Passive removal of manganese from acid mine drainage
- West Virginia Univ., Morgantown, WV (United States)
Removal of manganese (Mn) from mine drainage is difficult due to the abnormal chemistry of the element. The removal requires the oxidation of Mn(II) (the form found in mine drainage) to the more oxidized forms (Mn(III) or Mn(IV)). The more oxidized forms exist only as solids and will not return to Mn(II) spontaneously. Chemical treatment of Mn often requires a pH near 10 to initiate the oxidation quickly. A stabilized pH of 10 normally causes more harm to aquatic organisms than the Mn and is not desirable, making additional steps in the treatment necessary. Biological removal of Mn can be achieved at near neutral pH levels. The Shade Mining site in Somerset County, PA has been treating Mn to discharge limits since the early 1990`s (reducing Mn concentrations from 12 - 25 mg/L in the influent to <2 mg/L in the effluent). The treatment system consists of an anoxic limestone drain discharging into a wetland to remove iron, aluminum, and acidity, while increasing pH and alkalinity. The wetland effluent flows into two limestone beds (Mn removal). The limestone beds developed a black slime coating as the Mn removal increased. This system continues to remove Mn in all weather conditions and has not required chemical treatment since the black coating appeared on the limestone. A laboratory study was conducted using limestone collected from the Shade site to use the same naturally occurring Mn oxidizing microbes. The lab study compared W removal rates of microbial oxidation, MnO{sub 2} catalyzed limestone, and fresh uncoated limestone. The microbial removal performed the best (25 mg/L Mn reduced to <2 mg/L in 72 hours).
- OSTI ID:
- 613877
- Report Number(s):
- CONF-9705128-; TRN: 98:001000-0066
- Resource Relation:
- Conference: 14. annual national meeting of the American Society for Surface Mining and Reclamation (ASSMR), Austin, TX (United States), 10-15 May 1997; Other Information: PBD: 1997; Related Information: Is Part Of Vision 2000: An environmental commitment; Brandt, J.E.; Galevotic, J.R.; Kost, L.; Trouart, J. [eds.]; PB: 799 p.
- Country of Publication:
- United States
- Language:
- English
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