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

Journal Article · Mon Jan 01 00:00:00 EST 2007 · Chemosphere

DOI:https://doi.org/10.1016/j.chemosphere.2006.06.059· OSTI ID:944477

Viamajala, S; Peyton, B M; Richards, L A; Petersen, J N

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.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC36-99-GO10337
• OSTI ID: 944477
• Journal Information: Chemosphere, Vol. 66, Issue 6, 2007; ISSN 0045-6535
• Country of Publication: United States
• Language: English

Related Subjects

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