Study on mechanism of degradation 4-toluene sulfonic acid by sonophotocatalysis
超声波光催化协同降解对甲基苯磺酸水溶液的机理研究

Degradation of bio-refractory 4-Toluene sulfonic acid (4-TSA) in simulated wastewater by sonophotocatalysis was experimentally studied. The reaction mechanism was explored primarily by ultraviolet spectroscopy, infrared spectroscopy, mass spectrum, gas chromatography, high performance liquid chromatography, chemical oxygen demand and total organic carbon analysis. Results indicated that there was synergistic effect between ultrasonic and photocatalysis on degradation of 4-TSA; the removal rate reached to 93.4% under the optimum condition that included 30 mg/L of initial 4-TSA concentration, 100 mg/L of TiO2 concentration, 80 W and 45 kHz of ultrasonic power and frequency, pH 3.0 and 120 min of reaction time. The analysis showed that the intermediate products of oxidized 4-TSA were hydroquinone, p-benzoquinone, maleic acid, glyoxylic acid and other small organic molecules, and the ultimate products were H2O, CO2 and SO2-4.