Assessment of heavy metals contamination in the Nile River water and adjacent sediments: A case study from Khartoum City and Nile River State, Sudan

Abstract

The current study aims to investigate the heavy metals concentration and the degree of pollution in the water and adjacent sediment of the Nile River and its main tributaries at Khartoum City and River Nile State, Sudan. For this purpose, thirty-three water and sediment samples were collected from River Nile, Blue Nile, and White Nile. Water chemical properties and sediment physicо-chemical properties were measure. Concentrations of heavy metals (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, Zn) were determined for both sediment and water samples using inductively coupled plasma (ICP-OES). Enrichment factor (EF) and geo-accumulation index (Igeo) were applied to quantify heavy metals pollution levels in sediment samples. The revealed that only Fe metal detected in the water samples and its concentrations within the permissible maximum limit. This indicated that water is highly suitable for irrigation. Depending on calculated enrichment factor (EF) and geo-accumulation index (Igeo), sediment samples were found to be enriched and polluted with Mn and Mo particularly at Berber site which may as consequence of gold mining activities in this area. The study revealed relatively strong to strong correlation between heavy metals of Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti, Zn (r2=0.84 to 0.99) and significant negative correlation with Mo (r2=0.58 to 0.73). This study recommends regular monitoring of heavy metals in the Nile River and its main tributaries for conservation and protection from pollution.