Effects of H₂O₂ and low pH produced by gliding arc discharge on the inactivation of Escherichia Coli in water

The efficacy of gliding arc (GA) discharge for the generation of hydrogen peroxide (H₂O₂) and water with a low pH was studied because H₂O₂ combined with low-pH environment is known as a strong oxidizer that can be used for the bacterial inactivation. The ability of the GA discharge to inactivate Escherichia coli in water was tested experimentally, and the inactivation was found to increase with the plasma treatment time and rate of water injection flow to the GA discharge system. The best result showed a 2-log reduction of the number of colony-forming units of E. coli from 10⁴ to 10² at a water injection flow rate of 180 mL/min. Furthermore, pH in the plasma-treated water was decreased from 6.0 to 3.55 after 25 min of treatment.