1. Metal Binding and Sources of Humic Substances in Recent Sediments from the Cananéia-Iguape Estuarine-Lagoon Complex (South-Eastern Brazil)
- Author
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Stefano Covelli, Marco Contin, Christian Millo, Elisabete de Santis Braga, Matteo Crosera, Elisa Petranich, Carlo Bravo, Maria De Nobili, Elena Pavoni, Bruno Otero Sutti, Camila das Mercês Silva, Millo, C., Bravo, C., Covelli, S., Pavoni, E., Petranich, E., Contin, M., De Nobili, M., Crosera, M., Otero Sutti, B., Das Merces Silva, C., and Braga, E. S.
- Subjects
Technology ,QH301-705.5 ,QC1-999 ,Fulvic acid ,Drainage basin ,stable isotopes ,Trace metal contamination ,Sedimentary organic matter ,General Materials Science ,Organic matter ,Trace metal ,fulvic acids ,Biology (General) ,QD1-999 ,Instrumentation ,Fluid Flow and Transfer Processes ,chemistry.chemical_classification ,geography ,geography.geographical_feature_category ,Stable isotope ratio ,Physics ,Process Chemistry and Technology ,General Engineering ,Estuary ,Fulvic acids ,Humic acids ,Stable isotopes ,Engineering (General). Civil engineering (General) ,Stable isotope ,Computer Science Applications ,humic acids ,Chemistry ,chemistry ,Humic acid ,Isotopes of carbon ,Environmental chemistry ,TA1-2040 ,Mangrove ,trace metal contamination ,OCEANOGRAFIA - Abstract
The Cananéia-Iguape estuarine–lagoon complex (São Paulo state, Brazil) is a natural laboratory to study metal binding by humic substances (HS) in subtropical settings. This transitional environment is evolving into a freshwater environment due to water input from the Ribeira River, funneled through the Valo Grande Canal (Iguape). Past mining activities in the Ribeira River basin and maritime traffic are suspected to be potential sources of trace metals in the system. In this study, the trace metal contents of Free Humic Acids (FHA), Bound Humic Acids (BHA), and Fulvic Acids (FA) extracted from sedimentary organic matter were investigated. Moreover, the sources of HS were traced using their stable carbon isotope compositions and C/N ratios. The results suggested a mixed marine–terrestrial source of FHA, BHA, and FA. Copper and Cr were the most abundant trace metals bound to HS. On average, Cu showed concentrations of 176, 115, and 37.9 μg g−1 in FHA, BHA, and FA, respectively, whereas Cr showed average concentrations of 47.4, 86.3, and 43.9 μg g−1 in FHA, BHA, and FA, respectively. Marine FHA showed the highest binding capacity for trace metals, whereas terrestrial FA derived from the decay of mangrove organic matter showed the lowest binding capacity.
- Published
- 2021
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