REMOBILIZATION OF ANTHROPOGENIC COPPER DEPOSITED IN SEDIMENTS OF A TROPICAL ESTUARY

A four-step chemical extraction was applied to sediment cores from a h eavily polluted area in Guanabara Bay, Rio de Janeiro. The results sho w that a pronounced change in the proportions of remobilisable copper occurred from the time previous to the local industrialisation (after 1955) to the present. A predominant fraction of the anthropogenic copp er was remobilised after treatment with mild reagents. Extractions usi ng EDTA solutions were able to recover up to 70% of the total copper i n the sediments. Indications were found that estuarine particles (iron oxo-hydroxides, algae, etc.) are responsible for the transport of the anthropogenic copper to the sediments.