Interaction of Selected Actinides with Microorganisms Relevant to Nuclear Waste Disposal

The sorption behavior/ retardation of actinides (uranium) in deep geological formations like clay, granite or salt is determined by the constitution of the host rock material and the presence of bioligands and microbes. To which extent can bioligands and microbes lead to a mobilisation of the respective actinyl ion?
By presenting results of our current research categorical examples for the interaction of uranium(VI) with above mentioned interaction partners are given:

• Interaction with host rock material: the anaerobic sorption of U(VI) onto Opalinus Clay
• Interaction with bioligands: interaction of U(VI) with the model ligand benzoic acid investigated by UV-vis spectroscopy and cryo-TRLFS
• Interaction with microbes: interaction of U(VI) with the Äspö bacterium Pseudomonas fluorescens (HAADF-TEM measurements and uranium accumulation experiments)