Fate of ancient metallic deposits in a steel-making valley. Impact of dam opening on Zn and Fe speciation

In the Orne River, industrial residues were dumped during decades, stored under river waters. With the dam opening, the contaminated banks suffer oxidation, sunlight. The modification of hydrology also enhanced the erosion of bottom parts of the river banks (increase of water velocity), and increased the amplitude of water table oscillations. Using XAS experiments at Fe and Zn edge, we aim at following the mineralogical evolution of these ancient industrial deposits in order to assess the mobility of contaminants such as Zn.