Microbial Generation of Acid Mine Drainage: Its Bioremediation in Buenos Aires, Argentina

BENITEZ L.; PLAZA CAZON J.; WILLIS PORATTI G.; DONATI E.

Bioremediation in Latin America

SPRINGER

Año: 2014; p. 165 - 178

Acid mine drainages are highly acidic toxic solutions with elevated heavy metal concentrations. These acidic solutions are generated when rocks containing pyrite and other metal sulfides are brought and exposed to oxygen and water. The activity of iron- and sulfur-oxidizing microorganisms which thrive at a pH range of 1?4 can significantly catalyze that process and the resulting drainages produce a strong impact on the mining region causing contamination to streams and rivers and negative effects on the biodiversity. To reduce its impact, different physical, chemical, and biological treatments are used together in natural and constructed wetlands. Biosorption and bioprecipitation are two of the biological processes within the wetlands. In the first case nonviable biomasses can be used to retain heavy metals while in the second case the metals are precipitated as sulfides through the action of sulfate-reducing microorganisms. In this chapter we describe the situation in an abandoned silver?zinc?lead mine including acid mine drainage generation by microbial action and the evaluation of its treatment using biosorption on plant biomasses and bioprecipitation by sulfate-reducing bacteria