Bakırçay ve Gediz Nehri yüzey sedimentlerinde metal fraksiyonlarının incelenmesi

The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. The toxicity and fate of the water borne metal is dependent on its chemical form and therefore quantification of the different forms of metal is more meaningful than the estimation of its total metal concentrations. Surface sediments were sampled on January (rainy season) and July 2004 (dry season) at five sampling stations from the rivers. A five-step sequential extraction procedure was applied for the determination of the distribution of seven elements (Pb, Cr, Cu, Mn, Zn, Ni, Fe) in sediment samples collected at two rivers, Gediz and Bakırçay, located in western Turkey. Total metal (Hg, Cd, Pb, Cr, Cu, Mn, Zn, Ni, Fe) concentrations were measured at the sampling stations. The accuracy evaluated by comparing total trace metal concentrations with the sum of the five individual fractions proved to be satisfactory. The results of total metal concentrations showed high concentrations of Cd, Cr, Zn, Pb, Ni and Mn in Gediz and Cd, Pb, Zn in Bakırçay, undoubtedly as a result of contamination from the industrial activity. Large fractions of Zn, Cr, Cu, Ni, Pb and Fe were associated with residual fraction of sediment, whereas Mn was reducible fraction