Analysis of metals in mangrove ecosystem of Passa Vaca River, Salvador, Brazil

Abstract

The objective of this research was to make a preliminary assessment of environmental conditions with respect to the contribution of metals concentrations in the mangrove river sediment Passa Vaca, Salvador (BA). The metals were determined chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), barium (Ba), strontium (Sr), vanadium (V) and zinc (Zn). Surface sediment were collected at four points (P1, P2, P3 and P4) of the mangrove major anthropogenic influences. The samples were pre-treated by acid digestion and the determinations of metallic elements was by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP OES). The results reported values higher concentrations at point P4 concentrations for the Fe (28,101.65 µg g-1), followed by V (62.96 µg g-1), Mn (60.57 µg g-1) and Cr (53.09 µg g-1), while at point P2 higher concentration was found to Zn (47.95 µg g-1) P2. The correlation analysis and principal component (PCA) revealed a strong correlation between the metals studied among the finer fractions of the pellet and the elements Fe, Cr and Ni. Taking into account the values of the thresholds of adverse effects (TEL) of NOAA, the concentrations of Cu and Cr in P4, outperformed this index.