Sonoplasma Frequency Tuning of Electric Pulses to Modulate and Maximise Reactive Oxygen Species Generation

The wastewater problem is becoming an increasingly significant environmental issue affecting various aspects of human activities. The generation of reactive oxygen species (ROS) in water through certain physicochemical processes, which can oxidise or degrade various organic and chemical compounds, offers an effective purification method. The main advantage of these methods is the elimination of chemical reagents. The aim of this work is to investigate the possibility of regulating the ROS content in water by altering the characteristics of the plasma discharge that occurs under hydrodynamic cavitation in the water flow. The ROS concentration was determined using the permanganate oxidation titration technique. It was found that the content of various reactive oxygen species in water after treatment can be controlled by varying the power of the electrical pulses applied. Additionally, this study obtained the dependence of the ROS concentration in treated water samples on storage time, with results indicating that sonoplasma treatment has a prolonged effect on the antibacterial properties of water. The analysis of water samples using a biological test culture of Salmonella typhimurium revealed the bacteriostatic properties of the water for at least 48 h after sonoplasma discharge treatment.