Kerstin Hockmann

I am a junior research group leader in the field of interface geochemistry and passionate about exploring the coupled biogeochemical cycling of iron, carbon and sulfur and their impact on trace element availability in our human-impacted environment.  My group is currently growing and is part of the Group of Hydrology and the Experimental Biogeochemistry Group at University of Bayreuth. My research contributes to maintaining healthy soils as keystones for future food security, biodiversity and clean drinking water supply. 

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4 positions (Phd; 6-year postdoc, lab technician) opening soon in my group. Stay tuned or contact me to for early details.

Research interests

My research interests lie at the interface of mineralogy and environmental geochemistry. I use an integrated approach that investigates the mutual controls between mineralogical (trans)formations and element mobility in systems affected by anthropogenic activities (e.g. mining) or climate change (e.g. flooding). My research also aims at offering innovative answers to these problems by investigating novel sorbent materials (schwertmannite or ZVI) or engineered solutions (e.g. iron oxide precipitation) to improve water and soil quality. 

In terms of methods, I use in-situ field and model laboratory experiments and combine them with synchroton-based spectroscopic and microscopic techniques. This approach allows me 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 my 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.