Electrochemically Generated ROS Water for Rapid Disinfection and Biofilm Control in Real Waters

The intensifying global challenges of water scarcity and widespread microbial contamination underscore the urgent need for the development of efficient, chemical-free disinfection technologies. Here, we developed a compact boron-doped diamond (BDD)-based electrochemical water treatment system that generates reactive oxygen species (ROS) in situ and evaluated its antimicrobial performance using ROS-on/off controls. Bactericidal efficacy was assessed against representative Gram-negative Escherichia coli (E. coli), Gram-positive Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa), a clinically relevant Gram-negative pathogen with biofilm-forming and stress-resistant properties. Under ROS-on operation, viable counts were reduced from ~10⁶ CFU/mL to near the detection limit, corresponding to 5-6 log10 reductions across all tested species, whereas ROS-off treatment showed negligible effects. The system retained strong disinfection activity in complex real water matrices, including hand-washing water, laboratory wastewater, and pond wastewater. ROS-treated water also disrupted pre-formed mono-species biofilms in a time-dependent manner, as assessed by crystal violet staining and semi-quantitative biomass analysis. A preliminary mouse exposure assessment did not reveal obvious histopathological abnormalities or hematological changes under the tested conditions. These results demonstrate that BDD-enabled electrochemical ROS water provides a rapid, reagent-free approach for bacterial inactivation and biofilm control, with potential applicability across diverse water-related settings, while acknowledging that further studies on complex natural microbial communities are warranted.