Development of a plasma gun device with multijet array for treatment of liquids

The aim of the present work is the development of a non-equilibrium atmospheric pressure plasma multijet device for the treatment of liquids. The interest in plasma multijet device is due to the potentiality for scaling up of plasma jet applications, since such device allows for treatment of higher volume of liquid than single-jet system. The multijet device has been developed in the laboratories of GREMI (Groupe de Recherches sur l’Energétique des Milieux Ionisés) at Orléans, and afterward tested for liquid decontamination in the “Tesla Plasma Research lab” laboratories of the group for Industrial Applications of Plasmas at the Alma Mater Studiorum - Università di Bologna. A versatile multijet device, able to work both in ambient air with jets impinging on a liquid target or in underliquid condition, with plasma discharge formation in bubbles flushed inside the liquid has been realized. Different liquids have been exposed to the plasma investigating the change in pH value, conductivity, temperature and reactive species concentration induced in liquid after plasma treatment. Afterward, electrical characterization has been performed by means of voltage and current probes in order to evaluate the power consumption. Finally, decontamination activity of the plasma treatment has been investigated using a liquid solution inoculated with Escherichia coli revealing antibacterial efficacy.