Wang Jingzhu, Abe Akihisa, Wang Yiwei, Huang Chenguang
Key Laboratory for Mechanics in Fluid Solid Coupling Systems, Institute of Mechanics, Chinese Academy of Sciences, No. 15 Beisihuanxi Road, Haidian Distinct, Beijing 100190, China; School of Engineering Science, University of Chinese Academy of Sciences, China.
Graduate School of Maritime Sciences, Kobe University, 5-1-1 Fukaeminami-machi, Kobe 658-0022, Japan.
Ultrason Sonochem. 2018 Apr;42:541-550. doi: 10.1016/j.ultsonch.2017.11.047. Epub 2017 Dec 22.
The effect of shock sterilization on marine Vibrio sp. is investigated by carrying out a bio-experiment based on a bubble-shockwave interaction. In the experiments, underwater shock waves with different strength and frequencies are produced by a high-voltage power supply in a cylindrical water chamber. The bio-experimental results show marine Vibrio sp. is completely inactivated in a short time by a 1.0-Hz electric discharge. However, a high sterilization effect requires a strong and high frequency of the bubble motion, and it also depends on the lifetime of the bubble. Subsequently, by an experiment with an air gap to prevent the underwater shock waves entering the cell suspension, it is found that the introduction of a strong shock pressure is not entirely required to obtain the effective sterilization. On the other hand, the direct effect of the sterilization by rebound shock wave resulting from the bubble-shock wave interaction is examined in the experiments. The results suggest that free radicals mainly contribute to killing marine bacteria, and direct mechanical effects of the bubble motion are not responsible. In addition, the creation of the OH radical is indirectly confirmed by measuring the HO concentration. Finally, the Herring equation is solved to investigate the condition of free radical generation when considering the effect of thermal conductivity at the bubble interface. As a result, the effective sterilization conditions based on the bubble-shock wave interaction are clearly obtained.
通过基于气泡 - 冲击波相互作用开展生物实验，研究了冲击灭菌对海洋弧菌属的影响。在实验中，圆柱形水腔中的高压电源产生不同强度和频率的水下冲击波。生物实验结果表明，通过1.0赫兹放电，海洋弧菌属在短时间内完全失活。然而，高灭菌效果需要气泡运动强烈且频率高，并且还取决于气泡的寿命。随后，通过设置气隙以防止水下冲击波进入细胞悬浮液的实验发现，获得有效灭菌并不完全需要引入强冲击压力。另一方面，实验中研究了气泡 - 冲击波相互作用产生的反弹冲击波的直接灭菌效果。结果表明，自由基是杀灭海洋细菌的主要因素，而气泡运动的直接机械作用并非如此。此外，通过测量HO浓度间接证实了OH自由基的产生。最后，求解赫林方程以研究考虑气泡界面热导率影响时自由基产生的条件。结果明确得出了基于气泡 - 冲击波相互作用的有效灭菌条件。
