Distribution of acid-volatile sulfides and simultaneously extracted metals in Guanabara Bay: combination of anthropogenic, sedimentological, and geochemical processes.

Coastal sedimentary systems are affected by continental and marine metal pollutant inputs associated with different hydrodynamic characteristics and geochemical processes. These include the formation of acid-volatile sulfides (AVS) within sediments, which affects metal bioavailability and associated aquatic biota toxicity risks. Physicochemical changes in these environments in the face of extreme natural or man-made environmental influences can dramatically alter metal bioavailability and toxicity through metal binding and immobilization as insoluble sulfides.

Combining geochemical and chemometric tools to assess the environmental impact of potentially toxic elements in surface sediment samples from an urban river.

This article investigates sediments collected from the banks of the Subaé River located in Todos os Santos Bay in the state of Bahia, Brazil, in 2018, twenty-five years after the closing of a former lead alloy processing plant. Ten sediment samples were collected at different points of the course of the river and its estuarine region. Chemometric tools were used to determine geochemical correlations between the organic matter content and concentration of sulfides and potentially toxic metals.

Ecological risk evaluation of sediment metals in a tropical Euthrophic Bay, Guanabara Bay, Southeast Atlantic.

Surface sediments were collected from Guanabara Bay, at 14 stations distributed in five sectors, over three sampling campaigns. Analyses of metals, grain size fractions and total organic carbon analyses were performed. The geo-accumulation index and the enrichment factor were estimated to assess contamination status based on background values.