Metallic trace elements contained in the sediments of Dayet Er-Roumi Lake (Morocco)

Abstract

The contamination of aquatic ecosystems with metals remains a serious environmental problem of growing concern. Sediments are often studied as reservoirs or wells for many chemical pollutants. They are micropollutant traps; they also indicate the watercourse's historical pollution, lagoons, and lakes…Lake Dayet Er-Roumi (SIBE) is the only permanent natural lake in the Khemisset region (Morocco); this wetland is affected by several forms of pollution that are mainly linked to human activities (agricultural, domestic, industrial, etc.). The objective of our study is to contribute, through qualitative and quantitative analysis, to the assessment of lake sediment pollution by Spatio-temporal monitoring of certain toxic heavy metals such as Mn, Zn, Cr, Cd. These sediments are collected on the level of the lake's surface; the concentration of heavy metals was measured by microwave plasma atomic emission spectroscope (MP-AES). Metal analyses carried out at three measuring points during the winter season reveal a high concentration of Zn, Cr, and Mn at all stations during the winter season, which far exceeds the recommended standards, with a low level of Cd. The contamination factor "FC" and the degree of contamination "DC" reveal polymetallic contaminations dominated by two elements, zinc, and Chromium, which are the most worrying. These results clearly show that lake Dayet Er-Roumi is polluted; strategies to limit the lake's pollution must be implemented to avoid several ecological problems (fish mortality, etc.).