Micrometric pyrite catalyzes abiotic sulfidogenesis from elemental sulfur and hydrogen.

Hydrogen sulfide (HS) in environments with temperatures below 100 °C is generally assumed to be of microbial origin, while abiotic HS production is typically restricted to higher temperatures (T). In this study, we report an abiotic process for sulfidogenesis through the reduction of elemental sulfur (S) by hydrogen (H), mediated by pyrite (FeS). The process was investigated in detail at pH 4 and 80 °C, but experimental conditions ranged between 40 and 80 °C and pH 4-6.

Biosulfidogenesis Mediates Natural Attenuation in Acidic Mine Pit Lakes.

Acidic pit lakes are abandoned open pit mines filled with acid mine drainage (AMD)-highly acidic, metalliferous waters that pose a severe threat to the environment and are rarely properly remediated. Here, we investigated two meromictic, oligotrophic acidic mine pit lakes in the Iberian Pyrite Belt (IPB), Filón Centro (Tharsis) (FC) and La Zarza (LZ). We observed a natural attenuation of acidity and toxic metal concentrations towards the lake bottom, which was more pronounced in FC.