Sonophotochemical degradation of bisphenol a with solid catalysts

In order to investigate the degradation of bisphenol A (BPA) solution under sono, photo, sonocatalytic, photocatalytic and sonophotocatalytic processes, the BPA concentration and the total organic carbon (TOC) concentration were analyzed. The degradation rate of BPA was higher at high frequency (1 MHz) than at low frequency (300 kHz). At high frequency the acoustic period is shorter, and a high H₂O₂ concentration is therefore produced in aqueous solutions, which can enhance the degradation rate. The degradation rates of BPA were 0.0060, 0.0258, and 0.0451 min¹ under the sonocatalytic (1 MHz), photocatalytic and sonophotocatalytic processes respectively. The combined system of the sonochemical and photocatalytic processes can enhance the degradation rate of BPA compared with individual processes (sono and photocatalytic processes). The order of degradation of BPA (CuO > ZnO ≈ TiO₂) and TOC (TiO₂ > ZnO > CuO) differed for each of the three types of catalysts. The separation characteristics of catalysts were dissimilar for each of the two frequencies.