脉冲电磁场杀菌效应试验研究

Experimental study on sterilization effects of pulsed electromagnetic field

利用自行研制的直流脉冲发生装置产生的脉冲电磁场分别对生活污水和纯种大肠埃希氏菌液进行电磁处理 ,研究其对细菌的杀菌效果及机理 .实验表明电磁脉冲对生活污水及纯种菌液中的细菌都有明显的致死作用 .实验结果表明 ,停留时间、水流速度、线圈绕组、输出功率、脉冲频率对脉冲磁场的杀菌效果具有影响作用 ,在停留时间 1 2h ,输出功率 4 6 8W ,脉冲频率 6 5kHz ,水流速度 0 .3m s时 ,生活污水的细菌总数从 3.9× 1 0 7个 mL下降到 1 .5× 1 0 2 个 mL ,存活率达 1 0 - 5;大肠杆菌数从 2 .4× 1 0 6 个 mL下降到 3.6× 1 0 2 个 mL ,存活率为 1 0 - 4.在此条件下 ,四种质量浓度的纯种大肠埃希氏菌液经电磁处理后 ,其细菌的存活率均在 1 0 - 3～ 1 0 - 5.细菌细胞的扫描电镜照片表明电磁作用使细胞表面产生凹陷 ,孔洞 ,细胞质溶出现象 。

Developed an applicable direct current pulse generator to treat domestic wastewater and E. coli cells solution to study sterilization effects of pulsed electromagnetic field and found the involved mechanisms. It was found that the sterilization effects of pulsed electromagnetic field were obvious and its performances were related to treatment times, flow velocities, output powers, pulse frequencies and coil groups. With the treatment time 12 h, coil group 3 groups, output power 468 W, pulse frequency 65 kHz and flow velocity 0.3 m/s , the amounts of total bacterium and coliform per milliliter were decreased from 3.9×10 7 to 1.5×10 2 and from 2.4×10 6 to 3.6×10 2 respectively. Under the same test conditions, the sterilization effects of electromagnetic field on E. coli cells were also good . The survivability of E. coli cells were within 10 -3 and 10 -5 . The scanning electron micrographs of E. coli cells showed that the surface of the treated cell had dents, breaks, and pores. These provided evidences for the irreversible breakdown of cell membrane due to inductive current by the application of pulse electromagnetic field.