Complexations of Divalent Metallic Ions with Fulvic Acids
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Abstract
In this work, the interactions of the functional groups of fulvic acids with copper, cadmium and zinc bivalent ions was investigated by potentiometry. The BEST7 software was employed to investigate the interactions of the functional groups. The software SPE and SPEPLOT were used to generate and to plot the species diagrams. It was used the Suwannee River fulvic acid (SRFA) of the IHSS (International Humic Substances Society) to illustrate the process. The values of the proton dissociation and complexation constants with the divalent ions for each functional group were calculated and their values were very close to
those previously published. The functional group present in the highest quantity in the complexes was cathecol, and it complexed with all the divalent ions, although to a greater extent with Cu(II). According to the results obtained by potentiometry, the reactivity series for the divalent ions and the SRFA is: Cu(II) >> Cd(II) > Zn(II). Thus, the method employed could be useful to estimate the role of fulvic acids in the transport of metals in the aquatic environments.
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References
Ephraim, J. H. Heterogeneity as a concept in the interpretation of metal ion binding by humic substances. The binding of zinc by aquatic fulvic acid. Analytica Chimica Acta 267 (1) (1992) 39-45. https://doi.org/10.1016/0003-2670(92)85004-P
Bacstrom, M, Dario, M, Karlsson, S, Allard, B. Effects of a fulvic acid on the adsorption of mercury and cadmium on goethite. Science of the total Environment 364 (1-3) (2003) 257-268. https://doi.org/10.1016/S0048-9697(02)00573-9.
Eprahim J. H., Marinsky, J. A., Cramer, S. J. Complex-forming properties of natural organic acids: fulvic acids complexes with cobalt, zinc and europium. Talanta 36 (4) (1989) 439-443. https://doi.org/10.1016/0039-9140(89)80225-5.
Toxicological Profile for Zinc. National Technical Information Service (NTIS), USA, 1989 142 p.
Nantsis, E. A., Carper, W. R. Molecular Structure of divalent metal-ion-fulvic acids complexes. Journal of Molecular Structure 423 (3) (1998) 203-212. https://doi.org/10.1016/S0166-1280(97)00125-5.
Merabito, E., Radaelli, M, Corami, F., Turella, C., Toscano, G., Copodagliom G. Temporal evolution of cadmium, copper and lead concentration in the Venice lagoon. Water in relation with the speciation and dissolved/particulate partition. Marine Pollution Bulletin (in press). 129 (2) (2018) 884-892. https://doi.org/10.1016/j.marpolbul.2017.10.043.
Wang, F., Xu, S., Zhou, Y., Wang, R., Zhang., Trace elements exposure of whooper swans (Cygnus cygnus) wintering in a marine lagoon (Swan lake), northern China. Marine Pollution Bulletin, 119, (2) (2017) 60-67. https://doi.org/10.1016/j.marpolbul.2017.03.063.
Hernández-Crespo, C., Martín, M. Determination of Background levels and pollution assessment for seven metals (Cd, Cu, Ni, Pb, Zn, Fe, Mn) in sediments of a Mediterranean coastal lagoon. Catena, 133 (2015) 206-214. https://doi.org/10.1016/j.catena.2015.05.013.
Taria, J., Devenport, J., Townley, B., Dorador, C., Schneider, B., Tolorza, V., Von Turnpling W., Sources enrichment and redistribution of As, Cd, Cu, Li, Mo and Sb in the northern Atacama Region Chile: Implications for acid watersheds affected by mining. Journal of Geochemical Exploration, 185 (2018) 33-51. https://doi.org/10.1016/j.gexplo.2017.10.021.
Sargentini Jr., E., Rocha, J. C., Rosa, A. H., Zara, L. F., dos Santos, A. Substâncias Húmicas Aquáticas: Fracionamento molecular e caracterização de rearranjos internos após complexação com íons metálicos. Química Nova, 24, (3) (2001), 339-344. https://doi.org/10.1590/S0100-40422001000300010.
Yan, M., Dryer, D., Karshin, G.V., Benedetti, M.F., In situ study of binding of copper by fulvic acid: comparison of differential absorbance date and model predictions. Water Research, 47, (2), (2013) 588-596. https://doi.org/10.1016/j.watres.2012.10.020.
Vaz, D. O., Fernandes, A. N., Szpoganicz, B; Sierra, M. M. D. Potentiometric quantification and speciation of oxygenated groups in humic substances using Best7 software. Eclét. Quím. 35 (4) (2010) 147-152. https://doi.org/10.1590/S0100-46702010000400019.
Martell, A. E., Smith, R. M. Critical Stability Constants. Plenum Press, Ed., New York, 1st ed. 1982, ch.4.
Martell, A. E., Hancock, R. D. Metal Complexes in Aqueous Solutions, Plenum Publishing Corporation, New York, 1st ed. 1996, ch. 3.