Kerstin Hockmann

As of the winter semester 2024, I have taken up the Professorship for Applied Geochemistry at the University of Freiburg. My group is growing, and we are excited to tackle new research challenges and collaborate on innovative projects in the field of environmental and applied geochemistry in the years to come. 

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 4 positions (Phd; postdoc/senior researcher, lab manager) will be opening in my group this autumn. Stay tuned or feel free to contact me informally for early details.

Research interests

Our research group integrates applied and environmental geochemistry to investigate the geochemical cycling of elements in soils, sediments, and surface waters using an interdisciplinary approach. Our research focusses on (bio)geochemical reactions involving iron, carbon, and sulfur, and their influence on trace elements in environments affected by human activities and climate change. Furthermore, we aim to develop innovative solutions to these challenges through the exploration of novel remediation and engineered approaches.

In terms of methods, we use in-situ field and model laboratory experiments and combine them with synchroton-based spectroscopic and microscopic techniques. This approach allows us to obtain a fundamental geochemical understanding of environmental processes, which helps to derive effective strategies for treating existing contamination as well as managing pollution from future activities. 

Some of our current projects

Interplay between iron and antimony geochemistry

Antimony is a highly toxic environmental contaminant that is of growing concern. Over recent decades, dramatic increases in the production of Sb, due largely to its importance as a flame-retardant in electronics and plastics, has led to many cases of Sb release into the environment. In natural systems, the mobility of Sb is strongly affected by coprecipitation and adsorption interactions with Fe(III) oxide minerals. As such, the mineralogical transformation of Fe(III) oxides play a major role in determining the environmental fate and mobility of Sb. This project therefore investigates the impact of iron oxide (trans)formations on the speciation and mobility of antimony.

Schwertmannite  -  a novel sorbent for phosphate removal

Phosphate is a key nutrient in eutrophication and many efforts are undertaken to reduce its input into surface waters.  An iron-based adsorbent that may be an ideal candidate to remove phosphate from water is schwertmannite, a by-product from acid mine drainage treatment. In this project, we investigate the factors and kinetics controlling short-term phosphate incorporation into schwertmannite and the concomitant formation of secondary Fe phases such as microcrystalline Fe(III) oxides.

Release of antimony from synthetic clothes

This seemingly "exotic" project (at least in the context of my research) focuses on the potential for children clothes woven from synthetic fibers to release antimony. Antimony may be present in synthetic clothing fibers because it is used as a catalyst during their manufacture. In order to study exposure and potential negative health effects while children are using the garments, we used geochemical methods to determine total Sb concentrations in a range of clothing samples, and subjected the fabrics to extraction by artificial sweat and saliva.