Tonha M. S. auteur aut IRD Garnier J. auteur aut IRD Araujo D. F. auteur aut IRD Cunha B. C. A. auteur aut IRD Machado W. auteur aut IRD Dantas E. auteur aut IRD Araujo R. auteur aut IRD Kutter V. T. auteur aut IRD Bonnet Marie-Paule auteur aut IRD Seyler Patrick auteur aut IRD text journalArticle eng text/pdf born digital access The contamination of coastal environments by metallurgical wastes involves multiple biogeochemical processes; accordingly, understanding metal behavior and risk evaluation of contaminated areas, such as Sepetiba Bay (Rio de Janeiro. Brazil), remains challenging. This study coupled Zn isotopic analyses with sequential extractions (BCR) to investigate the mechanisms of Zn transfer between legacy electroplating waste and the main environments in Sepetiba Bay. This metallurgical waste showed a light bulk isotopic signature (delta(66/64) Znbulk(JMC )= +0.30 +/- 0.01 parts per thousand 2 s, n = 3) that was not distinct from the lithogenic geochemical baseline, but was different from signature of mangrove sediment considered as anthropogenic end member (delta(66/64) Zn-JMC = +0.86 +/- 0.15 parts per thousand) in a previous isotopic study in this area. Zn isotopic compositions of sediment samples (ranging from +0.20 to +0.98 parts per thousand) throughout the bay fit a mixing model involving multiple sources, consistent with previous studies. In the metallurgic zone, the exchangeable/carbonate fraction (ZnF1) exhibited high Zn concentrations (ZnF1 9840 mu g g(-1)) and a heavy isotopic composition (delta(66/64) ZnF1(JMC) = +1.10 +/- 0.01 parts per thousand). This finding showed that, in some cases, the bulk isotopic signature of waste is not the most relevant criterion for evaluating trace metal dispersion in the environment. Indeed, based on the BCR. it was observed that part of the anthropogenic metallurgical Zn was redistributed from the exchangeable/carbonate fraction in the waste to the surrounding mangrove sediment. Then, this contaminated sediment with heavy delta(66/64) Zn values was exported to other coastal environments. In Sepetiba Bay, contaminated sediments revealed a large concentration of ZnF1 fraction (up to 400 mu g g(-1)) with a heavy Zn isotopic signature. This signature also matched the Zn isotopic signature of oysters in Sepetiba Bay reported by other studies; hence, measurement of the isotopic exchangeable/carbonate fraction has important implications for tracing the transfer of anthropogenic Zn to biota. specialized Zinc isotopes Sequential extraction Zinc speciation Bioavailability Metallurgical wastes Coastal environment BRESIL RIO DE JANEIRO SEPETIBA BAIE 064 038 036 743 140610 [14 p.] 2020 0048-9697 https://www.documentation.ird.fr/hor/fdi:010079776 10.1016/j.scitotenv.2020.140610 0048-9697 [F B010079776] https://www.documentation.ird.fr/hor/fdi:010079776 https://www.documentation.ird.fr/intranet/publi/2020/10/010079776.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2020-11-12 2025-02-24 fdi:010079776 fre