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INNOVATIVE, IN SITU TREATMENT OF ACID MINE DRAINAGE USING SULFATE REDUCING BACTERIA
Citation:
Bless*, D R. INNOVATIVE, IN SITU TREATMENT OF ACID MINE DRAINAGE USING SULFATE REDUCING BACTERIA. Presented at Society of Environmental Toxicology and Chemistry, 22nd Annual Meeting in North America, Baltimore, MD, 11/11-15/2001.
Description:
Acid generation in abandoned mines is a widespread problem. There are a numberous quantity of abandoned mines in the west which have no power source, have limited physical accessibility and have limited remediation funds available. Acid is produced chemically, through pyritic mineral oxidation, and biologically, through bacterial metabolism. This project focuses on a passive source-control technology that has the potential to significantly retard or prevent acid generation at affected remote mine sites. The particular group of bacteria chosen for this demonstration, sulfate reducing bacteria (SRB) require a reducing environment and cannot tolerate aerobic conditions for extended periods. These common, ubiquitous, and non-pathogenic bacteria require a simple organic nutrient. The technology has the potential to reduce contamination of aqueous waste in three ways. First, dissolved sulfate is reduced to hydrogen sulfide through metaolic action by the SRB. Next, the hydrogen sulfide reacts with dissolved metals forming insoluble metal sulfides. Finally, the bacterial metabolism of the organic substrate produces biocarbonate, incrasing the pH of the solution and limiting further metal dissolution. The field demonstration ws initiated in 1993 and metal removal efficiencies have proven to be high for aluminum, cadmium, and copper. The technology is cost effective, passive and environmentally friendly. This project is funded by the USEPA's Mine Waste Technology Program.