自制了流面型冷电弧杀菌装置,并研究了外加电压、气体流量、菌液流量、细菌种类和杀菌时间等参数对该装置杀菌率的影响.结果表明,杀菌率随着外加电压升高、液体流量降低以及杀菌时间增加而升高,空气自然对流的杀菌效果优于强制对流,对革兰氏阴性菌的杀菌效果优于革兰氏阳性菌.在空气自然对流、外加电压为33kV和液体流量为80mL/min的条件下,对E.coli 987P的杀菌率达99.96%,所需时间不超过35s;而S.aureus需经过708后,才能达到相同的杀菌率.冷电弧处理后的液体温升不超过3℃.通过透射电镜图发现,处理后的大肠杆菌(E.coli 987P)细胞膜发生不可逆击穿,细胞内容物外流,最终导致菌体死亡。
A novel sterilization device was designed and manufactured, in which the liquid - film was surrounded by air. The effect of various experimental parameters such as extra - voltage, gas flow rate, liquid flow rate, different microorganisms and sterilizing time on the sterilization ratio was discussed. According to the experimental results, it was indicated that the sterilization effect became better with the increase of extra - voltage, treatment time, and with the decrease of liquid flow rate. The free convection for air is more effective to sterilization than the forced convection. Gram - negative bacteria( G- ) were easier to be killed than Gram- positive bacteria(G^+ ). Under the conditions of free convection for air, extra - voltage of 33 kV, and liquid flow rate of 80 mL/min, the sterilization ratio reached 99.96 % within 35 s for E. coli 987P and within 70s for S. aureus , respectively. The rise of temperature in liquid was less than 3 ℃ during the whole process. According to TEM photographs, it was conjectured that microorganisms were killed by cold plasma, because of the cell membrane breached, even ruptured and cellular macromolecules released. The novel device had the following advantages: short treatment time, low rise of temperature in liquid, and simple operation process.