BMBF Joint project PHYTOREST
Measures for radiation prevention and mitigation of low radioactively contaminated sites by phytoremediation and following utilization of the loaded plant residues (PHYTOREST)
Partner: University of Jena, Institute for Geosciences (GER)
Funding: Federal Ministry of Education and Research (BMBF)
Duration: May 2008 - April 2011
Project description:
In Eastern Thuringia and Saxony, former uranium mining led to numerous legacies, such as tailings piles, former open pit sites and large areas contaminated with low levels of heavy metals and radionuclides. These are weakly contaminated, but due to the complex material dynamics in the subsurface, spatially and temporally highly variable. In a joint project of the Friedrich-Schiller-University Jena and the Technical University Dresden, a radiation protection precaution of such contaminated large areas by remediation by means of phytoremediation and subsequent utilization of the contaminated plant residues was investigated within the framework of a joint project.
The focus of the investigations was the cost-efficient decontamination of moderately contaminated areas by reducing/immobilizing the heavy metal/radionuclide (SM/R) content in the soil in conjunction with increased biomass production. On the test field "Gessenwiese" in Eastern Thuringia the material flows and loads as well as redox conditions and transport mechanisms of SM/R in the effect path plant - soil - groundwater were balanced by lysimeters and soil hydrogeological measuring sites. Vessel and field experiments with different plant species were carried out by the IAK at the TU Dresden. The harvested plants were subsequently examined for their heavy metal content and for possibilities of their utilization.
The weakly contaminated biomass from the phytoremediation is to serve the energetic use by the production of biogas (project part waste management) as well as the material recycling (project part contaminated sites).
As first results of the investigations it was determined that e.g. triticale is well suitable as phytoremediation plant for this area due to its climatic suitability as well as its tolerance to acid sites. As a result of the lysimeter experiments, a reduction in the concentration of contaminants in the leachates, leachate recharge and loads was demonstrated when different soil additives were applied to the test field soil. In the subsequent utilization tests at IAK, it was found that the SM/R contained in the plant residues did not cause any inhibition of the biodegradation processes.