Kinetics of disinfection of Escherichia coli by catalytic ultrasonic irradiation with TiO2
Kinetics of disinfection of Escherichia coli by catalytic ultrasonic irradiation with TiO2
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DOI：
10.1016/j.bej.2005.04.028
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发表时间：
2005-10-01
影响因子：
3.9
通讯作者：
Shimizu, N
中科院分区：
文献类型：
--
作者：
Dadjour, MF;Ogino, C;Shimizu, N
研究了在TiO2光催化剂存在下，利用超声辐照系统对大肠杆菌进行消毒的动力学。研究发现，二氧化钛能显著改善消毒过程。在30min的照射时间内，在二氧化钛存在的情况下，活细胞的浓度下降了98%，而使用普通的超声波照射系统时，只观察到了13%的下降。二氧化钛对细胞的杀伤率也高于三氧化二铝。在检测的浓度范围内，杀菌率与二氧化钛的量成正比。在2.0g/mlTiO2光照射下，细胞浓度在10min内下降5个数量级。细胞浓度在10(3)~10(7)cfu/ml范围内对细胞杀伤过程无明显影响。通过检测组氨酸和谷胱甘肽等羟基自由基清除剂的作用，进一步探讨了细胞杀伤的机制。含有这些自由基清除剂的样品的消毒率降低，因此表明自由基在这一过程中起着重要作用。(C)2005 Elsevier B.V.保留所有权利。
The kinetics of disinfection of Escherichia coli, in the presence of a TiO2 photocatalyst, using an ultrasonic irradiation system was investigated. TiO2 was found to significantly improve the disinfection process. A 98% reduction in the concentrations of viable cells was obtained in the presence of TiO2 during a 30 min period of irradiation, while only a 13% reduction was observed when an ordinary ultrasonic irradiation system was used. The rate of cell killing was also higher in the presence of TiO2 compared with Al2O3. The rate of disinfection was proportional to the amount of TiO2 in the concentration range examined. Cell concentrations were decreased by an order of 5 within 10 min of irradiation in the presence of 2.0 g/ml TiO2. No significant effect of cell concentration on the cell-killing process was found in the range of 10(3) to 10(7) CFU/ml. The mechanism of cell killing was further investigated by examining the effects of OH radical scavengers, such as histidine and glutathione. The rate of disinfection was decreased in samples containing these radical scavengers, thus indicating that radicals are of major importance in this process. (c) 2005 Elsevier B.V. All rights reserved.