Department of Civil & Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore.
Water Res. 2013 Sep 1;47(13):4547-55. doi: 10.1016/j.watres.2013.04.056. Epub 2013 May 25.
In this study, an effective photocatalytic disinfection system was established using the newly emerged high power UVA/LED lamp. Crystallizing dish coated with TiO2 was prepared by 32-times impregnation-drying processes, and served as the supporting container for water samples. This study focused on the application of this UVA/LED system for the photocatalytic disinfection of selected antibiotic-resistant bacteria, Escherichia coli ATCC 700891. The disinfection performances were studied under various light intensities and illumination modes. Results show that higher light intensity could reach more significant inactivation of E. coli ATCC 700891. With the same UV dose, log-removal of antibiotic-resistant bacteria decreased with circle time in the studied range, while increased with duty circle. A "residual disinfecting effect" was found in the following dark period for bacteria collected at different phases of photocatalytic process. Residual disinfecting effect was found not significant for bacteria with 30 min periodic illumination. While residual disinfecting effect could kill almost all bacteria after 90 min UV periodic illumination within the following 240 min dark period.
在本研究中，使用新兴的高功率 UVA/LED 灯建立了一种有效的光催化消毒系统。采用 32 倍浸渍-干燥工艺制备了涂覆有 TiO2 的结晶皿，并用作水样的支撑容器。本研究重点研究了该 UVA/LED 系统在光催化消毒选定的抗生素耐药细菌大肠杆菌 ATCC 700891 中的应用。在不同光强和照明模式下研究了消毒性能。结果表明，更高的光强可以达到更显著的大肠杆菌 ATCC 700891 失活。在相同的紫外线剂量下，在所研究的范围内，抗生素耐药菌的对数减少随着循环时间的增加而增加，而随着占空比的增加而增加。在光催化过程的不同阶段收集的细菌在随后的黑暗期内发现了“残留消毒效果”。对于周期性光照 30 分钟的细菌，残留消毒效果不明显。然而，在随后的 240 分钟黑暗期内，经过 90 分钟的紫外线周期性光照后，残留消毒效果几乎可以杀死所有细菌。
