Coupled adsorption and electron transfer interface reactions governing the retention of redox-sensitive Se and Tc on Fe(II)/Fe(III) bearing clay minerals

The main task is to contribute to a better understanding of the coupled adsorption and electron transfer interface reactions governing the retention of redox-sensitive radionuclides on Fe(II()/Fe(III) bearing clay minerals. To address this issue, the interaction between redox-sensitive radionuclides (e.g. U, Tc, or Se), and purified Fe(II)/(III)-containing clay minerals will be investigated by combining adsorption experiments under different relevant geochemical conditions, molecular scale speciation using X-Ray adsorption spectroscopy and adsorption modelling. The aim is to correlate mineral properties with respect to its redox reactive iron content (structural/adsorbed) (i.e. abundance, location in the crystal structure, and oxidation state(s)) to the degree of radionuclides retention and molecular scale surface speciation.