Enrichment of sediments in urban rivers by heavy metals

The heavy metals contained in sediments may be responsible for constant degradation of rivers’ water quality, which circulate in an urban environment. Therefore, this study shows the pollution index and enrichment factor for each of these elements in river sediments. It was used the optical emission spectrometry with inductively coupled plasma (ICP-OES) and total organic carbon (TOC) by dry combustion. The enrichment factor of sediments were normalized by aluminium concentration. From the point of view of toxicology, the elements Ba, Cr, Pb and Zn, and the macro chemical elements Fe, Mg and Na showed to be more significant. When used the references of local background, the enrichment percentages for Ba, Cu, Cr, Ni, Zn, Mg and Na respectively were 39.3%, 44.3%, 56.3%, 18.6%, 140.2%, 18.4% and 295%. The percentage of TOC did not exceeded the limit of 1% at any of the points of sampling. According to the main worldwide guidelines, the obtained concentrations for Cd, Cr, Cu, Ni and Zn in the majority of the points of sampling, are rates from which can be expected adverse effects in the aquatic environment. This occur due to theirs capacities to release these elements in the flowing. Therefore, this study are relevant scientific data to indicate the water quality of urban rivers.