电场与放电杀菌技术应用于饮用水安全消毒的研究

Applications of electrical field and discharge in safe sterilization of drinking water

使用空气隔离-同轴降膜反应器对饮用水进行电场和放电杀菌,在输入电压10 kV、频率12.5 kHz、处理时间50 s时,细菌总数分别减少了3.77和3.85个数量级.研究结果表明,放电杀菌的能量利用率及杀菌效率均高于电场杀菌.流式细胞仪和荧光电镜检测发现,电场和放电杀菌均对细菌蛋白质造成损伤,且电场处理过的细菌存在可进行损伤修复的亚致死细胞,而放电杀菌则不存在亚致死现象,表明放电杀菌具有较高的杀灭率.杀菌过程中活性自由基检测结果表明电场杀菌技术不会产生自由基等活性物质,相比较而言电场杀菌具有较高的安全性.

An air-insulated coaxial-falling film reactor was applied in drinking water sterilization in this study. The sterilization efficiency test results indicated that under the operational condition of 10 kV input voltage, 12.5 kHz frequency and 50 s treatment time, the sterilization efficiency of corona discharge could achieve 3. 85 and 3.77 orders of ＇magnitude reduction for electric field sterilization. The higher sterilization efficiency for discharge sterilization was attributed to higher energy utilization efficiency compared with electric field sterilization. Furthermore, flow cytometer （FCM） and fluorescence microscope tests were utilized to reveal the sterilization mechanism. The results confirmed that both discharge and electric field sterilization can cause protein damage. However, in the case of electric field sterilization, the membrane damage was reversible, which resulted in the existence of sub-lethal cells. While in the case of discharge sterilization, the membrane damage was irreversible. The safety assessment of drinking water sterilization was also conducted by radical generation measurements. Our results showed that no radical was generated during electric field sterilization. Thus, based on all above mentioned results, electric field sterilization is a promising drinking water sterilization technology.