Fatores Que Afetam a Biodisponibilidade De Contaminantes Metálicos Em Sedimentos Superficiais Da Baía De Sepetiba, Rio De Janeiro, Brasil

Increase in the bioavailability of trace metals after sediment resuspension

“…The Cu concentrations increased 170.2%, and this expressive change could be related to the lower pH after 24 h of resuspension (Spearman, p < 0.05). This increase is in agreement with another findings described by Machado and coworkers [31], which evaluated the geochemical behavior of Cu in sediments from Guanabara Bay-RJ (Brazil), by Monte and coworkers [37], for sediments from Sepetiba Bay-RJ (Brazil) and by Morse [38], in experiments with sediments from Galveston Bay (Texas, USA), where the oxidative process of authigenic sedimentary pyrite was responsible for As, Hg and Cu release.…”

“…Significant differences for these metals were observed only between the central and external sectors (Kruskal-Wallis, p < 0.05). In comparison with the previous works, the bioavailable concentrations of Ni are higher than the range described by Monte et al [37] (0.63-1.48 mg kg −1 )-that used the same methodology as the present study-for Engenho Creek; and lower than the described by Rodrigues et al [46,48,49] (2.43-3.54 mg kg −1 ), that used a stronger extraction (6 mol L −1 HCl extraction), for Itaguaí Harbor, both in the Sepetiba Bay. However, according to these authors, the occurrence of Ni at the region appears to be natural, being similar to background concentrations.…”

“…In Brazil, Machado et al [31] studying the potential mobility of Cu in surface sediments of Guanabara Bay, Rio de Janeiro State, Monte et al [36] studying the bioavailability of Zn and Cd in contaminated sediments and Monte et al [37] studying on the bioavailability of potentially toxic trace metals (Cu, Ni and Pb), both from the Engenho Creek, Sepetiba Bay, RJ, through resuspension tests, verified an increase in the concentrations of these metals in the bioavailable fraction in the sediments after the test. Rodrigues et al [46,48,49], in a study with sediment profiles from Sepetiba Bay, RJ, verified that independently of the depth, there was a significant change in the physical-chemical conditions of the water and in the total organic carbon contents of the sediments after resuspension, which influenced the increase in the bioavailability of the Cd.…”