This work has the aim to develop suitable technologies for processes able to recover heavy metals from contaminated fly-ashes and to evaluate their potential as well as the ecological and the economic side-constraints. The one topic of this project is to utilize the heavy metals concentrated in filter fly-ashes by separating them following the principles of heavy metal sublimation / condensation that will be gained from the project mentioned above. The biochemical part of the project investigates the potential of biochemical heavy metal separation from fly-ashes by dissolving them in organic acids. In a second step these dissolved heavy metals will be taken up by special bacteria strains that are able to upgrade them extra- or intracellular. These experiments will be carried out in collaboration with the Institute for Biotechnology at the Technical University of Graz.