Crustal Geophysics and Geochemistry Science Center

Aqueous Geochemistry Research and Development
Biocatalysis Studies

Bacterial Sorption to Sulfide Mineral Surfaces

Mark Stanton

Bacteria participate in or catalyze many geochemical reactions of interest, such as oxidation of certain elements (ferrous iron, sulfur, manganese), reduction of other elements or species (ferric iron, nitrate), and organic carbon oxidation or fixation. Sorption of bacteria to mineral surfaces generally enhances their ability to accomplish a specific reaction.

The objective of the bacterial sorption task is to examine and develop methods to determine the number of bacteria (primarily iron-oxidizers) adsorbed onto sulfide mineral surfaces. Bacterial oxidation of sulfide minerals in mine wastes can lead to production of acid mine drainage (in addition to acidity that is generated by abiotic reactions). Understanding conditions that affect how bacteria attach to these minerals may be useful in mitigating acid drainage.

Photo of metal mine-waste pile.Photo of wetland adjacent to a draining mine adit in the San Juan Mountains.
Left photo: Iron- and sulfur-oxidizing bacteria are generally present in metal-mine waste piles. However, their spatial locations and numbers vary widely within the mine waste pile. Right photo: Surface of a wetland adjacent to a draining mine adit in the San Juan Mountains, southwestern Colorado. The bright color results from the formation of a layer of "iron-accumulating" bacteria known as Leptothrix.
[Large version of mine waste pile photo Large version of wetland photo]

Several methods can be used to determine numbers of bacteria, such as staining used in conjunction with direct microscopic counting, or cultural techniques. The columns shown here comprise one method that is currently being examined.
Schmatic drawing of two types of columns used in experiments: upflow column and static column.

Products

Reports in Proceedings of Professional Technical Meetings

  • Stanton, M.R., 2005, Baseline laboratory studies of sphalerite (ZnS) dissolution: effects on aqueous metal concentrations and solubilization rates, in Proceedings of the 2005 National Meeting of the American Society of Mining and Reclamation, Breckenridge, Colorado, June 19-23, 2005, p. 1155-1165. View PDF file of proceedings paper [583 KB].

Abstracts, Presentations, and Posters for Professional Technical Meetings

  • Stanton, M.R., 2004, The formation and composition of iron bogs and wetlands in the San Juan Mountains near Silverton, Colorado: State of the San Juans Conference, Mountain Studies Institute, Silverton, Colorado, September 24-26, 2004.
  • Stanton, M.R., 2005, Baseline laboratory studies of sphalerite (ZnS) dissolution: effects on aqueous metal concentrations and solubilization rates [abs.]: National Meeting of the American Society of Mining and Reclamation (ASMR), Breckenridge, Colorado, June 19-23, 2005. (Abstract and presentation) Available online at http://ces.ca.uky.edu/asmr/ASMR%20Proceedings/abstracts%202005.pdf. [PDF file, 584 KB]
  • Stanton, M.R., and Horton, R.J., 2002, Mine-dump simulators to study acid mine drainage processes [abs.]: Geological Society of America 2002 Annual Meeting, Denver, Colorado, October 27-30, 2002, Abstracts with Programs, v. 34, no. 6, Abstract 45554. (Abstract and poster) Available online at http://gsa.confex.com/gsa/2002AM/finalprogram/abstract_45554.htm.

Contact Information

Mark Stanton
Box 25046 Denver Federal Center MS 964D
Denver, CO 80225-0046
Phone: (303) 236-1924
Email: Mark Stanton

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