Immobilization of heavy metals in incinerator ash by the activity of Desulfovibrio desulfuricans

The ash produced by the incineration of domestic refuse contains significant amounts of heavy metals. Because incinerator ash is often disposed of by burial in landfills, leaching of the heavy metals into groundwater is an environmental hazard associated with incineration. Although ash is considered to have the potential to be highly toxic, the anaerobic sulfate reducing bacterium Desulfovibrio desulfuricans can grow in the presence of incinerator ash and significantly increase the leach resistance of the lead, cadmium, and chromium that is present in the ash. The data suggest that conditions compatible with microbial sulfidogenesis in landfills may be of value in preventing metal leaching should other containment strategies prove ineffective.