Through the Humboldt Research Fellowship, the Alexander von Humboldt Foundation sponsors researchers, postdoctoral and experienced, with above-average qualifications from across the globe.

Dr Anke Neumann has recently joined Section 3.5 Interface Geochemistry as a Senior Humboldt Research Fellow. She will spend the next 12 months at GFZ, collaborating with Liane G. Benning and her team to investigate nano-sized minerals that result from the interaction of the common soil and sediment constituents ferrous iron and clay minerals.

Anke received both her MSc and PhD from ETH Zurich, worked as an independent Postdoc in Bangladesh in collaboration with Eawag (Swiss Federal Institute of Aquatic Science and Technology) and George Mason University, and spent her postdoctoral fellowships at the University of Iowa. She then joined Newcastle University, UK, as a Lecturer, where she is still working as Senior Lecturer to date.

The research project

Clay minerals are ubiquitous in sediments and soils and have long been regarded as mostly unreactive but are emerging as potentially important redox-active minerals in natural environments. Intriguingly, their interaction with the naturally abundant reductant ferrous iron leads to the formation of transient, yet highly reactive mineral species capable of degrading recalcitrant contaminants. We suspect that the mineral identity and crystallinity of these mineral species is key to the reactivity observed and hence to understanding their role in many of Earth’s crucial element cycles, as well as nutrient availability, and contaminant degradation.

The target minerals are likely amorphous or nano-crystalline, present in low abundance and most often made up of particles of very small sizes (nanometer range). Thus, facilities and analytical tools that cannot just identify but fully characterize these nanophases are needed. At GFZ, high-resolution transmission electron microscopy (HR-TEM) and atomic pair distribution function (PDF) method will be used and complemented with Mössbauer spectroscopy at Newcastle University. Insights from this project will improve our understanding of how clay mineral redox reactions control the identity and reactivity of reactive mineral intermediates and, hence, how clay minerals control redox reactions on Earth.