Detection of dust canons and Physico-chemical analysis of its particles in Dezful area

To identify the physicochemical and atmospheric conditions of a dust storm at the Dezful station (As Dezful Regional Representative), at first the frequency of the dust storm phenomena was investigated at the Dezful station in Twenty years (1994 -2013). During three events on June 24, July 21, and July 28, 2018, dust samples were collected with sediment traps and physical condition was performed with X-ray diffraction device and chemical analysis of the elements and heavy metals detected by flame atomic absorption and dust particles were evaluated with the Igeo index. Also, the atmospheric circulation in the middle level of the atmosphere and sea level surface that led to a dust storm was identified by using ECMWF ERA-Interim meteorological data. The distribution of dust particles was detected with aerosol optic depth (AOD), and the pathway of dust particles was examined by the HYSPLIT model. The results represented that frequency of dust storm is an increasing trend which has led to a decrease in horizontal visibility in Dezful. The maximum of dust storm phenomena is in summer time and July; The minimum in the autumn time and January. The mean distribution of dust particles in Dezful showed that PM10 was dominant in the size of the silicate tissue. The elements of dominant were Mn, Zn, Pb, and Cd was 491, 311, 32.9, and 1.41 mg/kg respectively, which indicates moderate to severe contamination compared to the standard level. Among the soluble elements, Ca, K, Na, and Mg had the highest concentrations; the presence of these elements is evidence of their desert dust particles. Tracing and calculation of their backward pathway showed that the alluvial deposits of the Tigris and Euphrates in Iraq were its main focus.