Photodegradation of phenanthrene in the presence of humic substances and hydrogen peroxide

The photodegradation of phenanthrene in water was investigated for a variety of reaction conditions employing various fulvic acids (FAs) as photosensitizers and hydrogen peroxide as oxidant. All experiments were conducted by using artificial sunlight from Suntest apparatus (Hanau, Germany) as light source. The relative rates of phenanthrene photodegradation for the different experimental conditions were computed. Fulvic acids of different origins influenced the rate of sunlight-induced photodegradation of phenanthrene in different ways. Hydrogen peroxide vigorously enhanced the photodegradation rate of phenanthrene. The photoproducts identified were oxygenated products of aromatic ring, such as 9,10,-phenanthrenquinone, a group of hydroxyphenanthrene with hydroxyl at different position (1,3,4, and 9), 2,2′-biphenyldicarbonic acid, 2,2′-biphenyldialdehyde and 2-phenylbenzaldehyde. It can be consumed that the phenanthrene photodegraded via free radical mechanism.