Atmospheric Pressure Gas–Liquid Diffuse Nanosecond Pulse Discharge Used for Sterilization in Sewage

Abstract

In this paper, we present a large area nanosecond pulse gas‐liquid diffuse discharge plasma with small flow rate of helium as working gas. The discharge images, the waveforms of pulse voltage & current, the emission spectra, and the gas temperature are measured or calculated. As a energy‐efficient sterilization for sewage, the efficiency of sewage sterilization in both static liquid and flowed liquid are investigated. It is found that an optimal value of helium gas flow rate in the production of reactive oxygen species (OH, O) can be obtained when the He flow rate is 5 ml min−1, under this condition, high inactivation efficiencies of bacteria and fungus can be presented.

Needle-array to Plate DBD Plasma Using Sine AC and Nanosecond Pulse Excitations for Purpose of Improving Indoor Air Quality

“…In those applications, the improvement of IAQ and the energy utilization efficiency are important parameters that should be considered emphatically. Therefore, uniform or diffuse discharge has been paid more and more attention for the advantages in obtaining a plasma with characteristics of low temperature, uniform energy distribution and moderate current density 7 8 . Also, the diffuse plasma with suitable gas temperature can avoid the thermal damage of catalysts, when catalysts are used to produce a synergistic effect with NTP 9 10 .…”

Mechanism of pH Variation and H2O2 Generation in Water Exposed to Pulsed Discharge Plasma

“…Ar( 3 P) + H2O → Ar + H + OH (11) OH + OH → H2O2 (12) H2O2 → H2O2aq (13) As mentioned above, the electrical characteristics of the discharge are almost the same between the positive and negative polarities, so that the amounts of H2O2 generated in gas phase, as shown in (12), may be equivalent in both the polarities. In addition to the above H2O2 generation, H2O2aq may be generated from OHaq, which is generated by the reaction (3) when the positive pulsed discharge plasma is generated. This results in the deeper color shown in color change at 120 s after the positive discharge plasma initiation in Fig.…”

“…ON-THERMAL atmospheric pressure plasma in contact with water has been widely studied for realizing a variety of plasma applications such as agriculture [1], [2], sterilization [3], [4], medicine [5], [6], food processing [7], nanoparticle fabrication [8], etc. In general, many kinds of reactive oxygen species (ROS), such as H2O2, OH, and HO2 radicals, are produced in water by discharge plasma exposure, and these species have high oxidation potential; therefore, the water containing ROS contributes to disinfecting microorganisms [9] and decomposing organic dye [10], [11].…”

Measurement of reactive species in different solutions of bubble discharge with varying O2/N2 proportion in Ar: Analysis of reaction pathways

“…In the past few decades, increasing attention has been focused on atmospheric pressure plasma‐liquid systems (APP‐Ls), including their various applications, the physical and chemical processes of plasma–liquid interaction, and breakdown processes and mechanisms . APP‐Ls can be customarily divided into three categories according to the type of interactions with liquid: liquid phase discharges, discharges in gas phase with a liquid electrode, and bubble discharges.…”