连续流光催化消毒器灭活E.coli及病毒的性能

紫外消毒是污水处理常用技术.紫外线仅能破坏微生物的遗传物质,阻断其繁殖,并不能彻底杀死微生物,一旦停止紫外光照射,微生物可在修复酶的作用下恢复活性.光催化过程能产生强氧化性·OH,破坏细胞壁和细胞膜,彻底杀死微生物.为考察光催化技术消毒效率、抑制复活性能及应用潜力,在市售紫外消毒器中安装了光催化组件,搭建了连续流动式光催化消毒器.以大肠杆菌(E.coli)和噬菌体为目标物评价其消毒能力.紫外剂量50 m J·cm-2条件下,初始浓度3.40×106CFU·m L-1的E.coli原水流经紫外消毒器后被去除4.12 log10的E.coli,而流经光催化消毒器后去除4.79 log10.同时光催化处理后E.coli的光复活率仅为紫外消毒后的17%.连续运行40 h的灭菌能力稳定.光催化设备对噬菌体F2和噬菌体MS2的去除率分别为6.37 log10和6.00 log10,表明该设备也具有病毒去除能力.

The performance of continuous-flow photocatalytic device in inactivation of E. coli and bacteriophages

Ultraviolet (UV) disinfection is an alternative technology for wastewater disinfection. Since ultraviolet rays pass through cell walls of microorganisms and damage inner nucleic acid,the reproduction of microorganisms is blocked. However, microorganism may recover their activity under the action of the repairing enzyme when UV irradiation is stopped. While photocatalytic process can produce ·OH, whose oxidation capability is enough to damage cell walls and plasma membranes and then kill microorganisms completely. In order to evaluate the application potential of photocatalytic disinfection technology, we installed a photocatalytic module into a commercial UV sterilizer to build a continuous-flow photocatalysis device. During the disinfection processes taking E.coli as target, the photocatalysis device displayed the superior performance to UV process. 4.79 log₁₀ of E.coli (initial concentration is 3.40×10⁶ CFU·mL^-1) was removed under 50 mJ·cm^-2 of UV dosage, which was higher than that of UV process (4.12 log₁₀). The reactivation rate of E.coli after photocatalytic process was only one sixth as that after UV disinfection. During 40 h of continuous operation, the photocatalytic device displayed good stability. The removal rates of phage F2 and phage MS2 over this photocatalytic device were 6.37log₁₀ and 6.00log₁₀, respectively, suggesting photocatalysis also provides activity to kill bacteriophages.