Sources and distribution of trace metals in the Saricay Stream basin of southwestern Turkey

Abstract

Seasonal variation of the concentrations of trace metals ( Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured by ICP-AES in the water and sediment from the Saricay Stream, Geyik Dam and OrtakoyWell in the same basin. Comparisons between trace metal concentrations in water and sediment in three sources ( Stream, Dam and Well) were made. The concentrations of a large number of trace metals in the water and sediment were generally higher in the Stream than in the Well and Dam, particularly in summer. Trace metal concentration ranges in sediments of the Saricay Stream and its sources showed very wide ranges ( as mass ratio): Co: 5 - 476 mu g g(-1), Cr: 15 - 1308 mu g g(-1), Cu: 7 - 128 mu g g(-1), Fe: 1120 - 13210 mu g g(-1), Mn: 150 2613 mu g g(-1), Ni: 102 - 390 mu g g(-1), Pb: 0.7 - 31.3 mu g g(-1) and Zn: 18 - 304 mu g g(-1), whereas Cd was not detected. Trace metal concentration ranges found in waters were: Co: 9.5 - 20.7 mu g L-1, Cr: 20.3 - 284 mu g L-1, Cu: 170 - 840 mu g L-1, Fe: 176 - 1830 mu gL(-1), Mn: 29.3 387 mu g L-1, and Ni: 4.3 - 21.9 mu g L-1. Among the trace metals studied, Cd and Zn in two seasons and Pb in winter were usually not detected or in the recommended levels. In addition, Cd was not detected in the sediment during the winter season. The analysis of variance ( one-way ANOVA) and correlation matrix was employed for the sediment and water samples of the two field surveys ( summer and winter) comparison. The three sources showed differences in metal contents. The metal levels in sediments displayed marked seasonal and regional variations, which were attributed to anthropogenic influences and natural processes. In the Saricay Stream, high values of metals during the dry season showed an anthropological effect from small industry firms, e. g.: an olive mill and a dairy farm or water dilution during summer seasons. Finally, the pollution in this basin probably originated from small industrial, low quality coal-burned thermal power plants, and particularly agricultural and domestic waste discharges.