Carbon Fiber-Based Flow-Through Electrode System (FES) for Water Disinfection via Direct Oxidation Mechanism with a Sequential Reduction–Oxidation Process

Flow-through configuration for electrochemical disinfection is considered as a promising approach to minimize the formation of toxic byproducts and energy consumption via the enhanced convective mass transport as compared with conventional flow-by one. Under this hydrodynamic condition, it is essential to ascertain the effect of sequential electro-redox processes with the cathode/anode then anode/cathode arrangements on disinfection performance. Here, carbon fiber felt (CFF) was utilized to construct two flow-through electrode systems (FESs) with sequential reduction–oxidation (cathode-anode) or oxidation–reduction (anode–cathode) processes to systematically compare their disinfection performance toward a model Escherichia coli (E. coli) pathogen. In-situ sampling and live/dead backlight staining experiments revealed that E. coli inactivation mainly occurred on anode via an adsorption-inactivation-desorption process. In reduction–oxidation system, after the cathode-pretreatment, bulk solution pH increased...