Spatial distribution of heavy metals and Ecological Risk Assessment for the main sub-branches (Rayahs) sediments of Nile River, Egypt

Abstract

Sediments act as a sink or source of pollution under various conditions. Moreover, they can serve as pollution indicators. The present research aims to evaluate sediment quality associated with its content in heavy metals and the potential ecological risk, focusing on the sub-branches of Nile River (Rayahs) in Egypt, including El-Tawfiky (RT), El-Menoufy (RM), El-Behary (RB), and El-Nassery (RN). According to the results, El-Rayahs sediments are characterized by an increasing sand fraction, followed by mud. Regarding heavy metals pollution, Cd registered the highest pollution ranking, whereas Fe, Mn, Zn, Pb, and Ni exhibited the lowest effect. Furthermore, the ecological risk for El-Rayahs sediments increases northward; however, most sites either showed slight pollution or did not record any degree of contamination, except the northern stretch of El-Behery (El-Mahmoudia Canal), which is a very high-polluted zone, with high ecological risk according to the contamination degree (Cd) and potential ecological risk (RI) indices.