低场强脉冲电场杀灭水中大肠杆菌的实验研究

发布时间：2018-06-23 05:30

  本文选题：高频 + 低场强　； 参考：《浙江大学学报(工学版)》2015年04期

【摘要】：采用高频低场强脉冲电场系统对水中的大肠杆菌进行灭菌研究,探索反应器结构、电气参数及水质参数等对脉冲电场灭菌效率和能量效率的影响.圆筒式反应器体积为500mL,平均脉冲场强为3~12kV/cm,脉冲频率可以高达20kHz.最佳高压电极结构为6层均匀分布的直径为40mm的网电极.脉冲电场的杀菌效率和能量效率随着脉宽和场强的增大而提高,水的电导率影响波形和单脉冲能量的变化,从而影响杀菌效果,当初始细菌密度降低时有利于彻底杀光.脉冲频率对杀菌无明显影响,但高频率能够大幅缩短处理时间.当脉冲电压为6kV,脉宽为30μs,水的电导率为2.5μS/cm,细胞初始密度为103~106 cfu/mL时,在消耗能量200J/mL,水温40℃的前提下,脉冲电场处理后细菌密度下降了1、2个对数.当细菌初始密度低于1 250cfu/mL时,细菌被全部杀光,实现了非热低温灭菌.
[Abstract]:The sterilization of Escherichia coli in water was studied by using a high frequency and low field pulsed electric field system. The effects of reactor structure, electrical parameters and water quality parameters on the efficiency and energy efficiency of pulsed electric field sterilization were explored. The volume of the cylindrical reactor is 500mL, the average pulse field strength is 310kV / cm, and the pulse frequency can be up to 20kHz. The optimum structure of high voltage electrode is 6 layers of uniform distribution of the grid electrode with diameter of 40mm. The bactericidal efficiency and energy efficiency of pulsed electric field increase with the increase of pulse width and field strength. The conductivity of water affects the wave shape and the change of single pulse energy, thus affects the bactericidal effect. When the initial bacterial density decreases, it is advantageous to kill completely. Pulse frequency has no obvious effect on sterilization, but high frequency can significantly shorten the treatment time. When the pulse voltage is 6 kV, the pulse width is 30 渭 s, the water conductivity is 2.5 渭 s / cm, and the initial cell density is 103 渭 s / mL, the bacterial density decreases by 1 and 2 logarithms under the condition of energy consumption of 200 J / mL and water temperature of 40 鈩，

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