Presentation

Monday
8:15 Brent Means
10:10 James J. Gusek
12:40 Jonathan M. Dietz
2:15 Kimberly R. Weaver
4:00 Brent Means

Tuesday
8:45 Robert Kleinmann
9:15 Brent Means
9:30 James J. Gusek
10:00 Glenn C. Miller
10:30 Linda Ann Figueroa
12:40 Art Rose
1:10 Charles A. Cravotta III
1:40 Danielle M C Huminicki
2:50 Bernard Aube
3:20 Timothy K. Tsukamoto
3:50 Bradley R. Shultz
4:20 Kimberly R. Weaver

Wednesday
8:00 Linda Ann Figueroa
8:30 John Senko
9:00 Song Jin
10:10 Jonathan M. Dietz
10:40 Daryle H. Fish
12:40 John Chermak
1:10 Griff Wyatt
1:40 Dan Mueller
2:50 Sean C. Muller
3:20 Jack Adams
3:50 Roger Bason
3:50 Mark B. Carew

Thursday
8:00 Rep. John E. Peterson
8:30 Scott Sibley
9:00 Charles A. Cravotta III
9:30 Michael R. Silsbee
10:30 Lykourgos Iordanidis
11:00 Mark Conedera
11:30 Barry Scheetz
1:25 William Benusa
1:55 Mike Sawayda
2:25 Susan J. Tewalt
3:25 Robert S. Hedin
3:55 Chad J. Penn
4:25 Ron Neufeld

Wednesday 8:30 John Senko, Post-doctoral Research Associate, Dept of Civil & Environmental Engineering, Penn State University

Geomicrobiological characterization of Fe(II)- and Mn(II)-oxidizing activity at two mine drainage treatment sites

Author(s)

John M. Senko, Ph.D.
Center for Environmental Chemistry and Geochemistry
The Pennsylvania State University
University Park, PA 16802
senko@engr.psu.edu

William Burgos and Ashley Davidson
Penn State University

Abstract

We characterized geomicrobiological activities in two acid mine drainage treatment sites. A mine water discharge stream near Altoona, PA contains low pH (3.5) water with abundant soluble Fe(II) (2 mM), which remains at a high concentration over the course of the 29 m stream. Abundant Fe(III) crusts are evident in the stream, and oxygen concentration increases from approx. 5 ?M to approx. 135 ?M from the point of water emergence to the end of the stream. Fe(III) solids become less crystalline and less dense in regions as oxygen levels increase in the stream. Akaganeite and schwertmanninte predominate in the high-oxygen regions of the stream, while goethite is evident in the low-oxygen regions. Numbers of acidophilic, aerobic Fe(II)-oxidizing bacteria remain constant throughout the stream (approximately 6 x 104), suggesting that oxygen levels do not control numbers of Fe(II)-oxidizing bacteria, but may control the Fe(III) products formed by these organisms. Mn(II)-oxidizing activity was characterized in a limestone-based Mn removal bed located in Elk County, PA. Water (pH 5.2) emerges from an anoxic limestone drain and flows through a limestone bed where water pH increases to 6.5 at the end of the bed, with a corresponding decrease in soluble Mn(II) from 1.6 mM to less than 0.05 mM. Mn(II)-oxidizing bacteria comprise 20-44% of the total heterotrophic bacteria in the region of the bed where Mn(II) removal is occurring, suggesting that the prerequisite microorganisms for Mn(II) oxidation are present, and abundant in the Mn removal bed. Our results suggest that Fe(II)- or Mn(II)-oxidizing bacteria are present at acid mine drainage treatment sites whose activity may be exploited and stimulated for efficient removal of these metal contaminants.

Presentation

Biography

John Senko received a B.S. in Biology from St. Vincent College in Latrobe, PA, an M.S. in Biology from Duquesne University, Pittsburgh, PA studying the enzymology of nitrate reduction in the iron-reducing bacterium Geobacter metallireducens, and his Ph.D. from the University of Oklahoma, Norman, OK studying anaerobic uranium reduction and oxidation with Lee Krumholz and Joe Suflita. Currently, he's a post-doc with the Center for Environmental Chemistry and Geochemistry at Penn State, working with Bill Burgos.