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Reference : UMR7178-JEASCH2-003
Workplace : STRASBOURG
Date of publication : Thursday, August 01, 2019
Scientific Responsible name : mireille del nero
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 16 September 2019
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
The study will be performed in the framework of the European Programme JOPRAD (Joint Programming on Radioactive Waste Disposal). Gaining new insights into mechanisms and species of uranyl sorption and desorption at the compacted clay – solution interface, at a realistic and low concentration of uranyl in the range of the micromole per liter, is highly needed for providing refined mechanistic process understanding of radionuclide transport / retention in clay systems. Moreover, studying uranyl sorption reversibility and competitive processes due to the presence of multiple aqueous ligand and trace metal elements is mandatory for the transferability of experimental results on radionuclide behavior to “the real system”. The aim of the PhD fellowship is to contribute at the highest scientific and technical level to acquiring surface spectroscopic evidence on the mechanisms and species involved in the sorption / mobility of low concentration of uranyl in compacted clay systems as Opalinous clay and Callovo-Oxfordian clay (COX) by using a highly advanced surface spectroscopy technique, namely Attenuated Total Reflexion Fourier Transform Infrared Spectroscopy (ATR-FTIR) coupled with Coherence Probe Microscopy. The work will address the species and mechanisms taking place along the sorption / desorption process of uranyl at the compacted clays –solution interfaces, in the presence of competitive trace metals (Ni and Fe) and relevant aqueous ligands (phosphate ligands or small organic molecules), by means of ATR-FTIR monitoring of the interface during sorption experiments. Experiments of uranyl sorption will also be performed by using hematite-solution systems (to mimic potential formation of iron oxide layer at the clay-solution interface). Complementary analyses of the (initial and final) experimental solutions in contact with Opalinous and COX clays and hematite are envisaged by use of an advanced mass spectrometry technique, namely Electrospray Ionisation Fourier transform Mass Spectrometry (ESI-FTMS).
Keywords: molecular structure of surface complexes, spectroscopies, uptake mechanisms, sorption reversibility and competitive sorption.
The candidate should be chemist, physico-chemist or radiochemist with ability to conduct experimental work and spectroscopic analyses.
Rémi Barillon (firstname.lastname@example.org)
Mireille Del Nero (Mireille.email@example.com)
The job is to be provided inside the radiochmistry group of IPHC. The radiochemistry group counts about fifteen permanent staff (researchers, engineers and professors).
Constraints and risks
Contraintes habituelles d'un laboratoire de chimie
usual constraints of a chemistry lab
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