The concept of a water surface plasma source (WSPS) was proposed to directly interact plasmas with water for large area water treatment, which is the type of volume dielectric barrier discharge (vDBD) with plate-to-plate. One electrode is submerged in water, while the other is floated in air, which is covered with a dielectric material. The characteristics of the WSPS were investigated by using a complementary metal-oxidesemiconductor (CMOS) camera, voltage and current probes, and optical emission spectroscopy (OES). The electrochemical parameters of plasma-activated water (PAW, 2 L) after plasma treatment times of 3 min by the WSPS were analyzed by using a multiparameter meter. As results, the formation of the water wave due to plasma generation, caused by the effect of the induced polarization forces, was observed at the WSPS. By comparison with the tap water, the applied voltage of the distilled water required higher than 130% for stable operation of the WSPS due to lower electrical conductivity (EC). As gap distance between dielectric plate and water surface increased, the applied voltage increased. In addition, an increase of 2 mm in the water level from the lower electrode required an approximately 5% increase in applied voltages for the ignition and stable plasma generation of the WSPS. The dominant peaks that were for N 2 species system in the spectrum of plasmas at the WSPS were analyzed by using the OES. In the case of distilled water, the pH values decreased from 6.25 to 4.24 and the EC increased from 2.00 to 22.33 µS • cm by using multiparameter meter during plasma treatment, whereas in the case of tap water, the effects on the pH and EC were insignificant.
The experimental investigation of the effects of O2 injection on the magnetized Ar plasma flow in the linear plasma device was conducted by using the measurement of laser induced fluorescence (LIF) with electric probes. The LIF measurement was based on the Ar ion transition from the 3d4F7/2 metastable level to the 4p4D5/2 level at a wavelength of 668.61 nm. In addition, the analysis of ion velocity distribution functions (IVDFs) involved the detection of fluorescence light emitted from the 4p4D5/2 level to the 4s4P3/2 level, which had a wavelength of 442.72 nm. For a comprehensive analysis of the intricate interaction between O2 injection and the behavior of the Ar plasma flow, the oxygen was injected into the Ar plasma, and the O2/Ar ratio ranged from 0% to 14% while maintaining a constant pressure of 2 mTorr. The Zeeman splitting in the IVDFs was clearly observable for pure Ar plasma due to 800 G as the high magnetic field strength. The split form disappeared due to a small amount of oxygen injected as the O2/Ar ratio of 3.5%. The LIF intensity is in agreement with the tendency of plasma density due to the reduction of Ar ions by charge transfer, quenching, and neutralization as O2 is injected into the Ar plasma. The experimental results show that the effects on temperature and flow velocity for the Ar ions are insignificant when O2 is injected into the Ar plasma at the O2/Ar ratio of 0%–14%, in contrast to the large change in the electron temperature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.