Aqueous degradation of diclofenac by heterogeneous photocatalysis using nanostructured materials

作者：Martinez C; Canle L M^*; Fernandez M I; Santaballa J A; Faria J

来源：Applied Catalysis B: Environmental , 2011, 107(1-2): 110-118.

DOI：10.1016/j.apcatb.2011.07.003

• Persistent organic pollutants (POPs)
• Pharmaceuticals and personal care products (PPCPs)
• Heterogeneous photocatalysis
• Carbon nanotubes
• Diclofenac
• Reaction mechanisms

The photocatalytic degradation of diclofenac (DIC), 2-[2', 6'-(dichlorophenyl)amino]phenylacetic acid is investigated under near UV-Vis and UV irradiation, using commercial TiO2 P25, synthesized TiO2 (anatase and rutile) and functionalized multi-walled carbon nanotube (MWCNTox): anatase (10-MWCNTox-TiO2) suspensions as catalysts. Factors affecting the kinetics of the process, such as the type and load of photocatalyst, and the presence of dissolved O-2, or addition of H2O2 as co-oxidant have been compared. The degradation under UV irradiation is more effective than under near UV-Vis. Optimal conditions fora complete removal were obtained using synthesized anatase (0.5 g L-1) and 50% O-2 (v/v) under UV irradiation, with rate constants ca. 0.9 min(-1) (half-life time ca. 0.8 min). Eight photoproducts were observed from DIC photodegradation, mainly corresponding to photocyclisation (2-(8-chloro-9H-carbazol-1-yl)acetic acid, 1-chloro-8-methyl-9H-carbazole), decarboxylation (2,6-dichloro-N-o-tolylbenzenamine) and dehalogenation.

• 出版日期2011-8-31