The impact of nanosecond-pulsed non-thermal plasma-activated water on Escherichia coliK12 disinfection under various conditions

Plasma-activated water (PAW) is an innovative and environmentally friendly sterilisation method that leverages reactive nitrogen species (RNS) and reactive oxygen species (ROS) to eliminate bacteria and other pathogens without relying on chemical additives or high-energy inputs. This study focuses on nanosecond-pulse non-thermal plasma, an emerging green technology with limited research, to investigate how liquid volume, PAW production time, and bacterial treatment time influence RNS and ROS levels. Using a fixed power setting, we tested 100 mL and 200 mL PAW volumes and evaluated their efficacy in sterilizing Escherichia coli K12 bacterial cells after 5, 10, and 15 min of contact. The results demonstrated that 100 mL PAW treated for 4 min achieved the highest levels of nitrite and hydrogen peroxide, resulting in optimal sterilisation performance. In contrast, the duration of bacterial contact with PAW had a lesser impact. These findings provide new insights into optimising plasma-based sterilisation techniques with minimal environmental impact, offering practical guidance for sustainable applications in healthcare and industry. By showcasing how volume and discharge time can enhance the efficiency of PAW production, this research contributes to advancing net-zero technologies by reducing reliance on energy-intensive sterilisation methods, aligning with global efforts to achieve the UN Sustainable Development Goals.