Scalable and Durable Brush Electrodes in Locally Enhanced Electric Field Treatment Systems for Water Disinfection

Locally enhanced electric field treatment (LEEFT) has emerged as a promising chlorine-free approach for water disinfection. However, its practical deployment has been limited by challenges in electrode durability and system scalability. Herein, we report a robust stainless-steel brush designed to enable long-term operation and scalability of LEEFT electrodes. A tubular reactor with coaxial electrodes featuring the brush as the center electrode was developed to combine both macroscale and microscale electric field enhancements. Operational parameters, including waveform, frequency, voltage, and flow rate, were systematically optimized to maximize microbial inactivation while minimizing metal release. Flow cytometry and control experiments revealed electroporation, assisted by reactive oxygen species, as the primary disinfection mechanism. Under optimal unipolar pulse conditions with high duty cycle and frequency, the system achieved efficient inactivation at voltages in the tens of volts range. Notably, the LEEFT system with the brush electrode has remained effective for about half a year with minimal metal release, representing a 10-fold increase in lifespan compared to previous LEEFT configurations. This work demonstrates a scalable, durable, and chemical-free solution for decentralized and sustainable water disinfection.