https://www.omicsonline.org/peer-reviewed/enhanced-degradation-of-benzopyrene-in-coal-tar-contaminated-soilsrnusing-biodiesel-98390.html
Research Article
Enhanced Degradation of Benzo[ñ]Pyrene in Coal Tar Contaminated Soils
Using Biodiesel
Abstract
The biodegradation of the potent carcinogen, benzo[a]pyrene (BaP), and
other priority pollutants was investigated in un-weathered coal tar
contaminated soil over a period of 150 days. Results from the laboratory
microcosm experiments showed that after 60 days, the concentrations of
BaP were significantly reduced by 81%, in the biodiesel amended samples
compared to the 26% and 34% depletion in the control and nutrient-only
amended microcosms, respectively. The 3-ring PAH anthracene was also
almost completely biodegraded in the presence of biodiesel. However,
phenanthrene degradation was significantly inhibited in these samples as
only 3% reduction occurred as opposed to the 80% depletion observed in
the control. A stepwise treatment approach conducted on the coal tar
spiked soil also revealed a higher reduction in BaP (98%) in the
biodiesel amended microcosms compared to the control (29%) and further
enhanced the depletion of phenanthrene by 51% after 60 days of adding
biodiesel to soil initially treated with nutrients. Toxicity assays
showed that biodiesel amended microcosms stimulated phosphatase enzyme
activity and exhibited a lower toxic response to Microtox Vibrio
fischeri. Overall, the pattern observed in the removal of the PAHs using
biodiesel, suggests the co-metabolic action of ligninolytic fungi,
probably via lignin peroxidases, as also evidenced from the visible
growth of moulds after 14 days of amendment. The enhanced removal of
carcinogenic PAH and the reduced toxicity observed in soil after
biodiesel amendment, indicates that this bioremediation technique has
potential for full scale field trials.
