Identification of the Mineralogical and Morphological Composition of Dust Particles in Western Tehran Province

In recent years, droughts, frequent storms, industrial and mining activities have caused a rise in dust in suburbs Tehran, and developing west of the province of Teheran. The Mallard County is located in the west of the province of Tehran with arid and desert climate and has been selected as the study area. This study aims to determine the soluble metals, minerals and morphology of the original sediments and particulates in Mallard County and to determine the origin of the dust. Dust sediment was collected seasonally at 30 stations using dust collector. Soil and surface sediment sampling were conducted systematically and randomly on 14 pediment and playa facies and a total of 83 samples were taken from the work units. Scanning electron microscope (SEM) was used to determine the shape and size of dust particles, and X-ray diffraction (XRD) identified the minerals found in dust particles. The results showed that most of the chemical compounds in the dust particles consist of magnesium, phosphorus, potassium, iron, chromium, vanadium, nickel, lithium, molybdenum, caesium, scandium, zirconium and titanium. These elements are in the form of quartz, calcite and gypsum clay minerals with a coating of dolomite, hematite and muscovite minerals, with an internal origin that have been transported into the region from close distances or through wind flow. According to the results of the SEM analysis, the particle morphology is angular and semi-circular. Most dust particles can be evidence of the existence of a local and human source and are transported closely.