抄録
We discuss the promotion effect of the sonochemical. reactions due to acoustic cavitation. Degradation of polymer (Poly Ethylene Oxide, PEO) and dye (rhodamine B, RB) was examined at the frequencies of 20 and 500 kHz with irradiation power of 5 W for 90 min sonication time. The temperature is controlled at 25℃ and the amount of the solution was 50mL. Degradation. rates of PEO and RB are estimated from sonication time dependence of viscosity and absorbance, respectively. In the additive-free case, degradation of PEO under 20 kHz irradiation is more effective than that under 500 kHz. The degradation rate of PEO in. aqueous solutions involving TiO_2 was the highest under 500 kHz sonication when ultraviolet irradiation was used concurrently. The effect of degradation rate of polymer increased about six times compared with the result without additive. The degradation of RB was enhanced under 500 kHz sonication with UV and TiO_2. These results are interpreted in terms that the production of radicals contributes to degradation of polymers and dyes. We also investigated a pilot-scale sonochemical reactor of 120 L under 500kHz irradiation.
