Application of stable isotopes to assess reducing processes in lignite mining dumps

摘要

After the end of lignite exploitation in Eastern Germany mining areas, the abandoned pits were flooded by groundwater or river water inflow. The associated dump sites consist of heterogeneous material of Quaternary and Tertiary age, which contain sulfide minerals. Oxidation of these minerals leads to acidification, influencing the development of water quality in the lakes and the groundwater. An aggressive process is bacterial sulfate reduction. By means of sulfur and oxygen isotope analyses it is possible to verify the occurrence of this process, which proceeds only locally due to the inhomogeneity of the sediment distribution.