Mineralogy of harmattan dust over Iwo, South Western Nigeria

Abstract

Harmattan period in Nigeria, characterized by dust laden atmosphere begins from the month of November and ends in the month of March of the following year. Samples of harmattan dust were collected using clean plastic bowls of diameter 10 cm which were exposed indoor and on elevated platforms at different locations at Iwo. The bowls were exposed so as to collect dust particles for a period of five months (November to March) of the following year. A total of five (5) samples were collected and stored in desiccators prior to the analysis in order to avoid contamination which could affect the results. Mineral and Elemental study carried out on harmattan dust samples gathered at Iwo (7037’N, 4011’E), sub-sahara region of African city, shows the presence of elements such as K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Mo, As, Ce, Zr, Pb, V, and Sr in the dust samples collected. Minerals such as Quartz [SiO2], Gibbsite [Al(OH)3], Rutile [TiO2], Goethite [Fe2O3.H20] and Microcline [KAlSi308] were also found to be present in different percentages at the station under consideration. The mean soil content of the total size of particles for the harmattan season for the station was found to be (). The Enrichment Factor for the station was also calculated and showed the dust samples to be rich in Fe and K.