Impact of water quality parameters on bacteria inactivation by low-voltage electroporation: mechanism and control

Nanowire-assisted low-voltage electroporation enables efficient and energy-conserving bacteria inactivation without byproduct formation. This approach is promising for replacing traditional methods for reliable water disinfection. Nevertheless, studies of applying this approach to different water matrices have not yet been done. Here, we study the effect of primary water quality parameters (pH, ionic strength, ion type, and organic matters) on the effectiveness of bacteria inactivation by low-voltage electroporation. Our results show that while pH, ionic strength, and ion type cause little impact, high concentration (>5 mg L−1) of macromolecular organic matter (>5000 g mol−1) hampers the disinfection performance. These macromolecular organic matters tend to accumulate around or attach to the nanowires and hinder the bacteria from reaching the regions with enhanced electric field strength where inactivation occurs. Electrochemical reduction of the organic matters further reduces their solubility, resulting in more precipitation on the nanowires. To reduce such negative impacts, we have proposed and verified that applying alternating current instead of direct current can slow down the accumulation and electrochemical precipitation.