在可见光照射下使用C70-TiO2复合材料对大肠杆菌O157:H7进行高效光催化消毒
Efficient Photocatalytic Disinfection of Escherichia coli O157:H7 using C70-TiO2 Hybrid under Visible Light Irradiation.
作者信息
Ouyang Kai, Dai Ke, Walker Sharon L, Huang Qiaoyun, Yin Xixiang, Cai Peng
机构信息
State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, USA.
出版信息
Sci Rep. 2016 May 10;6:25702. doi: 10.1038/srep25702.
Efficient photocatalytic disinfection of Escherichia coli O157:H7 was achieved by using a C70 modified TiO2 (C70-TiO2) hybrid as a photocatalyst under visible light (λ > 420 nm) irradiation. Disinfection experiments showed that 73% of E. coli O157:H7 died within 2 h with a disinfection rate constant of k = 0.01 min(-1), which is three times that measured for TiO2. The mechanism of cell death was investigated by using several scavengers combined with a partition system. The results revealed that diffusing hydroxyl radicals play an important role in the photocatalytically initiated bacterial death, and direct contact between C70-TiO2 hybrid and bacteria is not indispensable in the photocatalytic disinfection process. Extracellular polymeric substances (EPS) of bacteria have little effect on the disinfection efficiency. Analyses of the inhibitory effect of C70-TiO2 thin films on E. coli O157:H7 showed a decrease of the bacterial concentration from 3 × 10(8) to 38 cfu mL(-1) in the solution with C70-TiO2 thin film in the first 2 h of irradiation and a complete inhibition of the growth of E. coli O157:H7 in the later 24 h irradiation.
通过使用C70修饰的TiO2（C70-TiO2）杂化物作为光催化剂，在可见光（λ> 420 nm）照射下实现了对大肠杆菌O157:H7的高效光催化消毒。消毒实验表明，73%的大肠杆菌O157:H7在2小时内死亡，消毒速率常数k = 0.01 min(-1)，这是TiO2测量值的三倍。通过使用几种清除剂结合分配系统研究了细胞死亡机制。结果表明，扩散的羟基自由基在光催化引发的细菌死亡中起重要作用，并且在光催化消毒过程中C70-TiO2杂化物与细菌之间的直接接触不是必不可少的。细菌的胞外聚合物（EPS）对消毒效率影响很小。对C70-TiO2薄膜对大肠杆菌O157:H7的抑制作用分析表明，在照射的前2小时内，含有C70-TiO2薄膜的溶液中细菌浓度从3×10(8)降至38 cfu mL(-1)，并且在随后的24小时照射中完全抑制了大肠杆菌O157:H7的生长。
Zotero 插件