GEOCHEMICAL CHARACTERISTICS OF RIVERBED SEDIMENTS IN THE DANUBE DELTA, ROMANIA.

Major (CaCO₃, TOC, and Fe₂O₃), minor (MnO and TiO2) and trace (Zr, Cr, V, Zn, Cu, Ni, As, Pb, and Hg) elements from surface riverbed sediments were determined at 66 locations in deltaic environment, along St. George distributary and in the interdistributary depressions of the Danube Delta. The studied area is characterized by terrigeneous, either non-carbonated or low calcareous sediments, quite poor in organic matter. Most of the studied heavy metals showed high spatial variability, generally with higher concentrations in interdistributary depressions and adjacent canals, as well as on the meander Mahmudia (M1). Ni, Cu, and Cr showed concentrations frequently exceeding the quality criteria set in the Romanian legislation. Contamination Factor (CF) and Pollution Load Index (PLI) were used to assess the level of heavy metal pollution in the studied area. [ABSTRACT FROM AUTHOR]