kim, Yong Pyo Kim, Chang Hoon Jung, Ji Yi Lee, Chosun University
Abstract Number: 766 Working Group: Aerosol Chemistry
Abstract PAHs and n–alkanes in atmospheric PM2.5 samples measured every 6th day during one year (from June 2015 to May 2016) at Anmyeon Island, a background site of South Korea were determined using GC–MS to evaluate contribution of fossil fuel combustion. PAHs are products of incomplete combustion, mainly from anthropogenic sources, while, n–alkanes are emitted by both anthropogenic and biogenic sources. Therefore, the source of organic aerosol in PM2.5 can be classified as fossil fuel combustion vs biogenic emission through the diagnostic ratios of PAHs and carbon number distribution of n–alkanes. Average concentration of PAHs was 2.83±3.44 ng/m3. While, n–alkanes concentrations ranged from 1.77 to 47.65 ng/m3 with an average of 14.02±10.26 ng/m3. The PAHs concentration was about one over higher in winter than summer, however, the difference of n–alkanes concentration was not large (about 3 times higher in winter). It might be due to the contribution of biogenic emission without seasonal variation. The Carbon Preference Index (CPI) values of n-alkane was ranged from 1.13 to 8.31. The CPI values showed close to unity during heating period, while, the CPI values in non–heating period showed higher than heating period. The contribution of mixture of biomass burning and coal burning smoke were found through diagnostic ratios of PAHs (Flt/Pyr, BaP/BeP and IcdP/BghiP) with a good linear relationship (R2 ≥ 0.58) between PAHs and fossil fuel derived n–alkanes, demonstrating that mixture of coal and biomass burning is the main contribution sources in the background site during heating period. The contribution of coal and biomass burning was approximately 35.8% of total variance in the PCA (Principle Component Analysis) and this contribution was evaluated as the influence of long range transport from outside the Anmyeon Island rather than impact of local emission based on the meteorological data and backward trajectory of air parcel analysis.