Study of Black Sand Particles from Sand Dunes in Badr, Saudi Arabia Using Electron Microscopy

Atmosphere

Haider Abbas Khwaja⁶  Omar Siraj Aburizaiza⁴  Daniel L. Hershey⁵  Azhar Siddique⁴  David A. Guerrieri P. E.⁵  Jahan Zeb⁴  Mohammad Abbass²  Donald R. Blake³  Mirza Mozammel Hussain⁶  Abdullah Jameel Aburiziza¹  Malissa A. Kramer⁵  Isobel J. Simpson³ 

[1] School of Medicine, Umm Ul Qura University, Mecca 21955, Saudi Arabia; E-Mail:;Civil Engineering Department, King Abdulaziz University, Jeddah 21589, Saudi Arabia; E-Mail:;Department of Chemistry, University of California-Irvine, Irvine, CA 92697, USA; E-Mails:;Unit for AinZubaida and Groundwater Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia; E-Mails:;New York State Department of Environmental Conservation, 625 Broadway, Albany, New York, NY 12233, USA; E-Mails:;Wadsworth Center, New York State Department of Health, Albany, New York, NY 12201, USA; E-Mail:

关键词: particulate;    urban aerosols;    Saudi Arabia;    sand;    scanning electron microscopy;   

DOI  :  10.3390/atmos6081175

来源: mdpi

【 摘 要 】

Particulate air pollution is a health concern. This study determines the microscopic make-up of different varieties of sand particles collected at a sand dune site in Badr, Saudi Arabia in 2012. Three categories of sand were studied: black sand, white sand, and volcanic sand. The study used multiple high resolution electron microscopies to study the morphologies, emission source types, size, and elemental composition of the particles, and to evaluate the presence of surface “coatings or contaminants” deposited or transported by the black sand particles. White sand was comprised of natural coarse particles linked to wind-blown releases from crustal surfaces, weathering of igneous/metamorphic rock sources, and volcanic activities. Black sand particles exhibited different morphologies and microstructures (surface roughness) compared with the white sand and volcanic sand. Morphological Scanning Electron Microscopy (SEM) and Laser Scanning Microscopy (LSM) analyses revealed that the black sand contained fine and ultrafine particles (50 to 500 nm ranges) and was strongly magnetic, indicating the mineral magnetite or elemental iron. Aqueous extracts of black sands were acidic (pH = 5.0). Fe, C, O, Ti, Si, V, and S dominated the composition of black sand. Results suggest that carbon and other contaminant fine particles were produced by fossil-fuel combustion and industrial emissions in heavily industrialized areas of Haifa and Yanbu, and transported as cloud condensation nuclei to Douf Mountain. The suite of techniques used in this study has yielded an in-depth characterization of sand particles. Such information will be needed in future environmental, toxicological, epidemiological, and source apportionment studies.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.