PHOTOCATALYTIC DEGRADATION OF TOLUENE IN WASTEWATER BY SUSPENDED AND DIPPING COATED TITANIUM DIOXIDE INCORPORATING WITH SURFACTANT

The toluene degradation in synthetic wastewater was performed by liquid-solid photocatalytic process using titanium dioxide (anatase phase) as the catalyst under UV irradiation and flowing oxygen gas. Two different systems of titania catalyst; suspension and dipping coated titanium dioxide catalysts containing 0.1-1.0 mM of sodium dodecylsulfate (SDS) surfactant, were carried out. The mixture was irradiated with UV lamp at 27 ± 1oC and toluene concentration was analyzed by HPLC. The toluene degradati on coefficients (C/C0) of 250 mL, 100 mg.L -1 toluene solution catalyzed by suspension titania and that containing dipping coated titania catalyst were compared. The toluene degradation catalyzed by 0.5 mg.L -1 suspension titania catalyst containing 0.6 mM surfactant was complete within 60 min, whereas the optimum of the toluene degradation coefficient for the dipping coated titania system containing 1.0 mM surfactant was 0.20 at 60 min. However, the maximum toluene degradation based on specific activity of the dipping coated titania with 1.0 mM SDS was 1,000 mg.g -1 titania, higher than that of the suspended titania which was 200 mg.g -1 . Furthermore, the toluene degradation by the