University of Vienna, Austria in collaboration with
Washington University in St. Louis, USA

PhD/Graduate Students Environmental Geochemistry

The research group Environmental Geochemistry of the University of Vienna, Austria invites appli-cations for a PhD position as part of an international collaborative project.

Fate of tetravalent uranium under reducing conditions

The stimulation of microbial reduction of the soluble hexavalent U [U(VI)] to sparingly soluble tetravalent U [U(IV)] has been exploited as an in-situ strategy for the immobilization of uranium in contaminated aquifers. The success of this strategy rests on the low solubility of U(IV) phases that are formed as the product of microbial reduction. Recent research efforts have shown that these reduction products do not only consist of stable crystalline mineral phases such as uraninite, but also of non-crystalline U(IV) species associated with biomass. While the thermodynamic properties and the mechanisms and rates of mobilization of such biomass-associated U(IV) phases are unknown, experimental evidence seems to indicate that they are more mobile and may impact the efficacy of uranium bioremediation. In this multinational collaborative project, researchers from Austria, USA, Germany, and Switzerland will investigate processes that may lead to the mobilization of U(IV) under reducing conditions.

The successful candidate will perform laboratory experiments at the University of Vienna and at Washington University in St. Louis, elucidating chemical mechanisms and rates of U(IV) mobilization from pure U(IV) phases and the transport of mobile U(IV) along soil columns. The observations will be complemented by uranium isotope fractionation studies performed at the University of Hannover, Germany. The observations will be quantitatively described using reactive transport models. The experiments and the modelling will be performed in the laboratories the Washington University in St. Louis (Prof. Giammar) as well as at the University of Vienna (Prof. Kraemer). Therefore, we seek a candidate who is willing to travel and to split her/his time between these two labs. Also, good communication skills are required to foster tight collaborative integration among the two laboratories.

We offer: an international, collaborative environment for research in environmental geochemistry, with a highly competitive team and first-rate infrastructure. The successful candidate will be hired by the University of Vienna, Austria, and will spend significant time at Washington University in St. Louis, USA. With 15 faculties, 4 centres, about 188 fields of study, approx. 9.400 members of staff, more than 90.000 students the University of Vienna offers various tools for career development including networks, conferences and participation in teaching at the Department of Environmental Geosciences. The candidate will have the opportunity to present his/her results in international journals and conferences.

We seek: a highly motivated individual who aims to develop mechanistic and quantitative approaches to environmental problems. Applicants for the PhD student position should have a masters degree in a relevant field (e.g. Environmental Aqueous Chemistry, Environmental Geochemistry, Environmental Engineering etc.) and a creative, inquiring and enthusiastic personality. They must have the ability to work independently and in a team. Good English language skills are essential, German language skills are not required. Experience in analytical chemistry and thermodynamic modelling is desirable. The University of Vienna intends to increase the number of women in research positions, and therefore specifically encourages applications by women. Among equally qualified applicants, women will receive preferential consideration.

For further information about the position, please contact Prof. Stephan Kraemer, University of Vienna ( Applications including a statement of research interests, a detailed Curriculum Vitae, and the names of two referees should be sent before August 1. 2017 by e-mail to: Applications are welcome until the position is filled. The starting date of the position can be negotiated.

published: 21 June 2017     Please mention EARTHWORKS when responding to this advertisement.