masoume darmany

One of the critical factors dust sources by less consideration is the role of geology and geomorphology as a source of dust emission. Geological units are one of the factors involved in the release of dust particles and the production of sediment.  Lithological components with high sensitivity to alteration, weathering, and erosion, play an influential role in the emission and distribution of dust particles. Based on research, Sarakhs County is one of the critical corridors of wind erosion and dust storms in Iran that is affected by 120-days’ winds of Sistan The sensitivity of the geological units to wind and water erosion in this area categories from medium to very high. To identify the chemical elements of the geological units and their roles in dust emission, soil samples were collected from the surface, and sub-surface layers of the geological units and airborne dust were also collected from the atmosphere. Samples were analyzed by induction spectroscopy to determine their chemical elements. To identify the origin of dust and its relationship with geological units and also their classification, factor and cluster analysis was performed. The results of factoring and clustering analysis showed the Sarakhs region with chemical elements sodium, zinc, lanthanum, arsenic, niobium, cadmium, nickel, lead, zinc, lithium, strontium, sulfur, sodium is in factor one with an evaporative and chemical origin, and with elements of aluminum e, iron, cobalt, thorium, manganese, boron, and titanium is in factor two with a detrital and terrestrial origin. Also, the chemical elements of dust in rural areas of Bazangan, Shorlugh, Baghbghoo, Padeh, and Baghak are in the same group with the geological units of Abe-Daraz, Chehel-e-Kaman, Quaternary deposits, bitter water, and Khangiran and have a common origin. The chemical elements barium, arsenic, sulfur, thorium, nickel, lithium were introduced based on enrichment factors with human origin (chemical-evaporative).

The city of Sarakhs is located in in Khorasan Razavi province, the northeast of Iran and has a dry and desert climate. Although this city has no problem in the field of gaseous pollutants, but dust causes more unhealthy days than before. The purpose of this study was to investigate the physical and chemical properties, identify dust particles minerals over Sarakhs city and identify sources of dust storms. Spatial repetition of dry particle sedimentation has taken place during the summer and autumn seasons of 2019. This study was performed on fine round particles with a size of less than 10 micrometers at a height of 2-4 meters above the ground. Using Inductively Coupled Plasma (ICP) and XRD, metals and minerals of dust particles were identified and, then, using Scanning Electron Microscope (SEM) and Particles Size Analysis (PSA), particle shape and size were determined. According to the results, metals Ca, Al, Na, Fe, S, Ti, Ba, Mg, Zn, and Sr have the highest concentrations of dust in designated villages. The study of dust particle mineralogy showed that the dust has a terrestrial origin and is very similar to the minerals in the dust of Sistan plain and Hamoon wetland. The highest concentrations of clay minerals are: Kaolinite, Chlorite, Quartz, Calcite Gypsum. Ca and Al with the highest concentration among soluble metals indicate the origin of dust in the region. Also for elements such as Sr, S, and Gypsum, an evaporative source can be considered. The high concentrations of toxic and chemical elements including As, Pb, and Zn can be attributed to Khangiran refinery. Therefore, dust in Sarakhs region has three sources of local origin, evaporation and chemical.