PHOTOCATALYTIC DEGRADATION OF THE HYDROPHOBIC PESTICIDE PERMETHRIN IN FLUORO SURFACTANT/TIO2 AQUEOUS DISPERSIONS

The hydrophobic permethrin can be easily photodecomposed into CO2 and Cl- ions in a fluoro surfactant / TiO2 aqueous dispersion, since permethrin can be solubilized in the micellae of non-photodegradable fluoro surfactants. The aromatic cleavage, dechlorination and CO2 evolution rates in the degradation of permethrin with the pure TiO2 (P-25) catalyst increase in the order of cationic surfactant < water < anionic surfactant system. Those with the modified TiO2 (T-805) catalyst increase in the order of anionic surfactant < water < cationic surfactant system.