Geochemistry/Biogeochemistry

My interest goes to the study of various element cycles in the subsurface of the Earth through isotopic analysis and development of analytical methods for solid and/or fluid samples.


I particularly worked on aquatic systems such as a river; e.g., to determinate the control-parameter of its chemistry, impact of weathering on its chemistry, anthropological discharge… Rivers are sources of element arrival to the ocean, processes controlling its charge need to be constrained to estimate impact on ocean chemistry and global cycle. I did a preliminar study of Boron and Carbon in the Rhône river in which B extraction methods and isotopic analysis have been tested.


At another scale, interactions between microorganisms and their environment have long been neglected in geosciences even if organisms can play a role in many natural chemical reactions (dissolution, precipitation, adsorption, fractionation…) . Interdependence of biological and geological systems are of particular interest for environmental sciences (waste treatments, water pollution…), geochemistry (cycling of elements in the earth surface), origin of life (bacteria in extreme living conditions)…
I worked on cycling of nitrogen in the ocean by studying natural isotopic variations of nitrates. A microbiological method of conversion (by denitrifiers) of nitrates to N2O have been realized to access to the isotopic signal in O and N. A better understanding of processes of interaction between N forms in water and organisms can help constraining N cycle and also give new microbiological methods of analysis.