Contamination Assessment by Heavy Metals of the Ykem River Sediments (Coastal Meseta, Morocco)

Abstract

The main objective of this study is to evaluate the degree of pollution of Wadi Ykem through a geochemical study allowing highlighting the physicochemical characteristics as well, the evaluation and the distribution of the heavy metal contents in the sediments. For the environmental assessment of its sediments, a study was carried out to determine the concentrations of major elements and trace elements (Cd, Cr, Al, Pb, Zn, Cu and Ni) during two different hydrological seasons: in summer (June 2017) and in winter (April 2018). In the two campaigns 20 sediment samples were collected in 10 sampling sites. The various sampling sites were distributed upstream and downstream of the Ykem river. These metals were analyzed at CNESTEN using the ICP MS technique. The geo-accumulation index, the Enrichment Factor (EF) and the Pollution Load Index (PLI) were used for the assessment of metallic contamination of the sediments. The results of this study show a homogeneous distribution of the contents of major elements with a dominance of the elements SiO2 and TiO2 in the two campaigns. High Cd contents which exceed the contents of geochemical backgrounds. High levels of Cd, Pb and Al. And low concentrations for (Cr, Ni, Cu, Zn) for the two campaigns. The PLI variations show that all the stations have PLI values greater than 1. The Enrichment Factor does not show contamination at all sampling stations. The values of Igeo show levels which vary from uncontaminated to moderately contaminated.