Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Sorption of Eu(III) on a natural hematite: Application of a surface complexation model

Journal Article · · Journal of Colloid and Interface Science
;  [1]; ;  [2]
  1. Univ. des Saarlandes, Saabruecken (Germany). Anorganische und Analytische Chemie und Radiochemie
  2. Forschungszentrum Karlsruhe (Germany). Inst. fuer Nukleare Entsorgungstechnik
The solid/water interface reaction is investigated for the sorption of the Eu{sup 3+} ion onto a well-characterized natural hematite at pH {le} 6 in 0.1 mol/L NaClO{sub 4}. Sorption isotherms are determined at different pH. The sorption of Eu{sup 3+} onto hematite at coverages <1% of the surface hydroxyl groups follows the ideal Nernst behavior and can be interpreted in terms of the surface complexation by the following equilibrium reaction: {triple_bond}XOH + EU{sup 3+} {leftrightarrow} {triple_bond}XOEu{sup 2+} + H{sup +} (log K{sub x}{sup int} = 2.50 {+-} 0.19). Complexation constants are calculated by either graphically interpreting the sorption isotherms or fitting the data using the code FITEQL. At higher surface coverages a deviation from the Nernst behavior is observed which can be described satisfactorily by a two-site surface complexation model, taking into account the lateral electrostatic interaction of surface-bound Eu(III): {triple_bond}YOH + Eu{sup 3+} {leftrightarrow} {triple_bond}YOEu{sup 2+} + H{sup +} (log K{sub y}{sup int} = {minus}0.82 {+-} 0.11). The experimental results are compared with data published in the literature, and the interpretation of sorption isotherms with regard to the sorption mechanisms is critically discussed.
OSTI ID:
316293
Journal Information:
Journal of Colloid and Interface Science, Journal Name: Journal of Colloid and Interface Science Journal Issue: 1 Vol. 208; ISSN 0021-9797; ISSN JCISA5
Country of Publication:
United States
Language:
English

Similar Records

Measurement and modeling of Th sorption onto TiO{sub 2}
Journal Article · Tue Dec 14 23:00:00 EST 1999 · Journal of Colloid and Interface Science · OSTI ID:20013631

Effect of salicylic acid upon trace-metal sorption (Cd, Zn, Co, and Mn) onto alumina, silica, and kaolinite as a function of pH
Journal Article · Sat May 01 00:00:00 EDT 1999 · Environmental Science and Technology · OSTI ID:354341

The effect of the ionic strength on the adsorption isotherms of nickel on silica
Journal Article · Sun Jun 01 00:00:00 EDT 1997 · Journal of Colloid and Interface Science · OSTI ID:514741