Spectroscopic Characterization of Dust-Fall Samples Collected from Greater Cairo, Egypt

Abstract

This work aimed to characterize dust-fall samples collected from street's trees in Greater Cairo (GC), Egypt, and its surroundings by different spectroscopic techniques, namely; X-ray diffraction (XRD), attenuated total-reflection Fourier transform infrared (ATR-FTIR), particle-size analyzer, and scanning electron microscopy (SEM) combined with energy dispersive X-ray measurements. Samples were collected from 19 different locations inside and outside of GC. Quantitative phase analysis of the dust-fall samples was performed using the Rietveld method. Results showed that the most frequently observed phases in the dust-fall samples were calcite (CaCO3), dolomite (CaMg(CO3)2), gypsum (CaSO4·2H2O), and quartz (SiO2) with average concentrations of 39 ± 16, 8 ± 7, 22 ± 13, and 33 ± 14 wt%, respectively. The occurrence of these constituents referred to a combination of different anthropogenic and natural sources. The ATR-FTIR results are in good agreements with XRD data of the different observed phases. Based on the SEM and particle-size measurements, quantitative determination of the particle-size distribution was described. It was found that not only the large-sized particles are deposited but also the small-sized ones (PM10 and PM2.5). In addition, the particle size of the collected dust-fall samples varied from 0.1 to 200 µm with an average particle size of 17.36 µm; however, the particle size ranged from 2.5 to 40 µm predominated in all of the dust-fall samples.

Accumulation and coarse mode aerosol concentrations and carbonaceous contents in the urban background atmosphere in Amman, Jordan

“…According to the ATR-FTIR analysis, the spectra showed three interesting major signals (Fig. 7) for carbon containing compounds that are emitted from fossil fuel combustion such as traffic tailpipe emissions (e.g., Siciliano et al 2018;Popovicheva et al 2017;Shaltout et al 2016;Agudelo-Castañeda et al 2015;Popovicheva et al 2015;Jiang et al 2011). The first signal (wave number 800-1100 cm −1 ; mass fraction 37.1-45.6%) represents polycyclic aromatic hydrocarbon compounds that contain functional groups such as sulfur, hydroxyl, or ester.…”

Computational prediction of dust deposition on solar panels

“…As a result, the user-defined power function of the velocity profile at the domain inlet is entered such that the wind speed has the selected values in Table 1 at a height 10 m from the ground. Dust diameters and materials are assumed based on the research of Shaltout et al ( 2016 ). The most frequently observed chemical compounds of dust in Cairo are dolomite of density, ρ = 2872 kg/m 3 , calcite of density, ρ = 2800 kg/m 3 , quartz of density, ρ = 2650 kg/m 3 , and gypsum of density, ρ = 2320 kg/m 3 .…”