Molecular Environmental Geochemistry
Research motivation
The speciation of major and trace elements controls their reactivity, mobility and bioavailability in natural and engineered environments. Knowledge on the relevant chemical species is therefore essential for the mechanistic understanding and quantitative modeling of the fate and impact of nutrients and contaminants in environmental systems.
Our research aims at elucidating biogeochemical processes by relating macroscopic observations from field
and laboratory studies to the reactivity and transformation of distinct
chemical species. In this context, element-specific X-ray absorption spectroscopy represents a key analytical tool as it provides direct insight into the speciation of elements even at trace levels and in complex environmental matrices.
Ongoing Projects
- Structure and morphology of Fe(III)-precipitates formed by Fe(II) oxidation in water and their impact on nutrient and contaminant dynamics [pdf].
- Behavior of engineered silver nanoparticles in wastewater treatment plants (within SNF NRP 64 [...]).
- Dynamics of Cu and Cd speciation and solubility over reduction-oxidation cycles in freshwater floodplain soils (Collaboration with ETH Zurich [...]).
- Colloidal and dissolved contaminant release from wetland soils during soil flooding and reduction (Collaboration with ETH Zurich [...]).
- Reduction and oxidation of iron in clays.
- Diagenetic evolution and mineral composition of Fe/Mn layers in the sediments of Lake Baikal [...].
- Variation in the speciation and isotope signature of Zn and Cu in the sediment of an eutrophic lake (Collaboration with University of Paris).
- Arsenic contamination of paddy soils through irrigation water in Bangladesh [...].