ABSTRACT
Acid mine drainage in the lignite mining area in southern Brandenburg, leads to acidification, mineral weathering, release of heavy metals and arsenic and in consequence to highly mineralised reduced groundwater, which is oxidised in the lake. The precipitation of secondary minerals in the lake lowers pH-values down to 2.8. The transformation of schwertmannite to goethite in the sediment has a barrier function for arsenic, which is accumulated in the goethite layer, whereas higher amounts of cationic heavy metals (e.g. Zn) could be detected in the schwertmannite layer.
