Photo-catalytic oxidation of surfactant (polyoxyethylene-alkyl-ether, C14H29O(CH2CH2)7H, hereinafter
referred as SS-70) enhanced by high power ultrasound is examined. The influences of the ultrasonic
power and the stirring speed on the degradation rate are investigated. 1000 ml of 100ppm SS-70 is decomposed
totally in about 20 minutes in the photo-catalytic process combined with the ultrasonic irradiation.
Without ultrasonic irradiation, the decomposition needs more than 1 hour. The optimum conditions for the
hybrid degradation process are discussed. It is found that the stirring speed largely influenced the degradation
efficiency. It is considered that the catalyst particles might be localized by ultrasonic standing wave,
and caused inhibition to the decomposition in the degradation process. However, by high stirring speed, the
inhibition could be overcome.
