Distribution and chemical fractionation of some heavy metals in bottom sediments of lake Nasser

Twenty-one bottom sediment samples were collected from Nasser lake and the heavy metals cadmium, chromium, cobalt, copper, nickel, lead and zinc extracted and partitioned into 6 fractions by single step leaching procedures. The 6 fractions were extracted by ammonium acetate; sodium acetate; acid oxalate; hydroxylamine hydrochloric acid; aque regia and a hydrofluoric, hydrochloric and nitric acid mixture for total metals. Only small amounts of heavy metals were extracted by ammonium acetate and this fraction was regarded as readily bioavailable as it was the most weakly bound. In the intermediate fractions several geochemical phases had the potential to release associated metals under changing environmental conditions of pH or redox potential. There are 33 references.