Photocatalytic degradation of polycyclic aromatic hydrocarbons

By using an ultrasonic cleaner, ten selected polycyclic aromatic hydrocarbons (PAHs) namely naphthalene (2 rings), acenaphthylene (3 rings phenanthrene (3 rings), anthracene (3 rings), pyrene (4 rings), benazo[a]anthracene (4 rings), chrysene (4 rings), benzo[a]pyrene (5 rings dibenzo[a,h]anthracene (5 rings) and benzo[g,h,i]perylene (6 rings) could be 100% extracted from aqueous solution within I h. Photocatalytic reactivity of these PAHs towards PCO was correlated to the water solubility and electron distribution over PAH molecules. Acetone, a common solvent, was found to improve pholocatalytic degradation PAHs, especially for phenanthrene, pyrene, benzo[a]anthracene and benzo[a]pyrene. It is believed that acetone enhanced the water solubility of PAHs so that PAHs could more readily contact with the photocatalyst to facilitate degradation. However, addition of acetone could lower photocatalytic degradation of some PAHs with comparatively low water solubility.