Skip to Main content Skip to Navigation
Journal articles

Remediation of $^{137}$Cs-contaminated concrete gravels by supercritical CO$_2$ extraction

Abstract : The removal of cesium contamination is a critical issue for the recycling of concrete gravel in most decommissioning sites . The high solvent strength and diffusivity of supercritical CO$_2$ make it an attractive choice as vector for extractant system in this context. Experimental extraction runs have been carried out in a radioactive environment on gravels contaminated with $^{137}$Cs. The best extraction system was found to be CalixOctyl (25,27-Bis(1-octyloxy)calix(4)arene-crown-6, 1,3-alternate) with pentadecafluorooctanoic acid as a modifier. The effects of various operating parameters were investigated, namely the coarseness of the gravel, the temperature of SC-CO$_2$, the residual water and initial cesium concentrations, and the amounts of extractant and modifier used. The yields from direct extraction were low (< 30percent), because of the virtually irreversible sorption of Cs in concrete. The best extraction yield of $\sim$55percent was achieved by leaching the concrete gravel with nitric acid prior to supercritical CO$_2$ extraction.
Complete list of metadata

Cited literature [84 references]  Display  Hide  Download
Contributor : Bibliothèque Cadarache <>
Submitted on : Tuesday, November 5, 2019 - 9:25:56 AM
Last modification on : Monday, March 29, 2021 - 2:48:08 PM
Long-term archiving on: : Thursday, February 6, 2020 - 7:51:52 PM


Files produced by the author(s)


  • HAL Id : cea-02339847, version 1



A. Leybros, N. Segond, Agnès Grandjean. Remediation of $^{137}$Cs-contaminated concrete gravels by supercritical CO$_2$ extraction. Chemosphere, Elsevier, 2018, 208, pp.838-845. ⟨cea-02339847⟩



Record views


Files downloads