at a glance

Presented by the    Universidade Federal Fluminense, the study Geodinâmica de Cádmio e Zinco na Baía de Sepetiba - Geodynamics of Cadmium and Zinc in the bay of Sepetiba, by Christovam Barcellos, The dynamics of cadmium (Cd) and Zinc (Zn) were studied in the Sepetiba Bay, located in the West Zone of the Metropolitan Region of Rio de Janeiro.

The emissions of these metals into the atmosphere, soil and water as a result of the principal activities of economic development in the drainage basin were estimated. Past works pointed towards a severe contamination of the sediments in the bay. Cd tends to accumulate in sediments in the coastal strip, north of the bay.

We noticed a significant enrichment in Cd and Zn in the sediments of the bay in comparison to the sediments in their continental origin. These accumulations can be augmented by cycles of re-suspension/deposition of sediments and production/degradation of organic material in the bay. A comparison of entry flows of metals and of sedimentation showed that the retention by the sediment at the bottom is the principal way to remove the metals from the system.