Photocatalytic degradation of paraquat Combined with a genotoxicity Study of the Intermediate Products

Photodegradation of paraquat in aqueous suspension of polycrystalline TiO2 : genotoxicity by using ames test

Photocatalytic Degradation of Paraquat and Genotoxicity of its Intermediate Products

Abstract The photocatalytic degradation of paraquat (1,1-dimethyl-4,4′-bipyridylium dichloride) aqueous solutions in the presence of polycrystalline TiO2 Degussa P25 irradiated by near-UV light was investigated. The substrate and total organic carbon concentrations were monitored by UV spectroscopy and TOC measurements, respectively: the complete photocatalytic mineralization of paraquat (20 ppm) was achieved after ca. 3 h of irradiation by using 0.4 g l−1 of catalyst amount at natural pH (ca 5.8). On the contrary no significant photodegradation of paraquat was observed in the absence of TiO2 under similar experimental conditions. To evaluate the genotoxicity of paraquat and its intermediat…