GEOC 145 |
| Tjisse Hiemstra, Department Environmental Sciences, subdepartment Soil Quality, Wageningen University, Dreijenplein 10, 6700 EC Wageningen, Netherlands and W. H. Van Riemsdijk, Department Environmental Sciences, subdepartment Soils Quality, Wageningen University, Dreijenplein 10, 6700 EC Wageningen, Netherlands. |
| Charged innersphere complexes are only partly incorporated in the surface of metal oxides. To account for this in surface complexation modeling, we developed the charge distribution (CD) model. Essential in the approach is the use of physically realistic species as observed with modern in situ spectroscopy. Bond lengths, binding mode and coordination numbers are used in the analysis. In the CD model, the charge of the adsorbed ion is distributed over the ligands. In turn, the ligands are distributed over the interfacial locations, depending on the structure of the surface complex. For many surface complexes of oxyanions, it has been shown that the CD can be assessed from interfacial ligand distribution. At present we will focus on the relation between charge distribution and the detailed structure of adsorbed cations, including the nature of ligands (O, OH,OH2). We have analyzed adsorption data for a series of very important and widely studied cations, comprising Hg2+, Pb2+, Cu2+, Cd2+, Zn2+, UO2+2 and NpO2+.
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Interfacial Phenomena: Linking Atomistic and Macroscopic Properties
8:05 AM-11:30 AM, Wednesday, March 31, 2004 Marriott -- Marquis NW, Oral
Division of Geochemistry |