Elevated sulfate reduction in metal-contaminated freshwater lake sediments

摘要: Although sulfate-reducing prokaryotes have long been studied as agents of metals bioremediation, impacts long-term exposure on biologically mediated sulfur cycling in natural systems remains poorly understood. The effects to metal stress the freshwater cycle were studied, with a focus biologic sulfate reduction using combination microbial and chemical methods. To examine after decades adaptation time, field-based experiment was conducted multiple study sites system historically impacted by nearby zinc smelter (Lake DePue, Illinois). Rates highest at most metals-contaminated (-35 {mu}mol/cm{sup 3}/day) decreased pore water arsenic contamination levels, while other environmental characteristics (i.e., pH, nutrient concentrations physical properties) showed little between-site variation. Correlations established an artificial neural network evaluate potentially non-linear relationships between rates (SRR) measured variables. SRR Lake DePue up 50 times higher than previously reported for lake sediments speciation Zn dominated presence ZnS shown X-ray Absorption Spectroscopy (XAS). These results suggest that might alter biogeochemicalmore » contributing reduction.« less