Evaluation of Oxidative Species in Gaseous and Liquid Phase Generated by Mini-Gliding Arc Discharge

Joanna Pawłat,Piotr Terebun,Barbora Tarabová,Michal Kwiatkowski,Katarína Kučerová,Karol Hensel,Zuzana Kovaľová,Zdenko Machala,Mário Janda

doi:10.1007/s11090-019-09974-9

Abstract

The gliding arc discharge plasma reactors are known as a source of non-equilibrium plasma at atmospheric pressure. In the present study, generation of dominant reactive oxygen and nitrogen species in gaseous and liquid phase in water by the compact gliding arc device (mini-GAD) and corresponding bactericidal effects were investigated. Water and phosphate buffer solutions were used as model liquids. Mini-GAD is a strong source of nitrogen oxides (up to 800 ppm NO and 200 ppm NO2) that result in high concentrations of nitrites and nitrates in water solutions. The highest bactericidal efficacy towards Escherichia coli was achieved for non-buffered water solution.

Highlights

Electrical discharges effecting the generation of plasma activated media (PAM)/plasma activated water (PAW) via non-thermal plasma formation are considered to be a relatively energy efficient method for production of active species
The time-integrated optical emission spectroscopy (OES) study confirmed that mini-GAD generates highly reactive non-equilibrium plasma, since the rotational temperature Tr derived from the N2 second positive system (SPS) spectra was always much lower than the corresponding vibrational temperature (Tv = 3500–5500 K)
We introduced and characterized a compact mini gliding arc source which is able to generate high concentrations of NOx in gaseous phase, which can be further transferred to the liquid media

Summary

Introduction

Electrical discharges effecting the generation of plasma activated media (PAM)/plasma activated water (PAW) via non-thermal plasma formation are considered to be a relatively energy efficient method for production of active species. Nitrogen and oxygen based gaseous products (NO, N O2, O3) generated by mini-GAD in atmospheric pressure N2/O2 mixtures in dependence on the molecular composition of feed gas were measured. In order to further investigate the reactive species generated by the mini-GAD in various gas mixtures, time-integrated optical emission spectroscopy (OES) was performed.

Results

Conclusion