Adsorption of polar organic molecules on sediments: Case-study on Callovian-Oxfordian claystone

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

“…2 ) 2is then expected above Then the complexation of Th(Cit) + by additional citrate, with a stoichiometry 1:1, would explains the decrease with a slope (-1), as observed at higher concentrations of citrate. This hypothesis is in agreement with sorption values previously measured for citrate on COx clay rock: R d (Citrate / COx) ~ 30-60 L kg -1 (Rasamimanana et al, 2017), as well as multidentate complexes, e.g. Eu-EDTAin the case of europium (Descostes et al, 2017).…”

“…C e (Organic) was then calculated from the initial concentration, C 0 (Organic). To that aim, the sorption of organic compounds on COx clay rock (Rasamimanana et al, 2017) was described by Langmuir Equation:…”

“…The Langmuir sorption parameters used to calculate C e (Organic), i.e. K(Organic/COx) and Q(Organic/COx), are taken from Rasamimanana et al (2017) and gathered in Table S4.…”

Influence of adipic acid on the speciation of Eu(III): Review of thermodynamic data in NaCl and NaClO4 media, and a new determination of Eu-adipate complexation constant in 0.5 mol·kgw−1 NaClO4 medium by time-resolved luminescence spectroscopy

“…As an anion it is likely to adsorb on cementitious minerals [64,65] and compete with anionic radionuclides [66]. In less alkaline media, the adsorption of adipate has recently been shown in the case of the Callovo-Oxfordian claystone in France [67]. Studies on the eventual impact on adsorption of Eu(III) in presence of adipic acid would then be desirable including the formation of ternary surface complex formation [23,68].…”

Mobility of organic compounds in a soft clay-rich rock (Tégulines clay, France)

“…The COx clay rock has been extensively studied in the context of the French Geological Radioactive Waste Disposal (Cigéo project). Corresponding studies investigated the interaction between inorganic or organic solutes and COx clay rock (Descostes et al, 2008;Melkior et al, 2007;Rasamimanana, 2017a;Savoye et al, 2012). Absorption of neutral hydrophobic compounds occurs in NOM (Vinsot et al, 2017), with an eventual contribution from clay minerals (Willemsen et al, 2019).…”