Retention potential of a drained wetland in the Lusatian lignite mining district, Briesener Niedermoor, Germany, Europe

Abstract Acid mine drainage (AMD) is one of the most important global causes for polluted water. It occurs in mining areas due to oxidation sulfide minerals. Depending on hydrological conditions, wetlands are considered suitable passive treatment AMD. The aim study was characterize long-term retention performance a drained wetland, Briesener Niedermoor, an iron and sulfate contaminated catchment area. site located Lusatian lignite district, Germany. Hydrological hydrochemical measurements as well time series groundwater surface water were evaluated saturation conditions species determined using Phreeqc Interactive E H –pH diagrams Fe–S–K–O–H system. Progressing peat degradation leads hydraulic behaviour wetland that more comparable rain bog than fen, thus pronounced oxic conditions. Groundwater feeds with significant loads sulfate, which temporally stored wetland. At low discharge, removed weak acidic pH buffered by dominant phase schwertmannite (Fe 8 O (OH) 6 SO 4 ), usually during summer months. In winter, greater availability initializes high source strength from cannot be retarded. Thus, only summer, there potential; potential not strong enough prevent inflow sulfate. Only rewetting may result restoration Niedermoor.