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J.C.M. de Wit

Bio: J.C.M. de Wit is an academic researcher. The author has contributed to research in topics: Proton binding & Ion binding. The author has an hindex of 14, co-authored 22 publications receiving 2197 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the charging behavior of metal (hydr)oxides has been investigated at the solid/solution interface of various types of O(H) and OH(H), which differ in the number of coordinating metal ions.

740 citations

Journal ArticleDOI
01 Aug 1994
TL;DR: Saar and Weber as discussed by the authors proposed an analytical competitive binding equation for heterogeneous surfaces based on a non-ideal local isotherm equation, which includes both lateral interactions and component-specific heterogeneity contributions.
Abstract: Adsorption on heterogeneous surfaces may be influenced not only by the heterogeneity but also by lateral interactions. For multicomponent solutions competition increases the complexity even further. In practice such complex systems frequently occur and to investigate the behavior of these systems it is rather useful to have analytical equations available which can describe the adsorption. Existing analytical mono- and multicomponent binding equations for heterogeneous surfaces are briefly reviewed. These equations are based on a high degree of ideality with respect to both the local isotherm and the affinity distribution for the different components. A new more generally valid analytical competitive binding equation is derived, using a nonideal local isotherm equation. In this local isotherm all component-specific nonideality is incorporated; i.e., it includes both lateral interactions and component-specific heterogeneity contributions. Under these conditions the remaining adsorbate-surface interactions can be characterized by an "intrinsic" affinity distribution that applies for all components. The features of the new equation are discussed and illustrated on the basis of some model calculations. The model is tested in practice using cadmium ion binding to fulvic acid at various pH values (data of Saar and Weber, Can. J. Chem. 57, 1263, 1979). These data cannot be modeled satisfactorily with the classical equation for multicomponent adsorption on heterogeneous surfaces. The newly derived equation gives excellent results.

302 citations

Journal ArticleDOI
TL;DR: In this paper, a first-order approach was proposed to model organic matter molecules as an ensemble of small rigid and impermeable cylindrical or spherical particles of a certain size and a variable surface charge density depending on pH and salt concentration.
Abstract: Ion binding to humic substances is influenced by the chemical heterogeneity and by the variable charge behavior of the humics. In this paper, we concentrate on the variable charge effects. To study these effects, acid/base titration data of 11 humic substances measured at a series of salt levels are analyzed. In a first-order approach, the organic matter molecules are treated as an ensemble of small rigid and impermeable cylindrical or spherical particles of a certain size and a variable surface charge density depending on pH and salt concentration. With double-layer models for such particles, the electrostatic effects on the proton binding can be described reasonably well. When the density of the humic material is used as a constraint, the radius of the spheres or the cylinders is the only adjustable parameter in the model

169 citations

Journal ArticleDOI
TL;DR: In this paper, the authors collected potentiometric titration data for a purified peat humic acid (PPHA) over a range of pH (pH 3.5-10.5) and KNO3 background electrolyte concentrations (0.001-0.3 M).

167 citations

01 Jan 1996
TL;DR: In this article, a comprehensive study on interactions between livestock production systems and the environment is presented, where the management of waste from animal product processing is the main subject of the study.
Abstract: Comprehensive study on interactions between livestock production systems and the environment. Management of waste from animal product processing is the main subject

162 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors present a review of the state-of-the-art in isotherm modeling, its fundamental characteristics and mathematical derivations, as well as the key advance of the error functions, its utilization principles together with the comparisons of linearized and nonlinearized isotherms models have been highlighted and discussed.

5,914 citations

Book
01 Jan 1971
TL;DR: In this paper, Ozaki et al. describe the dynamics of adsorption and Oxidation of organic Molecules on Illuminated Titanium Dioxide Particles Immersed in Water.
Abstract: 1: Magnetic Particles: Preparation, Properties and Applications: M. Ozaki. 2: Maghemite (gamma-Fe2O3): A Versatile Magnetic Colloidal Material C.J. Serna, M.P. Morales. 3: Dynamics of Adsorption and Oxidation of Organic Molecules on Illuminated Titanium Dioxide Particles Immersed in Water M.A. Blesa, R.J. Candal, S.A. Bilmes. 4: Colloidal Aggregation in Two-Dimensions A. Moncho-Jorda, F. Martinez-Lopez, M.A. Cabrerizo-Vilchez, R. Hidalgo Alvarez, M. Quesada-PMerez. 5: Kinetics of Particle and Protein Adsorption Z. Adamczyk.

1,870 citations

Journal ArticleDOI
01 Sep 2004
TL;DR: Empirical and mechanistic model approaches for heavy metal adsorption and parameter determination in such models have been reviewed and Sorption mechanisms in soils, the influence of surface functional groups and surface complexation as well as parameters influencing adsorbption are discussed.
Abstract: The article focuses on adsorption of heavy metal ions on soils and soils constituents such as clay minerals, metal (hydr)oxides, and soil organic matter. Empirical and mechanistic model approaches for heavy metal adsorption and parameter determination in such models have been reviewed. Sorption mechanisms in soils, the influence of surface functional groups and surface complexation as well as parameters influencing adsorption are discussed. The individual adsorption behavior of Cd, Cr, Pb, Cu, Mn, Zn and Co on soils and soil constituents is reviewed.

1,698 citations

Journal ArticleDOI
TL;DR: Criteria for choosing the optimum isotherm model is established through a critical review of different adsorption models and the use of various mathematically error functions such as linear regression analysis, nonlinear regressionAnalysis, and error functions for adsorption data optimization.

1,151 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present theories describing colloid mobilization, deposition, and transport, laboratory experiments in model systems designed to test these theories, and applications of these theories to colloid-facilitated transport experiments in natural groundwater systems.

1,145 citations