Available surface complexation models for birnessite required the inclusion of bidentate bonds or the adsorption of cation-hydroxy complexes to account for experimentally observed H/M exchange. These models contain inconsistencies and therefore the surface complexation on birnessite was re-examined. Structural data on birnessite indicate that sorption sites are located on three oxygens around a...

Various chemical models of ion adsorption are presented and discussed. Chemical models, such as surface complexation models, provide a molecular description of anion adsorption reactions using an equilibrium approach. Two such models, the constant capacitance model and the triple layer model, are described in the present study. Characteristics common to all the surface complexation models are e...

In this research, investigation of the adsorption isotherms and the effect of solution conditions such as pH and concentration of complexation of some amino acids with cobalt(II) nitrate six-hydrate upon multi-wall type carbon nanotube (CNT) were done. The adsorption capacity of complexation of amino acids onto the surface of carbon nanotube increased with the pH from acidic to alkaline. At pH ...

Adsorption is the net accumulation of a chemical species at the interface between a solid phase and an aqueous solution phase, leading to a loss from the solution phase (Sposito, 1989). Adsorption reactions can be described by various models. Empirical models provide descriptions of adsorption data without theoretical basis. Examples are the distribution coefficient, the Freundlich adsorption i...

Advances in Agronomy, Volume 90 Copyright 2006, Elsevier Inc. All rights reserved. 0065-2113/06 $35.00 DOI: 10.1016/S0065-2113(06)90005-4 II. M echanistic Studies of Cell Wall Adsorption A . P artitioning Relationships Versus Surface Complexation Modeling B . C onstraints on Bacterial Cell Wall‐Protonation Reactions C . C onstraints on Mechanisms of Metal Adsorption onto Bacteria I II. C hallen...

Previous research has shown that adsorption of many inorganic anions on soil mineral surfaces can be described equally well by chemical surface complexation models using either inneror outer-sphere surface complexes. At the same time, goodness of fit of these models to adsorption data has been used to distinguish between innerand outer-sphere adsorption mechanisms. In this study the ability of ...

In the presence of iron (Fe), dissolved organic matter (DOM) may bind considerable amounts of arsenic (As), through formation of Fe-bridged As-Fe-DOM complexes and surface complexation of As on DOM-stabilized Fe-colloids (collectively referred to as As-Fe-DOM complexation). However, direct (e.g., chromatographic and spectroscopic) evidence and fundamental kinetic and stability constants have be...