Pre-ionization hydrodynamic cavitation discharge for enhanced plasma activated water

Abstract

Plasma activated water (PAW), an aqueous solution containing reactive species generated via non-thermal plasma-liquid interactions, demonstrates strong redox activity and antimicrobial effects. This study introduces an innovative PAW generation approach employing pre-ionization-enhanced hydrodynamic cavitation discharge plasma. Numerical simulations characterize the flow field and electric field distributions within the system. Experimental diagnostics reveal that the optimized three-electrode geometry substantially enhances electric field strength, with air pre-ionization promoting discharge initiation and plasma volume expansion. The incorporation of a porous deflector plate in the hydrodynamic cavitation reactor improves flow patterns, amplifies negative pressure regions, and enhances gas–liquid mixing homogeneity, consequently extending plasma filaments and enlarging the discharge zone by 306.3%. Bactericidal assessment using Escherichia coli confirms the PAW efficacy, showing >99.99% inactivation within 30 min.