Investigations on Deposited Dust Fallout in Urban Doha: Characterization, Source Apportionment and Mitigation

Abstract

This preliminary study investigates and reports on the sources, characterization and possible mitigation of dust fallout in urban Doha, Qatar. Nine samples were collected from three different sites in close vicinity to the Solar Test Facility (STF) in west Doha during the winter of 2016 in Doha. The morphology and size distribution of the samples were analyzed using scanning electron and optical microscopy imaging techniques. It was found that the particulate matter had different shapes with an average particle size of 7.38 μm. The mass concentration of the elements, in order from greatest to smallest, was: Ca, Si, Fe, Mg, Al, Ti, K, Na, S, and Cl. The enrichment factor showed extremely high ratios of Cl and S, while Ca had significant enrichment value. The sources of PM samples were identified to be mainly of natural origin (around 60%) with the balance attributed to anthropogenic sources. The natural sources were related to soil/crustal matter, marine salt and desert dust while the anthropogenic sources were mainly due to transportation and construction activities, which have been experiencing dramatic increase during the past decade in Doha along with its rapid economic development. To this end, several possible mitigation strategies to abate urban PM and its harmful effects were also proposed considering the local living and cultural conditions in Qatar.