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Title: Solubilization, Solution Equilibria, and Biodegradation of PAH's under Thermophilic Conditions

Abstract

Biodegradation rates of PAHs are typically low at mesophilic conditions and it is believed that the kinetics of degradation is controlled by PAH solubility and mass transfer rates. Solubility tests were performed on phenanthrene, fluorene and fluoranthene at 20 C, 40 C and 60 C and, as expected, a significant increase in the equilibrium solubility concentration and of the rate of dissolution of these polycyclic aromatic hydrocarbons (PAHs) was observed with increasing temperature. A first-order model was used to describe the PAH dissolution kinetics and the thermodynamic property changes associated with the dissolution process (enthalpy, entropy and Gibb's free energy of solution) were evaluated. Further, other relevant thermodynamic properties for these PAHs, including the activity coefficients at infinite dilution, Henry's law constants and octanol-water partition coefficients, were calculated in the temperature range 20-60 C. In parallel with the dissolution studies, three thermophilic Geobacilli were isolated from compost that grew on phenanthrene at 60 C and degraded the PAH more rapidly than other reported mesophiles. Our results show that while solubilization rates of PAHs are significantly enhanced at elevated temperatures, the biodegradation of PAHs under thermophilic conditions is likely mass transfer limited due to enhanced degradation rates.

Authors:
; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
944477
DOE Contract Number:
AC36-99-GO10337
Resource Type:
Journal Article
Resource Relation:
Journal Name: Chemosphere; Journal Volume: 66; Journal Issue: 6, 2007
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; BIODEGRADATION; CONDENSED AROMATICS; DILUTION; DISSOLUTION; ENTHALPY; ENTROPY; FLUORENE; FREE ENERGY; KINETICS; MASS TRANSFER; MESOPHILIC CONDITIONS; PHENANTHRENE; POLYCYCLIC AROMATIC HYDROCARBONS; REACTION KINETICS; SOLUBILITY; THERMODYNAMIC ACTIVITY; THERMODYNAMIC PROPERTIES; THERMODYNAMICS; THERMOPHILIC CONDITIONS; Chemical Technologies

Citation Formats

Viamajala, S., Peyton, B. M., Richards, L. A., and Petersen, J. N.. Solubilization, Solution Equilibria, and Biodegradation of PAH's under Thermophilic Conditions. United States: N. p., 2007. Web. doi:10.1016/j.chemosphere.2006.06.059.
Viamajala, S., Peyton, B. M., Richards, L. A., & Petersen, J. N.. Solubilization, Solution Equilibria, and Biodegradation of PAH's under Thermophilic Conditions. United States. doi:10.1016/j.chemosphere.2006.06.059.
Viamajala, S., Peyton, B. M., Richards, L. A., and Petersen, J. N.. Mon . "Solubilization, Solution Equilibria, and Biodegradation of PAH's under Thermophilic Conditions". United States. doi:10.1016/j.chemosphere.2006.06.059.
@article{osti_944477,
title = {Solubilization, Solution Equilibria, and Biodegradation of PAH's under Thermophilic Conditions},
author = {Viamajala, S. and Peyton, B. M. and Richards, L. A. and Petersen, J. N.},
abstractNote = {Biodegradation rates of PAHs are typically low at mesophilic conditions and it is believed that the kinetics of degradation is controlled by PAH solubility and mass transfer rates. Solubility tests were performed on phenanthrene, fluorene and fluoranthene at 20 C, 40 C and 60 C and, as expected, a significant increase in the equilibrium solubility concentration and of the rate of dissolution of these polycyclic aromatic hydrocarbons (PAHs) was observed with increasing temperature. A first-order model was used to describe the PAH dissolution kinetics and the thermodynamic property changes associated with the dissolution process (enthalpy, entropy and Gibb's free energy of solution) were evaluated. Further, other relevant thermodynamic properties for these PAHs, including the activity coefficients at infinite dilution, Henry's law constants and octanol-water partition coefficients, were calculated in the temperature range 20-60 C. In parallel with the dissolution studies, three thermophilic Geobacilli were isolated from compost that grew on phenanthrene at 60 C and degraded the PAH more rapidly than other reported mesophiles. Our results show that while solubilization rates of PAHs are significantly enhanced at elevated temperatures, the biodegradation of PAHs under thermophilic conditions is likely mass transfer limited due to enhanced degradation rates.},
doi = {10.1016/j.chemosphere.2006.06.059},
journal = {Chemosphere},
number = 6, 2007,
volume = 66,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
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