Morphology, composition and source identification of urban aerosol particles in Vlora, Albania

Abstract

This research aims to investigate the morphological characteristics, chemical composition and possible sources of aerosol particles. Aerosol samples of the urban atmosphere were examined in the city of Vlora, located in the south of Albania. Scanning electron microscope JEOL JSM-563 equipped with an Oxford Link ISIS L300 for energy-dispersive X-ray [EDS] analysis was used to examine aerosol particles. In addition, images of aerosol particles were processed by ImageJ software for dimensional and morphological analyses. The primary data automatically generated by ImageJ were surface, perimeter, minimal and maximal size, circularity, and aspect ratio parameters. Then, the projected area diameter, volume equivalent diameter (dev), physical diameter, and aerodynamic diameter were calculated. Based on the results of particle morphology and chemical composition nine groups of aerosol particles were classified: aluminosilicates (fly ash and soil particles), Ca-rich particles, carbon particles (soot particles and biogenic particles), sea salt particles, Si-rich particles, Fe -rich particles, and mixed particles. The morphological analysis results indicated that aerosol particles were relatively distributed over a wide size range of 0.5 μm to 28 μm fitted to lognormal distributions. In the measured distributions a peak around 2 μm is dominant. By accounting for volume equivalent and diameter aerodynamic shape factor, this study develops the method of the aerodynamic diameter calculation.