SREL Reprint #2289

Abundance of iron-oxidizing thiobachilli and biological sulfur oxidation potential from soil impacted by coal and coal refuse piles

B. Klubek1, C. Schmidt1, and D. C. Adriano2

1Department of Plant and Soil Science, Southern Illinois University, Carbondale, IL 62901-4414, USA
2Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29801, USA

Abstract: This study was conducted to assess the abundance of iron-oxidizing bacteria and biological sulfur oxidation potential from soil impacted by coal and coal refuse from two coal-burning electric power facilities located at the U.S. Department of Energy's Savannah River Site (Aiken, S.C.) and the South Carolina Electric and Gas Site at Beech Island, S. C.

Significantly higher MPN counts of iron-oxidiziing bacteria were obtained from samples collected at the confluence of a coal storage runoff containment basin, a coal reject (refuse) pile, and an adjacent wetland at the Savannah River Site. Significant differences in pH, sulfate-S, ferrous- and ferric-iron were also obtained between sampling locations. No significant differences in ferric/ferrous ratios were determined. These ratios however, exceeded a value of 2.0 when sample pH values were less than 4.5.

Under optimal conditions, biological thiosulfate-S oxidation potentials (in vitro) showed a 4- to 7-day lag in the appearance of sulfate-S, and a final pH (after twenty-four days of perfusion) of 1.97 to 3.90. These results indicate that contamination of subsurface water by acidic leachate derived from thionic bacterial activity will occur if coal and coal refuse piles are not confined by an impermeable surface or containment facility.

Keywords: coal leachate, coal refuse, iron-oxidizing thiobacilli, biological thiosulfate oxidation potential

SREL Reprint #2289

Klubek, B., C. Schmidt, and D.C. Adriano. 1998. Abundance of iron-oxidizing thiobachilli and biological sulfur oxidation potential from soil impacted by coal and coal refuse piles. Water, Air, and Soil Pollution 106:1-16.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).