Qualitative and quantitative analysis of Eu and Cm association by selected plants from contaminated soils.
During the dismantling of nuclear facilities, contaminated soil is removed from its environment and temporarily stored until it is released or safely stored. Due to cost and capacity reasons and against the background of the increasing dismantling activity in Germany in the coming years, a minimization of the volume of contaminated soil to be finally stored is mandatory. In addition to a variety of physical and chemical remediation strategies, biological remediation processes in particular are characterized by their cost-effectiveness and environmental friendliness. Plants in particular have the ability to remove a wide range of contaminants, such as radionuclides, but also other heavy metals and organic chemicals from the soil. However, the interaction processes involved are poorly understood and experimental data on the interaction of lanthanides and actinides with plants are scarce.
The aim of this work is to assess the potential of selected plants for phytoremediation and to develop a molecular process understanding of the interaction of heavy metals with them. To this end, hydroponic bioassociation experiments are first performed using the spectroscopically easily accessible europium as a proxy for the trivalent lanthanides and highly radiotoxic actinides curium and americium. Special focus will be on the spectroscopic investigation of metal speciation in the growth medium and individual parts of the plant using TRLFS, and the spatial resolution of species distribution in plant parts and cells using chemical microscopy. Following on from this, the bioassociation of metals in model and real soils, for example from current deconstruction projects, will be investigated and the (micro-)spectroscopic analysis will be accompanied with regard to the macroscopic radionuclide distribution by autoradiography.
This work is part of the collaborative project "RENA" (Biological Radionuclide Removal by Utilization of Natural Association Processes), which is funded by the German Federal Ministry of Education and Research under grant number 02NUK066A.