Anaerobic biodegradation of naphthalene and anthracene using different terminal electron acceptors

Polycyclic aromatic hydrocarbons (PAHs) have been classified as priority pollutants by Environment Canada. Intrinsic anaerobic bioremediation of PAHs may offer a cheap and effective soil remediation strategy. The objectives of this research were to develop the methodology for analysis of two PAHs, naphthalene and anthracene, by fluorescence spectrophotometry, and to demonstrate the biodegradability and mineralization of naphthalene and anthracene under anaerobic conditions using different terminal electron acceptors (TEA). Results demonstrate that fluorescence spectrometry was an effective and highly sensitive method to monitor naphthalene degradation, measuring concentrations as low as 0.005 ppm based on my standard calibration curve. This is lower than the 0.01 ppm measured by HPLC methods.; The rate of naphthalene degradation in terms of various terminal electron acceptors was found to have the following order: O₂>NO₃>SO ₄2>Fe3+>>no TEA. Mineralization and naphthalene disappearance had a similar trend. These results demonstrate that naphthalene can be completely degraded by naphthalene degraders from a coal-tar contaminated sediment indicating that intrinsic biodegradation is potentially possible. This is the first report of PAH biodegradation using Fe3+ as a terminal electron acceptor.; In 160 days, mineralization of anthracene was also achieved using various TEAs but at a lower extent and rate compared to naphthalene. This may be due to its lower solubility in aqueous phase resulting in a poorer bioavailability.