Characterization of Atmospheric Particles for Source Apportionment Study

Abstract:

Fine (PM2.5) and coarse particles (PM10-2.5) are universal concerned due to their adverse effects to human. This study is designed to determine the mass and chemical compositions of PM2.5 and PM10-2.5 at the Asian Institute of Technology (AIT) campus, a suburb site of Bangkok in wet and dry season. One hundred and thirty seven pairs of PM2.5 and PM10-2.5 were collected using two co-located dichotomous samplers during the wet and dry seasons of Thailand (15 May 2007 – 29 February 2008). Higher concentrations of both PM2.5 and PM10-2.5 in dry season were observed than those in wet season. Thirty eight days were observed with PM2.5 exceeding the new US EPA 24-h standard (35 µg/m3). Hourly organic carbon and elemental carbon are also measured. The study also compared the performance of different black carbon monitoring techniques among semi-continuous EC/OC analyzer, Aethalometer series Continuous Soot Monitoring System (COSMOS), and Smoke Stained Reflectometer. Subsequently, the source apportionment of PM2.5 and PM10-2.5 was also determined using a receptor model (PMF) based on the PM composition data to identify the contributing sources to the PM. PMF analysis identified the major sources of PM10-2.5 were construction and soil during, whereas high contributions of diesel and biomass burning were determined for PM2.5.

Keywords: black carbon, elemental carbon, organic carbon