Reference : UMR7327-MARROU0-031
Workplace : ORLEANS
Date of publication : Tuesday, November 22, 2022
Type of Contract : FTC Scientist
Contract Period : 12 months
Expected date of employment : 1 February 2023
Proportion of work : Full time
Remuneration : Between 2805 and 3963 euros gross monthly
Desired level of education : PhD
Experience required : Indifferent
At CNRS, the ISTO laboratory, as part of its commitment to scientific research projects accelerating the energy transition, is participating with BRGM, University of Tours, project owners, and sector representatives of the industry to an ambitious regional project (AGREEGAS) in order to characterize the biogeochemical processes responsible for the clogging of very low-enthalpy geothermal doublets. In the Centre-Val de Loire Region, some installations exploiting shallow waters are faced with major malfunctions leading to costly maintenance operations, or even the shutdown of the exploitation. The main cause is the development of iron and manganese oxy-hydroxide deposits in the heat exchangers and sometimes in the well screens. The objective of the project is to better understand these clogging mechanisms leading to operating issues and to propose, on the one hand, recommendations based on a better characterization of these environments for new doublets and, on the other hand, remediation solutions for doublets already in operation.
The ISTO's scientific contribution aimed to study these key processes influencing mineral precipitation reactions. One of the technological lock is the characterization of the physical, chemical and microbial processes that trigger the precipitation of iron oxy/hydroxides during the geothermal fluid exploitation.
More specifically, the missions of the postdoctoral researcher come in four major tasks:
- Participation in on-site sampling campaigns: sampling, on-site measurements of physico-chemical parameters that may include speciation (especially iron: particulate iron, Fe2/Fe3), filtrations...;
- Analysis of solid and liquid samples: characterization of deposits (elemental analysis, XRD, SEM) and chemical composition of aqueous solutions ;
- Laboratory experiments: he / she will design and perform laboratory experiments (batch type closed systems) on water samples to analyze the influence of parameters (Temperature, pCO2, redox conditions) on precipitation kinetics. In case the processes are catalyzed by microorganisms, some monitoring of bacterial activity is planned from UV-Visible measurements.
- Interpretation of the results and numerical modeling to determine the major reaction mechanisms involved in deposition processes.
At last, the postdoc joining the project will be in charge of the valorization of the results (publications, presentations in specialized national and international conferences, etc.).
The project is financed by the Centre Val-de-Loire Region.
The candidate should have a PhD in geochemistry or microbiology and a solid knowledge in physico-chemical processes and reactive geochemistry. The candidate should have a strong aptitude for experimental work and be able to work independently. Skills in numerical modeling and couplings (THMC) applied to predictive geosciences will be appreciated. Oral and writing skills, both in French and English language, will also be required.
Send your CV, a motivation letter and reference letters.
Post-doctoral will work in close collaboration with the teams involved in the AGREEGAS project, experts in geochemistry and thermodynamic modelling, geology and microbiology. The research work will mainly be performed in ISTO - UMR 7327 (Orléans, France, https://www.isto-orleans.fr/en) and BRGM (Orléans, France, https://www.brgm.fr). The candidate will have access to all equipment of ISTO analytical platforms.
Constraints and risks
Regular missions to the sites studied (in the Centre Val-de-Loire Region) or to the project's partner laboratories are to be expected
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