Seasonality of the Airborne Ambient Soot Predominant Emission Sources Determined by Raman Microspectroscopy and Thermo-Optical Method

Raman microspectroscopy and thermo-optical-transmittance (TOT) method were used to study airborne ambient soot collected at the suburban air monitoring station in southern Poland during residential heating (January-February) non-heating (June–July) seasons of 2017. Carbonaceous material constituted on average 47.2 wt.% PM2.5 season 26.9 season. Average concentrations OC (37.5 ± 11.0 μg/m3) EC (5.3 1.1 significantly higher than those (OC = 2.65 0.78 μg/m3, 0.39 0.18 μg/m3). was a chief contributor TC mass concentration regardless All parameters indicated coal combustion biomass burning predominant sources Diesel soot, which is structurally less ordered from other sources, dominant The D1 G bands area ratio (D1A/GA) most sensitive parameter that discriminated between various with D1A/GA > 1 for diesel wood burning. Due high daily variability both TOT spectroscopy data, single-day measurements can be inconclusive regarding source apportionment. Long-time measurement campaigns are recommended.