PhD position in geochemistry: Characterizing Rare Earth Elements interactions with oxide mineral surfaces
SOLEIL is the French national synchrotron facility, located on the Saclay Plateau near Paris. It is a multi-disciplinary instrument and a research laboratory, whose mission is to run research programs using synchrotron radiation, to develop state-of-the-art instrumentation on the beamlines, and to make those available to the scientific community. SOLEIL, a unique tool for both academic research and industrial applications across a wide range of disciplines including physics, biology, chemistry etc., is used by over 5 000 researchers coming from France and abroad. It is based on a state-of-the-art synchrotron source, both in terms of brilliance and stability. The facility is a “public” company employing about 500 people, founded by the CNRS and the CEA, and partner of the Paris-Saclay University.
The proposed thesis project aims at contributing to the understanding and prediction of REE behavior in soil systems. In this topic, it will combine field investigations on an ancient mining site with sample synthesis and characterization to feed into predictive modelling of REE transfers. The work will focus on the characterization of REE interactions with mineral oxide surfaces through two representative REE Neodymium (Nd) and Samarium (Sm) as they enter into permanent magnet composition (NdFeB and SmCo), which demand is increasing for green energy technology; Sm being a REE with two oxidation states. Relevant mineral surfaces of Fe/Al oxides will be selected as model, according to the mineral composition of the old mine field studied. REE – surface interactions (including adsorption and coprecipitation) under various physico-chemical conditions (pH, redox, T, concentration, etc.) and sorbing phases ageing will be characterized using Surface-XAS and Resonant XPS. Emphasis on advanced X-ray absorption and diffraction techniques such as HERFD-XANES and Bragg-CDI will be made for this application. The results will be applied to field systems and serve as inputs in transport models
Presentation of the research project (cooperative aspect)
This PhD position is within the framework of a European ITN project named PANORAMAM: EuroPean trAining NetwOrk on Rare eArth elements environMental trAnsfer: from rock to human involving 15 PhD positions.
Under the supervision of Dr D. Vantelon, the PhD student will perform.
(1) Field investigations on an ancient mining site
(2) Synthesis of representative REE – mineral oxides interactions systems (i.e Nd and Sm on Fe/Al oxides, as a function of various physico-chemical conditions of formation)
(3) Characterization of oxides structures and REE-surfaces interactions
(4) Surface interactions modelling
(5) Implementation of predictive models for REE behavior in environmental systems
The project involves two strong collaborations with (1) the Instituto Superior Técnico and the Empresa de Desenvolvimento Mineiro for fieldwork and rock sampling in Portugal including required research stays (secondment) during 2 months and (2) the Geosciences Rennes Laboratoryfor preparation and synthesis of the samples.
Chemical, mineral and structural characterization of the samples will be performed at synchrotron SOLEIL
The PhD student will be also involved in scientific/soft-skills meetings and in research activities conducted in other laboratories/companies from Europe and associated countries.
An important component of the training will be the participation to 3 main major training events:
WS1-(December 2020) REE as emerging contaminants: Properties, uses and dissemination –Germany-fundamental REE biogeochemistry and currently known anthropogenic REE inputs into the environment
SS1 (May 2021) – AMD and REE contamination mitigation – Portugal-Management and remediation solutions of AMD in old mining areas and Management of WEEE, recycling areas
WS2 – Colloids and nanoparticles as REE vectors
France Structural characterization of colloids and nanoparticles by innovative and fine spectroscopic and scattering techniques: X-Ray absorption fluorescence and scattering, light scattering. REE interactions with bearing phases.
SS2 – (Eco)toxicology of REE –Germany- Eco)toxicological concepts and approaches, Physico-chemical properties of REE for bioavailability, ecotoxicity and environmental risk
In addition to these major milestones of the program, the PhD students will 1) continuously develop their core research skills via their own research project locally and within the network while at secondments and conferences, 2) receive a mandatory amount of hard and soft-skills training specific to their own doctoral school, along with mentoring by joint supervising bodies, 3) use conferences both as dissemination events for ESRs results and network events for progress reports and evaluations, and 4) collaborate into practical activities aimed at network-structuring legacy deliverables.
PANORAMA’s research objective is to elucidate the man-induced environmental dissemination of REE and the associated effects on the environmental health. For that purpose, interdisciplinary approaches are required combining geochemistry, ecotoxicology, hydrology, chemical analysis and coupling field monitoring, original in and ex situ experimental set-up and modelling from the element speciation to the environmental impact
PANORAMA’s key aim is to set-up an optimal scientific and non-scientific training to the understanding and forecasting of the environmental impacts of new emerging pollutants such as REE.
Informal enquiries may be addressed to the supervisor Dr. Delphine VANTELON – Tel: +33 (0)1 69 35 96 94 – firstname.lastname@example.org
Applications should include a cover/motivation letter, resume (CV), Bachelor and/or master’s degree transcript as well as the name and contact details of 2 to 3 referees. Applications should be done on-line at: https://www.synchrotron-soleil.fr/en/job-offers/phd-lucia