Heavy metals hazard in Rosetta Branch sediments, Egypt

The chemical concentrations of heavy metals can impact adversely on the sediments quality of the Rosetta Nile branch. To assess the degree of this adversely impact, 20 sediment samples were collected and analyzed for their content of heavy metals. Contamination indices are used to assess the heavy metals; single indices; index of geoaccumulation (I_geo), contamination factor (CF), enrichment factor (EF) and ecological risk factor (Er), as well as three integrated indices; degree of contamination (DC), pollution load index (PLI) and pollution ecological risk index (PRI). The elemental ratio and I_geo have indicated that the Rosetta bottom sediments are mainly moderately polluted by Cu, Co, Ni and Fe, moderately to strongly polluted with Cr and Zn and very strong polluted with Pb and Cd. Consequently, the geochemical enrichment of the studied elements indicated that the investigated area was subjected to chemical weathering and considered moderately-polluted to very strongly polluted. Accordingely, the studied elements classified into two groups; the first group includes Fe, Co, Cr and Ni, which are mainly of natural origin and controlled by the distribution of clay minerals. The second group includes Cu, Zn, Pb, Cd and Zn which originate from the industrial activities and irrigation drainage water . The study recommendation is the reduction of the anthropogenic effects through preventing irrigation with inadequately treated wastewater and prevents the discharge of industrial wastewater into the Nile, which has led to enhancement of the heavy metals in the freshwater source.