This study aimed at investigating the synergistic effect of temperature and biosurfactant on the biodegradation of phenanthrene in bioslurry. Bench-scale bioslurry experiments were conducted at 25 and 55°C. The desorption rate coefficients of phenanthrene (Kdes) obtained using the pseudo-first order model were 0.0026 and 0.0035kgmg-1h-1 at 25 and 55°C, respectively. Addition of 1500mgL-1 biosurfactant, produced by Acinetobacter calcoaceticus BU03, marginally increased the Kdes at 25°C since most of biosurfactant was sorbed onto soil; however, significantly increased the Kdes to 0.0087kgmg-1h-1 at 55°C as the thermophilic temperature reduced the adsorption of the biosurfactant onto soil and subsequently enhanced the desorption of phenanthrene. The biodegradation of phenanthrene well fitted pseudo-first order kinetics based on the assumption that biodegradation was limited by the desorption. About 78.7% of phenanthrene was degraded in 30 days at 25°C; and addition of biosurfactant did not affect the biodegradation. However, addition of the biosurfactant or inoculation of A. calcoaceticus BU03 at 55°C significantly enhanced the biodegradation by increasing the Kdes. Results indicate that synergistic application of thermophilic temperature and biosurfactant or inoculation of biosurfactant producing microorganisms is an effective and innovative method to enhance the efficiency of PAH degradation in bioslurry system.
Scopus Subject Areas
- Environmental Engineering
- Environmental Chemistry
- Waste Management and Disposal
- Health, Toxicology and Mutagenesis
- Acinetobacter calcoaceticus BU03