Nile River sediments

Averages for the 27 bulk samples are given in Table II for some of the elements measured. These averages, called Nile River Sediment Composite (NRSC), are very similar to the averages for modern Nile sediments compiled by Tobia and Sayer (2). This similarity clearly confirms that, other than the variations due to grain size (sand content), the modern Nile silts are quite uniform in composition. 

The Nile River provides a good example of the similarities and differences between sediments from the same river. The common origin of these Nile sediments is confirmed by the high degree of correlation in the elemental compositions between different Egyptian Nile sediment samples (2). 

In most areas of the wadi floor and the low desert area, the Nubian formation is covered by an average of 5-7 m of Pleistocene Nile silts (9). These older Nile sediments represent different episodes in the evolution of the Nile River (10-13), The oldest Nile sediments (called Protonile) in the area, exposed at high (about 125 m above sea level) Pleistocene terraces, were deposited during the Lower to Middle Paleolithic period (10). 

The Greek historian Herodotus coined the term delta for the landform where the Nile river flows into the Mediterranean Sea the sediment deposited at the river s mouth has the shape of the upper-case Greek letter A. 

China, the Colorado in the United States, and the Nile in Africa, are only some of the most famous examples. The construction of dams along these rivers allows flood control, and water for irrigation and power, but the retention of sediment behind the dams severely impacts some of the richest and most productive ecosystems in the world. 

Biodegradation aerobic t,/2 = 80-240 d for 1 pg/mL to biodegrade in sediment-water and anaerobic t,/2 > 650 d for 1 pg/mL to biodegrade in sediment-water both at 25°C (Muir Yarechewski 1982 quoted, Muir 1991). biological degradation rate followed a first order kinetics, with t,/2 = 8.9-18.2 d by raw water microflora from Rivere Nile, t,/2 = 4.0-6.9 d by raw water micro flora + sewage (El-Dib Abou-Waly 1998) Biotransformation ... 

Nilotic sediments were sampled across the river from Hierakonpolis from the Nekheb formation at El-Kab (78.5-80 m above sea level), which was thought to have been deposited beginning about 11,000 years ago (15). In addition, a series of 27 Nilotic sediments were collected from along a 350-km stretch of the Nile Valley in Upper Egypt. Because the Nile sedi-... 

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