Inorganic chemistry, granulometry and mineralogical characteristics of the dust fall over phosphate mine adjacent area, central Jordan

Abstract

Eight selected heavy metals and phosphorus (Fe, Zn, Pb, Cu, Cr, Cd, Ni and P) were analyzed in the dust fall samples collected from the surrounding areas adjacent to Al-Hisa phosphate mine central Jordan during summer 2008. The chemical analysis was done using the ICP-AES, after being digested with (HNO 3 /HCl/HF) acid mixture, beside the identification of their mineral constituents using the XRD. Moreover, the particulate matter (PM) size was investigated and divided into four fractions (PM 2.5 , PM 2.5-10 , PMC 10-100 and PM [100 ). The PM 10 -PM 100 were found to be the most abundant in the local atmosphere followed by PM 2.5 -PM 10 , while the respirable fraction (PM 2.5 ) and giant fraction (PM [100 ) showed lower levels. The studied samples contain less PM 2.5 and PM 10 particulates (9.39 and 28.67), respectively, than samples located far from the mine area (blank samples) (17.32 and 51.7) for PM 2.5 and PM 10 , respectively. The meteorological effects, mainly the prevailing wind direction beside the distance to emission sources affect the distribution of dust particle sizes. Heavy metal contents in studied samples are similar to some extent to those found in Isa Town (Bahraian), which related to similar arid and low precipitation climatic conditions. The effect of phosphate mining activities was obvious as indicated from the presence of apatite as the main mineral phase and the higher P contents. Moreover, the studied samples contain higher Zn, Ni, Cu and to lesser extent Cr than blank samples. They exhibited a significant positive correlation with P, as they are usually associated with the phosphate rocks.