3-year PhD position (m/f/d): Sulfur Cycling in Wetlands and its Coupling to Iron and Carbon

3-year Ph D position (m/f/d): Sulfur Cycling in Wetlands and its Coupling to Iron and Carbon Application deadline: 20.

September 2026 Start date: 1.

November 2026 Scope of work: Part-time position (70 %) Reference no.: 00005154 Project Description Sulfur cycling is a fascinating but still surprisingly understudied part of wetland biogeochemistry.

In oxygen-limited environments such as peatlands, the Wadden Sea, and other wetlands, sulfate can be rapidly transformed into sulfide.

Sulfide, in turn, reacts strongly with iron minerals and can promote the dissolution of Fe(III) oxides, setting off a cascade of reactions that influence both iron and carbon cycling.

Despite its importance, many aspects of sulfur cycling in terrestrial wetlands remain poorly understood.

One reason is that sulfur compounds are unstable, making them difficult to capture with conventional analytical methods.

This Ph D project will investigate sulfur redox transformations in wetlands and their links to iron and carbon cycling.

The project combines experimental work with analytical method development to characterize different sulfur species using techniques such as HPLC and LC-ICP-MS.

The project also offers the opportunity for fieldwork in the Black Forest, where the Ph D candidate will investigate sulfur pools and transformations in minerotrophic peatlands.

Tasks and Responsibilities Design and conduct laboratory experiments Apply and develop analytical methods for sulfur speciation Acquire and analyze synchrotron-based research data Identify suitable field sites in the Black Forest and establish contact with landowners and relevant authorities Publish research results in peer-reviewed journals and present them at conferences Contribute to teaching and supervise laboratory practical courses Your Profile A degree (MSc or equivalent) in environmental science, geoecology, environmental chemistry, geomicrobiology, or a related field Strong motivation for interdisciplinary research A collaborative mindset, scientific curiosity, and willingness to travel for field campaigns and networking events Strong interest in environmental geochemistry and analytical method development Excellent command of written and spoken English; knowledge of German is an advantage A driver's license (B) is beneficial We Offer An engaging and supportive working environment that fosters scientific curiosity, creativity, and interdisciplinary collaboration Access to state-of-the-art research facilities in our newly equipped laboratory Opportunities to attend and present your research at national and international conferences Close scientific supervision and comprehensive onboarding into the research group The position is limited to three years.

The salary will be determined in accordance with E13 TV-L.

Application Applications should be submitted through the University of Freiburg job portal and should include: A CV A motivation letter Copies of relevant degree certificates Contact information for two references Applications will be reviewed starting mid-October 2026, and the position will remain open until filled.

The ideal start date is November 2026 or as soon as possible thereafter.

Please send your application in English, citing the reference number 00005154, by 20.

September 2026 at the latest, to: Prof.

Kerstin Hockmann University of Freiburg Institute of Earth and Environmental Sciences Albertstraße 23b 79104 Freiburg i.

Br., Germany or electronically via the job portal.

For informal inquiries, please contact: Prof.

Dr.

Kerstin Hockmann kerstin. hockmann@geochem. uni-freiburg. de +49 761 203 6404 Further information: https://uni-freiburg. de/unr-geochem/ We will be particularly pleased to receive applications from women for the position advertised here.