ABSTRACT
The environmental impact of heavy metal contamination due to anthropogenic activities has increased enormously in the last years. The generation of high volumes of mixed-metal sludge is another drawback. Those residues require careful disposal, often in specially designated landfill sites. The hydrogen sulfide generated as a waste product by dissimilatory sulfate-reducing bacteria can be used for metal precipitation. It can react with metal ions present in contaminated waters and precipitate as insoluble metal sulfide. Metals that have more than two oxidation stages can be first reduced by SRM and eventually precipitated by direct or indirect action of SRM. In this case study, results about metal bioprecipitation using sulfate-reducing consortia from Copahue Volcano. Sediment samples were taken from different hot springs with geothermal activity at Copahue volcano. Bioprecipitation using sulfate-reducing microorganisms is a promising technology for the removal of heavy metals from contaminated waters. The precipitation values correlate with the tolerance of the consortia to the concentrations of heavy metals tested.
