Department of Chemical Engineering, University of Illinois at Chicago, 810 South Clinton Street, Chicago, IL 60607, United States.
Department of Civil and Environmental Engineering, Villanova University, 800 Lancaster Ave., Villanova, PA, 19085 United States.
J Hazard Mater. 2016 Dec 5;319:137-46. doi: 10.1016/j.jhazmat.2016.05.051. Epub 2016 May 17.
This study investigated the use of a sub-stoichiometric TiO2 reactive electrochemical membrane (REM) for the inactivation of a model Escherichia coli (E. coli) pathogen in chloride-free solutions. The filtration system was operated in dead-end, outside-in filtration model, using the REM as anode and a stainless steel mesh as cathode. A 1-log removal of E. coli was achieved when the electrochemical cell was operated at the open circuit potential, due to a simple bacteria-sieving mechanism. At applied cell potentials of 1.3 and 3.5V neither live nor dead E. coli cells were detected in the permeate stream (detection limit of 1.0 cell mL(-1)), which was attributed to enhanced electrostatic bacteria adsorption at the REM anode. Bacteria inactivation in the retentate solution increased as a function of the applied cell potential, which was attributed to transport of E. coli to the REM and stainless steel cathode surfaces, and direct contact with the local acidic and alkaline environment produced by water oxidation at the anode and cathode, respectively. Clear evidence for an E. coli inactivation mechanism mediated by either direct or indirect oxidation was not found. The low energy requirement of the process (2.0-88Whm(-3)) makes the REM an attractive method for potable water disinfection.
本研究探讨了亚化学计量 TiO2 反应性电化学膜（REM）在无氯溶液中灭活大肠杆菌（E. coli）模型病原体的应用。该过滤系统采用 REM 作为阳极和不锈钢网作为阴极，以死端、外进过滤模式运行。当电化学池在开路电位下运行时，由于简单的细菌筛滤机制，可实现 1 对数的大肠杆菌去除。在施加的 1.3 和 3.5V 池电压下，在渗透物流中未检测到活的或死的大肠杆菌细胞（检测限为 1.0 个细胞 mL(-1)），这归因于在 REM 阳极处增强的静电细菌吸附。截留液中的细菌失活随着施加的池电压的增加而增加，这归因于大肠杆菌向 REM 和不锈钢阴极表面的传输，以及与阳极和阴极处水氧化分别产生的局部酸性和碱性环境的直接接触。没有发现任何直接或间接氧化介导的大肠杆菌灭活机制的明确证据。该过程的低能耗（2.0-88Whm(-3)) 使 REM 成为饮用水消毒的一种有吸引力的方法。
