Characterization of Atmospheric Organic and Elemental Carbon of PM2.5 in a Typical Semi-Arid Area of Northeastern China

Received: July 28, 2011
Revised: July 10, 2012
Accepted: July 10, 2012
Download Citation: RIS|BibTeX|https://doi.org/10.4209/aaqr.2011.07.0110  

Cite this article:
Zhang, R., Tao, J., Ho, K., Shen, Z., Wang, G., Cao, J., Liu, S., Zhang, L. and Lee, S. (2012). Characterization of Atmospheric Organic and Elemental Carbon of PM2.5 in a Typical Semi-Arid Area of Northeastern China. Aerosol Air Qual. Res. 12: 792-802. https://doi.org/10.4209/aaqr.2011.07.0110

ABSTRACT

In the spring of 2006, daily particulate matter (PM_2.5) aerosol samples were collected in Tongyu, a semi-arid area in northeastern China. The concentrations of organic carbon (OC) and elemental carbon (EC) were determined with a thermal/optical carbon analyzer in the filter samples. The average concentrations of OC and EC in PM_2.5 were 14.1 ± 8.7 and 2.0 ± 1.3 μg/m³, respectively. A good correlation between OC and EC was observed during the spring season, suggesting that they might be derived from similar sources. The correlation between OC and K⁺ was high (R = 0.74), and the K⁺/OC ratio, as determined from their linear regression slope, reached 2.57. The good correlation and high K⁺/OC ratio indicated that biomass-burning was probably one of the major sources of OC in this region. The concentrations of estimated secondary organic carbon (SOC) in PM_2.5 in Tongyu ranged from below the detection limit to 26.1 μg/m³ (mean, 5.9 μg/m³). The percentages of SOC in OC and in PM_2.5 mass were 42.0% and 2.1%, respectively. The SOC concentrations during dust storm (DS) periods were higher than those during non-dust storm (NDS) ones, suggesting that chemical reaction processes involving gas-particle conversion occurred during the long-distance transport of aerosol particles.

Keywords: Organic carbon; Elemental carbon; Dust storm; Semi-arid area