Characterisation for some emission sources in CMB calculation for Mae Moh area, Thailand

Particulate samples of agricultural waste burning, straw burning, forest leaf burning, heavy duty truck emission, paved road dust, soil, agricultural soil, coal, electrostatic precipitator ash, and emission from stack power plant were collected from the Mae Moh area. Chemical compositions of sampling filters were analysed to determine the particulate matter source profiles. The analysis included ICP-MS for elemental compositions, ion chromatography for water soluble ions and CHNS/O for carbon species. In all biomass burning profiles organic carbon (OC) was higher during smouldering phase, while elemental carbon (EC) was higher during flaming phase. Results relating to biomass emission during flaming stage showed increase in K⁺. Organic and elemental carbons were the most abundant in biomass burning and truck exhaust. The abundance of EC was much lower, and the abundance of OC was much higher in biomass burning relative to truck exhaust emission. Al, K, Mg, Ca, and Fe were presented with high abundance in road dust, soil, coal, fly ash and stack samples. The differences in chemical compositions were not sufficient to distinguish geological material and fugitive dust sources. Fly ash profile differed from the others since OC and EC were not detected. Na and Zn were most abundant in stack samples. These findings served as a starting point for source contribution study. For future application of source apportionment using the CMB modelling technique, these source profiles should be appropriately grouped and selected to generate reliable outcomes.