Division of Environmental Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Yamaguchi 755-8611, Japan.
Water Res. 2013 Sep 1;47(13):4286-93. doi: 10.1016/j.watres.2013.04.053. Epub 2013 May 17.
Based on the production of gas bubbles with the support of a liquid film-forming apparatus, a device inducing contact between gas and water was used to inactivate pathogens for water disinfection. In this study, the inactivation effect of CO2 against Escherichia coli was investigated and compared with the effects of N2O and N2 under the same pressure (0.3-0.9 MPa), initial concentration, and temperature. The optimum conditions were found to be 0.7 MPa and an exposure time of 25 min. Under identical treatment conditions, a greater than 5.0-log reduction in E. coli was achieved by CO2, while 3.3 log and 2.4 log reductions were observed when N2O and N2 were used, respectively. Observation under scanning electron microscopy and measurement of bacterial cell substances by UV-absorbance revealed greater cell rupture of E. coli following treatment with CO2 than when treatment was conducted using N2O, N2 and untreated water. The physical effects of the pump, acidified characteristics and the release of intracellular substances caused by CO2 were bactericidal mechanism of this process. Overall, the results of this study indicate that CO2 has the disinfection potential without undesired by-product forming.
基于液体成膜装置产生气泡的原理，设计了一种气水接触装置用于杀灭水中病原体以实现水消毒。本研究对比考察了 CO2、N2O 和 N2 在相同压力（0.3-0.9 MPa）、初始浓度和温度条件下对大肠杆菌的灭活效果。结果表明，CO2 的最佳条件为 0.7 MPa 和 25 min。在相同的处理条件下，CO2 可使大肠杆菌减少 5.0 个对数级，而 N2O 和 N2 分别使大肠杆菌减少 3.3 个对数级和 2.4 个对数级。扫描电子显微镜观察和紫外吸收法测量细菌细胞物质表明，CO2 处理后的大肠杆菌细胞破裂程度大于 N2O、N2 和未处理水的处理效果。泵的物理作用、CO2 引起的酸化特性以及细胞内物质的释放是该过程的杀菌机制。总体而言，本研究结果表明 CO2 具有消毒潜力，且不会形成不良副产物。
