Экологическая и аналитическая токсикология

Chemical and Mineralogy Characteristics of Dust Collected Near the Phosphate Mining Basin of Gafsa (South-Western of Tunisia)

Abstract

Mohamed Raja, Taieb Dalila and Ben Brahim Ammar

The study aimed at chemical and mineralogical characterization of whole particulate matter (PM) in the vicinity of a mining phosphate basin at urban area in Gafsa. Heavy metals concentrations in PM samples (Cd, Fe, Cu, Mn, Cr, Zn, Ni, Al, Pb), MgO and SiO2 were determined by atomic absorption spectrometry. Calcium and phosphorus oxides (CaO, P2O5) were analyzed by Technicon Auto-analyzer. Potassium and sodium oxides (K2O, Na2O) were analyzed by flame photometer. Ionic species (S04 2-, Cl-, NO3 -) were quantified by ion chromatography while organic carbon (OC) content was determined using carbon sulfur Analyzer. The mineral phase identified by X-Ray powder diffraction technique and SEM-EDX provides information about morphology and chemical composition of PM. As regards the chemical characterization it was found that samples were enriched predominantly in SiO2, CaO and P2O5 which were detected only at mining area (S2 and S3) Weak concentrations of K2O, Na2O and MgO were also found. In addition the minerals phases identified in the samples were carbonate fluorapatite, Calcite, Heulandite, Gypsum and Dolomite. The values of ionic composition were in the flowing order SO4 2->Cl->NO3 -. Results also showed that heavy metals pollution increased by the proximity to the mining area. SEM-EDX revealed that particles are almost spherical.