An environmental assurance system by catalytic ultrasonic irradiation with functional TiO2 particles.

本研究的主要结果如下：1. TiO_2的存在促进了超声波辐照下OH自由基的生成。TiO_2的作用可能是由于气泡的异质形核，从而增强了空化能力。进一步研究了溶解气体对OH自由基生成的影响，结果表明：溶解气体对OH自由基生成的影响大小顺序为：Ar>O_2>N_2。辐照溶液的脱气完全抑制了OH自由基的形成。这些结果表明，即使在没有紫外线照射的情况下，TiO_2的存在也会加速超声照射过程中OH自由基的形成，并且该过程可能是通过诱导照射溶液中的气穴气泡来介导的。2.在TiO_2存在下，对双酚A（BPA）和五氯酚（PCP）进行超声降解，并用高效液相色谱/电子捕获检测器（HPLC/ECD）测定其浓度变化。BPA的初始浓度（1 ppm）随着照射时间的延长而逐渐降低，并且通过15分钟的超声波照射被完全分解。对五氯苯酚也观察到类似的结果。结果表明，TiO_2的杀菌率高于Al_2O_3，表明TiO_2具有更强的协同作用。结果表明，用该方法对大肠杆菌进行了消毒。Call表明，谷胱甘肽和组氨酸的加入可以抑制细胞消毒过程。超声波对TiO_2水溶液的辐照能产生大量的羟基自由基，羟基自由基是降解内分泌干扰物和病原微生物等有害物质的主要因素。

The results of this study are summarized as follows:1. The presence of TiO_2 accelerates the formation of OH raidicals during ultrasonic irradiation even in the absence of UV irradiation. The effect of TiO_2 may be due to the heterogeneous nucleation of bubbles, which enhances the cavitation power. The effect of dissolved gases on the formation of OH radicals was further studied and the power of the dissolved gases on the formation of OH radicals was in the order Xe>Ar>O_2>N_2. The degassing of the irradiation solution completely suppressed the formation of OH radicals. These results indicate that the presence of TiO_2 accelerates the formation of OH raidicals during ultrasonic irradiation even in the absence of UV irradiation and the process may be mediated through the induction of cavitation bubbles in irradiating solutions.2. Ultrasonification of bisphenol A (BPA) and pentachlorophenol (PCP), a representative endocrine disruptors, were carried out in the presence of TiO_2 and the change in the concentration of BPA and PCP were measured by HPLC/ECD. The initial concentration of BPA (1 ppm) was gradually decreased with the irradiation time and was totally decomposed by 15 minute irradiation of ultrasound. The similar results were observed for PCP.3. It was shown that the rate of disinfection obtained in the case of TiO_2 was higher than that observed in the presence of Al_2O_3, indicating a higher synergistic effect for TiO_2. The results obtained in the disinfection of E. call showed that the addition of glutathione and histidine could suppress the cell disinfection process. These results were supported by the same results obtained in the disinfection of Legionella, indicating the primary role of hydroxyl radicals in this process.The irradiation of ultrasound on TiO_2 in aqueous solution significantly generate hydroxyl radicals which is responsible for the decomposition of the hazardous materials such as endocrine disruptors and pathogenic microorganisms.