Use of sulfate reducing bacteria in acid mine drainage treatment
- Environmental Protection Agency, Cincinnati, OH (United States)
The environmental impacts caused by Acid Mine Drainage (AMD) were first recorded in 1556 by Georgius Agricola. In the United States 10,000 miles of streams and 29,000 surface acres of impoundments are estimated to be seriously affected by AMD. Abandoned surface mines are estimated to contribute about 15% of the drainage, while active mines (40%) and shaft and drift mines (45%) contribute the remainder. AMD results when metal sulfide minerals, particularly pyrite (FeS{sub 2}), come in contact with oxygen and water. Acid generation occurs when metal sulfide minerals are oxidized according to the Initiator Reaction: FeS{sub 2}(pyrite) + 3 1/2O{sub 2} + H{sub 2}O {yields} Fe{sup 2+} + 2SO{sub 4}{sup 2-} + 2H{sup +}. This reaction is one of many that results in increased metal mobility and increased acidity (lowered pH) of the mine water. The oxidation of ferrous sulfate is accelerated by bacterial action of Thiobacillus ferrooxidans, a naturally occurring bacterium that at pH 3.5 or less, can rapidly accelerate the conversion of dissolved Fe{sup 2+} (ferrous iron) to Fe{sup 3+} (ferric iron), and can act as an oxidant for the oxidation of pyrite. Ferric ions, as well as other metal ions, and the sulfuric acid have a deleterious influence on the biota of streams receiving AMD. The Lilly/Orphan Boy Mine, located in the Elliston Mining District of Powell County, Montana, was selected as the Sulfate Reducing Bacteria (SRB) technology demonstration site. The mine is situated on a patented claim on Deerlodge National Forest Land about 11 miles south of Elliston, Montana. This abandoned mining operation consists of a 250-foot shaft, four horizontal workings, and some stopping. The shaft is flooded with AMD to the 74-foot level and is discharging about 3 gallons per minute (gpm) at a pH of 3.0 from the adit associated with this level.
- OSTI ID:
- 111492
- Report Number(s):
- CONF-9504110-; TRN: 95:005009-0034
- Resource Relation:
- Conference: 21. Environmental Protection Agency (EPA) annual Risk Reduction Engineering Laboratory research symposium, Cincinnati, OH (United States), 4-6 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of 21st Annual RREL research symposium: Abstract proceedings; PB: 398 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
At-source Recovery of Rare Earth Elements from Coal Mine Drainage
Formation of secondary mineral coatings and the persistence of reduced metal-bearing phases in soils developing on historic coal mine spoil