Supervisors: Dr Dominik Weiss, Professors Martin Blunt and Mark Sephton from Imperial College London and

Professor Kate Maher from Stanford University

Duration: 36 months

Actinides are highly toxic elements released into the environment through a wide variety of anthropogenic activities.  This threatens precious groundwater resources and developing a thorough qualitative and quantitative understanding of the very complicated surface and subsurface processes with mineral and organic surfaces is needed. The groups at Imperial College London and Stanford University have been working extensively on this problem and aim to develop biogeochemical models that can predict the mobility of such actinides in the environment.  

To this end, we are now looking for a motivated candidate to develop surface complexation models (SCM) for inorganic and organic surface with a special focus on high pH and high salinity environments. Parameters that adequately account for the acid-base protolysis reactions of different mineral surfaces will be determined, enabling the estimation of the concentration of surface sites for the solid of interest from surface area and hydroxyl site density measurements and performing acid-base titrations. For the SCM, the remaining adjustable parameter is the binding constant for the nuclide sorption reactions, which will be obtained from batch experiments. The experimental conditions are chosen to match environmental conditions. We will use spectroscopy to investigate the surface complexes and to constrain the model parameters. We will also track how bacteria and actinides in porous and fractured rock using X-ray micro computed tomography.  The most successful SCM will be incorporated in the reactive transport models and tested against the laboratory experiments and, if time permits, field scale data from the real sites.

The successful student will benefit from interactions with research students at two leading research universities who work on various aspects of biogeochemistry and reactive transport modeling. All PhD students in the Department of Earth Science and Engineering at Imperial College are expected to deliver papers/posters at international conferences over the course of their PhD, as well as give internal departmental seminar each year. The successful candidate will also attend taught post-graduate level lectures at Stanford.

Applications for this project are invited from recently graduated undergraduates or MSc students in Chemistry, Engineering, or any relevant field with an interest in biogeochemistry, reactive transport modelling and an active interest in multidisciplinary research. 

General Details

The project is funded by the Department of Earth Science & Engineering and offers a tax-free stipend of £15,726 per annum. It is open to UK and non-UK EU nationals who have spent the previous three years in the UK undertaking education (undergraduate study or masters). Application forms and instructions can be obtained from our website (http://www3.imperial.ac.uk/earthscienceandengineering/courses/phdopportunities/phdapplicationprocedure). Further information about the project can be obtained from Dr Dominik Weiss (e-mail:d.weiss<στο>imperial.ac.uk)

Closing date: until position is filled

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