PHYSICO-CHEMICAL STUDIES ON THE SPECIATION OF HEAVY ELEMENTS IN THE RIVER NILE SEDIMENTS

Abstract

The suitability of the 0.5 N HCI solution for extraction of Fe, Mn, Ca, Mg, K, Na, Cd, Co, Cu, Pb, and Zn in the Nile sediments was evaluated by comparing its effectiveness with that of conventional acid oxalate and aqua regia extraction techniques. In addition, the spatial distribution of these elements of River Nile along the distance from Aswan to Giza was also investigated. The present study has shown that extraction using 0.5 N HCI solution provides a rapid, reliable and inexpensive method of measuring environmentally mobile element concentrations or a measure of anthropogenic concentrations of the River Nile sediments. Extraction data obtained revealed a significant level of pollution of the River Nile sediments by Cd, Co, Pb, and Zn. However, for all \ elements studied, the average total concentrations found in the Nile sediments were below the concentrations level in aquatic sediments at which is likely that associated waters may exceed the highest desirable level values for the particular ••element in water. The study has also shown the importance of different sediment characteristics in spatial distribution of heavy elements in the surface sediments of the River Nile.