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

主要研究结果如下：1.在没有紫外光照射的情况下，在超声波作用下，二氧化钛的存在也促进了羟基化合物的生成。二氧化钛的作用可能是由于气泡的非均相成核，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，得出溶解气体对OH自由基生成的影响为Xe&Gt；Ar&Gt；O_2&Gt；N_2。辐照溶液的脱气完全抑制了OH自由基的生成。这些结果表明，即使在没有紫外光照射的情况下，二氧化钛的存在也加速了超声辐照过程中羟基化合物的形成，这一过程可能是通过诱导辐照溶液中的空化气泡来实现的。在二氧化钛存在下，对具有代表性的内分泌干扰物双酚A(BPA)和五氯苯酚(PCP)进行了超声处理，并用高效液相色谱/电子捕获检测器测定了BPA和PCP的浓度变化。随着辐照时间的延长，双酚A的初始浓度(1ppm)逐渐降低，经15min的超声辐照后，双酚A完全分解。PCP.3也观察到了类似的结果。结果表明，二氧化钛的杀菌率高于三氧化二铝的杀菌率，说明二氧化钛具有较高的协同作用。对E.Call的杀菌实验结果表明，添加谷胱甘肽和组氨酸可以抑制细胞的杀菌过程。这些结果与军团菌消毒实验结果一致，表明羟基自由基在这一过程中起主要作用。超声波辐照水溶液中的二氧化钛产生大量羟基自由基，导致内分泌干扰物和病原微生物等有害物质的分解。

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.