Chemical forms of copper, zinc, lead and cadmium in sediments of the northern part of the Red Sea, Egypt

Total concentrations and chemical forms of heavy metals in sediment samples from the Gulf of Suez and the northern part of the Red Sea, collected during January 2003, were determined by atomic absorption spectrometry. Maximum concentrations of 49.56, 65.42, 33.52 and 3.52 µg/g were recorded for total Cu, Zn, Pb and Cd respectively at Adabiya location. These may reflect the high contribution of land-based activities in the northern part of the Gulf. Also, high percentages of heavy metals were found in the residual fraction (Cu=78.61, Zn=77.10 and Pb=66.80%) while a high percentage of Cd was found in the carbonate fraction (45.82%). However, few or negligible percentages were recorded in the exchangeable fractions (Cu=0.51, Zn=1.57 and Pb=1.74%). Concentration of Cd in the exchangeable fraction was too low to be detected.

Trace metal (Cu, Zn, Pb, Cr and Cd) concentrations of three subfractions of organic matter from Lake Mariut sediments, Egypt

Trace elements associated with organic subfractions (humic, fulvic, and non-humic substances) were identified for seven core sediments from Lake Mariut, Egypt. Results indicated that the amounts of trace metals in humic acid and non-humic substances decreased in the following order: Zn>Cu>Pb>Cr>Cd, while in fulvic acid the order the order was Cu>Zn>Pb>Cr>Cd. There is a higher contribution of Zn, Pb, Cu and Cr in humic acid compared to fulvic acid in most samples. Slight changes in the amounts of cadmium bounded with humic and fulvic acids was also found.