Portable Bulk-Water Disinfection by Live Capture of Bacteria with Divergently Branched Porous Graphite in Electric Fields

An easy access to clean water pivots function and development of a modern society. However, it remains arduous to develop energy-efficient, facile, and portable water treatment systems for point-of-use (POU) applications, which is particularly imperative for the safety and resilience of a society during extreme weathers and critical events. Here, we report an innovative working scheme and device prototype for water disinfection via directly capturing and removing pathogen cells from bulk water using strategically designed three-dimensional (3D) porous dendritic graphite foams (PDGF) in an AC field. The prototype, integrated in a 3D-printed portable water-purification module, can reproducibly remove 99.997 % E-coli bacteria in bulk water at only a few voltages with among the lowest energy consumption of 435.5 J·L-1. The unique PDGF foams, costing at only $1.42 per piece, can robustly operate for at least 20 times without functional degradation. Furthermore, we successfully unveil the unique disinfection mechanism with one-dimensional Brownian dynamics simulation. Finally, the system is applied and practically brings natural water in the Waller Creek at UT Austin to the safe drinking level. This research, including the innovative working mechanism based on dendritically porous graphite and the design scheme, could inspire a new device paradigm for POU water treatment.