Disinfection of Escherichia coli by a Reactive Electrochemical Membrane System Involving Activated Carbon Fiber Cloth (ACFC)

This study examined a novel reactive electrochemical membrane (REM) system with activated carbon fiber cloth (ACFC) serving simultaneously as the anode and the membrane to effectively disinfect water that was filtered through the device. An Escherichia coli strain was inoculated to water as a model pathogen. The influence of REM operation parameters, including the number of ACFC layers, voltage, flow rate and operation time, was evaluated. Up to 7.5 log unit reduction of E. coli concentration in water was achieved at the optimal treatment condition, while the energy consumption was 1.5 kWh/m3 per log unit reduction of E. coli. This makes it possible to use this ACFC-based REM technology for point-of-use water disinfection to provide clean water for underdeveloped regions. Further tests by free radical probing, Linear Scan Voltammetry (LSV) and Scanning Electron Microscopy (SEM) suggest that the disinfection involved the filtration/retention of bacteria on ACFC and attack by reactive oxygen species generated electrochemically on the anode.