Dynamics, cycling and tracing in ecosystems

The research carried out aims to understand the dynamics, cycle and impacts of organic and inorganic elements in the various environmental compartments (water, soil, atmosphere). Particular attention is paid to interactions between contaminants and biota (plants, microorganisms, humans) in order to characterise (eco)toxicological impacts, among other things. On a larger temporal and spatial scale, the evolution of soils under various constraints is studied.

Impact of contaminants on humans and the environment

The research carried out in the team aims to characterise the biophysical-chemical mechanisms of pollutant (eco)-toxicity in order to limit the risks. The team is internationally recognised for its work on the identification and tracing of metallic pollutants and the understanding of the biophysical-chemical mechanisms of toxicity on humans and the environment.

We focus on the origin, behaviour, and impact of metal pollutants in soil, water, and atmosphere, and the risks associated with (nano)-particulate and/or (nano)-carried contaminants. Aquatic, terrestrial mesocosms and pilot bioreactors are used to study direct exposure pathways (e.g. industrial activities, degradation of materials during their life cycle) and indirect exposure via water treatment plants (land application). We are also assessing biological effects following exposure to cocktails of emerging pollutants, as well as the development of antibiotic resistance in the presence of metals in organic waste.

The environmental impact of agricultural recycling of organic waste is studied through long-term experimental schemes (SOERE PRO). These long-term agro-environmental trials, some of which are linked to southern countries, allow the study of the cycle of (in)organic and microbial contaminants. The coupling between spectroscopy and isotopy is used to better constrain the biogeochemical cycle of metals in cultivated soils.

Bioavailability and biotransformation of metals and metalloids

The focus is on the role of biota in the fate of metals and metalloids within biogeochemical cycles. Indeed, fauna, flora, minerals and organic matter are in permanent feedback action and influence the dynamics of the elements, whether they are in nanoparticle form, organic complexes or dissolved.
Soil-plant transfers of contaminants are studied, with a focus on the role of root and microbial exudates.
Actions on silicon are developed on issues related to agriculture and soils in southern countries (Lebanon, India, Vietnam, Kenya). The questions addressed concern the impact of crops on bioavailable Si reserves or the role of phytoliths in the development of plants subjected to environmental stresses (i.e. drought, contaminants such as As)

Dynamics of organic matter and the C cycle

Our objective is to analyse and model C dynamics along the soil profile, in particular to highlight and quantify the effect of organo-mineral interaction on C stabilisation, vertical transport processes, the impact of climate change (precipitation), changes in use and practices on ecosystem C.

Pedogenesis under anthropogenic and climatic constraints

The work on soil pedogenesis under climatic and anthropogenic constraints concerns simple changes in use up to artificialization. The approaches aim to quantify the changes and kinetics: by field or experimental pedologies, modelling, isotopic tracing.