High‐Efficiency Bacterial Inactivation of a Plasma Water Treatment System Using Flexible Coplanar Dielectric Barrier Discharge

ABSTRACT A portable plasma water treatment (PWT) system, integrating a flexible coplanar dielectric barrier discharge (FCDBD) and a bipolar nanosecond pulse generator (BNPG), is designed for water sterilization. The FCDBD produces reactive species that are transported into water as microbubbles. This paper analyzes the discharge characteristics of BNPG‐driven FCDBD via electrical diagnostics, optical emission spectroscopy (OES), liquid‐phase plasma‐activated species diagnostics, and ozone quantification. This FCDBD‐based PWT system achieves a more than 5‐log reduction of Escherichia coli in 800 mL of water within 5 min, yielding a high bacterial inactivation energy efficiency (BIEE) of 3.64 × 10 6 CFU/J. By prolonging the residence time of high‐concentration ozone microbubbles at a low gas flow rate, the system presents a viable approach to outdoor water sterilization.