Bacterial Metal Sulfide Degradation - Pathways, Inhibition Measures, and Monitoring

摘要

Metal sulfides are degraded via thiosulfate (pyrite) or via polysulfides and sulfur (sphalerite, galena, chalcopyrite) by leaching bacteria. The attack on the crystal lattice is either effected by only iron(III) ions or by iron(III) ions and portons, respectively. Consequently, different endproducts are formed. For a control of ARD-processes, these reactions need to be known to regulate them. Experiments in percolators up to 65 m~3 with inorganic compounds like fluoride, concrete, or SDS resulted in differently lasting inhibition. Microcalorimetric measurements of microbial leach activity allow monitoring of these effects with respect to active bacterial cells, and, in addition, the amount or rate of dissolved metal sulfide allowing prediction of possible endangerment by ARD.