Fate of Crude Oil by the Combination of Photooxidation and Biodegradation

Photooxidation and biodegradation are the two most important factors involved in the transformation of crude oil or its products that are released into a marine environment. Natural microbial populations in seawater biodegraded 28% of crude oil within 8 weeks at 20 °C when sufficient nutrients were supplied to the seawater. Photooxidation mainly affected the aromatic compounds in crude oil and converted them to polar species. This treatment increased the amount of crude-oil components susceptible to biodegradation, and 36% of photooxidized crude oil could be degraded in 8 weeks at 20 °C. It is concluded that the susceptibility of crude oil to biodegradation is increased by its photooxidation.