Department of Civil Engineering, University of Salerno, via Giovanni Paolo II, 1, 84084 Fisciano, SA, Italy.
Department of Civil Engineering, University of Salerno, via Giovanni Paolo II, 1, 84084 Fisciano, SA, Italy.
Water Res. 2014 Apr 15;53:145-52. doi: 10.1016/j.watres.2014.01.020. Epub 2014 Jan 24.
The effect of TiO₂ photocatalysis on the inactivation of an antibiotic resistant Escherichia coli strain selected from an urban wastewater treatment plant (UWWTP) effluent was investigated. Different light sources including a 250 W wide spectrum lamp, a 125 W UV-A lamp and solar radiation, as well as, photocatalysts loadings (TiO₂ Degussa P25) in the range from 0.05 to 2.00 g TiO₂ L(-1) were evaluated. The higher efficiency (total bacterial inactivation after 10 min of irradiation) was observed in the absence of TiO₂ when the wastewater was irradiated using the 250 W lamp. In the presence of TiO₂ a decreasing inactivation trend was observed (99.76% and 72.22% inactivation after 10 min irradiation at 0.10 and 2.00 g TiO₂ L(-1) respectively). Under solar simulated conditions the highest inactivation efficiency (93.17%) after 10 min of irradiation was achieved at the lower photocatalyst loading (0.05 g TiO₂ L(-1)). The concept of "reactor optical thickness" was introduced to explain the rates of disinfection observed. The optimum photocatalyst loading estimated by radiation absorption-scattering modeling was found to be 0.1 g TiO₂ L(-1) for all lamps. The difference between experimental tests and modeling may be due to TiO₂ particles aggregation. Comparative kinetic tests between solar and solar simulated photocatalytic (SSP) processes using 0.05 g TiO₂ L(-1) in suspension showed a quite similar inactivation behavior up to 30 min of irradiation, but only the SSP process resulted in a total inactivation of bacteria after 60 min of exposure. Antibiotic resistant test (Kirby-Bauer) on survived colonies showed that the SSP and SP processes affected in different ways the resistance of E. coli strain to the target antibiotics.
研究了 TiO₂ 光催化对从城市污水处理厂（UWWTP）出水中选择的耐抗生素大肠杆菌菌株失活的影响。评估了不同的光源，包括 250 W 宽光谱灯、125 W UV-A 灯和太阳辐射，以及负载量为 0.05 至 2.00 g TiO₂ L(-1) 的 TiO₂ 催化剂。当废水在 250 W 灯照射下没有 TiO₂ 时，观察到更高的效率（照射 10 分钟后总细菌失活）。当存在 TiO₂ 时，观察到失活趋势下降（在 0.10 和 2.00 g TiO₂ L(-1) 时，照射 10 分钟后分别为 99.76%和 72.22%的失活）。在模拟太阳条件下，在较低的光催化剂负载（0.05 g TiO₂ L(-1)）下，照射 10 分钟后达到了最高的失活效率（93.17%）。引入了“反应器光学厚度”的概念来解释观察到的消毒速率。通过辐射吸收散射建模估算的最佳光催化剂负载量为所有灯的 0.1 g TiO₂ L(-1)。实验测试与模型之间的差异可能是由于 TiO₂ 颗粒聚集造成的。在悬浮液中使用 0.05 g TiO₂ L(-1)的太阳能和太阳能模拟（SSP）过程的比较动力学测试表明，在照射 30 分钟内，两种过程的失活行为非常相似，但只有 SSP 过程在暴露 60 分钟后才能完全使细菌失活。对存活菌落进行的耐抗生素测试（Kirby-Bauer）表明，SSP 和 SP 过程以不同的方式影响大肠杆菌菌株对目标抗生素的耐药性。
