MARMARA DENİZİ GÜNEYİ (KOCASU DELTASI) SEDİMENTLERİNDE AĞIR METAL KİRLİLİĞİNİN ARAŞTIRILMASI

Abstract

In order to investigate the heavy metal accumulation and its spatial distribution, the extent of the pollution and possible sources, 2 gravity cores of about 140 cm in length and 20 surface sediments from different depths taken in the Kocasu Delta located to the south of the Sea of Marmara with a research vessel named Selen belongs to the MTA General Directorate. In this context, grain size, organic carbon, total carbonate analyses, geochemical analyses (Fe, Zr, Cr, Mn, Ni, Cu, Zn, Cd, Pb, As, V, Sb) carried out on a totally of 74 sediment samples and the concentration values obtained have been evaluated according to depth and grain size, the relations between elements and other parameters have been investigated with some statistical methods. The mean shale metal concentration values were accepted as background values in the determination of possible metal pollution sizes in the sediment samples and the enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (Cf) and pollution load index (PLI) have been calculated for the pollution assessment of metals, respectively. According to the results of geochemical analysis, the mean concentrations of metals other than Cr, Ni and Pb elements were found to be below the world average shale values. The results of the mean enrichment factor (EF) and the pollution factor (Cf), especially the Cr, Ni and Pb metals, indicated that the enrichment/contamination was "low and/or moderate" when the elements were evaluated separately. The results of the average geo-accumulation index (Igeo) showed that core and surface sediments were of "low contamination" class for Cr, Ni and Pb metals. According to the PLI results obtained at each sampling station, when an assessment is made for the whole of the metals in question, it has been determined that the work area in general is not polluted. According to the results obtained, the mean accumulation levels of heavy metals in the study area have been determined as Ni>Pb> Cr>Zn>Sb>Fe>V>Mn>Cu>Zr>As>Cd. The enrichment of metals such as Cr, Ni and Pb in the study area of the Marmara Sea, it is known that the influence of the presence of various metal ores and mafic, ultramafic and granitic rocks with high baseline (background) values in the southern drainage basin of the Marmara Sea. Along with that, many industrial untreated wastewater discharges with different characteristics, domestic wastewater, solid waste and livestock manure storage areas, fertilizers and pesticides used in agricultural activities, and mining activities that are the main source of point pollution in the basin. All resources mentioned above have been seen as a possible source of Cr, Ni and Pb elements that provide “low to moderate” enrichment/contamination in this study.