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Complexation reactions in aquatic systems : an analytical approach / J. Buffle, translators S.P. Kounaves, A. Kounaves and R.S. Altman

01 Jan 1990-Vol. 1990, Iss: 1990, pp 1-99
About: The article was published on 1990-01-01 and is currently open access. It has received 812 citations till now.
Citations
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Journal ArticleDOI
TL;DR: The WHAM (Windermere Humic Aqueous Model) as mentioned in this paper is a simple inorganic speciation code for aqueous solutions that combines Humic Ion-Binding Model V with a simple, inorganic inorganic specciation code.

834 citations

Journal ArticleDOI
TL;DR: The NICCA-Donnan model as mentioned in this paper is a semi-empirical model that is similar to the NICA-donnan model except that it introduces an additional degree of scaling that ensures thermodynamic consistency and allows for variable stoichiometry of binding, which implicitly accounts for the large degree of chemical heterogeneity of humic particles.

775 citations

Journal ArticleDOI
TL;DR: Model V describes the binding of ions by humic substances in terms of complexation at discrete sites, modified by electrostatic attraction and/or repulsion, and also takes account of nonspecific binding due to counterion accumulation.

622 citations

Journal ArticleDOI
TL;DR: In this article, the physicochemical properties of the different groups of colloids are described, and the role of each colloid class is discussed with respect to homoaggregation (aggregation within a given colloid) and hetero-aggregation among different colloid types.
Abstract: This paper describes several possible interactions among the different types of organic and inorganic aquatic colloids, based on our present knowledge of their size, electric charge, and conformation. The physicochemical properties of the different groups of colloids are described. Emphasis is placed on the various types of organic components, including fulvic compounds. Subsequently, the role of each colloid class is discussed with respect to homoaggregation (aggregation within a given colloid class) and heteroaggregation (aggregation among different colloid types). On the basis of a synthesis of literature reports, microscopic observations of natural colloids, experimental results obtained with model systems, and numerical simulations, it is concluded that the formation of aggregates in aquatic systems can be understood by mainly considering the roles of three types of colloids: (i) compact inorganic colloids; (ii) large, rigid biopolymers; and (iii) either the soil-derived fulvic compounds or their eq...

576 citations

Journal ArticleDOI
01 Mar 2006
TL;DR: The pH-dependent adsorption of humic acid (HA) on magnetite and its effect on the surface charging and the aggregation of oxide particles were investigated and nanoparticles are stabilized in a way of combined steric and electrostatic effects.
Abstract: The pH-dependent adsorption of humic acid (HA) on magnetite and its effect on the surface charging and the aggregation of oxide particles were investigated. HA was extracted from brown coal. Synthetic magnetite was prepared by alkaline hydrolysis of iron(II) and iron(III) salts. The pH-dependent particle charge and aggregation, and coagulation kinetics at pH approximately 4 were measured by laser Doppler electrophoresis and dynamic light scattering. The charge of pure magnetite reverses from positive to negative at pH approximately 8, which may consider as isoelectric point (IEP). Near this pH, large aggregates form, while stable sols exist further from it. In the presence of increasing HA loading, the IEP shifts to lower pH, then at higher loading, magnetite becomes negatively charged even at low pHs, which indicate the neutralization and gradual recharging positive charges on surface. In acidic region, the trace HA amounts are adsorbed on magnetite surface as oppositely charged patches, systems become highly unstable due to heterocoagulation. Above the adsorption saturation, however, the nanoparticles are stabilized in a way of combined steric and electrostatic effects. The HA coated magnetite particles form stable colloidal dispersion, particle aggregation does not occur in a wide range of pH and salt tolerance is enhanced.

504 citations


Cites background from "Complexation reactions in aquatic s..."

  • ...Therefore, DOM has a great influence on the surface charge of the mineral particles, and not only the dissolved salts and the pH of solutions, but also the presence of charged macromolecules, such as humic substances affect the colloidal state of composite mineral dispersions of clays and metal oxides [1–5, 14]....

    [...]

  • ..., clay and metal oxide) particles [1–5]....

    [...]

References
More filters
Journal ArticleDOI
TL;DR: The WHAM (Windermere Humic Aqueous Model) as mentioned in this paper is a simple inorganic speciation code for aqueous solutions that combines Humic Ion-Binding Model V with a simple, inorganic inorganic specciation code.

834 citations

Journal ArticleDOI
TL;DR: The NICCA-Donnan model as mentioned in this paper is a semi-empirical model that is similar to the NICA-donnan model except that it introduces an additional degree of scaling that ensures thermodynamic consistency and allows for variable stoichiometry of binding, which implicitly accounts for the large degree of chemical heterogeneity of humic particles.

775 citations

Journal ArticleDOI
TL;DR: The Dynamic Green Ocean Model (DGOM) as mentioned in this paper is based on the identification of key plankton functional types that need to be simulated explicitly to capture important biogeochemical processes in the ocean, and sources of information necessary to parameterize each of these processes within a modeling framework.
Abstract: Ecosystem processes are important determinants of the biogeochemistry of the ocean, and they can be profoundly affected by changes in climate. Ocean models currently express ecosystem processes through empirically derived parameterizations that tightly link key geochemical tracers to ocean physics. The explicit inclusion of ecosystem processes in models will permit ecological changes to be taken into account, and will allow us to address several important questions, including the causes of observed glacial-interglacial changes in atmospheric trace gases and aerosols, and how the oceanic uptake of CO2 is likely to change in the future. There is an urgent need to assess our mechanistic understanding of the environmental factors that exert control over marine ecosystems, and to represent their natural complexity based on theoretical understanding. We present a prototype design for a Dynamic Green Ocean Model (DGOM) based on the identification of (a) key plankton functional types that need to be simulated explicitly to capture important biogeochemical processes in the ocean; (b) key processes controlling the growth and mortality of these functional types and hence their interactions; and (c) sources of information necessary to parameterize each of these processes within a modeling framework. We also develop a strategy for model evaluation, based on simulation of both past and present mean state and variability, and identify potential sources of validation data for each. Finally, we present a DGOM-based strategy for addressing key questions in ocean biogeochemistry. This paper thus presents ongoing work in ocean biogeochemical modeling, which, it is hoped will motivate international collaborations to improve our understanding of the role of the ocean in the climate system.

754 citations

Journal ArticleDOI
TL;DR: Model V describes the binding of ions by humic substances in terms of complexation at discrete sites, modified by electrostatic attraction and/or repulsion, and also takes account of nonspecific binding due to counterion accumulation.

622 citations

Journal ArticleDOI
TL;DR: In this article, the physicochemical properties of the different groups of colloids are described, and the role of each colloid class is discussed with respect to homoaggregation (aggregation within a given colloid) and hetero-aggregation among different colloid types.
Abstract: This paper describes several possible interactions among the different types of organic and inorganic aquatic colloids, based on our present knowledge of their size, electric charge, and conformation. The physicochemical properties of the different groups of colloids are described. Emphasis is placed on the various types of organic components, including fulvic compounds. Subsequently, the role of each colloid class is discussed with respect to homoaggregation (aggregation within a given colloid class) and heteroaggregation (aggregation among different colloid types). On the basis of a synthesis of literature reports, microscopic observations of natural colloids, experimental results obtained with model systems, and numerical simulations, it is concluded that the formation of aggregates in aquatic systems can be understood by mainly considering the roles of three types of colloids: (i) compact inorganic colloids; (ii) large, rigid biopolymers; and (iii) either the soil-derived fulvic compounds or their eq...

576 citations