INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Modeling the AcidBase Surface Properties of Aquatic Sediments
Autor/es:
L. BORGNINO; M. G. GARCIA; M. V. DEL HIDALGO; M. AVENA; C. P. DE PAULI; M. A. BLESA; P. J. DEPETRIS
Revista:
AQUATIC GEOCHEMISTRY
Editorial:
SPRINGER
Referencias:
Año: 2010 p. 1 - 13
ISSN:
1380-6165
Resumen:
We propose a model that explains the acidbase surface properties of clastic
sediments from two Argentinean reservoir lakes. The model uses potentiometric titration
data sets and fixed parameters such as the apparent stability constants and reaction stoichiometries
of acidbase equilibriums involving known mineral phases. The model considers
that sediments act as a set of independent sorption surfaces, such as organic matter,
clay silicate, and iron (hydr)oxides, thus the acidbase equilibrium and the correspondent
protolytic constants are represented by a humic acid, a Na-illite, and a poor crystalline Fehydr(
oxide). In agreement with experimental data, the model predicts that all sediment
samples show a similar charging behavior, increasing the negative charge as the pH
increases. The net charge of sediments is controlled by the presence of negatively charged
minerals and/or organic matter coatings. This reveals the great influence of clays and
organic matter functional groups on the acidbase surface properties of sediments, and
consequently on the surface reactivity toward contaminant transport.
organic matter functional groups on the acidbase surface properties of sediments, and
consequently on the surface reactivity toward contaminant transport.
organic matter functional groups on the acidbase surface properties of sediments, and
consequently on the surface reactivity toward contaminant transport.
organic matter functional groups on the acidbase surface properties of sediments, and
consequently on the surface reactivity toward contaminant transport.