Reusable adsorbents for dilute solution separation. 5. Photodegradation oforganic compounds on surfactant-modified titania

A semiconductor titania (TiO2) surface was modified by surfactant adsorptio n to make it more hydrophobic and to increase the adsorption of hydrophobic organic compounds (HOCs) and their photodegradation rates under UV irradia tion. Photocatalytic experiments using TiO2 suspensions were conducted in t he batch mode in a 10 ml reactor made of quartz, Two anionic surfactants, a hydrocarbon-based surfactant, sodium dodecylsulfate (SDS), and a fluorocar bon-based surfactant, potassium perfluorooctylsulfonate (PFOS), were used f or titania surface modification, A hydrophobic organic compound namely, 1,2 -dichlorobenzene (DCB), a chlorinated aromatic compound, was used as the te st HOC. PFOS, which is resistant to UV irradiation, increased both the adso rption and photodegradation of DCB on titania. SIDS, however, competed for photodegradation and inhibited the degradation of PCB. VD 2001 Elsevier Sci ence BN. All rights reserved.