Photodegradation of alpha-naphthaleneacetic acid in aqueous solution

Kinetic processes of alpha-naphthaleneacetic acid (NAA) photolysis were studied under different conditions. The results showed that the ultraviolet light was more effective than fluorescent light in promoting degradation, and the degradation of NAA under ultraviolet light followed the first order kinetics with the photolysis rate constant of 1.15 x 10(-2) min-1 and half-life time (t1/2) of 60 min. Further, it was proved that the photolysis rate was higher in the presence of oxygen, titanium dioxide (TiO2), and low pH (acidic solution). At last, two photolysis intermediates were identified by GC-MS and possible photolysis pathways were proposed.