Effects of organic acids on Eu(III) sorption on Na-bentonite

Abstract

Sorption of Eu(III) on Na-bentonite dispersed in sodium chloride media was studied as a function of pH via batch-type experiments. The sorption was found increased with the increasing pH. The sorption kinetics of Eu(III) on Na-bentonite in the absence and presence of different organic acids were described by pseudo-secondorder model at pH 6.0 ± 0.1. The effects of different types of organic acids on the sorption of Eu(III) to Na-bentonite were extensively investigated. It was found that the concentration ratio of Eu(III) to ligand is a critical factor to the effect of an organic acid on Eu(III) sorption.

Effect of organic compounds on the retention of radionuclides in clay rocks: Mechanisms and specificities of Eu(III), Th(IV), and U(VI)

“…The corresponding speciation is provided in Table S4. The sorption isotherms display a plateau at low organic concentrations followed by a decrease due to the complexation above a so-called "concentration edge" (Tits et al, 2005;Guo et al, 2015). The concentration edges are representative of the strength of the complexation of Eu(III) by the organic compounds, i.e.…”