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13 BIODEGRADATION OF PHENOL IN UNDERGROUND COAL GASIFICATION MATRIX MATERIALS Godwin B.O. Biezugbe, Remediation Engineer Geraghty & Miller, Inc., Environmental Services Midland, Texas 79701 David H. Foster, Associate Professor Department of Civil and Architectural Engineering University of Wyoming Laramie, Wyoming 82071 John P. Turner, Assistant Professor Department of Civil and Architectural Engineering University of Wyoming Laramie, Wyoming 82071 INTRODUCTION AND BACKGROUND Underground Coal Gasification (UCG) involves combustion of coal in-situ and subsequent recovery of combustible, low-BTU gas at the surface.1 A potential environmental impact of UCG is the generation of soluble organic and inorganic compounds, including phenol, in the matrix materials (coal) surrounding the combustion zone. The presence of phenol in the subsurface poses a potential threat to groundwater. While traditional pump and treat methods have been used for cleanup of UCG sites, results reported to date indicate only limited success.2 Bioremediation is a potentially more effective approach to site cleanup and may have environmental as well as economical advantages over pump and treat methods. This paper describes a laboratory study to evaluate the potential for biodegradation of phenol in UCG matrix materials. Two sets of laboratory tests were conducted using Wyoming subbituminous coal treated with various concentrations of phenol. These include: 1) adsorption tests, to characterize the isotherms for adsorption of phenol on representative UCG matrix materials, and 2) biodegradation tests, in which the Monod biokinetic parameters were determined as a function of initial phenol concentration, bacterial type and density, and nutrient type. METHODS AND MATERIALS Coal samples were obtained from Eagle Butte coal mine near Gillette, Wyoming. The Eagle Butte coal is a low-rank, subbituminous coal and is typical of Wyodak coals found in the Powder River Basin. It comes from the same seam and is essentially the same coal that forms the matrix material at Hoe Creek, a U.S Department of Energy UCG site a few away miles from Eagle Butte mine. Coal samples were crushed and sieved to 1/4 inch. This size is assumed to approximate the surface area of the fractured virgin coal seam surrounding the combustion zone following in situ combustion.3 ADSORPTION AND BIODEGRADATION TESTS Adsorption tests were performed in a batch mode in 50-mL Teflon centrifuge tubes. Equilibrium time of 96 hours was used, based upon previous work by Humenick et al.4 Tests were conducted at 5 initial aqueous-phase phenol concentrations, arranged in decreasing concentration order, at contact times of 2, 4, 8, 24, 48, and 96 hours. This arrangement produces a constant solid to solution ratio isotherm.' Approximately one gram of weighed coal was contacted with 45 mL of phenol solution and placed in a centrifuge tube. The tubes were sealed, placed in a wrist-action shaker, and allowed to equilibrate. Following each of the equilibration times cited above, tubes were centrifuged for 1 hr at 3,000 rpm. Supernatant from the tubes were decanted and phenol was extracted from each of the aqueous phases 47ih Purdue Industrial Waste Conference Proceedings, 1992 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 119
Object Description
Purdue Identification Number | ETRIWC199213 |
Title | Biodegradation of phenol in underground coal gasification matrix materials |
Author |
Biezugbe, Godwin B. O. Foster, David H. Turner, John P. |
Date of Original | 1992 |
Conference Title | Proceedings of the 47th Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://e-archives.lib.purdue.edu/u?/engext,43678 |
Extent of Original | p. 119-126 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-12-10 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 119 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | 13 BIODEGRADATION OF PHENOL IN UNDERGROUND COAL GASIFICATION MATRIX MATERIALS Godwin B.O. Biezugbe, Remediation Engineer Geraghty & Miller, Inc., Environmental Services Midland, Texas 79701 David H. Foster, Associate Professor Department of Civil and Architectural Engineering University of Wyoming Laramie, Wyoming 82071 John P. Turner, Assistant Professor Department of Civil and Architectural Engineering University of Wyoming Laramie, Wyoming 82071 INTRODUCTION AND BACKGROUND Underground Coal Gasification (UCG) involves combustion of coal in-situ and subsequent recovery of combustible, low-BTU gas at the surface.1 A potential environmental impact of UCG is the generation of soluble organic and inorganic compounds, including phenol, in the matrix materials (coal) surrounding the combustion zone. The presence of phenol in the subsurface poses a potential threat to groundwater. While traditional pump and treat methods have been used for cleanup of UCG sites, results reported to date indicate only limited success.2 Bioremediation is a potentially more effective approach to site cleanup and may have environmental as well as economical advantages over pump and treat methods. This paper describes a laboratory study to evaluate the potential for biodegradation of phenol in UCG matrix materials. Two sets of laboratory tests were conducted using Wyoming subbituminous coal treated with various concentrations of phenol. These include: 1) adsorption tests, to characterize the isotherms for adsorption of phenol on representative UCG matrix materials, and 2) biodegradation tests, in which the Monod biokinetic parameters were determined as a function of initial phenol concentration, bacterial type and density, and nutrient type. METHODS AND MATERIALS Coal samples were obtained from Eagle Butte coal mine near Gillette, Wyoming. The Eagle Butte coal is a low-rank, subbituminous coal and is typical of Wyodak coals found in the Powder River Basin. It comes from the same seam and is essentially the same coal that forms the matrix material at Hoe Creek, a U.S Department of Energy UCG site a few away miles from Eagle Butte mine. Coal samples were crushed and sieved to 1/4 inch. This size is assumed to approximate the surface area of the fractured virgin coal seam surrounding the combustion zone following in situ combustion.3 ADSORPTION AND BIODEGRADATION TESTS Adsorption tests were performed in a batch mode in 50-mL Teflon centrifuge tubes. Equilibrium time of 96 hours was used, based upon previous work by Humenick et al.4 Tests were conducted at 5 initial aqueous-phase phenol concentrations, arranged in decreasing concentration order, at contact times of 2, 4, 8, 24, 48, and 96 hours. This arrangement produces a constant solid to solution ratio isotherm.' Approximately one gram of weighed coal was contacted with 45 mL of phenol solution and placed in a centrifuge tube. The tubes were sealed, placed in a wrist-action shaker, and allowed to equilibrate. Following each of the equilibration times cited above, tubes were centrifuged for 1 hr at 3,000 rpm. Supernatant from the tubes were decanted and phenol was extracted from each of the aqueous phases 47ih Purdue Industrial Waste Conference Proceedings, 1992 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 119 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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